Merge branch 'sb/object-store-replace'
[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 #include "argv-array.h"
17 #include "repository.h"
18
19 /*
20 * List of all available backends
21 */
22 static struct ref_storage_be *refs_backends = &refs_be_files;
23
24 static struct ref_storage_be *find_ref_storage_backend(const char *name)
25 {
26 struct ref_storage_be *be;
27 for (be = refs_backends; be; be = be->next)
28 if (!strcmp(be->name, name))
29 return be;
30 return NULL;
31 }
32
33 int ref_storage_backend_exists(const char *name)
34 {
35 return find_ref_storage_backend(name) != NULL;
36 }
37
38 /*
39 * How to handle various characters in refnames:
40 * 0: An acceptable character for refs
41 * 1: End-of-component
42 * 2: ., look for a preceding . to reject .. in refs
43 * 3: {, look for a preceding @ to reject @{ in refs
44 * 4: A bad character: ASCII control characters, and
45 * ":", "?", "[", "\", "^", "~", SP, or TAB
46 * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
47 */
48 static unsigned char refname_disposition[256] = {
49 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
50 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
51 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
52 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
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, 4, 4, 0, 4, 0,
55 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
56 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
57 };
58
59 /*
60 * Try to read one refname component from the front of refname.
61 * Return the length of the component found, or -1 if the component is
62 * not legal. It is legal if it is something reasonable to have under
63 * ".git/refs/"; We do not like it if:
64 *
65 * - any path component of it begins with ".", or
66 * - it has double dots "..", or
67 * - it has ASCII control characters, or
68 * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
69 * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
70 * - it ends with a "/", or
71 * - it ends with ".lock", or
72 * - it contains a "@{" portion
73 */
74 static int check_refname_component(const char *refname, int *flags)
75 {
76 const char *cp;
77 char last = '\0';
78
79 for (cp = refname; ; cp++) {
80 int ch = *cp & 255;
81 unsigned char disp = refname_disposition[ch];
82 switch (disp) {
83 case 1:
84 goto out;
85 case 2:
86 if (last == '.')
87 return -1; /* Refname contains "..". */
88 break;
89 case 3:
90 if (last == '@')
91 return -1; /* Refname contains "@{". */
92 break;
93 case 4:
94 return -1;
95 case 5:
96 if (!(*flags & REFNAME_REFSPEC_PATTERN))
97 return -1; /* refspec can't be a pattern */
98
99 /*
100 * Unset the pattern flag so that we only accept
101 * a single asterisk for one side of refspec.
102 */
103 *flags &= ~ REFNAME_REFSPEC_PATTERN;
104 break;
105 }
106 last = ch;
107 }
108 out:
109 if (cp == refname)
110 return 0; /* Component has zero length. */
111 if (refname[0] == '.')
112 return -1; /* Component starts with '.'. */
113 if (cp - refname >= LOCK_SUFFIX_LEN &&
114 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
115 return -1; /* Refname ends with ".lock". */
116 return cp - refname;
117 }
118
119 int check_refname_format(const char *refname, int flags)
120 {
121 int component_len, component_count = 0;
122
123 if (!strcmp(refname, "@"))
124 /* Refname is a single character '@'. */
125 return -1;
126
127 while (1) {
128 /* We are at the start of a path component. */
129 component_len = check_refname_component(refname, &flags);
130 if (component_len <= 0)
131 return -1;
132
133 component_count++;
134 if (refname[component_len] == '\0')
135 break;
136 /* Skip to next component. */
137 refname += component_len + 1;
138 }
139
140 if (refname[component_len - 1] == '.')
141 return -1; /* Refname ends with '.'. */
142 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
143 return -1; /* Refname has only one component. */
144 return 0;
145 }
146
147 int refname_is_safe(const char *refname)
148 {
149 const char *rest;
150
151 if (skip_prefix(refname, "refs/", &rest)) {
152 char *buf;
153 int result;
154 size_t restlen = strlen(rest);
155
156 /* rest must not be empty, or start or end with "/" */
157 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
158 return 0;
159
160 /*
161 * Does the refname try to escape refs/?
162 * For example: refs/foo/../bar is safe but refs/foo/../../bar
163 * is not.
164 */
165 buf = xmallocz(restlen);
166 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
167 free(buf);
168 return result;
169 }
170
171 do {
172 if (!isupper(*refname) && *refname != '_')
173 return 0;
174 refname++;
175 } while (*refname);
176 return 1;
177 }
178
179 /*
180 * Return true if refname, which has the specified oid and flags, can
181 * be resolved to an object in the database. If the referred-to object
182 * does not exist, emit a warning and return false.
183 */
184 int ref_resolves_to_object(const char *refname,
185 const struct object_id *oid,
186 unsigned int flags)
187 {
188 if (flags & REF_ISBROKEN)
189 return 0;
190 if (!has_sha1_file(oid->hash)) {
191 error("%s does not point to a valid object!", refname);
192 return 0;
193 }
194 return 1;
195 }
196
197 char *refs_resolve_refdup(struct ref_store *refs,
198 const char *refname, int resolve_flags,
199 struct object_id *oid, int *flags)
200 {
201 const char *result;
202
203 result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
204 oid, flags);
205 return xstrdup_or_null(result);
206 }
207
208 char *resolve_refdup(const char *refname, int resolve_flags,
209 struct object_id *oid, int *flags)
210 {
211 return refs_resolve_refdup(get_main_ref_store(the_repository),
212 refname, resolve_flags,
213 oid, flags);
214 }
215
216 /* The argument to filter_refs */
217 struct ref_filter {
218 const char *pattern;
219 each_ref_fn *fn;
220 void *cb_data;
221 };
222
223 int refs_read_ref_full(struct ref_store *refs, const char *refname,
224 int resolve_flags, struct object_id *oid, int *flags)
225 {
226 if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
227 return 0;
228 return -1;
229 }
230
231 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
232 {
233 return refs_read_ref_full(get_main_ref_store(the_repository), refname,
234 resolve_flags, oid, flags);
235 }
236
237 int read_ref(const char *refname, struct object_id *oid)
238 {
239 return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
240 }
241
242 int ref_exists(const char *refname)
243 {
244 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
245 }
246
247 static int match_ref_pattern(const char *refname,
248 const struct string_list_item *item)
249 {
250 int matched = 0;
251 if (item->util == NULL) {
252 if (!wildmatch(item->string, refname, 0))
253 matched = 1;
254 } else {
255 const char *rest;
256 if (skip_prefix(refname, item->string, &rest) &&
257 (!*rest || *rest == '/'))
258 matched = 1;
259 }
260 return matched;
261 }
262
263 int ref_filter_match(const char *refname,
264 const struct string_list *include_patterns,
265 const struct string_list *exclude_patterns)
266 {
267 struct string_list_item *item;
268
269 if (exclude_patterns && exclude_patterns->nr) {
270 for_each_string_list_item(item, exclude_patterns) {
271 if (match_ref_pattern(refname, item))
272 return 0;
273 }
274 }
275
276 if (include_patterns && include_patterns->nr) {
277 int found = 0;
278 for_each_string_list_item(item, include_patterns) {
279 if (match_ref_pattern(refname, item)) {
280 found = 1;
281 break;
282 }
283 }
284
285 if (!found)
286 return 0;
287 }
288 return 1;
289 }
290
291 static int filter_refs(const char *refname, const struct object_id *oid,
292 int flags, void *data)
293 {
294 struct ref_filter *filter = (struct ref_filter *)data;
295
296 if (wildmatch(filter->pattern, refname, 0))
297 return 0;
298 return filter->fn(refname, oid, flags, filter->cb_data);
299 }
300
301 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
302 {
303 struct object *o = lookup_unknown_object(name->hash);
304
305 if (o->type == OBJ_NONE) {
306 int type = oid_object_info(name, NULL);
307 if (type < 0 || !object_as_type(o, type, 0))
308 return PEEL_INVALID;
309 }
310
311 if (o->type != OBJ_TAG)
312 return PEEL_NON_TAG;
313
314 o = deref_tag_noverify(o);
315 if (!o)
316 return PEEL_INVALID;
317
318 oidcpy(oid, &o->oid);
319 return PEEL_PEELED;
320 }
321
322 struct warn_if_dangling_data {
323 FILE *fp;
324 const char *refname;
325 const struct string_list *refnames;
326 const char *msg_fmt;
327 };
328
329 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
330 int flags, void *cb_data)
331 {
332 struct warn_if_dangling_data *d = cb_data;
333 const char *resolves_to;
334
335 if (!(flags & REF_ISSYMREF))
336 return 0;
337
338 resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
339 if (!resolves_to
340 || (d->refname
341 ? strcmp(resolves_to, d->refname)
342 : !string_list_has_string(d->refnames, resolves_to))) {
343 return 0;
344 }
345
346 fprintf(d->fp, d->msg_fmt, refname);
347 fputc('\n', d->fp);
348 return 0;
349 }
350
351 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
352 {
353 struct warn_if_dangling_data data;
354
355 data.fp = fp;
356 data.refname = refname;
357 data.refnames = NULL;
358 data.msg_fmt = msg_fmt;
359 for_each_rawref(warn_if_dangling_symref, &data);
360 }
361
362 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
363 {
364 struct warn_if_dangling_data data;
365
366 data.fp = fp;
367 data.refname = NULL;
368 data.refnames = refnames;
369 data.msg_fmt = msg_fmt;
370 for_each_rawref(warn_if_dangling_symref, &data);
371 }
372
373 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
374 {
375 return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
376 }
377
378 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
379 {
380 return refs_for_each_tag_ref(get_main_ref_store(the_repository), fn, cb_data);
381 }
382
383 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
384 {
385 return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
386 }
387
388 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
389 {
390 return refs_for_each_branch_ref(get_main_ref_store(the_repository), fn, cb_data);
391 }
392
393 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
394 {
395 return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
396 }
397
398 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
399 {
400 return refs_for_each_remote_ref(get_main_ref_store(the_repository), fn, cb_data);
401 }
402
403 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
404 {
405 struct strbuf buf = STRBUF_INIT;
406 int ret = 0;
407 struct object_id oid;
408 int flag;
409
410 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
411 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, &oid, &flag))
412 ret = fn(buf.buf, &oid, flag, cb_data);
413 strbuf_release(&buf);
414
415 return ret;
416 }
417
418 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
419 const char *pattern)
420 {
421 struct strbuf normalized_pattern = STRBUF_INIT;
422
423 if (*pattern == '/')
424 BUG("pattern must not start with '/'");
425
426 if (prefix) {
427 strbuf_addstr(&normalized_pattern, prefix);
428 }
429 else if (!starts_with(pattern, "refs/"))
430 strbuf_addstr(&normalized_pattern, "refs/");
431 strbuf_addstr(&normalized_pattern, pattern);
432 strbuf_strip_suffix(&normalized_pattern, "/");
433
434 item->string = strbuf_detach(&normalized_pattern, NULL);
435 item->util = has_glob_specials(pattern) ? NULL : item->string;
436 strbuf_release(&normalized_pattern);
437 }
438
439 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
440 const char *prefix, void *cb_data)
441 {
442 struct strbuf real_pattern = STRBUF_INIT;
443 struct ref_filter filter;
444 int ret;
445
446 if (!prefix && !starts_with(pattern, "refs/"))
447 strbuf_addstr(&real_pattern, "refs/");
448 else if (prefix)
449 strbuf_addstr(&real_pattern, prefix);
450 strbuf_addstr(&real_pattern, pattern);
451
452 if (!has_glob_specials(pattern)) {
453 /* Append implied '/' '*' if not present. */
454 strbuf_complete(&real_pattern, '/');
455 /* No need to check for '*', there is none. */
456 strbuf_addch(&real_pattern, '*');
457 }
458
459 filter.pattern = real_pattern.buf;
460 filter.fn = fn;
461 filter.cb_data = cb_data;
462 ret = for_each_ref(filter_refs, &filter);
463
464 strbuf_release(&real_pattern);
465 return ret;
466 }
467
468 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
469 {
470 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
471 }
472
473 const char *prettify_refname(const char *name)
474 {
475 if (skip_prefix(name, "refs/heads/", &name) ||
476 skip_prefix(name, "refs/tags/", &name) ||
477 skip_prefix(name, "refs/remotes/", &name))
478 ; /* nothing */
479 return name;
480 }
481
482 static const char *ref_rev_parse_rules[] = {
483 "%.*s",
484 "refs/%.*s",
485 "refs/tags/%.*s",
486 "refs/heads/%.*s",
487 "refs/remotes/%.*s",
488 "refs/remotes/%.*s/HEAD",
489 NULL
490 };
491
492 int refname_match(const char *abbrev_name, const char *full_name)
493 {
494 const char **p;
495 const int abbrev_name_len = strlen(abbrev_name);
496
497 for (p = ref_rev_parse_rules; *p; p++) {
498 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
499 return 1;
500 }
501 }
502
503 return 0;
504 }
505
506 /*
507 * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
508 * the results to 'prefixes'
509 */
510 void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
511 {
512 const char **p;
513 int len = strlen(prefix);
514
515 for (p = ref_rev_parse_rules; *p; p++)
516 argv_array_pushf(prefixes, *p, len, prefix);
517 }
518
519 /*
520 * *string and *len will only be substituted, and *string returned (for
521 * later free()ing) if the string passed in is a magic short-hand form
522 * to name a branch.
523 */
524 static char *substitute_branch_name(const char **string, int *len)
525 {
526 struct strbuf buf = STRBUF_INIT;
527 int ret = interpret_branch_name(*string, *len, &buf, 0);
528
529 if (ret == *len) {
530 size_t size;
531 *string = strbuf_detach(&buf, &size);
532 *len = size;
533 return (char *)*string;
534 }
535
536 return NULL;
537 }
538
539 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
540 {
541 char *last_branch = substitute_branch_name(&str, &len);
542 int refs_found = expand_ref(str, len, oid, ref);
543 free(last_branch);
544 return refs_found;
545 }
546
547 int expand_ref(const char *str, int len, struct object_id *oid, char **ref)
548 {
549 const char **p, *r;
550 int refs_found = 0;
551 struct strbuf fullref = STRBUF_INIT;
552
553 *ref = NULL;
554 for (p = ref_rev_parse_rules; *p; p++) {
555 struct object_id oid_from_ref;
556 struct object_id *this_result;
557 int flag;
558
559 this_result = refs_found ? &oid_from_ref : oid;
560 strbuf_reset(&fullref);
561 strbuf_addf(&fullref, *p, len, str);
562 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
563 this_result, &flag);
564 if (r) {
565 if (!refs_found++)
566 *ref = xstrdup(r);
567 if (!warn_ambiguous_refs)
568 break;
569 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
570 warning("ignoring dangling symref %s.", fullref.buf);
571 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
572 warning("ignoring broken ref %s.", fullref.buf);
573 }
574 }
575 strbuf_release(&fullref);
576 return refs_found;
577 }
578
579 int dwim_log(const char *str, int len, struct object_id *oid, char **log)
580 {
581 char *last_branch = substitute_branch_name(&str, &len);
582 const char **p;
583 int logs_found = 0;
584 struct strbuf path = STRBUF_INIT;
585
586 *log = NULL;
587 for (p = ref_rev_parse_rules; *p; p++) {
588 struct object_id hash;
589 const char *ref, *it;
590
591 strbuf_reset(&path);
592 strbuf_addf(&path, *p, len, str);
593 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
594 &hash, NULL);
595 if (!ref)
596 continue;
597 if (reflog_exists(path.buf))
598 it = path.buf;
599 else if (strcmp(ref, path.buf) && reflog_exists(ref))
600 it = ref;
601 else
602 continue;
603 if (!logs_found++) {
604 *log = xstrdup(it);
605 oidcpy(oid, &hash);
606 }
607 if (!warn_ambiguous_refs)
608 break;
609 }
610 strbuf_release(&path);
611 free(last_branch);
612 return logs_found;
613 }
614
615 static int is_per_worktree_ref(const char *refname)
616 {
617 return !strcmp(refname, "HEAD") ||
618 starts_with(refname, "refs/bisect/");
619 }
620
621 static int is_pseudoref_syntax(const char *refname)
622 {
623 const char *c;
624
625 for (c = refname; *c; c++) {
626 if (!isupper(*c) && *c != '-' && *c != '_')
627 return 0;
628 }
629
630 return 1;
631 }
632
633 enum ref_type ref_type(const char *refname)
634 {
635 if (is_per_worktree_ref(refname))
636 return REF_TYPE_PER_WORKTREE;
637 if (is_pseudoref_syntax(refname))
638 return REF_TYPE_PSEUDOREF;
639 return REF_TYPE_NORMAL;
640 }
641
642 long get_files_ref_lock_timeout_ms(void)
643 {
644 static int configured = 0;
645
646 /* The default timeout is 100 ms: */
647 static int timeout_ms = 100;
648
649 if (!configured) {
650 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
651 configured = 1;
652 }
653
654 return timeout_ms;
655 }
656
657 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
658 const struct object_id *old_oid, struct strbuf *err)
659 {
660 const char *filename;
661 int fd;
662 static struct lock_file lock;
663 struct strbuf buf = STRBUF_INIT;
664 int ret = -1;
665
666 if (!oid)
667 return 0;
668
669 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
670
671 filename = git_path("%s", pseudoref);
672 fd = hold_lock_file_for_update_timeout(&lock, filename,
673 LOCK_DIE_ON_ERROR,
674 get_files_ref_lock_timeout_ms());
675 if (fd < 0) {
676 strbuf_addf(err, "could not open '%s' for writing: %s",
677 filename, strerror(errno));
678 goto done;
679 }
680
681 if (old_oid) {
682 struct object_id actual_old_oid;
683
684 if (read_ref(pseudoref, &actual_old_oid))
685 die("could not read ref '%s'", pseudoref);
686 if (oidcmp(&actual_old_oid, old_oid)) {
687 strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
688 rollback_lock_file(&lock);
689 goto done;
690 }
691 }
692
693 if (write_in_full(fd, buf.buf, buf.len) < 0) {
694 strbuf_addf(err, "could not write to '%s'", filename);
695 rollback_lock_file(&lock);
696 goto done;
697 }
698
699 commit_lock_file(&lock);
700 ret = 0;
701 done:
702 strbuf_release(&buf);
703 return ret;
704 }
705
706 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
707 {
708 static struct lock_file lock;
709 const char *filename;
710
711 filename = git_path("%s", pseudoref);
712
713 if (old_oid && !is_null_oid(old_oid)) {
714 int fd;
715 struct object_id actual_old_oid;
716
717 fd = hold_lock_file_for_update_timeout(
718 &lock, filename, LOCK_DIE_ON_ERROR,
719 get_files_ref_lock_timeout_ms());
720 if (fd < 0)
721 die_errno(_("Could not open '%s' for writing"), filename);
722 if (read_ref(pseudoref, &actual_old_oid))
723 die("could not read ref '%s'", pseudoref);
724 if (oidcmp(&actual_old_oid, old_oid)) {
725 warning("Unexpected sha1 when deleting %s", pseudoref);
726 rollback_lock_file(&lock);
727 return -1;
728 }
729
730 unlink(filename);
731 rollback_lock_file(&lock);
732 } else {
733 unlink(filename);
734 }
735
736 return 0;
737 }
738
739 int refs_delete_ref(struct ref_store *refs, const char *msg,
740 const char *refname,
741 const struct object_id *old_oid,
742 unsigned int flags)
743 {
744 struct ref_transaction *transaction;
745 struct strbuf err = STRBUF_INIT;
746
747 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
748 assert(refs == get_main_ref_store(the_repository));
749 return delete_pseudoref(refname, old_oid);
750 }
751
752 transaction = ref_store_transaction_begin(refs, &err);
753 if (!transaction ||
754 ref_transaction_delete(transaction, refname, old_oid,
755 flags, msg, &err) ||
756 ref_transaction_commit(transaction, &err)) {
757 error("%s", err.buf);
758 ref_transaction_free(transaction);
759 strbuf_release(&err);
760 return 1;
761 }
762 ref_transaction_free(transaction);
763 strbuf_release(&err);
764 return 0;
765 }
766
767 int delete_ref(const char *msg, const char *refname,
768 const struct object_id *old_oid, unsigned int flags)
769 {
770 return refs_delete_ref(get_main_ref_store(the_repository), msg, refname,
771 old_oid, flags);
772 }
773
774 int copy_reflog_msg(char *buf, const char *msg)
775 {
776 char *cp = buf;
777 char c;
778 int wasspace = 1;
779
780 *cp++ = '\t';
781 while ((c = *msg++)) {
782 if (wasspace && isspace(c))
783 continue;
784 wasspace = isspace(c);
785 if (wasspace)
786 c = ' ';
787 *cp++ = c;
788 }
789 while (buf < cp && isspace(cp[-1]))
790 cp--;
791 *cp++ = '\n';
792 return cp - buf;
793 }
794
795 int should_autocreate_reflog(const char *refname)
796 {
797 switch (log_all_ref_updates) {
798 case LOG_REFS_ALWAYS:
799 return 1;
800 case LOG_REFS_NORMAL:
801 return starts_with(refname, "refs/heads/") ||
802 starts_with(refname, "refs/remotes/") ||
803 starts_with(refname, "refs/notes/") ||
804 !strcmp(refname, "HEAD");
805 default:
806 return 0;
807 }
808 }
809
810 int is_branch(const char *refname)
811 {
812 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
813 }
814
815 struct read_ref_at_cb {
816 const char *refname;
817 timestamp_t at_time;
818 int cnt;
819 int reccnt;
820 struct object_id *oid;
821 int found_it;
822
823 struct object_id ooid;
824 struct object_id noid;
825 int tz;
826 timestamp_t date;
827 char **msg;
828 timestamp_t *cutoff_time;
829 int *cutoff_tz;
830 int *cutoff_cnt;
831 };
832
833 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
834 const char *email, timestamp_t timestamp, int tz,
835 const char *message, void *cb_data)
836 {
837 struct read_ref_at_cb *cb = cb_data;
838
839 cb->reccnt++;
840 cb->tz = tz;
841 cb->date = timestamp;
842
843 if (timestamp <= cb->at_time || cb->cnt == 0) {
844 if (cb->msg)
845 *cb->msg = xstrdup(message);
846 if (cb->cutoff_time)
847 *cb->cutoff_time = timestamp;
848 if (cb->cutoff_tz)
849 *cb->cutoff_tz = tz;
850 if (cb->cutoff_cnt)
851 *cb->cutoff_cnt = cb->reccnt - 1;
852 /*
853 * we have not yet updated cb->[n|o]oid so they still
854 * hold the values for the previous record.
855 */
856 if (!is_null_oid(&cb->ooid)) {
857 oidcpy(cb->oid, noid);
858 if (oidcmp(&cb->ooid, noid))
859 warning("Log for ref %s has gap after %s.",
860 cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
861 }
862 else if (cb->date == cb->at_time)
863 oidcpy(cb->oid, noid);
864 else if (oidcmp(noid, cb->oid))
865 warning("Log for ref %s unexpectedly ended on %s.",
866 cb->refname, show_date(cb->date, cb->tz,
867 DATE_MODE(RFC2822)));
868 oidcpy(&cb->ooid, ooid);
869 oidcpy(&cb->noid, noid);
870 cb->found_it = 1;
871 return 1;
872 }
873 oidcpy(&cb->ooid, ooid);
874 oidcpy(&cb->noid, noid);
875 if (cb->cnt > 0)
876 cb->cnt--;
877 return 0;
878 }
879
880 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
881 const char *email, timestamp_t timestamp,
882 int tz, const char *message, void *cb_data)
883 {
884 struct read_ref_at_cb *cb = cb_data;
885
886 if (cb->msg)
887 *cb->msg = xstrdup(message);
888 if (cb->cutoff_time)
889 *cb->cutoff_time = timestamp;
890 if (cb->cutoff_tz)
891 *cb->cutoff_tz = tz;
892 if (cb->cutoff_cnt)
893 *cb->cutoff_cnt = cb->reccnt;
894 oidcpy(cb->oid, ooid);
895 if (is_null_oid(cb->oid))
896 oidcpy(cb->oid, noid);
897 /* We just want the first entry */
898 return 1;
899 }
900
901 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
902 struct object_id *oid, char **msg,
903 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
904 {
905 struct read_ref_at_cb cb;
906
907 memset(&cb, 0, sizeof(cb));
908 cb.refname = refname;
909 cb.at_time = at_time;
910 cb.cnt = cnt;
911 cb.msg = msg;
912 cb.cutoff_time = cutoff_time;
913 cb.cutoff_tz = cutoff_tz;
914 cb.cutoff_cnt = cutoff_cnt;
915 cb.oid = oid;
916
917 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
918
919 if (!cb.reccnt) {
920 if (flags & GET_OID_QUIETLY)
921 exit(128);
922 else
923 die("Log for %s is empty.", refname);
924 }
925 if (cb.found_it)
926 return 0;
927
928 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
929
930 return 1;
931 }
932
933 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
934 struct strbuf *err)
935 {
936 struct ref_transaction *tr;
937 assert(err);
938
939 tr = xcalloc(1, sizeof(struct ref_transaction));
940 tr->ref_store = refs;
941 return tr;
942 }
943
944 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
945 {
946 return ref_store_transaction_begin(get_main_ref_store(the_repository), err);
947 }
948
949 void ref_transaction_free(struct ref_transaction *transaction)
950 {
951 size_t i;
952
953 if (!transaction)
954 return;
955
956 switch (transaction->state) {
957 case REF_TRANSACTION_OPEN:
958 case REF_TRANSACTION_CLOSED:
959 /* OK */
960 break;
961 case REF_TRANSACTION_PREPARED:
962 die("BUG: free called on a prepared reference transaction");
963 break;
964 default:
965 die("BUG: unexpected reference transaction state");
966 break;
967 }
968
969 for (i = 0; i < transaction->nr; i++) {
970 free(transaction->updates[i]->msg);
971 free(transaction->updates[i]);
972 }
973 free(transaction->updates);
974 free(transaction);
975 }
976
977 struct ref_update *ref_transaction_add_update(
978 struct ref_transaction *transaction,
979 const char *refname, unsigned int flags,
980 const struct object_id *new_oid,
981 const struct object_id *old_oid,
982 const char *msg)
983 {
984 struct ref_update *update;
985
986 if (transaction->state != REF_TRANSACTION_OPEN)
987 die("BUG: update called for transaction that is not open");
988
989 FLEX_ALLOC_STR(update, refname, refname);
990 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
991 transaction->updates[transaction->nr++] = update;
992
993 update->flags = flags;
994
995 if (flags & REF_HAVE_NEW)
996 oidcpy(&update->new_oid, new_oid);
997 if (flags & REF_HAVE_OLD)
998 oidcpy(&update->old_oid, old_oid);
999 update->msg = xstrdup_or_null(msg);
1000 return update;
1001 }
1002
1003 int ref_transaction_update(struct ref_transaction *transaction,
1004 const char *refname,
1005 const struct object_id *new_oid,
1006 const struct object_id *old_oid,
1007 unsigned int flags, const char *msg,
1008 struct strbuf *err)
1009 {
1010 assert(err);
1011
1012 if ((new_oid && !is_null_oid(new_oid)) ?
1013 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
1014 !refname_is_safe(refname)) {
1015 strbuf_addf(err, "refusing to update ref with bad name '%s'",
1016 refname);
1017 return -1;
1018 }
1019
1020 if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1021 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1022
1023 flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1024
1025 ref_transaction_add_update(transaction, refname, flags,
1026 new_oid, old_oid, msg);
1027 return 0;
1028 }
1029
1030 int ref_transaction_create(struct ref_transaction *transaction,
1031 const char *refname,
1032 const struct object_id *new_oid,
1033 unsigned int flags, const char *msg,
1034 struct strbuf *err)
1035 {
1036 if (!new_oid || is_null_oid(new_oid))
1037 die("BUG: create called without valid new_oid");
1038 return ref_transaction_update(transaction, refname, new_oid,
1039 &null_oid, flags, msg, err);
1040 }
1041
1042 int ref_transaction_delete(struct ref_transaction *transaction,
1043 const char *refname,
1044 const struct object_id *old_oid,
1045 unsigned int flags, const char *msg,
1046 struct strbuf *err)
1047 {
1048 if (old_oid && is_null_oid(old_oid))
1049 die("BUG: delete called with old_oid set to zeros");
1050 return ref_transaction_update(transaction, refname,
1051 &null_oid, old_oid,
1052 flags, msg, err);
1053 }
1054
1055 int ref_transaction_verify(struct ref_transaction *transaction,
1056 const char *refname,
1057 const struct object_id *old_oid,
1058 unsigned int flags,
1059 struct strbuf *err)
1060 {
1061 if (!old_oid)
1062 die("BUG: verify called with old_oid set to NULL");
1063 return ref_transaction_update(transaction, refname,
1064 NULL, old_oid,
1065 flags, NULL, err);
1066 }
1067
1068 int refs_update_ref(struct ref_store *refs, const char *msg,
1069 const char *refname, const struct object_id *new_oid,
1070 const struct object_id *old_oid, unsigned int flags,
1071 enum action_on_err onerr)
1072 {
1073 struct ref_transaction *t = NULL;
1074 struct strbuf err = STRBUF_INIT;
1075 int ret = 0;
1076
1077 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1078 assert(refs == get_main_ref_store(the_repository));
1079 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1080 } else {
1081 t = ref_store_transaction_begin(refs, &err);
1082 if (!t ||
1083 ref_transaction_update(t, refname, new_oid, old_oid,
1084 flags, msg, &err) ||
1085 ref_transaction_commit(t, &err)) {
1086 ret = 1;
1087 ref_transaction_free(t);
1088 }
1089 }
1090 if (ret) {
1091 const char *str = "update_ref failed for ref '%s': %s";
1092
1093 switch (onerr) {
1094 case UPDATE_REFS_MSG_ON_ERR:
1095 error(str, refname, err.buf);
1096 break;
1097 case UPDATE_REFS_DIE_ON_ERR:
1098 die(str, refname, err.buf);
1099 break;
1100 case UPDATE_REFS_QUIET_ON_ERR:
1101 break;
1102 }
1103 strbuf_release(&err);
1104 return 1;
1105 }
1106 strbuf_release(&err);
1107 if (t)
1108 ref_transaction_free(t);
1109 return 0;
1110 }
1111
1112 int update_ref(const char *msg, const char *refname,
1113 const struct object_id *new_oid,
1114 const struct object_id *old_oid,
1115 unsigned int flags, enum action_on_err onerr)
1116 {
1117 return refs_update_ref(get_main_ref_store(the_repository), msg, refname, new_oid,
1118 old_oid, flags, onerr);
1119 }
1120
1121 char *shorten_unambiguous_ref(const char *refname, int strict)
1122 {
1123 int i;
1124 static char **scanf_fmts;
1125 static int nr_rules;
1126 char *short_name;
1127 struct strbuf resolved_buf = STRBUF_INIT;
1128
1129 if (!nr_rules) {
1130 /*
1131 * Pre-generate scanf formats from ref_rev_parse_rules[].
1132 * Generate a format suitable for scanf from a
1133 * ref_rev_parse_rules rule by interpolating "%s" at the
1134 * location of the "%.*s".
1135 */
1136 size_t total_len = 0;
1137 size_t offset = 0;
1138
1139 /* the rule list is NULL terminated, count them first */
1140 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1141 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1142 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1143
1144 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1145
1146 offset = 0;
1147 for (i = 0; i < nr_rules; i++) {
1148 assert(offset < total_len);
1149 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1150 offset += snprintf(scanf_fmts[i], total_len - offset,
1151 ref_rev_parse_rules[i], 2, "%s") + 1;
1152 }
1153 }
1154
1155 /* bail out if there are no rules */
1156 if (!nr_rules)
1157 return xstrdup(refname);
1158
1159 /* buffer for scanf result, at most refname must fit */
1160 short_name = xstrdup(refname);
1161
1162 /* skip first rule, it will always match */
1163 for (i = nr_rules - 1; i > 0 ; --i) {
1164 int j;
1165 int rules_to_fail = i;
1166 int short_name_len;
1167
1168 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1169 continue;
1170
1171 short_name_len = strlen(short_name);
1172
1173 /*
1174 * in strict mode, all (except the matched one) rules
1175 * must fail to resolve to a valid non-ambiguous ref
1176 */
1177 if (strict)
1178 rules_to_fail = nr_rules;
1179
1180 /*
1181 * check if the short name resolves to a valid ref,
1182 * but use only rules prior to the matched one
1183 */
1184 for (j = 0; j < rules_to_fail; j++) {
1185 const char *rule = ref_rev_parse_rules[j];
1186
1187 /* skip matched rule */
1188 if (i == j)
1189 continue;
1190
1191 /*
1192 * the short name is ambiguous, if it resolves
1193 * (with this previous rule) to a valid ref
1194 * read_ref() returns 0 on success
1195 */
1196 strbuf_reset(&resolved_buf);
1197 strbuf_addf(&resolved_buf, rule,
1198 short_name_len, short_name);
1199 if (ref_exists(resolved_buf.buf))
1200 break;
1201 }
1202
1203 /*
1204 * short name is non-ambiguous if all previous rules
1205 * haven't resolved to a valid ref
1206 */
1207 if (j == rules_to_fail) {
1208 strbuf_release(&resolved_buf);
1209 return short_name;
1210 }
1211 }
1212
1213 strbuf_release(&resolved_buf);
1214 free(short_name);
1215 return xstrdup(refname);
1216 }
1217
1218 static struct string_list *hide_refs;
1219
1220 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1221 {
1222 const char *key;
1223 if (!strcmp("transfer.hiderefs", var) ||
1224 (!parse_config_key(var, section, NULL, NULL, &key) &&
1225 !strcmp(key, "hiderefs"))) {
1226 char *ref;
1227 int len;
1228
1229 if (!value)
1230 return config_error_nonbool(var);
1231 ref = xstrdup(value);
1232 len = strlen(ref);
1233 while (len && ref[len - 1] == '/')
1234 ref[--len] = '\0';
1235 if (!hide_refs) {
1236 hide_refs = xcalloc(1, sizeof(*hide_refs));
1237 hide_refs->strdup_strings = 1;
1238 }
1239 string_list_append(hide_refs, ref);
1240 }
1241 return 0;
1242 }
1243
1244 int ref_is_hidden(const char *refname, const char *refname_full)
1245 {
1246 int i;
1247
1248 if (!hide_refs)
1249 return 0;
1250 for (i = hide_refs->nr - 1; i >= 0; i--) {
1251 const char *match = hide_refs->items[i].string;
1252 const char *subject;
1253 int neg = 0;
1254 const char *p;
1255
1256 if (*match == '!') {
1257 neg = 1;
1258 match++;
1259 }
1260
1261 if (*match == '^') {
1262 subject = refname_full;
1263 match++;
1264 } else {
1265 subject = refname;
1266 }
1267
1268 /* refname can be NULL when namespaces are used. */
1269 if (subject &&
1270 skip_prefix(subject, match, &p) &&
1271 (!*p || *p == '/'))
1272 return !neg;
1273 }
1274 return 0;
1275 }
1276
1277 const char *find_descendant_ref(const char *dirname,
1278 const struct string_list *extras,
1279 const struct string_list *skip)
1280 {
1281 int pos;
1282
1283 if (!extras)
1284 return NULL;
1285
1286 /*
1287 * Look at the place where dirname would be inserted into
1288 * extras. If there is an entry at that position that starts
1289 * with dirname (remember, dirname includes the trailing
1290 * slash) and is not in skip, then we have a conflict.
1291 */
1292 for (pos = string_list_find_insert_index(extras, dirname, 0);
1293 pos < extras->nr; pos++) {
1294 const char *extra_refname = extras->items[pos].string;
1295
1296 if (!starts_with(extra_refname, dirname))
1297 break;
1298
1299 if (!skip || !string_list_has_string(skip, extra_refname))
1300 return extra_refname;
1301 }
1302 return NULL;
1303 }
1304
1305 int refs_rename_ref_available(struct ref_store *refs,
1306 const char *old_refname,
1307 const char *new_refname)
1308 {
1309 struct string_list skip = STRING_LIST_INIT_NODUP;
1310 struct strbuf err = STRBUF_INIT;
1311 int ok;
1312
1313 string_list_insert(&skip, old_refname);
1314 ok = !refs_verify_refname_available(refs, new_refname,
1315 NULL, &skip, &err);
1316 if (!ok)
1317 error("%s", err.buf);
1318
1319 string_list_clear(&skip, 0);
1320 strbuf_release(&err);
1321 return ok;
1322 }
1323
1324 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1325 {
1326 struct object_id oid;
1327 int flag;
1328
1329 if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1330 &oid, &flag))
1331 return fn("HEAD", &oid, flag, cb_data);
1332
1333 return 0;
1334 }
1335
1336 int head_ref(each_ref_fn fn, void *cb_data)
1337 {
1338 return refs_head_ref(get_main_ref_store(the_repository), fn, cb_data);
1339 }
1340
1341 struct ref_iterator *refs_ref_iterator_begin(
1342 struct ref_store *refs,
1343 const char *prefix, int trim, int flags)
1344 {
1345 struct ref_iterator *iter;
1346
1347 if (ref_paranoia < 0)
1348 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1349 if (ref_paranoia)
1350 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1351
1352 iter = refs->be->iterator_begin(refs, prefix, flags);
1353
1354 /*
1355 * `iterator_begin()` already takes care of prefix, but we
1356 * might need to do some trimming:
1357 */
1358 if (trim)
1359 iter = prefix_ref_iterator_begin(iter, "", trim);
1360
1361 /* Sanity check for subclasses: */
1362 if (!iter->ordered)
1363 BUG("reference iterator is not ordered");
1364
1365 return iter;
1366 }
1367
1368 /*
1369 * Call fn for each reference in the specified submodule for which the
1370 * refname begins with prefix. If trim is non-zero, then trim that
1371 * many characters off the beginning of each refname before passing
1372 * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1373 * include broken references in the iteration. If fn ever returns a
1374 * non-zero value, stop the iteration and return that value;
1375 * otherwise, return 0.
1376 */
1377 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1378 each_ref_fn fn, int trim, int flags, void *cb_data)
1379 {
1380 struct ref_iterator *iter;
1381
1382 if (!refs)
1383 return 0;
1384
1385 iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1386
1387 return do_for_each_ref_iterator(iter, fn, cb_data);
1388 }
1389
1390 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1391 {
1392 return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1393 }
1394
1395 int for_each_ref(each_ref_fn fn, void *cb_data)
1396 {
1397 return refs_for_each_ref(get_main_ref_store(the_repository), fn, cb_data);
1398 }
1399
1400 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1401 each_ref_fn fn, void *cb_data)
1402 {
1403 return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1404 }
1405
1406 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1407 {
1408 return refs_for_each_ref_in(get_main_ref_store(the_repository), prefix, fn, cb_data);
1409 }
1410
1411 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1412 {
1413 unsigned int flag = 0;
1414
1415 if (broken)
1416 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1417 return do_for_each_ref(get_main_ref_store(the_repository),
1418 prefix, fn, 0, flag, cb_data);
1419 }
1420
1421 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1422 each_ref_fn fn, void *cb_data,
1423 unsigned int broken)
1424 {
1425 unsigned int flag = 0;
1426
1427 if (broken)
1428 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1429 return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1430 }
1431
1432 int for_each_replace_ref(struct repository *r, each_ref_fn fn, void *cb_data)
1433 {
1434 return do_for_each_ref(get_main_ref_store(r),
1435 git_replace_ref_base, fn,
1436 strlen(git_replace_ref_base),
1437 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1438 }
1439
1440 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1441 {
1442 struct strbuf buf = STRBUF_INIT;
1443 int ret;
1444 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1445 ret = do_for_each_ref(get_main_ref_store(the_repository),
1446 buf.buf, fn, 0, 0, cb_data);
1447 strbuf_release(&buf);
1448 return ret;
1449 }
1450
1451 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1452 {
1453 return do_for_each_ref(refs, "", fn, 0,
1454 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1455 }
1456
1457 int for_each_rawref(each_ref_fn fn, void *cb_data)
1458 {
1459 return refs_for_each_rawref(get_main_ref_store(the_repository), fn, cb_data);
1460 }
1461
1462 int refs_read_raw_ref(struct ref_store *ref_store,
1463 const char *refname, struct object_id *oid,
1464 struct strbuf *referent, unsigned int *type)
1465 {
1466 return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1467 }
1468
1469 /* This function needs to return a meaningful errno on failure */
1470 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1471 const char *refname,
1472 int resolve_flags,
1473 struct object_id *oid, int *flags)
1474 {
1475 static struct strbuf sb_refname = STRBUF_INIT;
1476 struct object_id unused_oid;
1477 int unused_flags;
1478 int symref_count;
1479
1480 if (!oid)
1481 oid = &unused_oid;
1482 if (!flags)
1483 flags = &unused_flags;
1484
1485 *flags = 0;
1486
1487 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1488 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1489 !refname_is_safe(refname)) {
1490 errno = EINVAL;
1491 return NULL;
1492 }
1493
1494 /*
1495 * dwim_ref() uses REF_ISBROKEN to distinguish between
1496 * missing refs and refs that were present but invalid,
1497 * to complain about the latter to stderr.
1498 *
1499 * We don't know whether the ref exists, so don't set
1500 * REF_ISBROKEN yet.
1501 */
1502 *flags |= REF_BAD_NAME;
1503 }
1504
1505 for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1506 unsigned int read_flags = 0;
1507
1508 if (refs_read_raw_ref(refs, refname,
1509 oid, &sb_refname, &read_flags)) {
1510 *flags |= read_flags;
1511
1512 /* In reading mode, refs must eventually resolve */
1513 if (resolve_flags & RESOLVE_REF_READING)
1514 return NULL;
1515
1516 /*
1517 * Otherwise a missing ref is OK. But the files backend
1518 * may show errors besides ENOENT if there are
1519 * similarly-named refs.
1520 */
1521 if (errno != ENOENT &&
1522 errno != EISDIR &&
1523 errno != ENOTDIR)
1524 return NULL;
1525
1526 oidclr(oid);
1527 if (*flags & REF_BAD_NAME)
1528 *flags |= REF_ISBROKEN;
1529 return refname;
1530 }
1531
1532 *flags |= read_flags;
1533
1534 if (!(read_flags & REF_ISSYMREF)) {
1535 if (*flags & REF_BAD_NAME) {
1536 oidclr(oid);
1537 *flags |= REF_ISBROKEN;
1538 }
1539 return refname;
1540 }
1541
1542 refname = sb_refname.buf;
1543 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1544 oidclr(oid);
1545 return refname;
1546 }
1547 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1548 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1549 !refname_is_safe(refname)) {
1550 errno = EINVAL;
1551 return NULL;
1552 }
1553
1554 *flags |= REF_ISBROKEN | REF_BAD_NAME;
1555 }
1556 }
1557
1558 errno = ELOOP;
1559 return NULL;
1560 }
1561
1562 /* backend functions */
1563 int refs_init_db(struct strbuf *err)
1564 {
1565 struct ref_store *refs = get_main_ref_store(the_repository);
1566
1567 return refs->be->init_db(refs, err);
1568 }
1569
1570 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1571 struct object_id *oid, int *flags)
1572 {
1573 return refs_resolve_ref_unsafe(get_main_ref_store(the_repository), refname,
1574 resolve_flags, oid, flags);
1575 }
1576
1577 int resolve_gitlink_ref(const char *submodule, const char *refname,
1578 struct object_id *oid)
1579 {
1580 struct ref_store *refs;
1581 int flags;
1582
1583 refs = get_submodule_ref_store(submodule);
1584
1585 if (!refs)
1586 return -1;
1587
1588 if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1589 is_null_oid(oid))
1590 return -1;
1591 return 0;
1592 }
1593
1594 struct ref_store_hash_entry
1595 {
1596 struct hashmap_entry ent; /* must be the first member! */
1597
1598 struct ref_store *refs;
1599
1600 /* NUL-terminated identifier of the ref store: */
1601 char name[FLEX_ARRAY];
1602 };
1603
1604 static int ref_store_hash_cmp(const void *unused_cmp_data,
1605 const void *entry, const void *entry_or_key,
1606 const void *keydata)
1607 {
1608 const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1609 const char *name = keydata ? keydata : e2->name;
1610
1611 return strcmp(e1->name, name);
1612 }
1613
1614 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1615 const char *name, struct ref_store *refs)
1616 {
1617 struct ref_store_hash_entry *entry;
1618
1619 FLEX_ALLOC_STR(entry, name, name);
1620 hashmap_entry_init(entry, strhash(name));
1621 entry->refs = refs;
1622 return entry;
1623 }
1624
1625 /* A hashmap of ref_stores, stored by submodule name: */
1626 static struct hashmap submodule_ref_stores;
1627
1628 /* A hashmap of ref_stores, stored by worktree id: */
1629 static struct hashmap worktree_ref_stores;
1630
1631 /*
1632 * Look up a ref store by name. If that ref_store hasn't been
1633 * registered yet, return NULL.
1634 */
1635 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1636 const char *name)
1637 {
1638 struct ref_store_hash_entry *entry;
1639
1640 if (!map->tablesize)
1641 /* It's initialized on demand in register_ref_store(). */
1642 return NULL;
1643
1644 entry = hashmap_get_from_hash(map, strhash(name), name);
1645 return entry ? entry->refs : NULL;
1646 }
1647
1648 /*
1649 * Create, record, and return a ref_store instance for the specified
1650 * gitdir.
1651 */
1652 static struct ref_store *ref_store_init(const char *gitdir,
1653 unsigned int flags)
1654 {
1655 const char *be_name = "files";
1656 struct ref_storage_be *be = find_ref_storage_backend(be_name);
1657 struct ref_store *refs;
1658
1659 if (!be)
1660 die("BUG: reference backend %s is unknown", be_name);
1661
1662 refs = be->init(gitdir, flags);
1663 return refs;
1664 }
1665
1666 struct ref_store *get_main_ref_store(struct repository *r)
1667 {
1668 if (r->refs)
1669 return r->refs;
1670
1671 r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
1672 return r->refs;
1673 }
1674
1675 /*
1676 * Associate a ref store with a name. It is a fatal error to call this
1677 * function twice for the same name.
1678 */
1679 static void register_ref_store_map(struct hashmap *map,
1680 const char *type,
1681 struct ref_store *refs,
1682 const char *name)
1683 {
1684 if (!map->tablesize)
1685 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1686
1687 if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1688 die("BUG: %s ref_store '%s' initialized twice", type, name);
1689 }
1690
1691 struct ref_store *get_submodule_ref_store(const char *submodule)
1692 {
1693 struct strbuf submodule_sb = STRBUF_INIT;
1694 struct ref_store *refs;
1695 char *to_free = NULL;
1696 size_t len;
1697
1698 if (!submodule)
1699 return NULL;
1700
1701 len = strlen(submodule);
1702 while (len && is_dir_sep(submodule[len - 1]))
1703 len--;
1704 if (!len)
1705 return NULL;
1706
1707 if (submodule[len])
1708 /* We need to strip off one or more trailing slashes */
1709 submodule = to_free = xmemdupz(submodule, len);
1710
1711 refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1712 if (refs)
1713 goto done;
1714
1715 strbuf_addstr(&submodule_sb, submodule);
1716 if (!is_nonbare_repository_dir(&submodule_sb))
1717 goto done;
1718
1719 if (submodule_to_gitdir(&submodule_sb, submodule))
1720 goto done;
1721
1722 /* assume that add_submodule_odb() has been called */
1723 refs = ref_store_init(submodule_sb.buf,
1724 REF_STORE_READ | REF_STORE_ODB);
1725 register_ref_store_map(&submodule_ref_stores, "submodule",
1726 refs, submodule);
1727
1728 done:
1729 strbuf_release(&submodule_sb);
1730 free(to_free);
1731
1732 return refs;
1733 }
1734
1735 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1736 {
1737 struct ref_store *refs;
1738 const char *id;
1739
1740 if (wt->is_current)
1741 return get_main_ref_store(the_repository);
1742
1743 id = wt->id ? wt->id : "/";
1744 refs = lookup_ref_store_map(&worktree_ref_stores, id);
1745 if (refs)
1746 return refs;
1747
1748 if (wt->id)
1749 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1750 REF_STORE_ALL_CAPS);
1751 else
1752 refs = ref_store_init(get_git_common_dir(),
1753 REF_STORE_ALL_CAPS);
1754
1755 if (refs)
1756 register_ref_store_map(&worktree_ref_stores, "worktree",
1757 refs, id);
1758 return refs;
1759 }
1760
1761 void base_ref_store_init(struct ref_store *refs,
1762 const struct ref_storage_be *be)
1763 {
1764 refs->be = be;
1765 }
1766
1767 /* backend functions */
1768 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1769 {
1770 return refs->be->pack_refs(refs, flags);
1771 }
1772
1773 int refs_peel_ref(struct ref_store *refs, const char *refname,
1774 struct object_id *oid)
1775 {
1776 int flag;
1777 struct object_id base;
1778
1779 if (current_ref_iter && current_ref_iter->refname == refname) {
1780 struct object_id peeled;
1781
1782 if (ref_iterator_peel(current_ref_iter, &peeled))
1783 return -1;
1784 oidcpy(oid, &peeled);
1785 return 0;
1786 }
1787
1788 if (refs_read_ref_full(refs, refname,
1789 RESOLVE_REF_READING, &base, &flag))
1790 return -1;
1791
1792 return peel_object(&base, oid);
1793 }
1794
1795 int peel_ref(const char *refname, struct object_id *oid)
1796 {
1797 return refs_peel_ref(get_main_ref_store(the_repository), refname, oid);
1798 }
1799
1800 int refs_create_symref(struct ref_store *refs,
1801 const char *ref_target,
1802 const char *refs_heads_master,
1803 const char *logmsg)
1804 {
1805 return refs->be->create_symref(refs, ref_target,
1806 refs_heads_master,
1807 logmsg);
1808 }
1809
1810 int create_symref(const char *ref_target, const char *refs_heads_master,
1811 const char *logmsg)
1812 {
1813 return refs_create_symref(get_main_ref_store(the_repository), ref_target,
1814 refs_heads_master, logmsg);
1815 }
1816
1817 int ref_update_reject_duplicates(struct string_list *refnames,
1818 struct strbuf *err)
1819 {
1820 size_t i, n = refnames->nr;
1821
1822 assert(err);
1823
1824 for (i = 1; i < n; i++) {
1825 int cmp = strcmp(refnames->items[i - 1].string,
1826 refnames->items[i].string);
1827
1828 if (!cmp) {
1829 strbuf_addf(err,
1830 "multiple updates for ref '%s' not allowed.",
1831 refnames->items[i].string);
1832 return 1;
1833 } else if (cmp > 0) {
1834 die("BUG: ref_update_reject_duplicates() received unsorted list");
1835 }
1836 }
1837 return 0;
1838 }
1839
1840 int ref_transaction_prepare(struct ref_transaction *transaction,
1841 struct strbuf *err)
1842 {
1843 struct ref_store *refs = transaction->ref_store;
1844
1845 switch (transaction->state) {
1846 case REF_TRANSACTION_OPEN:
1847 /* Good. */
1848 break;
1849 case REF_TRANSACTION_PREPARED:
1850 die("BUG: prepare called twice on reference transaction");
1851 break;
1852 case REF_TRANSACTION_CLOSED:
1853 die("BUG: prepare called on a closed reference transaction");
1854 break;
1855 default:
1856 die("BUG: unexpected reference transaction state");
1857 break;
1858 }
1859
1860 if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1861 strbuf_addstr(err,
1862 _("ref updates forbidden inside quarantine environment"));
1863 return -1;
1864 }
1865
1866 return refs->be->transaction_prepare(refs, transaction, err);
1867 }
1868
1869 int ref_transaction_abort(struct ref_transaction *transaction,
1870 struct strbuf *err)
1871 {
1872 struct ref_store *refs = transaction->ref_store;
1873 int ret = 0;
1874
1875 switch (transaction->state) {
1876 case REF_TRANSACTION_OPEN:
1877 /* No need to abort explicitly. */
1878 break;
1879 case REF_TRANSACTION_PREPARED:
1880 ret = refs->be->transaction_abort(refs, transaction, err);
1881 break;
1882 case REF_TRANSACTION_CLOSED:
1883 die("BUG: abort called on a closed reference transaction");
1884 break;
1885 default:
1886 die("BUG: unexpected reference transaction state");
1887 break;
1888 }
1889
1890 ref_transaction_free(transaction);
1891 return ret;
1892 }
1893
1894 int ref_transaction_commit(struct ref_transaction *transaction,
1895 struct strbuf *err)
1896 {
1897 struct ref_store *refs = transaction->ref_store;
1898 int ret;
1899
1900 switch (transaction->state) {
1901 case REF_TRANSACTION_OPEN:
1902 /* Need to prepare first. */
1903 ret = ref_transaction_prepare(transaction, err);
1904 if (ret)
1905 return ret;
1906 break;
1907 case REF_TRANSACTION_PREPARED:
1908 /* Fall through to finish. */
1909 break;
1910 case REF_TRANSACTION_CLOSED:
1911 die("BUG: commit called on a closed reference transaction");
1912 break;
1913 default:
1914 die("BUG: unexpected reference transaction state");
1915 break;
1916 }
1917
1918 return refs->be->transaction_finish(refs, transaction, err);
1919 }
1920
1921 int refs_verify_refname_available(struct ref_store *refs,
1922 const char *refname,
1923 const struct string_list *extras,
1924 const struct string_list *skip,
1925 struct strbuf *err)
1926 {
1927 const char *slash;
1928 const char *extra_refname;
1929 struct strbuf dirname = STRBUF_INIT;
1930 struct strbuf referent = STRBUF_INIT;
1931 struct object_id oid;
1932 unsigned int type;
1933 struct ref_iterator *iter;
1934 int ok;
1935 int ret = -1;
1936
1937 /*
1938 * For the sake of comments in this function, suppose that
1939 * refname is "refs/foo/bar".
1940 */
1941
1942 assert(err);
1943
1944 strbuf_grow(&dirname, strlen(refname) + 1);
1945 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1946 /* Expand dirname to the new prefix, not including the trailing slash: */
1947 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1948
1949 /*
1950 * We are still at a leading dir of the refname (e.g.,
1951 * "refs/foo"; if there is a reference with that name,
1952 * it is a conflict, *unless* it is in skip.
1953 */
1954 if (skip && string_list_has_string(skip, dirname.buf))
1955 continue;
1956
1957 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1958 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1959 dirname.buf, refname);
1960 goto cleanup;
1961 }
1962
1963 if (extras && string_list_has_string(extras, dirname.buf)) {
1964 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1965 refname, dirname.buf);
1966 goto cleanup;
1967 }
1968 }
1969
1970 /*
1971 * We are at the leaf of our refname (e.g., "refs/foo/bar").
1972 * There is no point in searching for a reference with that
1973 * name, because a refname isn't considered to conflict with
1974 * itself. But we still need to check for references whose
1975 * names are in the "refs/foo/bar/" namespace, because they
1976 * *do* conflict.
1977 */
1978 strbuf_addstr(&dirname, refname + dirname.len);
1979 strbuf_addch(&dirname, '/');
1980
1981 iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1982 DO_FOR_EACH_INCLUDE_BROKEN);
1983 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1984 if (skip &&
1985 string_list_has_string(skip, iter->refname))
1986 continue;
1987
1988 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1989 iter->refname, refname);
1990 ref_iterator_abort(iter);
1991 goto cleanup;
1992 }
1993
1994 if (ok != ITER_DONE)
1995 die("BUG: error while iterating over references");
1996
1997 extra_refname = find_descendant_ref(dirname.buf, extras, skip);
1998 if (extra_refname)
1999 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
2000 refname, extra_refname);
2001 else
2002 ret = 0;
2003
2004 cleanup:
2005 strbuf_release(&referent);
2006 strbuf_release(&dirname);
2007 return ret;
2008 }
2009
2010 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2011 {
2012 struct ref_iterator *iter;
2013
2014 iter = refs->be->reflog_iterator_begin(refs);
2015
2016 return do_for_each_ref_iterator(iter, fn, cb_data);
2017 }
2018
2019 int for_each_reflog(each_ref_fn fn, void *cb_data)
2020 {
2021 return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
2022 }
2023
2024 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2025 const char *refname,
2026 each_reflog_ent_fn fn,
2027 void *cb_data)
2028 {
2029 return refs->be->for_each_reflog_ent_reverse(refs, refname,
2030 fn, cb_data);
2031 }
2032
2033 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2034 void *cb_data)
2035 {
2036 return refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
2037 refname, fn, cb_data);
2038 }
2039
2040 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2041 each_reflog_ent_fn fn, void *cb_data)
2042 {
2043 return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2044 }
2045
2046 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2047 void *cb_data)
2048 {
2049 return refs_for_each_reflog_ent(get_main_ref_store(the_repository), refname,
2050 fn, cb_data);
2051 }
2052
2053 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2054 {
2055 return refs->be->reflog_exists(refs, refname);
2056 }
2057
2058 int reflog_exists(const char *refname)
2059 {
2060 return refs_reflog_exists(get_main_ref_store(the_repository), refname);
2061 }
2062
2063 int refs_create_reflog(struct ref_store *refs, const char *refname,
2064 int force_create, struct strbuf *err)
2065 {
2066 return refs->be->create_reflog(refs, refname, force_create, err);
2067 }
2068
2069 int safe_create_reflog(const char *refname, int force_create,
2070 struct strbuf *err)
2071 {
2072 return refs_create_reflog(get_main_ref_store(the_repository), refname,
2073 force_create, err);
2074 }
2075
2076 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2077 {
2078 return refs->be->delete_reflog(refs, refname);
2079 }
2080
2081 int delete_reflog(const char *refname)
2082 {
2083 return refs_delete_reflog(get_main_ref_store(the_repository), refname);
2084 }
2085
2086 int refs_reflog_expire(struct ref_store *refs,
2087 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->be->reflog_expire(refs, refname, oid, flags,
2095 prepare_fn, should_prune_fn,
2096 cleanup_fn, policy_cb_data);
2097 }
2098
2099 int reflog_expire(const char *refname, const struct object_id *oid,
2100 unsigned int flags,
2101 reflog_expiry_prepare_fn prepare_fn,
2102 reflog_expiry_should_prune_fn should_prune_fn,
2103 reflog_expiry_cleanup_fn cleanup_fn,
2104 void *policy_cb_data)
2105 {
2106 return refs_reflog_expire(get_main_ref_store(the_repository),
2107 refname, oid, flags,
2108 prepare_fn, should_prune_fn,
2109 cleanup_fn, policy_cb_data);
2110 }
2111
2112 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2113 struct strbuf *err)
2114 {
2115 struct ref_store *refs = transaction->ref_store;
2116
2117 return refs->be->initial_transaction_commit(refs, transaction, err);
2118 }
2119
2120 int refs_delete_refs(struct ref_store *refs, const char *msg,
2121 struct string_list *refnames, unsigned int flags)
2122 {
2123 return refs->be->delete_refs(refs, msg, refnames, flags);
2124 }
2125
2126 int delete_refs(const char *msg, struct string_list *refnames,
2127 unsigned int flags)
2128 {
2129 return refs_delete_refs(get_main_ref_store(the_repository), msg, refnames, flags);
2130 }
2131
2132 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2133 const char *newref, const char *logmsg)
2134 {
2135 return refs->be->rename_ref(refs, oldref, newref, logmsg);
2136 }
2137
2138 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2139 {
2140 return refs_rename_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2141 }
2142
2143 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2144 const char *newref, const char *logmsg)
2145 {
2146 return refs->be->copy_ref(refs, oldref, newref, logmsg);
2147 }
2148
2149 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2150 {
2151 return refs_copy_existing_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2152 }