refs: add ref_type function
[git/git.git] / refs.h
1 #ifndef REFS_H
2 #define REFS_H
3
4 /*
5 * A ref_transaction represents a collection of ref updates
6 * that should succeed or fail together.
7 *
8 * Calling sequence
9 * ----------------
10 * - Allocate and initialize a `struct ref_transaction` by calling
11 * `ref_transaction_begin()`.
12 *
13 * - List intended ref updates by calling functions like
14 * `ref_transaction_update()` and `ref_transaction_create()`.
15 *
16 * - Call `ref_transaction_commit()` to execute the transaction.
17 * If this succeeds, the ref updates will have taken place and
18 * the transaction cannot be rolled back.
19 *
20 * - At any time call `ref_transaction_free()` to discard the
21 * transaction and free associated resources. In particular,
22 * this rolls back the transaction if it has not been
23 * successfully committed.
24 *
25 * Error handling
26 * --------------
27 *
28 * On error, transaction functions append a message about what
29 * went wrong to the 'err' argument. The message mentions what
30 * ref was being updated (if any) when the error occurred so it
31 * can be passed to 'die' or 'error' as-is.
32 *
33 * The message is appended to err without first clearing err.
34 * err will not be '\n' terminated.
35 */
36 struct ref_transaction;
37
38 /*
39 * Bit values set in the flags argument passed to each_ref_fn():
40 */
41
42 /* Reference is a symbolic reference. */
43 #define REF_ISSYMREF 0x01
44
45 /* Reference is a packed reference. */
46 #define REF_ISPACKED 0x02
47
48 /*
49 * Reference cannot be resolved to an object name: dangling symbolic
50 * reference (directly or indirectly), corrupt reference file,
51 * reference exists but name is bad, or symbolic reference refers to
52 * ill-formatted reference name.
53 */
54 #define REF_ISBROKEN 0x04
55
56 /*
57 * Reference name is not well formed.
58 *
59 * See git-check-ref-format(1) for the definition of well formed ref names.
60 */
61 #define REF_BAD_NAME 0x08
62
63 /*
64 * The signature for the callback function for the for_each_*()
65 * functions below. The memory pointed to by the refname and sha1
66 * arguments is only guaranteed to be valid for the duration of a
67 * single callback invocation.
68 */
69 typedef int each_ref_fn(const char *refname,
70 const struct object_id *oid, int flags, void *cb_data);
71
72 /*
73 * The following functions invoke the specified callback function for
74 * each reference indicated. If the function ever returns a nonzero
75 * value, stop the iteration and return that value. Please note that
76 * it is not safe to modify references while an iteration is in
77 * progress, unless the same callback function invocation that
78 * modifies the reference also returns a nonzero value to immediately
79 * stop the iteration.
80 */
81 extern int head_ref(each_ref_fn, void *);
82 extern int for_each_ref(each_ref_fn, void *);
83 extern int for_each_ref_in(const char *, each_ref_fn, void *);
84 extern int for_each_tag_ref(each_ref_fn, void *);
85 extern int for_each_branch_ref(each_ref_fn, void *);
86 extern int for_each_remote_ref(each_ref_fn, void *);
87 extern int for_each_replace_ref(each_ref_fn, void *);
88 extern int for_each_glob_ref(each_ref_fn, const char *pattern, void *);
89 extern int for_each_glob_ref_in(each_ref_fn, const char *pattern, const char* prefix, void *);
90
91 extern int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
92 extern int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
93 extern int for_each_ref_in_submodule(const char *submodule, const char *prefix,
94 each_ref_fn fn, void *cb_data);
95 extern int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
96 extern int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
97 extern int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
98
99 extern int head_ref_namespaced(each_ref_fn fn, void *cb_data);
100 extern int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
101
102 static inline const char *has_glob_specials(const char *pattern)
103 {
104 return strpbrk(pattern, "?*[");
105 }
106
107 /* can be used to learn about broken ref and symref */
108 extern int for_each_rawref(each_ref_fn, void *);
109
110 extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
111 extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames);
112
113 /*
114 * Lock the packed-refs file for writing. Flags is passed to
115 * hold_lock_file_for_update(). Return 0 on success.
116 * Errno is set to something meaningful on error.
117 */
118 extern int lock_packed_refs(int flags);
119
120 /*
121 * Add a reference to the in-memory packed reference cache. This may
122 * only be called while the packed-refs file is locked (see
123 * lock_packed_refs()). To actually write the packed-refs file, call
124 * commit_packed_refs().
125 */
126 extern void add_packed_ref(const char *refname, const unsigned char *sha1);
127
128 /*
129 * Write the current version of the packed refs cache from memory to
130 * disk. The packed-refs file must already be locked for writing (see
131 * lock_packed_refs()). Return zero on success.
132 * Sets errno to something meaningful on error.
133 */
134 extern int commit_packed_refs(void);
135
136 /*
137 * Rollback the lockfile for the packed-refs file, and discard the
138 * in-memory packed reference cache. (The packed-refs file will be
139 * read anew if it is needed again after this function is called.)
140 */
141 extern void rollback_packed_refs(void);
142
143 /*
144 * Flags for controlling behaviour of pack_refs()
145 * PACK_REFS_PRUNE: Prune loose refs after packing
146 * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs
147 */
148 #define PACK_REFS_PRUNE 0x0001
149 #define PACK_REFS_ALL 0x0002
150
151 /*
152 * Write a packed-refs file for the current repository.
153 * flags: Combination of the above PACK_REFS_* flags.
154 */
155 int pack_refs(unsigned int flags);
156
157 /*
158 * Rewrite the packed-refs file, omitting any refs listed in
159 * 'refnames'. On error, packed-refs will be unchanged, the return
160 * value is nonzero, and a message about the error is written to the
161 * 'err' strbuf.
162 *
163 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.
164 */
165 extern int repack_without_refs(struct string_list *refnames,
166 struct strbuf *err);
167
168 extern int ref_exists(const char *);
169
170 extern int is_branch(const char *refname);
171
172 /*
173 * If refname is a non-symbolic reference that refers to a tag object,
174 * and the tag can be (recursively) dereferenced to a non-tag object,
175 * store the SHA1 of the referred-to object to sha1 and return 0. If
176 * any of these conditions are not met, return a non-zero value.
177 * Symbolic references are considered unpeelable, even if they
178 * ultimately resolve to a peelable tag.
179 */
180 extern int peel_ref(const char *refname, unsigned char *sha1);
181
182 /*
183 * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
184 * REF_NODEREF: act on the ref directly, instead of dereferencing
185 * symbolic references.
186 *
187 * Other flags are reserved for internal use.
188 */
189 #define REF_NODEREF 0x01
190 #define REF_FORCE_CREATE_REFLOG 0x40
191
192 /*
193 * Setup reflog before using. Fill in err and return -1 on failure.
194 */
195 int safe_create_reflog(const char *refname, int force_create, struct strbuf *err);
196
197 /** Reads log for the value of ref during at_time. **/
198 extern int read_ref_at(const char *refname, unsigned int flags,
199 unsigned long at_time, int cnt,
200 unsigned char *sha1, char **msg,
201 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
202
203 /** Check if a particular reflog exists */
204 extern int reflog_exists(const char *refname);
205
206 /** Delete a reflog */
207 extern int delete_reflog(const char *refname);
208
209 /* iterate over reflog entries */
210 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
211 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
212 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
213
214 /*
215 * Calls the specified function for each reflog file until it returns nonzero,
216 * and returns the value
217 */
218 extern int for_each_reflog(each_ref_fn, void *);
219
220 #define REFNAME_ALLOW_ONELEVEL 1
221 #define REFNAME_REFSPEC_PATTERN 2
222
223 /*
224 * Return 0 iff refname has the correct format for a refname according
225 * to the rules described in Documentation/git-check-ref-format.txt.
226 * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
227 * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
228 * allow a "*" wildcard character in place of one of the name
229 * components. No leading or repeated slashes are accepted.
230 */
231 extern int check_refname_format(const char *refname, int flags);
232
233 extern const char *prettify_refname(const char *refname);
234 extern char *shorten_unambiguous_ref(const char *refname, int strict);
235
236 /** rename ref, return 0 on success **/
237 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
238
239 /**
240 * Resolve refname in the nested "gitlink" repository that is located
241 * at path. If the resolution is successful, return 0 and set sha1 to
242 * the name of the object; otherwise, return a non-zero value.
243 */
244 extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
245
246 enum action_on_err {
247 UPDATE_REFS_MSG_ON_ERR,
248 UPDATE_REFS_DIE_ON_ERR,
249 UPDATE_REFS_QUIET_ON_ERR
250 };
251
252 /*
253 * Begin a reference transaction. The reference transaction must
254 * be freed by calling ref_transaction_free().
255 */
256 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
257
258 /*
259 * Reference transaction updates
260 *
261 * The following four functions add a reference check or update to a
262 * ref_transaction. They have some common similar parameters:
263 *
264 * transaction -- a pointer to an open ref_transaction, obtained
265 * from ref_transaction_begin().
266 *
267 * refname -- the name of the reference to be affected.
268 *
269 * flags -- flags affecting the update, passed to
270 * update_ref_lock(). Can be REF_NODEREF, which means that
271 * symbolic references should not be followed.
272 *
273 * msg -- a message describing the change (for the reflog).
274 *
275 * err -- a strbuf for receiving a description of any error that
276 * might have occured.
277 *
278 * The functions make internal copies of refname and msg, so the
279 * caller retains ownership of these parameters.
280 *
281 * The functions return 0 on success and non-zero on failure. A
282 * failure means that the transaction as a whole has failed and needs
283 * to be rolled back.
284 */
285
286 /*
287 * Add a reference update to transaction. new_sha1 is the value that
288 * the reference should have after the update, or null_sha1 if it
289 * should be deleted. If new_sha1 is NULL, then the reference is not
290 * changed at all. old_sha1 is the value that the reference must have
291 * before the update, or null_sha1 if it must not have existed
292 * beforehand. The old value is checked after the lock is taken to
293 * prevent races. If the old value doesn't agree with old_sha1, the
294 * whole transaction fails. If old_sha1 is NULL, then the previous
295 * value is not checked.
296 *
297 * See the above comment "Reference transaction updates" for more
298 * information.
299 */
300 int ref_transaction_update(struct ref_transaction *transaction,
301 const char *refname,
302 const unsigned char *new_sha1,
303 const unsigned char *old_sha1,
304 unsigned int flags, const char *msg,
305 struct strbuf *err);
306
307 /*
308 * Add a reference creation to transaction. new_sha1 is the value that
309 * the reference should have after the update; it must not be
310 * null_sha1. It is verified that the reference does not exist
311 * already.
312 *
313 * See the above comment "Reference transaction updates" for more
314 * information.
315 */
316 int ref_transaction_create(struct ref_transaction *transaction,
317 const char *refname,
318 const unsigned char *new_sha1,
319 unsigned int flags, const char *msg,
320 struct strbuf *err);
321
322 /*
323 * Add a reference deletion to transaction. If old_sha1 is non-NULL,
324 * then it holds the value that the reference should have had before
325 * the update (which must not be null_sha1).
326 *
327 * See the above comment "Reference transaction updates" for more
328 * information.
329 */
330 int ref_transaction_delete(struct ref_transaction *transaction,
331 const char *refname,
332 const unsigned char *old_sha1,
333 unsigned int flags, const char *msg,
334 struct strbuf *err);
335
336 /*
337 * Verify, within a transaction, that refname has the value old_sha1,
338 * or, if old_sha1 is null_sha1, then verify that the reference
339 * doesn't exist. old_sha1 must be non-NULL.
340 *
341 * See the above comment "Reference transaction updates" for more
342 * information.
343 */
344 int ref_transaction_verify(struct ref_transaction *transaction,
345 const char *refname,
346 const unsigned char *old_sha1,
347 unsigned int flags,
348 struct strbuf *err);
349
350 /*
351 * Commit all of the changes that have been queued in transaction, as
352 * atomically as possible.
353 *
354 * Returns 0 for success, or one of the below error codes for errors.
355 */
356 /* Naming conflict (for example, the ref names A and A/B conflict). */
357 #define TRANSACTION_NAME_CONFLICT -1
358 /* All other errors. */
359 #define TRANSACTION_GENERIC_ERROR -2
360 int ref_transaction_commit(struct ref_transaction *transaction,
361 struct strbuf *err);
362
363 /*
364 * Free an existing transaction and all associated data.
365 */
366 void ref_transaction_free(struct ref_transaction *transaction);
367
368 /**
369 * Lock, update, and unlock a single reference. This function
370 * basically does a transaction containing a single call to
371 * ref_transaction_update(). The parameters to this function have the
372 * same meaning as the corresponding parameters to
373 * ref_transaction_update(). Handle errors as requested by the `onerr`
374 * argument.
375 */
376 int update_ref(const char *msg, const char *refname,
377 const unsigned char *new_sha1, const unsigned char *old_sha1,
378 unsigned int flags, enum action_on_err onerr);
379
380 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
381 extern int ref_is_hidden(const char *);
382
383 enum ref_type {
384 REF_TYPE_PER_WORKTREE,
385 REF_TYPE_PSEUDOREF,
386 REF_TYPE_NORMAL,
387 };
388
389 enum ref_type ref_type(const char *refname);
390
391 enum expire_reflog_flags {
392 EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
393 EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
394 EXPIRE_REFLOGS_VERBOSE = 1 << 2,
395 EXPIRE_REFLOGS_REWRITE = 1 << 3
396 };
397
398 /*
399 * The following interface is used for reflog expiration. The caller
400 * calls reflog_expire(), supplying it with three callback functions,
401 * of the following types. The callback functions define the
402 * expiration policy that is desired.
403 *
404 * reflog_expiry_prepare_fn -- Called once after the reference is
405 * locked.
406 *
407 * reflog_expiry_should_prune_fn -- Called once for each entry in the
408 * existing reflog. It should return true iff that entry should be
409 * pruned.
410 *
411 * reflog_expiry_cleanup_fn -- Called once before the reference is
412 * unlocked again.
413 */
414 typedef void reflog_expiry_prepare_fn(const char *refname,
415 const unsigned char *sha1,
416 void *cb_data);
417 typedef int reflog_expiry_should_prune_fn(unsigned char *osha1,
418 unsigned char *nsha1,
419 const char *email,
420 unsigned long timestamp, int tz,
421 const char *message, void *cb_data);
422 typedef void reflog_expiry_cleanup_fn(void *cb_data);
423
424 /*
425 * Expire reflog entries for the specified reference. sha1 is the old
426 * value of the reference. flags is a combination of the constants in
427 * enum expire_reflog_flags. The three function pointers are described
428 * above. On success, return zero.
429 */
430 extern int reflog_expire(const char *refname, const unsigned char *sha1,
431 unsigned int flags,
432 reflog_expiry_prepare_fn prepare_fn,
433 reflog_expiry_should_prune_fn should_prune_fn,
434 reflog_expiry_cleanup_fn cleanup_fn,
435 void *policy_cb_data);
436
437 #endif /* REFS_H */