c590a992fb19ce92dcf0932b58f83b65028f8316
[git/git.git] / refs.c
1 /*
2 * The backend-independent part of the reference module.
3 */
4
5 #include "cache.h"
6 #include "config.h"
7 #include "hashmap.h"
8 #include "lockfile.h"
9 #include "iterator.h"
10 #include "refs.h"
11 #include "refs/refs-internal.h"
12 #include "object.h"
13 #include "tag.h"
14 #include "submodule.h"
15 #include "worktree.h"
16
17 /*
18 * List of all available backends
19 */
20 static struct ref_storage_be *refs_backends = &refs_be_files;
21
22 static struct ref_storage_be *find_ref_storage_backend(const char *name)
23 {
24 struct ref_storage_be *be;
25 for (be = refs_backends; be; be = be->next)
26 if (!strcmp(be->name, name))
27 return be;
28 return NULL;
29 }
30
31 int ref_storage_backend_exists(const char *name)
32 {
33 return find_ref_storage_backend(name) != NULL;
34 }
35
36 /*
37 * How to handle various characters in refnames:
38 * 0: An acceptable character for refs
39 * 1: End-of-component
40 * 2: ., look for a preceding . to reject .. in refs
41 * 3: {, look for a preceding @ to reject @{ in refs
42 * 4: A bad character: ASCII control characters, and
43 * ":", "?", "[", "\", "^", "~", SP, or TAB
44 * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
45 */
46 static unsigned char refname_disposition[256] = {
47 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
48 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
49 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
50 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
51 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
52 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
53 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
54 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
55 };
56
57 /*
58 * Try to read one refname component from the front of refname.
59 * Return the length of the component found, or -1 if the component is
60 * not legal. It is legal if it is something reasonable to have under
61 * ".git/refs/"; We do not like it if:
62 *
63 * - any path component of it begins with ".", or
64 * - it has double dots "..", or
65 * - it has ASCII control characters, or
66 * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
67 * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
68 * - it ends with a "/", or
69 * - it ends with ".lock", or
70 * - it contains a "@{" portion
71 */
72 static int check_refname_component(const char *refname, int *flags)
73 {
74 const char *cp;
75 char last = '\0';
76
77 for (cp = refname; ; cp++) {
78 int ch = *cp & 255;
79 unsigned char disp = refname_disposition[ch];
80 switch (disp) {
81 case 1:
82 goto out;
83 case 2:
84 if (last == '.')
85 return -1; /* Refname contains "..". */
86 break;
87 case 3:
88 if (last == '@')
89 return -1; /* Refname contains "@{". */
90 break;
91 case 4:
92 return -1;
93 case 5:
94 if (!(*flags & REFNAME_REFSPEC_PATTERN))
95 return -1; /* refspec can't be a pattern */
96
97 /*
98 * Unset the pattern flag so that we only accept
99 * a single asterisk for one side of refspec.
100 */
101 *flags &= ~ REFNAME_REFSPEC_PATTERN;
102 break;
103 }
104 last = ch;
105 }
106 out:
107 if (cp == refname)
108 return 0; /* Component has zero length. */
109 if (refname[0] == '.')
110 return -1; /* Component starts with '.'. */
111 if (cp - refname >= LOCK_SUFFIX_LEN &&
112 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
113 return -1; /* Refname ends with ".lock". */
114 return cp - refname;
115 }
116
117 int check_refname_format(const char *refname, int flags)
118 {
119 int component_len, component_count = 0;
120
121 if (!strcmp(refname, "@"))
122 /* Refname is a single character '@'. */
123 return -1;
124
125 while (1) {
126 /* We are at the start of a path component. */
127 component_len = check_refname_component(refname, &flags);
128 if (component_len <= 0)
129 return -1;
130
131 component_count++;
132 if (refname[component_len] == '\0')
133 break;
134 /* Skip to next component. */
135 refname += component_len + 1;
136 }
137
138 if (refname[component_len - 1] == '.')
139 return -1; /* Refname ends with '.'. */
140 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
141 return -1; /* Refname has only one component. */
142 return 0;
143 }
144
145 int refname_is_safe(const char *refname)
146 {
147 const char *rest;
148
149 if (skip_prefix(refname, "refs/", &rest)) {
150 char *buf;
151 int result;
152 size_t restlen = strlen(rest);
153
154 /* rest must not be empty, or start or end with "/" */
155 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
156 return 0;
157
158 /*
159 * Does the refname try to escape refs/?
160 * For example: refs/foo/../bar is safe but refs/foo/../../bar
161 * is not.
162 */
163 buf = xmallocz(restlen);
164 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
165 free(buf);
166 return result;
167 }
168
169 do {
170 if (!isupper(*refname) && *refname != '_')
171 return 0;
172 refname++;
173 } while (*refname);
174 return 1;
175 }
176
177 /*
178 * Return true if refname, which has the specified oid and flags, can
179 * be resolved to an object in the database. If the referred-to object
180 * does not exist, emit a warning and return false.
181 */
182 int ref_resolves_to_object(const char *refname,
183 const struct object_id *oid,
184 unsigned int flags)
185 {
186 if (flags & REF_ISBROKEN)
187 return 0;
188 if (!has_sha1_file(oid->hash)) {
189 error("%s does not point to a valid object!", refname);
190 return 0;
191 }
192 return 1;
193 }
194
195 char *refs_resolve_refdup(struct ref_store *refs,
196 const char *refname, int resolve_flags,
197 unsigned char *sha1, int *flags)
198 {
199 const char *result;
200
201 result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
202 sha1, flags);
203 return xstrdup_or_null(result);
204 }
205
206 char *resolve_refdup(const char *refname, int resolve_flags,
207 unsigned char *sha1, int *flags)
208 {
209 return refs_resolve_refdup(get_main_ref_store(),
210 refname, resolve_flags,
211 sha1, flags);
212 }
213
214 /* The argument to filter_refs */
215 struct ref_filter {
216 const char *pattern;
217 each_ref_fn *fn;
218 void *cb_data;
219 };
220
221 int refs_read_ref_full(struct ref_store *refs, const char *refname,
222 int resolve_flags, unsigned char *sha1, int *flags)
223 {
224 if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, sha1, flags))
225 return 0;
226 return -1;
227 }
228
229 int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
230 {
231 return refs_read_ref_full(get_main_ref_store(), refname,
232 resolve_flags, sha1, flags);
233 }
234
235 int read_ref(const char *refname, unsigned char *sha1)
236 {
237 return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);
238 }
239
240 int ref_exists(const char *refname)
241 {
242 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
243 }
244
245 static int filter_refs(const char *refname, const struct object_id *oid,
246 int flags, void *data)
247 {
248 struct ref_filter *filter = (struct ref_filter *)data;
249
250 if (wildmatch(filter->pattern, refname, 0))
251 return 0;
252 return filter->fn(refname, oid, flags, filter->cb_data);
253 }
254
255 enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
256 {
257 struct object *o = lookup_unknown_object(name);
258
259 if (o->type == OBJ_NONE) {
260 int type = sha1_object_info(name, NULL);
261 if (type < 0 || !object_as_type(o, type, 0))
262 return PEEL_INVALID;
263 }
264
265 if (o->type != OBJ_TAG)
266 return PEEL_NON_TAG;
267
268 o = deref_tag_noverify(o);
269 if (!o)
270 return PEEL_INVALID;
271
272 hashcpy(sha1, o->oid.hash);
273 return PEEL_PEELED;
274 }
275
276 struct warn_if_dangling_data {
277 FILE *fp;
278 const char *refname;
279 const struct string_list *refnames;
280 const char *msg_fmt;
281 };
282
283 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
284 int flags, void *cb_data)
285 {
286 struct warn_if_dangling_data *d = cb_data;
287 const char *resolves_to;
288
289 if (!(flags & REF_ISSYMREF))
290 return 0;
291
292 resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
293 if (!resolves_to
294 || (d->refname
295 ? strcmp(resolves_to, d->refname)
296 : !string_list_has_string(d->refnames, resolves_to))) {
297 return 0;
298 }
299
300 fprintf(d->fp, d->msg_fmt, refname);
301 fputc('\n', d->fp);
302 return 0;
303 }
304
305 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
306 {
307 struct warn_if_dangling_data data;
308
309 data.fp = fp;
310 data.refname = refname;
311 data.refnames = NULL;
312 data.msg_fmt = msg_fmt;
313 for_each_rawref(warn_if_dangling_symref, &data);
314 }
315
316 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
317 {
318 struct warn_if_dangling_data data;
319
320 data.fp = fp;
321 data.refname = NULL;
322 data.refnames = refnames;
323 data.msg_fmt = msg_fmt;
324 for_each_rawref(warn_if_dangling_symref, &data);
325 }
326
327 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
328 {
329 return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
330 }
331
332 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
333 {
334 return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
335 }
336
337 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
338 {
339 return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
340 }
341
342 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
343 {
344 return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
345 }
346
347 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
348 {
349 return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
350 }
351
352 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
353 {
354 return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
355 }
356
357 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
358 {
359 struct strbuf buf = STRBUF_INIT;
360 int ret = 0;
361 struct object_id oid;
362 int flag;
363
364 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
365 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, oid.hash, &flag))
366 ret = fn(buf.buf, &oid, flag, cb_data);
367 strbuf_release(&buf);
368
369 return ret;
370 }
371
372 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
373 const char *prefix, void *cb_data)
374 {
375 struct strbuf real_pattern = STRBUF_INIT;
376 struct ref_filter filter;
377 int ret;
378
379 if (!prefix && !starts_with(pattern, "refs/"))
380 strbuf_addstr(&real_pattern, "refs/");
381 else if (prefix)
382 strbuf_addstr(&real_pattern, prefix);
383 strbuf_addstr(&real_pattern, pattern);
384
385 if (!has_glob_specials(pattern)) {
386 /* Append implied '/' '*' if not present. */
387 strbuf_complete(&real_pattern, '/');
388 /* No need to check for '*', there is none. */
389 strbuf_addch(&real_pattern, '*');
390 }
391
392 filter.pattern = real_pattern.buf;
393 filter.fn = fn;
394 filter.cb_data = cb_data;
395 ret = for_each_ref(filter_refs, &filter);
396
397 strbuf_release(&real_pattern);
398 return ret;
399 }
400
401 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
402 {
403 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
404 }
405
406 const char *prettify_refname(const char *name)
407 {
408 if (skip_prefix(name, "refs/heads/", &name) ||
409 skip_prefix(name, "refs/tags/", &name) ||
410 skip_prefix(name, "refs/remotes/", &name))
411 ; /* nothing */
412 return name;
413 }
414
415 static const char *ref_rev_parse_rules[] = {
416 "%.*s",
417 "refs/%.*s",
418 "refs/tags/%.*s",
419 "refs/heads/%.*s",
420 "refs/remotes/%.*s",
421 "refs/remotes/%.*s/HEAD",
422 NULL
423 };
424
425 int refname_match(const char *abbrev_name, const char *full_name)
426 {
427 const char **p;
428 const int abbrev_name_len = strlen(abbrev_name);
429
430 for (p = ref_rev_parse_rules; *p; p++) {
431 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
432 return 1;
433 }
434 }
435
436 return 0;
437 }
438
439 /*
440 * *string and *len will only be substituted, and *string returned (for
441 * later free()ing) if the string passed in is a magic short-hand form
442 * to name a branch.
443 */
444 static char *substitute_branch_name(const char **string, int *len)
445 {
446 struct strbuf buf = STRBUF_INIT;
447 int ret = interpret_branch_name(*string, *len, &buf, 0);
448
449 if (ret == *len) {
450 size_t size;
451 *string = strbuf_detach(&buf, &size);
452 *len = size;
453 return (char *)*string;
454 }
455
456 return NULL;
457 }
458
459 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
460 {
461 char *last_branch = substitute_branch_name(&str, &len);
462 int refs_found = expand_ref(str, len, sha1, ref);
463 free(last_branch);
464 return refs_found;
465 }
466
467 int expand_ref(const char *str, int len, unsigned char *sha1, char **ref)
468 {
469 const char **p, *r;
470 int refs_found = 0;
471 struct strbuf fullref = STRBUF_INIT;
472
473 *ref = NULL;
474 for (p = ref_rev_parse_rules; *p; p++) {
475 unsigned char sha1_from_ref[20];
476 unsigned char *this_result;
477 int flag;
478
479 this_result = refs_found ? sha1_from_ref : sha1;
480 strbuf_reset(&fullref);
481 strbuf_addf(&fullref, *p, len, str);
482 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
483 this_result, &flag);
484 if (r) {
485 if (!refs_found++)
486 *ref = xstrdup(r);
487 if (!warn_ambiguous_refs)
488 break;
489 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
490 warning("ignoring dangling symref %s.", fullref.buf);
491 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
492 warning("ignoring broken ref %s.", fullref.buf);
493 }
494 }
495 strbuf_release(&fullref);
496 return refs_found;
497 }
498
499 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
500 {
501 char *last_branch = substitute_branch_name(&str, &len);
502 const char **p;
503 int logs_found = 0;
504 struct strbuf path = STRBUF_INIT;
505
506 *log = NULL;
507 for (p = ref_rev_parse_rules; *p; p++) {
508 unsigned char hash[20];
509 const char *ref, *it;
510
511 strbuf_reset(&path);
512 strbuf_addf(&path, *p, len, str);
513 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
514 hash, NULL);
515 if (!ref)
516 continue;
517 if (reflog_exists(path.buf))
518 it = path.buf;
519 else if (strcmp(ref, path.buf) && reflog_exists(ref))
520 it = ref;
521 else
522 continue;
523 if (!logs_found++) {
524 *log = xstrdup(it);
525 hashcpy(sha1, hash);
526 }
527 if (!warn_ambiguous_refs)
528 break;
529 }
530 strbuf_release(&path);
531 free(last_branch);
532 return logs_found;
533 }
534
535 static int is_per_worktree_ref(const char *refname)
536 {
537 return !strcmp(refname, "HEAD") ||
538 starts_with(refname, "refs/bisect/");
539 }
540
541 static int is_pseudoref_syntax(const char *refname)
542 {
543 const char *c;
544
545 for (c = refname; *c; c++) {
546 if (!isupper(*c) && *c != '-' && *c != '_')
547 return 0;
548 }
549
550 return 1;
551 }
552
553 enum ref_type ref_type(const char *refname)
554 {
555 if (is_per_worktree_ref(refname))
556 return REF_TYPE_PER_WORKTREE;
557 if (is_pseudoref_syntax(refname))
558 return REF_TYPE_PSEUDOREF;
559 return REF_TYPE_NORMAL;
560 }
561
562 long get_files_ref_lock_timeout_ms(void)
563 {
564 static int configured = 0;
565
566 /* The default timeout is 100 ms: */
567 static int timeout_ms = 100;
568
569 if (!configured) {
570 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
571 configured = 1;
572 }
573
574 return timeout_ms;
575 }
576
577 static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
578 const unsigned char *old_sha1, struct strbuf *err)
579 {
580 const char *filename;
581 int fd;
582 static struct lock_file lock;
583 struct strbuf buf = STRBUF_INIT;
584 int ret = -1;
585
586 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
587
588 filename = git_path("%s", pseudoref);
589 fd = hold_lock_file_for_update_timeout(&lock, filename,
590 LOCK_DIE_ON_ERROR,
591 get_files_ref_lock_timeout_ms());
592 if (fd < 0) {
593 strbuf_addf(err, "could not open '%s' for writing: %s",
594 filename, strerror(errno));
595 goto done;
596 }
597
598 if (old_sha1) {
599 unsigned char actual_old_sha1[20];
600
601 if (read_ref(pseudoref, actual_old_sha1))
602 die("could not read ref '%s'", pseudoref);
603 if (hashcmp(actual_old_sha1, old_sha1)) {
604 strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
605 rollback_lock_file(&lock);
606 goto done;
607 }
608 }
609
610 if (write_in_full(fd, buf.buf, buf.len) < 0) {
611 strbuf_addf(err, "could not write to '%s'", filename);
612 rollback_lock_file(&lock);
613 goto done;
614 }
615
616 commit_lock_file(&lock);
617 ret = 0;
618 done:
619 strbuf_release(&buf);
620 return ret;
621 }
622
623 static int delete_pseudoref(const char *pseudoref, const unsigned char *old_sha1)
624 {
625 static struct lock_file lock;
626 const char *filename;
627
628 filename = git_path("%s", pseudoref);
629
630 if (old_sha1 && !is_null_sha1(old_sha1)) {
631 int fd;
632 unsigned char actual_old_sha1[20];
633
634 fd = hold_lock_file_for_update_timeout(
635 &lock, filename, LOCK_DIE_ON_ERROR,
636 get_files_ref_lock_timeout_ms());
637 if (fd < 0)
638 die_errno(_("Could not open '%s' for writing"), filename);
639 if (read_ref(pseudoref, actual_old_sha1))
640 die("could not read ref '%s'", pseudoref);
641 if (hashcmp(actual_old_sha1, old_sha1)) {
642 warning("Unexpected sha1 when deleting %s", pseudoref);
643 rollback_lock_file(&lock);
644 return -1;
645 }
646
647 unlink(filename);
648 rollback_lock_file(&lock);
649 } else {
650 unlink(filename);
651 }
652
653 return 0;
654 }
655
656 int refs_delete_ref(struct ref_store *refs, const char *msg,
657 const char *refname,
658 const unsigned char *old_sha1,
659 unsigned int flags)
660 {
661 struct ref_transaction *transaction;
662 struct strbuf err = STRBUF_INIT;
663
664 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
665 assert(refs == get_main_ref_store());
666 return delete_pseudoref(refname, old_sha1);
667 }
668
669 transaction = ref_store_transaction_begin(refs, &err);
670 if (!transaction ||
671 ref_transaction_delete(transaction, refname, old_sha1,
672 flags, msg, &err) ||
673 ref_transaction_commit(transaction, &err)) {
674 error("%s", err.buf);
675 ref_transaction_free(transaction);
676 strbuf_release(&err);
677 return 1;
678 }
679 ref_transaction_free(transaction);
680 strbuf_release(&err);
681 return 0;
682 }
683
684 int delete_ref(const char *msg, const char *refname,
685 const unsigned char *old_sha1, unsigned int flags)
686 {
687 return refs_delete_ref(get_main_ref_store(), msg, refname,
688 old_sha1, flags);
689 }
690
691 int copy_reflog_msg(char *buf, const char *msg)
692 {
693 char *cp = buf;
694 char c;
695 int wasspace = 1;
696
697 *cp++ = '\t';
698 while ((c = *msg++)) {
699 if (wasspace && isspace(c))
700 continue;
701 wasspace = isspace(c);
702 if (wasspace)
703 c = ' ';
704 *cp++ = c;
705 }
706 while (buf < cp && isspace(cp[-1]))
707 cp--;
708 *cp++ = '\n';
709 return cp - buf;
710 }
711
712 int should_autocreate_reflog(const char *refname)
713 {
714 switch (log_all_ref_updates) {
715 case LOG_REFS_ALWAYS:
716 return 1;
717 case LOG_REFS_NORMAL:
718 return starts_with(refname, "refs/heads/") ||
719 starts_with(refname, "refs/remotes/") ||
720 starts_with(refname, "refs/notes/") ||
721 !strcmp(refname, "HEAD");
722 default:
723 return 0;
724 }
725 }
726
727 int is_branch(const char *refname)
728 {
729 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
730 }
731
732 struct read_ref_at_cb {
733 const char *refname;
734 timestamp_t at_time;
735 int cnt;
736 int reccnt;
737 unsigned char *sha1;
738 int found_it;
739
740 unsigned char osha1[20];
741 unsigned char nsha1[20];
742 int tz;
743 timestamp_t date;
744 char **msg;
745 timestamp_t *cutoff_time;
746 int *cutoff_tz;
747 int *cutoff_cnt;
748 };
749
750 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
751 const char *email, timestamp_t timestamp, int tz,
752 const char *message, void *cb_data)
753 {
754 struct read_ref_at_cb *cb = cb_data;
755
756 cb->reccnt++;
757 cb->tz = tz;
758 cb->date = timestamp;
759
760 if (timestamp <= cb->at_time || cb->cnt == 0) {
761 if (cb->msg)
762 *cb->msg = xstrdup(message);
763 if (cb->cutoff_time)
764 *cb->cutoff_time = timestamp;
765 if (cb->cutoff_tz)
766 *cb->cutoff_tz = tz;
767 if (cb->cutoff_cnt)
768 *cb->cutoff_cnt = cb->reccnt - 1;
769 /*
770 * we have not yet updated cb->[n|o]sha1 so they still
771 * hold the values for the previous record.
772 */
773 if (!is_null_sha1(cb->osha1)) {
774 hashcpy(cb->sha1, noid->hash);
775 if (hashcmp(cb->osha1, noid->hash))
776 warning("Log for ref %s has gap after %s.",
777 cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
778 }
779 else if (cb->date == cb->at_time)
780 hashcpy(cb->sha1, noid->hash);
781 else if (hashcmp(noid->hash, cb->sha1))
782 warning("Log for ref %s unexpectedly ended on %s.",
783 cb->refname, show_date(cb->date, cb->tz,
784 DATE_MODE(RFC2822)));
785 hashcpy(cb->osha1, ooid->hash);
786 hashcpy(cb->nsha1, noid->hash);
787 cb->found_it = 1;
788 return 1;
789 }
790 hashcpy(cb->osha1, ooid->hash);
791 hashcpy(cb->nsha1, noid->hash);
792 if (cb->cnt > 0)
793 cb->cnt--;
794 return 0;
795 }
796
797 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
798 const char *email, timestamp_t timestamp,
799 int tz, const char *message, void *cb_data)
800 {
801 struct read_ref_at_cb *cb = cb_data;
802
803 if (cb->msg)
804 *cb->msg = xstrdup(message);
805 if (cb->cutoff_time)
806 *cb->cutoff_time = timestamp;
807 if (cb->cutoff_tz)
808 *cb->cutoff_tz = tz;
809 if (cb->cutoff_cnt)
810 *cb->cutoff_cnt = cb->reccnt;
811 hashcpy(cb->sha1, ooid->hash);
812 if (is_null_sha1(cb->sha1))
813 hashcpy(cb->sha1, noid->hash);
814 /* We just want the first entry */
815 return 1;
816 }
817
818 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
819 unsigned char *sha1, char **msg,
820 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
821 {
822 struct read_ref_at_cb cb;
823
824 memset(&cb, 0, sizeof(cb));
825 cb.refname = refname;
826 cb.at_time = at_time;
827 cb.cnt = cnt;
828 cb.msg = msg;
829 cb.cutoff_time = cutoff_time;
830 cb.cutoff_tz = cutoff_tz;
831 cb.cutoff_cnt = cutoff_cnt;
832 cb.sha1 = sha1;
833
834 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
835
836 if (!cb.reccnt) {
837 if (flags & GET_OID_QUIETLY)
838 exit(128);
839 else
840 die("Log for %s is empty.", refname);
841 }
842 if (cb.found_it)
843 return 0;
844
845 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
846
847 return 1;
848 }
849
850 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
851 struct strbuf *err)
852 {
853 struct ref_transaction *tr;
854 assert(err);
855
856 tr = xcalloc(1, sizeof(struct ref_transaction));
857 tr->ref_store = refs;
858 return tr;
859 }
860
861 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
862 {
863 return ref_store_transaction_begin(get_main_ref_store(), err);
864 }
865
866 void ref_transaction_free(struct ref_transaction *transaction)
867 {
868 size_t i;
869
870 if (!transaction)
871 return;
872
873 switch (transaction->state) {
874 case REF_TRANSACTION_OPEN:
875 case REF_TRANSACTION_CLOSED:
876 /* OK */
877 break;
878 case REF_TRANSACTION_PREPARED:
879 die("BUG: free called on a prepared reference transaction");
880 break;
881 default:
882 die("BUG: unexpected reference transaction state");
883 break;
884 }
885
886 for (i = 0; i < transaction->nr; i++) {
887 free(transaction->updates[i]->msg);
888 free(transaction->updates[i]);
889 }
890 free(transaction->updates);
891 free(transaction);
892 }
893
894 struct ref_update *ref_transaction_add_update(
895 struct ref_transaction *transaction,
896 const char *refname, unsigned int flags,
897 const unsigned char *new_sha1,
898 const unsigned char *old_sha1,
899 const char *msg)
900 {
901 struct ref_update *update;
902
903 if (transaction->state != REF_TRANSACTION_OPEN)
904 die("BUG: update called for transaction that is not open");
905
906 if ((flags & REF_ISPRUNING) && !(flags & REF_NODEREF))
907 die("BUG: REF_ISPRUNING set without REF_NODEREF");
908
909 FLEX_ALLOC_STR(update, refname, refname);
910 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
911 transaction->updates[transaction->nr++] = update;
912
913 update->flags = flags;
914
915 if (flags & REF_HAVE_NEW)
916 hashcpy(update->new_oid.hash, new_sha1);
917 if (flags & REF_HAVE_OLD)
918 hashcpy(update->old_oid.hash, old_sha1);
919 update->msg = xstrdup_or_null(msg);
920 return update;
921 }
922
923 int ref_transaction_update(struct ref_transaction *transaction,
924 const char *refname,
925 const unsigned char *new_sha1,
926 const unsigned char *old_sha1,
927 unsigned int flags, const char *msg,
928 struct strbuf *err)
929 {
930 assert(err);
931
932 if ((new_sha1 && !is_null_sha1(new_sha1)) ?
933 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
934 !refname_is_safe(refname)) {
935 strbuf_addf(err, "refusing to update ref with bad name '%s'",
936 refname);
937 return -1;
938 }
939
940 flags &= REF_TRANSACTION_UPDATE_ALLOWED_FLAGS;
941
942 flags |= (new_sha1 ? REF_HAVE_NEW : 0) | (old_sha1 ? REF_HAVE_OLD : 0);
943
944 ref_transaction_add_update(transaction, refname, flags,
945 new_sha1, old_sha1, msg);
946 return 0;
947 }
948
949 int ref_transaction_create(struct ref_transaction *transaction,
950 const char *refname,
951 const unsigned char *new_sha1,
952 unsigned int flags, const char *msg,
953 struct strbuf *err)
954 {
955 if (!new_sha1 || is_null_sha1(new_sha1))
956 die("BUG: create called without valid new_sha1");
957 return ref_transaction_update(transaction, refname, new_sha1,
958 null_sha1, flags, msg, err);
959 }
960
961 int ref_transaction_delete(struct ref_transaction *transaction,
962 const char *refname,
963 const unsigned char *old_sha1,
964 unsigned int flags, const char *msg,
965 struct strbuf *err)
966 {
967 if (old_sha1 && is_null_sha1(old_sha1))
968 die("BUG: delete called with old_sha1 set to zeros");
969 return ref_transaction_update(transaction, refname,
970 null_sha1, old_sha1,
971 flags, msg, err);
972 }
973
974 int ref_transaction_verify(struct ref_transaction *transaction,
975 const char *refname,
976 const unsigned char *old_sha1,
977 unsigned int flags,
978 struct strbuf *err)
979 {
980 if (!old_sha1)
981 die("BUG: verify called with old_sha1 set to NULL");
982 return ref_transaction_update(transaction, refname,
983 NULL, old_sha1,
984 flags, NULL, err);
985 }
986
987 int update_ref_oid(const char *msg, const char *refname,
988 const struct object_id *new_oid, const struct object_id *old_oid,
989 unsigned int flags, enum action_on_err onerr)
990 {
991 return update_ref(msg, refname, new_oid ? new_oid->hash : NULL,
992 old_oid ? old_oid->hash : NULL, flags, onerr);
993 }
994
995 int refs_update_ref(struct ref_store *refs, const char *msg,
996 const char *refname, const unsigned char *new_sha1,
997 const unsigned char *old_sha1, unsigned int flags,
998 enum action_on_err onerr)
999 {
1000 struct ref_transaction *t = NULL;
1001 struct strbuf err = STRBUF_INIT;
1002 int ret = 0;
1003
1004 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1005 assert(refs == get_main_ref_store());
1006 ret = write_pseudoref(refname, new_sha1, old_sha1, &err);
1007 } else {
1008 t = ref_store_transaction_begin(refs, &err);
1009 if (!t ||
1010 ref_transaction_update(t, refname, new_sha1, old_sha1,
1011 flags, msg, &err) ||
1012 ref_transaction_commit(t, &err)) {
1013 ret = 1;
1014 ref_transaction_free(t);
1015 }
1016 }
1017 if (ret) {
1018 const char *str = "update_ref failed for ref '%s': %s";
1019
1020 switch (onerr) {
1021 case UPDATE_REFS_MSG_ON_ERR:
1022 error(str, refname, err.buf);
1023 break;
1024 case UPDATE_REFS_DIE_ON_ERR:
1025 die(str, refname, err.buf);
1026 break;
1027 case UPDATE_REFS_QUIET_ON_ERR:
1028 break;
1029 }
1030 strbuf_release(&err);
1031 return 1;
1032 }
1033 strbuf_release(&err);
1034 if (t)
1035 ref_transaction_free(t);
1036 return 0;
1037 }
1038
1039 int update_ref(const char *msg, const char *refname,
1040 const unsigned char *new_sha1,
1041 const unsigned char *old_sha1,
1042 unsigned int flags, enum action_on_err onerr)
1043 {
1044 return refs_update_ref(get_main_ref_store(), msg, refname, new_sha1,
1045 old_sha1, flags, onerr);
1046 }
1047
1048 char *shorten_unambiguous_ref(const char *refname, int strict)
1049 {
1050 int i;
1051 static char **scanf_fmts;
1052 static int nr_rules;
1053 char *short_name;
1054 struct strbuf resolved_buf = STRBUF_INIT;
1055
1056 if (!nr_rules) {
1057 /*
1058 * Pre-generate scanf formats from ref_rev_parse_rules[].
1059 * Generate a format suitable for scanf from a
1060 * ref_rev_parse_rules rule by interpolating "%s" at the
1061 * location of the "%.*s".
1062 */
1063 size_t total_len = 0;
1064 size_t offset = 0;
1065
1066 /* the rule list is NULL terminated, count them first */
1067 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1068 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1069 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1070
1071 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1072
1073 offset = 0;
1074 for (i = 0; i < nr_rules; i++) {
1075 assert(offset < total_len);
1076 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1077 offset += snprintf(scanf_fmts[i], total_len - offset,
1078 ref_rev_parse_rules[i], 2, "%s") + 1;
1079 }
1080 }
1081
1082 /* bail out if there are no rules */
1083 if (!nr_rules)
1084 return xstrdup(refname);
1085
1086 /* buffer for scanf result, at most refname must fit */
1087 short_name = xstrdup(refname);
1088
1089 /* skip first rule, it will always match */
1090 for (i = nr_rules - 1; i > 0 ; --i) {
1091 int j;
1092 int rules_to_fail = i;
1093 int short_name_len;
1094
1095 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1096 continue;
1097
1098 short_name_len = strlen(short_name);
1099
1100 /*
1101 * in strict mode, all (except the matched one) rules
1102 * must fail to resolve to a valid non-ambiguous ref
1103 */
1104 if (strict)
1105 rules_to_fail = nr_rules;
1106
1107 /*
1108 * check if the short name resolves to a valid ref,
1109 * but use only rules prior to the matched one
1110 */
1111 for (j = 0; j < rules_to_fail; j++) {
1112 const char *rule = ref_rev_parse_rules[j];
1113
1114 /* skip matched rule */
1115 if (i == j)
1116 continue;
1117
1118 /*
1119 * the short name is ambiguous, if it resolves
1120 * (with this previous rule) to a valid ref
1121 * read_ref() returns 0 on success
1122 */
1123 strbuf_reset(&resolved_buf);
1124 strbuf_addf(&resolved_buf, rule,
1125 short_name_len, short_name);
1126 if (ref_exists(resolved_buf.buf))
1127 break;
1128 }
1129
1130 /*
1131 * short name is non-ambiguous if all previous rules
1132 * haven't resolved to a valid ref
1133 */
1134 if (j == rules_to_fail) {
1135 strbuf_release(&resolved_buf);
1136 return short_name;
1137 }
1138 }
1139
1140 strbuf_release(&resolved_buf);
1141 free(short_name);
1142 return xstrdup(refname);
1143 }
1144
1145 static struct string_list *hide_refs;
1146
1147 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1148 {
1149 const char *key;
1150 if (!strcmp("transfer.hiderefs", var) ||
1151 (!parse_config_key(var, section, NULL, NULL, &key) &&
1152 !strcmp(key, "hiderefs"))) {
1153 char *ref;
1154 int len;
1155
1156 if (!value)
1157 return config_error_nonbool(var);
1158 ref = xstrdup(value);
1159 len = strlen(ref);
1160 while (len && ref[len - 1] == '/')
1161 ref[--len] = '\0';
1162 if (!hide_refs) {
1163 hide_refs = xcalloc(1, sizeof(*hide_refs));
1164 hide_refs->strdup_strings = 1;
1165 }
1166 string_list_append(hide_refs, ref);
1167 }
1168 return 0;
1169 }
1170
1171 int ref_is_hidden(const char *refname, const char *refname_full)
1172 {
1173 int i;
1174
1175 if (!hide_refs)
1176 return 0;
1177 for (i = hide_refs->nr - 1; i >= 0; i--) {
1178 const char *match = hide_refs->items[i].string;
1179 const char *subject;
1180 int neg = 0;
1181 const char *p;
1182
1183 if (*match == '!') {
1184 neg = 1;
1185 match++;
1186 }
1187
1188 if (*match == '^') {
1189 subject = refname_full;
1190 match++;
1191 } else {
1192 subject = refname;
1193 }
1194
1195 /* refname can be NULL when namespaces are used. */
1196 if (subject &&
1197 skip_prefix(subject, match, &p) &&
1198 (!*p || *p == '/'))
1199 return !neg;
1200 }
1201 return 0;
1202 }
1203
1204 const char *find_descendant_ref(const char *dirname,
1205 const struct string_list *extras,
1206 const struct string_list *skip)
1207 {
1208 int pos;
1209
1210 if (!extras)
1211 return NULL;
1212
1213 /*
1214 * Look at the place where dirname would be inserted into
1215 * extras. If there is an entry at that position that starts
1216 * with dirname (remember, dirname includes the trailing
1217 * slash) and is not in skip, then we have a conflict.
1218 */
1219 for (pos = string_list_find_insert_index(extras, dirname, 0);
1220 pos < extras->nr; pos++) {
1221 const char *extra_refname = extras->items[pos].string;
1222
1223 if (!starts_with(extra_refname, dirname))
1224 break;
1225
1226 if (!skip || !string_list_has_string(skip, extra_refname))
1227 return extra_refname;
1228 }
1229 return NULL;
1230 }
1231
1232 int refs_rename_ref_available(struct ref_store *refs,
1233 const char *old_refname,
1234 const char *new_refname)
1235 {
1236 struct string_list skip = STRING_LIST_INIT_NODUP;
1237 struct strbuf err = STRBUF_INIT;
1238 int ok;
1239
1240 string_list_insert(&skip, old_refname);
1241 ok = !refs_verify_refname_available(refs, new_refname,
1242 NULL, &skip, &err);
1243 if (!ok)
1244 error("%s", err.buf);
1245
1246 string_list_clear(&skip, 0);
1247 strbuf_release(&err);
1248 return ok;
1249 }
1250
1251 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1252 {
1253 struct object_id oid;
1254 int flag;
1255
1256 if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1257 oid.hash, &flag))
1258 return fn("HEAD", &oid, flag, cb_data);
1259
1260 return 0;
1261 }
1262
1263 int head_ref(each_ref_fn fn, void *cb_data)
1264 {
1265 return refs_head_ref(get_main_ref_store(), fn, cb_data);
1266 }
1267
1268 struct ref_iterator *refs_ref_iterator_begin(
1269 struct ref_store *refs,
1270 const char *prefix, int trim, int flags)
1271 {
1272 struct ref_iterator *iter;
1273
1274 if (ref_paranoia < 0)
1275 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1276 if (ref_paranoia)
1277 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1278
1279 iter = refs->be->iterator_begin(refs, prefix, flags);
1280
1281 /*
1282 * `iterator_begin()` already takes care of prefix, but we
1283 * might need to do some trimming:
1284 */
1285 if (trim)
1286 iter = prefix_ref_iterator_begin(iter, "", trim);
1287
1288 /* Sanity check for subclasses: */
1289 if (!iter->ordered)
1290 BUG("reference iterator is not ordered");
1291
1292 return iter;
1293 }
1294
1295 /*
1296 * Call fn for each reference in the specified submodule for which the
1297 * refname begins with prefix. If trim is non-zero, then trim that
1298 * many characters off the beginning of each refname before passing
1299 * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1300 * include broken references in the iteration. If fn ever returns a
1301 * non-zero value, stop the iteration and return that value;
1302 * otherwise, return 0.
1303 */
1304 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1305 each_ref_fn fn, int trim, int flags, void *cb_data)
1306 {
1307 struct ref_iterator *iter;
1308
1309 if (!refs)
1310 return 0;
1311
1312 iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1313
1314 return do_for_each_ref_iterator(iter, fn, cb_data);
1315 }
1316
1317 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1318 {
1319 return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1320 }
1321
1322 int for_each_ref(each_ref_fn fn, void *cb_data)
1323 {
1324 return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
1325 }
1326
1327 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1328 each_ref_fn fn, void *cb_data)
1329 {
1330 return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1331 }
1332
1333 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1334 {
1335 return refs_for_each_ref_in(get_main_ref_store(), prefix, fn, cb_data);
1336 }
1337
1338 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1339 {
1340 unsigned int flag = 0;
1341
1342 if (broken)
1343 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1344 return do_for_each_ref(get_main_ref_store(),
1345 prefix, fn, 0, flag, cb_data);
1346 }
1347
1348 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1349 each_ref_fn fn, void *cb_data,
1350 unsigned int broken)
1351 {
1352 unsigned int flag = 0;
1353
1354 if (broken)
1355 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1356 return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1357 }
1358
1359 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1360 {
1361 return do_for_each_ref(get_main_ref_store(),
1362 git_replace_ref_base, fn,
1363 strlen(git_replace_ref_base),
1364 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1365 }
1366
1367 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1368 {
1369 struct strbuf buf = STRBUF_INIT;
1370 int ret;
1371 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1372 ret = do_for_each_ref(get_main_ref_store(),
1373 buf.buf, fn, 0, 0, cb_data);
1374 strbuf_release(&buf);
1375 return ret;
1376 }
1377
1378 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1379 {
1380 return do_for_each_ref(refs, "", fn, 0,
1381 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1382 }
1383
1384 int for_each_rawref(each_ref_fn fn, void *cb_data)
1385 {
1386 return refs_for_each_rawref(get_main_ref_store(), fn, cb_data);
1387 }
1388
1389 int refs_read_raw_ref(struct ref_store *ref_store,
1390 const char *refname, unsigned char *sha1,
1391 struct strbuf *referent, unsigned int *type)
1392 {
1393 return ref_store->be->read_raw_ref(ref_store, refname, sha1, referent, type);
1394 }
1395
1396 /* This function needs to return a meaningful errno on failure */
1397 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1398 const char *refname,
1399 int resolve_flags,
1400 unsigned char *sha1, int *flags)
1401 {
1402 static struct strbuf sb_refname = STRBUF_INIT;
1403 struct object_id unused_oid;
1404 int unused_flags;
1405 int symref_count;
1406
1407 if (!sha1)
1408 sha1 = unused_oid.hash;
1409 if (!flags)
1410 flags = &unused_flags;
1411
1412 *flags = 0;
1413
1414 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1415 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1416 !refname_is_safe(refname)) {
1417 errno = EINVAL;
1418 return NULL;
1419 }
1420
1421 /*
1422 * dwim_ref() uses REF_ISBROKEN to distinguish between
1423 * missing refs and refs that were present but invalid,
1424 * to complain about the latter to stderr.
1425 *
1426 * We don't know whether the ref exists, so don't set
1427 * REF_ISBROKEN yet.
1428 */
1429 *flags |= REF_BAD_NAME;
1430 }
1431
1432 for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1433 unsigned int read_flags = 0;
1434
1435 if (refs_read_raw_ref(refs, refname,
1436 sha1, &sb_refname, &read_flags)) {
1437 *flags |= read_flags;
1438
1439 /* In reading mode, refs must eventually resolve */
1440 if (resolve_flags & RESOLVE_REF_READING)
1441 return NULL;
1442
1443 /*
1444 * Otherwise a missing ref is OK. But the files backend
1445 * may show errors besides ENOENT if there are
1446 * similarly-named refs.
1447 */
1448 if (errno != ENOENT &&
1449 errno != EISDIR &&
1450 errno != ENOTDIR)
1451 return NULL;
1452
1453 hashclr(sha1);
1454 if (*flags & REF_BAD_NAME)
1455 *flags |= REF_ISBROKEN;
1456 return refname;
1457 }
1458
1459 *flags |= read_flags;
1460
1461 if (!(read_flags & REF_ISSYMREF)) {
1462 if (*flags & REF_BAD_NAME) {
1463 hashclr(sha1);
1464 *flags |= REF_ISBROKEN;
1465 }
1466 return refname;
1467 }
1468
1469 refname = sb_refname.buf;
1470 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1471 hashclr(sha1);
1472 return refname;
1473 }
1474 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1475 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1476 !refname_is_safe(refname)) {
1477 errno = EINVAL;
1478 return NULL;
1479 }
1480
1481 *flags |= REF_ISBROKEN | REF_BAD_NAME;
1482 }
1483 }
1484
1485 errno = ELOOP;
1486 return NULL;
1487 }
1488
1489 /* backend functions */
1490 int refs_init_db(struct strbuf *err)
1491 {
1492 struct ref_store *refs = get_main_ref_store();
1493
1494 return refs->be->init_db(refs, err);
1495 }
1496
1497 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1498 unsigned char *sha1, int *flags)
1499 {
1500 return refs_resolve_ref_unsafe(get_main_ref_store(), refname,
1501 resolve_flags, sha1, flags);
1502 }
1503
1504 int resolve_gitlink_ref(const char *submodule, const char *refname,
1505 unsigned char *sha1)
1506 {
1507 struct ref_store *refs;
1508 int flags;
1509
1510 refs = get_submodule_ref_store(submodule);
1511
1512 if (!refs)
1513 return -1;
1514
1515 if (!refs_resolve_ref_unsafe(refs, refname, 0, sha1, &flags) ||
1516 is_null_sha1(sha1))
1517 return -1;
1518 return 0;
1519 }
1520
1521 struct ref_store_hash_entry
1522 {
1523 struct hashmap_entry ent; /* must be the first member! */
1524
1525 struct ref_store *refs;
1526
1527 /* NUL-terminated identifier of the ref store: */
1528 char name[FLEX_ARRAY];
1529 };
1530
1531 static int ref_store_hash_cmp(const void *unused_cmp_data,
1532 const void *entry, const void *entry_or_key,
1533 const void *keydata)
1534 {
1535 const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1536 const char *name = keydata ? keydata : e2->name;
1537
1538 return strcmp(e1->name, name);
1539 }
1540
1541 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1542 const char *name, struct ref_store *refs)
1543 {
1544 struct ref_store_hash_entry *entry;
1545
1546 FLEX_ALLOC_STR(entry, name, name);
1547 hashmap_entry_init(entry, strhash(name));
1548 entry->refs = refs;
1549 return entry;
1550 }
1551
1552 /* A pointer to the ref_store for the main repository: */
1553 static struct ref_store *main_ref_store;
1554
1555 /* A hashmap of ref_stores, stored by submodule name: */
1556 static struct hashmap submodule_ref_stores;
1557
1558 /* A hashmap of ref_stores, stored by worktree id: */
1559 static struct hashmap worktree_ref_stores;
1560
1561 /*
1562 * Look up a ref store by name. If that ref_store hasn't been
1563 * registered yet, return NULL.
1564 */
1565 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1566 const char *name)
1567 {
1568 struct ref_store_hash_entry *entry;
1569
1570 if (!map->tablesize)
1571 /* It's initialized on demand in register_ref_store(). */
1572 return NULL;
1573
1574 entry = hashmap_get_from_hash(map, strhash(name), name);
1575 return entry ? entry->refs : NULL;
1576 }
1577
1578 /*
1579 * Create, record, and return a ref_store instance for the specified
1580 * gitdir.
1581 */
1582 static struct ref_store *ref_store_init(const char *gitdir,
1583 unsigned int flags)
1584 {
1585 const char *be_name = "files";
1586 struct ref_storage_be *be = find_ref_storage_backend(be_name);
1587 struct ref_store *refs;
1588
1589 if (!be)
1590 die("BUG: reference backend %s is unknown", be_name);
1591
1592 refs = be->init(gitdir, flags);
1593 return refs;
1594 }
1595
1596 struct ref_store *get_main_ref_store(void)
1597 {
1598 if (main_ref_store)
1599 return main_ref_store;
1600
1601 main_ref_store = ref_store_init(get_git_dir(), REF_STORE_ALL_CAPS);
1602 return main_ref_store;
1603 }
1604
1605 /*
1606 * Associate a ref store with a name. It is a fatal error to call this
1607 * function twice for the same name.
1608 */
1609 static void register_ref_store_map(struct hashmap *map,
1610 const char *type,
1611 struct ref_store *refs,
1612 const char *name)
1613 {
1614 if (!map->tablesize)
1615 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1616
1617 if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1618 die("BUG: %s ref_store '%s' initialized twice", type, name);
1619 }
1620
1621 struct ref_store *get_submodule_ref_store(const char *submodule)
1622 {
1623 struct strbuf submodule_sb = STRBUF_INIT;
1624 struct ref_store *refs;
1625 char *to_free = NULL;
1626 size_t len;
1627
1628 if (!submodule)
1629 return NULL;
1630
1631 len = strlen(submodule);
1632 while (len && is_dir_sep(submodule[len - 1]))
1633 len--;
1634 if (!len)
1635 return NULL;
1636
1637 if (submodule[len])
1638 /* We need to strip off one or more trailing slashes */
1639 submodule = to_free = xmemdupz(submodule, len);
1640
1641 refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1642 if (refs)
1643 goto done;
1644
1645 strbuf_addstr(&submodule_sb, submodule);
1646 if (!is_nonbare_repository_dir(&submodule_sb))
1647 goto done;
1648
1649 if (submodule_to_gitdir(&submodule_sb, submodule))
1650 goto done;
1651
1652 /* assume that add_submodule_odb() has been called */
1653 refs = ref_store_init(submodule_sb.buf,
1654 REF_STORE_READ | REF_STORE_ODB);
1655 register_ref_store_map(&submodule_ref_stores, "submodule",
1656 refs, submodule);
1657
1658 done:
1659 strbuf_release(&submodule_sb);
1660 free(to_free);
1661
1662 return refs;
1663 }
1664
1665 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1666 {
1667 struct ref_store *refs;
1668 const char *id;
1669
1670 if (wt->is_current)
1671 return get_main_ref_store();
1672
1673 id = wt->id ? wt->id : "/";
1674 refs = lookup_ref_store_map(&worktree_ref_stores, id);
1675 if (refs)
1676 return refs;
1677
1678 if (wt->id)
1679 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1680 REF_STORE_ALL_CAPS);
1681 else
1682 refs = ref_store_init(get_git_common_dir(),
1683 REF_STORE_ALL_CAPS);
1684
1685 if (refs)
1686 register_ref_store_map(&worktree_ref_stores, "worktree",
1687 refs, id);
1688 return refs;
1689 }
1690
1691 void base_ref_store_init(struct ref_store *refs,
1692 const struct ref_storage_be *be)
1693 {
1694 refs->be = be;
1695 }
1696
1697 /* backend functions */
1698 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1699 {
1700 return refs->be->pack_refs(refs, flags);
1701 }
1702
1703 int refs_peel_ref(struct ref_store *refs, const char *refname,
1704 unsigned char *sha1)
1705 {
1706 int flag;
1707 unsigned char base[20];
1708
1709 if (current_ref_iter && current_ref_iter->refname == refname) {
1710 struct object_id peeled;
1711
1712 if (ref_iterator_peel(current_ref_iter, &peeled))
1713 return -1;
1714 hashcpy(sha1, peeled.hash);
1715 return 0;
1716 }
1717
1718 if (refs_read_ref_full(refs, refname,
1719 RESOLVE_REF_READING, base, &flag))
1720 return -1;
1721
1722 return peel_object(base, sha1);
1723 }
1724
1725 int peel_ref(const char *refname, unsigned char *sha1)
1726 {
1727 return refs_peel_ref(get_main_ref_store(), refname, sha1);
1728 }
1729
1730 int refs_create_symref(struct ref_store *refs,
1731 const char *ref_target,
1732 const char *refs_heads_master,
1733 const char *logmsg)
1734 {
1735 return refs->be->create_symref(refs, ref_target,
1736 refs_heads_master,
1737 logmsg);
1738 }
1739
1740 int create_symref(const char *ref_target, const char *refs_heads_master,
1741 const char *logmsg)
1742 {
1743 return refs_create_symref(get_main_ref_store(), ref_target,
1744 refs_heads_master, logmsg);
1745 }
1746
1747 int ref_update_reject_duplicates(struct string_list *refnames,
1748 struct strbuf *err)
1749 {
1750 size_t i, n = refnames->nr;
1751
1752 assert(err);
1753
1754 for (i = 1; i < n; i++) {
1755 int cmp = strcmp(refnames->items[i - 1].string,
1756 refnames->items[i].string);
1757
1758 if (!cmp) {
1759 strbuf_addf(err,
1760 "multiple updates for ref '%s' not allowed.",
1761 refnames->items[i].string);
1762 return 1;
1763 } else if (cmp > 0) {
1764 die("BUG: ref_update_reject_duplicates() received unsorted list");
1765 }
1766 }
1767 return 0;
1768 }
1769
1770 int ref_transaction_prepare(struct ref_transaction *transaction,
1771 struct strbuf *err)
1772 {
1773 struct ref_store *refs = transaction->ref_store;
1774
1775 switch (transaction->state) {
1776 case REF_TRANSACTION_OPEN:
1777 /* Good. */
1778 break;
1779 case REF_TRANSACTION_PREPARED:
1780 die("BUG: prepare called twice on reference transaction");
1781 break;
1782 case REF_TRANSACTION_CLOSED:
1783 die("BUG: prepare called on a closed reference transaction");
1784 break;
1785 default:
1786 die("BUG: unexpected reference transaction state");
1787 break;
1788 }
1789
1790 if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1791 strbuf_addstr(err,
1792 _("ref updates forbidden inside quarantine environment"));
1793 return -1;
1794 }
1795
1796 return refs->be->transaction_prepare(refs, transaction, err);
1797 }
1798
1799 int ref_transaction_abort(struct ref_transaction *transaction,
1800 struct strbuf *err)
1801 {
1802 struct ref_store *refs = transaction->ref_store;
1803 int ret = 0;
1804
1805 switch (transaction->state) {
1806 case REF_TRANSACTION_OPEN:
1807 /* No need to abort explicitly. */
1808 break;
1809 case REF_TRANSACTION_PREPARED:
1810 ret = refs->be->transaction_abort(refs, transaction, err);
1811 break;
1812 case REF_TRANSACTION_CLOSED:
1813 die("BUG: abort called on a closed reference transaction");
1814 break;
1815 default:
1816 die("BUG: unexpected reference transaction state");
1817 break;
1818 }
1819
1820 ref_transaction_free(transaction);
1821 return ret;
1822 }
1823
1824 int ref_transaction_commit(struct ref_transaction *transaction,
1825 struct strbuf *err)
1826 {
1827 struct ref_store *refs = transaction->ref_store;
1828 int ret;
1829
1830 switch (transaction->state) {
1831 case REF_TRANSACTION_OPEN:
1832 /* Need to prepare first. */
1833 ret = ref_transaction_prepare(transaction, err);
1834 if (ret)
1835 return ret;
1836 break;
1837 case REF_TRANSACTION_PREPARED:
1838 /* Fall through to finish. */
1839 break;
1840 case REF_TRANSACTION_CLOSED:
1841 die("BUG: commit called on a closed reference transaction");
1842 break;
1843 default:
1844 die("BUG: unexpected reference transaction state");
1845 break;
1846 }
1847
1848 return refs->be->transaction_finish(refs, transaction, err);
1849 }
1850
1851 int refs_verify_refname_available(struct ref_store *refs,
1852 const char *refname,
1853 const struct string_list *extras,
1854 const struct string_list *skip,
1855 struct strbuf *err)
1856 {
1857 const char *slash;
1858 const char *extra_refname;
1859 struct strbuf dirname = STRBUF_INIT;
1860 struct strbuf referent = STRBUF_INIT;
1861 struct object_id oid;
1862 unsigned int type;
1863 struct ref_iterator *iter;
1864 int ok;
1865 int ret = -1;
1866
1867 /*
1868 * For the sake of comments in this function, suppose that
1869 * refname is "refs/foo/bar".
1870 */
1871
1872 assert(err);
1873
1874 strbuf_grow(&dirname, strlen(refname) + 1);
1875 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1876 /* Expand dirname to the new prefix, not including the trailing slash: */
1877 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1878
1879 /*
1880 * We are still at a leading dir of the refname (e.g.,
1881 * "refs/foo"; if there is a reference with that name,
1882 * it is a conflict, *unless* it is in skip.
1883 */
1884 if (skip && string_list_has_string(skip, dirname.buf))
1885 continue;
1886
1887 if (!refs_read_raw_ref(refs, dirname.buf, oid.hash, &referent, &type)) {
1888 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1889 dirname.buf, refname);
1890 goto cleanup;
1891 }
1892
1893 if (extras && string_list_has_string(extras, dirname.buf)) {
1894 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1895 refname, dirname.buf);
1896 goto cleanup;
1897 }
1898 }
1899
1900 /*
1901 * We are at the leaf of our refname (e.g., "refs/foo/bar").
1902 * There is no point in searching for a reference with that
1903 * name, because a refname isn't considered to conflict with
1904 * itself. But we still need to check for references whose
1905 * names are in the "refs/foo/bar/" namespace, because they
1906 * *do* conflict.
1907 */
1908 strbuf_addstr(&dirname, refname + dirname.len);
1909 strbuf_addch(&dirname, '/');
1910
1911 iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1912 DO_FOR_EACH_INCLUDE_BROKEN);
1913 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1914 if (skip &&
1915 string_list_has_string(skip, iter->refname))
1916 continue;
1917
1918 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1919 iter->refname, refname);
1920 ref_iterator_abort(iter);
1921 goto cleanup;
1922 }
1923
1924 if (ok != ITER_DONE)
1925 die("BUG: error while iterating over references");
1926
1927 extra_refname = find_descendant_ref(dirname.buf, extras, skip);
1928 if (extra_refname)
1929 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1930 refname, extra_refname);
1931 else
1932 ret = 0;
1933
1934 cleanup:
1935 strbuf_release(&referent);
1936 strbuf_release(&dirname);
1937 return ret;
1938 }
1939
1940 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1941 {
1942 struct ref_iterator *iter;
1943
1944 iter = refs->be->reflog_iterator_begin(refs);
1945
1946 return do_for_each_ref_iterator(iter, fn, cb_data);
1947 }
1948
1949 int for_each_reflog(each_ref_fn fn, void *cb_data)
1950 {
1951 return refs_for_each_reflog(get_main_ref_store(), fn, cb_data);
1952 }
1953
1954 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
1955 const char *refname,
1956 each_reflog_ent_fn fn,
1957 void *cb_data)
1958 {
1959 return refs->be->for_each_reflog_ent_reverse(refs, refname,
1960 fn, cb_data);
1961 }
1962
1963 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
1964 void *cb_data)
1965 {
1966 return refs_for_each_reflog_ent_reverse(get_main_ref_store(),
1967 refname, fn, cb_data);
1968 }
1969
1970 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
1971 each_reflog_ent_fn fn, void *cb_data)
1972 {
1973 return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
1974 }
1975
1976 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
1977 void *cb_data)
1978 {
1979 return refs_for_each_reflog_ent(get_main_ref_store(), refname,
1980 fn, cb_data);
1981 }
1982
1983 int refs_reflog_exists(struct ref_store *refs, const char *refname)
1984 {
1985 return refs->be->reflog_exists(refs, refname);
1986 }
1987
1988 int reflog_exists(const char *refname)
1989 {
1990 return refs_reflog_exists(get_main_ref_store(), refname);
1991 }
1992
1993 int refs_create_reflog(struct ref_store *refs, const char *refname,
1994 int force_create, struct strbuf *err)
1995 {
1996 return refs->be->create_reflog(refs, refname, force_create, err);
1997 }
1998
1999 int safe_create_reflog(const char *refname, int force_create,
2000 struct strbuf *err)
2001 {
2002 return refs_create_reflog(get_main_ref_store(), refname,
2003 force_create, err);
2004 }
2005
2006 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2007 {
2008 return refs->be->delete_reflog(refs, refname);
2009 }
2010
2011 int delete_reflog(const char *refname)
2012 {
2013 return refs_delete_reflog(get_main_ref_store(), refname);
2014 }
2015
2016 int refs_reflog_expire(struct ref_store *refs,
2017 const char *refname, const unsigned char *sha1,
2018 unsigned int flags,
2019 reflog_expiry_prepare_fn prepare_fn,
2020 reflog_expiry_should_prune_fn should_prune_fn,
2021 reflog_expiry_cleanup_fn cleanup_fn,
2022 void *policy_cb_data)
2023 {
2024 return refs->be->reflog_expire(refs, refname, sha1, flags,
2025 prepare_fn, should_prune_fn,
2026 cleanup_fn, policy_cb_data);
2027 }
2028
2029 int reflog_expire(const char *refname, const unsigned char *sha1,
2030 unsigned int flags,
2031 reflog_expiry_prepare_fn prepare_fn,
2032 reflog_expiry_should_prune_fn should_prune_fn,
2033 reflog_expiry_cleanup_fn cleanup_fn,
2034 void *policy_cb_data)
2035 {
2036 return refs_reflog_expire(get_main_ref_store(),
2037 refname, sha1, flags,
2038 prepare_fn, should_prune_fn,
2039 cleanup_fn, policy_cb_data);
2040 }
2041
2042 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2043 struct strbuf *err)
2044 {
2045 struct ref_store *refs = transaction->ref_store;
2046
2047 return refs->be->initial_transaction_commit(refs, transaction, err);
2048 }
2049
2050 int refs_delete_refs(struct ref_store *refs, const char *msg,
2051 struct string_list *refnames, unsigned int flags)
2052 {
2053 return refs->be->delete_refs(refs, msg, refnames, flags);
2054 }
2055
2056 int delete_refs(const char *msg, struct string_list *refnames,
2057 unsigned int flags)
2058 {
2059 return refs_delete_refs(get_main_ref_store(), msg, refnames, flags);
2060 }
2061
2062 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2063 const char *newref, const char *logmsg)
2064 {
2065 return refs->be->rename_ref(refs, oldref, newref, logmsg);
2066 }
2067
2068 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2069 {
2070 return refs_rename_ref(get_main_ref_store(), oldref, newref, logmsg);
2071 }
2072
2073 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2074 const char *newref, const char *logmsg)
2075 {
2076 return refs->be->copy_ref(refs, oldref, newref, logmsg);
2077 }
2078
2079 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2080 {
2081 return refs_copy_existing_ref(get_main_ref_store(), oldref, newref, logmsg);
2082 }