12 files changed, 351 insertions, 20 deletions

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index b367c2a27..f389897d4 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -23,6 +23,8 @@ add_library(core STATIC
     file_sys/partition_filesystem.h
     file_sys/program_metadata.cpp
     file_sys/program_metadata.h
+    file_sys/romfs.cpp
+    file_sys/romfs.h
     file_sys/romfs_factory.cpp
     file_sys/romfs_factory.h
     file_sys/savedata_factory.cpp
@@ -35,6 +37,8 @@ add_library(core STATIC
     file_sys/vfs_offset.h
     file_sys/vfs_real.cpp
     file_sys/vfs_real.h
+    file_sys/vfs_vector.cpp
+    file_sys/vfs_vector.h
     frontend/emu_window.cpp
     frontend/emu_window.h
     frontend/framebuffer_layout.cpp
diff --git a/src/core/file_sys/content_archive.cpp b/src/core/file_sys/content_archive.cpp
index d6b20c047..61cb0bbe3 100644
--- a/src/core/file_sys/content_archive.cpp
+++ b/src/core/file_sys/content_archive.cpp
@@ -9,6 +9,7 @@
 #include "core/file_sys/content_archive.h"
 #include "core/file_sys/vfs_offset.h"
 #include "core/loader/loader.h"
+#include "romfs.h"
 
 namespace FileSys {
 
@@ -46,21 +47,9 @@ struct PFS0Superblock {
 };
 static_assert(sizeof(PFS0Superblock) == 0x200, "PFS0Superblock has incorrect size.");
 
-struct IVFCLevel {
-    u64_le offset;
-    u64_le size;
-    u32_le block_size;
-    u32_le reserved;
-};
-static_assert(sizeof(IVFCLevel) == 0x18, "IVFCLevel has incorrect size.");
-
 struct RomFSSuperblock {
     NCASectionHeaderBlock header_block;
-    u32_le magic;
-    u32_le magic_number;
-    INSERT_PADDING_BYTES(8);
-    std::array<IVFCLevel, 6> levels;
-    INSERT_PADDING_BYTES(64);
+    IVFCHeader ivfc;
 };
 static_assert(sizeof(RomFSSuperblock) == 0xE8, "RomFSSuperblock has incorrect size.");
 
@@ -92,8 +81,8 @@ NCA::NCA(VirtualFile file_) : file(std::move(file_)) {
 
             const size_t romfs_offset =
                 header.section_tables[i].media_offset * MEDIA_OFFSET_MULTIPLIER +
-                sb.levels[IVFC_MAX_LEVEL - 1].offset;
-            const size_t romfs_size = sb.levels[IVFC_MAX_LEVEL - 1].size;
+                sb.ivfc.levels[IVFC_MAX_LEVEL - 1].offset;
+            const size_t romfs_size = sb.ivfc.levels[IVFC_MAX_LEVEL - 1].size;
             files.emplace_back(std::make_shared<OffsetVfsFile>(file, romfs_size, romfs_offset));
             romfs = files.back();
         } else if (block.filesystem_type == NCASectionFilesystemType::PFS0) {
diff --git a/src/core/file_sys/romfs.cpp b/src/core/file_sys/romfs.cpp
new file mode 100644
index 000000000..ff3ddb29c
--- /dev/null
+++ b/src/core/file_sys/romfs.cpp
@@ -0,0 +1,124 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/common_types.h"
+#include "common/swap.h"
+#include "core/file_sys/romfs.h"
+#include "core/file_sys/vfs.h"
+#include "core/file_sys/vfs_offset.h"
+#include "core/file_sys/vfs_vector.h"
+
+namespace FileSys {
+
+constexpr u32 ROMFS_ENTRY_EMPTY = 0xFFFFFFFF;
+
+struct TableLocation {
+    u64_le offset;
+    u64_le size;
+};
+static_assert(sizeof(TableLocation) == 0x10, "TableLocation has incorrect size.");
+
+struct RomFSHeader {
+    u64_le header_size;
+    TableLocation directory_hash;
+    TableLocation directory_meta;
+    TableLocation file_hash;
+    TableLocation file_meta;
+    u64_le data_offset;
+};
+static_assert(sizeof(RomFSHeader) == 0x50, "RomFSHeader has incorrect size.");
+
+struct DirectoryEntry {
+    u32_le sibling;
+    u32_le child_dir;
+    u32_le child_file;
+    u32_le hash;
+    u32_le name_length;
+};
+static_assert(sizeof(DirectoryEntry) == 0x14, "DirectoryEntry has incorrect size.");
+
+struct FileEntry {
+    u32_le parent;
+    u32_le sibling;
+    u64_le offset;
+    u64_le size;
+    u32_le hash;
+    u32_le name_length;
+};
+static_assert(sizeof(FileEntry) == 0x20, "FileEntry has incorrect size.");
+
+template <typename Entry>
+static std::pair<Entry, std::string> GetEntry(const VirtualFile& file, size_t offset) {
+    Entry entry{};
+    if (file->ReadObject(&entry, offset) != sizeof(Entry))
+        return {};
+    std::string string(entry.name_length, '\0');
+    if (file->ReadArray(&string[0], string.size(), offset + sizeof(Entry)) != string.size())
+        return {};
+    return {entry, string};
+}
+
+void ProcessFile(VirtualFile file, size_t file_offset, size_t data_offset, u32 this_file_offset,
+                 std::shared_ptr<VectorVfsDirectory> parent) {
+    while (true) {
+        auto entry = GetEntry<FileEntry>(file, file_offset + this_file_offset);
+
+        parent->AddFile(std::make_shared<OffsetVfsFile>(
+            file, entry.first.size, entry.first.offset + data_offset, entry.second, parent));
+
+        if (entry.first.sibling == ROMFS_ENTRY_EMPTY)
+            break;
+
+        this_file_offset = entry.first.sibling;
+    }
+}
+
+void ProcessDirectory(VirtualFile file, size_t dir_offset, size_t file_offset, size_t data_offset,
+                      u32 this_dir_offset, std::shared_ptr<VectorVfsDirectory> parent) {
+    while (true) {
+        auto entry = GetEntry<DirectoryEntry>(file, dir_offset + this_dir_offset);
+        auto current = std::make_shared<VectorVfsDirectory>(
+            std::vector<VirtualFile>{}, std::vector<VirtualDir>{}, parent, entry.second);
+
+        if (entry.first.child_file != ROMFS_ENTRY_EMPTY) {
+            ProcessFile(file, file_offset, data_offset, entry.first.child_file, current);
+        }
+
+        if (entry.first.child_dir != ROMFS_ENTRY_EMPTY) {
+            ProcessDirectory(file, dir_offset, file_offset, data_offset, entry.first.child_dir,
+                             current);
+        }
+
+        parent->AddDirectory(current);
+        if (entry.first.sibling == ROMFS_ENTRY_EMPTY)
+            break;
+        this_dir_offset = entry.first.sibling;
+    }
+}
+
+VirtualDir ExtractRomFS(VirtualFile file) {
+    RomFSHeader header{};
+    if (file->ReadObject(&header) != sizeof(RomFSHeader))
+        return nullptr;
+
+    if (header.header_size != sizeof(RomFSHeader))
+        return nullptr;
+
+    const u64 file_offset = header.file_meta.offset;
+    const u64 dir_offset = header.directory_meta.offset + 4;
+
+    const auto root =
+        std::make_shared<VectorVfsDirectory>(std::vector<VirtualFile>{}, std::vector<VirtualDir>{},
+                                             file->GetContainingDirectory(), file->GetName());
+
+    ProcessDirectory(file, dir_offset, file_offset, header.data_offset, 0, root);
+
+    VirtualDir out = std::move(root);
+
+    while (out->GetSubdirectory("") != nullptr)
+        out = out->GetSubdirectory("");
+
+    return out;
+}
+} // namespace FileSys
diff --git a/src/core/file_sys/romfs.h b/src/core/file_sys/romfs.h
new file mode 100644
index 000000000..03a876d22
--- /dev/null
+++ b/src/core/file_sys/romfs.h
@@ -0,0 +1,35 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+#include "common/common_funcs.h"
+#include "common/swap.h"
+#include "core/file_sys/vfs.h"
+
+namespace FileSys {
+
+struct IVFCLevel {
+    u64_le offset;
+    u64_le size;
+    u32_le block_size;
+    u32_le reserved;
+};
+static_assert(sizeof(IVFCLevel) == 0x18, "IVFCLevel has incorrect size.");
+
+struct IVFCHeader {
+    u32_le magic;
+    u32_le magic_number;
+    INSERT_PADDING_BYTES(8);
+    std::array<IVFCLevel, 6> levels;
+    INSERT_PADDING_BYTES(64);
+};
+static_assert(sizeof(IVFCHeader) == 0xE0, "IVFCHeader has incorrect size.");
+
+// Converts a RomFS binary blob to VFS Filesystem
+// Returns nullptr on failure
+VirtualDir ExtractRomFS(VirtualFile file);
+
+} // namespace FileSys
diff --git a/src/core/file_sys/vfs.cpp b/src/core/file_sys/vfs.cpp
index b99a4fd5b..84a6a7397 100644
--- a/src/core/file_sys/vfs.cpp
+++ b/src/core/file_sys/vfs.cpp
@@ -46,6 +46,13 @@ size_t VfsFile::WriteBytes(const std::vector<u8>& data, size_t offset) {
     return Write(data.data(), data.size(), offset);
 }
 
+std::string VfsFile::GetFullPath() const {
+    if (GetContainingDirectory() == nullptr)
+        return "/" + GetName();
+
+    return GetContainingDirectory()->GetFullPath() + "/" + GetName();
+}
+
 std::shared_ptr<VfsFile> VfsDirectory::GetFileRelative(std::string_view path) const {
     auto vec = FileUtil::SplitPathComponents(path);
     vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
@@ -243,6 +250,13 @@ bool VfsDirectory::Copy(std::string_view src, std::string_view dest) {
     return f2->WriteBytes(f1->ReadAllBytes()) == f1->GetSize();
 }
 
+std::string VfsDirectory::GetFullPath() const {
+    if (IsRoot())
+        return GetName();
+
+    return GetParentDirectory()->GetFullPath() + "/" + GetName();
+}
+
 bool ReadOnlyVfsDirectory::IsWritable() const {
     return false;
 }
@@ -270,4 +284,13 @@ bool ReadOnlyVfsDirectory::DeleteFile(std::string_view name) {
 bool ReadOnlyVfsDirectory::Rename(std::string_view name) {
     return false;
 }
+
+bool VfsRawCopy(VirtualFile src, VirtualFile dest) {
+    if (src == nullptr || dest == nullptr)
+        return false;
+    if (!dest->Resize(src->GetSize()))
+        return false;
+    std::vector<u8> data = src->ReadAllBytes();
+    return dest->WriteBytes(data, 0) == data.size();
+}
 } // namespace FileSys
diff --git a/src/core/file_sys/vfs.h b/src/core/file_sys/vfs.h
index 4a13b8378..cf871edd6 100644
--- a/src/core/file_sys/vfs.h
+++ b/src/core/file_sys/vfs.h
@@ -113,6 +113,9 @@ struct VfsFile : NonCopyable {
 
     // Renames the file to name. Returns whether or not the operation was successsful.
     virtual bool Rename(std::string_view name) = 0;
+
+    // Returns the full path of this file as a string, recursively
+    virtual std::string GetFullPath() const;
 };
 
 // A class representing a directory in an abstract filesystem.
@@ -213,6 +216,17 @@ struct VfsDirectory : NonCopyable {
         return ReplaceFileWithSubdirectory(file_p, std::make_shared<Directory>(file_p));
     }
 
+    bool InterpretAsDirectory(const std::function<VirtualDir(VirtualFile)>& function,
+                              const std::string& file) {
+        auto file_p = GetFile(file);
+        if (file_p == nullptr)
+            return false;
+        return ReplaceFileWithSubdirectory(file_p, function(file_p));
+    }
+
+    // Returns the full path of this directory as a string, recursively
+    virtual std::string GetFullPath() const;
+
 protected:
     // Backend for InterpretAsDirectory.
     // Removes all references to file and adds a reference to dir in the directory's implementation.
@@ -230,4 +244,10 @@ struct ReadOnlyVfsDirectory : public VfsDirectory {
     bool DeleteFile(std::string_view name) override;
     bool Rename(std::string_view name) override;
 };
+
+// A method that copies the raw data between two different implementations of VirtualFile. If you
+// are using the same implementation, it is probably better to use the Copy method in the parent
+// directory of src/dest.
+bool VfsRawCopy(VirtualFile src, VirtualFile dest);
+
 } // namespace FileSys
diff --git a/src/core/file_sys/vfs_offset.cpp b/src/core/file_sys/vfs_offset.cpp
index a40331cef..847cde2f5 100644
--- a/src/core/file_sys/vfs_offset.cpp
+++ b/src/core/file_sys/vfs_offset.cpp
@@ -10,8 +10,9 @@
 namespace FileSys {
 
 OffsetVfsFile::OffsetVfsFile(std::shared_ptr<VfsFile> file_, size_t size_, size_t offset_,
-                             std::string name_)
-    : file(std::move(file_)), offset(offset_), size(size_), name(std::move(name_)) {}
+                             std::string name_, VirtualDir parent_)
+    : file(file_), offset(offset_), size(size_), name(std::move(name_)),
+      parent(parent_ == nullptr ? file->GetContainingDirectory() : std::move(parent_)) {}
 
 std::string OffsetVfsFile::GetName() const {
     return name.empty() ? file->GetName() : name;
@@ -35,7 +36,7 @@ bool OffsetVfsFile::Resize(size_t new_size) {
 }
 
 std::shared_ptr<VfsDirectory> OffsetVfsFile::GetContainingDirectory() const {
-    return file->GetContainingDirectory();
+    return parent;
 }
 
 bool OffsetVfsFile::IsWritable() const {
diff --git a/src/core/file_sys/vfs_offset.h b/src/core/file_sys/vfs_offset.h
index 4f471e3ba..235970dc5 100644
--- a/src/core/file_sys/vfs_offset.h
+++ b/src/core/file_sys/vfs_offset.h
@@ -17,7 +17,7 @@ namespace FileSys {
 // the size of this wrapper.
 struct OffsetVfsFile : public VfsFile {
     OffsetVfsFile(std::shared_ptr<VfsFile> file, size_t size, size_t offset = 0,
-                  std::string new_name = "");
+                  std::string new_name = "", VirtualDir new_parent = nullptr);
 
     std::string GetName() const override;
     size_t GetSize() const override;
@@ -44,6 +44,7 @@ private:
     size_t offset;
     size_t size;
     std::string name;
+    VirtualDir parent;
 };
 
 } // namespace FileSys
diff --git a/src/core/file_sys/vfs_real.cpp b/src/core/file_sys/vfs_real.cpp
index 9ce2e1efa..82d54da4a 100644
--- a/src/core/file_sys/vfs_real.cpp
+++ b/src/core/file_sys/vfs_real.cpp
@@ -195,6 +195,12 @@ bool RealVfsDirectory::Rename(std::string_view name) {
     return FileUtil::Rename(path, new_name);
 }
 
+std::string RealVfsDirectory::GetFullPath() const {
+    auto out = path;
+    std::replace(out.begin(), out.end(), '\\', '/');
+    return out;
+}
+
 bool RealVfsDirectory::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
     const auto iter = std::find(files.begin(), files.end(), file);
     if (iter == files.end())
diff --git a/src/core/file_sys/vfs_real.h b/src/core/file_sys/vfs_real.h
index 2151211c9..243d58576 100644
--- a/src/core/file_sys/vfs_real.h
+++ b/src/core/file_sys/vfs_real.h
@@ -41,7 +41,7 @@ private:
 
 // An implementation of VfsDirectory that represents a directory on the user's computer.
 struct RealVfsDirectory : public VfsDirectory {
-    RealVfsDirectory(const std::string& path, Mode perms);
+    RealVfsDirectory(const std::string& path, Mode perms = Mode::Read);
 
     std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
     std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
@@ -54,6 +54,7 @@ struct RealVfsDirectory : public VfsDirectory {
     bool DeleteSubdirectory(std::string_view name) override;
     bool DeleteFile(std::string_view name) override;
     bool Rename(std::string_view name) override;
+    std::string GetFullPath() const override;
 
 protected:
     bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
diff --git a/src/core/file_sys/vfs_vector.cpp b/src/core/file_sys/vfs_vector.cpp
new file mode 100644
index 000000000..4c6337e3a
--- /dev/null
+++ b/src/core/file_sys/vfs_vector.cpp
@@ -0,0 +1,83 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include "core/file_sys/vfs_vector.h"
+
+namespace FileSys {
+VectorVfsDirectory::VectorVfsDirectory(std::vector<VirtualFile> files_,
+                                       std::vector<VirtualDir> dirs_, VirtualDir parent_,
+                                       std::string name_)
+    : files(std::move(files_)), dirs(std::move(dirs_)), parent(std::move(parent_)),
+      name(std::move(name_)) {}
+
+std::vector<std::shared_ptr<VfsFile>> VectorVfsDirectory::GetFiles() const {
+    return files;
+}
+
+std::vector<std::shared_ptr<VfsDirectory>> VectorVfsDirectory::GetSubdirectories() const {
+    return dirs;
+}
+
+bool VectorVfsDirectory::IsWritable() const {
+    return false;
+}
+
+bool VectorVfsDirectory::IsReadable() const {
+    return true;
+}
+
+std::string VectorVfsDirectory::GetName() const {
+    return name;
+}
+std::shared_ptr<VfsDirectory> VectorVfsDirectory::GetParentDirectory() const {
+    return parent;
+}
+
+template <typename T>
+static bool FindAndRemoveVectorElement(std::vector<T>& vec, std::string_view name) {
+    auto iter = std::find_if(vec.begin(), vec.end(), [name](T e) { return e->GetName() == name; });
+    if (iter == vec.end())
+        return false;
+    auto old_size = vec.size();
+    vec.erase(iter);
+    return true;
+}
+
+bool VectorVfsDirectory::DeleteSubdirectory(std::string_view name) {
+    return FindAndRemoveVectorElement(dirs, name);
+}
+
+bool VectorVfsDirectory::DeleteFile(std::string_view name) {
+    return FindAndRemoveVectorElement(files, name);
+}
+
+bool VectorVfsDirectory::Rename(std::string_view name_) {
+    name = name_;
+    return true;
+}
+
+std::shared_ptr<VfsDirectory> VectorVfsDirectory::CreateSubdirectory(std::string_view name) {
+    return nullptr;
+}
+
+std::shared_ptr<VfsFile> VectorVfsDirectory::CreateFile(std::string_view name) {
+    return nullptr;
+}
+
+void VectorVfsDirectory::AddFile(VirtualFile file) {
+    files.push_back(std::move(file));
+}
+
+void VectorVfsDirectory::AddDirectory(VirtualDir dir) {
+    dirs.push_back(std::move(dir));
+}
+
+bool VectorVfsDirectory::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
+    if (!DeleteFile(file->GetName()))
+        return false;
+    dirs.emplace_back(dir);
+    return true;
+}
+} // namespace FileSys
diff --git a/src/core/file_sys/vfs_vector.h b/src/core/file_sys/vfs_vector.h
new file mode 100644
index 000000000..ba469647b
--- /dev/null
+++ b/src/core/file_sys/vfs_vector.h
@@ -0,0 +1,44 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/file_sys/vfs.h"
+
+namespace FileSys {
+
+// An implementation of VfsDirectory that maintains two vectors for subdirectories and files.
+// Vector data is supplied upon construction.
+struct VectorVfsDirectory : public VfsDirectory {
+    explicit VectorVfsDirectory(std::vector<VirtualFile> files = {},
+                                std::vector<VirtualDir> dirs = {}, VirtualDir parent = nullptr,
+                                std::string name = "");
+
+    std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
+    std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
+    bool IsWritable() const override;
+    bool IsReadable() const override;
+    std::string GetName() const override;
+    std::shared_ptr<VfsDirectory> GetParentDirectory() const override;
+    bool DeleteSubdirectory(std::string_view name) override;
+    bool DeleteFile(std::string_view name) override;
+    bool Rename(std::string_view name) override;
+    std::shared_ptr<VfsDirectory> CreateSubdirectory(std::string_view name) override;
+    std::shared_ptr<VfsFile> CreateFile(std::string_view name) override;
+
+    virtual void AddFile(VirtualFile file);
+    virtual void AddDirectory(VirtualDir dir);
+
+protected:
+    bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
+
+private:
+    std::vector<VirtualFile> files;
+    std::vector<VirtualDir> dirs;
+
+    VirtualDir parent;
+    std::string name;
+};
+
+} // namespace FileSys