git/tmp-objdir.h
Elijah Newren 7b90ab467a log: clean unneeded objects during log --remerge-diff
The --remerge-diff option will need to create new blobs and trees
representing the "automatic merge" state.  If one is traversing a
long project history, one can easily get hundreds of thousands of
loose objects generated during `log --remerge-diff`.  However, none of
those loose objects are needed after we have completed our diff
operation; they can be summarily deleted.

Add a new helper function to tmp_objdir to discard all the contained
objects, and call it after each merge is handled.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-02 10:02:27 -08:00

83 lines
2.6 KiB
C

#ifndef TMP_OBJDIR_H
#define TMP_OBJDIR_H
/*
* This API allows you to create a temporary object directory, advertise it to
* sub-processes via GIT_OBJECT_DIRECTORY and GIT_ALTERNATE_OBJECT_DIRECTORIES,
* and then either migrate its object into the main object directory, or remove
* it. The library handles unexpected signal/exit death by cleaning up the
* temporary directory.
*
* Example:
*
* struct tmp_objdir *t = tmp_objdir_create("incoming");
* if (!run_command_v_opt_cd_env(cmd, 0, NULL, tmp_objdir_env(t)) &&
* !tmp_objdir_migrate(t))
* printf("success!\n");
* else
* die("failed...tmp_objdir will clean up for us");
*
*/
struct tmp_objdir;
/*
* Create a new temporary object directory with the specified prefix;
* returns NULL on failure.
*/
struct tmp_objdir *tmp_objdir_create(const char *prefix);
/*
* Return a list of environment strings, suitable for use with
* child_process.env, that can be passed to child programs to make use of the
* temporary object directory.
*/
const char **tmp_objdir_env(const struct tmp_objdir *);
/*
* Finalize a temporary object directory by migrating its objects into the main
* object database, removing the temporary directory, and freeing any
* associated resources.
*/
int tmp_objdir_migrate(struct tmp_objdir *);
/*
* Destroy a temporary object directory, discarding any objects it contains.
*/
int tmp_objdir_destroy(struct tmp_objdir *);
/*
* Remove all objects from the temporary object directory, while leaving it
* around so more objects can be added.
*/
void tmp_objdir_discard_objects(struct tmp_objdir *);
/*
* Add the temporary object directory as an alternate object store in the
* current process.
*/
void tmp_objdir_add_as_alternate(const struct tmp_objdir *);
/*
* Replaces the writable object store in the current process with the temporary
* object directory and makes the former main object store an alternate.
* If will_destroy is nonzero, the object directory may not be migrated.
*/
void tmp_objdir_replace_primary_odb(struct tmp_objdir *, int will_destroy);
/*
* If the primary object database was replaced by a temporary object directory,
* restore it to its original value while keeping the directory contents around.
* Returns NULL if the primary object database was not replaced.
*/
struct tmp_objdir *tmp_objdir_unapply_primary_odb(void);
/*
* Reapplies the former primary temporary object database, after potentially
* changing its relative path.
*/
void tmp_objdir_reapply_primary_odb(struct tmp_objdir *, const char *old_cwd,
const char *new_cwd);
#endif /* TMP_OBJDIR_H */