fd29d894dc2f5ecf4cbcabc38196731f1ca2297d
[git/git.git] / refs.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
6
7 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8 #define REF_KNOWS_PEELED 04
9 #define REF_BROKEN 010
10
11 struct ref_list {
12 struct ref_list *next;
13 unsigned char flag; /* ISSYMREF? ISPACKED? */
14 unsigned char sha1[20];
15 unsigned char peeled[20];
16 char name[FLEX_ARRAY];
17 };
18
19 static const char *parse_ref_line(char *line, unsigned char *sha1)
20 {
21 /*
22 * 42: the answer to everything.
23 *
24 * In this case, it happens to be the answer to
25 * 40 (length of sha1 hex representation)
26 * +1 (space in between hex and name)
27 * +1 (newline at the end of the line)
28 */
29 int len = strlen(line) - 42;
30
31 if (len <= 0)
32 return NULL;
33 if (get_sha1_hex(line, sha1) < 0)
34 return NULL;
35 if (!isspace(line[40]))
36 return NULL;
37 line += 41;
38 if (isspace(*line))
39 return NULL;
40 if (line[len] != '\n')
41 return NULL;
42 line[len] = 0;
43
44 return line;
45 }
46
47 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
48 int flag, struct ref_list *list,
49 struct ref_list **new_entry)
50 {
51 int len;
52 struct ref_list *entry;
53
54 /* Allocate it and add it in.. */
55 len = strlen(name) + 1;
56 entry = xmalloc(sizeof(struct ref_list) + len);
57 hashcpy(entry->sha1, sha1);
58 hashclr(entry->peeled);
59 memcpy(entry->name, name, len);
60 entry->flag = flag;
61 entry->next = list;
62 if (new_entry)
63 *new_entry = entry;
64 return entry;
65 }
66
67 /* merge sort the ref list */
68 static struct ref_list *sort_ref_list(struct ref_list *list)
69 {
70 int psize, qsize, last_merge_count, cmp;
71 struct ref_list *p, *q, *l, *e;
72 struct ref_list *new_list = list;
73 int k = 1;
74 int merge_count = 0;
75
76 if (!list)
77 return list;
78
79 do {
80 last_merge_count = merge_count;
81 merge_count = 0;
82
83 psize = 0;
84
85 p = new_list;
86 q = new_list;
87 new_list = NULL;
88 l = NULL;
89
90 while (p) {
91 merge_count++;
92
93 while (psize < k && q->next) {
94 q = q->next;
95 psize++;
96 }
97 qsize = k;
98
99 while ((psize > 0) || (qsize > 0 && q)) {
100 if (qsize == 0 || !q) {
101 e = p;
102 p = p->next;
103 psize--;
104 } else if (psize == 0) {
105 e = q;
106 q = q->next;
107 qsize--;
108 } else {
109 cmp = strcmp(q->name, p->name);
110 if (cmp < 0) {
111 e = q;
112 q = q->next;
113 qsize--;
114 } else if (cmp > 0) {
115 e = p;
116 p = p->next;
117 psize--;
118 } else {
119 if (hashcmp(q->sha1, p->sha1))
120 die("Duplicated ref, and SHA1s don't match: %s",
121 q->name);
122 warning("Duplicated ref: %s", q->name);
123 e = q;
124 q = q->next;
125 qsize--;
126 free(e);
127 e = p;
128 p = p->next;
129 psize--;
130 }
131 }
132
133 e->next = NULL;
134
135 if (l)
136 l->next = e;
137 if (!new_list)
138 new_list = e;
139 l = e;
140 }
141
142 p = q;
143 };
144
145 k = k * 2;
146 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
147
148 return new_list;
149 }
150
151 /*
152 * Future: need to be in "struct repository"
153 * when doing a full libification.
154 */
155 static struct cached_refs {
156 char did_loose;
157 char did_packed;
158 struct ref_list *loose;
159 struct ref_list *packed;
160 } cached_refs, submodule_refs;
161 static struct ref_list *current_ref;
162
163 static struct ref_list *extra_refs;
164
165 static void free_ref_list(struct ref_list *list)
166 {
167 struct ref_list *next;
168 for ( ; list; list = next) {
169 next = list->next;
170 free(list);
171 }
172 }
173
174 static void invalidate_cached_refs(void)
175 {
176 struct cached_refs *ca = &cached_refs;
177
178 if (ca->did_loose && ca->loose)
179 free_ref_list(ca->loose);
180 if (ca->did_packed && ca->packed)
181 free_ref_list(ca->packed);
182 ca->loose = ca->packed = NULL;
183 ca->did_loose = ca->did_packed = 0;
184 }
185
186 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
187 {
188 struct ref_list *list = NULL;
189 struct ref_list *last = NULL;
190 char refline[PATH_MAX];
191 int flag = REF_ISPACKED;
192
193 while (fgets(refline, sizeof(refline), f)) {
194 unsigned char sha1[20];
195 const char *name;
196 static const char header[] = "# pack-refs with:";
197
198 if (!strncmp(refline, header, sizeof(header)-1)) {
199 const char *traits = refline + sizeof(header) - 1;
200 if (strstr(traits, " peeled "))
201 flag |= REF_KNOWS_PEELED;
202 /* perhaps other traits later as well */
203 continue;
204 }
205
206 name = parse_ref_line(refline, sha1);
207 if (name) {
208 list = add_ref(name, sha1, flag, list, &last);
209 continue;
210 }
211 if (last &&
212 refline[0] == '^' &&
213 strlen(refline) == 42 &&
214 refline[41] == '\n' &&
215 !get_sha1_hex(refline + 1, sha1))
216 hashcpy(last->peeled, sha1);
217 }
218 cached_refs->packed = sort_ref_list(list);
219 }
220
221 void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
222 {
223 extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
224 }
225
226 void clear_extra_refs(void)
227 {
228 free_ref_list(extra_refs);
229 extra_refs = NULL;
230 }
231
232 static struct ref_list *get_packed_refs(const char *submodule)
233 {
234 const char *packed_refs_file;
235 struct cached_refs *refs;
236
237 if (submodule) {
238 packed_refs_file = git_path_submodule(submodule, "packed-refs");
239 refs = &submodule_refs;
240 free_ref_list(refs->packed);
241 } else {
242 packed_refs_file = git_path("packed-refs");
243 refs = &cached_refs;
244 }
245
246 if (!refs->did_packed || submodule) {
247 FILE *f = fopen(packed_refs_file, "r");
248 refs->packed = NULL;
249 if (f) {
250 read_packed_refs(f, refs);
251 fclose(f);
252 }
253 refs->did_packed = 1;
254 }
255 return refs->packed;
256 }
257
258 static struct ref_list *get_ref_dir(const char *submodule, const char *base,
259 struct ref_list *list)
260 {
261 DIR *dir;
262 const char *path;
263
264 if (submodule)
265 path = git_path_submodule(submodule, "%s", base);
266 else
267 path = git_path("%s", base);
268
269
270 dir = opendir(path);
271
272 if (dir) {
273 struct dirent *de;
274 int baselen = strlen(base);
275 char *ref = xmalloc(baselen + 257);
276
277 memcpy(ref, base, baselen);
278 if (baselen && base[baselen-1] != '/')
279 ref[baselen++] = '/';
280
281 while ((de = readdir(dir)) != NULL) {
282 unsigned char sha1[20];
283 struct stat st;
284 int flag;
285 int namelen;
286 const char *refdir;
287
288 if (de->d_name[0] == '.')
289 continue;
290 namelen = strlen(de->d_name);
291 if (namelen > 255)
292 continue;
293 if (has_extension(de->d_name, ".lock"))
294 continue;
295 memcpy(ref + baselen, de->d_name, namelen+1);
296 refdir = submodule
297 ? git_path_submodule(submodule, "%s", ref)
298 : git_path("%s", ref);
299 if (stat(refdir, &st) < 0)
300 continue;
301 if (S_ISDIR(st.st_mode)) {
302 list = get_ref_dir(submodule, ref, list);
303 continue;
304 }
305 if (submodule) {
306 hashclr(sha1);
307 flag = 0;
308 if (resolve_gitlink_ref(submodule, ref, sha1) < 0) {
309 hashclr(sha1);
310 flag |= REF_BROKEN;
311 }
312 } else
313 if (!resolve_ref(ref, sha1, 1, &flag)) {
314 hashclr(sha1);
315 flag |= REF_BROKEN;
316 }
317 list = add_ref(ref, sha1, flag, list, NULL);
318 }
319 free(ref);
320 closedir(dir);
321 }
322 return sort_ref_list(list);
323 }
324
325 struct warn_if_dangling_data {
326 FILE *fp;
327 const char *refname;
328 const char *msg_fmt;
329 };
330
331 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
332 int flags, void *cb_data)
333 {
334 struct warn_if_dangling_data *d = cb_data;
335 const char *resolves_to;
336 unsigned char junk[20];
337
338 if (!(flags & REF_ISSYMREF))
339 return 0;
340
341 resolves_to = resolve_ref(refname, junk, 0, NULL);
342 if (!resolves_to || strcmp(resolves_to, d->refname))
343 return 0;
344
345 fprintf(d->fp, d->msg_fmt, refname);
346 return 0;
347 }
348
349 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
350 {
351 struct warn_if_dangling_data data;
352
353 data.fp = fp;
354 data.refname = refname;
355 data.msg_fmt = msg_fmt;
356 for_each_rawref(warn_if_dangling_symref, &data);
357 }
358
359 static struct ref_list *get_loose_refs(const char *submodule)
360 {
361 if (submodule) {
362 free_ref_list(submodule_refs.loose);
363 submodule_refs.loose = get_ref_dir(submodule, "refs", NULL);
364 return submodule_refs.loose;
365 }
366
367 if (!cached_refs.did_loose) {
368 cached_refs.loose = get_ref_dir(NULL, "refs", NULL);
369 cached_refs.did_loose = 1;
370 }
371 return cached_refs.loose;
372 }
373
374 /* We allow "recursive" symbolic refs. Only within reason, though */
375 #define MAXDEPTH 5
376 #define MAXREFLEN (1024)
377
378 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
379 {
380 FILE *f;
381 struct cached_refs refs;
382 struct ref_list *ref;
383 int retval;
384
385 strcpy(name + pathlen, "packed-refs");
386 f = fopen(name, "r");
387 if (!f)
388 return -1;
389 read_packed_refs(f, &refs);
390 fclose(f);
391 ref = refs.packed;
392 retval = -1;
393 while (ref) {
394 if (!strcmp(ref->name, refname)) {
395 retval = 0;
396 memcpy(result, ref->sha1, 20);
397 break;
398 }
399 ref = ref->next;
400 }
401 free_ref_list(refs.packed);
402 return retval;
403 }
404
405 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
406 {
407 int fd, len = strlen(refname);
408 char buffer[128], *p;
409
410 if (recursion > MAXDEPTH || len > MAXREFLEN)
411 return -1;
412 memcpy(name + pathlen, refname, len+1);
413 fd = open(name, O_RDONLY);
414 if (fd < 0)
415 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
416
417 len = read(fd, buffer, sizeof(buffer)-1);
418 close(fd);
419 if (len < 0)
420 return -1;
421 while (len && isspace(buffer[len-1]))
422 len--;
423 buffer[len] = 0;
424
425 /* Was it a detached head or an old-fashioned symlink? */
426 if (!get_sha1_hex(buffer, result))
427 return 0;
428
429 /* Symref? */
430 if (strncmp(buffer, "ref:", 4))
431 return -1;
432 p = buffer + 4;
433 while (isspace(*p))
434 p++;
435
436 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
437 }
438
439 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
440 {
441 int len = strlen(path), retval;
442 char *gitdir;
443 const char *tmp;
444
445 while (len && path[len-1] == '/')
446 len--;
447 if (!len)
448 return -1;
449 gitdir = xmalloc(len + MAXREFLEN + 8);
450 memcpy(gitdir, path, len);
451 memcpy(gitdir + len, "/.git", 6);
452 len += 5;
453
454 tmp = read_gitfile(gitdir);
455 if (tmp) {
456 free(gitdir);
457 len = strlen(tmp);
458 gitdir = xmalloc(len + MAXREFLEN + 3);
459 memcpy(gitdir, tmp, len);
460 }
461 gitdir[len] = '/';
462 gitdir[++len] = '\0';
463 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
464 free(gitdir);
465 return retval;
466 }
467
468 /*
469 * If the "reading" argument is set, this function finds out what _object_
470 * the ref points at by "reading" the ref. The ref, if it is not symbolic,
471 * has to exist, and if it is symbolic, it has to point at an existing ref,
472 * because the "read" goes through the symref to the ref it points at.
473 *
474 * The access that is not "reading" may often be "writing", but does not
475 * have to; it can be merely checking _where it leads to_. If it is a
476 * prelude to "writing" to the ref, a write to a symref that points at
477 * yet-to-be-born ref will create the real ref pointed by the symref.
478 * reading=0 allows the caller to check where such a symref leads to.
479 */
480 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
481 {
482 int depth = MAXDEPTH;
483 ssize_t len;
484 char buffer[256];
485 static char ref_buffer[256];
486
487 if (flag)
488 *flag = 0;
489
490 for (;;) {
491 char path[PATH_MAX];
492 struct stat st;
493 char *buf;
494 int fd;
495
496 if (--depth < 0)
497 return NULL;
498
499 git_snpath(path, sizeof(path), "%s", ref);
500 /* Special case: non-existing file. */
501 if (lstat(path, &st) < 0) {
502 struct ref_list *list = get_packed_refs(NULL);
503 while (list) {
504 if (!strcmp(ref, list->name)) {
505 hashcpy(sha1, list->sha1);
506 if (flag)
507 *flag |= REF_ISPACKED;
508 return ref;
509 }
510 list = list->next;
511 }
512 if (reading || errno != ENOENT)
513 return NULL;
514 hashclr(sha1);
515 return ref;
516 }
517
518 /* Follow "normalized" - ie "refs/.." symlinks by hand */
519 if (S_ISLNK(st.st_mode)) {
520 len = readlink(path, buffer, sizeof(buffer)-1);
521 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
522 buffer[len] = 0;
523 strcpy(ref_buffer, buffer);
524 ref = ref_buffer;
525 if (flag)
526 *flag |= REF_ISSYMREF;
527 continue;
528 }
529 }
530
531 /* Is it a directory? */
532 if (S_ISDIR(st.st_mode)) {
533 errno = EISDIR;
534 return NULL;
535 }
536
537 /*
538 * Anything else, just open it and try to use it as
539 * a ref
540 */
541 fd = open(path, O_RDONLY);
542 if (fd < 0)
543 return NULL;
544 len = read_in_full(fd, buffer, sizeof(buffer)-1);
545 close(fd);
546
547 /*
548 * Is it a symbolic ref?
549 */
550 if (len < 4 || memcmp("ref:", buffer, 4))
551 break;
552 buf = buffer + 4;
553 len -= 4;
554 while (len && isspace(*buf))
555 buf++, len--;
556 while (len && isspace(buf[len-1]))
557 len--;
558 buf[len] = 0;
559 memcpy(ref_buffer, buf, len + 1);
560 ref = ref_buffer;
561 if (flag)
562 *flag |= REF_ISSYMREF;
563 }
564 if (len < 40 || get_sha1_hex(buffer, sha1))
565 return NULL;
566 return ref;
567 }
568
569 /* The argument to filter_refs */
570 struct ref_filter {
571 const char *pattern;
572 each_ref_fn *fn;
573 void *cb_data;
574 };
575
576 int read_ref(const char *ref, unsigned char *sha1)
577 {
578 if (resolve_ref(ref, sha1, 1, NULL))
579 return 0;
580 return -1;
581 }
582
583 #define DO_FOR_EACH_INCLUDE_BROKEN 01
584 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
585 int flags, void *cb_data, struct ref_list *entry)
586 {
587 if (prefixcmp(entry->name, base))
588 return 0;
589
590 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
591 if (entry->flag & REF_BROKEN)
592 return 0; /* ignore dangling symref */
593 if (!has_sha1_file(entry->sha1)) {
594 error("%s does not point to a valid object!", entry->name);
595 return 0;
596 }
597 }
598 current_ref = entry;
599 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
600 }
601
602 static int filter_refs(const char *ref, const unsigned char *sha, int flags,
603 void *data)
604 {
605 struct ref_filter *filter = (struct ref_filter *)data;
606 if (fnmatch(filter->pattern, ref, 0))
607 return 0;
608 return filter->fn(ref, sha, flags, filter->cb_data);
609 }
610
611 int peel_ref(const char *ref, unsigned char *sha1)
612 {
613 int flag;
614 unsigned char base[20];
615 struct object *o;
616
617 if (current_ref && (current_ref->name == ref
618 || !strcmp(current_ref->name, ref))) {
619 if (current_ref->flag & REF_KNOWS_PEELED) {
620 hashcpy(sha1, current_ref->peeled);
621 return 0;
622 }
623 hashcpy(base, current_ref->sha1);
624 goto fallback;
625 }
626
627 if (!resolve_ref(ref, base, 1, &flag))
628 return -1;
629
630 if ((flag & REF_ISPACKED)) {
631 struct ref_list *list = get_packed_refs(NULL);
632
633 while (list) {
634 if (!strcmp(list->name, ref)) {
635 if (list->flag & REF_KNOWS_PEELED) {
636 hashcpy(sha1, list->peeled);
637 return 0;
638 }
639 /* older pack-refs did not leave peeled ones */
640 break;
641 }
642 list = list->next;
643 }
644 }
645
646 fallback:
647 o = parse_object(base);
648 if (o && o->type == OBJ_TAG) {
649 o = deref_tag(o, ref, 0);
650 if (o) {
651 hashcpy(sha1, o->sha1);
652 return 0;
653 }
654 }
655 return -1;
656 }
657
658 static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
659 int trim, int flags, void *cb_data)
660 {
661 int retval = 0;
662 struct ref_list *packed = get_packed_refs(submodule);
663 struct ref_list *loose = get_loose_refs(submodule);
664
665 struct ref_list *extra;
666
667 for (extra = extra_refs; extra; extra = extra->next)
668 retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
669
670 while (packed && loose) {
671 struct ref_list *entry;
672 int cmp = strcmp(packed->name, loose->name);
673 if (!cmp) {
674 packed = packed->next;
675 continue;
676 }
677 if (cmp > 0) {
678 entry = loose;
679 loose = loose->next;
680 } else {
681 entry = packed;
682 packed = packed->next;
683 }
684 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
685 if (retval)
686 goto end_each;
687 }
688
689 for (packed = packed ? packed : loose; packed; packed = packed->next) {
690 retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
691 if (retval)
692 goto end_each;
693 }
694
695 end_each:
696 current_ref = NULL;
697 return retval;
698 }
699
700
701 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
702 {
703 unsigned char sha1[20];
704 int flag;
705
706 if (submodule) {
707 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
708 return fn("HEAD", sha1, 0, cb_data);
709
710 return 0;
711 }
712
713 if (resolve_ref("HEAD", sha1, 1, &flag))
714 return fn("HEAD", sha1, flag, cb_data);
715
716 return 0;
717 }
718
719 int head_ref(each_ref_fn fn, void *cb_data)
720 {
721 return do_head_ref(NULL, fn, cb_data);
722 }
723
724 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
725 {
726 return do_head_ref(submodule, fn, cb_data);
727 }
728
729 int for_each_ref(each_ref_fn fn, void *cb_data)
730 {
731 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
732 }
733
734 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
735 {
736 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
737 }
738
739 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
740 {
741 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
742 }
743
744 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
745 each_ref_fn fn, void *cb_data)
746 {
747 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
748 }
749
750 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
751 {
752 return for_each_ref_in("refs/tags/", fn, cb_data);
753 }
754
755 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
756 {
757 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
758 }
759
760 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
761 {
762 return for_each_ref_in("refs/heads/", fn, cb_data);
763 }
764
765 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
766 {
767 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
768 }
769
770 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
771 {
772 return for_each_ref_in("refs/remotes/", fn, cb_data);
773 }
774
775 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
776 {
777 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
778 }
779
780 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
781 {
782 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
783 }
784
785 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
786 {
787 struct strbuf buf = STRBUF_INIT;
788 int ret = 0;
789 unsigned char sha1[20];
790 int flag;
791
792 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
793 if (resolve_ref(buf.buf, sha1, 1, &flag))
794 ret = fn(buf.buf, sha1, flag, cb_data);
795 strbuf_release(&buf);
796
797 return ret;
798 }
799
800 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
801 {
802 struct strbuf buf = STRBUF_INIT;
803 int ret;
804 strbuf_addf(&buf, "%srefs/", get_git_namespace());
805 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
806 strbuf_release(&buf);
807 return ret;
808 }
809
810 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
811 const char *prefix, void *cb_data)
812 {
813 struct strbuf real_pattern = STRBUF_INIT;
814 struct ref_filter filter;
815 int ret;
816
817 if (!prefix && prefixcmp(pattern, "refs/"))
818 strbuf_addstr(&real_pattern, "refs/");
819 else if (prefix)
820 strbuf_addstr(&real_pattern, prefix);
821 strbuf_addstr(&real_pattern, pattern);
822
823 if (!has_glob_specials(pattern)) {
824 /* Append implied '/' '*' if not present. */
825 if (real_pattern.buf[real_pattern.len - 1] != '/')
826 strbuf_addch(&real_pattern, '/');
827 /* No need to check for '*', there is none. */
828 strbuf_addch(&real_pattern, '*');
829 }
830
831 filter.pattern = real_pattern.buf;
832 filter.fn = fn;
833 filter.cb_data = cb_data;
834 ret = for_each_ref(filter_refs, &filter);
835
836 strbuf_release(&real_pattern);
837 return ret;
838 }
839
840 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
841 {
842 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
843 }
844
845 int for_each_rawref(each_ref_fn fn, void *cb_data)
846 {
847 return do_for_each_ref(NULL, "", fn, 0,
848 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
849 }
850
851 /*
852 * Make sure "ref" is something reasonable to have under ".git/refs/";
853 * We do not like it if:
854 *
855 * - any path component of it begins with ".", or
856 * - it has double dots "..", or
857 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
858 * - it ends with a "/".
859 * - it ends with ".lock"
860 * - it contains a "\" (backslash)
861 */
862
863 /* Return true iff ch is not allowed in reference names. */
864 static inline int bad_ref_char(int ch)
865 {
866 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
867 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
868 return 1;
869 /* 2.13 Pattern Matching Notation */
870 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
871 return 1;
872 return 0;
873 }
874
875 int check_ref_format(const char *ref)
876 {
877 int ch, level, last;
878 int ret = CHECK_REF_FORMAT_OK;
879 const char *cp = ref;
880
881 level = 0;
882 while (1) {
883 while ((ch = *cp++) == '/')
884 ; /* tolerate duplicated slashes */
885 if (!ch)
886 /* should not end with slashes */
887 return CHECK_REF_FORMAT_ERROR;
888
889 /* we are at the beginning of the path component */
890 if (ch == '.')
891 return CHECK_REF_FORMAT_ERROR;
892 if (bad_ref_char(ch)) {
893 if (ch == '*' && (!*cp || *cp == '/') &&
894 ret == CHECK_REF_FORMAT_OK)
895 ret = CHECK_REF_FORMAT_WILDCARD;
896 else
897 return CHECK_REF_FORMAT_ERROR;
898 }
899
900 last = ch;
901 /* scan the rest of the path component */
902 while ((ch = *cp++) != 0) {
903 if (bad_ref_char(ch))
904 return CHECK_REF_FORMAT_ERROR;
905 if (ch == '/')
906 break;
907 if (last == '.' && ch == '.')
908 return CHECK_REF_FORMAT_ERROR;
909 if (last == '@' && ch == '{')
910 return CHECK_REF_FORMAT_ERROR;
911 last = ch;
912 }
913 level++;
914 if (!ch) {
915 if (ref <= cp - 2 && cp[-2] == '.')
916 return CHECK_REF_FORMAT_ERROR;
917 if (level < 2)
918 return CHECK_REF_FORMAT_ONELEVEL;
919 if (has_extension(ref, ".lock"))
920 return CHECK_REF_FORMAT_ERROR;
921 return ret;
922 }
923 }
924 }
925
926 const char *prettify_refname(const char *name)
927 {
928 return name + (
929 !prefixcmp(name, "refs/heads/") ? 11 :
930 !prefixcmp(name, "refs/tags/") ? 10 :
931 !prefixcmp(name, "refs/remotes/") ? 13 :
932 0);
933 }
934
935 const char *ref_rev_parse_rules[] = {
936 "%.*s",
937 "refs/%.*s",
938 "refs/tags/%.*s",
939 "refs/heads/%.*s",
940 "refs/remotes/%.*s",
941 "refs/remotes/%.*s/HEAD",
942 NULL
943 };
944
945 const char *ref_fetch_rules[] = {
946 "%.*s",
947 "refs/%.*s",
948 "refs/heads/%.*s",
949 NULL
950 };
951
952 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
953 {
954 const char **p;
955 const int abbrev_name_len = strlen(abbrev_name);
956
957 for (p = rules; *p; p++) {
958 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
959 return 1;
960 }
961 }
962
963 return 0;
964 }
965
966 static struct ref_lock *verify_lock(struct ref_lock *lock,
967 const unsigned char *old_sha1, int mustexist)
968 {
969 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
970 error("Can't verify ref %s", lock->ref_name);
971 unlock_ref(lock);
972 return NULL;
973 }
974 if (hashcmp(lock->old_sha1, old_sha1)) {
975 error("Ref %s is at %s but expected %s", lock->ref_name,
976 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
977 unlock_ref(lock);
978 return NULL;
979 }
980 return lock;
981 }
982
983 static int remove_empty_directories(const char *file)
984 {
985 /* we want to create a file but there is a directory there;
986 * if that is an empty directory (or a directory that contains
987 * only empty directories), remove them.
988 */
989 struct strbuf path;
990 int result;
991
992 strbuf_init(&path, 20);
993 strbuf_addstr(&path, file);
994
995 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
996
997 strbuf_release(&path);
998
999 return result;
1000 }
1001
1002 static int is_refname_available(const char *ref, const char *oldref,
1003 struct ref_list *list, int quiet)
1004 {
1005 int namlen = strlen(ref); /* e.g. 'foo/bar' */
1006 while (list) {
1007 /* list->name could be 'foo' or 'foo/bar/baz' */
1008 if (!oldref || strcmp(oldref, list->name)) {
1009 int len = strlen(list->name);
1010 int cmplen = (namlen < len) ? namlen : len;
1011 const char *lead = (namlen < len) ? list->name : ref;
1012 if (!strncmp(ref, list->name, cmplen) &&
1013 lead[cmplen] == '/') {
1014 if (!quiet)
1015 error("'%s' exists; cannot create '%s'",
1016 list->name, ref);
1017 return 0;
1018 }
1019 }
1020 list = list->next;
1021 }
1022 return 1;
1023 }
1024
1025 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
1026 {
1027 char *ref_file;
1028 const char *orig_ref = ref;
1029 struct ref_lock *lock;
1030 int last_errno = 0;
1031 int type, lflags;
1032 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1033 int missing = 0;
1034
1035 lock = xcalloc(1, sizeof(struct ref_lock));
1036 lock->lock_fd = -1;
1037
1038 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
1039 if (!ref && errno == EISDIR) {
1040 /* we are trying to lock foo but we used to
1041 * have foo/bar which now does not exist;
1042 * it is normal for the empty directory 'foo'
1043 * to remain.
1044 */
1045 ref_file = git_path("%s", orig_ref);
1046 if (remove_empty_directories(ref_file)) {
1047 last_errno = errno;
1048 error("there are still refs under '%s'", orig_ref);
1049 goto error_return;
1050 }
1051 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
1052 }
1053 if (type_p)
1054 *type_p = type;
1055 if (!ref) {
1056 last_errno = errno;
1057 error("unable to resolve reference %s: %s",
1058 orig_ref, strerror(errno));
1059 goto error_return;
1060 }
1061 missing = is_null_sha1(lock->old_sha1);
1062 /* When the ref did not exist and we are creating it,
1063 * make sure there is no existing ref that is packed
1064 * whose name begins with our refname, nor a ref whose
1065 * name is a proper prefix of our refname.
1066 */
1067 if (missing &&
1068 !is_refname_available(ref, NULL, get_packed_refs(NULL), 0)) {
1069 last_errno = ENOTDIR;
1070 goto error_return;
1071 }
1072
1073 lock->lk = xcalloc(1, sizeof(struct lock_file));
1074
1075 lflags = LOCK_DIE_ON_ERROR;
1076 if (flags & REF_NODEREF) {
1077 ref = orig_ref;
1078 lflags |= LOCK_NODEREF;
1079 }
1080 lock->ref_name = xstrdup(ref);
1081 lock->orig_ref_name = xstrdup(orig_ref);
1082 ref_file = git_path("%s", ref);
1083 if (missing)
1084 lock->force_write = 1;
1085 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1086 lock->force_write = 1;
1087
1088 if (safe_create_leading_directories(ref_file)) {
1089 last_errno = errno;
1090 error("unable to create directory for %s", ref_file);
1091 goto error_return;
1092 }
1093
1094 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
1095 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
1096
1097 error_return:
1098 unlock_ref(lock);
1099 errno = last_errno;
1100 return NULL;
1101 }
1102
1103 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
1104 {
1105 char refpath[PATH_MAX];
1106 if (check_ref_format(ref))
1107 return NULL;
1108 strcpy(refpath, mkpath("refs/%s", ref));
1109 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
1110 }
1111
1112 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
1113 {
1114 switch (check_ref_format(ref)) {
1115 default:
1116 return NULL;
1117 case 0:
1118 case CHECK_REF_FORMAT_ONELEVEL:
1119 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
1120 }
1121 }
1122
1123 static struct lock_file packlock;
1124
1125 static int repack_without_ref(const char *refname)
1126 {
1127 struct ref_list *list, *packed_ref_list;
1128 int fd;
1129 int found = 0;
1130
1131 packed_ref_list = get_packed_refs(NULL);
1132 for (list = packed_ref_list; list; list = list->next) {
1133 if (!strcmp(refname, list->name)) {
1134 found = 1;
1135 break;
1136 }
1137 }
1138 if (!found)
1139 return 0;
1140 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1141 if (fd < 0) {
1142 unable_to_lock_error(git_path("packed-refs"), errno);
1143 return error("cannot delete '%s' from packed refs", refname);
1144 }
1145
1146 for (list = packed_ref_list; list; list = list->next) {
1147 char line[PATH_MAX + 100];
1148 int len;
1149
1150 if (!strcmp(refname, list->name))
1151 continue;
1152 len = snprintf(line, sizeof(line), "%s %s\n",
1153 sha1_to_hex(list->sha1), list->name);
1154 /* this should not happen but just being defensive */
1155 if (len > sizeof(line))
1156 die("too long a refname '%s'", list->name);
1157 write_or_die(fd, line, len);
1158 }
1159 return commit_lock_file(&packlock);
1160 }
1161
1162 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
1163 {
1164 struct ref_lock *lock;
1165 int err, i = 0, ret = 0, flag = 0;
1166
1167 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
1168 if (!lock)
1169 return 1;
1170 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
1171 /* loose */
1172 const char *path;
1173
1174 if (!(delopt & REF_NODEREF)) {
1175 i = strlen(lock->lk->filename) - 5; /* .lock */
1176 lock->lk->filename[i] = 0;
1177 path = lock->lk->filename;
1178 } else {
1179 path = git_path("%s", refname);
1180 }
1181 err = unlink_or_warn(path);
1182 if (err && errno != ENOENT)
1183 ret = 1;
1184
1185 if (!(delopt & REF_NODEREF))
1186 lock->lk->filename[i] = '.';
1187 }
1188 /* removing the loose one could have resurrected an earlier
1189 * packed one. Also, if it was not loose we need to repack
1190 * without it.
1191 */
1192 ret |= repack_without_ref(refname);
1193
1194 unlink_or_warn(git_path("logs/%s", lock->ref_name));
1195 invalidate_cached_refs();
1196 unlock_ref(lock);
1197 return ret;
1198 }
1199
1200 /*
1201 * People using contrib's git-new-workdir have .git/logs/refs ->
1202 * /some/other/path/.git/logs/refs, and that may live on another device.
1203 *
1204 * IOW, to avoid cross device rename errors, the temporary renamed log must
1205 * live into logs/refs.
1206 */
1207 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1208
1209 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
1210 {
1211 static const char renamed_ref[] = "RENAMED-REF";
1212 unsigned char sha1[20], orig_sha1[20];
1213 int flag = 0, logmoved = 0;
1214 struct ref_lock *lock;
1215 struct stat loginfo;
1216 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
1217 const char *symref = NULL;
1218
1219 if (log && S_ISLNK(loginfo.st_mode))
1220 return error("reflog for %s is a symlink", oldref);
1221
1222 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1223 if (flag & REF_ISSYMREF)
1224 return error("refname %s is a symbolic ref, renaming it is not supported",
1225 oldref);
1226 if (!symref)
1227 return error("refname %s not found", oldref);
1228
1229 if (!is_refname_available(newref, oldref, get_packed_refs(NULL), 0))
1230 return 1;
1231
1232 if (!is_refname_available(newref, oldref, get_loose_refs(NULL), 0))
1233 return 1;
1234
1235 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
1236 if (!lock)
1237 return error("unable to lock %s", renamed_ref);
1238 lock->force_write = 1;
1239 if (write_ref_sha1(lock, orig_sha1, logmsg))
1240 return error("unable to save current sha1 in %s", renamed_ref);
1241
1242 if (log && rename(git_path("logs/%s", oldref), git_path(TMP_RENAMED_LOG)))
1243 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
1244 oldref, strerror(errno));
1245
1246 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
1247 error("unable to delete old %s", oldref);
1248 goto rollback;
1249 }
1250
1251 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
1252 if (errno==EISDIR) {
1253 if (remove_empty_directories(git_path("%s", newref))) {
1254 error("Directory not empty: %s", newref);
1255 goto rollback;
1256 }
1257 } else {
1258 error("unable to delete existing %s", newref);
1259 goto rollback;
1260 }
1261 }
1262
1263 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1264 error("unable to create directory for %s", newref);
1265 goto rollback;
1266 }
1267
1268 retry:
1269 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newref))) {
1270 if (errno==EISDIR || errno==ENOTDIR) {
1271 /*
1272 * rename(a, b) when b is an existing
1273 * directory ought to result in ISDIR, but
1274 * Solaris 5.8 gives ENOTDIR. Sheesh.
1275 */
1276 if (remove_empty_directories(git_path("logs/%s", newref))) {
1277 error("Directory not empty: logs/%s", newref);
1278 goto rollback;
1279 }
1280 goto retry;
1281 } else {
1282 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
1283 newref, strerror(errno));
1284 goto rollback;
1285 }
1286 }
1287 logmoved = log;
1288
1289 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
1290 if (!lock) {
1291 error("unable to lock %s for update", newref);
1292 goto rollback;
1293 }
1294 lock->force_write = 1;
1295 hashcpy(lock->old_sha1, orig_sha1);
1296 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1297 error("unable to write current sha1 into %s", newref);
1298 goto rollback;
1299 }
1300
1301 return 0;
1302
1303 rollback:
1304 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1305 if (!lock) {
1306 error("unable to lock %s for rollback", oldref);
1307 goto rollbacklog;
1308 }
1309
1310 lock->force_write = 1;
1311 flag = log_all_ref_updates;
1312 log_all_ref_updates = 0;
1313 if (write_ref_sha1(lock, orig_sha1, NULL))
1314 error("unable to write current sha1 into %s", oldref);
1315 log_all_ref_updates = flag;
1316
1317 rollbacklog:
1318 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1319 error("unable to restore logfile %s from %s: %s",
1320 oldref, newref, strerror(errno));
1321 if (!logmoved && log &&
1322 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldref)))
1323 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
1324 oldref, strerror(errno));
1325
1326 return 1;
1327 }
1328
1329 int close_ref(struct ref_lock *lock)
1330 {
1331 if (close_lock_file(lock->lk))
1332 return -1;
1333 lock->lock_fd = -1;
1334 return 0;
1335 }
1336
1337 int commit_ref(struct ref_lock *lock)
1338 {
1339 if (commit_lock_file(lock->lk))
1340 return -1;
1341 lock->lock_fd = -1;
1342 return 0;
1343 }
1344
1345 void unlock_ref(struct ref_lock *lock)
1346 {
1347 /* Do not free lock->lk -- atexit() still looks at them */
1348 if (lock->lk)
1349 rollback_lock_file(lock->lk);
1350 free(lock->ref_name);
1351 free(lock->orig_ref_name);
1352 free(lock);
1353 }
1354
1355 /*
1356 * copy the reflog message msg to buf, which has been allocated sufficiently
1357 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1358 * because reflog file is one line per entry.
1359 */
1360 static int copy_msg(char *buf, const char *msg)
1361 {
1362 char *cp = buf;
1363 char c;
1364 int wasspace = 1;
1365
1366 *cp++ = '\t';
1367 while ((c = *msg++)) {
1368 if (wasspace && isspace(c))
1369 continue;
1370 wasspace = isspace(c);
1371 if (wasspace)
1372 c = ' ';
1373 *cp++ = c;
1374 }
1375 while (buf < cp && isspace(cp[-1]))
1376 cp--;
1377 *cp++ = '\n';
1378 return cp - buf;
1379 }
1380
1381 int log_ref_setup(const char *ref_name, char *logfile, int bufsize)
1382 {
1383 int logfd, oflags = O_APPEND | O_WRONLY;
1384
1385 git_snpath(logfile, bufsize, "logs/%s", ref_name);
1386 if (log_all_ref_updates &&
1387 (!prefixcmp(ref_name, "refs/heads/") ||
1388 !prefixcmp(ref_name, "refs/remotes/") ||
1389 !prefixcmp(ref_name, "refs/notes/") ||
1390 !strcmp(ref_name, "HEAD"))) {
1391 if (safe_create_leading_directories(logfile) < 0)
1392 return error("unable to create directory for %s",
1393 logfile);
1394 oflags |= O_CREAT;
1395 }
1396
1397 logfd = open(logfile, oflags, 0666);
1398 if (logfd < 0) {
1399 if (!(oflags & O_CREAT) && errno == ENOENT)
1400 return 0;
1401
1402 if ((oflags & O_CREAT) && errno == EISDIR) {
1403 if (remove_empty_directories(logfile)) {
1404 return error("There are still logs under '%s'",
1405 logfile);
1406 }
1407 logfd = open(logfile, oflags, 0666);
1408 }
1409
1410 if (logfd < 0)
1411 return error("Unable to append to %s: %s",
1412 logfile, strerror(errno));
1413 }
1414
1415 adjust_shared_perm(logfile);
1416 close(logfd);
1417 return 0;
1418 }
1419
1420 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1421 const unsigned char *new_sha1, const char *msg)
1422 {
1423 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1424 unsigned maxlen, len;
1425 int msglen;
1426 char log_file[PATH_MAX];
1427 char *logrec;
1428 const char *committer;
1429
1430 if (log_all_ref_updates < 0)
1431 log_all_ref_updates = !is_bare_repository();
1432
1433 result = log_ref_setup(ref_name, log_file, sizeof(log_file));
1434 if (result)
1435 return result;
1436
1437 logfd = open(log_file, oflags);
1438 if (logfd < 0)
1439 return 0;
1440 msglen = msg ? strlen(msg) : 0;
1441 committer = git_committer_info(0);
1442 maxlen = strlen(committer) + msglen + 100;
1443 logrec = xmalloc(maxlen);
1444 len = sprintf(logrec, "%s %s %s\n",
1445 sha1_to_hex(old_sha1),
1446 sha1_to_hex(new_sha1),
1447 committer);
1448 if (msglen)
1449 len += copy_msg(logrec + len - 1, msg) - 1;
1450 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1451 free(logrec);
1452 if (close(logfd) != 0 || written != len)
1453 return error("Unable to append to %s", log_file);
1454 return 0;
1455 }
1456
1457 static int is_branch(const char *refname)
1458 {
1459 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1460 }
1461
1462 int write_ref_sha1(struct ref_lock *lock,
1463 const unsigned char *sha1, const char *logmsg)
1464 {
1465 static char term = '\n';
1466 struct object *o;
1467
1468 if (!lock)
1469 return -1;
1470 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1471 unlock_ref(lock);
1472 return 0;
1473 }
1474 o = parse_object(sha1);
1475 if (!o) {
1476 error("Trying to write ref %s with nonexistent object %s",
1477 lock->ref_name, sha1_to_hex(sha1));
1478 unlock_ref(lock);
1479 return -1;
1480 }
1481 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1482 error("Trying to write non-commit object %s to branch %s",
1483 sha1_to_hex(sha1), lock->ref_name);
1484 unlock_ref(lock);
1485 return -1;
1486 }
1487 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1488 write_in_full(lock->lock_fd, &term, 1) != 1
1489 || close_ref(lock) < 0) {
1490 error("Couldn't write %s", lock->lk->filename);
1491 unlock_ref(lock);
1492 return -1;
1493 }
1494 invalidate_cached_refs();
1495 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1496 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1497 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1498 unlock_ref(lock);
1499 return -1;
1500 }
1501 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1502 /*
1503 * Special hack: If a branch is updated directly and HEAD
1504 * points to it (may happen on the remote side of a push
1505 * for example) then logically the HEAD reflog should be
1506 * updated too.
1507 * A generic solution implies reverse symref information,
1508 * but finding all symrefs pointing to the given branch
1509 * would be rather costly for this rare event (the direct
1510 * update of a branch) to be worth it. So let's cheat and
1511 * check with HEAD only which should cover 99% of all usage
1512 * scenarios (even 100% of the default ones).
1513 */
1514 unsigned char head_sha1[20];
1515 int head_flag;
1516 const char *head_ref;
1517 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1518 if (head_ref && (head_flag & REF_ISSYMREF) &&
1519 !strcmp(head_ref, lock->ref_name))
1520 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1521 }
1522 if (commit_ref(lock)) {
1523 error("Couldn't set %s", lock->ref_name);
1524 unlock_ref(lock);
1525 return -1;
1526 }
1527 unlock_ref(lock);
1528 return 0;
1529 }
1530
1531 int create_symref(const char *ref_target, const char *refs_heads_master,
1532 const char *logmsg)
1533 {
1534 const char *lockpath;
1535 char ref[1000];
1536 int fd, len, written;
1537 char *git_HEAD = git_pathdup("%s", ref_target);
1538 unsigned char old_sha1[20], new_sha1[20];
1539
1540 if (logmsg && read_ref(ref_target, old_sha1))
1541 hashclr(old_sha1);
1542
1543 if (safe_create_leading_directories(git_HEAD) < 0)
1544 return error("unable to create directory for %s", git_HEAD);
1545
1546 #ifndef NO_SYMLINK_HEAD
1547 if (prefer_symlink_refs) {
1548 unlink(git_HEAD);
1549 if (!symlink(refs_heads_master, git_HEAD))
1550 goto done;
1551 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1552 }
1553 #endif
1554
1555 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1556 if (sizeof(ref) <= len) {
1557 error("refname too long: %s", refs_heads_master);
1558 goto error_free_return;
1559 }
1560 lockpath = mkpath("%s.lock", git_HEAD);
1561 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1562 if (fd < 0) {
1563 error("Unable to open %s for writing", lockpath);
1564 goto error_free_return;
1565 }
1566 written = write_in_full(fd, ref, len);
1567 if (close(fd) != 0 || written != len) {
1568 error("Unable to write to %s", lockpath);
1569 goto error_unlink_return;
1570 }
1571 if (rename(lockpath, git_HEAD) < 0) {
1572 error("Unable to create %s", git_HEAD);
1573 goto error_unlink_return;
1574 }
1575 if (adjust_shared_perm(git_HEAD)) {
1576 error("Unable to fix permissions on %s", lockpath);
1577 error_unlink_return:
1578 unlink_or_warn(lockpath);
1579 error_free_return:
1580 free(git_HEAD);
1581 return -1;
1582 }
1583
1584 #ifndef NO_SYMLINK_HEAD
1585 done:
1586 #endif
1587 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1588 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1589
1590 free(git_HEAD);
1591 return 0;
1592 }
1593
1594 static char *ref_msg(const char *line, const char *endp)
1595 {
1596 const char *ep;
1597 line += 82;
1598 ep = memchr(line, '\n', endp - line);
1599 if (!ep)
1600 ep = endp;
1601 return xmemdupz(line, ep - line);
1602 }
1603
1604 int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
1605 {
1606 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1607 char *tz_c;
1608 int logfd, tz, reccnt = 0;
1609 struct stat st;
1610 unsigned long date;
1611 unsigned char logged_sha1[20];
1612 void *log_mapped;
1613 size_t mapsz;
1614
1615 logfile = git_path("logs/%s", ref);
1616 logfd = open(logfile, O_RDONLY, 0);
1617 if (logfd < 0)
1618 die_errno("Unable to read log '%s'", logfile);
1619 fstat(logfd, &st);
1620 if (!st.st_size)
1621 die("Log %s is empty.", logfile);
1622 mapsz = xsize_t(st.st_size);
1623 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1624 logdata = log_mapped;
1625 close(logfd);
1626
1627 lastrec = NULL;
1628 rec = logend = logdata + st.st_size;
1629 while (logdata < rec) {
1630 reccnt++;
1631 if (logdata < rec && *(rec-1) == '\n')
1632 rec--;
1633 lastgt = NULL;
1634 while (logdata < rec && *(rec-1) != '\n') {
1635 rec--;
1636 if (*rec == '>')
1637 lastgt = rec;
1638 }
1639 if (!lastgt)
1640 die("Log %s is corrupt.", logfile);
1641 date = strtoul(lastgt + 1, &tz_c, 10);
1642 if (date <= at_time || cnt == 0) {
1643 tz = strtoul(tz_c, NULL, 10);
1644 if (msg)
1645 *msg = ref_msg(rec, logend);
1646 if (cutoff_time)
1647 *cutoff_time = date;
1648 if (cutoff_tz)
1649 *cutoff_tz = tz;
1650 if (cutoff_cnt)
1651 *cutoff_cnt = reccnt - 1;
1652 if (lastrec) {
1653 if (get_sha1_hex(lastrec, logged_sha1))
1654 die("Log %s is corrupt.", logfile);
1655 if (get_sha1_hex(rec + 41, sha1))
1656 die("Log %s is corrupt.", logfile);
1657 if (hashcmp(logged_sha1, sha1)) {
1658 warning("Log %s has gap after %s.",
1659 logfile, show_date(date, tz, DATE_RFC2822));
1660 }
1661 }
1662 else if (date == at_time) {
1663 if (get_sha1_hex(rec + 41, sha1))
1664 die("Log %s is corrupt.", logfile);
1665 }
1666 else {
1667 if (get_sha1_hex(rec + 41, logged_sha1))
1668 die("Log %s is corrupt.", logfile);
1669 if (hashcmp(logged_sha1, sha1)) {
1670 warning("Log %s unexpectedly ended on %s.",
1671 logfile, show_date(date, tz, DATE_RFC2822));
1672 }
1673 }
1674 munmap(log_mapped, mapsz);
1675 return 0;
1676 }
1677 lastrec = rec;
1678 if (cnt > 0)
1679 cnt--;
1680 }
1681
1682 rec = logdata;
1683 while (rec < logend && *rec != '>' && *rec != '\n')
1684 rec++;
1685 if (rec == logend || *rec == '\n')
1686 die("Log %s is corrupt.", logfile);
1687 date = strtoul(rec + 1, &tz_c, 10);
1688 tz = strtoul(tz_c, NULL, 10);
1689 if (get_sha1_hex(logdata, sha1))
1690 die("Log %s is corrupt.", logfile);
1691 if (is_null_sha1(sha1)) {
1692 if (get_sha1_hex(logdata + 41, sha1))
1693 die("Log %s is corrupt.", logfile);
1694 }
1695 if (msg)
1696 *msg = ref_msg(logdata, logend);
1697 munmap(log_mapped, mapsz);
1698
1699 if (cutoff_time)
1700 *cutoff_time = date;
1701 if (cutoff_tz)
1702 *cutoff_tz = tz;
1703 if (cutoff_cnt)
1704 *cutoff_cnt = reccnt;
1705 return 1;
1706 }
1707
1708 int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
1709 {
1710 const char *logfile;
1711 FILE *logfp;
1712 struct strbuf sb = STRBUF_INIT;
1713 int ret = 0;
1714
1715 logfile = git_path("logs/%s", ref);
1716 logfp = fopen(logfile, "r");
1717 if (!logfp)
1718 return -1;
1719
1720 if (ofs) {
1721 struct stat statbuf;
1722 if (fstat(fileno(logfp), &statbuf) ||
1723 statbuf.st_size < ofs ||
1724 fseek(logfp, -ofs, SEEK_END) ||
1725 strbuf_getwholeline(&sb, logfp, '\n')) {
1726 fclose(logfp);
1727 strbuf_release(&sb);
1728 return -1;
1729 }
1730 }
1731
1732 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
1733 unsigned char osha1[20], nsha1[20];
1734 char *email_end, *message;
1735 unsigned long timestamp;
1736 int tz;
1737
1738 /* old SP new SP name <email> SP time TAB msg LF */
1739 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
1740 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
1741 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
1742 !(email_end = strchr(sb.buf + 82, '>')) ||
1743 email_end[1] != ' ' ||
1744 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1745 !message || message[0] != ' ' ||
1746 (message[1] != '+' && message[1] != '-') ||
1747 !isdigit(message[2]) || !isdigit(message[3]) ||
1748 !isdigit(message[4]) || !isdigit(message[5]))
1749 continue; /* corrupt? */
1750 email_end[1] = '\0';
1751 tz = strtol(message + 1, NULL, 10);
1752 if (message[6] != '\t')
1753 message += 6;
1754 else
1755 message += 7;
1756 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
1757 cb_data);
1758 if (ret)
1759 break;
1760 }
1761 fclose(logfp);
1762 strbuf_release(&sb);
1763 return ret;
1764 }
1765
1766 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1767 {
1768 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1769 }
1770
1771 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1772 {
1773 DIR *dir = opendir(git_path("logs/%s", base));
1774 int retval = 0;
1775
1776 if (dir) {
1777 struct dirent *de;
1778 int baselen = strlen(base);
1779 char *log = xmalloc(baselen + 257);
1780
1781 memcpy(log, base, baselen);
1782 if (baselen && base[baselen-1] != '/')
1783 log[baselen++] = '/';
1784
1785 while ((de = readdir(dir)) != NULL) {
1786 struct stat st;
1787 int namelen;
1788
1789 if (de->d_name[0] == '.')
1790 continue;
1791 namelen = strlen(de->d_name);
1792 if (namelen > 255)
1793 continue;
1794 if (has_extension(de->d_name, ".lock"))
1795 continue;
1796 memcpy(log + baselen, de->d_name, namelen+1);
1797 if (stat(git_path("logs/%s", log), &st) < 0)
1798 continue;
1799 if (S_ISDIR(st.st_mode)) {
1800 retval = do_for_each_reflog(log, fn, cb_data);
1801 } else {
1802 unsigned char sha1[20];
1803 if (!resolve_ref(log, sha1, 0, NULL))
1804 retval = error("bad ref for %s", log);
1805 else
1806 retval = fn(log, sha1, 0, cb_data);
1807 }
1808 if (retval)
1809 break;
1810 }
1811 free(log);
1812 closedir(dir);
1813 }
1814 else if (*base)
1815 return errno;
1816 return retval;
1817 }
1818
1819 int for_each_reflog(each_ref_fn fn, void *cb_data)
1820 {
1821 return do_for_each_reflog("", fn, cb_data);
1822 }
1823
1824 int update_ref(const char *action, const char *refname,
1825 const unsigned char *sha1, const unsigned char *oldval,
1826 int flags, enum action_on_err onerr)
1827 {
1828 static struct ref_lock *lock;
1829 lock = lock_any_ref_for_update(refname, oldval, flags);
1830 if (!lock) {
1831 const char *str = "Cannot lock the ref '%s'.";
1832 switch (onerr) {
1833 case MSG_ON_ERR: error(str, refname); break;
1834 case DIE_ON_ERR: die(str, refname); break;
1835 case QUIET_ON_ERR: break;
1836 }
1837 return 1;
1838 }
1839 if (write_ref_sha1(lock, sha1, action) < 0) {
1840 const char *str = "Cannot update the ref '%s'.";
1841 switch (onerr) {
1842 case MSG_ON_ERR: error(str, refname); break;
1843 case DIE_ON_ERR: die(str, refname); break;
1844 case QUIET_ON_ERR: break;
1845 }
1846 return 1;
1847 }
1848 return 0;
1849 }
1850
1851 int ref_exists(char *refname)
1852 {
1853 unsigned char sha1[20];
1854 return !!resolve_ref(refname, sha1, 1, NULL);
1855 }
1856
1857 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1858 {
1859 for ( ; list; list = list->next)
1860 if (!strcmp(list->name, name))
1861 return (struct ref *)list;
1862 return NULL;
1863 }
1864
1865 /*
1866 * generate a format suitable for scanf from a ref_rev_parse_rules
1867 * rule, that is replace the "%.*s" spec with a "%s" spec
1868 */
1869 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1870 {
1871 char *spec;
1872
1873 spec = strstr(rule, "%.*s");
1874 if (!spec || strstr(spec + 4, "%.*s"))
1875 die("invalid rule in ref_rev_parse_rules: %s", rule);
1876
1877 /* copy all until spec */
1878 strncpy(scanf_fmt, rule, spec - rule);
1879 scanf_fmt[spec - rule] = '\0';
1880 /* copy new spec */
1881 strcat(scanf_fmt, "%s");
1882 /* copy remaining rule */
1883 strcat(scanf_fmt, spec + 4);
1884
1885 return;
1886 }
1887
1888 char *shorten_unambiguous_ref(const char *ref, int strict)
1889 {
1890 int i;
1891 static char **scanf_fmts;
1892 static int nr_rules;
1893 char *short_name;
1894
1895 /* pre generate scanf formats from ref_rev_parse_rules[] */
1896 if (!nr_rules) {
1897 size_t total_len = 0;
1898
1899 /* the rule list is NULL terminated, count them first */
1900 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
1901 /* no +1 because strlen("%s") < strlen("%.*s") */
1902 total_len += strlen(ref_rev_parse_rules[nr_rules]);
1903
1904 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
1905
1906 total_len = 0;
1907 for (i = 0; i < nr_rules; i++) {
1908 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
1909 + total_len;
1910 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
1911 total_len += strlen(ref_rev_parse_rules[i]);
1912 }
1913 }
1914
1915 /* bail out if there are no rules */
1916 if (!nr_rules)
1917 return xstrdup(ref);
1918
1919 /* buffer for scanf result, at most ref must fit */
1920 short_name = xstrdup(ref);
1921
1922 /* skip first rule, it will always match */
1923 for (i = nr_rules - 1; i > 0 ; --i) {
1924 int j;
1925 int rules_to_fail = i;
1926 int short_name_len;
1927
1928 if (1 != sscanf(ref, scanf_fmts[i], short_name))
1929 continue;
1930
1931 short_name_len = strlen(short_name);
1932
1933 /*
1934 * in strict mode, all (except the matched one) rules
1935 * must fail to resolve to a valid non-ambiguous ref
1936 */
1937 if (strict)
1938 rules_to_fail = nr_rules;
1939
1940 /*
1941 * check if the short name resolves to a valid ref,
1942 * but use only rules prior to the matched one
1943 */
1944 for (j = 0; j < rules_to_fail; j++) {
1945 const char *rule = ref_rev_parse_rules[j];
1946 unsigned char short_objectname[20];
1947 char refname[PATH_MAX];
1948
1949 /* skip matched rule */
1950 if (i == j)
1951 continue;
1952
1953 /*
1954 * the short name is ambiguous, if it resolves
1955 * (with this previous rule) to a valid ref
1956 * read_ref() returns 0 on success
1957 */
1958 mksnpath(refname, sizeof(refname),
1959 rule, short_name_len, short_name);
1960 if (!read_ref(refname, short_objectname))
1961 break;
1962 }
1963
1964 /*
1965 * short name is non-ambiguous if all previous rules
1966 * haven't resolved to a valid ref
1967 */
1968 if (j == rules_to_fail)
1969 return short_name;
1970 }
1971
1972 free(short_name);
1973 return xstrdup(ref);
1974 }