|  | #ifndef REFS_H | 
|  | #define REFS_H | 
|  |  | 
|  | struct ref_lock { | 
|  | char *ref_file; | 
|  | char *log_file; | 
|  | struct lock_file *lk; | 
|  | unsigned char old_sha1[20]; | 
|  | int lock_fd; | 
|  | int force_write; | 
|  | }; | 
|  |  | 
|  | /* | 
|  | * 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); | 
|  |  | 
|  | /** Reads log for the value of ref during at_time. **/ | 
|  | extern int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1); | 
|  |  | 
|  | /** Returns 0 if target has the right format for a ref. **/ | 
|  | extern int check_ref_format(const char *target); | 
|  |  | 
|  | #endif /* REFS_H */ |