Merge branch 'bb/unicode-10.0' into maint
[git/git.git] / refs.c
1 /*
2 * The backend-independent part of the reference module.
3 */
4
5 #include "cache.h"
6 #include "hashmap.h"
7 #include "lockfile.h"
8 #include "iterator.h"
9 #include "refs.h"
10 #include "refs/refs-internal.h"
11 #include "object.h"
12 #include "tag.h"
13 #include "submodule.h"
14
15 /*
16 * List of all available backends
17 */
18 static struct ref_storage_be *refs_backends = &refs_be_files;
19
20 static struct ref_storage_be *find_ref_storage_backend(const char *name)
21 {
22 struct ref_storage_be *be;
23 for (be = refs_backends; be; be = be->next)
24 if (!strcmp(be->name, name))
25 return be;
26 return NULL;
27 }
28
29 int ref_storage_backend_exists(const char *name)
30 {
31 return find_ref_storage_backend(name) != NULL;
32 }
33
34 /*
35 * How to handle various characters in refnames:
36 * 0: An acceptable character for refs
37 * 1: End-of-component
38 * 2: ., look for a preceding . to reject .. in refs
39 * 3: {, look for a preceding @ to reject @{ in refs
40 * 4: A bad character: ASCII control characters, and
41 * ":", "?", "[", "\", "^", "~", SP, or TAB
42 * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
43 */
44 static unsigned char refname_disposition[256] = {
45 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
46 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
47 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
48 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
49 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
50 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
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, 3, 0, 0, 4, 4
53 };
54
55 /*
56 * Try to read one refname component from the front of refname.
57 * Return the length of the component found, or -1 if the component is
58 * not legal. It is legal if it is something reasonable to have under
59 * ".git/refs/"; We do not like it if:
60 *
61 * - any path component of it begins with ".", or
62 * - it has double dots "..", or
63 * - it has ASCII control characters, or
64 * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
65 * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
66 * - it ends with a "/", or
67 * - it ends with ".lock", or
68 * - it contains a "@{" portion
69 */
70 static int check_refname_component(const char *refname, int *flags)
71 {
72 const char *cp;
73 char last = '\0';
74
75 for (cp = refname; ; cp++) {
76 int ch = *cp & 255;
77 unsigned char disp = refname_disposition[ch];
78 switch (disp) {
79 case 1:
80 goto out;
81 case 2:
82 if (last == '.')
83 return -1; /* Refname contains "..". */
84 break;
85 case 3:
86 if (last == '@')
87 return -1; /* Refname contains "@{". */
88 break;
89 case 4:
90 return -1;
91 case 5:
92 if (!(*flags & REFNAME_REFSPEC_PATTERN))
93 return -1; /* refspec can't be a pattern */
94
95 /*
96 * Unset the pattern flag so that we only accept
97 * a single asterisk for one side of refspec.
98 */
99 *flags &= ~ REFNAME_REFSPEC_PATTERN;
100 break;
101 }
102 last = ch;
103 }
104 out:
105 if (cp == refname)
106 return 0; /* Component has zero length. */
107 if (refname[0] == '.')
108 return -1; /* Component starts with '.'. */
109 if (cp - refname >= LOCK_SUFFIX_LEN &&
110 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
111 return -1; /* Refname ends with ".lock". */
112 return cp - refname;
113 }
114
115 int check_refname_format(const char *refname, int flags)
116 {
117 int component_len, component_count = 0;
118
119 if (!strcmp(refname, "@"))
120 /* Refname is a single character '@'. */
121 return -1;
122
123 while (1) {
124 /* We are at the start of a path component. */
125 component_len = check_refname_component(refname, &flags);
126 if (component_len <= 0)
127 return -1;
128
129 component_count++;
130 if (refname[component_len] == '\0')
131 break;
132 /* Skip to next component. */
133 refname += component_len + 1;
134 }
135
136 if (refname[component_len - 1] == '.')
137 return -1; /* Refname ends with '.'. */
138 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
139 return -1; /* Refname has only one component. */
140 return 0;
141 }
142
143 int refname_is_safe(const char *refname)
144 {
145 const char *rest;
146
147 if (skip_prefix(refname, "refs/", &rest)) {
148 char *buf;
149 int result;
150 size_t restlen = strlen(rest);
151
152 /* rest must not be empty, or start or end with "/" */
153 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
154 return 0;
155
156 /*
157 * Does the refname try to escape refs/?
158 * For example: refs/foo/../bar is safe but refs/foo/../../bar
159 * is not.
160 */
161 buf = xmallocz(restlen);
162 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
163 free(buf);
164 return result;
165 }
166
167 do {
168 if (!isupper(*refname) && *refname != '_')
169 return 0;
170 refname++;
171 } while (*refname);
172 return 1;
173 }
174
175 char *refs_resolve_refdup(struct ref_store *refs,
176 const char *refname, int resolve_flags,
177 unsigned char *sha1, int *flags)
178 {
179 const char *result;
180
181 result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
182 sha1, flags);
183 return xstrdup_or_null(result);
184 }
185
186 char *resolve_refdup(const char *refname, int resolve_flags,
187 unsigned char *sha1, int *flags)
188 {
189 return refs_resolve_refdup(get_main_ref_store(),
190 refname, resolve_flags,
191 sha1, flags);
192 }
193
194 /* The argument to filter_refs */
195 struct ref_filter {
196 const char *pattern;
197 each_ref_fn *fn;
198 void *cb_data;
199 };
200
201 int refs_read_ref_full(struct ref_store *refs, const char *refname,
202 int resolve_flags, unsigned char *sha1, int *flags)
203 {
204 if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, sha1, flags))
205 return 0;
206 return -1;
207 }
208
209 int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
210 {
211 return refs_read_ref_full(get_main_ref_store(), refname,
212 resolve_flags, sha1, flags);
213 }
214
215 int read_ref(const char *refname, unsigned char *sha1)
216 {
217 return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);
218 }
219
220 int ref_exists(const char *refname)
221 {
222 unsigned char sha1[20];
223 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);
224 }
225
226 static int filter_refs(const char *refname, const struct object_id *oid,
227 int flags, void *data)
228 {
229 struct ref_filter *filter = (struct ref_filter *)data;
230
231 if (wildmatch(filter->pattern, refname, 0, NULL))
232 return 0;
233 return filter->fn(refname, oid, flags, filter->cb_data);
234 }
235
236 enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
237 {
238 struct object *o = lookup_unknown_object(name);
239
240 if (o->type == OBJ_NONE) {
241 int type = sha1_object_info(name, NULL);
242 if (type < 0 || !object_as_type(o, type, 0))
243 return PEEL_INVALID;
244 }
245
246 if (o->type != OBJ_TAG)
247 return PEEL_NON_TAG;
248
249 o = deref_tag_noverify(o);
250 if (!o)
251 return PEEL_INVALID;
252
253 hashcpy(sha1, o->oid.hash);
254 return PEEL_PEELED;
255 }
256
257 struct warn_if_dangling_data {
258 FILE *fp;
259 const char *refname;
260 const struct string_list *refnames;
261 const char *msg_fmt;
262 };
263
264 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
265 int flags, void *cb_data)
266 {
267 struct warn_if_dangling_data *d = cb_data;
268 const char *resolves_to;
269 struct object_id junk;
270
271 if (!(flags & REF_ISSYMREF))
272 return 0;
273
274 resolves_to = resolve_ref_unsafe(refname, 0, junk.hash, NULL);
275 if (!resolves_to
276 || (d->refname
277 ? strcmp(resolves_to, d->refname)
278 : !string_list_has_string(d->refnames, resolves_to))) {
279 return 0;
280 }
281
282 fprintf(d->fp, d->msg_fmt, refname);
283 fputc('\n', d->fp);
284 return 0;
285 }
286
287 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
288 {
289 struct warn_if_dangling_data data;
290
291 data.fp = fp;
292 data.refname = refname;
293 data.refnames = NULL;
294 data.msg_fmt = msg_fmt;
295 for_each_rawref(warn_if_dangling_symref, &data);
296 }
297
298 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
299 {
300 struct warn_if_dangling_data data;
301
302 data.fp = fp;
303 data.refname = NULL;
304 data.refnames = refnames;
305 data.msg_fmt = msg_fmt;
306 for_each_rawref(warn_if_dangling_symref, &data);
307 }
308
309 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
310 {
311 return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
312 }
313
314 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
315 {
316 return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
317 }
318
319 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
320 {
321 return refs_for_each_tag_ref(get_submodule_ref_store(submodule),
322 fn, cb_data);
323 }
324
325 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
326 {
327 return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
328 }
329
330 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
331 {
332 return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
333 }
334
335 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
336 {
337 return refs_for_each_branch_ref(get_submodule_ref_store(submodule),
338 fn, cb_data);
339 }
340
341 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
342 {
343 return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
344 }
345
346 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
347 {
348 return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
349 }
350
351 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
352 {
353 return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
354 fn, cb_data);
355 }
356
357 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
358 {
359 struct strbuf buf = STRBUF_INIT;
360 int ret = 0;
361 struct object_id oid;
362 int flag;
363
364 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
365 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, oid.hash, &flag))
366 ret = fn(buf.buf, &oid, flag, cb_data);
367 strbuf_release(&buf);
368
369 return ret;
370 }
371
372 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
373 const char *prefix, void *cb_data)
374 {
375 struct strbuf real_pattern = STRBUF_INIT;
376 struct ref_filter filter;
377 int ret;
378
379 if (!prefix && !starts_with(pattern, "refs/"))
380 strbuf_addstr(&real_pattern, "refs/");
381 else if (prefix)
382 strbuf_addstr(&real_pattern, prefix);
383 strbuf_addstr(&real_pattern, pattern);
384
385 if (!has_glob_specials(pattern)) {
386 /* Append implied '/' '*' if not present. */
387 strbuf_complete(&real_pattern, '/');
388 /* No need to check for '*', there is none. */
389 strbuf_addch(&real_pattern, '*');
390 }
391
392 filter.pattern = real_pattern.buf;
393 filter.fn = fn;
394 filter.cb_data = cb_data;
395 ret = for_each_ref(filter_refs, &filter);
396
397 strbuf_release(&real_pattern);
398 return ret;
399 }
400
401 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
402 {
403 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
404 }
405
406 const char *prettify_refname(const char *name)
407 {
408 if (skip_prefix(name, "refs/heads/", &name) ||
409 skip_prefix(name, "refs/tags/", &name) ||
410 skip_prefix(name, "refs/remotes/", &name))
411 ; /* nothing */
412 return name;
413 }
414
415 static const char *ref_rev_parse_rules[] = {
416 "%.*s",
417 "refs/%.*s",
418 "refs/tags/%.*s",
419 "refs/heads/%.*s",
420 "refs/remotes/%.*s",
421 "refs/remotes/%.*s/HEAD",
422 NULL
423 };
424
425 int refname_match(const char *abbrev_name, const char *full_name)
426 {
427 const char **p;
428 const int abbrev_name_len = strlen(abbrev_name);
429
430 for (p = ref_rev_parse_rules; *p; p++) {
431 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
432 return 1;
433 }
434 }
435
436 return 0;
437 }
438
439 /*
440 * *string and *len will only be substituted, and *string returned (for
441 * later free()ing) if the string passed in is a magic short-hand form
442 * to name a branch.
443 */
444 static char *substitute_branch_name(const char **string, int *len)
445 {
446 struct strbuf buf = STRBUF_INIT;
447 int ret = interpret_branch_name(*string, *len, &buf, 0);
448
449 if (ret == *len) {
450 size_t size;
451 *string = strbuf_detach(&buf, &size);
452 *len = size;
453 return (char *)*string;
454 }
455
456 return NULL;
457 }
458
459 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
460 {
461 char *last_branch = substitute_branch_name(&str, &len);
462 int refs_found = expand_ref(str, len, sha1, ref);
463 free(last_branch);
464 return refs_found;
465 }
466
467 int expand_ref(const char *str, int len, unsigned char *sha1, char **ref)
468 {
469 const char **p, *r;
470 int refs_found = 0;
471 struct strbuf fullref = STRBUF_INIT;
472
473 *ref = NULL;
474 for (p = ref_rev_parse_rules; *p; p++) {
475 unsigned char sha1_from_ref[20];
476 unsigned char *this_result;
477 int flag;
478
479 this_result = refs_found ? sha1_from_ref : sha1;
480 strbuf_reset(&fullref);
481 strbuf_addf(&fullref, *p, len, str);
482 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
483 this_result, &flag);
484 if (r) {
485 if (!refs_found++)
486 *ref = xstrdup(r);
487 if (!warn_ambiguous_refs)
488 break;
489 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
490 warning("ignoring dangling symref %s.", fullref.buf);
491 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
492 warning("ignoring broken ref %s.", fullref.buf);
493 }
494 }
495 strbuf_release(&fullref);
496 return refs_found;
497 }
498
499 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
500 {
501 char *last_branch = substitute_branch_name(&str, &len);
502 const char **p;
503 int logs_found = 0;
504 struct strbuf path = STRBUF_INIT;
505
506 *log = NULL;
507 for (p = ref_rev_parse_rules; *p; p++) {
508 unsigned char hash[20];
509 const char *ref, *it;
510
511 strbuf_reset(&path);
512 strbuf_addf(&path, *p, len, str);
513 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
514 hash, NULL);
515 if (!ref)
516 continue;
517 if (reflog_exists(path.buf))
518 it = path.buf;
519 else if (strcmp(ref, path.buf) && reflog_exists(ref))
520 it = ref;
521 else
522 continue;
523 if (!logs_found++) {
524 *log = xstrdup(it);
525 hashcpy(sha1, hash);
526 }
527 if (!warn_ambiguous_refs)
528 break;
529 }
530 strbuf_release(&path);
531 free(last_branch);
532 return logs_found;
533 }
534
535 static int is_per_worktree_ref(const char *refname)
536 {
537 return !strcmp(refname, "HEAD") ||
538 starts_with(refname, "refs/bisect/");
539 }
540
541 static int is_pseudoref_syntax(const char *refname)
542 {
543 const char *c;
544
545 for (c = refname; *c; c++) {
546 if (!isupper(*c) && *c != '-' && *c != '_')
547 return 0;
548 }
549
550 return 1;
551 }
552
553 enum ref_type ref_type(const char *refname)
554 {
555 if (is_per_worktree_ref(refname))
556 return REF_TYPE_PER_WORKTREE;
557 if (is_pseudoref_syntax(refname))
558 return REF_TYPE_PSEUDOREF;
559 return REF_TYPE_NORMAL;
560 }
561
562 static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
563 const unsigned char *old_sha1, struct strbuf *err)
564 {
565 const char *filename;
566 int fd;
567 static struct lock_file lock;
568 struct strbuf buf = STRBUF_INIT;
569 int ret = -1;
570
571 strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
572
573 filename = git_path("%s", pseudoref);
574 fd = hold_lock_file_for_update(&lock, filename, LOCK_DIE_ON_ERROR);
575 if (fd < 0) {
576 strbuf_addf(err, "could not open '%s' for writing: %s",
577 filename, strerror(errno));
578 return -1;
579 }
580
581 if (old_sha1) {
582 unsigned char actual_old_sha1[20];
583
584 if (read_ref(pseudoref, actual_old_sha1))
585 die("could not read ref '%s'", pseudoref);
586 if (hashcmp(actual_old_sha1, old_sha1)) {
587 strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
588 rollback_lock_file(&lock);
589 goto done;
590 }
591 }
592
593 if (write_in_full(fd, buf.buf, buf.len) != buf.len) {
594 strbuf_addf(err, "could not write to '%s'", filename);
595 rollback_lock_file(&lock);
596 goto done;
597 }
598
599 commit_lock_file(&lock);
600 ret = 0;
601 done:
602 strbuf_release(&buf);
603 return ret;
604 }
605
606 static int delete_pseudoref(const char *pseudoref, const unsigned char *old_sha1)
607 {
608 static struct lock_file lock;
609 const char *filename;
610
611 filename = git_path("%s", pseudoref);
612
613 if (old_sha1 && !is_null_sha1(old_sha1)) {
614 int fd;
615 unsigned char actual_old_sha1[20];
616
617 fd = hold_lock_file_for_update(&lock, filename,
618 LOCK_DIE_ON_ERROR);
619 if (fd < 0)
620 die_errno(_("Could not open '%s' for writing"), filename);
621 if (read_ref(pseudoref, actual_old_sha1))
622 die("could not read ref '%s'", pseudoref);
623 if (hashcmp(actual_old_sha1, old_sha1)) {
624 warning("Unexpected sha1 when deleting %s", pseudoref);
625 rollback_lock_file(&lock);
626 return -1;
627 }
628
629 unlink(filename);
630 rollback_lock_file(&lock);
631 } else {
632 unlink(filename);
633 }
634
635 return 0;
636 }
637
638 int refs_delete_ref(struct ref_store *refs, const char *msg,
639 const char *refname,
640 const unsigned char *old_sha1,
641 unsigned int flags)
642 {
643 struct ref_transaction *transaction;
644 struct strbuf err = STRBUF_INIT;
645
646 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
647 assert(refs == get_main_ref_store());
648 return delete_pseudoref(refname, old_sha1);
649 }
650
651 transaction = ref_store_transaction_begin(refs, &err);
652 if (!transaction ||
653 ref_transaction_delete(transaction, refname, old_sha1,
654 flags, msg, &err) ||
655 ref_transaction_commit(transaction, &err)) {
656 error("%s", err.buf);
657 ref_transaction_free(transaction);
658 strbuf_release(&err);
659 return 1;
660 }
661 ref_transaction_free(transaction);
662 strbuf_release(&err);
663 return 0;
664 }
665
666 int delete_ref(const char *msg, const char *refname,
667 const unsigned char *old_sha1, unsigned int flags)
668 {
669 return refs_delete_ref(get_main_ref_store(), msg, refname,
670 old_sha1, flags);
671 }
672
673 int copy_reflog_msg(char *buf, const char *msg)
674 {
675 char *cp = buf;
676 char c;
677 int wasspace = 1;
678
679 *cp++ = '\t';
680 while ((c = *msg++)) {
681 if (wasspace && isspace(c))
682 continue;
683 wasspace = isspace(c);
684 if (wasspace)
685 c = ' ';
686 *cp++ = c;
687 }
688 while (buf < cp && isspace(cp[-1]))
689 cp--;
690 *cp++ = '\n';
691 return cp - buf;
692 }
693
694 int should_autocreate_reflog(const char *refname)
695 {
696 switch (log_all_ref_updates) {
697 case LOG_REFS_ALWAYS:
698 return 1;
699 case LOG_REFS_NORMAL:
700 return starts_with(refname, "refs/heads/") ||
701 starts_with(refname, "refs/remotes/") ||
702 starts_with(refname, "refs/notes/") ||
703 !strcmp(refname, "HEAD");
704 default:
705 return 0;
706 }
707 }
708
709 int is_branch(const char *refname)
710 {
711 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
712 }
713
714 struct read_ref_at_cb {
715 const char *refname;
716 unsigned long at_time;
717 int cnt;
718 int reccnt;
719 unsigned char *sha1;
720 int found_it;
721
722 unsigned char osha1[20];
723 unsigned char nsha1[20];
724 int tz;
725 unsigned long date;
726 char **msg;
727 unsigned long *cutoff_time;
728 int *cutoff_tz;
729 int *cutoff_cnt;
730 };
731
732 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
733 const char *email, unsigned long timestamp, int tz,
734 const char *message, void *cb_data)
735 {
736 struct read_ref_at_cb *cb = cb_data;
737
738 cb->reccnt++;
739 cb->tz = tz;
740 cb->date = timestamp;
741
742 if (timestamp <= cb->at_time || cb->cnt == 0) {
743 if (cb->msg)
744 *cb->msg = xstrdup(message);
745 if (cb->cutoff_time)
746 *cb->cutoff_time = timestamp;
747 if (cb->cutoff_tz)
748 *cb->cutoff_tz = tz;
749 if (cb->cutoff_cnt)
750 *cb->cutoff_cnt = cb->reccnt - 1;
751 /*
752 * we have not yet updated cb->[n|o]sha1 so they still
753 * hold the values for the previous record.
754 */
755 if (!is_null_sha1(cb->osha1)) {
756 hashcpy(cb->sha1, noid->hash);
757 if (hashcmp(cb->osha1, noid->hash))
758 warning("Log for ref %s has gap after %s.",
759 cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
760 }
761 else if (cb->date == cb->at_time)
762 hashcpy(cb->sha1, noid->hash);
763 else if (hashcmp(noid->hash, cb->sha1))
764 warning("Log for ref %s unexpectedly ended on %s.",
765 cb->refname, show_date(cb->date, cb->tz,
766 DATE_MODE(RFC2822)));
767 hashcpy(cb->osha1, ooid->hash);
768 hashcpy(cb->nsha1, noid->hash);
769 cb->found_it = 1;
770 return 1;
771 }
772 hashcpy(cb->osha1, ooid->hash);
773 hashcpy(cb->nsha1, noid->hash);
774 if (cb->cnt > 0)
775 cb->cnt--;
776 return 0;
777 }
778
779 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
780 const char *email, unsigned long timestamp,
781 int tz, const char *message, void *cb_data)
782 {
783 struct read_ref_at_cb *cb = cb_data;
784
785 if (cb->msg)
786 *cb->msg = xstrdup(message);
787 if (cb->cutoff_time)
788 *cb->cutoff_time = timestamp;
789 if (cb->cutoff_tz)
790 *cb->cutoff_tz = tz;
791 if (cb->cutoff_cnt)
792 *cb->cutoff_cnt = cb->reccnt;
793 hashcpy(cb->sha1, ooid->hash);
794 if (is_null_sha1(cb->sha1))
795 hashcpy(cb->sha1, noid->hash);
796 /* We just want the first entry */
797 return 1;
798 }
799
800 int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt,
801 unsigned char *sha1, char **msg,
802 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
803 {
804 struct read_ref_at_cb cb;
805
806 memset(&cb, 0, sizeof(cb));
807 cb.refname = refname;
808 cb.at_time = at_time;
809 cb.cnt = cnt;
810 cb.msg = msg;
811 cb.cutoff_time = cutoff_time;
812 cb.cutoff_tz = cutoff_tz;
813 cb.cutoff_cnt = cutoff_cnt;
814 cb.sha1 = sha1;
815
816 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
817
818 if (!cb.reccnt) {
819 if (flags & GET_SHA1_QUIETLY)
820 exit(128);
821 else
822 die("Log for %s is empty.", refname);
823 }
824 if (cb.found_it)
825 return 0;
826
827 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
828
829 return 1;
830 }
831
832 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
833 struct strbuf *err)
834 {
835 struct ref_transaction *tr;
836 assert(err);
837
838 tr = xcalloc(1, sizeof(struct ref_transaction));
839 tr->ref_store = refs;
840 return tr;
841 }
842
843 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
844 {
845 return ref_store_transaction_begin(get_main_ref_store(), err);
846 }
847
848 void ref_transaction_free(struct ref_transaction *transaction)
849 {
850 int i;
851
852 if (!transaction)
853 return;
854
855 for (i = 0; i < transaction->nr; i++) {
856 free(transaction->updates[i]->msg);
857 free(transaction->updates[i]);
858 }
859 free(transaction->updates);
860 free(transaction);
861 }
862
863 struct ref_update *ref_transaction_add_update(
864 struct ref_transaction *transaction,
865 const char *refname, unsigned int flags,
866 const unsigned char *new_sha1,
867 const unsigned char *old_sha1,
868 const char *msg)
869 {
870 struct ref_update *update;
871
872 if (transaction->state != REF_TRANSACTION_OPEN)
873 die("BUG: update called for transaction that is not open");
874
875 if ((flags & REF_ISPRUNING) && !(flags & REF_NODEREF))
876 die("BUG: REF_ISPRUNING set without REF_NODEREF");
877
878 FLEX_ALLOC_STR(update, refname, refname);
879 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
880 transaction->updates[transaction->nr++] = update;
881
882 update->flags = flags;
883
884 if (flags & REF_HAVE_NEW)
885 hashcpy(update->new_sha1, new_sha1);
886 if (flags & REF_HAVE_OLD)
887 hashcpy(update->old_sha1, old_sha1);
888 update->msg = xstrdup_or_null(msg);
889 return update;
890 }
891
892 int ref_transaction_update(struct ref_transaction *transaction,
893 const char *refname,
894 const unsigned char *new_sha1,
895 const unsigned char *old_sha1,
896 unsigned int flags, const char *msg,
897 struct strbuf *err)
898 {
899 assert(err);
900
901 if ((new_sha1 && !is_null_sha1(new_sha1)) ?
902 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
903 !refname_is_safe(refname)) {
904 strbuf_addf(err, "refusing to update ref with bad name '%s'",
905 refname);
906 return -1;
907 }
908
909 flags |= (new_sha1 ? REF_HAVE_NEW : 0) | (old_sha1 ? REF_HAVE_OLD : 0);
910
911 ref_transaction_add_update(transaction, refname, flags,
912 new_sha1, old_sha1, msg);
913 return 0;
914 }
915
916 int ref_transaction_create(struct ref_transaction *transaction,
917 const char *refname,
918 const unsigned char *new_sha1,
919 unsigned int flags, const char *msg,
920 struct strbuf *err)
921 {
922 if (!new_sha1 || is_null_sha1(new_sha1))
923 die("BUG: create called without valid new_sha1");
924 return ref_transaction_update(transaction, refname, new_sha1,
925 null_sha1, flags, msg, err);
926 }
927
928 int ref_transaction_delete(struct ref_transaction *transaction,
929 const char *refname,
930 const unsigned char *old_sha1,
931 unsigned int flags, const char *msg,
932 struct strbuf *err)
933 {
934 if (old_sha1 && is_null_sha1(old_sha1))
935 die("BUG: delete called with old_sha1 set to zeros");
936 return ref_transaction_update(transaction, refname,
937 null_sha1, old_sha1,
938 flags, msg, err);
939 }
940
941 int ref_transaction_verify(struct ref_transaction *transaction,
942 const char *refname,
943 const unsigned char *old_sha1,
944 unsigned int flags,
945 struct strbuf *err)
946 {
947 if (!old_sha1)
948 die("BUG: verify called with old_sha1 set to NULL");
949 return ref_transaction_update(transaction, refname,
950 NULL, old_sha1,
951 flags, NULL, err);
952 }
953
954 int update_ref_oid(const char *msg, const char *refname,
955 const struct object_id *new_oid, const struct object_id *old_oid,
956 unsigned int flags, enum action_on_err onerr)
957 {
958 return update_ref(msg, refname, new_oid ? new_oid->hash : NULL,
959 old_oid ? old_oid->hash : NULL, flags, onerr);
960 }
961
962 int refs_update_ref(struct ref_store *refs, const char *msg,
963 const char *refname, const unsigned char *new_sha1,
964 const unsigned char *old_sha1, unsigned int flags,
965 enum action_on_err onerr)
966 {
967 struct ref_transaction *t = NULL;
968 struct strbuf err = STRBUF_INIT;
969 int ret = 0;
970
971 if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
972 assert(refs == get_main_ref_store());
973 ret = write_pseudoref(refname, new_sha1, old_sha1, &err);
974 } else {
975 t = ref_store_transaction_begin(refs, &err);
976 if (!t ||
977 ref_transaction_update(t, refname, new_sha1, old_sha1,
978 flags, msg, &err) ||
979 ref_transaction_commit(t, &err)) {
980 ret = 1;
981 ref_transaction_free(t);
982 }
983 }
984 if (ret) {
985 const char *str = "update_ref failed for ref '%s': %s";
986
987 switch (onerr) {
988 case UPDATE_REFS_MSG_ON_ERR:
989 error(str, refname, err.buf);
990 break;
991 case UPDATE_REFS_DIE_ON_ERR:
992 die(str, refname, err.buf);
993 break;
994 case UPDATE_REFS_QUIET_ON_ERR:
995 break;
996 }
997 strbuf_release(&err);
998 return 1;
999 }
1000 strbuf_release(&err);
1001 if (t)
1002 ref_transaction_free(t);
1003 return 0;
1004 }
1005
1006 int update_ref(const char *msg, const char *refname,
1007 const unsigned char *new_sha1,
1008 const unsigned char *old_sha1,
1009 unsigned int flags, enum action_on_err onerr)
1010 {
1011 return refs_update_ref(get_main_ref_store(), msg, refname, new_sha1,
1012 old_sha1, flags, onerr);
1013 }
1014
1015 char *shorten_unambiguous_ref(const char *refname, int strict)
1016 {
1017 int i;
1018 static char **scanf_fmts;
1019 static int nr_rules;
1020 char *short_name;
1021 struct strbuf resolved_buf = STRBUF_INIT;
1022
1023 if (!nr_rules) {
1024 /*
1025 * Pre-generate scanf formats from ref_rev_parse_rules[].
1026 * Generate a format suitable for scanf from a
1027 * ref_rev_parse_rules rule by interpolating "%s" at the
1028 * location of the "%.*s".
1029 */
1030 size_t total_len = 0;
1031 size_t offset = 0;
1032
1033 /* the rule list is NULL terminated, count them first */
1034 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1035 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1036 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1037
1038 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1039
1040 offset = 0;
1041 for (i = 0; i < nr_rules; i++) {
1042 assert(offset < total_len);
1043 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1044 offset += snprintf(scanf_fmts[i], total_len - offset,
1045 ref_rev_parse_rules[i], 2, "%s") + 1;
1046 }
1047 }
1048
1049 /* bail out if there are no rules */
1050 if (!nr_rules)
1051 return xstrdup(refname);
1052
1053 /* buffer for scanf result, at most refname must fit */
1054 short_name = xstrdup(refname);
1055
1056 /* skip first rule, it will always match */
1057 for (i = nr_rules - 1; i > 0 ; --i) {
1058 int j;
1059 int rules_to_fail = i;
1060 int short_name_len;
1061
1062 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1063 continue;
1064
1065 short_name_len = strlen(short_name);
1066
1067 /*
1068 * in strict mode, all (except the matched one) rules
1069 * must fail to resolve to a valid non-ambiguous ref
1070 */
1071 if (strict)
1072 rules_to_fail = nr_rules;
1073
1074 /*
1075 * check if the short name resolves to a valid ref,
1076 * but use only rules prior to the matched one
1077 */
1078 for (j = 0; j < rules_to_fail; j++) {
1079 const char *rule = ref_rev_parse_rules[j];
1080
1081 /* skip matched rule */
1082 if (i == j)
1083 continue;
1084
1085 /*
1086 * the short name is ambiguous, if it resolves
1087 * (with this previous rule) to a valid ref
1088 * read_ref() returns 0 on success
1089 */
1090 strbuf_reset(&resolved_buf);
1091 strbuf_addf(&resolved_buf, rule,
1092 short_name_len, short_name);
1093 if (ref_exists(resolved_buf.buf))
1094 break;
1095 }
1096
1097 /*
1098 * short name is non-ambiguous if all previous rules
1099 * haven't resolved to a valid ref
1100 */
1101 if (j == rules_to_fail) {
1102 strbuf_release(&resolved_buf);
1103 return short_name;
1104 }
1105 }
1106
1107 strbuf_release(&resolved_buf);
1108 free(short_name);
1109 return xstrdup(refname);
1110 }
1111
1112 static struct string_list *hide_refs;
1113
1114 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1115 {
1116 const char *key;
1117 if (!strcmp("transfer.hiderefs", var) ||
1118 (!parse_config_key(var, section, NULL, NULL, &key) &&
1119 !strcmp(key, "hiderefs"))) {
1120 char *ref;
1121 int len;
1122
1123 if (!value)
1124 return config_error_nonbool(var);
1125 ref = xstrdup(value);
1126 len = strlen(ref);
1127 while (len && ref[len - 1] == '/')
1128 ref[--len] = '\0';
1129 if (!hide_refs) {
1130 hide_refs = xcalloc(1, sizeof(*hide_refs));
1131 hide_refs->strdup_strings = 1;
1132 }
1133 string_list_append(hide_refs, ref);
1134 }
1135 return 0;
1136 }
1137
1138 int ref_is_hidden(const char *refname, const char *refname_full)
1139 {
1140 int i;
1141
1142 if (!hide_refs)
1143 return 0;
1144 for (i = hide_refs->nr - 1; i >= 0; i--) {
1145 const char *match = hide_refs->items[i].string;
1146 const char *subject;
1147 int neg = 0;
1148 int len;
1149
1150 if (*match == '!') {
1151 neg = 1;
1152 match++;
1153 }
1154
1155 if (*match == '^') {
1156 subject = refname_full;
1157 match++;
1158 } else {
1159 subject = refname;
1160 }
1161
1162 /* refname can be NULL when namespaces are used. */
1163 if (!subject || !starts_with(subject, match))
1164 continue;
1165 len = strlen(match);
1166 if (!subject[len] || subject[len] == '/')
1167 return !neg;
1168 }
1169 return 0;
1170 }
1171
1172 const char *find_descendant_ref(const char *dirname,
1173 const struct string_list *extras,
1174 const struct string_list *skip)
1175 {
1176 int pos;
1177
1178 if (!extras)
1179 return NULL;
1180
1181 /*
1182 * Look at the place where dirname would be inserted into
1183 * extras. If there is an entry at that position that starts
1184 * with dirname (remember, dirname includes the trailing
1185 * slash) and is not in skip, then we have a conflict.
1186 */
1187 for (pos = string_list_find_insert_index(extras, dirname, 0);
1188 pos < extras->nr; pos++) {
1189 const char *extra_refname = extras->items[pos].string;
1190
1191 if (!starts_with(extra_refname, dirname))
1192 break;
1193
1194 if (!skip || !string_list_has_string(skip, extra_refname))
1195 return extra_refname;
1196 }
1197 return NULL;
1198 }
1199
1200 int refs_rename_ref_available(struct ref_store *refs,
1201 const char *old_refname,
1202 const char *new_refname)
1203 {
1204 struct string_list skip = STRING_LIST_INIT_NODUP;
1205 struct strbuf err = STRBUF_INIT;
1206 int ok;
1207
1208 string_list_insert(&skip, old_refname);
1209 ok = !refs_verify_refname_available(refs, new_refname,
1210 NULL, &skip, &err);
1211 if (!ok)
1212 error("%s", err.buf);
1213
1214 string_list_clear(&skip, 0);
1215 strbuf_release(&err);
1216 return ok;
1217 }
1218
1219 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1220 {
1221 struct object_id oid;
1222 int flag;
1223
1224 if (submodule) {
1225 if (resolve_gitlink_ref(submodule, "HEAD", oid.hash) == 0)
1226 return fn("HEAD", &oid, 0, cb_data);
1227
1228 return 0;
1229 }
1230
1231 if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag))
1232 return fn("HEAD", &oid, flag, cb_data);
1233
1234 return 0;
1235 }
1236
1237 int head_ref(each_ref_fn fn, void *cb_data)
1238 {
1239 return head_ref_submodule(NULL, fn, cb_data);
1240 }
1241
1242 struct ref_iterator *refs_ref_iterator_begin(
1243 struct ref_store *refs,
1244 const char *prefix, int trim, int flags)
1245 {
1246 struct ref_iterator *iter;
1247
1248 iter = refs->be->iterator_begin(refs, prefix, flags);
1249 iter = prefix_ref_iterator_begin(iter, prefix, trim);
1250
1251 return iter;
1252 }
1253
1254 /*
1255 * Call fn for each reference in the specified submodule for which the
1256 * refname begins with prefix. If trim is non-zero, then trim that
1257 * many characters off the beginning of each refname before passing
1258 * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1259 * include broken references in the iteration. If fn ever returns a
1260 * non-zero value, stop the iteration and return that value;
1261 * otherwise, return 0.
1262 */
1263 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1264 each_ref_fn fn, int trim, int flags, void *cb_data)
1265 {
1266 struct ref_iterator *iter;
1267
1268 if (!refs)
1269 return 0;
1270
1271 iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1272
1273 return do_for_each_ref_iterator(iter, fn, cb_data);
1274 }
1275
1276 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1277 {
1278 return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1279 }
1280
1281 int for_each_ref(each_ref_fn fn, void *cb_data)
1282 {
1283 return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
1284 }
1285
1286 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1287 {
1288 return refs_for_each_ref(get_submodule_ref_store(submodule), fn, cb_data);
1289 }
1290
1291 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1292 each_ref_fn fn, void *cb_data)
1293 {
1294 return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1295 }
1296
1297 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1298 {
1299 return refs_for_each_ref_in(get_main_ref_store(), prefix, fn, cb_data);
1300 }
1301
1302 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1303 {
1304 unsigned int flag = 0;
1305
1306 if (broken)
1307 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1308 return do_for_each_ref(get_main_ref_store(),
1309 prefix, fn, 0, flag, cb_data);
1310 }
1311
1312 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1313 each_ref_fn fn, void *cb_data)
1314 {
1315 return refs_for_each_ref_in(get_submodule_ref_store(submodule),
1316 prefix, fn, cb_data);
1317 }
1318
1319 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1320 {
1321 return do_for_each_ref(get_main_ref_store(),
1322 git_replace_ref_base, fn,
1323 strlen(git_replace_ref_base),
1324 0, cb_data);
1325 }
1326
1327 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1328 {
1329 struct strbuf buf = STRBUF_INIT;
1330 int ret;
1331 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1332 ret = do_for_each_ref(get_main_ref_store(),
1333 buf.buf, fn, 0, 0, cb_data);
1334 strbuf_release(&buf);
1335 return ret;
1336 }
1337
1338 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1339 {
1340 return do_for_each_ref(refs, "", fn, 0,
1341 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1342 }
1343
1344 int for_each_rawref(each_ref_fn fn, void *cb_data)
1345 {
1346 return refs_for_each_rawref(get_main_ref_store(), fn, cb_data);
1347 }
1348
1349 int refs_read_raw_ref(struct ref_store *ref_store,
1350 const char *refname, unsigned char *sha1,
1351 struct strbuf *referent, unsigned int *type)
1352 {
1353 return ref_store->be->read_raw_ref(ref_store, refname, sha1, referent, type);
1354 }
1355
1356 /* This function needs to return a meaningful errno on failure */
1357 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1358 const char *refname,
1359 int resolve_flags,
1360 unsigned char *sha1, int *flags)
1361 {
1362 static struct strbuf sb_refname = STRBUF_INIT;
1363 int unused_flags;
1364 int symref_count;
1365
1366 if (!flags)
1367 flags = &unused_flags;
1368
1369 *flags = 0;
1370
1371 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1372 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1373 !refname_is_safe(refname)) {
1374 errno = EINVAL;
1375 return NULL;
1376 }
1377
1378 /*
1379 * dwim_ref() uses REF_ISBROKEN to distinguish between
1380 * missing refs and refs that were present but invalid,
1381 * to complain about the latter to stderr.
1382 *
1383 * We don't know whether the ref exists, so don't set
1384 * REF_ISBROKEN yet.
1385 */
1386 *flags |= REF_BAD_NAME;
1387 }
1388
1389 for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1390 unsigned int read_flags = 0;
1391
1392 if (refs_read_raw_ref(refs, refname,
1393 sha1, &sb_refname, &read_flags)) {
1394 *flags |= read_flags;
1395 if (errno != ENOENT || (resolve_flags & RESOLVE_REF_READING))
1396 return NULL;
1397 hashclr(sha1);
1398 if (*flags & REF_BAD_NAME)
1399 *flags |= REF_ISBROKEN;
1400 return refname;
1401 }
1402
1403 *flags |= read_flags;
1404
1405 if (!(read_flags & REF_ISSYMREF)) {
1406 if (*flags & REF_BAD_NAME) {
1407 hashclr(sha1);
1408 *flags |= REF_ISBROKEN;
1409 }
1410 return refname;
1411 }
1412
1413 refname = sb_refname.buf;
1414 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1415 hashclr(sha1);
1416 return refname;
1417 }
1418 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1419 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1420 !refname_is_safe(refname)) {
1421 errno = EINVAL;
1422 return NULL;
1423 }
1424
1425 *flags |= REF_ISBROKEN | REF_BAD_NAME;
1426 }
1427 }
1428
1429 errno = ELOOP;
1430 return NULL;
1431 }
1432
1433 /* backend functions */
1434 int refs_init_db(struct strbuf *err)
1435 {
1436 struct ref_store *refs = get_main_ref_store();
1437
1438 return refs->be->init_db(refs, err);
1439 }
1440
1441 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1442 unsigned char *sha1, int *flags)
1443 {
1444 return refs_resolve_ref_unsafe(get_main_ref_store(), refname,
1445 resolve_flags, sha1, flags);
1446 }
1447
1448 int resolve_gitlink_ref(const char *submodule, const char *refname,
1449 unsigned char *sha1)
1450 {
1451 size_t len = strlen(submodule);
1452 struct ref_store *refs;
1453 int flags;
1454
1455 while (len && submodule[len - 1] == '/')
1456 len--;
1457
1458 if (!len)
1459 return -1;
1460
1461 if (submodule[len]) {
1462 /* We need to strip off one or more trailing slashes */
1463 char *stripped = xmemdupz(submodule, len);
1464
1465 refs = get_submodule_ref_store(stripped);
1466 free(stripped);
1467 } else {
1468 refs = get_submodule_ref_store(submodule);
1469 }
1470
1471 if (!refs)
1472 return -1;
1473
1474 if (!refs_resolve_ref_unsafe(refs, refname, 0, sha1, &flags) ||
1475 is_null_sha1(sha1))
1476 return -1;
1477 return 0;
1478 }
1479
1480 struct submodule_hash_entry
1481 {
1482 struct hashmap_entry ent; /* must be the first member! */
1483
1484 struct ref_store *refs;
1485
1486 /* NUL-terminated name of submodule: */
1487 char submodule[FLEX_ARRAY];
1488 };
1489
1490 static int submodule_hash_cmp(const void *entry, const void *entry_or_key,
1491 const void *keydata)
1492 {
1493 const struct submodule_hash_entry *e1 = entry, *e2 = entry_or_key;
1494 const char *submodule = keydata ? keydata : e2->submodule;
1495
1496 return strcmp(e1->submodule, submodule);
1497 }
1498
1499 static struct submodule_hash_entry *alloc_submodule_hash_entry(
1500 const char *submodule, struct ref_store *refs)
1501 {
1502 struct submodule_hash_entry *entry;
1503
1504 FLEX_ALLOC_STR(entry, submodule, submodule);
1505 hashmap_entry_init(entry, strhash(submodule));
1506 entry->refs = refs;
1507 return entry;
1508 }
1509
1510 /* A pointer to the ref_store for the main repository: */
1511 static struct ref_store *main_ref_store;
1512
1513 /* A hashmap of ref_stores, stored by submodule name: */
1514 static struct hashmap submodule_ref_stores;
1515
1516 /*
1517 * Return the ref_store instance for the specified submodule. If that
1518 * ref_store hasn't been initialized yet, return NULL.
1519 */
1520 static struct ref_store *lookup_submodule_ref_store(const char *submodule)
1521 {
1522 struct submodule_hash_entry *entry;
1523
1524 if (!submodule_ref_stores.tablesize)
1525 /* It's initialized on demand in register_ref_store(). */
1526 return NULL;
1527
1528 entry = hashmap_get_from_hash(&submodule_ref_stores,
1529 strhash(submodule), submodule);
1530 return entry ? entry->refs : NULL;
1531 }
1532
1533 /*
1534 * Create, record, and return a ref_store instance for the specified
1535 * gitdir.
1536 */
1537 static struct ref_store *ref_store_init(const char *gitdir,
1538 unsigned int flags)
1539 {
1540 const char *be_name = "files";
1541 struct ref_storage_be *be = find_ref_storage_backend(be_name);
1542 struct ref_store *refs;
1543
1544 if (!be)
1545 die("BUG: reference backend %s is unknown", be_name);
1546
1547 refs = be->init(gitdir, flags);
1548 return refs;
1549 }
1550
1551 struct ref_store *get_main_ref_store(void)
1552 {
1553 if (main_ref_store)
1554 return main_ref_store;
1555
1556 main_ref_store = ref_store_init(get_git_dir(),
1557 (REF_STORE_READ |
1558 REF_STORE_WRITE |
1559 REF_STORE_ODB |
1560 REF_STORE_MAIN));
1561 return main_ref_store;
1562 }
1563
1564 /*
1565 * Register the specified ref_store to be the one that should be used
1566 * for submodule. It is a fatal error to call this function twice for
1567 * the same submodule.
1568 */
1569 static void register_submodule_ref_store(struct ref_store *refs,
1570 const char *submodule)
1571 {
1572 if (!submodule_ref_stores.tablesize)
1573 hashmap_init(&submodule_ref_stores, submodule_hash_cmp, 0);
1574
1575 if (hashmap_put(&submodule_ref_stores,
1576 alloc_submodule_hash_entry(submodule, refs)))
1577 die("BUG: ref_store for submodule '%s' initialized twice",
1578 submodule);
1579 }
1580
1581 struct ref_store *get_submodule_ref_store(const char *submodule)
1582 {
1583 struct strbuf submodule_sb = STRBUF_INIT;
1584 struct ref_store *refs;
1585 int ret;
1586
1587 if (!submodule || !*submodule) {
1588 /*
1589 * FIXME: This case is ideally not allowed. But that
1590 * can't happen until we clean up all the callers.
1591 */
1592 return get_main_ref_store();
1593 }
1594
1595 refs = lookup_submodule_ref_store(submodule);
1596 if (refs)
1597 return refs;
1598
1599 strbuf_addstr(&submodule_sb, submodule);
1600 ret = is_nonbare_repository_dir(&submodule_sb);
1601 strbuf_release(&submodule_sb);
1602 if (!ret)
1603 return NULL;
1604
1605 ret = submodule_to_gitdir(&submodule_sb, submodule);
1606 if (ret) {
1607 strbuf_release(&submodule_sb);
1608 return NULL;
1609 }
1610
1611 /* assume that add_submodule_odb() has been called */
1612 refs = ref_store_init(submodule_sb.buf,
1613 REF_STORE_READ | REF_STORE_ODB);
1614 register_submodule_ref_store(refs, submodule);
1615
1616 strbuf_release(&submodule_sb);
1617 return refs;
1618 }
1619
1620 void base_ref_store_init(struct ref_store *refs,
1621 const struct ref_storage_be *be)
1622 {
1623 refs->be = be;
1624 }
1625
1626 /* backend functions */
1627 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1628 {
1629 return refs->be->pack_refs(refs, flags);
1630 }
1631
1632 int refs_peel_ref(struct ref_store *refs, const char *refname,
1633 unsigned char *sha1)
1634 {
1635 return refs->be->peel_ref(refs, refname, sha1);
1636 }
1637
1638 int peel_ref(const char *refname, unsigned char *sha1)
1639 {
1640 return refs_peel_ref(get_main_ref_store(), refname, sha1);
1641 }
1642
1643 int refs_create_symref(struct ref_store *refs,
1644 const char *ref_target,
1645 const char *refs_heads_master,
1646 const char *logmsg)
1647 {
1648 return refs->be->create_symref(refs, ref_target,
1649 refs_heads_master,
1650 logmsg);
1651 }
1652
1653 int create_symref(const char *ref_target, const char *refs_heads_master,
1654 const char *logmsg)
1655 {
1656 return refs_create_symref(get_main_ref_store(), ref_target,
1657 refs_heads_master, logmsg);
1658 }
1659
1660 int ref_transaction_commit(struct ref_transaction *transaction,
1661 struct strbuf *err)
1662 {
1663 struct ref_store *refs = transaction->ref_store;
1664
1665 if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1666 strbuf_addstr(err,
1667 _("ref updates forbidden inside quarantine environment"));
1668 return -1;
1669 }
1670
1671 return refs->be->transaction_commit(refs, transaction, err);
1672 }
1673
1674 int refs_verify_refname_available(struct ref_store *refs,
1675 const char *refname,
1676 const struct string_list *extras,
1677 const struct string_list *skip,
1678 struct strbuf *err)
1679 {
1680 const char *slash;
1681 const char *extra_refname;
1682 struct strbuf dirname = STRBUF_INIT;
1683 struct strbuf referent = STRBUF_INIT;
1684 struct object_id oid;
1685 unsigned int type;
1686 struct ref_iterator *iter;
1687 int ok;
1688 int ret = -1;
1689
1690 /*
1691 * For the sake of comments in this function, suppose that
1692 * refname is "refs/foo/bar".
1693 */
1694
1695 assert(err);
1696
1697 strbuf_grow(&dirname, strlen(refname) + 1);
1698 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1699 /* Expand dirname to the new prefix, not including the trailing slash: */
1700 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1701
1702 /*
1703 * We are still at a leading dir of the refname (e.g.,
1704 * "refs/foo"; if there is a reference with that name,
1705 * it is a conflict, *unless* it is in skip.
1706 */
1707 if (skip && string_list_has_string(skip, dirname.buf))
1708 continue;
1709
1710 if (!refs_read_raw_ref(refs, dirname.buf, oid.hash, &referent, &type)) {
1711 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1712 dirname.buf, refname);
1713 goto cleanup;
1714 }
1715
1716 if (extras && string_list_has_string(extras, dirname.buf)) {
1717 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1718 refname, dirname.buf);
1719 goto cleanup;
1720 }
1721 }
1722
1723 /*
1724 * We are at the leaf of our refname (e.g., "refs/foo/bar").
1725 * There is no point in searching for a reference with that
1726 * name, because a refname isn't considered to conflict with
1727 * itself. But we still need to check for references whose
1728 * names are in the "refs/foo/bar/" namespace, because they
1729 * *do* conflict.
1730 */
1731 strbuf_addstr(&dirname, refname + dirname.len);
1732 strbuf_addch(&dirname, '/');
1733
1734 iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1735 DO_FOR_EACH_INCLUDE_BROKEN);
1736 while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1737 if (skip &&
1738 string_list_has_string(skip, iter->refname))
1739 continue;
1740
1741 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1742 iter->refname, refname);
1743 ref_iterator_abort(iter);
1744 goto cleanup;
1745 }
1746
1747 if (ok != ITER_DONE)
1748 die("BUG: error while iterating over references");
1749
1750 extra_refname = find_descendant_ref(dirname.buf, extras, skip);
1751 if (extra_refname)
1752 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1753 refname, extra_refname);
1754 else
1755 ret = 0;
1756
1757 cleanup:
1758 strbuf_release(&referent);
1759 strbuf_release(&dirname);
1760 return ret;
1761 }
1762
1763 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1764 {
1765 struct ref_iterator *iter;
1766
1767 iter = refs->be->reflog_iterator_begin(refs);
1768
1769 return do_for_each_ref_iterator(iter, fn, cb_data);
1770 }
1771
1772 int for_each_reflog(each_ref_fn fn, void *cb_data)
1773 {
1774 return refs_for_each_reflog(get_main_ref_store(), fn, cb_data);
1775 }
1776
1777 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
1778 const char *refname,
1779 each_reflog_ent_fn fn,
1780 void *cb_data)
1781 {
1782 return refs->be->for_each_reflog_ent_reverse(refs, refname,
1783 fn, cb_data);
1784 }
1785
1786 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
1787 void *cb_data)
1788 {
1789 return refs_for_each_reflog_ent_reverse(get_main_ref_store(),
1790 refname, fn, cb_data);
1791 }
1792
1793 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
1794 each_reflog_ent_fn fn, void *cb_data)
1795 {
1796 return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
1797 }
1798
1799 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
1800 void *cb_data)
1801 {
1802 return refs_for_each_reflog_ent(get_main_ref_store(), refname,
1803 fn, cb_data);
1804 }
1805
1806 int refs_reflog_exists(struct ref_store *refs, const char *refname)
1807 {
1808 return refs->be->reflog_exists(refs, refname);
1809 }
1810
1811 int reflog_exists(const char *refname)
1812 {
1813 return refs_reflog_exists(get_main_ref_store(), refname);
1814 }
1815
1816 int refs_create_reflog(struct ref_store *refs, const char *refname,
1817 int force_create, struct strbuf *err)
1818 {
1819 return refs->be->create_reflog(refs, refname, force_create, err);
1820 }
1821
1822 int safe_create_reflog(const char *refname, int force_create,
1823 struct strbuf *err)
1824 {
1825 return refs_create_reflog(get_main_ref_store(), refname,
1826 force_create, err);
1827 }
1828
1829 int refs_delete_reflog(struct ref_store *refs, const char *refname)
1830 {
1831 return refs->be->delete_reflog(refs, refname);
1832 }
1833
1834 int delete_reflog(const char *refname)
1835 {
1836 return refs_delete_reflog(get_main_ref_store(), refname);
1837 }
1838
1839 int refs_reflog_expire(struct ref_store *refs,
1840 const char *refname, const unsigned char *sha1,
1841 unsigned int flags,
1842 reflog_expiry_prepare_fn prepare_fn,
1843 reflog_expiry_should_prune_fn should_prune_fn,
1844 reflog_expiry_cleanup_fn cleanup_fn,
1845 void *policy_cb_data)
1846 {
1847 return refs->be->reflog_expire(refs, refname, sha1, flags,
1848 prepare_fn, should_prune_fn,
1849 cleanup_fn, policy_cb_data);
1850 }
1851
1852 int reflog_expire(const char *refname, const unsigned char *sha1,
1853 unsigned int flags,
1854 reflog_expiry_prepare_fn prepare_fn,
1855 reflog_expiry_should_prune_fn should_prune_fn,
1856 reflog_expiry_cleanup_fn cleanup_fn,
1857 void *policy_cb_data)
1858 {
1859 return refs_reflog_expire(get_main_ref_store(),
1860 refname, sha1, flags,
1861 prepare_fn, should_prune_fn,
1862 cleanup_fn, policy_cb_data);
1863 }
1864
1865 int initial_ref_transaction_commit(struct ref_transaction *transaction,
1866 struct strbuf *err)
1867 {
1868 struct ref_store *refs = transaction->ref_store;
1869
1870 return refs->be->initial_transaction_commit(refs, transaction, err);
1871 }
1872
1873 int refs_delete_refs(struct ref_store *refs, struct string_list *refnames,
1874 unsigned int flags)
1875 {
1876 return refs->be->delete_refs(refs, refnames, flags);
1877 }
1878
1879 int delete_refs(struct string_list *refnames, unsigned int flags)
1880 {
1881 return refs_delete_refs(get_main_ref_store(), refnames, flags);
1882 }
1883
1884 int refs_rename_ref(struct ref_store *refs, const char *oldref,
1885 const char *newref, const char *logmsg)
1886 {
1887 return refs->be->rename_ref(refs, oldref, newref, logmsg);
1888 }
1889
1890 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
1891 {
1892 return refs_rename_ref(get_main_ref_store(), oldref, newref, logmsg);
1893 }