Merge branch 'dt/refs-pseudo'
[git/git.git] / refs.h
1 #ifndef REFS_H
2 #define REFS_H
3
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
55 extern const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
56 unsigned char *sha1, int *flags);
57
58 extern char *resolve_refdup(const char *refname, int resolve_flags,
59 unsigned char *sha1, int *flags);
60
61 extern int read_ref_full(const char *refname, int resolve_flags,
62 unsigned char *sha1, int *flags);
63 extern int read_ref(const char *refname, unsigned char *sha1);
64
65 extern int ref_exists(const char *refname);
66
67 extern int is_branch(const char *refname);
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 */
77 extern int peel_ref(const char *refname, unsigned char *sha1);
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 */
84 extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
85
86 /*
87 * Return true iff abbrev_name is a possible abbreviation for
88 * full_name according to the rules defined by ref_rev_parse_rules in
89 * refs.c.
90 */
91 extern int refname_match(const char *abbrev_name, const char *full_name);
92
93 extern int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref);
94 extern int dwim_log(const char *str, int len, unsigned char *sha1, char **ref);
95
96 /*
97 * A ref_transaction represents a collection of ref updates
98 * that should succeed or fail together.
99 *
100 * Calling sequence
101 * ----------------
102 * - Allocate and initialize a `struct ref_transaction` by calling
103 * `ref_transaction_begin()`.
104 *
105 * - List intended ref updates by calling functions like
106 * `ref_transaction_update()` and `ref_transaction_create()`.
107 *
108 * - Call `ref_transaction_commit()` to execute the transaction.
109 * If this succeeds, the ref updates will have taken place and
110 * the transaction cannot be rolled back.
111 *
112 * - At any time call `ref_transaction_free()` to discard the
113 * transaction and free associated resources. In particular,
114 * this rolls back the transaction if it has not been
115 * successfully committed.
116 *
117 * Error handling
118 * --------------
119 *
120 * On error, transaction functions append a message about what
121 * went wrong to the 'err' argument. The message mentions what
122 * ref was being updated (if any) when the error occurred so it
123 * can be passed to 'die' or 'error' as-is.
124 *
125 * The message is appended to err without first clearing err.
126 * err will not be '\n' terminated.
127 */
128 struct ref_transaction;
129
130 /*
131 * Bit values set in the flags argument passed to each_ref_fn():
132 */
133
134 /* Reference is a symbolic reference. */
135 #define REF_ISSYMREF 0x01
136
137 /* Reference is a packed reference. */
138 #define REF_ISPACKED 0x02
139
140 /*
141 * Reference cannot be resolved to an object name: dangling symbolic
142 * reference (directly or indirectly), corrupt reference file,
143 * reference exists but name is bad, or symbolic reference refers to
144 * ill-formatted reference name.
145 */
146 #define REF_ISBROKEN 0x04
147
148 /*
149 * Reference name is not well formed.
150 *
151 * See git-check-ref-format(1) for the definition of well formed ref names.
152 */
153 #define REF_BAD_NAME 0x08
154
155 /*
156 * The signature for the callback function for the for_each_*()
157 * functions below. The memory pointed to by the refname and sha1
158 * arguments is only guaranteed to be valid for the duration of a
159 * single callback invocation.
160 */
161 typedef int each_ref_fn(const char *refname,
162 const struct object_id *oid, int flags, void *cb_data);
163
164 /*
165 * The following functions invoke the specified callback function for
166 * each reference indicated. If the function ever returns a nonzero
167 * value, stop the iteration and return that value. Please note that
168 * it is not safe to modify references while an iteration is in
169 * progress, unless the same callback function invocation that
170 * modifies the reference also returns a nonzero value to immediately
171 * stop the iteration.
172 */
173 extern int head_ref(each_ref_fn fn, void *cb_data);
174 extern int for_each_ref(each_ref_fn fn, void *cb_data);
175 extern int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data);
176 extern int for_each_tag_ref(each_ref_fn fn, void *cb_data);
177 extern int for_each_branch_ref(each_ref_fn fn, void *cb_data);
178 extern int for_each_remote_ref(each_ref_fn fn, void *cb_data);
179 extern int for_each_replace_ref(each_ref_fn fn, void *cb_data);
180 extern int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data);
181 extern int for_each_glob_ref_in(each_ref_fn fn, const char *pattern, const char *prefix, void *cb_data);
182
183 extern int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
184 extern int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
185 extern int for_each_ref_in_submodule(const char *submodule, const char *prefix,
186 each_ref_fn fn, void *cb_data);
187 extern int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
188 extern int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
189 extern int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
190
191 extern int head_ref_namespaced(each_ref_fn fn, void *cb_data);
192 extern int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
193
194 /* can be used to learn about broken ref and symref */
195 extern int for_each_rawref(each_ref_fn fn, void *cb_data);
196
197 static inline const char *has_glob_specials(const char *pattern)
198 {
199 return strpbrk(pattern, "?*[");
200 }
201
202 extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
203 extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames);
204
205 /*
206 * Flags for controlling behaviour of pack_refs()
207 * PACK_REFS_PRUNE: Prune loose refs after packing
208 * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs
209 */
210 #define PACK_REFS_PRUNE 0x0001
211 #define PACK_REFS_ALL 0x0002
212
213 /*
214 * Write a packed-refs file for the current repository.
215 * flags: Combination of the above PACK_REFS_* flags.
216 */
217 int pack_refs(unsigned int flags);
218
219 /*
220 * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
221 * REF_NODEREF: act on the ref directly, instead of dereferencing
222 * symbolic references.
223 *
224 * Other flags are reserved for internal use.
225 */
226 #define REF_NODEREF 0x01
227 #define REF_FORCE_CREATE_REFLOG 0x40
228
229 /*
230 * Setup reflog before using. Fill in err and return -1 on failure.
231 */
232 int safe_create_reflog(const char *refname, int force_create, struct strbuf *err);
233
234 /** Reads log for the value of ref during at_time. **/
235 extern int read_ref_at(const char *refname, unsigned int flags,
236 unsigned long at_time, int cnt,
237 unsigned char *sha1, char **msg,
238 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
239
240 /** Check if a particular reflog exists */
241 extern int reflog_exists(const char *refname);
242
243 /*
244 * Delete the specified reference. If old_sha1 is non-NULL, then
245 * verify that the current value of the reference is old_sha1 before
246 * deleting it. If old_sha1 is NULL, delete the reference if it
247 * exists, regardless of its old value. It is an error for old_sha1 to
248 * be NULL_SHA1. flags is passed through to ref_transaction_delete().
249 */
250 extern int delete_ref(const char *refname, const unsigned char *old_sha1,
251 unsigned int flags);
252
253 /*
254 * Delete the specified references. If there are any problems, emit
255 * errors but attempt to keep going (i.e., the deletes are not done in
256 * an all-or-nothing transaction).
257 */
258 extern int delete_refs(struct string_list *refnames);
259
260 /** Delete a reflog */
261 extern int delete_reflog(const char *refname);
262
263 /* iterate over reflog entries */
264 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
265 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
266 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
267
268 /*
269 * Calls the specified function for each reflog file until it returns nonzero,
270 * and returns the value
271 */
272 extern int for_each_reflog(each_ref_fn, void *);
273
274 #define REFNAME_ALLOW_ONELEVEL 1
275 #define REFNAME_REFSPEC_PATTERN 2
276
277 /*
278 * Return 0 iff refname has the correct format for a refname according
279 * to the rules described in Documentation/git-check-ref-format.txt.
280 * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
281 * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
282 * allow a single "*" wildcard character in the refspec. No leading or
283 * repeated slashes are accepted.
284 */
285 extern int check_refname_format(const char *refname, int flags);
286
287 extern const char *prettify_refname(const char *refname);
288
289 extern char *shorten_unambiguous_ref(const char *refname, int strict);
290
291 /** rename ref, return 0 on success **/
292 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
293
294 extern int create_symref(const char *ref, const char *refs_heads_master, const char *logmsg);
295
296 enum action_on_err {
297 UPDATE_REFS_MSG_ON_ERR,
298 UPDATE_REFS_DIE_ON_ERR,
299 UPDATE_REFS_QUIET_ON_ERR
300 };
301
302 /*
303 * Begin a reference transaction. The reference transaction must
304 * be freed by calling ref_transaction_free().
305 */
306 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
307
308 /*
309 * Reference transaction updates
310 *
311 * The following four functions add a reference check or update to a
312 * ref_transaction. They have some common similar parameters:
313 *
314 * transaction -- a pointer to an open ref_transaction, obtained
315 * from ref_transaction_begin().
316 *
317 * refname -- the name of the reference to be affected.
318 *
319 * flags -- flags affecting the update, passed to
320 * update_ref_lock(). Can be REF_NODEREF, which means that
321 * symbolic references should not be followed.
322 *
323 * msg -- a message describing the change (for the reflog).
324 *
325 * err -- a strbuf for receiving a description of any error that
326 * might have occured.
327 *
328 * The functions make internal copies of refname and msg, so the
329 * caller retains ownership of these parameters.
330 *
331 * The functions return 0 on success and non-zero on failure. A
332 * failure means that the transaction as a whole has failed and needs
333 * to be rolled back.
334 */
335
336 /*
337 * Add a reference update to transaction. new_sha1 is the value that
338 * the reference should have after the update, or null_sha1 if it
339 * should be deleted. If new_sha1 is NULL, then the reference is not
340 * changed at all. old_sha1 is the value that the reference must have
341 * before the update, or null_sha1 if it must not have existed
342 * beforehand. The old value is checked after the lock is taken to
343 * prevent races. If the old value doesn't agree with old_sha1, the
344 * whole transaction fails. If old_sha1 is NULL, then the previous
345 * value is not checked.
346 *
347 * See the above comment "Reference transaction updates" for more
348 * information.
349 */
350 int ref_transaction_update(struct ref_transaction *transaction,
351 const char *refname,
352 const unsigned char *new_sha1,
353 const unsigned char *old_sha1,
354 unsigned int flags, const char *msg,
355 struct strbuf *err);
356
357 /*
358 * Add a reference creation to transaction. new_sha1 is the value that
359 * the reference should have after the update; it must not be
360 * null_sha1. It is verified that the reference does not exist
361 * already.
362 *
363 * See the above comment "Reference transaction updates" for more
364 * information.
365 */
366 int ref_transaction_create(struct ref_transaction *transaction,
367 const char *refname,
368 const unsigned char *new_sha1,
369 unsigned int flags, const char *msg,
370 struct strbuf *err);
371
372 /*
373 * Add a reference deletion to transaction. If old_sha1 is non-NULL,
374 * then it holds the value that the reference should have had before
375 * the update (which must not be null_sha1).
376 *
377 * See the above comment "Reference transaction updates" for more
378 * information.
379 */
380 int ref_transaction_delete(struct ref_transaction *transaction,
381 const char *refname,
382 const unsigned char *old_sha1,
383 unsigned int flags, const char *msg,
384 struct strbuf *err);
385
386 /*
387 * Verify, within a transaction, that refname has the value old_sha1,
388 * or, if old_sha1 is null_sha1, then verify that the reference
389 * doesn't exist. old_sha1 must be non-NULL.
390 *
391 * See the above comment "Reference transaction updates" for more
392 * information.
393 */
394 int ref_transaction_verify(struct ref_transaction *transaction,
395 const char *refname,
396 const unsigned char *old_sha1,
397 unsigned int flags,
398 struct strbuf *err);
399
400 /*
401 * Commit all of the changes that have been queued in transaction, as
402 * atomically as possible.
403 *
404 * Returns 0 for success, or one of the below error codes for errors.
405 */
406 /* Naming conflict (for example, the ref names A and A/B conflict). */
407 #define TRANSACTION_NAME_CONFLICT -1
408 /* All other errors. */
409 #define TRANSACTION_GENERIC_ERROR -2
410 int ref_transaction_commit(struct ref_transaction *transaction,
411 struct strbuf *err);
412
413 /*
414 * Like ref_transaction_commit(), but optimized for creating
415 * references when originally initializing a repository (e.g., by "git
416 * clone"). It writes the new references directly to packed-refs
417 * without locking the individual references.
418 *
419 * It is a bug to call this function when there might be other
420 * processes accessing the repository or if there are existing
421 * references that might conflict with the ones being created. All
422 * old_sha1 values must either be absent or NULL_SHA1.
423 */
424 int initial_ref_transaction_commit(struct ref_transaction *transaction,
425 struct strbuf *err);
426
427 /*
428 * Free an existing transaction and all associated data.
429 */
430 void ref_transaction_free(struct ref_transaction *transaction);
431
432 /**
433 * Lock, update, and unlock a single reference. This function
434 * basically does a transaction containing a single call to
435 * ref_transaction_update(). The parameters to this function have the
436 * same meaning as the corresponding parameters to
437 * ref_transaction_update(). Handle errors as requested by the `onerr`
438 * argument.
439 */
440 int update_ref(const char *msg, const char *refname,
441 const unsigned char *new_sha1, const unsigned char *old_sha1,
442 unsigned int flags, enum action_on_err onerr);
443
444 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
445
446 extern int ref_is_hidden(const char *);
447
448 enum ref_type {
449 REF_TYPE_PER_WORKTREE,
450 REF_TYPE_PSEUDOREF,
451 REF_TYPE_NORMAL,
452 };
453
454 enum ref_type ref_type(const char *refname);
455
456 enum expire_reflog_flags {
457 EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
458 EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
459 EXPIRE_REFLOGS_VERBOSE = 1 << 2,
460 EXPIRE_REFLOGS_REWRITE = 1 << 3
461 };
462
463 /*
464 * The following interface is used for reflog expiration. The caller
465 * calls reflog_expire(), supplying it with three callback functions,
466 * of the following types. The callback functions define the
467 * expiration policy that is desired.
468 *
469 * reflog_expiry_prepare_fn -- Called once after the reference is
470 * locked.
471 *
472 * reflog_expiry_should_prune_fn -- Called once for each entry in the
473 * existing reflog. It should return true iff that entry should be
474 * pruned.
475 *
476 * reflog_expiry_cleanup_fn -- Called once before the reference is
477 * unlocked again.
478 */
479 typedef void reflog_expiry_prepare_fn(const char *refname,
480 const unsigned char *sha1,
481 void *cb_data);
482 typedef int reflog_expiry_should_prune_fn(unsigned char *osha1,
483 unsigned char *nsha1,
484 const char *email,
485 unsigned long timestamp, int tz,
486 const char *message, void *cb_data);
487 typedef void reflog_expiry_cleanup_fn(void *cb_data);
488
489 /*
490 * Expire reflog entries for the specified reference. sha1 is the old
491 * value of the reference. flags is a combination of the constants in
492 * enum expire_reflog_flags. The three function pointers are described
493 * above. On success, return zero.
494 */
495 extern int reflog_expire(const char *refname, const unsigned char *sha1,
496 unsigned int flags,
497 reflog_expiry_prepare_fn prepare_fn,
498 reflog_expiry_should_prune_fn should_prune_fn,
499 reflog_expiry_cleanup_fn cleanup_fn,
500 void *policy_cb_data);
501
502 #endif /* REFS_H */