refs.c: make get_main_ref_store() public and use it
[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
9 /*
10 * Resolve a reference, recursively following symbolic refererences.
11 *
12 * Store the referred-to object's name in sha1 and return the name of
13 * the non-symbolic reference that ultimately pointed at it. The
14 * return value, if not NULL, is a pointer into either a static buffer
15 * or the input ref.
16 *
17 * If the reference cannot be resolved to an object, the behavior
18 * depends on the RESOLVE_REF_READING flag:
19 *
20 * - If RESOLVE_REF_READING is set, return NULL.
21 *
22 * - If RESOLVE_REF_READING is not set, clear sha1 and return the name of
23 * the last reference name in the chain, which will either be a non-symbolic
24 * reference or an undefined reference. If this is a prelude to
25 * "writing" to the ref, the return value is the name of the ref
26 * that will actually be created or changed.
27 *
28 * If the RESOLVE_REF_NO_RECURSE flag is passed, only resolves one
29 * level of symbolic reference. The value stored in sha1 for a symbolic
30 * reference will always be null_sha1 in this case, and the return
31 * value is the reference that the symref refers to directly.
32 *
33 * If flags is non-NULL, set the value that it points to the
34 * combination of REF_ISPACKED (if the reference was found among the
35 * packed references), REF_ISSYMREF (if the initial reference was a
36 * symbolic reference), REF_BAD_NAME (if the reference name is ill
37 * formed --- see RESOLVE_REF_ALLOW_BAD_NAME below), and REF_ISBROKEN
38 * (if the ref is malformed or has a bad name). See refs.h for more detail
39 * on each flag.
40 *
41 * If ref is not a properly-formatted, normalized reference, return
42 * NULL. If more than MAXDEPTH recursive symbolic lookups are needed,
43 * give up and return NULL.
44 *
45 * RESOLVE_REF_ALLOW_BAD_NAME allows resolving refs even when their
46 * name is invalid according to git-check-ref-format(1). If the name
47 * is bad then the value stored in sha1 will be null_sha1 and the two
48 * flags REF_ISBROKEN and REF_BAD_NAME will be set.
49 *
50 * Even with RESOLVE_REF_ALLOW_BAD_NAME, names that escape the refs/
51 * directory and do not consist of all caps and underscores cannot be
52 * resolved. The function returns NULL for such ref names.
53 * Caps and underscores refers to the special refs, such as HEAD,
54 * FETCH_HEAD and friends, that all live outside of the refs/ directory.
55 */
56 #define RESOLVE_REF_READING 0x01
57 #define RESOLVE_REF_NO_RECURSE 0x02
58 #define RESOLVE_REF_ALLOW_BAD_NAME 0x04
59
60 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
61 unsigned char *sha1, int *flags);
62
63 char *resolve_refdup(const char *refname, int resolve_flags,
64 unsigned char *sha1, int *flags);
65
66 int read_ref_full(const char *refname, int resolve_flags,
67 unsigned char *sha1, int *flags);
68 int read_ref(const char *refname, unsigned char *sha1);
69
70 int ref_exists(const char *refname);
71
72 int should_autocreate_reflog(const char *refname);
73
74 int is_branch(const char *refname);
75
76 extern int refs_init_db(struct strbuf *err);
77
78 /*
79 * If refname is a non-symbolic reference that refers to a tag object,
80 * and the tag can be (recursively) dereferenced to a non-tag object,
81 * store the SHA1 of the referred-to object to sha1 and return 0. If
82 * any of these conditions are not met, return a non-zero value.
83 * Symbolic references are considered unpeelable, even if they
84 * ultimately resolve to a peelable tag.
85 */
86 int peel_ref(const char *refname, unsigned char *sha1);
87
88 /**
89 * Resolve refname in the nested "gitlink" repository in the specified
90 * submodule (which must be non-NULL). If the resolution is
91 * successful, return 0 and set sha1 to the name of the object;
92 * otherwise, return a non-zero value.
93 */
94 int resolve_gitlink_ref(const char *submodule, const char *refname,
95 unsigned char *sha1);
96
97 /*
98 * Return true iff abbrev_name is a possible abbreviation for
99 * full_name according to the rules defined by ref_rev_parse_rules in
100 * refs.c.
101 */
102 int refname_match(const char *abbrev_name, const char *full_name);
103
104 int expand_ref(const char *str, int len, unsigned char *sha1, char **ref);
105 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref);
106 int dwim_log(const char *str, int len, unsigned char *sha1, char **ref);
107
108 /*
109 * A ref_transaction represents a collection of ref updates
110 * that should succeed or fail together.
111 *
112 * Calling sequence
113 * ----------------
114 * - Allocate and initialize a `struct ref_transaction` by calling
115 * `ref_transaction_begin()`.
116 *
117 * - List intended ref updates by calling functions like
118 * `ref_transaction_update()` and `ref_transaction_create()`.
119 *
120 * - Call `ref_transaction_commit()` to execute the transaction.
121 * If this succeeds, the ref updates will have taken place and
122 * the transaction cannot be rolled back.
123 *
124 * - Instead of `ref_transaction_commit`, use
125 * `initial_ref_transaction_commit()` if the ref database is known
126 * to be empty (e.g. during clone). This is likely to be much
127 * faster.
128 *
129 * - At any time call `ref_transaction_free()` to discard the
130 * transaction and free associated resources. In particular,
131 * this rolls back the transaction if it has not been
132 * successfully committed.
133 *
134 * Error handling
135 * --------------
136 *
137 * On error, transaction functions append a message about what
138 * went wrong to the 'err' argument. The message mentions what
139 * ref was being updated (if any) when the error occurred so it
140 * can be passed to 'die' or 'error' as-is.
141 *
142 * The message is appended to err without first clearing err.
143 * err will not be '\n' terminated.
144 *
145 * Caveats
146 * -------
147 *
148 * Note that no locks are taken, and no refs are read, until
149 * `ref_transaction_commit` is called. So `ref_transaction_verify`
150 * won't report a verification failure until the commit is attempted.
151 */
152 struct ref_transaction;
153
154 /*
155 * Bit values set in the flags argument passed to each_ref_fn() and
156 * stored in ref_iterator::flags. Other bits are for internal use
157 * only:
158 */
159
160 /* Reference is a symbolic reference. */
161 #define REF_ISSYMREF 0x01
162
163 /* Reference is a packed reference. */
164 #define REF_ISPACKED 0x02
165
166 /*
167 * Reference cannot be resolved to an object name: dangling symbolic
168 * reference (directly or indirectly), corrupt reference file,
169 * reference exists but name is bad, or symbolic reference refers to
170 * ill-formatted reference name.
171 */
172 #define REF_ISBROKEN 0x04
173
174 /*
175 * Reference name is not well formed.
176 *
177 * See git-check-ref-format(1) for the definition of well formed ref names.
178 */
179 #define REF_BAD_NAME 0x08
180
181 /*
182 * The signature for the callback function for the for_each_*()
183 * functions below. The memory pointed to by the refname and sha1
184 * arguments is only guaranteed to be valid for the duration of a
185 * single callback invocation.
186 */
187 typedef int each_ref_fn(const char *refname,
188 const struct object_id *oid, int flags, void *cb_data);
189
190 /*
191 * The following functions invoke the specified callback function for
192 * each reference indicated. If the function ever returns a nonzero
193 * value, stop the iteration and return that value. Please note that
194 * it is not safe to modify references while an iteration is in
195 * progress, unless the same callback function invocation that
196 * modifies the reference also returns a nonzero value to immediately
197 * stop the iteration.
198 */
199 int head_ref(each_ref_fn fn, void *cb_data);
200 int for_each_ref(each_ref_fn fn, void *cb_data);
201 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data);
202 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data,
203 unsigned int broken);
204 int for_each_tag_ref(each_ref_fn fn, void *cb_data);
205 int for_each_branch_ref(each_ref_fn fn, void *cb_data);
206 int for_each_remote_ref(each_ref_fn fn, void *cb_data);
207 int for_each_replace_ref(each_ref_fn fn, void *cb_data);
208 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data);
209 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
210 const char *prefix, void *cb_data);
211
212 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
213 int for_each_ref_submodule(const char *submodule,
214 each_ref_fn fn, void *cb_data);
215 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
216 each_ref_fn fn, void *cb_data);
217 int for_each_tag_ref_submodule(const char *submodule,
218 each_ref_fn fn, void *cb_data);
219 int for_each_branch_ref_submodule(const char *submodule,
220 each_ref_fn fn, void *cb_data);
221 int for_each_remote_ref_submodule(const char *submodule,
222 each_ref_fn fn, void *cb_data);
223
224 int head_ref_namespaced(each_ref_fn fn, void *cb_data);
225 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
226
227 /* can be used to learn about broken ref and symref */
228 int for_each_rawref(each_ref_fn fn, void *cb_data);
229
230 static inline const char *has_glob_specials(const char *pattern)
231 {
232 return strpbrk(pattern, "?*[");
233 }
234
235 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
236 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt,
237 const struct string_list *refnames);
238
239 /*
240 * Flags for controlling behaviour of pack_refs()
241 * PACK_REFS_PRUNE: Prune loose refs after packing
242 * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs
243 */
244 #define PACK_REFS_PRUNE 0x0001
245 #define PACK_REFS_ALL 0x0002
246
247 /*
248 * Write a packed-refs file for the current repository.
249 * flags: Combination of the above PACK_REFS_* flags.
250 */
251 int pack_refs(unsigned int flags);
252
253 /*
254 * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
255 * REF_NODEREF: act on the ref directly, instead of dereferencing
256 * symbolic references.
257 *
258 * Other flags are reserved for internal use.
259 */
260 #define REF_NODEREF 0x01
261 #define REF_FORCE_CREATE_REFLOG 0x40
262
263 /*
264 * Setup reflog before using. Fill in err and return -1 on failure.
265 */
266 int safe_create_reflog(const char *refname, int force_create, struct strbuf *err);
267
268 /** Reads log for the value of ref during at_time. **/
269 int read_ref_at(const char *refname, unsigned int flags,
270 unsigned long at_time, int cnt,
271 unsigned char *sha1, char **msg,
272 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
273
274 /** Check if a particular reflog exists */
275 int reflog_exists(const char *refname);
276
277 /*
278 * Delete the specified reference. If old_sha1 is non-NULL, then
279 * verify that the current value of the reference is old_sha1 before
280 * deleting it. If old_sha1 is NULL, delete the reference if it
281 * exists, regardless of its old value. It is an error for old_sha1 to
282 * be NULL_SHA1. flags is passed through to ref_transaction_delete().
283 */
284 int delete_ref(const char *msg, const char *refname,
285 const unsigned char *old_sha1, unsigned int flags);
286
287 /*
288 * Delete the specified references. If there are any problems, emit
289 * errors but attempt to keep going (i.e., the deletes are not done in
290 * an all-or-nothing transaction). flags is passed through to
291 * ref_transaction_delete().
292 */
293 int delete_refs(struct string_list *refnames, unsigned int flags);
294
295 /** Delete a reflog */
296 int delete_reflog(const char *refname);
297
298 /* iterate over reflog entries */
299 typedef int each_reflog_ent_fn(
300 struct object_id *old_oid, struct object_id *new_oid,
301 const char *committer, unsigned long timestamp,
302 int tz, const char *msg, void *cb_data);
303
304 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
305 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
306
307 /*
308 * Calls the specified function for each reflog file until it returns nonzero,
309 * and returns the value
310 */
311 int for_each_reflog(each_ref_fn fn, void *cb_data);
312
313 #define REFNAME_ALLOW_ONELEVEL 1
314 #define REFNAME_REFSPEC_PATTERN 2
315
316 /*
317 * Return 0 iff refname has the correct format for a refname according
318 * to the rules described in Documentation/git-check-ref-format.txt.
319 * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
320 * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
321 * allow a single "*" wildcard character in the refspec. No leading or
322 * repeated slashes are accepted.
323 */
324 int check_refname_format(const char *refname, int flags);
325
326 const char *prettify_refname(const char *refname);
327
328 char *shorten_unambiguous_ref(const char *refname, int strict);
329
330 /** rename ref, return 0 on success **/
331 int rename_ref(const char *oldref, const char *newref, const char *logmsg);
332
333 int create_symref(const char *refname, const char *target, const char *logmsg);
334
335 /*
336 * Update HEAD of the specified gitdir.
337 * Similar to create_symref("relative-git-dir/HEAD", target, NULL), but
338 * this can update the main working tree's HEAD regardless of where
339 * $GIT_DIR points to.
340 * Return 0 if successful, non-zero otherwise.
341 * */
342 int set_worktree_head_symref(const char *gitdir, const char *target,
343 const char *logmsg);
344
345 enum action_on_err {
346 UPDATE_REFS_MSG_ON_ERR,
347 UPDATE_REFS_DIE_ON_ERR,
348 UPDATE_REFS_QUIET_ON_ERR
349 };
350
351 /*
352 * Begin a reference transaction. The reference transaction must
353 * be freed by calling ref_transaction_free().
354 */
355 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
356
357 /*
358 * Reference transaction updates
359 *
360 * The following four functions add a reference check or update to a
361 * ref_transaction. They have some common similar parameters:
362 *
363 * transaction -- a pointer to an open ref_transaction, obtained
364 * from ref_transaction_begin().
365 *
366 * refname -- the name of the reference to be affected.
367 *
368 * flags -- flags affecting the update, passed to
369 * update_ref_lock(). Can be REF_NODEREF, which means that
370 * symbolic references should not be followed.
371 *
372 * msg -- a message describing the change (for the reflog).
373 *
374 * err -- a strbuf for receiving a description of any error that
375 * might have occurred.
376 *
377 * The functions make internal copies of refname and msg, so the
378 * caller retains ownership of these parameters.
379 *
380 * The functions return 0 on success and non-zero on failure. A
381 * failure means that the transaction as a whole has failed and needs
382 * to be rolled back.
383 */
384
385 /*
386 * Add a reference update to transaction. new_sha1 is the value that
387 * the reference should have after the update, or null_sha1 if it
388 * should be deleted. If new_sha1 is NULL, then the reference is not
389 * changed at all. old_sha1 is the value that the reference must have
390 * before the update, or null_sha1 if it must not have existed
391 * beforehand. The old value is checked after the lock is taken to
392 * prevent races. If the old value doesn't agree with old_sha1, the
393 * whole transaction fails. If old_sha1 is NULL, then the previous
394 * value is not checked.
395 *
396 * See the above comment "Reference transaction updates" for more
397 * information.
398 */
399 int ref_transaction_update(struct ref_transaction *transaction,
400 const char *refname,
401 const unsigned char *new_sha1,
402 const unsigned char *old_sha1,
403 unsigned int flags, const char *msg,
404 struct strbuf *err);
405
406 /*
407 * Add a reference creation to transaction. new_sha1 is the value that
408 * the reference should have after the update; it must not be
409 * null_sha1. It is verified that the reference does not exist
410 * already.
411 *
412 * See the above comment "Reference transaction updates" for more
413 * information.
414 */
415 int ref_transaction_create(struct ref_transaction *transaction,
416 const char *refname,
417 const unsigned char *new_sha1,
418 unsigned int flags, const char *msg,
419 struct strbuf *err);
420
421 /*
422 * Add a reference deletion to transaction. If old_sha1 is non-NULL,
423 * then it holds the value that the reference should have had before
424 * the update (which must not be null_sha1).
425 *
426 * See the above comment "Reference transaction updates" for more
427 * information.
428 */
429 int ref_transaction_delete(struct ref_transaction *transaction,
430 const char *refname,
431 const unsigned char *old_sha1,
432 unsigned int flags, const char *msg,
433 struct strbuf *err);
434
435 /*
436 * Verify, within a transaction, that refname has the value old_sha1,
437 * or, if old_sha1 is null_sha1, then verify that the reference
438 * doesn't exist. old_sha1 must be non-NULL.
439 *
440 * See the above comment "Reference transaction updates" for more
441 * information.
442 */
443 int ref_transaction_verify(struct ref_transaction *transaction,
444 const char *refname,
445 const unsigned char *old_sha1,
446 unsigned int flags,
447 struct strbuf *err);
448
449 /*
450 * Commit all of the changes that have been queued in transaction, as
451 * atomically as possible.
452 *
453 * Returns 0 for success, or one of the below error codes for errors.
454 */
455 /* Naming conflict (for example, the ref names A and A/B conflict). */
456 #define TRANSACTION_NAME_CONFLICT -1
457 /* All other errors. */
458 #define TRANSACTION_GENERIC_ERROR -2
459 int ref_transaction_commit(struct ref_transaction *transaction,
460 struct strbuf *err);
461
462 /*
463 * Like ref_transaction_commit(), but optimized for creating
464 * references when originally initializing a repository (e.g., by "git
465 * clone"). It writes the new references directly to packed-refs
466 * without locking the individual references.
467 *
468 * It is a bug to call this function when there might be other
469 * processes accessing the repository or if there are existing
470 * references that might conflict with the ones being created. All
471 * old_sha1 values must either be absent or NULL_SHA1.
472 */
473 int initial_ref_transaction_commit(struct ref_transaction *transaction,
474 struct strbuf *err);
475
476 /*
477 * Free an existing transaction and all associated data.
478 */
479 void ref_transaction_free(struct ref_transaction *transaction);
480
481 /**
482 * Lock, update, and unlock a single reference. This function
483 * basically does a transaction containing a single call to
484 * ref_transaction_update(). The parameters to this function have the
485 * same meaning as the corresponding parameters to
486 * ref_transaction_update(). Handle errors as requested by the `onerr`
487 * argument.
488 */
489 int update_ref(const char *msg, const char *refname,
490 const unsigned char *new_sha1, const unsigned char *old_sha1,
491 unsigned int flags, enum action_on_err onerr);
492 int update_ref_oid(const char *msg, const char *refname,
493 const struct object_id *new_oid, const struct object_id *old_oid,
494 unsigned int flags, enum action_on_err onerr);
495
496 int parse_hide_refs_config(const char *var, const char *value, const char *);
497
498 /*
499 * Check whether a ref is hidden. If no namespace is set, both the first and
500 * the second parameter point to the full ref name. If a namespace is set and
501 * the ref is inside that namespace, the first parameter is a pointer to the
502 * name of the ref with the namespace prefix removed. If a namespace is set and
503 * the ref is outside that namespace, the first parameter is NULL. The second
504 * parameter always points to the full ref name.
505 */
506 int ref_is_hidden(const char *, const char *);
507
508 enum ref_type {
509 REF_TYPE_PER_WORKTREE,
510 REF_TYPE_PSEUDOREF,
511 REF_TYPE_NORMAL,
512 };
513
514 enum ref_type ref_type(const char *refname);
515
516 enum expire_reflog_flags {
517 EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
518 EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
519 EXPIRE_REFLOGS_VERBOSE = 1 << 2,
520 EXPIRE_REFLOGS_REWRITE = 1 << 3
521 };
522
523 /*
524 * The following interface is used for reflog expiration. The caller
525 * calls reflog_expire(), supplying it with three callback functions,
526 * of the following types. The callback functions define the
527 * expiration policy that is desired.
528 *
529 * reflog_expiry_prepare_fn -- Called once after the reference is
530 * locked.
531 *
532 * reflog_expiry_should_prune_fn -- Called once for each entry in the
533 * existing reflog. It should return true iff that entry should be
534 * pruned.
535 *
536 * reflog_expiry_cleanup_fn -- Called once before the reference is
537 * unlocked again.
538 */
539 typedef void reflog_expiry_prepare_fn(const char *refname,
540 const unsigned char *sha1,
541 void *cb_data);
542 typedef int reflog_expiry_should_prune_fn(unsigned char *osha1,
543 unsigned char *nsha1,
544 const char *email,
545 unsigned long timestamp, int tz,
546 const char *message, void *cb_data);
547 typedef void reflog_expiry_cleanup_fn(void *cb_data);
548
549 /*
550 * Expire reflog entries for the specified reference. sha1 is the old
551 * value of the reference. flags is a combination of the constants in
552 * enum expire_reflog_flags. The three function pointers are described
553 * above. On success, return zero.
554 */
555 int reflog_expire(const char *refname, const unsigned char *sha1,
556 unsigned int flags,
557 reflog_expiry_prepare_fn prepare_fn,
558 reflog_expiry_should_prune_fn should_prune_fn,
559 reflog_expiry_cleanup_fn cleanup_fn,
560 void *policy_cb_data);
561
562 int ref_storage_backend_exists(const char *name);
563
564 struct ref_store *get_main_ref_store(void);
565
566 #endif /* REFS_H */