Merge branch 'js/rebase-deprecate-preserve-merges'
[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_object_file(oid)) {
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         const char *prefix;
221         each_ref_fn *fn;
222         void *cb_data;
223 };
224
225 int refs_read_ref_full(struct ref_store *refs, const char *refname,
226                        int resolve_flags, struct object_id *oid, int *flags)
227 {
228         if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
229                 return 0;
230         return -1;
231 }
232
233 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
234 {
235         return refs_read_ref_full(get_main_ref_store(the_repository), refname,
236                                   resolve_flags, oid, flags);
237 }
238
239 int read_ref(const char *refname, struct object_id *oid)
240 {
241         return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
242 }
243
244 static int refs_ref_exists(struct ref_store *refs, const char *refname)
245 {
246         return !!refs_resolve_ref_unsafe(refs, refname, RESOLVE_REF_READING, NULL, NULL);
247 }
248
249 int ref_exists(const char *refname)
250 {
251         return refs_ref_exists(get_main_ref_store(the_repository), refname);
252 }
253
254 static int match_ref_pattern(const char *refname,
255                              const struct string_list_item *item)
256 {
257         int matched = 0;
258         if (item->util == NULL) {
259                 if (!wildmatch(item->string, refname, 0))
260                         matched = 1;
261         } else {
262                 const char *rest;
263                 if (skip_prefix(refname, item->string, &rest) &&
264                     (!*rest || *rest == '/'))
265                         matched = 1;
266         }
267         return matched;
268 }
269
270 int ref_filter_match(const char *refname,
271                      const struct string_list *include_patterns,
272                      const struct string_list *exclude_patterns)
273 {
274         struct string_list_item *item;
275
276         if (exclude_patterns && exclude_patterns->nr) {
277                 for_each_string_list_item(item, exclude_patterns) {
278                         if (match_ref_pattern(refname, item))
279                                 return 0;
280                 }
281         }
282
283         if (include_patterns && include_patterns->nr) {
284                 int found = 0;
285                 for_each_string_list_item(item, include_patterns) {
286                         if (match_ref_pattern(refname, item)) {
287                                 found = 1;
288                                 break;
289                         }
290                 }
291
292                 if (!found)
293                         return 0;
294         }
295         return 1;
296 }
297
298 static int filter_refs(const char *refname, const struct object_id *oid,
299                            int flags, void *data)
300 {
301         struct ref_filter *filter = (struct ref_filter *)data;
302
303         if (wildmatch(filter->pattern, refname, 0))
304                 return 0;
305         if (filter->prefix)
306                 skip_prefix(refname, filter->prefix, &refname);
307         return filter->fn(refname, oid, flags, filter->cb_data);
308 }
309
310 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
311 {
312         struct object *o = lookup_unknown_object(name->hash);
313
314         if (o->type == OBJ_NONE) {
315                 int type = oid_object_info(the_repository, name, NULL);
316                 if (type < 0 || !object_as_type(the_repository, o, type, 0))
317                         return PEEL_INVALID;
318         }
319
320         if (o->type != OBJ_TAG)
321                 return PEEL_NON_TAG;
322
323         o = deref_tag_noverify(o);
324         if (!o)
325                 return PEEL_INVALID;
326
327         oidcpy(oid, &o->oid);
328         return PEEL_PEELED;
329 }
330
331 struct warn_if_dangling_data {
332         FILE *fp;
333         const char *refname;
334         const struct string_list *refnames;
335         const char *msg_fmt;
336 };
337
338 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
339                                    int flags, void *cb_data)
340 {
341         struct warn_if_dangling_data *d = cb_data;
342         const char *resolves_to;
343
344         if (!(flags & REF_ISSYMREF))
345                 return 0;
346
347         resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
348         if (!resolves_to
349             || (d->refname
350                 ? strcmp(resolves_to, d->refname)
351                 : !string_list_has_string(d->refnames, resolves_to))) {
352                 return 0;
353         }
354
355         fprintf(d->fp, d->msg_fmt, refname);
356         fputc('\n', d->fp);
357         return 0;
358 }
359
360 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
361 {
362         struct warn_if_dangling_data data;
363
364         data.fp = fp;
365         data.refname = refname;
366         data.refnames = NULL;
367         data.msg_fmt = msg_fmt;
368         for_each_rawref(warn_if_dangling_symref, &data);
369 }
370
371 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
372 {
373         struct warn_if_dangling_data data;
374
375         data.fp = fp;
376         data.refname = NULL;
377         data.refnames = refnames;
378         data.msg_fmt = msg_fmt;
379         for_each_rawref(warn_if_dangling_symref, &data);
380 }
381
382 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
383 {
384         return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
385 }
386
387 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
388 {
389         return refs_for_each_tag_ref(get_main_ref_store(the_repository), fn, cb_data);
390 }
391
392 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
393 {
394         return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
395 }
396
397 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
398 {
399         return refs_for_each_branch_ref(get_main_ref_store(the_repository), fn, cb_data);
400 }
401
402 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
403 {
404         return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
405 }
406
407 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
408 {
409         return refs_for_each_remote_ref(get_main_ref_store(the_repository), fn, cb_data);
410 }
411
412 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
413 {
414         struct strbuf buf = STRBUF_INIT;
415         int ret = 0;
416         struct object_id oid;
417         int flag;
418
419         strbuf_addf(&buf, "%sHEAD", get_git_namespace());
420         if (!read_ref_full(buf.buf, RESOLVE_REF_READING, &oid, &flag))
421                 ret = fn(buf.buf, &oid, flag, cb_data);
422         strbuf_release(&buf);
423
424         return ret;
425 }
426
427 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
428                         const char *pattern)
429 {
430         struct strbuf normalized_pattern = STRBUF_INIT;
431
432         if (*pattern == '/')
433                 BUG("pattern must not start with '/'");
434
435         if (prefix) {
436                 strbuf_addstr(&normalized_pattern, prefix);
437         }
438         else if (!starts_with(pattern, "refs/"))
439                 strbuf_addstr(&normalized_pattern, "refs/");
440         strbuf_addstr(&normalized_pattern, pattern);
441         strbuf_strip_suffix(&normalized_pattern, "/");
442
443         item->string = strbuf_detach(&normalized_pattern, NULL);
444         item->util = has_glob_specials(pattern) ? NULL : item->string;
445         strbuf_release(&normalized_pattern);
446 }
447
448 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
449         const char *prefix, void *cb_data)
450 {
451         struct strbuf real_pattern = STRBUF_INIT;
452         struct ref_filter filter;
453         int ret;
454
455         if (!prefix && !starts_with(pattern, "refs/"))
456                 strbuf_addstr(&real_pattern, "refs/");
457         else if (prefix)
458                 strbuf_addstr(&real_pattern, prefix);
459         strbuf_addstr(&real_pattern, pattern);
460
461         if (!has_glob_specials(pattern)) {
462                 /* Append implied '/' '*' if not present. */
463                 strbuf_complete(&real_pattern, '/');
464                 /* No need to check for '*', there is none. */
465                 strbuf_addch(&real_pattern, '*');
466         }
467
468         filter.pattern = real_pattern.buf;
469         filter.prefix = prefix;
470         filter.fn = fn;
471         filter.cb_data = cb_data;
472         ret = for_each_ref(filter_refs, &filter);
473
474         strbuf_release(&real_pattern);
475         return ret;
476 }
477
478 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
479 {
480         return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
481 }
482
483 const char *prettify_refname(const char *name)
484 {
485         if (skip_prefix(name, "refs/heads/", &name) ||
486             skip_prefix(name, "refs/tags/", &name) ||
487             skip_prefix(name, "refs/remotes/", &name))
488                 ; /* nothing */
489         return name;
490 }
491
492 static const char *ref_rev_parse_rules[] = {
493         "%.*s",
494         "refs/%.*s",
495         "refs/tags/%.*s",
496         "refs/heads/%.*s",
497         "refs/remotes/%.*s",
498         "refs/remotes/%.*s/HEAD",
499         NULL
500 };
501
502 #define NUM_REV_PARSE_RULES (ARRAY_SIZE(ref_rev_parse_rules) - 1)
503
504 /*
505  * Is it possible that the caller meant full_name with abbrev_name?
506  * If so return a non-zero value to signal "yes"; the magnitude of
507  * the returned value gives the precedence used for disambiguation.
508  *
509  * If abbrev_name cannot mean full_name, return 0.
510  */
511 int refname_match(const char *abbrev_name, const char *full_name)
512 {
513         const char **p;
514         const int abbrev_name_len = strlen(abbrev_name);
515         const int num_rules = NUM_REV_PARSE_RULES;
516
517         for (p = ref_rev_parse_rules; *p; p++)
518                 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name)))
519                         return &ref_rev_parse_rules[num_rules] - p;
520
521         return 0;
522 }
523
524 /*
525  * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
526  * the results to 'prefixes'
527  */
528 void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
529 {
530         const char **p;
531         int len = strlen(prefix);
532
533         for (p = ref_rev_parse_rules; *p; p++)
534                 argv_array_pushf(prefixes, *p, len, prefix);
535 }
536
537 /*
538  * *string and *len will only be substituted, and *string returned (for
539  * later free()ing) if the string passed in is a magic short-hand form
540  * to name a branch.
541  */
542 static char *substitute_branch_name(struct repository *r,
543                                     const char **string, int *len)
544 {
545         struct strbuf buf = STRBUF_INIT;
546         int ret = repo_interpret_branch_name(r, *string, *len, &buf, 0);
547
548         if (ret == *len) {
549                 size_t size;
550                 *string = strbuf_detach(&buf, &size);
551                 *len = size;
552                 return (char *)*string;
553         }
554
555         return NULL;
556 }
557
558 int repo_dwim_ref(struct repository *r, const char *str, int len,
559                   struct object_id *oid, char **ref)
560 {
561         char *last_branch = substitute_branch_name(r, &str, &len);
562         int   refs_found  = expand_ref(r, str, len, oid, ref);
563         free(last_branch);
564         return refs_found;
565 }
566
567 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
568 {
569         return repo_dwim_ref(the_repository, str, len, oid, ref);
570 }
571
572 int expand_ref(struct repository *repo, const char *str, int len,
573                struct object_id *oid, char **ref)
574 {
575         const char **p, *r;
576         int refs_found = 0;
577         struct strbuf fullref = STRBUF_INIT;
578
579         *ref = NULL;
580         for (p = ref_rev_parse_rules; *p; p++) {
581                 struct object_id oid_from_ref;
582                 struct object_id *this_result;
583                 int flag;
584
585                 this_result = refs_found ? &oid_from_ref : oid;
586                 strbuf_reset(&fullref);
587                 strbuf_addf(&fullref, *p, len, str);
588                 r = refs_resolve_ref_unsafe(get_main_ref_store(repo),
589                                             fullref.buf, RESOLVE_REF_READING,
590                                             this_result, &flag);
591                 if (r) {
592                         if (!refs_found++)
593                                 *ref = xstrdup(r);
594                         if (!warn_ambiguous_refs)
595                                 break;
596                 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
597                         warning(_("ignoring dangling symref %s"), fullref.buf);
598                 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
599                         warning(_("ignoring broken ref %s"), fullref.buf);
600                 }
601         }
602         strbuf_release(&fullref);
603         return refs_found;
604 }
605
606 int repo_dwim_log(struct repository *r, const char *str, int len,
607                   struct object_id *oid, char **log)
608 {
609         struct ref_store *refs = get_main_ref_store(r);
610         char *last_branch = substitute_branch_name(r, &str, &len);
611         const char **p;
612         int logs_found = 0;
613         struct strbuf path = STRBUF_INIT;
614
615         *log = NULL;
616         for (p = ref_rev_parse_rules; *p; p++) {
617                 struct object_id hash;
618                 const char *ref, *it;
619
620                 strbuf_reset(&path);
621                 strbuf_addf(&path, *p, len, str);
622                 ref = refs_resolve_ref_unsafe(refs, path.buf,
623                                               RESOLVE_REF_READING,
624                                               &hash, NULL);
625                 if (!ref)
626                         continue;
627                 if (refs_reflog_exists(refs, path.buf))
628                         it = path.buf;
629                 else if (strcmp(ref, path.buf) &&
630                          refs_reflog_exists(refs, ref))
631                         it = ref;
632                 else
633                         continue;
634                 if (!logs_found++) {
635                         *log = xstrdup(it);
636                         oidcpy(oid, &hash);
637                 }
638                 if (!warn_ambiguous_refs)
639                         break;
640         }
641         strbuf_release(&path);
642         free(last_branch);
643         return logs_found;
644 }
645
646 int dwim_log(const char *str, int len, struct object_id *oid, char **log)
647 {
648         return repo_dwim_log(the_repository, str, len, oid, log);
649 }
650
651 static int is_per_worktree_ref(const char *refname)
652 {
653         return !strcmp(refname, "HEAD") ||
654                 starts_with(refname, "refs/worktree/") ||
655                 starts_with(refname, "refs/bisect/") ||
656                 starts_with(refname, "refs/rewritten/");
657 }
658
659 static int is_pseudoref_syntax(const char *refname)
660 {
661         const char *c;
662
663         for (c = refname; *c; c++) {
664                 if (!isupper(*c) && *c != '-' && *c != '_')
665                         return 0;
666         }
667
668         return 1;
669 }
670
671 static int is_main_pseudoref_syntax(const char *refname)
672 {
673         return skip_prefix(refname, "main-worktree/", &refname) &&
674                 *refname &&
675                 is_pseudoref_syntax(refname);
676 }
677
678 static int is_other_pseudoref_syntax(const char *refname)
679 {
680         if (!skip_prefix(refname, "worktrees/", &refname))
681                 return 0;
682         refname = strchr(refname, '/');
683         if (!refname || !refname[1])
684                 return 0;
685         return is_pseudoref_syntax(refname + 1);
686 }
687
688 enum ref_type ref_type(const char *refname)
689 {
690         if (is_per_worktree_ref(refname))
691                 return REF_TYPE_PER_WORKTREE;
692         if (is_pseudoref_syntax(refname))
693                 return REF_TYPE_PSEUDOREF;
694         if (is_main_pseudoref_syntax(refname))
695                 return REF_TYPE_MAIN_PSEUDOREF;
696         if (is_other_pseudoref_syntax(refname))
697                 return REF_TYPE_OTHER_PSEUDOREF;
698         return REF_TYPE_NORMAL;
699 }
700
701 long get_files_ref_lock_timeout_ms(void)
702 {
703         static int configured = 0;
704
705         /* The default timeout is 100 ms: */
706         static int timeout_ms = 100;
707
708         if (!configured) {
709                 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
710                 configured = 1;
711         }
712
713         return timeout_ms;
714 }
715
716 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
717                            const struct object_id *old_oid, struct strbuf *err)
718 {
719         const char *filename;
720         int fd;
721         struct lock_file lock = LOCK_INIT;
722         struct strbuf buf = STRBUF_INIT;
723         int ret = -1;
724
725         if (!oid)
726                 return 0;
727
728         strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
729
730         filename = git_path("%s", pseudoref);
731         fd = hold_lock_file_for_update_timeout(&lock, filename, 0,
732                                                get_files_ref_lock_timeout_ms());
733         if (fd < 0) {
734                 strbuf_addf(err, _("could not open '%s' for writing: %s"),
735                             filename, strerror(errno));
736                 goto done;
737         }
738
739         if (old_oid) {
740                 struct object_id actual_old_oid;
741
742                 if (read_ref(pseudoref, &actual_old_oid)) {
743                         if (!is_null_oid(old_oid)) {
744                                 strbuf_addf(err, _("could not read ref '%s'"),
745                                             pseudoref);
746                                 rollback_lock_file(&lock);
747                                 goto done;
748                         }
749                 } else if (is_null_oid(old_oid)) {
750                         strbuf_addf(err, _("ref '%s' already exists"),
751                                     pseudoref);
752                         rollback_lock_file(&lock);
753                         goto done;
754                 } else if (!oideq(&actual_old_oid, old_oid)) {
755                         strbuf_addf(err, _("unexpected object ID when writing '%s'"),
756                                     pseudoref);
757                         rollback_lock_file(&lock);
758                         goto done;
759                 }
760         }
761
762         if (write_in_full(fd, buf.buf, buf.len) < 0) {
763                 strbuf_addf(err, _("could not write to '%s'"), filename);
764                 rollback_lock_file(&lock);
765                 goto done;
766         }
767
768         commit_lock_file(&lock);
769         ret = 0;
770 done:
771         strbuf_release(&buf);
772         return ret;
773 }
774
775 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
776 {
777         const char *filename;
778
779         filename = git_path("%s", pseudoref);
780
781         if (old_oid && !is_null_oid(old_oid)) {
782                 struct lock_file lock = LOCK_INIT;
783                 int fd;
784                 struct object_id actual_old_oid;
785
786                 fd = hold_lock_file_for_update_timeout(
787                                 &lock, filename, 0,
788                                 get_files_ref_lock_timeout_ms());
789                 if (fd < 0) {
790                         error_errno(_("could not open '%s' for writing"),
791                                     filename);
792                         return -1;
793                 }
794                 if (read_ref(pseudoref, &actual_old_oid))
795                         die(_("could not read ref '%s'"), pseudoref);
796                 if (!oideq(&actual_old_oid, old_oid)) {
797                         error(_("unexpected object ID when deleting '%s'"),
798                               pseudoref);
799                         rollback_lock_file(&lock);
800                         return -1;
801                 }
802
803                 unlink(filename);
804                 rollback_lock_file(&lock);
805         } else {
806                 unlink(filename);
807         }
808
809         return 0;
810 }
811
812 int refs_delete_ref(struct ref_store *refs, const char *msg,
813                     const char *refname,
814                     const struct object_id *old_oid,
815                     unsigned int flags)
816 {
817         struct ref_transaction *transaction;
818         struct strbuf err = STRBUF_INIT;
819
820         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
821                 assert(refs == get_main_ref_store(the_repository));
822                 return delete_pseudoref(refname, old_oid);
823         }
824
825         transaction = ref_store_transaction_begin(refs, &err);
826         if (!transaction ||
827             ref_transaction_delete(transaction, refname, old_oid,
828                                    flags, msg, &err) ||
829             ref_transaction_commit(transaction, &err)) {
830                 error("%s", err.buf);
831                 ref_transaction_free(transaction);
832                 strbuf_release(&err);
833                 return 1;
834         }
835         ref_transaction_free(transaction);
836         strbuf_release(&err);
837         return 0;
838 }
839
840 int delete_ref(const char *msg, const char *refname,
841                const struct object_id *old_oid, unsigned int flags)
842 {
843         return refs_delete_ref(get_main_ref_store(the_repository), msg, refname,
844                                old_oid, flags);
845 }
846
847 void copy_reflog_msg(struct strbuf *sb, const char *msg)
848 {
849         char c;
850         int wasspace = 1;
851
852         strbuf_addch(sb, '\t');
853         while ((c = *msg++)) {
854                 if (wasspace && isspace(c))
855                         continue;
856                 wasspace = isspace(c);
857                 if (wasspace)
858                         c = ' ';
859                 strbuf_addch(sb, c);
860         }
861         strbuf_rtrim(sb);
862 }
863
864 int should_autocreate_reflog(const char *refname)
865 {
866         switch (log_all_ref_updates) {
867         case LOG_REFS_ALWAYS:
868                 return 1;
869         case LOG_REFS_NORMAL:
870                 return starts_with(refname, "refs/heads/") ||
871                         starts_with(refname, "refs/remotes/") ||
872                         starts_with(refname, "refs/notes/") ||
873                         !strcmp(refname, "HEAD");
874         default:
875                 return 0;
876         }
877 }
878
879 int is_branch(const char *refname)
880 {
881         return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
882 }
883
884 struct read_ref_at_cb {
885         const char *refname;
886         timestamp_t at_time;
887         int cnt;
888         int reccnt;
889         struct object_id *oid;
890         int found_it;
891
892         struct object_id ooid;
893         struct object_id noid;
894         int tz;
895         timestamp_t date;
896         char **msg;
897         timestamp_t *cutoff_time;
898         int *cutoff_tz;
899         int *cutoff_cnt;
900 };
901
902 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
903                 const char *email, timestamp_t timestamp, int tz,
904                 const char *message, void *cb_data)
905 {
906         struct read_ref_at_cb *cb = cb_data;
907
908         cb->reccnt++;
909         cb->tz = tz;
910         cb->date = timestamp;
911
912         if (timestamp <= cb->at_time || cb->cnt == 0) {
913                 if (cb->msg)
914                         *cb->msg = xstrdup(message);
915                 if (cb->cutoff_time)
916                         *cb->cutoff_time = timestamp;
917                 if (cb->cutoff_tz)
918                         *cb->cutoff_tz = tz;
919                 if (cb->cutoff_cnt)
920                         *cb->cutoff_cnt = cb->reccnt - 1;
921                 /*
922                  * we have not yet updated cb->[n|o]oid so they still
923                  * hold the values for the previous record.
924                  */
925                 if (!is_null_oid(&cb->ooid)) {
926                         oidcpy(cb->oid, noid);
927                         if (!oideq(&cb->ooid, noid))
928                                 warning(_("log for ref %s has gap after %s"),
929                                         cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
930                 }
931                 else if (cb->date == cb->at_time)
932                         oidcpy(cb->oid, noid);
933                 else if (!oideq(noid, cb->oid))
934                         warning(_("log for ref %s unexpectedly ended on %s"),
935                                 cb->refname, show_date(cb->date, cb->tz,
936                                                        DATE_MODE(RFC2822)));
937                 oidcpy(&cb->ooid, ooid);
938                 oidcpy(&cb->noid, noid);
939                 cb->found_it = 1;
940                 return 1;
941         }
942         oidcpy(&cb->ooid, ooid);
943         oidcpy(&cb->noid, noid);
944         if (cb->cnt > 0)
945                 cb->cnt--;
946         return 0;
947 }
948
949 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
950                                   const char *email, timestamp_t timestamp,
951                                   int tz, const char *message, void *cb_data)
952 {
953         struct read_ref_at_cb *cb = cb_data;
954
955         if (cb->msg)
956                 *cb->msg = xstrdup(message);
957         if (cb->cutoff_time)
958                 *cb->cutoff_time = timestamp;
959         if (cb->cutoff_tz)
960                 *cb->cutoff_tz = tz;
961         if (cb->cutoff_cnt)
962                 *cb->cutoff_cnt = cb->reccnt;
963         oidcpy(cb->oid, ooid);
964         if (is_null_oid(cb->oid))
965                 oidcpy(cb->oid, noid);
966         /* We just want the first entry */
967         return 1;
968 }
969
970 int read_ref_at(struct ref_store *refs, const char *refname,
971                 unsigned int flags, timestamp_t at_time, int cnt,
972                 struct object_id *oid, char **msg,
973                 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
974 {
975         struct read_ref_at_cb cb;
976
977         memset(&cb, 0, sizeof(cb));
978         cb.refname = refname;
979         cb.at_time = at_time;
980         cb.cnt = cnt;
981         cb.msg = msg;
982         cb.cutoff_time = cutoff_time;
983         cb.cutoff_tz = cutoff_tz;
984         cb.cutoff_cnt = cutoff_cnt;
985         cb.oid = oid;
986
987         refs_for_each_reflog_ent_reverse(refs, refname, read_ref_at_ent, &cb);
988
989         if (!cb.reccnt) {
990                 if (flags & GET_OID_QUIETLY)
991                         exit(128);
992                 else
993                         die(_("log for %s is empty"), refname);
994         }
995         if (cb.found_it)
996                 return 0;
997
998         refs_for_each_reflog_ent(refs, refname, read_ref_at_ent_oldest, &cb);
999
1000         return 1;
1001 }
1002
1003 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
1004                                                     struct strbuf *err)
1005 {
1006         struct ref_transaction *tr;
1007         assert(err);
1008
1009         tr = xcalloc(1, sizeof(struct ref_transaction));
1010         tr->ref_store = refs;
1011         return tr;
1012 }
1013
1014 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
1015 {
1016         return ref_store_transaction_begin(get_main_ref_store(the_repository), err);
1017 }
1018
1019 void ref_transaction_free(struct ref_transaction *transaction)
1020 {
1021         size_t i;
1022
1023         if (!transaction)
1024                 return;
1025
1026         switch (transaction->state) {
1027         case REF_TRANSACTION_OPEN:
1028         case REF_TRANSACTION_CLOSED:
1029                 /* OK */
1030                 break;
1031         case REF_TRANSACTION_PREPARED:
1032                 BUG("free called on a prepared reference transaction");
1033                 break;
1034         default:
1035                 BUG("unexpected reference transaction state");
1036                 break;
1037         }
1038
1039         for (i = 0; i < transaction->nr; i++) {
1040                 free(transaction->updates[i]->msg);
1041                 free(transaction->updates[i]);
1042         }
1043         free(transaction->updates);
1044         free(transaction);
1045 }
1046
1047 struct ref_update *ref_transaction_add_update(
1048                 struct ref_transaction *transaction,
1049                 const char *refname, unsigned int flags,
1050                 const struct object_id *new_oid,
1051                 const struct object_id *old_oid,
1052                 const char *msg)
1053 {
1054         struct ref_update *update;
1055
1056         if (transaction->state != REF_TRANSACTION_OPEN)
1057                 BUG("update called for transaction that is not open");
1058
1059         FLEX_ALLOC_STR(update, refname, refname);
1060         ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
1061         transaction->updates[transaction->nr++] = update;
1062
1063         update->flags = flags;
1064
1065         if (flags & REF_HAVE_NEW)
1066                 oidcpy(&update->new_oid, new_oid);
1067         if (flags & REF_HAVE_OLD)
1068                 oidcpy(&update->old_oid, old_oid);
1069         update->msg = xstrdup_or_null(msg);
1070         return update;
1071 }
1072
1073 int ref_transaction_update(struct ref_transaction *transaction,
1074                            const char *refname,
1075                            const struct object_id *new_oid,
1076                            const struct object_id *old_oid,
1077                            unsigned int flags, const char *msg,
1078                            struct strbuf *err)
1079 {
1080         assert(err);
1081
1082         if ((new_oid && !is_null_oid(new_oid)) ?
1083             check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
1084             !refname_is_safe(refname)) {
1085                 strbuf_addf(err, _("refusing to update ref with bad name '%s'"),
1086                             refname);
1087                 return -1;
1088         }
1089
1090         if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1091                 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1092
1093         flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1094
1095         ref_transaction_add_update(transaction, refname, flags,
1096                                    new_oid, old_oid, msg);
1097         return 0;
1098 }
1099
1100 int ref_transaction_create(struct ref_transaction *transaction,
1101                            const char *refname,
1102                            const struct object_id *new_oid,
1103                            unsigned int flags, const char *msg,
1104                            struct strbuf *err)
1105 {
1106         if (!new_oid || is_null_oid(new_oid))
1107                 BUG("create called without valid new_oid");
1108         return ref_transaction_update(transaction, refname, new_oid,
1109                                       &null_oid, flags, msg, err);
1110 }
1111
1112 int ref_transaction_delete(struct ref_transaction *transaction,
1113                            const char *refname,
1114                            const struct object_id *old_oid,
1115                            unsigned int flags, const char *msg,
1116                            struct strbuf *err)
1117 {
1118         if (old_oid && is_null_oid(old_oid))
1119                 BUG("delete called with old_oid set to zeros");
1120         return ref_transaction_update(transaction, refname,
1121                                       &null_oid, old_oid,
1122                                       flags, msg, err);
1123 }
1124
1125 int ref_transaction_verify(struct ref_transaction *transaction,
1126                            const char *refname,
1127                            const struct object_id *old_oid,
1128                            unsigned int flags,
1129                            struct strbuf *err)
1130 {
1131         if (!old_oid)
1132                 BUG("verify called with old_oid set to NULL");
1133         return ref_transaction_update(transaction, refname,
1134                                       NULL, old_oid,
1135                                       flags, NULL, err);
1136 }
1137
1138 int refs_update_ref(struct ref_store *refs, const char *msg,
1139                     const char *refname, const struct object_id *new_oid,
1140                     const struct object_id *old_oid, unsigned int flags,
1141                     enum action_on_err onerr)
1142 {
1143         struct ref_transaction *t = NULL;
1144         struct strbuf err = STRBUF_INIT;
1145         int ret = 0;
1146
1147         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1148                 assert(refs == get_main_ref_store(the_repository));
1149                 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1150         } else {
1151                 t = ref_store_transaction_begin(refs, &err);
1152                 if (!t ||
1153                     ref_transaction_update(t, refname, new_oid, old_oid,
1154                                            flags, msg, &err) ||
1155                     ref_transaction_commit(t, &err)) {
1156                         ret = 1;
1157                         ref_transaction_free(t);
1158                 }
1159         }
1160         if (ret) {
1161                 const char *str = _("update_ref failed for ref '%s': %s");
1162
1163                 switch (onerr) {
1164                 case UPDATE_REFS_MSG_ON_ERR:
1165                         error(str, refname, err.buf);
1166                         break;
1167                 case UPDATE_REFS_DIE_ON_ERR:
1168                         die(str, refname, err.buf);
1169                         break;
1170                 case UPDATE_REFS_QUIET_ON_ERR:
1171                         break;
1172                 }
1173                 strbuf_release(&err);
1174                 return 1;
1175         }
1176         strbuf_release(&err);
1177         if (t)
1178                 ref_transaction_free(t);
1179         return 0;
1180 }
1181
1182 int update_ref(const char *msg, const char *refname,
1183                const struct object_id *new_oid,
1184                const struct object_id *old_oid,
1185                unsigned int flags, enum action_on_err onerr)
1186 {
1187         return refs_update_ref(get_main_ref_store(the_repository), msg, refname, new_oid,
1188                                old_oid, flags, onerr);
1189 }
1190
1191 char *refs_shorten_unambiguous_ref(struct ref_store *refs,
1192                                    const char *refname, int strict)
1193 {
1194         int i;
1195         static char **scanf_fmts;
1196         static int nr_rules;
1197         char *short_name;
1198         struct strbuf resolved_buf = STRBUF_INIT;
1199
1200         if (!nr_rules) {
1201                 /*
1202                  * Pre-generate scanf formats from ref_rev_parse_rules[].
1203                  * Generate a format suitable for scanf from a
1204                  * ref_rev_parse_rules rule by interpolating "%s" at the
1205                  * location of the "%.*s".
1206                  */
1207                 size_t total_len = 0;
1208                 size_t offset = 0;
1209
1210                 /* the rule list is NULL terminated, count them first */
1211                 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1212                         /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1213                         total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1214
1215                 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1216
1217                 offset = 0;
1218                 for (i = 0; i < nr_rules; i++) {
1219                         assert(offset < total_len);
1220                         scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1221                         offset += xsnprintf(scanf_fmts[i], total_len - offset,
1222                                             ref_rev_parse_rules[i], 2, "%s") + 1;
1223                 }
1224         }
1225
1226         /* bail out if there are no rules */
1227         if (!nr_rules)
1228                 return xstrdup(refname);
1229
1230         /* buffer for scanf result, at most refname must fit */
1231         short_name = xstrdup(refname);
1232
1233         /* skip first rule, it will always match */
1234         for (i = nr_rules - 1; i > 0 ; --i) {
1235                 int j;
1236                 int rules_to_fail = i;
1237                 int short_name_len;
1238
1239                 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1240                         continue;
1241
1242                 short_name_len = strlen(short_name);
1243
1244                 /*
1245                  * in strict mode, all (except the matched one) rules
1246                  * must fail to resolve to a valid non-ambiguous ref
1247                  */
1248                 if (strict)
1249                         rules_to_fail = nr_rules;
1250
1251                 /*
1252                  * check if the short name resolves to a valid ref,
1253                  * but use only rules prior to the matched one
1254                  */
1255                 for (j = 0; j < rules_to_fail; j++) {
1256                         const char *rule = ref_rev_parse_rules[j];
1257
1258                         /* skip matched rule */
1259                         if (i == j)
1260                                 continue;
1261
1262                         /*
1263                          * the short name is ambiguous, if it resolves
1264                          * (with this previous rule) to a valid ref
1265                          * read_ref() returns 0 on success
1266                          */
1267                         strbuf_reset(&resolved_buf);
1268                         strbuf_addf(&resolved_buf, rule,
1269                                     short_name_len, short_name);
1270                         if (refs_ref_exists(refs, resolved_buf.buf))
1271                                 break;
1272                 }
1273
1274                 /*
1275                  * short name is non-ambiguous if all previous rules
1276                  * haven't resolved to a valid ref
1277                  */
1278                 if (j == rules_to_fail) {
1279                         strbuf_release(&resolved_buf);
1280                         return short_name;
1281                 }
1282         }
1283
1284         strbuf_release(&resolved_buf);
1285         free(short_name);
1286         return xstrdup(refname);
1287 }
1288
1289 char *shorten_unambiguous_ref(const char *refname, int strict)
1290 {
1291         return refs_shorten_unambiguous_ref(get_main_ref_store(the_repository),
1292                                             refname, strict);
1293 }
1294
1295 static struct string_list *hide_refs;
1296
1297 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1298 {
1299         const char *key;
1300         if (!strcmp("transfer.hiderefs", var) ||
1301             (!parse_config_key(var, section, NULL, NULL, &key) &&
1302              !strcmp(key, "hiderefs"))) {
1303                 char *ref;
1304                 int len;
1305
1306                 if (!value)
1307                         return config_error_nonbool(var);
1308                 ref = xstrdup(value);
1309                 len = strlen(ref);
1310                 while (len && ref[len - 1] == '/')
1311                         ref[--len] = '\0';
1312                 if (!hide_refs) {
1313                         hide_refs = xcalloc(1, sizeof(*hide_refs));
1314                         hide_refs->strdup_strings = 1;
1315                 }
1316                 string_list_append(hide_refs, ref);
1317         }
1318         return 0;
1319 }
1320
1321 int ref_is_hidden(const char *refname, const char *refname_full)
1322 {
1323         int i;
1324
1325         if (!hide_refs)
1326                 return 0;
1327         for (i = hide_refs->nr - 1; i >= 0; i--) {
1328                 const char *match = hide_refs->items[i].string;
1329                 const char *subject;
1330                 int neg = 0;
1331                 const char *p;
1332
1333                 if (*match == '!') {
1334                         neg = 1;
1335                         match++;
1336                 }
1337
1338                 if (*match == '^') {
1339                         subject = refname_full;
1340                         match++;
1341                 } else {
1342                         subject = refname;
1343                 }
1344
1345                 /* refname can be NULL when namespaces are used. */
1346                 if (subject &&
1347                     skip_prefix(subject, match, &p) &&
1348                     (!*p || *p == '/'))
1349                         return !neg;
1350         }
1351         return 0;
1352 }
1353
1354 const char *find_descendant_ref(const char *dirname,
1355                                 const struct string_list *extras,
1356                                 const struct string_list *skip)
1357 {
1358         int pos;
1359
1360         if (!extras)
1361                 return NULL;
1362
1363         /*
1364          * Look at the place where dirname would be inserted into
1365          * extras. If there is an entry at that position that starts
1366          * with dirname (remember, dirname includes the trailing
1367          * slash) and is not in skip, then we have a conflict.
1368          */
1369         for (pos = string_list_find_insert_index(extras, dirname, 0);
1370              pos < extras->nr; pos++) {
1371                 const char *extra_refname = extras->items[pos].string;
1372
1373                 if (!starts_with(extra_refname, dirname))
1374                         break;
1375
1376                 if (!skip || !string_list_has_string(skip, extra_refname))
1377                         return extra_refname;
1378         }
1379         return NULL;
1380 }
1381
1382 int refs_rename_ref_available(struct ref_store *refs,
1383                               const char *old_refname,
1384                               const char *new_refname)
1385 {
1386         struct string_list skip = STRING_LIST_INIT_NODUP;
1387         struct strbuf err = STRBUF_INIT;
1388         int ok;
1389
1390         string_list_insert(&skip, old_refname);
1391         ok = !refs_verify_refname_available(refs, new_refname,
1392                                             NULL, &skip, &err);
1393         if (!ok)
1394                 error("%s", err.buf);
1395
1396         string_list_clear(&skip, 0);
1397         strbuf_release(&err);
1398         return ok;
1399 }
1400
1401 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1402 {
1403         struct object_id oid;
1404         int flag;
1405
1406         if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1407                                 &oid, &flag))
1408                 return fn("HEAD", &oid, flag, cb_data);
1409
1410         return 0;
1411 }
1412
1413 int head_ref(each_ref_fn fn, void *cb_data)
1414 {
1415         return refs_head_ref(get_main_ref_store(the_repository), fn, cb_data);
1416 }
1417
1418 struct ref_iterator *refs_ref_iterator_begin(
1419                 struct ref_store *refs,
1420                 const char *prefix, int trim, int flags)
1421 {
1422         struct ref_iterator *iter;
1423
1424         if (ref_paranoia < 0)
1425                 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1426         if (ref_paranoia)
1427                 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1428
1429         iter = refs->be->iterator_begin(refs, prefix, flags);
1430
1431         /*
1432          * `iterator_begin()` already takes care of prefix, but we
1433          * might need to do some trimming:
1434          */
1435         if (trim)
1436                 iter = prefix_ref_iterator_begin(iter, "", trim);
1437
1438         /* Sanity check for subclasses: */
1439         if (!iter->ordered)
1440                 BUG("reference iterator is not ordered");
1441
1442         return iter;
1443 }
1444
1445 /*
1446  * Call fn for each reference in the specified submodule for which the
1447  * refname begins with prefix. If trim is non-zero, then trim that
1448  * many characters off the beginning of each refname before passing
1449  * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1450  * include broken references in the iteration. If fn ever returns a
1451  * non-zero value, stop the iteration and return that value;
1452  * otherwise, return 0.
1453  */
1454 static int do_for_each_repo_ref(struct repository *r, const char *prefix,
1455                                 each_repo_ref_fn fn, int trim, int flags,
1456                                 void *cb_data)
1457 {
1458         struct ref_iterator *iter;
1459         struct ref_store *refs = get_main_ref_store(r);
1460
1461         if (!refs)
1462                 return 0;
1463
1464         iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1465
1466         return do_for_each_repo_ref_iterator(r, iter, fn, cb_data);
1467 }
1468
1469 struct do_for_each_ref_help {
1470         each_ref_fn *fn;
1471         void *cb_data;
1472 };
1473
1474 static int do_for_each_ref_helper(struct repository *r,
1475                                   const char *refname,
1476                                   const struct object_id *oid,
1477                                   int flags,
1478                                   void *cb_data)
1479 {
1480         struct do_for_each_ref_help *hp = cb_data;
1481
1482         return hp->fn(refname, oid, flags, hp->cb_data);
1483 }
1484
1485 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1486                            each_ref_fn fn, int trim, int flags, void *cb_data)
1487 {
1488         struct ref_iterator *iter;
1489         struct do_for_each_ref_help hp = { fn, cb_data };
1490
1491         if (!refs)
1492                 return 0;
1493
1494         iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1495
1496         return do_for_each_repo_ref_iterator(the_repository, iter,
1497                                         do_for_each_ref_helper, &hp);
1498 }
1499
1500 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1501 {
1502         return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1503 }
1504
1505 int for_each_ref(each_ref_fn fn, void *cb_data)
1506 {
1507         return refs_for_each_ref(get_main_ref_store(the_repository), fn, cb_data);
1508 }
1509
1510 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1511                          each_ref_fn fn, void *cb_data)
1512 {
1513         return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1514 }
1515
1516 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1517 {
1518         return refs_for_each_ref_in(get_main_ref_store(the_repository), prefix, fn, cb_data);
1519 }
1520
1521 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1522 {
1523         unsigned int flag = 0;
1524
1525         if (broken)
1526                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1527         return do_for_each_ref(get_main_ref_store(the_repository),
1528                                prefix, fn, 0, flag, cb_data);
1529 }
1530
1531 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1532                              each_ref_fn fn, void *cb_data,
1533                              unsigned int broken)
1534 {
1535         unsigned int flag = 0;
1536
1537         if (broken)
1538                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1539         return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1540 }
1541
1542 int for_each_replace_ref(struct repository *r, each_repo_ref_fn fn, void *cb_data)
1543 {
1544         return do_for_each_repo_ref(r, git_replace_ref_base, fn,
1545                                     strlen(git_replace_ref_base),
1546                                     DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1547 }
1548
1549 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1550 {
1551         struct strbuf buf = STRBUF_INIT;
1552         int ret;
1553         strbuf_addf(&buf, "%srefs/", get_git_namespace());
1554         ret = do_for_each_ref(get_main_ref_store(the_repository),
1555                               buf.buf, fn, 0, 0, cb_data);
1556         strbuf_release(&buf);
1557         return ret;
1558 }
1559
1560 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1561 {
1562         return do_for_each_ref(refs, "", fn, 0,
1563                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1564 }
1565
1566 int for_each_rawref(each_ref_fn fn, void *cb_data)
1567 {
1568         return refs_for_each_rawref(get_main_ref_store(the_repository), fn, cb_data);
1569 }
1570
1571 int refs_read_raw_ref(struct ref_store *ref_store,
1572                       const char *refname, struct object_id *oid,
1573                       struct strbuf *referent, unsigned int *type)
1574 {
1575         return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1576 }
1577
1578 /* This function needs to return a meaningful errno on failure */
1579 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1580                                     const char *refname,
1581                                     int resolve_flags,
1582                                     struct object_id *oid, int *flags)
1583 {
1584         static struct strbuf sb_refname = STRBUF_INIT;
1585         struct object_id unused_oid;
1586         int unused_flags;
1587         int symref_count;
1588
1589         if (!oid)
1590                 oid = &unused_oid;
1591         if (!flags)
1592                 flags = &unused_flags;
1593
1594         *flags = 0;
1595
1596         if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1597                 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1598                     !refname_is_safe(refname)) {
1599                         errno = EINVAL;
1600                         return NULL;
1601                 }
1602
1603                 /*
1604                  * dwim_ref() uses REF_ISBROKEN to distinguish between
1605                  * missing refs and refs that were present but invalid,
1606                  * to complain about the latter to stderr.
1607                  *
1608                  * We don't know whether the ref exists, so don't set
1609                  * REF_ISBROKEN yet.
1610                  */
1611                 *flags |= REF_BAD_NAME;
1612         }
1613
1614         for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1615                 unsigned int read_flags = 0;
1616
1617                 if (refs_read_raw_ref(refs, refname,
1618                                       oid, &sb_refname, &read_flags)) {
1619                         *flags |= read_flags;
1620
1621                         /* In reading mode, refs must eventually resolve */
1622                         if (resolve_flags & RESOLVE_REF_READING)
1623                                 return NULL;
1624
1625                         /*
1626                          * Otherwise a missing ref is OK. But the files backend
1627                          * may show errors besides ENOENT if there are
1628                          * similarly-named refs.
1629                          */
1630                         if (errno != ENOENT &&
1631                             errno != EISDIR &&
1632                             errno != ENOTDIR)
1633                                 return NULL;
1634
1635                         oidclr(oid);
1636                         if (*flags & REF_BAD_NAME)
1637                                 *flags |= REF_ISBROKEN;
1638                         return refname;
1639                 }
1640
1641                 *flags |= read_flags;
1642
1643                 if (!(read_flags & REF_ISSYMREF)) {
1644                         if (*flags & REF_BAD_NAME) {
1645                                 oidclr(oid);
1646                                 *flags |= REF_ISBROKEN;
1647                         }
1648                         return refname;
1649                 }
1650
1651                 refname = sb_refname.buf;
1652                 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1653                         oidclr(oid);
1654                         return refname;
1655                 }
1656                 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1657                         if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1658                             !refname_is_safe(refname)) {
1659                                 errno = EINVAL;
1660                                 return NULL;
1661                         }
1662
1663                         *flags |= REF_ISBROKEN | REF_BAD_NAME;
1664                 }
1665         }
1666
1667         errno = ELOOP;
1668         return NULL;
1669 }
1670
1671 /* backend functions */
1672 int refs_init_db(struct strbuf *err)
1673 {
1674         struct ref_store *refs = get_main_ref_store(the_repository);
1675
1676         return refs->be->init_db(refs, err);
1677 }
1678
1679 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1680                                struct object_id *oid, int *flags)
1681 {
1682         return refs_resolve_ref_unsafe(get_main_ref_store(the_repository), refname,
1683                                        resolve_flags, oid, flags);
1684 }
1685
1686 int resolve_gitlink_ref(const char *submodule, const char *refname,
1687                         struct object_id *oid)
1688 {
1689         struct ref_store *refs;
1690         int flags;
1691
1692         refs = get_submodule_ref_store(submodule);
1693
1694         if (!refs)
1695                 return -1;
1696
1697         if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1698             is_null_oid(oid))
1699                 return -1;
1700         return 0;
1701 }
1702
1703 struct ref_store_hash_entry
1704 {
1705         struct hashmap_entry ent; /* must be the first member! */
1706
1707         struct ref_store *refs;
1708
1709         /* NUL-terminated identifier of the ref store: */
1710         char name[FLEX_ARRAY];
1711 };
1712
1713 static int ref_store_hash_cmp(const void *unused_cmp_data,
1714                               const void *entry, const void *entry_or_key,
1715                               const void *keydata)
1716 {
1717         const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1718         const char *name = keydata ? keydata : e2->name;
1719
1720         return strcmp(e1->name, name);
1721 }
1722
1723 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1724                 const char *name, struct ref_store *refs)
1725 {
1726         struct ref_store_hash_entry *entry;
1727
1728         FLEX_ALLOC_STR(entry, name, name);
1729         hashmap_entry_init(entry, strhash(name));
1730         entry->refs = refs;
1731         return entry;
1732 }
1733
1734 /* A hashmap of ref_stores, stored by submodule name: */
1735 static struct hashmap submodule_ref_stores;
1736
1737 /* A hashmap of ref_stores, stored by worktree id: */
1738 static struct hashmap worktree_ref_stores;
1739
1740 /*
1741  * Look up a ref store by name. If that ref_store hasn't been
1742  * registered yet, return NULL.
1743  */
1744 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1745                                               const char *name)
1746 {
1747         struct ref_store_hash_entry *entry;
1748
1749         if (!map->tablesize)
1750                 /* It's initialized on demand in register_ref_store(). */
1751                 return NULL;
1752
1753         entry = hashmap_get_from_hash(map, strhash(name), name);
1754         return entry ? entry->refs : NULL;
1755 }
1756
1757 /*
1758  * Create, record, and return a ref_store instance for the specified
1759  * gitdir.
1760  */
1761 static struct ref_store *ref_store_init(const char *gitdir,
1762                                         unsigned int flags)
1763 {
1764         const char *be_name = "files";
1765         struct ref_storage_be *be = find_ref_storage_backend(be_name);
1766         struct ref_store *refs;
1767
1768         if (!be)
1769                 BUG("reference backend %s is unknown", be_name);
1770
1771         refs = be->init(gitdir, flags);
1772         return refs;
1773 }
1774
1775 struct ref_store *get_main_ref_store(struct repository *r)
1776 {
1777         if (r->refs)
1778                 return r->refs;
1779
1780         if (!r->gitdir)
1781                 BUG("attempting to get main_ref_store outside of repository");
1782
1783         r->refs = ref_store_init(r->gitdir, REF_STORE_ALL_CAPS);
1784         return r->refs;
1785 }
1786
1787 /*
1788  * Associate a ref store with a name. It is a fatal error to call this
1789  * function twice for the same name.
1790  */
1791 static void register_ref_store_map(struct hashmap *map,
1792                                    const char *type,
1793                                    struct ref_store *refs,
1794                                    const char *name)
1795 {
1796         if (!map->tablesize)
1797                 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1798
1799         if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1800                 BUG("%s ref_store '%s' initialized twice", type, name);
1801 }
1802
1803 struct ref_store *get_submodule_ref_store(const char *submodule)
1804 {
1805         struct strbuf submodule_sb = STRBUF_INIT;
1806         struct ref_store *refs;
1807         char *to_free = NULL;
1808         size_t len;
1809
1810         if (!submodule)
1811                 return NULL;
1812
1813         len = strlen(submodule);
1814         while (len && is_dir_sep(submodule[len - 1]))
1815                 len--;
1816         if (!len)
1817                 return NULL;
1818
1819         if (submodule[len])
1820                 /* We need to strip off one or more trailing slashes */
1821                 submodule = to_free = xmemdupz(submodule, len);
1822
1823         refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1824         if (refs)
1825                 goto done;
1826
1827         strbuf_addstr(&submodule_sb, submodule);
1828         if (!is_nonbare_repository_dir(&submodule_sb))
1829                 goto done;
1830
1831         if (submodule_to_gitdir(&submodule_sb, submodule))
1832                 goto done;
1833
1834         /* assume that add_submodule_odb() has been called */
1835         refs = ref_store_init(submodule_sb.buf,
1836                               REF_STORE_READ | REF_STORE_ODB);
1837         register_ref_store_map(&submodule_ref_stores, "submodule",
1838                                refs, submodule);
1839
1840 done:
1841         strbuf_release(&submodule_sb);
1842         free(to_free);
1843
1844         return refs;
1845 }
1846
1847 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1848 {
1849         struct ref_store *refs;
1850         const char *id;
1851
1852         if (wt->is_current)
1853                 return get_main_ref_store(the_repository);
1854
1855         id = wt->id ? wt->id : "/";
1856         refs = lookup_ref_store_map(&worktree_ref_stores, id);
1857         if (refs)
1858                 return refs;
1859
1860         if (wt->id)
1861                 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1862                                       REF_STORE_ALL_CAPS);
1863         else
1864                 refs = ref_store_init(get_git_common_dir(),
1865                                       REF_STORE_ALL_CAPS);
1866
1867         if (refs)
1868                 register_ref_store_map(&worktree_ref_stores, "worktree",
1869                                        refs, id);
1870         return refs;
1871 }
1872
1873 void base_ref_store_init(struct ref_store *refs,
1874                          const struct ref_storage_be *be)
1875 {
1876         refs->be = be;
1877 }
1878
1879 /* backend functions */
1880 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1881 {
1882         return refs->be->pack_refs(refs, flags);
1883 }
1884
1885 int refs_peel_ref(struct ref_store *refs, const char *refname,
1886                   struct object_id *oid)
1887 {
1888         int flag;
1889         struct object_id base;
1890
1891         if (current_ref_iter && current_ref_iter->refname == refname) {
1892                 struct object_id peeled;
1893
1894                 if (ref_iterator_peel(current_ref_iter, &peeled))
1895                         return -1;
1896                 oidcpy(oid, &peeled);
1897                 return 0;
1898         }
1899
1900         if (refs_read_ref_full(refs, refname,
1901                                RESOLVE_REF_READING, &base, &flag))
1902                 return -1;
1903
1904         return peel_object(&base, oid);
1905 }
1906
1907 int peel_ref(const char *refname, struct object_id *oid)
1908 {
1909         return refs_peel_ref(get_main_ref_store(the_repository), refname, oid);
1910 }
1911
1912 int refs_create_symref(struct ref_store *refs,
1913                        const char *ref_target,
1914                        const char *refs_heads_master,
1915                        const char *logmsg)
1916 {
1917         return refs->be->create_symref(refs, ref_target,
1918                                        refs_heads_master,
1919                                        logmsg);
1920 }
1921
1922 int create_symref(const char *ref_target, const char *refs_heads_master,
1923                   const char *logmsg)
1924 {
1925         return refs_create_symref(get_main_ref_store(the_repository), ref_target,
1926                                   refs_heads_master, logmsg);
1927 }
1928
1929 int ref_update_reject_duplicates(struct string_list *refnames,
1930                                  struct strbuf *err)
1931 {
1932         size_t i, n = refnames->nr;
1933
1934         assert(err);
1935
1936         for (i = 1; i < n; i++) {
1937                 int cmp = strcmp(refnames->items[i - 1].string,
1938                                  refnames->items[i].string);
1939
1940                 if (!cmp) {
1941                         strbuf_addf(err,
1942                                     _("multiple updates for ref '%s' not allowed"),
1943                                     refnames->items[i].string);
1944                         return 1;
1945                 } else if (cmp > 0) {
1946                         BUG("ref_update_reject_duplicates() received unsorted list");
1947                 }
1948         }
1949         return 0;
1950 }
1951
1952 int ref_transaction_prepare(struct ref_transaction *transaction,
1953                             struct strbuf *err)
1954 {
1955         struct ref_store *refs = transaction->ref_store;
1956
1957         switch (transaction->state) {
1958         case REF_TRANSACTION_OPEN:
1959                 /* Good. */
1960                 break;
1961         case REF_TRANSACTION_PREPARED:
1962                 BUG("prepare called twice on reference transaction");
1963                 break;
1964         case REF_TRANSACTION_CLOSED:
1965                 BUG("prepare called on a closed reference transaction");
1966                 break;
1967         default:
1968                 BUG("unexpected reference transaction state");
1969                 break;
1970         }
1971
1972         if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1973                 strbuf_addstr(err,
1974                               _("ref updates forbidden inside quarantine environment"));
1975                 return -1;
1976         }
1977
1978         return refs->be->transaction_prepare(refs, transaction, err);
1979 }
1980
1981 int ref_transaction_abort(struct ref_transaction *transaction,
1982                           struct strbuf *err)
1983 {
1984         struct ref_store *refs = transaction->ref_store;
1985         int ret = 0;
1986
1987         switch (transaction->state) {
1988         case REF_TRANSACTION_OPEN:
1989                 /* No need to abort explicitly. */
1990                 break;
1991         case REF_TRANSACTION_PREPARED:
1992                 ret = refs->be->transaction_abort(refs, transaction, err);
1993                 break;
1994         case REF_TRANSACTION_CLOSED:
1995                 BUG("abort called on a closed reference transaction");
1996                 break;
1997         default:
1998                 BUG("unexpected reference transaction state");
1999                 break;
2000         }
2001
2002         ref_transaction_free(transaction);
2003         return ret;
2004 }
2005
2006 int ref_transaction_commit(struct ref_transaction *transaction,
2007                            struct strbuf *err)
2008 {
2009         struct ref_store *refs = transaction->ref_store;
2010         int ret;
2011
2012         switch (transaction->state) {
2013         case REF_TRANSACTION_OPEN:
2014                 /* Need to prepare first. */
2015                 ret = ref_transaction_prepare(transaction, err);
2016                 if (ret)
2017                         return ret;
2018                 break;
2019         case REF_TRANSACTION_PREPARED:
2020                 /* Fall through to finish. */
2021                 break;
2022         case REF_TRANSACTION_CLOSED:
2023                 BUG("commit called on a closed reference transaction");
2024                 break;
2025         default:
2026                 BUG("unexpected reference transaction state");
2027                 break;
2028         }
2029
2030         return refs->be->transaction_finish(refs, transaction, err);
2031 }
2032
2033 int refs_verify_refname_available(struct ref_store *refs,
2034                                   const char *refname,
2035                                   const struct string_list *extras,
2036                                   const struct string_list *skip,
2037                                   struct strbuf *err)
2038 {
2039         const char *slash;
2040         const char *extra_refname;
2041         struct strbuf dirname = STRBUF_INIT;
2042         struct strbuf referent = STRBUF_INIT;
2043         struct object_id oid;
2044         unsigned int type;
2045         struct ref_iterator *iter;
2046         int ok;
2047         int ret = -1;
2048
2049         /*
2050          * For the sake of comments in this function, suppose that
2051          * refname is "refs/foo/bar".
2052          */
2053
2054         assert(err);
2055
2056         strbuf_grow(&dirname, strlen(refname) + 1);
2057         for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
2058                 /* Expand dirname to the new prefix, not including the trailing slash: */
2059                 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
2060
2061                 /*
2062                  * We are still at a leading dir of the refname (e.g.,
2063                  * "refs/foo"; if there is a reference with that name,
2064                  * it is a conflict, *unless* it is in skip.
2065                  */
2066                 if (skip && string_list_has_string(skip, dirname.buf))
2067                         continue;
2068
2069                 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
2070                         strbuf_addf(err, _("'%s' exists; cannot create '%s'"),
2071                                     dirname.buf, refname);
2072                         goto cleanup;
2073                 }
2074
2075                 if (extras && string_list_has_string(extras, dirname.buf)) {
2076                         strbuf_addf(err, _("cannot process '%s' and '%s' at the same time"),
2077                                     refname, dirname.buf);
2078                         goto cleanup;
2079                 }
2080         }
2081
2082         /*
2083          * We are at the leaf of our refname (e.g., "refs/foo/bar").
2084          * There is no point in searching for a reference with that
2085          * name, because a refname isn't considered to conflict with
2086          * itself. But we still need to check for references whose
2087          * names are in the "refs/foo/bar/" namespace, because they
2088          * *do* conflict.
2089          */
2090         strbuf_addstr(&dirname, refname + dirname.len);
2091         strbuf_addch(&dirname, '/');
2092
2093         iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
2094                                        DO_FOR_EACH_INCLUDE_BROKEN);
2095         while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
2096                 if (skip &&
2097                     string_list_has_string(skip, iter->refname))
2098                         continue;
2099
2100                 strbuf_addf(err, _("'%s' exists; cannot create '%s'"),
2101                             iter->refname, refname);
2102                 ref_iterator_abort(iter);
2103                 goto cleanup;
2104         }
2105
2106         if (ok != ITER_DONE)
2107                 BUG("error while iterating over references");
2108
2109         extra_refname = find_descendant_ref(dirname.buf, extras, skip);
2110         if (extra_refname)
2111                 strbuf_addf(err, _("cannot process '%s' and '%s' at the same time"),
2112                             refname, extra_refname);
2113         else
2114                 ret = 0;
2115
2116 cleanup:
2117         strbuf_release(&referent);
2118         strbuf_release(&dirname);
2119         return ret;
2120 }
2121
2122 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2123 {
2124         struct ref_iterator *iter;
2125         struct do_for_each_ref_help hp = { fn, cb_data };
2126
2127         iter = refs->be->reflog_iterator_begin(refs);
2128
2129         return do_for_each_repo_ref_iterator(the_repository, iter,
2130                                              do_for_each_ref_helper, &hp);
2131 }
2132
2133 int for_each_reflog(each_ref_fn fn, void *cb_data)
2134 {
2135         return refs_for_each_reflog(get_main_ref_store(the_repository), fn, cb_data);
2136 }
2137
2138 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2139                                      const char *refname,
2140                                      each_reflog_ent_fn fn,
2141                                      void *cb_data)
2142 {
2143         return refs->be->for_each_reflog_ent_reverse(refs, refname,
2144                                                      fn, cb_data);
2145 }
2146
2147 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2148                                 void *cb_data)
2149 {
2150         return refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
2151                                                 refname, fn, cb_data);
2152 }
2153
2154 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2155                              each_reflog_ent_fn fn, void *cb_data)
2156 {
2157         return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2158 }
2159
2160 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2161                         void *cb_data)
2162 {
2163         return refs_for_each_reflog_ent(get_main_ref_store(the_repository), refname,
2164                                         fn, cb_data);
2165 }
2166
2167 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2168 {
2169         return refs->be->reflog_exists(refs, refname);
2170 }
2171
2172 int reflog_exists(const char *refname)
2173 {
2174         return refs_reflog_exists(get_main_ref_store(the_repository), refname);
2175 }
2176
2177 int refs_create_reflog(struct ref_store *refs, const char *refname,
2178                        int force_create, struct strbuf *err)
2179 {
2180         return refs->be->create_reflog(refs, refname, force_create, err);
2181 }
2182
2183 int safe_create_reflog(const char *refname, int force_create,
2184                        struct strbuf *err)
2185 {
2186         return refs_create_reflog(get_main_ref_store(the_repository), refname,
2187                                   force_create, err);
2188 }
2189
2190 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2191 {
2192         return refs->be->delete_reflog(refs, refname);
2193 }
2194
2195 int delete_reflog(const char *refname)
2196 {
2197         return refs_delete_reflog(get_main_ref_store(the_repository), refname);
2198 }
2199
2200 int refs_reflog_expire(struct ref_store *refs,
2201                        const char *refname, const struct object_id *oid,
2202                        unsigned int flags,
2203                        reflog_expiry_prepare_fn prepare_fn,
2204                        reflog_expiry_should_prune_fn should_prune_fn,
2205                        reflog_expiry_cleanup_fn cleanup_fn,
2206                        void *policy_cb_data)
2207 {
2208         return refs->be->reflog_expire(refs, refname, oid, flags,
2209                                        prepare_fn, should_prune_fn,
2210                                        cleanup_fn, policy_cb_data);
2211 }
2212
2213 int reflog_expire(const char *refname, const struct object_id *oid,
2214                   unsigned int flags,
2215                   reflog_expiry_prepare_fn prepare_fn,
2216                   reflog_expiry_should_prune_fn should_prune_fn,
2217                   reflog_expiry_cleanup_fn cleanup_fn,
2218                   void *policy_cb_data)
2219 {
2220         return refs_reflog_expire(get_main_ref_store(the_repository),
2221                                   refname, oid, flags,
2222                                   prepare_fn, should_prune_fn,
2223                                   cleanup_fn, policy_cb_data);
2224 }
2225
2226 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2227                                    struct strbuf *err)
2228 {
2229         struct ref_store *refs = transaction->ref_store;
2230
2231         return refs->be->initial_transaction_commit(refs, transaction, err);
2232 }
2233
2234 int refs_delete_refs(struct ref_store *refs, const char *msg,
2235                      struct string_list *refnames, unsigned int flags)
2236 {
2237         return refs->be->delete_refs(refs, msg, refnames, flags);
2238 }
2239
2240 int delete_refs(const char *msg, struct string_list *refnames,
2241                 unsigned int flags)
2242 {
2243         return refs_delete_refs(get_main_ref_store(the_repository), msg, refnames, flags);
2244 }
2245
2246 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2247                     const char *newref, const char *logmsg)
2248 {
2249         return refs->be->rename_ref(refs, oldref, newref, logmsg);
2250 }
2251
2252 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2253 {
2254         return refs_rename_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2255 }
2256
2257 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2258                     const char *newref, const char *logmsg)
2259 {
2260         return refs->be->copy_ref(refs, oldref, newref, logmsg);
2261 }
2262
2263 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2264 {
2265         return refs_copy_existing_ref(get_main_ref_store(the_repository), oldref, newref, logmsg);
2266 }