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