git/refs.h
Michael Haggerty 432ad41e60 refs: store references hierarchically
Store references hierarchically in a tree that matches the
pseudo-directory structure of the reference names.  Add a new kind of
ref_entry (with flag REF_DIR) to represent a whole subdirectory of
references.  Sort ref_dirs one subdirectory at a time.

NOTE: the dirs can now be sorted as a side-effect of other function
calls.  Therefore, it would be problematic to do something from a
each_ref_fn callback that could provoke the sorting of a directory
that is currently being iterated over (i.e., the directory containing
the entry that is being processed or any of its parents).

This is a bit far-fetched, because a directory is always sorted just
before being iterated over.  Therefore, read-only accesses cannot
trigger the sorting of a directory whose iteration has already
started.  But if a callback function would add a reference to a parent
directory of the reference in the iteration, then try to resolve a
reference under that directory, a re-sort could be triggered and cause
the iteration to work incorrectly.

Nevertheless...add a comment in refs.h warning against modifications
during iteration.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-04-10 15:55:55 -07:00

151 lines
6.0 KiB
C

#ifndef REFS_H
#define REFS_H
struct ref_lock {
char *ref_name;
char *orig_ref_name;
struct lock_file *lk;
unsigned char old_sha1[20];
int lock_fd;
int force_write;
};
#define REF_ISSYMREF 0x01
#define REF_ISPACKED 0x02
#define REF_ISBROKEN 0x04
/*
* Calls the specified function for each ref file until it returns
* nonzero, and returns the value. Please note that it is not safe to
* modify references while an iteration is in progress, unless the
* same callback function invocation that modifies the reference also
* returns a nonzero value to immediately stop the iteration.
*/
typedef int each_ref_fn(const char *refname, const unsigned char *sha1, int flags, void *cb_data);
extern int head_ref(each_ref_fn, void *);
extern int for_each_ref(each_ref_fn, void *);
extern int for_each_ref_in(const char *, each_ref_fn, void *);
extern int for_each_tag_ref(each_ref_fn, void *);
extern int for_each_branch_ref(each_ref_fn, void *);
extern int for_each_remote_ref(each_ref_fn, void *);
extern int for_each_replace_ref(each_ref_fn, void *);
extern int for_each_glob_ref(each_ref_fn, const char *pattern, void *);
extern int for_each_glob_ref_in(each_ref_fn, const char *pattern, const char* prefix, void *);
extern int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
extern int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
extern int for_each_ref_in_submodule(const char *submodule, const char *prefix,
each_ref_fn fn, void *cb_data);
extern int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
extern int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
extern int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
extern int head_ref_namespaced(each_ref_fn fn, void *cb_data);
extern int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
static inline const char *has_glob_specials(const char *pattern)
{
return strpbrk(pattern, "?*[");
}
/* can be used to learn about broken ref and symref */
extern int for_each_rawref(each_ref_fn, void *);
extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
/*
* Add a reference to the in-memory packed reference cache. To actually
* write the reference to the packed-refs file, call pack_refs().
*/
extern void add_packed_ref(const char *refname, const unsigned char *sha1);
extern int ref_exists(const char *);
extern int peel_ref(const char *refname, 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 *refname, const unsigned char *old_sha1);
/** Locks any ref (for 'HEAD' type refs). */
#define REF_NODEREF 0x01
extern struct ref_lock *lock_any_ref_for_update(const char *refname,
const unsigned char *old_sha1,
int flags);
/** Close the file descriptor owned by a lock and return the status */
extern int close_ref(struct ref_lock *lock);
/** Close and commit the ref locked by the lock */
extern int commit_ref(struct ref_lock *lock);
/** 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);
/*
* Invalidate the reference cache for the specified submodule. Use
* submodule=NULL to invalidate the cache for the main module. This
* function must be called if references are changed via a mechanism
* other than the refs API.
*/
extern void invalidate_ref_cache(const char *submodule);
/** Setup reflog before using. **/
int log_ref_setup(const char *ref_name, char *logfile, int bufsize);
/** Reads log for the value of ref during at_time. **/
extern int read_ref_at(const char *refname, unsigned long at_time, int cnt,
unsigned char *sha1, char **msg,
unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
/* iterate over reflog entries */
typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long, void *cb_data);
/*
* Calls the specified function for each reflog file until it returns nonzero,
* and returns the value
*/
extern int for_each_reflog(each_ref_fn, void *);
#define REFNAME_ALLOW_ONELEVEL 1
#define REFNAME_REFSPEC_PATTERN 2
#define REFNAME_DOT_COMPONENT 4
/*
* Return 0 iff refname has the correct format for a refname according
* to the rules described in Documentation/git-check-ref-format.txt.
* If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
* reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
* allow a "*" wildcard character in place of one of the name
* components. No leading or repeated slashes are accepted. If
* REFNAME_DOT_COMPONENT is set in flags, then allow refname
* components to start with "." (but not a whole component equal to
* "." or "..").
*/
extern int check_refname_format(const char *refname, int flags);
extern const char *prettify_refname(const char *refname);
extern char *shorten_unambiguous_ref(const char *refname, int strict);
/** rename ref, return 0 on success **/
extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
/**
* Resolve refname in the nested "gitlink" repository that is located
* at path. If the resolution is successful, return 0 and set sha1 to
* the name of the object; otherwise, return a non-zero value.
*/
extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
/** lock a ref and then write its file */
enum action_on_err { MSG_ON_ERR, DIE_ON_ERR, QUIET_ON_ERR };
int update_ref(const char *action, const char *refname,
const unsigned char *sha1, const unsigned char *oldval,
int flags, enum action_on_err onerr);
#endif /* REFS_H */