ls-remote: pass ref prefixes when requesting a remote's refs
[git/git.git] / refs.c
1 /*
2 * The backend-independent part of the reference module.
3 */
4
5 #include "cache.h"
6 #include "config.h"
7 #include "hashmap.h"
8 #include "lockfile.h"
9 #include "iterator.h"
10 #include "refs.h"
11 #include "refs/refs-internal.h"
12 #include "object.h"
13 #include "tag.h"
14 #include "submodule.h"
15 #include "worktree.h"
16 #include "argv-array.h"
17
18 /*
19 * List of all available backends
20 */
21 static struct ref_storage_be *refs_backends = &refs_be_files;
22
23 static struct ref_storage_be *find_ref_storage_backend(const char *name)
24 {
25 struct ref_storage_be *be;
26 for (be = refs_backends; be; be = be->next)
27 if (!strcmp(be->name, name))
28 return be;
29 return NULL;
30 }
31
32 int ref_storage_backend_exists(const char *name)
33 {
34 return find_ref_storage_backend(name) != NULL;
35 }
36
37 /*
38 * How to handle various characters in refnames:
39 * 0: An acceptable character for refs
40 * 1: End-of-component
41 * 2: ., look for a preceding . to reject .. in refs
42 * 3: {, look for a preceding @ to reject @{ in refs
43 * 4: A bad character: ASCII control characters, and
44 * ":", "?", "[", "\", "^", "~", SP, or TAB
45 * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
46 */
47 static unsigned char refname_disposition[256] = {
48 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
49 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
50 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
51 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
52 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
53 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
54 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
55 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
56 };
57
58 /*
59 * Try to read one refname component from the front of refname.
60 * Return the length of the component found, or -1 if the component is
61 * not legal. It is legal if it is something reasonable to have under
62 * ".git/refs/"; We do not like it if:
63 *
64 * - any path component of it begins with ".", or
65 * - it has double dots "..", or
66 * - it has ASCII control characters, or
67 * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
68 * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
69 * - it ends with a "/", or
70 * - it ends with ".lock", or
71 * - it contains a "@{" portion
72 */
73 static int check_refname_component(const char *refname, int *flags)
74 {
75 const char *cp;
76 char last = '\0';
77
78 for (cp = refname; ; cp++) {
79 int ch = *cp & 255;
80 unsigned char disp = refname_disposition[ch];
81 switch (disp) {
82 case 1:
83 goto out;
84 case 2:
85 if (last == '.')
86 return -1; /* Refname contains "..". */
87 break;
88 case 3:
89 if (last == '@')
90 return -1; /* Refname contains "@{". */
91 break;
92 case 4:
93 return -1;
94 case 5:
95 if (!(*flags & REFNAME_REFSPEC_PATTERN))
96 return -1; /* refspec can't be a pattern */
97
98 /*
99 * Unset the pattern flag so that we only accept
100 * a single asterisk for one side of refspec.
101 */
102 *flags &= ~ REFNAME_REFSPEC_PATTERN;
103 break;
104 }
105 last = ch;
106 }
107 out:
108 if (cp == refname)
109 return 0; /* Component has zero length. */
110 if (refname[0] == '.')
111 return -1; /* Component starts with '.'. */
112 if (cp - refname >= LOCK_SUFFIX_LEN &&
113 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
114 return -1; /* Refname ends with ".lock". */
115 return cp - refname;
116 }
117
118 int check_refname_format(const char *refname, int flags)
119 {
120 int component_len, component_count = 0;
121
122 if (!strcmp(refname, "@"))
123 /* Refname is a single character '@'. */
124 return -1;
125
126 while (1) {
127 /* We are at the start of a path component. */
128 component_len = check_refname_component(refname, &flags);
129 if (component_len <= 0)
130 return -1;
131
132 component_count++;
133 if (refname[component_len] == '\0')
134 break;
135 /* Skip to next component. */
136 refname += component_len + 1;
137 }
138
139 if (refname[component_len - 1] == '.')
140 return -1; /* Refname ends with '.'. */
141 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
142 return -1; /* Refname has only one component. */
143 return 0;
144 }
145
146 int refname_is_safe(const char *refname)
147 {
148 const char *rest;
149
150 if (skip_prefix(refname, "refs/", &rest)) {
151 char *buf;
152 int result;
153 size_t restlen = strlen(rest);
154
155 /* rest must not be empty, or start or end with "/" */
156 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
157 return 0;
158
159 /*
160 * Does the refname try to escape refs/?
161 * For example: refs/foo/../bar is safe but refs/foo/../../bar
162 * is not.
163 */
164 buf = xmallocz(restlen);
165 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
166 free(buf);
167 return result;
168 }
169
170 do {
171 if (!isupper(*refname) && *refname != '_')
172 return 0;
173 refname++;
174 } while (*refname);
175 return 1;
176 }
177
178 /*
179 * Return true if refname, which has the specified oid and flags, can
180 * be resolved to an object in the database. If the referred-to object
181 * does not exist, emit a warning and return false.
182 */
183 int ref_resolves_to_object(const char *refname,
184 const struct object_id *oid,
185 unsigned int flags)
186 {
187 if (flags & REF_ISBROKEN)
188 return 0;
189 if (!has_sha1_file(oid->hash)) {
190 error("%s does not point to a valid object!", refname);
191 return 0;
192 }
193 return 1;
194 }
195
196 char *refs_resolve_refdup(struct ref_store *refs,
197 const char *refname, int resolve_flags,
198 struct object_id *oid, int *flags)
199 {
200 const char *result;
201
202 result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
203 oid, flags);
204 return xstrdup_or_null(result);
205 }
206
207 char *resolve_refdup(const char *refname, int resolve_flags,
208 struct object_id *oid, int *flags)
209 {
210 return refs_resolve_refdup(get_main_ref_store(),
211 refname, resolve_flags,
212 oid, flags);
213 }
214
215 /* The argument to filter_refs */
216 struct ref_filter {
217 const char *pattern;
218 each_ref_fn *fn;
219 void *cb_data;
220 };
221
222 int refs_read_ref_full(struct ref_store *refs, const char *refname,
223 int resolve_flags, struct object_id *oid, int *flags)
224 {
225 if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, oid, flags))
226 return 0;
227 return -1;
228 }
229
230 int read_ref_full(const char *refname, int resolve_flags, struct object_id *oid, int *flags)
231 {
232 return refs_read_ref_full(get_main_ref_store(), refname,
233 resolve_flags, oid, flags);
234 }
235
236 int read_ref(const char *refname, struct object_id *oid)
237 {
238 return read_ref_full(refname, RESOLVE_REF_READING, oid, NULL);
239 }
240
241 int ref_exists(const char *refname)
242 {
243 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, NULL, NULL);
244 }
245
246 static int match_ref_pattern(const char *refname,
247 const struct string_list_item *item)
248 {
249 int matched = 0;
250 if (item->util == NULL) {
251 if (!wildmatch(item->string, refname, 0))
252 matched = 1;
253 } else {
254 const char *rest;
255 if (skip_prefix(refname, item->string, &rest) &&
256 (!*rest || *rest == '/'))
257 matched = 1;
258 }
259 return matched;
260 }
261
262 int ref_filter_match(const char *refname,
263 const struct string_list *include_patterns,
264 const struct string_list *exclude_patterns)
265 {
266 struct string_list_item *item;
267
268 if (exclude_patterns && exclude_patterns->nr) {
269 for_each_string_list_item(item, exclude_patterns) {
270 if (match_ref_pattern(refname, item))
271 return 0;
272 }
273 }
274
275 if (include_patterns && include_patterns->nr) {
276 int found = 0;
277 for_each_string_list_item(item, include_patterns) {
278 if (match_ref_pattern(refname, item)) {
279 found = 1;
280 break;
281 }
282 }
283
284 if (!found)
285 return 0;
286 }
287 return 1;
288 }
289
290 static int filter_refs(const char *refname, const struct object_id *oid,
291 int flags, void *data)
292 {
293 struct ref_filter *filter = (struct ref_filter *)data;
294
295 if (wildmatch(filter->pattern, refname, 0))
296 return 0;
297 return filter->fn(refname, oid, flags, filter->cb_data);
298 }
299
300 enum peel_status peel_object(const struct object_id *name, struct object_id *oid)
301 {
302 struct object *o = lookup_unknown_object(name->hash);
303
304 if (o->type == OBJ_NONE) {
305 int type = sha1_object_info(name->hash, NULL);
306 if (type < 0 || !object_as_type(o, type, 0))
307 return PEEL_INVALID;
308 }
309
310 if (o->type != OBJ_TAG)
311 return PEEL_NON_TAG;
312
313 o = deref_tag_noverify(o);
314 if (!o)
315 return PEEL_INVALID;
316
317 oidcpy(oid, &o->oid);
318 return PEEL_PEELED;
319 }
320
321 struct warn_if_dangling_data {
322 FILE *fp;
323 const char *refname;
324 const struct string_list *refnames;
325 const char *msg_fmt;
326 };
327
328 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
329 int flags, void *cb_data)
330 {
331 struct warn_if_dangling_data *d = cb_data;
332 const char *resolves_to;
333
334 if (!(flags & REF_ISSYMREF))
335 return 0;
336
337 resolves_to = resolve_ref_unsafe(refname, 0, NULL, NULL);
338 if (!resolves_to
339 || (d->refname
340 ? strcmp(resolves_to, d->refname)
341 : !string_list_has_string(d->refnames, resolves_to))) {
342 return 0;
343 }
344
345 fprintf(d->fp, d->msg_fmt, refname);
346 fputc('\n', d->fp);
347 return 0;
348 }
349
350 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
351 {
352 struct warn_if_dangling_data data;
353
354 data.fp = fp;
355 data.refname = refname;
356 data.refnames = NULL;
357 data.msg_fmt = msg_fmt;
358 for_each_rawref(warn_if_dangling_symref, &data);
359 }
360
361 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
362 {
363 struct warn_if_dangling_data data;
364
365 data.fp = fp;
366 data.refname = NULL;
367 data.refnames = refnames;
368 data.msg_fmt = msg_fmt;
369 for_each_rawref(warn_if_dangling_symref, &data);
370 }
371
372 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
373 {
374 return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
375 }
376
377 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
378 {
379 return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
380 }
381
382 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
383 {
384 return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
385 }
386
387 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
388 {
389 return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
390 }
391
392 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
393 {
394 return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
395 }
396
397 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
398 {
399 return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
400 }
401
402 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
403 {
404 struct strbuf buf = STRBUF_INIT;
405 int ret = 0;
406 struct object_id oid;
407 int flag;
408
409 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
410 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, &oid, &flag))
411 ret = fn(buf.buf, &oid, flag, cb_data);
412 strbuf_release(&buf);
413
414 return ret;
415 }
416
417 void normalize_glob_ref(struct string_list_item *item, const char *prefix,
418 const char *pattern)
419 {
420 struct strbuf normalized_pattern = STRBUF_INIT;
421
422 if (*pattern == '/')
423 BUG("pattern must not start with '/'");
424
425 if (prefix) {
426 strbuf_addstr(&normalized_pattern, prefix);
427 }
428 else if (!starts_with(pattern, "refs/"))
429 strbuf_addstr(&normalized_pattern, "refs/");
430 strbuf_addstr(&normalized_pattern, pattern);
431 strbuf_strip_suffix(&normalized_pattern, "/");
432
433 item->string = strbuf_detach(&normalized_pattern, NULL);
434 item->util = has_glob_specials(pattern) ? NULL : item->string;
435 strbuf_release(&normalized_pattern);
436 }
437
438 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
439 const char *prefix, void *cb_data)
440 {
441 struct strbuf real_pattern = STRBUF_INIT;
442 struct ref_filter filter;
443 int ret;
444
445 if (!prefix && !starts_with(pattern, "refs/"))
446 strbuf_addstr(&real_pattern, "refs/");
447 else if (prefix)
448 strbuf_addstr(&real_pattern, prefix);
449 strbuf_addstr(&real_pattern, pattern);
450
451 if (!has_glob_specials(pattern)) {
452 /* Append implied '/' '*' if not present. */
453 strbuf_complete(&real_pattern, '/');
454 /* No need to check for '*', there is none. */
455 strbuf_addch(&real_pattern, '*');
456 }
457
458 filter.pattern = real_pattern.buf;
459 filter.fn = fn;
460 filter.cb_data = cb_data;
461 ret = for_each_ref(filter_refs, &filter);
462
463 strbuf_release(&real_pattern);
464 return ret;
465 }
466
467 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
468 {
469 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
470 }
471
472 const char *prettify_refname(const char *name)
473 {
474 if (skip_prefix(name, "refs/heads/", &name) ||
475 skip_prefix(name, "refs/tags/", &name) ||
476 skip_prefix(name, "refs/remotes/", &name))
477 ; /* nothing */
478 return name;
479 }
480
481 static const char *ref_rev_parse_rules[] = {
482 "%.*s",
483 "refs/%.*s",
484 "refs/tags/%.*s",
485 "refs/heads/%.*s",
486 "refs/remotes/%.*s",
487 "refs/remotes/%.*s/HEAD",
488 NULL
489 };
490
491 int refname_match(const char *abbrev_name, const char *full_name)
492 {
493 const char **p;
494 const int abbrev_name_len = strlen(abbrev_name);
495
496 for (p = ref_rev_parse_rules; *p; p++) {
497 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
498 return 1;
499 }
500 }
501
502 return 0;
503 }
504
505 /*
506 * Given a 'prefix' expand it by the rules in 'ref_rev_parse_rules' and add
507 * the results to 'prefixes'
508 */
509 void expand_ref_prefix(struct argv_array *prefixes, const char *prefix)
510 {
511 const char **p;
512 int len = strlen(prefix);
513
514 for (p = ref_rev_parse_rules; *p; p++)
515 argv_array_pushf(prefixes, *p, len, prefix);
516 }
517
518 /*
519 * *string and *len will only be substituted, and *string returned (for
520 * later free()ing) if the string passed in is a magic short-hand form
521 * to name a branch.
522 */
523 static char *substitute_branch_name(const char **string, int *len)
524 {
525 struct strbuf buf = STRBUF_INIT;
526 int ret = interpret_branch_name(*string, *len, &buf, 0);
527
528 if (ret == *len) {
529 size_t size;
530 *string = strbuf_detach(&buf, &size);
531 *len = size;
532 return (char *)*string;
533 }
534
535 return NULL;
536 }
537
538 int dwim_ref(const char *str, int len, struct object_id *oid, char **ref)
539 {
540 char *last_branch = substitute_branch_name(&str, &len);
541 int refs_found = expand_ref(str, len, oid, ref);
542 free(last_branch);
543 return refs_found;
544 }
545
546 int expand_ref(const char *str, int len, struct object_id *oid, char **ref)
547 {
548 const char **p, *r;
549 int refs_found = 0;
550 struct strbuf fullref = STRBUF_INIT;
551
552 *ref = NULL;
553 for (p = ref_rev_parse_rules; *p; p++) {
554 struct object_id oid_from_ref;
555 struct object_id *this_result;
556 int flag;
557
558 this_result = refs_found ? &oid_from_ref : oid;
559 strbuf_reset(&fullref);
560 strbuf_addf(&fullref, *p, len, str);
561 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
562 this_result, &flag);
563 if (r) {
564 if (!refs_found++)
565 *ref = xstrdup(r);
566 if (!warn_ambiguous_refs)
567 break;
568 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
569 warning("ignoring dangling symref %s.", fullref.buf);
570 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
571 warning("ignoring broken ref %s.", fullref.buf);
572 }
573 }
574 strbuf_release(&fullref);
575 return refs_found;
576 }
577
578 int dwim_log(const char *str, int len, struct object_id *oid, char **log)
579 {
580 char *last_branch = substitute_branch_name(&str, &len);
581 const char **p;
582 int logs_found = 0;
583 struct strbuf path = STRBUF_INIT;
584
585 *log = NULL;
586 for (p = ref_rev_parse_rules; *p; p++) {
587 struct object_id hash;
588 const char *ref, *it;
589
590 strbuf_reset(&path);
591 strbuf_addf(&path, *p, len, str);
592 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
593 &hash, NULL);
594 if (!ref)
595 continue;
596 if (reflog_exists(path.buf))
597 it = path.buf;
598 else if (strcmp(ref, path.buf) && reflog_exists(ref))
599 it = ref;
600 else
601 continue;
602 if (!logs_found++) {
603 *log = xstrdup(it);
604 oidcpy(oid, &hash);
605 }
606 if (!warn_ambiguous_refs)
607 break;
608 }
609 strbuf_release(&path);
610 free(last_branch);
611 return logs_found;
612 }
613
614 static int is_per_worktree_ref(const char *refname)
615 {
616 return !strcmp(refname, "HEAD") ||
617 starts_with(refname, "refs/bisect/");
618 }
619
620 static int is_pseudoref_syntax(const char *refname)
621 {
622 const char *c;
623
624 for (c = refname; *c; c++) {
625 if (!isupper(*c) && *c != '-' && *c != '_')
626 return 0;
627 }
628
629 return 1;
630 }
631
632 enum ref_type ref_type(const char *refname)
633 {
634 if (is_per_worktree_ref(refname))
635 return REF_TYPE_PER_WORKTREE;
636 if (is_pseudoref_syntax(refname))
637 return REF_TYPE_PSEUDOREF;
638 return REF_TYPE_NORMAL;
639 }
640
641 long get_files_ref_lock_timeout_ms(void)
642 {
643 static int configured = 0;
644
645 /* The default timeout is 100 ms: */
646 static int timeout_ms = 100;
647
648 if (!configured) {
649 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
650 configured = 1;
651 }
652
653 return timeout_ms;
654 }
655
656 static int write_pseudoref(const char *pseudoref, const struct object_id *oid,
657 const struct object_id *old_oid, struct strbuf *err)
658 {
659 const char *filename;
660 int fd;
661 static struct lock_file lock;
662 struct strbuf buf = STRBUF_INIT;
663 int ret = -1;
664
665 if (!oid)
666 return 0;
667
668 strbuf_addf(&buf, "%s\n", oid_to_hex(oid));
669
670 filename = git_path("%s", pseudoref);
671 fd = hold_lock_file_for_update_timeout(&lock, filename,
672 LOCK_DIE_ON_ERROR,
673 get_files_ref_lock_timeout_ms());
674 if (fd < 0) {
675 strbuf_addf(err, "could not open '%s' for writing: %s",
676 filename, strerror(errno));
677 goto done;
678 }
679
680 if (old_oid) {
681 struct object_id actual_old_oid;
682
683 if (read_ref(pseudoref, &actual_old_oid))
684 die("could not read ref '%s'", pseudoref);
685 if (oidcmp(&actual_old_oid, old_oid)) {
686 strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
687 rollback_lock_file(&lock);
688 goto done;
689 }
690 }
691
692 if (write_in_full(fd, buf.buf, buf.len) < 0) {
693 strbuf_addf(err, "could not write to '%s'", filename);
694 rollback_lock_file(&lock);
695 goto done;
696 }
697
698 commit_lock_file(&lock);
699 ret = 0;
700 done:
701 strbuf_release(&buf);
702 return ret;
703 }
704
705 static int delete_pseudoref(const char *pseudoref, const struct object_id *old_oid)
706 {
707 static struct lock_file lock;
708 const char *filename;
709
710 filename = git_path("%s", pseudoref);
711
712 if (old_oid && !is_null_oid(old_oid)) {
713 int fd;
714 struct object_id actual_old_oid;
715
716 fd = hold_lock_file_for_update_timeout(
717 &lock, filename, LOCK_DIE_ON_ERROR,
718 get_files_ref_lock_timeout_ms());
719 if (fd < 0)
720 die_errno(_("Could not open '%s' for writing"), filename);
721 if (read_ref(pseudoref, &actual_old_oid))
722 die("could not read ref '%s'", pseudoref);
723 if (oidcmp(&actual_old_oid, old_oid)) {
724 warning("Unexpected sha1 when deleting %s", pseudoref);
725 rollback_lock_file(&lock);
726 return -1;
727 }
728
729 unlink(filename);
730 rollback_lock_file(&lock);
731 } else {
732 unlink(filename);
733 }
734
735 return 0;
736 }
737
738 int refs_delete_ref(struct ref_store *refs, const char *msg,
739 const char *refname,
740 const struct object_id *old_oid,
741 unsigned int flags)
742 {
743 struct ref_transaction *transaction;
744 struct strbuf err = STRBUF_INIT;
745
746 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
747 assert(refs == get_main_ref_store());
748 return delete_pseudoref(refname, old_oid);
749 }
750
751 transaction = ref_store_transaction_begin(refs, &err);
752 if (!transaction ||
753 ref_transaction_delete(transaction, refname, old_oid,
754 flags, msg, &err) ||
755 ref_transaction_commit(transaction, &err)) {
756 error("%s", err.buf);
757 ref_transaction_free(transaction);
758 strbuf_release(&err);
759 return 1;
760 }
761 ref_transaction_free(transaction);
762 strbuf_release(&err);
763 return 0;
764 }
765
766 int delete_ref(const char *msg, const char *refname,
767 const struct object_id *old_oid, unsigned int flags)
768 {
769 return refs_delete_ref(get_main_ref_store(), msg, refname,
770 old_oid, flags);
771 }
772
773 int copy_reflog_msg(char *buf, const char *msg)
774 {
775 char *cp = buf;
776 char c;
777 int wasspace = 1;
778
779 *cp++ = '\t';
780 while ((c = *msg++)) {
781 if (wasspace && isspace(c))
782 continue;
783 wasspace = isspace(c);
784 if (wasspace)
785 c = ' ';
786 *cp++ = c;
787 }
788 while (buf < cp && isspace(cp[-1]))
789 cp--;
790 *cp++ = '\n';
791 return cp - buf;
792 }
793
794 int should_autocreate_reflog(const char *refname)
795 {
796 switch (log_all_ref_updates) {
797 case LOG_REFS_ALWAYS:
798 return 1;
799 case LOG_REFS_NORMAL:
800 return starts_with(refname, "refs/heads/") ||
801 starts_with(refname, "refs/remotes/") ||
802 starts_with(refname, "refs/notes/") ||
803 !strcmp(refname, "HEAD");
804 default:
805 return 0;
806 }
807 }
808
809 int is_branch(const char *refname)
810 {
811 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
812 }
813
814 struct read_ref_at_cb {
815 const char *refname;
816 timestamp_t at_time;
817 int cnt;
818 int reccnt;
819 struct object_id *oid;
820 int found_it;
821
822 struct object_id ooid;
823 struct object_id noid;
824 int tz;
825 timestamp_t date;
826 char **msg;
827 timestamp_t *cutoff_time;
828 int *cutoff_tz;
829 int *cutoff_cnt;
830 };
831
832 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
833 const char *email, timestamp_t timestamp, int tz,
834 const char *message, void *cb_data)
835 {
836 struct read_ref_at_cb *cb = cb_data;
837
838 cb->reccnt++;
839 cb->tz = tz;
840 cb->date = timestamp;
841
842 if (timestamp <= cb->at_time || cb->cnt == 0) {
843 if (cb->msg)
844 *cb->msg = xstrdup(message);
845 if (cb->cutoff_time)
846 *cb->cutoff_time = timestamp;
847 if (cb->cutoff_tz)
848 *cb->cutoff_tz = tz;
849 if (cb->cutoff_cnt)
850 *cb->cutoff_cnt = cb->reccnt - 1;
851 /*
852 * we have not yet updated cb->[n|o]oid so they still
853 * hold the values for the previous record.
854 */
855 if (!is_null_oid(&cb->ooid)) {
856 oidcpy(cb->oid, noid);
857 if (oidcmp(&cb->ooid, noid))
858 warning("Log for ref %s has gap after %s.",
859 cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
860 }
861 else if (cb->date == cb->at_time)
862 oidcpy(cb->oid, noid);
863 else if (oidcmp(noid, cb->oid))
864 warning("Log for ref %s unexpectedly ended on %s.",
865 cb->refname, show_date(cb->date, cb->tz,
866 DATE_MODE(RFC2822)));
867 oidcpy(&cb->ooid, ooid);
868 oidcpy(&cb->noid, noid);
869 cb->found_it = 1;
870 return 1;
871 }
872 oidcpy(&cb->ooid, ooid);
873 oidcpy(&cb->noid, noid);
874 if (cb->cnt > 0)
875 cb->cnt--;
876 return 0;
877 }
878
879 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
880 const char *email, timestamp_t timestamp,
881 int tz, const char *message, void *cb_data)
882 {
883 struct read_ref_at_cb *cb = cb_data;
884
885 if (cb->msg)
886 *cb->msg = xstrdup(message);
887 if (cb->cutoff_time)
888 *cb->cutoff_time = timestamp;
889 if (cb->cutoff_tz)
890 *cb->cutoff_tz = tz;
891 if (cb->cutoff_cnt)
892 *cb->cutoff_cnt = cb->reccnt;
893 oidcpy(cb->oid, ooid);
894 if (is_null_oid(cb->oid))
895 oidcpy(cb->oid, noid);
896 /* We just want the first entry */
897 return 1;
898 }
899
900 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
901 struct object_id *oid, char **msg,
902 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
903 {
904 struct read_ref_at_cb cb;
905
906 memset(&cb, 0, sizeof(cb));
907 cb.refname = refname;
908 cb.at_time = at_time;
909 cb.cnt = cnt;
910 cb.msg = msg;
911 cb.cutoff_time = cutoff_time;
912 cb.cutoff_tz = cutoff_tz;
913 cb.cutoff_cnt = cutoff_cnt;
914 cb.oid = oid;
915
916 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
917
918 if (!cb.reccnt) {
919 if (flags & GET_OID_QUIETLY)
920 exit(128);
921 else
922 die("Log for %s is empty.", refname);
923 }
924 if (cb.found_it)
925 return 0;
926
927 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
928
929 return 1;
930 }
931
932 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
933 struct strbuf *err)
934 {
935 struct ref_transaction *tr;
936 assert(err);
937
938 tr = xcalloc(1, sizeof(struct ref_transaction));
939 tr->ref_store = refs;
940 return tr;
941 }
942
943 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
944 {
945 return ref_store_transaction_begin(get_main_ref_store(), err);
946 }
947
948 void ref_transaction_free(struct ref_transaction *transaction)
949 {
950 size_t i;
951
952 if (!transaction)
953 return;
954
955 switch (transaction->state) {
956 case REF_TRANSACTION_OPEN:
957 case REF_TRANSACTION_CLOSED:
958 /* OK */
959 break;
960 case REF_TRANSACTION_PREPARED:
961 die("BUG: free called on a prepared reference transaction");
962 break;
963 default:
964 die("BUG: unexpected reference transaction state");
965 break;
966 }
967
968 for (i = 0; i < transaction->nr; i++) {
969 free(transaction->updates[i]->msg);
970 free(transaction->updates[i]);
971 }
972 free(transaction->updates);
973 free(transaction);
974 }
975
976 struct ref_update *ref_transaction_add_update(
977 struct ref_transaction *transaction,
978 const char *refname, unsigned int flags,
979 const struct object_id *new_oid,
980 const struct object_id *old_oid,
981 const char *msg)
982 {
983 struct ref_update *update;
984
985 if (transaction->state != REF_TRANSACTION_OPEN)
986 die("BUG: update called for transaction that is not open");
987
988 FLEX_ALLOC_STR(update, refname, refname);
989 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
990 transaction->updates[transaction->nr++] = update;
991
992 update->flags = flags;
993
994 if (flags & REF_HAVE_NEW)
995 oidcpy(&update->new_oid, new_oid);
996 if (flags & REF_HAVE_OLD)
997 oidcpy(&update->old_oid, old_oid);
998 update->msg = xstrdup_or_null(msg);
999 return update;
1000 }
1001
1002 int ref_transaction_update(struct ref_transaction *transaction,
1003 const char *refname,
1004 const struct object_id *new_oid,
1005 const struct object_id *old_oid,
1006 unsigned int flags, const char *msg,
1007 struct strbuf *err)
1008 {
1009 assert(err);
1010
1011 if ((new_oid && !is_null_oid(new_oid)) ?
1012 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
1013 !refname_is_safe(refname)) {
1014 strbuf_addf(err, "refusing to update ref with bad name '%s'",
1015 refname);
1016 return -1;
1017 }
1018
1019 if (flags & ~REF_TRANSACTION_UPDATE_ALLOWED_FLAGS)
1020 BUG("illegal flags 0x%x passed to ref_transaction_update()", flags);
1021
1022 flags |= (new_oid ? REF_HAVE_NEW : 0) | (old_oid ? REF_HAVE_OLD : 0);
1023
1024 ref_transaction_add_update(transaction, refname, flags,
1025 new_oid, old_oid, msg);
1026 return 0;
1027 }
1028
1029 int ref_transaction_create(struct ref_transaction *transaction,
1030 const char *refname,
1031 const struct object_id *new_oid,
1032 unsigned int flags, const char *msg,
1033 struct strbuf *err)
1034 {
1035 if (!new_oid || is_null_oid(new_oid))
1036 die("BUG: create called without valid new_oid");
1037 return ref_transaction_update(transaction, refname, new_oid,
1038 &null_oid, flags, msg, err);
1039 }
1040
1041 int ref_transaction_delete(struct ref_transaction *transaction,
1042 const char *refname,
1043 const struct object_id *old_oid,
1044 unsigned int flags, const char *msg,
1045 struct strbuf *err)
1046 {
1047 if (old_oid && is_null_oid(old_oid))
1048 die("BUG: delete called with old_oid set to zeros");
1049 return ref_transaction_update(transaction, refname,
1050 &null_oid, old_oid,
1051 flags, msg, err);
1052 }
1053
1054 int ref_transaction_verify(struct ref_transaction *transaction,
1055 const char *refname,
1056 const struct object_id *old_oid,
1057 unsigned int flags,
1058 struct strbuf *err)
1059 {
1060 if (!old_oid)
1061 die("BUG: verify called with old_oid set to NULL");
1062 return ref_transaction_update(transaction, refname,
1063 NULL, old_oid,
1064 flags, NULL, err);
1065 }
1066
1067 int refs_update_ref(struct ref_store *refs, const char *msg,
1068 const char *refname, const struct object_id *new_oid,
1069 const struct object_id *old_oid, unsigned int flags,
1070 enum action_on_err onerr)
1071 {
1072 struct ref_transaction *t = NULL;
1073 struct strbuf err = STRBUF_INIT;
1074 int ret = 0;
1075
1076 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1077 assert(refs == get_main_ref_store());
1078 ret = write_pseudoref(refname, new_oid, old_oid, &err);
1079 } else {
1080 t = ref_store_transaction_begin(refs, &err);
1081 if (!t ||
1082 ref_transaction_update(t, refname, new_oid, old_oid,
1083 flags, msg, &err) ||
1084 ref_transaction_commit(t, &err)) {
1085 ret = 1;
1086 ref_transaction_free(t);
1087 }
1088 }
1089 if (ret) {
1090 const char *str = "update_ref failed for ref '%s': %s";
1091
1092 switch (onerr) {
1093 case UPDATE_REFS_MSG_ON_ERR:
1094 error(str, refname, err.buf);
1095 break;
1096 case UPDATE_REFS_DIE_ON_ERR:
1097 die(str, refname, err.buf);
1098 break;
1099 case UPDATE_REFS_QUIET_ON_ERR:
1100 break;
1101 }
1102 strbuf_release(&err);
1103 return 1;
1104 }
1105 strbuf_release(&err);
1106 if (t)
1107 ref_transaction_free(t);
1108 return 0;
1109 }
1110
1111 int update_ref(const char *msg, const char *refname,
1112 const struct object_id *new_oid,
1113 const struct object_id *old_oid,
1114 unsigned int flags, enum action_on_err onerr)
1115 {
1116 return refs_update_ref(get_main_ref_store(), msg, refname, new_oid,
1117 old_oid, flags, onerr);
1118 }
1119
1120 char *shorten_unambiguous_ref(const char *refname, int strict)
1121 {
1122 int i;
1123 static char **scanf_fmts;
1124 static int nr_rules;
1125 char *short_name;
1126 struct strbuf resolved_buf = STRBUF_INIT;
1127
1128 if (!nr_rules) {
1129 /*
1130 * Pre-generate scanf formats from ref_rev_parse_rules[].
1131 * Generate a format suitable for scanf from a
1132 * ref_rev_parse_rules rule by interpolating "%s" at the
1133 * location of the "%.*s".
1134 */
1135 size_t total_len = 0;
1136 size_t offset = 0;
1137
1138 /* the rule list is NULL terminated, count them first */
1139 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1140 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1141 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1142
1143 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1144
1145 offset = 0;
1146 for (i = 0; i < nr_rules; i++) {
1147 assert(offset < total_len);
1148 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1149 offset += snprintf(scanf_fmts[i], total_len - offset,
1150 ref_rev_parse_rules[i], 2, "%s") + 1;
1151 }
1152 }
1153
1154 /* bail out if there are no rules */
1155 if (!nr_rules)
1156 return xstrdup(refname);
1157
1158 /* buffer for scanf result, at most refname must fit */
1159 short_name = xstrdup(refname);
1160
1161 /* skip first rule, it will always match */
1162 for (i = nr_rules - 1; i > 0 ; --i) {
1163 int j;
1164 int rules_to_fail = i;
1165 int short_name_len;
1166
1167 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1168 continue;
1169
1170 short_name_len = strlen(short_name);
1171
1172 /*
1173 * in strict mode, all (except the matched one) rules
1174 * must fail to resolve to a valid non-ambiguous ref
1175 */
1176 if (strict)
1177 rules_to_fail = nr_rules;
1178
1179 /*
1180 * check if the short name resolves to a valid ref,
1181 * but use only rules prior to the matched one
1182 */
1183 for (j = 0; j < rules_to_fail; j++) {
1184 const char *rule = ref_rev_parse_rules[j];
1185
1186 /* skip matched rule */
1187 if (i == j)
1188 continue;
1189
1190 /*
1191 * the short name is ambiguous, if it resolves
1192 * (with this previous rule) to a valid ref
1193 * read_ref() returns 0 on success
1194 */
1195 strbuf_reset(&resolved_buf);
1196 strbuf_addf(&resolved_buf, rule,
1197 short_name_len, short_name);
1198 if (ref_exists(resolved_buf.buf))
1199 break;
1200 }
1201
1202 /*
1203 * short name is non-ambiguous if all previous rules
1204 * haven't resolved to a valid ref
1205 */
1206 if (j == rules_to_fail) {
1207 strbuf_release(&resolved_buf);
1208 return short_name;
1209 }
1210 }
1211
1212 strbuf_release(&resolved_buf);
1213 free(short_name);
1214 return xstrdup(refname);
1215 }
1216
1217 static struct string_list *hide_refs;
1218
1219 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1220 {
1221 const char *key;
1222 if (!strcmp("transfer.hiderefs", var) ||
1223 (!parse_config_key(var, section, NULL, NULL, &key) &&
1224 !strcmp(key, "hiderefs"))) {
1225 char *ref;
1226 int len;
1227
1228 if (!value)
1229 return config_error_nonbool(var);
1230 ref = xstrdup(value);
1231 len = strlen(ref);
1232 while (len && ref[len - 1] == '/')
1233 ref[--len] = '\0';
1234 if (!hide_refs) {
1235 hide_refs = xcalloc(1, sizeof(*hide_refs));
1236 hide_refs->strdup_strings = 1;
1237 }
1238 string_list_append(hide_refs, ref);
1239 }
1240 return 0;
1241 }
1242
1243 int ref_is_hidden(const char *refname, const char *refname_full)
1244 {
1245 int i;
1246
1247 if (!hide_refs)
1248 return 0;
1249 for (i = hide_refs->nr - 1; i >= 0; i--) {
1250 const char *match = hide_refs->items[i].string;
1251 const char *subject;
1252 int neg = 0;
1253 const char *p;
1254
1255 if (*match == '!') {
1256 neg = 1;
1257 match++;
1258 }
1259
1260 if (*match == '^') {
1261 subject = refname_full;
1262 match++;
1263 } else {
1264 subject = refname;
1265 }
1266
1267 /* refname can be NULL when namespaces are used. */
1268 if (subject &&
1269 skip_prefix(subject, match, &p) &&
1270 (!*p || *p == '/'))
1271 return !neg;
1272 }
1273 return 0;
1274 }
1275
1276 const char *find_descendant_ref(const char *dirname,
1277 const struct string_list *extras,
1278 const struct string_list *skip)
1279 {
1280 int pos;
1281
1282 if (!extras)
1283 return NULL;
1284
1285 /*
1286 * Look at the place where dirname would be inserted into
1287 * extras. If there is an entry at that position that starts
1288 * with dirname (remember, dirname includes the trailing
1289 * slash) and is not in skip, then we have a conflict.
1290 */
1291 for (pos = string_list_find_insert_index(extras, dirname, 0);
1292 pos < extras->nr; pos++) {
1293 const char *extra_refname = extras->items[pos].string;
1294
1295 if (!starts_with(extra_refname, dirname))
1296 break;
1297
1298 if (!skip || !string_list_has_string(skip, extra_refname))
1299 return extra_refname;
1300 }
1301 return NULL;
1302 }
1303
1304 int refs_rename_ref_available(struct ref_store *refs,
1305 const char *old_refname,
1306 const char *new_refname)
1307 {
1308 struct string_list skip = STRING_LIST_INIT_NODUP;
1309 struct strbuf err = STRBUF_INIT;
1310 int ok;
1311
1312 string_list_insert(&skip, old_refname);
1313 ok = !refs_verify_refname_available(refs, new_refname,
1314 NULL, &skip, &err);
1315 if (!ok)
1316 error("%s", err.buf);
1317
1318 string_list_clear(&skip, 0);
1319 strbuf_release(&err);
1320 return ok;
1321 }
1322
1323 int refs_head_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1324 {
1325 struct object_id oid;
1326 int flag;
1327
1328 if (!refs_read_ref_full(refs, "HEAD", RESOLVE_REF_READING,
1329 &oid, &flag))
1330 return fn("HEAD", &oid, flag, cb_data);
1331
1332 return 0;
1333 }
1334
1335 int head_ref(each_ref_fn fn, void *cb_data)
1336 {
1337 return refs_head_ref(get_main_ref_store(), fn, cb_data);
1338 }
1339
1340 struct ref_iterator *refs_ref_iterator_begin(
1341 struct ref_store *refs,
1342 const char *prefix, int trim, int flags)
1343 {
1344 struct ref_iterator *iter;
1345
1346 if (ref_paranoia < 0)
1347 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1348 if (ref_paranoia)
1349 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1350
1351 iter = refs->be->iterator_begin(refs, prefix, flags);
1352
1353 /*
1354 * `iterator_begin()` already takes care of prefix, but we
1355 * might need to do some trimming:
1356 */
1357 if (trim)
1358 iter = prefix_ref_iterator_begin(iter, "", trim);
1359
1360 /* Sanity check for subclasses: */
1361 if (!iter->ordered)
1362 BUG("reference iterator is not ordered");
1363
1364 return iter;
1365 }
1366
1367 /*
1368 * Call fn for each reference in the specified submodule for which the
1369 * refname begins with prefix. If trim is non-zero, then trim that
1370 * many characters off the beginning of each refname before passing
1371 * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1372 * include broken references in the iteration. If fn ever returns a
1373 * non-zero value, stop the iteration and return that value;
1374 * otherwise, return 0.
1375 */
1376 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1377 each_ref_fn fn, int trim, int flags, void *cb_data)
1378 {
1379 struct ref_iterator *iter;
1380
1381 if (!refs)
1382 return 0;
1383
1384 iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1385
1386 return do_for_each_ref_iterator(iter, fn, cb_data);
1387 }
1388
1389 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1390 {
1391 return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1392 }
1393
1394 int for_each_ref(each_ref_fn fn, void *cb_data)
1395 {
1396 return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
1397 }
1398
1399 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1400 each_ref_fn fn, void *cb_data)
1401 {
1402 return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1403 }
1404
1405 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1406 {
1407 return refs_for_each_ref_in(get_main_ref_store(), prefix, fn, cb_data);
1408 }
1409
1410 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1411 {
1412 unsigned int flag = 0;
1413
1414 if (broken)
1415 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1416 return do_for_each_ref(get_main_ref_store(),
1417 prefix, fn, 0, flag, cb_data);
1418 }
1419
1420 int refs_for_each_fullref_in(struct ref_store *refs, const char *prefix,
1421 each_ref_fn fn, void *cb_data,
1422 unsigned int broken)
1423 {
1424 unsigned int flag = 0;
1425
1426 if (broken)
1427 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1428 return do_for_each_ref(refs, prefix, fn, 0, flag, cb_data);
1429 }
1430
1431 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1432 {
1433 return do_for_each_ref(get_main_ref_store(),
1434 git_replace_ref_base, fn,
1435 strlen(git_replace_ref_base),
1436 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1437 }
1438
1439 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1440 {
1441 struct strbuf buf = STRBUF_INIT;
1442 int ret;
1443 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1444 ret = do_for_each_ref(get_main_ref_store(),
1445 buf.buf, fn, 0, 0, cb_data);
1446 strbuf_release(&buf);
1447 return ret;
1448 }
1449
1450 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1451 {
1452 return do_for_each_ref(refs, "", fn, 0,
1453 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1454 }
1455
1456 int for_each_rawref(each_ref_fn fn, void *cb_data)
1457 {
1458 return refs_for_each_rawref(get_main_ref_store(), fn, cb_data);
1459 }
1460
1461 int refs_read_raw_ref(struct ref_store *ref_store,
1462 const char *refname, struct object_id *oid,
1463 struct strbuf *referent, unsigned int *type)
1464 {
1465 return ref_store->be->read_raw_ref(ref_store, refname, oid, referent, type);
1466 }
1467
1468 /* This function needs to return a meaningful errno on failure */
1469 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1470 const char *refname,
1471 int resolve_flags,
1472 struct object_id *oid, int *flags)
1473 {
1474 static struct strbuf sb_refname = STRBUF_INIT;
1475 struct object_id unused_oid;
1476 int unused_flags;
1477 int symref_count;
1478
1479 if (!oid)
1480 oid = &unused_oid;
1481 if (!flags)
1482 flags = &unused_flags;
1483
1484 *flags = 0;
1485
1486 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1487 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1488 !refname_is_safe(refname)) {
1489 errno = EINVAL;
1490 return NULL;
1491 }
1492
1493 /*
1494 * dwim_ref() uses REF_ISBROKEN to distinguish between
1495 * missing refs and refs that were present but invalid,
1496 * to complain about the latter to stderr.
1497 *
1498 * We don't know whether the ref exists, so don't set
1499 * REF_ISBROKEN yet.
1500 */
1501 *flags |= REF_BAD_NAME;
1502 }
1503
1504 for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1505 unsigned int read_flags = 0;
1506
1507 if (refs_read_raw_ref(refs, refname,
1508 oid, &sb_refname, &read_flags)) {
1509 *flags |= read_flags;
1510
1511 /* In reading mode, refs must eventually resolve */
1512 if (resolve_flags & RESOLVE_REF_READING)
1513 return NULL;
1514
1515 /*
1516 * Otherwise a missing ref is OK. But the files backend
1517 * may show errors besides ENOENT if there are
1518 * similarly-named refs.
1519 */
1520 if (errno != ENOENT &&
1521 errno != EISDIR &&
1522 errno != ENOTDIR)
1523 return NULL;
1524
1525 oidclr(oid);
1526 if (*flags & REF_BAD_NAME)
1527 *flags |= REF_ISBROKEN;
1528 return refname;
1529 }
1530
1531 *flags |= read_flags;
1532
1533 if (!(read_flags & REF_ISSYMREF)) {
1534 if (*flags & REF_BAD_NAME) {
1535 oidclr(oid);
1536 *flags |= REF_ISBROKEN;
1537 }
1538 return refname;
1539 }
1540
1541 refname = sb_refname.buf;
1542 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1543 oidclr(oid);
1544 return refname;
1545 }
1546 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1547 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1548 !refname_is_safe(refname)) {
1549 errno = EINVAL;
1550 return NULL;
1551 }
1552
1553 *flags |= REF_ISBROKEN | REF_BAD_NAME;
1554 }
1555 }
1556
1557 errno = ELOOP;
1558 return NULL;
1559 }
1560
1561 /* backend functions */
1562 int refs_init_db(struct strbuf *err)
1563 {
1564 struct ref_store *refs = get_main_ref_store();
1565
1566 return refs->be->init_db(refs, err);
1567 }
1568
1569 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1570 struct object_id *oid, int *flags)
1571 {
1572 return refs_resolve_ref_unsafe(get_main_ref_store(), refname,
1573 resolve_flags, oid, flags);
1574 }
1575
1576 int resolve_gitlink_ref(const char *submodule, const char *refname,
1577 struct object_id *oid)
1578 {
1579 struct ref_store *refs;
1580 int flags;
1581
1582 refs = get_submodule_ref_store(submodule);
1583
1584 if (!refs)
1585 return -1;
1586
1587 if (!refs_resolve_ref_unsafe(refs, refname, 0, oid, &flags) ||
1588 is_null_oid(oid))
1589 return -1;
1590 return 0;
1591 }
1592
1593 struct ref_store_hash_entry
1594 {
1595 struct hashmap_entry ent; /* must be the first member! */
1596
1597 struct ref_store *refs;
1598
1599 /* NUL-terminated identifier of the ref store: */
1600 char name[FLEX_ARRAY];
1601 };
1602
1603 static int ref_store_hash_cmp(const void *unused_cmp_data,
1604 const void *entry, const void *entry_or_key,
1605 const void *keydata)
1606 {
1607 const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1608 const char *name = keydata ? keydata : e2->name;
1609
1610 return strcmp(e1->name, name);
1611 }
1612
1613 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1614 const char *name, struct ref_store *refs)
1615 {
1616 struct ref_store_hash_entry *entry;
1617
1618 FLEX_ALLOC_STR(entry, name, name);
1619 hashmap_entry_init(entry, strhash(name));
1620 entry->refs = refs;
1621 return entry;
1622 }
1623
1624 /* A pointer to the ref_store for the main repository: */
1625 static struct ref_store *main_ref_store;
1626
1627 /* A hashmap of ref_stores, stored by submodule name: */
1628 static struct hashmap submodule_ref_stores;
1629
1630 /* A hashmap of ref_stores, stored by worktree id: */
1631 static struct hashmap worktree_ref_stores;
1632
1633 /*
1634 * Look up a ref store by name. If that ref_store hasn't been
1635 * registered yet, return NULL.
1636 */
1637 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1638 const char *name)
1639 {
1640 struct ref_store_hash_entry *entry;
1641
1642 if (!map->tablesize)
1643 /* It's initialized on demand in register_ref_store(). */
1644 return NULL;
1645
1646 entry = hashmap_get_from_hash(map, strhash(name), name);
1647 return entry ? entry->refs : NULL;
1648 }
1649
1650 /*
1651 * Create, record, and return a ref_store instance for the specified
1652 * gitdir.
1653 */
1654 static struct ref_store *ref_store_init(const char *gitdir,
1655 unsigned int flags)
1656 {
1657 const char *be_name = "files";
1658 struct ref_storage_be *be = find_ref_storage_backend(be_name);
1659 struct ref_store *refs;
1660
1661 if (!be)
1662 die("BUG: reference backend %s is unknown", be_name);
1663
1664 refs = be->init(gitdir, flags);
1665 return refs;
1666 }
1667
1668 struct ref_store *get_main_ref_store(void)
1669 {
1670 if (main_ref_store)
1671 return main_ref_store;
1672
1673 main_ref_store = ref_store_init(get_git_dir(), REF_STORE_ALL_CAPS);
1674 return main_ref_store;
1675 }
1676
1677 /*
1678 * Associate a ref store with a name. It is a fatal error to call this
1679 * function twice for the same name.
1680 */
1681 static void register_ref_store_map(struct hashmap *map,
1682 const char *type,
1683 struct ref_store *refs,
1684 const char *name)
1685 {
1686 if (!map->tablesize)
1687 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1688
1689 if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1690 die("BUG: %s ref_store '%s' initialized twice", type, name);
1691 }
1692
1693 struct ref_store *get_submodule_ref_store(const char *submodule)
1694 {
1695 struct strbuf submodule_sb = STRBUF_INIT;
1696 struct ref_store *refs;
1697 char *to_free = NULL;
1698 size_t len;
1699
1700 if (!submodule)
1701 return NULL;
1702
1703 len = strlen(submodule);
1704 while (len && is_dir_sep(submodule[len - 1]))
1705 len--;
1706 if (!len)
1707 return NULL;
1708
1709 if (submodule[len])
1710 /* We need to strip off one or more trailing slashes */
1711 submodule = to_free = xmemdupz(submodule, len);
1712
1713 refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1714 if (refs)
1715 goto done;
1716
1717 strbuf_addstr(&submodule_sb, submodule);
1718 if (!is_nonbare_repository_dir(&submodule_sb))
1719 goto done;
1720
1721 if (submodule_to_gitdir(&submodule_sb, submodule))
1722 goto done;
1723
1724 /* assume that add_submodule_odb() has been called */
1725 refs = ref_store_init(submodule_sb.buf,
1726 REF_STORE_READ | REF_STORE_ODB);
1727 register_ref_store_map(&submodule_ref_stores, "submodule",
1728 refs, submodule);
1729
1730 done:
1731 strbuf_release(&submodule_sb);
1732 free(to_free);
1733
1734 return refs;
1735 }
1736
1737 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1738 {
1739 struct ref_store *refs;
1740 const char *id;
1741
1742 if (wt->is_current)
1743 return get_main_ref_store();
1744
1745 id = wt->id ? wt->id : "/";
1746 refs = lookup_ref_store_map(&worktree_ref_stores, id);
1747 if (refs)
1748 return refs;
1749
1750 if (wt->id)
1751 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1752 REF_STORE_ALL_CAPS);
1753 else
1754 refs = ref_store_init(get_git_common_dir(),
1755 REF_STORE_ALL_CAPS);
1756
1757 if (refs)
1758 register_ref_store_map(&worktree_ref_stores, "worktree",
1759 refs, id);
1760 return refs;
1761 }
1762
1763 void base_ref_store_init(struct ref_store *refs,
1764 const struct ref_storage_be *be)
1765 {
1766 refs->be = be;
1767 }
1768
1769 /* backend functions */
1770 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1771 {
1772 return refs->be->pack_refs(refs, flags);
1773 }
1774
1775 int refs_peel_ref(struct ref_store *refs, const char *refname,
1776 struct object_id *oid)
1777 {
1778 int flag;
1779 struct object_id base;
1780
1781 if (current_ref_iter && current_ref_iter->refname == refname) {
1782 struct object_id peeled;
1783
1784 if (ref_iterator_peel(current_ref_iter, &peeled))
1785 return -1;
1786 oidcpy(oid, &peeled);
1787 return 0;
1788 }
1789
1790 if (refs_read_ref_full(refs, refname,
1791 RESOLVE_REF_READING, &base, &flag))
1792 return -1;
1793
1794 return peel_object(&base, oid);
1795 }
1796
1797 int peel_ref(const char *refname, struct object_id *oid)
1798 {
1799 return refs_peel_ref(get_main_ref_store(), refname, oid);
1800 }
1801
1802 int refs_create_symref(struct ref_store *refs,
1803 const char *ref_target,
1804 const char *refs_heads_master,
1805 const char *logmsg)
1806 {
1807 return refs->be->create_symref(refs, ref_target,
1808 refs_heads_master,
1809 logmsg);
1810 }
1811
1812 int create_symref(const char *ref_target, const char *refs_heads_master,
1813 const char *logmsg)
1814 {
1815 return refs_create_symref(get_main_ref_store(), ref_target,
1816 refs_heads_master, logmsg);
1817 }
1818
1819 int ref_update_reject_duplicates(struct string_list *refnames,
1820 struct strbuf *err)
1821 {
1822 size_t i, n = refnames->nr;
1823
1824 assert(err);
1825
1826 for (i = 1; i < n; i++) {
1827 int cmp = strcmp(refnames->items[i - 1].string,
1828 refnames->items[i].string);
1829
1830 if (!cmp) {
1831 strbuf_addf(err,
1832 "multiple updates for ref '%s' not allowed.",
1833 refnames->items[i].string);
1834 return 1;
1835 } else if (cmp > 0) {
1836 die("BUG: ref_update_reject_duplicates() received unsorted list");
1837 }
1838 }
1839 return 0;
1840 }
1841
1842 int ref_transaction_prepare(struct ref_transaction *transaction,
1843 struct strbuf *err)
1844 {
1845 struct ref_store *refs = transaction->ref_store;
1846
1847 switch (transaction->state) {
1848 case REF_TRANSACTION_OPEN:
1849 /* Good. */
1850 break;
1851 case REF_TRANSACTION_PREPARED:
1852 die("BUG: prepare called twice on reference transaction");
1853 break;
1854 case REF_TRANSACTION_CLOSED:
1855 die("BUG: prepare called on a closed reference transaction");
1856 break;
1857 default:
1858 die("BUG: unexpected reference transaction state");
1859 break;
1860 }
1861
1862 if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1863 strbuf_addstr(err,
1864 _("ref updates forbidden inside quarantine environment"));
1865 return -1;
1866 }
1867
1868 return refs->be->transaction_prepare(refs, transaction, err);
1869 }
1870
1871 int ref_transaction_abort(struct ref_transaction *transaction,
1872 struct strbuf *err)
1873 {
1874 struct ref_store *refs = transaction->ref_store;
1875 int ret = 0;
1876
1877 switch (transaction->state) {
1878 case REF_TRANSACTION_OPEN:
1879 /* No need to abort explicitly. */
1880 break;
1881 case REF_TRANSACTION_PREPARED:
1882 ret = refs->be->transaction_abort(refs, transaction, err);
1883 break;
1884 case REF_TRANSACTION_CLOSED:
1885 die("BUG: abort called on a closed reference transaction");
1886 break;
1887 default:
1888 die("BUG: unexpected reference transaction state");
1889 break;
1890 }
1891
1892 ref_transaction_free(transaction);
1893 return ret;
1894 }
1895
1896 int ref_transaction_commit(struct ref_transaction *transaction,
1897 struct strbuf *err)
1898 {
1899 struct ref_store *refs = transaction->ref_store;
1900 int ret;
1901
1902 switch (transaction->state) {
1903 case REF_TRANSACTION_OPEN:
1904 /* Need to prepare first. */
1905 ret = ref_transaction_prepare(transaction, err);
1906 if (ret)
1907 return ret;
1908 break;
1909 case REF_TRANSACTION_PREPARED:
1910 /* Fall through to finish. */
1911 break;
1912 case REF_TRANSACTION_CLOSED:
1913 die("BUG: commit called on a closed reference transaction");
1914 break;
1915 default:
1916 die("BUG: unexpected reference transaction state");
1917 break;
1918 }
1919
1920 return refs->be->transaction_finish(refs, transaction, err);
1921 }
1922
1923 int refs_verify_refname_available(struct ref_store *refs,
1924 const char *refname,
1925 const struct string_list *extras,
1926 const struct string_list *skip,
1927 struct strbuf *err)
1928 {
1929 const char *slash;
1930 const char *extra_refname;
1931 struct strbuf dirname = STRBUF_INIT;
1932 struct strbuf referent = STRBUF_INIT;
1933 struct object_id oid;
1934 unsigned int type;
1935 struct ref_iterator *iter;
1936 int ok;
1937 int ret = -1;
1938
1939 /*
1940 * For the sake of comments in this function, suppose that
1941 * refname is "refs/foo/bar".
1942 */
1943
1944 assert(err);
1945
1946 strbuf_grow(&dirname, strlen(refname) + 1);
1947 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1948 /* Expand dirname to the new prefix, not including the trailing slash: */
1949 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1950
1951 /*
1952 * We are still at a leading dir of the refname (e.g.,
1953 * "refs/foo"; if there is a reference with that name,
1954 * it is a conflict, *unless* it is in skip.
1955 */
1956 if (skip && string_list_has_string(skip, dirname.buf))
1957 continue;
1958
1959 if (!refs_read_raw_ref(refs, dirname.buf, &oid, &referent, &type)) {
1960 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1961 dirname.buf, refname);
1962 goto cleanup;
1963 }
1964
1965 if (extras && string_list_has_string(extras, dirname.buf)) {
1966 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1967 refname, dirname.buf);
1968 goto cleanup;
1969 }
1970 }
1971
1972 /*
1973 * We are at the leaf of our refname (e.g., "refs/foo/bar").
1974 * There is no point in searching for a reference with that
1975 * name, because a refname isn't considered to conflict with
1976 * itself. But we still need to check for references whose
1977 * names are in the "refs/foo/bar/" namespace, because they
1978 * *do* conflict.
1979 */
1980 strbuf_addstr(&dirname, refname + dirname.len);
1981 strbuf_addch(&dirname, '/');
1982
1983 iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1984 DO_FOR_EACH_INCLUDE_BROKEN);
1985 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1986 if (skip &&
1987 string_list_has_string(skip, iter->refname))
1988 continue;
1989
1990 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1991 iter->refname, refname);
1992 ref_iterator_abort(iter);
1993 goto cleanup;
1994 }
1995
1996 if (ok != ITER_DONE)
1997 die("BUG: error while iterating over references");
1998
1999 extra_refname = find_descendant_ref(dirname.buf, extras, skip);
2000 if (extra_refname)
2001 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
2002 refname, extra_refname);
2003 else
2004 ret = 0;
2005
2006 cleanup:
2007 strbuf_release(&referent);
2008 strbuf_release(&dirname);
2009 return ret;
2010 }
2011
2012 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
2013 {
2014 struct ref_iterator *iter;
2015
2016 iter = refs->be->reflog_iterator_begin(refs);
2017
2018 return do_for_each_ref_iterator(iter, fn, cb_data);
2019 }
2020
2021 int for_each_reflog(each_ref_fn fn, void *cb_data)
2022 {
2023 return refs_for_each_reflog(get_main_ref_store(), fn, cb_data);
2024 }
2025
2026 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
2027 const char *refname,
2028 each_reflog_ent_fn fn,
2029 void *cb_data)
2030 {
2031 return refs->be->for_each_reflog_ent_reverse(refs, refname,
2032 fn, cb_data);
2033 }
2034
2035 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
2036 void *cb_data)
2037 {
2038 return refs_for_each_reflog_ent_reverse(get_main_ref_store(),
2039 refname, fn, cb_data);
2040 }
2041
2042 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
2043 each_reflog_ent_fn fn, void *cb_data)
2044 {
2045 return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
2046 }
2047
2048 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
2049 void *cb_data)
2050 {
2051 return refs_for_each_reflog_ent(get_main_ref_store(), refname,
2052 fn, cb_data);
2053 }
2054
2055 int refs_reflog_exists(struct ref_store *refs, const char *refname)
2056 {
2057 return refs->be->reflog_exists(refs, refname);
2058 }
2059
2060 int reflog_exists(const char *refname)
2061 {
2062 return refs_reflog_exists(get_main_ref_store(), refname);
2063 }
2064
2065 int refs_create_reflog(struct ref_store *refs, const char *refname,
2066 int force_create, struct strbuf *err)
2067 {
2068 return refs->be->create_reflog(refs, refname, force_create, err);
2069 }
2070
2071 int safe_create_reflog(const char *refname, int force_create,
2072 struct strbuf *err)
2073 {
2074 return refs_create_reflog(get_main_ref_store(), refname,
2075 force_create, err);
2076 }
2077
2078 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2079 {
2080 return refs->be->delete_reflog(refs, refname);
2081 }
2082
2083 int delete_reflog(const char *refname)
2084 {
2085 return refs_delete_reflog(get_main_ref_store(), refname);
2086 }
2087
2088 int refs_reflog_expire(struct ref_store *refs,
2089 const char *refname, const struct object_id *oid,
2090 unsigned int flags,
2091 reflog_expiry_prepare_fn prepare_fn,
2092 reflog_expiry_should_prune_fn should_prune_fn,
2093 reflog_expiry_cleanup_fn cleanup_fn,
2094 void *policy_cb_data)
2095 {
2096 return refs->be->reflog_expire(refs, refname, oid, flags,
2097 prepare_fn, should_prune_fn,
2098 cleanup_fn, policy_cb_data);
2099 }
2100
2101 int reflog_expire(const char *refname, const struct object_id *oid,
2102 unsigned int flags,
2103 reflog_expiry_prepare_fn prepare_fn,
2104 reflog_expiry_should_prune_fn should_prune_fn,
2105 reflog_expiry_cleanup_fn cleanup_fn,
2106 void *policy_cb_data)
2107 {
2108 return refs_reflog_expire(get_main_ref_store(),
2109 refname, oid, flags,
2110 prepare_fn, should_prune_fn,
2111 cleanup_fn, policy_cb_data);
2112 }
2113
2114 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2115 struct strbuf *err)
2116 {
2117 struct ref_store *refs = transaction->ref_store;
2118
2119 return refs->be->initial_transaction_commit(refs, transaction, err);
2120 }
2121
2122 int refs_delete_refs(struct ref_store *refs, const char *msg,
2123 struct string_list *refnames, unsigned int flags)
2124 {
2125 return refs->be->delete_refs(refs, msg, refnames, flags);
2126 }
2127
2128 int delete_refs(const char *msg, struct string_list *refnames,
2129 unsigned int flags)
2130 {
2131 return refs_delete_refs(get_main_ref_store(), msg, refnames, flags);
2132 }
2133
2134 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2135 const char *newref, const char *logmsg)
2136 {
2137 return refs->be->rename_ref(refs, oldref, newref, logmsg);
2138 }
2139
2140 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2141 {
2142 return refs_rename_ref(get_main_ref_store(), oldref, newref, logmsg);
2143 }
2144
2145 int refs_copy_existing_ref(struct ref_store *refs, const char *oldref,
2146 const char *newref, const char *logmsg)
2147 {
2148 return refs->be->copy_ref(refs, oldref, newref, logmsg);
2149 }
2150
2151 int copy_existing_ref(const char *oldref, const char *newref, const char *logmsg)
2152 {
2153 return refs_copy_existing_ref(get_main_ref_store(), oldref, newref, logmsg);
2154 }