20ba82b4343ff2ef72cea32deec8a8d7fbd6def7
[git/git.git] / refs.c
1 /*
2 * The backend-independent part of the reference module.
3 */
4
5 #include "cache.h"
6 #include "config.h"
7 #include "hashmap.h"
8 #include "lockfile.h"
9 #include "iterator.h"
10 #include "refs.h"
11 #include "refs/refs-internal.h"
12 #include "object.h"
13 #include "tag.h"
14 #include "submodule.h"
15 #include "worktree.h"
16
17 /*
18 * List of all available backends
19 */
20 static struct ref_storage_be *refs_backends = &refs_be_files;
21
22 static struct ref_storage_be *find_ref_storage_backend(const char *name)
23 {
24 struct ref_storage_be *be;
25 for (be = refs_backends; be; be = be->next)
26 if (!strcmp(be->name, name))
27 return be;
28 return NULL;
29 }
30
31 int ref_storage_backend_exists(const char *name)
32 {
33 return find_ref_storage_backend(name) != NULL;
34 }
35
36 /*
37 * How to handle various characters in refnames:
38 * 0: An acceptable character for refs
39 * 1: End-of-component
40 * 2: ., look for a preceding . to reject .. in refs
41 * 3: {, look for a preceding @ to reject @{ in refs
42 * 4: A bad character: ASCII control characters, and
43 * ":", "?", "[", "\", "^", "~", SP, or TAB
44 * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
45 */
46 static unsigned char refname_disposition[256] = {
47 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
48 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
49 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
50 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
51 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
52 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
53 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
54 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
55 };
56
57 /*
58 * Try to read one refname component from the front of refname.
59 * Return the length of the component found, or -1 if the component is
60 * not legal. It is legal if it is something reasonable to have under
61 * ".git/refs/"; We do not like it if:
62 *
63 * - any path component of it begins with ".", or
64 * - it has double dots "..", or
65 * - it has ASCII control characters, or
66 * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
67 * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
68 * - it ends with a "/", or
69 * - it ends with ".lock", or
70 * - it contains a "@{" portion
71 */
72 static int check_refname_component(const char *refname, int *flags)
73 {
74 const char *cp;
75 char last = '\0';
76
77 for (cp = refname; ; cp++) {
78 int ch = *cp & 255;
79 unsigned char disp = refname_disposition[ch];
80 switch (disp) {
81 case 1:
82 goto out;
83 case 2:
84 if (last == '.')
85 return -1; /* Refname contains "..". */
86 break;
87 case 3:
88 if (last == '@')
89 return -1; /* Refname contains "@{". */
90 break;
91 case 4:
92 return -1;
93 case 5:
94 if (!(*flags & REFNAME_REFSPEC_PATTERN))
95 return -1; /* refspec can't be a pattern */
96
97 /*
98 * Unset the pattern flag so that we only accept
99 * a single asterisk for one side of refspec.
100 */
101 *flags &= ~ REFNAME_REFSPEC_PATTERN;
102 break;
103 }
104 last = ch;
105 }
106 out:
107 if (cp == refname)
108 return 0; /* Component has zero length. */
109 if (refname[0] == '.')
110 return -1; /* Component starts with '.'. */
111 if (cp - refname >= LOCK_SUFFIX_LEN &&
112 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
113 return -1; /* Refname ends with ".lock". */
114 return cp - refname;
115 }
116
117 int check_refname_format(const char *refname, int flags)
118 {
119 int component_len, component_count = 0;
120
121 if (!strcmp(refname, "@"))
122 /* Refname is a single character '@'. */
123 return -1;
124
125 while (1) {
126 /* We are at the start of a path component. */
127 component_len = check_refname_component(refname, &flags);
128 if (component_len <= 0)
129 return -1;
130
131 component_count++;
132 if (refname[component_len] == '\0')
133 break;
134 /* Skip to next component. */
135 refname += component_len + 1;
136 }
137
138 if (refname[component_len - 1] == '.')
139 return -1; /* Refname ends with '.'. */
140 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
141 return -1; /* Refname has only one component. */
142 return 0;
143 }
144
145 int refname_is_safe(const char *refname)
146 {
147 const char *rest;
148
149 if (skip_prefix(refname, "refs/", &rest)) {
150 char *buf;
151 int result;
152 size_t restlen = strlen(rest);
153
154 /* rest must not be empty, or start or end with "/" */
155 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
156 return 0;
157
158 /*
159 * Does the refname try to escape refs/?
160 * For example: refs/foo/../bar is safe but refs/foo/../../bar
161 * is not.
162 */
163 buf = xmallocz(restlen);
164 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
165 free(buf);
166 return result;
167 }
168
169 do {
170 if (!isupper(*refname) && *refname != '_')
171 return 0;
172 refname++;
173 } while (*refname);
174 return 1;
175 }
176
177 /*
178 * Return true if refname, which has the specified oid and flags, can
179 * be resolved to an object in the database. If the referred-to object
180 * does not exist, emit a warning and return false.
181 */
182 int ref_resolves_to_object(const char *refname,
183 const struct object_id *oid,
184 unsigned int flags)
185 {
186 if (flags & REF_ISBROKEN)
187 return 0;
188 if (!has_sha1_file(oid->hash)) {
189 error("%s does not point to a valid object!", refname);
190 return 0;
191 }
192 return 1;
193 }
194
195 char *refs_resolve_refdup(struct ref_store *refs,
196 const char *refname, int resolve_flags,
197 struct object_id *oid, int *flags)
198 {
199 const char *result;
200
201 result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
202 oid, flags);
203 return xstrdup_or_null(result);
204 }
205
206 char *resolve_refdup(const char *refname, int resolve_flags,
207 struct object_id *oid, int *flags)
208 {
209 return refs_resolve_refdup(get_main_ref_store(),
210 refname, resolve_flags,
211 oid, flags);
212 }
213
214 /* The argument to filter_refs */
215 struct ref_filter {
216 const char *pattern;
217 each_ref_fn *fn;
218 void *cb_data;
219 };
220
221 int refs_read_ref_full(struct ref_store *refs, const char *refname,
222 int resolve_flags, struct object_id *oid, int *flags)
223 {
224 if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
225 return 0;
226 return -1;
227 }
228
229 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
230 {
231 return refs_read_ref_full(get_main_ref_store(), refname,
232 resolve_flags, oid, flags);
233 }
234
235 int read_ref(const char *refname, struct object_id *oid)
236 {
237 return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
238 }
239
240 int ref_exists(const char *refname)
241 {
242 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
243 }
244
245 static int match_ref_pattern(const char *refname,
246 const struct string_list_item *item)
247 {
248 int matched = 0;
249 if (item->util == NULL) {
250 if (!wildmatch(item->string, refname, 0))
251 matched = 1;
252 } else {
253 const char *rest;
254 if (skip_prefix(refname, item->string, &rest) &&
255 (!*rest || *rest == '/'))
256 matched = 1;
257 }
258 return matched;
259 }
260
261 int ref_filter_match(const char *refname,
262 const struct string_list *include_patterns,
263 const struct string_list *exclude_patterns)
264 {
265 struct string_list_item *item;
266
267 if (exclude_patterns && exclude_patterns->nr) {
268 for_each_string_list_item(item, exclude_patterns) {
269 if (match_ref_pattern(refname, item))
270 return 0;
271 }
272 }
273
274 if (include_patterns && include_patterns->nr) {
275 int found = 0;
276 for_each_string_list_item(item, include_patterns) {
277 if (match_ref_pattern(refname, item)) {
278 found = 1;
279 break;
280 }
281 }
282
283 if (!found)
284 return 0;
285 }
286 return 1;
287 }
288
289 static int filter_refs(const char *refname, const struct object_id *oid,
290 int flags, void *data)
291 {
292 struct ref_filter *filter = (struct ref_filter *)data;
293
294 if (wildmatch(filter->pattern, refname, 0))
295 return 0;
296 return filter->fn(refname, oid, flags, filter->cb_data);
297 }
298
299 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
300 {
301 struct object *o = lookup_unknown_object(name->hash);
302
303 if (o->type == OBJ_NONE) {
304 int type = sha1_object_info(name->hash, NULL);
305 if (type < 0 || !object_as_type(o, type, 0))
306 return PEEL_INVALID;
307 }
308
309 if (o->type != OBJ_TAG)
310 return PEEL_NON_TAG;
311
312 o = deref_tag_noverify(o);
313 if (!o)
314 return PEEL_INVALID;
315
316 oidcpy(oid, &o->oid);
317 return PEEL_PEELED;
318 }
319
320 struct warn_if_dangling_data {
321 FILE *fp;
322 const char *refname;
323 const struct string_list *refnames;
324 const char *msg_fmt;
325 };
326
327 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
328 int flags, void *cb_data)
329 {
330 struct warn_if_dangling_data *d = cb_data;
331 const char *resolves_to;
332
333 if (!(flags & REF_ISSYMREF))
334 return 0;
335
336 resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
337 if (!resolves_to
338 || (d->refname
339 ? strcmp(resolves_to, d->refname)
340 : !string_list_has_string(d->refnames, resolves_to))) {
341 return 0;
342 }
343
344 fprintf(d->fp, d->msg_fmt, refname);
345 fputc('\n', d->fp);
346 return 0;
347 }
348
349 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
350 {
351 struct warn_if_dangling_data data;
352
353 data.fp = fp;
354 data.refname = refname;
355 data.refnames = NULL;
356 data.msg_fmt = msg_fmt;
357 for_each_rawref(warn_if_dangling_symref, &data);
358 }
359
360 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
361 {
362 struct warn_if_dangling_data data;
363
364 data.fp = fp;
365 data.refname = NULL;
366 data.refnames = refnames;
367 data.msg_fmt = msg_fmt;
368 for_each_rawref(warn_if_dangling_symref, &data);
369 }
370
371 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
372 {
373 return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
374 }
375
376 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
377 {
378 return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
379 }
380
381 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
382 {
383 return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
384 }
385
386 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
387 {
388 return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
389 }
390
391 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
392 {
393 return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
394 }
395
396 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
397 {
398 return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
399 }
400
401 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
402 {
403 struct strbuf buf = STRBUF_INIT;
404 int ret = 0;
405 struct object_id oid;
406 int flag;
407
408 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
409 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, &oid, &flag))
410 ret = fn(buf.buf, &oid, flag, cb_data);
411 strbuf_release(&buf);
412
413 return ret;
414 }
415
416 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
417 const char *pattern)
418 {
419 struct strbuf normalized_pattern = STRBUF_INIT;
420
421 if (*pattern == '/')
422 BUG("pattern must not start with '/'");
423
424 if (prefix) {
425 strbuf_addstr(&normalized_pattern, prefix);
426 }
427 else if (!starts_with(pattern, "refs/"))
428 strbuf_addstr(&normalized_pattern, "refs/");
429 strbuf_addstr(&normalized_pattern, pattern);
430 strbuf_strip_suffix(&normalized_pattern, "/");
431
432 item->string = strbuf_detach(&normalized_pattern, NULL);
433 item->util = has_glob_specials(pattern) ? NULL : item->string;
434 strbuf_release(&normalized_pattern);
435 }
436
437 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
438 const char *prefix, void *cb_data)
439 {
440 struct strbuf real_pattern = STRBUF_INIT;
441 struct ref_filter filter;
442 int ret;
443
444 if (!prefix && !starts_with(pattern, "refs/"))
445 strbuf_addstr(&real_pattern, "refs/");
446 else if (prefix)
447 strbuf_addstr(&real_pattern, prefix);
448 strbuf_addstr(&real_pattern, pattern);
449
450 if (!has_glob_specials(pattern)) {
451 /* Append implied '/' '*' if not present. */
452 strbuf_complete(&real_pattern, '/');
453 /* No need to check for '*', there is none. */
454 strbuf_addch(&real_pattern, '*');
455 }
456
457 filter.pattern = real_pattern.buf;
458 filter.fn = fn;
459 filter.cb_data = cb_data;
460 ret = for_each_ref(filter_refs, &filter);
461
462 strbuf_release(&real_pattern);
463 return ret;
464 }
465
466 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
467 {
468 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
469 }
470
471 const char *prettify_refname(const char *name)
472 {
473 if (skip_prefix(name, "refs/heads/", &name) ||
474 skip_prefix(name, "refs/tags/", &name) ||
475 skip_prefix(name, "refs/remotes/", &name))
476 ; /* nothing */
477 return name;
478 }
479
480 static const char *ref_rev_parse_rules[] = {
481 "%.*s",
482 "refs/%.*s",
483 "refs/tags/%.*s",
484 "refs/heads/%.*s",
485 "refs/remotes/%.*s",
486 "refs/remotes/%.*s/HEAD",
487 NULL
488 };
489
490 int refname_match(const char *abbrev_name, const char *full_name)
491 {
492 const char **p;
493 const int abbrev_name_len = strlen(abbrev_name);
494
495 for (p = ref_rev_parse_rules; *p; p++) {
496 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
497 return 1;
498 }
499 }
500
501 return 0;
502 }
503
504 /*
505 * *string and *len will only be substituted, and *string returned (for
506 * later free()ing) if the string passed in is a magic short-hand form
507 * to name a branch.
508 */
509 static char *substitute_branch_name(const char **string, int *len)
510 {
511 struct strbuf buf = STRBUF_INIT;
512 int ret = interpret_branch_name(*string, *len, &buf, 0);
513
514 if (ret == *len) {
515 size_t size;
516 *string = strbuf_detach(&buf, &size);
517 *len = size;
518 return (char *)*string;
519 }
520
521 return NULL;
522 }
523
524 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
525 {
526 char *last_branch = substitute_branch_name(&str, &len);
527 int refs_found = expand_ref(str, len, oid, ref);
528 free(last_branch);
529 return refs_found;
530 }
531
532 int expand_ref(const char *str, int len, struct object_id *oid, char **ref)
533 {
534 const char **p, *r;
535 int refs_found = 0;
536 struct strbuf fullref = STRBUF_INIT;
537
538 *ref = NULL;
539 for (p = ref_rev_parse_rules; *p; p++) {
540 struct object_id oid_from_ref;
541 struct object_id *this_result;
542 int flag;
543
544 this_result = refs_found ? &oid_from_ref : oid;
545 strbuf_reset(&fullref);
546 strbuf_addf(&fullref, *p, len, str);
547 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
548 this_result, &flag);
549 if (r) {
550 if (!refs_found++)
551 *ref = xstrdup(r);
552 if (!warn_ambiguous_refs)
553 break;
554 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
555 warning("ignoring dangling symref %s.", fullref.buf);
556 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
557 warning("ignoring broken ref %s.", fullref.buf);
558 }
559 }
560 strbuf_release(&fullref);
561 return refs_found;
562 }
563
564 int dwim_log(const char *str, int len, struct object_id *oid, char **log)
565 {
566 char *last_branch = substitute_branch_name(&str, &len);
567 const char **p;
568 int logs_found = 0;
569 struct strbuf path = STRBUF_INIT;
570
571 *log = NULL;
572 for (p = ref_rev_parse_rules; *p; p++) {
573 struct object_id hash;
574 const char *ref, *it;
575
576 strbuf_reset(&path);
577 strbuf_addf(&path, *p, len, str);
578 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
579 &hash, NULL);
580 if (!ref)
581 continue;
582 if (reflog_exists(path.buf))
583 it = path.buf;
584 else if (strcmp(ref, path.buf) && reflog_exists(ref))
585 it = ref;
586 else
587 continue;
588 if (!logs_found++) {
589 *log = xstrdup(it);
590 oidcpy(oid, &hash);
591 }
592 if (!warn_ambiguous_refs)
593 break;
594 }
595 strbuf_release(&path);
596 free(last_branch);
597 return logs_found;
598 }
599
600 static int is_per_worktree_ref(const char *refname)
601 {
602 return !strcmp(refname, "HEAD") ||
603 starts_with(refname, "refs/bisect/");
604 }
605
606 static int is_pseudoref_syntax(const char *refname)
607 {
608 const char *c;
609
610 for (c = refname; *c; c++) {
611 if (!isupper(*c) && *c != '-' && *c != '_')
612 return 0;
613 }
614
615 return 1;
616 }
617
618 enum ref_type ref_type(const char *refname)
619 {
620 if (is_per_worktree_ref(refname))
621 return REF_TYPE_PER_WORKTREE;
622 if (is_pseudoref_syntax(refname))
623 return REF_TYPE_PSEUDOREF;
624 return REF_TYPE_NORMAL;
625 }
626
627 long get_files_ref_lock_timeout_ms(void)
628 {
629 static int configured = 0;
630
631 /* The default timeout is 100 ms: */
632 static int timeout_ms = 100;
633
634 if (!configured) {
635 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
636 configured = 1;
637 }
638
639 return timeout_ms;
640 }
641
642 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
643 const struct object_id *old_oid, struct strbuf *err)
644 {
645 const char *filename;
646 int fd;
647 static struct lock_file lock;
648 struct strbuf buf = STRBUF_INIT;
649 int ret = -1;
650
651 if (!oid)
652 return 0;
653
654 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
655
656 filename = git_path("%s", pseudoref);
657 fd = hold_lock_file_for_update_timeout(&lock, filename,
658 LOCK_DIE_ON_ERROR,
659 get_files_ref_lock_timeout_ms());
660 if (fd < 0) {
661 strbuf_addf(err, "could not open '%s' for writing: %s",
662 filename, strerror(errno));
663 goto done;
664 }
665
666 if (old_oid) {
667 struct object_id actual_old_oid;
668
669 if (read_ref(pseudoref, &actual_old_oid))
670 die("could not read ref '%s'", pseudoref);
671 if (oidcmp(&actual_old_oid, old_oid)) {
672 strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
673 rollback_lock_file(&lock);
674 goto done;
675 }
676 }
677
678 if (write_in_full(fd, buf.buf, buf.len) < 0) {
679 strbuf_addf(err, "could not write to '%s'", filename);
680 rollback_lock_file(&lock);
681 goto done;
682 }
683
684 commit_lock_file(&lock);
685 ret = 0;
686 done:
687 strbuf_release(&buf);
688 return ret;
689 }
690
691 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
692 {
693 static struct lock_file lock;
694 const char *filename;
695
696 filename = git_path("%s", pseudoref);
697
698 if (old_oid && !is_null_oid(old_oid)) {
699 int fd;
700 struct object_id actual_old_oid;
701
702 fd = hold_lock_file_for_update_timeout(
703 &lock, filename, LOCK_DIE_ON_ERROR,
704 get_files_ref_lock_timeout_ms());
705 if (fd < 0)
706 die_errno(_("Could not open '%s' for writing"), filename);
707 if (read_ref(pseudoref, &actual_old_oid))
708 die("could not read ref '%s'", pseudoref);
709 if (oidcmp(&actual_old_oid, old_oid)) {
710 warning("Unexpected sha1 when deleting %s", pseudoref);
711 rollback_lock_file(&lock);
712 return -1;
713 }
714
715 unlink(filename);
716 rollback_lock_file(&lock);
717 } else {
718 unlink(filename);
719 }
720
721 return 0;
722 }
723
724 int refs_delete_ref(struct ref_store *refs, const char *msg,
725 const char *refname,
726 const struct object_id *old_oid,
727 unsigned int flags)
728 {
729 struct ref_transaction *transaction;
730 struct strbuf err = STRBUF_INIT;
731
732 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
733 assert(refs == get_main_ref_store());
734 return delete_pseudoref(refname, old_oid);
735 }
736
737 transaction = ref_store_transaction_begin(refs, &err);
738 if (!transaction ||
739 ref_transaction_delete(transaction, refname, old_oid,
740 flags, msg, &err) ||
741 ref_transaction_commit(transaction, &err)) {
742 error("%s", err.buf);
743 ref_transaction_free(transaction);
744 strbuf_release(&err);
745 return 1;
746 }
747 ref_transaction_free(transaction);
748 strbuf_release(&err);
749 return 0;
750 }
751
752 int delete_ref(const char *msg, const char *refname,
753 const struct object_id *old_oid, unsigned int flags)
754 {
755 return refs_delete_ref(get_main_ref_store(), msg, refname,
756 old_oid, flags);
757 }
758
759 int copy_reflog_msg(char *buf, const char *msg)
760 {
761 char *cp = buf;
762 char c;
763 int wasspace = 1;
764
765 *cp++ = '\t';
766 while ((c = *msg++)) {
767 if (wasspace && isspace(c))
768 continue;
769 wasspace = isspace(c);
770 if (wasspace)
771 c = ' ';
772 *cp++ = c;
773 }
774 while (buf < cp && isspace(cp[-1]))
775 cp--;
776 *cp++ = '\n';
777 return cp - buf;
778 }
779
780 int should_autocreate_reflog(const char *refname)
781 {
782 switch (log_all_ref_updates) {
783 case LOG_REFS_ALWAYS:
784 return 1;
785 case LOG_REFS_NORMAL:
786 return starts_with(refname, "refs/heads/") ||
787 starts_with(refname, "refs/remotes/") ||
788 starts_with(refname, "refs/notes/") ||
789 !strcmp(refname, "HEAD");
790 default:
791 return 0;
792 }
793 }
794
795 int is_branch(const char *refname)
796 {
797 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
798 }
799
800 struct read_ref_at_cb {
801 const char *refname;
802 timestamp_t at_time;
803 int cnt;
804 int reccnt;
805 struct object_id *oid;
806 int found_it;
807
808 struct object_id ooid;
809 struct object_id noid;
810 int tz;
811 timestamp_t date;
812 char **msg;
813 timestamp_t *cutoff_time;
814 int *cutoff_tz;
815 int *cutoff_cnt;
816 };
817
818 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
819 const char *email, timestamp_t timestamp, int tz,
820 const char *message, void *cb_data)
821 {
822 struct read_ref_at_cb *cb = cb_data;
823
824 cb->reccnt++;
825 cb->tz = tz;
826 cb->date = timestamp;
827
828 if (timestamp <= cb->at_time || cb->cnt == 0) {
829 if (cb->msg)
830 *cb->msg = xstrdup(message);
831 if (cb->cutoff_time)
832 *cb->cutoff_time = timestamp;
833 if (cb->cutoff_tz)
834 *cb->cutoff_tz = tz;
835 if (cb->cutoff_cnt)
836 *cb->cutoff_cnt = cb->reccnt - 1;
837 /*
838 * we have not yet updated cb->[n|o]oid so they still
839 * hold the values for the previous record.
840 */
841 if (!is_null_oid(&cb->ooid)) {
842 oidcpy(cb->oid, noid);
843 if (oidcmp(&cb->ooid, noid))
844 warning("Log for ref %s has gap after %s.",
845 cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
846 }
847 else if (cb->date == cb->at_time)
848 oidcpy(cb->oid, noid);
849 else if (oidcmp(noid, cb->oid))
850 warning("Log for ref %s unexpectedly ended on %s.",
851 cb->refname, show_date(cb->date, cb->tz,
852 DATE_MODE(RFC2822)));
853 oidcpy(&cb->ooid, ooid);
854 oidcpy(&cb->noid, noid);
855 cb->found_it = 1;
856 return 1;
857 }
858 oidcpy(&cb->ooid, ooid);
859 oidcpy(&cb->noid, noid);
860 if (cb->cnt > 0)
861 cb->cnt--;
862 return 0;
863 }
864
865 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
866 const char *email, timestamp_t timestamp,
867 int tz, const char *message, void *cb_data)
868 {
869 struct read_ref_at_cb *cb = cb_data;
870
871 if (cb->msg)
872 *cb->msg = xstrdup(message);
873 if (cb->cutoff_time)
874 *cb->cutoff_time = timestamp;
875 if (cb->cutoff_tz)
876 *cb->cutoff_tz = tz;
877 if (cb->cutoff_cnt)
878 *cb->cutoff_cnt = cb->reccnt;
879 oidcpy(cb->oid, ooid);
880 if (is_null_oid(cb->oid))
881 oidcpy(cb->oid, noid);
882 /* We just want the first entry */
883 return 1;
884 }
885
886 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
887 struct object_id *oid, char **msg,
888 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
889 {
890 struct read_ref_at_cb cb;
891
892 memset(&cb, 0, sizeof(cb));
893 cb.refname = refname;
894 cb.at_time = at_time;
895 cb.cnt = cnt;
896 cb.msg = msg;
897 cb.cutoff_time = cutoff_time;
898 cb.cutoff_tz = cutoff_tz;
899 cb.cutoff_cnt = cutoff_cnt;
900 cb.oid = oid;
901
902 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
903
904 if (!cb.reccnt) {
905 if (flags & GET_OID_QUIETLY)
906 exit(128);
907 else
908 die("Log for %s is empty.", refname);
909 }
910 if (cb.found_it)
911 return 0;
912
913 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
914
915 return 1;
916 }
917
918 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
919 struct strbuf *err)
920 {
921 struct ref_transaction *tr;
922 assert(err);
923
924 tr = xcalloc(1, sizeof(struct ref_transaction));
925 tr->ref_store = refs;
926 return tr;
927 }
928
929 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
930 {
931 return ref_store_transaction_begin(get_main_ref_store(), err);
932 }
933
934 void ref_transaction_free(struct ref_transaction *transaction)
935 {
936 size_t i;
937
938 if (!transaction)
939 return;
940
941 switch (transaction->state) {
942 case REF_TRANSACTION_OPEN:
943 case REF_TRANSACTION_CLOSED:
944 /* OK */
945 break;
946 case REF_TRANSACTION_PREPARED:
947 die("BUG: free called on a prepared reference transaction");
948 break;
949 default:
950 die("BUG: unexpected reference transaction state");
951 break;
952 }
953
954 for (i = 0; i < transaction->nr; i++) {
955 free(transaction->updates[i]->msg);
956 free(transaction->updates[i]);
957 }
958 free(transaction->updates);
959 free(transaction);
960 }
961
962 struct ref_update *ref_transaction_add_update(
963 struct ref_transaction *transaction,
964 const char *refname, unsigned int flags,
965 const struct object_id *new_oid,
966 const struct object_id *old_oid,
967 const char *msg)
968 {
969 struct ref_update *update;
970
971 if (transaction->state != REF_TRANSACTION_OPEN)
972 die("BUG: update called for transaction that is not open");
973
974 FLEX_ALLOC_STR(update, refname, refname);
975 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
976 transaction->updates[transaction->nr++] = update;
977
978 update->flags = flags;
979
980 if (flags & REF_HAVE_NEW)
981 oidcpy(&update->new_oid, new_oid);
982 if (flags & REF_HAVE_OLD)
983 oidcpy(&update->old_oid, old_oid);
984 update->msg = xstrdup_or_null(msg);
985 return update;
986 }
987
988 int ref_transaction_update(struct ref_transaction *transaction,
989 const char *refname,
990 const struct object_id *new_oid,
991 const struct object_id *old_oid,
992 unsigned int flags, const char *msg,
993 struct strbuf *err)
994 {
995 assert(err);
996
997 if ((new_oid && !is_null_oid(new_oid)) ?
998 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
999 !refname_is_safe(refname)) {
1000 strbuf_addf(err, "refusing to update ref with bad name '%s'",
1001 refname);
1002 return -1;
1003 }
1004
1005 if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1006 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1007
1008 flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1009
1010 ref_transaction_add_update(transaction, refname, flags,
1011 new_oid, old_oid, msg);
1012 return 0;
1013 }
1014
1015 int ref_transaction_create(struct ref_transaction *transaction,
1016 const char *refname,
1017 const struct object_id *new_oid,
1018 unsigned int flags, const char *msg,
1019 struct strbuf *err)
1020 {
1021 if (!new_oid || is_null_oid(new_oid))
1022 die("BUG: create called without valid new_oid");
1023 return ref_transaction_update(transaction, refname, new_oid,
1024 &null_oid, flags, msg, err);
1025 }
1026
1027 int ref_transaction_delete(struct ref_transaction *transaction,
1028 const char *refname,
1029 const struct object_id *old_oid,
1030 unsigned int flags, const char *msg,
1031 struct strbuf *err)
1032 {
1033 if (old_oid && is_null_oid(old_oid))
1034 die("BUG: delete called with old_oid set to zeros");
1035 return ref_transaction_update(transaction, refname,
1036 &null_oid, old_oid,
1037 flags, msg, err);
1038 }
1039
1040 int ref_transaction_verify(struct ref_transaction *transaction,
1041 const char *refname,
1042 const struct object_id *old_oid,
1043 unsigned int flags,
1044 struct strbuf *err)
1045 {
1046 if (!old_oid)
1047 die("BUG: verify called with old_oid set to NULL");
1048 return ref_transaction_update(transaction, refname,
1049 NULL, old_oid,
1050 flags, NULL, err);
1051 }
1052
1053 int refs_update_ref(struct ref_store *refs, const char *msg,
1054 const char *refname, const struct object_id *new_oid,
1055 const struct object_id *old_oid, unsigned int flags,
1056 enum action_on_err onerr)
1057 {
1058 struct ref_transaction *t = NULL;
1059 struct strbuf err = STRBUF_INIT;
1060 int ret = 0;
1061
1062 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1063 assert(refs == get_main_ref_store());
1064 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1065 } else {
1066 t = ref_store_transaction_begin(refs, &err);
1067 if (!t ||
1068 ref_transaction_update(t, refname, new_oid, old_oid,
1069 flags, msg, &err) ||
1070 ref_transaction_commit(t, &err)) {
1071 ret = 1;
1072 ref_transaction_free(t);
1073 }
1074 }
1075 if (ret) {
1076 const char *str = "update_ref failed for ref '%s': %s";
1077
1078 switch (onerr) {
1079 case UPDATE_REFS_MSG_ON_ERR:
1080 error(str, refname, err.buf);
1081 break;
1082 case UPDATE_REFS_DIE_ON_ERR:
1083 die(str, refname, err.buf);
1084 break;
1085 case UPDATE_REFS_QUIET_ON_ERR:
1086 break;
1087 }
1088 strbuf_release(&err);
1089 return 1;
1090 }
1091 strbuf_release(&err);
1092 if (t)
1093 ref_transaction_free(t);
1094 return 0;
1095 }
1096
1097 int update_ref(const char *msg, const char *refname,
1098 const struct object_id *new_oid,
1099 const struct object_id *old_oid,
1100 unsigned int flags, enum action_on_err onerr)
1101 {
1102 return refs_update_ref(get_main_ref_store(), msg, refname, new_oid,
1103 old_oid, flags, onerr);
1104 }
1105
1106 char *shorten_unambiguous_ref(const char *refname, int strict)
1107 {
1108 int i;
1109 static char **scanf_fmts;
1110 static int nr_rules;
1111 char *short_name;
1112 struct strbuf resolved_buf = STRBUF_INIT;
1113
1114 if (!nr_rules) {
1115 /*
1116 * Pre-generate scanf formats from ref_rev_parse_rules[].
1117 * Generate a format suitable for scanf from a
1118 * ref_rev_parse_rules rule by interpolating "%s" at the
1119 * location of the "%.*s".
1120 */
1121 size_t total_len = 0;
1122 size_t offset = 0;
1123
1124 /* the rule list is NULL terminated, count them first */
1125 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1126 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1127 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1128
1129 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1130
1131 offset = 0;
1132 for (i = 0; i < nr_rules; i++) {
1133 assert(offset < total_len);
1134 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1135 offset += snprintf(scanf_fmts[i], total_len - offset,
1136 ref_rev_parse_rules[i], 2, "%s") + 1;
1137 }
1138 }
1139
1140 /* bail out if there are no rules */
1141 if (!nr_rules)
1142 return xstrdup(refname);
1143
1144 /* buffer for scanf result, at most refname must fit */
1145 short_name = xstrdup(refname);
1146
1147 /* skip first rule, it will always match */
1148 for (i = nr_rules - 1; i > 0 ; --i) {
1149 int j;
1150 int rules_to_fail = i;
1151 int short_name_len;
1152
1153 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1154 continue;
1155
1156 short_name_len = strlen(short_name);
1157
1158 /*
1159 * in strict mode, all (except the matched one) rules
1160 * must fail to resolve to a valid non-ambiguous ref
1161 */
1162 if (strict)
1163 rules_to_fail = nr_rules;
1164
1165 /*
1166 * check if the short name resolves to a valid ref,
1167 * but use only rules prior to the matched one
1168 */
1169 for (j = 0; j < rules_to_fail; j++) {
1170 const char *rule = ref_rev_parse_rules[j];
1171
1172 /* skip matched rule */
1173 if (i == j)
1174 continue;
1175
1176 /*
1177 * the short name is ambiguous, if it resolves
1178 * (with this previous rule) to a valid ref
1179 * read_ref() returns 0 on success
1180 */
1181 strbuf_reset(&resolved_buf);
1182 strbuf_addf(&resolved_buf, rule,
1183 short_name_len, short_name);
1184 if (ref_exists(resolved_buf.buf))
1185 break;
1186 }
1187
1188 /*
1189 * short name is non-ambiguous if all previous rules
1190 * haven't resolved to a valid ref
1191 */
1192 if (j == rules_to_fail) {
1193 strbuf_release(&resolved_buf);
1194 return short_name;
1195 }
1196 }
1197
1198 strbuf_release(&resolved_buf);
1199 free(short_name);
1200 return xstrdup(refname);
1201 }
1202
1203 static struct string_list *hide_refs;
1204
1205 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1206 {
1207 const char *key;
1208 if (!strcmp("transfer.hiderefs", var) ||
1209 (!parse_config_key(var, section, NULL, NULL, &key) &&
1210 !strcmp(key, "hiderefs"))) {
1211 char *ref;
1212 int len;
1213
1214 if (!value)
1215 return config_error_nonbool(var);
1216 ref = xstrdup(value);
1217 len = strlen(ref);
1218 while (len && ref[len - 1] == '/')
1219 ref[--len] = '\0';
1220 if (!hide_refs) {
1221 hide_refs = xcalloc(1, sizeof(*hide_refs));
1222 hide_refs->strdup_strings = 1;
1223 }
1224 string_list_append(hide_refs, ref);
1225 }
1226 return 0;
1227 }
1228
1229 int ref_is_hidden(const char *refname, const char *refname_full)
1230 {
1231 int i;
1232
1233 if (!hide_refs)
1234 return 0;
1235 for (i = hide_refs->nr - 1; i >= 0; i--) {
1236 const char *match = hide_refs->items[i].string;
1237 const char *subject;
1238 int neg = 0;
1239 const char *p;
1240
1241 if (*match == '!') {
1242 neg = 1;
1243 match++;
1244 }
1245
1246 if (*match == '^') {
1247 subject = refname_full;
1248 match++;
1249 } else {
1250 subject = refname;
1251 }
1252
1253 /* refname can be NULL when namespaces are used. */
1254 if (subject &&
1255 skip_prefix(subject, match, &p) &&
1256 (!*p || *p == '/'))
1257 return !neg;
1258 }
1259 return 0;
1260 }
1261
1262 const char *find_descendant_ref(const char *dirname,
1263 const struct string_list *extras,
1264 const struct string_list *skip)
1265 {
1266 int pos;
1267
1268 if (!extras)
1269 return NULL;
1270
1271 /*
1272 * Look at the place where dirname would be inserted into
1273 * extras. If there is an entry at that position that starts
1274 * with dirname (remember, dirname includes the trailing
1275 * slash) and is not in skip, then we have a conflict.
1276 */
1277 for (pos = string_list_find_insert_index(extras, dirname, 0);
1278 pos < extras->nr; pos++) {
1279 const char *extra_refname = extras->items[pos].string;
1280
1281 if (!starts_with(extra_refname, dirname))
1282 break;
1283
1284 if (!skip || !string_list_has_string(skip, extra_refname))
1285 return extra_refname;
1286 }
1287 return NULL;
1288 }
1289
1290 int refs_rename_ref_available(struct ref_store *refs,
1291 const char *old_refname,
1292 const char *new_refname)
1293 {
1294 struct string_list skip = STRING_LIST_INIT_NODUP;
1295 struct strbuf err = STRBUF_INIT;
1296 int ok;
1297
1298 string_list_insert(&skip, old_refname);
1299 ok = !refs_verify_refname_available(refs, new_refname,
1300 NULL, &skip, &err);
1301 if (!ok)
1302 error("%s", err.buf);
1303
1304 string_list_clear(&skip, 0);
1305 strbuf_release(&err);
1306 return ok;
1307 }
1308
1309 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1310 {
1311 struct object_id oid;
1312 int flag;
1313
1314 if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1315 &oid, &flag))
1316 return fn("HEAD", &oid, flag, cb_data);
1317
1318 return 0;
1319 }
1320
1321 int head_ref(each_ref_fn fn, void *cb_data)
1322 {
1323 return refs_head_ref(get_main_ref_store(), fn, cb_data);
1324 }
1325
1326 struct ref_iterator *refs_ref_iterator_begin(
1327 struct ref_store *refs,
1328 const char *prefix, int trim, int flags)
1329 {
1330 struct ref_iterator *iter;
1331
1332 if (ref_paranoia < 0)
1333 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1334 if (ref_paranoia)
1335 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1336
1337 iter = refs->be->iterator_begin(refs, prefix, flags);
1338
1339 /*
1340 * `iterator_begin()` already takes care of prefix, but we
1341 * might need to do some trimming:
1342 */
1343 if (trim)
1344 iter = prefix_ref_iterator_begin(iter, "", trim);
1345
1346 /* Sanity check for subclasses: */
1347 if (!iter->ordered)
1348 BUG("reference iterator is not ordered");
1349
1350 return iter;
1351 }
1352
1353 /*
1354 * Call fn for each reference in the specified submodule for which the
1355 * refname begins with prefix. If trim is non-zero, then trim that
1356 * many characters off the beginning of each refname before passing
1357 * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1358 * include broken references in the iteration. If fn ever returns a
1359 * non-zero value, stop the iteration and return that value;
1360 * otherwise, return 0.
1361 */
1362 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1363 each_ref_fn fn, int trim, int flags, void *cb_data)
1364 {
1365 struct ref_iterator *iter;
1366
1367 if (!refs)
1368 return 0;
1369
1370 iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1371
1372 return do_for_each_ref_iterator(iter, fn, cb_data);
1373 }
1374
1375 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1376 {
1377 return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1378 }
1379
1380 int for_each_ref(each_ref_fn fn, void *cb_data)
1381 {
1382 return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
1383 }
1384
1385 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1386 each_ref_fn fn, void *cb_data)
1387 {
1388 return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1389 }
1390
1391 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1392 {
1393 return refs_for_each_ref_in(get_main_ref_store(), prefix, fn, cb_data);
1394 }
1395
1396 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1397 {
1398 unsigned int flag = 0;
1399
1400 if (broken)
1401 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1402 return do_for_each_ref(get_main_ref_store(),
1403 prefix, fn, 0, flag, cb_data);
1404 }
1405
1406 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1407 each_ref_fn fn, void *cb_data,
1408 unsigned int broken)
1409 {
1410 unsigned int flag = 0;
1411
1412 if (broken)
1413 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1414 return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1415 }
1416
1417 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1418 {
1419 return do_for_each_ref(get_main_ref_store(),
1420 git_replace_ref_base, fn,
1421 strlen(git_replace_ref_base),
1422 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1423 }
1424
1425 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1426 {
1427 struct strbuf buf = STRBUF_INIT;
1428 int ret;
1429 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1430 ret = do_for_each_ref(get_main_ref_store(),
1431 buf.buf, fn, 0, 0, cb_data);
1432 strbuf_release(&buf);
1433 return ret;
1434 }
1435
1436 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1437 {
1438 return do_for_each_ref(refs, "", fn, 0,
1439 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1440 }
1441
1442 int for_each_rawref(each_ref_fn fn, void *cb_data)
1443 {
1444 return refs_for_each_rawref(get_main_ref_store(), fn, cb_data);
1445 }
1446
1447 int refs_read_raw_ref(struct ref_store *ref_store,
1448 const char *refname, struct object_id *oid,
1449 struct strbuf *referent, unsigned int *type)
1450 {
1451 return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1452 }
1453
1454 /* This function needs to return a meaningful errno on failure */
1455 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1456 const char *refname,
1457 int resolve_flags,
1458 struct object_id *oid, int *flags)
1459 {
1460 static struct strbuf sb_refname = STRBUF_INIT;
1461 struct object_id unused_oid;
1462 int unused_flags;
1463 int symref_count;
1464
1465 if (!oid)
1466 oid = &unused_oid;
1467 if (!flags)
1468 flags = &unused_flags;
1469
1470 *flags = 0;
1471
1472 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1473 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1474 !refname_is_safe(refname)) {
1475 errno = EINVAL;
1476 return NULL;
1477 }
1478
1479 /*
1480 * dwim_ref() uses REF_ISBROKEN to distinguish between
1481 * missing refs and refs that were present but invalid,
1482 * to complain about the latter to stderr.
1483 *
1484 * We don't know whether the ref exists, so don't set
1485 * REF_ISBROKEN yet.
1486 */
1487 *flags |= REF_BAD_NAME;
1488 }
1489
1490 for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1491 unsigned int read_flags = 0;
1492
1493 if (refs_read_raw_ref(refs, refname,
1494 oid, &sb_refname, &read_flags)) {
1495 *flags |= read_flags;
1496
1497 /* In reading mode, refs must eventually resolve */
1498 if (resolve_flags & RESOLVE_REF_READING)
1499 return NULL;
1500
1501 /*
1502 * Otherwise a missing ref is OK. But the files backend
1503 * may show errors besides ENOENT if there are
1504 * similarly-named refs.
1505 */
1506 if (errno != ENOENT &&
1507 errno != EISDIR &&
1508 errno != ENOTDIR)
1509 return NULL;
1510
1511 oidclr(oid);
1512 if (*flags & REF_BAD_NAME)
1513 *flags |= REF_ISBROKEN;
1514 return refname;
1515 }
1516
1517 *flags |= read_flags;
1518
1519 if (!(read_flags & REF_ISSYMREF)) {
1520 if (*flags & REF_BAD_NAME) {
1521 oidclr(oid);
1522 *flags |= REF_ISBROKEN;
1523 }
1524 return refname;
1525 }
1526
1527 refname = sb_refname.buf;
1528 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1529 oidclr(oid);
1530 return refname;
1531 }
1532 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1533 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1534 !refname_is_safe(refname)) {
1535 errno = EINVAL;
1536 return NULL;
1537 }
1538
1539 *flags |= REF_ISBROKEN | REF_BAD_NAME;
1540 }
1541 }
1542
1543 errno = ELOOP;
1544 return NULL;
1545 }
1546
1547 /* backend functions */
1548 int refs_init_db(struct strbuf *err)
1549 {
1550 struct ref_store *refs = get_main_ref_store();
1551
1552 return refs->be->init_db(refs, err);
1553 }
1554
1555 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1556 struct object_id *oid, int *flags)
1557 {
1558 return refs_resolve_ref_unsafe(get_main_ref_store(), refname,
1559 resolve_flags, oid, flags);
1560 }
1561
1562 int resolve_gitlink_ref(const char *submodule, const char *refname,
1563 struct object_id *oid)
1564 {
1565 struct ref_store *refs;
1566 int flags;
1567
1568 refs = get_submodule_ref_store(submodule);
1569
1570 if (!refs)
1571 return -1;
1572
1573 if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1574 is_null_oid(oid))
1575 return -1;
1576 return 0;
1577 }
1578
1579 struct ref_store_hash_entry
1580 {
1581 struct hashmap_entry ent; /* must be the first member! */
1582
1583 struct ref_store *refs;
1584
1585 /* NUL-terminated identifier of the ref store: */
1586 char name[FLEX_ARRAY];
1587 };
1588
1589 static int ref_store_hash_cmp(const void *unused_cmp_data,
1590 const void *entry, const void *entry_or_key,
1591 const void *keydata)
1592 {
1593 const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1594 const char *name = keydata ? keydata : e2->name;
1595
1596 return strcmp(e1->name, name);
1597 }
1598
1599 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1600 const char *name, struct ref_store *refs)
1601 {
1602 struct ref_store_hash_entry *entry;
1603
1604 FLEX_ALLOC_STR(entry, name, name);
1605 hashmap_entry_init(entry, strhash(name));
1606 entry->refs = refs;
1607 return entry;
1608 }
1609
1610 /* A pointer to the ref_store for the main repository: */
1611 static struct ref_store *main_ref_store;
1612
1613 /* A hashmap of ref_stores, stored by submodule name: */
1614 static struct hashmap submodule_ref_stores;
1615
1616 /* A hashmap of ref_stores, stored by worktree id: */
1617 static struct hashmap worktree_ref_stores;
1618
1619 /*
1620 * Look up a ref store by name. If that ref_store hasn't been
1621 * registered yet, return NULL.
1622 */
1623 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1624 const char *name)
1625 {
1626 struct ref_store_hash_entry *entry;
1627
1628 if (!map->tablesize)
1629 /* It's initialized on demand in register_ref_store(). */
1630 return NULL;
1631
1632 entry = hashmap_get_from_hash(map, strhash(name), name);
1633 return entry ? entry->refs : NULL;
1634 }
1635
1636 /*
1637 * Create, record, and return a ref_store instance for the specified
1638 * gitdir.
1639 */
1640 static struct ref_store *ref_store_init(const char *gitdir,
1641 unsigned int flags)
1642 {
1643 const char *be_name = "files";
1644 struct ref_storage_be *be = find_ref_storage_backend(be_name);
1645 struct ref_store *refs;
1646
1647 if (!be)
1648 die("BUG: reference backend %s is unknown", be_name);
1649
1650 refs = be->init(gitdir, flags);
1651 return refs;
1652 }
1653
1654 struct ref_store *get_main_ref_store(void)
1655 {
1656 if (main_ref_store)
1657 return main_ref_store;
1658
1659 main_ref_store = ref_store_init(get_git_dir(), REF_STORE_ALL_CAPS);
1660 return main_ref_store;
1661 }
1662
1663 /*
1664 * Associate a ref store with a name. It is a fatal error to call this
1665 * function twice for the same name.
1666 */
1667 static void register_ref_store_map(struct hashmap *map,
1668 const char *type,
1669 struct ref_store *refs,
1670 const char *name)
1671 {
1672 if (!map->tablesize)
1673 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1674
1675 if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1676 die("BUG: %s ref_store '%s' initialized twice", type, name);
1677 }
1678
1679 struct ref_store *get_submodule_ref_store(const char *submodule)
1680 {
1681 struct strbuf submodule_sb = STRBUF_INIT;
1682 struct ref_store *refs;
1683 char *to_free = NULL;
1684 size_t len;
1685
1686 if (!submodule)
1687 return NULL;
1688
1689 len = strlen(submodule);
1690 while (len && is_dir_sep(submodule[len - 1]))
1691 len--;
1692 if (!len)
1693 return NULL;
1694
1695 if (submodule[len])
1696 /* We need to strip off one or more trailing slashes */
1697 submodule = to_free = xmemdupz(submodule, len);
1698
1699 refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1700 if (refs)
1701 goto done;
1702
1703 strbuf_addstr(&submodule_sb, submodule);
1704 if (!is_nonbare_repository_dir(&submodule_sb))
1705 goto done;
1706
1707 if (submodule_to_gitdir(&submodule_sb, submodule))
1708 goto done;
1709
1710 /* assume that add_submodule_odb() has been called */
1711 refs = ref_store_init(submodule_sb.buf,
1712 REF_STORE_READ | REF_STORE_ODB);
1713 register_ref_store_map(&submodule_ref_stores, "submodule",
1714 refs, submodule);
1715
1716 done:
1717 strbuf_release(&submodule_sb);
1718 free(to_free);
1719
1720 return refs;
1721 }
1722
1723 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1724 {
1725 struct ref_store *refs;
1726 const char *id;
1727
1728 if (wt->is_current)
1729 return get_main_ref_store();
1730
1731 id = wt->id ? wt->id : "/";
1732 refs = lookup_ref_store_map(&worktree_ref_stores, id);
1733 if (refs)
1734 return refs;
1735
1736 if (wt->id)
1737 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1738 REF_STORE_ALL_CAPS);
1739 else
1740 refs = ref_store_init(get_git_common_dir(),
1741 REF_STORE_ALL_CAPS);
1742
1743 if (refs)
1744 register_ref_store_map(&worktree_ref_stores, "worktree",
1745 refs, id);
1746 return refs;
1747 }
1748
1749 void base_ref_store_init(struct ref_store *refs,
1750 const struct ref_storage_be *be)
1751 {
1752 refs->be = be;
1753 }
1754
1755 /* backend functions */
1756 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1757 {
1758 return refs->be->pack_refs(refs, flags);
1759 }
1760
1761 int refs_peel_ref(struct ref_store *refs, const char *refname,
1762 struct object_id *oid)
1763 {
1764 int flag;
1765 struct object_id base;
1766
1767 if (current_ref_iter && current_ref_iter->refname == refname) {
1768 struct object_id peeled;
1769
1770 if (ref_iterator_peel(current_ref_iter, &peeled))
1771 return -1;
1772 oidcpy(oid, &peeled);
1773 return 0;
1774 }
1775
1776 if (refs_read_ref_full(refs, refname,
1777 RESOLVE_REF_READING, &base, &flag))
1778 return -1;
1779
1780 return peel_object(&base, oid);
1781 }
1782
1783 int peel_ref(const char *refname, struct object_id *oid)
1784 {
1785 return refs_peel_ref(get_main_ref_store(), refname, oid);
1786 }
1787
1788 int refs_create_symref(struct ref_store *refs,
1789 const char *ref_target,
1790 const char *refs_heads_master,
1791 const char *logmsg)
1792 {
1793 return refs->be->create_symref(refs, ref_target,
1794 refs_heads_master,
1795 logmsg);
1796 }
1797
1798 int create_symref(const char *ref_target, const char *refs_heads_master,
1799 const char *logmsg)
1800 {
1801 return refs_create_symref(get_main_ref_store(), ref_target,
1802 refs_heads_master, logmsg);
1803 }
1804
1805 int ref_update_reject_duplicates(struct string_list *refnames,
1806 struct strbuf *err)
1807 {
1808 size_t i, n = refnames->nr;
1809
1810 assert(err);
1811
1812 for (i = 1; i < n; i++) {
1813 int cmp = strcmp(refnames->items[i - 1].string,
1814 refnames->items[i].string);
1815
1816 if (!cmp) {
1817 strbuf_addf(err,
1818 "multiple updates for ref '%s' not allowed.",
1819 refnames->items[i].string);
1820 return 1;
1821 } else if (cmp > 0) {
1822 die("BUG: ref_update_reject_duplicates() received unsorted list");
1823 }
1824 }
1825 return 0;
1826 }
1827
1828 int ref_transaction_prepare(struct ref_transaction *transaction,
1829 struct strbuf *err)
1830 {
1831 struct ref_store *refs = transaction->ref_store;
1832
1833 switch (transaction->state) {
1834 case REF_TRANSACTION_OPEN:
1835 /* Good. */
1836 break;
1837 case REF_TRANSACTION_PREPARED:
1838 die("BUG: prepare called twice on reference transaction");
1839 break;
1840 case REF_TRANSACTION_CLOSED:
1841 die("BUG: prepare called on a closed reference transaction");
1842 break;
1843 default:
1844 die("BUG: unexpected reference transaction state");
1845 break;
1846 }
1847
1848 if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1849 strbuf_addstr(err,
1850 _("ref updates forbidden inside quarantine environment"));
1851 return -1;
1852 }
1853
1854 return refs->be->transaction_prepare(refs, transaction, err);
1855 }
1856
1857 int ref_transaction_abort(struct ref_transaction *transaction,
1858 struct strbuf *err)
1859 {
1860 struct ref_store *refs = transaction->ref_store;
1861 int ret = 0;
1862
1863 switch (transaction->state) {
1864 case REF_TRANSACTION_OPEN:
1865 /* No need to abort explicitly. */
1866 break;
1867 case REF_TRANSACTION_PREPARED:
1868 ret = refs->be->transaction_abort(refs, transaction, err);
1869 break;
1870 case REF_TRANSACTION_CLOSED:
1871 die("BUG: abort called on a closed reference transaction");
1872 break;
1873 default:
1874 die("BUG: unexpected reference transaction state");
1875 break;
1876 }
1877
1878 ref_transaction_free(transaction);
1879 return ret;
1880 }
1881
1882 int ref_transaction_commit(struct ref_transaction *transaction,
1883 struct strbuf *err)
1884 {
1885 struct ref_store *refs = transaction->ref_store;
1886 int ret;
1887
1888 switch (transaction->state) {
1889 case REF_TRANSACTION_OPEN:
1890 /* Need to prepare first. */
1891 ret = ref_transaction_prepare(transaction, err);
1892 if (ret)
1893 return ret;
1894 break;
1895 case REF_TRANSACTION_PREPARED:
1896 /* Fall through to finish. */
1897 break;
1898 case REF_TRANSACTION_CLOSED:
1899 die("BUG: commit called on a closed reference transaction");
1900 break;
1901 default:
1902 die("BUG: unexpected reference transaction state");
1903 break;
1904 }
1905
1906 return refs->be->transaction_finish(refs, transaction, err);
1907 }
1908
1909 int refs_verify_refname_available(struct ref_store *refs,
1910 const char *refname,
1911 const struct string_list *extras,
1912 const struct string_list *skip,
1913 struct strbuf *err)
1914 {
1915 const char *slash;
1916 const char *extra_refname;
1917 struct strbuf dirname = STRBUF_INIT;
1918 struct strbuf referent = STRBUF_INIT;
1919 struct object_id oid;
1920 unsigned int type;
1921 struct ref_iterator *iter;
1922 int ok;
1923 int ret = -1;
1924
1925 /*
1926 * For the sake of comments in this function, suppose that
1927 * refname is "refs/foo/bar".
1928 */
1929
1930 assert(err);
1931
1932 strbuf_grow(&dirname, strlen(refname) + 1);
1933 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1934 /* Expand dirname to the new prefix, not including the trailing slash: */
1935 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1936
1937 /*
1938 * We are still at a leading dir of the refname (e.g.,
1939 * "refs/foo"; if there is a reference with that name,
1940 * it is a conflict, *unless* it is in skip.
1941 */
1942 if (skip && string_list_has_string(skip, dirname.buf))
1943 continue;
1944
1945 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1946 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1947 dirname.buf, refname);
1948 goto cleanup;
1949 }
1950
1951 if (extras && string_list_has_string(extras, dirname.buf)) {
1952 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1953 refname, dirname.buf);
1954 goto cleanup;
1955 }
1956 }
1957
1958 /*
1959 * We are at the leaf of our refname (e.g., "refs/foo/bar").
1960 * There is no point in searching for a reference with that
1961 * name, because a refname isn't considered to conflict with
1962 * itself. But we still need to check for references whose
1963 * names are in the "refs/foo/bar/" namespace, because they
1964 * *do* conflict.
1965 */
1966 strbuf_addstr(&dirname, refname + dirname.len);
1967 strbuf_addch(&dirname, '/');
1968
1969 iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1970 DO_FOR_EACH_INCLUDE_BROKEN);
1971 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1972 if (skip &&
1973 string_list_has_string(skip, iter->refname))
1974 continue;
1975
1976 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1977 iter->refname, refname);
1978 ref_iterator_abort(iter);
1979 goto cleanup;
1980 }
1981
1982 if (ok != ITER_DONE)
1983 die("BUG: error while iterating over references");
1984
1985 extra_refname = find_descendant_ref(dirname.buf, extras, skip);
1986 if (extra_refname)
1987 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1988 refname, extra_refname);
1989 else
1990 ret = 0;
1991
1992 cleanup:
1993 strbuf_release(&referent);
1994 strbuf_release(&dirname);
1995 return ret;
1996 }
1997
1998 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1999 {
2000 struct ref_iterator *iter;
2001
2002 iter = refs->be->reflog_iterator_begin(refs);
2003
2004 return do_for_each_ref_iterator(iter, fn, cb_data);
2005 }
2006
2007 int for_each_reflog(each_ref_fn fn, void *cb_data)
2008 {
2009 return refs_for_each_reflog(get_main_ref_store(), fn, cb_data);
2010 }
2011
2012 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2013 const char *refname,
2014 each_reflog_ent_fn fn,
2015 void *cb_data)
2016 {
2017 return refs->be->for_each_reflog_ent_reverse(refs, refname,
2018 fn, cb_data);
2019 }
2020
2021 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2022 void *cb_data)
2023 {
2024 return refs_for_each_reflog_ent_reverse(get_main_ref_store(),
2025 refname, fn, cb_data);
2026 }
2027
2028 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2029 each_reflog_ent_fn fn, void *cb_data)
2030 {
2031 return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2032 }
2033
2034 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2035 void *cb_data)
2036 {
2037 return refs_for_each_reflog_ent(get_main_ref_store(), refname,
2038 fn, cb_data);
2039 }
2040
2041 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2042 {
2043 return refs->be->reflog_exists(refs, refname);
2044 }
2045
2046 int reflog_exists(const char *refname)
2047 {
2048 return refs_reflog_exists(get_main_ref_store(), refname);
2049 }
2050
2051 int refs_create_reflog(struct ref_store *refs, const char *refname,
2052 int force_create, struct strbuf *err)
2053 {
2054 return refs->be->create_reflog(refs, refname, force_create, err);
2055 }
2056
2057 int safe_create_reflog(const char *refname, int force_create,
2058 struct strbuf *err)
2059 {
2060 return refs_create_reflog(get_main_ref_store(), refname,
2061 force_create, err);
2062 }
2063
2064 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2065 {
2066 return refs->be->delete_reflog(refs, refname);
2067 }
2068
2069 int delete_reflog(const char *refname)
2070 {
2071 return refs_delete_reflog(get_main_ref_store(), refname);
2072 }
2073
2074 int refs_reflog_expire(struct ref_store *refs,
2075 const char *refname, const struct object_id *oid,
2076 unsigned int flags,
2077 reflog_expiry_prepare_fn prepare_fn,
2078 reflog_expiry_should_prune_fn should_prune_fn,
2079 reflog_expiry_cleanup_fn cleanup_fn,
2080 void *policy_cb_data)
2081 {
2082 return refs->be->reflog_expire(refs, refname, oid, flags,
2083 prepare_fn, should_prune_fn,
2084 cleanup_fn, policy_cb_data);
2085 }
2086
2087 int reflog_expire(const char *refname, const struct object_id *oid,
2088 unsigned int flags,
2089 reflog_expiry_prepare_fn prepare_fn,
2090 reflog_expiry_should_prune_fn should_prune_fn,
2091 reflog_expiry_cleanup_fn cleanup_fn,
2092 void *policy_cb_data)
2093 {
2094 return refs_reflog_expire(get_main_ref_store(),
2095 refname, oid, flags,
2096 prepare_fn, should_prune_fn,
2097 cleanup_fn, policy_cb_data);
2098 }
2099
2100 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2101 struct strbuf *err)
2102 {
2103 struct ref_store *refs = transaction->ref_store;
2104
2105 return refs->be->initial_transaction_commit(refs, transaction, err);
2106 }
2107
2108 int refs_delete_refs(struct ref_store *refs, const char *msg,
2109 struct string_list *refnames, unsigned int flags)
2110 {
2111 return refs->be->delete_refs(refs, msg, refnames, flags);
2112 }
2113
2114 int delete_refs(const char *msg, struct string_list *refnames,
2115 unsigned int flags)
2116 {
2117 return refs_delete_refs(get_main_ref_store(), msg, refnames, flags);
2118 }
2119
2120 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2121 const char *newref, const char *logmsg)
2122 {
2123 return refs->be->rename_ref(refs, oldref, newref, logmsg);
2124 }
2125
2126 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2127 {
2128 return refs_rename_ref(get_main_ref_store(), oldref, newref, logmsg);
2129 }
2130
2131 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2132 const char *newref, const char *logmsg)
2133 {
2134 return refs->be->copy_ref(refs, oldref, newref, logmsg);
2135 }
2136
2137 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2138 {
2139 return refs_copy_existing_ref(get_main_ref_store(), oldref, newref, logmsg);
2140 }