initial_ref_transaction_commit(): check for ref D/F conflicts
[git/git.git] / refs.h
CommitLineData
95fc7512
DB
1#ifndef REFS_H
2#define REFS_H
3
b416af5b
RS
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 */
caa4046c
MH
36struct ref_transaction;
37
89df9c84
MH
38/*
39 * Bit values set in the flags argument passed to each_ref_fn():
40 */
41
42/* Reference is a symbolic reference. */
98ac34b2 43#define REF_ISSYMREF 0x01
89df9c84
MH
44
45/* Reference is a packed reference. */
98ac34b2 46#define REF_ISPACKED 0x02
89df9c84
MH
47
48/*
49 * Reference cannot be resolved to an object name: dangling symbolic
d0f810f0
RS
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.
89df9c84 53 */
98ac34b2 54#define REF_ISBROKEN 0x04
f4204ab9 55
d0f810f0
RS
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
8a65ff76 63/*
4f78c24c
MH
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 */
69typedef int each_ref_fn(const char *refname,
2b2a5be3
MH
70 const struct object_id *oid, int flags, void *cb_data);
71
4f78c24c
MH
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.
8a65ff76 80 */
cb5d709f
JH
81extern int head_ref(each_ref_fn, void *);
82extern int for_each_ref(each_ref_fn, void *);
2a8177b6 83extern int for_each_ref_in(const char *, each_ref_fn, void *);
cb5d709f
JH
84extern int for_each_tag_ref(each_ref_fn, void *);
85extern int for_each_branch_ref(each_ref_fn, void *);
86extern int for_each_remote_ref(each_ref_fn, void *);
29268700 87extern int for_each_replace_ref(each_ref_fn, void *);
d08bae7e 88extern int for_each_glob_ref(each_ref_fn, const char *pattern, void *);
b09fe971 89extern int for_each_glob_ref_in(each_ref_fn, const char *pattern, const char* prefix, void *);
8a65ff76 90
9ef6aeb0
HV
91extern int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
92extern int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
93extern int for_each_ref_in_submodule(const char *submodule, const char *prefix,
94 each_ref_fn fn, void *cb_data);
95extern int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
96extern int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
97extern int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
98
a1bea2c1
JT
99extern int head_ref_namespaced(each_ref_fn fn, void *cb_data);
100extern int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
101
894a9d33
TR
102static inline const char *has_glob_specials(const char *pattern)
103{
104 return strpbrk(pattern, "?*[");
105}
106
f8948e2f
JH
107/* can be used to learn about broken ref and symref */
108extern int for_each_rawref(each_ref_fn, void *);
109
3cf6134a 110extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
24d36f14 111extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames);
f8948e2f 112
32d462ce
MH
113/*
114 * Flags for controlling behaviour of pack_refs()
115 * PACK_REFS_PRUNE: Prune loose refs after packing
116 * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs
117 */
118#define PACK_REFS_PRUNE 0x0001
119#define PACK_REFS_ALL 0x0002
120
121/*
122 * Write a packed-refs file for the current repository.
123 * flags: Combination of the above PACK_REFS_* flags.
124 */
125int pack_refs(unsigned int flags);
126
2c5c66be 127extern int ref_exists(const char *);
e142a3c6 128
e7e0f26e
RS
129extern int is_branch(const char *refname);
130
2312a793
MH
131/*
132 * If refname is a non-symbolic reference that refers to a tag object,
133 * and the tag can be (recursively) dereferenced to a non-tag object,
134 * store the SHA1 of the referred-to object to sha1 and return 0. If
135 * any of these conditions are not met, return a non-zero value.
136 * Symbolic references are considered unpeelable, even if they
137 * ultimately resolve to a peelable tag.
138 */
dfefa935 139extern int peel_ref(const char *refname, unsigned char *sha1);
cf0adba7 140
835e3c99 141/*
31e07f76 142 * Flags controlling ref_transaction_update(), ref_transaction_create(), etc.
029cdb4a
RS
143 * REF_NODEREF: act on the ref directly, instead of dereferencing
144 * symbolic references.
145 *
581d4e0c 146 * Other flags are reserved for internal use.
835e3c99 147 */
68db31cc 148#define REF_NODEREF 0x01
95fc7512 149
bd3b02da
RS
150/*
151 * Setup reflog before using. Set errno to something meaningful on failure.
152 */
1a83c240 153int log_ref_setup(const char *refname, struct strbuf *logfile);
859c3017 154
d556fae2 155/** Reads log for the value of ref during at_time. **/
c41a87dd
DA
156extern int read_ref_at(const char *refname, unsigned int flags,
157 unsigned long at_time, int cnt,
dfefa935
MH
158 unsigned char *sha1, char **msg,
159 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
d556fae2 160
4da58835
RS
161/** Check if a particular reflog exists */
162extern int reflog_exists(const char *refname);
163
fc1c2168
MH
164/*
165 * Delete the specified reference. If old_sha1 is non-NULL and not
166 * NULL_SHA1, then verify that the current value of the reference is
167 * old_sha1 before deleting it. If old_sha1 is NULL or NULL_SHA1,
168 * delete the reference if it exists, regardless of its old value.
169 * flags is passed through to ref_transaction_delete().
170 */
171extern int delete_ref(const char *refname, const unsigned char *old_sha1,
172 unsigned int flags);
173
98ffd5ff
MH
174/*
175 * Delete the specified references. If there are any problems, emit
176 * errors but attempt to keep going (i.e., the deletes are not done in
177 * an all-or-nothing transaction).
178 */
179extern int delete_refs(struct string_list *refnames);
180
4da58835
RS
181/** Delete a reflog */
182extern int delete_reflog(const char *refname);
183
2ff81662 184/* iterate over reflog entries */
883d60fa 185typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
dfefa935 186int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
98f85ff4 187int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
2ff81662 188
eb8381c8
NP
189/*
190 * Calls the specified function for each reflog file until it returns nonzero,
191 * and returns the value
192 */
193extern int for_each_reflog(each_ref_fn, void *);
194
8d9c5010
MH
195#define REFNAME_ALLOW_ONELEVEL 1
196#define REFNAME_REFSPEC_PATTERN 2
197
198/*
dfefa935
MH
199 * Return 0 iff refname has the correct format for a refname according
200 * to the rules described in Documentation/git-check-ref-format.txt.
201 * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
8d9c5010
MH
202 * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
203 * allow a "*" wildcard character in place of one of the name
f3cc52d8 204 * components. No leading or repeated slashes are accepted.
8d9c5010 205 */
dfefa935 206extern int check_refname_format(const char *refname, int flags);
95fc7512 207
4577e483 208extern const char *prettify_refname(const char *refname);
dfefa935 209extern char *shorten_unambiguous_ref(const char *refname, int strict);
a9c37a72 210
c976d415 211/** rename ref, return 0 on success **/
678d0f4c 212extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
c976d415 213
7f820bd9
MH
214/**
215 * Resolve refname in the nested "gitlink" repository that is located
216 * at path. If the resolution is successful, return 0 and set sha1 to
217 * the name of the object; otherwise, return a non-zero value.
218 */
219extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
0ebde32c 220
f4124112
MH
221enum action_on_err {
222 UPDATE_REFS_MSG_ON_ERR,
223 UPDATE_REFS_DIE_ON_ERR,
224 UPDATE_REFS_QUIET_ON_ERR
225};
226
caa4046c
MH
227/*
228 * Begin a reference transaction. The reference transaction must
33f9fc59 229 * be freed by calling ref_transaction_free().
caa4046c 230 */
93a644ea 231struct ref_transaction *ref_transaction_begin(struct strbuf *err);
caa4046c 232
caa4046c 233/*
d1dd721f
MH
234 * Reference transaction updates
235 *
236 * The following four functions add a reference check or update to a
237 * ref_transaction. They have some common similar parameters:
238 *
239 * transaction -- a pointer to an open ref_transaction, obtained
240 * from ref_transaction_begin().
241 *
242 * refname -- the name of the reference to be affected.
243 *
244 * flags -- flags affecting the update, passed to
245 * update_ref_lock(). Can be REF_NODEREF, which means that
246 * symbolic references should not be followed.
247 *
248 * msg -- a message describing the change (for the reflog).
249 *
250 * err -- a strbuf for receiving a description of any error that
251 * might have occured.
252 *
253 * The functions make internal copies of refname and msg, so the
254 * caller retains ownership of these parameters.
255 *
256 * The functions return 0 on success and non-zero on failure. A
257 * failure means that the transaction as a whole has failed and needs
258 * to be rolled back.
caa4046c
MH
259 */
260
caa4046c 261/*
16180334
MH
262 * Add a reference update to transaction. new_sha1 is the value that
263 * the reference should have after the update, or null_sha1 if it
264 * should be deleted. If new_sha1 is NULL, then the reference is not
265 * changed at all. old_sha1 is the value that the reference must have
266 * before the update, or null_sha1 if it must not have existed
267 * beforehand. The old value is checked after the lock is taken to
268 * prevent races. If the old value doesn't agree with old_sha1, the
269 * whole transaction fails. If old_sha1 is NULL, then the previous
270 * value is not checked.
271 *
d1dd721f
MH
272 * See the above comment "Reference transaction updates" for more
273 * information.
caa4046c 274 */
8e34800e
RS
275int ref_transaction_update(struct ref_transaction *transaction,
276 const char *refname,
277 const unsigned char *new_sha1,
278 const unsigned char *old_sha1,
1d147bdf 279 unsigned int flags, const char *msg,
8e34800e 280 struct strbuf *err);
caa4046c
MH
281
282/*
d1dd721f
MH
283 * Add a reference creation to transaction. new_sha1 is the value that
284 * the reference should have after the update; it must not be
285 * null_sha1. It is verified that the reference does not exist
caa4046c 286 * already.
d1dd721f
MH
287 *
288 * See the above comment "Reference transaction updates" for more
289 * information.
caa4046c 290 */
b416af5b
RS
291int ref_transaction_create(struct ref_transaction *transaction,
292 const char *refname,
293 const unsigned char *new_sha1,
fec14ec3 294 unsigned int flags, const char *msg,
b416af5b 295 struct strbuf *err);
caa4046c
MH
296
297/*
d1dd721f
MH
298 * Add a reference deletion to transaction. If old_sha1 is non-NULL,
299 * then it holds the value that the reference should have had before
300 * the update (which must not be null_sha1).
301 *
302 * See the above comment "Reference transaction updates" for more
303 * information.
caa4046c 304 */
8c8bdc0d
RS
305int ref_transaction_delete(struct ref_transaction *transaction,
306 const char *refname,
307 const unsigned char *old_sha1,
fb5a6bb6 308 unsigned int flags, const char *msg,
8c8bdc0d 309 struct strbuf *err);
caa4046c 310
16180334
MH
311/*
312 * Verify, within a transaction, that refname has the value old_sha1,
313 * or, if old_sha1 is null_sha1, then verify that the reference
d1dd721f
MH
314 * doesn't exist. old_sha1 must be non-NULL.
315 *
316 * See the above comment "Reference transaction updates" for more
317 * information.
16180334
MH
318 */
319int ref_transaction_verify(struct ref_transaction *transaction,
320 const char *refname,
321 const unsigned char *old_sha1,
322 unsigned int flags,
323 struct strbuf *err);
324
caa4046c
MH
325/*
326 * Commit all of the changes that have been queued in transaction, as
28e6a97e
RS
327 * atomically as possible.
328 *
329 * Returns 0 for success, or one of the below error codes for errors.
caa4046c 330 */
28e6a97e
RS
331/* Naming conflict (for example, the ref names A and A/B conflict). */
332#define TRANSACTION_NAME_CONFLICT -1
333/* All other errors. */
334#define TRANSACTION_GENERIC_ERROR -2
caa4046c 335int ref_transaction_commit(struct ref_transaction *transaction,
db7516ab 336 struct strbuf *err);
caa4046c 337
58f233ce
MH
338/*
339 * Like ref_transaction_commit(), but optimized for creating
340 * references when originally initializing a repository (e.g., by "git
341 * clone"). It writes the new references directly to packed-refs
342 * without locking the individual references.
343 *
344 * It is a bug to call this function when there might be other
345 * processes accessing the repository or if there are existing
346 * references that might conflict with the ones being created. All
347 * old_sha1 values must either be absent or NULL_SHA1.
348 */
349int initial_ref_transaction_commit(struct ref_transaction *transaction,
350 struct strbuf *err);
351
026bd1d3
RS
352/*
353 * Free an existing transaction and all associated data.
354 */
355void ref_transaction_free(struct ref_transaction *transaction);
356
4b7b520b
MH
357/**
358 * Lock, update, and unlock a single reference. This function
359 * basically does a transaction containing a single call to
360 * ref_transaction_update(). The parameters to this function have the
361 * same meaning as the corresponding parameters to
362 * ref_transaction_update(). Handle errors as requested by the `onerr`
363 * argument.
364 */
365int update_ref(const char *msg, const char *refname,
366 const unsigned char *new_sha1, const unsigned char *old_sha1,
fec14ec3 367 unsigned int flags, enum action_on_err onerr);
3d9f037c 368
daebaa78
JH
369extern int parse_hide_refs_config(const char *var, const char *value, const char *);
370extern int ref_is_hidden(const char *);
371
fa5b1830
MH
372enum expire_reflog_flags {
373 EXPIRE_REFLOGS_DRY_RUN = 1 << 0,
374 EXPIRE_REFLOGS_UPDATE_REF = 1 << 1,
375 EXPIRE_REFLOGS_VERBOSE = 1 << 2,
376 EXPIRE_REFLOGS_REWRITE = 1 << 3
377};
378
379/*
380 * The following interface is used for reflog expiration. The caller
381 * calls reflog_expire(), supplying it with three callback functions,
382 * of the following types. The callback functions define the
383 * expiration policy that is desired.
384 *
385 * reflog_expiry_prepare_fn -- Called once after the reference is
386 * locked.
387 *
388 * reflog_expiry_should_prune_fn -- Called once for each entry in the
389 * existing reflog. It should return true iff that entry should be
390 * pruned.
391 *
392 * reflog_expiry_cleanup_fn -- Called once before the reference is
393 * unlocked again.
394 */
395typedef void reflog_expiry_prepare_fn(const char *refname,
396 const unsigned char *sha1,
397 void *cb_data);
398typedef int reflog_expiry_should_prune_fn(unsigned char *osha1,
399 unsigned char *nsha1,
400 const char *email,
401 unsigned long timestamp, int tz,
402 const char *message, void *cb_data);
403typedef void reflog_expiry_cleanup_fn(void *cb_data);
404
405/*
406 * Expire reflog entries for the specified reference. sha1 is the old
407 * value of the reference. flags is a combination of the constants in
408 * enum expire_reflog_flags. The three function pointers are described
409 * above. On success, return zero.
410 */
411extern int reflog_expire(const char *refname, const unsigned char *sha1,
412 unsigned int flags,
413 reflog_expiry_prepare_fn prepare_fn,
414 reflog_expiry_should_prune_fn should_prune_fn,
415 reflog_expiry_cleanup_fn cleanup_fn,
416 void *policy_cb_data);
417
95fc7512 418#endif /* REFS_H */