Merge branch 'jm/maint-gitweb-filter-forks-fix' into maint
[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 static inline int bad_ref_char(int ch)
864 {
865 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
866 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
867 return 1;
868 /* 2.13 Pattern Matching Notation */
869 if (ch == '?' || ch == '[') /* Unsupported */
870 return 1;
871 if (ch == '*') /* Supported at the end */
872 return 2;
873 return 0;
874 }
875
876 int check_ref_format(const char *ref)
877 {
878 int ch, level, bad_type, last;
879 int ret = CHECK_REF_FORMAT_OK;
880 const char *cp = ref;
881
882 level = 0;
883 while (1) {
884 while ((ch = *cp++) == '/')
885 ; /* tolerate duplicated slashes */
886 if (!ch)
887 /* should not end with slashes */
888 return CHECK_REF_FORMAT_ERROR;
889
890 /* we are at the beginning of the path component */
891 if (ch == '.')
892 return CHECK_REF_FORMAT_ERROR;
893 bad_type = bad_ref_char(ch);
894 if (bad_type) {
895 if (bad_type == 2 && (!*cp || *cp == '/') &&
896 ret == CHECK_REF_FORMAT_OK)
897 ret = CHECK_REF_FORMAT_WILDCARD;
898 else
899 return CHECK_REF_FORMAT_ERROR;
900 }
901
902 last = ch;
903 /* scan the rest of the path component */
904 while ((ch = *cp++) != 0) {
905 bad_type = bad_ref_char(ch);
906 if (bad_type)
907 return CHECK_REF_FORMAT_ERROR;
908 if (ch == '/')
909 break;
910 if (last == '.' && ch == '.')
911 return CHECK_REF_FORMAT_ERROR;
912 if (last == '@' && ch == '{')
913 return CHECK_REF_FORMAT_ERROR;
914 last = ch;
915 }
916 level++;
917 if (!ch) {
918 if (ref <= cp - 2 && cp[-2] == '.')
919 return CHECK_REF_FORMAT_ERROR;
920 if (level < 2)
921 return CHECK_REF_FORMAT_ONELEVEL;
922 if (has_extension(ref, ".lock"))
923 return CHECK_REF_FORMAT_ERROR;
924 return ret;
925 }
926 }
927 }
928
929 const char *prettify_refname(const char *name)
930 {
931 return name + (
932 !prefixcmp(name, "refs/heads/") ? 11 :
933 !prefixcmp(name, "refs/tags/") ? 10 :
934 !prefixcmp(name, "refs/remotes/") ? 13 :
935 0);
936 }
937
938 const char *ref_rev_parse_rules[] = {
939 "%.*s",
940 "refs/%.*s",
941 "refs/tags/%.*s",
942 "refs/heads/%.*s",
943 "refs/remotes/%.*s",
944 "refs/remotes/%.*s/HEAD",
945 NULL
946 };
947
948 const char *ref_fetch_rules[] = {
949 "%.*s",
950 "refs/%.*s",
951 "refs/heads/%.*s",
952 NULL
953 };
954
955 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
956 {
957 const char **p;
958 const int abbrev_name_len = strlen(abbrev_name);
959
960 for (p = rules; *p; p++) {
961 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
962 return 1;
963 }
964 }
965
966 return 0;
967 }
968
969 static struct ref_lock *verify_lock(struct ref_lock *lock,
970 const unsigned char *old_sha1, int mustexist)
971 {
972 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
973 error("Can't verify ref %s", lock->ref_name);
974 unlock_ref(lock);
975 return NULL;
976 }
977 if (hashcmp(lock->old_sha1, old_sha1)) {
978 error("Ref %s is at %s but expected %s", lock->ref_name,
979 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
980 unlock_ref(lock);
981 return NULL;
982 }
983 return lock;
984 }
985
986 static int remove_empty_directories(const char *file)
987 {
988 /* we want to create a file but there is a directory there;
989 * if that is an empty directory (or a directory that contains
990 * only empty directories), remove them.
991 */
992 struct strbuf path;
993 int result;
994
995 strbuf_init(&path, 20);
996 strbuf_addstr(&path, file);
997
998 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
999
1000 strbuf_release(&path);
1001
1002 return result;
1003 }
1004
1005 static int is_refname_available(const char *ref, const char *oldref,
1006 struct ref_list *list, int quiet)
1007 {
1008 int namlen = strlen(ref); /* e.g. 'foo/bar' */
1009 while (list) {
1010 /* list->name could be 'foo' or 'foo/bar/baz' */
1011 if (!oldref || strcmp(oldref, list->name)) {
1012 int len = strlen(list->name);
1013 int cmplen = (namlen < len) ? namlen : len;
1014 const char *lead = (namlen < len) ? list->name : ref;
1015 if (!strncmp(ref, list->name, cmplen) &&
1016 lead[cmplen] == '/') {
1017 if (!quiet)
1018 error("'%s' exists; cannot create '%s'",
1019 list->name, ref);
1020 return 0;
1021 }
1022 }
1023 list = list->next;
1024 }
1025 return 1;
1026 }
1027
1028 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
1029 {
1030 char *ref_file;
1031 const char *orig_ref = ref;
1032 struct ref_lock *lock;
1033 int last_errno = 0;
1034 int type, lflags;
1035 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1036 int missing = 0;
1037
1038 lock = xcalloc(1, sizeof(struct ref_lock));
1039 lock->lock_fd = -1;
1040
1041 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
1042 if (!ref && errno == EISDIR) {
1043 /* we are trying to lock foo but we used to
1044 * have foo/bar which now does not exist;
1045 * it is normal for the empty directory 'foo'
1046 * to remain.
1047 */
1048 ref_file = git_path("%s", orig_ref);
1049 if (remove_empty_directories(ref_file)) {
1050 last_errno = errno;
1051 error("there are still refs under '%s'", orig_ref);
1052 goto error_return;
1053 }
1054 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
1055 }
1056 if (type_p)
1057 *type_p = type;
1058 if (!ref) {
1059 last_errno = errno;
1060 error("unable to resolve reference %s: %s",
1061 orig_ref, strerror(errno));
1062 goto error_return;
1063 }
1064 missing = is_null_sha1(lock->old_sha1);
1065 /* When the ref did not exist and we are creating it,
1066 * make sure there is no existing ref that is packed
1067 * whose name begins with our refname, nor a ref whose
1068 * name is a proper prefix of our refname.
1069 */
1070 if (missing &&
1071 !is_refname_available(ref, NULL, get_packed_refs(NULL), 0)) {
1072 last_errno = ENOTDIR;
1073 goto error_return;
1074 }
1075
1076 lock->lk = xcalloc(1, sizeof(struct lock_file));
1077
1078 lflags = LOCK_DIE_ON_ERROR;
1079 if (flags & REF_NODEREF) {
1080 ref = orig_ref;
1081 lflags |= LOCK_NODEREF;
1082 }
1083 lock->ref_name = xstrdup(ref);
1084 lock->orig_ref_name = xstrdup(orig_ref);
1085 ref_file = git_path("%s", ref);
1086 if (missing)
1087 lock->force_write = 1;
1088 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1089 lock->force_write = 1;
1090
1091 if (safe_create_leading_directories(ref_file)) {
1092 last_errno = errno;
1093 error("unable to create directory for %s", ref_file);
1094 goto error_return;
1095 }
1096
1097 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
1098 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
1099
1100 error_return:
1101 unlock_ref(lock);
1102 errno = last_errno;
1103 return NULL;
1104 }
1105
1106 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
1107 {
1108 char refpath[PATH_MAX];
1109 if (check_ref_format(ref))
1110 return NULL;
1111 strcpy(refpath, mkpath("refs/%s", ref));
1112 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
1113 }
1114
1115 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
1116 {
1117 switch (check_ref_format(ref)) {
1118 default:
1119 return NULL;
1120 case 0:
1121 case CHECK_REF_FORMAT_ONELEVEL:
1122 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
1123 }
1124 }
1125
1126 static struct lock_file packlock;
1127
1128 static int repack_without_ref(const char *refname)
1129 {
1130 struct ref_list *list, *packed_ref_list;
1131 int fd;
1132 int found = 0;
1133
1134 packed_ref_list = get_packed_refs(NULL);
1135 for (list = packed_ref_list; list; list = list->next) {
1136 if (!strcmp(refname, list->name)) {
1137 found = 1;
1138 break;
1139 }
1140 }
1141 if (!found)
1142 return 0;
1143 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1144 if (fd < 0) {
1145 unable_to_lock_error(git_path("packed-refs"), errno);
1146 return error("cannot delete '%s' from packed refs", refname);
1147 }
1148
1149 for (list = packed_ref_list; list; list = list->next) {
1150 char line[PATH_MAX + 100];
1151 int len;
1152
1153 if (!strcmp(refname, list->name))
1154 continue;
1155 len = snprintf(line, sizeof(line), "%s %s\n",
1156 sha1_to_hex(list->sha1), list->name);
1157 /* this should not happen but just being defensive */
1158 if (len > sizeof(line))
1159 die("too long a refname '%s'", list->name);
1160 write_or_die(fd, line, len);
1161 }
1162 return commit_lock_file(&packlock);
1163 }
1164
1165 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
1166 {
1167 struct ref_lock *lock;
1168 int err, i = 0, ret = 0, flag = 0;
1169
1170 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
1171 if (!lock)
1172 return 1;
1173 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
1174 /* loose */
1175 const char *path;
1176
1177 if (!(delopt & REF_NODEREF)) {
1178 i = strlen(lock->lk->filename) - 5; /* .lock */
1179 lock->lk->filename[i] = 0;
1180 path = lock->lk->filename;
1181 } else {
1182 path = git_path("%s", refname);
1183 }
1184 err = unlink_or_warn(path);
1185 if (err && errno != ENOENT)
1186 ret = 1;
1187
1188 if (!(delopt & REF_NODEREF))
1189 lock->lk->filename[i] = '.';
1190 }
1191 /* removing the loose one could have resurrected an earlier
1192 * packed one. Also, if it was not loose we need to repack
1193 * without it.
1194 */
1195 ret |= repack_without_ref(refname);
1196
1197 unlink_or_warn(git_path("logs/%s", lock->ref_name));
1198 invalidate_cached_refs();
1199 unlock_ref(lock);
1200 return ret;
1201 }
1202
1203 /*
1204 * People using contrib's git-new-workdir have .git/logs/refs ->
1205 * /some/other/path/.git/logs/refs, and that may live on another device.
1206 *
1207 * IOW, to avoid cross device rename errors, the temporary renamed log must
1208 * live into logs/refs.
1209 */
1210 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1211
1212 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
1213 {
1214 static const char renamed_ref[] = "RENAMED-REF";
1215 unsigned char sha1[20], orig_sha1[20];
1216 int flag = 0, logmoved = 0;
1217 struct ref_lock *lock;
1218 struct stat loginfo;
1219 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
1220 const char *symref = NULL;
1221
1222 if (log && S_ISLNK(loginfo.st_mode))
1223 return error("reflog for %s is a symlink", oldref);
1224
1225 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1226 if (flag & REF_ISSYMREF)
1227 return error("refname %s is a symbolic ref, renaming it is not supported",
1228 oldref);
1229 if (!symref)
1230 return error("refname %s not found", oldref);
1231
1232 if (!is_refname_available(newref, oldref, get_packed_refs(NULL), 0))
1233 return 1;
1234
1235 if (!is_refname_available(newref, oldref, get_loose_refs(NULL), 0))
1236 return 1;
1237
1238 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
1239 if (!lock)
1240 return error("unable to lock %s", renamed_ref);
1241 lock->force_write = 1;
1242 if (write_ref_sha1(lock, orig_sha1, logmsg))
1243 return error("unable to save current sha1 in %s", renamed_ref);
1244
1245 if (log && rename(git_path("logs/%s", oldref), git_path(TMP_RENAMED_LOG)))
1246 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
1247 oldref, strerror(errno));
1248
1249 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
1250 error("unable to delete old %s", oldref);
1251 goto rollback;
1252 }
1253
1254 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
1255 if (errno==EISDIR) {
1256 if (remove_empty_directories(git_path("%s", newref))) {
1257 error("Directory not empty: %s", newref);
1258 goto rollback;
1259 }
1260 } else {
1261 error("unable to delete existing %s", newref);
1262 goto rollback;
1263 }
1264 }
1265
1266 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1267 error("unable to create directory for %s", newref);
1268 goto rollback;
1269 }
1270
1271 retry:
1272 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newref))) {
1273 if (errno==EISDIR || errno==ENOTDIR) {
1274 /*
1275 * rename(a, b) when b is an existing
1276 * directory ought to result in ISDIR, but
1277 * Solaris 5.8 gives ENOTDIR. Sheesh.
1278 */
1279 if (remove_empty_directories(git_path("logs/%s", newref))) {
1280 error("Directory not empty: logs/%s", newref);
1281 goto rollback;
1282 }
1283 goto retry;
1284 } else {
1285 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
1286 newref, strerror(errno));
1287 goto rollback;
1288 }
1289 }
1290 logmoved = log;
1291
1292 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
1293 if (!lock) {
1294 error("unable to lock %s for update", newref);
1295 goto rollback;
1296 }
1297 lock->force_write = 1;
1298 hashcpy(lock->old_sha1, orig_sha1);
1299 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1300 error("unable to write current sha1 into %s", newref);
1301 goto rollback;
1302 }
1303
1304 return 0;
1305
1306 rollback:
1307 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1308 if (!lock) {
1309 error("unable to lock %s for rollback", oldref);
1310 goto rollbacklog;
1311 }
1312
1313 lock->force_write = 1;
1314 flag = log_all_ref_updates;
1315 log_all_ref_updates = 0;
1316 if (write_ref_sha1(lock, orig_sha1, NULL))
1317 error("unable to write current sha1 into %s", oldref);
1318 log_all_ref_updates = flag;
1319
1320 rollbacklog:
1321 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1322 error("unable to restore logfile %s from %s: %s",
1323 oldref, newref, strerror(errno));
1324 if (!logmoved && log &&
1325 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldref)))
1326 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
1327 oldref, strerror(errno));
1328
1329 return 1;
1330 }
1331
1332 int close_ref(struct ref_lock *lock)
1333 {
1334 if (close_lock_file(lock->lk))
1335 return -1;
1336 lock->lock_fd = -1;
1337 return 0;
1338 }
1339
1340 int commit_ref(struct ref_lock *lock)
1341 {
1342 if (commit_lock_file(lock->lk))
1343 return -1;
1344 lock->lock_fd = -1;
1345 return 0;
1346 }
1347
1348 void unlock_ref(struct ref_lock *lock)
1349 {
1350 /* Do not free lock->lk -- atexit() still looks at them */
1351 if (lock->lk)
1352 rollback_lock_file(lock->lk);
1353 free(lock->ref_name);
1354 free(lock->orig_ref_name);
1355 free(lock);
1356 }
1357
1358 /*
1359 * copy the reflog message msg to buf, which has been allocated sufficiently
1360 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1361 * because reflog file is one line per entry.
1362 */
1363 static int copy_msg(char *buf, const char *msg)
1364 {
1365 char *cp = buf;
1366 char c;
1367 int wasspace = 1;
1368
1369 *cp++ = '\t';
1370 while ((c = *msg++)) {
1371 if (wasspace && isspace(c))
1372 continue;
1373 wasspace = isspace(c);
1374 if (wasspace)
1375 c = ' ';
1376 *cp++ = c;
1377 }
1378 while (buf < cp && isspace(cp[-1]))
1379 cp--;
1380 *cp++ = '\n';
1381 return cp - buf;
1382 }
1383
1384 int log_ref_setup(const char *ref_name, char *logfile, int bufsize)
1385 {
1386 int logfd, oflags = O_APPEND | O_WRONLY;
1387
1388 git_snpath(logfile, bufsize, "logs/%s", ref_name);
1389 if (log_all_ref_updates &&
1390 (!prefixcmp(ref_name, "refs/heads/") ||
1391 !prefixcmp(ref_name, "refs/remotes/") ||
1392 !prefixcmp(ref_name, "refs/notes/") ||
1393 !strcmp(ref_name, "HEAD"))) {
1394 if (safe_create_leading_directories(logfile) < 0)
1395 return error("unable to create directory for %s",
1396 logfile);
1397 oflags |= O_CREAT;
1398 }
1399
1400 logfd = open(logfile, oflags, 0666);
1401 if (logfd < 0) {
1402 if (!(oflags & O_CREAT) && errno == ENOENT)
1403 return 0;
1404
1405 if ((oflags & O_CREAT) && errno == EISDIR) {
1406 if (remove_empty_directories(logfile)) {
1407 return error("There are still logs under '%s'",
1408 logfile);
1409 }
1410 logfd = open(logfile, oflags, 0666);
1411 }
1412
1413 if (logfd < 0)
1414 return error("Unable to append to %s: %s",
1415 logfile, strerror(errno));
1416 }
1417
1418 adjust_shared_perm(logfile);
1419 close(logfd);
1420 return 0;
1421 }
1422
1423 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1424 const unsigned char *new_sha1, const char *msg)
1425 {
1426 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1427 unsigned maxlen, len;
1428 int msglen;
1429 char log_file[PATH_MAX];
1430 char *logrec;
1431 const char *committer;
1432
1433 if (log_all_ref_updates < 0)
1434 log_all_ref_updates = !is_bare_repository();
1435
1436 result = log_ref_setup(ref_name, log_file, sizeof(log_file));
1437 if (result)
1438 return result;
1439
1440 logfd = open(log_file, oflags);
1441 if (logfd < 0)
1442 return 0;
1443 msglen = msg ? strlen(msg) : 0;
1444 committer = git_committer_info(0);
1445 maxlen = strlen(committer) + msglen + 100;
1446 logrec = xmalloc(maxlen);
1447 len = sprintf(logrec, "%s %s %s\n",
1448 sha1_to_hex(old_sha1),
1449 sha1_to_hex(new_sha1),
1450 committer);
1451 if (msglen)
1452 len += copy_msg(logrec + len - 1, msg) - 1;
1453 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1454 free(logrec);
1455 if (close(logfd) != 0 || written != len)
1456 return error("Unable to append to %s", log_file);
1457 return 0;
1458 }
1459
1460 static int is_branch(const char *refname)
1461 {
1462 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1463 }
1464
1465 int write_ref_sha1(struct ref_lock *lock,
1466 const unsigned char *sha1, const char *logmsg)
1467 {
1468 static char term = '\n';
1469 struct object *o;
1470
1471 if (!lock)
1472 return -1;
1473 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1474 unlock_ref(lock);
1475 return 0;
1476 }
1477 o = parse_object(sha1);
1478 if (!o) {
1479 error("Trying to write ref %s with nonexistent object %s",
1480 lock->ref_name, sha1_to_hex(sha1));
1481 unlock_ref(lock);
1482 return -1;
1483 }
1484 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1485 error("Trying to write non-commit object %s to branch %s",
1486 sha1_to_hex(sha1), lock->ref_name);
1487 unlock_ref(lock);
1488 return -1;
1489 }
1490 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1491 write_in_full(lock->lock_fd, &term, 1) != 1
1492 || close_ref(lock) < 0) {
1493 error("Couldn't write %s", lock->lk->filename);
1494 unlock_ref(lock);
1495 return -1;
1496 }
1497 invalidate_cached_refs();
1498 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1499 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1500 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1501 unlock_ref(lock);
1502 return -1;
1503 }
1504 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1505 /*
1506 * Special hack: If a branch is updated directly and HEAD
1507 * points to it (may happen on the remote side of a push
1508 * for example) then logically the HEAD reflog should be
1509 * updated too.
1510 * A generic solution implies reverse symref information,
1511 * but finding all symrefs pointing to the given branch
1512 * would be rather costly for this rare event (the direct
1513 * update of a branch) to be worth it. So let's cheat and
1514 * check with HEAD only which should cover 99% of all usage
1515 * scenarios (even 100% of the default ones).
1516 */
1517 unsigned char head_sha1[20];
1518 int head_flag;
1519 const char *head_ref;
1520 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1521 if (head_ref && (head_flag & REF_ISSYMREF) &&
1522 !strcmp(head_ref, lock->ref_name))
1523 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1524 }
1525 if (commit_ref(lock)) {
1526 error("Couldn't set %s", lock->ref_name);
1527 unlock_ref(lock);
1528 return -1;
1529 }
1530 unlock_ref(lock);
1531 return 0;
1532 }
1533
1534 int create_symref(const char *ref_target, const char *refs_heads_master,
1535 const char *logmsg)
1536 {
1537 const char *lockpath;
1538 char ref[1000];
1539 int fd, len, written;
1540 char *git_HEAD = git_pathdup("%s", ref_target);
1541 unsigned char old_sha1[20], new_sha1[20];
1542
1543 if (logmsg && read_ref(ref_target, old_sha1))
1544 hashclr(old_sha1);
1545
1546 if (safe_create_leading_directories(git_HEAD) < 0)
1547 return error("unable to create directory for %s", git_HEAD);
1548
1549 #ifndef NO_SYMLINK_HEAD
1550 if (prefer_symlink_refs) {
1551 unlink(git_HEAD);
1552 if (!symlink(refs_heads_master, git_HEAD))
1553 goto done;
1554 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1555 }
1556 #endif
1557
1558 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1559 if (sizeof(ref) <= len) {
1560 error("refname too long: %s", refs_heads_master);
1561 goto error_free_return;
1562 }
1563 lockpath = mkpath("%s.lock", git_HEAD);
1564 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1565 if (fd < 0) {
1566 error("Unable to open %s for writing", lockpath);
1567 goto error_free_return;
1568 }
1569 written = write_in_full(fd, ref, len);
1570 if (close(fd) != 0 || written != len) {
1571 error("Unable to write to %s", lockpath);
1572 goto error_unlink_return;
1573 }
1574 if (rename(lockpath, git_HEAD) < 0) {
1575 error("Unable to create %s", git_HEAD);
1576 goto error_unlink_return;
1577 }
1578 if (adjust_shared_perm(git_HEAD)) {
1579 error("Unable to fix permissions on %s", lockpath);
1580 error_unlink_return:
1581 unlink_or_warn(lockpath);
1582 error_free_return:
1583 free(git_HEAD);
1584 return -1;
1585 }
1586
1587 #ifndef NO_SYMLINK_HEAD
1588 done:
1589 #endif
1590 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1591 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1592
1593 free(git_HEAD);
1594 return 0;
1595 }
1596
1597 static char *ref_msg(const char *line, const char *endp)
1598 {
1599 const char *ep;
1600 line += 82;
1601 ep = memchr(line, '\n', endp - line);
1602 if (!ep)
1603 ep = endp;
1604 return xmemdupz(line, ep - line);
1605 }
1606
1607 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)
1608 {
1609 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1610 char *tz_c;
1611 int logfd, tz, reccnt = 0;
1612 struct stat st;
1613 unsigned long date;
1614 unsigned char logged_sha1[20];
1615 void *log_mapped;
1616 size_t mapsz;
1617
1618 logfile = git_path("logs/%s", ref);
1619 logfd = open(logfile, O_RDONLY, 0);
1620 if (logfd < 0)
1621 die_errno("Unable to read log '%s'", logfile);
1622 fstat(logfd, &st);
1623 if (!st.st_size)
1624 die("Log %s is empty.", logfile);
1625 mapsz = xsize_t(st.st_size);
1626 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1627 logdata = log_mapped;
1628 close(logfd);
1629
1630 lastrec = NULL;
1631 rec = logend = logdata + st.st_size;
1632 while (logdata < rec) {
1633 reccnt++;
1634 if (logdata < rec && *(rec-1) == '\n')
1635 rec--;
1636 lastgt = NULL;
1637 while (logdata < rec && *(rec-1) != '\n') {
1638 rec--;
1639 if (*rec == '>')
1640 lastgt = rec;
1641 }
1642 if (!lastgt)
1643 die("Log %s is corrupt.", logfile);
1644 date = strtoul(lastgt + 1, &tz_c, 10);
1645 if (date <= at_time || cnt == 0) {
1646 tz = strtoul(tz_c, NULL, 10);
1647 if (msg)
1648 *msg = ref_msg(rec, logend);
1649 if (cutoff_time)
1650 *cutoff_time = date;
1651 if (cutoff_tz)
1652 *cutoff_tz = tz;
1653 if (cutoff_cnt)
1654 *cutoff_cnt = reccnt - 1;
1655 if (lastrec) {
1656 if (get_sha1_hex(lastrec, logged_sha1))
1657 die("Log %s is corrupt.", logfile);
1658 if (get_sha1_hex(rec + 41, sha1))
1659 die("Log %s is corrupt.", logfile);
1660 if (hashcmp(logged_sha1, sha1)) {
1661 warning("Log %s has gap after %s.",
1662 logfile, show_date(date, tz, DATE_RFC2822));
1663 }
1664 }
1665 else if (date == at_time) {
1666 if (get_sha1_hex(rec + 41, sha1))
1667 die("Log %s is corrupt.", logfile);
1668 }
1669 else {
1670 if (get_sha1_hex(rec + 41, logged_sha1))
1671 die("Log %s is corrupt.", logfile);
1672 if (hashcmp(logged_sha1, sha1)) {
1673 warning("Log %s unexpectedly ended on %s.",
1674 logfile, show_date(date, tz, DATE_RFC2822));
1675 }
1676 }
1677 munmap(log_mapped, mapsz);
1678 return 0;
1679 }
1680 lastrec = rec;
1681 if (cnt > 0)
1682 cnt--;
1683 }
1684
1685 rec = logdata;
1686 while (rec < logend && *rec != '>' && *rec != '\n')
1687 rec++;
1688 if (rec == logend || *rec == '\n')
1689 die("Log %s is corrupt.", logfile);
1690 date = strtoul(rec + 1, &tz_c, 10);
1691 tz = strtoul(tz_c, NULL, 10);
1692 if (get_sha1_hex(logdata, sha1))
1693 die("Log %s is corrupt.", logfile);
1694 if (is_null_sha1(sha1)) {
1695 if (get_sha1_hex(logdata + 41, sha1))
1696 die("Log %s is corrupt.", logfile);
1697 }
1698 if (msg)
1699 *msg = ref_msg(logdata, logend);
1700 munmap(log_mapped, mapsz);
1701
1702 if (cutoff_time)
1703 *cutoff_time = date;
1704 if (cutoff_tz)
1705 *cutoff_tz = tz;
1706 if (cutoff_cnt)
1707 *cutoff_cnt = reccnt;
1708 return 1;
1709 }
1710
1711 int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
1712 {
1713 const char *logfile;
1714 FILE *logfp;
1715 struct strbuf sb = STRBUF_INIT;
1716 int ret = 0;
1717
1718 logfile = git_path("logs/%s", ref);
1719 logfp = fopen(logfile, "r");
1720 if (!logfp)
1721 return -1;
1722
1723 if (ofs) {
1724 struct stat statbuf;
1725 if (fstat(fileno(logfp), &statbuf) ||
1726 statbuf.st_size < ofs ||
1727 fseek(logfp, -ofs, SEEK_END) ||
1728 strbuf_getwholeline(&sb, logfp, '\n')) {
1729 fclose(logfp);
1730 strbuf_release(&sb);
1731 return -1;
1732 }
1733 }
1734
1735 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
1736 unsigned char osha1[20], nsha1[20];
1737 char *email_end, *message;
1738 unsigned long timestamp;
1739 int tz;
1740
1741 /* old SP new SP name <email> SP time TAB msg LF */
1742 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
1743 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
1744 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
1745 !(email_end = strchr(sb.buf + 82, '>')) ||
1746 email_end[1] != ' ' ||
1747 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1748 !message || message[0] != ' ' ||
1749 (message[1] != '+' && message[1] != '-') ||
1750 !isdigit(message[2]) || !isdigit(message[3]) ||
1751 !isdigit(message[4]) || !isdigit(message[5]))
1752 continue; /* corrupt? */
1753 email_end[1] = '\0';
1754 tz = strtol(message + 1, NULL, 10);
1755 if (message[6] != '\t')
1756 message += 6;
1757 else
1758 message += 7;
1759 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
1760 cb_data);
1761 if (ret)
1762 break;
1763 }
1764 fclose(logfp);
1765 strbuf_release(&sb);
1766 return ret;
1767 }
1768
1769 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1770 {
1771 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1772 }
1773
1774 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1775 {
1776 DIR *dir = opendir(git_path("logs/%s", base));
1777 int retval = 0;
1778
1779 if (dir) {
1780 struct dirent *de;
1781 int baselen = strlen(base);
1782 char *log = xmalloc(baselen + 257);
1783
1784 memcpy(log, base, baselen);
1785 if (baselen && base[baselen-1] != '/')
1786 log[baselen++] = '/';
1787
1788 while ((de = readdir(dir)) != NULL) {
1789 struct stat st;
1790 int namelen;
1791
1792 if (de->d_name[0] == '.')
1793 continue;
1794 namelen = strlen(de->d_name);
1795 if (namelen > 255)
1796 continue;
1797 if (has_extension(de->d_name, ".lock"))
1798 continue;
1799 memcpy(log + baselen, de->d_name, namelen+1);
1800 if (stat(git_path("logs/%s", log), &st) < 0)
1801 continue;
1802 if (S_ISDIR(st.st_mode)) {
1803 retval = do_for_each_reflog(log, fn, cb_data);
1804 } else {
1805 unsigned char sha1[20];
1806 if (!resolve_ref(log, sha1, 0, NULL))
1807 retval = error("bad ref for %s", log);
1808 else
1809 retval = fn(log, sha1, 0, cb_data);
1810 }
1811 if (retval)
1812 break;
1813 }
1814 free(log);
1815 closedir(dir);
1816 }
1817 else if (*base)
1818 return errno;
1819 return retval;
1820 }
1821
1822 int for_each_reflog(each_ref_fn fn, void *cb_data)
1823 {
1824 return do_for_each_reflog("", fn, cb_data);
1825 }
1826
1827 int update_ref(const char *action, const char *refname,
1828 const unsigned char *sha1, const unsigned char *oldval,
1829 int flags, enum action_on_err onerr)
1830 {
1831 static struct ref_lock *lock;
1832 lock = lock_any_ref_for_update(refname, oldval, flags);
1833 if (!lock) {
1834 const char *str = "Cannot lock the ref '%s'.";
1835 switch (onerr) {
1836 case MSG_ON_ERR: error(str, refname); break;
1837 case DIE_ON_ERR: die(str, refname); break;
1838 case QUIET_ON_ERR: break;
1839 }
1840 return 1;
1841 }
1842 if (write_ref_sha1(lock, sha1, action) < 0) {
1843 const char *str = "Cannot update the ref '%s'.";
1844 switch (onerr) {
1845 case MSG_ON_ERR: error(str, refname); break;
1846 case DIE_ON_ERR: die(str, refname); break;
1847 case QUIET_ON_ERR: break;
1848 }
1849 return 1;
1850 }
1851 return 0;
1852 }
1853
1854 int ref_exists(char *refname)
1855 {
1856 unsigned char sha1[20];
1857 return !!resolve_ref(refname, sha1, 1, NULL);
1858 }
1859
1860 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1861 {
1862 for ( ; list; list = list->next)
1863 if (!strcmp(list->name, name))
1864 return (struct ref *)list;
1865 return NULL;
1866 }
1867
1868 /*
1869 * generate a format suitable for scanf from a ref_rev_parse_rules
1870 * rule, that is replace the "%.*s" spec with a "%s" spec
1871 */
1872 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1873 {
1874 char *spec;
1875
1876 spec = strstr(rule, "%.*s");
1877 if (!spec || strstr(spec + 4, "%.*s"))
1878 die("invalid rule in ref_rev_parse_rules: %s", rule);
1879
1880 /* copy all until spec */
1881 strncpy(scanf_fmt, rule, spec - rule);
1882 scanf_fmt[spec - rule] = '\0';
1883 /* copy new spec */
1884 strcat(scanf_fmt, "%s");
1885 /* copy remaining rule */
1886 strcat(scanf_fmt, spec + 4);
1887
1888 return;
1889 }
1890
1891 char *shorten_unambiguous_ref(const char *ref, int strict)
1892 {
1893 int i;
1894 static char **scanf_fmts;
1895 static int nr_rules;
1896 char *short_name;
1897
1898 /* pre generate scanf formats from ref_rev_parse_rules[] */
1899 if (!nr_rules) {
1900 size_t total_len = 0;
1901
1902 /* the rule list is NULL terminated, count them first */
1903 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
1904 /* no +1 because strlen("%s") < strlen("%.*s") */
1905 total_len += strlen(ref_rev_parse_rules[nr_rules]);
1906
1907 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
1908
1909 total_len = 0;
1910 for (i = 0; i < nr_rules; i++) {
1911 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
1912 + total_len;
1913 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
1914 total_len += strlen(ref_rev_parse_rules[i]);
1915 }
1916 }
1917
1918 /* bail out if there are no rules */
1919 if (!nr_rules)
1920 return xstrdup(ref);
1921
1922 /* buffer for scanf result, at most ref must fit */
1923 short_name = xstrdup(ref);
1924
1925 /* skip first rule, it will always match */
1926 for (i = nr_rules - 1; i > 0 ; --i) {
1927 int j;
1928 int rules_to_fail = i;
1929 int short_name_len;
1930
1931 if (1 != sscanf(ref, scanf_fmts[i], short_name))
1932 continue;
1933
1934 short_name_len = strlen(short_name);
1935
1936 /*
1937 * in strict mode, all (except the matched one) rules
1938 * must fail to resolve to a valid non-ambiguous ref
1939 */
1940 if (strict)
1941 rules_to_fail = nr_rules;
1942
1943 /*
1944 * check if the short name resolves to a valid ref,
1945 * but use only rules prior to the matched one
1946 */
1947 for (j = 0; j < rules_to_fail; j++) {
1948 const char *rule = ref_rev_parse_rules[j];
1949 unsigned char short_objectname[20];
1950 char refname[PATH_MAX];
1951
1952 /* skip matched rule */
1953 if (i == j)
1954 continue;
1955
1956 /*
1957 * the short name is ambiguous, if it resolves
1958 * (with this previous rule) to a valid ref
1959 * read_ref() returns 0 on success
1960 */
1961 mksnpath(refname, sizeof(refname),
1962 rule, short_name_len, short_name);
1963 if (!read_ref(refname, short_objectname))
1964 break;
1965 }
1966
1967 /*
1968 * short name is non-ambiguous if all previous rules
1969 * haven't resolved to a valid ref
1970 */
1971 if (j == rules_to_fail)
1972 return short_name;
1973 }
1974
1975 free(short_name);
1976 return xstrdup(ref);
1977 }