resolve_gitlink_ref(): avoid memory allocation in many cases
[git/git.git] / refs.h
CommitLineData
95fc7512
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1#ifndef REFS_H
2#define REFS_H
3
fb58c8d5
MH
4/*
5 * Resolve a reference, recursively following symbolic refererences.
6 *
7 * Store the referred-to object's name in sha1 and return the name of
8 * the non-symbolic reference that ultimately pointed at it. The
9 * return value, if not NULL, is a pointer into either a static buffer
10 * or the input ref.
11 *
12 * If the reference cannot be resolved to an object, the behavior
13 * depends on the RESOLVE_REF_READING flag:
14 *
15 * - If RESOLVE_REF_READING is set, return NULL.
16 *
17 * - If RESOLVE_REF_READING is not set, clear sha1 and return the name of
18 * the last reference name in the chain, which will either be a non-symbolic
19 * reference or an undefined reference. If this is a prelude to
20 * "writing" to the ref, the return value is the name of the ref
21 * that will actually be created or changed.
22 *
23 * If the RESOLVE_REF_NO_RECURSE flag is passed, only resolves one
24 * level of symbolic reference. The value stored in sha1 for a symbolic
25 * reference will always be null_sha1 in this case, and the return
26 * value is the reference that the symref refers to directly.
27 *
28 * If flags is non-NULL, set the value that it points to the
29 * combination of REF_ISPACKED (if the reference was found among the
30 * packed references), REF_ISSYMREF (if the initial reference was a
31 * symbolic reference), REF_BAD_NAME (if the reference name is ill
32 * formed --- see RESOLVE_REF_ALLOW_BAD_NAME below), and REF_ISBROKEN
33 * (if the ref is malformed or has a bad name). See refs.h for more detail
34 * on each flag.
35 *
36 * If ref is not a properly-formatted, normalized reference, return
37 * NULL. If more than MAXDEPTH recursive symbolic lookups are needed,
38 * give up and return NULL.
39 *
40 * RESOLVE_REF_ALLOW_BAD_NAME allows resolving refs even when their
41 * name is invalid according to git-check-ref-format(1). If the name
42 * is bad then the value stored in sha1 will be null_sha1 and the two
43 * flags REF_ISBROKEN and REF_BAD_NAME will be set.
44 *
45 * Even with RESOLVE_REF_ALLOW_BAD_NAME, names that escape the refs/
46 * directory and do not consist of all caps and underscores cannot be
47 * resolved. The function returns NULL for such ref names.
48 * Caps and underscores refers to the special refs, such as HEAD,
49 * FETCH_HEAD and friends, that all live outside of the refs/ directory.
50 */
51#define RESOLVE_REF_READING 0x01
52#define RESOLVE_REF_NO_RECURSE 0x02
53#define RESOLVE_REF_ALLOW_BAD_NAME 0x04
54
1354c9b2
MH
55const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
56 unsigned char *sha1, int *flags);
fb58c8d5 57
1354c9b2
MH
58char *resolve_refdup(const char *refname, int resolve_flags,
59 unsigned char *sha1, int *flags);
fb58c8d5 60
1354c9b2
MH
61int read_ref_full(const char *refname, int resolve_flags,
62 unsigned char *sha1, int *flags);
63int read_ref(const char *refname, unsigned char *sha1);
fb58c8d5 64
1354c9b2 65int ref_exists(const char *refname);
fb58c8d5 66
1354c9b2 67int is_branch(const char *refname);
fb58c8d5
MH
68
69/*
70 * If refname is a non-symbolic reference that refers to a tag object,
71 * and the tag can be (recursively) dereferenced to a non-tag object,
72 * store the SHA1 of the referred-to object to sha1 and return 0. If
73 * any of these conditions are not met, return a non-zero value.
74 * Symbolic references are considered unpeelable, even if they
75 * ultimately resolve to a peelable tag.
76 */
1354c9b2 77int peel_ref(const char *refname, unsigned char *sha1);
fb58c8d5
MH
78
79/**
80 * Resolve refname in the nested "gitlink" repository that is located
81 * at path. If the resolution is successful, return 0 and set sha1 to
82 * the name of the object; otherwise, return a non-zero value.
83 */
1354c9b2
MH
84int resolve_gitlink_ref(const char *path, const char *refname,
85 unsigned char *sha1);
fb58c8d5
MH
86
87/*
88 * Return true iff abbrev_name is a possible abbreviation for
89 * full_name according to the rules defined by ref_rev_parse_rules in
90 * refs.c.
91 */
1354c9b2 92int refname_match(const char *abbrev_name, const char *full_name);
fb58c8d5 93
1354c9b2
MH
94int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref);
95int dwim_log(const char *str, int len, unsigned char *sha1, char **ref);
fb58c8d5 96
b416af5b
RS
97/*
98 * A ref_transaction represents a collection of ref updates
99 * that should succeed or fail together.
100 *
101 * Calling sequence
102 * ----------------
103 * - Allocate and initialize a `struct ref_transaction` by calling
104 * `ref_transaction_begin()`.
105 *
106 * - List intended ref updates by calling functions like
107 * `ref_transaction_update()` and `ref_transaction_create()`.
108 *
109 * - Call `ref_transaction_commit()` to execute the transaction.
110 * If this succeeds, the ref updates will have taken place and
111 * the transaction cannot be rolled back.
112 *
49386868
DT
113 * - Instead of `ref_transaction_commit`, use
114 * `initial_ref_transaction_commit()` if the ref database is known
115 * to be empty (e.g. during clone). This is likely to be much
116 * faster.
117 *
b416af5b
RS
118 * - At any time call `ref_transaction_free()` to discard the
119 * transaction and free associated resources. In particular,
120 * this rolls back the transaction if it has not been
121 * successfully committed.
122 *
123 * Error handling
124 * --------------
125 *
126 * On error, transaction functions append a message about what
127 * went wrong to the 'err' argument. The message mentions what
128 * ref was being updated (if any) when the error occurred so it
129 * can be passed to 'die' or 'error' as-is.
130 *
131 * The message is appended to err without first clearing err.
132 * err will not be '\n' terminated.
49386868
DT
133 *
134 * Caveats
135 * -------
136 *
137 * Note that no locks are taken, and no refs are read, until
138 * `ref_transaction_commit` is called. So `ref_transaction_verify`
139 * won't report a verification failure until the commit is attempted.
b416af5b 140 */
caa4046c
MH
141struct ref_transaction;
142
89df9c84 143/*
3bc581b9
MH
144 * Bit values set in the flags argument passed to each_ref_fn() and
145 * stored in ref_iterator::flags. Other bits are for internal use
146 * only:
89df9c84
MH
147 */
148
149/* Reference is a symbolic reference. */
98ac34b2 150#define REF_ISSYMREF 0x01
89df9c84
MH
151
152/* Reference is a packed reference. */
98ac34b2 153#define REF_ISPACKED 0x02
89df9c84
MH
154
155/*
156 * Reference cannot be resolved to an object name: dangling symbolic
d0f810f0
RS
157 * reference (directly or indirectly), corrupt reference file,
158 * reference exists but name is bad, or symbolic reference refers to
159 * ill-formatted reference name.
89df9c84 160 */
98ac34b2 161#define REF_ISBROKEN 0x04
f4204ab9 162
d0f810f0
RS
163/*
164 * Reference name is not well formed.
165 *
166 * See git-check-ref-format(1) for the definition of well formed ref names.
167 */
168#define REF_BAD_NAME 0x08
169
8a65ff76 170/*
4f78c24c
MH
171 * The signature for the callback function for the for_each_*()
172 * functions below. The memory pointed to by the refname and sha1
173 * arguments is only guaranteed to be valid for the duration of a
174 * single callback invocation.
175 */
176typedef int each_ref_fn(const char *refname,
2b2a5be3
MH
177 const struct object_id *oid, int flags, void *cb_data);
178
4f78c24c
MH
179/*
180 * The following functions invoke the specified callback function for
181 * each reference indicated. If the function ever returns a nonzero
182 * value, stop the iteration and return that value. Please note that
183 * it is not safe to modify references while an iteration is in
184 * progress, unless the same callback function invocation that
185 * modifies the reference also returns a nonzero value to immediately
186 * stop the iteration.
8a65ff76 187 */
1354c9b2
MH
188int head_ref(each_ref_fn fn, void *cb_data);
189int for_each_ref(each_ref_fn fn, void *cb_data);
190int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data);
191int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data,
192 unsigned int broken);
193int for_each_tag_ref(each_ref_fn fn, void *cb_data);
194int for_each_branch_ref(each_ref_fn fn, void *cb_data);
195int for_each_remote_ref(each_ref_fn fn, void *cb_data);
196int for_each_replace_ref(each_ref_fn fn, void *cb_data);
197int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data);
198int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
199 const char *prefix, void *cb_data);
200
201int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
202int for_each_ref_submodule(const char *submodule,
203 each_ref_fn fn, void *cb_data);
204int for_each_ref_in_submodule(const char *submodule, const char *prefix,
9ef6aeb0 205 each_ref_fn fn, void *cb_data);
1354c9b2
MH
206int for_each_tag_ref_submodule(const char *submodule,
207 each_ref_fn fn, void *cb_data);
208int for_each_branch_ref_submodule(const char *submodule,
209 each_ref_fn fn, void *cb_data);
210int for_each_remote_ref_submodule(const char *submodule,
211 each_ref_fn fn, void *cb_data);
9ef6aeb0 212
1354c9b2
MH
213int head_ref_namespaced(each_ref_fn fn, void *cb_data);
214int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
a1bea2c1 215
fb58c8d5 216/* can be used to learn about broken ref and symref */
1354c9b2 217int for_each_rawref(each_ref_fn fn, void *cb_data);
fb58c8d5 218
894a9d33
TR
219static inline const char *has_glob_specials(const char *pattern)
220{
221 return strpbrk(pattern, "?*[");
222}
223
1354c9b2
MH
224void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
225void warn_dangling_symrefs(FILE *fp, const char *msg_fmt,
226 const struct string_list *refnames);
f8948e2f 227
32d462ce
MH
228/*
229 * Flags for controlling behaviour of pack_refs()
230 * PACK_REFS_PRUNE: Prune loose refs after packing
231 * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs
232 */
233#define PACK_REFS_PRUNE 0x0001
234#define PACK_REFS_ALL 0x0002
235
236/*
237 * Write a packed-refs file for the current repository.
238 * flags: Combination of the above PACK_REFS_* flags.
239 */
240int pack_refs(unsigned int flags);
241
835e3c99 242/*
31e07f76 243 * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
029cdb4a
RS
244 * REF_NODEREF: act on the ref directly, instead of dereferencing
245 * symbolic references.
246 *
581d4e0c 247 * Other flags are reserved for internal use.
835e3c99 248 */
68db31cc 249#define REF_NODEREF 0x01
0f2a71d9 250#define REF_FORCE_CREATE_REFLOG 0x40
95fc7512 251
bd3b02da 252/*
a4c653df 253 * Setup reflog before using. Fill in err and return -1 on failure.
bd3b02da 254 */
abd0cd3a 255int safe_create_reflog(const char *refname, int force_create, struct strbuf *err);
859c3017 256
d556fae2 257/** Reads log for the value of ref during at_time. **/
1354c9b2
MH
258int read_ref_at(const char *refname, unsigned int flags,
259 unsigned long at_time, int cnt,
260 unsigned char *sha1, char **msg,
261 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
d556fae2 262
4da58835 263/** Check if a particular reflog exists */
1354c9b2 264int reflog_exists(const char *refname);
4da58835 265
fc1c2168 266/*
1c03c4d3
MH
267 * Delete the specified reference. If old_sha1 is non-NULL, then
268 * verify that the current value of the reference is old_sha1 before
269 * deleting it. If old_sha1 is NULL, delete the reference if it
270 * exists, regardless of its old value. It is an error for old_sha1 to
271 * be NULL_SHA1. flags is passed through to ref_transaction_delete().
fc1c2168 272 */
1354c9b2
MH
273int delete_ref(const char *refname, const unsigned char *old_sha1,
274 unsigned int flags);
fc1c2168 275
98ffd5ff
MH
276/*
277 * Delete the specified references. If there are any problems, emit
278 * errors but attempt to keep going (i.e., the deletes are not done in
c5f04ddd
MH
279 * an all-or-nothing transaction). flags is passed through to
280 * ref_transaction_delete().
98ffd5ff 281 */
c5f04ddd 282int delete_refs(struct string_list *refnames, unsigned int flags);
98ffd5ff 283
4da58835 284/** Delete a reflog */
1354c9b2 285int delete_reflog(const char *refname);
4da58835 286
2ff81662 287/* iterate over reflog entries */
1354c9b2
MH
288typedef int each_reflog_ent_fn(
289 unsigned char *old_sha1, unsigned char *new_sha1,
290 const char *committer, unsigned long timestamp,
291 int tz, const char *msg, void *cb_data);
292
dfefa935 293int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
98f85ff4 294int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
2ff81662 295
eb8381c8
NP
296/*
297 * Calls the specified function for each reflog file until it returns nonzero,
298 * and returns the value
299 */
1354c9b2 300int for_each_reflog(each_ref_fn fn, void *cb_data);
eb8381c8 301
8d9c5010
MH
302#define REFNAME_ALLOW_ONELEVEL 1
303#define REFNAME_REFSPEC_PATTERN 2
304
305/*
dfefa935
MH
306 * Return 0 iff refname has the correct format for a refname according
307 * to the rules described in Documentation/git-check-ref-format.txt.
308 * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
8d9c5010 309 * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
cd377f45
JK
310 * allow a single "*" wildcard character in the refspec. No leading or
311 * repeated slashes are accepted.
8d9c5010 312 */
1354c9b2 313int check_refname_format(const char *refname, int flags);
95fc7512 314
1354c9b2 315const char *prettify_refname(const char *refname);
fb58c8d5 316
1354c9b2 317char *shorten_unambiguous_ref(const char *refname, int strict);
a9c37a72 318
c976d415 319/** rename ref, return 0 on success **/
1354c9b2 320int rename_ref(const char *oldref, const char *newref, const char *logmsg);
c976d415 321
1354c9b2 322int create_symref(const char *refname, const char *target, const char *logmsg);
0ebde32c 323
2233066e
KY
324/*
325 * Update HEAD of the specified gitdir.
326 * Similar to create_symref("relative-git-dir/HEAD", target, NULL), but
327 * this can update the main working tree's HEAD regardless of where
328 * $GIT_DIR points to.
329 * Return 0 if successful, non-zero otherwise.
330 * */
1354c9b2 331int set_worktree_head_symref(const char *gitdir, const char *target);
2233066e 332
f4124112
MH
333enum action_on_err {
334 UPDATE_REFS_MSG_ON_ERR,
335 UPDATE_REFS_DIE_ON_ERR,
336 UPDATE_REFS_QUIET_ON_ERR
337};
338
caa4046c
MH
339/*
340 * Begin a reference transaction. The reference transaction must
33f9fc59 341 * be freed by calling ref_transaction_free().
caa4046c 342 */
93a644ea 343struct ref_transaction *ref_transaction_begin(struct strbuf *err);
caa4046c 344
caa4046c 345/*
d1dd721f
MH
346 * Reference transaction updates
347 *
348 * The following four functions add a reference check or update to a
349 * ref_transaction. They have some common similar parameters:
350 *
351 * transaction -- a pointer to an open ref_transaction, obtained
352 * from ref_transaction_begin().
353 *
354 * refname -- the name of the reference to be affected.
355 *
356 * flags -- flags affecting the update, passed to
357 * update_ref_lock(). Can be REF_NODEREF, which means that
358 * symbolic references should not be followed.
359 *
360 * msg -- a message describing the change (for the reflog).
361 *
362 * err -- a strbuf for receiving a description of any error that
363 * might have occured.
364 *
365 * The functions make internal copies of refname and msg, so the
366 * caller retains ownership of these parameters.
367 *
368 * The functions return 0 on success and non-zero on failure. A
369 * failure means that the transaction as a whole has failed and needs
370 * to be rolled back.
caa4046c
MH
371 */
372
caa4046c 373/*
16180334
MH
374 * Add a reference update to transaction. new_sha1 is the value that
375 * the reference should have after the update, or null_sha1 if it
376 * should be deleted. If new_sha1 is NULL, then the reference is not
377 * changed at all. old_sha1 is the value that the reference must have
378 * before the update, or null_sha1 if it must not have existed
379 * beforehand. The old value is checked after the lock is taken to
380 * prevent races. If the old value doesn't agree with old_sha1, the
381 * whole transaction fails. If old_sha1 is NULL, then the previous
382 * value is not checked.
383 *
d1dd721f
MH
384 * See the above comment "Reference transaction updates" for more
385 * information.
caa4046c 386 */
8e34800e
RS
387int ref_transaction_update(struct ref_transaction *transaction,
388 const char *refname,
389 const unsigned char *new_sha1,
390 const unsigned char *old_sha1,
1d147bdf 391 unsigned int flags, const char *msg,
8e34800e 392 struct strbuf *err);
caa4046c
MH
393
394/*
d1dd721f
MH
395 * Add a reference creation to transaction. new_sha1 is the value that
396 * the reference should have after the update; it must not be
397 * null_sha1. It is verified that the reference does not exist
caa4046c 398 * already.
d1dd721f
MH
399 *
400 * See the above comment "Reference transaction updates" for more
401 * information.
caa4046c 402 */
b416af5b
RS
403int ref_transaction_create(struct ref_transaction *transaction,
404 const char *refname,
405 const unsigned char *new_sha1,
fec14ec3 406 unsigned int flags, const char *msg,
b416af5b 407 struct strbuf *err);
caa4046c
MH
408
409/*
d1dd721f
MH
410 * Add a reference deletion to transaction. If old_sha1 is non-NULL,
411 * then it holds the value that the reference should have had before
412 * the update (which must not be null_sha1).
413 *
414 * See the above comment "Reference transaction updates" for more
415 * information.
caa4046c 416 */
8c8bdc0d
RS
417int ref_transaction_delete(struct ref_transaction *transaction,
418 const char *refname,
419 const unsigned char *old_sha1,
fb5a6bb6 420 unsigned int flags, const char *msg,
8c8bdc0d 421 struct strbuf *err);
caa4046c 422
16180334
MH
423/*
424 * Verify, within a transaction, that refname has the value old_sha1,
425 * or, if old_sha1 is null_sha1, then verify that the reference
d1dd721f
MH
426 * doesn't exist. old_sha1 must be non-NULL.
427 *
428 * See the above comment "Reference transaction updates" for more
429 * information.
16180334
MH
430 */
431int ref_transaction_verify(struct ref_transaction *transaction,
432 const char *refname,
433 const unsigned char *old_sha1,
434 unsigned int flags,
435 struct strbuf *err);
436
caa4046c
MH
437/*
438 * Commit all of the changes that have been queued in transaction, as
28e6a97e
RS
439 * atomically as possible.
440 *
441 * Returns 0 for success, or one of the below error codes for errors.
caa4046c 442 */
28e6a97e
RS
443/* Naming conflict (for example, the ref names A and A/B conflict). */
444#define TRANSACTION_NAME_CONFLICT -1
445/* All other errors. */
446#define TRANSACTION_GENERIC_ERROR -2
caa4046c 447int ref_transaction_commit(struct ref_transaction *transaction,
db7516ab 448 struct strbuf *err);
caa4046c 449
58f233ce
MH
450/*
451 * Like ref_transaction_commit(), but optimized for creating
452 * references when originally initializing a repository (e.g., by "git
453 * clone"). It writes the new references directly to packed-refs
454 * without locking the individual references.
455 *
456 * It is a bug to call this function when there might be other
457 * processes accessing the repository or if there are existing
458 * references that might conflict with the ones being created. All
459 * old_sha1 values must either be absent or NULL_SHA1.
460 */
461int initial_ref_transaction_commit(struct ref_transaction *transaction,
462 struct strbuf *err);
463
026bd1d3
RS
464/*
465 * Free an existing transaction and all associated data.
466 */
467void ref_transaction_free(struct ref_transaction *transaction);
468
4b7b520b
MH
469/**
470 * Lock, update, and unlock a single reference. This function
471 * basically does a transaction containing a single call to
472 * ref_transaction_update(). The parameters to this function have the
473 * same meaning as the corresponding parameters to
474 * ref_transaction_update(). Handle errors as requested by the `onerr`
475 * argument.
476 */
477int update_ref(const char *msg, const char *refname,
478 const unsigned char *new_sha1, const unsigned char *old_sha1,
fec14ec3 479 unsigned int flags, enum action_on_err onerr);
3d9f037c 480
1354c9b2 481int parse_hide_refs_config(const char *var, const char *value, const char *);
fb58c8d5 482
78a766ab
LF
483/*
484 * Check whether a ref is hidden. If no namespace is set, both the first and
485 * the second parameter point to the full ref name. If a namespace is set and
486 * the ref is inside that namespace, the first parameter is a pointer to the
487 * name of the ref with the namespace prefix removed. If a namespace is set and
488 * the ref is outside that namespace, the first parameter is NULL. The second
489 * parameter always points to the full ref name.
490 */
1354c9b2 491int ref_is_hidden(const char *, const char *);
daebaa78 492
266b1827
DT
493enum ref_type {
494 REF_TYPE_PER_WORKTREE,
495 REF_TYPE_PSEUDOREF,
496 REF_TYPE_NORMAL,
497};
498
499enum ref_type ref_type(const char *refname);
500
fa5b1830
MH
501enum expire_reflog_flags {
502 EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
503 EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
504 EXPIRE_REFLOGS_VERBOSE = 1 << 2,
505 EXPIRE_REFLOGS_REWRITE = 1 << 3
506};
507
508/*
509 * The following interface is used for reflog expiration. The caller
510 * calls reflog_expire(), supplying it with three callback functions,
511 * of the following types. The callback functions define the
512 * expiration policy that is desired.
513 *
514 * reflog_expiry_prepare_fn -- Called once after the reference is
515 * locked.
516 *
517 * reflog_expiry_should_prune_fn -- Called once for each entry in the
518 * existing reflog. It should return true iff that entry should be
519 * pruned.
520 *
521 * reflog_expiry_cleanup_fn -- Called once before the reference is
522 * unlocked again.
523 */
524typedef void reflog_expiry_prepare_fn(const char *refname,
525 const unsigned char *sha1,
526 void *cb_data);
527typedef int reflog_expiry_should_prune_fn(unsigned char *osha1,
528 unsigned char *nsha1,
529 const char *email,
530 unsigned long timestamp, int tz,
531 const char *message, void *cb_data);
532typedef void reflog_expiry_cleanup_fn(void *cb_data);
533
534/*
535 * Expire reflog entries for the specified reference. sha1 is the old
536 * value of the reference. flags is a combination of the constants in
537 * enum expire_reflog_flags. The three function pointers are described
538 * above. On success, return zero.
539 */
1354c9b2
MH
540int reflog_expire(const char *refname, const unsigned char *sha1,
541 unsigned int flags,
542 reflog_expiry_prepare_fn prepare_fn,
543 reflog_expiry_should_prune_fn should_prune_fn,
544 reflog_expiry_cleanup_fn cleanup_fn,
545 void *policy_cb_data);
fa5b1830 546
3dce444f
RS
547int ref_storage_backend_exists(const char *name);
548
95fc7512 549#endif /* REFS_H */