packed-ref cache: forbid dot-components in refnames
[git/git.git] / refs.h
1 #ifndef REFS_H
2 #define REFS_H
3
4 struct ref_lock {
5 char *ref_name;
6 char *orig_ref_name;
7 struct lock_file *lk;
8 unsigned char old_sha1[20];
9 int lock_fd;
10 int force_write;
11 };
12
13 /*
14 * A ref_transaction represents a collection of ref updates
15 * that should succeed or fail together.
16 *
17 * Calling sequence
18 * ----------------
19 * - Allocate and initialize a `struct ref_transaction` by calling
20 * `ref_transaction_begin()`.
21 *
22 * - List intended ref updates by calling functions like
23 * `ref_transaction_update()` and `ref_transaction_create()`.
24 *
25 * - Call `ref_transaction_commit()` to execute the transaction.
26 * If this succeeds, the ref updates will have taken place and
27 * the transaction cannot be rolled back.
28 *
29 * - At any time call `ref_transaction_free()` to discard the
30 * transaction and free associated resources. In particular,
31 * this rolls back the transaction if it has not been
32 * successfully committed.
33 *
34 * Error handling
35 * --------------
36 *
37 * On error, transaction functions append a message about what
38 * went wrong to the 'err' argument. The message mentions what
39 * ref was being updated (if any) when the error occurred so it
40 * can be passed to 'die' or 'error' as-is.
41 *
42 * The message is appended to err without first clearing err.
43 * err will not be '\n' terminated.
44 */
45 struct ref_transaction;
46
47 /*
48 * Bit values set in the flags argument passed to each_ref_fn():
49 */
50
51 /* Reference is a symbolic reference. */
52 #define REF_ISSYMREF 0x01
53
54 /* Reference is a packed reference. */
55 #define REF_ISPACKED 0x02
56
57 /*
58 * Reference cannot be resolved to an object name: dangling symbolic
59 * reference (directly or indirectly), corrupt reference file, or
60 * symbolic reference refers to ill-formatted reference name.
61 */
62 #define REF_ISBROKEN 0x04
63
64 /*
65 * The signature for the callback function for the for_each_*()
66 * functions below. The memory pointed to by the refname and sha1
67 * arguments is only guaranteed to be valid for the duration of a
68 * single callback invocation.
69 */
70 typedef int each_ref_fn(const char *refname,
71 const unsigned char *sha1, int flags, void *cb_data);
72
73 /*
74 * The following functions invoke the specified callback function for
75 * each reference indicated. If the function ever returns a nonzero
76 * value, stop the iteration and return that value. Please note that
77 * it is not safe to modify references while an iteration is in
78 * progress, unless the same callback function invocation that
79 * modifies the reference also returns a nonzero value to immediately
80 * stop the iteration.
81 */
82 extern int head_ref(each_ref_fn, void *);
83 extern int for_each_ref(each_ref_fn, void *);
84 extern int for_each_ref_in(const char *, each_ref_fn, void *);
85 extern int for_each_tag_ref(each_ref_fn, void *);
86 extern int for_each_branch_ref(each_ref_fn, void *);
87 extern int for_each_remote_ref(each_ref_fn, void *);
88 extern int for_each_replace_ref(each_ref_fn, void *);
89 extern int for_each_glob_ref(each_ref_fn, const char *pattern, void *);
90 extern int for_each_glob_ref_in(each_ref_fn, const char *pattern, const char* prefix, void *);
91
92 extern int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
93 extern int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
94 extern int for_each_ref_in_submodule(const char *submodule, const char *prefix,
95 each_ref_fn fn, void *cb_data);
96 extern int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
97 extern int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
98 extern int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data);
99
100 extern int head_ref_namespaced(each_ref_fn fn, void *cb_data);
101 extern int for_each_namespaced_ref(each_ref_fn fn, void *cb_data);
102
103 static inline const char *has_glob_specials(const char *pattern)
104 {
105 return strpbrk(pattern, "?*[");
106 }
107
108 /* can be used to learn about broken ref and symref */
109 extern int for_each_rawref(each_ref_fn, void *);
110
111 extern void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname);
112 extern void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames);
113
114 /*
115 * Lock the packed-refs file for writing. Flags is passed to
116 * hold_lock_file_for_update(). Return 0 on success.
117 * Errno is set to something meaningful on error.
118 */
119 extern int lock_packed_refs(int flags);
120
121 /*
122 * Add a reference to the in-memory packed reference cache. This may
123 * only be called while the packed-refs file is locked (see
124 * lock_packed_refs()). To actually write the packed-refs file, call
125 * commit_packed_refs().
126 */
127 extern void add_packed_ref(const char *refname, const unsigned char *sha1);
128
129 /*
130 * Write the current version of the packed refs cache from memory to
131 * disk. The packed-refs file must already be locked for writing (see
132 * lock_packed_refs()). Return zero on success.
133 * Sets errno to something meaningful on error.
134 */
135 extern int commit_packed_refs(void);
136
137 /*
138 * Rollback the lockfile for the packed-refs file, and discard the
139 * in-memory packed reference cache. (The packed-refs file will be
140 * read anew if it is needed again after this function is called.)
141 */
142 extern void rollback_packed_refs(void);
143
144 /*
145 * Flags for controlling behaviour of pack_refs()
146 * PACK_REFS_PRUNE: Prune loose refs after packing
147 * PACK_REFS_ALL: Pack _all_ refs, not just tags and already packed refs
148 */
149 #define PACK_REFS_PRUNE 0x0001
150 #define PACK_REFS_ALL 0x0002
151
152 /*
153 * Write a packed-refs file for the current repository.
154 * flags: Combination of the above PACK_REFS_* flags.
155 */
156 int pack_refs(unsigned int flags);
157
158 extern int repack_without_refs(const char **refnames, int n,
159 struct strbuf *err);
160
161 extern int ref_exists(const char *);
162
163 extern int is_branch(const char *refname);
164
165 /*
166 * If refname is a non-symbolic reference that refers to a tag object,
167 * and the tag can be (recursively) dereferenced to a non-tag object,
168 * store the SHA1 of the referred-to object to sha1 and return 0. If
169 * any of these conditions are not met, return a non-zero value.
170 * Symbolic references are considered unpeelable, even if they
171 * ultimately resolve to a peelable tag.
172 */
173 extern int peel_ref(const char *refname, unsigned char *sha1);
174
175 /*
176 * Flags controlling lock_any_ref_for_update(), ref_transaction_update(),
177 * ref_transaction_create(), etc.
178 * REF_NODEREF: act on the ref directly, instead of dereferencing
179 * symbolic references.
180 * REF_DELETING: tolerate broken refs
181 *
182 * Flags >= 0x100 are reserved for internal use.
183 */
184 #define REF_NODEREF 0x01
185 #define REF_DELETING 0x02
186 /*
187 * This function sets errno to something meaningful on failure.
188 */
189 extern struct ref_lock *lock_any_ref_for_update(const char *refname,
190 const unsigned char *old_sha1,
191 int flags, int *type_p);
192
193 /** Close the file descriptor owned by a lock and return the status */
194 extern int close_ref(struct ref_lock *lock);
195
196 /** Close and commit the ref locked by the lock */
197 extern int commit_ref(struct ref_lock *lock);
198
199 /** Release any lock taken but not written. **/
200 extern void unlock_ref(struct ref_lock *lock);
201
202 /*
203 * Setup reflog before using. Set errno to something meaningful on failure.
204 */
205 int log_ref_setup(const char *refname, char *logfile, int bufsize);
206
207 /** Reads log for the value of ref during at_time. **/
208 extern int read_ref_at(const char *refname, unsigned int flags,
209 unsigned long at_time, int cnt,
210 unsigned char *sha1, char **msg,
211 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt);
212
213 /** Check if a particular reflog exists */
214 extern int reflog_exists(const char *refname);
215
216 /** Delete a reflog */
217 extern int delete_reflog(const char *refname);
218
219 /* iterate over reflog entries */
220 typedef int each_reflog_ent_fn(unsigned char *osha1, unsigned char *nsha1, const char *, unsigned long, int, const char *, void *);
221 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data);
222 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data);
223
224 /*
225 * Calls the specified function for each reflog file until it returns nonzero,
226 * and returns the value
227 */
228 extern int for_each_reflog(each_ref_fn, void *);
229
230 #define REFNAME_ALLOW_ONELEVEL 1
231 #define REFNAME_REFSPEC_PATTERN 2
232
233 /*
234 * Return 0 iff refname has the correct format for a refname according
235 * to the rules described in Documentation/git-check-ref-format.txt.
236 * If REFNAME_ALLOW_ONELEVEL is set in flags, then accept one-level
237 * reference names. If REFNAME_REFSPEC_PATTERN is set in flags, then
238 * allow a "*" wildcard character in place of one of the name
239 * components. No leading or repeated slashes are accepted.
240 */
241 extern int check_refname_format(const char *refname, int flags);
242
243 extern const char *prettify_refname(const char *refname);
244 extern char *shorten_unambiguous_ref(const char *refname, int strict);
245
246 /** rename ref, return 0 on success **/
247 extern int rename_ref(const char *oldref, const char *newref, const char *logmsg);
248
249 /**
250 * Resolve refname in the nested "gitlink" repository that is located
251 * at path. If the resolution is successful, return 0 and set sha1 to
252 * the name of the object; otherwise, return a non-zero value.
253 */
254 extern int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1);
255
256 enum action_on_err {
257 UPDATE_REFS_MSG_ON_ERR,
258 UPDATE_REFS_DIE_ON_ERR,
259 UPDATE_REFS_QUIET_ON_ERR
260 };
261
262 /*
263 * Begin a reference transaction. The reference transaction must
264 * be freed by calling ref_transaction_free().
265 */
266 struct ref_transaction *ref_transaction_begin(struct strbuf *err);
267
268 /*
269 * The following functions add a reference check or update to a
270 * ref_transaction. In all of them, refname is the name of the
271 * reference to be affected. The functions make internal copies of
272 * refname and msg, so the caller retains ownership of these parameters.
273 * flags can be REF_NODEREF; it is passed to update_ref_lock().
274 */
275
276 /*
277 * Add a reference update to transaction. new_sha1 is the value that
278 * the reference should have after the update, or zeros if it should
279 * be deleted. If have_old is true, then old_sha1 holds the value
280 * that the reference should have had before the update, or zeros if
281 * it must not have existed beforehand.
282 * Function returns 0 on success and non-zero on failure. A failure to update
283 * means that the transaction as a whole has failed and will need to be
284 * rolled back.
285 */
286 int ref_transaction_update(struct ref_transaction *transaction,
287 const char *refname,
288 const unsigned char *new_sha1,
289 const unsigned char *old_sha1,
290 int flags, int have_old, const char *msg,
291 struct strbuf *err);
292
293 /*
294 * Add a reference creation to transaction. new_sha1 is the value
295 * that the reference should have after the update; it must not be the
296 * null SHA-1. It is verified that the reference does not exist
297 * already.
298 * Function returns 0 on success and non-zero on failure. A failure to create
299 * means that the transaction as a whole has failed and will need to be
300 * rolled back.
301 */
302 int ref_transaction_create(struct ref_transaction *transaction,
303 const char *refname,
304 const unsigned char *new_sha1,
305 int flags, const char *msg,
306 struct strbuf *err);
307
308 /*
309 * Add a reference deletion to transaction. If have_old is true, then
310 * old_sha1 holds the value that the reference should have had before
311 * the update (which must not be the null SHA-1).
312 * Function returns 0 on success and non-zero on failure. A failure to delete
313 * means that the transaction as a whole has failed and will need to be
314 * rolled back.
315 */
316 int ref_transaction_delete(struct ref_transaction *transaction,
317 const char *refname,
318 const unsigned char *old_sha1,
319 int flags, int have_old, const char *msg,
320 struct strbuf *err);
321
322 /*
323 * Commit all of the changes that have been queued in transaction, as
324 * atomically as possible.
325 *
326 * Returns 0 for success, or one of the below error codes for errors.
327 */
328 /* Naming conflict (for example, the ref names A and A/B conflict). */
329 #define TRANSACTION_NAME_CONFLICT -1
330 /* All other errors. */
331 #define TRANSACTION_GENERIC_ERROR -2
332 int ref_transaction_commit(struct ref_transaction *transaction,
333 struct strbuf *err);
334
335 /*
336 * Free an existing transaction and all associated data.
337 */
338 void ref_transaction_free(struct ref_transaction *transaction);
339
340 /** Lock a ref and then write its file */
341 int update_ref(const char *action, const char *refname,
342 const unsigned char *sha1, const unsigned char *oldval,
343 int flags, enum action_on_err onerr);
344
345 extern int parse_hide_refs_config(const char *var, const char *value, const char *);
346 extern int ref_is_hidden(const char *);
347
348 #endif /* REFS_H */