git/refs.h
Shawn Pearce 4bd18c43d9 Improve abstraction of ref lock/write.
Created 'struct ref_lock' to contain the data necessary to perform
a ref update.  This change improves writing a ref as the file names
are generated only once (rather than twice) and supports following
symrefs (up to the maximum depth).  Further the ref_lock structure
provides room to extend the update API with ref logging.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-05-17 17:36:36 -07:00

40 lines
1.5 KiB
C

#ifndef REFS_H
#define REFS_H
struct ref_lock {
char *ref_file;
char *lock_file;
unsigned char old_sha1[20];
int lock_fd;
};
/*
* Calls the specified function for each ref file until it returns nonzero,
* and returns the value
*/
extern int head_ref(int (*fn)(const char *path, const unsigned char *sha1));
extern int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1));
extern int for_each_tag_ref(int (*fn)(const char *path, const unsigned char *sha1));
extern int for_each_branch_ref(int (*fn)(const char *path, const unsigned char *sha1));
extern int for_each_remote_ref(int (*fn)(const char *path, const unsigned char *sha1));
/** Reads the refs file specified into sha1 **/
extern int get_ref_sha1(const char *ref, unsigned char *sha1);
/** Locks a "refs/" ref returning the lock on success and NULL on failure. **/
extern struct ref_lock* lock_ref_sha1(const char *ref, const unsigned char *old_sha1, int mustexist);
/** Locks any ref (for 'HEAD' type refs). */
extern struct ref_lock* lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int mustexist);
/** Release any lock taken but not written. **/
extern void unlock_ref (struct ref_lock *lock);
/** Writes sha1 into the ref specified by the lock. **/
extern int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *msg);
/** Returns 0 if target has the right format for a ref. **/
extern int check_ref_format(const char *target);
#endif /* REFS_H */