Merge branch 'rs/win32-syslog-leakfix'
[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 char *refs_resolve_refdup(struct ref_store *refs,
178 const char *refname, int resolve_flags,
179 unsigned char *sha1, int *flags)
180 {
181 const char *result;
182
183 result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
184 sha1, flags);
185 return xstrdup_or_null(result);
186 }
187
188 char *resolve_refdup(const char *refname, int resolve_flags,
189 unsigned char *sha1, int *flags)
190 {
191 return refs_resolve_refdup(get_main_ref_store(),
192 refname, resolve_flags,
193 sha1, flags);
194 }
195
196 /* The argument to filter_refs */
197 struct ref_filter {
198 const char *pattern;
199 each_ref_fn *fn;
200 void *cb_data;
201 };
202
203 int refs_read_ref_full(struct ref_store *refs, const char *refname,
204 int resolve_flags, unsigned char *sha1, int *flags)
205 {
206 if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, sha1, flags))
207 return 0;
208 return -1;
209 }
210
211 int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
212 {
213 return refs_read_ref_full(get_main_ref_store(), refname,
214 resolve_flags, sha1, flags);
215 }
216
217 int read_ref(const char *refname, unsigned char *sha1)
218 {
219 return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);
220 }
221
222 int ref_exists(const char *refname)
223 {
224 unsigned char sha1[20];
225 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);
226 }
227
228 static int filter_refs(const char *refname, const struct object_id *oid,
229 int flags, void *data)
230 {
231 struct ref_filter *filter = (struct ref_filter *)data;
232
233 if (wildmatch(filter->pattern, refname, 0))
234 return 0;
235 return filter->fn(refname, oid, flags, filter->cb_data);
236 }
237
238 enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
239 {
240 struct object *o = lookup_unknown_object(name);
241
242 if (o->type == OBJ_NONE) {
243 int type = sha1_object_info(name, NULL);
244 if (type < 0 || !object_as_type(o, type, 0))
245 return PEEL_INVALID;
246 }
247
248 if (o->type != OBJ_TAG)
249 return PEEL_NON_TAG;
250
251 o = deref_tag_noverify(o);
252 if (!o)
253 return PEEL_INVALID;
254
255 hashcpy(sha1, o->oid.hash);
256 return PEEL_PEELED;
257 }
258
259 struct warn_if_dangling_data {
260 FILE *fp;
261 const char *refname;
262 const struct string_list *refnames;
263 const char *msg_fmt;
264 };
265
266 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
267 int flags, void *cb_data)
268 {
269 struct warn_if_dangling_data *d = cb_data;
270 const char *resolves_to;
271 struct object_id junk;
272
273 if (!(flags & REF_ISSYMREF))
274 return 0;
275
276 resolves_to = resolve_ref_unsafe(refname, 0, junk.hash, NULL);
277 if (!resolves_to
278 || (d->refname
279 ? strcmp(resolves_to, d->refname)
280 : !string_list_has_string(d->refnames, resolves_to))) {
281 return 0;
282 }
283
284 fprintf(d->fp, d->msg_fmt, refname);
285 fputc('\n', d->fp);
286 return 0;
287 }
288
289 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
290 {
291 struct warn_if_dangling_data data;
292
293 data.fp = fp;
294 data.refname = refname;
295 data.refnames = NULL;
296 data.msg_fmt = msg_fmt;
297 for_each_rawref(warn_if_dangling_symref, &data);
298 }
299
300 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
301 {
302 struct warn_if_dangling_data data;
303
304 data.fp = fp;
305 data.refname = NULL;
306 data.refnames = refnames;
307 data.msg_fmt = msg_fmt;
308 for_each_rawref(warn_if_dangling_symref, &data);
309 }
310
311 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
312 {
313 return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
314 }
315
316 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
317 {
318 return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
319 }
320
321 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
322 {
323 return refs_for_each_tag_ref(get_submodule_ref_store(submodule),
324 fn, cb_data);
325 }
326
327 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
328 {
329 return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
330 }
331
332 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
333 {
334 return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
335 }
336
337 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
338 {
339 return refs_for_each_branch_ref(get_submodule_ref_store(submodule),
340 fn, cb_data);
341 }
342
343 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
344 {
345 return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
346 }
347
348 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
349 {
350 return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
351 }
352
353 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
354 {
355 return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
356 fn, cb_data);
357 }
358
359 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
360 {
361 struct strbuf buf = STRBUF_INIT;
362 int ret = 0;
363 struct object_id oid;
364 int flag;
365
366 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
367 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, oid.hash, &flag))
368 ret = fn(buf.buf, &oid, flag, cb_data);
369 strbuf_release(&buf);
370
371 return ret;
372 }
373
374 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
375 const char *prefix, void *cb_data)
376 {
377 struct strbuf real_pattern = STRBUF_INIT;
378 struct ref_filter filter;
379 int ret;
380
381 if (!prefix && !starts_with(pattern, "refs/"))
382 strbuf_addstr(&real_pattern, "refs/");
383 else if (prefix)
384 strbuf_addstr(&real_pattern, prefix);
385 strbuf_addstr(&real_pattern, pattern);
386
387 if (!has_glob_specials(pattern)) {
388 /* Append implied '/' '*' if not present. */
389 strbuf_complete(&real_pattern, '/');
390 /* No need to check for '*', there is none. */
391 strbuf_addch(&real_pattern, '*');
392 }
393
394 filter.pattern = real_pattern.buf;
395 filter.fn = fn;
396 filter.cb_data = cb_data;
397 ret = for_each_ref(filter_refs, &filter);
398
399 strbuf_release(&real_pattern);
400 return ret;
401 }
402
403 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
404 {
405 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
406 }
407
408 const char *prettify_refname(const char *name)
409 {
410 if (skip_prefix(name, "refs/heads/", &name) ||
411 skip_prefix(name, "refs/tags/", &name) ||
412 skip_prefix(name, "refs/remotes/", &name))
413 ; /* nothing */
414 return name;
415 }
416
417 static const char *ref_rev_parse_rules[] = {
418 "%.*s",
419 "refs/%.*s",
420 "refs/tags/%.*s",
421 "refs/heads/%.*s",
422 "refs/remotes/%.*s",
423 "refs/remotes/%.*s/HEAD",
424 NULL
425 };
426
427 int refname_match(const char *abbrev_name, const char *full_name)
428 {
429 const char **p;
430 const int abbrev_name_len = strlen(abbrev_name);
431
432 for (p = ref_rev_parse_rules; *p; p++) {
433 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
434 return 1;
435 }
436 }
437
438 return 0;
439 }
440
441 /*
442 * *string and *len will only be substituted, and *string returned (for
443 * later free()ing) if the string passed in is a magic short-hand form
444 * to name a branch.
445 */
446 static char *substitute_branch_name(const char **string, int *len)
447 {
448 struct strbuf buf = STRBUF_INIT;
449 int ret = interpret_branch_name(*string, *len, &buf, 0);
450
451 if (ret == *len) {
452 size_t size;
453 *string = strbuf_detach(&buf, &size);
454 *len = size;
455 return (char *)*string;
456 }
457
458 return NULL;
459 }
460
461 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
462 {
463 char *last_branch = substitute_branch_name(&str, &len);
464 int refs_found = expand_ref(str, len, sha1, ref);
465 free(last_branch);
466 return refs_found;
467 }
468
469 int expand_ref(const char *str, int len, unsigned char *sha1, char **ref)
470 {
471 const char **p, *r;
472 int refs_found = 0;
473 struct strbuf fullref = STRBUF_INIT;
474
475 *ref = NULL;
476 for (p = ref_rev_parse_rules; *p; p++) {
477 unsigned char sha1_from_ref[20];
478 unsigned char *this_result;
479 int flag;
480
481 this_result = refs_found ? sha1_from_ref : sha1;
482 strbuf_reset(&fullref);
483 strbuf_addf(&fullref, *p, len, str);
484 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
485 this_result, &flag);
486 if (r) {
487 if (!refs_found++)
488 *ref = xstrdup(r);
489 if (!warn_ambiguous_refs)
490 break;
491 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
492 warning("ignoring dangling symref %s.", fullref.buf);
493 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
494 warning("ignoring broken ref %s.", fullref.buf);
495 }
496 }
497 strbuf_release(&fullref);
498 return refs_found;
499 }
500
501 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
502 {
503 char *last_branch = substitute_branch_name(&str, &len);
504 const char **p;
505 int logs_found = 0;
506 struct strbuf path = STRBUF_INIT;
507
508 *log = NULL;
509 for (p = ref_rev_parse_rules; *p; p++) {
510 unsigned char hash[20];
511 const char *ref, *it;
512
513 strbuf_reset(&path);
514 strbuf_addf(&path, *p, len, str);
515 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
516 hash, NULL);
517 if (!ref)
518 continue;
519 if (reflog_exists(path.buf))
520 it = path.buf;
521 else if (strcmp(ref, path.buf) && reflog_exists(ref))
522 it = ref;
523 else
524 continue;
525 if (!logs_found++) {
526 *log = xstrdup(it);
527 hashcpy(sha1, hash);
528 }
529 if (!warn_ambiguous_refs)
530 break;
531 }
532 strbuf_release(&path);
533 free(last_branch);
534 return logs_found;
535 }
536
537 static int is_per_worktree_ref(const char *refname)
538 {
539 return !strcmp(refname, "HEAD") ||
540 starts_with(refname, "refs/bisect/");
541 }
542
543 static int is_pseudoref_syntax(const char *refname)
544 {
545 const char *c;
546
547 for (c = refname; *c; c++) {
548 if (!isupper(*c) && *c != '-' && *c != '_')
549 return 0;
550 }
551
552 return 1;
553 }
554
555 enum ref_type ref_type(const char *refname)
556 {
557 if (is_per_worktree_ref(refname))
558 return REF_TYPE_PER_WORKTREE;
559 if (is_pseudoref_syntax(refname))
560 return REF_TYPE_PSEUDOREF;
561 return REF_TYPE_NORMAL;
562 }
563
564 static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
565 const unsigned char *old_sha1, struct strbuf *err)
566 {
567 const char *filename;
568 int fd;
569 static struct lock_file lock;
570 struct strbuf buf = STRBUF_INIT;
571 int ret = -1;
572
573 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
574
575 filename = git_path("%s", pseudoref);
576 fd = hold_lock_file_for_update(&lock, filename, LOCK_DIE_ON_ERROR);
577 if (fd < 0) {
578 strbuf_addf(err, "could not open '%s' for writing: %s",
579 filename, strerror(errno));
580 return -1;
581 }
582
583 if (old_sha1) {
584 unsigned char actual_old_sha1[20];
585
586 if (read_ref(pseudoref, actual_old_sha1))
587 die("could not read ref '%s'", pseudoref);
588 if (hashcmp(actual_old_sha1, old_sha1)) {
589 strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
590 rollback_lock_file(&lock);
591 goto done;
592 }
593 }
594
595 if (write_in_full(fd, buf.buf, buf.len) != buf.len) {
596 strbuf_addf(err, "could not write to '%s'", filename);
597 rollback_lock_file(&lock);
598 goto done;
599 }
600
601 commit_lock_file(&lock);
602 ret = 0;
603 done:
604 strbuf_release(&buf);
605 return ret;
606 }
607
608 static int delete_pseudoref(const char *pseudoref, const unsigned char *old_sha1)
609 {
610 static struct lock_file lock;
611 const char *filename;
612
613 filename = git_path("%s", pseudoref);
614
615 if (old_sha1 && !is_null_sha1(old_sha1)) {
616 int fd;
617 unsigned char actual_old_sha1[20];
618
619 fd = hold_lock_file_for_update(&lock, filename,
620 LOCK_DIE_ON_ERROR);
621 if (fd < 0)
622 die_errno(_("Could not open '%s' for writing"), filename);
623 if (read_ref(pseudoref, actual_old_sha1))
624 die("could not read ref '%s'", pseudoref);
625 if (hashcmp(actual_old_sha1, old_sha1)) {
626 warning("Unexpected sha1 when deleting %s", pseudoref);
627 rollback_lock_file(&lock);
628 return -1;
629 }
630
631 unlink(filename);
632 rollback_lock_file(&lock);
633 } else {
634 unlink(filename);
635 }
636
637 return 0;
638 }
639
640 int refs_delete_ref(struct ref_store *refs, const char *msg,
641 const char *refname,
642 const unsigned char *old_sha1,
643 unsigned int flags)
644 {
645 struct ref_transaction *transaction;
646 struct strbuf err = STRBUF_INIT;
647
648 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
649 assert(refs == get_main_ref_store());
650 return delete_pseudoref(refname, old_sha1);
651 }
652
653 transaction = ref_store_transaction_begin(refs, &err);
654 if (!transaction ||
655 ref_transaction_delete(transaction, refname, old_sha1,
656 flags, msg, &err) ||
657 ref_transaction_commit(transaction, &err)) {
658 error("%s", err.buf);
659 ref_transaction_free(transaction);
660 strbuf_release(&err);
661 return 1;
662 }
663 ref_transaction_free(transaction);
664 strbuf_release(&err);
665 return 0;
666 }
667
668 int delete_ref(const char *msg, const char *refname,
669 const unsigned char *old_sha1, unsigned int flags)
670 {
671 return refs_delete_ref(get_main_ref_store(), msg, refname,
672 old_sha1, flags);
673 }
674
675 int copy_reflog_msg(char *buf, const char *msg)
676 {
677 char *cp = buf;
678 char c;
679 int wasspace = 1;
680
681 *cp++ = '\t';
682 while ((c = *msg++)) {
683 if (wasspace && isspace(c))
684 continue;
685 wasspace = isspace(c);
686 if (wasspace)
687 c = ' ';
688 *cp++ = c;
689 }
690 while (buf < cp && isspace(cp[-1]))
691 cp--;
692 *cp++ = '\n';
693 return cp - buf;
694 }
695
696 int should_autocreate_reflog(const char *refname)
697 {
698 switch (log_all_ref_updates) {
699 case LOG_REFS_ALWAYS:
700 return 1;
701 case LOG_REFS_NORMAL:
702 return starts_with(refname, "refs/heads/") ||
703 starts_with(refname, "refs/remotes/") ||
704 starts_with(refname, "refs/notes/") ||
705 !strcmp(refname, "HEAD");
706 default:
707 return 0;
708 }
709 }
710
711 int is_branch(const char *refname)
712 {
713 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
714 }
715
716 struct read_ref_at_cb {
717 const char *refname;
718 timestamp_t at_time;
719 int cnt;
720 int reccnt;
721 unsigned char *sha1;
722 int found_it;
723
724 unsigned char osha1[20];
725 unsigned char nsha1[20];
726 int tz;
727 timestamp_t date;
728 char **msg;
729 timestamp_t *cutoff_time;
730 int *cutoff_tz;
731 int *cutoff_cnt;
732 };
733
734 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
735 const char *email, timestamp_t timestamp, int tz,
736 const char *message, void *cb_data)
737 {
738 struct read_ref_at_cb *cb = cb_data;
739
740 cb->reccnt++;
741 cb->tz = tz;
742 cb->date = timestamp;
743
744 if (timestamp <= cb->at_time || cb->cnt == 0) {
745 if (cb->msg)
746 *cb->msg = xstrdup(message);
747 if (cb->cutoff_time)
748 *cb->cutoff_time = timestamp;
749 if (cb->cutoff_tz)
750 *cb->cutoff_tz = tz;
751 if (cb->cutoff_cnt)
752 *cb->cutoff_cnt = cb->reccnt - 1;
753 /*
754 * we have not yet updated cb->[n|o]sha1 so they still
755 * hold the values for the previous record.
756 */
757 if (!is_null_sha1(cb->osha1)) {
758 hashcpy(cb->sha1, noid->hash);
759 if (hashcmp(cb->osha1, noid->hash))
760 warning("Log for ref %s has gap after %s.",
761 cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
762 }
763 else if (cb->date == cb->at_time)
764 hashcpy(cb->sha1, noid->hash);
765 else if (hashcmp(noid->hash, cb->sha1))
766 warning("Log for ref %s unexpectedly ended on %s.",
767 cb->refname, show_date(cb->date, cb->tz,
768 DATE_MODE(RFC2822)));
769 hashcpy(cb->osha1, ooid->hash);
770 hashcpy(cb->nsha1, noid->hash);
771 cb->found_it = 1;
772 return 1;
773 }
774 hashcpy(cb->osha1, ooid->hash);
775 hashcpy(cb->nsha1, noid->hash);
776 if (cb->cnt > 0)
777 cb->cnt--;
778 return 0;
779 }
780
781 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
782 const char *email, timestamp_t timestamp,
783 int tz, const char *message, void *cb_data)
784 {
785 struct read_ref_at_cb *cb = cb_data;
786
787 if (cb->msg)
788 *cb->msg = xstrdup(message);
789 if (cb->cutoff_time)
790 *cb->cutoff_time = timestamp;
791 if (cb->cutoff_tz)
792 *cb->cutoff_tz = tz;
793 if (cb->cutoff_cnt)
794 *cb->cutoff_cnt = cb->reccnt;
795 hashcpy(cb->sha1, ooid->hash);
796 if (is_null_sha1(cb->sha1))
797 hashcpy(cb->sha1, noid->hash);
798 /* We just want the first entry */
799 return 1;
800 }
801
802 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
803 unsigned char *sha1, char **msg,
804 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
805 {
806 struct read_ref_at_cb cb;
807
808 memset(&cb, 0, sizeof(cb));
809 cb.refname = refname;
810 cb.at_time = at_time;
811 cb.cnt = cnt;
812 cb.msg = msg;
813 cb.cutoff_time = cutoff_time;
814 cb.cutoff_tz = cutoff_tz;
815 cb.cutoff_cnt = cutoff_cnt;
816 cb.sha1 = sha1;
817
818 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
819
820 if (!cb.reccnt) {
821 if (flags & GET_OID_QUIETLY)
822 exit(128);
823 else
824 die("Log for %s is empty.", refname);
825 }
826 if (cb.found_it)
827 return 0;
828
829 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
830
831 return 1;
832 }
833
834 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
835 struct strbuf *err)
836 {
837 struct ref_transaction *tr;
838 assert(err);
839
840 tr = xcalloc(1, sizeof(struct ref_transaction));
841 tr->ref_store = refs;
842 return tr;
843 }
844
845 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
846 {
847 return ref_store_transaction_begin(get_main_ref_store(), err);
848 }
849
850 void ref_transaction_free(struct ref_transaction *transaction)
851 {
852 size_t i;
853
854 if (!transaction)
855 return;
856
857 switch (transaction->state) {
858 case REF_TRANSACTION_OPEN:
859 case REF_TRANSACTION_CLOSED:
860 /* OK */
861 break;
862 case REF_TRANSACTION_PREPARED:
863 die("BUG: free called on a prepared reference transaction");
864 break;
865 default:
866 die("BUG: unexpected reference transaction state");
867 break;
868 }
869
870 for (i = 0; i < transaction->nr; i++) {
871 free(transaction->updates[i]->msg);
872 free(transaction->updates[i]);
873 }
874 free(transaction->updates);
875 free(transaction);
876 }
877
878 struct ref_update *ref_transaction_add_update(
879 struct ref_transaction *transaction,
880 const char *refname, unsigned int flags,
881 const unsigned char *new_sha1,
882 const unsigned char *old_sha1,
883 const char *msg)
884 {
885 struct ref_update *update;
886
887 if (transaction->state != REF_TRANSACTION_OPEN)
888 die("BUG: update called for transaction that is not open");
889
890 if ((flags & REF_ISPRUNING) && !(flags & REF_NODEREF))
891 die("BUG: REF_ISPRUNING set without REF_NODEREF");
892
893 FLEX_ALLOC_STR(update, refname, refname);
894 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
895 transaction->updates[transaction->nr++] = update;
896
897 update->flags = flags;
898
899 if (flags & REF_HAVE_NEW)
900 hashcpy(update->new_oid.hash, new_sha1);
901 if (flags & REF_HAVE_OLD)
902 hashcpy(update->old_oid.hash, old_sha1);
903 update->msg = xstrdup_or_null(msg);
904 return update;
905 }
906
907 int ref_transaction_update(struct ref_transaction *transaction,
908 const char *refname,
909 const unsigned char *new_sha1,
910 const unsigned char *old_sha1,
911 unsigned int flags, const char *msg,
912 struct strbuf *err)
913 {
914 assert(err);
915
916 if ((new_sha1 && !is_null_sha1(new_sha1)) ?
917 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
918 !refname_is_safe(refname)) {
919 strbuf_addf(err, "refusing to update ref with bad name '%s'",
920 refname);
921 return -1;
922 }
923
924 flags |= (new_sha1 ? REF_HAVE_NEW : 0) | (old_sha1 ? REF_HAVE_OLD : 0);
925
926 ref_transaction_add_update(transaction, refname, flags,
927 new_sha1, old_sha1, msg);
928 return 0;
929 }
930
931 int ref_transaction_create(struct ref_transaction *transaction,
932 const char *refname,
933 const unsigned char *new_sha1,
934 unsigned int flags, const char *msg,
935 struct strbuf *err)
936 {
937 if (!new_sha1 || is_null_sha1(new_sha1))
938 die("BUG: create called without valid new_sha1");
939 return ref_transaction_update(transaction, refname, new_sha1,
940 null_sha1, flags, msg, err);
941 }
942
943 int ref_transaction_delete(struct ref_transaction *transaction,
944 const char *refname,
945 const unsigned char *old_sha1,
946 unsigned int flags, const char *msg,
947 struct strbuf *err)
948 {
949 if (old_sha1 && is_null_sha1(old_sha1))
950 die("BUG: delete called with old_sha1 set to zeros");
951 return ref_transaction_update(transaction, refname,
952 null_sha1, old_sha1,
953 flags, msg, err);
954 }
955
956 int ref_transaction_verify(struct ref_transaction *transaction,
957 const char *refname,
958 const unsigned char *old_sha1,
959 unsigned int flags,
960 struct strbuf *err)
961 {
962 if (!old_sha1)
963 die("BUG: verify called with old_sha1 set to NULL");
964 return ref_transaction_update(transaction, refname,
965 NULL, old_sha1,
966 flags, NULL, err);
967 }
968
969 int update_ref_oid(const char *msg, const char *refname,
970 const struct object_id *new_oid, const struct object_id *old_oid,
971 unsigned int flags, enum action_on_err onerr)
972 {
973 return update_ref(msg, refname, new_oid ? new_oid->hash : NULL,
974 old_oid ? old_oid->hash : NULL, flags, onerr);
975 }
976
977 int refs_update_ref(struct ref_store *refs, const char *msg,
978 const char *refname, const unsigned char *new_sha1,
979 const unsigned char *old_sha1, unsigned int flags,
980 enum action_on_err onerr)
981 {
982 struct ref_transaction *t = NULL;
983 struct strbuf err = STRBUF_INIT;
984 int ret = 0;
985
986 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
987 assert(refs == get_main_ref_store());
988 ret = write_pseudoref(refname, new_sha1, old_sha1, &err);
989 } else {
990 t = ref_store_transaction_begin(refs, &err);
991 if (!t ||
992 ref_transaction_update(t, refname, new_sha1, old_sha1,
993 flags, msg, &err) ||
994 ref_transaction_commit(t, &err)) {
995 ret = 1;
996 ref_transaction_free(t);
997 }
998 }
999 if (ret) {
1000 const char *str = "update_ref failed for ref '%s': %s";
1001
1002 switch (onerr) {
1003 case UPDATE_REFS_MSG_ON_ERR:
1004 error(str, refname, err.buf);
1005 break;
1006 case UPDATE_REFS_DIE_ON_ERR:
1007 die(str, refname, err.buf);
1008 break;
1009 case UPDATE_REFS_QUIET_ON_ERR:
1010 break;
1011 }
1012 strbuf_release(&err);
1013 return 1;
1014 }
1015 strbuf_release(&err);
1016 if (t)
1017 ref_transaction_free(t);
1018 return 0;
1019 }
1020
1021 int update_ref(const char *msg, const char *refname,
1022 const unsigned char *new_sha1,
1023 const unsigned char *old_sha1,
1024 unsigned int flags, enum action_on_err onerr)
1025 {
1026 return refs_update_ref(get_main_ref_store(), msg, refname, new_sha1,
1027 old_sha1, flags, onerr);
1028 }
1029
1030 char *shorten_unambiguous_ref(const char *refname, int strict)
1031 {
1032 int i;
1033 static char **scanf_fmts;
1034 static int nr_rules;
1035 char *short_name;
1036 struct strbuf resolved_buf = STRBUF_INIT;
1037
1038 if (!nr_rules) {
1039 /*
1040 * Pre-generate scanf formats from ref_rev_parse_rules[].
1041 * Generate a format suitable for scanf from a
1042 * ref_rev_parse_rules rule by interpolating "%s" at the
1043 * location of the "%.*s".
1044 */
1045 size_t total_len = 0;
1046 size_t offset = 0;
1047
1048 /* the rule list is NULL terminated, count them first */
1049 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1050 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1051 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1052
1053 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1054
1055 offset = 0;
1056 for (i = 0; i < nr_rules; i++) {
1057 assert(offset < total_len);
1058 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1059 offset += snprintf(scanf_fmts[i], total_len - offset,
1060 ref_rev_parse_rules[i], 2, "%s") + 1;
1061 }
1062 }
1063
1064 /* bail out if there are no rules */
1065 if (!nr_rules)
1066 return xstrdup(refname);
1067
1068 /* buffer for scanf result, at most refname must fit */
1069 short_name = xstrdup(refname);
1070
1071 /* skip first rule, it will always match */
1072 for (i = nr_rules - 1; i > 0 ; --i) {
1073 int j;
1074 int rules_to_fail = i;
1075 int short_name_len;
1076
1077 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1078 continue;
1079
1080 short_name_len = strlen(short_name);
1081
1082 /*
1083 * in strict mode, all (except the matched one) rules
1084 * must fail to resolve to a valid non-ambiguous ref
1085 */
1086 if (strict)
1087 rules_to_fail = nr_rules;
1088
1089 /*
1090 * check if the short name resolves to a valid ref,
1091 * but use only rules prior to the matched one
1092 */
1093 for (j = 0; j < rules_to_fail; j++) {
1094 const char *rule = ref_rev_parse_rules[j];
1095
1096 /* skip matched rule */
1097 if (i == j)
1098 continue;
1099
1100 /*
1101 * the short name is ambiguous, if it resolves
1102 * (with this previous rule) to a valid ref
1103 * read_ref() returns 0 on success
1104 */
1105 strbuf_reset(&resolved_buf);
1106 strbuf_addf(&resolved_buf, rule,
1107 short_name_len, short_name);
1108 if (ref_exists(resolved_buf.buf))
1109 break;
1110 }
1111
1112 /*
1113 * short name is non-ambiguous if all previous rules
1114 * haven't resolved to a valid ref
1115 */
1116 if (j == rules_to_fail) {
1117 strbuf_release(&resolved_buf);
1118 return short_name;
1119 }
1120 }
1121
1122 strbuf_release(&resolved_buf);
1123 free(short_name);
1124 return xstrdup(refname);
1125 }
1126
1127 static struct string_list *hide_refs;
1128
1129 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1130 {
1131 const char *key;
1132 if (!strcmp("transfer.hiderefs", var) ||
1133 (!parse_config_key(var, section, NULL, NULL, &key) &&
1134 !strcmp(key, "hiderefs"))) {
1135 char *ref;
1136 int len;
1137
1138 if (!value)
1139 return config_error_nonbool(var);
1140 ref = xstrdup(value);
1141 len = strlen(ref);
1142 while (len && ref[len - 1] == '/')
1143 ref[--len] = '\0';
1144 if (!hide_refs) {
1145 hide_refs = xcalloc(1, sizeof(*hide_refs));
1146 hide_refs->strdup_strings = 1;
1147 }
1148 string_list_append(hide_refs, ref);
1149 }
1150 return 0;
1151 }
1152
1153 int ref_is_hidden(const char *refname, const char *refname_full)
1154 {
1155 int i;
1156
1157 if (!hide_refs)
1158 return 0;
1159 for (i = hide_refs->nr - 1; i >= 0; i--) {
1160 const char *match = hide_refs->items[i].string;
1161 const char *subject;
1162 int neg = 0;
1163 const char *p;
1164
1165 if (*match == '!') {
1166 neg = 1;
1167 match++;
1168 }
1169
1170 if (*match == '^') {
1171 subject = refname_full;
1172 match++;
1173 } else {
1174 subject = refname;
1175 }
1176
1177 /* refname can be NULL when namespaces are used. */
1178 if (subject &&
1179 skip_prefix(subject, match, &p) &&
1180 (!*p || *p == '/'))
1181 return !neg;
1182 }
1183 return 0;
1184 }
1185
1186 const char *find_descendant_ref(const char *dirname,
1187 const struct string_list *extras,
1188 const struct string_list *skip)
1189 {
1190 int pos;
1191
1192 if (!extras)
1193 return NULL;
1194
1195 /*
1196 * Look at the place where dirname would be inserted into
1197 * extras. If there is an entry at that position that starts
1198 * with dirname (remember, dirname includes the trailing
1199 * slash) and is not in skip, then we have a conflict.
1200 */
1201 for (pos = string_list_find_insert_index(extras, dirname, 0);
1202 pos < extras->nr; pos++) {
1203 const char *extra_refname = extras->items[pos].string;
1204
1205 if (!starts_with(extra_refname, dirname))
1206 break;
1207
1208 if (!skip || !string_list_has_string(skip, extra_refname))
1209 return extra_refname;
1210 }
1211 return NULL;
1212 }
1213
1214 int refs_rename_ref_available(struct ref_store *refs,
1215 const char *old_refname,
1216 const char *new_refname)
1217 {
1218 struct string_list skip = STRING_LIST_INIT_NODUP;
1219 struct strbuf err = STRBUF_INIT;
1220 int ok;
1221
1222 string_list_insert(&skip, old_refname);
1223 ok = !refs_verify_refname_available(refs, new_refname,
1224 NULL, &skip, &err);
1225 if (!ok)
1226 error("%s", err.buf);
1227
1228 string_list_clear(&skip, 0);
1229 strbuf_release(&err);
1230 return ok;
1231 }
1232
1233 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1234 {
1235 struct object_id oid;
1236 int flag;
1237
1238 if (submodule) {
1239 if (resolve_gitlink_ref(submodule, "HEAD", oid.hash) == 0)
1240 return fn("HEAD", &oid, 0, cb_data);
1241
1242 return 0;
1243 }
1244
1245 if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag))
1246 return fn("HEAD", &oid, flag, cb_data);
1247
1248 return 0;
1249 }
1250
1251 int head_ref(each_ref_fn fn, void *cb_data)
1252 {
1253 return head_ref_submodule(NULL, fn, cb_data);
1254 }
1255
1256 struct ref_iterator *refs_ref_iterator_begin(
1257 struct ref_store *refs,
1258 const char *prefix, int trim, int flags)
1259 {
1260 struct ref_iterator *iter;
1261
1262 if (ref_paranoia < 0)
1263 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1264 if (ref_paranoia)
1265 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1266
1267 iter = refs->be->iterator_begin(refs, prefix, flags);
1268
1269 /*
1270 * `iterator_begin()` already takes care of prefix, but we
1271 * might need to do some trimming:
1272 */
1273 if (trim)
1274 iter = prefix_ref_iterator_begin(iter, "", trim);
1275
1276 return iter;
1277 }
1278
1279 /*
1280 * Call fn for each reference in the specified submodule for which the
1281 * refname begins with prefix. If trim is non-zero, then trim that
1282 * many characters off the beginning of each refname before passing
1283 * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1284 * include broken references in the iteration. If fn ever returns a
1285 * non-zero value, stop the iteration and return that value;
1286 * otherwise, return 0.
1287 */
1288 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1289 each_ref_fn fn, int trim, int flags, void *cb_data)
1290 {
1291 struct ref_iterator *iter;
1292
1293 if (!refs)
1294 return 0;
1295
1296 iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1297
1298 return do_for_each_ref_iterator(iter, fn, cb_data);
1299 }
1300
1301 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1302 {
1303 return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1304 }
1305
1306 int for_each_ref(each_ref_fn fn, void *cb_data)
1307 {
1308 return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
1309 }
1310
1311 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1312 {
1313 return refs_for_each_ref(get_submodule_ref_store(submodule), fn, cb_data);
1314 }
1315
1316 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1317 each_ref_fn fn, void *cb_data)
1318 {
1319 return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1320 }
1321
1322 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1323 {
1324 return refs_for_each_ref_in(get_main_ref_store(), prefix, fn, cb_data);
1325 }
1326
1327 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1328 {
1329 unsigned int flag = 0;
1330
1331 if (broken)
1332 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1333 return do_for_each_ref(get_main_ref_store(),
1334 prefix, fn, 0, flag, cb_data);
1335 }
1336
1337 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1338 each_ref_fn fn, void *cb_data)
1339 {
1340 return refs_for_each_ref_in(get_submodule_ref_store(submodule),
1341 prefix, fn, cb_data);
1342 }
1343
1344 int for_each_fullref_in_submodule(const char *submodule, const char *prefix,
1345 each_ref_fn fn, void *cb_data,
1346 unsigned int broken)
1347 {
1348 unsigned int flag = 0;
1349
1350 if (broken)
1351 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1352 return do_for_each_ref(get_submodule_ref_store(submodule),
1353 prefix, fn, 0, flag, cb_data);
1354 }
1355
1356 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1357 {
1358 return do_for_each_ref(get_main_ref_store(),
1359 git_replace_ref_base, fn,
1360 strlen(git_replace_ref_base),
1361 0, cb_data);
1362 }
1363
1364 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1365 {
1366 struct strbuf buf = STRBUF_INIT;
1367 int ret;
1368 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1369 ret = do_for_each_ref(get_main_ref_store(),
1370 buf.buf, fn, 0, 0, cb_data);
1371 strbuf_release(&buf);
1372 return ret;
1373 }
1374
1375 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1376 {
1377 return do_for_each_ref(refs, "", fn, 0,
1378 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1379 }
1380
1381 int for_each_rawref(each_ref_fn fn, void *cb_data)
1382 {
1383 return refs_for_each_rawref(get_main_ref_store(), fn, cb_data);
1384 }
1385
1386 int refs_read_raw_ref(struct ref_store *ref_store,
1387 const char *refname, unsigned char *sha1,
1388 struct strbuf *referent, unsigned int *type)
1389 {
1390 return ref_store->be->read_raw_ref(ref_store, refname, sha1, referent, type);
1391 }
1392
1393 /* This function needs to return a meaningful errno on failure */
1394 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1395 const char *refname,
1396 int resolve_flags,
1397 unsigned char *sha1, int *flags)
1398 {
1399 static struct strbuf sb_refname = STRBUF_INIT;
1400 int unused_flags;
1401 int symref_count;
1402
1403 if (!flags)
1404 flags = &unused_flags;
1405
1406 *flags = 0;
1407
1408 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1409 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1410 !refname_is_safe(refname)) {
1411 errno = EINVAL;
1412 return NULL;
1413 }
1414
1415 /*
1416 * dwim_ref() uses REF_ISBROKEN to distinguish between
1417 * missing refs and refs that were present but invalid,
1418 * to complain about the latter to stderr.
1419 *
1420 * We don't know whether the ref exists, so don't set
1421 * REF_ISBROKEN yet.
1422 */
1423 *flags |= REF_BAD_NAME;
1424 }
1425
1426 for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1427 unsigned int read_flags = 0;
1428
1429 if (refs_read_raw_ref(refs, refname,
1430 sha1, &sb_refname, &read_flags)) {
1431 *flags |= read_flags;
1432 if (errno != ENOENT || (resolve_flags & RESOLVE_REF_READING))
1433 return NULL;
1434 hashclr(sha1);
1435 if (*flags & REF_BAD_NAME)
1436 *flags |= REF_ISBROKEN;
1437 return refname;
1438 }
1439
1440 *flags |= read_flags;
1441
1442 if (!(read_flags & REF_ISSYMREF)) {
1443 if (*flags & REF_BAD_NAME) {
1444 hashclr(sha1);
1445 *flags |= REF_ISBROKEN;
1446 }
1447 return refname;
1448 }
1449
1450 refname = sb_refname.buf;
1451 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1452 hashclr(sha1);
1453 return refname;
1454 }
1455 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1456 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1457 !refname_is_safe(refname)) {
1458 errno = EINVAL;
1459 return NULL;
1460 }
1461
1462 *flags |= REF_ISBROKEN | REF_BAD_NAME;
1463 }
1464 }
1465
1466 errno = ELOOP;
1467 return NULL;
1468 }
1469
1470 /* backend functions */
1471 int refs_init_db(struct strbuf *err)
1472 {
1473 struct ref_store *refs = get_main_ref_store();
1474
1475 return refs->be->init_db(refs, err);
1476 }
1477
1478 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1479 unsigned char *sha1, int *flags)
1480 {
1481 return refs_resolve_ref_unsafe(get_main_ref_store(), refname,
1482 resolve_flags, sha1, flags);
1483 }
1484
1485 int resolve_gitlink_ref(const char *submodule, const char *refname,
1486 unsigned char *sha1)
1487 {
1488 size_t len = strlen(submodule);
1489 struct ref_store *refs;
1490 int flags;
1491
1492 while (len && submodule[len - 1] == '/')
1493 len--;
1494
1495 if (!len)
1496 return -1;
1497
1498 if (submodule[len]) {
1499 /* We need to strip off one or more trailing slashes */
1500 char *stripped = xmemdupz(submodule, len);
1501
1502 refs = get_submodule_ref_store(stripped);
1503 free(stripped);
1504 } else {
1505 refs = get_submodule_ref_store(submodule);
1506 }
1507
1508 if (!refs)
1509 return -1;
1510
1511 if (!refs_resolve_ref_unsafe(refs, refname, 0, sha1, &flags) ||
1512 is_null_sha1(sha1))
1513 return -1;
1514 return 0;
1515 }
1516
1517 struct ref_store_hash_entry
1518 {
1519 struct hashmap_entry ent; /* must be the first member! */
1520
1521 struct ref_store *refs;
1522
1523 /* NUL-terminated identifier of the ref store: */
1524 char name[FLEX_ARRAY];
1525 };
1526
1527 static int ref_store_hash_cmp(const void *unused_cmp_data,
1528 const void *entry, const void *entry_or_key,
1529 const void *keydata)
1530 {
1531 const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1532 const char *name = keydata ? keydata : e2->name;
1533
1534 return strcmp(e1->name, name);
1535 }
1536
1537 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1538 const char *name, struct ref_store *refs)
1539 {
1540 struct ref_store_hash_entry *entry;
1541
1542 FLEX_ALLOC_STR(entry, name, name);
1543 hashmap_entry_init(entry, strhash(name));
1544 entry->refs = refs;
1545 return entry;
1546 }
1547
1548 /* A pointer to the ref_store for the main repository: */
1549 static struct ref_store *main_ref_store;
1550
1551 /* A hashmap of ref_stores, stored by submodule name: */
1552 static struct hashmap submodule_ref_stores;
1553
1554 /* A hashmap of ref_stores, stored by worktree id: */
1555 static struct hashmap worktree_ref_stores;
1556
1557 /*
1558 * Look up a ref store by name. If that ref_store hasn't been
1559 * registered yet, return NULL.
1560 */
1561 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1562 const char *name)
1563 {
1564 struct ref_store_hash_entry *entry;
1565
1566 if (!map->tablesize)
1567 /* It's initialized on demand in register_ref_store(). */
1568 return NULL;
1569
1570 entry = hashmap_get_from_hash(map, strhash(name), name);
1571 return entry ? entry->refs : NULL;
1572 }
1573
1574 /*
1575 * Create, record, and return a ref_store instance for the specified
1576 * gitdir.
1577 */
1578 static struct ref_store *ref_store_init(const char *gitdir,
1579 unsigned int flags)
1580 {
1581 const char *be_name = "files";
1582 struct ref_storage_be *be = find_ref_storage_backend(be_name);
1583 struct ref_store *refs;
1584
1585 if (!be)
1586 die("BUG: reference backend %s is unknown", be_name);
1587
1588 refs = be->init(gitdir, flags);
1589 return refs;
1590 }
1591
1592 struct ref_store *get_main_ref_store(void)
1593 {
1594 if (main_ref_store)
1595 return main_ref_store;
1596
1597 main_ref_store = ref_store_init(get_git_dir(), REF_STORE_ALL_CAPS);
1598 return main_ref_store;
1599 }
1600
1601 /*
1602 * Associate a ref store with a name. It is a fatal error to call this
1603 * function twice for the same name.
1604 */
1605 static void register_ref_store_map(struct hashmap *map,
1606 const char *type,
1607 struct ref_store *refs,
1608 const char *name)
1609 {
1610 if (!map->tablesize)
1611 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1612
1613 if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1614 die("BUG: %s ref_store '%s' initialized twice", type, name);
1615 }
1616
1617 struct ref_store *get_submodule_ref_store(const char *submodule)
1618 {
1619 struct strbuf submodule_sb = STRBUF_INIT;
1620 struct ref_store *refs;
1621 int ret;
1622
1623 if (!submodule || !*submodule) {
1624 /*
1625 * FIXME: This case is ideally not allowed. But that
1626 * can't happen until we clean up all the callers.
1627 */
1628 return get_main_ref_store();
1629 }
1630
1631 refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1632 if (refs)
1633 return refs;
1634
1635 strbuf_addstr(&submodule_sb, submodule);
1636 ret = is_nonbare_repository_dir(&submodule_sb);
1637 strbuf_release(&submodule_sb);
1638 if (!ret)
1639 return NULL;
1640
1641 ret = submodule_to_gitdir(&submodule_sb, submodule);
1642 if (ret) {
1643 strbuf_release(&submodule_sb);
1644 return NULL;
1645 }
1646
1647 /* assume that add_submodule_odb() has been called */
1648 refs = ref_store_init(submodule_sb.buf,
1649 REF_STORE_READ | REF_STORE_ODB);
1650 register_ref_store_map(&submodule_ref_stores, "submodule",
1651 refs, submodule);
1652
1653 strbuf_release(&submodule_sb);
1654 return refs;
1655 }
1656
1657 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1658 {
1659 struct ref_store *refs;
1660 const char *id;
1661
1662 if (wt->is_current)
1663 return get_main_ref_store();
1664
1665 id = wt->id ? wt->id : "/";
1666 refs = lookup_ref_store_map(&worktree_ref_stores, id);
1667 if (refs)
1668 return refs;
1669
1670 if (wt->id)
1671 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1672 REF_STORE_ALL_CAPS);
1673 else
1674 refs = ref_store_init(get_git_common_dir(),
1675 REF_STORE_ALL_CAPS);
1676
1677 if (refs)
1678 register_ref_store_map(&worktree_ref_stores, "worktree",
1679 refs, id);
1680 return refs;
1681 }
1682
1683 void base_ref_store_init(struct ref_store *refs,
1684 const struct ref_storage_be *be)
1685 {
1686 refs->be = be;
1687 }
1688
1689 /* backend functions */
1690 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1691 {
1692 return refs->be->pack_refs(refs, flags);
1693 }
1694
1695 int refs_peel_ref(struct ref_store *refs, const char *refname,
1696 unsigned char *sha1)
1697 {
1698 return refs->be->peel_ref(refs, refname, sha1);
1699 }
1700
1701 int peel_ref(const char *refname, unsigned char *sha1)
1702 {
1703 return refs_peel_ref(get_main_ref_store(), refname, sha1);
1704 }
1705
1706 int refs_create_symref(struct ref_store *refs,
1707 const char *ref_target,
1708 const char *refs_heads_master,
1709 const char *logmsg)
1710 {
1711 return refs->be->create_symref(refs, ref_target,
1712 refs_heads_master,
1713 logmsg);
1714 }
1715
1716 int create_symref(const char *ref_target, const char *refs_heads_master,
1717 const char *logmsg)
1718 {
1719 return refs_create_symref(get_main_ref_store(), ref_target,
1720 refs_heads_master, logmsg);
1721 }
1722
1723 int ref_update_reject_duplicates(struct string_list *refnames,
1724 struct strbuf *err)
1725 {
1726 size_t i, n = refnames->nr;
1727
1728 assert(err);
1729
1730 for (i = 1; i < n; i++) {
1731 int cmp = strcmp(refnames->items[i - 1].string,
1732 refnames->items[i].string);
1733
1734 if (!cmp) {
1735 strbuf_addf(err,
1736 "multiple updates for ref '%s' not allowed.",
1737 refnames->items[i].string);
1738 return 1;
1739 } else if (cmp > 0) {
1740 die("BUG: ref_update_reject_duplicates() received unsorted list");
1741 }
1742 }
1743 return 0;
1744 }
1745
1746 int ref_transaction_prepare(struct ref_transaction *transaction,
1747 struct strbuf *err)
1748 {
1749 struct ref_store *refs = transaction->ref_store;
1750
1751 switch (transaction->state) {
1752 case REF_TRANSACTION_OPEN:
1753 /* Good. */
1754 break;
1755 case REF_TRANSACTION_PREPARED:
1756 die("BUG: prepare called twice on reference transaction");
1757 break;
1758 case REF_TRANSACTION_CLOSED:
1759 die("BUG: prepare called on a closed reference transaction");
1760 break;
1761 default:
1762 die("BUG: unexpected reference transaction state");
1763 break;
1764 }
1765
1766 if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1767 strbuf_addstr(err,
1768 _("ref updates forbidden inside quarantine environment"));
1769 return -1;
1770 }
1771
1772 return refs->be->transaction_prepare(refs, transaction, err);
1773 }
1774
1775 int ref_transaction_abort(struct ref_transaction *transaction,
1776 struct strbuf *err)
1777 {
1778 struct ref_store *refs = transaction->ref_store;
1779 int ret = 0;
1780
1781 switch (transaction->state) {
1782 case REF_TRANSACTION_OPEN:
1783 /* No need to abort explicitly. */
1784 break;
1785 case REF_TRANSACTION_PREPARED:
1786 ret = refs->be->transaction_abort(refs, transaction, err);
1787 break;
1788 case REF_TRANSACTION_CLOSED:
1789 die("BUG: abort called on a closed reference transaction");
1790 break;
1791 default:
1792 die("BUG: unexpected reference transaction state");
1793 break;
1794 }
1795
1796 ref_transaction_free(transaction);
1797 return ret;
1798 }
1799
1800 int ref_transaction_commit(struct ref_transaction *transaction,
1801 struct strbuf *err)
1802 {
1803 struct ref_store *refs = transaction->ref_store;
1804 int ret;
1805
1806 switch (transaction->state) {
1807 case REF_TRANSACTION_OPEN:
1808 /* Need to prepare first. */
1809 ret = ref_transaction_prepare(transaction, err);
1810 if (ret)
1811 return ret;
1812 break;
1813 case REF_TRANSACTION_PREPARED:
1814 /* Fall through to finish. */
1815 break;
1816 case REF_TRANSACTION_CLOSED:
1817 die("BUG: commit called on a closed reference transaction");
1818 break;
1819 default:
1820 die("BUG: unexpected reference transaction state");
1821 break;
1822 }
1823
1824 return refs->be->transaction_finish(refs, transaction, err);
1825 }
1826
1827 int refs_verify_refname_available(struct ref_store *refs,
1828 const char *refname,
1829 const struct string_list *extras,
1830 const struct string_list *skip,
1831 struct strbuf *err)
1832 {
1833 const char *slash;
1834 const char *extra_refname;
1835 struct strbuf dirname = STRBUF_INIT;
1836 struct strbuf referent = STRBUF_INIT;
1837 struct object_id oid;
1838 unsigned int type;
1839 struct ref_iterator *iter;
1840 int ok;
1841 int ret = -1;
1842
1843 /*
1844 * For the sake of comments in this function, suppose that
1845 * refname is "refs/foo/bar".
1846 */
1847
1848 assert(err);
1849
1850 strbuf_grow(&dirname, strlen(refname) + 1);
1851 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1852 /* Expand dirname to the new prefix, not including the trailing slash: */
1853 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1854
1855 /*
1856 * We are still at a leading dir of the refname (e.g.,
1857 * "refs/foo"; if there is a reference with that name,
1858 * it is a conflict, *unless* it is in skip.
1859 */
1860 if (skip && string_list_has_string(skip, dirname.buf))
1861 continue;
1862
1863 if (!refs_read_raw_ref(refs, dirname.buf, oid.hash, &referent, &type)) {
1864 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1865 dirname.buf, refname);
1866 goto cleanup;
1867 }
1868
1869 if (extras && string_list_has_string(extras, dirname.buf)) {
1870 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1871 refname, dirname.buf);
1872 goto cleanup;
1873 }
1874 }
1875
1876 /*
1877 * We are at the leaf of our refname (e.g., "refs/foo/bar").
1878 * There is no point in searching for a reference with that
1879 * name, because a refname isn't considered to conflict with
1880 * itself. But we still need to check for references whose
1881 * names are in the "refs/foo/bar/" namespace, because they
1882 * *do* conflict.
1883 */
1884 strbuf_addstr(&dirname, refname + dirname.len);
1885 strbuf_addch(&dirname, '/');
1886
1887 iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1888 DO_FOR_EACH_INCLUDE_BROKEN);
1889 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1890 if (skip &&
1891 string_list_has_string(skip, iter->refname))
1892 continue;
1893
1894 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1895 iter->refname, refname);
1896 ref_iterator_abort(iter);
1897 goto cleanup;
1898 }
1899
1900 if (ok != ITER_DONE)
1901 die("BUG: error while iterating over references");
1902
1903 extra_refname = find_descendant_ref(dirname.buf, extras, skip);
1904 if (extra_refname)
1905 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1906 refname, extra_refname);
1907 else
1908 ret = 0;
1909
1910 cleanup:
1911 strbuf_release(&referent);
1912 strbuf_release(&dirname);
1913 return ret;
1914 }
1915
1916 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1917 {
1918 struct ref_iterator *iter;
1919
1920 iter = refs->be->reflog_iterator_begin(refs);
1921
1922 return do_for_each_ref_iterator(iter, fn, cb_data);
1923 }
1924
1925 int for_each_reflog(each_ref_fn fn, void *cb_data)
1926 {
1927 return refs_for_each_reflog(get_main_ref_store(), fn, cb_data);
1928 }
1929
1930 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
1931 const char *refname,
1932 each_reflog_ent_fn fn,
1933 void *cb_data)
1934 {
1935 return refs->be->for_each_reflog_ent_reverse(refs, refname,
1936 fn, cb_data);
1937 }
1938
1939 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
1940 void *cb_data)
1941 {
1942 return refs_for_each_reflog_ent_reverse(get_main_ref_store(),
1943 refname, fn, cb_data);
1944 }
1945
1946 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
1947 each_reflog_ent_fn fn, void *cb_data)
1948 {
1949 return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
1950 }
1951
1952 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
1953 void *cb_data)
1954 {
1955 return refs_for_each_reflog_ent(get_main_ref_store(), refname,
1956 fn, cb_data);
1957 }
1958
1959 int refs_reflog_exists(struct ref_store *refs, const char *refname)
1960 {
1961 return refs->be->reflog_exists(refs, refname);
1962 }
1963
1964 int reflog_exists(const char *refname)
1965 {
1966 return refs_reflog_exists(get_main_ref_store(), refname);
1967 }
1968
1969 int refs_create_reflog(struct ref_store *refs, const char *refname,
1970 int force_create, struct strbuf *err)
1971 {
1972 return refs->be->create_reflog(refs, refname, force_create, err);
1973 }
1974
1975 int safe_create_reflog(const char *refname, int force_create,
1976 struct strbuf *err)
1977 {
1978 return refs_create_reflog(get_main_ref_store(), refname,
1979 force_create, err);
1980 }
1981
1982 int refs_delete_reflog(struct ref_store *refs, const char *refname)
1983 {
1984 return refs->be->delete_reflog(refs, refname);
1985 }
1986
1987 int delete_reflog(const char *refname)
1988 {
1989 return refs_delete_reflog(get_main_ref_store(), refname);
1990 }
1991
1992 int refs_reflog_expire(struct ref_store *refs,
1993 const char *refname, const unsigned char *sha1,
1994 unsigned int flags,
1995 reflog_expiry_prepare_fn prepare_fn,
1996 reflog_expiry_should_prune_fn should_prune_fn,
1997 reflog_expiry_cleanup_fn cleanup_fn,
1998 void *policy_cb_data)
1999 {
2000 return refs->be->reflog_expire(refs, refname, sha1, flags,
2001 prepare_fn, should_prune_fn,
2002 cleanup_fn, policy_cb_data);
2003 }
2004
2005 int reflog_expire(const char *refname, const unsigned char *sha1,
2006 unsigned int flags,
2007 reflog_expiry_prepare_fn prepare_fn,
2008 reflog_expiry_should_prune_fn should_prune_fn,
2009 reflog_expiry_cleanup_fn cleanup_fn,
2010 void *policy_cb_data)
2011 {
2012 return refs_reflog_expire(get_main_ref_store(),
2013 refname, sha1, flags,
2014 prepare_fn, should_prune_fn,
2015 cleanup_fn, policy_cb_data);
2016 }
2017
2018 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2019 struct strbuf *err)
2020 {
2021 struct ref_store *refs = transaction->ref_store;
2022
2023 return refs->be->initial_transaction_commit(refs, transaction, err);
2024 }
2025
2026 int refs_delete_refs(struct ref_store *refs, const char *msg,
2027 struct string_list *refnames, unsigned int flags)
2028 {
2029 return refs->be->delete_refs(refs, msg, refnames, flags);
2030 }
2031
2032 int delete_refs(const char *msg, struct string_list *refnames,
2033 unsigned int flags)
2034 {
2035 return refs_delete_refs(get_main_ref_store(), msg, refnames, flags);
2036 }
2037
2038 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2039 const char *newref, const char *logmsg)
2040 {
2041 return refs->be->rename_ref(refs, oldref, newref, logmsg);
2042 }
2043
2044 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2045 {
2046 return refs_rename_ref(get_main_ref_store(), oldref, newref, logmsg);
2047 }