Merge branch 'rs/plug-leak-in-pack-bitmaps' into maint
[git.git] / refs.h
blobcf642e6ddc438be77d64797a4dbcf790262a9fed
1 #ifndef REFS_H
2 #define REFS_H
4 /*
5 * A ref_transaction represents a collection of ref updates
6 * that should succeed or fail together.
8 * Calling sequence
9 * ----------------
10 * - Allocate and initialize a `struct ref_transaction` by calling
11 * `ref_transaction_begin()`.
13 * - List intended ref updates by calling functions like
14 * `ref_transaction_update()` and `ref_transaction_create()`.
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.
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.
25 * Error handling
26 * --------------
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.
33 * The message is appended to err without first clearing err.
34 * err will not be '\n' terminated.
36 struct ref_transaction;
39 * Bit values set in the flags argument passed to each_ref_fn():
42 /* Reference is a symbolic reference. */
43 #define REF_ISSYMREF 0x01
45 /* Reference is a packed reference. */
46 #define REF_ISPACKED 0x02
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.
54 #define REF_ISBROKEN 0x04
57 * Reference name is not well formed.
59 * See git-check-ref-format(1) for the definition of well formed ref names.
61 #define REF_BAD_NAME 0x08
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.
69 typedef int each_ref_fn(const char *refname,
70 const unsigned char *sha1, int flags, void *cb_data);
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.
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 *);
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);
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);
102 static inline const char *has_glob_specials(const char *pattern)
104 return strpbrk(pattern, "?*[");
107 /* can be used to learn about broken ref and symref */
108 extern int for_each_rawref(each_ref_fn, void *);
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);
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.
118 extern int lock_packed_refs(int flags);
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().
126 extern void add_packed_ref(const char *refname, const unsigned char *sha1);
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.
134 extern int commit_packed_refs(void);
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.)
141 extern void rollback_packed_refs(void);
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
148 #define PACK_REFS_PRUNE 0x0001
149 #define PACK_REFS_ALL 0x0002
152 * Write a packed-refs file for the current repository.
153 * flags: Combination of the above PACK_REFS_* flags.
155 int pack_refs(unsigned int flags);
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.
163 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.
165 extern int repack_without_refs(struct string_list *refnames,
166 struct strbuf *err);
168 extern int ref_exists(const char *);
170 extern int is_branch(const char *refname);
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.
180 extern int peel_ref(const char *refname, unsigned char *sha1);
183 * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
184 * REF_NODEREF: act on the ref directly, instead of dereferencing
185 * symbolic references.
187 * Other flags are reserved for internal use.
189 #define REF_NODEREF 0x01
192 * Setup reflog before using. Set errno to something meaningful on failure.
194 int log_ref_setup(const char *refname, char *logfile, int bufsize);
196 /** Reads log for the value of ref during at_time. **/
197 extern int read_ref_at(const char *refname, unsigned int flags,
198 unsigned long at_time, int cnt,
199 unsigned char *sha1, char **msg,
200 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
202 /** Check if a particular reflog exists */
203 extern int reflog_exists(const char *refname);
205 /** Delete a reflog */
206 extern int delete_reflog(const char *refname);
208 /* iterate over reflog entries */
209 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
210 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
211 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
214 * Calls the specified function for each reflog file until it returns nonzero,
215 * and returns the value
217 extern int for_each_reflog(each_ref_fn, void *);
219 #define REFNAME_ALLOW_ONELEVEL 1
220 #define REFNAME_REFSPEC_PATTERN 2
223 * Return 0 iff refname has the correct format for a refname according
224 * to the rules described in Documentation/git-check-ref-format.txt.
225 * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
226 * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
227 * allow a "*" wildcard character in place of one of the name
228 * components. No leading or repeated slashes are accepted.
230 extern int check_refname_format(const char *refname, int flags);
232 extern const char *prettify_refname(const char *refname);
233 extern char *shorten_unambiguous_ref(const char *refname, int strict);
235 /** rename ref, return 0 on success **/
236 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
239 * Resolve refname in the nested "gitlink" repository that is located
240 * at path. If the resolution is successful, return 0 and set sha1 to
241 * the name of the object; otherwise, return a non-zero value.
243 extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
245 enum action_on_err {
246 UPDATE_REFS_MSG_ON_ERR,
247 UPDATE_REFS_DIE_ON_ERR,
248 UPDATE_REFS_QUIET_ON_ERR
252 * Begin a reference transaction. The reference transaction must
253 * be freed by calling ref_transaction_free().
255 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
258 * Reference transaction updates
260 * The following four functions add a reference check or update to a
261 * ref_transaction. They have some common similar parameters:
263 * transaction -- a pointer to an open ref_transaction, obtained
264 * from ref_transaction_begin().
266 * refname -- the name of the reference to be affected.
268 * flags -- flags affecting the update, passed to
269 * update_ref_lock(). Can be REF_NODEREF, which means that
270 * symbolic references should not be followed.
272 * msg -- a message describing the change (for the reflog).
274 * err -- a strbuf for receiving a description of any error that
275 * might have occured.
277 * The functions make internal copies of refname and msg, so the
278 * caller retains ownership of these parameters.
280 * The functions return 0 on success and non-zero on failure. A
281 * failure means that the transaction as a whole has failed and needs
282 * to be rolled back.
286 * Add a reference update to transaction. new_sha1 is the value that
287 * the reference should have after the update, or null_sha1 if it
288 * should be deleted. If new_sha1 is NULL, then the reference is not
289 * changed at all. old_sha1 is the value that the reference must have
290 * before the update, or null_sha1 if it must not have existed
291 * beforehand. The old value is checked after the lock is taken to
292 * prevent races. If the old value doesn't agree with old_sha1, the
293 * whole transaction fails. If old_sha1 is NULL, then the previous
294 * value is not checked.
296 * See the above comment "Reference transaction updates" for more
297 * information.
299 int ref_transaction_update(struct ref_transaction *transaction,
300 const char *refname,
301 const unsigned char *new_sha1,
302 const unsigned char *old_sha1,
303 unsigned int flags, const char *msg,
304 struct strbuf *err);
307 * Add a reference creation to transaction. new_sha1 is the value that
308 * the reference should have after the update; it must not be
309 * null_sha1. It is verified that the reference does not exist
310 * already.
312 * See the above comment "Reference transaction updates" for more
313 * information.
315 int ref_transaction_create(struct ref_transaction *transaction,
316 const char *refname,
317 const unsigned char *new_sha1,
318 unsigned int flags, const char *msg,
319 struct strbuf *err);
322 * Add a reference deletion to transaction. If old_sha1 is non-NULL,
323 * then it holds the value that the reference should have had before
324 * the update (which must not be null_sha1).
326 * See the above comment "Reference transaction updates" for more
327 * information.
329 int ref_transaction_delete(struct ref_transaction *transaction,
330 const char *refname,
331 const unsigned char *old_sha1,
332 unsigned int flags, const char *msg,
333 struct strbuf *err);
336 * Verify, within a transaction, that refname has the value old_sha1,
337 * or, if old_sha1 is null_sha1, then verify that the reference
338 * doesn't exist. old_sha1 must be non-NULL.
340 * See the above comment "Reference transaction updates" for more
341 * information.
343 int ref_transaction_verify(struct ref_transaction *transaction,
344 const char *refname,
345 const unsigned char *old_sha1,
346 unsigned int flags,
347 struct strbuf *err);
350 * Commit all of the changes that have been queued in transaction, as
351 * atomically as possible.
353 * Returns 0 for success, or one of the below error codes for errors.
355 /* Naming conflict (for example, the ref names A and A/B conflict). */
356 #define TRANSACTION_NAME_CONFLICT -1
357 /* All other errors. */
358 #define TRANSACTION_GENERIC_ERROR -2
359 int ref_transaction_commit(struct ref_transaction *transaction,
360 struct strbuf *err);
363 * Free an existing transaction and all associated data.
365 void ref_transaction_free(struct ref_transaction *transaction);
368 * Lock, update, and unlock a single reference. This function
369 * basically does a transaction containing a single call to
370 * ref_transaction_update(). The parameters to this function have the
371 * same meaning as the corresponding parameters to
372 * ref_transaction_update(). Handle errors as requested by the `onerr`
373 * argument.
375 int update_ref(const char *msg, const char *refname,
376 const unsigned char *new_sha1, const unsigned char *old_sha1,
377 unsigned int flags, enum action_on_err onerr);
379 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
380 extern int ref_is_hidden(const char *);
382 enum expire_reflog_flags {
383 EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
384 EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
385 EXPIRE_REFLOGS_VERBOSE = 1 << 2,
386 EXPIRE_REFLOGS_REWRITE = 1 << 3
390 * The following interface is used for reflog expiration. The caller
391 * calls reflog_expire(), supplying it with three callback functions,
392 * of the following types. The callback functions define the
393 * expiration policy that is desired.
395 * reflog_expiry_prepare_fn -- Called once after the reference is
396 * locked.
398 * reflog_expiry_should_prune_fn -- Called once for each entry in the
399 * existing reflog. It should return true iff that entry should be
400 * pruned.
402 * reflog_expiry_cleanup_fn -- Called once before the reference is
403 * unlocked again.
405 typedef void reflog_expiry_prepare_fn(const char *refname,
406 const unsigned char *sha1,
407 void *cb_data);
408 typedef int reflog_expiry_should_prune_fn(unsigned char *osha1,
409 unsigned char *nsha1,
410 const char *email,
411 unsigned long timestamp, int tz,
412 const char *message, void *cb_data);
413 typedef void reflog_expiry_cleanup_fn(void *cb_data);
416 * Expire reflog entries for the specified reference. sha1 is the old
417 * value of the reference. flags is a combination of the constants in
418 * enum expire_reflog_flags. The three function pointers are described
419 * above. On success, return zero.
421 extern int reflog_expire(const char *refname, const unsigned char *sha1,
422 unsigned int flags,
423 reflog_expiry_prepare_fn prepare_fn,
424 reflog_expiry_should_prune_fn should_prune_fn,
425 reflog_expiry_cleanup_fn cleanup_fn,
426 void *policy_cb_data);
428 #endif /* REFS_H */