1#ifndef REFS_H
2#define REFS_H
3
4struct object_id;
5struct ref_store;
6struct repository;
7struct strbuf;
8struct string_list;
9struct string_list_item;
10struct worktree;
11
12/*
13 * Resolve a reference, recursively following symbolic refererences.
14 *
15 * Return the name of the non-symbolic reference that ultimately pointed
16 * at the resolved object name. The return value, if not NULL, is a
17 * pointer into either a static buffer or the input ref.
18 *
19 * If oid is non-NULL, store the referred-to object's name in it.
20 *
21 * If the reference cannot be resolved to an object, the behavior
22 * depends on the RESOLVE_REF_READING flag:
23 *
24 * - If RESOLVE_REF_READING is set, return NULL.
25 *
26 * - If RESOLVE_REF_READING is not set, clear oid and return the name of
27 * the last reference name in the chain, which will either be a non-symbolic
28 * reference or an undefined reference. If this is a prelude to
29 * "writing" to the ref, the return value is the name of the ref
30 * that will actually be created or changed.
31 *
32 * If the RESOLVE_REF_NO_RECURSE flag is passed, only resolves one
33 * level of symbolic reference. The value stored in oid for a symbolic
34 * reference will always be null_oid in this case, and the return
35 * value is the reference that the symref refers to directly.
36 *
37 * If flags is non-NULL, set the value that it points to the
38 * combination of REF_ISPACKED (if the reference was found among the
39 * packed references), REF_ISSYMREF (if the initial reference was a
40 * symbolic reference), REF_BAD_NAME (if the reference name is ill
41 * formed --- see RESOLVE_REF_ALLOW_BAD_NAME below), and REF_ISBROKEN
42 * (if the ref is malformed or has a bad name). See refs.h for more detail
43 * on each flag.
44 *
45 * If ref is not a properly-formatted, normalized reference, return
46 * NULL. If more than MAXDEPTH recursive symbolic lookups are needed,
47 * give up and return NULL.
48 *
49 * RESOLVE_REF_ALLOW_BAD_NAME allows resolving refs even when their
50 * name is invalid according to git-check-ref-format(1). If the name
51 * is bad then the value stored in oid will be null_oid and the two
52 * flags REF_ISBROKEN and REF_BAD_NAME will be set.
53 *
54 * Even with RESOLVE_REF_ALLOW_BAD_NAME, names that escape the refs/
55 * directory and do not consist of all caps and underscores cannot be
56 * resolved. The function returns NULL for such ref names.
57 * Caps and underscores refers to the special refs, such as HEAD,
58 * FETCH_HEAD and friends, that all live outside of the refs/ directory.
59 */
60#define RESOLVE_REF_READING 0x01
61#define RESOLVE_REF_NO_RECURSE 0x02
62#define RESOLVE_REF_ALLOW_BAD_NAME 0x04
63
64const char *refs_resolve_ref_unsafe(struct ref_store *refs,
65 const char *refname,
66 int resolve_flags,
67 struct object_id *oid,
68 int *flags);
69const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
70 struct object_id *oid, int *flags);
71
72char *refs_resolve_refdup(struct ref_store *refs,
73 const char *refname, int resolve_flags,
74 struct object_id *oid, int *flags);
75char *resolve_refdup(const char *refname, int resolve_flags,
76 struct object_id *oid, int *flags);
77
78int refs_read_ref_full(struct ref_store *refs, const char *refname,
79 int resolve_flags, struct object_id *oid, int *flags);
80int read_ref_full(const char *refname, int resolve_flags,
81 struct object_id *oid, int *flags);
82int read_ref(const char *refname, struct object_id *oid);
83
84/*
85 * Return 0 if a reference named refname could be created without
86 * conflicting with the name of an existing reference. Otherwise,
87 * return a negative value and write an explanation to err. If extras
88 * is non-NULL, it is a list of additional refnames with which refname
89 * is not allowed to conflict. If skip is non-NULL, ignore potential
90 * conflicts with refs in skip (e.g., because they are scheduled for
91 * deletion in the same operation). Behavior is undefined if the same
92 * name is listed in both extras and skip.
93 *
94 * Two reference names conflict if one of them exactly matches the
95 * leading components of the other; e.g., "foo/bar" conflicts with
96 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
97 * "foo/barbados".
98 *
99 * extras and skip must be sorted.
100 */
101
102int refs_verify_refname_available(struct ref_store *refs,
103 const char *refname,
104 const struct string_list *extras,
105 const struct string_list *skip,
106 struct strbuf *err);
107
108int ref_exists(const char *refname);
109
110int should_autocreate_reflog(const char *refname);
111
112int is_branch(const char *refname);
113
114extern int refs_init_db(struct strbuf *err);
115
116/*
117 * If refname is a non-symbolic reference that refers to a tag object,
118 * and the tag can be (recursively) dereferenced to a non-tag object,
119 * store the object ID of the referred-to object to oid and return 0.
120 * If any of these conditions are not met, return a non-zero value.
121 * Symbolic references are considered unpeelable, even if they
122 * ultimately resolve to a peelable tag.
123 */
124int refs_peel_ref(struct ref_store *refs, const char *refname,
125 struct object_id *oid);
126int peel_ref(const char *refname, struct object_id *oid);
127
128/**
129 * Resolve refname in the nested "gitlink" repository in the specified
130 * submodule (which must be non-NULL). If the resolution is
131 * successful, return 0 and set oid to the name of the object;
132 * otherwise, return a non-zero value.
133 */
134int resolve_gitlink_ref(const char *submodule, const char *refname,
135 struct object_id *oid);
136
137/*
138 * Return true iff abbrev_name is a possible abbreviation for
139 * full_name according to the rules defined by ref_rev_parse_rules in
140 * refs.c.
141 */
142int refname_match(const char *abbrev_name, const char *full_name);
143
144/*
145 * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
146 * the results to 'prefixes'
147 */
148struct argv_array;
149void expand_ref_prefix(struct argv_array *prefixes, const char *prefix);
150
151int expand_ref(const char *str, int len, struct object_id *oid, char **ref);
152int dwim_ref(const char *str, int len, struct object_id *oid, char **ref);
153int dwim_log(const char *str, int len, struct object_id *oid, char **ref);
154
155/*
156 * A ref_transaction represents a collection of reference updates that
157 * should succeed or fail together.
158 *
159 * Calling sequence
160 * ----------------
161 *
162 * - Allocate and initialize a `struct ref_transaction` by calling
163 * `ref_transaction_begin()`.
164 *
165 * - Specify the intended ref updates by calling one or more of the
166 * following functions:
167 * - `ref_transaction_update()`
168 * - `ref_transaction_create()`
169 * - `ref_transaction_delete()`
170 * - `ref_transaction_verify()`
171 *
172 * - Then either:
173 *
174 * - Optionally call `ref_transaction_prepare()` to prepare the
175 * transaction. This locks all references, checks preconditions,
176 * etc. but doesn't finalize anything. If this step fails, the
177 * transaction has been closed and can only be freed. If this step
178 * succeeds, then `ref_transaction_commit()` is almost certain to
179 * succeed. However, you can still call `ref_transaction_abort()`
180 * if you decide not to commit the transaction after all.
181 *
182 * - Call `ref_transaction_commit()` to execute the transaction,
183 * make the changes permanent, and release all locks. If you
184 * haven't already called `ref_transaction_prepare()`, then
185 * `ref_transaction_commit()` calls it for you.
186 *
187 * Or
188 *
189 * - Call `initial_ref_transaction_commit()` if the ref database is
190 * known to be empty and have no other writers (e.g. during
191 * clone). This is likely to be much faster than
192 * `ref_transaction_commit()`. `ref_transaction_prepare()` should
193 * *not* be called before `initial_ref_transaction_commit()`.
194 *
195 * - Then finally, call `ref_transaction_free()` to free the
196 * `ref_transaction` data structure.
197 *
198 * At any time before calling `ref_transaction_commit()`, you can call
199 * `ref_transaction_abort()` to abort the transaction, rollback any
200 * locks, and free any associated resources (including the
201 * `ref_transaction` data structure).
202 *
203 * Putting it all together, a complete reference update looks like
204 *
205 * struct ref_transaction *transaction;
206 * struct strbuf err = STRBUF_INIT;
207 * int ret = 0;
208 *
209 * transaction = ref_store_transaction_begin(refs, &err);
210 * if (!transaction ||
211 * ref_transaction_update(...) ||
212 * ref_transaction_create(...) ||
213 * ...etc... ||
214 * ref_transaction_commit(transaction, &err)) {
215 * error("%s", err.buf);
216 * ret = -1;
217 * }
218 * ref_transaction_free(transaction);
219 * strbuf_release(&err);
220 * return ret;
221 *
222 * Error handling
223 * --------------
224 *
225 * On error, transaction functions append a message about what
226 * went wrong to the 'err' argument. The message mentions what
227 * ref was being updated (if any) when the error occurred so it
228 * can be passed to 'die' or 'error' as-is.
229 *
230 * The message is appended to err without first clearing err.
231 * err will not be '\n' terminated.
232 *
233 * Caveats
234 * -------
235 *
236 * Note that no locks are taken, and no refs are read, until
237 * `ref_transaction_prepare()` or `ref_transaction_commit()` is
238 * called. So, for example, `ref_transaction_verify()` won't report a
239 * verification failure until the commit is attempted.
240 */
241struct ref_transaction;
242
243/*
244 * Bit values set in the flags argument passed to each_ref_fn() and
245 * stored in ref_iterator::flags. Other bits are for internal use
246 * only:
247 */
248
249/* Reference is a symbolic reference. */
250#define REF_ISSYMREF 0x01
251
252/* Reference is a packed reference. */
253#define REF_ISPACKED 0x02
254
255/*
256 * Reference cannot be resolved to an object name: dangling symbolic
257 * reference (directly or indirectly), corrupt reference file,
258 * reference exists but name is bad, or symbolic reference refers to
259 * ill-formatted reference name.
260 */
261#define REF_ISBROKEN 0x04
262
263/*
264 * Reference name is not well formed.
265 *
266 * See git-check-ref-format(1) for the definition of well formed ref names.
267 */
268#define REF_BAD_NAME 0x08
269
270/*
271 * The signature for the callback function for the for_each_*()
272 * functions below. The memory pointed to by the refname and oid
273 * arguments is only guaranteed to be valid for the duration of a
274 * single callback invocation.
275 */
276typedef int each_ref_fn(const char *refname,
277 const struct object_id *oid, int flags, void *cb_data);
278
279/*
280 * The following functions invoke the specified callback function for
281 * each reference indicated. If the function ever returns a nonzero
282 * value, stop the iteration and return that value. Please note that
283 * it is not safe to modify references while an iteration is in
284 * progress, unless the same callback function invocation that
285 * modifies the reference also returns a nonzero value to immediately
286 * stop the iteration. Returned references are sorted.
287 */
288int refs_head_ref(struct ref_store *refs,
289 each_ref_fn fn, void *cb_data);
290int refs_for_each_ref(struct ref_store *refs,
291 each_ref_fn fn, void *cb_data);
292int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
293 each_ref_fn fn, void *cb_data);
294int refs_for_each_tag_ref(struct ref_store *refs,
295 each_ref_fn fn, void *cb_data);
296int refs_for_each_branch_ref(struct ref_store *refs,
297 each_ref_fn fn, void *cb_data);
298int refs_for_each_remote_ref(struct ref_store *refs,
299 each_ref_fn fn, void *cb_data);
300
301int head_ref(each_ref_fn fn, void *cb_data);
302int for_each_ref(each_ref_fn fn, void *cb_data);
303int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data);
304int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
305 each_ref_fn fn, void *cb_data,
306 unsigned int broken);
307int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data,
308 unsigned int broken);
309int for_each_tag_ref(each_ref_fn fn, void *cb_data);
310int for_each_branch_ref(each_ref_fn fn, void *cb_data);
311int for_each_remote_ref(each_ref_fn fn, void *cb_data);
312int for_each_replace_ref(struct repository *r, each_ref_fn fn, void *cb_data);
313int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data);
314int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
315 const char *prefix, void *cb_data);
316
317int head_ref_namespaced(each_ref_fn fn, void *cb_data);
318int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
319
320/* can be used to learn about broken ref and symref */
321int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data);
322int for_each_rawref(each_ref_fn fn, void *cb_data);
323
324/*
325 * Normalizes partial refs to their fully qualified form.
326 * Will prepend <prefix> to the <pattern> if it doesn't start with 'refs/'.
327 * <prefix> will default to 'refs/' if NULL.
328 *
329 * item.string will be set to the result.
330 * item.util will be set to NULL if <pattern> contains glob characters, or
331 * non-NULL if it doesn't.
332 */
333void normalize_glob_ref(struct string_list_item *item, const char *prefix,
334 const char *pattern);
335
336/*
337 * Returns 0 if refname matches any of the exclude_patterns, or if it doesn't
338 * match any of the include_patterns. Returns 1 otherwise.
339 *
340 * If pattern list is NULL or empty, matching against that list is skipped.
341 * This has the effect of matching everything by default, unless the user
342 * specifies rules otherwise.
343 */
344int ref_filter_match(const char *refname,
345 const struct string_list *include_patterns,
346 const struct string_list *exclude_patterns);
347
348static inline const char *has_glob_specials(const char *pattern)
349{
350 return strpbrk(pattern, "?*[");
351}
352
353void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
354void warn_dangling_symrefs(FILE *fp, const char *msg_fmt,
355 const struct string_list *refnames);
356
357/*
358 * Flags for controlling behaviour of pack_refs()
359 * PACK_REFS_PRUNE: Prune loose refs after packing
360 * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs
361 */
362#define PACK_REFS_PRUNE 0x0001
363#define PACK_REFS_ALL 0x0002
364
365/*
366 * Write a packed-refs file for the current repository.
367 * flags: Combination of the above PACK_REFS_* flags.
368 */
369int refs_pack_refs(struct ref_store *refs, unsigned int flags);
370
371/*
372 * Setup reflog before using. Fill in err and return -1 on failure.
373 */
374int refs_create_reflog(struct ref_store *refs, const char *refname,
375 int force_create, struct strbuf *err);
376int safe_create_reflog(const char *refname, int force_create, struct strbuf *err);
377
378/** Reads log for the value of ref during at_time. **/
379int read_ref_at(const char *refname, unsigned int flags,
380 timestamp_t at_time, int cnt,
381 struct object_id *oid, char **msg,
382 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
383
384/** Check if a particular reflog exists */
385int refs_reflog_exists(struct ref_store *refs, const char *refname);
386int reflog_exists(const char *refname);
387
388/*
389 * Delete the specified reference. If old_oid is non-NULL, then
390 * verify that the current value of the reference is old_oid before
391 * deleting it. If old_oid is NULL, delete the reference if it
392 * exists, regardless of its old value. It is an error for old_oid to
393 * be null_oid. msg and flags are passed through to
394 * ref_transaction_delete().
395 */
396int refs_delete_ref(struct ref_store *refs, const char *msg,
397 const char *refname,
398 const struct object_id *old_oid,
399 unsigned int flags);
400int delete_ref(const char *msg, const char *refname,
401 const struct object_id *old_oid, unsigned int flags);
402
403/*
404 * Delete the specified references. If there are any problems, emit
405 * errors but attempt to keep going (i.e., the deletes are not done in
406 * an all-or-nothing transaction). msg and flags are passed through to
407 * ref_transaction_delete().
408 */
409int refs_delete_refs(struct ref_store *refs, const char *msg,
410 struct string_list *refnames, unsigned int flags);
411int delete_refs(const char *msg, struct string_list *refnames,
412 unsigned int flags);
413
414/** Delete a reflog */
415int refs_delete_reflog(struct ref_store *refs, const char *refname);
416int delete_reflog(const char *refname);
417
418/* iterate over reflog entries */
419typedef int each_reflog_ent_fn(
420 struct object_id *old_oid, struct object_id *new_oid,
421 const char *committer, timestamp_t timestamp,
422 int tz, const char *msg, void *cb_data);
423
424int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
425 each_reflog_ent_fn fn, void *cb_data);
426int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
427 const char *refname,
428 each_reflog_ent_fn fn,
429 void *cb_data);
430int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
431int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
432
433/*
434 * Calls the specified function for each reflog file until it returns nonzero,
435 * and returns the value. Reflog file order is unspecified.
436 */
437int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data);
438int for_each_reflog(each_ref_fn fn, void *cb_data);
439
440#define REFNAME_ALLOW_ONELEVEL 1
441#define REFNAME_REFSPEC_PATTERN 2
442
443/*
444 * Return 0 iff refname has the correct format for a refname according
445 * to the rules described in Documentation/git-check-ref-format.txt.
446 * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
447 * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
448 * allow a single "*" wildcard character in the refspec. No leading or
449 * repeated slashes are accepted.
450 */
451int check_refname_format(const char *refname, int flags);
452
453const char *prettify_refname(const char *refname);
454
455char *shorten_unambiguous_ref(const char *refname, int strict);
456
457/** rename ref, return 0 on success **/
458int refs_rename_ref(struct ref_store *refs, const char *oldref,
459 const char *newref, const char *logmsg);
460int rename_ref(const char *oldref, const char *newref,
461 const char *logmsg);
462
463/** copy ref, return 0 on success **/
464int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
465 const char *newref, const char *logmsg);
466int copy_existing_ref(const char *oldref, const char *newref,
467 const char *logmsg);
468
469int refs_create_symref(struct ref_store *refs, const char *refname,
470 const char *target, const char *logmsg);
471int create_symref(const char *refname, const char *target, const char *logmsg);
472
473enum action_on_err {
474 UPDATE_REFS_MSG_ON_ERR,
475 UPDATE_REFS_DIE_ON_ERR,
476 UPDATE_REFS_QUIET_ON_ERR
477};
478
479/*
480 * Begin a reference transaction. The reference transaction must
481 * be freed by calling ref_transaction_free().
482 */
483struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
484 struct strbuf *err);
485struct ref_transaction *ref_transaction_begin(struct strbuf *err);
486
487/*
488 * Reference transaction updates
489 *
490 * The following four functions add a reference check or update to a
491 * ref_transaction. They have some common similar parameters:
492 *
493 * transaction -- a pointer to an open ref_transaction, obtained
494 * from ref_transaction_begin().
495 *
496 * refname -- the name of the reference to be affected.
497 *
498 * new_oid -- the object ID that should be set to be the new value
499 * of the reference. Some functions allow this parameter to be
500 * NULL, meaning that the reference is not changed, or
501 * null_oid, meaning that the reference should be deleted. A
502 * copy of this value is made in the transaction.
503 *
504 * old_oid -- the object ID that the reference must have before
505 * the update. Some functions allow this parameter to be NULL,
506 * meaning that the old value of the reference is not checked,
507 * or null_oid, meaning that the reference must not exist
508 * before the update. A copy of this value is made in the
509 * transaction.
510 *
511 * flags -- flags affecting the update, passed to
512 * update_ref_lock(). Possible flags: REF_NO_DEREF,
513 * REF_FORCE_CREATE_REFLOG. See those constants for more
514 * information.
515 *
516 * msg -- a message describing the change (for the reflog).
517 *
518 * err -- a strbuf for receiving a description of any error that
519 * might have occurred.
520 *
521 * The functions make internal copies of refname and msg, so the
522 * caller retains ownership of these parameters.
523 *
524 * The functions return 0 on success and non-zero on failure. A
525 * failure means that the transaction as a whole has failed and needs
526 * to be rolled back.
527 */
528
529/*
530 * The following flags can be passed to ref_transaction_update() etc.
531 * Internally, they are stored in `ref_update::flags`, along with some
532 * internal flags.
533 */
534
535/*
536 * Act on the ref directly; i.e., without dereferencing symbolic refs.
537 * If this flag is not specified, then symbolic references are
538 * dereferenced and the update is applied to the referent.
539 */
540#define REF_NO_DEREF (1 << 0)
541
542/*
543 * Force the creation of a reflog for this reference, even if it
544 * didn't previously have a reflog.
545 */
546#define REF_FORCE_CREATE_REFLOG (1 << 1)
547
548/*
549 * Bitmask of all of the flags that are allowed to be passed in to
550 * ref_transaction_update() and friends:
551 */
552#define REF_TRANSACTION_UPDATE_ALLOWED_FLAGS \
553 (REF_NO_DEREF | REF_FORCE_CREATE_REFLOG)
554
555/*
556 * Add a reference update to transaction. `new_oid` is the value that
557 * the reference should have after the update, or `null_oid` if it
558 * should be deleted. If `new_oid` is NULL, then the reference is not
559 * changed at all. `old_oid` is the value that the reference must have
560 * before the update, or `null_oid` if it must not have existed
561 * beforehand. The old value is checked after the lock is taken to
562 * prevent races. If the old value doesn't agree with old_oid, the
563 * whole transaction fails. If old_oid is NULL, then the previous
564 * value is not checked.
565 *
566 * See the above comment "Reference transaction updates" for more
567 * information.
568 */
569int ref_transaction_update(struct ref_transaction *transaction,
570 const char *refname,
571 const struct object_id *new_oid,
572 const struct object_id *old_oid,
573 unsigned int flags, const char *msg,
574 struct strbuf *err);
575
576/*
577 * Add a reference creation to transaction. new_oid is the value that
578 * the reference should have after the update; it must not be
579 * null_oid. It is verified that the reference does not exist
580 * already.
581 *
582 * See the above comment "Reference transaction updates" for more
583 * information.
584 */
585int ref_transaction_create(struct ref_transaction *transaction,
586 const char *refname,
587 const struct object_id *new_oid,
588 unsigned int flags, const char *msg,
589 struct strbuf *err);
590
591/*
592 * Add a reference deletion to transaction. If old_oid is non-NULL,
593 * then it holds the value that the reference should have had before
594 * the update (which must not be null_oid).
595 *
596 * See the above comment "Reference transaction updates" for more
597 * information.
598 */
599int ref_transaction_delete(struct ref_transaction *transaction,
600 const char *refname,
601 const struct object_id *old_oid,
602 unsigned int flags, const char *msg,
603 struct strbuf *err);
604
605/*
606 * Verify, within a transaction, that refname has the value old_oid,
607 * or, if old_oid is null_oid, then verify that the reference
608 * doesn't exist. old_oid must be non-NULL.
609 *
610 * See the above comment "Reference transaction updates" for more
611 * information.
612 */
613int ref_transaction_verify(struct ref_transaction *transaction,
614 const char *refname,
615 const struct object_id *old_oid,
616 unsigned int flags,
617 struct strbuf *err);
618
619/* Naming conflict (for example, the ref names A and A/B conflict). */
620#define TRANSACTION_NAME_CONFLICT -1
621/* All other errors. */
622#define TRANSACTION_GENERIC_ERROR -2
623
624/*
625 * Perform the preparatory stages of committing `transaction`. Acquire
626 * any needed locks, check preconditions, etc.; basically, do as much
627 * as possible to ensure that the transaction will be able to go
628 * through, stopping just short of making any irrevocable or
629 * user-visible changes. The updates that this function prepares can
630 * be finished up by calling `ref_transaction_commit()` or rolled back
631 * by calling `ref_transaction_abort()`.
632 *
633 * On success, return 0 and leave the transaction in "prepared" state.
634 * On failure, abort the transaction, write an error message to `err`,
635 * and return one of the `TRANSACTION_*` constants.
636 *
637 * Callers who don't need such fine-grained control over committing
638 * reference transactions should just call `ref_transaction_commit()`.
639 */
640int ref_transaction_prepare(struct ref_transaction *transaction,
641 struct strbuf *err);
642
643/*
644 * Commit all of the changes that have been queued in transaction, as
645 * atomically as possible. On success, return 0 and leave the
646 * transaction in "closed" state. On failure, roll back the
647 * transaction, write an error message to `err`, and return one of the
648 * `TRANSACTION_*` constants
649 */
650int ref_transaction_commit(struct ref_transaction *transaction,
651 struct strbuf *err);
652
653/*
654 * Abort `transaction`, which has been begun and possibly prepared,
655 * but not yet committed.
656 */
657int ref_transaction_abort(struct ref_transaction *transaction,
658 struct strbuf *err);
659
660/*
661 * Like ref_transaction_commit(), but optimized for creating
662 * references when originally initializing a repository (e.g., by "git
663 * clone"). It writes the new references directly to packed-refs
664 * without locking the individual references.
665 *
666 * It is a bug to call this function when there might be other
667 * processes accessing the repository or if there are existing
668 * references that might conflict with the ones being created. All
669 * old_oid values must either be absent or null_oid.
670 */
671int initial_ref_transaction_commit(struct ref_transaction *transaction,
672 struct strbuf *err);
673
674/*
675 * Free `*transaction` and all associated data.
676 */
677void ref_transaction_free(struct ref_transaction *transaction);
678
679/**
680 * Lock, update, and unlock a single reference. This function
681 * basically does a transaction containing a single call to
682 * ref_transaction_update(). The parameters to this function have the
683 * same meaning as the corresponding parameters to
684 * ref_transaction_update(). Handle errors as requested by the `onerr`
685 * argument.
686 */
687int refs_update_ref(struct ref_store *refs, const char *msg, const char *refname,
688 const struct object_id *new_oid, const struct object_id *old_oid,
689 unsigned int flags, enum action_on_err onerr);
690int update_ref(const char *msg, const char *refname,
691 const struct object_id *new_oid, const struct object_id *old_oid,
692 unsigned int flags, enum action_on_err onerr);
693
694int parse_hide_refs_config(const char *var, const char *value, const char *);
695
696/*
697 * Check whether a ref is hidden. If no namespace is set, both the first and
698 * the second parameter point to the full ref name. If a namespace is set and
699 * the ref is inside that namespace, the first parameter is a pointer to the
700 * name of the ref with the namespace prefix removed. If a namespace is set and
701 * the ref is outside that namespace, the first parameter is NULL. The second
702 * parameter always points to the full ref name.
703 */
704int ref_is_hidden(const char *, const char *);
705
706enum ref_type {
707 REF_TYPE_PER_WORKTREE,
708 REF_TYPE_PSEUDOREF,
709 REF_TYPE_NORMAL,
710};
711
712enum ref_type ref_type(const char *refname);
713
714enum expire_reflog_flags {
715 EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
716 EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
717 EXPIRE_REFLOGS_VERBOSE = 1 << 2,
718 EXPIRE_REFLOGS_REWRITE = 1 << 3
719};
720
721/*
722 * The following interface is used for reflog expiration. The caller
723 * calls reflog_expire(), supplying it with three callback functions,
724 * of the following types. The callback functions define the
725 * expiration policy that is desired.
726 *
727 * reflog_expiry_prepare_fn -- Called once after the reference is
728 * locked.
729 *
730 * reflog_expiry_should_prune_fn -- Called once for each entry in the
731 * existing reflog. It should return true iff that entry should be
732 * pruned.
733 *
734 * reflog_expiry_cleanup_fn -- Called once before the reference is
735 * unlocked again.
736 */
737typedef void reflog_expiry_prepare_fn(const char *refname,
738 const struct object_id *oid,
739 void *cb_data);
740typedef int reflog_expiry_should_prune_fn(struct object_id *ooid,
741 struct object_id *noid,
742 const char *email,
743 timestamp_t timestamp, int tz,
744 const char *message, void *cb_data);
745typedef void reflog_expiry_cleanup_fn(void *cb_data);
746
747/*
748 * Expire reflog entries for the specified reference. oid is the old
749 * value of the reference. flags is a combination of the constants in
750 * enum expire_reflog_flags. The three function pointers are described
751 * above. On success, return zero.
752 */
753int refs_reflog_expire(struct ref_store *refs,
754 const char *refname,
755 const struct object_id *oid,
756 unsigned int flags,
757 reflog_expiry_prepare_fn prepare_fn,
758 reflog_expiry_should_prune_fn should_prune_fn,
759 reflog_expiry_cleanup_fn cleanup_fn,
760 void *policy_cb_data);
761int reflog_expire(const char *refname, const struct object_id *oid,
762 unsigned int flags,
763 reflog_expiry_prepare_fn prepare_fn,
764 reflog_expiry_should_prune_fn should_prune_fn,
765 reflog_expiry_cleanup_fn cleanup_fn,
766 void *policy_cb_data);
767
768int ref_storage_backend_exists(const char *name);
769
770struct ref_store *get_main_ref_store(struct repository *r);
771/*
772 * Return the ref_store instance for the specified submodule. For the
773 * main repository, use submodule==NULL; such a call cannot fail. For
774 * a submodule, the submodule must exist and be a nonbare repository,
775 * otherwise return NULL. If the requested reference store has not yet
776 * been initialized, initialize it first.
777 *
778 * For backwards compatibility, submodule=="" is treated the same as
779 * submodule==NULL.
780 */
781struct ref_store *get_submodule_ref_store(const char *submodule);
782struct ref_store *get_worktree_ref_store(const struct worktree *wt);
783
784#endif /* REFS_H */
785