service/fsp_srv: Implement CleanDirectoryRecursively

This is the same behavior-wise as DeleteDirectoryRecursively, with the
only difference being that it doesn't delete the top level directory in
the hierarchy, so given:

root_dir/
  - some_dir/
    - File.txt
  - OtherFile.txt

The end result is just:

root_dir/

1 files changed, 11 insertions, 4 deletions

diff --git a/src/core/file_sys/vfs.h b/src/core/file_sys/vfs.h
index 002f99d4e..6e1db36f1 100644
--- a/src/core/file_sys/vfs.h
+++ b/src/core/file_sys/vfs.h
@@ -245,12 +245,18 @@ public:
     // any failure.
     virtual std::shared_ptr<VfsDirectory> CreateDirectoryAbsolute(std::string_view path);
 
-    // Deletes the subdirectory with name and returns true on success.
+    // Deletes the subdirectory with the given name and returns true on success.
     virtual bool DeleteSubdirectory(std::string_view name) = 0;
-    // Deletes all subdirectories and files of subdirectory with name recirsively and then deletes
-    // the subdirectory. Returns true on success.
+
+    // Deletes all subdirectories and files within the provided directory and then deletes
+    // the directory itself. Returns true on success.
     virtual bool DeleteSubdirectoryRecursive(std::string_view name);
-    // Returnes whether or not the file with name name was deleted successfully.
+
+    // Deletes all subdirectories and files within the provided directory.
+    // Unlike DeleteSubdirectoryRecursive, this does not delete the provided directory.
+    virtual bool CleanSubdirectoryRecursive(std::string_view name);
+
+    // Returns whether or not the file with name name was deleted successfully.
     virtual bool DeleteFile(std::string_view name) = 0;
 
     // Returns whether or not this directory was renamed to name.
@@ -277,6 +283,7 @@ public:
     std::shared_ptr<VfsDirectory> CreateSubdirectory(std::string_view name) override;
     std::shared_ptr<VfsFile> CreateFile(std::string_view name) override;
     bool DeleteSubdirectory(std::string_view name) override;
+    bool CleanSubdirectoryRecursive(std::string_view name) override;
     bool DeleteFile(std::string_view name) override;
     bool Rename(std::string_view name) override;
 };