2d6b6263fc207d790b5ee61332d051e549d24e0c
[git/git.git] / refs.h
1 #ifndef REFS_H
2 #define REFS_H
3
4 struct object_id;
5 struct strbuf;
6 struct string_list;
7
8 /*
9 * Resolve a reference, recursively following symbolic refererences.
10 *
11 * Store the referred-to object's name in sha1 and return the name of
12 * the non-symbolic reference that ultimately pointed at it. The
13 * return value, if not NULL, is a pointer into either a static buffer
14 * or the input ref.
15 *
16 * If the reference cannot be resolved to an object, the behavior
17 * depends on the RESOLVE_REF_READING flag:
18 *
19 * - If RESOLVE_REF_READING is set, return NULL.
20 *
21 * - If RESOLVE_REF_READING is not set, clear sha1 and return the name of
22 * the last reference name in the chain, which will either be a non-symbolic
23 * reference or an undefined reference. If this is a prelude to
24 * "writing" to the ref, the return value is the name of the ref
25 * that will actually be created or changed.
26 *
27 * If the RESOLVE_REF_NO_RECURSE flag is passed, only resolves one
28 * level of symbolic reference. The value stored in sha1 for a symbolic
29 * reference will always be null_sha1 in this case, and the return
30 * value is the reference that the symref refers to directly.
31 *
32 * If flags is non-NULL, set the value that it points to the
33 * combination of REF_ISPACKED (if the reference was found among the
34 * packed references), REF_ISSYMREF (if the initial reference was a
35 * symbolic reference), REF_BAD_NAME (if the reference name is ill
36 * formed --- see RESOLVE_REF_ALLOW_BAD_NAME below), and REF_ISBROKEN
37 * (if the ref is malformed or has a bad name). See refs.h for more detail
38 * on each flag.
39 *
40 * If ref is not a properly-formatted, normalized reference, return
41 * NULL. If more than MAXDEPTH recursive symbolic lookups are needed,
42 * give up and return NULL.
43 *
44 * RESOLVE_REF_ALLOW_BAD_NAME allows resolving refs even when their
45 * name is invalid according to git-check-ref-format(1). If the name
46 * is bad then the value stored in sha1 will be null_sha1 and the two
47 * flags REF_ISBROKEN and REF_BAD_NAME will be set.
48 *
49 * Even with RESOLVE_REF_ALLOW_BAD_NAME, names that escape the refs/
50 * directory and do not consist of all caps and underscores cannot be
51 * resolved. The function returns NULL for such ref names.
52 * Caps and underscores refers to the special refs, such as HEAD,
53 * FETCH_HEAD and friends, that all live outside of the refs/ directory.
54 */
55 #define RESOLVE_REF_READING 0x01
56 #define RESOLVE_REF_NO_RECURSE 0x02
57 #define RESOLVE_REF_ALLOW_BAD_NAME 0x04
58
59 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
60 unsigned char *sha1, int *flags);
61
62 char *resolve_refdup(const char *refname, int resolve_flags,
63 unsigned char *sha1, int *flags);
64
65 int read_ref_full(const char *refname, int resolve_flags,
66 unsigned char *sha1, int *flags);
67 int read_ref(const char *refname, unsigned char *sha1);
68
69 int ref_exists(const char *refname);
70
71 int should_autocreate_reflog(const char *refname);
72
73 int is_branch(const char *refname);
74
75 extern int refs_init_db(struct strbuf *err);
76
77 /*
78 * If refname is a non-symbolic reference that refers to a tag object,
79 * and the tag can be (recursively) dereferenced to a non-tag object,
80 * store the SHA1 of the referred-to object to sha1 and return 0. If
81 * any of these conditions are not met, return a non-zero value.
82 * Symbolic references are considered unpeelable, even if they
83 * ultimately resolve to a peelable tag.
84 */
85 int peel_ref(const char *refname, unsigned char *sha1);
86
87 /**
88 * Resolve refname in the nested "gitlink" repository in the specified
89 * submodule (which must be non-NULL). If the resolution is
90 * successful, return 0 and set sha1 to the name of the object;
91 * otherwise, return a non-zero value.
92 */
93 int resolve_gitlink_ref(const char *submodule, const char *refname,
94 unsigned char *sha1);
95
96 /*
97 * Return true iff abbrev_name is a possible abbreviation for
98 * full_name according to the rules defined by ref_rev_parse_rules in
99 * refs.c.
100 */
101 int refname_match(const char *abbrev_name, const char *full_name);
102
103 int expand_ref(const char *str, int len, unsigned char *sha1, char **ref);
104 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref);
105 int dwim_log(const char *str, int len, unsigned char *sha1, char **ref);
106
107 /*
108 * A ref_transaction represents a collection of ref updates
109 * that should succeed or fail together.
110 *
111 * Calling sequence
112 * ----------------
113 * - Allocate and initialize a `struct ref_transaction` by calling
114 * `ref_transaction_begin()`.
115 *
116 * - List intended ref updates by calling functions like
117 * `ref_transaction_update()` and `ref_transaction_create()`.
118 *
119 * - Call `ref_transaction_commit()` to execute the transaction.
120 * If this succeeds, the ref updates will have taken place and
121 * the transaction cannot be rolled back.
122 *
123 * - Instead of `ref_transaction_commit`, use
124 * `initial_ref_transaction_commit()` if the ref database is known
125 * to be empty (e.g. during clone). This is likely to be much
126 * faster.
127 *
128 * - At any time call `ref_transaction_free()` to discard the
129 * transaction and free associated resources. In particular,
130 * this rolls back the transaction if it has not been
131 * successfully committed.
132 *
133 * Error handling
134 * --------------
135 *
136 * On error, transaction functions append a message about what
137 * went wrong to the 'err' argument. The message mentions what
138 * ref was being updated (if any) when the error occurred so it
139 * can be passed to 'die' or 'error' as-is.
140 *
141 * The message is appended to err without first clearing err.
142 * err will not be '\n' terminated.
143 *
144 * Caveats
145 * -------
146 *
147 * Note that no locks are taken, and no refs are read, until
148 * `ref_transaction_commit` is called. So `ref_transaction_verify`
149 * won't report a verification failure until the commit is attempted.
150 */
151 struct ref_transaction;
152
153 /*
154 * Bit values set in the flags argument passed to each_ref_fn() and
155 * stored in ref_iterator::flags. Other bits are for internal use
156 * only:
157 */
158
159 /* Reference is a symbolic reference. */
160 #define REF_ISSYMREF 0x01
161
162 /* Reference is a packed reference. */
163 #define REF_ISPACKED 0x02
164
165 /*
166 * Reference cannot be resolved to an object name: dangling symbolic
167 * reference (directly or indirectly), corrupt reference file,
168 * reference exists but name is bad, or symbolic reference refers to
169 * ill-formatted reference name.
170 */
171 #define REF_ISBROKEN 0x04
172
173 /*
174 * Reference name is not well formed.
175 *
176 * See git-check-ref-format(1) for the definition of well formed ref names.
177 */
178 #define REF_BAD_NAME 0x08
179
180 /*
181 * The signature for the callback function for the for_each_*()
182 * functions below. The memory pointed to by the refname and sha1
183 * arguments is only guaranteed to be valid for the duration of a
184 * single callback invocation.
185 */
186 typedef int each_ref_fn(const char *refname,
187 const struct object_id *oid, int flags, void *cb_data);
188
189 /*
190 * The following functions invoke the specified callback function for
191 * each reference indicated. If the function ever returns a nonzero
192 * value, stop the iteration and return that value. Please note that
193 * it is not safe to modify references while an iteration is in
194 * progress, unless the same callback function invocation that
195 * modifies the reference also returns a nonzero value to immediately
196 * stop the iteration.
197 */
198 int head_ref(each_ref_fn fn, void *cb_data);
199 int for_each_ref(each_ref_fn fn, void *cb_data);
200 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data);
201 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data,
202 unsigned int broken);
203 int for_each_tag_ref(each_ref_fn fn, void *cb_data);
204 int for_each_branch_ref(each_ref_fn fn, void *cb_data);
205 int for_each_remote_ref(each_ref_fn fn, void *cb_data);
206 int for_each_replace_ref(each_ref_fn fn, void *cb_data);
207 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data);
208 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
209 const char *prefix, void *cb_data);
210
211 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
212 int for_each_ref_submodule(const char *submodule,
213 each_ref_fn fn, void *cb_data);
214 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
215 each_ref_fn fn, void *cb_data);
216 int for_each_tag_ref_submodule(const char *submodule,
217 each_ref_fn fn, void *cb_data);
218 int for_each_branch_ref_submodule(const char *submodule,
219 each_ref_fn fn, void *cb_data);
220 int for_each_remote_ref_submodule(const char *submodule,
221 each_ref_fn fn, void *cb_data);
222
223 int head_ref_namespaced(each_ref_fn fn, void *cb_data);
224 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
225
226 /* can be used to learn about broken ref and symref */
227 int for_each_rawref(each_ref_fn fn, void *cb_data);
228
229 static inline const char *has_glob_specials(const char *pattern)
230 {
231 return strpbrk(pattern, "?*[");
232 }
233
234 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
235 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt,
236 const struct string_list *refnames);
237
238 /*
239 * Flags for controlling behaviour of pack_refs()
240 * PACK_REFS_PRUNE: Prune loose refs after packing
241 * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs
242 */
243 #define PACK_REFS_PRUNE 0x0001
244 #define PACK_REFS_ALL 0x0002
245
246 /*
247 * Write a packed-refs file for the current repository.
248 * flags: Combination of the above PACK_REFS_* flags.
249 */
250 int pack_refs(unsigned int flags);
251
252 /*
253 * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
254 * REF_NODEREF: act on the ref directly, instead of dereferencing
255 * symbolic references.
256 *
257 * Other flags are reserved for internal use.
258 */
259 #define REF_NODEREF 0x01
260 #define REF_FORCE_CREATE_REFLOG 0x40
261
262 /*
263 * Setup reflog before using. Fill in err and return -1 on failure.
264 */
265 int safe_create_reflog(const char *refname, int force_create, struct strbuf *err);
266
267 /** Reads log for the value of ref during at_time. **/
268 int read_ref_at(const char *refname, unsigned int flags,
269 unsigned long at_time, int cnt,
270 unsigned char *sha1, char **msg,
271 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
272
273 /** Check if a particular reflog exists */
274 int reflog_exists(const char *refname);
275
276 /*
277 * Delete the specified reference. If old_sha1 is non-NULL, then
278 * verify that the current value of the reference is old_sha1 before
279 * deleting it. If old_sha1 is NULL, delete the reference if it
280 * exists, regardless of its old value. It is an error for old_sha1 to
281 * be NULL_SHA1. flags is passed through to ref_transaction_delete().
282 */
283 int delete_ref(const char *msg, const char *refname,
284 const unsigned char *old_sha1, unsigned int flags);
285
286 /*
287 * Delete the specified references. If there are any problems, emit
288 * errors but attempt to keep going (i.e., the deletes are not done in
289 * an all-or-nothing transaction). flags is passed through to
290 * ref_transaction_delete().
291 */
292 int delete_refs(struct string_list *refnames, unsigned int flags);
293
294 /** Delete a reflog */
295 int delete_reflog(const char *refname);
296
297 /* iterate over reflog entries */
298 typedef int each_reflog_ent_fn(
299 struct object_id *old_oid, struct object_id *new_oid,
300 const char *committer, unsigned long timestamp,
301 int tz, const char *msg, void *cb_data);
302
303 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
304 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
305
306 /*
307 * Calls the specified function for each reflog file until it returns nonzero,
308 * and returns the value
309 */
310 int for_each_reflog(each_ref_fn fn, void *cb_data);
311
312 #define REFNAME_ALLOW_ONELEVEL 1
313 #define REFNAME_REFSPEC_PATTERN 2
314
315 /*
316 * Return 0 iff refname has the correct format for a refname according
317 * to the rules described in Documentation/git-check-ref-format.txt.
318 * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
319 * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
320 * allow a single "*" wildcard character in the refspec. No leading or
321 * repeated slashes are accepted.
322 */
323 int check_refname_format(const char *refname, int flags);
324
325 const char *prettify_refname(const char *refname);
326
327 char *shorten_unambiguous_ref(const char *refname, int strict);
328
329 /** rename ref, return 0 on success **/
330 int rename_ref(const char *oldref, const char *newref, const char *logmsg);
331
332 int create_symref(const char *refname, const char *target, const char *logmsg);
333
334 /*
335 * Update HEAD of the specified gitdir.
336 * Similar to create_symref("relative-git-dir/HEAD", target, NULL), but
337 * this can update the main working tree's HEAD regardless of where
338 * $GIT_DIR points to.
339 * Return 0 if successful, non-zero otherwise.
340 * */
341 int set_worktree_head_symref(const char *gitdir, const char *target,
342 const char *logmsg);
343
344 enum action_on_err {
345 UPDATE_REFS_MSG_ON_ERR,
346 UPDATE_REFS_DIE_ON_ERR,
347 UPDATE_REFS_QUIET_ON_ERR
348 };
349
350 /*
351 * Begin a reference transaction. The reference transaction must
352 * be freed by calling ref_transaction_free().
353 */
354 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
355
356 /*
357 * Reference transaction updates
358 *
359 * The following four functions add a reference check or update to a
360 * ref_transaction. They have some common similar parameters:
361 *
362 * transaction -- a pointer to an open ref_transaction, obtained
363 * from ref_transaction_begin().
364 *
365 * refname -- the name of the reference to be affected.
366 *
367 * flags -- flags affecting the update, passed to
368 * update_ref_lock(). Can be REF_NODEREF, which means that
369 * symbolic references should not be followed.
370 *
371 * msg -- a message describing the change (for the reflog).
372 *
373 * err -- a strbuf for receiving a description of any error that
374 * might have occurred.
375 *
376 * The functions make internal copies of refname and msg, so the
377 * caller retains ownership of these parameters.
378 *
379 * The functions return 0 on success and non-zero on failure. A
380 * failure means that the transaction as a whole has failed and needs
381 * to be rolled back.
382 */
383
384 /*
385 * Add a reference update to transaction. new_sha1 is the value that
386 * the reference should have after the update, or null_sha1 if it
387 * should be deleted. If new_sha1 is NULL, then the reference is not
388 * changed at all. old_sha1 is the value that the reference must have
389 * before the update, or null_sha1 if it must not have existed
390 * beforehand. The old value is checked after the lock is taken to
391 * prevent races. If the old value doesn't agree with old_sha1, the
392 * whole transaction fails. If old_sha1 is NULL, then the previous
393 * value is not checked.
394 *
395 * See the above comment "Reference transaction updates" for more
396 * information.
397 */
398 int ref_transaction_update(struct ref_transaction *transaction,
399 const char *refname,
400 const unsigned char *new_sha1,
401 const unsigned char *old_sha1,
402 unsigned int flags, const char *msg,
403 struct strbuf *err);
404
405 /*
406 * Add a reference creation to transaction. new_sha1 is the value that
407 * the reference should have after the update; it must not be
408 * null_sha1. It is verified that the reference does not exist
409 * already.
410 *
411 * See the above comment "Reference transaction updates" for more
412 * information.
413 */
414 int ref_transaction_create(struct ref_transaction *transaction,
415 const char *refname,
416 const unsigned char *new_sha1,
417 unsigned int flags, const char *msg,
418 struct strbuf *err);
419
420 /*
421 * Add a reference deletion to transaction. If old_sha1 is non-NULL,
422 * then it holds the value that the reference should have had before
423 * the update (which must not be null_sha1).
424 *
425 * See the above comment "Reference transaction updates" for more
426 * information.
427 */
428 int ref_transaction_delete(struct ref_transaction *transaction,
429 const char *refname,
430 const unsigned char *old_sha1,
431 unsigned int flags, const char *msg,
432 struct strbuf *err);
433
434 /*
435 * Verify, within a transaction, that refname has the value old_sha1,
436 * or, if old_sha1 is null_sha1, then verify that the reference
437 * doesn't exist. old_sha1 must be non-NULL.
438 *
439 * See the above comment "Reference transaction updates" for more
440 * information.
441 */
442 int ref_transaction_verify(struct ref_transaction *transaction,
443 const char *refname,
444 const unsigned char *old_sha1,
445 unsigned int flags,
446 struct strbuf *err);
447
448 /*
449 * Commit all of the changes that have been queued in transaction, as
450 * atomically as possible.
451 *
452 * Returns 0 for success, or one of the below error codes for errors.
453 */
454 /* Naming conflict (for example, the ref names A and A/B conflict). */
455 #define TRANSACTION_NAME_CONFLICT -1
456 /* All other errors. */
457 #define TRANSACTION_GENERIC_ERROR -2
458 int ref_transaction_commit(struct ref_transaction *transaction,
459 struct strbuf *err);
460
461 /*
462 * Like ref_transaction_commit(), but optimized for creating
463 * references when originally initializing a repository (e.g., by "git
464 * clone"). It writes the new references directly to packed-refs
465 * without locking the individual references.
466 *
467 * It is a bug to call this function when there might be other
468 * processes accessing the repository or if there are existing
469 * references that might conflict with the ones being created. All
470 * old_sha1 values must either be absent or NULL_SHA1.
471 */
472 int initial_ref_transaction_commit(struct ref_transaction *transaction,
473 struct strbuf *err);
474
475 /*
476 * Free an existing transaction and all associated data.
477 */
478 void ref_transaction_free(struct ref_transaction *transaction);
479
480 /**
481 * Lock, update, and unlock a single reference. This function
482 * basically does a transaction containing a single call to
483 * ref_transaction_update(). The parameters to this function have the
484 * same meaning as the corresponding parameters to
485 * ref_transaction_update(). Handle errors as requested by the `onerr`
486 * argument.
487 */
488 int update_ref(const char *msg, const char *refname,
489 const unsigned char *new_sha1, const unsigned char *old_sha1,
490 unsigned int flags, enum action_on_err onerr);
491 int update_ref_oid(const char *msg, const char *refname,
492 const struct object_id *new_oid, const struct object_id *old_oid,
493 unsigned int flags, enum action_on_err onerr);
494
495 int parse_hide_refs_config(const char *var, const char *value, const char *);
496
497 /*
498 * Check whether a ref is hidden. If no namespace is set, both the first and
499 * the second parameter point to the full ref name. If a namespace is set and
500 * the ref is inside that namespace, the first parameter is a pointer to the
501 * name of the ref with the namespace prefix removed. If a namespace is set and
502 * the ref is outside that namespace, the first parameter is NULL. The second
503 * parameter always points to the full ref name.
504 */
505 int ref_is_hidden(const char *, const char *);
506
507 enum ref_type {
508 REF_TYPE_PER_WORKTREE,
509 REF_TYPE_PSEUDOREF,
510 REF_TYPE_NORMAL,
511 };
512
513 enum ref_type ref_type(const char *refname);
514
515 enum expire_reflog_flags {
516 EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
517 EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
518 EXPIRE_REFLOGS_VERBOSE = 1 << 2,
519 EXPIRE_REFLOGS_REWRITE = 1 << 3
520 };
521
522 /*
523 * The following interface is used for reflog expiration. The caller
524 * calls reflog_expire(), supplying it with three callback functions,
525 * of the following types. The callback functions define the
526 * expiration policy that is desired.
527 *
528 * reflog_expiry_prepare_fn -- Called once after the reference is
529 * locked.
530 *
531 * reflog_expiry_should_prune_fn -- Called once for each entry in the
532 * existing reflog. It should return true iff that entry should be
533 * pruned.
534 *
535 * reflog_expiry_cleanup_fn -- Called once before the reference is
536 * unlocked again.
537 */
538 typedef void reflog_expiry_prepare_fn(const char *refname,
539 const unsigned char *sha1,
540 void *cb_data);
541 typedef int reflog_expiry_should_prune_fn(unsigned char *osha1,
542 unsigned char *nsha1,
543 const char *email,
544 unsigned long timestamp, int tz,
545 const char *message, void *cb_data);
546 typedef void reflog_expiry_cleanup_fn(void *cb_data);
547
548 /*
549 * Expire reflog entries for the specified reference. sha1 is the old
550 * value of the reference. flags is a combination of the constants in
551 * enum expire_reflog_flags. The three function pointers are described
552 * above. On success, return zero.
553 */
554 int reflog_expire(const char *refname, const unsigned char *sha1,
555 unsigned int flags,
556 reflog_expiry_prepare_fn prepare_fn,
557 reflog_expiry_should_prune_fn should_prune_fn,
558 reflog_expiry_cleanup_fn cleanup_fn,
559 void *policy_cb_data);
560
561 int ref_storage_backend_exists(const char *name);
562
563 #endif /* REFS_H */