Merge branch 'bp/log-ref-write-fd-with-strbuf'
[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-store.h"
13 #include "object.h"
14 #include "tag.h"
15 #include "submodule.h"
16 #include "worktree.h"
17 #include "argv-array.h"
18 #include "repository.h"
19
20 /*
21 * List of all available backends
22 */
23 static struct ref_storage_be *refs_backends = &refs_be_files;
24
25 static struct ref_storage_be *find_ref_storage_backend(const char *name)
26 {
27 struct ref_storage_be *be;
28 for (be = refs_backends; be; be = be->next)
29 if (!strcmp(be->name, name))
30 return be;
31 return NULL;
32 }
33
34 int ref_storage_backend_exists(const char *name)
35 {
36 return find_ref_storage_backend(name) != NULL;
37 }
38
39 /*
40 * How to handle various characters in refnames:
41 * 0: An acceptable character for refs
42 * 1: End-of-component
43 * 2: ., look for a preceding . to reject .. in refs
44 * 3: {, look for a preceding @ to reject @{ in refs
45 * 4: A bad character: ASCII control characters, and
46 * ":", "?", "[", "\", "^", "~", SP, or TAB
47 * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
48 */
49 static unsigned char refname_disposition[256] = {
50 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
51 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
52 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
53 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
54 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
55 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
56 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
57 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
58 };
59
60 /*
61 * Try to read one refname component from the front of refname.
62 * Return the length of the component found, or -1 if the component is
63 * not legal. It is legal if it is something reasonable to have under
64 * ".git/refs/"; We do not like it if:
65 *
66 * - any path component of it begins with ".", or
67 * - it has double dots "..", or
68 * - it has ASCII control characters, or
69 * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
70 * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
71 * - it ends with a "/", or
72 * - it ends with ".lock", or
73 * - it contains a "@{" portion
74 */
75 static int check_refname_component(const char *refname, int *flags)
76 {
77 const char *cp;
78 char last = '\0';
79
80 for (cp = refname; ; cp++) {
81 int ch = *cp & 255;
82 unsigned char disp = refname_disposition[ch];
83 switch (disp) {
84 case 1:
85 goto out;
86 case 2:
87 if (last == '.')
88 return -1; /* Refname contains "..". */
89 break;
90 case 3:
91 if (last == '@')
92 return -1; /* Refname contains "@{". */
93 break;
94 case 4:
95 return -1;
96 case 5:
97 if (!(*flags & REFNAME_REFSPEC_PATTERN))
98 return -1; /* refspec can't be a pattern */
99
100 /*
101 * Unset the pattern flag so that we only accept
102 * a single asterisk for one side of refspec.
103 */
104 *flags &= ~ REFNAME_REFSPEC_PATTERN;
105 break;
106 }
107 last = ch;
108 }
109 out:
110 if (cp == refname)
111 return 0; /* Component has zero length. */
112 if (refname[0] == '.')
113 return -1; /* Component starts with '.'. */
114 if (cp - refname >= LOCK_SUFFIX_LEN &&
115 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
116 return -1; /* Refname ends with ".lock". */
117 return cp - refname;
118 }
119
120 int check_refname_format(const char *refname, int flags)
121 {
122 int component_len, component_count = 0;
123
124 if (!strcmp(refname, "@"))
125 /* Refname is a single character '@'. */
126 return -1;
127
128 while (1) {
129 /* We are at the start of a path component. */
130 component_len = check_refname_component(refname, &flags);
131 if (component_len <= 0)
132 return -1;
133
134 component_count++;
135 if (refname[component_len] == '\0')
136 break;
137 /* Skip to next component. */
138 refname += component_len + 1;
139 }
140
141 if (refname[component_len - 1] == '.')
142 return -1; /* Refname ends with '.'. */
143 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
144 return -1; /* Refname has only one component. */
145 return 0;
146 }
147
148 int refname_is_safe(const char *refname)
149 {
150 const char *rest;
151
152 if (skip_prefix(refname, "refs/", &rest)) {
153 char *buf;
154 int result;
155 size_t restlen = strlen(rest);
156
157 /* rest must not be empty, or start or end with "/" */
158 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
159 return 0;
160
161 /*
162 * Does the refname try to escape refs/?
163 * For example: refs/foo/../bar is safe but refs/foo/../../bar
164 * is not.
165 */
166 buf = xmallocz(restlen);
167 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
168 free(buf);
169 return result;
170 }
171
172 do {
173 if (!isupper(*refname) && *refname != '_')
174 return 0;
175 refname++;
176 } while (*refname);
177 return 1;
178 }
179
180 /*
181 * Return true if refname, which has the specified oid and flags, can
182 * be resolved to an object in the database. If the referred-to object
183 * does not exist, emit a warning and return false.
184 */
185 int ref_resolves_to_object(const char *refname,
186 const struct object_id *oid,
187 unsigned int flags)
188 {
189 if (flags & REF_ISBROKEN)
190 return 0;
191 if (!has_sha1_file(oid->hash)) {
192 error("%s does not point to a valid object!", refname);
193 return 0;
194 }
195 return 1;
196 }
197
198 char *refs_resolve_refdup(struct ref_store *refs,
199 const char *refname, int resolve_flags,
200 struct object_id *oid, int *flags)
201 {
202 const char *result;
203
204 result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
205 oid, flags);
206 return xstrdup_or_null(result);
207 }
208
209 char *resolve_refdup(const char *refname, int resolve_flags,
210 struct object_id *oid, int *flags)
211 {
212 return refs_resolve_refdup(get_main_ref_store(the_repository),
213 refname, resolve_flags,
214 oid, flags);
215 }
216
217 /* The argument to filter_refs */
218 struct ref_filter {
219 const char *pattern;
220 each_ref_fn *fn;
221 void *cb_data;
222 };
223
224 int refs_read_ref_full(struct ref_store *refs, const char *refname,
225 int resolve_flags, struct object_id *oid, int *flags)
226 {
227 if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
228 return 0;
229 return -1;
230 }
231
232 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
233 {
234 return refs_read_ref_full(get_main_ref_store(the_repository), refname,
235 resolve_flags, oid, flags);
236 }
237
238 int read_ref(const char *refname, struct object_id *oid)
239 {
240 return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
241 }
242
243 int ref_exists(const char *refname)
244 {
245 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
246 }
247
248 static int match_ref_pattern(const char *refname,
249 const struct string_list_item *item)
250 {
251 int matched = 0;
252 if (item->util == NULL) {
253 if (!wildmatch(item->string, refname, 0))
254 matched = 1;
255 } else {
256 const char *rest;
257 if (skip_prefix(refname, item->string, &rest) &&
258 (!*rest || *rest == '/'))
259 matched = 1;
260 }
261 return matched;
262 }
263
264 int ref_filter_match(const char *refname,
265 const struct string_list *include_patterns,
266 const struct string_list *exclude_patterns)
267 {
268 struct string_list_item *item;
269
270 if (exclude_patterns && exclude_patterns->nr) {
271 for_each_string_list_item(item, exclude_patterns) {
272 if (match_ref_pattern(refname, item))
273 return 0;
274 }
275 }
276
277 if (include_patterns && include_patterns->nr) {
278 int found = 0;
279 for_each_string_list_item(item, include_patterns) {
280 if (match_ref_pattern(refname, item)) {
281 found = 1;
282 break;
283 }
284 }
285
286 if (!found)
287 return 0;
288 }
289 return 1;
290 }
291
292 static int filter_refs(const char *refname, const struct object_id *oid,
293 int flags, void *data)
294 {
295 struct ref_filter *filter = (struct ref_filter *)data;
296
297 if (wildmatch(filter->pattern, refname, 0))
298 return 0;
299 return filter->fn(refname, oid, flags, filter->cb_data);
300 }
301
302 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
303 {
304 struct object *o = lookup_unknown_object(name->hash);
305
306 if (o->type == OBJ_NONE) {
307 int type = oid_object_info(the_repository, name, NULL);
308 if (type < 0 || !object_as_type(o, type, 0))
309 return PEEL_INVALID;
310 }
311
312 if (o->type != OBJ_TAG)
313 return PEEL_NON_TAG;
314
315 o = deref_tag_noverify(o);
316 if (!o)
317 return PEEL_INVALID;
318
319 oidcpy(oid, &o->oid);
320 return PEEL_PEELED;
321 }
322
323 struct warn_if_dangling_data {
324 FILE *fp;
325 const char *refname;
326 const struct string_list *refnames;
327 const char *msg_fmt;
328 };
329
330 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
331 int flags, void *cb_data)
332 {
333 struct warn_if_dangling_data *d = cb_data;
334 const char *resolves_to;
335
336 if (!(flags & REF_ISSYMREF))
337 return 0;
338
339 resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
340 if (!resolves_to
341 || (d->refname
342 ? strcmp(resolves_to, d->refname)
343 : !string_list_has_string(d->refnames, resolves_to))) {
344 return 0;
345 }
346
347 fprintf(d->fp, d->msg_fmt, refname);
348 fputc('\n', d->fp);
349 return 0;
350 }
351
352 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
353 {
354 struct warn_if_dangling_data data;
355
356 data.fp = fp;
357 data.refname = refname;
358 data.refnames = NULL;
359 data.msg_fmt = msg_fmt;
360 for_each_rawref(warn_if_dangling_symref, &data);
361 }
362
363 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
364 {
365 struct warn_if_dangling_data data;
366
367 data.fp = fp;
368 data.refname = NULL;
369 data.refnames = refnames;
370 data.msg_fmt = msg_fmt;
371 for_each_rawref(warn_if_dangling_symref, &data);
372 }
373
374 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
375 {
376 return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
377 }
378
379 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
380 {
381 return refs_for_each_tag_ref(get_main_ref_store(the_repository), fn, cb_data);
382 }
383
384 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
385 {
386 return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
387 }
388
389 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
390 {
391 return refs_for_each_branch_ref(get_main_ref_store(the_repository), fn, cb_data);
392 }
393
394 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
395 {
396 return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
397 }
398
399 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
400 {
401 return refs_for_each_remote_ref(get_main_ref_store(the_repository), fn, cb_data);
402 }
403
404 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
405 {
406 struct strbuf buf = STRBUF_INIT;
407 int ret = 0;
408 struct object_id oid;
409 int flag;
410
411 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
412 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, &oid, &flag))
413 ret = fn(buf.buf, &oid, flag, cb_data);
414 strbuf_release(&buf);
415
416 return ret;
417 }
418
419 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
420 const char *pattern)
421 {
422 struct strbuf normalized_pattern = STRBUF_INIT;
423
424 if (*pattern == '/')
425 BUG("pattern must not start with '/'");
426
427 if (prefix) {
428 strbuf_addstr(&normalized_pattern, prefix);
429 }
430 else if (!starts_with(pattern, "refs/"))
431 strbuf_addstr(&normalized_pattern, "refs/");
432 strbuf_addstr(&normalized_pattern, pattern);
433 strbuf_strip_suffix(&normalized_pattern, "/");
434
435 item->string = strbuf_detach(&normalized_pattern, NULL);
436 item->util = has_glob_specials(pattern) ? NULL : item->string;
437 strbuf_release(&normalized_pattern);
438 }
439
440 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
441 const char *prefix, void *cb_data)
442 {
443 struct strbuf real_pattern = STRBUF_INIT;
444 struct ref_filter filter;
445 int ret;
446
447 if (!prefix && !starts_with(pattern, "refs/"))
448 strbuf_addstr(&real_pattern, "refs/");
449 else if (prefix)
450 strbuf_addstr(&real_pattern, prefix);
451 strbuf_addstr(&real_pattern, pattern);
452
453 if (!has_glob_specials(pattern)) {
454 /* Append implied '/' '*' if not present. */
455 strbuf_complete(&real_pattern, '/');
456 /* No need to check for '*', there is none. */
457 strbuf_addch(&real_pattern, '*');
458 }
459
460 filter.pattern = real_pattern.buf;
461 filter.fn = fn;
462 filter.cb_data = cb_data;
463 ret = for_each_ref(filter_refs, &filter);
464
465 strbuf_release(&real_pattern);
466 return ret;
467 }
468
469 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
470 {
471 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
472 }
473
474 const char *prettify_refname(const char *name)
475 {
476 if (skip_prefix(name, "refs/heads/", &name) ||
477 skip_prefix(name, "refs/tags/", &name) ||
478 skip_prefix(name, "refs/remotes/", &name))
479 ; /* nothing */
480 return name;
481 }
482
483 static const char *ref_rev_parse_rules[] = {
484 "%.*s",
485 "refs/%.*s",
486 "refs/tags/%.*s",
487 "refs/heads/%.*s",
488 "refs/remotes/%.*s",
489 "refs/remotes/%.*s/HEAD",
490 NULL
491 };
492
493 int refname_match(const char *abbrev_name, const char *full_name)
494 {
495 const char **p;
496 const int abbrev_name_len = strlen(abbrev_name);
497
498 for (p = ref_rev_parse_rules; *p; p++) {
499 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
500 return 1;
501 }
502 }
503
504 return 0;
505 }
506
507 /*
508 * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
509 * the results to 'prefixes'
510 */
511 void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
512 {
513 const char **p;
514 int len = strlen(prefix);
515
516 for (p = ref_rev_parse_rules; *p; p++)
517 argv_array_pushf(prefixes, *p, len, prefix);
518 }
519
520 /*
521 * *string and *len will only be substituted, and *string returned (for
522 * later free()ing) if the string passed in is a magic short-hand form
523 * to name a branch.
524 */
525 static char *substitute_branch_name(const char **string, int *len)
526 {
527 struct strbuf buf = STRBUF_INIT;
528 int ret = interpret_branch_name(*string, *len, &buf, 0);
529
530 if (ret == *len) {
531 size_t size;
532 *string = strbuf_detach(&buf, &size);
533 *len = size;
534 return (char *)*string;
535 }
536
537 return NULL;
538 }
539
540 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
541 {
542 char *last_branch = substitute_branch_name(&str, &len);
543 int refs_found = expand_ref(str, len, oid, ref);
544 free(last_branch);
545 return refs_found;
546 }
547
548 int expand_ref(const char *str, int len, struct object_id *oid, char **ref)
549 {
550 const char **p, *r;
551 int refs_found = 0;
552 struct strbuf fullref = STRBUF_INIT;
553
554 *ref = NULL;
555 for (p = ref_rev_parse_rules; *p; p++) {
556 struct object_id oid_from_ref;
557 struct object_id *this_result;
558 int flag;
559
560 this_result = refs_found ? &oid_from_ref : oid;
561 strbuf_reset(&fullref);
562 strbuf_addf(&fullref, *p, len, str);
563 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
564 this_result, &flag);
565 if (r) {
566 if (!refs_found++)
567 *ref = xstrdup(r);
568 if (!warn_ambiguous_refs)
569 break;
570 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
571 warning("ignoring dangling symref %s.", fullref.buf);
572 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
573 warning("ignoring broken ref %s.", fullref.buf);
574 }
575 }
576 strbuf_release(&fullref);
577 return refs_found;
578 }
579
580 int dwim_log(const char *str, int len, struct object_id *oid, char **log)
581 {
582 char *last_branch = substitute_branch_name(&str, &len);
583 const char **p;
584 int logs_found = 0;
585 struct strbuf path = STRBUF_INIT;
586
587 *log = NULL;
588 for (p = ref_rev_parse_rules; *p; p++) {
589 struct object_id hash;
590 const char *ref, *it;
591
592 strbuf_reset(&path);
593 strbuf_addf(&path, *p, len, str);
594 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
595 &hash, NULL);
596 if (!ref)
597 continue;
598 if (reflog_exists(path.buf))
599 it = path.buf;
600 else if (strcmp(ref, path.buf) && reflog_exists(ref))
601 it = ref;
602 else
603 continue;
604 if (!logs_found++) {
605 *log = xstrdup(it);
606 oidcpy(oid, &hash);
607 }
608 if (!warn_ambiguous_refs)
609 break;
610 }
611 strbuf_release(&path);
612 free(last_branch);
613 return logs_found;
614 }
615
616 static int is_per_worktree_ref(const char *refname)
617 {
618 return !strcmp(refname, "HEAD") ||
619 starts_with(refname, "refs/bisect/") ||
620 starts_with(refname, "refs/rewritten/");
621 }
622
623 static int is_pseudoref_syntax(const char *refname)
624 {
625 const char *c;
626
627 for (c = refname; *c; c++) {
628 if (!isupper(*c) && *c != '-' && *c != '_')
629 return 0;
630 }
631
632 return 1;
633 }
634
635 enum ref_type ref_type(const char *refname)
636 {
637 if (is_per_worktree_ref(refname))
638 return REF_TYPE_PER_WORKTREE;
639 if (is_pseudoref_syntax(refname))
640 return REF_TYPE_PSEUDOREF;
641 return REF_TYPE_NORMAL;
642 }
643
644 long get_files_ref_lock_timeout_ms(void)
645 {
646 static int configured = 0;
647
648 /* The default timeout is 100 ms: */
649 static int timeout_ms = 100;
650
651 if (!configured) {
652 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
653 configured = 1;
654 }
655
656 return timeout_ms;
657 }
658
659 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
660 const struct object_id *old_oid, struct strbuf *err)
661 {
662 const char *filename;
663 int fd;
664 struct lock_file lock = LOCK_INIT;
665 struct strbuf buf = STRBUF_INIT;
666 int ret = -1;
667
668 if (!oid)
669 return 0;
670
671 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
672
673 filename = git_path("%s", pseudoref);
674 fd = hold_lock_file_for_update_timeout(&lock, filename, 0,
675 get_files_ref_lock_timeout_ms());
676 if (fd < 0) {
677 strbuf_addf(err, "could not open '%s' for writing: %s",
678 filename, strerror(errno));
679 goto done;
680 }
681
682 if (old_oid) {
683 struct object_id actual_old_oid;
684
685 if (read_ref(pseudoref, &actual_old_oid)) {
686 if (!is_null_oid(old_oid)) {
687 strbuf_addf(err, "could not read ref '%s'",
688 pseudoref);
689 rollback_lock_file(&lock);
690 goto done;
691 }
692 } else if (is_null_oid(old_oid)) {
693 strbuf_addf(err, "ref '%s' already exists",
694 pseudoref);
695 rollback_lock_file(&lock);
696 goto done;
697 } else if (oidcmp(&actual_old_oid, old_oid)) {
698 strbuf_addf(err, "unexpected object ID when writing '%s'",
699 pseudoref);
700 rollback_lock_file(&lock);
701 goto done;
702 }
703 }
704
705 if (write_in_full(fd, buf.buf, buf.len) < 0) {
706 strbuf_addf(err, "could not write to '%s'", filename);
707 rollback_lock_file(&lock);
708 goto done;
709 }
710
711 commit_lock_file(&lock);
712 ret = 0;
713 done:
714 strbuf_release(&buf);
715 return ret;
716 }
717
718 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
719 {
720 const char *filename;
721
722 filename = git_path("%s", pseudoref);
723
724 if (old_oid && !is_null_oid(old_oid)) {
725 struct lock_file lock = LOCK_INIT;
726 int fd;
727 struct object_id actual_old_oid;
728
729 fd = hold_lock_file_for_update_timeout(
730 &lock, filename, 0,
731 get_files_ref_lock_timeout_ms());
732 if (fd < 0) {
733 error_errno(_("could not open '%s' for writing"),
734 filename);
735 return -1;
736 }
737 if (read_ref(pseudoref, &actual_old_oid))
738 die("could not read ref '%s'", pseudoref);
739 if (oidcmp(&actual_old_oid, old_oid)) {
740 error("unexpected object ID when deleting '%s'",
741 pseudoref);
742 rollback_lock_file(&lock);
743 return -1;
744 }
745
746 unlink(filename);
747 rollback_lock_file(&lock);
748 } else {
749 unlink(filename);
750 }
751
752 return 0;
753 }
754
755 int refs_delete_ref(struct ref_store *refs, const char *msg,
756 const char *refname,
757 const struct object_id *old_oid,
758 unsigned int flags)
759 {
760 struct ref_transaction *transaction;
761 struct strbuf err = STRBUF_INIT;
762
763 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
764 assert(refs == get_main_ref_store(the_repository));
765 return delete_pseudoref(refname, old_oid);
766 }
767
768 transaction = ref_store_transaction_begin(refs, &err);
769 if (!transaction ||
770 ref_transaction_delete(transaction, refname, old_oid,
771 flags, msg, &err) ||
772 ref_transaction_commit(transaction, &err)) {
773 error("%s", err.buf);
774 ref_transaction_free(transaction);
775 strbuf_release(&err);
776 return 1;
777 }
778 ref_transaction_free(transaction);
779 strbuf_release(&err);
780 return 0;
781 }
782
783 int delete_ref(const char *msg, const char *refname,
784 const struct object_id *old_oid, unsigned int flags)
785 {
786 return refs_delete_ref(get_main_ref_store(the_repository), msg, refname,
787 old_oid, flags);
788 }
789
790 void copy_reflog_msg(struct strbuf *sb, const char *msg)
791 {
792 char c;
793 int wasspace = 1;
794
795 strbuf_addch(sb, '\t');
796 while ((c = *msg++)) {
797 if (wasspace && isspace(c))
798 continue;
799 wasspace = isspace(c);
800 if (wasspace)
801 c = ' ';
802 strbuf_addch(sb, c);
803 }
804 strbuf_rtrim(sb);
805 }
806
807 int should_autocreate_reflog(const char *refname)
808 {
809 switch (log_all_ref_updates) {
810 case LOG_REFS_ALWAYS:
811 return 1;
812 case LOG_REFS_NORMAL:
813 return starts_with(refname, "refs/heads/") ||
814 starts_with(refname, "refs/remotes/") ||
815 starts_with(refname, "refs/notes/") ||
816 !strcmp(refname, "HEAD");
817 default:
818 return 0;
819 }
820 }
821
822 int is_branch(const char *refname)
823 {
824 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
825 }
826
827 struct read_ref_at_cb {
828 const char *refname;
829 timestamp_t at_time;
830 int cnt;
831 int reccnt;
832 struct object_id *oid;
833 int found_it;
834
835 struct object_id ooid;
836 struct object_id noid;
837 int tz;
838 timestamp_t date;
839 char **msg;
840 timestamp_t *cutoff_time;
841 int *cutoff_tz;
842 int *cutoff_cnt;
843 };
844
845 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
846 const char *email, timestamp_t timestamp, int tz,
847 const char *message, void *cb_data)
848 {
849 struct read_ref_at_cb *cb = cb_data;
850
851 cb->reccnt++;
852 cb->tz = tz;
853 cb->date = timestamp;
854
855 if (timestamp <= cb->at_time || cb->cnt == 0) {
856 if (cb->msg)
857 *cb->msg = xstrdup(message);
858 if (cb->cutoff_time)
859 *cb->cutoff_time = timestamp;
860 if (cb->cutoff_tz)
861 *cb->cutoff_tz = tz;
862 if (cb->cutoff_cnt)
863 *cb->cutoff_cnt = cb->reccnt - 1;
864 /*
865 * we have not yet updated cb->[n|o]oid so they still
866 * hold the values for the previous record.
867 */
868 if (!is_null_oid(&cb->ooid)) {
869 oidcpy(cb->oid, noid);
870 if (oidcmp(&cb->ooid, noid))
871 warning("Log for ref %s has gap after %s.",
872 cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
873 }
874 else if (cb->date == cb->at_time)
875 oidcpy(cb->oid, noid);
876 else if (oidcmp(noid, cb->oid))
877 warning("Log for ref %s unexpectedly ended on %s.",
878 cb->refname, show_date(cb->date, cb->tz,
879 DATE_MODE(RFC2822)));
880 oidcpy(&cb->ooid, ooid);
881 oidcpy(&cb->noid, noid);
882 cb->found_it = 1;
883 return 1;
884 }
885 oidcpy(&cb->ooid, ooid);
886 oidcpy(&cb->noid, noid);
887 if (cb->cnt > 0)
888 cb->cnt--;
889 return 0;
890 }
891
892 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
893 const char *email, timestamp_t timestamp,
894 int tz, const char *message, void *cb_data)
895 {
896 struct read_ref_at_cb *cb = cb_data;
897
898 if (cb->msg)
899 *cb->msg = xstrdup(message);
900 if (cb->cutoff_time)
901 *cb->cutoff_time = timestamp;
902 if (cb->cutoff_tz)
903 *cb->cutoff_tz = tz;
904 if (cb->cutoff_cnt)
905 *cb->cutoff_cnt = cb->reccnt;
906 oidcpy(cb->oid, ooid);
907 if (is_null_oid(cb->oid))
908 oidcpy(cb->oid, noid);
909 /* We just want the first entry */
910 return 1;
911 }
912
913 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
914 struct object_id *oid, char **msg,
915 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
916 {
917 struct read_ref_at_cb cb;
918
919 memset(&cb, 0, sizeof(cb));
920 cb.refname = refname;
921 cb.at_time = at_time;
922 cb.cnt = cnt;
923 cb.msg = msg;
924 cb.cutoff_time = cutoff_time;
925 cb.cutoff_tz = cutoff_tz;
926 cb.cutoff_cnt = cutoff_cnt;
927 cb.oid = oid;
928
929 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
930
931 if (!cb.reccnt) {
932 if (flags & GET_OID_QUIETLY)
933 exit(128);
934 else
935 die("Log for %s is empty.", refname);
936 }
937 if (cb.found_it)
938 return 0;
939
940 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
941
942 return 1;
943 }
944
945 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
946 struct strbuf *err)
947 {
948 struct ref_transaction *tr;
949 assert(err);
950
951 tr = xcalloc(1, sizeof(struct ref_transaction));
952 tr->ref_store = refs;
953 return tr;
954 }
955
956 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
957 {
958 return ref_store_transaction_begin(get_main_ref_store(the_repository), err);
959 }
960
961 void ref_transaction_free(struct ref_transaction *transaction)
962 {
963 size_t i;
964
965 if (!transaction)
966 return;
967
968 switch (transaction->state) {
969 case REF_TRANSACTION_OPEN:
970 case REF_TRANSACTION_CLOSED:
971 /* OK */
972 break;
973 case REF_TRANSACTION_PREPARED:
974 BUG("free called on a prepared reference transaction");
975 break;
976 default:
977 BUG("unexpected reference transaction state");
978 break;
979 }
980
981 for (i = 0; i < transaction->nr; i++) {
982 free(transaction->updates[i]->msg);
983 free(transaction->updates[i]);
984 }
985 free(transaction->updates);
986 free(transaction);
987 }
988
989 struct ref_update *ref_transaction_add_update(
990 struct ref_transaction *transaction,
991 const char *refname, unsigned int flags,
992 const struct object_id *new_oid,
993 const struct object_id *old_oid,
994 const char *msg)
995 {
996 struct ref_update *update;
997
998 if (transaction->state != REF_TRANSACTION_OPEN)
999 BUG("update called for transaction that is not open");
1000
1001 FLEX_ALLOC_STR(update, refname, refname);
1002 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
1003 transaction->updates[transaction->nr++] = update;
1004
1005 update->flags = flags;
1006
1007 if (flags & REF_HAVE_NEW)
1008 oidcpy(&update->new_oid, new_oid);
1009 if (flags & REF_HAVE_OLD)
1010 oidcpy(&update->old_oid, old_oid);
1011 update->msg = xstrdup_or_null(msg);
1012 return update;
1013 }
1014
1015 int ref_transaction_update(struct ref_transaction *transaction,
1016 const char *refname,
1017 const struct object_id *new_oid,
1018 const struct object_id *old_oid,
1019 unsigned int flags, const char *msg,
1020 struct strbuf *err)
1021 {
1022 assert(err);
1023
1024 if ((new_oid && !is_null_oid(new_oid)) ?
1025 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
1026 !refname_is_safe(refname)) {
1027 strbuf_addf(err, "refusing to update ref with bad name '%s'",
1028 refname);
1029 return -1;
1030 }
1031
1032 if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1033 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1034
1035 flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1036
1037 ref_transaction_add_update(transaction, refname, flags,
1038 new_oid, old_oid, msg);
1039 return 0;
1040 }
1041
1042 int ref_transaction_create(struct ref_transaction *transaction,
1043 const char *refname,
1044 const struct object_id *new_oid,
1045 unsigned int flags, const char *msg,
1046 struct strbuf *err)
1047 {
1048 if (!new_oid || is_null_oid(new_oid))
1049 BUG("create called without valid new_oid");
1050 return ref_transaction_update(transaction, refname, new_oid,
1051 &null_oid, flags, msg, err);
1052 }
1053
1054 int ref_transaction_delete(struct ref_transaction *transaction,
1055 const char *refname,
1056 const struct object_id *old_oid,
1057 unsigned int flags, const char *msg,
1058 struct strbuf *err)
1059 {
1060 if (old_oid && is_null_oid(old_oid))
1061 BUG("delete called with old_oid set to zeros");
1062 return ref_transaction_update(transaction, refname,
1063 &null_oid, old_oid,
1064 flags, msg, err);
1065 }
1066
1067 int ref_transaction_verify(struct ref_transaction *transaction,
1068 const char *refname,
1069 const struct object_id *old_oid,
1070 unsigned int flags,
1071 struct strbuf *err)
1072 {
1073 if (!old_oid)
1074 BUG("verify called with old_oid set to NULL");
1075 return ref_transaction_update(transaction, refname,
1076 NULL, old_oid,
1077 flags, NULL, err);
1078 }
1079
1080 int refs_update_ref(struct ref_store *refs, const char *msg,
1081 const char *refname, const struct object_id *new_oid,
1082 const struct object_id *old_oid, unsigned int flags,
1083 enum action_on_err onerr)
1084 {
1085 struct ref_transaction *t = NULL;
1086 struct strbuf err = STRBUF_INIT;
1087 int ret = 0;
1088
1089 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1090 assert(refs == get_main_ref_store(the_repository));
1091 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1092 } else {
1093 t = ref_store_transaction_begin(refs, &err);
1094 if (!t ||
1095 ref_transaction_update(t, refname, new_oid, old_oid,
1096 flags, msg, &err) ||
1097 ref_transaction_commit(t, &err)) {
1098 ret = 1;
1099 ref_transaction_free(t);
1100 }
1101 }
1102 if (ret) {
1103 const char *str = "update_ref failed for ref '%s': %s";
1104
1105 switch (onerr) {
1106 case UPDATE_REFS_MSG_ON_ERR:
1107 error(str, refname, err.buf);
1108 break;
1109 case UPDATE_REFS_DIE_ON_ERR:
1110 die(str, refname, err.buf);
1111 break;
1112 case UPDATE_REFS_QUIET_ON_ERR:
1113 break;
1114 }
1115 strbuf_release(&err);
1116 return 1;
1117 }
1118 strbuf_release(&err);
1119 if (t)
1120 ref_transaction_free(t);
1121 return 0;
1122 }
1123
1124 int update_ref(const char *msg, const char *refname,
1125 const struct object_id *new_oid,
1126 const struct object_id *old_oid,
1127 unsigned int flags, enum action_on_err onerr)
1128 {
1129 return refs_update_ref(get_main_ref_store(the_repository), msg, refname, new_oid,
1130 old_oid, flags, onerr);
1131 }
1132
1133 char *shorten_unambiguous_ref(const char *refname, int strict)
1134 {
1135 int i;
1136 static char **scanf_fmts;
1137 static int nr_rules;
1138 char *short_name;
1139 struct strbuf resolved_buf = STRBUF_INIT;
1140
1141 if (!nr_rules) {
1142 /*
1143 * Pre-generate scanf formats from ref_rev_parse_rules[].
1144 * Generate a format suitable for scanf from a
1145 * ref_rev_parse_rules rule by interpolating "%s" at the
1146 * location of the "%.*s".
1147 */
1148 size_t total_len = 0;
1149 size_t offset = 0;
1150
1151 /* the rule list is NULL terminated, count them first */
1152 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1153 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1154 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1155
1156 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1157
1158 offset = 0;
1159 for (i = 0; i < nr_rules; i++) {
1160 assert(offset < total_len);
1161 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1162 offset += xsnprintf(scanf_fmts[i], total_len - offset,
1163 ref_rev_parse_rules[i], 2, "%s") + 1;
1164 }
1165 }
1166
1167 /* bail out if there are no rules */
1168 if (!nr_rules)
1169 return xstrdup(refname);
1170
1171 /* buffer for scanf result, at most refname must fit */
1172 short_name = xstrdup(refname);
1173
1174 /* skip first rule, it will always match */
1175 for (i = nr_rules - 1; i > 0 ; --i) {
1176 int j;
1177 int rules_to_fail = i;
1178 int short_name_len;
1179
1180 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1181 continue;
1182
1183 short_name_len = strlen(short_name);
1184
1185 /*
1186 * in strict mode, all (except the matched one) rules
1187 * must fail to resolve to a valid non-ambiguous ref
1188 */
1189 if (strict)
1190 rules_to_fail = nr_rules;
1191
1192 /*
1193 * check if the short name resolves to a valid ref,
1194 * but use only rules prior to the matched one
1195 */
1196 for (j = 0; j < rules_to_fail; j++) {
1197 const char *rule = ref_rev_parse_rules[j];
1198
1199 /* skip matched rule */
1200 if (i == j)
1201 continue;
1202
1203 /*
1204 * the short name is ambiguous, if it resolves
1205 * (with this previous rule) to a valid ref
1206 * read_ref() returns 0 on success
1207 */
1208 strbuf_reset(&resolved_buf);
1209 strbuf_addf(&resolved_buf, rule,
1210 short_name_len, short_name);
1211 if (ref_exists(resolved_buf.buf))
1212 break;
1213 }
1214
1215 /*
1216 * short name is non-ambiguous if all previous rules
1217 * haven't resolved to a valid ref
1218 */
1219 if (j == rules_to_fail) {
1220 strbuf_release(&resolved_buf);
1221 return short_name;
1222 }
1223 }
1224
1225 strbuf_release(&resolved_buf);
1226 free(short_name);
1227 return xstrdup(refname);
1228 }
1229
1230 static struct string_list *hide_refs;
1231
1232 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1233 {
1234 const char *key;
1235 if (!strcmp("transfer.hiderefs", var) ||
1236 (!parse_config_key(var, section, NULL, NULL, &key) &&
1237 !strcmp(key, "hiderefs"))) {
1238 char *ref;
1239 int len;
1240
1241 if (!value)
1242 return config_error_nonbool(var);
1243 ref = xstrdup(value);
1244 len = strlen(ref);
1245 while (len && ref[len - 1] == '/')
1246 ref[--len] = '\0';
1247 if (!hide_refs) {
1248 hide_refs = xcalloc(1, sizeof(*hide_refs));
1249 hide_refs->strdup_strings = 1;
1250 }
1251 string_list_append(hide_refs, ref);
1252 }
1253 return 0;
1254 }
1255
1256 int ref_is_hidden(const char *refname, const char *refname_full)
1257 {
1258 int i;
1259
1260 if (!hide_refs)
1261 return 0;
1262 for (i = hide_refs->nr - 1; i >= 0; i--) {
1263 const char *match = hide_refs->items[i].string;
1264 const char *subject;
1265 int neg = 0;
1266 const char *p;
1267
1268 if (*match == '!') {
1269 neg = 1;
1270 match++;
1271 }
1272
1273 if (*match == '^') {
1274 subject = refname_full;
1275 match++;
1276 } else {
1277 subject = refname;
1278 }
1279
1280 /* refname can be NULL when namespaces are used. */
1281 if (subject &&
1282 skip_prefix(subject, match, &p) &&
1283 (!*p || *p == '/'))
1284 return !neg;
1285 }
1286 return 0;
1287 }
1288
1289 const char *find_descendant_ref(const char *dirname,
1290 const struct string_list *extras,
1291 const struct string_list *skip)
1292 {
1293 int pos;
1294
1295 if (!extras)
1296 return NULL;
1297
1298 /*
1299 * Look at the place where dirname would be inserted into
1300 * extras. If there is an entry at that position that starts
1301 * with dirname (remember, dirname includes the trailing
1302 * slash) and is not in skip, then we have a conflict.
1303 */
1304 for (pos = string_list_find_insert_index(extras, dirname, 0);
1305 pos < extras->nr; pos++) {
1306 const char *extra_refname = extras->items[pos].string;
1307
1308 if (!starts_with(extra_refname, dirname))
1309 break;
1310
1311 if (!skip || !string_list_has_string(skip, extra_refname))
1312 return extra_refname;
1313 }
1314 return NULL;
1315 }
1316
1317 int refs_rename_ref_available(struct ref_store *refs,
1318 const char *old_refname,
1319 const char *new_refname)
1320 {
1321 struct string_list skip = STRING_LIST_INIT_NODUP;
1322 struct strbuf err = STRBUF_INIT;
1323 int ok;
1324
1325 string_list_insert(&skip, old_refname);
1326 ok = !refs_verify_refname_available(refs, new_refname,
1327 NULL, &skip, &err);
1328 if (!ok)
1329 error("%s", err.buf);
1330
1331 string_list_clear(&skip, 0);
1332 strbuf_release(&err);
1333 return ok;
1334 }
1335
1336 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1337 {
1338 struct object_id oid;
1339 int flag;
1340
1341 if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1342 &oid, &flag))
1343 return fn("HEAD", &oid, flag, cb_data);
1344
1345 return 0;
1346 }
1347
1348 int head_ref(each_ref_fn fn, void *cb_data)
1349 {
1350 return refs_head_ref(get_main_ref_store(the_repository), fn, cb_data);
1351 }
1352
1353 struct ref_iterator *refs_ref_iterator_begin(
1354 struct ref_store *refs,
1355 const char *prefix, int trim, int flags)
1356 {
1357 struct ref_iterator *iter;
1358
1359 if (ref_paranoia < 0)
1360 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1361 if (ref_paranoia)
1362 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1363
1364 iter = refs->be->iterator_begin(refs, prefix, flags);
1365
1366 /*
1367 * `iterator_begin()` already takes care of prefix, but we
1368 * might need to do some trimming:
1369 */
1370 if (trim)
1371 iter = prefix_ref_iterator_begin(iter, "", trim);
1372
1373 /* Sanity check for subclasses: */
1374 if (!iter->ordered)
1375 BUG("reference iterator is not ordered");
1376
1377 return iter;
1378 }
1379
1380 /*
1381 * Call fn for each reference in the specified submodule for which the
1382 * refname begins with prefix. If trim is non-zero, then trim that
1383 * many characters off the beginning of each refname before passing
1384 * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1385 * include broken references in the iteration. If fn ever returns a
1386 * non-zero value, stop the iteration and return that value;
1387 * otherwise, return 0.
1388 */
1389 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1390 each_ref_fn fn, int trim, int flags, void *cb_data)
1391 {
1392 struct ref_iterator *iter;
1393
1394 if (!refs)
1395 return 0;
1396
1397 iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1398
1399 return do_for_each_ref_iterator(iter, fn, cb_data);
1400 }
1401
1402 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1403 {
1404 return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1405 }
1406
1407 int for_each_ref(each_ref_fn fn, void *cb_data)
1408 {
1409 return refs_for_each_ref(get_main_ref_store(the_repository), fn, cb_data);
1410 }
1411
1412 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1413 each_ref_fn fn, void *cb_data)
1414 {
1415 return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1416 }
1417
1418 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1419 {
1420 return refs_for_each_ref_in(get_main_ref_store(the_repository), prefix, fn, cb_data);
1421 }
1422
1423 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, 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(get_main_ref_store(the_repository),
1430 prefix, fn, 0, flag, cb_data);
1431 }
1432
1433 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1434 each_ref_fn fn, void *cb_data,
1435 unsigned int broken)
1436 {
1437 unsigned int flag = 0;
1438
1439 if (broken)
1440 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1441 return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1442 }
1443
1444 int for_each_replace_ref(struct repository *r, each_ref_fn fn, void *cb_data)
1445 {
1446 return do_for_each_ref(get_main_ref_store(r),
1447 git_replace_ref_base, fn,
1448 strlen(git_replace_ref_base),
1449 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1450 }
1451
1452 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1453 {
1454 struct strbuf buf = STRBUF_INIT;
1455 int ret;
1456 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1457 ret = do_for_each_ref(get_main_ref_store(the_repository),
1458 buf.buf, fn, 0, 0, cb_data);
1459 strbuf_release(&buf);
1460 return ret;
1461 }
1462
1463 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1464 {
1465 return do_for_each_ref(refs, "", fn, 0,
1466 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1467 }
1468
1469 int for_each_rawref(each_ref_fn fn, void *cb_data)
1470 {
1471 return refs_for_each_rawref(get_main_ref_store(the_repository), fn, cb_data);
1472 }
1473
1474 int refs_read_raw_ref(struct ref_store *ref_store,
1475 const char *refname, struct object_id *oid,
1476 struct strbuf *referent, unsigned int *type)
1477 {
1478 return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1479 }
1480
1481 /* This function needs to return a meaningful errno on failure */
1482 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1483 const char *refname,
1484 int resolve_flags,
1485 struct object_id *oid, int *flags)
1486 {
1487 static struct strbuf sb_refname = STRBUF_INIT;
1488 struct object_id unused_oid;
1489 int unused_flags;
1490 int symref_count;
1491
1492 if (!oid)
1493 oid = &unused_oid;
1494 if (!flags)
1495 flags = &unused_flags;
1496
1497 *flags = 0;
1498
1499 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1500 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1501 !refname_is_safe(refname)) {
1502 errno = EINVAL;
1503 return NULL;
1504 }
1505
1506 /*
1507 * dwim_ref() uses REF_ISBROKEN to distinguish between
1508 * missing refs and refs that were present but invalid,
1509 * to complain about the latter to stderr.
1510 *
1511 * We don't know whether the ref exists, so don't set
1512 * REF_ISBROKEN yet.
1513 */
1514 *flags |= REF_BAD_NAME;
1515 }
1516
1517 for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1518 unsigned int read_flags = 0;
1519
1520 if (refs_read_raw_ref(refs, refname,
1521 oid, &sb_refname, &read_flags)) {
1522 *flags |= read_flags;
1523
1524 /* In reading mode, refs must eventually resolve */
1525 if (resolve_flags & RESOLVE_REF_READING)
1526 return NULL;
1527
1528 /*
1529 * Otherwise a missing ref is OK. But the files backend
1530 * may show errors besides ENOENT if there are
1531 * similarly-named refs.
1532 */
1533 if (errno != ENOENT &&
1534 errno != EISDIR &&
1535 errno != ENOTDIR)
1536 return NULL;
1537
1538 oidclr(oid);
1539 if (*flags & REF_BAD_NAME)
1540 *flags |= REF_ISBROKEN;
1541 return refname;
1542 }
1543
1544 *flags |= read_flags;
1545
1546 if (!(read_flags & REF_ISSYMREF)) {
1547 if (*flags & REF_BAD_NAME) {
1548 oidclr(oid);
1549 *flags |= REF_ISBROKEN;
1550 }
1551 return refname;
1552 }
1553
1554 refname = sb_refname.buf;
1555 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1556 oidclr(oid);
1557 return refname;
1558 }
1559 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1560 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1561 !refname_is_safe(refname)) {
1562 errno = EINVAL;
1563 return NULL;
1564 }
1565
1566 *flags |= REF_ISBROKEN | REF_BAD_NAME;
1567 }
1568 }
1569
1570 errno = ELOOP;
1571 return NULL;
1572 }
1573
1574 /* backend functions */
1575 int refs_init_db(struct strbuf *err)
1576 {
1577 struct ref_store *refs = get_main_ref_store(the_repository);
1578
1579 return refs->be->init_db(refs, err);
1580 }
1581
1582 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1583 struct object_id *oid, int *flags)
1584 {
1585 return refs_resolve_ref_unsafe(get_main_ref_store(the_repository), refname,
1586 resolve_flags, oid, flags);
1587 }
1588
1589 int resolve_gitlink_ref(const char *submodule, const char *refname,
1590 struct object_id *oid)
1591 {
1592 struct ref_store *refs;
1593 int flags;
1594
1595 refs = get_submodule_ref_store(submodule);
1596
1597 if (!refs)
1598 return -1;
1599
1600 if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1601 is_null_oid(oid))
1602 return -1;
1603 return 0;
1604 }
1605
1606 struct ref_store_hash_entry
1607 {
1608 struct hashmap_entry ent; /* must be the first member! */
1609
1610 struct ref_store *refs;
1611
1612 /* NUL-terminated identifier of the ref store: */
1613 char name[FLEX_ARRAY];
1614 };
1615
1616 static int ref_store_hash_cmp(const void *unused_cmp_data,
1617 const void *entry, const void *entry_or_key,
1618 const void *keydata)
1619 {
1620 const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1621 const char *name = keydata ? keydata : e2->name;
1622
1623 return strcmp(e1->name, name);
1624 }
1625
1626 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1627 const char *name, struct ref_store *refs)
1628 {
1629 struct ref_store_hash_entry *entry;
1630
1631 FLEX_ALLOC_STR(entry, name, name);
1632 hashmap_entry_init(entry, strhash(name));
1633 entry->refs = refs;
1634 return entry;
1635 }
1636
1637 /* A hashmap of ref_stores, stored by submodule name: */
1638 static struct hashmap submodule_ref_stores;
1639
1640 /* A hashmap of ref_stores, stored by worktree id: */
1641 static struct hashmap worktree_ref_stores;
1642
1643 /*
1644 * Look up a ref store by name. If that ref_store hasn't been
1645 * registered yet, return NULL.
1646 */
1647 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1648 const char *name)
1649 {
1650 struct ref_store_hash_entry *entry;
1651
1652 if (!map->tablesize)
1653 /* It's initialized on demand in register_ref_store(). */
1654 return NULL;
1655
1656 entry = hashmap_get_from_hash(map, strhash(name), name);
1657 return entry ? entry->refs : NULL;
1658 }
1659
1660 /*
1661 * Create, record, and return a ref_store instance for the specified
1662 * gitdir.
1663 */
1664 static struct ref_store *ref_store_init(const char *gitdir,
1665 unsigned int flags)
1666 {
1667 const char *be_name = "files";
1668 struct ref_storage_be *be = find_ref_storage_backend(be_name);
1669 struct ref_store *refs;
1670
1671 if (!be)
1672 BUG("reference backend %s is unknown", be_name);
1673
1674 refs = be->init(gitdir, flags);
1675 return refs;
1676 }
1677
1678 struct ref_store *get_main_ref_store(struct repository *r)
1679 {
1680 if (r->refs)
1681 return r->refs;
1682
1683 if (!r->gitdir)
1684 BUG("attempting to get main_ref_store outside of repository");
1685
1686 r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
1687 return r->refs;
1688 }
1689
1690 /*
1691 * Associate a ref store with a name. It is a fatal error to call this
1692 * function twice for the same name.
1693 */
1694 static void register_ref_store_map(struct hashmap *map,
1695 const char *type,
1696 struct ref_store *refs,
1697 const char *name)
1698 {
1699 if (!map->tablesize)
1700 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1701
1702 if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1703 BUG("%s ref_store '%s' initialized twice", type, name);
1704 }
1705
1706 struct ref_store *get_submodule_ref_store(const char *submodule)
1707 {
1708 struct strbuf submodule_sb = STRBUF_INIT;
1709 struct ref_store *refs;
1710 char *to_free = NULL;
1711 size_t len;
1712
1713 if (!submodule)
1714 return NULL;
1715
1716 len = strlen(submodule);
1717 while (len && is_dir_sep(submodule[len - 1]))
1718 len--;
1719 if (!len)
1720 return NULL;
1721
1722 if (submodule[len])
1723 /* We need to strip off one or more trailing slashes */
1724 submodule = to_free = xmemdupz(submodule, len);
1725
1726 refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1727 if (refs)
1728 goto done;
1729
1730 strbuf_addstr(&submodule_sb, submodule);
1731 if (!is_nonbare_repository_dir(&submodule_sb))
1732 goto done;
1733
1734 if (submodule_to_gitdir(&submodule_sb, submodule))
1735 goto done;
1736
1737 /* assume that add_submodule_odb() has been called */
1738 refs = ref_store_init(submodule_sb.buf,
1739 REF_STORE_READ | REF_STORE_ODB);
1740 register_ref_store_map(&submodule_ref_stores, "submodule",
1741 refs, submodule);
1742
1743 done:
1744 strbuf_release(&submodule_sb);
1745 free(to_free);
1746
1747 return refs;
1748 }
1749
1750 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1751 {
1752 struct ref_store *refs;
1753 const char *id;
1754
1755 if (wt->is_current)
1756 return get_main_ref_store(the_repository);
1757
1758 id = wt->id ? wt->id : "/";
1759 refs = lookup_ref_store_map(&worktree_ref_stores, id);
1760 if (refs)
1761 return refs;
1762
1763 if (wt->id)
1764 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1765 REF_STORE_ALL_CAPS);
1766 else
1767 refs = ref_store_init(get_git_common_dir(),
1768 REF_STORE_ALL_CAPS);
1769
1770 if (refs)
1771 register_ref_store_map(&worktree_ref_stores, "worktree",
1772 refs, id);
1773 return refs;
1774 }
1775
1776 void base_ref_store_init(struct ref_store *refs,
1777 const struct ref_storage_be *be)
1778 {
1779 refs->be = be;
1780 }
1781
1782 /* backend functions */
1783 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1784 {
1785 return refs->be->pack_refs(refs, flags);
1786 }
1787
1788 int refs_peel_ref(struct ref_store *refs, const char *refname,
1789 struct object_id *oid)
1790 {
1791 int flag;
1792 struct object_id base;
1793
1794 if (current_ref_iter && current_ref_iter->refname == refname) {
1795 struct object_id peeled;
1796
1797 if (ref_iterator_peel(current_ref_iter, &peeled))
1798 return -1;
1799 oidcpy(oid, &peeled);
1800 return 0;
1801 }
1802
1803 if (refs_read_ref_full(refs, refname,
1804 RESOLVE_REF_READING, &base, &flag))
1805 return -1;
1806
1807 return peel_object(&base, oid);
1808 }
1809
1810 int peel_ref(const char *refname, struct object_id *oid)
1811 {
1812 return refs_peel_ref(get_main_ref_store(the_repository), refname, oid);
1813 }
1814
1815 int refs_create_symref(struct ref_store *refs,
1816 const char *ref_target,
1817 const char *refs_heads_master,
1818 const char *logmsg)
1819 {
1820 return refs->be->create_symref(refs, ref_target,
1821 refs_heads_master,
1822 logmsg);
1823 }
1824
1825 int create_symref(const char *ref_target, const char *refs_heads_master,
1826 const char *logmsg)
1827 {
1828 return refs_create_symref(get_main_ref_store(the_repository), ref_target,
1829 refs_heads_master, logmsg);
1830 }
1831
1832 int ref_update_reject_duplicates(struct string_list *refnames,
1833 struct strbuf *err)
1834 {
1835 size_t i, n = refnames->nr;
1836
1837 assert(err);
1838
1839 for (i = 1; i < n; i++) {
1840 int cmp = strcmp(refnames->items[i - 1].string,
1841 refnames->items[i].string);
1842
1843 if (!cmp) {
1844 strbuf_addf(err,
1845 "multiple updates for ref '%s' not allowed.",
1846 refnames->items[i].string);
1847 return 1;
1848 } else if (cmp > 0) {
1849 BUG("ref_update_reject_duplicates() received unsorted list");
1850 }
1851 }
1852 return 0;
1853 }
1854
1855 int ref_transaction_prepare(struct ref_transaction *transaction,
1856 struct strbuf *err)
1857 {
1858 struct ref_store *refs = transaction->ref_store;
1859
1860 switch (transaction->state) {
1861 case REF_TRANSACTION_OPEN:
1862 /* Good. */
1863 break;
1864 case REF_TRANSACTION_PREPARED:
1865 BUG("prepare called twice on reference transaction");
1866 break;
1867 case REF_TRANSACTION_CLOSED:
1868 BUG("prepare called on a closed reference transaction");
1869 break;
1870 default:
1871 BUG("unexpected reference transaction state");
1872 break;
1873 }
1874
1875 if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1876 strbuf_addstr(err,
1877 _("ref updates forbidden inside quarantine environment"));
1878 return -1;
1879 }
1880
1881 return refs->be->transaction_prepare(refs, transaction, err);
1882 }
1883
1884 int ref_transaction_abort(struct ref_transaction *transaction,
1885 struct strbuf *err)
1886 {
1887 struct ref_store *refs = transaction->ref_store;
1888 int ret = 0;
1889
1890 switch (transaction->state) {
1891 case REF_TRANSACTION_OPEN:
1892 /* No need to abort explicitly. */
1893 break;
1894 case REF_TRANSACTION_PREPARED:
1895 ret = refs->be->transaction_abort(refs, transaction, err);
1896 break;
1897 case REF_TRANSACTION_CLOSED:
1898 BUG("abort called on a closed reference transaction");
1899 break;
1900 default:
1901 BUG("unexpected reference transaction state");
1902 break;
1903 }
1904
1905 ref_transaction_free(transaction);
1906 return ret;
1907 }
1908
1909 int ref_transaction_commit(struct ref_transaction *transaction,
1910 struct strbuf *err)
1911 {
1912 struct ref_store *refs = transaction->ref_store;
1913 int ret;
1914
1915 switch (transaction->state) {
1916 case REF_TRANSACTION_OPEN:
1917 /* Need to prepare first. */
1918 ret = ref_transaction_prepare(transaction, err);
1919 if (ret)
1920 return ret;
1921 break;
1922 case REF_TRANSACTION_PREPARED:
1923 /* Fall through to finish. */
1924 break;
1925 case REF_TRANSACTION_CLOSED:
1926 BUG("commit called on a closed reference transaction");
1927 break;
1928 default:
1929 BUG("unexpected reference transaction state");
1930 break;
1931 }
1932
1933 return refs->be->transaction_finish(refs, transaction, err);
1934 }
1935
1936 int refs_verify_refname_available(struct ref_store *refs,
1937 const char *refname,
1938 const struct string_list *extras,
1939 const struct string_list *skip,
1940 struct strbuf *err)
1941 {
1942 const char *slash;
1943 const char *extra_refname;
1944 struct strbuf dirname = STRBUF_INIT;
1945 struct strbuf referent = STRBUF_INIT;
1946 struct object_id oid;
1947 unsigned int type;
1948 struct ref_iterator *iter;
1949 int ok;
1950 int ret = -1;
1951
1952 /*
1953 * For the sake of comments in this function, suppose that
1954 * refname is "refs/foo/bar".
1955 */
1956
1957 assert(err);
1958
1959 strbuf_grow(&dirname, strlen(refname) + 1);
1960 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1961 /* Expand dirname to the new prefix, not including the trailing slash: */
1962 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1963
1964 /*
1965 * We are still at a leading dir of the refname (e.g.,
1966 * "refs/foo"; if there is a reference with that name,
1967 * it is a conflict, *unless* it is in skip.
1968 */
1969 if (skip && string_list_has_string(skip, dirname.buf))
1970 continue;
1971
1972 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1973 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1974 dirname.buf, refname);
1975 goto cleanup;
1976 }
1977
1978 if (extras && string_list_has_string(extras, dirname.buf)) {
1979 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1980 refname, dirname.buf);
1981 goto cleanup;
1982 }
1983 }
1984
1985 /*
1986 * We are at the leaf of our refname (e.g., "refs/foo/bar").
1987 * There is no point in searching for a reference with that
1988 * name, because a refname isn't considered to conflict with
1989 * itself. But we still need to check for references whose
1990 * names are in the "refs/foo/bar/" namespace, because they
1991 * *do* conflict.
1992 */
1993 strbuf_addstr(&dirname, refname + dirname.len);
1994 strbuf_addch(&dirname, '/');
1995
1996 iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1997 DO_FOR_EACH_INCLUDE_BROKEN);
1998 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1999 if (skip &&
2000 string_list_has_string(skip, iter->refname))
2001 continue;
2002
2003 strbuf_addf(err, "'%s' exists; cannot create '%s'",
2004 iter->refname, refname);
2005 ref_iterator_abort(iter);
2006 goto cleanup;
2007 }
2008
2009 if (ok != ITER_DONE)
2010 BUG("error while iterating over references");
2011
2012 extra_refname = find_descendant_ref(dirname.buf, extras, skip);
2013 if (extra_refname)
2014 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
2015 refname, extra_refname);
2016 else
2017 ret = 0;
2018
2019 cleanup:
2020 strbuf_release(&referent);
2021 strbuf_release(&dirname);
2022 return ret;
2023 }
2024
2025 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2026 {
2027 struct ref_iterator *iter;
2028
2029 iter = refs->be->reflog_iterator_begin(refs);
2030
2031 return do_for_each_ref_iterator(iter, fn, cb_data);
2032 }
2033
2034 int for_each_reflog(each_ref_fn fn, void *cb_data)
2035 {
2036 return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
2037 }
2038
2039 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2040 const char *refname,
2041 each_reflog_ent_fn fn,
2042 void *cb_data)
2043 {
2044 return refs->be->for_each_reflog_ent_reverse(refs, refname,
2045 fn, cb_data);
2046 }
2047
2048 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2049 void *cb_data)
2050 {
2051 return refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
2052 refname, fn, cb_data);
2053 }
2054
2055 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2056 each_reflog_ent_fn fn, void *cb_data)
2057 {
2058 return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2059 }
2060
2061 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2062 void *cb_data)
2063 {
2064 return refs_for_each_reflog_ent(get_main_ref_store(the_repository), refname,
2065 fn, cb_data);
2066 }
2067
2068 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2069 {
2070 return refs->be->reflog_exists(refs, refname);
2071 }
2072
2073 int reflog_exists(const char *refname)
2074 {
2075 return refs_reflog_exists(get_main_ref_store(the_repository), refname);
2076 }
2077
2078 int refs_create_reflog(struct ref_store *refs, const char *refname,
2079 int force_create, struct strbuf *err)
2080 {
2081 return refs->be->create_reflog(refs, refname, force_create, err);
2082 }
2083
2084 int safe_create_reflog(const char *refname, int force_create,
2085 struct strbuf *err)
2086 {
2087 return refs_create_reflog(get_main_ref_store(the_repository), refname,
2088 force_create, err);
2089 }
2090
2091 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2092 {
2093 return refs->be->delete_reflog(refs, refname);
2094 }
2095
2096 int delete_reflog(const char *refname)
2097 {
2098 return refs_delete_reflog(get_main_ref_store(the_repository), refname);
2099 }
2100
2101 int refs_reflog_expire(struct ref_store *refs,
2102 const char *refname, const struct object_id *oid,
2103 unsigned int flags,
2104 reflog_expiry_prepare_fn prepare_fn,
2105 reflog_expiry_should_prune_fn should_prune_fn,
2106 reflog_expiry_cleanup_fn cleanup_fn,
2107 void *policy_cb_data)
2108 {
2109 return refs->be->reflog_expire(refs, refname, oid, flags,
2110 prepare_fn, should_prune_fn,
2111 cleanup_fn, policy_cb_data);
2112 }
2113
2114 int reflog_expire(const char *refname, const struct object_id *oid,
2115 unsigned int flags,
2116 reflog_expiry_prepare_fn prepare_fn,
2117 reflog_expiry_should_prune_fn should_prune_fn,
2118 reflog_expiry_cleanup_fn cleanup_fn,
2119 void *policy_cb_data)
2120 {
2121 return refs_reflog_expire(get_main_ref_store(the_repository),
2122 refname, oid, flags,
2123 prepare_fn, should_prune_fn,
2124 cleanup_fn, policy_cb_data);
2125 }
2126
2127 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2128 struct strbuf *err)
2129 {
2130 struct ref_store *refs = transaction->ref_store;
2131
2132 return refs->be->initial_transaction_commit(refs, transaction, err);
2133 }
2134
2135 int refs_delete_refs(struct ref_store *refs, const char *msg,
2136 struct string_list *refnames, unsigned int flags)
2137 {
2138 return refs->be->delete_refs(refs, msg, refnames, flags);
2139 }
2140
2141 int delete_refs(const char *msg, struct string_list *refnames,
2142 unsigned int flags)
2143 {
2144 return refs_delete_refs(get_main_ref_store(the_repository), msg, refnames, flags);
2145 }
2146
2147 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2148 const char *newref, const char *logmsg)
2149 {
2150 return refs->be->rename_ref(refs, oldref, newref, logmsg);
2151 }
2152
2153 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2154 {
2155 return refs_rename_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2156 }
2157
2158 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2159 const char *newref, const char *logmsg)
2160 {
2161 return refs->be->copy_ref(refs, oldref, newref, logmsg);
2162 }
2163
2164 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2165 {
2166 return refs_copy_existing_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2167 }