summaryrefslogtreecommitdiff
path: root/sqlite3.h
diff options
context:
space:
mode:
authorGravatar Vincent Rischmann2020-12-23 01:55:03 +0100
committerGravatar Vincent Rischmann2021-01-09 17:08:11 +0100
commit11f5eda938432c16b0e924fea944973945a480b7 (patch)
tree2927f8327b28c74f86fec8aa9f766cadab840fb7 /sqlite3.h
parentallow building with the bundled sqlite source code (diff)
downloadzig-sqlite-11f5eda938432c16b0e924fea944973945a480b7.tar.gz
zig-sqlite-11f5eda938432c16b0e924fea944973945a480b7.tar.xz
zig-sqlite-11f5eda938432c16b0e924fea944973945a480b7.zip
bundle the sqlite amalgamation
Diffstat (limited to '')
-rw-r--r--sqlite3.h12237
1 files changed, 12237 insertions, 0 deletions
diff --git a/sqlite3.h b/sqlite3.h
new file mode 100644
index 0000000..9098a37
--- /dev/null
+++ b/sqlite3.h
@@ -0,0 +1,12237 @@
1/*
2** 2001-09-15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This header file defines the interface that the SQLite library
13** presents to client programs. If a C-function, structure, datatype,
14** or constant definition does not appear in this file, then it is
15** not a published API of SQLite, is subject to change without
16** notice, and should not be referenced by programs that use SQLite.
17**
18** Some of the definitions that are in this file are marked as
19** "experimental". Experimental interfaces are normally new
20** features recently added to SQLite. We do not anticipate changes
21** to experimental interfaces but reserve the right to make minor changes
22** if experience from use "in the wild" suggest such changes are prudent.
23**
24** The official C-language API documentation for SQLite is derived
25** from comments in this file. This file is the authoritative source
26** on how SQLite interfaces are supposed to operate.
27**
28** The name of this file under configuration management is "sqlite.h.in".
29** The makefile makes some minor changes to this file (such as inserting
30** the version number) and changes its name to "sqlite3.h" as
31** part of the build process.
32*/
33#ifndef SQLITE3_H
34#define SQLITE3_H
35#include <stdarg.h> /* Needed for the definition of va_list */
36
37/*
38** Make sure we can call this stuff from C++.
39*/
40#ifdef __cplusplus
41extern "C" {
42#endif
43
44
45/*
46** Provide the ability to override linkage features of the interface.
47*/
48#ifndef SQLITE_EXTERN
49# define SQLITE_EXTERN extern
50#endif
51#ifndef SQLITE_API
52# define SQLITE_API
53#endif
54#ifndef SQLITE_CDECL
55# define SQLITE_CDECL
56#endif
57#ifndef SQLITE_APICALL
58# define SQLITE_APICALL
59#endif
60#ifndef SQLITE_STDCALL
61# define SQLITE_STDCALL SQLITE_APICALL
62#endif
63#ifndef SQLITE_CALLBACK
64# define SQLITE_CALLBACK
65#endif
66#ifndef SQLITE_SYSAPI
67# define SQLITE_SYSAPI
68#endif
69
70/*
71** These no-op macros are used in front of interfaces to mark those
72** interfaces as either deprecated or experimental. New applications
73** should not use deprecated interfaces - they are supported for backwards
74** compatibility only. Application writers should be aware that
75** experimental interfaces are subject to change in point releases.
76**
77** These macros used to resolve to various kinds of compiler magic that
78** would generate warning messages when they were used. But that
79** compiler magic ended up generating such a flurry of bug reports
80** that we have taken it all out and gone back to using simple
81** noop macros.
82*/
83#define SQLITE_DEPRECATED
84#define SQLITE_EXPERIMENTAL
85
86/*
87** Ensure these symbols were not defined by some previous header file.
88*/
89#ifdef SQLITE_VERSION
90# undef SQLITE_VERSION
91#endif
92#ifdef SQLITE_VERSION_NUMBER
93# undef SQLITE_VERSION_NUMBER
94#endif
95
96/*
97** CAPI3REF: Compile-Time Library Version Numbers
98**
99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
100** evaluates to a string literal that is the SQLite version in the
101** format "X.Y.Z" where X is the major version number (always 3 for
102** SQLite3) and Y is the minor version number and Z is the release number.)^
103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
105** numbers used in [SQLITE_VERSION].)^
106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
107** be larger than the release from which it is derived. Either Y will
108** be held constant and Z will be incremented or else Y will be incremented
109** and Z will be reset to zero.
110**
111** Since [version 3.6.18] ([dateof:3.6.18]),
112** SQLite source code has been stored in the
113** <a href="http://www.fossil-scm.org/">Fossil configuration management
114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
115** a string which identifies a particular check-in of SQLite
116** within its configuration management system. ^The SQLITE_SOURCE_ID
117** string contains the date and time of the check-in (UTC) and a SHA1
118** or SHA3-256 hash of the entire source tree. If the source code has
119** been edited in any way since it was last checked in, then the last
120** four hexadecimal digits of the hash may be modified.
121**
122** See also: [sqlite3_libversion()],
123** [sqlite3_libversion_number()], [sqlite3_sourceid()],
124** [sqlite_version()] and [sqlite_source_id()].
125*/
126#define SQLITE_VERSION "3.34.0"
127#define SQLITE_VERSION_NUMBER 3034000
128#define SQLITE_SOURCE_ID "2020-12-01 16:14:00 a26b6597e3ae272231b96f9982c3bcc17ddec2f2b6eb4df06a224b91089fed5b"
129
130/*
131** CAPI3REF: Run-Time Library Version Numbers
132** KEYWORDS: sqlite3_version sqlite3_sourceid
133**
134** These interfaces provide the same information as the [SQLITE_VERSION],
135** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
136** but are associated with the library instead of the header file. ^(Cautious
137** programmers might include assert() statements in their application to
138** verify that values returned by these interfaces match the macros in
139** the header, and thus ensure that the application is
140** compiled with matching library and header files.
141**
142** <blockquote><pre>
143** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
144** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
145** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
146** </pre></blockquote>)^
147**
148** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
149** macro. ^The sqlite3_libversion() function returns a pointer to the
150** to the sqlite3_version[] string constant. The sqlite3_libversion()
151** function is provided for use in DLLs since DLL users usually do not have
152** direct access to string constants within the DLL. ^The
153** sqlite3_libversion_number() function returns an integer equal to
154** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
155** a pointer to a string constant whose value is the same as the
156** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
157** using an edited copy of [the amalgamation], then the last four characters
158** of the hash might be different from [SQLITE_SOURCE_ID].)^
159**
160** See also: [sqlite_version()] and [sqlite_source_id()].
161*/
162SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
163SQLITE_API const char *sqlite3_libversion(void);
164SQLITE_API const char *sqlite3_sourceid(void);
165SQLITE_API int sqlite3_libversion_number(void);
166
167/*
168** CAPI3REF: Run-Time Library Compilation Options Diagnostics
169**
170** ^The sqlite3_compileoption_used() function returns 0 or 1
171** indicating whether the specified option was defined at
172** compile time. ^The SQLITE_ prefix may be omitted from the
173** option name passed to sqlite3_compileoption_used().
174**
175** ^The sqlite3_compileoption_get() function allows iterating
176** over the list of options that were defined at compile time by
177** returning the N-th compile time option string. ^If N is out of range,
178** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
179** prefix is omitted from any strings returned by
180** sqlite3_compileoption_get().
181**
182** ^Support for the diagnostic functions sqlite3_compileoption_used()
183** and sqlite3_compileoption_get() may be omitted by specifying the
184** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
185**
186** See also: SQL functions [sqlite_compileoption_used()] and
187** [sqlite_compileoption_get()] and the [compile_options pragma].
188*/
189#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
190SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
191SQLITE_API const char *sqlite3_compileoption_get(int N);
192#else
193# define sqlite3_compileoption_used(X) 0
194# define sqlite3_compileoption_get(X) ((void*)0)
195#endif
196
197/*
198** CAPI3REF: Test To See If The Library Is Threadsafe
199**
200** ^The sqlite3_threadsafe() function returns zero if and only if
201** SQLite was compiled with mutexing code omitted due to the
202** [SQLITE_THREADSAFE] compile-time option being set to 0.
203**
204** SQLite can be compiled with or without mutexes. When
205** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
206** are enabled and SQLite is threadsafe. When the
207** [SQLITE_THREADSAFE] macro is 0,
208** the mutexes are omitted. Without the mutexes, it is not safe
209** to use SQLite concurrently from more than one thread.
210**
211** Enabling mutexes incurs a measurable performance penalty.
212** So if speed is of utmost importance, it makes sense to disable
213** the mutexes. But for maximum safety, mutexes should be enabled.
214** ^The default behavior is for mutexes to be enabled.
215**
216** This interface can be used by an application to make sure that the
217** version of SQLite that it is linking against was compiled with
218** the desired setting of the [SQLITE_THREADSAFE] macro.
219**
220** This interface only reports on the compile-time mutex setting
221** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
222** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
223** can be fully or partially disabled using a call to [sqlite3_config()]
224** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
225** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
226** sqlite3_threadsafe() function shows only the compile-time setting of
227** thread safety, not any run-time changes to that setting made by
228** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
229** is unchanged by calls to sqlite3_config().)^
230**
231** See the [threading mode] documentation for additional information.
232*/
233SQLITE_API int sqlite3_threadsafe(void);
234
235/*
236** CAPI3REF: Database Connection Handle
237** KEYWORDS: {database connection} {database connections}
238**
239** Each open SQLite database is represented by a pointer to an instance of
240** the opaque structure named "sqlite3". It is useful to think of an sqlite3
241** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
242** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
243** and [sqlite3_close_v2()] are its destructors. There are many other
244** interfaces (such as
245** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
246** [sqlite3_busy_timeout()] to name but three) that are methods on an
247** sqlite3 object.
248*/
249typedef struct sqlite3 sqlite3;
250
251/*
252** CAPI3REF: 64-Bit Integer Types
253** KEYWORDS: sqlite_int64 sqlite_uint64
254**
255** Because there is no cross-platform way to specify 64-bit integer types
256** SQLite includes typedefs for 64-bit signed and unsigned integers.
257**
258** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
259** The sqlite_int64 and sqlite_uint64 types are supported for backwards
260** compatibility only.
261**
262** ^The sqlite3_int64 and sqlite_int64 types can store integer values
263** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
264** sqlite3_uint64 and sqlite_uint64 types can store integer values
265** between 0 and +18446744073709551615 inclusive.
266*/
267#ifdef SQLITE_INT64_TYPE
268 typedef SQLITE_INT64_TYPE sqlite_int64;
269# ifdef SQLITE_UINT64_TYPE
270 typedef SQLITE_UINT64_TYPE sqlite_uint64;
271# else
272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
273# endif
274#elif defined(_MSC_VER) || defined(__BORLANDC__)
275 typedef __int64 sqlite_int64;
276 typedef unsigned __int64 sqlite_uint64;
277#else
278 typedef long long int sqlite_int64;
279 typedef unsigned long long int sqlite_uint64;
280#endif
281typedef sqlite_int64 sqlite3_int64;
282typedef sqlite_uint64 sqlite3_uint64;
283
284/*
285** If compiling for a processor that lacks floating point support,
286** substitute integer for floating-point.
287*/
288#ifdef SQLITE_OMIT_FLOATING_POINT
289# define double sqlite3_int64
290#endif
291
292/*
293** CAPI3REF: Closing A Database Connection
294** DESTRUCTOR: sqlite3
295**
296** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
297** for the [sqlite3] object.
298** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
299** the [sqlite3] object is successfully destroyed and all associated
300** resources are deallocated.
301**
302** Ideally, applications should [sqlite3_finalize | finalize] all
303** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
304** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
305** with the [sqlite3] object prior to attempting to close the object.
306** ^If the database connection is associated with unfinalized prepared
307** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
308** sqlite3_close() will leave the database connection open and return
309** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
310** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
311** it returns [SQLITE_OK] regardless, but instead of deallocating the database
312** connection immediately, it marks the database connection as an unusable
313** "zombie" and makes arrangements to automatically deallocate the database
314** connection after all prepared statements are finalized, all BLOB handles
315** are closed, and all backups have finished. The sqlite3_close_v2() interface
316** is intended for use with host languages that are garbage collected, and
317** where the order in which destructors are called is arbitrary.
318**
319** ^If an [sqlite3] object is destroyed while a transaction is open,
320** the transaction is automatically rolled back.
321**
322** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
323** must be either a NULL
324** pointer or an [sqlite3] object pointer obtained
325** from [sqlite3_open()], [sqlite3_open16()], or
326** [sqlite3_open_v2()], and not previously closed.
327** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
328** argument is a harmless no-op.
329*/
330SQLITE_API int sqlite3_close(sqlite3*);
331SQLITE_API int sqlite3_close_v2(sqlite3*);
332
333/*
334** The type for a callback function.
335** This is legacy and deprecated. It is included for historical
336** compatibility and is not documented.
337*/
338typedef int (*sqlite3_callback)(void*,int,char**, char**);
339
340/*
341** CAPI3REF: One-Step Query Execution Interface
342** METHOD: sqlite3
343**
344** The sqlite3_exec() interface is a convenience wrapper around
345** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
346** that allows an application to run multiple statements of SQL
347** without having to use a lot of C code.
348**
349** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
350** semicolon-separate SQL statements passed into its 2nd argument,
351** in the context of the [database connection] passed in as its 1st
352** argument. ^If the callback function of the 3rd argument to
353** sqlite3_exec() is not NULL, then it is invoked for each result row
354** coming out of the evaluated SQL statements. ^The 4th argument to
355** sqlite3_exec() is relayed through to the 1st argument of each
356** callback invocation. ^If the callback pointer to sqlite3_exec()
357** is NULL, then no callback is ever invoked and result rows are
358** ignored.
359**
360** ^If an error occurs while evaluating the SQL statements passed into
361** sqlite3_exec(), then execution of the current statement stops and
362** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
363** is not NULL then any error message is written into memory obtained
364** from [sqlite3_malloc()] and passed back through the 5th parameter.
365** To avoid memory leaks, the application should invoke [sqlite3_free()]
366** on error message strings returned through the 5th parameter of
367** sqlite3_exec() after the error message string is no longer needed.
368** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
369** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
370** NULL before returning.
371**
372** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
373** routine returns SQLITE_ABORT without invoking the callback again and
374** without running any subsequent SQL statements.
375**
376** ^The 2nd argument to the sqlite3_exec() callback function is the
377** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
378** callback is an array of pointers to strings obtained as if from
379** [sqlite3_column_text()], one for each column. ^If an element of a
380** result row is NULL then the corresponding string pointer for the
381** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
382** sqlite3_exec() callback is an array of pointers to strings where each
383** entry represents the name of corresponding result column as obtained
384** from [sqlite3_column_name()].
385**
386** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
387** to an empty string, or a pointer that contains only whitespace and/or
388** SQL comments, then no SQL statements are evaluated and the database
389** is not changed.
390**
391** Restrictions:
392**
393** <ul>
394** <li> The application must ensure that the 1st parameter to sqlite3_exec()
395** is a valid and open [database connection].
396** <li> The application must not close the [database connection] specified by
397** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
398** <li> The application must not modify the SQL statement text passed into
399** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
400** </ul>
401*/
402SQLITE_API int sqlite3_exec(
403 sqlite3*, /* An open database */
404 const char *sql, /* SQL to be evaluated */
405 int (*callback)(void*,int,char**,char**), /* Callback function */
406 void *, /* 1st argument to callback */
407 char **errmsg /* Error msg written here */
408);
409
410/*
411** CAPI3REF: Result Codes
412** KEYWORDS: {result code definitions}
413**
414** Many SQLite functions return an integer result code from the set shown
415** here in order to indicate success or failure.
416**
417** New error codes may be added in future versions of SQLite.
418**
419** See also: [extended result code definitions]
420*/
421#define SQLITE_OK 0 /* Successful result */
422/* beginning-of-error-codes */
423#define SQLITE_ERROR 1 /* Generic error */
424#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
425#define SQLITE_PERM 3 /* Access permission denied */
426#define SQLITE_ABORT 4 /* Callback routine requested an abort */
427#define SQLITE_BUSY 5 /* The database file is locked */
428#define SQLITE_LOCKED 6 /* A table in the database is locked */
429#define SQLITE_NOMEM 7 /* A malloc() failed */
430#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
431#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
432#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
433#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
434#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
435#define SQLITE_FULL 13 /* Insertion failed because database is full */
436#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
437#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
438#define SQLITE_EMPTY 16 /* Internal use only */
439#define SQLITE_SCHEMA 17 /* The database schema changed */
440#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
441#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
442#define SQLITE_MISMATCH 20 /* Data type mismatch */
443#define SQLITE_MISUSE 21 /* Library used incorrectly */
444#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
445#define SQLITE_AUTH 23 /* Authorization denied */
446#define SQLITE_FORMAT 24 /* Not used */
447#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
448#define SQLITE_NOTADB 26 /* File opened that is not a database file */
449#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
450#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
451#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
452#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
453/* end-of-error-codes */
454
455/*
456** CAPI3REF: Extended Result Codes
457** KEYWORDS: {extended result code definitions}
458**
459** In its default configuration, SQLite API routines return one of 30 integer
460** [result codes]. However, experience has shown that many of
461** these result codes are too coarse-grained. They do not provide as
462** much information about problems as programmers might like. In an effort to
463** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
464** and later) include
465** support for additional result codes that provide more detailed information
466** about errors. These [extended result codes] are enabled or disabled
467** on a per database connection basis using the
468** [sqlite3_extended_result_codes()] API. Or, the extended code for
469** the most recent error can be obtained using
470** [sqlite3_extended_errcode()].
471*/
472#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
473#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
474#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
475#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
476#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
477#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
478#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
479#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
480#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
481#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
482#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
483#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
484#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
485#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
486#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
487#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
488#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
489#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
490#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
491#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
492#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
493#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
494#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
495#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
496#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
497#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
498#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
499#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
500#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
501#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
502#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
503#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
504#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
505#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
506#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
507#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
508#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
509#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
510#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
511#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
512#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
513#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
514#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
515#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
516#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
517#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
518#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
519#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
520#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
521#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
522#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
523#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
524#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
525#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
526#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
527#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
528#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
529#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
530#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
531#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
532#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
533#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
534#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
535#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
536#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
537#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
538#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
539#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
540#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
541#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
542#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
543#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
544#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
545#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8))
546
547/*
548** CAPI3REF: Flags For File Open Operations
549**
550** These bit values are intended for use in the
551** 3rd parameter to the [sqlite3_open_v2()] interface and
552** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
553*/
554#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
555#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
556#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
557#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
558#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
559#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
560#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
561#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
562#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
563#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
564#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
565#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
566#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
567#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
568#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
569#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
570#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
571#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
572#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
573#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
574#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
575
576/* Reserved: 0x00F00000 */
577/* Legacy compatibility: */
578#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
579
580
581/*
582** CAPI3REF: Device Characteristics
583**
584** The xDeviceCharacteristics method of the [sqlite3_io_methods]
585** object returns an integer which is a vector of these
586** bit values expressing I/O characteristics of the mass storage
587** device that holds the file that the [sqlite3_io_methods]
588** refers to.
589**
590** The SQLITE_IOCAP_ATOMIC property means that all writes of
591** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
592** mean that writes of blocks that are nnn bytes in size and
593** are aligned to an address which is an integer multiple of
594** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
595** that when data is appended to a file, the data is appended
596** first then the size of the file is extended, never the other
597** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
598** information is written to disk in the same order as calls
599** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
600** after reboot following a crash or power loss, the only bytes in a
601** file that were written at the application level might have changed
602** and that adjacent bytes, even bytes within the same sector are
603** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
604** flag indicates that a file cannot be deleted when open. The
605** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
606** read-only media and cannot be changed even by processes with
607** elevated privileges.
608**
609** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
610** filesystem supports doing multiple write operations atomically when those
611** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
612** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
613*/
614#define SQLITE_IOCAP_ATOMIC 0x00000001
615#define SQLITE_IOCAP_ATOMIC512 0x00000002
616#define SQLITE_IOCAP_ATOMIC1K 0x00000004
617#define SQLITE_IOCAP_ATOMIC2K 0x00000008
618#define SQLITE_IOCAP_ATOMIC4K 0x00000010
619#define SQLITE_IOCAP_ATOMIC8K 0x00000020
620#define SQLITE_IOCAP_ATOMIC16K 0x00000040
621#define SQLITE_IOCAP_ATOMIC32K 0x00000080
622#define SQLITE_IOCAP_ATOMIC64K 0x00000100
623#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
624#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
625#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
626#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
627#define SQLITE_IOCAP_IMMUTABLE 0x00002000
628#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
629
630/*
631** CAPI3REF: File Locking Levels
632**
633** SQLite uses one of these integer values as the second
634** argument to calls it makes to the xLock() and xUnlock() methods
635** of an [sqlite3_io_methods] object.
636*/
637#define SQLITE_LOCK_NONE 0
638#define SQLITE_LOCK_SHARED 1
639#define SQLITE_LOCK_RESERVED 2
640#define SQLITE_LOCK_PENDING 3
641#define SQLITE_LOCK_EXCLUSIVE 4
642
643/*
644** CAPI3REF: Synchronization Type Flags
645**
646** When SQLite invokes the xSync() method of an
647** [sqlite3_io_methods] object it uses a combination of
648** these integer values as the second argument.
649**
650** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
651** sync operation only needs to flush data to mass storage. Inode
652** information need not be flushed. If the lower four bits of the flag
653** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
654** If the lower four bits equal SQLITE_SYNC_FULL, that means
655** to use Mac OS X style fullsync instead of fsync().
656**
657** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
658** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
659** settings. The [synchronous pragma] determines when calls to the
660** xSync VFS method occur and applies uniformly across all platforms.
661** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
662** energetic or rigorous or forceful the sync operations are and
663** only make a difference on Mac OSX for the default SQLite code.
664** (Third-party VFS implementations might also make the distinction
665** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
666** operating systems natively supported by SQLite, only Mac OSX
667** cares about the difference.)
668*/
669#define SQLITE_SYNC_NORMAL 0x00002
670#define SQLITE_SYNC_FULL 0x00003
671#define SQLITE_SYNC_DATAONLY 0x00010
672
673/*
674** CAPI3REF: OS Interface Open File Handle
675**
676** An [sqlite3_file] object represents an open file in the
677** [sqlite3_vfs | OS interface layer]. Individual OS interface
678** implementations will
679** want to subclass this object by appending additional fields
680** for their own use. The pMethods entry is a pointer to an
681** [sqlite3_io_methods] object that defines methods for performing
682** I/O operations on the open file.
683*/
684typedef struct sqlite3_file sqlite3_file;
685struct sqlite3_file {
686 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
687};
688
689/*
690** CAPI3REF: OS Interface File Virtual Methods Object
691**
692** Every file opened by the [sqlite3_vfs.xOpen] method populates an
693** [sqlite3_file] object (or, more commonly, a subclass of the
694** [sqlite3_file] object) with a pointer to an instance of this object.
695** This object defines the methods used to perform various operations
696** against the open file represented by the [sqlite3_file] object.
697**
698** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
699** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
700** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
701** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
702** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
703** to NULL.
704**
705** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
706** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
707** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
708** flag may be ORed in to indicate that only the data of the file
709** and not its inode needs to be synced.
710**
711** The integer values to xLock() and xUnlock() are one of
712** <ul>
713** <li> [SQLITE_LOCK_NONE],
714** <li> [SQLITE_LOCK_SHARED],
715** <li> [SQLITE_LOCK_RESERVED],
716** <li> [SQLITE_LOCK_PENDING], or
717** <li> [SQLITE_LOCK_EXCLUSIVE].
718** </ul>
719** xLock() increases the lock. xUnlock() decreases the lock.
720** The xCheckReservedLock() method checks whether any database connection,
721** either in this process or in some other process, is holding a RESERVED,
722** PENDING, or EXCLUSIVE lock on the file. It returns true
723** if such a lock exists and false otherwise.
724**
725** The xFileControl() method is a generic interface that allows custom
726** VFS implementations to directly control an open file using the
727** [sqlite3_file_control()] interface. The second "op" argument is an
728** integer opcode. The third argument is a generic pointer intended to
729** point to a structure that may contain arguments or space in which to
730** write return values. Potential uses for xFileControl() might be
731** functions to enable blocking locks with timeouts, to change the
732** locking strategy (for example to use dot-file locks), to inquire
733** about the status of a lock, or to break stale locks. The SQLite
734** core reserves all opcodes less than 100 for its own use.
735** A [file control opcodes | list of opcodes] less than 100 is available.
736** Applications that define a custom xFileControl method should use opcodes
737** greater than 100 to avoid conflicts. VFS implementations should
738** return [SQLITE_NOTFOUND] for file control opcodes that they do not
739** recognize.
740**
741** The xSectorSize() method returns the sector size of the
742** device that underlies the file. The sector size is the
743** minimum write that can be performed without disturbing
744** other bytes in the file. The xDeviceCharacteristics()
745** method returns a bit vector describing behaviors of the
746** underlying device:
747**
748** <ul>
749** <li> [SQLITE_IOCAP_ATOMIC]
750** <li> [SQLITE_IOCAP_ATOMIC512]
751** <li> [SQLITE_IOCAP_ATOMIC1K]
752** <li> [SQLITE_IOCAP_ATOMIC2K]
753** <li> [SQLITE_IOCAP_ATOMIC4K]
754** <li> [SQLITE_IOCAP_ATOMIC8K]
755** <li> [SQLITE_IOCAP_ATOMIC16K]
756** <li> [SQLITE_IOCAP_ATOMIC32K]
757** <li> [SQLITE_IOCAP_ATOMIC64K]
758** <li> [SQLITE_IOCAP_SAFE_APPEND]
759** <li> [SQLITE_IOCAP_SEQUENTIAL]
760** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
761** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
762** <li> [SQLITE_IOCAP_IMMUTABLE]
763** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
764** </ul>
765**
766** The SQLITE_IOCAP_ATOMIC property means that all writes of
767** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
768** mean that writes of blocks that are nnn bytes in size and
769** are aligned to an address which is an integer multiple of
770** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
771** that when data is appended to a file, the data is appended
772** first then the size of the file is extended, never the other
773** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
774** information is written to disk in the same order as calls
775** to xWrite().
776**
777** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
778** in the unread portions of the buffer with zeros. A VFS that
779** fails to zero-fill short reads might seem to work. However,
780** failure to zero-fill short reads will eventually lead to
781** database corruption.
782*/
783typedef struct sqlite3_io_methods sqlite3_io_methods;
784struct sqlite3_io_methods {
785 int iVersion;
786 int (*xClose)(sqlite3_file*);
787 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
788 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
789 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
790 int (*xSync)(sqlite3_file*, int flags);
791 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
792 int (*xLock)(sqlite3_file*, int);
793 int (*xUnlock)(sqlite3_file*, int);
794 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
795 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
796 int (*xSectorSize)(sqlite3_file*);
797 int (*xDeviceCharacteristics)(sqlite3_file*);
798 /* Methods above are valid for version 1 */
799 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
800 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
801 void (*xShmBarrier)(sqlite3_file*);
802 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
803 /* Methods above are valid for version 2 */
804 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
805 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
806 /* Methods above are valid for version 3 */
807 /* Additional methods may be added in future releases */
808};
809
810/*
811** CAPI3REF: Standard File Control Opcodes
812** KEYWORDS: {file control opcodes} {file control opcode}
813**
814** These integer constants are opcodes for the xFileControl method
815** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
816** interface.
817**
818** <ul>
819** <li>[[SQLITE_FCNTL_LOCKSTATE]]
820** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
821** opcode causes the xFileControl method to write the current state of
822** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
823** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
824** into an integer that the pArg argument points to. This capability
825** is used during testing and is only available when the SQLITE_TEST
826** compile-time option is used.
827**
828** <li>[[SQLITE_FCNTL_SIZE_HINT]]
829** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
830** layer a hint of how large the database file will grow to be during the
831** current transaction. This hint is not guaranteed to be accurate but it
832** is often close. The underlying VFS might choose to preallocate database
833** file space based on this hint in order to help writes to the database
834** file run faster.
835**
836** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
837** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
838** implements [sqlite3_deserialize()] to set an upper bound on the size
839** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
840** If the integer pointed to is negative, then it is filled in with the
841** current limit. Otherwise the limit is set to the larger of the value
842** of the integer pointed to and the current database size. The integer
843** pointed to is set to the new limit.
844**
845** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
846** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
847** extends and truncates the database file in chunks of a size specified
848** by the user. The fourth argument to [sqlite3_file_control()] should
849** point to an integer (type int) containing the new chunk-size to use
850** for the nominated database. Allocating database file space in large
851** chunks (say 1MB at a time), may reduce file-system fragmentation and
852** improve performance on some systems.
853**
854** <li>[[SQLITE_FCNTL_FILE_POINTER]]
855** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
856** to the [sqlite3_file] object associated with a particular database
857** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
858**
859** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
860** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
861** to the [sqlite3_file] object associated with the journal file (either
862** the [rollback journal] or the [write-ahead log]) for a particular database
863** connection. See also [SQLITE_FCNTL_FILE_POINTER].
864**
865** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
866** No longer in use.
867**
868** <li>[[SQLITE_FCNTL_SYNC]]
869** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
870** sent to the VFS immediately before the xSync method is invoked on a
871** database file descriptor. Or, if the xSync method is not invoked
872** because the user has configured SQLite with
873** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
874** of the xSync method. In most cases, the pointer argument passed with
875** this file-control is NULL. However, if the database file is being synced
876** as part of a multi-database commit, the argument points to a nul-terminated
877** string containing the transactions super-journal file name. VFSes that
878** do not need this signal should silently ignore this opcode. Applications
879** should not call [sqlite3_file_control()] with this opcode as doing so may
880** disrupt the operation of the specialized VFSes that do require it.
881**
882** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
883** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
884** and sent to the VFS after a transaction has been committed immediately
885** but before the database is unlocked. VFSes that do not need this signal
886** should silently ignore this opcode. Applications should not call
887** [sqlite3_file_control()] with this opcode as doing so may disrupt the
888** operation of the specialized VFSes that do require it.
889**
890** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
891** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
892** retry counts and intervals for certain disk I/O operations for the
893** windows [VFS] in order to provide robustness in the presence of
894** anti-virus programs. By default, the windows VFS will retry file read,
895** file write, and file delete operations up to 10 times, with a delay
896** of 25 milliseconds before the first retry and with the delay increasing
897** by an additional 25 milliseconds with each subsequent retry. This
898** opcode allows these two values (10 retries and 25 milliseconds of delay)
899** to be adjusted. The values are changed for all database connections
900** within the same process. The argument is a pointer to an array of two
901** integers where the first integer is the new retry count and the second
902** integer is the delay. If either integer is negative, then the setting
903** is not changed but instead the prior value of that setting is written
904** into the array entry, allowing the current retry settings to be
905** interrogated. The zDbName parameter is ignored.
906**
907** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
908** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
909** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
910** write ahead log ([WAL file]) and shared memory
911** files used for transaction control
912** are automatically deleted when the latest connection to the database
913** closes. Setting persistent WAL mode causes those files to persist after
914** close. Persisting the files is useful when other processes that do not
915** have write permission on the directory containing the database file want
916** to read the database file, as the WAL and shared memory files must exist
917** in order for the database to be readable. The fourth parameter to
918** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
919** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
920** WAL mode. If the integer is -1, then it is overwritten with the current
921** WAL persistence setting.
922**
923** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
924** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
925** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
926** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
927** xDeviceCharacteristics methods. The fourth parameter to
928** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
929** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
930** mode. If the integer is -1, then it is overwritten with the current
931** zero-damage mode setting.
932**
933** <li>[[SQLITE_FCNTL_OVERWRITE]]
934** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
935** a write transaction to indicate that, unless it is rolled back for some
936** reason, the entire database file will be overwritten by the current
937** transaction. This is used by VACUUM operations.
938**
939** <li>[[SQLITE_FCNTL_VFSNAME]]
940** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
941** all [VFSes] in the VFS stack. The names are of all VFS shims and the
942** final bottom-level VFS are written into memory obtained from
943** [sqlite3_malloc()] and the result is stored in the char* variable
944** that the fourth parameter of [sqlite3_file_control()] points to.
945** The caller is responsible for freeing the memory when done. As with
946** all file-control actions, there is no guarantee that this will actually
947** do anything. Callers should initialize the char* variable to a NULL
948** pointer in case this file-control is not implemented. This file-control
949** is intended for diagnostic use only.
950**
951** <li>[[SQLITE_FCNTL_VFS_POINTER]]
952** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
953** [VFSes] currently in use. ^(The argument X in
954** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
955** of type "[sqlite3_vfs] **". This opcodes will set *X
956** to a pointer to the top-level VFS.)^
957** ^When there are multiple VFS shims in the stack, this opcode finds the
958** upper-most shim only.
959**
960** <li>[[SQLITE_FCNTL_PRAGMA]]
961** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
962** file control is sent to the open [sqlite3_file] object corresponding
963** to the database file to which the pragma statement refers. ^The argument
964** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
965** pointers to strings (char**) in which the second element of the array
966** is the name of the pragma and the third element is the argument to the
967** pragma or NULL if the pragma has no argument. ^The handler for an
968** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
969** of the char** argument point to a string obtained from [sqlite3_mprintf()]
970** or the equivalent and that string will become the result of the pragma or
971** the error message if the pragma fails. ^If the
972** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
973** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
974** file control returns [SQLITE_OK], then the parser assumes that the
975** VFS has handled the PRAGMA itself and the parser generates a no-op
976** prepared statement if result string is NULL, or that returns a copy
977** of the result string if the string is non-NULL.
978** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
979** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
980** that the VFS encountered an error while handling the [PRAGMA] and the
981** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
982** file control occurs at the beginning of pragma statement analysis and so
983** it is able to override built-in [PRAGMA] statements.
984**
985** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
986** ^The [SQLITE_FCNTL_BUSYHANDLER]
987** file-control may be invoked by SQLite on the database file handle
988** shortly after it is opened in order to provide a custom VFS with access
989** to the connection's busy-handler callback. The argument is of type (void**)
990** - an array of two (void *) values. The first (void *) actually points
991** to a function of type (int (*)(void *)). In order to invoke the connection's
992** busy-handler, this function should be invoked with the second (void *) in
993** the array as the only argument. If it returns non-zero, then the operation
994** should be retried. If it returns zero, the custom VFS should abandon the
995** current operation.
996**
997** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
998** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
999** to have SQLite generate a
1000** temporary filename using the same algorithm that is followed to generate
1001** temporary filenames for TEMP tables and other internal uses. The
1002** argument should be a char** which will be filled with the filename
1003** written into memory obtained from [sqlite3_malloc()]. The caller should
1004** invoke [sqlite3_free()] on the result to avoid a memory leak.
1005**
1006** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1007** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1008** maximum number of bytes that will be used for memory-mapped I/O.
1009** The argument is a pointer to a value of type sqlite3_int64 that
1010** is an advisory maximum number of bytes in the file to memory map. The
1011** pointer is overwritten with the old value. The limit is not changed if
1012** the value originally pointed to is negative, and so the current limit
1013** can be queried by passing in a pointer to a negative number. This
1014** file-control is used internally to implement [PRAGMA mmap_size].
1015**
1016** <li>[[SQLITE_FCNTL_TRACE]]
1017** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1018** to the VFS about what the higher layers of the SQLite stack are doing.
1019** This file control is used by some VFS activity tracing [shims].
1020** The argument is a zero-terminated string. Higher layers in the
1021** SQLite stack may generate instances of this file control if
1022** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1023**
1024** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1025** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1026** pointer to an integer and it writes a boolean into that integer depending
1027** on whether or not the file has been renamed, moved, or deleted since it
1028** was first opened.
1029**
1030** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1031** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1032** underlying native file handle associated with a file handle. This file
1033** control interprets its argument as a pointer to a native file handle and
1034** writes the resulting value there.
1035**
1036** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1037** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1038** opcode causes the xFileControl method to swap the file handle with the one
1039** pointed to by the pArg argument. This capability is used during testing
1040** and only needs to be supported when SQLITE_TEST is defined.
1041**
1042** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1043** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1044** be advantageous to block on the next WAL lock if the lock is not immediately
1045** available. The WAL subsystem issues this signal during rare
1046** circumstances in order to fix a problem with priority inversion.
1047** Applications should <em>not</em> use this file-control.
1048**
1049** <li>[[SQLITE_FCNTL_ZIPVFS]]
1050** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1051** VFS should return SQLITE_NOTFOUND for this opcode.
1052**
1053** <li>[[SQLITE_FCNTL_RBU]]
1054** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1055** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1056** this opcode.
1057**
1058** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1059** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1060** the file descriptor is placed in "batch write mode", which
1061** means all subsequent write operations will be deferred and done
1062** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1063** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1064** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1065** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1066** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1067** no VFS interface calls on the same [sqlite3_file] file descriptor
1068** except for calls to the xWrite method and the xFileControl method
1069** with [SQLITE_FCNTL_SIZE_HINT].
1070**
1071** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1072** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1073** operations since the previous successful call to
1074** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1075** This file control returns [SQLITE_OK] if and only if the writes were
1076** all performed successfully and have been committed to persistent storage.
1077** ^Regardless of whether or not it is successful, this file control takes
1078** the file descriptor out of batch write mode so that all subsequent
1079** write operations are independent.
1080** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1081** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1082**
1083** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1084** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1085** operations since the previous successful call to
1086** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1087** ^This file control takes the file descriptor out of batch write mode
1088** so that all subsequent write operations are independent.
1089** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1090** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1091**
1092** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1093** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1094** to block for up to M milliseconds before failing when attempting to
1095** obtain a file lock using the xLock or xShmLock methods of the VFS.
1096** The parameter is a pointer to a 32-bit signed integer that contains
1097** the value that M is to be set to. Before returning, the 32-bit signed
1098** integer is overwritten with the previous value of M.
1099**
1100** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1101** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1102** a database file. The argument is a pointer to a 32-bit unsigned integer.
1103** The "data version" for the pager is written into the pointer. The
1104** "data version" changes whenever any change occurs to the corresponding
1105** database file, either through SQL statements on the same database
1106** connection or through transactions committed by separate database
1107** connections possibly in other processes. The [sqlite3_total_changes()]
1108** interface can be used to find if any database on the connection has changed,
1109** but that interface responds to changes on TEMP as well as MAIN and does
1110** not provide a mechanism to detect changes to MAIN only. Also, the
1111** [sqlite3_total_changes()] interface responds to internal changes only and
1112** omits changes made by other database connections. The
1113** [PRAGMA data_version] command provides a mechanism to detect changes to
1114** a single attached database that occur due to other database connections,
1115** but omits changes implemented by the database connection on which it is
1116** called. This file control is the only mechanism to detect changes that
1117** happen either internally or externally and that are associated with
1118** a particular attached database.
1119**
1120** <li>[[SQLITE_FCNTL_CKPT_START]]
1121** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1122** in wal mode before the client starts to copy pages from the wal
1123** file to the database file.
1124**
1125** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1126** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1127** in wal mode after the client has finished copying pages from the wal
1128** file to the database file, but before the *-shm file is updated to
1129** record the fact that the pages have been checkpointed.
1130** </ul>
1131*/
1132#define SQLITE_FCNTL_LOCKSTATE 1
1133#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1134#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1135#define SQLITE_FCNTL_LAST_ERRNO 4
1136#define SQLITE_FCNTL_SIZE_HINT 5
1137#define SQLITE_FCNTL_CHUNK_SIZE 6
1138#define SQLITE_FCNTL_FILE_POINTER 7
1139#define SQLITE_FCNTL_SYNC_OMITTED 8
1140#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1141#define SQLITE_FCNTL_PERSIST_WAL 10
1142#define SQLITE_FCNTL_OVERWRITE 11
1143#define SQLITE_FCNTL_VFSNAME 12
1144#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1145#define SQLITE_FCNTL_PRAGMA 14
1146#define SQLITE_FCNTL_BUSYHANDLER 15
1147#define SQLITE_FCNTL_TEMPFILENAME 16
1148#define SQLITE_FCNTL_MMAP_SIZE 18
1149#define SQLITE_FCNTL_TRACE 19
1150#define SQLITE_FCNTL_HAS_MOVED 20
1151#define SQLITE_FCNTL_SYNC 21
1152#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1153#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1154#define SQLITE_FCNTL_WAL_BLOCK 24
1155#define SQLITE_FCNTL_ZIPVFS 25
1156#define SQLITE_FCNTL_RBU 26
1157#define SQLITE_FCNTL_VFS_POINTER 27
1158#define SQLITE_FCNTL_JOURNAL_POINTER 28
1159#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1160#define SQLITE_FCNTL_PDB 30
1161#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1162#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1163#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1164#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1165#define SQLITE_FCNTL_DATA_VERSION 35
1166#define SQLITE_FCNTL_SIZE_LIMIT 36
1167#define SQLITE_FCNTL_CKPT_DONE 37
1168#define SQLITE_FCNTL_RESERVE_BYTES 38
1169#define SQLITE_FCNTL_CKPT_START 39
1170
1171/* deprecated names */
1172#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1173#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1174#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1175
1176
1177/*
1178** CAPI3REF: Mutex Handle
1179**
1180** The mutex module within SQLite defines [sqlite3_mutex] to be an
1181** abstract type for a mutex object. The SQLite core never looks
1182** at the internal representation of an [sqlite3_mutex]. It only
1183** deals with pointers to the [sqlite3_mutex] object.
1184**
1185** Mutexes are created using [sqlite3_mutex_alloc()].
1186*/
1187typedef struct sqlite3_mutex sqlite3_mutex;
1188
1189/*
1190** CAPI3REF: Loadable Extension Thunk
1191**
1192** A pointer to the opaque sqlite3_api_routines structure is passed as
1193** the third parameter to entry points of [loadable extensions]. This
1194** structure must be typedefed in order to work around compiler warnings
1195** on some platforms.
1196*/
1197typedef struct sqlite3_api_routines sqlite3_api_routines;
1198
1199/*
1200** CAPI3REF: OS Interface Object
1201**
1202** An instance of the sqlite3_vfs object defines the interface between
1203** the SQLite core and the underlying operating system. The "vfs"
1204** in the name of the object stands for "virtual file system". See
1205** the [VFS | VFS documentation] for further information.
1206**
1207** The VFS interface is sometimes extended by adding new methods onto
1208** the end. Each time such an extension occurs, the iVersion field
1209** is incremented. The iVersion value started out as 1 in
1210** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1211** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1212** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1213** may be appended to the sqlite3_vfs object and the iVersion value
1214** may increase again in future versions of SQLite.
1215** Note that due to an oversight, the structure
1216** of the sqlite3_vfs object changed in the transition from
1217** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1218** and yet the iVersion field was not increased.
1219**
1220** The szOsFile field is the size of the subclassed [sqlite3_file]
1221** structure used by this VFS. mxPathname is the maximum length of
1222** a pathname in this VFS.
1223**
1224** Registered sqlite3_vfs objects are kept on a linked list formed by
1225** the pNext pointer. The [sqlite3_vfs_register()]
1226** and [sqlite3_vfs_unregister()] interfaces manage this list
1227** in a thread-safe way. The [sqlite3_vfs_find()] interface
1228** searches the list. Neither the application code nor the VFS
1229** implementation should use the pNext pointer.
1230**
1231** The pNext field is the only field in the sqlite3_vfs
1232** structure that SQLite will ever modify. SQLite will only access
1233** or modify this field while holding a particular static mutex.
1234** The application should never modify anything within the sqlite3_vfs
1235** object once the object has been registered.
1236**
1237** The zName field holds the name of the VFS module. The name must
1238** be unique across all VFS modules.
1239**
1240** [[sqlite3_vfs.xOpen]]
1241** ^SQLite guarantees that the zFilename parameter to xOpen
1242** is either a NULL pointer or string obtained
1243** from xFullPathname() with an optional suffix added.
1244** ^If a suffix is added to the zFilename parameter, it will
1245** consist of a single "-" character followed by no more than
1246** 11 alphanumeric and/or "-" characters.
1247** ^SQLite further guarantees that
1248** the string will be valid and unchanged until xClose() is
1249** called. Because of the previous sentence,
1250** the [sqlite3_file] can safely store a pointer to the
1251** filename if it needs to remember the filename for some reason.
1252** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1253** must invent its own temporary name for the file. ^Whenever the
1254** xFilename parameter is NULL it will also be the case that the
1255** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1256**
1257** The flags argument to xOpen() includes all bits set in
1258** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1259** or [sqlite3_open16()] is used, then flags includes at least
1260** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1261** If xOpen() opens a file read-only then it sets *pOutFlags to
1262** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1263**
1264** ^(SQLite will also add one of the following flags to the xOpen()
1265** call, depending on the object being opened:
1266**
1267** <ul>
1268** <li> [SQLITE_OPEN_MAIN_DB]
1269** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1270** <li> [SQLITE_OPEN_TEMP_DB]
1271** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1272** <li> [SQLITE_OPEN_TRANSIENT_DB]
1273** <li> [SQLITE_OPEN_SUBJOURNAL]
1274** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1275** <li> [SQLITE_OPEN_WAL]
1276** </ul>)^
1277**
1278** The file I/O implementation can use the object type flags to
1279** change the way it deals with files. For example, an application
1280** that does not care about crash recovery or rollback might make
1281** the open of a journal file a no-op. Writes to this journal would
1282** also be no-ops, and any attempt to read the journal would return
1283** SQLITE_IOERR. Or the implementation might recognize that a database
1284** file will be doing page-aligned sector reads and writes in a random
1285** order and set up its I/O subsystem accordingly.
1286**
1287** SQLite might also add one of the following flags to the xOpen method:
1288**
1289** <ul>
1290** <li> [SQLITE_OPEN_DELETEONCLOSE]
1291** <li> [SQLITE_OPEN_EXCLUSIVE]
1292** </ul>
1293**
1294** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1295** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1296** will be set for TEMP databases and their journals, transient
1297** databases, and subjournals.
1298**
1299** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1300** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1301** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1302** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1303** SQLITE_OPEN_CREATE, is used to indicate that file should always
1304** be created, and that it is an error if it already exists.
1305** It is <i>not</i> used to indicate the file should be opened
1306** for exclusive access.
1307**
1308** ^At least szOsFile bytes of memory are allocated by SQLite
1309** to hold the [sqlite3_file] structure passed as the third
1310** argument to xOpen. The xOpen method does not have to
1311** allocate the structure; it should just fill it in. Note that
1312** the xOpen method must set the sqlite3_file.pMethods to either
1313** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1314** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1315** element will be valid after xOpen returns regardless of the success
1316** or failure of the xOpen call.
1317**
1318** [[sqlite3_vfs.xAccess]]
1319** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1320** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1321** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1322** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1323** flag is never actually used and is not implemented in the built-in
1324** VFSes of SQLite. The file is named by the second argument and can be a
1325** directory. The xAccess method returns [SQLITE_OK] on success or some
1326** non-zero error code if there is an I/O error or if the name of
1327** the file given in the second argument is illegal. If SQLITE_OK
1328** is returned, then non-zero or zero is written into *pResOut to indicate
1329** whether or not the file is accessible.
1330**
1331** ^SQLite will always allocate at least mxPathname+1 bytes for the
1332** output buffer xFullPathname. The exact size of the output buffer
1333** is also passed as a parameter to both methods. If the output buffer
1334** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1335** handled as a fatal error by SQLite, vfs implementations should endeavor
1336** to prevent this by setting mxPathname to a sufficiently large value.
1337**
1338** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1339** interfaces are not strictly a part of the filesystem, but they are
1340** included in the VFS structure for completeness.
1341** The xRandomness() function attempts to return nBytes bytes
1342** of good-quality randomness into zOut. The return value is
1343** the actual number of bytes of randomness obtained.
1344** The xSleep() method causes the calling thread to sleep for at
1345** least the number of microseconds given. ^The xCurrentTime()
1346** method returns a Julian Day Number for the current date and time as
1347** a floating point value.
1348** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1349** Day Number multiplied by 86400000 (the number of milliseconds in
1350** a 24-hour day).
1351** ^SQLite will use the xCurrentTimeInt64() method to get the current
1352** date and time if that method is available (if iVersion is 2 or
1353** greater and the function pointer is not NULL) and will fall back
1354** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1355**
1356** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1357** are not used by the SQLite core. These optional interfaces are provided
1358** by some VFSes to facilitate testing of the VFS code. By overriding
1359** system calls with functions under its control, a test program can
1360** simulate faults and error conditions that would otherwise be difficult
1361** or impossible to induce. The set of system calls that can be overridden
1362** varies from one VFS to another, and from one version of the same VFS to the
1363** next. Applications that use these interfaces must be prepared for any
1364** or all of these interfaces to be NULL or for their behavior to change
1365** from one release to the next. Applications must not attempt to access
1366** any of these methods if the iVersion of the VFS is less than 3.
1367*/
1368typedef struct sqlite3_vfs sqlite3_vfs;
1369typedef void (*sqlite3_syscall_ptr)(void);
1370struct sqlite3_vfs {
1371 int iVersion; /* Structure version number (currently 3) */
1372 int szOsFile; /* Size of subclassed sqlite3_file */
1373 int mxPathname; /* Maximum file pathname length */
1374 sqlite3_vfs *pNext; /* Next registered VFS */
1375 const char *zName; /* Name of this virtual file system */
1376 void *pAppData; /* Pointer to application-specific data */
1377 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1378 int flags, int *pOutFlags);
1379 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1380 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1381 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1382 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1383 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1384 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1385 void (*xDlClose)(sqlite3_vfs*, void*);
1386 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1387 int (*xSleep)(sqlite3_vfs*, int microseconds);
1388 int (*xCurrentTime)(sqlite3_vfs*, double*);
1389 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1390 /*
1391 ** The methods above are in version 1 of the sqlite_vfs object
1392 ** definition. Those that follow are added in version 2 or later
1393 */
1394 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1395 /*
1396 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1397 ** Those below are for version 3 and greater.
1398 */
1399 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1400 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1401 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1402 /*
1403 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1404 ** New fields may be appended in future versions. The iVersion
1405 ** value will increment whenever this happens.
1406 */
1407};
1408
1409/*
1410** CAPI3REF: Flags for the xAccess VFS method
1411**
1412** These integer constants can be used as the third parameter to
1413** the xAccess method of an [sqlite3_vfs] object. They determine
1414** what kind of permissions the xAccess method is looking for.
1415** With SQLITE_ACCESS_EXISTS, the xAccess method
1416** simply checks whether the file exists.
1417** With SQLITE_ACCESS_READWRITE, the xAccess method
1418** checks whether the named directory is both readable and writable
1419** (in other words, if files can be added, removed, and renamed within
1420** the directory).
1421** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1422** [temp_store_directory pragma], though this could change in a future
1423** release of SQLite.
1424** With SQLITE_ACCESS_READ, the xAccess method
1425** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1426** currently unused, though it might be used in a future release of
1427** SQLite.
1428*/
1429#define SQLITE_ACCESS_EXISTS 0
1430#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1431#define SQLITE_ACCESS_READ 2 /* Unused */
1432
1433/*
1434** CAPI3REF: Flags for the xShmLock VFS method
1435**
1436** These integer constants define the various locking operations
1437** allowed by the xShmLock method of [sqlite3_io_methods]. The
1438** following are the only legal combinations of flags to the
1439** xShmLock method:
1440**
1441** <ul>
1442** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1443** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1444** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1445** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1446** </ul>
1447**
1448** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1449** was given on the corresponding lock.
1450**
1451** The xShmLock method can transition between unlocked and SHARED or
1452** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1453** and EXCLUSIVE.
1454*/
1455#define SQLITE_SHM_UNLOCK 1
1456#define SQLITE_SHM_LOCK 2
1457#define SQLITE_SHM_SHARED 4
1458#define SQLITE_SHM_EXCLUSIVE 8
1459
1460/*
1461** CAPI3REF: Maximum xShmLock index
1462**
1463** The xShmLock method on [sqlite3_io_methods] may use values
1464** between 0 and this upper bound as its "offset" argument.
1465** The SQLite core will never attempt to acquire or release a
1466** lock outside of this range
1467*/
1468#define SQLITE_SHM_NLOCK 8
1469
1470
1471/*
1472** CAPI3REF: Initialize The SQLite Library
1473**
1474** ^The sqlite3_initialize() routine initializes the
1475** SQLite library. ^The sqlite3_shutdown() routine
1476** deallocates any resources that were allocated by sqlite3_initialize().
1477** These routines are designed to aid in process initialization and
1478** shutdown on embedded systems. Workstation applications using
1479** SQLite normally do not need to invoke either of these routines.
1480**
1481** A call to sqlite3_initialize() is an "effective" call if it is
1482** the first time sqlite3_initialize() is invoked during the lifetime of
1483** the process, or if it is the first time sqlite3_initialize() is invoked
1484** following a call to sqlite3_shutdown(). ^(Only an effective call
1485** of sqlite3_initialize() does any initialization. All other calls
1486** are harmless no-ops.)^
1487**
1488** A call to sqlite3_shutdown() is an "effective" call if it is the first
1489** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1490** an effective call to sqlite3_shutdown() does any deinitialization.
1491** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1492**
1493** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1494** is not. The sqlite3_shutdown() interface must only be called from a
1495** single thread. All open [database connections] must be closed and all
1496** other SQLite resources must be deallocated prior to invoking
1497** sqlite3_shutdown().
1498**
1499** Among other things, ^sqlite3_initialize() will invoke
1500** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1501** will invoke sqlite3_os_end().
1502**
1503** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1504** ^If for some reason, sqlite3_initialize() is unable to initialize
1505** the library (perhaps it is unable to allocate a needed resource such
1506** as a mutex) it returns an [error code] other than [SQLITE_OK].
1507**
1508** ^The sqlite3_initialize() routine is called internally by many other
1509** SQLite interfaces so that an application usually does not need to
1510** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1511** calls sqlite3_initialize() so the SQLite library will be automatically
1512** initialized when [sqlite3_open()] is called if it has not be initialized
1513** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1514** compile-time option, then the automatic calls to sqlite3_initialize()
1515** are omitted and the application must call sqlite3_initialize() directly
1516** prior to using any other SQLite interface. For maximum portability,
1517** it is recommended that applications always invoke sqlite3_initialize()
1518** directly prior to using any other SQLite interface. Future releases
1519** of SQLite may require this. In other words, the behavior exhibited
1520** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1521** default behavior in some future release of SQLite.
1522**
1523** The sqlite3_os_init() routine does operating-system specific
1524** initialization of the SQLite library. The sqlite3_os_end()
1525** routine undoes the effect of sqlite3_os_init(). Typical tasks
1526** performed by these routines include allocation or deallocation
1527** of static resources, initialization of global variables,
1528** setting up a default [sqlite3_vfs] module, or setting up
1529** a default configuration using [sqlite3_config()].
1530**
1531** The application should never invoke either sqlite3_os_init()
1532** or sqlite3_os_end() directly. The application should only invoke
1533** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1534** interface is called automatically by sqlite3_initialize() and
1535** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1536** implementations for sqlite3_os_init() and sqlite3_os_end()
1537** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1538** When [custom builds | built for other platforms]
1539** (using the [SQLITE_OS_OTHER=1] compile-time
1540** option) the application must supply a suitable implementation for
1541** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1542** implementation of sqlite3_os_init() or sqlite3_os_end()
1543** must return [SQLITE_OK] on success and some other [error code] upon
1544** failure.
1545*/
1546SQLITE_API int sqlite3_initialize(void);
1547SQLITE_API int sqlite3_shutdown(void);
1548SQLITE_API int sqlite3_os_init(void);
1549SQLITE_API int sqlite3_os_end(void);
1550
1551/*
1552** CAPI3REF: Configuring The SQLite Library
1553**
1554** The sqlite3_config() interface is used to make global configuration
1555** changes to SQLite in order to tune SQLite to the specific needs of
1556** the application. The default configuration is recommended for most
1557** applications and so this routine is usually not necessary. It is
1558** provided to support rare applications with unusual needs.
1559**
1560** <b>The sqlite3_config() interface is not threadsafe. The application
1561** must ensure that no other SQLite interfaces are invoked by other
1562** threads while sqlite3_config() is running.</b>
1563**
1564** The sqlite3_config() interface
1565** may only be invoked prior to library initialization using
1566** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1567** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1568** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1569** Note, however, that ^sqlite3_config() can be called as part of the
1570** implementation of an application-defined [sqlite3_os_init()].
1571**
1572** The first argument to sqlite3_config() is an integer
1573** [configuration option] that determines
1574** what property of SQLite is to be configured. Subsequent arguments
1575** vary depending on the [configuration option]
1576** in the first argument.
1577**
1578** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1579** ^If the option is unknown or SQLite is unable to set the option
1580** then this routine returns a non-zero [error code].
1581*/
1582SQLITE_API int sqlite3_config(int, ...);
1583
1584/*
1585** CAPI3REF: Configure database connections
1586** METHOD: sqlite3
1587**
1588** The sqlite3_db_config() interface is used to make configuration
1589** changes to a [database connection]. The interface is similar to
1590** [sqlite3_config()] except that the changes apply to a single
1591** [database connection] (specified in the first argument).
1592**
1593** The second argument to sqlite3_db_config(D,V,...) is the
1594** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1595** that indicates what aspect of the [database connection] is being configured.
1596** Subsequent arguments vary depending on the configuration verb.
1597**
1598** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1599** the call is considered successful.
1600*/
1601SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1602
1603/*
1604** CAPI3REF: Memory Allocation Routines
1605**
1606** An instance of this object defines the interface between SQLite
1607** and low-level memory allocation routines.
1608**
1609** This object is used in only one place in the SQLite interface.
1610** A pointer to an instance of this object is the argument to
1611** [sqlite3_config()] when the configuration option is
1612** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1613** By creating an instance of this object
1614** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1615** during configuration, an application can specify an alternative
1616** memory allocation subsystem for SQLite to use for all of its
1617** dynamic memory needs.
1618**
1619** Note that SQLite comes with several [built-in memory allocators]
1620** that are perfectly adequate for the overwhelming majority of applications
1621** and that this object is only useful to a tiny minority of applications
1622** with specialized memory allocation requirements. This object is
1623** also used during testing of SQLite in order to specify an alternative
1624** memory allocator that simulates memory out-of-memory conditions in
1625** order to verify that SQLite recovers gracefully from such
1626** conditions.
1627**
1628** The xMalloc, xRealloc, and xFree methods must work like the
1629** malloc(), realloc() and free() functions from the standard C library.
1630** ^SQLite guarantees that the second argument to
1631** xRealloc is always a value returned by a prior call to xRoundup.
1632**
1633** xSize should return the allocated size of a memory allocation
1634** previously obtained from xMalloc or xRealloc. The allocated size
1635** is always at least as big as the requested size but may be larger.
1636**
1637** The xRoundup method returns what would be the allocated size of
1638** a memory allocation given a particular requested size. Most memory
1639** allocators round up memory allocations at least to the next multiple
1640** of 8. Some allocators round up to a larger multiple or to a power of 2.
1641** Every memory allocation request coming in through [sqlite3_malloc()]
1642** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1643** that causes the corresponding memory allocation to fail.
1644**
1645** The xInit method initializes the memory allocator. For example,
1646** it might allocate any required mutexes or initialize internal data
1647** structures. The xShutdown method is invoked (indirectly) by
1648** [sqlite3_shutdown()] and should deallocate any resources acquired
1649** by xInit. The pAppData pointer is used as the only parameter to
1650** xInit and xShutdown.
1651**
1652** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1653** the xInit method, so the xInit method need not be threadsafe. The
1654** xShutdown method is only called from [sqlite3_shutdown()] so it does
1655** not need to be threadsafe either. For all other methods, SQLite
1656** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1657** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1658** it is by default) and so the methods are automatically serialized.
1659** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1660** methods must be threadsafe or else make their own arrangements for
1661** serialization.
1662**
1663** SQLite will never invoke xInit() more than once without an intervening
1664** call to xShutdown().
1665*/
1666typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1667struct sqlite3_mem_methods {
1668 void *(*xMalloc)(int); /* Memory allocation function */
1669 void (*xFree)(void*); /* Free a prior allocation */
1670 void *(*xRealloc)(void*,int); /* Resize an allocation */
1671 int (*xSize)(void*); /* Return the size of an allocation */
1672 int (*xRoundup)(int); /* Round up request size to allocation size */
1673 int (*xInit)(void*); /* Initialize the memory allocator */
1674 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1675 void *pAppData; /* Argument to xInit() and xShutdown() */
1676};
1677
1678/*
1679** CAPI3REF: Configuration Options
1680** KEYWORDS: {configuration option}
1681**
1682** These constants are the available integer configuration options that
1683** can be passed as the first argument to the [sqlite3_config()] interface.
1684**
1685** New configuration options may be added in future releases of SQLite.
1686** Existing configuration options might be discontinued. Applications
1687** should check the return code from [sqlite3_config()] to make sure that
1688** the call worked. The [sqlite3_config()] interface will return a
1689** non-zero [error code] if a discontinued or unsupported configuration option
1690** is invoked.
1691**
1692** <dl>
1693** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1694** <dd>There are no arguments to this option. ^This option sets the
1695** [threading mode] to Single-thread. In other words, it disables
1696** all mutexing and puts SQLite into a mode where it can only be used
1697** by a single thread. ^If SQLite is compiled with
1698** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1699** it is not possible to change the [threading mode] from its default
1700** value of Single-thread and so [sqlite3_config()] will return
1701** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1702** configuration option.</dd>
1703**
1704** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1705** <dd>There are no arguments to this option. ^This option sets the
1706** [threading mode] to Multi-thread. In other words, it disables
1707** mutexing on [database connection] and [prepared statement] objects.
1708** The application is responsible for serializing access to
1709** [database connections] and [prepared statements]. But other mutexes
1710** are enabled so that SQLite will be safe to use in a multi-threaded
1711** environment as long as no two threads attempt to use the same
1712** [database connection] at the same time. ^If SQLite is compiled with
1713** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1714** it is not possible to set the Multi-thread [threading mode] and
1715** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1716** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1717**
1718** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1719** <dd>There are no arguments to this option. ^This option sets the
1720** [threading mode] to Serialized. In other words, this option enables
1721** all mutexes including the recursive
1722** mutexes on [database connection] and [prepared statement] objects.
1723** In this mode (which is the default when SQLite is compiled with
1724** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1725** to [database connections] and [prepared statements] so that the
1726** application is free to use the same [database connection] or the
1727** same [prepared statement] in different threads at the same time.
1728** ^If SQLite is compiled with
1729** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1730** it is not possible to set the Serialized [threading mode] and
1731** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1732** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1733**
1734** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1735** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1736** a pointer to an instance of the [sqlite3_mem_methods] structure.
1737** The argument specifies
1738** alternative low-level memory allocation routines to be used in place of
1739** the memory allocation routines built into SQLite.)^ ^SQLite makes
1740** its own private copy of the content of the [sqlite3_mem_methods] structure
1741** before the [sqlite3_config()] call returns.</dd>
1742**
1743** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1744** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1745** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1746** The [sqlite3_mem_methods]
1747** structure is filled with the currently defined memory allocation routines.)^
1748** This option can be used to overload the default memory allocation
1749** routines with a wrapper that simulations memory allocation failure or
1750** tracks memory usage, for example. </dd>
1751**
1752** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1753** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1754** type int, interpreted as a boolean, which if true provides a hint to
1755** SQLite that it should avoid large memory allocations if possible.
1756** SQLite will run faster if it is free to make large memory allocations,
1757** but some application might prefer to run slower in exchange for
1758** guarantees about memory fragmentation that are possible if large
1759** allocations are avoided. This hint is normally off.
1760** </dd>
1761**
1762** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1763** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1764** interpreted as a boolean, which enables or disables the collection of
1765** memory allocation statistics. ^(When memory allocation statistics are
1766** disabled, the following SQLite interfaces become non-operational:
1767** <ul>
1768** <li> [sqlite3_hard_heap_limit64()]
1769** <li> [sqlite3_memory_used()]
1770** <li> [sqlite3_memory_highwater()]
1771** <li> [sqlite3_soft_heap_limit64()]
1772** <li> [sqlite3_status64()]
1773** </ul>)^
1774** ^Memory allocation statistics are enabled by default unless SQLite is
1775** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1776** allocation statistics are disabled by default.
1777** </dd>
1778**
1779** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1780** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1781** </dd>
1782**
1783** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1784** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1785** that SQLite can use for the database page cache with the default page
1786** cache implementation.
1787** This configuration option is a no-op if an application-defined page
1788** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1789** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1790** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1791** and the number of cache lines (N).
1792** The sz argument should be the size of the largest database page
1793** (a power of two between 512 and 65536) plus some extra bytes for each
1794** page header. ^The number of extra bytes needed by the page header
1795** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1796** ^It is harmless, apart from the wasted memory,
1797** for the sz parameter to be larger than necessary. The pMem
1798** argument must be either a NULL pointer or a pointer to an 8-byte
1799** aligned block of memory of at least sz*N bytes, otherwise
1800** subsequent behavior is undefined.
1801** ^When pMem is not NULL, SQLite will strive to use the memory provided
1802** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1803** a page cache line is larger than sz bytes or if all of the pMem buffer
1804** is exhausted.
1805** ^If pMem is NULL and N is non-zero, then each database connection
1806** does an initial bulk allocation for page cache memory
1807** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1808** of -1024*N bytes if N is negative, . ^If additional
1809** page cache memory is needed beyond what is provided by the initial
1810** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1811** additional cache line. </dd>
1812**
1813** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1814** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1815** that SQLite will use for all of its dynamic memory allocation needs
1816** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1817** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1818** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1819** [SQLITE_ERROR] if invoked otherwise.
1820** ^There are three arguments to SQLITE_CONFIG_HEAP:
1821** An 8-byte aligned pointer to the memory,
1822** the number of bytes in the memory buffer, and the minimum allocation size.
1823** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1824** to using its default memory allocator (the system malloc() implementation),
1825** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1826** memory pointer is not NULL then the alternative memory
1827** allocator is engaged to handle all of SQLites memory allocation needs.
1828** The first pointer (the memory pointer) must be aligned to an 8-byte
1829** boundary or subsequent behavior of SQLite will be undefined.
1830** The minimum allocation size is capped at 2**12. Reasonable values
1831** for the minimum allocation size are 2**5 through 2**8.</dd>
1832**
1833** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1834** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1835** pointer to an instance of the [sqlite3_mutex_methods] structure.
1836** The argument specifies alternative low-level mutex routines to be used
1837** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1838** the content of the [sqlite3_mutex_methods] structure before the call to
1839** [sqlite3_config()] returns. ^If SQLite is compiled with
1840** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1841** the entire mutexing subsystem is omitted from the build and hence calls to
1842** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1843** return [SQLITE_ERROR].</dd>
1844**
1845** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1846** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1847** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1848** [sqlite3_mutex_methods]
1849** structure is filled with the currently defined mutex routines.)^
1850** This option can be used to overload the default mutex allocation
1851** routines with a wrapper used to track mutex usage for performance
1852** profiling or testing, for example. ^If SQLite is compiled with
1853** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1854** the entire mutexing subsystem is omitted from the build and hence calls to
1855** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1856** return [SQLITE_ERROR].</dd>
1857**
1858** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1859** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1860** the default size of lookaside memory on each [database connection].
1861** The first argument is the
1862** size of each lookaside buffer slot and the second is the number of
1863** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1864** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1865** option to [sqlite3_db_config()] can be used to change the lookaside
1866** configuration on individual connections.)^ </dd>
1867**
1868** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1869** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1870** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1871** the interface to a custom page cache implementation.)^
1872** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1873**
1874** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1875** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1876** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1877** the current page cache implementation into that object.)^ </dd>
1878**
1879** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1880** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1881** global [error log].
1882** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1883** function with a call signature of void(*)(void*,int,const char*),
1884** and a pointer to void. ^If the function pointer is not NULL, it is
1885** invoked by [sqlite3_log()] to process each logging event. ^If the
1886** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1887** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1888** passed through as the first parameter to the application-defined logger
1889** function whenever that function is invoked. ^The second parameter to
1890** the logger function is a copy of the first parameter to the corresponding
1891** [sqlite3_log()] call and is intended to be a [result code] or an
1892** [extended result code]. ^The third parameter passed to the logger is
1893** log message after formatting via [sqlite3_snprintf()].
1894** The SQLite logging interface is not reentrant; the logger function
1895** supplied by the application must not invoke any SQLite interface.
1896** In a multi-threaded application, the application-defined logger
1897** function must be threadsafe. </dd>
1898**
1899** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1900** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1901** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1902** then URI handling is globally disabled.)^ ^If URI handling is globally
1903** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1904** [sqlite3_open16()] or
1905** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1906** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1907** connection is opened. ^If it is globally disabled, filenames are
1908** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1909** database connection is opened. ^(By default, URI handling is globally
1910** disabled. The default value may be changed by compiling with the
1911** [SQLITE_USE_URI] symbol defined.)^
1912**
1913** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1914** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1915** argument which is interpreted as a boolean in order to enable or disable
1916** the use of covering indices for full table scans in the query optimizer.
1917** ^The default setting is determined
1918** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1919** if that compile-time option is omitted.
1920** The ability to disable the use of covering indices for full table scans
1921** is because some incorrectly coded legacy applications might malfunction
1922** when the optimization is enabled. Providing the ability to
1923** disable the optimization allows the older, buggy application code to work
1924** without change even with newer versions of SQLite.
1925**
1926** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1927** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1928** <dd> These options are obsolete and should not be used by new code.
1929** They are retained for backwards compatibility but are now no-ops.
1930** </dd>
1931**
1932** [[SQLITE_CONFIG_SQLLOG]]
1933** <dt>SQLITE_CONFIG_SQLLOG
1934** <dd>This option is only available if sqlite is compiled with the
1935** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1936** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1937** The second should be of type (void*). The callback is invoked by the library
1938** in three separate circumstances, identified by the value passed as the
1939** fourth parameter. If the fourth parameter is 0, then the database connection
1940** passed as the second argument has just been opened. The third argument
1941** points to a buffer containing the name of the main database file. If the
1942** fourth parameter is 1, then the SQL statement that the third parameter
1943** points to has just been executed. Or, if the fourth parameter is 2, then
1944** the connection being passed as the second parameter is being closed. The
1945** third parameter is passed NULL In this case. An example of using this
1946** configuration option can be seen in the "test_sqllog.c" source file in
1947** the canonical SQLite source tree.</dd>
1948**
1949** [[SQLITE_CONFIG_MMAP_SIZE]]
1950** <dt>SQLITE_CONFIG_MMAP_SIZE
1951** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1952** that are the default mmap size limit (the default setting for
1953** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1954** ^The default setting can be overridden by each database connection using
1955** either the [PRAGMA mmap_size] command, or by using the
1956** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1957** will be silently truncated if necessary so that it does not exceed the
1958** compile-time maximum mmap size set by the
1959** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1960** ^If either argument to this option is negative, then that argument is
1961** changed to its compile-time default.
1962**
1963** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1964** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1965** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1966** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1967** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1968** that specifies the maximum size of the created heap.
1969**
1970** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1971** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1972** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1973** is a pointer to an integer and writes into that integer the number of extra
1974** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1975** The amount of extra space required can change depending on the compiler,
1976** target platform, and SQLite version.
1977**
1978** [[SQLITE_CONFIG_PMASZ]]
1979** <dt>SQLITE_CONFIG_PMASZ
1980** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1981** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1982** sorter to that integer. The default minimum PMA Size is set by the
1983** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1984** to help with sort operations when multithreaded sorting
1985** is enabled (using the [PRAGMA threads] command) and the amount of content
1986** to be sorted exceeds the page size times the minimum of the
1987** [PRAGMA cache_size] setting and this value.
1988**
1989** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1990** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1991** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1992** becomes the [statement journal] spill-to-disk threshold.
1993** [Statement journals] are held in memory until their size (in bytes)
1994** exceeds this threshold, at which point they are written to disk.
1995** Or if the threshold is -1, statement journals are always held
1996** exclusively in memory.
1997** Since many statement journals never become large, setting the spill
1998** threshold to a value such as 64KiB can greatly reduce the amount of
1999** I/O required to support statement rollback.
2000** The default value for this setting is controlled by the
2001** [SQLITE_STMTJRNL_SPILL] compile-time option.
2002**
2003** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2004** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2005** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2006** of type (int) - the new value of the sorter-reference size threshold.
2007** Usually, when SQLite uses an external sort to order records according
2008** to an ORDER BY clause, all fields required by the caller are present in the
2009** sorted records. However, if SQLite determines based on the declared type
2010** of a table column that its values are likely to be very large - larger
2011** than the configured sorter-reference size threshold - then a reference
2012** is stored in each sorted record and the required column values loaded
2013** from the database as records are returned in sorted order. The default
2014** value for this option is to never use this optimization. Specifying a
2015** negative value for this option restores the default behaviour.
2016** This option is only available if SQLite is compiled with the
2017** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2018**
2019** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2020** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2021** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2022** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2023** database created using [sqlite3_deserialize()]. This default maximum
2024** size can be adjusted up or down for individual databases using the
2025** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2026** configuration setting is never used, then the default maximum is determined
2027** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2028** compile-time option is not set, then the default maximum is 1073741824.
2029** </dl>
2030*/
2031#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2032#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2033#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2034#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2035#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2036#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2037#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2038#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2039#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2040#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2041#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2042/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2043#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2044#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2045#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2046#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2047#define SQLITE_CONFIG_URI 17 /* int */
2048#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2049#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2050#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2051#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2052#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2053#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2054#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2055#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2056#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2057#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2058#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2059#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2060
2061/*
2062** CAPI3REF: Database Connection Configuration Options
2063**
2064** These constants are the available integer configuration options that
2065** can be passed as the second argument to the [sqlite3_db_config()] interface.
2066**
2067** New configuration options may be added in future releases of SQLite.
2068** Existing configuration options might be discontinued. Applications
2069** should check the return code from [sqlite3_db_config()] to make sure that
2070** the call worked. ^The [sqlite3_db_config()] interface will return a
2071** non-zero [error code] if a discontinued or unsupported configuration option
2072** is invoked.
2073**
2074** <dl>
2075** [[SQLITE_DBCONFIG_LOOKASIDE]]
2076** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2077** <dd> ^This option takes three additional arguments that determine the
2078** [lookaside memory allocator] configuration for the [database connection].
2079** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2080** pointer to a memory buffer to use for lookaside memory.
2081** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2082** may be NULL in which case SQLite will allocate the
2083** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2084** size of each lookaside buffer slot. ^The third argument is the number of
2085** slots. The size of the buffer in the first argument must be greater than
2086** or equal to the product of the second and third arguments. The buffer
2087** must be aligned to an 8-byte boundary. ^If the second argument to
2088** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2089** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2090** configuration for a database connection can only be changed when that
2091** connection is not currently using lookaside memory, or in other words
2092** when the "current value" returned by
2093** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2094** Any attempt to change the lookaside memory configuration when lookaside
2095** memory is in use leaves the configuration unchanged and returns
2096** [SQLITE_BUSY].)^</dd>
2097**
2098** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2099** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2100** <dd> ^This option is used to enable or disable the enforcement of
2101** [foreign key constraints]. There should be two additional arguments.
2102** The first argument is an integer which is 0 to disable FK enforcement,
2103** positive to enable FK enforcement or negative to leave FK enforcement
2104** unchanged. The second parameter is a pointer to an integer into which
2105** is written 0 or 1 to indicate whether FK enforcement is off or on
2106** following this call. The second parameter may be a NULL pointer, in
2107** which case the FK enforcement setting is not reported back. </dd>
2108**
2109** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2110** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2111** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2112** There should be two additional arguments.
2113** The first argument is an integer which is 0 to disable triggers,
2114** positive to enable triggers or negative to leave the setting unchanged.
2115** The second parameter is a pointer to an integer into which
2116** is written 0 or 1 to indicate whether triggers are disabled or enabled
2117** following this call. The second parameter may be a NULL pointer, in
2118** which case the trigger setting is not reported back. </dd>
2119**
2120** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2121** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2122** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2123** There should be two additional arguments.
2124** The first argument is an integer which is 0 to disable views,
2125** positive to enable views or negative to leave the setting unchanged.
2126** The second parameter is a pointer to an integer into which
2127** is written 0 or 1 to indicate whether views are disabled or enabled
2128** following this call. The second parameter may be a NULL pointer, in
2129** which case the view setting is not reported back. </dd>
2130**
2131** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2132** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2133** <dd> ^This option is used to enable or disable the
2134** [fts3_tokenizer()] function which is part of the
2135** [FTS3] full-text search engine extension.
2136** There should be two additional arguments.
2137** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2138** positive to enable fts3_tokenizer() or negative to leave the setting
2139** unchanged.
2140** The second parameter is a pointer to an integer into which
2141** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2142** following this call. The second parameter may be a NULL pointer, in
2143** which case the new setting is not reported back. </dd>
2144**
2145** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2146** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2147** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2148** interface independently of the [load_extension()] SQL function.
2149** The [sqlite3_enable_load_extension()] API enables or disables both the
2150** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2151** There should be two additional arguments.
2152** When the first argument to this interface is 1, then only the C-API is
2153** enabled and the SQL function remains disabled. If the first argument to
2154** this interface is 0, then both the C-API and the SQL function are disabled.
2155** If the first argument is -1, then no changes are made to state of either the
2156** C-API or the SQL function.
2157** The second parameter is a pointer to an integer into which
2158** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2159** is disabled or enabled following this call. The second parameter may
2160** be a NULL pointer, in which case the new setting is not reported back.
2161** </dd>
2162**
2163** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2164** <dd> ^This option is used to change the name of the "main" database
2165** schema. ^The sole argument is a pointer to a constant UTF8 string
2166** which will become the new schema name in place of "main". ^SQLite
2167** does not make a copy of the new main schema name string, so the application
2168** must ensure that the argument passed into this DBCONFIG option is unchanged
2169** until after the database connection closes.
2170** </dd>
2171**
2172** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2173** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2174** <dd> Usually, when a database in wal mode is closed or detached from a
2175** database handle, SQLite checks if this will mean that there are now no
2176** connections at all to the database. If so, it performs a checkpoint
2177** operation before closing the connection. This option may be used to
2178** override this behaviour. The first parameter passed to this operation
2179** is an integer - positive to disable checkpoints-on-close, or zero (the
2180** default) to enable them, and negative to leave the setting unchanged.
2181** The second parameter is a pointer to an integer
2182** into which is written 0 or 1 to indicate whether checkpoints-on-close
2183** have been disabled - 0 if they are not disabled, 1 if they are.
2184** </dd>
2185**
2186** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2187** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2188** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2189** a single SQL query statement will always use the same algorithm regardless
2190** of values of [bound parameters].)^ The QPSG disables some query optimizations
2191** that look at the values of bound parameters, which can make some queries
2192** slower. But the QPSG has the advantage of more predictable behavior. With
2193** the QPSG active, SQLite will always use the same query plan in the field as
2194** was used during testing in the lab.
2195** The first argument to this setting is an integer which is 0 to disable
2196** the QPSG, positive to enable QPSG, or negative to leave the setting
2197** unchanged. The second parameter is a pointer to an integer into which
2198** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2199** following this call.
2200** </dd>
2201**
2202** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2203** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2204** include output for any operations performed by trigger programs. This
2205** option is used to set or clear (the default) a flag that governs this
2206** behavior. The first parameter passed to this operation is an integer -
2207** positive to enable output for trigger programs, or zero to disable it,
2208** or negative to leave the setting unchanged.
2209** The second parameter is a pointer to an integer into which is written
2210** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2211** it is not disabled, 1 if it is.
2212** </dd>
2213**
2214** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2215** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2216** [VACUUM] in order to reset a database back to an empty database
2217** with no schema and no content. The following process works even for
2218** a badly corrupted database file:
2219** <ol>
2220** <li> If the database connection is newly opened, make sure it has read the
2221** database schema by preparing then discarding some query against the
2222** database, or calling sqlite3_table_column_metadata(), ignoring any
2223** errors. This step is only necessary if the application desires to keep
2224** the database in WAL mode after the reset if it was in WAL mode before
2225** the reset.
2226** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2227** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2228** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2229** </ol>
2230** Because resetting a database is destructive and irreversible, the
2231** process requires the use of this obscure API and multiple steps to help
2232** ensure that it does not happen by accident.
2233**
2234** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2235** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2236** "defensive" flag for a database connection. When the defensive
2237** flag is enabled, language features that allow ordinary SQL to
2238** deliberately corrupt the database file are disabled. The disabled
2239** features include but are not limited to the following:
2240** <ul>
2241** <li> The [PRAGMA writable_schema=ON] statement.
2242** <li> The [PRAGMA journal_mode=OFF] statement.
2243** <li> Writes to the [sqlite_dbpage] virtual table.
2244** <li> Direct writes to [shadow tables].
2245** </ul>
2246** </dd>
2247**
2248** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2249** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2250** "writable_schema" flag. This has the same effect and is logically equivalent
2251** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2252** The first argument to this setting is an integer which is 0 to disable
2253** the writable_schema, positive to enable writable_schema, or negative to
2254** leave the setting unchanged. The second parameter is a pointer to an
2255** integer into which is written 0 or 1 to indicate whether the writable_schema
2256** is enabled or disabled following this call.
2257** </dd>
2258**
2259** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2260** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2261** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2262** the legacy behavior of the [ALTER TABLE RENAME] command such it
2263** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2264** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2265** additional information. This feature can also be turned on and off
2266** using the [PRAGMA legacy_alter_table] statement.
2267** </dd>
2268**
2269** [[SQLITE_DBCONFIG_DQS_DML]]
2270** <dt>SQLITE_DBCONFIG_DQS_DML</td>
2271** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2272** the legacy [double-quoted string literal] misfeature for DML statements
2273** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2274** default value of this setting is determined by the [-DSQLITE_DQS]
2275** compile-time option.
2276** </dd>
2277**
2278** [[SQLITE_DBCONFIG_DQS_DDL]]
2279** <dt>SQLITE_DBCONFIG_DQS_DDL</td>
2280** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2281** the legacy [double-quoted string literal] misfeature for DDL statements,
2282** such as CREATE TABLE and CREATE INDEX. The
2283** default value of this setting is determined by the [-DSQLITE_DQS]
2284** compile-time option.
2285** </dd>
2286**
2287** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2288** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td>
2289** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2290** assume that database schemas are untainted by malicious content.
2291** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2292** takes additional defensive steps to protect the application from harm
2293** including:
2294** <ul>
2295** <li> Prohibit the use of SQL functions inside triggers, views,
2296** CHECK constraints, DEFAULT clauses, expression indexes,
2297** partial indexes, or generated columns
2298** unless those functions are tagged with [SQLITE_INNOCUOUS].
2299** <li> Prohibit the use of virtual tables inside of triggers or views
2300** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2301** </ul>
2302** This setting defaults to "on" for legacy compatibility, however
2303** all applications are advised to turn it off if possible. This setting
2304** can also be controlled using the [PRAGMA trusted_schema] statement.
2305** </dd>
2306**
2307** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2308** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td>
2309** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2310** the legacy file format flag. When activated, this flag causes all newly
2311** created database file to have a schema format version number (the 4-byte
2312** integer found at offset 44 into the database header) of 1. This in turn
2313** means that the resulting database file will be readable and writable by
2314** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2315** newly created databases are generally not understandable by SQLite versions
2316** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2317** is now scarcely any need to generated database files that are compatible
2318** all the way back to version 3.0.0, and so this setting is of little
2319** practical use, but is provided so that SQLite can continue to claim the
2320** ability to generate new database files that are compatible with version
2321** 3.0.0.
2322** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2323** the [VACUUM] command will fail with an obscure error when attempting to
2324** process a table with generated columns and a descending index. This is
2325** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2326** either generated columns or decending indexes.
2327** </dd>
2328** </dl>
2329*/
2330#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2331#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2332#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2333#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2334#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2335#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2336#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2337#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2338#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2339#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2340#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2341#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2342#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2343#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2344#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2345#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2346#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2347#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2348#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */
2349
2350/*
2351** CAPI3REF: Enable Or Disable Extended Result Codes
2352** METHOD: sqlite3
2353**
2354** ^The sqlite3_extended_result_codes() routine enables or disables the
2355** [extended result codes] feature of SQLite. ^The extended result
2356** codes are disabled by default for historical compatibility.
2357*/
2358SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2359
2360/*
2361** CAPI3REF: Last Insert Rowid
2362** METHOD: sqlite3
2363**
2364** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2365** has a unique 64-bit signed
2366** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2367** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2368** names are not also used by explicitly declared columns. ^If
2369** the table has a column of type [INTEGER PRIMARY KEY] then that column
2370** is another alias for the rowid.
2371**
2372** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2373** the most recent successful [INSERT] into a rowid table or [virtual table]
2374** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2375** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2376** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2377** zero.
2378**
2379** As well as being set automatically as rows are inserted into database
2380** tables, the value returned by this function may be set explicitly by
2381** [sqlite3_set_last_insert_rowid()]
2382**
2383** Some virtual table implementations may INSERT rows into rowid tables as
2384** part of committing a transaction (e.g. to flush data accumulated in memory
2385** to disk). In this case subsequent calls to this function return the rowid
2386** associated with these internal INSERT operations, which leads to
2387** unintuitive results. Virtual table implementations that do write to rowid
2388** tables in this way can avoid this problem by restoring the original
2389** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2390** control to the user.
2391**
2392** ^(If an [INSERT] occurs within a trigger then this routine will
2393** return the [rowid] of the inserted row as long as the trigger is
2394** running. Once the trigger program ends, the value returned
2395** by this routine reverts to what it was before the trigger was fired.)^
2396**
2397** ^An [INSERT] that fails due to a constraint violation is not a
2398** successful [INSERT] and does not change the value returned by this
2399** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2400** and INSERT OR ABORT make no changes to the return value of this
2401** routine when their insertion fails. ^(When INSERT OR REPLACE
2402** encounters a constraint violation, it does not fail. The
2403** INSERT continues to completion after deleting rows that caused
2404** the constraint problem so INSERT OR REPLACE will always change
2405** the return value of this interface.)^
2406**
2407** ^For the purposes of this routine, an [INSERT] is considered to
2408** be successful even if it is subsequently rolled back.
2409**
2410** This function is accessible to SQL statements via the
2411** [last_insert_rowid() SQL function].
2412**
2413** If a separate thread performs a new [INSERT] on the same
2414** database connection while the [sqlite3_last_insert_rowid()]
2415** function is running and thus changes the last insert [rowid],
2416** then the value returned by [sqlite3_last_insert_rowid()] is
2417** unpredictable and might not equal either the old or the new
2418** last insert [rowid].
2419*/
2420SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2421
2422/*
2423** CAPI3REF: Set the Last Insert Rowid value.
2424** METHOD: sqlite3
2425**
2426** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2427** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2428** without inserting a row into the database.
2429*/
2430SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2431
2432/*
2433** CAPI3REF: Count The Number Of Rows Modified
2434** METHOD: sqlite3
2435**
2436** ^This function returns the number of rows modified, inserted or
2437** deleted by the most recently completed INSERT, UPDATE or DELETE
2438** statement on the database connection specified by the only parameter.
2439** ^Executing any other type of SQL statement does not modify the value
2440** returned by this function.
2441**
2442** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2443** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2444** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2445**
2446** Changes to a view that are intercepted by
2447** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2448** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2449** DELETE statement run on a view is always zero. Only changes made to real
2450** tables are counted.
2451**
2452** Things are more complicated if the sqlite3_changes() function is
2453** executed while a trigger program is running. This may happen if the
2454** program uses the [changes() SQL function], or if some other callback
2455** function invokes sqlite3_changes() directly. Essentially:
2456**
2457** <ul>
2458** <li> ^(Before entering a trigger program the value returned by
2459** sqlite3_changes() function is saved. After the trigger program
2460** has finished, the original value is restored.)^
2461**
2462** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2463** statement sets the value returned by sqlite3_changes()
2464** upon completion as normal. Of course, this value will not include
2465** any changes performed by sub-triggers, as the sqlite3_changes()
2466** value will be saved and restored after each sub-trigger has run.)^
2467** </ul>
2468**
2469** ^This means that if the changes() SQL function (or similar) is used
2470** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2471** returns the value as set when the calling statement began executing.
2472** ^If it is used by the second or subsequent such statement within a trigger
2473** program, the value returned reflects the number of rows modified by the
2474** previous INSERT, UPDATE or DELETE statement within the same trigger.
2475**
2476** If a separate thread makes changes on the same database connection
2477** while [sqlite3_changes()] is running then the value returned
2478** is unpredictable and not meaningful.
2479**
2480** See also:
2481** <ul>
2482** <li> the [sqlite3_total_changes()] interface
2483** <li> the [count_changes pragma]
2484** <li> the [changes() SQL function]
2485** <li> the [data_version pragma]
2486** </ul>
2487*/
2488SQLITE_API int sqlite3_changes(sqlite3*);
2489
2490/*
2491** CAPI3REF: Total Number Of Rows Modified
2492** METHOD: sqlite3
2493**
2494** ^This function returns the total number of rows inserted, modified or
2495** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2496** since the database connection was opened, including those executed as
2497** part of trigger programs. ^Executing any other type of SQL statement
2498** does not affect the value returned by sqlite3_total_changes().
2499**
2500** ^Changes made as part of [foreign key actions] are included in the
2501** count, but those made as part of REPLACE constraint resolution are
2502** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2503** are not counted.
2504**
2505** The [sqlite3_total_changes(D)] interface only reports the number
2506** of rows that changed due to SQL statement run against database
2507** connection D. Any changes by other database connections are ignored.
2508** To detect changes against a database file from other database
2509** connections use the [PRAGMA data_version] command or the
2510** [SQLITE_FCNTL_DATA_VERSION] [file control].
2511**
2512** If a separate thread makes changes on the same database connection
2513** while [sqlite3_total_changes()] is running then the value
2514** returned is unpredictable and not meaningful.
2515**
2516** See also:
2517** <ul>
2518** <li> the [sqlite3_changes()] interface
2519** <li> the [count_changes pragma]
2520** <li> the [changes() SQL function]
2521** <li> the [data_version pragma]
2522** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2523** </ul>
2524*/
2525SQLITE_API int sqlite3_total_changes(sqlite3*);
2526
2527/*
2528** CAPI3REF: Interrupt A Long-Running Query
2529** METHOD: sqlite3
2530**
2531** ^This function causes any pending database operation to abort and
2532** return at its earliest opportunity. This routine is typically
2533** called in response to a user action such as pressing "Cancel"
2534** or Ctrl-C where the user wants a long query operation to halt
2535** immediately.
2536**
2537** ^It is safe to call this routine from a thread different from the
2538** thread that is currently running the database operation. But it
2539** is not safe to call this routine with a [database connection] that
2540** is closed or might close before sqlite3_interrupt() returns.
2541**
2542** ^If an SQL operation is very nearly finished at the time when
2543** sqlite3_interrupt() is called, then it might not have an opportunity
2544** to be interrupted and might continue to completion.
2545**
2546** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2547** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2548** that is inside an explicit transaction, then the entire transaction
2549** will be rolled back automatically.
2550**
2551** ^The sqlite3_interrupt(D) call is in effect until all currently running
2552** SQL statements on [database connection] D complete. ^Any new SQL statements
2553** that are started after the sqlite3_interrupt() call and before the
2554** running statement count reaches zero are interrupted as if they had been
2555** running prior to the sqlite3_interrupt() call. ^New SQL statements
2556** that are started after the running statement count reaches zero are
2557** not effected by the sqlite3_interrupt().
2558** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2559** SQL statements is a no-op and has no effect on SQL statements
2560** that are started after the sqlite3_interrupt() call returns.
2561*/
2562SQLITE_API void sqlite3_interrupt(sqlite3*);
2563
2564/*
2565** CAPI3REF: Determine If An SQL Statement Is Complete
2566**
2567** These routines are useful during command-line input to determine if the
2568** currently entered text seems to form a complete SQL statement or
2569** if additional input is needed before sending the text into
2570** SQLite for parsing. ^These routines return 1 if the input string
2571** appears to be a complete SQL statement. ^A statement is judged to be
2572** complete if it ends with a semicolon token and is not a prefix of a
2573** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2574** string literals or quoted identifier names or comments are not
2575** independent tokens (they are part of the token in which they are
2576** embedded) and thus do not count as a statement terminator. ^Whitespace
2577** and comments that follow the final semicolon are ignored.
2578**
2579** ^These routines return 0 if the statement is incomplete. ^If a
2580** memory allocation fails, then SQLITE_NOMEM is returned.
2581**
2582** ^These routines do not parse the SQL statements thus
2583** will not detect syntactically incorrect SQL.
2584**
2585** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2586** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2587** automatically by sqlite3_complete16(). If that initialization fails,
2588** then the return value from sqlite3_complete16() will be non-zero
2589** regardless of whether or not the input SQL is complete.)^
2590**
2591** The input to [sqlite3_complete()] must be a zero-terminated
2592** UTF-8 string.
2593**
2594** The input to [sqlite3_complete16()] must be a zero-terminated
2595** UTF-16 string in native byte order.
2596*/
2597SQLITE_API int sqlite3_complete(const char *sql);
2598SQLITE_API int sqlite3_complete16(const void *sql);
2599
2600/*
2601** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2602** KEYWORDS: {busy-handler callback} {busy handler}
2603** METHOD: sqlite3
2604**
2605** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2606** that might be invoked with argument P whenever
2607** an attempt is made to access a database table associated with
2608** [database connection] D when another thread
2609** or process has the table locked.
2610** The sqlite3_busy_handler() interface is used to implement
2611** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2612**
2613** ^If the busy callback is NULL, then [SQLITE_BUSY]
2614** is returned immediately upon encountering the lock. ^If the busy callback
2615** is not NULL, then the callback might be invoked with two arguments.
2616**
2617** ^The first argument to the busy handler is a copy of the void* pointer which
2618** is the third argument to sqlite3_busy_handler(). ^The second argument to
2619** the busy handler callback is the number of times that the busy handler has
2620** been invoked previously for the same locking event. ^If the
2621** busy callback returns 0, then no additional attempts are made to
2622** access the database and [SQLITE_BUSY] is returned
2623** to the application.
2624** ^If the callback returns non-zero, then another attempt
2625** is made to access the database and the cycle repeats.
2626**
2627** The presence of a busy handler does not guarantee that it will be invoked
2628** when there is lock contention. ^If SQLite determines that invoking the busy
2629** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2630** to the application instead of invoking the
2631** busy handler.
2632** Consider a scenario where one process is holding a read lock that
2633** it is trying to promote to a reserved lock and
2634** a second process is holding a reserved lock that it is trying
2635** to promote to an exclusive lock. The first process cannot proceed
2636** because it is blocked by the second and the second process cannot
2637** proceed because it is blocked by the first. If both processes
2638** invoke the busy handlers, neither will make any progress. Therefore,
2639** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2640** will induce the first process to release its read lock and allow
2641** the second process to proceed.
2642**
2643** ^The default busy callback is NULL.
2644**
2645** ^(There can only be a single busy handler defined for each
2646** [database connection]. Setting a new busy handler clears any
2647** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2648** or evaluating [PRAGMA busy_timeout=N] will change the
2649** busy handler and thus clear any previously set busy handler.
2650**
2651** The busy callback should not take any actions which modify the
2652** database connection that invoked the busy handler. In other words,
2653** the busy handler is not reentrant. Any such actions
2654** result in undefined behavior.
2655**
2656** A busy handler must not close the database connection
2657** or [prepared statement] that invoked the busy handler.
2658*/
2659SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2660
2661/*
2662** CAPI3REF: Set A Busy Timeout
2663** METHOD: sqlite3
2664**
2665** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2666** for a specified amount of time when a table is locked. ^The handler
2667** will sleep multiple times until at least "ms" milliseconds of sleeping
2668** have accumulated. ^After at least "ms" milliseconds of sleeping,
2669** the handler returns 0 which causes [sqlite3_step()] to return
2670** [SQLITE_BUSY].
2671**
2672** ^Calling this routine with an argument less than or equal to zero
2673** turns off all busy handlers.
2674**
2675** ^(There can only be a single busy handler for a particular
2676** [database connection] at any given moment. If another busy handler
2677** was defined (using [sqlite3_busy_handler()]) prior to calling
2678** this routine, that other busy handler is cleared.)^
2679**
2680** See also: [PRAGMA busy_timeout]
2681*/
2682SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2683
2684/*
2685** CAPI3REF: Convenience Routines For Running Queries
2686** METHOD: sqlite3
2687**
2688** This is a legacy interface that is preserved for backwards compatibility.
2689** Use of this interface is not recommended.
2690**
2691** Definition: A <b>result table</b> is memory data structure created by the
2692** [sqlite3_get_table()] interface. A result table records the
2693** complete query results from one or more queries.
2694**
2695** The table conceptually has a number of rows and columns. But
2696** these numbers are not part of the result table itself. These
2697** numbers are obtained separately. Let N be the number of rows
2698** and M be the number of columns.
2699**
2700** A result table is an array of pointers to zero-terminated UTF-8 strings.
2701** There are (N+1)*M elements in the array. The first M pointers point
2702** to zero-terminated strings that contain the names of the columns.
2703** The remaining entries all point to query results. NULL values result
2704** in NULL pointers. All other values are in their UTF-8 zero-terminated
2705** string representation as returned by [sqlite3_column_text()].
2706**
2707** A result table might consist of one or more memory allocations.
2708** It is not safe to pass a result table directly to [sqlite3_free()].
2709** A result table should be deallocated using [sqlite3_free_table()].
2710**
2711** ^(As an example of the result table format, suppose a query result
2712** is as follows:
2713**
2714** <blockquote><pre>
2715** Name | Age
2716** -----------------------
2717** Alice | 43
2718** Bob | 28
2719** Cindy | 21
2720** </pre></blockquote>
2721**
2722** There are two columns (M==2) and three rows (N==3). Thus the
2723** result table has 8 entries. Suppose the result table is stored
2724** in an array named azResult. Then azResult holds this content:
2725**
2726** <blockquote><pre>
2727** azResult&#91;0] = "Name";
2728** azResult&#91;1] = "Age";
2729** azResult&#91;2] = "Alice";
2730** azResult&#91;3] = "43";
2731** azResult&#91;4] = "Bob";
2732** azResult&#91;5] = "28";
2733** azResult&#91;6] = "Cindy";
2734** azResult&#91;7] = "21";
2735** </pre></blockquote>)^
2736**
2737** ^The sqlite3_get_table() function evaluates one or more
2738** semicolon-separated SQL statements in the zero-terminated UTF-8
2739** string of its 2nd parameter and returns a result table to the
2740** pointer given in its 3rd parameter.
2741**
2742** After the application has finished with the result from sqlite3_get_table(),
2743** it must pass the result table pointer to sqlite3_free_table() in order to
2744** release the memory that was malloced. Because of the way the
2745** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2746** function must not try to call [sqlite3_free()] directly. Only
2747** [sqlite3_free_table()] is able to release the memory properly and safely.
2748**
2749** The sqlite3_get_table() interface is implemented as a wrapper around
2750** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2751** to any internal data structures of SQLite. It uses only the public
2752** interface defined here. As a consequence, errors that occur in the
2753** wrapper layer outside of the internal [sqlite3_exec()] call are not
2754** reflected in subsequent calls to [sqlite3_errcode()] or
2755** [sqlite3_errmsg()].
2756*/
2757SQLITE_API int sqlite3_get_table(
2758 sqlite3 *db, /* An open database */
2759 const char *zSql, /* SQL to be evaluated */
2760 char ***pazResult, /* Results of the query */
2761 int *pnRow, /* Number of result rows written here */
2762 int *pnColumn, /* Number of result columns written here */
2763 char **pzErrmsg /* Error msg written here */
2764);
2765SQLITE_API void sqlite3_free_table(char **result);
2766
2767/*
2768** CAPI3REF: Formatted String Printing Functions
2769**
2770** These routines are work-alikes of the "printf()" family of functions
2771** from the standard C library.
2772** These routines understand most of the common formatting options from
2773** the standard library printf()
2774** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2775** See the [built-in printf()] documentation for details.
2776**
2777** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2778** results into memory obtained from [sqlite3_malloc64()].
2779** The strings returned by these two routines should be
2780** released by [sqlite3_free()]. ^Both routines return a
2781** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2782** memory to hold the resulting string.
2783**
2784** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2785** the standard C library. The result is written into the
2786** buffer supplied as the second parameter whose size is given by
2787** the first parameter. Note that the order of the
2788** first two parameters is reversed from snprintf().)^ This is an
2789** historical accident that cannot be fixed without breaking
2790** backwards compatibility. ^(Note also that sqlite3_snprintf()
2791** returns a pointer to its buffer instead of the number of
2792** characters actually written into the buffer.)^ We admit that
2793** the number of characters written would be a more useful return
2794** value but we cannot change the implementation of sqlite3_snprintf()
2795** now without breaking compatibility.
2796**
2797** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2798** guarantees that the buffer is always zero-terminated. ^The first
2799** parameter "n" is the total size of the buffer, including space for
2800** the zero terminator. So the longest string that can be completely
2801** written will be n-1 characters.
2802**
2803** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2804**
2805** See also: [built-in printf()], [printf() SQL function]
2806*/
2807SQLITE_API char *sqlite3_mprintf(const char*,...);
2808SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2809SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2810SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2811
2812/*
2813** CAPI3REF: Memory Allocation Subsystem
2814**
2815** The SQLite core uses these three routines for all of its own
2816** internal memory allocation needs. "Core" in the previous sentence
2817** does not include operating-system specific [VFS] implementation. The
2818** Windows VFS uses native malloc() and free() for some operations.
2819**
2820** ^The sqlite3_malloc() routine returns a pointer to a block
2821** of memory at least N bytes in length, where N is the parameter.
2822** ^If sqlite3_malloc() is unable to obtain sufficient free
2823** memory, it returns a NULL pointer. ^If the parameter N to
2824** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2825** a NULL pointer.
2826**
2827** ^The sqlite3_malloc64(N) routine works just like
2828** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2829** of a signed 32-bit integer.
2830**
2831** ^Calling sqlite3_free() with a pointer previously returned
2832** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2833** that it might be reused. ^The sqlite3_free() routine is
2834** a no-op if is called with a NULL pointer. Passing a NULL pointer
2835** to sqlite3_free() is harmless. After being freed, memory
2836** should neither be read nor written. Even reading previously freed
2837** memory might result in a segmentation fault or other severe error.
2838** Memory corruption, a segmentation fault, or other severe error
2839** might result if sqlite3_free() is called with a non-NULL pointer that
2840** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2841**
2842** ^The sqlite3_realloc(X,N) interface attempts to resize a
2843** prior memory allocation X to be at least N bytes.
2844** ^If the X parameter to sqlite3_realloc(X,N)
2845** is a NULL pointer then its behavior is identical to calling
2846** sqlite3_malloc(N).
2847** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2848** negative then the behavior is exactly the same as calling
2849** sqlite3_free(X).
2850** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2851** of at least N bytes in size or NULL if insufficient memory is available.
2852** ^If M is the size of the prior allocation, then min(N,M) bytes
2853** of the prior allocation are copied into the beginning of buffer returned
2854** by sqlite3_realloc(X,N) and the prior allocation is freed.
2855** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2856** prior allocation is not freed.
2857**
2858** ^The sqlite3_realloc64(X,N) interfaces works the same as
2859** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2860** of a 32-bit signed integer.
2861**
2862** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2863** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2864** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2865** ^The value returned by sqlite3_msize(X) might be larger than the number
2866** of bytes requested when X was allocated. ^If X is a NULL pointer then
2867** sqlite3_msize(X) returns zero. If X points to something that is not
2868** the beginning of memory allocation, or if it points to a formerly
2869** valid memory allocation that has now been freed, then the behavior
2870** of sqlite3_msize(X) is undefined and possibly harmful.
2871**
2872** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2873** sqlite3_malloc64(), and sqlite3_realloc64()
2874** is always aligned to at least an 8 byte boundary, or to a
2875** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2876** option is used.
2877**
2878** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2879** must be either NULL or else pointers obtained from a prior
2880** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2881** not yet been released.
2882**
2883** The application must not read or write any part of
2884** a block of memory after it has been released using
2885** [sqlite3_free()] or [sqlite3_realloc()].
2886*/
2887SQLITE_API void *sqlite3_malloc(int);
2888SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2889SQLITE_API void *sqlite3_realloc(void*, int);
2890SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2891SQLITE_API void sqlite3_free(void*);
2892SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2893
2894/*
2895** CAPI3REF: Memory Allocator Statistics
2896**
2897** SQLite provides these two interfaces for reporting on the status
2898** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2899** routines, which form the built-in memory allocation subsystem.
2900**
2901** ^The [sqlite3_memory_used()] routine returns the number of bytes
2902** of memory currently outstanding (malloced but not freed).
2903** ^The [sqlite3_memory_highwater()] routine returns the maximum
2904** value of [sqlite3_memory_used()] since the high-water mark
2905** was last reset. ^The values returned by [sqlite3_memory_used()] and
2906** [sqlite3_memory_highwater()] include any overhead
2907** added by SQLite in its implementation of [sqlite3_malloc()],
2908** but not overhead added by the any underlying system library
2909** routines that [sqlite3_malloc()] may call.
2910**
2911** ^The memory high-water mark is reset to the current value of
2912** [sqlite3_memory_used()] if and only if the parameter to
2913** [sqlite3_memory_highwater()] is true. ^The value returned
2914** by [sqlite3_memory_highwater(1)] is the high-water mark
2915** prior to the reset.
2916*/
2917SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2918SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2919
2920/*
2921** CAPI3REF: Pseudo-Random Number Generator
2922**
2923** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2924** select random [ROWID | ROWIDs] when inserting new records into a table that
2925** already uses the largest possible [ROWID]. The PRNG is also used for
2926** the built-in random() and randomblob() SQL functions. This interface allows
2927** applications to access the same PRNG for other purposes.
2928**
2929** ^A call to this routine stores N bytes of randomness into buffer P.
2930** ^The P parameter can be a NULL pointer.
2931**
2932** ^If this routine has not been previously called or if the previous
2933** call had N less than one or a NULL pointer for P, then the PRNG is
2934** seeded using randomness obtained from the xRandomness method of
2935** the default [sqlite3_vfs] object.
2936** ^If the previous call to this routine had an N of 1 or more and a
2937** non-NULL P then the pseudo-randomness is generated
2938** internally and without recourse to the [sqlite3_vfs] xRandomness
2939** method.
2940*/
2941SQLITE_API void sqlite3_randomness(int N, void *P);
2942
2943/*
2944** CAPI3REF: Compile-Time Authorization Callbacks
2945** METHOD: sqlite3
2946** KEYWORDS: {authorizer callback}
2947**
2948** ^This routine registers an authorizer callback with a particular
2949** [database connection], supplied in the first argument.
2950** ^The authorizer callback is invoked as SQL statements are being compiled
2951** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2952** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
2953** and [sqlite3_prepare16_v3()]. ^At various
2954** points during the compilation process, as logic is being created
2955** to perform various actions, the authorizer callback is invoked to
2956** see if those actions are allowed. ^The authorizer callback should
2957** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2958** specific action but allow the SQL statement to continue to be
2959** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2960** rejected with an error. ^If the authorizer callback returns
2961** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2962** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2963** the authorizer will fail with an error message.
2964**
2965** When the callback returns [SQLITE_OK], that means the operation
2966** requested is ok. ^When the callback returns [SQLITE_DENY], the
2967** [sqlite3_prepare_v2()] or equivalent call that triggered the
2968** authorizer will fail with an error message explaining that
2969** access is denied.
2970**
2971** ^The first parameter to the authorizer callback is a copy of the third
2972** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2973** to the callback is an integer [SQLITE_COPY | action code] that specifies
2974** the particular action to be authorized. ^The third through sixth parameters
2975** to the callback are either NULL pointers or zero-terminated strings
2976** that contain additional details about the action to be authorized.
2977** Applications must always be prepared to encounter a NULL pointer in any
2978** of the third through the sixth parameters of the authorization callback.
2979**
2980** ^If the action code is [SQLITE_READ]
2981** and the callback returns [SQLITE_IGNORE] then the
2982** [prepared statement] statement is constructed to substitute
2983** a NULL value in place of the table column that would have
2984** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2985** return can be used to deny an untrusted user access to individual
2986** columns of a table.
2987** ^When a table is referenced by a [SELECT] but no column values are
2988** extracted from that table (for example in a query like
2989** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
2990** is invoked once for that table with a column name that is an empty string.
2991** ^If the action code is [SQLITE_DELETE] and the callback returns
2992** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2993** [truncate optimization] is disabled and all rows are deleted individually.
2994**
2995** An authorizer is used when [sqlite3_prepare | preparing]
2996** SQL statements from an untrusted source, to ensure that the SQL statements
2997** do not try to access data they are not allowed to see, or that they do not
2998** try to execute malicious statements that damage the database. For
2999** example, an application may allow a user to enter arbitrary
3000** SQL queries for evaluation by a database. But the application does
3001** not want the user to be able to make arbitrary changes to the
3002** database. An authorizer could then be put in place while the
3003** user-entered SQL is being [sqlite3_prepare | prepared] that
3004** disallows everything except [SELECT] statements.
3005**
3006** Applications that need to process SQL from untrusted sources
3007** might also consider lowering resource limits using [sqlite3_limit()]
3008** and limiting database size using the [max_page_count] [PRAGMA]
3009** in addition to using an authorizer.
3010**
3011** ^(Only a single authorizer can be in place on a database connection
3012** at a time. Each call to sqlite3_set_authorizer overrides the
3013** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3014** The authorizer is disabled by default.
3015**
3016** The authorizer callback must not do anything that will modify
3017** the database connection that invoked the authorizer callback.
3018** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3019** database connections for the meaning of "modify" in this paragraph.
3020**
3021** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3022** statement might be re-prepared during [sqlite3_step()] due to a
3023** schema change. Hence, the application should ensure that the
3024** correct authorizer callback remains in place during the [sqlite3_step()].
3025**
3026** ^Note that the authorizer callback is invoked only during
3027** [sqlite3_prepare()] or its variants. Authorization is not
3028** performed during statement evaluation in [sqlite3_step()], unless
3029** as stated in the previous paragraph, sqlite3_step() invokes
3030** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3031*/
3032SQLITE_API int sqlite3_set_authorizer(
3033 sqlite3*,
3034 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3035 void *pUserData
3036);
3037
3038/*
3039** CAPI3REF: Authorizer Return Codes
3040**
3041** The [sqlite3_set_authorizer | authorizer callback function] must
3042** return either [SQLITE_OK] or one of these two constants in order
3043** to signal SQLite whether or not the action is permitted. See the
3044** [sqlite3_set_authorizer | authorizer documentation] for additional
3045** information.
3046**
3047** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3048** returned from the [sqlite3_vtab_on_conflict()] interface.
3049*/
3050#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3051#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3052
3053/*
3054** CAPI3REF: Authorizer Action Codes
3055**
3056** The [sqlite3_set_authorizer()] interface registers a callback function
3057** that is invoked to authorize certain SQL statement actions. The
3058** second parameter to the callback is an integer code that specifies
3059** what action is being authorized. These are the integer action codes that
3060** the authorizer callback may be passed.
3061**
3062** These action code values signify what kind of operation is to be
3063** authorized. The 3rd and 4th parameters to the authorization
3064** callback function will be parameters or NULL depending on which of these
3065** codes is used as the second parameter. ^(The 5th parameter to the
3066** authorizer callback is the name of the database ("main", "temp",
3067** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3068** is the name of the inner-most trigger or view that is responsible for
3069** the access attempt or NULL if this access attempt is directly from
3070** top-level SQL code.
3071*/
3072/******************************************* 3rd ************ 4th ***********/
3073#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3074#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3075#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3076#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3077#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3078#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3079#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3080#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3081#define SQLITE_DELETE 9 /* Table Name NULL */
3082#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3083#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3084#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3085#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3086#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3087#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3088#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3089#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3090#define SQLITE_INSERT 18 /* Table Name NULL */
3091#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3092#define SQLITE_READ 20 /* Table Name Column Name */
3093#define SQLITE_SELECT 21 /* NULL NULL */
3094#define SQLITE_TRANSACTION 22 /* Operation NULL */
3095#define SQLITE_UPDATE 23 /* Table Name Column Name */
3096#define SQLITE_ATTACH 24 /* Filename NULL */
3097#define SQLITE_DETACH 25 /* Database Name NULL */
3098#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3099#define SQLITE_REINDEX 27 /* Index Name NULL */
3100#define SQLITE_ANALYZE 28 /* Table Name NULL */
3101#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3102#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3103#define SQLITE_FUNCTION 31 /* NULL Function Name */
3104#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3105#define SQLITE_COPY 0 /* No longer used */
3106#define SQLITE_RECURSIVE 33 /* NULL NULL */
3107
3108/*
3109** CAPI3REF: Tracing And Profiling Functions
3110** METHOD: sqlite3
3111**
3112** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3113** instead of the routines described here.
3114**
3115** These routines register callback functions that can be used for
3116** tracing and profiling the execution of SQL statements.
3117**
3118** ^The callback function registered by sqlite3_trace() is invoked at
3119** various times when an SQL statement is being run by [sqlite3_step()].
3120** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3121** SQL statement text as the statement first begins executing.
3122** ^(Additional sqlite3_trace() callbacks might occur
3123** as each triggered subprogram is entered. The callbacks for triggers
3124** contain a UTF-8 SQL comment that identifies the trigger.)^
3125**
3126** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3127** the length of [bound parameter] expansion in the output of sqlite3_trace().
3128**
3129** ^The callback function registered by sqlite3_profile() is invoked
3130** as each SQL statement finishes. ^The profile callback contains
3131** the original statement text and an estimate of wall-clock time
3132** of how long that statement took to run. ^The profile callback
3133** time is in units of nanoseconds, however the current implementation
3134** is only capable of millisecond resolution so the six least significant
3135** digits in the time are meaningless. Future versions of SQLite
3136** might provide greater resolution on the profiler callback. Invoking
3137** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3138** profile callback.
3139*/
3140SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3141 void(*xTrace)(void*,const char*), void*);
3142SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3143 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3144
3145/*
3146** CAPI3REF: SQL Trace Event Codes
3147** KEYWORDS: SQLITE_TRACE
3148**
3149** These constants identify classes of events that can be monitored
3150** using the [sqlite3_trace_v2()] tracing logic. The M argument
3151** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3152** the following constants. ^The first argument to the trace callback
3153** is one of the following constants.
3154**
3155** New tracing constants may be added in future releases.
3156**
3157** ^A trace callback has four arguments: xCallback(T,C,P,X).
3158** ^The T argument is one of the integer type codes above.
3159** ^The C argument is a copy of the context pointer passed in as the
3160** fourth argument to [sqlite3_trace_v2()].
3161** The P and X arguments are pointers whose meanings depend on T.
3162**
3163** <dl>
3164** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3165** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3166** first begins running and possibly at other times during the
3167** execution of the prepared statement, such as at the start of each
3168** trigger subprogram. ^The P argument is a pointer to the
3169** [prepared statement]. ^The X argument is a pointer to a string which
3170** is the unexpanded SQL text of the prepared statement or an SQL comment
3171** that indicates the invocation of a trigger. ^The callback can compute
3172** the same text that would have been returned by the legacy [sqlite3_trace()]
3173** interface by using the X argument when X begins with "--" and invoking
3174** [sqlite3_expanded_sql(P)] otherwise.
3175**
3176** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3177** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3178** information as is provided by the [sqlite3_profile()] callback.
3179** ^The P argument is a pointer to the [prepared statement] and the
3180** X argument points to a 64-bit integer which is the estimated of
3181** the number of nanosecond that the prepared statement took to run.
3182** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3183**
3184** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3185** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3186** statement generates a single row of result.
3187** ^The P argument is a pointer to the [prepared statement] and the
3188** X argument is unused.
3189**
3190** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3191** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3192** connection closes.
3193** ^The P argument is a pointer to the [database connection] object
3194** and the X argument is unused.
3195** </dl>
3196*/
3197#define SQLITE_TRACE_STMT 0x01
3198#define SQLITE_TRACE_PROFILE 0x02
3199#define SQLITE_TRACE_ROW 0x04
3200#define SQLITE_TRACE_CLOSE 0x08
3201
3202/*
3203** CAPI3REF: SQL Trace Hook
3204** METHOD: sqlite3
3205**
3206** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3207** function X against [database connection] D, using property mask M
3208** and context pointer P. ^If the X callback is
3209** NULL or if the M mask is zero, then tracing is disabled. The
3210** M argument should be the bitwise OR-ed combination of
3211** zero or more [SQLITE_TRACE] constants.
3212**
3213** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
3214** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3215**
3216** ^The X callback is invoked whenever any of the events identified by
3217** mask M occur. ^The integer return value from the callback is currently
3218** ignored, though this may change in future releases. Callback
3219** implementations should return zero to ensure future compatibility.
3220**
3221** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3222** ^The T argument is one of the [SQLITE_TRACE]
3223** constants to indicate why the callback was invoked.
3224** ^The C argument is a copy of the context pointer.
3225** The P and X arguments are pointers whose meanings depend on T.
3226**
3227** The sqlite3_trace_v2() interface is intended to replace the legacy
3228** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3229** are deprecated.
3230*/
3231SQLITE_API int sqlite3_trace_v2(
3232 sqlite3*,
3233 unsigned uMask,
3234 int(*xCallback)(unsigned,void*,void*,void*),
3235 void *pCtx
3236);
3237
3238/*
3239** CAPI3REF: Query Progress Callbacks
3240** METHOD: sqlite3
3241**
3242** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3243** function X to be invoked periodically during long running calls to
3244** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3245** database connection D. An example use for this
3246** interface is to keep a GUI updated during a large query.
3247**
3248** ^The parameter P is passed through as the only parameter to the
3249** callback function X. ^The parameter N is the approximate number of
3250** [virtual machine instructions] that are evaluated between successive
3251** invocations of the callback X. ^If N is less than one then the progress
3252** handler is disabled.
3253**
3254** ^Only a single progress handler may be defined at one time per
3255** [database connection]; setting a new progress handler cancels the
3256** old one. ^Setting parameter X to NULL disables the progress handler.
3257** ^The progress handler is also disabled by setting N to a value less
3258** than 1.
3259**
3260** ^If the progress callback returns non-zero, the operation is
3261** interrupted. This feature can be used to implement a
3262** "Cancel" button on a GUI progress dialog box.
3263**
3264** The progress handler callback must not do anything that will modify
3265** the database connection that invoked the progress handler.
3266** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3267** database connections for the meaning of "modify" in this paragraph.
3268**
3269*/
3270SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3271
3272/*
3273** CAPI3REF: Opening A New Database Connection
3274** CONSTRUCTOR: sqlite3
3275**
3276** ^These routines open an SQLite database file as specified by the
3277** filename argument. ^The filename argument is interpreted as UTF-8 for
3278** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3279** order for sqlite3_open16(). ^(A [database connection] handle is usually
3280** returned in *ppDb, even if an error occurs. The only exception is that
3281** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3282** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3283** object.)^ ^(If the database is opened (and/or created) successfully, then
3284** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3285** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3286** an English language description of the error following a failure of any
3287** of the sqlite3_open() routines.
3288**
3289** ^The default encoding will be UTF-8 for databases created using
3290** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3291** created using sqlite3_open16() will be UTF-16 in the native byte order.
3292**
3293** Whether or not an error occurs when it is opened, resources
3294** associated with the [database connection] handle should be released by
3295** passing it to [sqlite3_close()] when it is no longer required.
3296**
3297** The sqlite3_open_v2() interface works like sqlite3_open()
3298** except that it accepts two additional parameters for additional control
3299** over the new database connection. ^(The flags parameter to
3300** sqlite3_open_v2() must include, at a minimum, one of the following
3301** three flag combinations:)^
3302**
3303** <dl>
3304** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3305** <dd>The database is opened in read-only mode. If the database does not
3306** already exist, an error is returned.</dd>)^
3307**
3308** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3309** <dd>The database is opened for reading and writing if possible, or reading
3310** only if the file is write protected by the operating system. In either
3311** case the database must already exist, otherwise an error is returned.</dd>)^
3312**
3313** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3314** <dd>The database is opened for reading and writing, and is created if
3315** it does not already exist. This is the behavior that is always used for
3316** sqlite3_open() and sqlite3_open16().</dd>)^
3317** </dl>
3318**
3319** In addition to the required flags, the following optional flags are
3320** also supported:
3321**
3322** <dl>
3323** ^(<dt>[SQLITE_OPEN_URI]</dt>
3324** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3325**
3326** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3327** <dd>The database will be opened as an in-memory database. The database
3328** is named by the "filename" argument for the purposes of cache-sharing,
3329** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3330** </dd>)^
3331**
3332** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3333** <dd>The new database connection will use the "multi-thread"
3334** [threading mode].)^ This means that separate threads are allowed
3335** to use SQLite at the same time, as long as each thread is using
3336** a different [database connection].
3337**
3338** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3339** <dd>The new database connection will use the "serialized"
3340** [threading mode].)^ This means the multiple threads can safely
3341** attempt to use the same database connection at the same time.
3342** (Mutexes will block any actual concurrency, but in this mode
3343** there is no harm in trying.)
3344**
3345** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3346** <dd>The database is opened [shared cache] enabled, overriding
3347** the default shared cache setting provided by
3348** [sqlite3_enable_shared_cache()].)^
3349**
3350** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3351** <dd>The database is opened [shared cache] disabled, overriding
3352** the default shared cache setting provided by
3353** [sqlite3_enable_shared_cache()].)^
3354**
3355** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3356** <dd>The database filename is not allowed to be a symbolic link</dd>
3357** </dl>)^
3358**
3359** If the 3rd parameter to sqlite3_open_v2() is not one of the
3360** required combinations shown above optionally combined with other
3361** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3362** then the behavior is undefined.
3363**
3364** ^The fourth parameter to sqlite3_open_v2() is the name of the
3365** [sqlite3_vfs] object that defines the operating system interface that
3366** the new database connection should use. ^If the fourth parameter is
3367** a NULL pointer then the default [sqlite3_vfs] object is used.
3368**
3369** ^If the filename is ":memory:", then a private, temporary in-memory database
3370** is created for the connection. ^This in-memory database will vanish when
3371** the database connection is closed. Future versions of SQLite might
3372** make use of additional special filenames that begin with the ":" character.
3373** It is recommended that when a database filename actually does begin with
3374** a ":" character you should prefix the filename with a pathname such as
3375** "./" to avoid ambiguity.
3376**
3377** ^If the filename is an empty string, then a private, temporary
3378** on-disk database will be created. ^This private database will be
3379** automatically deleted as soon as the database connection is closed.
3380**
3381** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3382**
3383** ^If [URI filename] interpretation is enabled, and the filename argument
3384** begins with "file:", then the filename is interpreted as a URI. ^URI
3385** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3386** set in the third argument to sqlite3_open_v2(), or if it has
3387** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3388** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3389** URI filename interpretation is turned off
3390** by default, but future releases of SQLite might enable URI filename
3391** interpretation by default. See "[URI filenames]" for additional
3392** information.
3393**
3394** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3395** authority, then it must be either an empty string or the string
3396** "localhost". ^If the authority is not an empty string or "localhost", an
3397** error is returned to the caller. ^The fragment component of a URI, if
3398** present, is ignored.
3399**
3400** ^SQLite uses the path component of the URI as the name of the disk file
3401** which contains the database. ^If the path begins with a '/' character,
3402** then it is interpreted as an absolute path. ^If the path does not begin
3403** with a '/' (meaning that the authority section is omitted from the URI)
3404** then the path is interpreted as a relative path.
3405** ^(On windows, the first component of an absolute path
3406** is a drive specification (e.g. "C:").)^
3407**
3408** [[core URI query parameters]]
3409** The query component of a URI may contain parameters that are interpreted
3410** either by SQLite itself, or by a [VFS | custom VFS implementation].
3411** SQLite and its built-in [VFSes] interpret the
3412** following query parameters:
3413**
3414** <ul>
3415** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3416** a VFS object that provides the operating system interface that should
3417** be used to access the database file on disk. ^If this option is set to
3418** an empty string the default VFS object is used. ^Specifying an unknown
3419** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3420** present, then the VFS specified by the option takes precedence over
3421** the value passed as the fourth parameter to sqlite3_open_v2().
3422**
3423** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3424** "rwc", or "memory". Attempting to set it to any other value is
3425** an error)^.
3426** ^If "ro" is specified, then the database is opened for read-only
3427** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3428** third argument to sqlite3_open_v2(). ^If the mode option is set to
3429** "rw", then the database is opened for read-write (but not create)
3430** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3431** been set. ^Value "rwc" is equivalent to setting both
3432** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3433** set to "memory" then a pure [in-memory database] that never reads
3434** or writes from disk is used. ^It is an error to specify a value for
3435** the mode parameter that is less restrictive than that specified by
3436** the flags passed in the third parameter to sqlite3_open_v2().
3437**
3438** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3439** "private". ^Setting it to "shared" is equivalent to setting the
3440** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3441** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3442** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3443** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3444** a URI filename, its value overrides any behavior requested by setting
3445** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3446**
3447** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3448** [powersafe overwrite] property does or does not apply to the
3449** storage media on which the database file resides.
3450**
3451** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3452** which if set disables file locking in rollback journal modes. This
3453** is useful for accessing a database on a filesystem that does not
3454** support locking. Caution: Database corruption might result if two
3455** or more processes write to the same database and any one of those
3456** processes uses nolock=1.
3457**
3458** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3459** parameter that indicates that the database file is stored on
3460** read-only media. ^When immutable is set, SQLite assumes that the
3461** database file cannot be changed, even by a process with higher
3462** privilege, and so the database is opened read-only and all locking
3463** and change detection is disabled. Caution: Setting the immutable
3464** property on a database file that does in fact change can result
3465** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3466** See also: [SQLITE_IOCAP_IMMUTABLE].
3467**
3468** </ul>
3469**
3470** ^Specifying an unknown parameter in the query component of a URI is not an
3471** error. Future versions of SQLite might understand additional query
3472** parameters. See "[query parameters with special meaning to SQLite]" for
3473** additional information.
3474**
3475** [[URI filename examples]] <h3>URI filename examples</h3>
3476**
3477** <table border="1" align=center cellpadding=5>
3478** <tr><th> URI filenames <th> Results
3479** <tr><td> file:data.db <td>
3480** Open the file "data.db" in the current directory.
3481** <tr><td> file:/home/fred/data.db<br>
3482** file:///home/fred/data.db <br>
3483** file://localhost/home/fred/data.db <br> <td>
3484** Open the database file "/home/fred/data.db".
3485** <tr><td> file://darkstar/home/fred/data.db <td>
3486** An error. "darkstar" is not a recognized authority.
3487** <tr><td style="white-space:nowrap">
3488** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3489** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3490** C:. Note that the %20 escaping in this example is not strictly
3491** necessary - space characters can be used literally
3492** in URI filenames.
3493** <tr><td> file:data.db?mode=ro&cache=private <td>
3494** Open file "data.db" in the current directory for read-only access.
3495** Regardless of whether or not shared-cache mode is enabled by
3496** default, use a private cache.
3497** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3498** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3499** that uses dot-files in place of posix advisory locking.
3500** <tr><td> file:data.db?mode=readonly <td>
3501** An error. "readonly" is not a valid option for the "mode" parameter.
3502** </table>
3503**
3504** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3505** query components of a URI. A hexadecimal escape sequence consists of a
3506** percent sign - "%" - followed by exactly two hexadecimal digits
3507** specifying an octet value. ^Before the path or query components of a
3508** URI filename are interpreted, they are encoded using UTF-8 and all
3509** hexadecimal escape sequences replaced by a single byte containing the
3510** corresponding octet. If this process generates an invalid UTF-8 encoding,
3511** the results are undefined.
3512**
3513** <b>Note to Windows users:</b> The encoding used for the filename argument
3514** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3515** codepage is currently defined. Filenames containing international
3516** characters must be converted to UTF-8 prior to passing them into
3517** sqlite3_open() or sqlite3_open_v2().
3518**
3519** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3520** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3521** features that require the use of temporary files may fail.
3522**
3523** See also: [sqlite3_temp_directory]
3524*/
3525SQLITE_API int sqlite3_open(
3526 const char *filename, /* Database filename (UTF-8) */
3527 sqlite3 **ppDb /* OUT: SQLite db handle */
3528);
3529SQLITE_API int sqlite3_open16(
3530 const void *filename, /* Database filename (UTF-16) */
3531 sqlite3 **ppDb /* OUT: SQLite db handle */
3532);
3533SQLITE_API int sqlite3_open_v2(
3534 const char *filename, /* Database filename (UTF-8) */
3535 sqlite3 **ppDb, /* OUT: SQLite db handle */
3536 int flags, /* Flags */
3537 const char *zVfs /* Name of VFS module to use */
3538);
3539
3540/*
3541** CAPI3REF: Obtain Values For URI Parameters
3542**
3543** These are utility routines, useful to [VFS|custom VFS implementations],
3544** that check if a database file was a URI that contained a specific query
3545** parameter, and if so obtains the value of that query parameter.
3546**
3547** The first parameter to these interfaces (hereafter referred to
3548** as F) must be one of:
3549** <ul>
3550** <li> A database filename pointer created by the SQLite core and
3551** passed into the xOpen() method of a VFS implemention, or
3552** <li> A filename obtained from [sqlite3_db_filename()], or
3553** <li> A new filename constructed using [sqlite3_create_filename()].
3554** </ul>
3555** If the F parameter is not one of the above, then the behavior is
3556** undefined and probably undesirable. Older versions of SQLite were
3557** more tolerant of invalid F parameters than newer versions.
3558**
3559** If F is a suitable filename (as described in the previous paragraph)
3560** and if P is the name of the query parameter, then
3561** sqlite3_uri_parameter(F,P) returns the value of the P
3562** parameter if it exists or a NULL pointer if P does not appear as a
3563** query parameter on F. If P is a query parameter of F and it
3564** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3565** a pointer to an empty string.
3566**
3567** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3568** parameter and returns true (1) or false (0) according to the value
3569** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3570** value of query parameter P is one of "yes", "true", or "on" in any
3571** case or if the value begins with a non-zero number. The
3572** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3573** query parameter P is one of "no", "false", or "off" in any case or
3574** if the value begins with a numeric zero. If P is not a query
3575** parameter on F or if the value of P does not match any of the
3576** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3577**
3578** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3579** 64-bit signed integer and returns that integer, or D if P does not
3580** exist. If the value of P is something other than an integer, then
3581** zero is returned.
3582**
3583** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3584** the value) of the N-th query parameter for filename F, or a NULL
3585** pointer if N is less than zero or greater than the number of query
3586** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3587** the name of the first query parameter, 1 for the second parameter, and
3588** so forth.
3589**
3590** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3591** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3592** is not a database file pathname pointer that the SQLite core passed
3593** into the xOpen VFS method, then the behavior of this routine is undefined
3594** and probably undesirable.
3595**
3596** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3597** parameter can also be the name of a rollback journal file or WAL file
3598** in addition to the main database file. Prior to version 3.31.0, these
3599** routines would only work if F was the name of the main database file.
3600** When the F parameter is the name of the rollback journal or WAL file,
3601** it has access to all the same query parameters as were found on the
3602** main database file.
3603**
3604** See the [URI filename] documentation for additional information.
3605*/
3606SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3607SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3608SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3609SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N);
3610
3611/*
3612** CAPI3REF: Translate filenames
3613**
3614** These routines are available to [VFS|custom VFS implementations] for
3615** translating filenames between the main database file, the journal file,
3616** and the WAL file.
3617**
3618** If F is the name of an sqlite database file, journal file, or WAL file
3619** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3620** returns the name of the corresponding database file.
3621**
3622** If F is the name of an sqlite database file, journal file, or WAL file
3623** passed by the SQLite core into the VFS, or if F is a database filename
3624** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3625** returns the name of the corresponding rollback journal file.
3626**
3627** If F is the name of an sqlite database file, journal file, or WAL file
3628** that was passed by the SQLite core into the VFS, or if F is a database
3629** filename obtained from [sqlite3_db_filename()], then
3630** sqlite3_filename_wal(F) returns the name of the corresponding
3631** WAL file.
3632**
3633** In all of the above, if F is not the name of a database, journal or WAL
3634** filename passed into the VFS from the SQLite core and F is not the
3635** return value from [sqlite3_db_filename()], then the result is
3636** undefined and is likely a memory access violation.
3637*/
3638SQLITE_API const char *sqlite3_filename_database(const char*);
3639SQLITE_API const char *sqlite3_filename_journal(const char*);
3640SQLITE_API const char *sqlite3_filename_wal(const char*);
3641
3642/*
3643** CAPI3REF: Database File Corresponding To A Journal
3644**
3645** ^If X is the name of a rollback or WAL-mode journal file that is
3646** passed into the xOpen method of [sqlite3_vfs], then
3647** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3648** object that represents the main database file.
3649**
3650** This routine is intended for use in custom [VFS] implementations
3651** only. It is not a general-purpose interface.
3652** The argument sqlite3_file_object(X) must be a filename pointer that
3653** has been passed into [sqlite3_vfs].xOpen method where the
3654** flags parameter to xOpen contains one of the bits
3655** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3656** of this routine results in undefined and probably undesirable
3657** behavior.
3658*/
3659SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3660
3661/*
3662** CAPI3REF: Create and Destroy VFS Filenames
3663**
3664** These interfces are provided for use by [VFS shim] implementations and
3665** are not useful outside of that context.
3666**
3667** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3668** database filename D with corresponding journal file J and WAL file W and
3669** with N URI parameters key/values pairs in the array P. The result from
3670** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3671** is safe to pass to routines like:
3672** <ul>
3673** <li> [sqlite3_uri_parameter()],
3674** <li> [sqlite3_uri_boolean()],
3675** <li> [sqlite3_uri_int64()],
3676** <li> [sqlite3_uri_key()],
3677** <li> [sqlite3_filename_database()],
3678** <li> [sqlite3_filename_journal()], or
3679** <li> [sqlite3_filename_wal()].
3680** </ul>
3681** If a memory allocation error occurs, sqlite3_create_filename() might
3682** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3683** must be released by a corresponding call to sqlite3_free_filename(Y).
3684**
3685** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3686** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3687** to a key and value for a query parameter. The P parameter may be a NULL
3688** pointer if N is zero. None of the 2*N pointers in the P array may be
3689** NULL pointers and key pointers should not be empty strings.
3690** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3691** be NULL pointers, though they can be empty strings.
3692**
3693** The sqlite3_free_filename(Y) routine releases a memory allocation
3694** previously obtained from sqlite3_create_filename(). Invoking
3695** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3696**
3697** If the Y parameter to sqlite3_free_filename(Y) is anything other
3698** than a NULL pointer or a pointer previously acquired from
3699** sqlite3_create_filename(), then bad things such as heap
3700** corruption or segfaults may occur. The value Y should be
3701** used again after sqlite3_free_filename(Y) has been called. This means
3702** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3703** then the corresponding [sqlite3_module.xClose() method should also be
3704** invoked prior to calling sqlite3_free_filename(Y).
3705*/
3706SQLITE_API char *sqlite3_create_filename(
3707 const char *zDatabase,
3708 const char *zJournal,
3709 const char *zWal,
3710 int nParam,
3711 const char **azParam
3712);
3713SQLITE_API void sqlite3_free_filename(char*);
3714
3715/*
3716** CAPI3REF: Error Codes And Messages
3717** METHOD: sqlite3
3718**
3719** ^If the most recent sqlite3_* API call associated with
3720** [database connection] D failed, then the sqlite3_errcode(D) interface
3721** returns the numeric [result code] or [extended result code] for that
3722** API call.
3723** ^The sqlite3_extended_errcode()
3724** interface is the same except that it always returns the
3725** [extended result code] even when extended result codes are
3726** disabled.
3727**
3728** The values returned by sqlite3_errcode() and/or
3729** sqlite3_extended_errcode() might change with each API call.
3730** Except, there are some interfaces that are guaranteed to never
3731** change the value of the error code. The error-code preserving
3732** interfaces are:
3733**
3734** <ul>
3735** <li> sqlite3_errcode()
3736** <li> sqlite3_extended_errcode()
3737** <li> sqlite3_errmsg()
3738** <li> sqlite3_errmsg16()
3739** </ul>
3740**
3741** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3742** text that describes the error, as either UTF-8 or UTF-16 respectively.
3743** ^(Memory to hold the error message string is managed internally.
3744** The application does not need to worry about freeing the result.
3745** However, the error string might be overwritten or deallocated by
3746** subsequent calls to other SQLite interface functions.)^
3747**
3748** ^The sqlite3_errstr() interface returns the English-language text
3749** that describes the [result code], as UTF-8.
3750** ^(Memory to hold the error message string is managed internally
3751** and must not be freed by the application)^.
3752**
3753** When the serialized [threading mode] is in use, it might be the
3754** case that a second error occurs on a separate thread in between
3755** the time of the first error and the call to these interfaces.
3756** When that happens, the second error will be reported since these
3757** interfaces always report the most recent result. To avoid
3758** this, each thread can obtain exclusive use of the [database connection] D
3759** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3760** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3761** all calls to the interfaces listed here are completed.
3762**
3763** If an interface fails with SQLITE_MISUSE, that means the interface
3764** was invoked incorrectly by the application. In that case, the
3765** error code and message may or may not be set.
3766*/
3767SQLITE_API int sqlite3_errcode(sqlite3 *db);
3768SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3769SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3770SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3771SQLITE_API const char *sqlite3_errstr(int);
3772
3773/*
3774** CAPI3REF: Prepared Statement Object
3775** KEYWORDS: {prepared statement} {prepared statements}
3776**
3777** An instance of this object represents a single SQL statement that
3778** has been compiled into binary form and is ready to be evaluated.
3779**
3780** Think of each SQL statement as a separate computer program. The
3781** original SQL text is source code. A prepared statement object
3782** is the compiled object code. All SQL must be converted into a
3783** prepared statement before it can be run.
3784**
3785** The life-cycle of a prepared statement object usually goes like this:
3786**
3787** <ol>
3788** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3789** <li> Bind values to [parameters] using the sqlite3_bind_*()
3790** interfaces.
3791** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3792** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3793** to step 2. Do this zero or more times.
3794** <li> Destroy the object using [sqlite3_finalize()].
3795** </ol>
3796*/
3797typedef struct sqlite3_stmt sqlite3_stmt;
3798
3799/*
3800** CAPI3REF: Run-time Limits
3801** METHOD: sqlite3
3802**
3803** ^(This interface allows the size of various constructs to be limited
3804** on a connection by connection basis. The first parameter is the
3805** [database connection] whose limit is to be set or queried. The
3806** second parameter is one of the [limit categories] that define a
3807** class of constructs to be size limited. The third parameter is the
3808** new limit for that construct.)^
3809**
3810** ^If the new limit is a negative number, the limit is unchanged.
3811** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3812** [limits | hard upper bound]
3813** set at compile-time by a C preprocessor macro called
3814** [limits | SQLITE_MAX_<i>NAME</i>].
3815** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3816** ^Attempts to increase a limit above its hard upper bound are
3817** silently truncated to the hard upper bound.
3818**
3819** ^Regardless of whether or not the limit was changed, the
3820** [sqlite3_limit()] interface returns the prior value of the limit.
3821** ^Hence, to find the current value of a limit without changing it,
3822** simply invoke this interface with the third parameter set to -1.
3823**
3824** Run-time limits are intended for use in applications that manage
3825** both their own internal database and also databases that are controlled
3826** by untrusted external sources. An example application might be a
3827** web browser that has its own databases for storing history and
3828** separate databases controlled by JavaScript applications downloaded
3829** off the Internet. The internal databases can be given the
3830** large, default limits. Databases managed by external sources can
3831** be given much smaller limits designed to prevent a denial of service
3832** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3833** interface to further control untrusted SQL. The size of the database
3834** created by an untrusted script can be contained using the
3835** [max_page_count] [PRAGMA].
3836**
3837** New run-time limit categories may be added in future releases.
3838*/
3839SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3840
3841/*
3842** CAPI3REF: Run-Time Limit Categories
3843** KEYWORDS: {limit category} {*limit categories}
3844**
3845** These constants define various performance limits
3846** that can be lowered at run-time using [sqlite3_limit()].
3847** The synopsis of the meanings of the various limits is shown below.
3848** Additional information is available at [limits | Limits in SQLite].
3849**
3850** <dl>
3851** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3852** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3853**
3854** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3855** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3856**
3857** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3858** <dd>The maximum number of columns in a table definition or in the
3859** result set of a [SELECT] or the maximum number of columns in an index
3860** or in an ORDER BY or GROUP BY clause.</dd>)^
3861**
3862** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3863** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3864**
3865** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3866** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3867**
3868** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3869** <dd>The maximum number of instructions in a virtual machine program
3870** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3871** the equivalent tries to allocate space for more than this many opcodes
3872** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3873**
3874** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3875** <dd>The maximum number of arguments on a function.</dd>)^
3876**
3877** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3878** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3879**
3880** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3881** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3882** <dd>The maximum length of the pattern argument to the [LIKE] or
3883** [GLOB] operators.</dd>)^
3884**
3885** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3886** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3887** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3888**
3889** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3890** <dd>The maximum depth of recursion for triggers.</dd>)^
3891**
3892** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3893** <dd>The maximum number of auxiliary worker threads that a single
3894** [prepared statement] may start.</dd>)^
3895** </dl>
3896*/
3897#define SQLITE_LIMIT_LENGTH 0
3898#define SQLITE_LIMIT_SQL_LENGTH 1
3899#define SQLITE_LIMIT_COLUMN 2
3900#define SQLITE_LIMIT_EXPR_DEPTH 3
3901#define SQLITE_LIMIT_COMPOUND_SELECT 4
3902#define SQLITE_LIMIT_VDBE_OP 5
3903#define SQLITE_LIMIT_FUNCTION_ARG 6
3904#define SQLITE_LIMIT_ATTACHED 7
3905#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3906#define SQLITE_LIMIT_VARIABLE_NUMBER 9
3907#define SQLITE_LIMIT_TRIGGER_DEPTH 10
3908#define SQLITE_LIMIT_WORKER_THREADS 11
3909
3910/*
3911** CAPI3REF: Prepare Flags
3912**
3913** These constants define various flags that can be passed into
3914** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
3915** [sqlite3_prepare16_v3()] interfaces.
3916**
3917** New flags may be added in future releases of SQLite.
3918**
3919** <dl>
3920** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
3921** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
3922** that the prepared statement will be retained for a long time and
3923** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
3924** and [sqlite3_prepare16_v3()] assume that the prepared statement will
3925** be used just once or at most a few times and then destroyed using
3926** [sqlite3_finalize()] relatively soon. The current implementation acts
3927** on this hint by avoiding the use of [lookaside memory] so as not to
3928** deplete the limited store of lookaside memory. Future versions of
3929** SQLite may act on this hint differently.
3930**
3931** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
3932** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
3933** to be required for any prepared statement that wanted to use the
3934** [sqlite3_normalized_sql()] interface. However, the
3935** [sqlite3_normalized_sql()] interface is now available to all
3936** prepared statements, regardless of whether or not they use this
3937** flag.
3938**
3939** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
3940** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
3941** to return an error (error code SQLITE_ERROR) if the statement uses
3942** any virtual tables.
3943** </dl>
3944*/
3945#define SQLITE_PREPARE_PERSISTENT 0x01
3946#define SQLITE_PREPARE_NORMALIZE 0x02
3947#define SQLITE_PREPARE_NO_VTAB 0x04
3948
3949/*
3950** CAPI3REF: Compiling An SQL Statement
3951** KEYWORDS: {SQL statement compiler}
3952** METHOD: sqlite3
3953** CONSTRUCTOR: sqlite3_stmt
3954**
3955** To execute an SQL statement, it must first be compiled into a byte-code
3956** program using one of these routines. Or, in other words, these routines
3957** are constructors for the [prepared statement] object.
3958**
3959** The preferred routine to use is [sqlite3_prepare_v2()]. The
3960** [sqlite3_prepare()] interface is legacy and should be avoided.
3961** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
3962** for special purposes.
3963**
3964** The use of the UTF-8 interfaces is preferred, as SQLite currently
3965** does all parsing using UTF-8. The UTF-16 interfaces are provided
3966** as a convenience. The UTF-16 interfaces work by converting the
3967** input text into UTF-8, then invoking the corresponding UTF-8 interface.
3968**
3969** The first argument, "db", is a [database connection] obtained from a
3970** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3971** [sqlite3_open16()]. The database connection must not have been closed.
3972**
3973** The second argument, "zSql", is the statement to be compiled, encoded
3974** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
3975** and sqlite3_prepare_v3()
3976** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
3977** and sqlite3_prepare16_v3() use UTF-16.
3978**
3979** ^If the nByte argument is negative, then zSql is read up to the
3980** first zero terminator. ^If nByte is positive, then it is the
3981** number of bytes read from zSql. ^If nByte is zero, then no prepared
3982** statement is generated.
3983** If the caller knows that the supplied string is nul-terminated, then
3984** there is a small performance advantage to passing an nByte parameter that
3985** is the number of bytes in the input string <i>including</i>
3986** the nul-terminator.
3987**
3988** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3989** past the end of the first SQL statement in zSql. These routines only
3990** compile the first statement in zSql, so *pzTail is left pointing to
3991** what remains uncompiled.
3992**
3993** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3994** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3995** to NULL. ^If the input text contains no SQL (if the input is an empty
3996** string or a comment) then *ppStmt is set to NULL.
3997** The calling procedure is responsible for deleting the compiled
3998** SQL statement using [sqlite3_finalize()] after it has finished with it.
3999** ppStmt may not be NULL.
4000**
4001** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4002** otherwise an [error code] is returned.
4003**
4004** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4005** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4006** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4007** are retained for backwards compatibility, but their use is discouraged.
4008** ^In the "vX" interfaces, the prepared statement
4009** that is returned (the [sqlite3_stmt] object) contains a copy of the
4010** original SQL text. This causes the [sqlite3_step()] interface to
4011** behave differently in three ways:
4012**
4013** <ol>
4014** <li>
4015** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4016** always used to do, [sqlite3_step()] will automatically recompile the SQL
4017** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4018** retries will occur before sqlite3_step() gives up and returns an error.
4019** </li>
4020**
4021** <li>
4022** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4023** [error codes] or [extended error codes]. ^The legacy behavior was that
4024** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4025** and the application would have to make a second call to [sqlite3_reset()]
4026** in order to find the underlying cause of the problem. With the "v2" prepare
4027** interfaces, the underlying reason for the error is returned immediately.
4028** </li>
4029**
4030** <li>
4031** ^If the specific value bound to a [parameter | host parameter] in the
4032** WHERE clause might influence the choice of query plan for a statement,
4033** then the statement will be automatically recompiled, as if there had been
4034** a schema change, on the first [sqlite3_step()] call following any change
4035** to the [sqlite3_bind_text | bindings] of that [parameter].
4036** ^The specific value of a WHERE-clause [parameter] might influence the
4037** choice of query plan if the parameter is the left-hand side of a [LIKE]
4038** or [GLOB] operator or if the parameter is compared to an indexed column
4039** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4040** </li>
4041** </ol>
4042**
4043** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4044** the extra prepFlags parameter, which is a bit array consisting of zero or
4045** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4046** sqlite3_prepare_v2() interface works exactly the same as
4047** sqlite3_prepare_v3() with a zero prepFlags parameter.
4048*/
4049SQLITE_API int sqlite3_prepare(
4050 sqlite3 *db, /* Database handle */
4051 const char *zSql, /* SQL statement, UTF-8 encoded */
4052 int nByte, /* Maximum length of zSql in bytes. */
4053 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4054 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4055);
4056SQLITE_API int sqlite3_prepare_v2(
4057 sqlite3 *db, /* Database handle */
4058 const char *zSql, /* SQL statement, UTF-8 encoded */
4059 int nByte, /* Maximum length of zSql in bytes. */
4060 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4061 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4062);
4063SQLITE_API int sqlite3_prepare_v3(
4064 sqlite3 *db, /* Database handle */
4065 const char *zSql, /* SQL statement, UTF-8 encoded */
4066 int nByte, /* Maximum length of zSql in bytes. */
4067 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4068 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4069 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4070);
4071SQLITE_API int sqlite3_prepare16(
4072 sqlite3 *db, /* Database handle */
4073 const void *zSql, /* SQL statement, UTF-16 encoded */
4074 int nByte, /* Maximum length of zSql in bytes. */
4075 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4076 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4077);
4078SQLITE_API int sqlite3_prepare16_v2(
4079 sqlite3 *db, /* Database handle */
4080 const void *zSql, /* SQL statement, UTF-16 encoded */
4081 int nByte, /* Maximum length of zSql in bytes. */
4082 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4083 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4084);
4085SQLITE_API int sqlite3_prepare16_v3(
4086 sqlite3 *db, /* Database handle */
4087 const void *zSql, /* SQL statement, UTF-16 encoded */
4088 int nByte, /* Maximum length of zSql in bytes. */
4089 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4090 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4091 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4092);
4093
4094/*
4095** CAPI3REF: Retrieving Statement SQL
4096** METHOD: sqlite3_stmt
4097**
4098** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4099** SQL text used to create [prepared statement] P if P was
4100** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4101** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4102** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4103** string containing the SQL text of prepared statement P with
4104** [bound parameters] expanded.
4105** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4106** string containing the normalized SQL text of prepared statement P. The
4107** semantics used to normalize a SQL statement are unspecified and subject
4108** to change. At a minimum, literal values will be replaced with suitable
4109** placeholders.
4110**
4111** ^(For example, if a prepared statement is created using the SQL
4112** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4113** and parameter :xyz is unbound, then sqlite3_sql() will return
4114** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4115** will return "SELECT 2345,NULL".)^
4116**
4117** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4118** is available to hold the result, or if the result would exceed the
4119** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4120**
4121** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4122** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4123** option causes sqlite3_expanded_sql() to always return NULL.
4124**
4125** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4126** are managed by SQLite and are automatically freed when the prepared
4127** statement is finalized.
4128** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4129** is obtained from [sqlite3_malloc()] and must be free by the application
4130** by passing it to [sqlite3_free()].
4131*/
4132SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4133SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4134SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4135
4136/*
4137** CAPI3REF: Determine If An SQL Statement Writes The Database
4138** METHOD: sqlite3_stmt
4139**
4140** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4141** and only if the [prepared statement] X makes no direct changes to
4142** the content of the database file.
4143**
4144** Note that [application-defined SQL functions] or
4145** [virtual tables] might change the database indirectly as a side effect.
4146** ^(For example, if an application defines a function "eval()" that
4147** calls [sqlite3_exec()], then the following SQL statement would
4148** change the database file through side-effects:
4149**
4150** <blockquote><pre>
4151** SELECT eval('DELETE FROM t1') FROM t2;
4152** </pre></blockquote>
4153**
4154** But because the [SELECT] statement does not change the database file
4155** directly, sqlite3_stmt_readonly() would still return true.)^
4156**
4157** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4158** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4159** since the statements themselves do not actually modify the database but
4160** rather they control the timing of when other statements modify the
4161** database. ^The [ATTACH] and [DETACH] statements also cause
4162** sqlite3_stmt_readonly() to return true since, while those statements
4163** change the configuration of a database connection, they do not make
4164** changes to the content of the database files on disk.
4165** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4166** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4167** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4168** sqlite3_stmt_readonly() returns false for those commands.
4169*/
4170SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4171
4172/*
4173** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4174** METHOD: sqlite3_stmt
4175**
4176** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4177** prepared statement S is an EXPLAIN statement, or 2 if the
4178** statement S is an EXPLAIN QUERY PLAN.
4179** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4180** an ordinary statement or a NULL pointer.
4181*/
4182SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4183
4184/*
4185** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4186** METHOD: sqlite3_stmt
4187**
4188** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4189** [prepared statement] S has been stepped at least once using
4190** [sqlite3_step(S)] but has neither run to completion (returned
4191** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4192** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4193** interface returns false if S is a NULL pointer. If S is not a
4194** NULL pointer and is not a pointer to a valid [prepared statement]
4195** object, then the behavior is undefined and probably undesirable.
4196**
4197** This interface can be used in combination [sqlite3_next_stmt()]
4198** to locate all prepared statements associated with a database
4199** connection that are in need of being reset. This can be used,
4200** for example, in diagnostic routines to search for prepared
4201** statements that are holding a transaction open.
4202*/
4203SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4204
4205/*
4206** CAPI3REF: Dynamically Typed Value Object
4207** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4208**
4209** SQLite uses the sqlite3_value object to represent all values
4210** that can be stored in a database table. SQLite uses dynamic typing
4211** for the values it stores. ^Values stored in sqlite3_value objects
4212** can be integers, floating point values, strings, BLOBs, or NULL.
4213**
4214** An sqlite3_value object may be either "protected" or "unprotected".
4215** Some interfaces require a protected sqlite3_value. Other interfaces
4216** will accept either a protected or an unprotected sqlite3_value.
4217** Every interface that accepts sqlite3_value arguments specifies
4218** whether or not it requires a protected sqlite3_value. The
4219** [sqlite3_value_dup()] interface can be used to construct a new
4220** protected sqlite3_value from an unprotected sqlite3_value.
4221**
4222** The terms "protected" and "unprotected" refer to whether or not
4223** a mutex is held. An internal mutex is held for a protected
4224** sqlite3_value object but no mutex is held for an unprotected
4225** sqlite3_value object. If SQLite is compiled to be single-threaded
4226** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4227** or if SQLite is run in one of reduced mutex modes
4228** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4229** then there is no distinction between protected and unprotected
4230** sqlite3_value objects and they can be used interchangeably. However,
4231** for maximum code portability it is recommended that applications
4232** still make the distinction between protected and unprotected
4233** sqlite3_value objects even when not strictly required.
4234**
4235** ^The sqlite3_value objects that are passed as parameters into the
4236** implementation of [application-defined SQL functions] are protected.
4237** ^The sqlite3_value object returned by
4238** [sqlite3_column_value()] is unprotected.
4239** Unprotected sqlite3_value objects may only be used as arguments
4240** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4241** [sqlite3_value_dup()].
4242** The [sqlite3_value_blob | sqlite3_value_type()] family of
4243** interfaces require protected sqlite3_value objects.
4244*/
4245typedef struct sqlite3_value sqlite3_value;
4246
4247/*
4248** CAPI3REF: SQL Function Context Object
4249**
4250** The context in which an SQL function executes is stored in an
4251** sqlite3_context object. ^A pointer to an sqlite3_context object
4252** is always first parameter to [application-defined SQL functions].
4253** The application-defined SQL function implementation will pass this
4254** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4255** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4256** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4257** and/or [sqlite3_set_auxdata()].
4258*/
4259typedef struct sqlite3_context sqlite3_context;
4260
4261/*
4262** CAPI3REF: Binding Values To Prepared Statements
4263** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4264** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4265** METHOD: sqlite3_stmt
4266**
4267** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4268** literals may be replaced by a [parameter] that matches one of following
4269** templates:
4270**
4271** <ul>
4272** <li> ?
4273** <li> ?NNN
4274** <li> :VVV
4275** <li> @VVV
4276** <li> $VVV
4277** </ul>
4278**
4279** In the templates above, NNN represents an integer literal,
4280** and VVV represents an alphanumeric identifier.)^ ^The values of these
4281** parameters (also called "host parameter names" or "SQL parameters")
4282** can be set using the sqlite3_bind_*() routines defined here.
4283**
4284** ^The first argument to the sqlite3_bind_*() routines is always
4285** a pointer to the [sqlite3_stmt] object returned from
4286** [sqlite3_prepare_v2()] or its variants.
4287**
4288** ^The second argument is the index of the SQL parameter to be set.
4289** ^The leftmost SQL parameter has an index of 1. ^When the same named
4290** SQL parameter is used more than once, second and subsequent
4291** occurrences have the same index as the first occurrence.
4292** ^The index for named parameters can be looked up using the
4293** [sqlite3_bind_parameter_index()] API if desired. ^The index
4294** for "?NNN" parameters is the value of NNN.
4295** ^The NNN value must be between 1 and the [sqlite3_limit()]
4296** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4297**
4298** ^The third argument is the value to bind to the parameter.
4299** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4300** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4301** is ignored and the end result is the same as sqlite3_bind_null().
4302** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4303** it should be a pointer to well-formed UTF8 text.
4304** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4305** it should be a pointer to well-formed UTF16 text.
4306** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4307** it should be a pointer to a well-formed unicode string that is
4308** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4309** otherwise.
4310**
4311** [[byte-order determination rules]] ^The byte-order of
4312** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4313** found in first character, which is removed, or in the absence of a BOM
4314** the byte order is the native byte order of the host
4315** machine for sqlite3_bind_text16() or the byte order specified in
4316** the 6th parameter for sqlite3_bind_text64().)^
4317** ^If UTF16 input text contains invalid unicode
4318** characters, then SQLite might change those invalid characters
4319** into the unicode replacement character: U+FFFD.
4320**
4321** ^(In those routines that have a fourth argument, its value is the
4322** number of bytes in the parameter. To be clear: the value is the
4323** number of <u>bytes</u> in the value, not the number of characters.)^
4324** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4325** is negative, then the length of the string is
4326** the number of bytes up to the first zero terminator.
4327** If the fourth parameter to sqlite3_bind_blob() is negative, then
4328** the behavior is undefined.
4329** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4330** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4331** that parameter must be the byte offset
4332** where the NUL terminator would occur assuming the string were NUL
4333** terminated. If any NUL characters occurs at byte offsets less than
4334** the value of the fourth parameter then the resulting string value will
4335** contain embedded NULs. The result of expressions involving strings
4336** with embedded NULs is undefined.
4337**
4338** ^The fifth argument to the BLOB and string binding interfaces
4339** is a destructor used to dispose of the BLOB or
4340** string after SQLite has finished with it. ^The destructor is called
4341** to dispose of the BLOB or string even if the call to the bind API fails,
4342** except the destructor is not called if the third parameter is a NULL
4343** pointer or the fourth parameter is negative.
4344** ^If the fifth argument is
4345** the special value [SQLITE_STATIC], then SQLite assumes that the
4346** information is in static, unmanaged space and does not need to be freed.
4347** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
4348** SQLite makes its own private copy of the data immediately, before
4349** the sqlite3_bind_*() routine returns.
4350**
4351** ^The sixth argument to sqlite3_bind_text64() must be one of
4352** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4353** to specify the encoding of the text in the third parameter. If
4354** the sixth argument to sqlite3_bind_text64() is not one of the
4355** allowed values shown above, or if the text encoding is different
4356** from the encoding specified by the sixth parameter, then the behavior
4357** is undefined.
4358**
4359** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4360** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4361** (just an integer to hold its size) while it is being processed.
4362** Zeroblobs are intended to serve as placeholders for BLOBs whose
4363** content is later written using
4364** [sqlite3_blob_open | incremental BLOB I/O] routines.
4365** ^A negative value for the zeroblob results in a zero-length BLOB.
4366**
4367** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4368** [prepared statement] S to have an SQL value of NULL, but to also be
4369** associated with the pointer P of type T. ^D is either a NULL pointer or
4370** a pointer to a destructor function for P. ^SQLite will invoke the
4371** destructor D with a single argument of P when it is finished using
4372** P. The T parameter should be a static string, preferably a string
4373** literal. The sqlite3_bind_pointer() routine is part of the
4374** [pointer passing interface] added for SQLite 3.20.0.
4375**
4376** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4377** for the [prepared statement] or with a prepared statement for which
4378** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4379** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4380** routine is passed a [prepared statement] that has been finalized, the
4381** result is undefined and probably harmful.
4382**
4383** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4384** ^Unbound parameters are interpreted as NULL.
4385**
4386** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4387** [error code] if anything goes wrong.
4388** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4389** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4390** [SQLITE_MAX_LENGTH].
4391** ^[SQLITE_RANGE] is returned if the parameter
4392** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4393**
4394** See also: [sqlite3_bind_parameter_count()],
4395** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4396*/
4397SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4398SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4399 void(*)(void*));
4400SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4401SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4402SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4403SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4404SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4405SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4406SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4407 void(*)(void*), unsigned char encoding);
4408SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4409SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4410SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4411SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4412
4413/*
4414** CAPI3REF: Number Of SQL Parameters
4415** METHOD: sqlite3_stmt
4416**
4417** ^This routine can be used to find the number of [SQL parameters]
4418** in a [prepared statement]. SQL parameters are tokens of the
4419** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4420** placeholders for values that are [sqlite3_bind_blob | bound]
4421** to the parameters at a later time.
4422**
4423** ^(This routine actually returns the index of the largest (rightmost)
4424** parameter. For all forms except ?NNN, this will correspond to the
4425** number of unique parameters. If parameters of the ?NNN form are used,
4426** there may be gaps in the list.)^
4427**
4428** See also: [sqlite3_bind_blob|sqlite3_bind()],
4429** [sqlite3_bind_parameter_name()], and
4430** [sqlite3_bind_parameter_index()].
4431*/
4432SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4433
4434/*
4435** CAPI3REF: Name Of A Host Parameter
4436** METHOD: sqlite3_stmt
4437**
4438** ^The sqlite3_bind_parameter_name(P,N) interface returns
4439** the name of the N-th [SQL parameter] in the [prepared statement] P.
4440** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4441** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4442** respectively.
4443** In other words, the initial ":" or "$" or "@" or "?"
4444** is included as part of the name.)^
4445** ^Parameters of the form "?" without a following integer have no name
4446** and are referred to as "nameless" or "anonymous parameters".
4447**
4448** ^The first host parameter has an index of 1, not 0.
4449**
4450** ^If the value N is out of range or if the N-th parameter is
4451** nameless, then NULL is returned. ^The returned string is
4452** always in UTF-8 encoding even if the named parameter was
4453** originally specified as UTF-16 in [sqlite3_prepare16()],
4454** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4455**
4456** See also: [sqlite3_bind_blob|sqlite3_bind()],
4457** [sqlite3_bind_parameter_count()], and
4458** [sqlite3_bind_parameter_index()].
4459*/
4460SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4461
4462/*
4463** CAPI3REF: Index Of A Parameter With A Given Name
4464** METHOD: sqlite3_stmt
4465**
4466** ^Return the index of an SQL parameter given its name. ^The
4467** index value returned is suitable for use as the second
4468** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4469** is returned if no matching parameter is found. ^The parameter
4470** name must be given in UTF-8 even if the original statement
4471** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4472** [sqlite3_prepare16_v3()].
4473**
4474** See also: [sqlite3_bind_blob|sqlite3_bind()],
4475** [sqlite3_bind_parameter_count()], and
4476** [sqlite3_bind_parameter_name()].
4477*/
4478SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4479
4480/*
4481** CAPI3REF: Reset All Bindings On A Prepared Statement
4482** METHOD: sqlite3_stmt
4483**
4484** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4485** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4486** ^Use this routine to reset all host parameters to NULL.
4487*/
4488SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4489
4490/*
4491** CAPI3REF: Number Of Columns In A Result Set
4492** METHOD: sqlite3_stmt
4493**
4494** ^Return the number of columns in the result set returned by the
4495** [prepared statement]. ^If this routine returns 0, that means the
4496** [prepared statement] returns no data (for example an [UPDATE]).
4497** ^However, just because this routine returns a positive number does not
4498** mean that one or more rows of data will be returned. ^A SELECT statement
4499** will always have a positive sqlite3_column_count() but depending on the
4500** WHERE clause constraints and the table content, it might return no rows.
4501**
4502** See also: [sqlite3_data_count()]
4503*/
4504SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4505
4506/*
4507** CAPI3REF: Column Names In A Result Set
4508** METHOD: sqlite3_stmt
4509**
4510** ^These routines return the name assigned to a particular column
4511** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4512** interface returns a pointer to a zero-terminated UTF-8 string
4513** and sqlite3_column_name16() returns a pointer to a zero-terminated
4514** UTF-16 string. ^The first parameter is the [prepared statement]
4515** that implements the [SELECT] statement. ^The second parameter is the
4516** column number. ^The leftmost column is number 0.
4517**
4518** ^The returned string pointer is valid until either the [prepared statement]
4519** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4520** reprepared by the first call to [sqlite3_step()] for a particular run
4521** or until the next call to
4522** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4523**
4524** ^If sqlite3_malloc() fails during the processing of either routine
4525** (for example during a conversion from UTF-8 to UTF-16) then a
4526** NULL pointer is returned.
4527**
4528** ^The name of a result column is the value of the "AS" clause for
4529** that column, if there is an AS clause. If there is no AS clause
4530** then the name of the column is unspecified and may change from
4531** one release of SQLite to the next.
4532*/
4533SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4534SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4535
4536/*
4537** CAPI3REF: Source Of Data In A Query Result
4538** METHOD: sqlite3_stmt
4539**
4540** ^These routines provide a means to determine the database, table, and
4541** table column that is the origin of a particular result column in
4542** [SELECT] statement.
4543** ^The name of the database or table or column can be returned as
4544** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4545** the database name, the _table_ routines return the table name, and
4546** the origin_ routines return the column name.
4547** ^The returned string is valid until the [prepared statement] is destroyed
4548** using [sqlite3_finalize()] or until the statement is automatically
4549** reprepared by the first call to [sqlite3_step()] for a particular run
4550** or until the same information is requested
4551** again in a different encoding.
4552**
4553** ^The names returned are the original un-aliased names of the
4554** database, table, and column.
4555**
4556** ^The first argument to these interfaces is a [prepared statement].
4557** ^These functions return information about the Nth result column returned by
4558** the statement, where N is the second function argument.
4559** ^The left-most column is column 0 for these routines.
4560**
4561** ^If the Nth column returned by the statement is an expression or
4562** subquery and is not a column value, then all of these functions return
4563** NULL. ^These routines might also return NULL if a memory allocation error
4564** occurs. ^Otherwise, they return the name of the attached database, table,
4565** or column that query result column was extracted from.
4566**
4567** ^As with all other SQLite APIs, those whose names end with "16" return
4568** UTF-16 encoded strings and the other functions return UTF-8.
4569**
4570** ^These APIs are only available if the library was compiled with the
4571** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4572**
4573** If two or more threads call one or more
4574** [sqlite3_column_database_name | column metadata interfaces]
4575** for the same [prepared statement] and result column
4576** at the same time then the results are undefined.
4577*/
4578SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4579SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4580SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4581SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4582SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4583SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4584
4585/*
4586** CAPI3REF: Declared Datatype Of A Query Result
4587** METHOD: sqlite3_stmt
4588**
4589** ^(The first parameter is a [prepared statement].
4590** If this statement is a [SELECT] statement and the Nth column of the
4591** returned result set of that [SELECT] is a table column (not an
4592** expression or subquery) then the declared type of the table
4593** column is returned.)^ ^If the Nth column of the result set is an
4594** expression or subquery, then a NULL pointer is returned.
4595** ^The returned string is always UTF-8 encoded.
4596**
4597** ^(For example, given the database schema:
4598**
4599** CREATE TABLE t1(c1 VARIANT);
4600**
4601** and the following statement to be compiled:
4602**
4603** SELECT c1 + 1, c1 FROM t1;
4604**
4605** this routine would return the string "VARIANT" for the second result
4606** column (i==1), and a NULL pointer for the first result column (i==0).)^
4607**
4608** ^SQLite uses dynamic run-time typing. ^So just because a column
4609** is declared to contain a particular type does not mean that the
4610** data stored in that column is of the declared type. SQLite is
4611** strongly typed, but the typing is dynamic not static. ^Type
4612** is associated with individual values, not with the containers
4613** used to hold those values.
4614*/
4615SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4616SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4617
4618/*
4619** CAPI3REF: Evaluate An SQL Statement
4620** METHOD: sqlite3_stmt
4621**
4622** After a [prepared statement] has been prepared using any of
4623** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4624** or [sqlite3_prepare16_v3()] or one of the legacy
4625** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4626** must be called one or more times to evaluate the statement.
4627**
4628** The details of the behavior of the sqlite3_step() interface depend
4629** on whether the statement was prepared using the newer "vX" interfaces
4630** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4631** [sqlite3_prepare16_v2()] or the older legacy
4632** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4633** new "vX" interface is recommended for new applications but the legacy
4634** interface will continue to be supported.
4635**
4636** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4637** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4638** ^With the "v2" interface, any of the other [result codes] or
4639** [extended result codes] might be returned as well.
4640**
4641** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4642** database locks it needs to do its job. ^If the statement is a [COMMIT]
4643** or occurs outside of an explicit transaction, then you can retry the
4644** statement. If the statement is not a [COMMIT] and occurs within an
4645** explicit transaction then you should rollback the transaction before
4646** continuing.
4647**
4648** ^[SQLITE_DONE] means that the statement has finished executing
4649** successfully. sqlite3_step() should not be called again on this virtual
4650** machine without first calling [sqlite3_reset()] to reset the virtual
4651** machine back to its initial state.
4652**
4653** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4654** is returned each time a new row of data is ready for processing by the
4655** caller. The values may be accessed using the [column access functions].
4656** sqlite3_step() is called again to retrieve the next row of data.
4657**
4658** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4659** violation) has occurred. sqlite3_step() should not be called again on
4660** the VM. More information may be found by calling [sqlite3_errmsg()].
4661** ^With the legacy interface, a more specific error code (for example,
4662** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4663** can be obtained by calling [sqlite3_reset()] on the
4664** [prepared statement]. ^In the "v2" interface,
4665** the more specific error code is returned directly by sqlite3_step().
4666**
4667** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4668** Perhaps it was called on a [prepared statement] that has
4669** already been [sqlite3_finalize | finalized] or on one that had
4670** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4671** be the case that the same database connection is being used by two or
4672** more threads at the same moment in time.
4673**
4674** For all versions of SQLite up to and including 3.6.23.1, a call to
4675** [sqlite3_reset()] was required after sqlite3_step() returned anything
4676** other than [SQLITE_ROW] before any subsequent invocation of
4677** sqlite3_step(). Failure to reset the prepared statement using
4678** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4679** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4680** sqlite3_step() began
4681** calling [sqlite3_reset()] automatically in this circumstance rather
4682** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4683** break because any application that ever receives an SQLITE_MISUSE error
4684** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4685** can be used to restore the legacy behavior.
4686**
4687** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4688** API always returns a generic error code, [SQLITE_ERROR], following any
4689** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4690** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4691** specific [error codes] that better describes the error.
4692** We admit that this is a goofy design. The problem has been fixed
4693** with the "v2" interface. If you prepare all of your SQL statements
4694** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4695** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4696** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4697** then the more specific [error codes] are returned directly
4698** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4699*/
4700SQLITE_API int sqlite3_step(sqlite3_stmt*);
4701
4702/*
4703** CAPI3REF: Number of columns in a result set
4704** METHOD: sqlite3_stmt
4705**
4706** ^The sqlite3_data_count(P) interface returns the number of columns in the
4707** current row of the result set of [prepared statement] P.
4708** ^If prepared statement P does not have results ready to return
4709** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
4710** interfaces) then sqlite3_data_count(P) returns 0.
4711** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4712** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4713** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4714** will return non-zero if previous call to [sqlite3_step](P) returned
4715** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4716** where it always returns zero since each step of that multi-step
4717** pragma returns 0 columns of data.
4718**
4719** See also: [sqlite3_column_count()]
4720*/
4721SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4722
4723/*
4724** CAPI3REF: Fundamental Datatypes
4725** KEYWORDS: SQLITE_TEXT
4726**
4727** ^(Every value in SQLite has one of five fundamental datatypes:
4728**
4729** <ul>
4730** <li> 64-bit signed integer
4731** <li> 64-bit IEEE floating point number
4732** <li> string
4733** <li> BLOB
4734** <li> NULL
4735** </ul>)^
4736**
4737** These constants are codes for each of those types.
4738**
4739** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4740** for a completely different meaning. Software that links against both
4741** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4742** SQLITE_TEXT.
4743*/
4744#define SQLITE_INTEGER 1
4745#define SQLITE_FLOAT 2
4746#define SQLITE_BLOB 4
4747#define SQLITE_NULL 5
4748#ifdef SQLITE_TEXT
4749# undef SQLITE_TEXT
4750#else
4751# define SQLITE_TEXT 3
4752#endif
4753#define SQLITE3_TEXT 3
4754
4755/*
4756** CAPI3REF: Result Values From A Query
4757** KEYWORDS: {column access functions}
4758** METHOD: sqlite3_stmt
4759**
4760** <b>Summary:</b>
4761** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4762** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
4763** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
4764** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
4765** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
4766** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
4767** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
4768** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
4769** [sqlite3_value|unprotected sqlite3_value] object.
4770** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4771** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
4772** or a UTF-8 TEXT result in bytes
4773** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
4774** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4775** TEXT in bytes
4776** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
4777** datatype of the result
4778** </table></blockquote>
4779**
4780** <b>Details:</b>
4781**
4782** ^These routines return information about a single column of the current
4783** result row of a query. ^In every case the first argument is a pointer
4784** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4785** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4786** and the second argument is the index of the column for which information
4787** should be returned. ^The leftmost column of the result set has the index 0.
4788** ^The number of columns in the result can be determined using
4789** [sqlite3_column_count()].
4790**
4791** If the SQL statement does not currently point to a valid row, or if the
4792** column index is out of range, the result is undefined.
4793** These routines may only be called when the most recent call to
4794** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4795** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4796** If any of these routines are called after [sqlite3_reset()] or
4797** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4798** something other than [SQLITE_ROW], the results are undefined.
4799** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4800** are called from a different thread while any of these routines
4801** are pending, then the results are undefined.
4802**
4803** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4804** each return the value of a result column in a specific data format. If
4805** the result column is not initially in the requested format (for example,
4806** if the query returns an integer but the sqlite3_column_text() interface
4807** is used to extract the value) then an automatic type conversion is performed.
4808**
4809** ^The sqlite3_column_type() routine returns the
4810** [SQLITE_INTEGER | datatype code] for the initial data type
4811** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4812** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4813** The return value of sqlite3_column_type() can be used to decide which
4814** of the first six interface should be used to extract the column value.
4815** The value returned by sqlite3_column_type() is only meaningful if no
4816** automatic type conversions have occurred for the value in question.
4817** After a type conversion, the result of calling sqlite3_column_type()
4818** is undefined, though harmless. Future
4819** versions of SQLite may change the behavior of sqlite3_column_type()
4820** following a type conversion.
4821**
4822** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4823** or sqlite3_column_bytes16() interfaces can be used to determine the size
4824** of that BLOB or string.
4825**
4826** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4827** routine returns the number of bytes in that BLOB or string.
4828** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4829** the string to UTF-8 and then returns the number of bytes.
4830** ^If the result is a numeric value then sqlite3_column_bytes() uses
4831** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4832** the number of bytes in that string.
4833** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4834**
4835** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4836** routine returns the number of bytes in that BLOB or string.
4837** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4838** the string to UTF-16 and then returns the number of bytes.
4839** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4840** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4841** the number of bytes in that string.
4842** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4843**
4844** ^The values returned by [sqlite3_column_bytes()] and
4845** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4846** of the string. ^For clarity: the values returned by
4847** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4848** bytes in the string, not the number of characters.
4849**
4850** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4851** even empty strings, are always zero-terminated. ^The return
4852** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4853**
4854** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4855** [unprotected sqlite3_value] object. In a multithreaded environment,
4856** an unprotected sqlite3_value object may only be used safely with
4857** [sqlite3_bind_value()] and [sqlite3_result_value()].
4858** If the [unprotected sqlite3_value] object returned by
4859** [sqlite3_column_value()] is used in any other way, including calls
4860** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4861** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4862** Hence, the sqlite3_column_value() interface
4863** is normally only useful within the implementation of
4864** [application-defined SQL functions] or [virtual tables], not within
4865** top-level application code.
4866**
4867** The these routines may attempt to convert the datatype of the result.
4868** ^For example, if the internal representation is FLOAT and a text result
4869** is requested, [sqlite3_snprintf()] is used internally to perform the
4870** conversion automatically. ^(The following table details the conversions
4871** that are applied:
4872**
4873** <blockquote>
4874** <table border="1">
4875** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4876**
4877** <tr><td> NULL <td> INTEGER <td> Result is 0
4878** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4879** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4880** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4881** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4882** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4883** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4884** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4885** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4886** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4887** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4888** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
4889** <tr><td> TEXT <td> BLOB <td> No change
4890** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4891** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
4892** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4893** </table>
4894** </blockquote>)^
4895**
4896** Note that when type conversions occur, pointers returned by prior
4897** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4898** sqlite3_column_text16() may be invalidated.
4899** Type conversions and pointer invalidations might occur
4900** in the following cases:
4901**
4902** <ul>
4903** <li> The initial content is a BLOB and sqlite3_column_text() or
4904** sqlite3_column_text16() is called. A zero-terminator might
4905** need to be added to the string.</li>
4906** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4907** sqlite3_column_text16() is called. The content must be converted
4908** to UTF-16.</li>
4909** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4910** sqlite3_column_text() is called. The content must be converted
4911** to UTF-8.</li>
4912** </ul>
4913**
4914** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4915** not invalidate a prior pointer, though of course the content of the buffer
4916** that the prior pointer references will have been modified. Other kinds
4917** of conversion are done in place when it is possible, but sometimes they
4918** are not possible and in those cases prior pointers are invalidated.
4919**
4920** The safest policy is to invoke these routines
4921** in one of the following ways:
4922**
4923** <ul>
4924** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4925** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4926** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4927** </ul>
4928**
4929** In other words, you should call sqlite3_column_text(),
4930** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4931** into the desired format, then invoke sqlite3_column_bytes() or
4932** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4933** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4934** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4935** with calls to sqlite3_column_bytes().
4936**
4937** ^The pointers returned are valid until a type conversion occurs as
4938** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4939** [sqlite3_finalize()] is called. ^The memory space used to hold strings
4940** and BLOBs is freed automatically. Do not pass the pointers returned
4941** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4942** [sqlite3_free()].
4943**
4944** As long as the input parameters are correct, these routines will only
4945** fail if an out-of-memory error occurs during a format conversion.
4946** Only the following subset of interfaces are subject to out-of-memory
4947** errors:
4948**
4949** <ul>
4950** <li> sqlite3_column_blob()
4951** <li> sqlite3_column_text()
4952** <li> sqlite3_column_text16()
4953** <li> sqlite3_column_bytes()
4954** <li> sqlite3_column_bytes16()
4955** </ul>
4956**
4957** If an out-of-memory error occurs, then the return value from these
4958** routines is the same as if the column had contained an SQL NULL value.
4959** Valid SQL NULL returns can be distinguished from out-of-memory errors
4960** by invoking the [sqlite3_errcode()] immediately after the suspect
4961** return value is obtained and before any
4962** other SQLite interface is called on the same [database connection].
4963*/
4964SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4965SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4966SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4967SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4968SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4969SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4970SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4971SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4972SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4973SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4974
4975/*
4976** CAPI3REF: Destroy A Prepared Statement Object
4977** DESTRUCTOR: sqlite3_stmt
4978**
4979** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4980** ^If the most recent evaluation of the statement encountered no errors
4981** or if the statement is never been evaluated, then sqlite3_finalize() returns
4982** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4983** sqlite3_finalize(S) returns the appropriate [error code] or
4984** [extended error code].
4985**
4986** ^The sqlite3_finalize(S) routine can be called at any point during
4987** the life cycle of [prepared statement] S:
4988** before statement S is ever evaluated, after
4989** one or more calls to [sqlite3_reset()], or after any call
4990** to [sqlite3_step()] regardless of whether or not the statement has
4991** completed execution.
4992**
4993** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4994**
4995** The application must finalize every [prepared statement] in order to avoid
4996** resource leaks. It is a grievous error for the application to try to use
4997** a prepared statement after it has been finalized. Any use of a prepared
4998** statement after it has been finalized can result in undefined and
4999** undesirable behavior such as segfaults and heap corruption.
5000*/
5001SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5002
5003/*
5004** CAPI3REF: Reset A Prepared Statement Object
5005** METHOD: sqlite3_stmt
5006**
5007** The sqlite3_reset() function is called to reset a [prepared statement]
5008** object back to its initial state, ready to be re-executed.
5009** ^Any SQL statement variables that had values bound to them using
5010** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5011** Use [sqlite3_clear_bindings()] to reset the bindings.
5012**
5013** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5014** back to the beginning of its program.
5015**
5016** ^If the most recent call to [sqlite3_step(S)] for the
5017** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
5018** or if [sqlite3_step(S)] has never before been called on S,
5019** then [sqlite3_reset(S)] returns [SQLITE_OK].
5020**
5021** ^If the most recent call to [sqlite3_step(S)] for the
5022** [prepared statement] S indicated an error, then
5023** [sqlite3_reset(S)] returns an appropriate [error code].
5024**
5025** ^The [sqlite3_reset(S)] interface does not change the values
5026** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5027*/
5028SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5029
5030/*
5031** CAPI3REF: Create Or Redefine SQL Functions
5032** KEYWORDS: {function creation routines}
5033** METHOD: sqlite3
5034**
5035** ^These functions (collectively known as "function creation routines")
5036** are used to add SQL functions or aggregates or to redefine the behavior
5037** of existing SQL functions or aggregates. The only differences between
5038** the three "sqlite3_create_function*" routines are the text encoding
5039** expected for the second parameter (the name of the function being
5040** created) and the presence or absence of a destructor callback for
5041** the application data pointer. Function sqlite3_create_window_function()
5042** is similar, but allows the user to supply the extra callback functions
5043** needed by [aggregate window functions].
5044**
5045** ^The first parameter is the [database connection] to which the SQL
5046** function is to be added. ^If an application uses more than one database
5047** connection then application-defined SQL functions must be added
5048** to each database connection separately.
5049**
5050** ^The second parameter is the name of the SQL function to be created or
5051** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5052** representation, exclusive of the zero-terminator. ^Note that the name
5053** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5054** ^Any attempt to create a function with a longer name
5055** will result in [SQLITE_MISUSE] being returned.
5056**
5057** ^The third parameter (nArg)
5058** is the number of arguments that the SQL function or
5059** aggregate takes. ^If this parameter is -1, then the SQL function or
5060** aggregate may take any number of arguments between 0 and the limit
5061** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5062** parameter is less than -1 or greater than 127 then the behavior is
5063** undefined.
5064**
5065** ^The fourth parameter, eTextRep, specifies what
5066** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5067** its parameters. The application should set this parameter to
5068** [SQLITE_UTF16LE] if the function implementation invokes
5069** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5070** implementation invokes [sqlite3_value_text16be()] on an input, or
5071** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5072** otherwise. ^The same SQL function may be registered multiple times using
5073** different preferred text encodings, with different implementations for
5074** each encoding.
5075** ^When multiple implementations of the same function are available, SQLite
5076** will pick the one that involves the least amount of data conversion.
5077**
5078** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5079** to signal that the function will always return the same result given
5080** the same inputs within a single SQL statement. Most SQL functions are
5081** deterministic. The built-in [random()] SQL function is an example of a
5082** function that is not deterministic. The SQLite query planner is able to
5083** perform additional optimizations on deterministic functions, so use
5084** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5085**
5086** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5087** flag, which if present prevents the function from being invoked from
5088** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5089** index expressions, or the WHERE clause of partial indexes.
5090**
5091** <span style="background-color:#ffff90;">
5092** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5093** all application-defined SQL functions that do not need to be
5094** used inside of triggers, view, CHECK constraints, or other elements of
5095** the database schema. This flags is especially recommended for SQL
5096** functions that have side effects or reveal internal application state.
5097** Without this flag, an attacker might be able to modify the schema of
5098** a database file to include invocations of the function with parameters
5099** chosen by the attacker, which the application will then execute when
5100** the database file is opened and read.
5101** </span>
5102**
5103** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5104** function can gain access to this pointer using [sqlite3_user_data()].)^
5105**
5106** ^The sixth, seventh and eighth parameters passed to the three
5107** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5108** pointers to C-language functions that implement the SQL function or
5109** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5110** callback only; NULL pointers must be passed as the xStep and xFinal
5111** parameters. ^An aggregate SQL function requires an implementation of xStep
5112** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5113** SQL function or aggregate, pass NULL pointers for all three function
5114** callbacks.
5115**
5116** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5117** and xInverse) passed to sqlite3_create_window_function are pointers to
5118** C-language callbacks that implement the new function. xStep and xFinal
5119** must both be non-NULL. xValue and xInverse may either both be NULL, in
5120** which case a regular aggregate function is created, or must both be
5121** non-NULL, in which case the new function may be used as either an aggregate
5122** or aggregate window function. More details regarding the implementation
5123** of aggregate window functions are
5124** [user-defined window functions|available here].
5125**
5126** ^(If the final parameter to sqlite3_create_function_v2() or
5127** sqlite3_create_window_function() is not NULL, then it is destructor for
5128** the application data pointer. The destructor is invoked when the function
5129** is deleted, either by being overloaded or when the database connection
5130** closes.)^ ^The destructor is also invoked if the call to
5131** sqlite3_create_function_v2() fails. ^When the destructor callback is
5132** invoked, it is passed a single argument which is a copy of the application
5133** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5134**
5135** ^It is permitted to register multiple implementations of the same
5136** functions with the same name but with either differing numbers of
5137** arguments or differing preferred text encodings. ^SQLite will use
5138** the implementation that most closely matches the way in which the
5139** SQL function is used. ^A function implementation with a non-negative
5140** nArg parameter is a better match than a function implementation with
5141** a negative nArg. ^A function where the preferred text encoding
5142** matches the database encoding is a better
5143** match than a function where the encoding is different.
5144** ^A function where the encoding difference is between UTF16le and UTF16be
5145** is a closer match than a function where the encoding difference is
5146** between UTF8 and UTF16.
5147**
5148** ^Built-in functions may be overloaded by new application-defined functions.
5149**
5150** ^An application-defined function is permitted to call other
5151** SQLite interfaces. However, such calls must not
5152** close the database connection nor finalize or reset the prepared
5153** statement in which the function is running.
5154*/
5155SQLITE_API int sqlite3_create_function(
5156 sqlite3 *db,
5157 const char *zFunctionName,
5158 int nArg,
5159 int eTextRep,
5160 void *pApp,
5161 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5162 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5163 void (*xFinal)(sqlite3_context*)
5164);
5165SQLITE_API int sqlite3_create_function16(
5166 sqlite3 *db,
5167 const void *zFunctionName,
5168 int nArg,
5169 int eTextRep,
5170 void *pApp,
5171 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5172 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5173 void (*xFinal)(sqlite3_context*)
5174);
5175SQLITE_API int sqlite3_create_function_v2(
5176 sqlite3 *db,
5177 const char *zFunctionName,
5178 int nArg,
5179 int eTextRep,
5180 void *pApp,
5181 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5182 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5183 void (*xFinal)(sqlite3_context*),
5184 void(*xDestroy)(void*)
5185);
5186SQLITE_API int sqlite3_create_window_function(
5187 sqlite3 *db,
5188 const char *zFunctionName,
5189 int nArg,
5190 int eTextRep,
5191 void *pApp,
5192 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5193 void (*xFinal)(sqlite3_context*),
5194 void (*xValue)(sqlite3_context*),
5195 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5196 void(*xDestroy)(void*)
5197);
5198
5199/*
5200** CAPI3REF: Text Encodings
5201**
5202** These constant define integer codes that represent the various
5203** text encodings supported by SQLite.
5204*/
5205#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5206#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5207#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5208#define SQLITE_UTF16 4 /* Use native byte order */
5209#define SQLITE_ANY 5 /* Deprecated */
5210#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5211
5212/*
5213** CAPI3REF: Function Flags
5214**
5215** These constants may be ORed together with the
5216** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5217** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5218** [sqlite3_create_function_v2()].
5219**
5220** <dl>
5221** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5222** The SQLITE_DETERMINISTIC flag means that the new function always gives
5223** the same output when the input parameters are the same.
5224** The [abs|abs() function] is deterministic, for example, but
5225** [randomblob|randomblob()] is not. Functions must
5226** be deterministic in order to be used in certain contexts such as
5227** with the WHERE clause of [partial indexes] or in [generated columns].
5228** SQLite might also optimize deterministic functions by factoring them
5229** out of inner loops.
5230** </dd>
5231**
5232** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5233** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5234** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5235** schema structures such as [CHECK constraints], [DEFAULT clauses],
5236** [expression indexes], [partial indexes], or [generated columns].
5237** The SQLITE_DIRECTONLY flags is a security feature which is recommended
5238** for all [application-defined SQL functions], and especially for functions
5239** that have side-effects or that could potentially leak sensitive
5240** information.
5241** </dd>
5242**
5243** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5244** The SQLITE_INNOCUOUS flag means that the function is unlikely
5245** to cause problems even if misused. An innocuous function should have
5246** no side effects and should not depend on any values other than its
5247** input parameters. The [abs|abs() function] is an example of an
5248** innocuous function.
5249** The [load_extension() SQL function] is not innocuous because of its
5250** side effects.
5251** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5252** exactly the same. The [random|random() function] is an example of a
5253** function that is innocuous but not deterministic.
5254** <p>Some heightened security settings
5255** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5256** disable the use of SQL functions inside views and triggers and in
5257** schema structures such as [CHECK constraints], [DEFAULT clauses],
5258** [expression indexes], [partial indexes], and [generated columns] unless
5259** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5260** are innocuous. Developers are advised to avoid using the
5261** SQLITE_INNOCUOUS flag for application-defined functions unless the
5262** function has been carefully audited and found to be free of potentially
5263** security-adverse side-effects and information-leaks.
5264** </dd>
5265**
5266** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5267** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
5268** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5269** Specifying this flag makes no difference for scalar or aggregate user
5270** functions. However, if it is not specified for a user-defined window
5271** function, then any sub-types belonging to arguments passed to the window
5272** function may be discarded before the window function is called (i.e.
5273** sqlite3_value_subtype() will always return 0).
5274** </dd>
5275** </dl>
5276*/
5277#define SQLITE_DETERMINISTIC 0x000000800
5278#define SQLITE_DIRECTONLY 0x000080000
5279#define SQLITE_SUBTYPE 0x000100000
5280#define SQLITE_INNOCUOUS 0x000200000
5281
5282/*
5283** CAPI3REF: Deprecated Functions
5284** DEPRECATED
5285**
5286** These functions are [deprecated]. In order to maintain
5287** backwards compatibility with older code, these functions continue
5288** to be supported. However, new applications should avoid
5289** the use of these functions. To encourage programmers to avoid
5290** these functions, we will not explain what they do.
5291*/
5292#ifndef SQLITE_OMIT_DEPRECATED
5293SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5294SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5295SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5296SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5297SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5298SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5299 void*,sqlite3_int64);
5300#endif
5301
5302/*
5303** CAPI3REF: Obtaining SQL Values
5304** METHOD: sqlite3_value
5305**
5306** <b>Summary:</b>
5307** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5308** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
5309** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
5310** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
5311** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
5312** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
5313** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
5314** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
5315** the native byteorder
5316** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
5317** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
5318** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5319** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
5320** or a UTF-8 TEXT in bytes
5321** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
5322** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5323** TEXT in bytes
5324** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
5325** datatype of the value
5326** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
5327** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
5328** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
5329** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
5330** against a virtual table.
5331** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
5332** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
5333** </table></blockquote>
5334**
5335** <b>Details:</b>
5336**
5337** These routines extract type, size, and content information from
5338** [protected sqlite3_value] objects. Protected sqlite3_value objects
5339** are used to pass parameter information into the functions that
5340** implement [application-defined SQL functions] and [virtual tables].
5341**
5342** These routines work only with [protected sqlite3_value] objects.
5343** Any attempt to use these routines on an [unprotected sqlite3_value]
5344** is not threadsafe.
5345**
5346** ^These routines work just like the corresponding [column access functions]
5347** except that these routines take a single [protected sqlite3_value] object
5348** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5349**
5350** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5351** in the native byte-order of the host machine. ^The
5352** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5353** extract UTF-16 strings as big-endian and little-endian respectively.
5354**
5355** ^If [sqlite3_value] object V was initialized
5356** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5357** and if X and Y are strings that compare equal according to strcmp(X,Y),
5358** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5359** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5360** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5361**
5362** ^(The sqlite3_value_type(V) interface returns the
5363** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5364** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5365** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5366** Other interfaces might change the datatype for an sqlite3_value object.
5367** For example, if the datatype is initially SQLITE_INTEGER and
5368** sqlite3_value_text(V) is called to extract a text value for that
5369** integer, then subsequent calls to sqlite3_value_type(V) might return
5370** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5371** occurs is undefined and may change from one release of SQLite to the next.
5372**
5373** ^(The sqlite3_value_numeric_type() interface attempts to apply
5374** numeric affinity to the value. This means that an attempt is
5375** made to convert the value to an integer or floating point. If
5376** such a conversion is possible without loss of information (in other
5377** words, if the value is a string that looks like a number)
5378** then the conversion is performed. Otherwise no conversion occurs.
5379** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5380**
5381** ^Within the [xUpdate] method of a [virtual table], the
5382** sqlite3_value_nochange(X) interface returns true if and only if
5383** the column corresponding to X is unchanged by the UPDATE operation
5384** that the xUpdate method call was invoked to implement and if
5385** and the prior [xColumn] method call that was invoked to extracted
5386** the value for that column returned without setting a result (probably
5387** because it queried [sqlite3_vtab_nochange()] and found that the column
5388** was unchanging). ^Within an [xUpdate] method, any value for which
5389** sqlite3_value_nochange(X) is true will in all other respects appear
5390** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5391** than within an [xUpdate] method call for an UPDATE statement, then
5392** the return value is arbitrary and meaningless.
5393**
5394** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5395** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5396** interfaces. ^If X comes from an SQL literal value, or a table column,
5397** or an expression, then sqlite3_value_frombind(X) returns zero.
5398**
5399** Please pay particular attention to the fact that the pointer returned
5400** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5401** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5402** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5403** or [sqlite3_value_text16()].
5404**
5405** These routines must be called from the same thread as
5406** the SQL function that supplied the [sqlite3_value*] parameters.
5407**
5408** As long as the input parameter is correct, these routines can only
5409** fail if an out-of-memory error occurs during a format conversion.
5410** Only the following subset of interfaces are subject to out-of-memory
5411** errors:
5412**
5413** <ul>
5414** <li> sqlite3_value_blob()
5415** <li> sqlite3_value_text()
5416** <li> sqlite3_value_text16()
5417** <li> sqlite3_value_text16le()
5418** <li> sqlite3_value_text16be()
5419** <li> sqlite3_value_bytes()
5420** <li> sqlite3_value_bytes16()
5421** </ul>
5422**
5423** If an out-of-memory error occurs, then the return value from these
5424** routines is the same as if the column had contained an SQL NULL value.
5425** Valid SQL NULL returns can be distinguished from out-of-memory errors
5426** by invoking the [sqlite3_errcode()] immediately after the suspect
5427** return value is obtained and before any
5428** other SQLite interface is called on the same [database connection].
5429*/
5430SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5431SQLITE_API double sqlite3_value_double(sqlite3_value*);
5432SQLITE_API int sqlite3_value_int(sqlite3_value*);
5433SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5434SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5435SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5436SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5437SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5438SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5439SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5440SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5441SQLITE_API int sqlite3_value_type(sqlite3_value*);
5442SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5443SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5444SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5445
5446/*
5447** CAPI3REF: Finding The Subtype Of SQL Values
5448** METHOD: sqlite3_value
5449**
5450** The sqlite3_value_subtype(V) function returns the subtype for
5451** an [application-defined SQL function] argument V. The subtype
5452** information can be used to pass a limited amount of context from
5453** one SQL function to another. Use the [sqlite3_result_subtype()]
5454** routine to set the subtype for the return value of an SQL function.
5455*/
5456SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5457
5458/*
5459** CAPI3REF: Copy And Free SQL Values
5460** METHOD: sqlite3_value
5461**
5462** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5463** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5464** is a [protected sqlite3_value] object even if the input is not.
5465** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5466** memory allocation fails.
5467**
5468** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5469** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5470** then sqlite3_value_free(V) is a harmless no-op.
5471*/
5472SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5473SQLITE_API void sqlite3_value_free(sqlite3_value*);
5474
5475/*
5476** CAPI3REF: Obtain Aggregate Function Context
5477** METHOD: sqlite3_context
5478**
5479** Implementations of aggregate SQL functions use this
5480** routine to allocate memory for storing their state.
5481**
5482** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5483** for a particular aggregate function, SQLite allocates
5484** N bytes of memory, zeroes out that memory, and returns a pointer
5485** to the new memory. ^On second and subsequent calls to
5486** sqlite3_aggregate_context() for the same aggregate function instance,
5487** the same buffer is returned. Sqlite3_aggregate_context() is normally
5488** called once for each invocation of the xStep callback and then one
5489** last time when the xFinal callback is invoked. ^(When no rows match
5490** an aggregate query, the xStep() callback of the aggregate function
5491** implementation is never called and xFinal() is called exactly once.
5492** In those cases, sqlite3_aggregate_context() might be called for the
5493** first time from within xFinal().)^
5494**
5495** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5496** when first called if N is less than or equal to zero or if a memory
5497** allocate error occurs.
5498**
5499** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5500** determined by the N parameter on first successful call. Changing the
5501** value of N in any subsequent call to sqlite3_aggregate_context() within
5502** the same aggregate function instance will not resize the memory
5503** allocation.)^ Within the xFinal callback, it is customary to set
5504** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5505** pointless memory allocations occur.
5506**
5507** ^SQLite automatically frees the memory allocated by
5508** sqlite3_aggregate_context() when the aggregate query concludes.
5509**
5510** The first parameter must be a copy of the
5511** [sqlite3_context | SQL function context] that is the first parameter
5512** to the xStep or xFinal callback routine that implements the aggregate
5513** function.
5514**
5515** This routine must be called from the same thread in which
5516** the aggregate SQL function is running.
5517*/
5518SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5519
5520/*
5521** CAPI3REF: User Data For Functions
5522** METHOD: sqlite3_context
5523**
5524** ^The sqlite3_user_data() interface returns a copy of
5525** the pointer that was the pUserData parameter (the 5th parameter)
5526** of the [sqlite3_create_function()]
5527** and [sqlite3_create_function16()] routines that originally
5528** registered the application defined function.
5529**
5530** This routine must be called from the same thread in which
5531** the application-defined function is running.
5532*/
5533SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5534
5535/*
5536** CAPI3REF: Database Connection For Functions
5537** METHOD: sqlite3_context
5538**
5539** ^The sqlite3_context_db_handle() interface returns a copy of
5540** the pointer to the [database connection] (the 1st parameter)
5541** of the [sqlite3_create_function()]
5542** and [sqlite3_create_function16()] routines that originally
5543** registered the application defined function.
5544*/
5545SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5546
5547/*
5548** CAPI3REF: Function Auxiliary Data
5549** METHOD: sqlite3_context
5550**
5551** These functions may be used by (non-aggregate) SQL functions to
5552** associate metadata with argument values. If the same value is passed to
5553** multiple invocations of the same SQL function during query execution, under
5554** some circumstances the associated metadata may be preserved. An example
5555** of where this might be useful is in a regular-expression matching
5556** function. The compiled version of the regular expression can be stored as
5557** metadata associated with the pattern string.
5558** Then as long as the pattern string remains the same,
5559** the compiled regular expression can be reused on multiple
5560** invocations of the same function.
5561**
5562** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5563** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5564** value to the application-defined function. ^N is zero for the left-most
5565** function argument. ^If there is no metadata
5566** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5567** returns a NULL pointer.
5568**
5569** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5570** argument of the application-defined function. ^Subsequent
5571** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5572** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5573** NULL if the metadata has been discarded.
5574** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5575** SQLite will invoke the destructor function X with parameter P exactly
5576** once, when the metadata is discarded.
5577** SQLite is free to discard the metadata at any time, including: <ul>
5578** <li> ^(when the corresponding function parameter changes)^, or
5579** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5580** SQL statement)^, or
5581** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5582** parameter)^, or
5583** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5584** allocation error occurs.)^ </ul>
5585**
5586** Note the last bullet in particular. The destructor X in
5587** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5588** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5589** should be called near the end of the function implementation and the
5590** function implementation should not make any use of P after
5591** sqlite3_set_auxdata() has been called.
5592**
5593** ^(In practice, metadata is preserved between function calls for
5594** function parameters that are compile-time constants, including literal
5595** values and [parameters] and expressions composed from the same.)^
5596**
5597** The value of the N parameter to these interfaces should be non-negative.
5598** Future enhancements may make use of negative N values to define new
5599** kinds of function caching behavior.
5600**
5601** These routines must be called from the same thread in which
5602** the SQL function is running.
5603*/
5604SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5605SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5606
5607
5608/*
5609** CAPI3REF: Constants Defining Special Destructor Behavior
5610**
5611** These are special values for the destructor that is passed in as the
5612** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5613** argument is SQLITE_STATIC, it means that the content pointer is constant
5614** and will never change. It does not need to be destroyed. ^The
5615** SQLITE_TRANSIENT value means that the content will likely change in
5616** the near future and that SQLite should make its own private copy of
5617** the content before returning.
5618**
5619** The typedef is necessary to work around problems in certain
5620** C++ compilers.
5621*/
5622typedef void (*sqlite3_destructor_type)(void*);
5623#define SQLITE_STATIC ((sqlite3_destructor_type)0)
5624#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5625
5626/*
5627** CAPI3REF: Setting The Result Of An SQL Function
5628** METHOD: sqlite3_context
5629**
5630** These routines are used by the xFunc or xFinal callbacks that
5631** implement SQL functions and aggregates. See
5632** [sqlite3_create_function()] and [sqlite3_create_function16()]
5633** for additional information.
5634**
5635** These functions work very much like the [parameter binding] family of
5636** functions used to bind values to host parameters in prepared statements.
5637** Refer to the [SQL parameter] documentation for additional information.
5638**
5639** ^The sqlite3_result_blob() interface sets the result from
5640** an application-defined function to be the BLOB whose content is pointed
5641** to by the second parameter and which is N bytes long where N is the
5642** third parameter.
5643**
5644** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5645** interfaces set the result of the application-defined function to be
5646** a BLOB containing all zero bytes and N bytes in size.
5647**
5648** ^The sqlite3_result_double() interface sets the result from
5649** an application-defined function to be a floating point value specified
5650** by its 2nd argument.
5651**
5652** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5653** cause the implemented SQL function to throw an exception.
5654** ^SQLite uses the string pointed to by the
5655** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5656** as the text of an error message. ^SQLite interprets the error
5657** message string from sqlite3_result_error() as UTF-8. ^SQLite
5658** interprets the string from sqlite3_result_error16() as UTF-16 using
5659** the same [byte-order determination rules] as [sqlite3_bind_text16()].
5660** ^If the third parameter to sqlite3_result_error()
5661** or sqlite3_result_error16() is negative then SQLite takes as the error
5662** message all text up through the first zero character.
5663** ^If the third parameter to sqlite3_result_error() or
5664** sqlite3_result_error16() is non-negative then SQLite takes that many
5665** bytes (not characters) from the 2nd parameter as the error message.
5666** ^The sqlite3_result_error() and sqlite3_result_error16()
5667** routines make a private copy of the error message text before
5668** they return. Hence, the calling function can deallocate or
5669** modify the text after they return without harm.
5670** ^The sqlite3_result_error_code() function changes the error code
5671** returned by SQLite as a result of an error in a function. ^By default,
5672** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5673** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5674**
5675** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5676** error indicating that a string or BLOB is too long to represent.
5677**
5678** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5679** error indicating that a memory allocation failed.
5680**
5681** ^The sqlite3_result_int() interface sets the return value
5682** of the application-defined function to be the 32-bit signed integer
5683** value given in the 2nd argument.
5684** ^The sqlite3_result_int64() interface sets the return value
5685** of the application-defined function to be the 64-bit signed integer
5686** value given in the 2nd argument.
5687**
5688** ^The sqlite3_result_null() interface sets the return value
5689** of the application-defined function to be NULL.
5690**
5691** ^The sqlite3_result_text(), sqlite3_result_text16(),
5692** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5693** set the return value of the application-defined function to be
5694** a text string which is represented as UTF-8, UTF-16 native byte order,
5695** UTF-16 little endian, or UTF-16 big endian, respectively.
5696** ^The sqlite3_result_text64() interface sets the return value of an
5697** application-defined function to be a text string in an encoding
5698** specified by the fifth (and last) parameter, which must be one
5699** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5700** ^SQLite takes the text result from the application from
5701** the 2nd parameter of the sqlite3_result_text* interfaces.
5702** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5703** is negative, then SQLite takes result text from the 2nd parameter
5704** through the first zero character.
5705** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5706** is non-negative, then as many bytes (not characters) of the text
5707** pointed to by the 2nd parameter are taken as the application-defined
5708** function result. If the 3rd parameter is non-negative, then it
5709** must be the byte offset into the string where the NUL terminator would
5710** appear if the string where NUL terminated. If any NUL characters occur
5711** in the string at a byte offset that is less than the value of the 3rd
5712** parameter, then the resulting string will contain embedded NULs and the
5713** result of expressions operating on strings with embedded NULs is undefined.
5714** ^If the 4th parameter to the sqlite3_result_text* interfaces
5715** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5716** function as the destructor on the text or BLOB result when it has
5717** finished using that result.
5718** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5719** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5720** assumes that the text or BLOB result is in constant space and does not
5721** copy the content of the parameter nor call a destructor on the content
5722** when it has finished using that result.
5723** ^If the 4th parameter to the sqlite3_result_text* interfaces
5724** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5725** then SQLite makes a copy of the result into space obtained
5726** from [sqlite3_malloc()] before it returns.
5727**
5728** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
5729** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
5730** when the encoding is not UTF8, if the input UTF16 begins with a
5731** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
5732** string and the rest of the string is interpreted according to the
5733** byte-order specified by the BOM. ^The byte-order specified by
5734** the BOM at the beginning of the text overrides the byte-order
5735** specified by the interface procedure. ^So, for example, if
5736** sqlite3_result_text16le() is invoked with text that begins
5737** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
5738** first two bytes of input are skipped and the remaining input
5739** is interpreted as UTF16BE text.
5740**
5741** ^For UTF16 input text to the sqlite3_result_text16(),
5742** sqlite3_result_text16be(), sqlite3_result_text16le(), and
5743** sqlite3_result_text64() routines, if the text contains invalid
5744** UTF16 characters, the invalid characters might be converted
5745** into the unicode replacement character, U+FFFD.
5746**
5747** ^The sqlite3_result_value() interface sets the result of
5748** the application-defined function to be a copy of the
5749** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5750** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5751** so that the [sqlite3_value] specified in the parameter may change or
5752** be deallocated after sqlite3_result_value() returns without harm.
5753** ^A [protected sqlite3_value] object may always be used where an
5754** [unprotected sqlite3_value] object is required, so either
5755** kind of [sqlite3_value] object can be used with this interface.
5756**
5757** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5758** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5759** also associates the host-language pointer P or type T with that
5760** NULL value such that the pointer can be retrieved within an
5761** [application-defined SQL function] using [sqlite3_value_pointer()].
5762** ^If the D parameter is not NULL, then it is a pointer to a destructor
5763** for the P parameter. ^SQLite invokes D with P as its only argument
5764** when SQLite is finished with P. The T parameter should be a static
5765** string and preferably a string literal. The sqlite3_result_pointer()
5766** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5767**
5768** If these routines are called from within the different thread
5769** than the one containing the application-defined function that received
5770** the [sqlite3_context] pointer, the results are undefined.
5771*/
5772SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5773SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5774 sqlite3_uint64,void(*)(void*));
5775SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5776SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5777SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5778SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5779SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5780SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5781SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5782SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5783SQLITE_API void sqlite3_result_null(sqlite3_context*);
5784SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5785SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5786 void(*)(void*), unsigned char encoding);
5787SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5788SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5789SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5790SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5791SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5792SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5793SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5794
5795
5796/*
5797** CAPI3REF: Setting The Subtype Of An SQL Function
5798** METHOD: sqlite3_context
5799**
5800** The sqlite3_result_subtype(C,T) function causes the subtype of
5801** the result from the [application-defined SQL function] with
5802** [sqlite3_context] C to be the value T. Only the lower 8 bits
5803** of the subtype T are preserved in current versions of SQLite;
5804** higher order bits are discarded.
5805** The number of subtype bytes preserved by SQLite might increase
5806** in future releases of SQLite.
5807*/
5808SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5809
5810/*
5811** CAPI3REF: Define New Collating Sequences
5812** METHOD: sqlite3
5813**
5814** ^These functions add, remove, or modify a [collation] associated
5815** with the [database connection] specified as the first argument.
5816**
5817** ^The name of the collation is a UTF-8 string
5818** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5819** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5820** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5821** considered to be the same name.
5822**
5823** ^(The third argument (eTextRep) must be one of the constants:
5824** <ul>
5825** <li> [SQLITE_UTF8],
5826** <li> [SQLITE_UTF16LE],
5827** <li> [SQLITE_UTF16BE],
5828** <li> [SQLITE_UTF16], or
5829** <li> [SQLITE_UTF16_ALIGNED].
5830** </ul>)^
5831** ^The eTextRep argument determines the encoding of strings passed
5832** to the collating function callback, xCompare.
5833** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5834** force strings to be UTF16 with native byte order.
5835** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5836** on an even byte address.
5837**
5838** ^The fourth argument, pArg, is an application data pointer that is passed
5839** through as the first argument to the collating function callback.
5840**
5841** ^The fifth argument, xCompare, is a pointer to the collating function.
5842** ^Multiple collating functions can be registered using the same name but
5843** with different eTextRep parameters and SQLite will use whichever
5844** function requires the least amount of data transformation.
5845** ^If the xCompare argument is NULL then the collating function is
5846** deleted. ^When all collating functions having the same name are deleted,
5847** that collation is no longer usable.
5848**
5849** ^The collating function callback is invoked with a copy of the pArg
5850** application data pointer and with two strings in the encoding specified
5851** by the eTextRep argument. The two integer parameters to the collating
5852** function callback are the length of the two strings, in bytes. The collating
5853** function must return an integer that is negative, zero, or positive
5854** if the first string is less than, equal to, or greater than the second,
5855** respectively. A collating function must always return the same answer
5856** given the same inputs. If two or more collating functions are registered
5857** to the same collation name (using different eTextRep values) then all
5858** must give an equivalent answer when invoked with equivalent strings.
5859** The collating function must obey the following properties for all
5860** strings A, B, and C:
5861**
5862** <ol>
5863** <li> If A==B then B==A.
5864** <li> If A==B and B==C then A==C.
5865** <li> If A&lt;B THEN B&gt;A.
5866** <li> If A&lt;B and B&lt;C then A&lt;C.
5867** </ol>
5868**
5869** If a collating function fails any of the above constraints and that
5870** collating function is registered and used, then the behavior of SQLite
5871** is undefined.
5872**
5873** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5874** with the addition that the xDestroy callback is invoked on pArg when
5875** the collating function is deleted.
5876** ^Collating functions are deleted when they are overridden by later
5877** calls to the collation creation functions or when the
5878** [database connection] is closed using [sqlite3_close()].
5879**
5880** ^The xDestroy callback is <u>not</u> called if the
5881** sqlite3_create_collation_v2() function fails. Applications that invoke
5882** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5883** check the return code and dispose of the application data pointer
5884** themselves rather than expecting SQLite to deal with it for them.
5885** This is different from every other SQLite interface. The inconsistency
5886** is unfortunate but cannot be changed without breaking backwards
5887** compatibility.
5888**
5889** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
5890*/
5891SQLITE_API int sqlite3_create_collation(
5892 sqlite3*,
5893 const char *zName,
5894 int eTextRep,
5895 void *pArg,
5896 int(*xCompare)(void*,int,const void*,int,const void*)
5897);
5898SQLITE_API int sqlite3_create_collation_v2(
5899 sqlite3*,
5900 const char *zName,
5901 int eTextRep,
5902 void *pArg,
5903 int(*xCompare)(void*,int,const void*,int,const void*),
5904 void(*xDestroy)(void*)
5905);
5906SQLITE_API int sqlite3_create_collation16(
5907 sqlite3*,
5908 const void *zName,
5909 int eTextRep,
5910 void *pArg,
5911 int(*xCompare)(void*,int,const void*,int,const void*)
5912);
5913
5914/*
5915** CAPI3REF: Collation Needed Callbacks
5916** METHOD: sqlite3
5917**
5918** ^To avoid having to register all collation sequences before a database
5919** can be used, a single callback function may be registered with the
5920** [database connection] to be invoked whenever an undefined collation
5921** sequence is required.
5922**
5923** ^If the function is registered using the sqlite3_collation_needed() API,
5924** then it is passed the names of undefined collation sequences as strings
5925** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5926** the names are passed as UTF-16 in machine native byte order.
5927** ^A call to either function replaces the existing collation-needed callback.
5928**
5929** ^(When the callback is invoked, the first argument passed is a copy
5930** of the second argument to sqlite3_collation_needed() or
5931** sqlite3_collation_needed16(). The second argument is the database
5932** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5933** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5934** sequence function required. The fourth parameter is the name of the
5935** required collation sequence.)^
5936**
5937** The callback function should register the desired collation using
5938** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5939** [sqlite3_create_collation_v2()].
5940*/
5941SQLITE_API int sqlite3_collation_needed(
5942 sqlite3*,
5943 void*,
5944 void(*)(void*,sqlite3*,int eTextRep,const char*)
5945);
5946SQLITE_API int sqlite3_collation_needed16(
5947 sqlite3*,
5948 void*,
5949 void(*)(void*,sqlite3*,int eTextRep,const void*)
5950);
5951
5952#ifdef SQLITE_ENABLE_CEROD
5953/*
5954** Specify the activation key for a CEROD database. Unless
5955** activated, none of the CEROD routines will work.
5956*/
5957SQLITE_API void sqlite3_activate_cerod(
5958 const char *zPassPhrase /* Activation phrase */
5959);
5960#endif
5961
5962/*
5963** CAPI3REF: Suspend Execution For A Short Time
5964**
5965** The sqlite3_sleep() function causes the current thread to suspend execution
5966** for at least a number of milliseconds specified in its parameter.
5967**
5968** If the operating system does not support sleep requests with
5969** millisecond time resolution, then the time will be rounded up to
5970** the nearest second. The number of milliseconds of sleep actually
5971** requested from the operating system is returned.
5972**
5973** ^SQLite implements this interface by calling the xSleep()
5974** method of the default [sqlite3_vfs] object. If the xSleep() method
5975** of the default VFS is not implemented correctly, or not implemented at
5976** all, then the behavior of sqlite3_sleep() may deviate from the description
5977** in the previous paragraphs.
5978*/
5979SQLITE_API int sqlite3_sleep(int);
5980
5981/*
5982** CAPI3REF: Name Of The Folder Holding Temporary Files
5983**
5984** ^(If this global variable is made to point to a string which is
5985** the name of a folder (a.k.a. directory), then all temporary files
5986** created by SQLite when using a built-in [sqlite3_vfs | VFS]
5987** will be placed in that directory.)^ ^If this variable
5988** is a NULL pointer, then SQLite performs a search for an appropriate
5989** temporary file directory.
5990**
5991** Applications are strongly discouraged from using this global variable.
5992** It is required to set a temporary folder on Windows Runtime (WinRT).
5993** But for all other platforms, it is highly recommended that applications
5994** neither read nor write this variable. This global variable is a relic
5995** that exists for backwards compatibility of legacy applications and should
5996** be avoided in new projects.
5997**
5998** It is not safe to read or modify this variable in more than one
5999** thread at a time. It is not safe to read or modify this variable
6000** if a [database connection] is being used at the same time in a separate
6001** thread.
6002** It is intended that this variable be set once
6003** as part of process initialization and before any SQLite interface
6004** routines have been called and that this variable remain unchanged
6005** thereafter.
6006**
6007** ^The [temp_store_directory pragma] may modify this variable and cause
6008** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6009** the [temp_store_directory pragma] always assumes that any string
6010** that this variable points to is held in memory obtained from
6011** [sqlite3_malloc] and the pragma may attempt to free that memory
6012** using [sqlite3_free].
6013** Hence, if this variable is modified directly, either it should be
6014** made NULL or made to point to memory obtained from [sqlite3_malloc]
6015** or else the use of the [temp_store_directory pragma] should be avoided.
6016** Except when requested by the [temp_store_directory pragma], SQLite
6017** does not free the memory that sqlite3_temp_directory points to. If
6018** the application wants that memory to be freed, it must do
6019** so itself, taking care to only do so after all [database connection]
6020** objects have been destroyed.
6021**
6022** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6023** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6024** features that require the use of temporary files may fail. Here is an
6025** example of how to do this using C++ with the Windows Runtime:
6026**
6027** <blockquote><pre>
6028** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6029** &nbsp; TemporaryFolder->Path->Data();
6030** char zPathBuf&#91;MAX_PATH + 1&#93;;
6031** memset(zPathBuf, 0, sizeof(zPathBuf));
6032** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6033** &nbsp; NULL, NULL);
6034** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6035** </pre></blockquote>
6036*/
6037SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6038
6039/*
6040** CAPI3REF: Name Of The Folder Holding Database Files
6041**
6042** ^(If this global variable is made to point to a string which is
6043** the name of a folder (a.k.a. directory), then all database files
6044** specified with a relative pathname and created or accessed by
6045** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6046** to be relative to that directory.)^ ^If this variable is a NULL
6047** pointer, then SQLite assumes that all database files specified
6048** with a relative pathname are relative to the current directory
6049** for the process. Only the windows VFS makes use of this global
6050** variable; it is ignored by the unix VFS.
6051**
6052** Changing the value of this variable while a database connection is
6053** open can result in a corrupt database.
6054**
6055** It is not safe to read or modify this variable in more than one
6056** thread at a time. It is not safe to read or modify this variable
6057** if a [database connection] is being used at the same time in a separate
6058** thread.
6059** It is intended that this variable be set once
6060** as part of process initialization and before any SQLite interface
6061** routines have been called and that this variable remain unchanged
6062** thereafter.
6063**
6064** ^The [data_store_directory pragma] may modify this variable and cause
6065** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6066** the [data_store_directory pragma] always assumes that any string
6067** that this variable points to is held in memory obtained from
6068** [sqlite3_malloc] and the pragma may attempt to free that memory
6069** using [sqlite3_free].
6070** Hence, if this variable is modified directly, either it should be
6071** made NULL or made to point to memory obtained from [sqlite3_malloc]
6072** or else the use of the [data_store_directory pragma] should be avoided.
6073*/
6074SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6075
6076/*
6077** CAPI3REF: Win32 Specific Interface
6078**
6079** These interfaces are available only on Windows. The
6080** [sqlite3_win32_set_directory] interface is used to set the value associated
6081** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6082** zValue, depending on the value of the type parameter. The zValue parameter
6083** should be NULL to cause the previous value to be freed via [sqlite3_free];
6084** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6085** prior to being used. The [sqlite3_win32_set_directory] interface returns
6086** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6087** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6088** [sqlite3_data_directory] variable is intended to act as a replacement for
6089** the current directory on the sub-platforms of Win32 where that concept is
6090** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6091** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6092** sqlite3_win32_set_directory interface except the string parameter must be
6093** UTF-8 or UTF-16, respectively.
6094*/
6095SQLITE_API int sqlite3_win32_set_directory(
6096 unsigned long type, /* Identifier for directory being set or reset */
6097 void *zValue /* New value for directory being set or reset */
6098);
6099SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6100SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6101
6102/*
6103** CAPI3REF: Win32 Directory Types
6104**
6105** These macros are only available on Windows. They define the allowed values
6106** for the type argument to the [sqlite3_win32_set_directory] interface.
6107*/
6108#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6109#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6110
6111/*
6112** CAPI3REF: Test For Auto-Commit Mode
6113** KEYWORDS: {autocommit mode}
6114** METHOD: sqlite3
6115**
6116** ^The sqlite3_get_autocommit() interface returns non-zero or
6117** zero if the given database connection is or is not in autocommit mode,
6118** respectively. ^Autocommit mode is on by default.
6119** ^Autocommit mode is disabled by a [BEGIN] statement.
6120** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6121**
6122** If certain kinds of errors occur on a statement within a multi-statement
6123** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6124** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6125** transaction might be rolled back automatically. The only way to
6126** find out whether SQLite automatically rolled back the transaction after
6127** an error is to use this function.
6128**
6129** If another thread changes the autocommit status of the database
6130** connection while this routine is running, then the return value
6131** is undefined.
6132*/
6133SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6134
6135/*
6136** CAPI3REF: Find The Database Handle Of A Prepared Statement
6137** METHOD: sqlite3_stmt
6138**
6139** ^The sqlite3_db_handle interface returns the [database connection] handle
6140** to which a [prepared statement] belongs. ^The [database connection]
6141** returned by sqlite3_db_handle is the same [database connection]
6142** that was the first argument
6143** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6144** create the statement in the first place.
6145*/
6146SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6147
6148/*
6149** CAPI3REF: Return The Filename For A Database Connection
6150** METHOD: sqlite3
6151**
6152** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6153** associated with database N of connection D.
6154** ^If there is no attached database N on the database
6155** connection D, or if database N is a temporary or in-memory database, then
6156** this function will return either a NULL pointer or an empty string.
6157**
6158** ^The string value returned by this routine is owned and managed by
6159** the database connection. ^The value will be valid until the database N
6160** is [DETACH]-ed or until the database connection closes.
6161**
6162** ^The filename returned by this function is the output of the
6163** xFullPathname method of the [VFS]. ^In other words, the filename
6164** will be an absolute pathname, even if the filename used
6165** to open the database originally was a URI or relative pathname.
6166**
6167** If the filename pointer returned by this routine is not NULL, then it
6168** can be used as the filename input parameter to these routines:
6169** <ul>
6170** <li> [sqlite3_uri_parameter()]
6171** <li> [sqlite3_uri_boolean()]
6172** <li> [sqlite3_uri_int64()]
6173** <li> [sqlite3_filename_database()]
6174** <li> [sqlite3_filename_journal()]
6175** <li> [sqlite3_filename_wal()]
6176** </ul>
6177*/
6178SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6179
6180/*
6181** CAPI3REF: Determine if a database is read-only
6182** METHOD: sqlite3
6183**
6184** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6185** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6186** the name of a database on connection D.
6187*/
6188SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6189
6190/*
6191** CAPI3REF: Determine the transaction state of a database
6192** METHOD: sqlite3
6193**
6194** ^The sqlite3_txn_state(D,S) interface returns the current
6195** [transaction state] of schema S in database connection D. ^If S is NULL,
6196** then the highest transaction state of any schema on database connection D
6197** is returned. Transaction states are (in order of lowest to highest):
6198** <ol>
6199** <li value="0"> SQLITE_TXN_NONE
6200** <li value="1"> SQLITE_TXN_READ
6201** <li value="2"> SQLITE_TXN_WRITE
6202** </ol>
6203** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6204** a valid schema, then -1 is returned.
6205*/
6206SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6207
6208/*
6209** CAPI3REF: Allowed return values from [sqlite3_txn_state()]
6210** KEYWORDS: {transaction state}
6211**
6212** These constants define the current transaction state of a database file.
6213** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6214** constants in order to describe the transaction state of schema S
6215** in [database connection] D.
6216**
6217** <dl>
6218** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6219** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6220** pending.</dd>
6221**
6222** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6223** <dd>The SQLITE_TXN_READ state means that the database is currently
6224** in a read transaction. Content has been read from the database file
6225** but nothing in the database file has changed. The transaction state
6226** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
6227** no other conflicting concurrent write transactions. The transaction
6228** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6229** [COMMIT].</dd>
6230**
6231** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6232** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6233** in a write transaction. Content has been written to the database file
6234** but has not yet committed. The transaction state will change to
6235** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6236*/
6237#define SQLITE_TXN_NONE 0
6238#define SQLITE_TXN_READ 1
6239#define SQLITE_TXN_WRITE 2
6240
6241/*
6242** CAPI3REF: Find the next prepared statement
6243** METHOD: sqlite3
6244**
6245** ^This interface returns a pointer to the next [prepared statement] after
6246** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6247** then this interface returns a pointer to the first prepared statement
6248** associated with the database connection pDb. ^If no prepared statement
6249** satisfies the conditions of this routine, it returns NULL.
6250**
6251** The [database connection] pointer D in a call to
6252** [sqlite3_next_stmt(D,S)] must refer to an open database
6253** connection and in particular must not be a NULL pointer.
6254*/
6255SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6256
6257/*
6258** CAPI3REF: Commit And Rollback Notification Callbacks
6259** METHOD: sqlite3
6260**
6261** ^The sqlite3_commit_hook() interface registers a callback
6262** function to be invoked whenever a transaction is [COMMIT | committed].
6263** ^Any callback set by a previous call to sqlite3_commit_hook()
6264** for the same database connection is overridden.
6265** ^The sqlite3_rollback_hook() interface registers a callback
6266** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6267** ^Any callback set by a previous call to sqlite3_rollback_hook()
6268** for the same database connection is overridden.
6269** ^The pArg argument is passed through to the callback.
6270** ^If the callback on a commit hook function returns non-zero,
6271** then the commit is converted into a rollback.
6272**
6273** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6274** return the P argument from the previous call of the same function
6275** on the same [database connection] D, or NULL for
6276** the first call for each function on D.
6277**
6278** The commit and rollback hook callbacks are not reentrant.
6279** The callback implementation must not do anything that will modify
6280** the database connection that invoked the callback. Any actions
6281** to modify the database connection must be deferred until after the
6282** completion of the [sqlite3_step()] call that triggered the commit
6283** or rollback hook in the first place.
6284** Note that running any other SQL statements, including SELECT statements,
6285** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6286** the database connections for the meaning of "modify" in this paragraph.
6287**
6288** ^Registering a NULL function disables the callback.
6289**
6290** ^When the commit hook callback routine returns zero, the [COMMIT]
6291** operation is allowed to continue normally. ^If the commit hook
6292** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6293** ^The rollback hook is invoked on a rollback that results from a commit
6294** hook returning non-zero, just as it would be with any other rollback.
6295**
6296** ^For the purposes of this API, a transaction is said to have been
6297** rolled back if an explicit "ROLLBACK" statement is executed, or
6298** an error or constraint causes an implicit rollback to occur.
6299** ^The rollback callback is not invoked if a transaction is
6300** automatically rolled back because the database connection is closed.
6301**
6302** See also the [sqlite3_update_hook()] interface.
6303*/
6304SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6305SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6306
6307/*
6308** CAPI3REF: Data Change Notification Callbacks
6309** METHOD: sqlite3
6310**
6311** ^The sqlite3_update_hook() interface registers a callback function
6312** with the [database connection] identified by the first argument
6313** to be invoked whenever a row is updated, inserted or deleted in
6314** a [rowid table].
6315** ^Any callback set by a previous call to this function
6316** for the same database connection is overridden.
6317**
6318** ^The second argument is a pointer to the function to invoke when a
6319** row is updated, inserted or deleted in a rowid table.
6320** ^The first argument to the callback is a copy of the third argument
6321** to sqlite3_update_hook().
6322** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6323** or [SQLITE_UPDATE], depending on the operation that caused the callback
6324** to be invoked.
6325** ^The third and fourth arguments to the callback contain pointers to the
6326** database and table name containing the affected row.
6327** ^The final callback parameter is the [rowid] of the row.
6328** ^In the case of an update, this is the [rowid] after the update takes place.
6329**
6330** ^(The update hook is not invoked when internal system tables are
6331** modified (i.e. sqlite_sequence).)^
6332** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6333**
6334** ^In the current implementation, the update hook
6335** is not invoked when conflicting rows are deleted because of an
6336** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6337** invoked when rows are deleted using the [truncate optimization].
6338** The exceptions defined in this paragraph might change in a future
6339** release of SQLite.
6340**
6341** The update hook implementation must not do anything that will modify
6342** the database connection that invoked the update hook. Any actions
6343** to modify the database connection must be deferred until after the
6344** completion of the [sqlite3_step()] call that triggered the update hook.
6345** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6346** database connections for the meaning of "modify" in this paragraph.
6347**
6348** ^The sqlite3_update_hook(D,C,P) function
6349** returns the P argument from the previous call
6350** on the same [database connection] D, or NULL for
6351** the first call on D.
6352**
6353** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6354** and [sqlite3_preupdate_hook()] interfaces.
6355*/
6356SQLITE_API void *sqlite3_update_hook(
6357 sqlite3*,
6358 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6359 void*
6360);
6361
6362/*
6363** CAPI3REF: Enable Or Disable Shared Pager Cache
6364**
6365** ^(This routine enables or disables the sharing of the database cache
6366** and schema data structures between [database connection | connections]
6367** to the same database. Sharing is enabled if the argument is true
6368** and disabled if the argument is false.)^
6369**
6370** ^Cache sharing is enabled and disabled for an entire process.
6371** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6372** In prior versions of SQLite,
6373** sharing was enabled or disabled for each thread separately.
6374**
6375** ^(The cache sharing mode set by this interface effects all subsequent
6376** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6377** Existing database connections continue to use the sharing mode
6378** that was in effect at the time they were opened.)^
6379**
6380** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6381** successfully. An [error code] is returned otherwise.)^
6382**
6383** ^Shared cache is disabled by default. It is recommended that it stay
6384** that way. In other words, do not use this routine. This interface
6385** continues to be provided for historical compatibility, but its use is
6386** discouraged. Any use of shared cache is discouraged. If shared cache
6387** must be used, it is recommended that shared cache only be enabled for
6388** individual database connections using the [sqlite3_open_v2()] interface
6389** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6390**
6391** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6392** and will always return SQLITE_MISUSE. On those systems,
6393** shared cache mode should be enabled per-database connection via
6394** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6395**
6396** This interface is threadsafe on processors where writing a
6397** 32-bit integer is atomic.
6398**
6399** See Also: [SQLite Shared-Cache Mode]
6400*/
6401SQLITE_API int sqlite3_enable_shared_cache(int);
6402
6403/*
6404** CAPI3REF: Attempt To Free Heap Memory
6405**
6406** ^The sqlite3_release_memory() interface attempts to free N bytes
6407** of heap memory by deallocating non-essential memory allocations
6408** held by the database library. Memory used to cache database
6409** pages to improve performance is an example of non-essential memory.
6410** ^sqlite3_release_memory() returns the number of bytes actually freed,
6411** which might be more or less than the amount requested.
6412** ^The sqlite3_release_memory() routine is a no-op returning zero
6413** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6414**
6415** See also: [sqlite3_db_release_memory()]
6416*/
6417SQLITE_API int sqlite3_release_memory(int);
6418
6419/*
6420** CAPI3REF: Free Memory Used By A Database Connection
6421** METHOD: sqlite3
6422**
6423** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6424** memory as possible from database connection D. Unlike the
6425** [sqlite3_release_memory()] interface, this interface is in effect even
6426** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6427** omitted.
6428**
6429** See also: [sqlite3_release_memory()]
6430*/
6431SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6432
6433/*
6434** CAPI3REF: Impose A Limit On Heap Size
6435**
6436** These interfaces impose limits on the amount of heap memory that will be
6437** by all database connections within a single process.
6438**
6439** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6440** soft limit on the amount of heap memory that may be allocated by SQLite.
6441** ^SQLite strives to keep heap memory utilization below the soft heap
6442** limit by reducing the number of pages held in the page cache
6443** as heap memory usages approaches the limit.
6444** ^The soft heap limit is "soft" because even though SQLite strives to stay
6445** below the limit, it will exceed the limit rather than generate
6446** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6447** is advisory only.
6448**
6449** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
6450** N bytes on the amount of memory that will be allocated. ^The
6451** sqlite3_hard_heap_limit64(N) interface is similar to
6452** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
6453** when the hard heap limit is reached.
6454**
6455** ^The return value from both sqlite3_soft_heap_limit64() and
6456** sqlite3_hard_heap_limit64() is the size of
6457** the heap limit prior to the call, or negative in the case of an
6458** error. ^If the argument N is negative
6459** then no change is made to the heap limit. Hence, the current
6460** size of heap limits can be determined by invoking
6461** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
6462**
6463** ^Setting the heap limits to zero disables the heap limiter mechanism.
6464**
6465** ^The soft heap limit may not be greater than the hard heap limit.
6466** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
6467** is invoked with a value of N that is greater than the hard heap limit,
6468** the the soft heap limit is set to the value of the hard heap limit.
6469** ^The soft heap limit is automatically enabled whenever the hard heap
6470** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
6471** the soft heap limit is outside the range of 1..N, then the soft heap
6472** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
6473** hard heap limit is enabled makes the soft heap limit equal to the
6474** hard heap limit.
6475**
6476** The memory allocation limits can also be adjusted using
6477** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
6478**
6479** ^(The heap limits are not enforced in the current implementation
6480** if one or more of following conditions are true:
6481**
6482** <ul>
6483** <li> The limit value is set to zero.
6484** <li> Memory accounting is disabled using a combination of the
6485** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6486** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6487** <li> An alternative page cache implementation is specified using
6488** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6489** <li> The page cache allocates from its own memory pool supplied
6490** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6491** from the heap.
6492** </ul>)^
6493**
6494** The circumstances under which SQLite will enforce the heap limits may
6495** changes in future releases of SQLite.
6496*/
6497SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6498SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
6499
6500/*
6501** CAPI3REF: Deprecated Soft Heap Limit Interface
6502** DEPRECATED
6503**
6504** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6505** interface. This routine is provided for historical compatibility
6506** only. All new applications should use the
6507** [sqlite3_soft_heap_limit64()] interface rather than this one.
6508*/
6509SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6510
6511
6512/*
6513** CAPI3REF: Extract Metadata About A Column Of A Table
6514** METHOD: sqlite3
6515**
6516** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6517** information about column C of table T in database D
6518** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6519** interface returns SQLITE_OK and fills in the non-NULL pointers in
6520** the final five arguments with appropriate values if the specified
6521** column exists. ^The sqlite3_table_column_metadata() interface returns
6522** SQLITE_ERROR if the specified column does not exist.
6523** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6524** NULL pointer, then this routine simply checks for the existence of the
6525** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6526** does not. If the table name parameter T in a call to
6527** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6528** undefined behavior.
6529**
6530** ^The column is identified by the second, third and fourth parameters to
6531** this function. ^(The second parameter is either the name of the database
6532** (i.e. "main", "temp", or an attached database) containing the specified
6533** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6534** for the table using the same algorithm used by the database engine to
6535** resolve unqualified table references.
6536**
6537** ^The third and fourth parameters to this function are the table and column
6538** name of the desired column, respectively.
6539**
6540** ^Metadata is returned by writing to the memory locations passed as the 5th
6541** and subsequent parameters to this function. ^Any of these arguments may be
6542** NULL, in which case the corresponding element of metadata is omitted.
6543**
6544** ^(<blockquote>
6545** <table border="1">
6546** <tr><th> Parameter <th> Output<br>Type <th> Description
6547**
6548** <tr><td> 5th <td> const char* <td> Data type
6549** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6550** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6551** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6552** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6553** </table>
6554** </blockquote>)^
6555**
6556** ^The memory pointed to by the character pointers returned for the
6557** declaration type and collation sequence is valid until the next
6558** call to any SQLite API function.
6559**
6560** ^If the specified table is actually a view, an [error code] is returned.
6561**
6562** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6563** is not a [WITHOUT ROWID] table and an
6564** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6565** parameters are set for the explicitly declared column. ^(If there is no
6566** [INTEGER PRIMARY KEY] column, then the outputs
6567** for the [rowid] are set as follows:
6568**
6569** <pre>
6570** data type: "INTEGER"
6571** collation sequence: "BINARY"
6572** not null: 0
6573** primary key: 1
6574** auto increment: 0
6575** </pre>)^
6576**
6577** ^This function causes all database schemas to be read from disk and
6578** parsed, if that has not already been done, and returns an error if
6579** any errors are encountered while loading the schema.
6580*/
6581SQLITE_API int sqlite3_table_column_metadata(
6582 sqlite3 *db, /* Connection handle */
6583 const char *zDbName, /* Database name or NULL */
6584 const char *zTableName, /* Table name */
6585 const char *zColumnName, /* Column name */
6586 char const **pzDataType, /* OUTPUT: Declared data type */
6587 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6588 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6589 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6590 int *pAutoinc /* OUTPUT: True if column is auto-increment */
6591);
6592
6593/*
6594** CAPI3REF: Load An Extension
6595** METHOD: sqlite3
6596**
6597** ^This interface loads an SQLite extension library from the named file.
6598**
6599** ^The sqlite3_load_extension() interface attempts to load an
6600** [SQLite extension] library contained in the file zFile. If
6601** the file cannot be loaded directly, attempts are made to load
6602** with various operating-system specific extensions added.
6603** So for example, if "samplelib" cannot be loaded, then names like
6604** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6605** be tried also.
6606**
6607** ^The entry point is zProc.
6608** ^(zProc may be 0, in which case SQLite will try to come up with an
6609** entry point name on its own. It first tries "sqlite3_extension_init".
6610** If that does not work, it constructs a name "sqlite3_X_init" where the
6611** X is consists of the lower-case equivalent of all ASCII alphabetic
6612** characters in the filename from the last "/" to the first following
6613** "." and omitting any initial "lib".)^
6614** ^The sqlite3_load_extension() interface returns
6615** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6616** ^If an error occurs and pzErrMsg is not 0, then the
6617** [sqlite3_load_extension()] interface shall attempt to
6618** fill *pzErrMsg with error message text stored in memory
6619** obtained from [sqlite3_malloc()]. The calling function
6620** should free this memory by calling [sqlite3_free()].
6621**
6622** ^Extension loading must be enabled using
6623** [sqlite3_enable_load_extension()] or
6624** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6625** prior to calling this API,
6626** otherwise an error will be returned.
6627**
6628** <b>Security warning:</b> It is recommended that the
6629** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6630** interface. The use of the [sqlite3_enable_load_extension()] interface
6631** should be avoided. This will keep the SQL function [load_extension()]
6632** disabled and prevent SQL injections from giving attackers
6633** access to extension loading capabilities.
6634**
6635** See also the [load_extension() SQL function].
6636*/
6637SQLITE_API int sqlite3_load_extension(
6638 sqlite3 *db, /* Load the extension into this database connection */
6639 const char *zFile, /* Name of the shared library containing extension */
6640 const char *zProc, /* Entry point. Derived from zFile if 0 */
6641 char **pzErrMsg /* Put error message here if not 0 */
6642);
6643
6644/*
6645** CAPI3REF: Enable Or Disable Extension Loading
6646** METHOD: sqlite3
6647**
6648** ^So as not to open security holes in older applications that are
6649** unprepared to deal with [extension loading], and as a means of disabling
6650** [extension loading] while evaluating user-entered SQL, the following API
6651** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6652**
6653** ^Extension loading is off by default.
6654** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6655** to turn extension loading on and call it with onoff==0 to turn
6656** it back off again.
6657**
6658** ^This interface enables or disables both the C-API
6659** [sqlite3_load_extension()] and the SQL function [load_extension()].
6660** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6661** to enable or disable only the C-API.)^
6662**
6663** <b>Security warning:</b> It is recommended that extension loading
6664** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
6665** rather than this interface, so the [load_extension()] SQL function
6666** remains disabled. This will prevent SQL injections from giving attackers
6667** access to extension loading capabilities.
6668*/
6669SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6670
6671/*
6672** CAPI3REF: Automatically Load Statically Linked Extensions
6673**
6674** ^This interface causes the xEntryPoint() function to be invoked for
6675** each new [database connection] that is created. The idea here is that
6676** xEntryPoint() is the entry point for a statically linked [SQLite extension]
6677** that is to be automatically loaded into all new database connections.
6678**
6679** ^(Even though the function prototype shows that xEntryPoint() takes
6680** no arguments and returns void, SQLite invokes xEntryPoint() with three
6681** arguments and expects an integer result as if the signature of the
6682** entry point where as follows:
6683**
6684** <blockquote><pre>
6685** &nbsp; int xEntryPoint(
6686** &nbsp; sqlite3 *db,
6687** &nbsp; const char **pzErrMsg,
6688** &nbsp; const struct sqlite3_api_routines *pThunk
6689** &nbsp; );
6690** </pre></blockquote>)^
6691**
6692** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6693** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6694** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6695** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6696** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6697** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6698** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6699**
6700** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6701** on the list of automatic extensions is a harmless no-op. ^No entry point
6702** will be called more than once for each database connection that is opened.
6703**
6704** See also: [sqlite3_reset_auto_extension()]
6705** and [sqlite3_cancel_auto_extension()]
6706*/
6707SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6708
6709/*
6710** CAPI3REF: Cancel Automatic Extension Loading
6711**
6712** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6713** initialization routine X that was registered using a prior call to
6714** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6715** routine returns 1 if initialization routine X was successfully
6716** unregistered and it returns 0 if X was not on the list of initialization
6717** routines.
6718*/
6719SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6720
6721/*
6722** CAPI3REF: Reset Automatic Extension Loading
6723**
6724** ^This interface disables all automatic extensions previously
6725** registered using [sqlite3_auto_extension()].
6726*/
6727SQLITE_API void sqlite3_reset_auto_extension(void);
6728
6729/*
6730** The interface to the virtual-table mechanism is currently considered
6731** to be experimental. The interface might change in incompatible ways.
6732** If this is a problem for you, do not use the interface at this time.
6733**
6734** When the virtual-table mechanism stabilizes, we will declare the
6735** interface fixed, support it indefinitely, and remove this comment.
6736*/
6737
6738/*
6739** Structures used by the virtual table interface
6740*/
6741typedef struct sqlite3_vtab sqlite3_vtab;
6742typedef struct sqlite3_index_info sqlite3_index_info;
6743typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6744typedef struct sqlite3_module sqlite3_module;
6745
6746/*
6747** CAPI3REF: Virtual Table Object
6748** KEYWORDS: sqlite3_module {virtual table module}
6749**
6750** This structure, sometimes called a "virtual table module",
6751** defines the implementation of a [virtual table].
6752** This structure consists mostly of methods for the module.
6753**
6754** ^A virtual table module is created by filling in a persistent
6755** instance of this structure and passing a pointer to that instance
6756** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6757** ^The registration remains valid until it is replaced by a different
6758** module or until the [database connection] closes. The content
6759** of this structure must not change while it is registered with
6760** any database connection.
6761*/
6762struct sqlite3_module {
6763 int iVersion;
6764 int (*xCreate)(sqlite3*, void *pAux,
6765 int argc, const char *const*argv,
6766 sqlite3_vtab **ppVTab, char**);
6767 int (*xConnect)(sqlite3*, void *pAux,
6768 int argc, const char *const*argv,
6769 sqlite3_vtab **ppVTab, char**);
6770 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6771 int (*xDisconnect)(sqlite3_vtab *pVTab);
6772 int (*xDestroy)(sqlite3_vtab *pVTab);
6773 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6774 int (*xClose)(sqlite3_vtab_cursor*);
6775 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6776 int argc, sqlite3_value **argv);
6777 int (*xNext)(sqlite3_vtab_cursor*);
6778 int (*xEof)(sqlite3_vtab_cursor*);
6779 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6780 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
6781 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
6782 int (*xBegin)(sqlite3_vtab *pVTab);
6783 int (*xSync)(sqlite3_vtab *pVTab);
6784 int (*xCommit)(sqlite3_vtab *pVTab);
6785 int (*xRollback)(sqlite3_vtab *pVTab);
6786 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
6787 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
6788 void **ppArg);
6789 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
6790 /* The methods above are in version 1 of the sqlite_module object. Those
6791 ** below are for version 2 and greater. */
6792 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
6793 int (*xRelease)(sqlite3_vtab *pVTab, int);
6794 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
6795 /* The methods above are in versions 1 and 2 of the sqlite_module object.
6796 ** Those below are for version 3 and greater. */
6797 int (*xShadowName)(const char*);
6798};
6799
6800/*
6801** CAPI3REF: Virtual Table Indexing Information
6802** KEYWORDS: sqlite3_index_info
6803**
6804** The sqlite3_index_info structure and its substructures is used as part
6805** of the [virtual table] interface to
6806** pass information into and receive the reply from the [xBestIndex]
6807** method of a [virtual table module]. The fields under **Inputs** are the
6808** inputs to xBestIndex and are read-only. xBestIndex inserts its
6809** results into the **Outputs** fields.
6810**
6811** ^(The aConstraint[] array records WHERE clause constraints of the form:
6812**
6813** <blockquote>column OP expr</blockquote>
6814**
6815** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
6816** stored in aConstraint[].op using one of the
6817** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
6818** ^(The index of the column is stored in
6819** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
6820** expr on the right-hand side can be evaluated (and thus the constraint
6821** is usable) and false if it cannot.)^
6822**
6823** ^The optimizer automatically inverts terms of the form "expr OP column"
6824** and makes other simplifications to the WHERE clause in an attempt to
6825** get as many WHERE clause terms into the form shown above as possible.
6826** ^The aConstraint[] array only reports WHERE clause terms that are
6827** relevant to the particular virtual table being queried.
6828**
6829** ^Information about the ORDER BY clause is stored in aOrderBy[].
6830** ^Each term of aOrderBy records a column of the ORDER BY clause.
6831**
6832** The colUsed field indicates which columns of the virtual table may be
6833** required by the current scan. Virtual table columns are numbered from
6834** zero in the order in which they appear within the CREATE TABLE statement
6835** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
6836** the corresponding bit is set within the colUsed mask if the column may be
6837** required by SQLite. If the table has at least 64 columns and any column
6838** to the right of the first 63 is required, then bit 63 of colUsed is also
6839** set. In other words, column iCol may be required if the expression
6840** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
6841** non-zero.
6842**
6843** The [xBestIndex] method must fill aConstraintUsage[] with information
6844** about what parameters to pass to xFilter. ^If argvIndex>0 then
6845** the right-hand side of the corresponding aConstraint[] is evaluated
6846** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
6847** is true, then the constraint is assumed to be fully handled by the
6848** virtual table and might not be checked again by the byte code.)^ ^(The
6849** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
6850** is left in its default setting of false, the constraint will always be
6851** checked separately in byte code. If the omit flag is change to true, then
6852** the constraint may or may not be checked in byte code. In other words,
6853** when the omit flag is true there is no guarantee that the constraint will
6854** not be checked again using byte code.)^
6855**
6856** ^The idxNum and idxPtr values are recorded and passed into the
6857** [xFilter] method.
6858** ^[sqlite3_free()] is used to free idxPtr if and only if
6859** needToFreeIdxPtr is true.
6860**
6861** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
6862** the correct order to satisfy the ORDER BY clause so that no separate
6863** sorting step is required.
6864**
6865** ^The estimatedCost value is an estimate of the cost of a particular
6866** strategy. A cost of N indicates that the cost of the strategy is similar
6867** to a linear scan of an SQLite table with N rows. A cost of log(N)
6868** indicates that the expense of the operation is similar to that of a
6869** binary search on a unique indexed field of an SQLite table with N rows.
6870**
6871** ^The estimatedRows value is an estimate of the number of rows that
6872** will be returned by the strategy.
6873**
6874** The xBestIndex method may optionally populate the idxFlags field with a
6875** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
6876** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
6877** assumes that the strategy may visit at most one row.
6878**
6879** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
6880** SQLite also assumes that if a call to the xUpdate() method is made as
6881** part of the same statement to delete or update a virtual table row and the
6882** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
6883** any database changes. In other words, if the xUpdate() returns
6884** SQLITE_CONSTRAINT, the database contents must be exactly as they were
6885** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
6886** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
6887** the xUpdate method are automatically rolled back by SQLite.
6888**
6889** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
6890** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
6891** If a virtual table extension is
6892** used with an SQLite version earlier than 3.8.2, the results of attempting
6893** to read or write the estimatedRows field are undefined (but are likely
6894** to include crashing the application). The estimatedRows field should
6895** therefore only be used if [sqlite3_libversion_number()] returns a
6896** value greater than or equal to 3008002. Similarly, the idxFlags field
6897** was added for [version 3.9.0] ([dateof:3.9.0]).
6898** It may therefore only be used if
6899** sqlite3_libversion_number() returns a value greater than or equal to
6900** 3009000.
6901*/
6902struct sqlite3_index_info {
6903 /* Inputs */
6904 int nConstraint; /* Number of entries in aConstraint */
6905 struct sqlite3_index_constraint {
6906 int iColumn; /* Column constrained. -1 for ROWID */
6907 unsigned char op; /* Constraint operator */
6908 unsigned char usable; /* True if this constraint is usable */
6909 int iTermOffset; /* Used internally - xBestIndex should ignore */
6910 } *aConstraint; /* Table of WHERE clause constraints */
6911 int nOrderBy; /* Number of terms in the ORDER BY clause */
6912 struct sqlite3_index_orderby {
6913 int iColumn; /* Column number */
6914 unsigned char desc; /* True for DESC. False for ASC. */
6915 } *aOrderBy; /* The ORDER BY clause */
6916 /* Outputs */
6917 struct sqlite3_index_constraint_usage {
6918 int argvIndex; /* if >0, constraint is part of argv to xFilter */
6919 unsigned char omit; /* Do not code a test for this constraint */
6920 } *aConstraintUsage;
6921 int idxNum; /* Number used to identify the index */
6922 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
6923 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
6924 int orderByConsumed; /* True if output is already ordered */
6925 double estimatedCost; /* Estimated cost of using this index */
6926 /* Fields below are only available in SQLite 3.8.2 and later */
6927 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
6928 /* Fields below are only available in SQLite 3.9.0 and later */
6929 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
6930 /* Fields below are only available in SQLite 3.10.0 and later */
6931 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
6932};
6933
6934/*
6935** CAPI3REF: Virtual Table Scan Flags
6936**
6937** Virtual table implementations are allowed to set the
6938** [sqlite3_index_info].idxFlags field to some combination of
6939** these bits.
6940*/
6941#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
6942
6943/*
6944** CAPI3REF: Virtual Table Constraint Operator Codes
6945**
6946** These macros define the allowed values for the
6947** [sqlite3_index_info].aConstraint[].op field. Each value represents
6948** an operator that is part of a constraint term in the wHERE clause of
6949** a query that uses a [virtual table].
6950*/
6951#define SQLITE_INDEX_CONSTRAINT_EQ 2
6952#define SQLITE_INDEX_CONSTRAINT_GT 4
6953#define SQLITE_INDEX_CONSTRAINT_LE 8
6954#define SQLITE_INDEX_CONSTRAINT_LT 16
6955#define SQLITE_INDEX_CONSTRAINT_GE 32
6956#define SQLITE_INDEX_CONSTRAINT_MATCH 64
6957#define SQLITE_INDEX_CONSTRAINT_LIKE 65
6958#define SQLITE_INDEX_CONSTRAINT_GLOB 66
6959#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
6960#define SQLITE_INDEX_CONSTRAINT_NE 68
6961#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
6962#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
6963#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
6964#define SQLITE_INDEX_CONSTRAINT_IS 72
6965#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
6966
6967/*
6968** CAPI3REF: Register A Virtual Table Implementation
6969** METHOD: sqlite3
6970**
6971** ^These routines are used to register a new [virtual table module] name.
6972** ^Module names must be registered before
6973** creating a new [virtual table] using the module and before using a
6974** preexisting [virtual table] for the module.
6975**
6976** ^The module name is registered on the [database connection] specified
6977** by the first parameter. ^The name of the module is given by the
6978** second parameter. ^The third parameter is a pointer to
6979** the implementation of the [virtual table module]. ^The fourth
6980** parameter is an arbitrary client data pointer that is passed through
6981** into the [xCreate] and [xConnect] methods of the virtual table module
6982** when a new virtual table is be being created or reinitialized.
6983**
6984** ^The sqlite3_create_module_v2() interface has a fifth parameter which
6985** is a pointer to a destructor for the pClientData. ^SQLite will
6986** invoke the destructor function (if it is not NULL) when SQLite
6987** no longer needs the pClientData pointer. ^The destructor will also
6988** be invoked if the call to sqlite3_create_module_v2() fails.
6989** ^The sqlite3_create_module()
6990** interface is equivalent to sqlite3_create_module_v2() with a NULL
6991** destructor.
6992**
6993** ^If the third parameter (the pointer to the sqlite3_module object) is
6994** NULL then no new module is create and any existing modules with the
6995** same name are dropped.
6996**
6997** See also: [sqlite3_drop_modules()]
6998*/
6999SQLITE_API int sqlite3_create_module(
7000 sqlite3 *db, /* SQLite connection to register module with */
7001 const char *zName, /* Name of the module */
7002 const sqlite3_module *p, /* Methods for the module */
7003 void *pClientData /* Client data for xCreate/xConnect */
7004);
7005SQLITE_API int sqlite3_create_module_v2(
7006 sqlite3 *db, /* SQLite connection to register module with */
7007 const char *zName, /* Name of the module */
7008 const sqlite3_module *p, /* Methods for the module */
7009 void *pClientData, /* Client data for xCreate/xConnect */
7010 void(*xDestroy)(void*) /* Module destructor function */
7011);
7012
7013/*
7014** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7015** METHOD: sqlite3
7016**
7017** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7018** table modules from database connection D except those named on list L.
7019** The L parameter must be either NULL or a pointer to an array of pointers
7020** to strings where the array is terminated by a single NULL pointer.
7021** ^If the L parameter is NULL, then all virtual table modules are removed.
7022**
7023** See also: [sqlite3_create_module()]
7024*/
7025SQLITE_API int sqlite3_drop_modules(
7026 sqlite3 *db, /* Remove modules from this connection */
7027 const char **azKeep /* Except, do not remove the ones named here */
7028);
7029
7030/*
7031** CAPI3REF: Virtual Table Instance Object
7032** KEYWORDS: sqlite3_vtab
7033**
7034** Every [virtual table module] implementation uses a subclass
7035** of this object to describe a particular instance
7036** of the [virtual table]. Each subclass will
7037** be tailored to the specific needs of the module implementation.
7038** The purpose of this superclass is to define certain fields that are
7039** common to all module implementations.
7040**
7041** ^Virtual tables methods can set an error message by assigning a
7042** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7043** take care that any prior string is freed by a call to [sqlite3_free()]
7044** prior to assigning a new string to zErrMsg. ^After the error message
7045** is delivered up to the client application, the string will be automatically
7046** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7047*/
7048struct sqlite3_vtab {
7049 const sqlite3_module *pModule; /* The module for this virtual table */
7050 int nRef; /* Number of open cursors */
7051 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7052 /* Virtual table implementations will typically add additional fields */
7053};
7054
7055/*
7056** CAPI3REF: Virtual Table Cursor Object
7057** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7058**
7059** Every [virtual table module] implementation uses a subclass of the
7060** following structure to describe cursors that point into the
7061** [virtual table] and are used
7062** to loop through the virtual table. Cursors are created using the
7063** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7064** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7065** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7066** of the module. Each module implementation will define
7067** the content of a cursor structure to suit its own needs.
7068**
7069** This superclass exists in order to define fields of the cursor that
7070** are common to all implementations.
7071*/
7072struct sqlite3_vtab_cursor {
7073 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7074 /* Virtual table implementations will typically add additional fields */
7075};
7076
7077/*
7078** CAPI3REF: Declare The Schema Of A Virtual Table
7079**
7080** ^The [xCreate] and [xConnect] methods of a
7081** [virtual table module] call this interface
7082** to declare the format (the names and datatypes of the columns) of
7083** the virtual tables they implement.
7084*/
7085SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7086
7087/*
7088** CAPI3REF: Overload A Function For A Virtual Table
7089** METHOD: sqlite3
7090**
7091** ^(Virtual tables can provide alternative implementations of functions
7092** using the [xFindFunction] method of the [virtual table module].
7093** But global versions of those functions
7094** must exist in order to be overloaded.)^
7095**
7096** ^(This API makes sure a global version of a function with a particular
7097** name and number of parameters exists. If no such function exists
7098** before this API is called, a new function is created.)^ ^The implementation
7099** of the new function always causes an exception to be thrown. So
7100** the new function is not good for anything by itself. Its only
7101** purpose is to be a placeholder function that can be overloaded
7102** by a [virtual table].
7103*/
7104SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7105
7106/*
7107** The interface to the virtual-table mechanism defined above (back up
7108** to a comment remarkably similar to this one) is currently considered
7109** to be experimental. The interface might change in incompatible ways.
7110** If this is a problem for you, do not use the interface at this time.
7111**
7112** When the virtual-table mechanism stabilizes, we will declare the
7113** interface fixed, support it indefinitely, and remove this comment.
7114*/
7115
7116/*
7117** CAPI3REF: A Handle To An Open BLOB
7118** KEYWORDS: {BLOB handle} {BLOB handles}
7119**
7120** An instance of this object represents an open BLOB on which
7121** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7122** ^Objects of this type are created by [sqlite3_blob_open()]
7123** and destroyed by [sqlite3_blob_close()].
7124** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7125** can be used to read or write small subsections of the BLOB.
7126** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7127*/
7128typedef struct sqlite3_blob sqlite3_blob;
7129
7130/*
7131** CAPI3REF: Open A BLOB For Incremental I/O
7132** METHOD: sqlite3
7133** CONSTRUCTOR: sqlite3_blob
7134**
7135** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7136** in row iRow, column zColumn, table zTable in database zDb;
7137** in other words, the same BLOB that would be selected by:
7138**
7139** <pre>
7140** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7141** </pre>)^
7142**
7143** ^(Parameter zDb is not the filename that contains the database, but
7144** rather the symbolic name of the database. For attached databases, this is
7145** the name that appears after the AS keyword in the [ATTACH] statement.
7146** For the main database file, the database name is "main". For TEMP
7147** tables, the database name is "temp".)^
7148**
7149** ^If the flags parameter is non-zero, then the BLOB is opened for read
7150** and write access. ^If the flags parameter is zero, the BLOB is opened for
7151** read-only access.
7152**
7153** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7154** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7155** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7156** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7157** on *ppBlob after this function it returns.
7158**
7159** This function fails with SQLITE_ERROR if any of the following are true:
7160** <ul>
7161** <li> ^(Database zDb does not exist)^,
7162** <li> ^(Table zTable does not exist within database zDb)^,
7163** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7164** <li> ^(Column zColumn does not exist)^,
7165** <li> ^(Row iRow is not present in the table)^,
7166** <li> ^(The specified column of row iRow contains a value that is not
7167** a TEXT or BLOB value)^,
7168** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7169** constraint and the blob is being opened for read/write access)^,
7170** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7171** column zColumn is part of a [child key] definition and the blob is
7172** being opened for read/write access)^.
7173** </ul>
7174**
7175** ^Unless it returns SQLITE_MISUSE, this function sets the
7176** [database connection] error code and message accessible via
7177** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7178**
7179** A BLOB referenced by sqlite3_blob_open() may be read using the
7180** [sqlite3_blob_read()] interface and modified by using
7181** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7182** different row of the same table using the [sqlite3_blob_reopen()]
7183** interface. However, the column, table, or database of a [BLOB handle]
7184** cannot be changed after the [BLOB handle] is opened.
7185**
7186** ^(If the row that a BLOB handle points to is modified by an
7187** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7188** then the BLOB handle is marked as "expired".
7189** This is true if any column of the row is changed, even a column
7190** other than the one the BLOB handle is open on.)^
7191** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7192** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7193** ^(Changes written into a BLOB prior to the BLOB expiring are not
7194** rolled back by the expiration of the BLOB. Such changes will eventually
7195** commit if the transaction continues to completion.)^
7196**
7197** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7198** the opened blob. ^The size of a blob may not be changed by this
7199** interface. Use the [UPDATE] SQL command to change the size of a
7200** blob.
7201**
7202** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7203** and the built-in [zeroblob] SQL function may be used to create a
7204** zero-filled blob to read or write using the incremental-blob interface.
7205**
7206** To avoid a resource leak, every open [BLOB handle] should eventually
7207** be released by a call to [sqlite3_blob_close()].
7208**
7209** See also: [sqlite3_blob_close()],
7210** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7211** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7212*/
7213SQLITE_API int sqlite3_blob_open(
7214 sqlite3*,
7215 const char *zDb,
7216 const char *zTable,
7217 const char *zColumn,
7218 sqlite3_int64 iRow,
7219 int flags,
7220 sqlite3_blob **ppBlob
7221);
7222
7223/*
7224** CAPI3REF: Move a BLOB Handle to a New Row
7225** METHOD: sqlite3_blob
7226**
7227** ^This function is used to move an existing [BLOB handle] so that it points
7228** to a different row of the same database table. ^The new row is identified
7229** by the rowid value passed as the second argument. Only the row can be
7230** changed. ^The database, table and column on which the blob handle is open
7231** remain the same. Moving an existing [BLOB handle] to a new row is
7232** faster than closing the existing handle and opening a new one.
7233**
7234** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7235** it must exist and there must be either a blob or text value stored in
7236** the nominated column.)^ ^If the new row is not present in the table, or if
7237** it does not contain a blob or text value, or if another error occurs, an
7238** SQLite error code is returned and the blob handle is considered aborted.
7239** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7240** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7241** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7242** always returns zero.
7243**
7244** ^This function sets the database handle error code and message.
7245*/
7246SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7247
7248/*
7249** CAPI3REF: Close A BLOB Handle
7250** DESTRUCTOR: sqlite3_blob
7251**
7252** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7253** unconditionally. Even if this routine returns an error code, the
7254** handle is still closed.)^
7255**
7256** ^If the blob handle being closed was opened for read-write access, and if
7257** the database is in auto-commit mode and there are no other open read-write
7258** blob handles or active write statements, the current transaction is
7259** committed. ^If an error occurs while committing the transaction, an error
7260** code is returned and the transaction rolled back.
7261**
7262** Calling this function with an argument that is not a NULL pointer or an
7263** open blob handle results in undefined behaviour. ^Calling this routine
7264** with a null pointer (such as would be returned by a failed call to
7265** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7266** is passed a valid open blob handle, the values returned by the
7267** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7268*/
7269SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7270
7271/*
7272** CAPI3REF: Return The Size Of An Open BLOB
7273** METHOD: sqlite3_blob
7274**
7275** ^Returns the size in bytes of the BLOB accessible via the
7276** successfully opened [BLOB handle] in its only argument. ^The
7277** incremental blob I/O routines can only read or overwriting existing
7278** blob content; they cannot change the size of a blob.
7279**
7280** This routine only works on a [BLOB handle] which has been created
7281** by a prior successful call to [sqlite3_blob_open()] and which has not
7282** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7283** to this routine results in undefined and probably undesirable behavior.
7284*/
7285SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7286
7287/*
7288** CAPI3REF: Read Data From A BLOB Incrementally
7289** METHOD: sqlite3_blob
7290**
7291** ^(This function is used to read data from an open [BLOB handle] into a
7292** caller-supplied buffer. N bytes of data are copied into buffer Z
7293** from the open BLOB, starting at offset iOffset.)^
7294**
7295** ^If offset iOffset is less than N bytes from the end of the BLOB,
7296** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7297** less than zero, [SQLITE_ERROR] is returned and no data is read.
7298** ^The size of the blob (and hence the maximum value of N+iOffset)
7299** can be determined using the [sqlite3_blob_bytes()] interface.
7300**
7301** ^An attempt to read from an expired [BLOB handle] fails with an
7302** error code of [SQLITE_ABORT].
7303**
7304** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7305** Otherwise, an [error code] or an [extended error code] is returned.)^
7306**
7307** This routine only works on a [BLOB handle] which has been created
7308** by a prior successful call to [sqlite3_blob_open()] and which has not
7309** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7310** to this routine results in undefined and probably undesirable behavior.
7311**
7312** See also: [sqlite3_blob_write()].
7313*/
7314SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7315
7316/*
7317** CAPI3REF: Write Data Into A BLOB Incrementally
7318** METHOD: sqlite3_blob
7319**
7320** ^(This function is used to write data into an open [BLOB handle] from a
7321** caller-supplied buffer. N bytes of data are copied from the buffer Z
7322** into the open BLOB, starting at offset iOffset.)^
7323**
7324** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7325** Otherwise, an [error code] or an [extended error code] is returned.)^
7326** ^Unless SQLITE_MISUSE is returned, this function sets the
7327** [database connection] error code and message accessible via
7328** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7329**
7330** ^If the [BLOB handle] passed as the first argument was not opened for
7331** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7332** this function returns [SQLITE_READONLY].
7333**
7334** This function may only modify the contents of the BLOB; it is
7335** not possible to increase the size of a BLOB using this API.
7336** ^If offset iOffset is less than N bytes from the end of the BLOB,
7337** [SQLITE_ERROR] is returned and no data is written. The size of the
7338** BLOB (and hence the maximum value of N+iOffset) can be determined
7339** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7340** than zero [SQLITE_ERROR] is returned and no data is written.
7341**
7342** ^An attempt to write to an expired [BLOB handle] fails with an
7343** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7344** before the [BLOB handle] expired are not rolled back by the
7345** expiration of the handle, though of course those changes might
7346** have been overwritten by the statement that expired the BLOB handle
7347** or by other independent statements.
7348**
7349** This routine only works on a [BLOB handle] which has been created
7350** by a prior successful call to [sqlite3_blob_open()] and which has not
7351** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7352** to this routine results in undefined and probably undesirable behavior.
7353**
7354** See also: [sqlite3_blob_read()].
7355*/
7356SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7357
7358/*
7359** CAPI3REF: Virtual File System Objects
7360**
7361** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7362** that SQLite uses to interact
7363** with the underlying operating system. Most SQLite builds come with a
7364** single default VFS that is appropriate for the host computer.
7365** New VFSes can be registered and existing VFSes can be unregistered.
7366** The following interfaces are provided.
7367**
7368** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7369** ^Names are case sensitive.
7370** ^Names are zero-terminated UTF-8 strings.
7371** ^If there is no match, a NULL pointer is returned.
7372** ^If zVfsName is NULL then the default VFS is returned.
7373**
7374** ^New VFSes are registered with sqlite3_vfs_register().
7375** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7376** ^The same VFS can be registered multiple times without injury.
7377** ^To make an existing VFS into the default VFS, register it again
7378** with the makeDflt flag set. If two different VFSes with the
7379** same name are registered, the behavior is undefined. If a
7380** VFS is registered with a name that is NULL or an empty string,
7381** then the behavior is undefined.
7382**
7383** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7384** ^(If the default VFS is unregistered, another VFS is chosen as
7385** the default. The choice for the new VFS is arbitrary.)^
7386*/
7387SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7388SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7389SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7390
7391/*
7392** CAPI3REF: Mutexes
7393**
7394** The SQLite core uses these routines for thread
7395** synchronization. Though they are intended for internal
7396** use by SQLite, code that links against SQLite is
7397** permitted to use any of these routines.
7398**
7399** The SQLite source code contains multiple implementations
7400** of these mutex routines. An appropriate implementation
7401** is selected automatically at compile-time. The following
7402** implementations are available in the SQLite core:
7403**
7404** <ul>
7405** <li> SQLITE_MUTEX_PTHREADS
7406** <li> SQLITE_MUTEX_W32
7407** <li> SQLITE_MUTEX_NOOP
7408** </ul>
7409**
7410** The SQLITE_MUTEX_NOOP implementation is a set of routines
7411** that does no real locking and is appropriate for use in
7412** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7413** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7414** and Windows.
7415**
7416** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7417** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7418** implementation is included with the library. In this case the
7419** application must supply a custom mutex implementation using the
7420** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7421** before calling sqlite3_initialize() or any other public sqlite3_
7422** function that calls sqlite3_initialize().
7423**
7424** ^The sqlite3_mutex_alloc() routine allocates a new
7425** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
7426** routine returns NULL if it is unable to allocate the requested
7427** mutex. The argument to sqlite3_mutex_alloc() must one of these
7428** integer constants:
7429**
7430** <ul>
7431** <li> SQLITE_MUTEX_FAST
7432** <li> SQLITE_MUTEX_RECURSIVE
7433** <li> SQLITE_MUTEX_STATIC_MAIN
7434** <li> SQLITE_MUTEX_STATIC_MEM
7435** <li> SQLITE_MUTEX_STATIC_OPEN
7436** <li> SQLITE_MUTEX_STATIC_PRNG
7437** <li> SQLITE_MUTEX_STATIC_LRU
7438** <li> SQLITE_MUTEX_STATIC_PMEM
7439** <li> SQLITE_MUTEX_STATIC_APP1
7440** <li> SQLITE_MUTEX_STATIC_APP2
7441** <li> SQLITE_MUTEX_STATIC_APP3
7442** <li> SQLITE_MUTEX_STATIC_VFS1
7443** <li> SQLITE_MUTEX_STATIC_VFS2
7444** <li> SQLITE_MUTEX_STATIC_VFS3
7445** </ul>
7446**
7447** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
7448** cause sqlite3_mutex_alloc() to create
7449** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
7450** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
7451** The mutex implementation does not need to make a distinction
7452** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
7453** not want to. SQLite will only request a recursive mutex in
7454** cases where it really needs one. If a faster non-recursive mutex
7455** implementation is available on the host platform, the mutex subsystem
7456** might return such a mutex in response to SQLITE_MUTEX_FAST.
7457**
7458** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
7459** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
7460** a pointer to a static preexisting mutex. ^Nine static mutexes are
7461** used by the current version of SQLite. Future versions of SQLite
7462** may add additional static mutexes. Static mutexes are for internal
7463** use by SQLite only. Applications that use SQLite mutexes should
7464** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
7465** SQLITE_MUTEX_RECURSIVE.
7466**
7467** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
7468** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
7469** returns a different mutex on every call. ^For the static
7470** mutex types, the same mutex is returned on every call that has
7471** the same type number.
7472**
7473** ^The sqlite3_mutex_free() routine deallocates a previously
7474** allocated dynamic mutex. Attempting to deallocate a static
7475** mutex results in undefined behavior.
7476**
7477** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7478** to enter a mutex. ^If another thread is already within the mutex,
7479** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7480** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7481** upon successful entry. ^(Mutexes created using
7482** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
7483** In such cases, the
7484** mutex must be exited an equal number of times before another thread
7485** can enter.)^ If the same thread tries to enter any mutex other
7486** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
7487**
7488** ^(Some systems (for example, Windows 95) do not support the operation
7489** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
7490** will always return SQLITE_BUSY. The SQLite core only ever uses
7491** sqlite3_mutex_try() as an optimization so this is acceptable
7492** behavior.)^
7493**
7494** ^The sqlite3_mutex_leave() routine exits a mutex that was
7495** previously entered by the same thread. The behavior
7496** is undefined if the mutex is not currently entered by the
7497** calling thread or is not currently allocated.
7498**
7499** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
7500** sqlite3_mutex_leave() is a NULL pointer, then all three routines
7501** behave as no-ops.
7502**
7503** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7504*/
7505SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7506SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7507SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7508SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7509SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7510
7511/*
7512** CAPI3REF: Mutex Methods Object
7513**
7514** An instance of this structure defines the low-level routines
7515** used to allocate and use mutexes.
7516**
7517** Usually, the default mutex implementations provided by SQLite are
7518** sufficient, however the application has the option of substituting a custom
7519** implementation for specialized deployments or systems for which SQLite
7520** does not provide a suitable implementation. In this case, the application
7521** creates and populates an instance of this structure to pass
7522** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7523** Additionally, an instance of this structure can be used as an
7524** output variable when querying the system for the current mutex
7525** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7526**
7527** ^The xMutexInit method defined by this structure is invoked as
7528** part of system initialization by the sqlite3_initialize() function.
7529** ^The xMutexInit routine is called by SQLite exactly once for each
7530** effective call to [sqlite3_initialize()].
7531**
7532** ^The xMutexEnd method defined by this structure is invoked as
7533** part of system shutdown by the sqlite3_shutdown() function. The
7534** implementation of this method is expected to release all outstanding
7535** resources obtained by the mutex methods implementation, especially
7536** those obtained by the xMutexInit method. ^The xMutexEnd()
7537** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7538**
7539** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7540** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7541** xMutexNotheld) implement the following interfaces (respectively):
7542**
7543** <ul>
7544** <li> [sqlite3_mutex_alloc()] </li>
7545** <li> [sqlite3_mutex_free()] </li>
7546** <li> [sqlite3_mutex_enter()] </li>
7547** <li> [sqlite3_mutex_try()] </li>
7548** <li> [sqlite3_mutex_leave()] </li>
7549** <li> [sqlite3_mutex_held()] </li>
7550** <li> [sqlite3_mutex_notheld()] </li>
7551** </ul>)^
7552**
7553** The only difference is that the public sqlite3_XXX functions enumerated
7554** above silently ignore any invocations that pass a NULL pointer instead
7555** of a valid mutex handle. The implementations of the methods defined
7556** by this structure are not required to handle this case. The results
7557** of passing a NULL pointer instead of a valid mutex handle are undefined
7558** (i.e. it is acceptable to provide an implementation that segfaults if
7559** it is passed a NULL pointer).
7560**
7561** The xMutexInit() method must be threadsafe. It must be harmless to
7562** invoke xMutexInit() multiple times within the same process and without
7563** intervening calls to xMutexEnd(). Second and subsequent calls to
7564** xMutexInit() must be no-ops.
7565**
7566** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7567** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
7568** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7569** memory allocation for a fast or recursive mutex.
7570**
7571** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7572** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7573** If xMutexInit fails in any way, it is expected to clean up after itself
7574** prior to returning.
7575*/
7576typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7577struct sqlite3_mutex_methods {
7578 int (*xMutexInit)(void);
7579 int (*xMutexEnd)(void);
7580 sqlite3_mutex *(*xMutexAlloc)(int);
7581 void (*xMutexFree)(sqlite3_mutex *);
7582 void (*xMutexEnter)(sqlite3_mutex *);
7583 int (*xMutexTry)(sqlite3_mutex *);
7584 void (*xMutexLeave)(sqlite3_mutex *);
7585 int (*xMutexHeld)(sqlite3_mutex *);
7586 int (*xMutexNotheld)(sqlite3_mutex *);
7587};
7588
7589/*
7590** CAPI3REF: Mutex Verification Routines
7591**
7592** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
7593** are intended for use inside assert() statements. The SQLite core
7594** never uses these routines except inside an assert() and applications
7595** are advised to follow the lead of the core. The SQLite core only
7596** provides implementations for these routines when it is compiled
7597** with the SQLITE_DEBUG flag. External mutex implementations
7598** are only required to provide these routines if SQLITE_DEBUG is
7599** defined and if NDEBUG is not defined.
7600**
7601** These routines should return true if the mutex in their argument
7602** is held or not held, respectively, by the calling thread.
7603**
7604** The implementation is not required to provide versions of these
7605** routines that actually work. If the implementation does not provide working
7606** versions of these routines, it should at least provide stubs that always
7607** return true so that one does not get spurious assertion failures.
7608**
7609** If the argument to sqlite3_mutex_held() is a NULL pointer then
7610** the routine should return 1. This seems counter-intuitive since
7611** clearly the mutex cannot be held if it does not exist. But
7612** the reason the mutex does not exist is because the build is not
7613** using mutexes. And we do not want the assert() containing the
7614** call to sqlite3_mutex_held() to fail, so a non-zero return is
7615** the appropriate thing to do. The sqlite3_mutex_notheld()
7616** interface should also return 1 when given a NULL pointer.
7617*/
7618#ifndef NDEBUG
7619SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7620SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7621#endif
7622
7623/*
7624** CAPI3REF: Mutex Types
7625**
7626** The [sqlite3_mutex_alloc()] interface takes a single argument
7627** which is one of these integer constants.
7628**
7629** The set of static mutexes may change from one SQLite release to the
7630** next. Applications that override the built-in mutex logic must be
7631** prepared to accommodate additional static mutexes.
7632*/
7633#define SQLITE_MUTEX_FAST 0
7634#define SQLITE_MUTEX_RECURSIVE 1
7635#define SQLITE_MUTEX_STATIC_MAIN 2
7636#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7637#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7638#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
7639#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
7640#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7641#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7642#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
7643#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7644#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7645#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7646#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7647#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7648#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
7649
7650/* Legacy compatibility: */
7651#define SQLITE_MUTEX_STATIC_MASTER 2
7652
7653
7654/*
7655** CAPI3REF: Retrieve the mutex for a database connection
7656** METHOD: sqlite3
7657**
7658** ^This interface returns a pointer the [sqlite3_mutex] object that
7659** serializes access to the [database connection] given in the argument
7660** when the [threading mode] is Serialized.
7661** ^If the [threading mode] is Single-thread or Multi-thread then this
7662** routine returns a NULL pointer.
7663*/
7664SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7665
7666/*
7667** CAPI3REF: Low-Level Control Of Database Files
7668** METHOD: sqlite3
7669** KEYWORDS: {file control}
7670**
7671** ^The [sqlite3_file_control()] interface makes a direct call to the
7672** xFileControl method for the [sqlite3_io_methods] object associated
7673** with a particular database identified by the second argument. ^The
7674** name of the database is "main" for the main database or "temp" for the
7675** TEMP database, or the name that appears after the AS keyword for
7676** databases that are added using the [ATTACH] SQL command.
7677** ^A NULL pointer can be used in place of "main" to refer to the
7678** main database file.
7679** ^The third and fourth parameters to this routine
7680** are passed directly through to the second and third parameters of
7681** the xFileControl method. ^The return value of the xFileControl
7682** method becomes the return value of this routine.
7683**
7684** A few opcodes for [sqlite3_file_control()] are handled directly
7685** by the SQLite core and never invoke the
7686** sqlite3_io_methods.xFileControl method.
7687** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
7688** a pointer to the underlying [sqlite3_file] object to be written into
7689** the space pointed to by the 4th parameter. The
7690** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
7691** the [sqlite3_file] object associated with the journal file instead of
7692** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
7693** a pointer to the underlying [sqlite3_vfs] object for the file.
7694** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
7695** from the pager.
7696**
7697** ^If the second parameter (zDbName) does not match the name of any
7698** open database file, then SQLITE_ERROR is returned. ^This error
7699** code is not remembered and will not be recalled by [sqlite3_errcode()]
7700** or [sqlite3_errmsg()]. The underlying xFileControl method might
7701** also return SQLITE_ERROR. There is no way to distinguish between
7702** an incorrect zDbName and an SQLITE_ERROR return from the underlying
7703** xFileControl method.
7704**
7705** See also: [file control opcodes]
7706*/
7707SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
7708
7709/*
7710** CAPI3REF: Testing Interface
7711**
7712** ^The sqlite3_test_control() interface is used to read out internal
7713** state of SQLite and to inject faults into SQLite for testing
7714** purposes. ^The first parameter is an operation code that determines
7715** the number, meaning, and operation of all subsequent parameters.
7716**
7717** This interface is not for use by applications. It exists solely
7718** for verifying the correct operation of the SQLite library. Depending
7719** on how the SQLite library is compiled, this interface might not exist.
7720**
7721** The details of the operation codes, their meanings, the parameters
7722** they take, and what they do are all subject to change without notice.
7723** Unlike most of the SQLite API, this function is not guaranteed to
7724** operate consistently from one release to the next.
7725*/
7726SQLITE_API int sqlite3_test_control(int op, ...);
7727
7728/*
7729** CAPI3REF: Testing Interface Operation Codes
7730**
7731** These constants are the valid operation code parameters used
7732** as the first argument to [sqlite3_test_control()].
7733**
7734** These parameters and their meanings are subject to change
7735** without notice. These values are for testing purposes only.
7736** Applications should not use any of these parameters or the
7737** [sqlite3_test_control()] interface.
7738*/
7739#define SQLITE_TESTCTRL_FIRST 5
7740#define SQLITE_TESTCTRL_PRNG_SAVE 5
7741#define SQLITE_TESTCTRL_PRNG_RESTORE 6
7742#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
7743#define SQLITE_TESTCTRL_BITVEC_TEST 8
7744#define SQLITE_TESTCTRL_FAULT_INSTALL 9
7745#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
7746#define SQLITE_TESTCTRL_PENDING_BYTE 11
7747#define SQLITE_TESTCTRL_ASSERT 12
7748#define SQLITE_TESTCTRL_ALWAYS 13
7749#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
7750#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
7751#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
7752#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
7753#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
7754#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
7755#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
7756#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
7757#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
7758#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
7759#define SQLITE_TESTCTRL_BYTEORDER 22
7760#define SQLITE_TESTCTRL_ISINIT 23
7761#define SQLITE_TESTCTRL_SORTER_MMAP 24
7762#define SQLITE_TESTCTRL_IMPOSTER 25
7763#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
7764#define SQLITE_TESTCTRL_RESULT_INTREAL 27
7765#define SQLITE_TESTCTRL_PRNG_SEED 28
7766#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
7767#define SQLITE_TESTCTRL_SEEK_COUNT 30
7768#define SQLITE_TESTCTRL_LAST 30 /* Largest TESTCTRL */
7769
7770/*
7771** CAPI3REF: SQL Keyword Checking
7772**
7773** These routines provide access to the set of SQL language keywords
7774** recognized by SQLite. Applications can uses these routines to determine
7775** whether or not a specific identifier needs to be escaped (for example,
7776** by enclosing in double-quotes) so as not to confuse the parser.
7777**
7778** The sqlite3_keyword_count() interface returns the number of distinct
7779** keywords understood by SQLite.
7780**
7781** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
7782** makes *Z point to that keyword expressed as UTF8 and writes the number
7783** of bytes in the keyword into *L. The string that *Z points to is not
7784** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
7785** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
7786** or L are NULL or invalid pointers then calls to
7787** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
7788**
7789** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
7790** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
7791** if it is and zero if not.
7792**
7793** The parser used by SQLite is forgiving. It is often possible to use
7794** a keyword as an identifier as long as such use does not result in a
7795** parsing ambiguity. For example, the statement
7796** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
7797** creates a new table named "BEGIN" with three columns named
7798** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
7799** using keywords as identifiers. Common techniques used to avoid keyword
7800** name collisions include:
7801** <ul>
7802** <li> Put all identifier names inside double-quotes. This is the official
7803** SQL way to escape identifier names.
7804** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
7805** but it is what SQL Server does and so lots of programmers use this
7806** technique.
7807** <li> Begin every identifier with the letter "Z" as no SQL keywords start
7808** with "Z".
7809** <li> Include a digit somewhere in every identifier name.
7810** </ul>
7811**
7812** Note that the number of keywords understood by SQLite can depend on
7813** compile-time options. For example, "VACUUM" is not a keyword if
7814** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
7815** new keywords may be added to future releases of SQLite.
7816*/
7817SQLITE_API int sqlite3_keyword_count(void);
7818SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
7819SQLITE_API int sqlite3_keyword_check(const char*,int);
7820
7821/*
7822** CAPI3REF: Dynamic String Object
7823** KEYWORDS: {dynamic string}
7824**
7825** An instance of the sqlite3_str object contains a dynamically-sized
7826** string under construction.
7827**
7828** The lifecycle of an sqlite3_str object is as follows:
7829** <ol>
7830** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
7831** <li> ^Text is appended to the sqlite3_str object using various
7832** methods, such as [sqlite3_str_appendf()].
7833** <li> ^The sqlite3_str object is destroyed and the string it created
7834** is returned using the [sqlite3_str_finish()] interface.
7835** </ol>
7836*/
7837typedef struct sqlite3_str sqlite3_str;
7838
7839/*
7840** CAPI3REF: Create A New Dynamic String Object
7841** CONSTRUCTOR: sqlite3_str
7842**
7843** ^The [sqlite3_str_new(D)] interface allocates and initializes
7844** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
7845** [sqlite3_str_new()] must be freed by a subsequent call to
7846** [sqlite3_str_finish(X)].
7847**
7848** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
7849** valid [sqlite3_str] object, though in the event of an out-of-memory
7850** error the returned object might be a special singleton that will
7851** silently reject new text, always return SQLITE_NOMEM from
7852** [sqlite3_str_errcode()], always return 0 for
7853** [sqlite3_str_length()], and always return NULL from
7854** [sqlite3_str_finish(X)]. It is always safe to use the value
7855** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
7856** to any of the other [sqlite3_str] methods.
7857**
7858** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
7859** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
7860** length of the string contained in the [sqlite3_str] object will be
7861** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
7862** of [SQLITE_MAX_LENGTH].
7863*/
7864SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
7865
7866/*
7867** CAPI3REF: Finalize A Dynamic String
7868** DESTRUCTOR: sqlite3_str
7869**
7870** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
7871** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
7872** that contains the constructed string. The calling application should
7873** pass the returned value to [sqlite3_free()] to avoid a memory leak.
7874** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
7875** errors were encountered during construction of the string. ^The
7876** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
7877** string in [sqlite3_str] object X is zero bytes long.
7878*/
7879SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
7880
7881/*
7882** CAPI3REF: Add Content To A Dynamic String
7883** METHOD: sqlite3_str
7884**
7885** These interfaces add content to an sqlite3_str object previously obtained
7886** from [sqlite3_str_new()].
7887**
7888** ^The [sqlite3_str_appendf(X,F,...)] and
7889** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
7890** functionality of SQLite to append formatted text onto the end of
7891** [sqlite3_str] object X.
7892**
7893** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
7894** onto the end of the [sqlite3_str] object X. N must be non-negative.
7895** S must contain at least N non-zero bytes of content. To append a
7896** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
7897** method instead.
7898**
7899** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
7900** zero-terminated string S onto the end of [sqlite3_str] object X.
7901**
7902** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
7903** single-byte character C onto the end of [sqlite3_str] object X.
7904** ^This method can be used, for example, to add whitespace indentation.
7905**
7906** ^The [sqlite3_str_reset(X)] method resets the string under construction
7907** inside [sqlite3_str] object X back to zero bytes in length.
7908**
7909** These methods do not return a result code. ^If an error occurs, that fact
7910** is recorded in the [sqlite3_str] object and can be recovered by a
7911** subsequent call to [sqlite3_str_errcode(X)].
7912*/
7913SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
7914SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
7915SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
7916SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
7917SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
7918SQLITE_API void sqlite3_str_reset(sqlite3_str*);
7919
7920/*
7921** CAPI3REF: Status Of A Dynamic String
7922** METHOD: sqlite3_str
7923**
7924** These interfaces return the current status of an [sqlite3_str] object.
7925**
7926** ^If any prior errors have occurred while constructing the dynamic string
7927** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
7928** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
7929** [SQLITE_NOMEM] following any out-of-memory error, or
7930** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
7931** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
7932**
7933** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
7934** of the dynamic string under construction in [sqlite3_str] object X.
7935** ^The length returned by [sqlite3_str_length(X)] does not include the
7936** zero-termination byte.
7937**
7938** ^The [sqlite3_str_value(X)] method returns a pointer to the current
7939** content of the dynamic string under construction in X. The value
7940** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
7941** and might be freed or altered by any subsequent method on the same
7942** [sqlite3_str] object. Applications must not used the pointer returned
7943** [sqlite3_str_value(X)] after any subsequent method call on the same
7944** object. ^Applications may change the content of the string returned
7945** by [sqlite3_str_value(X)] as long as they do not write into any bytes
7946** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
7947** write any byte after any subsequent sqlite3_str method call.
7948*/
7949SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
7950SQLITE_API int sqlite3_str_length(sqlite3_str*);
7951SQLITE_API char *sqlite3_str_value(sqlite3_str*);
7952
7953/*
7954** CAPI3REF: SQLite Runtime Status
7955**
7956** ^These interfaces are used to retrieve runtime status information
7957** about the performance of SQLite, and optionally to reset various
7958** highwater marks. ^The first argument is an integer code for
7959** the specific parameter to measure. ^(Recognized integer codes
7960** are of the form [status parameters | SQLITE_STATUS_...].)^
7961** ^The current value of the parameter is returned into *pCurrent.
7962** ^The highest recorded value is returned in *pHighwater. ^If the
7963** resetFlag is true, then the highest record value is reset after
7964** *pHighwater is written. ^(Some parameters do not record the highest
7965** value. For those parameters
7966** nothing is written into *pHighwater and the resetFlag is ignored.)^
7967** ^(Other parameters record only the highwater mark and not the current
7968** value. For these latter parameters nothing is written into *pCurrent.)^
7969**
7970** ^The sqlite3_status() and sqlite3_status64() routines return
7971** SQLITE_OK on success and a non-zero [error code] on failure.
7972**
7973** If either the current value or the highwater mark is too large to
7974** be represented by a 32-bit integer, then the values returned by
7975** sqlite3_status() are undefined.
7976**
7977** See also: [sqlite3_db_status()]
7978*/
7979SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
7980SQLITE_API int sqlite3_status64(
7981 int op,
7982 sqlite3_int64 *pCurrent,
7983 sqlite3_int64 *pHighwater,
7984 int resetFlag
7985);
7986
7987
7988/*
7989** CAPI3REF: Status Parameters
7990** KEYWORDS: {status parameters}
7991**
7992** These integer constants designate various run-time status parameters
7993** that can be returned by [sqlite3_status()].
7994**
7995** <dl>
7996** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
7997** <dd>This parameter is the current amount of memory checked out
7998** using [sqlite3_malloc()], either directly or indirectly. The
7999** figure includes calls made to [sqlite3_malloc()] by the application
8000** and internal memory usage by the SQLite library. Auxiliary page-cache
8001** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8002** this parameter. The amount returned is the sum of the allocation
8003** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8004**
8005** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8006** <dd>This parameter records the largest memory allocation request
8007** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8008** internal equivalents). Only the value returned in the
8009** *pHighwater parameter to [sqlite3_status()] is of interest.
8010** The value written into the *pCurrent parameter is undefined.</dd>)^
8011**
8012** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8013** <dd>This parameter records the number of separate memory allocations
8014** currently checked out.</dd>)^
8015**
8016** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8017** <dd>This parameter returns the number of pages used out of the
8018** [pagecache memory allocator] that was configured using
8019** [SQLITE_CONFIG_PAGECACHE]. The
8020** value returned is in pages, not in bytes.</dd>)^
8021**
8022** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8023** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8024** <dd>This parameter returns the number of bytes of page cache
8025** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8026** buffer and where forced to overflow to [sqlite3_malloc()]. The
8027** returned value includes allocations that overflowed because they
8028** where too large (they were larger than the "sz" parameter to
8029** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8030** no space was left in the page cache.</dd>)^
8031**
8032** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8033** <dd>This parameter records the largest memory allocation request
8034** handed to the [pagecache memory allocator]. Only the value returned in the
8035** *pHighwater parameter to [sqlite3_status()] is of interest.
8036** The value written into the *pCurrent parameter is undefined.</dd>)^
8037**
8038** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8039** <dd>No longer used.</dd>
8040**
8041** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8042** <dd>No longer used.</dd>
8043**
8044** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8045** <dd>No longer used.</dd>
8046**
8047** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8048** <dd>The *pHighwater parameter records the deepest parser stack.
8049** The *pCurrent value is undefined. The *pHighwater value is only
8050** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8051** </dl>
8052**
8053** New status parameters may be added from time to time.
8054*/
8055#define SQLITE_STATUS_MEMORY_USED 0
8056#define SQLITE_STATUS_PAGECACHE_USED 1
8057#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8058#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8059#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8060#define SQLITE_STATUS_MALLOC_SIZE 5
8061#define SQLITE_STATUS_PARSER_STACK 6
8062#define SQLITE_STATUS_PAGECACHE_SIZE 7
8063#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8064#define SQLITE_STATUS_MALLOC_COUNT 9
8065
8066/*
8067** CAPI3REF: Database Connection Status
8068** METHOD: sqlite3
8069**
8070** ^This interface is used to retrieve runtime status information
8071** about a single [database connection]. ^The first argument is the
8072** database connection object to be interrogated. ^The second argument
8073** is an integer constant, taken from the set of
8074** [SQLITE_DBSTATUS options], that
8075** determines the parameter to interrogate. The set of
8076** [SQLITE_DBSTATUS options] is likely
8077** to grow in future releases of SQLite.
8078**
8079** ^The current value of the requested parameter is written into *pCur
8080** and the highest instantaneous value is written into *pHiwtr. ^If
8081** the resetFlg is true, then the highest instantaneous value is
8082** reset back down to the current value.
8083**
8084** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8085** non-zero [error code] on failure.
8086**
8087** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8088*/
8089SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8090
8091/*
8092** CAPI3REF: Status Parameters for database connections
8093** KEYWORDS: {SQLITE_DBSTATUS options}
8094**
8095** These constants are the available integer "verbs" that can be passed as
8096** the second argument to the [sqlite3_db_status()] interface.
8097**
8098** New verbs may be added in future releases of SQLite. Existing verbs
8099** might be discontinued. Applications should check the return code from
8100** [sqlite3_db_status()] to make sure that the call worked.
8101** The [sqlite3_db_status()] interface will return a non-zero error code
8102** if a discontinued or unsupported verb is invoked.
8103**
8104** <dl>
8105** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8106** <dd>This parameter returns the number of lookaside memory slots currently
8107** checked out.</dd>)^
8108**
8109** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8110** <dd>This parameter returns the number of malloc attempts that were
8111** satisfied using lookaside memory. Only the high-water value is meaningful;
8112** the current value is always zero.)^
8113**
8114** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8115** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8116** <dd>This parameter returns the number malloc attempts that might have
8117** been satisfied using lookaside memory but failed due to the amount of
8118** memory requested being larger than the lookaside slot size.
8119** Only the high-water value is meaningful;
8120** the current value is always zero.)^
8121**
8122** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8123** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8124** <dd>This parameter returns the number malloc attempts that might have
8125** been satisfied using lookaside memory but failed due to all lookaside
8126** memory already being in use.
8127** Only the high-water value is meaningful;
8128** the current value is always zero.)^
8129**
8130** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8131** <dd>This parameter returns the approximate number of bytes of heap
8132** memory used by all pager caches associated with the database connection.)^
8133** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8134**
8135** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8136** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8137** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8138** pager cache is shared between two or more connections the bytes of heap
8139** memory used by that pager cache is divided evenly between the attached
8140** connections.)^ In other words, if none of the pager caches associated
8141** with the database connection are shared, this request returns the same
8142** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8143** shared, the value returned by this call will be smaller than that returned
8144** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8145** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8146**
8147** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8148** <dd>This parameter returns the approximate number of bytes of heap
8149** memory used to store the schema for all databases associated
8150** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8151** ^The full amount of memory used by the schemas is reported, even if the
8152** schema memory is shared with other database connections due to
8153** [shared cache mode] being enabled.
8154** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8155**
8156** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8157** <dd>This parameter returns the approximate number of bytes of heap
8158** and lookaside memory used by all prepared statements associated with
8159** the database connection.)^
8160** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8161** </dd>
8162**
8163** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8164** <dd>This parameter returns the number of pager cache hits that have
8165** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8166** is always 0.
8167** </dd>
8168**
8169** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8170** <dd>This parameter returns the number of pager cache misses that have
8171** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8172** is always 0.
8173** </dd>
8174**
8175** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8176** <dd>This parameter returns the number of dirty cache entries that have
8177** been written to disk. Specifically, the number of pages written to the
8178** wal file in wal mode databases, or the number of pages written to the
8179** database file in rollback mode databases. Any pages written as part of
8180** transaction rollback or database recovery operations are not included.
8181** If an IO or other error occurs while writing a page to disk, the effect
8182** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8183** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8184** </dd>
8185**
8186** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8187** <dd>This parameter returns the number of dirty cache entries that have
8188** been written to disk in the middle of a transaction due to the page
8189** cache overflowing. Transactions are more efficient if they are written
8190** to disk all at once. When pages spill mid-transaction, that introduces
8191** additional overhead. This parameter can be used help identify
8192** inefficiencies that can be resolved by increasing the cache size.
8193** </dd>
8194**
8195** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8196** <dd>This parameter returns zero for the current value if and only if
8197** all foreign key constraints (deferred or immediate) have been
8198** resolved.)^ ^The highwater mark is always 0.
8199** </dd>
8200** </dl>
8201*/
8202#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8203#define SQLITE_DBSTATUS_CACHE_USED 1
8204#define SQLITE_DBSTATUS_SCHEMA_USED 2
8205#define SQLITE_DBSTATUS_STMT_USED 3
8206#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8207#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8208#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8209#define SQLITE_DBSTATUS_CACHE_HIT 7
8210#define SQLITE_DBSTATUS_CACHE_MISS 8
8211#define SQLITE_DBSTATUS_CACHE_WRITE 9
8212#define SQLITE_DBSTATUS_DEFERRED_FKS 10
8213#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8214#define SQLITE_DBSTATUS_CACHE_SPILL 12
8215#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8216
8217
8218/*
8219** CAPI3REF: Prepared Statement Status
8220** METHOD: sqlite3_stmt
8221**
8222** ^(Each prepared statement maintains various
8223** [SQLITE_STMTSTATUS counters] that measure the number
8224** of times it has performed specific operations.)^ These counters can
8225** be used to monitor the performance characteristics of the prepared
8226** statements. For example, if the number of table steps greatly exceeds
8227** the number of table searches or result rows, that would tend to indicate
8228** that the prepared statement is using a full table scan rather than
8229** an index.
8230**
8231** ^(This interface is used to retrieve and reset counter values from
8232** a [prepared statement]. The first argument is the prepared statement
8233** object to be interrogated. The second argument
8234** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8235** to be interrogated.)^
8236** ^The current value of the requested counter is returned.
8237** ^If the resetFlg is true, then the counter is reset to zero after this
8238** interface call returns.
8239**
8240** See also: [sqlite3_status()] and [sqlite3_db_status()].
8241*/
8242SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8243
8244/*
8245** CAPI3REF: Status Parameters for prepared statements
8246** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8247**
8248** These preprocessor macros define integer codes that name counter
8249** values associated with the [sqlite3_stmt_status()] interface.
8250** The meanings of the various counters are as follows:
8251**
8252** <dl>
8253** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8254** <dd>^This is the number of times that SQLite has stepped forward in
8255** a table as part of a full table scan. Large numbers for this counter
8256** may indicate opportunities for performance improvement through
8257** careful use of indices.</dd>
8258**
8259** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8260** <dd>^This is the number of sort operations that have occurred.
8261** A non-zero value in this counter may indicate an opportunity to
8262** improvement performance through careful use of indices.</dd>
8263**
8264** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8265** <dd>^This is the number of rows inserted into transient indices that
8266** were created automatically in order to help joins run faster.
8267** A non-zero value in this counter may indicate an opportunity to
8268** improvement performance by adding permanent indices that do not
8269** need to be reinitialized each time the statement is run.</dd>
8270**
8271** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8272** <dd>^This is the number of virtual machine operations executed
8273** by the prepared statement if that number is less than or equal
8274** to 2147483647. The number of virtual machine operations can be
8275** used as a proxy for the total work done by the prepared statement.
8276** If the number of virtual machine operations exceeds 2147483647
8277** then the value returned by this statement status code is undefined.
8278**
8279** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8280** <dd>^This is the number of times that the prepare statement has been
8281** automatically regenerated due to schema changes or changes to
8282** [bound parameters] that might affect the query plan.
8283**
8284** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8285** <dd>^This is the number of times that the prepared statement has
8286** been run. A single "run" for the purposes of this counter is one
8287** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8288** The counter is incremented on the first [sqlite3_step()] call of each
8289** cycle.
8290**
8291** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8292** <dd>^This is the approximate number of bytes of heap memory
8293** used to store the prepared statement. ^This value is not actually
8294** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8295** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8296** </dd>
8297** </dl>
8298*/
8299#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8300#define SQLITE_STMTSTATUS_SORT 2
8301#define SQLITE_STMTSTATUS_AUTOINDEX 3
8302#define SQLITE_STMTSTATUS_VM_STEP 4
8303#define SQLITE_STMTSTATUS_REPREPARE 5
8304#define SQLITE_STMTSTATUS_RUN 6
8305#define SQLITE_STMTSTATUS_MEMUSED 99
8306
8307/*
8308** CAPI3REF: Custom Page Cache Object
8309**
8310** The sqlite3_pcache type is opaque. It is implemented by
8311** the pluggable module. The SQLite core has no knowledge of
8312** its size or internal structure and never deals with the
8313** sqlite3_pcache object except by holding and passing pointers
8314** to the object.
8315**
8316** See [sqlite3_pcache_methods2] for additional information.
8317*/
8318typedef struct sqlite3_pcache sqlite3_pcache;
8319
8320/*
8321** CAPI3REF: Custom Page Cache Object
8322**
8323** The sqlite3_pcache_page object represents a single page in the
8324** page cache. The page cache will allocate instances of this
8325** object. Various methods of the page cache use pointers to instances
8326** of this object as parameters or as their return value.
8327**
8328** See [sqlite3_pcache_methods2] for additional information.
8329*/
8330typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8331struct sqlite3_pcache_page {
8332 void *pBuf; /* The content of the page */
8333 void *pExtra; /* Extra information associated with the page */
8334};
8335
8336/*
8337** CAPI3REF: Application Defined Page Cache.
8338** KEYWORDS: {page cache}
8339**
8340** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8341** register an alternative page cache implementation by passing in an
8342** instance of the sqlite3_pcache_methods2 structure.)^
8343** In many applications, most of the heap memory allocated by
8344** SQLite is used for the page cache.
8345** By implementing a
8346** custom page cache using this API, an application can better control
8347** the amount of memory consumed by SQLite, the way in which
8348** that memory is allocated and released, and the policies used to
8349** determine exactly which parts of a database file are cached and for
8350** how long.
8351**
8352** The alternative page cache mechanism is an
8353** extreme measure that is only needed by the most demanding applications.
8354** The built-in page cache is recommended for most uses.
8355**
8356** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8357** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8358** the application may discard the parameter after the call to
8359** [sqlite3_config()] returns.)^
8360**
8361** [[the xInit() page cache method]]
8362** ^(The xInit() method is called once for each effective
8363** call to [sqlite3_initialize()])^
8364** (usually only once during the lifetime of the process). ^(The xInit()
8365** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8366** The intent of the xInit() method is to set up global data structures
8367** required by the custom page cache implementation.
8368** ^(If the xInit() method is NULL, then the
8369** built-in default page cache is used instead of the application defined
8370** page cache.)^
8371**
8372** [[the xShutdown() page cache method]]
8373** ^The xShutdown() method is called by [sqlite3_shutdown()].
8374** It can be used to clean up
8375** any outstanding resources before process shutdown, if required.
8376** ^The xShutdown() method may be NULL.
8377**
8378** ^SQLite automatically serializes calls to the xInit method,
8379** so the xInit method need not be threadsafe. ^The
8380** xShutdown method is only called from [sqlite3_shutdown()] so it does
8381** not need to be threadsafe either. All other methods must be threadsafe
8382** in multithreaded applications.
8383**
8384** ^SQLite will never invoke xInit() more than once without an intervening
8385** call to xShutdown().
8386**
8387** [[the xCreate() page cache methods]]
8388** ^SQLite invokes the xCreate() method to construct a new cache instance.
8389** SQLite will typically create one cache instance for each open database file,
8390** though this is not guaranteed. ^The
8391** first parameter, szPage, is the size in bytes of the pages that must
8392** be allocated by the cache. ^szPage will always a power of two. ^The
8393** second parameter szExtra is a number of bytes of extra storage
8394** associated with each page cache entry. ^The szExtra parameter will
8395** a number less than 250. SQLite will use the
8396** extra szExtra bytes on each page to store metadata about the underlying
8397** database page on disk. The value passed into szExtra depends
8398** on the SQLite version, the target platform, and how SQLite was compiled.
8399** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8400** created will be used to cache database pages of a file stored on disk, or
8401** false if it is used for an in-memory database. The cache implementation
8402** does not have to do anything special based with the value of bPurgeable;
8403** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
8404** never invoke xUnpin() except to deliberately delete a page.
8405** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
8406** false will always have the "discard" flag set to true.
8407** ^Hence, a cache created with bPurgeable false will
8408** never contain any unpinned pages.
8409**
8410** [[the xCachesize() page cache method]]
8411** ^(The xCachesize() method may be called at any time by SQLite to set the
8412** suggested maximum cache-size (number of pages stored by) the cache
8413** instance passed as the first argument. This is the value configured using
8414** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
8415** parameter, the implementation is not required to do anything with this
8416** value; it is advisory only.
8417**
8418** [[the xPagecount() page cache methods]]
8419** The xPagecount() method must return the number of pages currently
8420** stored in the cache, both pinned and unpinned.
8421**
8422** [[the xFetch() page cache methods]]
8423** The xFetch() method locates a page in the cache and returns a pointer to
8424** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
8425** The pBuf element of the returned sqlite3_pcache_page object will be a
8426** pointer to a buffer of szPage bytes used to store the content of a
8427** single database page. The pExtra element of sqlite3_pcache_page will be
8428** a pointer to the szExtra bytes of extra storage that SQLite has requested
8429** for each entry in the page cache.
8430**
8431** The page to be fetched is determined by the key. ^The minimum key value
8432** is 1. After it has been retrieved using xFetch, the page is considered
8433** to be "pinned".
8434**
8435** If the requested page is already in the page cache, then the page cache
8436** implementation must return a pointer to the page buffer with its content
8437** intact. If the requested page is not already in the cache, then the
8438** cache implementation should use the value of the createFlag
8439** parameter to help it determined what action to take:
8440**
8441** <table border=1 width=85% align=center>
8442** <tr><th> createFlag <th> Behavior when page is not already in cache
8443** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
8444** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
8445** Otherwise return NULL.
8446** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
8447** NULL if allocating a new page is effectively impossible.
8448** </table>
8449**
8450** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
8451** will only use a createFlag of 2 after a prior call with a createFlag of 1
8452** failed.)^ In between the xFetch() calls, SQLite may
8453** attempt to unpin one or more cache pages by spilling the content of
8454** pinned pages to disk and synching the operating system disk cache.
8455**
8456** [[the xUnpin() page cache method]]
8457** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
8458** as its second argument. If the third parameter, discard, is non-zero,
8459** then the page must be evicted from the cache.
8460** ^If the discard parameter is
8461** zero, then the page may be discarded or retained at the discretion of
8462** page cache implementation. ^The page cache implementation
8463** may choose to evict unpinned pages at any time.
8464**
8465** The cache must not perform any reference counting. A single
8466** call to xUnpin() unpins the page regardless of the number of prior calls
8467** to xFetch().
8468**
8469** [[the xRekey() page cache methods]]
8470** The xRekey() method is used to change the key value associated with the
8471** page passed as the second argument. If the cache
8472** previously contains an entry associated with newKey, it must be
8473** discarded. ^Any prior cache entry associated with newKey is guaranteed not
8474** to be pinned.
8475**
8476** When SQLite calls the xTruncate() method, the cache must discard all
8477** existing cache entries with page numbers (keys) greater than or equal
8478** to the value of the iLimit parameter passed to xTruncate(). If any
8479** of these pages are pinned, they are implicitly unpinned, meaning that
8480** they can be safely discarded.
8481**
8482** [[the xDestroy() page cache method]]
8483** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8484** All resources associated with the specified cache should be freed. ^After
8485** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8486** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8487** functions.
8488**
8489** [[the xShrink() page cache method]]
8490** ^SQLite invokes the xShrink() method when it wants the page cache to
8491** free up as much of heap memory as possible. The page cache implementation
8492** is not obligated to free any memory, but well-behaved implementations should
8493** do their best.
8494*/
8495typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8496struct sqlite3_pcache_methods2 {
8497 int iVersion;
8498 void *pArg;
8499 int (*xInit)(void*);
8500 void (*xShutdown)(void*);
8501 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8502 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8503 int (*xPagecount)(sqlite3_pcache*);
8504 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8505 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
8506 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
8507 unsigned oldKey, unsigned newKey);
8508 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8509 void (*xDestroy)(sqlite3_pcache*);
8510 void (*xShrink)(sqlite3_pcache*);
8511};
8512
8513/*
8514** This is the obsolete pcache_methods object that has now been replaced
8515** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8516** retained in the header file for backwards compatibility only.
8517*/
8518typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8519struct sqlite3_pcache_methods {
8520 void *pArg;
8521 int (*xInit)(void*);
8522 void (*xShutdown)(void*);
8523 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8524 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8525 int (*xPagecount)(sqlite3_pcache*);
8526 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8527 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8528 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8529 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8530 void (*xDestroy)(sqlite3_pcache*);
8531};
8532
8533
8534/*
8535** CAPI3REF: Online Backup Object
8536**
8537** The sqlite3_backup object records state information about an ongoing
8538** online backup operation. ^The sqlite3_backup object is created by
8539** a call to [sqlite3_backup_init()] and is destroyed by a call to
8540** [sqlite3_backup_finish()].
8541**
8542** See Also: [Using the SQLite Online Backup API]
8543*/
8544typedef struct sqlite3_backup sqlite3_backup;
8545
8546/*
8547** CAPI3REF: Online Backup API.
8548**
8549** The backup API copies the content of one database into another.
8550** It is useful either for creating backups of databases or
8551** for copying in-memory databases to or from persistent files.
8552**
8553** See Also: [Using the SQLite Online Backup API]
8554**
8555** ^SQLite holds a write transaction open on the destination database file
8556** for the duration of the backup operation.
8557** ^The source database is read-locked only while it is being read;
8558** it is not locked continuously for the entire backup operation.
8559** ^Thus, the backup may be performed on a live source database without
8560** preventing other database connections from
8561** reading or writing to the source database while the backup is underway.
8562**
8563** ^(To perform a backup operation:
8564** <ol>
8565** <li><b>sqlite3_backup_init()</b> is called once to initialize the
8566** backup,
8567** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
8568** the data between the two databases, and finally
8569** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8570** associated with the backup operation.
8571** </ol>)^
8572** There should be exactly one call to sqlite3_backup_finish() for each
8573** successful call to sqlite3_backup_init().
8574**
8575** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8576**
8577** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8578** [database connection] associated with the destination database
8579** and the database name, respectively.
8580** ^The database name is "main" for the main database, "temp" for the
8581** temporary database, or the name specified after the AS keyword in
8582** an [ATTACH] statement for an attached database.
8583** ^The S and M arguments passed to
8584** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8585** and database name of the source database, respectively.
8586** ^The source and destination [database connections] (parameters S and D)
8587** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8588** an error.
8589**
8590** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8591** there is already a read or read-write transaction open on the
8592** destination database.
8593**
8594** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8595** returned and an error code and error message are stored in the
8596** destination [database connection] D.
8597** ^The error code and message for the failed call to sqlite3_backup_init()
8598** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8599** [sqlite3_errmsg16()] functions.
8600** ^A successful call to sqlite3_backup_init() returns a pointer to an
8601** [sqlite3_backup] object.
8602** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
8603** sqlite3_backup_finish() functions to perform the specified backup
8604** operation.
8605**
8606** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8607**
8608** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
8609** the source and destination databases specified by [sqlite3_backup] object B.
8610** ^If N is negative, all remaining source pages are copied.
8611** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8612** are still more pages to be copied, then the function returns [SQLITE_OK].
8613** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8614** from source to destination, then it returns [SQLITE_DONE].
8615** ^If an error occurs while running sqlite3_backup_step(B,N),
8616** then an [error code] is returned. ^As well as [SQLITE_OK] and
8617** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8618** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8619** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8620**
8621** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8622** <ol>
8623** <li> the destination database was opened read-only, or
8624** <li> the destination database is using write-ahead-log journaling
8625** and the destination and source page sizes differ, or
8626** <li> the destination database is an in-memory database and the
8627** destination and source page sizes differ.
8628** </ol>)^
8629**
8630** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8631** the [sqlite3_busy_handler | busy-handler function]
8632** is invoked (if one is specified). ^If the
8633** busy-handler returns non-zero before the lock is available, then
8634** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8635** sqlite3_backup_step() can be retried later. ^If the source
8636** [database connection]
8637** is being used to write to the source database when sqlite3_backup_step()
8638** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8639** case the call to sqlite3_backup_step() can be retried later on. ^(If
8640** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
8641** [SQLITE_READONLY] is returned, then
8642** there is no point in retrying the call to sqlite3_backup_step(). These
8643** errors are considered fatal.)^ The application must accept
8644** that the backup operation has failed and pass the backup operation handle
8645** to the sqlite3_backup_finish() to release associated resources.
8646**
8647** ^The first call to sqlite3_backup_step() obtains an exclusive lock
8648** on the destination file. ^The exclusive lock is not released until either
8649** sqlite3_backup_finish() is called or the backup operation is complete
8650** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8651** sqlite3_backup_step() obtains a [shared lock] on the source database that
8652** lasts for the duration of the sqlite3_backup_step() call.
8653** ^Because the source database is not locked between calls to
8654** sqlite3_backup_step(), the source database may be modified mid-way
8655** through the backup process. ^If the source database is modified by an
8656** external process or via a database connection other than the one being
8657** used by the backup operation, then the backup will be automatically
8658** restarted by the next call to sqlite3_backup_step(). ^If the source
8659** database is modified by the using the same database connection as is used
8660** by the backup operation, then the backup database is automatically
8661** updated at the same time.
8662**
8663** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8664**
8665** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
8666** application wishes to abandon the backup operation, the application
8667** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8668** ^The sqlite3_backup_finish() interfaces releases all
8669** resources associated with the [sqlite3_backup] object.
8670** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8671** active write-transaction on the destination database is rolled back.
8672** The [sqlite3_backup] object is invalid
8673** and may not be used following a call to sqlite3_backup_finish().
8674**
8675** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
8676** sqlite3_backup_step() errors occurred, regardless or whether or not
8677** sqlite3_backup_step() completed.
8678** ^If an out-of-memory condition or IO error occurred during any prior
8679** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
8680** sqlite3_backup_finish() returns the corresponding [error code].
8681**
8682** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
8683** is not a permanent error and does not affect the return value of
8684** sqlite3_backup_finish().
8685**
8686** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
8687** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
8688**
8689** ^The sqlite3_backup_remaining() routine returns the number of pages still
8690** to be backed up at the conclusion of the most recent sqlite3_backup_step().
8691** ^The sqlite3_backup_pagecount() routine returns the total number of pages
8692** in the source database at the conclusion of the most recent
8693** sqlite3_backup_step().
8694** ^(The values returned by these functions are only updated by
8695** sqlite3_backup_step(). If the source database is modified in a way that
8696** changes the size of the source database or the number of pages remaining,
8697** those changes are not reflected in the output of sqlite3_backup_pagecount()
8698** and sqlite3_backup_remaining() until after the next
8699** sqlite3_backup_step().)^
8700**
8701** <b>Concurrent Usage of Database Handles</b>
8702**
8703** ^The source [database connection] may be used by the application for other
8704** purposes while a backup operation is underway or being initialized.
8705** ^If SQLite is compiled and configured to support threadsafe database
8706** connections, then the source database connection may be used concurrently
8707** from within other threads.
8708**
8709** However, the application must guarantee that the destination
8710** [database connection] is not passed to any other API (by any thread) after
8711** sqlite3_backup_init() is called and before the corresponding call to
8712** sqlite3_backup_finish(). SQLite does not currently check to see
8713** if the application incorrectly accesses the destination [database connection]
8714** and so no error code is reported, but the operations may malfunction
8715** nevertheless. Use of the destination database connection while a
8716** backup is in progress might also also cause a mutex deadlock.
8717**
8718** If running in [shared cache mode], the application must
8719** guarantee that the shared cache used by the destination database
8720** is not accessed while the backup is running. In practice this means
8721** that the application must guarantee that the disk file being
8722** backed up to is not accessed by any connection within the process,
8723** not just the specific connection that was passed to sqlite3_backup_init().
8724**
8725** The [sqlite3_backup] object itself is partially threadsafe. Multiple
8726** threads may safely make multiple concurrent calls to sqlite3_backup_step().
8727** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
8728** APIs are not strictly speaking threadsafe. If they are invoked at the
8729** same time as another thread is invoking sqlite3_backup_step() it is
8730** possible that they return invalid values.
8731*/
8732SQLITE_API sqlite3_backup *sqlite3_backup_init(
8733 sqlite3 *pDest, /* Destination database handle */
8734 const char *zDestName, /* Destination database name */
8735 sqlite3 *pSource, /* Source database handle */
8736 const char *zSourceName /* Source database name */
8737);
8738SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
8739SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
8740SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
8741SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
8742
8743/*
8744** CAPI3REF: Unlock Notification
8745** METHOD: sqlite3
8746**
8747** ^When running in shared-cache mode, a database operation may fail with
8748** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
8749** individual tables within the shared-cache cannot be obtained. See
8750** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
8751** ^This API may be used to register a callback that SQLite will invoke
8752** when the connection currently holding the required lock relinquishes it.
8753** ^This API is only available if the library was compiled with the
8754** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
8755**
8756** See Also: [Using the SQLite Unlock Notification Feature].
8757**
8758** ^Shared-cache locks are released when a database connection concludes
8759** its current transaction, either by committing it or rolling it back.
8760**
8761** ^When a connection (known as the blocked connection) fails to obtain a
8762** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
8763** identity of the database connection (the blocking connection) that
8764** has locked the required resource is stored internally. ^After an
8765** application receives an SQLITE_LOCKED error, it may call the
8766** sqlite3_unlock_notify() method with the blocked connection handle as
8767** the first argument to register for a callback that will be invoked
8768** when the blocking connections current transaction is concluded. ^The
8769** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
8770** call that concludes the blocking connection's transaction.
8771**
8772** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
8773** there is a chance that the blocking connection will have already
8774** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
8775** If this happens, then the specified callback is invoked immediately,
8776** from within the call to sqlite3_unlock_notify().)^
8777**
8778** ^If the blocked connection is attempting to obtain a write-lock on a
8779** shared-cache table, and more than one other connection currently holds
8780** a read-lock on the same table, then SQLite arbitrarily selects one of
8781** the other connections to use as the blocking connection.
8782**
8783** ^(There may be at most one unlock-notify callback registered by a
8784** blocked connection. If sqlite3_unlock_notify() is called when the
8785** blocked connection already has a registered unlock-notify callback,
8786** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
8787** called with a NULL pointer as its second argument, then any existing
8788** unlock-notify callback is canceled. ^The blocked connections
8789** unlock-notify callback may also be canceled by closing the blocked
8790** connection using [sqlite3_close()].
8791**
8792** The unlock-notify callback is not reentrant. If an application invokes
8793** any sqlite3_xxx API functions from within an unlock-notify callback, a
8794** crash or deadlock may be the result.
8795**
8796** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
8797** returns SQLITE_OK.
8798**
8799** <b>Callback Invocation Details</b>
8800**
8801** When an unlock-notify callback is registered, the application provides a
8802** single void* pointer that is passed to the callback when it is invoked.
8803** However, the signature of the callback function allows SQLite to pass
8804** it an array of void* context pointers. The first argument passed to
8805** an unlock-notify callback is a pointer to an array of void* pointers,
8806** and the second is the number of entries in the array.
8807**
8808** When a blocking connection's transaction is concluded, there may be
8809** more than one blocked connection that has registered for an unlock-notify
8810** callback. ^If two or more such blocked connections have specified the
8811** same callback function, then instead of invoking the callback function
8812** multiple times, it is invoked once with the set of void* context pointers
8813** specified by the blocked connections bundled together into an array.
8814** This gives the application an opportunity to prioritize any actions
8815** related to the set of unblocked database connections.
8816**
8817** <b>Deadlock Detection</b>
8818**
8819** Assuming that after registering for an unlock-notify callback a
8820** database waits for the callback to be issued before taking any further
8821** action (a reasonable assumption), then using this API may cause the
8822** application to deadlock. For example, if connection X is waiting for
8823** connection Y's transaction to be concluded, and similarly connection
8824** Y is waiting on connection X's transaction, then neither connection
8825** will proceed and the system may remain deadlocked indefinitely.
8826**
8827** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
8828** detection. ^If a given call to sqlite3_unlock_notify() would put the
8829** system in a deadlocked state, then SQLITE_LOCKED is returned and no
8830** unlock-notify callback is registered. The system is said to be in
8831** a deadlocked state if connection A has registered for an unlock-notify
8832** callback on the conclusion of connection B's transaction, and connection
8833** B has itself registered for an unlock-notify callback when connection
8834** A's transaction is concluded. ^Indirect deadlock is also detected, so
8835** the system is also considered to be deadlocked if connection B has
8836** registered for an unlock-notify callback on the conclusion of connection
8837** C's transaction, where connection C is waiting on connection A. ^Any
8838** number of levels of indirection are allowed.
8839**
8840** <b>The "DROP TABLE" Exception</b>
8841**
8842** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
8843** always appropriate to call sqlite3_unlock_notify(). There is however,
8844** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
8845** SQLite checks if there are any currently executing SELECT statements
8846** that belong to the same connection. If there are, SQLITE_LOCKED is
8847** returned. In this case there is no "blocking connection", so invoking
8848** sqlite3_unlock_notify() results in the unlock-notify callback being
8849** invoked immediately. If the application then re-attempts the "DROP TABLE"
8850** or "DROP INDEX" query, an infinite loop might be the result.
8851**
8852** One way around this problem is to check the extended error code returned
8853** by an sqlite3_step() call. ^(If there is a blocking connection, then the
8854** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
8855** the special "DROP TABLE/INDEX" case, the extended error code is just
8856** SQLITE_LOCKED.)^
8857*/
8858SQLITE_API int sqlite3_unlock_notify(
8859 sqlite3 *pBlocked, /* Waiting connection */
8860 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
8861 void *pNotifyArg /* Argument to pass to xNotify */
8862);
8863
8864
8865/*
8866** CAPI3REF: String Comparison
8867**
8868** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
8869** and extensions to compare the contents of two buffers containing UTF-8
8870** strings in a case-independent fashion, using the same definition of "case
8871** independence" that SQLite uses internally when comparing identifiers.
8872*/
8873SQLITE_API int sqlite3_stricmp(const char *, const char *);
8874SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
8875
8876/*
8877** CAPI3REF: String Globbing
8878*
8879** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
8880** string X matches the [GLOB] pattern P.
8881** ^The definition of [GLOB] pattern matching used in
8882** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
8883** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
8884** is case sensitive.
8885**
8886** Note that this routine returns zero on a match and non-zero if the strings
8887** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8888**
8889** See also: [sqlite3_strlike()].
8890*/
8891SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
8892
8893/*
8894** CAPI3REF: String LIKE Matching
8895*
8896** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
8897** string X matches the [LIKE] pattern P with escape character E.
8898** ^The definition of [LIKE] pattern matching used in
8899** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
8900** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
8901** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
8902** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
8903** insensitive - equivalent upper and lower case ASCII characters match
8904** one another.
8905**
8906** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
8907** only ASCII characters are case folded.
8908**
8909** Note that this routine returns zero on a match and non-zero if the strings
8910** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8911**
8912** See also: [sqlite3_strglob()].
8913*/
8914SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
8915
8916/*
8917** CAPI3REF: Error Logging Interface
8918**
8919** ^The [sqlite3_log()] interface writes a message into the [error log]
8920** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
8921** ^If logging is enabled, the zFormat string and subsequent arguments are
8922** used with [sqlite3_snprintf()] to generate the final output string.
8923**
8924** The sqlite3_log() interface is intended for use by extensions such as
8925** virtual tables, collating functions, and SQL functions. While there is
8926** nothing to prevent an application from calling sqlite3_log(), doing so
8927** is considered bad form.
8928**
8929** The zFormat string must not be NULL.
8930**
8931** To avoid deadlocks and other threading problems, the sqlite3_log() routine
8932** will not use dynamically allocated memory. The log message is stored in
8933** a fixed-length buffer on the stack. If the log message is longer than
8934** a few hundred characters, it will be truncated to the length of the
8935** buffer.
8936*/
8937SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
8938
8939/*
8940** CAPI3REF: Write-Ahead Log Commit Hook
8941** METHOD: sqlite3
8942**
8943** ^The [sqlite3_wal_hook()] function is used to register a callback that
8944** is invoked each time data is committed to a database in wal mode.
8945**
8946** ^(The callback is invoked by SQLite after the commit has taken place and
8947** the associated write-lock on the database released)^, so the implementation
8948** may read, write or [checkpoint] the database as required.
8949**
8950** ^The first parameter passed to the callback function when it is invoked
8951** is a copy of the third parameter passed to sqlite3_wal_hook() when
8952** registering the callback. ^The second is a copy of the database handle.
8953** ^The third parameter is the name of the database that was written to -
8954** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
8955** is the number of pages currently in the write-ahead log file,
8956** including those that were just committed.
8957**
8958** The callback function should normally return [SQLITE_OK]. ^If an error
8959** code is returned, that error will propagate back up through the
8960** SQLite code base to cause the statement that provoked the callback
8961** to report an error, though the commit will have still occurred. If the
8962** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
8963** that does not correspond to any valid SQLite error code, the results
8964** are undefined.
8965**
8966** A single database handle may have at most a single write-ahead log callback
8967** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
8968** previously registered write-ahead log callback. ^Note that the
8969** [sqlite3_wal_autocheckpoint()] interface and the
8970** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
8971** overwrite any prior [sqlite3_wal_hook()] settings.
8972*/
8973SQLITE_API void *sqlite3_wal_hook(
8974 sqlite3*,
8975 int(*)(void *,sqlite3*,const char*,int),
8976 void*
8977);
8978
8979/*
8980** CAPI3REF: Configure an auto-checkpoint
8981** METHOD: sqlite3
8982**
8983** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
8984** [sqlite3_wal_hook()] that causes any database on [database connection] D
8985** to automatically [checkpoint]
8986** after committing a transaction if there are N or
8987** more frames in the [write-ahead log] file. ^Passing zero or
8988** a negative value as the nFrame parameter disables automatic
8989** checkpoints entirely.
8990**
8991** ^The callback registered by this function replaces any existing callback
8992** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
8993** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
8994** configured by this function.
8995**
8996** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
8997** from SQL.
8998**
8999** ^Checkpoints initiated by this mechanism are
9000** [sqlite3_wal_checkpoint_v2|PASSIVE].
9001**
9002** ^Every new [database connection] defaults to having the auto-checkpoint
9003** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9004** pages. The use of this interface
9005** is only necessary if the default setting is found to be suboptimal
9006** for a particular application.
9007*/
9008SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9009
9010/*
9011** CAPI3REF: Checkpoint a database
9012** METHOD: sqlite3
9013**
9014** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9015** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9016**
9017** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9018** [write-ahead log] for database X on [database connection] D to be
9019** transferred into the database file and for the write-ahead log to
9020** be reset. See the [checkpointing] documentation for addition
9021** information.
9022**
9023** This interface used to be the only way to cause a checkpoint to
9024** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9025** interface was added. This interface is retained for backwards
9026** compatibility and as a convenience for applications that need to manually
9027** start a callback but which do not need the full power (and corresponding
9028** complication) of [sqlite3_wal_checkpoint_v2()].
9029*/
9030SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9031
9032/*
9033** CAPI3REF: Checkpoint a database
9034** METHOD: sqlite3
9035**
9036** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9037** operation on database X of [database connection] D in mode M. Status
9038** information is written back into integers pointed to by L and C.)^
9039** ^(The M parameter must be a valid [checkpoint mode]:)^
9040**
9041** <dl>
9042** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9043** ^Checkpoint as many frames as possible without waiting for any database
9044** readers or writers to finish, then sync the database file if all frames
9045** in the log were checkpointed. ^The [busy-handler callback]
9046** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9047** ^On the other hand, passive mode might leave the checkpoint unfinished
9048** if there are concurrent readers or writers.
9049**
9050** <dt>SQLITE_CHECKPOINT_FULL<dd>
9051** ^This mode blocks (it invokes the
9052** [sqlite3_busy_handler|busy-handler callback]) until there is no
9053** database writer and all readers are reading from the most recent database
9054** snapshot. ^It then checkpoints all frames in the log file and syncs the
9055** database file. ^This mode blocks new database writers while it is pending,
9056** but new database readers are allowed to continue unimpeded.
9057**
9058** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9059** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9060** that after checkpointing the log file it blocks (calls the
9061** [busy-handler callback])
9062** until all readers are reading from the database file only. ^This ensures
9063** that the next writer will restart the log file from the beginning.
9064** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9065** database writer attempts while it is pending, but does not impede readers.
9066**
9067** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9068** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9069** addition that it also truncates the log file to zero bytes just prior
9070** to a successful return.
9071** </dl>
9072**
9073** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9074** the log file or to -1 if the checkpoint could not run because
9075** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9076** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9077** log file (including any that were already checkpointed before the function
9078** was called) or to -1 if the checkpoint could not run due to an error or
9079** because the database is not in WAL mode. ^Note that upon successful
9080** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9081** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9082**
9083** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9084** any other process is running a checkpoint operation at the same time, the
9085** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9086** busy-handler configured, it will not be invoked in this case.
9087**
9088** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9089** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9090** obtained immediately, and a busy-handler is configured, it is invoked and
9091** the writer lock retried until either the busy-handler returns 0 or the lock
9092** is successfully obtained. ^The busy-handler is also invoked while waiting for
9093** database readers as described above. ^If the busy-handler returns 0 before
9094** the writer lock is obtained or while waiting for database readers, the
9095** checkpoint operation proceeds from that point in the same way as
9096** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9097** without blocking any further. ^SQLITE_BUSY is returned in this case.
9098**
9099** ^If parameter zDb is NULL or points to a zero length string, then the
9100** specified operation is attempted on all WAL databases [attached] to
9101** [database connection] db. In this case the
9102** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9103** an SQLITE_BUSY error is encountered when processing one or more of the
9104** attached WAL databases, the operation is still attempted on any remaining
9105** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9106** error occurs while processing an attached database, processing is abandoned
9107** and the error code is returned to the caller immediately. ^If no error
9108** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9109** databases, SQLITE_OK is returned.
9110**
9111** ^If database zDb is the name of an attached database that is not in WAL
9112** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9113** zDb is not NULL (or a zero length string) and is not the name of any
9114** attached database, SQLITE_ERROR is returned to the caller.
9115**
9116** ^Unless it returns SQLITE_MISUSE,
9117** the sqlite3_wal_checkpoint_v2() interface
9118** sets the error information that is queried by
9119** [sqlite3_errcode()] and [sqlite3_errmsg()].
9120**
9121** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9122** from SQL.
9123*/
9124SQLITE_API int sqlite3_wal_checkpoint_v2(
9125 sqlite3 *db, /* Database handle */
9126 const char *zDb, /* Name of attached database (or NULL) */
9127 int eMode, /* SQLITE_CHECKPOINT_* value */
9128 int *pnLog, /* OUT: Size of WAL log in frames */
9129 int *pnCkpt /* OUT: Total number of frames checkpointed */
9130);
9131
9132/*
9133** CAPI3REF: Checkpoint Mode Values
9134** KEYWORDS: {checkpoint mode}
9135**
9136** These constants define all valid values for the "checkpoint mode" passed
9137** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9138** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9139** meaning of each of these checkpoint modes.
9140*/
9141#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9142#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9143#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
9144#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9145
9146/*
9147** CAPI3REF: Virtual Table Interface Configuration
9148**
9149** This function may be called by either the [xConnect] or [xCreate] method
9150** of a [virtual table] implementation to configure
9151** various facets of the virtual table interface.
9152**
9153** If this interface is invoked outside the context of an xConnect or
9154** xCreate virtual table method then the behavior is undefined.
9155**
9156** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9157** [database connection] in which the virtual table is being created and
9158** which is passed in as the first argument to the [xConnect] or [xCreate]
9159** method that is invoking sqlite3_vtab_config(). The C parameter is one
9160** of the [virtual table configuration options]. The presence and meaning
9161** of parameters after C depend on which [virtual table configuration option]
9162** is used.
9163*/
9164SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9165
9166/*
9167** CAPI3REF: Virtual Table Configuration Options
9168** KEYWORDS: {virtual table configuration options}
9169** KEYWORDS: {virtual table configuration option}
9170**
9171** These macros define the various options to the
9172** [sqlite3_vtab_config()] interface that [virtual table] implementations
9173** can use to customize and optimize their behavior.
9174**
9175** <dl>
9176** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9177** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9178** <dd>Calls of the form
9179** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9180** where X is an integer. If X is zero, then the [virtual table] whose
9181** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9182** support constraints. In this configuration (which is the default) if
9183** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9184** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9185** specified as part of the users SQL statement, regardless of the actual
9186** ON CONFLICT mode specified.
9187**
9188** If X is non-zero, then the virtual table implementation guarantees
9189** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9190** any modifications to internal or persistent data structures have been made.
9191** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9192** is able to roll back a statement or database transaction, and abandon
9193** or continue processing the current SQL statement as appropriate.
9194** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9195** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9196** had been ABORT.
9197**
9198** Virtual table implementations that are required to handle OR REPLACE
9199** must do so within the [xUpdate] method. If a call to the
9200** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9201** CONFLICT policy is REPLACE, the virtual table implementation should
9202** silently replace the appropriate rows within the xUpdate callback and
9203** return SQLITE_OK. Or, if this is not possible, it may return
9204** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9205** constraint handling.
9206** </dd>
9207**
9208** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9209** <dd>Calls of the form
9210** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9211** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9212** prohibits that virtual table from being used from within triggers and
9213** views.
9214** </dd>
9215**
9216** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9217** <dd>Calls of the form
9218** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9219** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9220** identify that virtual table as being safe to use from within triggers
9221** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9222** virtual table can do no serious harm even if it is controlled by a
9223** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9224** flag unless absolutely necessary.
9225** </dd>
9226** </dl>
9227*/
9228#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9229#define SQLITE_VTAB_INNOCUOUS 2
9230#define SQLITE_VTAB_DIRECTONLY 3
9231
9232/*
9233** CAPI3REF: Determine The Virtual Table Conflict Policy
9234**
9235** This function may only be called from within a call to the [xUpdate] method
9236** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9237** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9238** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9239** of the SQL statement that triggered the call to the [xUpdate] method of the
9240** [virtual table].
9241*/
9242SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9243
9244/*
9245** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9246**
9247** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9248** method of a [virtual table], then it might return true if the
9249** column is being fetched as part of an UPDATE operation during which the
9250** column value will not change. The virtual table implementation can use
9251** this hint as permission to substitute a return value that is less
9252** expensive to compute and that the corresponding
9253** [xUpdate] method understands as a "no-change" value.
9254**
9255** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9256** the column is not changed by the UPDATE statement, then the xColumn
9257** method can optionally return without setting a result, without calling
9258** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9259** In that case, [sqlite3_value_nochange(X)] will return true for the
9260** same column in the [xUpdate] method.
9261**
9262** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
9263** implementations should continue to give a correct answer even if the
9264** sqlite3_vtab_nochange() interface were to always return false. In the
9265** current implementation, the sqlite3_vtab_nochange() interface does always
9266** returns false for the enhanced [UPDATE FROM] statement.
9267*/
9268SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9269
9270/*
9271** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9272**
9273** This function may only be called from within a call to the [xBestIndex]
9274** method of a [virtual table].
9275**
9276** The first argument must be the sqlite3_index_info object that is the
9277** first parameter to the xBestIndex() method. The second argument must be
9278** an index into the aConstraint[] array belonging to the sqlite3_index_info
9279** structure passed to xBestIndex. This function returns a pointer to a buffer
9280** containing the name of the collation sequence for the corresponding
9281** constraint.
9282*/
9283SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9284
9285/*
9286** CAPI3REF: Conflict resolution modes
9287** KEYWORDS: {conflict resolution mode}
9288**
9289** These constants are returned by [sqlite3_vtab_on_conflict()] to
9290** inform a [virtual table] implementation what the [ON CONFLICT] mode
9291** is for the SQL statement being evaluated.
9292**
9293** Note that the [SQLITE_IGNORE] constant is also used as a potential
9294** return value from the [sqlite3_set_authorizer()] callback and that
9295** [SQLITE_ABORT] is also a [result code].
9296*/
9297#define SQLITE_ROLLBACK 1
9298/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
9299#define SQLITE_FAIL 3
9300/* #define SQLITE_ABORT 4 // Also an error code */
9301#define SQLITE_REPLACE 5
9302
9303/*
9304** CAPI3REF: Prepared Statement Scan Status Opcodes
9305** KEYWORDS: {scanstatus options}
9306**
9307** The following constants can be used for the T parameter to the
9308** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
9309** different metric for sqlite3_stmt_scanstatus() to return.
9310**
9311** When the value returned to V is a string, space to hold that string is
9312** managed by the prepared statement S and will be automatically freed when
9313** S is finalized.
9314**
9315** <dl>
9316** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
9317** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
9318** set to the total number of times that the X-th loop has run.</dd>
9319**
9320** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
9321** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
9322** to the total number of rows examined by all iterations of the X-th loop.</dd>
9323**
9324** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
9325** <dd>^The "double" variable pointed to by the V parameter will be set to the
9326** query planner's estimate for the average number of rows output from each
9327** iteration of the X-th loop. If the query planner's estimates was accurate,
9328** then this value will approximate the quotient NVISIT/NLOOP and the
9329** product of this value for all prior loops with the same SELECTID will
9330** be the NLOOP value for the current loop.
9331**
9332** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
9333** <dd>^The "const char *" variable pointed to by the V parameter will be set
9334** to a zero-terminated UTF-8 string containing the name of the index or table
9335** used for the X-th loop.
9336**
9337** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
9338** <dd>^The "const char *" variable pointed to by the V parameter will be set
9339** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
9340** description for the X-th loop.
9341**
9342** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
9343** <dd>^The "int" variable pointed to by the V parameter will be set to the
9344** "select-id" for the X-th loop. The select-id identifies which query or
9345** subquery the loop is part of. The main query has a select-id of zero.
9346** The select-id is the same value as is output in the first column
9347** of an [EXPLAIN QUERY PLAN] query.
9348** </dl>
9349*/
9350#define SQLITE_SCANSTAT_NLOOP 0
9351#define SQLITE_SCANSTAT_NVISIT 1
9352#define SQLITE_SCANSTAT_EST 2
9353#define SQLITE_SCANSTAT_NAME 3
9354#define SQLITE_SCANSTAT_EXPLAIN 4
9355#define SQLITE_SCANSTAT_SELECTID 5
9356
9357/*
9358** CAPI3REF: Prepared Statement Scan Status
9359** METHOD: sqlite3_stmt
9360**
9361** This interface returns information about the predicted and measured
9362** performance for pStmt. Advanced applications can use this
9363** interface to compare the predicted and the measured performance and
9364** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
9365**
9366** Since this interface is expected to be rarely used, it is only
9367** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
9368** compile-time option.
9369**
9370** The "iScanStatusOp" parameter determines which status information to return.
9371** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
9372** of this interface is undefined.
9373** ^The requested measurement is written into a variable pointed to by
9374** the "pOut" parameter.
9375** Parameter "idx" identifies the specific loop to retrieve statistics for.
9376** Loops are numbered starting from zero. ^If idx is out of range - less than
9377** zero or greater than or equal to the total number of loops used to implement
9378** the statement - a non-zero value is returned and the variable that pOut
9379** points to is unchanged.
9380**
9381** ^Statistics might not be available for all loops in all statements. ^In cases
9382** where there exist loops with no available statistics, this function behaves
9383** as if the loop did not exist - it returns non-zero and leave the variable
9384** that pOut points to unchanged.
9385**
9386** See also: [sqlite3_stmt_scanstatus_reset()]
9387*/
9388SQLITE_API int sqlite3_stmt_scanstatus(
9389 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
9390 int idx, /* Index of loop to report on */
9391 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
9392 void *pOut /* Result written here */
9393);
9394
9395/*
9396** CAPI3REF: Zero Scan-Status Counters
9397** METHOD: sqlite3_stmt
9398**
9399** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
9400**
9401** This API is only available if the library is built with pre-processor
9402** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
9403*/
9404SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
9405
9406/*
9407** CAPI3REF: Flush caches to disk mid-transaction
9408** METHOD: sqlite3
9409**
9410** ^If a write-transaction is open on [database connection] D when the
9411** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
9412** pages in the pager-cache that are not currently in use are written out
9413** to disk. A dirty page may be in use if a database cursor created by an
9414** active SQL statement is reading from it, or if it is page 1 of a database
9415** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
9416** interface flushes caches for all schemas - "main", "temp", and
9417** any [attached] databases.
9418**
9419** ^If this function needs to obtain extra database locks before dirty pages
9420** can be flushed to disk, it does so. ^If those locks cannot be obtained
9421** immediately and there is a busy-handler callback configured, it is invoked
9422** in the usual manner. ^If the required lock still cannot be obtained, then
9423** the database is skipped and an attempt made to flush any dirty pages
9424** belonging to the next (if any) database. ^If any databases are skipped
9425** because locks cannot be obtained, but no other error occurs, this
9426** function returns SQLITE_BUSY.
9427**
9428** ^If any other error occurs while flushing dirty pages to disk (for
9429** example an IO error or out-of-memory condition), then processing is
9430** abandoned and an SQLite [error code] is returned to the caller immediately.
9431**
9432** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
9433**
9434** ^This function does not set the database handle error code or message
9435** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
9436*/
9437SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
9438
9439/*
9440** CAPI3REF: The pre-update hook.
9441** METHOD: sqlite3
9442**
9443** ^These interfaces are only available if SQLite is compiled using the
9444** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
9445**
9446** ^The [sqlite3_preupdate_hook()] interface registers a callback function
9447** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
9448** on a database table.
9449** ^At most one preupdate hook may be registered at a time on a single
9450** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
9451** the previous setting.
9452** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
9453** with a NULL pointer as the second parameter.
9454** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
9455** the first parameter to callbacks.
9456**
9457** ^The preupdate hook only fires for changes to real database tables; the
9458** preupdate hook is not invoked for changes to [virtual tables] or to
9459** system tables like sqlite_sequence or sqlite_stat1.
9460**
9461** ^The second parameter to the preupdate callback is a pointer to
9462** the [database connection] that registered the preupdate hook.
9463** ^The third parameter to the preupdate callback is one of the constants
9464** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
9465** kind of update operation that is about to occur.
9466** ^(The fourth parameter to the preupdate callback is the name of the
9467** database within the database connection that is being modified. This
9468** will be "main" for the main database or "temp" for TEMP tables or
9469** the name given after the AS keyword in the [ATTACH] statement for attached
9470** databases.)^
9471** ^The fifth parameter to the preupdate callback is the name of the
9472** table that is being modified.
9473**
9474** For an UPDATE or DELETE operation on a [rowid table], the sixth
9475** parameter passed to the preupdate callback is the initial [rowid] of the
9476** row being modified or deleted. For an INSERT operation on a rowid table,
9477** or any operation on a WITHOUT ROWID table, the value of the sixth
9478** parameter is undefined. For an INSERT or UPDATE on a rowid table the
9479** seventh parameter is the final rowid value of the row being inserted
9480** or updated. The value of the seventh parameter passed to the callback
9481** function is not defined for operations on WITHOUT ROWID tables, or for
9482** DELETE operations on rowid tables.
9483**
9484** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
9485** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
9486** provide additional information about a preupdate event. These routines
9487** may only be called from within a preupdate callback. Invoking any of
9488** these routines from outside of a preupdate callback or with a
9489** [database connection] pointer that is different from the one supplied
9490** to the preupdate callback results in undefined and probably undesirable
9491** behavior.
9492**
9493** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
9494** in the row that is being inserted, updated, or deleted.
9495**
9496** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
9497** a [protected sqlite3_value] that contains the value of the Nth column of
9498** the table row before it is updated. The N parameter must be between 0
9499** and one less than the number of columns or the behavior will be
9500** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
9501** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
9502** behavior is undefined. The [sqlite3_value] that P points to
9503** will be destroyed when the preupdate callback returns.
9504**
9505** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
9506** a [protected sqlite3_value] that contains the value of the Nth column of
9507** the table row after it is updated. The N parameter must be between 0
9508** and one less than the number of columns or the behavior will be
9509** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
9510** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
9511** behavior is undefined. The [sqlite3_value] that P points to
9512** will be destroyed when the preupdate callback returns.
9513**
9514** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
9515** callback was invoked as a result of a direct insert, update, or delete
9516** operation; or 1 for inserts, updates, or deletes invoked by top-level
9517** triggers; or 2 for changes resulting from triggers called by top-level
9518** triggers; and so forth.
9519**
9520** See also: [sqlite3_update_hook()]
9521*/
9522#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
9523SQLITE_API void *sqlite3_preupdate_hook(
9524 sqlite3 *db,
9525 void(*xPreUpdate)(
9526 void *pCtx, /* Copy of third arg to preupdate_hook() */
9527 sqlite3 *db, /* Database handle */
9528 int op, /* SQLITE_UPDATE, DELETE or INSERT */
9529 char const *zDb, /* Database name */
9530 char const *zName, /* Table name */
9531 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
9532 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
9533 ),
9534 void*
9535);
9536SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
9537SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
9538SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
9539SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
9540#endif
9541
9542/*
9543** CAPI3REF: Low-level system error code
9544** METHOD: sqlite3
9545**
9546** ^Attempt to return the underlying operating system error code or error
9547** number that caused the most recent I/O error or failure to open a file.
9548** The return value is OS-dependent. For example, on unix systems, after
9549** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
9550** called to get back the underlying "errno" that caused the problem, such
9551** as ENOSPC, EAUTH, EISDIR, and so forth.
9552*/
9553SQLITE_API int sqlite3_system_errno(sqlite3*);
9554
9555/*
9556** CAPI3REF: Database Snapshot
9557** KEYWORDS: {snapshot} {sqlite3_snapshot}
9558**
9559** An instance of the snapshot object records the state of a [WAL mode]
9560** database for some specific point in history.
9561**
9562** In [WAL mode], multiple [database connections] that are open on the
9563** same database file can each be reading a different historical version
9564** of the database file. When a [database connection] begins a read
9565** transaction, that connection sees an unchanging copy of the database
9566** as it existed for the point in time when the transaction first started.
9567** Subsequent changes to the database from other connections are not seen
9568** by the reader until a new read transaction is started.
9569**
9570** The sqlite3_snapshot object records state information about an historical
9571** version of the database file so that it is possible to later open a new read
9572** transaction that sees that historical version of the database rather than
9573** the most recent version.
9574*/
9575typedef struct sqlite3_snapshot {
9576 unsigned char hidden[48];
9577} sqlite3_snapshot;
9578
9579/*
9580** CAPI3REF: Record A Database Snapshot
9581** CONSTRUCTOR: sqlite3_snapshot
9582**
9583** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
9584** new [sqlite3_snapshot] object that records the current state of
9585** schema S in database connection D. ^On success, the
9586** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
9587** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
9588** If there is not already a read-transaction open on schema S when
9589** this function is called, one is opened automatically.
9590**
9591** The following must be true for this function to succeed. If any of
9592** the following statements are false when sqlite3_snapshot_get() is
9593** called, SQLITE_ERROR is returned. The final value of *P is undefined
9594** in this case.
9595**
9596** <ul>
9597** <li> The database handle must not be in [autocommit mode].
9598**
9599** <li> Schema S of [database connection] D must be a [WAL mode] database.
9600**
9601** <li> There must not be a write transaction open on schema S of database
9602** connection D.
9603**
9604** <li> One or more transactions must have been written to the current wal
9605** file since it was created on disk (by any connection). This means
9606** that a snapshot cannot be taken on a wal mode database with no wal
9607** file immediately after it is first opened. At least one transaction
9608** must be written to it first.
9609** </ul>
9610**
9611** This function may also return SQLITE_NOMEM. If it is called with the
9612** database handle in autocommit mode but fails for some other reason,
9613** whether or not a read transaction is opened on schema S is undefined.
9614**
9615** The [sqlite3_snapshot] object returned from a successful call to
9616** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
9617** to avoid a memory leak.
9618**
9619** The [sqlite3_snapshot_get()] interface is only available when the
9620** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9621*/
9622SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
9623 sqlite3 *db,
9624 const char *zSchema,
9625 sqlite3_snapshot **ppSnapshot
9626);
9627
9628/*
9629** CAPI3REF: Start a read transaction on an historical snapshot
9630** METHOD: sqlite3_snapshot
9631**
9632** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
9633** transaction or upgrades an existing one for schema S of
9634** [database connection] D such that the read transaction refers to
9635** historical [snapshot] P, rather than the most recent change to the
9636** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
9637** on success or an appropriate [error code] if it fails.
9638**
9639** ^In order to succeed, the database connection must not be in
9640** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
9641** is already a read transaction open on schema S, then the database handle
9642** must have no active statements (SELECT statements that have been passed
9643** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
9644** SQLITE_ERROR is returned if either of these conditions is violated, or
9645** if schema S does not exist, or if the snapshot object is invalid.
9646**
9647** ^A call to sqlite3_snapshot_open() will fail to open if the specified
9648** snapshot has been overwritten by a [checkpoint]. In this case
9649** SQLITE_ERROR_SNAPSHOT is returned.
9650**
9651** If there is already a read transaction open when this function is
9652** invoked, then the same read transaction remains open (on the same
9653** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
9654** is returned. If another error code - for example SQLITE_PROTOCOL or an
9655** SQLITE_IOERR error code - is returned, then the final state of the
9656** read transaction is undefined. If SQLITE_OK is returned, then the
9657** read transaction is now open on database snapshot P.
9658**
9659** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
9660** database connection D does not know that the database file for
9661** schema S is in [WAL mode]. A database connection might not know
9662** that the database file is in [WAL mode] if there has been no prior
9663** I/O on that database connection, or if the database entered [WAL mode]
9664** after the most recent I/O on the database connection.)^
9665** (Hint: Run "[PRAGMA application_id]" against a newly opened
9666** database connection in order to make it ready to use snapshots.)
9667**
9668** The [sqlite3_snapshot_open()] interface is only available when the
9669** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9670*/
9671SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
9672 sqlite3 *db,
9673 const char *zSchema,
9674 sqlite3_snapshot *pSnapshot
9675);
9676
9677/*
9678** CAPI3REF: Destroy a snapshot
9679** DESTRUCTOR: sqlite3_snapshot
9680**
9681** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
9682** The application must eventually free every [sqlite3_snapshot] object
9683** using this routine to avoid a memory leak.
9684**
9685** The [sqlite3_snapshot_free()] interface is only available when the
9686** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9687*/
9688SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
9689
9690/*
9691** CAPI3REF: Compare the ages of two snapshot handles.
9692** METHOD: sqlite3_snapshot
9693**
9694** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
9695** of two valid snapshot handles.
9696**
9697** If the two snapshot handles are not associated with the same database
9698** file, the result of the comparison is undefined.
9699**
9700** Additionally, the result of the comparison is only valid if both of the
9701** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
9702** last time the wal file was deleted. The wal file is deleted when the
9703** database is changed back to rollback mode or when the number of database
9704** clients drops to zero. If either snapshot handle was obtained before the
9705** wal file was last deleted, the value returned by this function
9706** is undefined.
9707**
9708** Otherwise, this API returns a negative value if P1 refers to an older
9709** snapshot than P2, zero if the two handles refer to the same database
9710** snapshot, and a positive value if P1 is a newer snapshot than P2.
9711**
9712** This interface is only available if SQLite is compiled with the
9713** [SQLITE_ENABLE_SNAPSHOT] option.
9714*/
9715SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
9716 sqlite3_snapshot *p1,
9717 sqlite3_snapshot *p2
9718);
9719
9720/*
9721** CAPI3REF: Recover snapshots from a wal file
9722** METHOD: sqlite3_snapshot
9723**
9724** If a [WAL file] remains on disk after all database connections close
9725** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
9726** or because the last process to have the database opened exited without
9727** calling [sqlite3_close()]) and a new connection is subsequently opened
9728** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
9729** will only be able to open the last transaction added to the WAL file
9730** even though the WAL file contains other valid transactions.
9731**
9732** This function attempts to scan the WAL file associated with database zDb
9733** of database handle db and make all valid snapshots available to
9734** sqlite3_snapshot_open(). It is an error if there is already a read
9735** transaction open on the database, or if the database is not a WAL mode
9736** database.
9737**
9738** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
9739**
9740** This interface is only available if SQLite is compiled with the
9741** [SQLITE_ENABLE_SNAPSHOT] option.
9742*/
9743SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
9744
9745/*
9746** CAPI3REF: Serialize a database
9747**
9748** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
9749** that is a serialization of the S database on [database connection] D.
9750** If P is not a NULL pointer, then the size of the database in bytes
9751** is written into *P.
9752**
9753** For an ordinary on-disk database file, the serialization is just a
9754** copy of the disk file. For an in-memory database or a "TEMP" database,
9755** the serialization is the same sequence of bytes which would be written
9756** to disk if that database where backed up to disk.
9757**
9758** The usual case is that sqlite3_serialize() copies the serialization of
9759** the database into memory obtained from [sqlite3_malloc64()] and returns
9760** a pointer to that memory. The caller is responsible for freeing the
9761** returned value to avoid a memory leak. However, if the F argument
9762** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
9763** are made, and the sqlite3_serialize() function will return a pointer
9764** to the contiguous memory representation of the database that SQLite
9765** is currently using for that database, or NULL if the no such contiguous
9766** memory representation of the database exists. A contiguous memory
9767** representation of the database will usually only exist if there has
9768** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
9769** values of D and S.
9770** The size of the database is written into *P even if the
9771** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
9772** of the database exists.
9773**
9774** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
9775** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
9776** allocation error occurs.
9777**
9778** This interface is only available if SQLite is compiled with the
9779** [SQLITE_ENABLE_DESERIALIZE] option.
9780*/
9781SQLITE_API unsigned char *sqlite3_serialize(
9782 sqlite3 *db, /* The database connection */
9783 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
9784 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
9785 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
9786);
9787
9788/*
9789** CAPI3REF: Flags for sqlite3_serialize
9790**
9791** Zero or more of the following constants can be OR-ed together for
9792** the F argument to [sqlite3_serialize(D,S,P,F)].
9793**
9794** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
9795** a pointer to contiguous in-memory database that it is currently using,
9796** without making a copy of the database. If SQLite is not currently using
9797** a contiguous in-memory database, then this option causes
9798** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
9799** using a contiguous in-memory database if it has been initialized by a
9800** prior call to [sqlite3_deserialize()].
9801*/
9802#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
9803
9804/*
9805** CAPI3REF: Deserialize a database
9806**
9807** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
9808** [database connection] D to disconnect from database S and then
9809** reopen S as an in-memory database based on the serialization contained
9810** in P. The serialized database P is N bytes in size. M is the size of
9811** the buffer P, which might be larger than N. If M is larger than N, and
9812** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
9813** permitted to add content to the in-memory database as long as the total
9814** size does not exceed M bytes.
9815**
9816** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
9817** invoke sqlite3_free() on the serialization buffer when the database
9818** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
9819** SQLite will try to increase the buffer size using sqlite3_realloc64()
9820** if writes on the database cause it to grow larger than M bytes.
9821**
9822** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
9823** database is currently in a read transaction or is involved in a backup
9824** operation.
9825**
9826** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
9827** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
9828** [sqlite3_free()] is invoked on argument P prior to returning.
9829**
9830** This interface is only available if SQLite is compiled with the
9831** [SQLITE_ENABLE_DESERIALIZE] option.
9832*/
9833SQLITE_API int sqlite3_deserialize(
9834 sqlite3 *db, /* The database connection */
9835 const char *zSchema, /* Which DB to reopen with the deserialization */
9836 unsigned char *pData, /* The serialized database content */
9837 sqlite3_int64 szDb, /* Number bytes in the deserialization */
9838 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
9839 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
9840);
9841
9842/*
9843** CAPI3REF: Flags for sqlite3_deserialize()
9844**
9845** The following are allowed values for 6th argument (the F argument) to
9846** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
9847**
9848** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
9849** in the P argument is held in memory obtained from [sqlite3_malloc64()]
9850** and that SQLite should take ownership of this memory and automatically
9851** free it when it has finished using it. Without this flag, the caller
9852** is responsible for freeing any dynamically allocated memory.
9853**
9854** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
9855** grow the size of the database using calls to [sqlite3_realloc64()]. This
9856** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
9857** Without this flag, the deserialized database cannot increase in size beyond
9858** the number of bytes specified by the M parameter.
9859**
9860** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
9861** should be treated as read-only.
9862*/
9863#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
9864#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
9865#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
9866
9867/*
9868** Undo the hack that converts floating point types to integer for
9869** builds on processors without floating point support.
9870*/
9871#ifdef SQLITE_OMIT_FLOATING_POINT
9872# undef double
9873#endif
9874
9875#ifdef __cplusplus
9876} /* End of the 'extern "C"' block */
9877#endif
9878#endif /* SQLITE3_H */
9879
9880/******** Begin file sqlite3rtree.h *********/
9881/*
9882** 2010 August 30
9883**
9884** The author disclaims copyright to this source code. In place of
9885** a legal notice, here is a blessing:
9886**
9887** May you do good and not evil.
9888** May you find forgiveness for yourself and forgive others.
9889** May you share freely, never taking more than you give.
9890**
9891*************************************************************************
9892*/
9893
9894#ifndef _SQLITE3RTREE_H_
9895#define _SQLITE3RTREE_H_
9896
9897
9898#ifdef __cplusplus
9899extern "C" {
9900#endif
9901
9902typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
9903typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
9904
9905/* The double-precision datatype used by RTree depends on the
9906** SQLITE_RTREE_INT_ONLY compile-time option.
9907*/
9908#ifdef SQLITE_RTREE_INT_ONLY
9909 typedef sqlite3_int64 sqlite3_rtree_dbl;
9910#else
9911 typedef double sqlite3_rtree_dbl;
9912#endif
9913
9914/*
9915** Register a geometry callback named zGeom that can be used as part of an
9916** R-Tree geometry query as follows:
9917**
9918** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
9919*/
9920SQLITE_API int sqlite3_rtree_geometry_callback(
9921 sqlite3 *db,
9922 const char *zGeom,
9923 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
9924 void *pContext
9925);
9926
9927
9928/*
9929** A pointer to a structure of the following type is passed as the first
9930** argument to callbacks registered using rtree_geometry_callback().
9931*/
9932struct sqlite3_rtree_geometry {
9933 void *pContext; /* Copy of pContext passed to s_r_g_c() */
9934 int nParam; /* Size of array aParam[] */
9935 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
9936 void *pUser; /* Callback implementation user data */
9937 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
9938};
9939
9940/*
9941** Register a 2nd-generation geometry callback named zScore that can be
9942** used as part of an R-Tree geometry query as follows:
9943**
9944** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
9945*/
9946SQLITE_API int sqlite3_rtree_query_callback(
9947 sqlite3 *db,
9948 const char *zQueryFunc,
9949 int (*xQueryFunc)(sqlite3_rtree_query_info*),
9950 void *pContext,
9951 void (*xDestructor)(void*)
9952);
9953
9954
9955/*
9956** A pointer to a structure of the following type is passed as the
9957** argument to scored geometry callback registered using
9958** sqlite3_rtree_query_callback().
9959**
9960** Note that the first 5 fields of this structure are identical to
9961** sqlite3_rtree_geometry. This structure is a subclass of
9962** sqlite3_rtree_geometry.
9963*/
9964struct sqlite3_rtree_query_info {
9965 void *pContext; /* pContext from when function registered */
9966 int nParam; /* Number of function parameters */
9967 sqlite3_rtree_dbl *aParam; /* value of function parameters */
9968 void *pUser; /* callback can use this, if desired */
9969 void (*xDelUser)(void*); /* function to free pUser */
9970 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
9971 unsigned int *anQueue; /* Number of pending entries in the queue */
9972 int nCoord; /* Number of coordinates */
9973 int iLevel; /* Level of current node or entry */
9974 int mxLevel; /* The largest iLevel value in the tree */
9975 sqlite3_int64 iRowid; /* Rowid for current entry */
9976 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
9977 int eParentWithin; /* Visibility of parent node */
9978 int eWithin; /* OUT: Visibility */
9979 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
9980 /* The following fields are only available in 3.8.11 and later */
9981 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
9982};
9983
9984/*
9985** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
9986*/
9987#define NOT_WITHIN 0 /* Object completely outside of query region */
9988#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
9989#define FULLY_WITHIN 2 /* Object fully contained within query region */
9990
9991
9992#ifdef __cplusplus
9993} /* end of the 'extern "C"' block */
9994#endif
9995
9996#endif /* ifndef _SQLITE3RTREE_H_ */
9997
9998/******** End of sqlite3rtree.h *********/
9999/******** Begin file sqlite3session.h *********/
10000
10001#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10002#define __SQLITESESSION_H_ 1
10003
10004/*
10005** Make sure we can call this stuff from C++.
10006*/
10007#ifdef __cplusplus
10008extern "C" {
10009#endif
10010
10011
10012/*
10013** CAPI3REF: Session Object Handle
10014**
10015** An instance of this object is a [session] that can be used to
10016** record changes to a database.
10017*/
10018typedef struct sqlite3_session sqlite3_session;
10019
10020/*
10021** CAPI3REF: Changeset Iterator Handle
10022**
10023** An instance of this object acts as a cursor for iterating
10024** over the elements of a [changeset] or [patchset].
10025*/
10026typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10027
10028/*
10029** CAPI3REF: Create A New Session Object
10030** CONSTRUCTOR: sqlite3_session
10031**
10032** Create a new session object attached to database handle db. If successful,
10033** a pointer to the new object is written to *ppSession and SQLITE_OK is
10034** returned. If an error occurs, *ppSession is set to NULL and an SQLite
10035** error code (e.g. SQLITE_NOMEM) is returned.
10036**
10037** It is possible to create multiple session objects attached to a single
10038** database handle.
10039**
10040** Session objects created using this function should be deleted using the
10041** [sqlite3session_delete()] function before the database handle that they
10042** are attached to is itself closed. If the database handle is closed before
10043** the session object is deleted, then the results of calling any session
10044** module function, including [sqlite3session_delete()] on the session object
10045** are undefined.
10046**
10047** Because the session module uses the [sqlite3_preupdate_hook()] API, it
10048** is not possible for an application to register a pre-update hook on a
10049** database handle that has one or more session objects attached. Nor is
10050** it possible to create a session object attached to a database handle for
10051** which a pre-update hook is already defined. The results of attempting
10052** either of these things are undefined.
10053**
10054** The session object will be used to create changesets for tables in
10055** database zDb, where zDb is either "main", or "temp", or the name of an
10056** attached database. It is not an error if database zDb is not attached
10057** to the database when the session object is created.
10058*/
10059SQLITE_API int sqlite3session_create(
10060 sqlite3 *db, /* Database handle */
10061 const char *zDb, /* Name of db (e.g. "main") */
10062 sqlite3_session **ppSession /* OUT: New session object */
10063);
10064
10065/*
10066** CAPI3REF: Delete A Session Object
10067** DESTRUCTOR: sqlite3_session
10068**
10069** Delete a session object previously allocated using
10070** [sqlite3session_create()]. Once a session object has been deleted, the
10071** results of attempting to use pSession with any other session module
10072** function are undefined.
10073**
10074** Session objects must be deleted before the database handle to which they
10075** are attached is closed. Refer to the documentation for
10076** [sqlite3session_create()] for details.
10077*/
10078SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
10079
10080
10081/*
10082** CAPI3REF: Enable Or Disable A Session Object
10083** METHOD: sqlite3_session
10084**
10085** Enable or disable the recording of changes by a session object. When
10086** enabled, a session object records changes made to the database. When
10087** disabled - it does not. A newly created session object is enabled.
10088** Refer to the documentation for [sqlite3session_changeset()] for further
10089** details regarding how enabling and disabling a session object affects
10090** the eventual changesets.
10091**
10092** Passing zero to this function disables the session. Passing a value
10093** greater than zero enables it. Passing a value less than zero is a
10094** no-op, and may be used to query the current state of the session.
10095**
10096** The return value indicates the final state of the session object: 0 if
10097** the session is disabled, or 1 if it is enabled.
10098*/
10099SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
10100
10101/*
10102** CAPI3REF: Set Or Clear the Indirect Change Flag
10103** METHOD: sqlite3_session
10104**
10105** Each change recorded by a session object is marked as either direct or
10106** indirect. A change is marked as indirect if either:
10107**
10108** <ul>
10109** <li> The session object "indirect" flag is set when the change is
10110** made, or
10111** <li> The change is made by an SQL trigger or foreign key action
10112** instead of directly as a result of a users SQL statement.
10113** </ul>
10114**
10115** If a single row is affected by more than one operation within a session,
10116** then the change is considered indirect if all operations meet the criteria
10117** for an indirect change above, or direct otherwise.
10118**
10119** This function is used to set, clear or query the session object indirect
10120** flag. If the second argument passed to this function is zero, then the
10121** indirect flag is cleared. If it is greater than zero, the indirect flag
10122** is set. Passing a value less than zero does not modify the current value
10123** of the indirect flag, and may be used to query the current state of the
10124** indirect flag for the specified session object.
10125**
10126** The return value indicates the final state of the indirect flag: 0 if
10127** it is clear, or 1 if it is set.
10128*/
10129SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
10130
10131/*
10132** CAPI3REF: Attach A Table To A Session Object
10133** METHOD: sqlite3_session
10134**
10135** If argument zTab is not NULL, then it is the name of a table to attach
10136** to the session object passed as the first argument. All subsequent changes
10137** made to the table while the session object is enabled will be recorded. See
10138** documentation for [sqlite3session_changeset()] for further details.
10139**
10140** Or, if argument zTab is NULL, then changes are recorded for all tables
10141** in the database. If additional tables are added to the database (by
10142** executing "CREATE TABLE" statements) after this call is made, changes for
10143** the new tables are also recorded.
10144**
10145** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
10146** defined as part of their CREATE TABLE statement. It does not matter if the
10147** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
10148** KEY may consist of a single column, or may be a composite key.
10149**
10150** It is not an error if the named table does not exist in the database. Nor
10151** is it an error if the named table does not have a PRIMARY KEY. However,
10152** no changes will be recorded in either of these scenarios.
10153**
10154** Changes are not recorded for individual rows that have NULL values stored
10155** in one or more of their PRIMARY KEY columns.
10156**
10157** SQLITE_OK is returned if the call completes without error. Or, if an error
10158** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
10159**
10160** <h3>Special sqlite_stat1 Handling</h3>
10161**
10162** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
10163** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
10164** <pre>
10165** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
10166** </pre>
10167**
10168** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
10169** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
10170** are recorded for rows for which (idx IS NULL) is true. However, for such
10171** rows a zero-length blob (SQL value X'') is stored in the changeset or
10172** patchset instead of a NULL value. This allows such changesets to be
10173** manipulated by legacy implementations of sqlite3changeset_invert(),
10174** concat() and similar.
10175**
10176** The sqlite3changeset_apply() function automatically converts the
10177** zero-length blob back to a NULL value when updating the sqlite_stat1
10178** table. However, if the application calls sqlite3changeset_new(),
10179** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
10180** iterator directly (including on a changeset iterator passed to a
10181** conflict-handler callback) then the X'' value is returned. The application
10182** must translate X'' to NULL itself if required.
10183**
10184** Legacy (older than 3.22.0) versions of the sessions module cannot capture
10185** changes made to the sqlite_stat1 table. Legacy versions of the
10186** sqlite3changeset_apply() function silently ignore any modifications to the
10187** sqlite_stat1 table that are part of a changeset or patchset.
10188*/
10189SQLITE_API int sqlite3session_attach(
10190 sqlite3_session *pSession, /* Session object */
10191 const char *zTab /* Table name */
10192);
10193
10194/*
10195** CAPI3REF: Set a table filter on a Session Object.
10196** METHOD: sqlite3_session
10197**
10198** The second argument (xFilter) is the "filter callback". For changes to rows
10199** in tables that are not attached to the Session object, the filter is called
10200** to determine whether changes to the table's rows should be tracked or not.
10201** If xFilter returns 0, changes are not tracked. Note that once a table is
10202** attached, xFilter will not be called again.
10203*/
10204SQLITE_API void sqlite3session_table_filter(
10205 sqlite3_session *pSession, /* Session object */
10206 int(*xFilter)(
10207 void *pCtx, /* Copy of third arg to _filter_table() */
10208 const char *zTab /* Table name */
10209 ),
10210 void *pCtx /* First argument passed to xFilter */
10211);
10212
10213/*
10214** CAPI3REF: Generate A Changeset From A Session Object
10215** METHOD: sqlite3_session
10216**
10217** Obtain a changeset containing changes to the tables attached to the
10218** session object passed as the first argument. If successful,
10219** set *ppChangeset to point to a buffer containing the changeset
10220** and *pnChangeset to the size of the changeset in bytes before returning
10221** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
10222** zero and return an SQLite error code.
10223**
10224** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
10225** each representing a change to a single row of an attached table. An INSERT
10226** change contains the values of each field of a new database row. A DELETE
10227** contains the original values of each field of a deleted database row. An
10228** UPDATE change contains the original values of each field of an updated
10229** database row along with the updated values for each updated non-primary-key
10230** column. It is not possible for an UPDATE change to represent a change that
10231** modifies the values of primary key columns. If such a change is made, it
10232** is represented in a changeset as a DELETE followed by an INSERT.
10233**
10234** Changes are not recorded for rows that have NULL values stored in one or
10235** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
10236** no corresponding change is present in the changesets returned by this
10237** function. If an existing row with one or more NULL values stored in
10238** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
10239** only an INSERT is appears in the changeset. Similarly, if an existing row
10240** with non-NULL PRIMARY KEY values is updated so that one or more of its
10241** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
10242** DELETE change only.
10243**
10244** The contents of a changeset may be traversed using an iterator created
10245** using the [sqlite3changeset_start()] API. A changeset may be applied to
10246** a database with a compatible schema using the [sqlite3changeset_apply()]
10247** API.
10248**
10249** Within a changeset generated by this function, all changes related to a
10250** single table are grouped together. In other words, when iterating through
10251** a changeset or when applying a changeset to a database, all changes related
10252** to a single table are processed before moving on to the next table. Tables
10253** are sorted in the same order in which they were attached (or auto-attached)
10254** to the sqlite3_session object. The order in which the changes related to
10255** a single table are stored is undefined.
10256**
10257** Following a successful call to this function, it is the responsibility of
10258** the caller to eventually free the buffer that *ppChangeset points to using
10259** [sqlite3_free()].
10260**
10261** <h3>Changeset Generation</h3>
10262**
10263** Once a table has been attached to a session object, the session object
10264** records the primary key values of all new rows inserted into the table.
10265** It also records the original primary key and other column values of any
10266** deleted or updated rows. For each unique primary key value, data is only
10267** recorded once - the first time a row with said primary key is inserted,
10268** updated or deleted in the lifetime of the session.
10269**
10270** There is one exception to the previous paragraph: when a row is inserted,
10271** updated or deleted, if one or more of its primary key columns contain a
10272** NULL value, no record of the change is made.
10273**
10274** The session object therefore accumulates two types of records - those
10275** that consist of primary key values only (created when the user inserts
10276** a new record) and those that consist of the primary key values and the
10277** original values of other table columns (created when the users deletes
10278** or updates a record).
10279**
10280** When this function is called, the requested changeset is created using
10281** both the accumulated records and the current contents of the database
10282** file. Specifically:
10283**
10284** <ul>
10285** <li> For each record generated by an insert, the database is queried
10286** for a row with a matching primary key. If one is found, an INSERT
10287** change is added to the changeset. If no such row is found, no change
10288** is added to the changeset.
10289**
10290** <li> For each record generated by an update or delete, the database is
10291** queried for a row with a matching primary key. If such a row is
10292** found and one or more of the non-primary key fields have been
10293** modified from their original values, an UPDATE change is added to
10294** the changeset. Or, if no such row is found in the table, a DELETE
10295** change is added to the changeset. If there is a row with a matching
10296** primary key in the database, but all fields contain their original
10297** values, no change is added to the changeset.
10298** </ul>
10299**
10300** This means, amongst other things, that if a row is inserted and then later
10301** deleted while a session object is active, neither the insert nor the delete
10302** will be present in the changeset. Or if a row is deleted and then later a
10303** row with the same primary key values inserted while a session object is
10304** active, the resulting changeset will contain an UPDATE change instead of
10305** a DELETE and an INSERT.
10306**
10307** When a session object is disabled (see the [sqlite3session_enable()] API),
10308** it does not accumulate records when rows are inserted, updated or deleted.
10309** This may appear to have some counter-intuitive effects if a single row
10310** is written to more than once during a session. For example, if a row
10311** is inserted while a session object is enabled, then later deleted while
10312** the same session object is disabled, no INSERT record will appear in the
10313** changeset, even though the delete took place while the session was disabled.
10314** Or, if one field of a row is updated while a session is disabled, and
10315** another field of the same row is updated while the session is enabled, the
10316** resulting changeset will contain an UPDATE change that updates both fields.
10317*/
10318SQLITE_API int sqlite3session_changeset(
10319 sqlite3_session *pSession, /* Session object */
10320 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
10321 void **ppChangeset /* OUT: Buffer containing changeset */
10322);
10323
10324/*
10325** CAPI3REF: Load The Difference Between Tables Into A Session
10326** METHOD: sqlite3_session
10327**
10328** If it is not already attached to the session object passed as the first
10329** argument, this function attaches table zTbl in the same manner as the
10330** [sqlite3session_attach()] function. If zTbl does not exist, or if it
10331** does not have a primary key, this function is a no-op (but does not return
10332** an error).
10333**
10334** Argument zFromDb must be the name of a database ("main", "temp" etc.)
10335** attached to the same database handle as the session object that contains
10336** a table compatible with the table attached to the session by this function.
10337** A table is considered compatible if it:
10338**
10339** <ul>
10340** <li> Has the same name,
10341** <li> Has the same set of columns declared in the same order, and
10342** <li> Has the same PRIMARY KEY definition.
10343** </ul>
10344**
10345** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
10346** are compatible but do not have any PRIMARY KEY columns, it is not an error
10347** but no changes are added to the session object. As with other session
10348** APIs, tables without PRIMARY KEYs are simply ignored.
10349**
10350** This function adds a set of changes to the session object that could be
10351** used to update the table in database zFrom (call this the "from-table")
10352** so that its content is the same as the table attached to the session
10353** object (call this the "to-table"). Specifically:
10354**
10355** <ul>
10356** <li> For each row (primary key) that exists in the to-table but not in
10357** the from-table, an INSERT record is added to the session object.
10358**
10359** <li> For each row (primary key) that exists in the to-table but not in
10360** the from-table, a DELETE record is added to the session object.
10361**
10362** <li> For each row (primary key) that exists in both tables, but features
10363** different non-PK values in each, an UPDATE record is added to the
10364** session.
10365** </ul>
10366**
10367** To clarify, if this function is called and then a changeset constructed
10368** using [sqlite3session_changeset()], then after applying that changeset to
10369** database zFrom the contents of the two compatible tables would be
10370** identical.
10371**
10372** It an error if database zFrom does not exist or does not contain the
10373** required compatible table.
10374**
10375** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
10376** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
10377** may be set to point to a buffer containing an English language error
10378** message. It is the responsibility of the caller to free this buffer using
10379** sqlite3_free().
10380*/
10381SQLITE_API int sqlite3session_diff(
10382 sqlite3_session *pSession,
10383 const char *zFromDb,
10384 const char *zTbl,
10385 char **pzErrMsg
10386);
10387
10388
10389/*
10390** CAPI3REF: Generate A Patchset From A Session Object
10391** METHOD: sqlite3_session
10392**
10393** The differences between a patchset and a changeset are that:
10394**
10395** <ul>
10396** <li> DELETE records consist of the primary key fields only. The
10397** original values of other fields are omitted.
10398** <li> The original values of any modified fields are omitted from
10399** UPDATE records.
10400** </ul>
10401**
10402** A patchset blob may be used with up to date versions of all
10403** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
10404** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
10405** attempting to use a patchset blob with old versions of the
10406** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
10407**
10408** Because the non-primary key "old.*" fields are omitted, no
10409** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
10410** is passed to the sqlite3changeset_apply() API. Other conflict types work
10411** in the same way as for changesets.
10412**
10413** Changes within a patchset are ordered in the same way as for changesets
10414** generated by the sqlite3session_changeset() function (i.e. all changes for
10415** a single table are grouped together, tables appear in the order in which
10416** they were attached to the session object).
10417*/
10418SQLITE_API int sqlite3session_patchset(
10419 sqlite3_session *pSession, /* Session object */
10420 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
10421 void **ppPatchset /* OUT: Buffer containing patchset */
10422);
10423
10424/*
10425** CAPI3REF: Test if a changeset has recorded any changes.
10426**
10427** Return non-zero if no changes to attached tables have been recorded by
10428** the session object passed as the first argument. Otherwise, if one or
10429** more changes have been recorded, return zero.
10430**
10431** Even if this function returns zero, it is possible that calling
10432** [sqlite3session_changeset()] on the session handle may still return a
10433** changeset that contains no changes. This can happen when a row in
10434** an attached table is modified and then later on the original values
10435** are restored. However, if this function returns non-zero, then it is
10436** guaranteed that a call to sqlite3session_changeset() will return a
10437** changeset containing zero changes.
10438*/
10439SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
10440
10441/*
10442** CAPI3REF: Create An Iterator To Traverse A Changeset
10443** CONSTRUCTOR: sqlite3_changeset_iter
10444**
10445** Create an iterator used to iterate through the contents of a changeset.
10446** If successful, *pp is set to point to the iterator handle and SQLITE_OK
10447** is returned. Otherwise, if an error occurs, *pp is set to zero and an
10448** SQLite error code is returned.
10449**
10450** The following functions can be used to advance and query a changeset
10451** iterator created by this function:
10452**
10453** <ul>
10454** <li> [sqlite3changeset_next()]
10455** <li> [sqlite3changeset_op()]
10456** <li> [sqlite3changeset_new()]
10457** <li> [sqlite3changeset_old()]
10458** </ul>
10459**
10460** It is the responsibility of the caller to eventually destroy the iterator
10461** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
10462** changeset (pChangeset) must remain valid until after the iterator is
10463** destroyed.
10464**
10465** Assuming the changeset blob was created by one of the
10466** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
10467** [sqlite3changeset_invert()] functions, all changes within the changeset
10468** that apply to a single table are grouped together. This means that when
10469** an application iterates through a changeset using an iterator created by
10470** this function, all changes that relate to a single table are visited
10471** consecutively. There is no chance that the iterator will visit a change
10472** the applies to table X, then one for table Y, and then later on visit
10473** another change for table X.
10474**
10475** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
10476** may be modified by passing a combination of
10477** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
10478**
10479** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
10480** and therefore subject to change.
10481*/
10482SQLITE_API int sqlite3changeset_start(
10483 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10484 int nChangeset, /* Size of changeset blob in bytes */
10485 void *pChangeset /* Pointer to blob containing changeset */
10486);
10487SQLITE_API int sqlite3changeset_start_v2(
10488 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10489 int nChangeset, /* Size of changeset blob in bytes */
10490 void *pChangeset, /* Pointer to blob containing changeset */
10491 int flags /* SESSION_CHANGESETSTART_* flags */
10492);
10493
10494/*
10495** CAPI3REF: Flags for sqlite3changeset_start_v2
10496**
10497** The following flags may passed via the 4th parameter to
10498** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
10499**
10500** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
10501** Invert the changeset while iterating through it. This is equivalent to
10502** inverting a changeset using sqlite3changeset_invert() before applying it.
10503** It is an error to specify this flag with a patchset.
10504*/
10505#define SQLITE_CHANGESETSTART_INVERT 0x0002
10506
10507
10508/*
10509** CAPI3REF: Advance A Changeset Iterator
10510** METHOD: sqlite3_changeset_iter
10511**
10512** This function may only be used with iterators created by the function
10513** [sqlite3changeset_start()]. If it is called on an iterator passed to
10514** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
10515** is returned and the call has no effect.
10516**
10517** Immediately after an iterator is created by sqlite3changeset_start(), it
10518** does not point to any change in the changeset. Assuming the changeset
10519** is not empty, the first call to this function advances the iterator to
10520** point to the first change in the changeset. Each subsequent call advances
10521** the iterator to point to the next change in the changeset (if any). If
10522** no error occurs and the iterator points to a valid change after a call
10523** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
10524** Otherwise, if all changes in the changeset have already been visited,
10525** SQLITE_DONE is returned.
10526**
10527** If an error occurs, an SQLite error code is returned. Possible error
10528** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
10529** SQLITE_NOMEM.
10530*/
10531SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
10532
10533/*
10534** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
10535** METHOD: sqlite3_changeset_iter
10536**
10537** The pIter argument passed to this function may either be an iterator
10538** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10539** created by [sqlite3changeset_start()]. In the latter case, the most recent
10540** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
10541** is not the case, this function returns [SQLITE_MISUSE].
10542**
10543** If argument pzTab is not NULL, then *pzTab is set to point to a
10544** nul-terminated utf-8 encoded string containing the name of the table
10545** affected by the current change. The buffer remains valid until either
10546** sqlite3changeset_next() is called on the iterator or until the
10547** conflict-handler function returns. If pnCol is not NULL, then *pnCol is
10548** set to the number of columns in the table affected by the change. If
10549** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
10550** is an indirect change, or false (0) otherwise. See the documentation for
10551** [sqlite3session_indirect()] for a description of direct and indirect
10552** changes. Finally, if pOp is not NULL, then *pOp is set to one of
10553** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the
10554** type of change that the iterator currently points to.
10555**
10556** If no error occurs, SQLITE_OK is returned. If an error does occur, an
10557** SQLite error code is returned. The values of the output variables may not
10558** be trusted in this case.
10559*/
10560SQLITE_API int sqlite3changeset_op(
10561 sqlite3_changeset_iter *pIter, /* Iterator object */
10562 const char **pzTab, /* OUT: Pointer to table name */
10563 int *pnCol, /* OUT: Number of columns in table */
10564 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
10565 int *pbIndirect /* OUT: True for an 'indirect' change */
10566);
10567
10568/*
10569** CAPI3REF: Obtain The Primary Key Definition Of A Table
10570** METHOD: sqlite3_changeset_iter
10571**
10572** For each modified table, a changeset includes the following:
10573**
10574** <ul>
10575** <li> The number of columns in the table, and
10576** <li> Which of those columns make up the tables PRIMARY KEY.
10577** </ul>
10578**
10579** This function is used to find which columns comprise the PRIMARY KEY of
10580** the table modified by the change that iterator pIter currently points to.
10581** If successful, *pabPK is set to point to an array of nCol entries, where
10582** nCol is the number of columns in the table. Elements of *pabPK are set to
10583** 0x01 if the corresponding column is part of the tables primary key, or
10584** 0x00 if it is not.
10585**
10586** If argument pnCol is not NULL, then *pnCol is set to the number of columns
10587** in the table.
10588**
10589** If this function is called when the iterator does not point to a valid
10590** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
10591** SQLITE_OK is returned and the output variables populated as described
10592** above.
10593*/
10594SQLITE_API int sqlite3changeset_pk(
10595 sqlite3_changeset_iter *pIter, /* Iterator object */
10596 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
10597 int *pnCol /* OUT: Number of entries in output array */
10598);
10599
10600/*
10601** CAPI3REF: Obtain old.* Values From A Changeset Iterator
10602** METHOD: sqlite3_changeset_iter
10603**
10604** The pIter argument passed to this function may either be an iterator
10605** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10606** created by [sqlite3changeset_start()]. In the latter case, the most recent
10607** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10608** Furthermore, it may only be called if the type of change that the iterator
10609** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
10610** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10611**
10612** Argument iVal must be greater than or equal to 0, and less than the number
10613** of columns in the table affected by the current change. Otherwise,
10614** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10615**
10616** If successful, this function sets *ppValue to point to a protected
10617** sqlite3_value object containing the iVal'th value from the vector of
10618** original row values stored as part of the UPDATE or DELETE change and
10619** returns SQLITE_OK. The name of the function comes from the fact that this
10620** is similar to the "old.*" columns available to update or delete triggers.
10621**
10622** If some other error occurs (e.g. an OOM condition), an SQLite error code
10623** is returned and *ppValue is set to NULL.
10624*/
10625SQLITE_API int sqlite3changeset_old(
10626 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10627 int iVal, /* Column number */
10628 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
10629);
10630
10631/*
10632** CAPI3REF: Obtain new.* Values From A Changeset Iterator
10633** METHOD: sqlite3_changeset_iter
10634**
10635** The pIter argument passed to this function may either be an iterator
10636** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10637** created by [sqlite3changeset_start()]. In the latter case, the most recent
10638** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10639** Furthermore, it may only be called if the type of change that the iterator
10640** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
10641** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10642**
10643** Argument iVal must be greater than or equal to 0, and less than the number
10644** of columns in the table affected by the current change. Otherwise,
10645** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10646**
10647** If successful, this function sets *ppValue to point to a protected
10648** sqlite3_value object containing the iVal'th value from the vector of
10649** new row values stored as part of the UPDATE or INSERT change and
10650** returns SQLITE_OK. If the change is an UPDATE and does not include
10651** a new value for the requested column, *ppValue is set to NULL and
10652** SQLITE_OK returned. The name of the function comes from the fact that
10653** this is similar to the "new.*" columns available to update or delete
10654** triggers.
10655**
10656** If some other error occurs (e.g. an OOM condition), an SQLite error code
10657** is returned and *ppValue is set to NULL.
10658*/
10659SQLITE_API int sqlite3changeset_new(
10660 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10661 int iVal, /* Column number */
10662 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
10663);
10664
10665/*
10666** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
10667** METHOD: sqlite3_changeset_iter
10668**
10669** This function should only be used with iterator objects passed to a
10670** conflict-handler callback by [sqlite3changeset_apply()] with either
10671** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
10672** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
10673** is set to NULL.
10674**
10675** Argument iVal must be greater than or equal to 0, and less than the number
10676** of columns in the table affected by the current change. Otherwise,
10677** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10678**
10679** If successful, this function sets *ppValue to point to a protected
10680** sqlite3_value object containing the iVal'th value from the
10681** "conflicting row" associated with the current conflict-handler callback
10682** and returns SQLITE_OK.
10683**
10684** If some other error occurs (e.g. an OOM condition), an SQLite error code
10685** is returned and *ppValue is set to NULL.
10686*/
10687SQLITE_API int sqlite3changeset_conflict(
10688 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10689 int iVal, /* Column number */
10690 sqlite3_value **ppValue /* OUT: Value from conflicting row */
10691);
10692
10693/*
10694** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
10695** METHOD: sqlite3_changeset_iter
10696**
10697** This function may only be called with an iterator passed to an
10698** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
10699** it sets the output variable to the total number of known foreign key
10700** violations in the destination database and returns SQLITE_OK.
10701**
10702** In all other cases this function returns SQLITE_MISUSE.
10703*/
10704SQLITE_API int sqlite3changeset_fk_conflicts(
10705 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10706 int *pnOut /* OUT: Number of FK violations */
10707);
10708
10709
10710/*
10711** CAPI3REF: Finalize A Changeset Iterator
10712** METHOD: sqlite3_changeset_iter
10713**
10714** This function is used to finalize an iterator allocated with
10715** [sqlite3changeset_start()].
10716**
10717** This function should only be called on iterators created using the
10718** [sqlite3changeset_start()] function. If an application calls this
10719** function with an iterator passed to a conflict-handler by
10720** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
10721** call has no effect.
10722**
10723** If an error was encountered within a call to an sqlite3changeset_xxx()
10724** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
10725** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
10726** to that error is returned by this function. Otherwise, SQLITE_OK is
10727** returned. This is to allow the following pattern (pseudo-code):
10728**
10729** <pre>
10730** sqlite3changeset_start();
10731** while( SQLITE_ROW==sqlite3changeset_next() ){
10732** // Do something with change.
10733** }
10734** rc = sqlite3changeset_finalize();
10735** if( rc!=SQLITE_OK ){
10736** // An error has occurred
10737** }
10738** </pre>
10739*/
10740SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
10741
10742/*
10743** CAPI3REF: Invert A Changeset
10744**
10745** This function is used to "invert" a changeset object. Applying an inverted
10746** changeset to a database reverses the effects of applying the uninverted
10747** changeset. Specifically:
10748**
10749** <ul>
10750** <li> Each DELETE change is changed to an INSERT, and
10751** <li> Each INSERT change is changed to a DELETE, and
10752** <li> For each UPDATE change, the old.* and new.* values are exchanged.
10753** </ul>
10754**
10755** This function does not change the order in which changes appear within
10756** the changeset. It merely reverses the sense of each individual change.
10757**
10758** If successful, a pointer to a buffer containing the inverted changeset
10759** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
10760** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
10761** zeroed and an SQLite error code returned.
10762**
10763** It is the responsibility of the caller to eventually call sqlite3_free()
10764** on the *ppOut pointer to free the buffer allocation following a successful
10765** call to this function.
10766**
10767** WARNING/TODO: This function currently assumes that the input is a valid
10768** changeset. If it is not, the results are undefined.
10769*/
10770SQLITE_API int sqlite3changeset_invert(
10771 int nIn, const void *pIn, /* Input changeset */
10772 int *pnOut, void **ppOut /* OUT: Inverse of input */
10773);
10774
10775/*
10776** CAPI3REF: Concatenate Two Changeset Objects
10777**
10778** This function is used to concatenate two changesets, A and B, into a
10779** single changeset. The result is a changeset equivalent to applying
10780** changeset A followed by changeset B.
10781**
10782** This function combines the two input changesets using an
10783** sqlite3_changegroup object. Calling it produces similar results as the
10784** following code fragment:
10785**
10786** <pre>
10787** sqlite3_changegroup *pGrp;
10788** rc = sqlite3_changegroup_new(&pGrp);
10789** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
10790** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
10791** if( rc==SQLITE_OK ){
10792** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
10793** }else{
10794** *ppOut = 0;
10795** *pnOut = 0;
10796** }
10797** </pre>
10798**
10799** Refer to the sqlite3_changegroup documentation below for details.
10800*/
10801SQLITE_API int sqlite3changeset_concat(
10802 int nA, /* Number of bytes in buffer pA */
10803 void *pA, /* Pointer to buffer containing changeset A */
10804 int nB, /* Number of bytes in buffer pB */
10805 void *pB, /* Pointer to buffer containing changeset B */
10806 int *pnOut, /* OUT: Number of bytes in output changeset */
10807 void **ppOut /* OUT: Buffer containing output changeset */
10808);
10809
10810
10811/*
10812** CAPI3REF: Changegroup Handle
10813**
10814** A changegroup is an object used to combine two or more
10815** [changesets] or [patchsets]
10816*/
10817typedef struct sqlite3_changegroup sqlite3_changegroup;
10818
10819/*
10820** CAPI3REF: Create A New Changegroup Object
10821** CONSTRUCTOR: sqlite3_changegroup
10822**
10823** An sqlite3_changegroup object is used to combine two or more changesets
10824** (or patchsets) into a single changeset (or patchset). A single changegroup
10825** object may combine changesets or patchsets, but not both. The output is
10826** always in the same format as the input.
10827**
10828** If successful, this function returns SQLITE_OK and populates (*pp) with
10829** a pointer to a new sqlite3_changegroup object before returning. The caller
10830** should eventually free the returned object using a call to
10831** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
10832** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
10833**
10834** The usual usage pattern for an sqlite3_changegroup object is as follows:
10835**
10836** <ul>
10837** <li> It is created using a call to sqlite3changegroup_new().
10838**
10839** <li> Zero or more changesets (or patchsets) are added to the object
10840** by calling sqlite3changegroup_add().
10841**
10842** <li> The result of combining all input changesets together is obtained
10843** by the application via a call to sqlite3changegroup_output().
10844**
10845** <li> The object is deleted using a call to sqlite3changegroup_delete().
10846** </ul>
10847**
10848** Any number of calls to add() and output() may be made between the calls to
10849** new() and delete(), and in any order.
10850**
10851** As well as the regular sqlite3changegroup_add() and
10852** sqlite3changegroup_output() functions, also available are the streaming
10853** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
10854*/
10855SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
10856
10857/*
10858** CAPI3REF: Add A Changeset To A Changegroup
10859** METHOD: sqlite3_changegroup
10860**
10861** Add all changes within the changeset (or patchset) in buffer pData (size
10862** nData bytes) to the changegroup.
10863**
10864** If the buffer contains a patchset, then all prior calls to this function
10865** on the same changegroup object must also have specified patchsets. Or, if
10866** the buffer contains a changeset, so must have the earlier calls to this
10867** function. Otherwise, SQLITE_ERROR is returned and no changes are added
10868** to the changegroup.
10869**
10870** Rows within the changeset and changegroup are identified by the values in
10871** their PRIMARY KEY columns. A change in the changeset is considered to
10872** apply to the same row as a change already present in the changegroup if
10873** the two rows have the same primary key.
10874**
10875** Changes to rows that do not already appear in the changegroup are
10876** simply copied into it. Or, if both the new changeset and the changegroup
10877** contain changes that apply to a single row, the final contents of the
10878** changegroup depends on the type of each change, as follows:
10879**
10880** <table border=1 style="margin-left:8ex;margin-right:8ex">
10881** <tr><th style="white-space:pre">Existing Change </th>
10882** <th style="white-space:pre">New Change </th>
10883** <th>Output Change
10884** <tr><td>INSERT <td>INSERT <td>
10885** The new change is ignored. This case does not occur if the new
10886** changeset was recorded immediately after the changesets already
10887** added to the changegroup.
10888** <tr><td>INSERT <td>UPDATE <td>
10889** The INSERT change remains in the changegroup. The values in the
10890** INSERT change are modified as if the row was inserted by the
10891** existing change and then updated according to the new change.
10892** <tr><td>INSERT <td>DELETE <td>
10893** The existing INSERT is removed from the changegroup. The DELETE is
10894** not added.
10895** <tr><td>UPDATE <td>INSERT <td>
10896** The new change is ignored. This case does not occur if the new
10897** changeset was recorded immediately after the changesets already
10898** added to the changegroup.
10899** <tr><td>UPDATE <td>UPDATE <td>
10900** The existing UPDATE remains within the changegroup. It is amended
10901** so that the accompanying values are as if the row was updated once
10902** by the existing change and then again by the new change.
10903** <tr><td>UPDATE <td>DELETE <td>
10904** The existing UPDATE is replaced by the new DELETE within the
10905** changegroup.
10906** <tr><td>DELETE <td>INSERT <td>
10907** If one or more of the column values in the row inserted by the
10908** new change differ from those in the row deleted by the existing
10909** change, the existing DELETE is replaced by an UPDATE within the
10910** changegroup. Otherwise, if the inserted row is exactly the same
10911** as the deleted row, the existing DELETE is simply discarded.
10912** <tr><td>DELETE <td>UPDATE <td>
10913** The new change is ignored. This case does not occur if the new
10914** changeset was recorded immediately after the changesets already
10915** added to the changegroup.
10916** <tr><td>DELETE <td>DELETE <td>
10917** The new change is ignored. This case does not occur if the new
10918** changeset was recorded immediately after the changesets already
10919** added to the changegroup.
10920** </table>
10921**
10922** If the new changeset contains changes to a table that is already present
10923** in the changegroup, then the number of columns and the position of the
10924** primary key columns for the table must be consistent. If this is not the
10925** case, this function fails with SQLITE_SCHEMA. If the input changeset
10926** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
10927** returned. Or, if an out-of-memory condition occurs during processing, this
10928** function returns SQLITE_NOMEM. In all cases, if an error occurs the state
10929** of the final contents of the changegroup is undefined.
10930**
10931** If no error occurs, SQLITE_OK is returned.
10932*/
10933SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
10934
10935/*
10936** CAPI3REF: Obtain A Composite Changeset From A Changegroup
10937** METHOD: sqlite3_changegroup
10938**
10939** Obtain a buffer containing a changeset (or patchset) representing the
10940** current contents of the changegroup. If the inputs to the changegroup
10941** were themselves changesets, the output is a changeset. Or, if the
10942** inputs were patchsets, the output is also a patchset.
10943**
10944** As with the output of the sqlite3session_changeset() and
10945** sqlite3session_patchset() functions, all changes related to a single
10946** table are grouped together in the output of this function. Tables appear
10947** in the same order as for the very first changeset added to the changegroup.
10948** If the second or subsequent changesets added to the changegroup contain
10949** changes for tables that do not appear in the first changeset, they are
10950** appended onto the end of the output changeset, again in the order in
10951** which they are first encountered.
10952**
10953** If an error occurs, an SQLite error code is returned and the output
10954** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
10955** is returned and the output variables are set to the size of and a
10956** pointer to the output buffer, respectively. In this case it is the
10957** responsibility of the caller to eventually free the buffer using a
10958** call to sqlite3_free().
10959*/
10960SQLITE_API int sqlite3changegroup_output(
10961 sqlite3_changegroup*,
10962 int *pnData, /* OUT: Size of output buffer in bytes */
10963 void **ppData /* OUT: Pointer to output buffer */
10964);
10965
10966/*
10967** CAPI3REF: Delete A Changegroup Object
10968** DESTRUCTOR: sqlite3_changegroup
10969*/
10970SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
10971
10972/*
10973** CAPI3REF: Apply A Changeset To A Database
10974**
10975** Apply a changeset or patchset to a database. These functions attempt to
10976** update the "main" database attached to handle db with the changes found in
10977** the changeset passed via the second and third arguments.
10978**
10979** The fourth argument (xFilter) passed to these functions is the "filter
10980** callback". If it is not NULL, then for each table affected by at least one
10981** change in the changeset, the filter callback is invoked with
10982** the table name as the second argument, and a copy of the context pointer
10983** passed as the sixth argument as the first. If the "filter callback"
10984** returns zero, then no attempt is made to apply any changes to the table.
10985** Otherwise, if the return value is non-zero or the xFilter argument to
10986** is NULL, all changes related to the table are attempted.
10987**
10988** For each table that is not excluded by the filter callback, this function
10989** tests that the target database contains a compatible table. A table is
10990** considered compatible if all of the following are true:
10991**
10992** <ul>
10993** <li> The table has the same name as the name recorded in the
10994** changeset, and
10995** <li> The table has at least as many columns as recorded in the
10996** changeset, and
10997** <li> The table has primary key columns in the same position as
10998** recorded in the changeset.
10999** </ul>
11000**
11001** If there is no compatible table, it is not an error, but none of the
11002** changes associated with the table are applied. A warning message is issued
11003** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
11004** one such warning is issued for each table in the changeset.
11005**
11006** For each change for which there is a compatible table, an attempt is made
11007** to modify the table contents according to the UPDATE, INSERT or DELETE
11008** change. If a change cannot be applied cleanly, the conflict handler
11009** function passed as the fifth argument to sqlite3changeset_apply() may be
11010** invoked. A description of exactly when the conflict handler is invoked for
11011** each type of change is below.
11012**
11013** Unlike the xFilter argument, xConflict may not be passed NULL. The results
11014** of passing anything other than a valid function pointer as the xConflict
11015** argument are undefined.
11016**
11017** Each time the conflict handler function is invoked, it must return one
11018** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
11019** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
11020** if the second argument passed to the conflict handler is either
11021** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
11022** returns an illegal value, any changes already made are rolled back and
11023** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
11024** actions are taken by sqlite3changeset_apply() depending on the value
11025** returned by each invocation of the conflict-handler function. Refer to
11026** the documentation for the three
11027** [SQLITE_CHANGESET_OMIT|available return values] for details.
11028**
11029** <dl>
11030** <dt>DELETE Changes<dd>
11031** For each DELETE change, the function checks if the target database
11032** contains a row with the same primary key value (or values) as the
11033** original row values stored in the changeset. If it does, and the values
11034** stored in all non-primary key columns also match the values stored in
11035** the changeset the row is deleted from the target database.
11036**
11037** If a row with matching primary key values is found, but one or more of
11038** the non-primary key fields contains a value different from the original
11039** row value stored in the changeset, the conflict-handler function is
11040** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
11041** database table has more columns than are recorded in the changeset,
11042** only the values of those non-primary key fields are compared against
11043** the current database contents - any trailing database table columns
11044** are ignored.
11045**
11046** If no row with matching primary key values is found in the database,
11047** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11048** passed as the second argument.
11049**
11050** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
11051** (which can only happen if a foreign key constraint is violated), the
11052** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
11053** passed as the second argument. This includes the case where the DELETE
11054** operation is attempted because an earlier call to the conflict handler
11055** function returned [SQLITE_CHANGESET_REPLACE].
11056**
11057** <dt>INSERT Changes<dd>
11058** For each INSERT change, an attempt is made to insert the new row into
11059** the database. If the changeset row contains fewer fields than the
11060** database table, the trailing fields are populated with their default
11061** values.
11062**
11063** If the attempt to insert the row fails because the database already
11064** contains a row with the same primary key values, the conflict handler
11065** function is invoked with the second argument set to
11066** [SQLITE_CHANGESET_CONFLICT].
11067**
11068** If the attempt to insert the row fails because of some other constraint
11069** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
11070** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
11071** This includes the case where the INSERT operation is re-attempted because
11072** an earlier call to the conflict handler function returned
11073** [SQLITE_CHANGESET_REPLACE].
11074**
11075** <dt>UPDATE Changes<dd>
11076** For each UPDATE change, the function checks if the target database
11077** contains a row with the same primary key value (or values) as the
11078** original row values stored in the changeset. If it does, and the values
11079** stored in all modified non-primary key columns also match the values
11080** stored in the changeset the row is updated within the target database.
11081**
11082** If a row with matching primary key values is found, but one or more of
11083** the modified non-primary key fields contains a value different from an
11084** original row value stored in the changeset, the conflict-handler function
11085** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
11086** UPDATE changes only contain values for non-primary key fields that are
11087** to be modified, only those fields need to match the original values to
11088** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
11089**
11090** If no row with matching primary key values is found in the database,
11091** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11092** passed as the second argument.
11093**
11094** If the UPDATE operation is attempted, but SQLite returns
11095** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
11096** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
11097** This includes the case where the UPDATE operation is attempted after
11098** an earlier call to the conflict handler function returned
11099** [SQLITE_CHANGESET_REPLACE].
11100** </dl>
11101**
11102** It is safe to execute SQL statements, including those that write to the
11103** table that the callback related to, from within the xConflict callback.
11104** This can be used to further customize the application's conflict
11105** resolution strategy.
11106**
11107** All changes made by these functions are enclosed in a savepoint transaction.
11108** If any other error (aside from a constraint failure when attempting to
11109** write to the target database) occurs, then the savepoint transaction is
11110** rolled back, restoring the target database to its original state, and an
11111** SQLite error code returned.
11112**
11113** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
11114** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
11115** may set (*ppRebase) to point to a "rebase" that may be used with the
11116** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
11117** is set to the size of the buffer in bytes. It is the responsibility of the
11118** caller to eventually free any such buffer using sqlite3_free(). The buffer
11119** is only allocated and populated if one or more conflicts were encountered
11120** while applying the patchset. See comments surrounding the sqlite3_rebaser
11121** APIs for further details.
11122**
11123** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
11124** may be modified by passing a combination of
11125** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
11126**
11127** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
11128** and therefore subject to change.
11129*/
11130SQLITE_API int sqlite3changeset_apply(
11131 sqlite3 *db, /* Apply change to "main" db of this handle */
11132 int nChangeset, /* Size of changeset in bytes */
11133 void *pChangeset, /* Changeset blob */
11134 int(*xFilter)(
11135 void *pCtx, /* Copy of sixth arg to _apply() */
11136 const char *zTab /* Table name */
11137 ),
11138 int(*xConflict)(
11139 void *pCtx, /* Copy of sixth arg to _apply() */
11140 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11141 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11142 ),
11143 void *pCtx /* First argument passed to xConflict */
11144);
11145SQLITE_API int sqlite3changeset_apply_v2(
11146 sqlite3 *db, /* Apply change to "main" db of this handle */
11147 int nChangeset, /* Size of changeset in bytes */
11148 void *pChangeset, /* Changeset blob */
11149 int(*xFilter)(
11150 void *pCtx, /* Copy of sixth arg to _apply() */
11151 const char *zTab /* Table name */
11152 ),
11153 int(*xConflict)(
11154 void *pCtx, /* Copy of sixth arg to _apply() */
11155 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11156 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11157 ),
11158 void *pCtx, /* First argument passed to xConflict */
11159 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
11160 int flags /* SESSION_CHANGESETAPPLY_* flags */
11161);
11162
11163/*
11164** CAPI3REF: Flags for sqlite3changeset_apply_v2
11165**
11166** The following flags may passed via the 9th parameter to
11167** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
11168**
11169** <dl>
11170** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
11171** Usually, the sessions module encloses all operations performed by
11172** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
11173** SAVEPOINT is committed if the changeset or patchset is successfully
11174** applied, or rolled back if an error occurs. Specifying this flag
11175** causes the sessions module to omit this savepoint. In this case, if the
11176** caller has an open transaction or savepoint when apply_v2() is called,
11177** it may revert the partially applied changeset by rolling it back.
11178**
11179** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11180** Invert the changeset before applying it. This is equivalent to inverting
11181** a changeset using sqlite3changeset_invert() before applying it. It is
11182** an error to specify this flag with a patchset.
11183*/
11184#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
11185#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
11186
11187/*
11188** CAPI3REF: Constants Passed To The Conflict Handler
11189**
11190** Values that may be passed as the second argument to a conflict-handler.
11191**
11192** <dl>
11193** <dt>SQLITE_CHANGESET_DATA<dd>
11194** The conflict handler is invoked with CHANGESET_DATA as the second argument
11195** when processing a DELETE or UPDATE change if a row with the required
11196** PRIMARY KEY fields is present in the database, but one or more other
11197** (non primary-key) fields modified by the update do not contain the
11198** expected "before" values.
11199**
11200** The conflicting row, in this case, is the database row with the matching
11201** primary key.
11202**
11203** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
11204** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
11205** argument when processing a DELETE or UPDATE change if a row with the
11206** required PRIMARY KEY fields is not present in the database.
11207**
11208** There is no conflicting row in this case. The results of invoking the
11209** sqlite3changeset_conflict() API are undefined.
11210**
11211** <dt>SQLITE_CHANGESET_CONFLICT<dd>
11212** CHANGESET_CONFLICT is passed as the second argument to the conflict
11213** handler while processing an INSERT change if the operation would result
11214** in duplicate primary key values.
11215**
11216** The conflicting row in this case is the database row with the matching
11217** primary key.
11218**
11219** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
11220** If foreign key handling is enabled, and applying a changeset leaves the
11221** database in a state containing foreign key violations, the conflict
11222** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
11223** exactly once before the changeset is committed. If the conflict handler
11224** returns CHANGESET_OMIT, the changes, including those that caused the
11225** foreign key constraint violation, are committed. Or, if it returns
11226** CHANGESET_ABORT, the changeset is rolled back.
11227**
11228** No current or conflicting row information is provided. The only function
11229** it is possible to call on the supplied sqlite3_changeset_iter handle
11230** is sqlite3changeset_fk_conflicts().
11231**
11232** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
11233** If any other constraint violation occurs while applying a change (i.e.
11234** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
11235** invoked with CHANGESET_CONSTRAINT as the second argument.
11236**
11237** There is no conflicting row in this case. The results of invoking the
11238** sqlite3changeset_conflict() API are undefined.
11239**
11240** </dl>
11241*/
11242#define SQLITE_CHANGESET_DATA 1
11243#define SQLITE_CHANGESET_NOTFOUND 2
11244#define SQLITE_CHANGESET_CONFLICT 3
11245#define SQLITE_CHANGESET_CONSTRAINT 4
11246#define SQLITE_CHANGESET_FOREIGN_KEY 5
11247
11248/*
11249** CAPI3REF: Constants Returned By The Conflict Handler
11250**
11251** A conflict handler callback must return one of the following three values.
11252**
11253** <dl>
11254** <dt>SQLITE_CHANGESET_OMIT<dd>
11255** If a conflict handler returns this value no special action is taken. The
11256** change that caused the conflict is not applied. The session module
11257** continues to the next change in the changeset.
11258**
11259** <dt>SQLITE_CHANGESET_REPLACE<dd>
11260** This value may only be returned if the second argument to the conflict
11261** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
11262** is not the case, any changes applied so far are rolled back and the
11263** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
11264**
11265** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
11266** handler, then the conflicting row is either updated or deleted, depending
11267** on the type of change.
11268**
11269** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
11270** handler, then the conflicting row is removed from the database and a
11271** second attempt to apply the change is made. If this second attempt fails,
11272** the original row is restored to the database before continuing.
11273**
11274** <dt>SQLITE_CHANGESET_ABORT<dd>
11275** If this value is returned, any changes applied so far are rolled back
11276** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
11277** </dl>
11278*/
11279#define SQLITE_CHANGESET_OMIT 0
11280#define SQLITE_CHANGESET_REPLACE 1
11281#define SQLITE_CHANGESET_ABORT 2
11282
11283/*
11284** CAPI3REF: Rebasing changesets
11285** EXPERIMENTAL
11286**
11287** Suppose there is a site hosting a database in state S0. And that
11288** modifications are made that move that database to state S1 and a
11289** changeset recorded (the "local" changeset). Then, a changeset based
11290** on S0 is received from another site (the "remote" changeset) and
11291** applied to the database. The database is then in state
11292** (S1+"remote"), where the exact state depends on any conflict
11293** resolution decisions (OMIT or REPLACE) made while applying "remote".
11294** Rebasing a changeset is to update it to take those conflict
11295** resolution decisions into account, so that the same conflicts
11296** do not have to be resolved elsewhere in the network.
11297**
11298** For example, if both the local and remote changesets contain an
11299** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
11300**
11301** local: INSERT INTO t1 VALUES(1, 'v1');
11302** remote: INSERT INTO t1 VALUES(1, 'v2');
11303**
11304** and the conflict resolution is REPLACE, then the INSERT change is
11305** removed from the local changeset (it was overridden). Or, if the
11306** conflict resolution was "OMIT", then the local changeset is modified
11307** to instead contain:
11308**
11309** UPDATE t1 SET b = 'v2' WHERE a=1;
11310**
11311** Changes within the local changeset are rebased as follows:
11312**
11313** <dl>
11314** <dt>Local INSERT<dd>
11315** This may only conflict with a remote INSERT. If the conflict
11316** resolution was OMIT, then add an UPDATE change to the rebased
11317** changeset. Or, if the conflict resolution was REPLACE, add
11318** nothing to the rebased changeset.
11319**
11320** <dt>Local DELETE<dd>
11321** This may conflict with a remote UPDATE or DELETE. In both cases the
11322** only possible resolution is OMIT. If the remote operation was a
11323** DELETE, then add no change to the rebased changeset. If the remote
11324** operation was an UPDATE, then the old.* fields of change are updated
11325** to reflect the new.* values in the UPDATE.
11326**
11327** <dt>Local UPDATE<dd>
11328** This may conflict with a remote UPDATE or DELETE. If it conflicts
11329** with a DELETE, and the conflict resolution was OMIT, then the update
11330** is changed into an INSERT. Any undefined values in the new.* record
11331** from the update change are filled in using the old.* values from
11332** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
11333** the UPDATE change is simply omitted from the rebased changeset.
11334**
11335** If conflict is with a remote UPDATE and the resolution is OMIT, then
11336** the old.* values are rebased using the new.* values in the remote
11337** change. Or, if the resolution is REPLACE, then the change is copied
11338** into the rebased changeset with updates to columns also updated by
11339** the conflicting remote UPDATE removed. If this means no columns would
11340** be updated, the change is omitted.
11341** </dl>
11342**
11343** A local change may be rebased against multiple remote changes
11344** simultaneously. If a single key is modified by multiple remote
11345** changesets, they are combined as follows before the local changeset
11346** is rebased:
11347**
11348** <ul>
11349** <li> If there has been one or more REPLACE resolutions on a
11350** key, it is rebased according to a REPLACE.
11351**
11352** <li> If there have been no REPLACE resolutions on a key, then
11353** the local changeset is rebased according to the most recent
11354** of the OMIT resolutions.
11355** </ul>
11356**
11357** Note that conflict resolutions from multiple remote changesets are
11358** combined on a per-field basis, not per-row. This means that in the
11359** case of multiple remote UPDATE operations, some fields of a single
11360** local change may be rebased for REPLACE while others are rebased for
11361** OMIT.
11362**
11363** In order to rebase a local changeset, the remote changeset must first
11364** be applied to the local database using sqlite3changeset_apply_v2() and
11365** the buffer of rebase information captured. Then:
11366**
11367** <ol>
11368** <li> An sqlite3_rebaser object is created by calling
11369** sqlite3rebaser_create().
11370** <li> The new object is configured with the rebase buffer obtained from
11371** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
11372** If the local changeset is to be rebased against multiple remote
11373** changesets, then sqlite3rebaser_configure() should be called
11374** multiple times, in the same order that the multiple
11375** sqlite3changeset_apply_v2() calls were made.
11376** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
11377** <li> The sqlite3_rebaser object is deleted by calling
11378** sqlite3rebaser_delete().
11379** </ol>
11380*/
11381typedef struct sqlite3_rebaser sqlite3_rebaser;
11382
11383/*
11384** CAPI3REF: Create a changeset rebaser object.
11385** EXPERIMENTAL
11386**
11387** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
11388** point to the new object and return SQLITE_OK. Otherwise, if an error
11389** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
11390** to NULL.
11391*/
11392SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
11393
11394/*
11395** CAPI3REF: Configure a changeset rebaser object.
11396** EXPERIMENTAL
11397**
11398** Configure the changeset rebaser object to rebase changesets according
11399** to the conflict resolutions described by buffer pRebase (size nRebase
11400** bytes), which must have been obtained from a previous call to
11401** sqlite3changeset_apply_v2().
11402*/
11403SQLITE_API int sqlite3rebaser_configure(
11404 sqlite3_rebaser*,
11405 int nRebase, const void *pRebase
11406);
11407
11408/*
11409** CAPI3REF: Rebase a changeset
11410** EXPERIMENTAL
11411**
11412** Argument pIn must point to a buffer containing a changeset nIn bytes
11413** in size. This function allocates and populates a buffer with a copy
11414** of the changeset rebased according to the configuration of the
11415** rebaser object passed as the first argument. If successful, (*ppOut)
11416** is set to point to the new buffer containing the rebased changeset and
11417** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
11418** responsibility of the caller to eventually free the new buffer using
11419** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
11420** are set to zero and an SQLite error code returned.
11421*/
11422SQLITE_API int sqlite3rebaser_rebase(
11423 sqlite3_rebaser*,
11424 int nIn, const void *pIn,
11425 int *pnOut, void **ppOut
11426);
11427
11428/*
11429** CAPI3REF: Delete a changeset rebaser object.
11430** EXPERIMENTAL
11431**
11432** Delete the changeset rebaser object and all associated resources. There
11433** should be one call to this function for each successful invocation
11434** of sqlite3rebaser_create().
11435*/
11436SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
11437
11438/*
11439** CAPI3REF: Streaming Versions of API functions.
11440**
11441** The six streaming API xxx_strm() functions serve similar purposes to the
11442** corresponding non-streaming API functions:
11443**
11444** <table border=1 style="margin-left:8ex;margin-right:8ex">
11445** <tr><th>Streaming function<th>Non-streaming equivalent</th>
11446** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
11447** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
11448** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
11449** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
11450** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
11451** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
11452** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
11453** </table>
11454**
11455** Non-streaming functions that accept changesets (or patchsets) as input
11456** require that the entire changeset be stored in a single buffer in memory.
11457** Similarly, those that return a changeset or patchset do so by returning
11458** a pointer to a single large buffer allocated using sqlite3_malloc().
11459** Normally this is convenient. However, if an application running in a
11460** low-memory environment is required to handle very large changesets, the
11461** large contiguous memory allocations required can become onerous.
11462**
11463** In order to avoid this problem, instead of a single large buffer, input
11464** is passed to a streaming API functions by way of a callback function that
11465** the sessions module invokes to incrementally request input data as it is
11466** required. In all cases, a pair of API function parameters such as
11467**
11468** <pre>
11469** &nbsp; int nChangeset,
11470** &nbsp; void *pChangeset,
11471** </pre>
11472**
11473** Is replaced by:
11474**
11475** <pre>
11476** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
11477** &nbsp; void *pIn,
11478** </pre>
11479**
11480** Each time the xInput callback is invoked by the sessions module, the first
11481** argument passed is a copy of the supplied pIn context pointer. The second
11482** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
11483** error occurs the xInput method should copy up to (*pnData) bytes of data
11484** into the buffer and set (*pnData) to the actual number of bytes copied
11485** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
11486** should be set to zero to indicate this. Or, if an error occurs, an SQLite
11487** error code should be returned. In all cases, if an xInput callback returns
11488** an error, all processing is abandoned and the streaming API function
11489** returns a copy of the error code to the caller.
11490**
11491** In the case of sqlite3changeset_start_strm(), the xInput callback may be
11492** invoked by the sessions module at any point during the lifetime of the
11493** iterator. If such an xInput callback returns an error, the iterator enters
11494** an error state, whereby all subsequent calls to iterator functions
11495** immediately fail with the same error code as returned by xInput.
11496**
11497** Similarly, streaming API functions that return changesets (or patchsets)
11498** return them in chunks by way of a callback function instead of via a
11499** pointer to a single large buffer. In this case, a pair of parameters such
11500** as:
11501**
11502** <pre>
11503** &nbsp; int *pnChangeset,
11504** &nbsp; void **ppChangeset,
11505** </pre>
11506**
11507** Is replaced by:
11508**
11509** <pre>
11510** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
11511** &nbsp; void *pOut
11512** </pre>
11513**
11514** The xOutput callback is invoked zero or more times to return data to
11515** the application. The first parameter passed to each call is a copy of the
11516** pOut pointer supplied by the application. The second parameter, pData,
11517** points to a buffer nData bytes in size containing the chunk of output
11518** data being returned. If the xOutput callback successfully processes the
11519** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
11520** it should return some other SQLite error code. In this case processing
11521** is immediately abandoned and the streaming API function returns a copy
11522** of the xOutput error code to the application.
11523**
11524** The sessions module never invokes an xOutput callback with the third
11525** parameter set to a value less than or equal to zero. Other than this,
11526** no guarantees are made as to the size of the chunks of data returned.
11527*/
11528SQLITE_API int sqlite3changeset_apply_strm(
11529 sqlite3 *db, /* Apply change to "main" db of this handle */
11530 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11531 void *pIn, /* First arg for xInput */
11532 int(*xFilter)(
11533 void *pCtx, /* Copy of sixth arg to _apply() */
11534 const char *zTab /* Table name */
11535 ),
11536 int(*xConflict)(
11537 void *pCtx, /* Copy of sixth arg to _apply() */
11538 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11539 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11540 ),
11541 void *pCtx /* First argument passed to xConflict */
11542);
11543SQLITE_API int sqlite3changeset_apply_v2_strm(
11544 sqlite3 *db, /* Apply change to "main" db of this handle */
11545 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11546 void *pIn, /* First arg for xInput */
11547 int(*xFilter)(
11548 void *pCtx, /* Copy of sixth arg to _apply() */
11549 const char *zTab /* Table name */
11550 ),
11551 int(*xConflict)(
11552 void *pCtx, /* Copy of sixth arg to _apply() */
11553 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11554 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11555 ),
11556 void *pCtx, /* First argument passed to xConflict */
11557 void **ppRebase, int *pnRebase,
11558 int flags
11559);
11560SQLITE_API int sqlite3changeset_concat_strm(
11561 int (*xInputA)(void *pIn, void *pData, int *pnData),
11562 void *pInA,
11563 int (*xInputB)(void *pIn, void *pData, int *pnData),
11564 void *pInB,
11565 int (*xOutput)(void *pOut, const void *pData, int nData),
11566 void *pOut
11567);
11568SQLITE_API int sqlite3changeset_invert_strm(
11569 int (*xInput)(void *pIn, void *pData, int *pnData),
11570 void *pIn,
11571 int (*xOutput)(void *pOut, const void *pData, int nData),
11572 void *pOut
11573);
11574SQLITE_API int sqlite3changeset_start_strm(
11575 sqlite3_changeset_iter **pp,
11576 int (*xInput)(void *pIn, void *pData, int *pnData),
11577 void *pIn
11578);
11579SQLITE_API int sqlite3changeset_start_v2_strm(
11580 sqlite3_changeset_iter **pp,
11581 int (*xInput)(void *pIn, void *pData, int *pnData),
11582 void *pIn,
11583 int flags
11584);
11585SQLITE_API int sqlite3session_changeset_strm(
11586 sqlite3_session *pSession,
11587 int (*xOutput)(void *pOut, const void *pData, int nData),
11588 void *pOut
11589);
11590SQLITE_API int sqlite3session_patchset_strm(
11591 sqlite3_session *pSession,
11592 int (*xOutput)(void *pOut, const void *pData, int nData),
11593 void *pOut
11594);
11595SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
11596 int (*xInput)(void *pIn, void *pData, int *pnData),
11597 void *pIn
11598);
11599SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
11600 int (*xOutput)(void *pOut, const void *pData, int nData),
11601 void *pOut
11602);
11603SQLITE_API int sqlite3rebaser_rebase_strm(
11604 sqlite3_rebaser *pRebaser,
11605 int (*xInput)(void *pIn, void *pData, int *pnData),
11606 void *pIn,
11607 int (*xOutput)(void *pOut, const void *pData, int nData),
11608 void *pOut
11609);
11610
11611/*
11612** CAPI3REF: Configure global parameters
11613**
11614** The sqlite3session_config() interface is used to make global configuration
11615** changes to the sessions module in order to tune it to the specific needs
11616** of the application.
11617**
11618** The sqlite3session_config() interface is not threadsafe. If it is invoked
11619** while any other thread is inside any other sessions method then the
11620** results are undefined. Furthermore, if it is invoked after any sessions
11621** related objects have been created, the results are also undefined.
11622**
11623** The first argument to the sqlite3session_config() function must be one
11624** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
11625** interpretation of the (void*) value passed as the second parameter and
11626** the effect of calling this function depends on the value of the first
11627** parameter.
11628**
11629** <dl>
11630** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
11631** By default, the sessions module streaming interfaces attempt to input
11632** and output data in approximately 1 KiB chunks. This operand may be used
11633** to set and query the value of this configuration setting. The pointer
11634** passed as the second argument must point to a value of type (int).
11635** If this value is greater than 0, it is used as the new streaming data
11636** chunk size for both input and output. Before returning, the (int) value
11637** pointed to by pArg is set to the final value of the streaming interface
11638** chunk size.
11639** </dl>
11640**
11641** This function returns SQLITE_OK if successful, or an SQLite error code
11642** otherwise.
11643*/
11644SQLITE_API int sqlite3session_config(int op, void *pArg);
11645
11646/*
11647** CAPI3REF: Values for sqlite3session_config().
11648*/
11649#define SQLITE_SESSION_CONFIG_STRMSIZE 1
11650
11651/*
11652** Make sure we can call this stuff from C++.
11653*/
11654#ifdef __cplusplus
11655}
11656#endif
11657
11658#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
11659
11660/******** End of sqlite3session.h *********/
11661/******** Begin file fts5.h *********/
11662/*
11663** 2014 May 31
11664**
11665** The author disclaims copyright to this source code. In place of
11666** a legal notice, here is a blessing:
11667**
11668** May you do good and not evil.
11669** May you find forgiveness for yourself and forgive others.
11670** May you share freely, never taking more than you give.
11671**
11672******************************************************************************
11673**
11674** Interfaces to extend FTS5. Using the interfaces defined in this file,
11675** FTS5 may be extended with:
11676**
11677** * custom tokenizers, and
11678** * custom auxiliary functions.
11679*/
11680
11681
11682#ifndef _FTS5_H
11683#define _FTS5_H
11684
11685
11686#ifdef __cplusplus
11687extern "C" {
11688#endif
11689
11690/*************************************************************************
11691** CUSTOM AUXILIARY FUNCTIONS
11692**
11693** Virtual table implementations may overload SQL functions by implementing
11694** the sqlite3_module.xFindFunction() method.
11695*/
11696
11697typedef struct Fts5ExtensionApi Fts5ExtensionApi;
11698typedef struct Fts5Context Fts5Context;
11699typedef struct Fts5PhraseIter Fts5PhraseIter;
11700
11701typedef void (*fts5_extension_function)(
11702 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
11703 Fts5Context *pFts, /* First arg to pass to pApi functions */
11704 sqlite3_context *pCtx, /* Context for returning result/error */
11705 int nVal, /* Number of values in apVal[] array */
11706 sqlite3_value **apVal /* Array of trailing arguments */
11707);
11708
11709struct Fts5PhraseIter {
11710 const unsigned char *a;
11711 const unsigned char *b;
11712};
11713
11714/*
11715** EXTENSION API FUNCTIONS
11716**
11717** xUserData(pFts):
11718** Return a copy of the context pointer the extension function was
11719** registered with.
11720**
11721** xColumnTotalSize(pFts, iCol, pnToken):
11722** If parameter iCol is less than zero, set output variable *pnToken
11723** to the total number of tokens in the FTS5 table. Or, if iCol is
11724** non-negative but less than the number of columns in the table, return
11725** the total number of tokens in column iCol, considering all rows in
11726** the FTS5 table.
11727**
11728** If parameter iCol is greater than or equal to the number of columns
11729** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11730** an OOM condition or IO error), an appropriate SQLite error code is
11731** returned.
11732**
11733** xColumnCount(pFts):
11734** Return the number of columns in the table.
11735**
11736** xColumnSize(pFts, iCol, pnToken):
11737** If parameter iCol is less than zero, set output variable *pnToken
11738** to the total number of tokens in the current row. Or, if iCol is
11739** non-negative but less than the number of columns in the table, set
11740** *pnToken to the number of tokens in column iCol of the current row.
11741**
11742** If parameter iCol is greater than or equal to the number of columns
11743** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11744** an OOM condition or IO error), an appropriate SQLite error code is
11745** returned.
11746**
11747** This function may be quite inefficient if used with an FTS5 table
11748** created with the "columnsize=0" option.
11749**
11750** xColumnText:
11751** This function attempts to retrieve the text of column iCol of the
11752** current document. If successful, (*pz) is set to point to a buffer
11753** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
11754** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
11755** if an error occurs, an SQLite error code is returned and the final values
11756** of (*pz) and (*pn) are undefined.
11757**
11758** xPhraseCount:
11759** Returns the number of phrases in the current query expression.
11760**
11761** xPhraseSize:
11762** Returns the number of tokens in phrase iPhrase of the query. Phrases
11763** are numbered starting from zero.
11764**
11765** xInstCount:
11766** Set *pnInst to the total number of occurrences of all phrases within
11767** the query within the current row. Return SQLITE_OK if successful, or
11768** an error code (i.e. SQLITE_NOMEM) if an error occurs.
11769**
11770** This API can be quite slow if used with an FTS5 table created with the
11771** "detail=none" or "detail=column" option. If the FTS5 table is created
11772** with either "detail=none" or "detail=column" and "content=" option
11773** (i.e. if it is a contentless table), then this API always returns 0.
11774**
11775** xInst:
11776** Query for the details of phrase match iIdx within the current row.
11777** Phrase matches are numbered starting from zero, so the iIdx argument
11778** should be greater than or equal to zero and smaller than the value
11779** output by xInstCount().
11780**
11781** Usually, output parameter *piPhrase is set to the phrase number, *piCol
11782** to the column in which it occurs and *piOff the token offset of the
11783** first token of the phrase. Returns SQLITE_OK if successful, or an error
11784** code (i.e. SQLITE_NOMEM) if an error occurs.
11785**
11786** This API can be quite slow if used with an FTS5 table created with the
11787** "detail=none" or "detail=column" option.
11788**
11789** xRowid:
11790** Returns the rowid of the current row.
11791**
11792** xTokenize:
11793** Tokenize text using the tokenizer belonging to the FTS5 table.
11794**
11795** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
11796** This API function is used to query the FTS table for phrase iPhrase
11797** of the current query. Specifically, a query equivalent to:
11798**
11799** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
11800**
11801** with $p set to a phrase equivalent to the phrase iPhrase of the
11802** current query is executed. Any column filter that applies to
11803** phrase iPhrase of the current query is included in $p. For each
11804** row visited, the callback function passed as the fourth argument
11805** is invoked. The context and API objects passed to the callback
11806** function may be used to access the properties of each matched row.
11807** Invoking Api.xUserData() returns a copy of the pointer passed as
11808** the third argument to pUserData.
11809**
11810** If the callback function returns any value other than SQLITE_OK, the
11811** query is abandoned and the xQueryPhrase function returns immediately.
11812** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
11813** Otherwise, the error code is propagated upwards.
11814**
11815** If the query runs to completion without incident, SQLITE_OK is returned.
11816** Or, if some error occurs before the query completes or is aborted by
11817** the callback, an SQLite error code is returned.
11818**
11819**
11820** xSetAuxdata(pFts5, pAux, xDelete)
11821**
11822** Save the pointer passed as the second argument as the extension function's
11823** "auxiliary data". The pointer may then be retrieved by the current or any
11824** future invocation of the same fts5 extension function made as part of
11825** the same MATCH query using the xGetAuxdata() API.
11826**
11827** Each extension function is allocated a single auxiliary data slot for
11828** each FTS query (MATCH expression). If the extension function is invoked
11829** more than once for a single FTS query, then all invocations share a
11830** single auxiliary data context.
11831**
11832** If there is already an auxiliary data pointer when this function is
11833** invoked, then it is replaced by the new pointer. If an xDelete callback
11834** was specified along with the original pointer, it is invoked at this
11835** point.
11836**
11837** The xDelete callback, if one is specified, is also invoked on the
11838** auxiliary data pointer after the FTS5 query has finished.
11839**
11840** If an error (e.g. an OOM condition) occurs within this function,
11841** the auxiliary data is set to NULL and an error code returned. If the
11842** xDelete parameter was not NULL, it is invoked on the auxiliary data
11843** pointer before returning.
11844**
11845**
11846** xGetAuxdata(pFts5, bClear)
11847**
11848** Returns the current auxiliary data pointer for the fts5 extension
11849** function. See the xSetAuxdata() method for details.
11850**
11851** If the bClear argument is non-zero, then the auxiliary data is cleared
11852** (set to NULL) before this function returns. In this case the xDelete,
11853** if any, is not invoked.
11854**
11855**
11856** xRowCount(pFts5, pnRow)
11857**
11858** This function is used to retrieve the total number of rows in the table.
11859** In other words, the same value that would be returned by:
11860**
11861** SELECT count(*) FROM ftstable;
11862**
11863** xPhraseFirst()
11864** This function is used, along with type Fts5PhraseIter and the xPhraseNext
11865** method, to iterate through all instances of a single query phrase within
11866** the current row. This is the same information as is accessible via the
11867** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
11868** to use, this API may be faster under some circumstances. To iterate
11869** through instances of phrase iPhrase, use the following code:
11870**
11871** Fts5PhraseIter iter;
11872** int iCol, iOff;
11873** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
11874** iCol>=0;
11875** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
11876** ){
11877** // An instance of phrase iPhrase at offset iOff of column iCol
11878** }
11879**
11880** The Fts5PhraseIter structure is defined above. Applications should not
11881** modify this structure directly - it should only be used as shown above
11882** with the xPhraseFirst() and xPhraseNext() API methods (and by
11883** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
11884**
11885** This API can be quite slow if used with an FTS5 table created with the
11886** "detail=none" or "detail=column" option. If the FTS5 table is created
11887** with either "detail=none" or "detail=column" and "content=" option
11888** (i.e. if it is a contentless table), then this API always iterates
11889** through an empty set (all calls to xPhraseFirst() set iCol to -1).
11890**
11891** xPhraseNext()
11892** See xPhraseFirst above.
11893**
11894** xPhraseFirstColumn()
11895** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
11896** and xPhraseNext() APIs described above. The difference is that instead
11897** of iterating through all instances of a phrase in the current row, these
11898** APIs are used to iterate through the set of columns in the current row
11899** that contain one or more instances of a specified phrase. For example:
11900**
11901** Fts5PhraseIter iter;
11902** int iCol;
11903** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
11904** iCol>=0;
11905** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
11906** ){
11907** // Column iCol contains at least one instance of phrase iPhrase
11908** }
11909**
11910** This API can be quite slow if used with an FTS5 table created with the
11911** "detail=none" option. If the FTS5 table is created with either
11912** "detail=none" "content=" option (i.e. if it is a contentless table),
11913** then this API always iterates through an empty set (all calls to
11914** xPhraseFirstColumn() set iCol to -1).
11915**
11916** The information accessed using this API and its companion
11917** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
11918** (or xInst/xInstCount). The chief advantage of this API is that it is
11919** significantly more efficient than those alternatives when used with
11920** "detail=column" tables.
11921**
11922** xPhraseNextColumn()
11923** See xPhraseFirstColumn above.
11924*/
11925struct Fts5ExtensionApi {
11926 int iVersion; /* Currently always set to 3 */
11927
11928 void *(*xUserData)(Fts5Context*);
11929
11930 int (*xColumnCount)(Fts5Context*);
11931 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
11932 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
11933
11934 int (*xTokenize)(Fts5Context*,
11935 const char *pText, int nText, /* Text to tokenize */
11936 void *pCtx, /* Context passed to xToken() */
11937 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
11938 );
11939
11940 int (*xPhraseCount)(Fts5Context*);
11941 int (*xPhraseSize)(Fts5Context*, int iPhrase);
11942
11943 int (*xInstCount)(Fts5Context*, int *pnInst);
11944 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
11945
11946 sqlite3_int64 (*xRowid)(Fts5Context*);
11947 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
11948 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
11949
11950 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
11951 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
11952 );
11953 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
11954 void *(*xGetAuxdata)(Fts5Context*, int bClear);
11955
11956 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
11957 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
11958
11959 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
11960 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
11961};
11962
11963/*
11964** CUSTOM AUXILIARY FUNCTIONS
11965*************************************************************************/
11966
11967/*************************************************************************
11968** CUSTOM TOKENIZERS
11969**
11970** Applications may also register custom tokenizer types. A tokenizer
11971** is registered by providing fts5 with a populated instance of the
11972** following structure. All structure methods must be defined, setting
11973** any member of the fts5_tokenizer struct to NULL leads to undefined
11974** behaviour. The structure methods are expected to function as follows:
11975**
11976** xCreate:
11977** This function is used to allocate and initialize a tokenizer instance.
11978** A tokenizer instance is required to actually tokenize text.
11979**
11980** The first argument passed to this function is a copy of the (void*)
11981** pointer provided by the application when the fts5_tokenizer object
11982** was registered with FTS5 (the third argument to xCreateTokenizer()).
11983** The second and third arguments are an array of nul-terminated strings
11984** containing the tokenizer arguments, if any, specified following the
11985** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
11986** to create the FTS5 table.
11987**
11988** The final argument is an output variable. If successful, (*ppOut)
11989** should be set to point to the new tokenizer handle and SQLITE_OK
11990** returned. If an error occurs, some value other than SQLITE_OK should
11991** be returned. In this case, fts5 assumes that the final value of *ppOut
11992** is undefined.
11993**
11994** xDelete:
11995** This function is invoked to delete a tokenizer handle previously
11996** allocated using xCreate(). Fts5 guarantees that this function will
11997** be invoked exactly once for each successful call to xCreate().
11998**
11999** xTokenize:
12000** This function is expected to tokenize the nText byte string indicated
12001** by argument pText. pText may or may not be nul-terminated. The first
12002** argument passed to this function is a pointer to an Fts5Tokenizer object
12003** returned by an earlier call to xCreate().
12004**
12005** The second argument indicates the reason that FTS5 is requesting
12006** tokenization of the supplied text. This is always one of the following
12007** four values:
12008**
12009** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
12010** or removed from the FTS table. The tokenizer is being invoked to
12011** determine the set of tokens to add to (or delete from) the
12012** FTS index.
12013**
12014** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
12015** against the FTS index. The tokenizer is being called to tokenize
12016** a bareword or quoted string specified as part of the query.
12017**
12018** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
12019** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
12020** followed by a "*" character, indicating that the last token
12021** returned by the tokenizer will be treated as a token prefix.
12022**
12023** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
12024** satisfy an fts5_api.xTokenize() request made by an auxiliary
12025** function. Or an fts5_api.xColumnSize() request made by the same
12026** on a columnsize=0 database.
12027** </ul>
12028**
12029** For each token in the input string, the supplied callback xToken() must
12030** be invoked. The first argument to it should be a copy of the pointer
12031** passed as the second argument to xTokenize(). The third and fourth
12032** arguments are a pointer to a buffer containing the token text, and the
12033** size of the token in bytes. The 4th and 5th arguments are the byte offsets
12034** of the first byte of and first byte immediately following the text from
12035** which the token is derived within the input.
12036**
12037** The second argument passed to the xToken() callback ("tflags") should
12038** normally be set to 0. The exception is if the tokenizer supports
12039** synonyms. In this case see the discussion below for details.
12040**
12041** FTS5 assumes the xToken() callback is invoked for each token in the
12042** order that they occur within the input text.
12043**
12044** If an xToken() callback returns any value other than SQLITE_OK, then
12045** the tokenization should be abandoned and the xTokenize() method should
12046** immediately return a copy of the xToken() return value. Or, if the
12047** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
12048** if an error occurs with the xTokenize() implementation itself, it
12049** may abandon the tokenization and return any error code other than
12050** SQLITE_OK or SQLITE_DONE.
12051**
12052** SYNONYM SUPPORT
12053**
12054** Custom tokenizers may also support synonyms. Consider a case in which a
12055** user wishes to query for a phrase such as "first place". Using the
12056** built-in tokenizers, the FTS5 query 'first + place' will match instances
12057** of "first place" within the document set, but not alternative forms
12058** such as "1st place". In some applications, it would be better to match
12059** all instances of "first place" or "1st place" regardless of which form
12060** the user specified in the MATCH query text.
12061**
12062** There are several ways to approach this in FTS5:
12063**
12064** <ol><li> By mapping all synonyms to a single token. In this case, using
12065** the above example, this means that the tokenizer returns the
12066** same token for inputs "first" and "1st". Say that token is in
12067** fact "first", so that when the user inserts the document "I won
12068** 1st place" entries are added to the index for tokens "i", "won",
12069** "first" and "place". If the user then queries for '1st + place',
12070** the tokenizer substitutes "first" for "1st" and the query works
12071** as expected.
12072**
12073** <li> By querying the index for all synonyms of each query term
12074** separately. In this case, when tokenizing query text, the
12075** tokenizer may provide multiple synonyms for a single term
12076** within the document. FTS5 then queries the index for each
12077** synonym individually. For example, faced with the query:
12078**
12079** <codeblock>
12080** ... MATCH 'first place'</codeblock>
12081**
12082** the tokenizer offers both "1st" and "first" as synonyms for the
12083** first token in the MATCH query and FTS5 effectively runs a query
12084** similar to:
12085**
12086** <codeblock>
12087** ... MATCH '(first OR 1st) place'</codeblock>
12088**
12089** except that, for the purposes of auxiliary functions, the query
12090** still appears to contain just two phrases - "(first OR 1st)"
12091** being treated as a single phrase.
12092**
12093** <li> By adding multiple synonyms for a single term to the FTS index.
12094** Using this method, when tokenizing document text, the tokenizer
12095** provides multiple synonyms for each token. So that when a
12096** document such as "I won first place" is tokenized, entries are
12097** added to the FTS index for "i", "won", "first", "1st" and
12098** "place".
12099**
12100** This way, even if the tokenizer does not provide synonyms
12101** when tokenizing query text (it should not - to do so would be
12102** inefficient), it doesn't matter if the user queries for
12103** 'first + place' or '1st + place', as there are entries in the
12104** FTS index corresponding to both forms of the first token.
12105** </ol>
12106**
12107** Whether it is parsing document or query text, any call to xToken that
12108** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
12109** is considered to supply a synonym for the previous token. For example,
12110** when parsing the document "I won first place", a tokenizer that supports
12111** synonyms would call xToken() 5 times, as follows:
12112**
12113** <codeblock>
12114** xToken(pCtx, 0, "i", 1, 0, 1);
12115** xToken(pCtx, 0, "won", 3, 2, 5);
12116** xToken(pCtx, 0, "first", 5, 6, 11);
12117** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
12118** xToken(pCtx, 0, "place", 5, 12, 17);
12119**</codeblock>
12120**
12121** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
12122** xToken() is called. Multiple synonyms may be specified for a single token
12123** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
12124** There is no limit to the number of synonyms that may be provided for a
12125** single token.
12126**
12127** In many cases, method (1) above is the best approach. It does not add
12128** extra data to the FTS index or require FTS5 to query for multiple terms,
12129** so it is efficient in terms of disk space and query speed. However, it
12130** does not support prefix queries very well. If, as suggested above, the
12131** token "first" is substituted for "1st" by the tokenizer, then the query:
12132**
12133** <codeblock>
12134** ... MATCH '1s*'</codeblock>
12135**
12136** will not match documents that contain the token "1st" (as the tokenizer
12137** will probably not map "1s" to any prefix of "first").
12138**
12139** For full prefix support, method (3) may be preferred. In this case,
12140** because the index contains entries for both "first" and "1st", prefix
12141** queries such as 'fi*' or '1s*' will match correctly. However, because
12142** extra entries are added to the FTS index, this method uses more space
12143** within the database.
12144**
12145** Method (2) offers a midpoint between (1) and (3). Using this method,
12146** a query such as '1s*' will match documents that contain the literal
12147** token "1st", but not "first" (assuming the tokenizer is not able to
12148** provide synonyms for prefixes). However, a non-prefix query like '1st'
12149** will match against "1st" and "first". This method does not require
12150** extra disk space, as no extra entries are added to the FTS index.
12151** On the other hand, it may require more CPU cycles to run MATCH queries,
12152** as separate queries of the FTS index are required for each synonym.
12153**
12154** When using methods (2) or (3), it is important that the tokenizer only
12155** provide synonyms when tokenizing document text (method (2)) or query
12156** text (method (3)), not both. Doing so will not cause any errors, but is
12157** inefficient.
12158*/
12159typedef struct Fts5Tokenizer Fts5Tokenizer;
12160typedef struct fts5_tokenizer fts5_tokenizer;
12161struct fts5_tokenizer {
12162 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
12163 void (*xDelete)(Fts5Tokenizer*);
12164 int (*xTokenize)(Fts5Tokenizer*,
12165 void *pCtx,
12166 int flags, /* Mask of FTS5_TOKENIZE_* flags */
12167 const char *pText, int nText,
12168 int (*xToken)(
12169 void *pCtx, /* Copy of 2nd argument to xTokenize() */
12170 int tflags, /* Mask of FTS5_TOKEN_* flags */
12171 const char *pToken, /* Pointer to buffer containing token */
12172 int nToken, /* Size of token in bytes */
12173 int iStart, /* Byte offset of token within input text */
12174 int iEnd /* Byte offset of end of token within input text */
12175 )
12176 );
12177};
12178
12179/* Flags that may be passed as the third argument to xTokenize() */
12180#define FTS5_TOKENIZE_QUERY 0x0001
12181#define FTS5_TOKENIZE_PREFIX 0x0002
12182#define FTS5_TOKENIZE_DOCUMENT 0x0004
12183#define FTS5_TOKENIZE_AUX 0x0008
12184
12185/* Flags that may be passed by the tokenizer implementation back to FTS5
12186** as the third argument to the supplied xToken callback. */
12187#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
12188
12189/*
12190** END OF CUSTOM TOKENIZERS
12191*************************************************************************/
12192
12193/*************************************************************************
12194** FTS5 EXTENSION REGISTRATION API
12195*/
12196typedef struct fts5_api fts5_api;
12197struct fts5_api {
12198 int iVersion; /* Currently always set to 2 */
12199
12200 /* Create a new tokenizer */
12201 int (*xCreateTokenizer)(
12202 fts5_api *pApi,
12203 const char *zName,
12204 void *pContext,
12205 fts5_tokenizer *pTokenizer,
12206 void (*xDestroy)(void*)
12207 );
12208
12209 /* Find an existing tokenizer */
12210 int (*xFindTokenizer)(
12211 fts5_api *pApi,
12212 const char *zName,
12213 void **ppContext,
12214 fts5_tokenizer *pTokenizer
12215 );
12216
12217 /* Create a new auxiliary function */
12218 int (*xCreateFunction)(
12219 fts5_api *pApi,
12220 const char *zName,
12221 void *pContext,
12222 fts5_extension_function xFunction,
12223 void (*xDestroy)(void*)
12224 );
12225};
12226
12227/*
12228** END OF REGISTRATION API
12229*************************************************************************/
12230
12231#ifdef __cplusplus
12232} /* end of the 'extern "C"' block */
12233#endif
12234
12235#endif /* _FTS5_H */
12236
12237/******** End of fts5.h *********/