01be5ae32fb01298ff6c0738ac4adfe42643b682
[git/git.git] / refs.h
1 #ifndef REFS_H
2 #define REFS_H
3
4 struct object_id;
5 struct ref_store;
6 struct strbuf;
7 struct string_list;
8 struct worktree;
9
10 /*
11 * Resolve a reference, recursively following symbolic refererences.
12 *
13 * Return the name of the non-symbolic reference that ultimately pointed
14 * at the resolved object name. The return value, if not NULL, is a
15 * pointer into either a static buffer or the input ref.
16 *
17 * If oid is non-NULL, store the referred-to object's name in it.
18 *
19 * If the reference cannot be resolved to an object, the behavior
20 * depends on the RESOLVE_REF_READING flag:
21 *
22 * - If RESOLVE_REF_READING is set, return NULL.
23 *
24 * - If RESOLVE_REF_READING is not set, clear oid and return the name of
25 * the last reference name in the chain, which will either be a non-symbolic
26 * reference or an undefined reference. If this is a prelude to
27 * "writing" to the ref, the return value is the name of the ref
28 * that will actually be created or changed.
29 *
30 * If the RESOLVE_REF_NO_RECURSE flag is passed, only resolves one
31 * level of symbolic reference. The value stored in oid for a symbolic
32 * reference will always be null_oid in this case, and the return
33 * value is the reference that the symref refers to directly.
34 *
35 * If flags is non-NULL, set the value that it points to the
36 * combination of REF_ISPACKED (if the reference was found among the
37 * packed references), REF_ISSYMREF (if the initial reference was a
38 * symbolic reference), REF_BAD_NAME (if the reference name is ill
39 * formed --- see RESOLVE_REF_ALLOW_BAD_NAME below), and REF_ISBROKEN
40 * (if the ref is malformed or has a bad name). See refs.h for more detail
41 * on each flag.
42 *
43 * If ref is not a properly-formatted, normalized reference, return
44 * NULL. If more than MAXDEPTH recursive symbolic lookups are needed,
45 * give up and return NULL.
46 *
47 * RESOLVE_REF_ALLOW_BAD_NAME allows resolving refs even when their
48 * name is invalid according to git-check-ref-format(1). If the name
49 * is bad then the value stored in oid will be null_oid and the two
50 * flags REF_ISBROKEN and REF_BAD_NAME will be set.
51 *
52 * Even with RESOLVE_REF_ALLOW_BAD_NAME, names that escape the refs/
53 * directory and do not consist of all caps and underscores cannot be
54 * resolved. The function returns NULL for such ref names.
55 * Caps and underscores refers to the special refs, such as HEAD,
56 * FETCH_HEAD and friends, that all live outside of the refs/ directory.
57 */
58 #define RESOLVE_REF_READING 0x01
59 #define RESOLVE_REF_NO_RECURSE 0x02
60 #define RESOLVE_REF_ALLOW_BAD_NAME 0x04
61
62 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
63 const char *refname,
64 int resolve_flags,
65 struct object_id *oid,
66 int *flags);
67 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
68 struct object_id *oid, int *flags);
69
70 char *refs_resolve_refdup(struct ref_store *refs,
71 const char *refname, int resolve_flags,
72 struct object_id *oid, int *flags);
73 char *resolve_refdup(const char *refname, int resolve_flags,
74 struct object_id *oid, int *flags);
75
76 int refs_read_ref_full(struct ref_store *refs, const char *refname,
77 int resolve_flags, struct object_id *oid, int *flags);
78 int read_ref_full(const char *refname, int resolve_flags,
79 struct object_id *oid, int *flags);
80 int read_ref(const char *refname, struct object_id *oid);
81
82 /*
83 * Return 0 if a reference named refname could be created without
84 * conflicting with the name of an existing reference. Otherwise,
85 * return a negative value and write an explanation to err. If extras
86 * is non-NULL, it is a list of additional refnames with which refname
87 * is not allowed to conflict. If skip is non-NULL, ignore potential
88 * conflicts with refs in skip (e.g., because they are scheduled for
89 * deletion in the same operation). Behavior is undefined if the same
90 * name is listed in both extras and skip.
91 *
92 * Two reference names conflict if one of them exactly matches the
93 * leading components of the other; e.g., "foo/bar" conflicts with
94 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
95 * "foo/barbados".
96 *
97 * extras and skip must be sorted.
98 */
99
100 int refs_verify_refname_available(struct ref_store *refs,
101 const char *refname,
102 const struct string_list *extras,
103 const struct string_list *skip,
104 struct strbuf *err);
105
106 int ref_exists(const char *refname);
107
108 int should_autocreate_reflog(const char *refname);
109
110 int is_branch(const char *refname);
111
112 extern int refs_init_db(struct strbuf *err);
113
114 /*
115 * If refname is a non-symbolic reference that refers to a tag object,
116 * and the tag can be (recursively) dereferenced to a non-tag object,
117 * store the object ID of the referred-to object to oid and return 0.
118 * If any of these conditions are not met, return a non-zero value.
119 * Symbolic references are considered unpeelable, even if they
120 * ultimately resolve to a peelable tag.
121 */
122 int refs_peel_ref(struct ref_store *refs, const char *refname,
123 struct object_id *oid);
124 int peel_ref(const char *refname, struct object_id *oid);
125
126 /**
127 * Resolve refname in the nested "gitlink" repository in the specified
128 * submodule (which must be non-NULL). If the resolution is
129 * successful, return 0 and set oid to the name of the object;
130 * otherwise, return a non-zero value.
131 */
132 int resolve_gitlink_ref(const char *submodule, const char *refname,
133 struct object_id *oid);
134
135 /*
136 * Return true iff abbrev_name is a possible abbreviation for
137 * full_name according to the rules defined by ref_rev_parse_rules in
138 * refs.c.
139 */
140 int refname_match(const char *abbrev_name, const char *full_name);
141
142 int expand_ref(const char *str, int len, struct object_id *oid, char **ref);
143 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref);
144 int dwim_log(const char *str, int len, struct object_id *oid, char **ref);
145
146 /*
147 * A ref_transaction represents a collection of reference updates that
148 * should succeed or fail together.
149 *
150 * Calling sequence
151 * ----------------
152 *
153 * - Allocate and initialize a `struct ref_transaction` by calling
154 * `ref_transaction_begin()`.
155 *
156 * - Specify the intended ref updates by calling one or more of the
157 * following functions:
158 * - `ref_transaction_update()`
159 * - `ref_transaction_create()`
160 * - `ref_transaction_delete()`
161 * - `ref_transaction_verify()`
162 *
163 * - Then either:
164 *
165 * - Optionally call `ref_transaction_prepare()` to prepare the
166 * transaction. This locks all references, checks preconditions,
167 * etc. but doesn't finalize anything. If this step fails, the
168 * transaction has been closed and can only be freed. If this step
169 * succeeds, then `ref_transaction_commit()` is almost certain to
170 * succeed. However, you can still call `ref_transaction_abort()`
171 * if you decide not to commit the transaction after all.
172 *
173 * - Call `ref_transaction_commit()` to execute the transaction,
174 * make the changes permanent, and release all locks. If you
175 * haven't already called `ref_transaction_prepare()`, then
176 * `ref_transaction_commit()` calls it for you.
177 *
178 * Or
179 *
180 * - Call `initial_ref_transaction_commit()` if the ref database is
181 * known to be empty and have no other writers (e.g. during
182 * clone). This is likely to be much faster than
183 * `ref_transaction_commit()`. `ref_transaction_prepare()` should
184 * *not* be called before `initial_ref_transaction_commit()`.
185 *
186 * - Then finally, call `ref_transaction_free()` to free the
187 * `ref_transaction` data structure.
188 *
189 * At any time before calling `ref_transaction_commit()`, you can call
190 * `ref_transaction_abort()` to abort the transaction, rollback any
191 * locks, and free any associated resources (including the
192 * `ref_transaction` data structure).
193 *
194 * Putting it all together, a complete reference update looks like
195 *
196 * struct ref_transaction *transaction;
197 * struct strbuf err = STRBUF_INIT;
198 * int ret = 0;
199 *
200 * transaction = ref_store_transaction_begin(refs, &err);
201 * if (!transaction ||
202 * ref_transaction_update(...) ||
203 * ref_transaction_create(...) ||
204 * ...etc... ||
205 * ref_transaction_commit(transaction, &err)) {
206 * error("%s", err.buf);
207 * ret = -1;
208 * }
209 * ref_transaction_free(transaction);
210 * strbuf_release(&err);
211 * return ret;
212 *
213 * Error handling
214 * --------------
215 *
216 * On error, transaction functions append a message about what
217 * went wrong to the 'err' argument. The message mentions what
218 * ref was being updated (if any) when the error occurred so it
219 * can be passed to 'die' or 'error' as-is.
220 *
221 * The message is appended to err without first clearing err.
222 * err will not be '\n' terminated.
223 *
224 * Caveats
225 * -------
226 *
227 * Note that no locks are taken, and no refs are read, until
228 * `ref_transaction_prepare()` or `ref_transaction_commit()` is
229 * called. So, for example, `ref_transaction_verify()` won't report a
230 * verification failure until the commit is attempted.
231 */
232 struct ref_transaction;
233
234 /*
235 * Bit values set in the flags argument passed to each_ref_fn() and
236 * stored in ref_iterator::flags. Other bits are for internal use
237 * only:
238 */
239
240 /* Reference is a symbolic reference. */
241 #define REF_ISSYMREF 0x01
242
243 /* Reference is a packed reference. */
244 #define REF_ISPACKED 0x02
245
246 /*
247 * Reference cannot be resolved to an object name: dangling symbolic
248 * reference (directly or indirectly), corrupt reference file,
249 * reference exists but name is bad, or symbolic reference refers to
250 * ill-formatted reference name.
251 */
252 #define REF_ISBROKEN 0x04
253
254 /*
255 * Reference name is not well formed.
256 *
257 * See git-check-ref-format(1) for the definition of well formed ref names.
258 */
259 #define REF_BAD_NAME 0x08
260
261 /*
262 * The signature for the callback function for the for_each_*()
263 * functions below. The memory pointed to by the refname and oid
264 * arguments is only guaranteed to be valid for the duration of a
265 * single callback invocation.
266 */
267 typedef int each_ref_fn(const char *refname,
268 const struct object_id *oid, int flags, void *cb_data);
269
270 /*
271 * The following functions invoke the specified callback function for
272 * each reference indicated. If the function ever returns a nonzero
273 * value, stop the iteration and return that value. Please note that
274 * it is not safe to modify references while an iteration is in
275 * progress, unless the same callback function invocation that
276 * modifies the reference also returns a nonzero value to immediately
277 * stop the iteration. Returned references are sorted.
278 */
279 int refs_head_ref(struct ref_store *refs,
280 each_ref_fn fn, void *cb_data);
281 int refs_for_each_ref(struct ref_store *refs,
282 each_ref_fn fn, void *cb_data);
283 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
284 each_ref_fn fn, void *cb_data);
285 int refs_for_each_tag_ref(struct ref_store *refs,
286 each_ref_fn fn, void *cb_data);
287 int refs_for_each_branch_ref(struct ref_store *refs,
288 each_ref_fn fn, void *cb_data);
289 int refs_for_each_remote_ref(struct ref_store *refs,
290 each_ref_fn fn, void *cb_data);
291
292 int head_ref(each_ref_fn fn, void *cb_data);
293 int for_each_ref(each_ref_fn fn, void *cb_data);
294 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data);
295 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
296 each_ref_fn fn, void *cb_data,
297 unsigned int broken);
298 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data,
299 unsigned int broken);
300 int for_each_tag_ref(each_ref_fn fn, void *cb_data);
301 int for_each_branch_ref(each_ref_fn fn, void *cb_data);
302 int for_each_remote_ref(each_ref_fn fn, void *cb_data);
303 int for_each_replace_ref(each_ref_fn fn, void *cb_data);
304 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data);
305 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
306 const char *prefix, void *cb_data);
307
308 int head_ref_namespaced(each_ref_fn fn, void *cb_data);
309 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
310
311 /* can be used to learn about broken ref and symref */
312 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data);
313 int for_each_rawref(each_ref_fn fn, void *cb_data);
314
315 /*
316 * Normalizes partial refs to their fully qualified form.
317 * Will prepend <prefix> to the <pattern> if it doesn't start with 'refs/'.
318 * <prefix> will default to 'refs/' if NULL.
319 *
320 * item.string will be set to the result.
321 * item.util will be set to NULL if <pattern> contains glob characters, or
322 * non-NULL if it doesn't.
323 */
324 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
325 const char *pattern);
326
327 /*
328 * Returns 0 if refname matches any of the exclude_patterns, or if it doesn't
329 * match any of the include_patterns. Returns 1 otherwise.
330 *
331 * If pattern list is NULL or empty, matching against that list is skipped.
332 * This has the effect of matching everything by default, unless the user
333 * specifies rules otherwise.
334 */
335 int ref_filter_match(const char *refname,
336 const struct string_list *include_patterns,
337 const struct string_list *exclude_patterns);
338
339 static inline const char *has_glob_specials(const char *pattern)
340 {
341 return strpbrk(pattern, "?*[");
342 }
343
344 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
345 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt,
346 const struct string_list *refnames);
347
348 /*
349 * Flags for controlling behaviour of pack_refs()
350 * PACK_REFS_PRUNE: Prune loose refs after packing
351 * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs
352 */
353 #define PACK_REFS_PRUNE 0x0001
354 #define PACK_REFS_ALL 0x0002
355
356 /*
357 * Write a packed-refs file for the current repository.
358 * flags: Combination of the above PACK_REFS_* flags.
359 */
360 int refs_pack_refs(struct ref_store *refs, unsigned int flags);
361
362 /*
363 * Setup reflog before using. Fill in err and return -1 on failure.
364 */
365 int refs_create_reflog(struct ref_store *refs, const char *refname,
366 int force_create, struct strbuf *err);
367 int safe_create_reflog(const char *refname, int force_create, struct strbuf *err);
368
369 /** Reads log for the value of ref during at_time. **/
370 int read_ref_at(const char *refname, unsigned int flags,
371 timestamp_t at_time, int cnt,
372 struct object_id *oid, char **msg,
373 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
374
375 /** Check if a particular reflog exists */
376 int refs_reflog_exists(struct ref_store *refs, const char *refname);
377 int reflog_exists(const char *refname);
378
379 /*
380 * Delete the specified reference. If old_oid is non-NULL, then
381 * verify that the current value of the reference is old_oid before
382 * deleting it. If old_oid is NULL, delete the reference if it
383 * exists, regardless of its old value. It is an error for old_oid to
384 * be null_oid. msg and flags are passed through to
385 * ref_transaction_delete().
386 */
387 int refs_delete_ref(struct ref_store *refs, const char *msg,
388 const char *refname,
389 const struct object_id *old_oid,
390 unsigned int flags);
391 int delete_ref(const char *msg, const char *refname,
392 const struct object_id *old_oid, unsigned int flags);
393
394 /*
395 * Delete the specified references. If there are any problems, emit
396 * errors but attempt to keep going (i.e., the deletes are not done in
397 * an all-or-nothing transaction). msg and flags are passed through to
398 * ref_transaction_delete().
399 */
400 int refs_delete_refs(struct ref_store *refs, const char *msg,
401 struct string_list *refnames, unsigned int flags);
402 int delete_refs(const char *msg, struct string_list *refnames,
403 unsigned int flags);
404
405 /** Delete a reflog */
406 int refs_delete_reflog(struct ref_store *refs, const char *refname);
407 int delete_reflog(const char *refname);
408
409 /* iterate over reflog entries */
410 typedef int each_reflog_ent_fn(
411 struct object_id *old_oid, struct object_id *new_oid,
412 const char *committer, timestamp_t timestamp,
413 int tz, const char *msg, void *cb_data);
414
415 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
416 each_reflog_ent_fn fn, void *cb_data);
417 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
418 const char *refname,
419 each_reflog_ent_fn fn,
420 void *cb_data);
421 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
422 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
423
424 /*
425 * Calls the specified function for each reflog file until it returns nonzero,
426 * and returns the value. Reflog file order is unspecified.
427 */
428 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data);
429 int for_each_reflog(each_ref_fn fn, void *cb_data);
430
431 #define REFNAME_ALLOW_ONELEVEL 1
432 #define REFNAME_REFSPEC_PATTERN 2
433
434 /*
435 * Return 0 iff refname has the correct format for a refname according
436 * to the rules described in Documentation/git-check-ref-format.txt.
437 * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
438 * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
439 * allow a single "*" wildcard character in the refspec. No leading or
440 * repeated slashes are accepted.
441 */
442 int check_refname_format(const char *refname, int flags);
443
444 const char *prettify_refname(const char *refname);
445
446 char *shorten_unambiguous_ref(const char *refname, int strict);
447
448 /** rename ref, return 0 on success **/
449 int refs_rename_ref(struct ref_store *refs, const char *oldref,
450 const char *newref, const char *logmsg);
451 int rename_ref(const char *oldref, const char *newref,
452 const char *logmsg);
453
454 /** copy ref, return 0 on success **/
455 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
456 const char *newref, const char *logmsg);
457 int copy_existing_ref(const char *oldref, const char *newref,
458 const char *logmsg);
459
460 int refs_create_symref(struct ref_store *refs, const char *refname,
461 const char *target, const char *logmsg);
462 int create_symref(const char *refname, const char *target, const char *logmsg);
463
464 enum action_on_err {
465 UPDATE_REFS_MSG_ON_ERR,
466 UPDATE_REFS_DIE_ON_ERR,
467 UPDATE_REFS_QUIET_ON_ERR
468 };
469
470 /*
471 * Begin a reference transaction. The reference transaction must
472 * be freed by calling ref_transaction_free().
473 */
474 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
475 struct strbuf *err);
476 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
477
478 /*
479 * Reference transaction updates
480 *
481 * The following four functions add a reference check or update to a
482 * ref_transaction. They have some common similar parameters:
483 *
484 * transaction -- a pointer to an open ref_transaction, obtained
485 * from ref_transaction_begin().
486 *
487 * refname -- the name of the reference to be affected.
488 *
489 * new_oid -- the object ID that should be set to be the new value
490 * of the reference. Some functions allow this parameter to be
491 * NULL, meaning that the reference is not changed, or
492 * null_oid, meaning that the reference should be deleted. A
493 * copy of this value is made in the transaction.
494 *
495 * old_oid -- the object ID that the reference must have before
496 * the update. Some functions allow this parameter to be NULL,
497 * meaning that the old value of the reference is not checked,
498 * or null_oid, meaning that the reference must not exist
499 * before the update. A copy of this value is made in the
500 * transaction.
501 *
502 * flags -- flags affecting the update, passed to
503 * update_ref_lock(). Possible flags: REF_NO_DEREF,
504 * REF_FORCE_CREATE_REFLOG. See those constants for more
505 * information.
506 *
507 * msg -- a message describing the change (for the reflog).
508 *
509 * err -- a strbuf for receiving a description of any error that
510 * might have occurred.
511 *
512 * The functions make internal copies of refname and msg, so the
513 * caller retains ownership of these parameters.
514 *
515 * The functions return 0 on success and non-zero on failure. A
516 * failure means that the transaction as a whole has failed and needs
517 * to be rolled back.
518 */
519
520 /*
521 * The following flags can be passed to ref_transaction_update() etc.
522 * Internally, they are stored in `ref_update::flags`, along with some
523 * internal flags.
524 */
525
526 /*
527 * Act on the ref directly; i.e., without dereferencing symbolic refs.
528 * If this flag is not specified, then symbolic references are
529 * dereferenced and the update is applied to the referent.
530 */
531 #define REF_NO_DEREF (1 << 0)
532
533 /*
534 * Force the creation of a reflog for this reference, even if it
535 * didn't previously have a reflog.
536 */
537 #define REF_FORCE_CREATE_REFLOG (1 << 1)
538
539 /*
540 * Bitmask of all of the flags that are allowed to be passed in to
541 * ref_transaction_update() and friends:
542 */
543 #define REF_TRANSACTION_UPDATE_ALLOWED_FLAGS \
544 (REF_NO_DEREF | REF_FORCE_CREATE_REFLOG)
545
546 /*
547 * Add a reference update to transaction. `new_oid` is the value that
548 * the reference should have after the update, or `null_oid` if it
549 * should be deleted. If `new_oid` is NULL, then the reference is not
550 * changed at all. `old_oid` is the value that the reference must have
551 * before the update, or `null_oid` if it must not have existed
552 * beforehand. The old value is checked after the lock is taken to
553 * prevent races. If the old value doesn't agree with old_oid, the
554 * whole transaction fails. If old_oid is NULL, then the previous
555 * value is not checked.
556 *
557 * See the above comment "Reference transaction updates" for more
558 * information.
559 */
560 int ref_transaction_update(struct ref_transaction *transaction,
561 const char *refname,
562 const struct object_id *new_oid,
563 const struct object_id *old_oid,
564 unsigned int flags, const char *msg,
565 struct strbuf *err);
566
567 /*
568 * Add a reference creation to transaction. new_oid is the value that
569 * the reference should have after the update; it must not be
570 * null_oid. It is verified that the reference does not exist
571 * already.
572 *
573 * See the above comment "Reference transaction updates" for more
574 * information.
575 */
576 int ref_transaction_create(struct ref_transaction *transaction,
577 const char *refname,
578 const struct object_id *new_oid,
579 unsigned int flags, const char *msg,
580 struct strbuf *err);
581
582 /*
583 * Add a reference deletion to transaction. If old_oid is non-NULL,
584 * then it holds the value that the reference should have had before
585 * the update (which must not be null_oid).
586 *
587 * See the above comment "Reference transaction updates" for more
588 * information.
589 */
590 int ref_transaction_delete(struct ref_transaction *transaction,
591 const char *refname,
592 const struct object_id *old_oid,
593 unsigned int flags, const char *msg,
594 struct strbuf *err);
595
596 /*
597 * Verify, within a transaction, that refname has the value old_oid,
598 * or, if old_oid is null_oid, then verify that the reference
599 * doesn't exist. old_oid must be non-NULL.
600 *
601 * See the above comment "Reference transaction updates" for more
602 * information.
603 */
604 int ref_transaction_verify(struct ref_transaction *transaction,
605 const char *refname,
606 const struct object_id *old_oid,
607 unsigned int flags,
608 struct strbuf *err);
609
610 /* Naming conflict (for example, the ref names A and A/B conflict). */
611 #define TRANSACTION_NAME_CONFLICT -1
612 /* All other errors. */
613 #define TRANSACTION_GENERIC_ERROR -2
614
615 /*
616 * Perform the preparatory stages of committing `transaction`. Acquire
617 * any needed locks, check preconditions, etc.; basically, do as much
618 * as possible to ensure that the transaction will be able to go
619 * through, stopping just short of making any irrevocable or
620 * user-visible changes. The updates that this function prepares can
621 * be finished up by calling `ref_transaction_commit()` or rolled back
622 * by calling `ref_transaction_abort()`.
623 *
624 * On success, return 0 and leave the transaction in "prepared" state.
625 * On failure, abort the transaction, write an error message to `err`,
626 * and return one of the `TRANSACTION_*` constants.
627 *
628 * Callers who don't need such fine-grained control over committing
629 * reference transactions should just call `ref_transaction_commit()`.
630 */
631 int ref_transaction_prepare(struct ref_transaction *transaction,
632 struct strbuf *err);
633
634 /*
635 * Commit all of the changes that have been queued in transaction, as
636 * atomically as possible. On success, return 0 and leave the
637 * transaction in "closed" state. On failure, roll back the
638 * transaction, write an error message to `err`, and return one of the
639 * `TRANSACTION_*` constants
640 */
641 int ref_transaction_commit(struct ref_transaction *transaction,
642 struct strbuf *err);
643
644 /*
645 * Abort `transaction`, which has been begun and possibly prepared,
646 * but not yet committed.
647 */
648 int ref_transaction_abort(struct ref_transaction *transaction,
649 struct strbuf *err);
650
651 /*
652 * Like ref_transaction_commit(), but optimized for creating
653 * references when originally initializing a repository (e.g., by "git
654 * clone"). It writes the new references directly to packed-refs
655 * without locking the individual references.
656 *
657 * It is a bug to call this function when there might be other
658 * processes accessing the repository or if there are existing
659 * references that might conflict with the ones being created. All
660 * old_oid values must either be absent or null_oid.
661 */
662 int initial_ref_transaction_commit(struct ref_transaction *transaction,
663 struct strbuf *err);
664
665 /*
666 * Free `*transaction` and all associated data.
667 */
668 void ref_transaction_free(struct ref_transaction *transaction);
669
670 /**
671 * Lock, update, and unlock a single reference. This function
672 * basically does a transaction containing a single call to
673 * ref_transaction_update(). The parameters to this function have the
674 * same meaning as the corresponding parameters to
675 * ref_transaction_update(). Handle errors as requested by the `onerr`
676 * argument.
677 */
678 int refs_update_ref(struct ref_store *refs, const char *msg, const char *refname,
679 const struct object_id *new_oid, const struct object_id *old_oid,
680 unsigned int flags, enum action_on_err onerr);
681 int update_ref(const char *msg, const char *refname,
682 const struct object_id *new_oid, const struct object_id *old_oid,
683 unsigned int flags, enum action_on_err onerr);
684
685 int parse_hide_refs_config(const char *var, const char *value, const char *);
686
687 /*
688 * Check whether a ref is hidden. If no namespace is set, both the first and
689 * the second parameter point to the full ref name. If a namespace is set and
690 * the ref is inside that namespace, the first parameter is a pointer to the
691 * name of the ref with the namespace prefix removed. If a namespace is set and
692 * the ref is outside that namespace, the first parameter is NULL. The second
693 * parameter always points to the full ref name.
694 */
695 int ref_is_hidden(const char *, const char *);
696
697 enum ref_type {
698 REF_TYPE_PER_WORKTREE,
699 REF_TYPE_PSEUDOREF,
700 REF_TYPE_NORMAL,
701 };
702
703 enum ref_type ref_type(const char *refname);
704
705 enum expire_reflog_flags {
706 EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
707 EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
708 EXPIRE_REFLOGS_VERBOSE = 1 << 2,
709 EXPIRE_REFLOGS_REWRITE = 1 << 3
710 };
711
712 /*
713 * The following interface is used for reflog expiration. The caller
714 * calls reflog_expire(), supplying it with three callback functions,
715 * of the following types. The callback functions define the
716 * expiration policy that is desired.
717 *
718 * reflog_expiry_prepare_fn -- Called once after the reference is
719 * locked.
720 *
721 * reflog_expiry_should_prune_fn -- Called once for each entry in the
722 * existing reflog. It should return true iff that entry should be
723 * pruned.
724 *
725 * reflog_expiry_cleanup_fn -- Called once before the reference is
726 * unlocked again.
727 */
728 typedef void reflog_expiry_prepare_fn(const char *refname,
729 const struct object_id *oid,
730 void *cb_data);
731 typedef int reflog_expiry_should_prune_fn(struct object_id *ooid,
732 struct object_id *noid,
733 const char *email,
734 timestamp_t timestamp, int tz,
735 const char *message, void *cb_data);
736 typedef void reflog_expiry_cleanup_fn(void *cb_data);
737
738 /*
739 * Expire reflog entries for the specified reference. oid is the old
740 * value of the reference. flags is a combination of the constants in
741 * enum expire_reflog_flags. The three function pointers are described
742 * above. On success, return zero.
743 */
744 int refs_reflog_expire(struct ref_store *refs,
745 const char *refname,
746 const struct object_id *oid,
747 unsigned int flags,
748 reflog_expiry_prepare_fn prepare_fn,
749 reflog_expiry_should_prune_fn should_prune_fn,
750 reflog_expiry_cleanup_fn cleanup_fn,
751 void *policy_cb_data);
752 int reflog_expire(const char *refname, const struct object_id *oid,
753 unsigned int flags,
754 reflog_expiry_prepare_fn prepare_fn,
755 reflog_expiry_should_prune_fn should_prune_fn,
756 reflog_expiry_cleanup_fn cleanup_fn,
757 void *policy_cb_data);
758
759 int ref_storage_backend_exists(const char *name);
760
761 struct ref_store *get_main_ref_store(void);
762 /*
763 * Return the ref_store instance for the specified submodule. For the
764 * main repository, use submodule==NULL; such a call cannot fail. For
765 * a submodule, the submodule must exist and be a nonbare repository,
766 * otherwise return NULL. If the requested reference store has not yet
767 * been initialized, initialize it first.
768 *
769 * For backwards compatibility, submodule=="" is treated the same as
770 * submodule==NULL.
771 */
772 struct ref_store *get_submodule_ref_store(const char *submodule);
773 struct ref_store *get_worktree_ref_store(const struct worktree *wt);
774
775 #endif /* REFS_H */