GIT 1.6.4
[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
10 struct ref_list {
11 struct ref_list *next;
12 unsigned char flag; /* ISSYMREF? ISPACKED? */
13 unsigned char sha1[20];
14 unsigned char peeled[20];
15 char name[FLEX_ARRAY];
16 };
17
18 static const char *parse_ref_line(char *line, unsigned char *sha1)
19 {
20 /*
21 * 42: the answer to everything.
22 *
23 * In this case, it happens to be the answer to
24 * 40 (length of sha1 hex representation)
25 * +1 (space in between hex and name)
26 * +1 (newline at the end of the line)
27 */
28 int len = strlen(line) - 42;
29
30 if (len <= 0)
31 return NULL;
32 if (get_sha1_hex(line, sha1) < 0)
33 return NULL;
34 if (!isspace(line[40]))
35 return NULL;
36 line += 41;
37 if (isspace(*line))
38 return NULL;
39 if (line[len] != '\n')
40 return NULL;
41 line[len] = 0;
42
43 return line;
44 }
45
46 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
47 int flag, struct ref_list *list,
48 struct ref_list **new_entry)
49 {
50 int len;
51 struct ref_list *entry;
52
53 /* Allocate it and add it in.. */
54 len = strlen(name) + 1;
55 entry = xmalloc(sizeof(struct ref_list) + len);
56 hashcpy(entry->sha1, sha1);
57 hashclr(entry->peeled);
58 memcpy(entry->name, name, len);
59 entry->flag = flag;
60 entry->next = list;
61 if (new_entry)
62 *new_entry = entry;
63 return entry;
64 }
65
66 /* merge sort the ref list */
67 static struct ref_list *sort_ref_list(struct ref_list *list)
68 {
69 int psize, qsize, last_merge_count, cmp;
70 struct ref_list *p, *q, *l, *e;
71 struct ref_list *new_list = list;
72 int k = 1;
73 int merge_count = 0;
74
75 if (!list)
76 return list;
77
78 do {
79 last_merge_count = merge_count;
80 merge_count = 0;
81
82 psize = 0;
83
84 p = new_list;
85 q = new_list;
86 new_list = NULL;
87 l = NULL;
88
89 while (p) {
90 merge_count++;
91
92 while (psize < k && q->next) {
93 q = q->next;
94 psize++;
95 }
96 qsize = k;
97
98 while ((psize > 0) || (qsize > 0 && q)) {
99 if (qsize == 0 || !q) {
100 e = p;
101 p = p->next;
102 psize--;
103 } else if (psize == 0) {
104 e = q;
105 q = q->next;
106 qsize--;
107 } else {
108 cmp = strcmp(q->name, p->name);
109 if (cmp < 0) {
110 e = q;
111 q = q->next;
112 qsize--;
113 } else if (cmp > 0) {
114 e = p;
115 p = p->next;
116 psize--;
117 } else {
118 if (hashcmp(q->sha1, p->sha1))
119 die("Duplicated ref, and SHA1s don't match: %s",
120 q->name);
121 warning("Duplicated ref: %s", q->name);
122 e = q;
123 q = q->next;
124 qsize--;
125 free(e);
126 e = p;
127 p = p->next;
128 psize--;
129 }
130 }
131
132 e->next = NULL;
133
134 if (l)
135 l->next = e;
136 if (!new_list)
137 new_list = e;
138 l = e;
139 }
140
141 p = q;
142 };
143
144 k = k * 2;
145 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
146
147 return new_list;
148 }
149
150 /*
151 * Future: need to be in "struct repository"
152 * when doing a full libification.
153 */
154 static struct cached_refs {
155 char did_loose;
156 char did_packed;
157 struct ref_list *loose;
158 struct ref_list *packed;
159 } cached_refs;
160 static struct ref_list *current_ref;
161
162 static struct ref_list *extra_refs;
163
164 static void free_ref_list(struct ref_list *list)
165 {
166 struct ref_list *next;
167 for ( ; list; list = next) {
168 next = list->next;
169 free(list);
170 }
171 }
172
173 static void invalidate_cached_refs(void)
174 {
175 struct cached_refs *ca = &cached_refs;
176
177 if (ca->did_loose && ca->loose)
178 free_ref_list(ca->loose);
179 if (ca->did_packed && ca->packed)
180 free_ref_list(ca->packed);
181 ca->loose = ca->packed = NULL;
182 ca->did_loose = ca->did_packed = 0;
183 }
184
185 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
186 {
187 struct ref_list *list = NULL;
188 struct ref_list *last = NULL;
189 char refline[PATH_MAX];
190 int flag = REF_ISPACKED;
191
192 while (fgets(refline, sizeof(refline), f)) {
193 unsigned char sha1[20];
194 const char *name;
195 static const char header[] = "# pack-refs with:";
196
197 if (!strncmp(refline, header, sizeof(header)-1)) {
198 const char *traits = refline + sizeof(header) - 1;
199 if (strstr(traits, " peeled "))
200 flag |= REF_KNOWS_PEELED;
201 /* perhaps other traits later as well */
202 continue;
203 }
204
205 name = parse_ref_line(refline, sha1);
206 if (name) {
207 list = add_ref(name, sha1, flag, list, &last);
208 continue;
209 }
210 if (last &&
211 refline[0] == '^' &&
212 strlen(refline) == 42 &&
213 refline[41] == '\n' &&
214 !get_sha1_hex(refline + 1, sha1))
215 hashcpy(last->peeled, sha1);
216 }
217 cached_refs->packed = sort_ref_list(list);
218 }
219
220 void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
221 {
222 extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
223 }
224
225 void clear_extra_refs(void)
226 {
227 free_ref_list(extra_refs);
228 extra_refs = NULL;
229 }
230
231 static struct ref_list *get_packed_refs(void)
232 {
233 if (!cached_refs.did_packed) {
234 FILE *f = fopen(git_path("packed-refs"), "r");
235 cached_refs.packed = NULL;
236 if (f) {
237 read_packed_refs(f, &cached_refs);
238 fclose(f);
239 }
240 cached_refs.did_packed = 1;
241 }
242 return cached_refs.packed;
243 }
244
245 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
246 {
247 DIR *dir = opendir(git_path("%s", base));
248
249 if (dir) {
250 struct dirent *de;
251 int baselen = strlen(base);
252 char *ref = xmalloc(baselen + 257);
253
254 memcpy(ref, base, baselen);
255 if (baselen && base[baselen-1] != '/')
256 ref[baselen++] = '/';
257
258 while ((de = readdir(dir)) != NULL) {
259 unsigned char sha1[20];
260 struct stat st;
261 int flag;
262 int namelen;
263
264 if (de->d_name[0] == '.')
265 continue;
266 namelen = strlen(de->d_name);
267 if (namelen > 255)
268 continue;
269 if (has_extension(de->d_name, ".lock"))
270 continue;
271 memcpy(ref + baselen, de->d_name, namelen+1);
272 if (stat(git_path("%s", ref), &st) < 0)
273 continue;
274 if (S_ISDIR(st.st_mode)) {
275 list = get_ref_dir(ref, list);
276 continue;
277 }
278 if (!resolve_ref(ref, sha1, 1, &flag))
279 hashclr(sha1);
280 list = add_ref(ref, sha1, flag, list, NULL);
281 }
282 free(ref);
283 closedir(dir);
284 }
285 return sort_ref_list(list);
286 }
287
288 struct warn_if_dangling_data {
289 const char *refname;
290 const char *msg_fmt;
291 };
292
293 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
294 int flags, void *cb_data)
295 {
296 struct warn_if_dangling_data *d = cb_data;
297 const char *resolves_to;
298 unsigned char junk[20];
299
300 if (!(flags & REF_ISSYMREF))
301 return 0;
302
303 resolves_to = resolve_ref(refname, junk, 0, NULL);
304 if (!resolves_to || strcmp(resolves_to, d->refname))
305 return 0;
306
307 printf(d->msg_fmt, refname);
308 return 0;
309 }
310
311 void warn_dangling_symref(const char *msg_fmt, const char *refname)
312 {
313 struct warn_if_dangling_data data = { refname, msg_fmt };
314 for_each_rawref(warn_if_dangling_symref, &data);
315 }
316
317 static struct ref_list *get_loose_refs(void)
318 {
319 if (!cached_refs.did_loose) {
320 cached_refs.loose = get_ref_dir("refs", NULL);
321 cached_refs.did_loose = 1;
322 }
323 return cached_refs.loose;
324 }
325
326 /* We allow "recursive" symbolic refs. Only within reason, though */
327 #define MAXDEPTH 5
328 #define MAXREFLEN (1024)
329
330 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
331 {
332 FILE *f;
333 struct cached_refs refs;
334 struct ref_list *ref;
335 int retval;
336
337 strcpy(name + pathlen, "packed-refs");
338 f = fopen(name, "r");
339 if (!f)
340 return -1;
341 read_packed_refs(f, &refs);
342 fclose(f);
343 ref = refs.packed;
344 retval = -1;
345 while (ref) {
346 if (!strcmp(ref->name, refname)) {
347 retval = 0;
348 memcpy(result, ref->sha1, 20);
349 break;
350 }
351 ref = ref->next;
352 }
353 free_ref_list(refs.packed);
354 return retval;
355 }
356
357 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
358 {
359 int fd, len = strlen(refname);
360 char buffer[128], *p;
361
362 if (recursion > MAXDEPTH || len > MAXREFLEN)
363 return -1;
364 memcpy(name + pathlen, refname, len+1);
365 fd = open(name, O_RDONLY);
366 if (fd < 0)
367 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
368
369 len = read(fd, buffer, sizeof(buffer)-1);
370 close(fd);
371 if (len < 0)
372 return -1;
373 while (len && isspace(buffer[len-1]))
374 len--;
375 buffer[len] = 0;
376
377 /* Was it a detached head or an old-fashioned symlink? */
378 if (!get_sha1_hex(buffer, result))
379 return 0;
380
381 /* Symref? */
382 if (strncmp(buffer, "ref:", 4))
383 return -1;
384 p = buffer + 4;
385 while (isspace(*p))
386 p++;
387
388 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
389 }
390
391 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
392 {
393 int len = strlen(path), retval;
394 char *gitdir;
395 const char *tmp;
396
397 while (len && path[len-1] == '/')
398 len--;
399 if (!len)
400 return -1;
401 gitdir = xmalloc(len + MAXREFLEN + 8);
402 memcpy(gitdir, path, len);
403 memcpy(gitdir + len, "/.git", 6);
404 len += 5;
405
406 tmp = read_gitfile_gently(gitdir);
407 if (tmp) {
408 free(gitdir);
409 len = strlen(tmp);
410 gitdir = xmalloc(len + MAXREFLEN + 3);
411 memcpy(gitdir, tmp, len);
412 }
413 gitdir[len] = '/';
414 gitdir[++len] = '\0';
415 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
416 free(gitdir);
417 return retval;
418 }
419
420 /*
421 * If the "reading" argument is set, this function finds out what _object_
422 * the ref points at by "reading" the ref. The ref, if it is not symbolic,
423 * has to exist, and if it is symbolic, it has to point at an existing ref,
424 * because the "read" goes through the symref to the ref it points at.
425 *
426 * The access that is not "reading" may often be "writing", but does not
427 * have to; it can be merely checking _where it leads to_. If it is a
428 * prelude to "writing" to the ref, a write to a symref that points at
429 * yet-to-be-born ref will create the real ref pointed by the symref.
430 * reading=0 allows the caller to check where such a symref leads to.
431 */
432 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
433 {
434 int depth = MAXDEPTH;
435 ssize_t len;
436 char buffer[256];
437 static char ref_buffer[256];
438
439 if (flag)
440 *flag = 0;
441
442 for (;;) {
443 char path[PATH_MAX];
444 struct stat st;
445 char *buf;
446 int fd;
447
448 if (--depth < 0)
449 return NULL;
450
451 git_snpath(path, sizeof(path), "%s", ref);
452 /* Special case: non-existing file. */
453 if (lstat(path, &st) < 0) {
454 struct ref_list *list = get_packed_refs();
455 while (list) {
456 if (!strcmp(ref, list->name)) {
457 hashcpy(sha1, list->sha1);
458 if (flag)
459 *flag |= REF_ISPACKED;
460 return ref;
461 }
462 list = list->next;
463 }
464 if (reading || errno != ENOENT)
465 return NULL;
466 hashclr(sha1);
467 return ref;
468 }
469
470 /* Follow "normalized" - ie "refs/.." symlinks by hand */
471 if (S_ISLNK(st.st_mode)) {
472 len = readlink(path, buffer, sizeof(buffer)-1);
473 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
474 buffer[len] = 0;
475 strcpy(ref_buffer, buffer);
476 ref = ref_buffer;
477 if (flag)
478 *flag |= REF_ISSYMREF;
479 continue;
480 }
481 }
482
483 /* Is it a directory? */
484 if (S_ISDIR(st.st_mode)) {
485 errno = EISDIR;
486 return NULL;
487 }
488
489 /*
490 * Anything else, just open it and try to use it as
491 * a ref
492 */
493 fd = open(path, O_RDONLY);
494 if (fd < 0)
495 return NULL;
496 len = read_in_full(fd, buffer, sizeof(buffer)-1);
497 close(fd);
498
499 /*
500 * Is it a symbolic ref?
501 */
502 if (len < 4 || memcmp("ref:", buffer, 4))
503 break;
504 buf = buffer + 4;
505 len -= 4;
506 while (len && isspace(*buf))
507 buf++, len--;
508 while (len && isspace(buf[len-1]))
509 len--;
510 buf[len] = 0;
511 memcpy(ref_buffer, buf, len + 1);
512 ref = ref_buffer;
513 if (flag)
514 *flag |= REF_ISSYMREF;
515 }
516 if (len < 40 || get_sha1_hex(buffer, sha1))
517 return NULL;
518 return ref;
519 }
520
521 int read_ref(const char *ref, unsigned char *sha1)
522 {
523 if (resolve_ref(ref, sha1, 1, NULL))
524 return 0;
525 return -1;
526 }
527
528 #define DO_FOR_EACH_INCLUDE_BROKEN 01
529 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
530 int flags, void *cb_data, struct ref_list *entry)
531 {
532 if (strncmp(base, entry->name, trim))
533 return 0;
534 /* Is this a "negative ref" that represents a deleted ref? */
535 if (is_null_sha1(entry->sha1))
536 return 0;
537 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
538 if (!has_sha1_file(entry->sha1)) {
539 error("%s does not point to a valid object!", entry->name);
540 return 0;
541 }
542 }
543 current_ref = entry;
544 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
545 }
546
547 int peel_ref(const char *ref, unsigned char *sha1)
548 {
549 int flag;
550 unsigned char base[20];
551 struct object *o;
552
553 if (current_ref && (current_ref->name == ref
554 || !strcmp(current_ref->name, ref))) {
555 if (current_ref->flag & REF_KNOWS_PEELED) {
556 hashcpy(sha1, current_ref->peeled);
557 return 0;
558 }
559 hashcpy(base, current_ref->sha1);
560 goto fallback;
561 }
562
563 if (!resolve_ref(ref, base, 1, &flag))
564 return -1;
565
566 if ((flag & REF_ISPACKED)) {
567 struct ref_list *list = get_packed_refs();
568
569 while (list) {
570 if (!strcmp(list->name, ref)) {
571 if (list->flag & REF_KNOWS_PEELED) {
572 hashcpy(sha1, list->peeled);
573 return 0;
574 }
575 /* older pack-refs did not leave peeled ones */
576 break;
577 }
578 list = list->next;
579 }
580 }
581
582 fallback:
583 o = parse_object(base);
584 if (o && o->type == OBJ_TAG) {
585 o = deref_tag(o, ref, 0);
586 if (o) {
587 hashcpy(sha1, o->sha1);
588 return 0;
589 }
590 }
591 return -1;
592 }
593
594 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
595 int flags, void *cb_data)
596 {
597 int retval = 0;
598 struct ref_list *packed = get_packed_refs();
599 struct ref_list *loose = get_loose_refs();
600
601 struct ref_list *extra;
602
603 for (extra = extra_refs; extra; extra = extra->next)
604 retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
605
606 while (packed && loose) {
607 struct ref_list *entry;
608 int cmp = strcmp(packed->name, loose->name);
609 if (!cmp) {
610 packed = packed->next;
611 continue;
612 }
613 if (cmp > 0) {
614 entry = loose;
615 loose = loose->next;
616 } else {
617 entry = packed;
618 packed = packed->next;
619 }
620 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
621 if (retval)
622 goto end_each;
623 }
624
625 for (packed = packed ? packed : loose; packed; packed = packed->next) {
626 retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
627 if (retval)
628 goto end_each;
629 }
630
631 end_each:
632 current_ref = NULL;
633 return retval;
634 }
635
636 int head_ref(each_ref_fn fn, void *cb_data)
637 {
638 unsigned char sha1[20];
639 int flag;
640
641 if (resolve_ref("HEAD", sha1, 1, &flag))
642 return fn("HEAD", sha1, flag, cb_data);
643 return 0;
644 }
645
646 int for_each_ref(each_ref_fn fn, void *cb_data)
647 {
648 return do_for_each_ref("refs/", fn, 0, 0, cb_data);
649 }
650
651 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
652 {
653 return do_for_each_ref(prefix, fn, strlen(prefix), 0, cb_data);
654 }
655
656 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
657 {
658 return for_each_ref_in("refs/tags/", fn, cb_data);
659 }
660
661 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
662 {
663 return for_each_ref_in("refs/heads/", fn, cb_data);
664 }
665
666 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
667 {
668 return for_each_ref_in("refs/remotes/", fn, cb_data);
669 }
670
671 int for_each_rawref(each_ref_fn fn, void *cb_data)
672 {
673 return do_for_each_ref("refs/", fn, 0,
674 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
675 }
676
677 /*
678 * Make sure "ref" is something reasonable to have under ".git/refs/";
679 * We do not like it if:
680 *
681 * - any path component of it begins with ".", or
682 * - it has double dots "..", or
683 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
684 * - it ends with a "/".
685 * - it ends with ".lock"
686 * - it contains a "\" (backslash)
687 */
688
689 static inline int bad_ref_char(int ch)
690 {
691 if (((unsigned) ch) <= ' ' ||
692 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
693 return 1;
694 /* 2.13 Pattern Matching Notation */
695 if (ch == '?' || ch == '[') /* Unsupported */
696 return 1;
697 if (ch == '*') /* Supported at the end */
698 return 2;
699 return 0;
700 }
701
702 int check_ref_format(const char *ref)
703 {
704 int ch, level, bad_type, last;
705 int ret = CHECK_REF_FORMAT_OK;
706 const char *cp = ref;
707
708 level = 0;
709 while (1) {
710 while ((ch = *cp++) == '/')
711 ; /* tolerate duplicated slashes */
712 if (!ch)
713 /* should not end with slashes */
714 return CHECK_REF_FORMAT_ERROR;
715
716 /* we are at the beginning of the path component */
717 if (ch == '.')
718 return CHECK_REF_FORMAT_ERROR;
719 bad_type = bad_ref_char(ch);
720 if (bad_type) {
721 if (bad_type == 2 && (!*cp || *cp == '/') &&
722 ret == CHECK_REF_FORMAT_OK)
723 ret = CHECK_REF_FORMAT_WILDCARD;
724 else
725 return CHECK_REF_FORMAT_ERROR;
726 }
727
728 last = ch;
729 /* scan the rest of the path component */
730 while ((ch = *cp++) != 0) {
731 bad_type = bad_ref_char(ch);
732 if (bad_type)
733 return CHECK_REF_FORMAT_ERROR;
734 if (ch == '/')
735 break;
736 if (last == '.' && ch == '.')
737 return CHECK_REF_FORMAT_ERROR;
738 if (last == '@' && ch == '{')
739 return CHECK_REF_FORMAT_ERROR;
740 last = ch;
741 }
742 level++;
743 if (!ch) {
744 if (ref <= cp - 2 && cp[-2] == '.')
745 return CHECK_REF_FORMAT_ERROR;
746 if (level < 2)
747 return CHECK_REF_FORMAT_ONELEVEL;
748 if (has_extension(ref, ".lock"))
749 return CHECK_REF_FORMAT_ERROR;
750 return ret;
751 }
752 }
753 }
754
755 const char *prettify_refname(const char *name)
756 {
757 return name + (
758 !prefixcmp(name, "refs/heads/") ? 11 :
759 !prefixcmp(name, "refs/tags/") ? 10 :
760 !prefixcmp(name, "refs/remotes/") ? 13 :
761 0);
762 }
763
764 const char *ref_rev_parse_rules[] = {
765 "%.*s",
766 "refs/%.*s",
767 "refs/tags/%.*s",
768 "refs/heads/%.*s",
769 "refs/remotes/%.*s",
770 "refs/remotes/%.*s/HEAD",
771 NULL
772 };
773
774 const char *ref_fetch_rules[] = {
775 "%.*s",
776 "refs/%.*s",
777 "refs/heads/%.*s",
778 NULL
779 };
780
781 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
782 {
783 const char **p;
784 const int abbrev_name_len = strlen(abbrev_name);
785
786 for (p = rules; *p; p++) {
787 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
788 return 1;
789 }
790 }
791
792 return 0;
793 }
794
795 static struct ref_lock *verify_lock(struct ref_lock *lock,
796 const unsigned char *old_sha1, int mustexist)
797 {
798 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
799 error("Can't verify ref %s", lock->ref_name);
800 unlock_ref(lock);
801 return NULL;
802 }
803 if (hashcmp(lock->old_sha1, old_sha1)) {
804 error("Ref %s is at %s but expected %s", lock->ref_name,
805 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
806 unlock_ref(lock);
807 return NULL;
808 }
809 return lock;
810 }
811
812 static int remove_empty_directories(const char *file)
813 {
814 /* we want to create a file but there is a directory there;
815 * if that is an empty directory (or a directory that contains
816 * only empty directories), remove them.
817 */
818 struct strbuf path;
819 int result;
820
821 strbuf_init(&path, 20);
822 strbuf_addstr(&path, file);
823
824 result = remove_dir_recursively(&path, 1);
825
826 strbuf_release(&path);
827
828 return result;
829 }
830
831 static int is_refname_available(const char *ref, const char *oldref,
832 struct ref_list *list, int quiet)
833 {
834 int namlen = strlen(ref); /* e.g. 'foo/bar' */
835 while (list) {
836 /* list->name could be 'foo' or 'foo/bar/baz' */
837 if (!oldref || strcmp(oldref, list->name)) {
838 int len = strlen(list->name);
839 int cmplen = (namlen < len) ? namlen : len;
840 const char *lead = (namlen < len) ? list->name : ref;
841 if (!strncmp(ref, list->name, cmplen) &&
842 lead[cmplen] == '/') {
843 if (!quiet)
844 error("'%s' exists; cannot create '%s'",
845 list->name, ref);
846 return 0;
847 }
848 }
849 list = list->next;
850 }
851 return 1;
852 }
853
854 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
855 {
856 char *ref_file;
857 const char *orig_ref = ref;
858 struct ref_lock *lock;
859 int last_errno = 0;
860 int type, lflags;
861 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
862 int missing = 0;
863
864 lock = xcalloc(1, sizeof(struct ref_lock));
865 lock->lock_fd = -1;
866
867 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
868 if (!ref && errno == EISDIR) {
869 /* we are trying to lock foo but we used to
870 * have foo/bar which now does not exist;
871 * it is normal for the empty directory 'foo'
872 * to remain.
873 */
874 ref_file = git_path("%s", orig_ref);
875 if (remove_empty_directories(ref_file)) {
876 last_errno = errno;
877 error("there are still refs under '%s'", orig_ref);
878 goto error_return;
879 }
880 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
881 }
882 if (type_p)
883 *type_p = type;
884 if (!ref) {
885 last_errno = errno;
886 error("unable to resolve reference %s: %s",
887 orig_ref, strerror(errno));
888 goto error_return;
889 }
890 missing = is_null_sha1(lock->old_sha1);
891 /* When the ref did not exist and we are creating it,
892 * make sure there is no existing ref that is packed
893 * whose name begins with our refname, nor a ref whose
894 * name is a proper prefix of our refname.
895 */
896 if (missing &&
897 !is_refname_available(ref, NULL, get_packed_refs(), 0)) {
898 last_errno = ENOTDIR;
899 goto error_return;
900 }
901
902 lock->lk = xcalloc(1, sizeof(struct lock_file));
903
904 lflags = LOCK_DIE_ON_ERROR;
905 if (flags & REF_NODEREF) {
906 ref = orig_ref;
907 lflags |= LOCK_NODEREF;
908 }
909 lock->ref_name = xstrdup(ref);
910 lock->orig_ref_name = xstrdup(orig_ref);
911 ref_file = git_path("%s", ref);
912 if (missing)
913 lock->force_write = 1;
914 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
915 lock->force_write = 1;
916
917 if (safe_create_leading_directories(ref_file)) {
918 last_errno = errno;
919 error("unable to create directory for %s", ref_file);
920 goto error_return;
921 }
922
923 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
924 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
925
926 error_return:
927 unlock_ref(lock);
928 errno = last_errno;
929 return NULL;
930 }
931
932 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
933 {
934 char refpath[PATH_MAX];
935 if (check_ref_format(ref))
936 return NULL;
937 strcpy(refpath, mkpath("refs/%s", ref));
938 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
939 }
940
941 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
942 {
943 switch (check_ref_format(ref)) {
944 default:
945 return NULL;
946 case 0:
947 case CHECK_REF_FORMAT_ONELEVEL:
948 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
949 }
950 }
951
952 static struct lock_file packlock;
953
954 static int repack_without_ref(const char *refname)
955 {
956 struct ref_list *list, *packed_ref_list;
957 int fd;
958 int found = 0;
959
960 packed_ref_list = get_packed_refs();
961 for (list = packed_ref_list; list; list = list->next) {
962 if (!strcmp(refname, list->name)) {
963 found = 1;
964 break;
965 }
966 }
967 if (!found)
968 return 0;
969 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
970 if (fd < 0)
971 return error("cannot delete '%s' from packed refs", refname);
972
973 for (list = packed_ref_list; list; list = list->next) {
974 char line[PATH_MAX + 100];
975 int len;
976
977 if (!strcmp(refname, list->name))
978 continue;
979 len = snprintf(line, sizeof(line), "%s %s\n",
980 sha1_to_hex(list->sha1), list->name);
981 /* this should not happen but just being defensive */
982 if (len > sizeof(line))
983 die("too long a refname '%s'", list->name);
984 write_or_die(fd, line, len);
985 }
986 return commit_lock_file(&packlock);
987 }
988
989 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
990 {
991 struct ref_lock *lock;
992 int err, i = 0, ret = 0, flag = 0;
993
994 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
995 if (!lock)
996 return 1;
997 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
998 /* loose */
999 const char *path;
1000
1001 if (!(delopt & REF_NODEREF)) {
1002 i = strlen(lock->lk->filename) - 5; /* .lock */
1003 lock->lk->filename[i] = 0;
1004 path = lock->lk->filename;
1005 } else {
1006 path = git_path("%s", refname);
1007 }
1008 err = unlink_or_warn(path);
1009 if (err && errno != ENOENT)
1010 ret = 1;
1011
1012 if (!(delopt & REF_NODEREF))
1013 lock->lk->filename[i] = '.';
1014 }
1015 /* removing the loose one could have resurrected an earlier
1016 * packed one. Also, if it was not loose we need to repack
1017 * without it.
1018 */
1019 ret |= repack_without_ref(refname);
1020
1021 unlink_or_warn(git_path("logs/%s", lock->ref_name));
1022 invalidate_cached_refs();
1023 unlock_ref(lock);
1024 return ret;
1025 }
1026
1027 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
1028 {
1029 static const char renamed_ref[] = "RENAMED-REF";
1030 unsigned char sha1[20], orig_sha1[20];
1031 int flag = 0, logmoved = 0;
1032 struct ref_lock *lock;
1033 struct stat loginfo;
1034 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
1035 const char *symref = NULL;
1036
1037 if (log && S_ISLNK(loginfo.st_mode))
1038 return error("reflog for %s is a symlink", oldref);
1039
1040 symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1041 if (flag & REF_ISSYMREF)
1042 return error("refname %s is a symbolic ref, renaming it is not supported",
1043 oldref);
1044 if (!symref)
1045 return error("refname %s not found", oldref);
1046
1047 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
1048 return 1;
1049
1050 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
1051 return 1;
1052
1053 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
1054 if (!lock)
1055 return error("unable to lock %s", renamed_ref);
1056 lock->force_write = 1;
1057 if (write_ref_sha1(lock, orig_sha1, logmsg))
1058 return error("unable to save current sha1 in %s", renamed_ref);
1059
1060 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
1061 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
1062 oldref, strerror(errno));
1063
1064 if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
1065 error("unable to delete old %s", oldref);
1066 goto rollback;
1067 }
1068
1069 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
1070 if (errno==EISDIR) {
1071 if (remove_empty_directories(git_path("%s", newref))) {
1072 error("Directory not empty: %s", newref);
1073 goto rollback;
1074 }
1075 } else {
1076 error("unable to delete existing %s", newref);
1077 goto rollback;
1078 }
1079 }
1080
1081 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1082 error("unable to create directory for %s", newref);
1083 goto rollback;
1084 }
1085
1086 retry:
1087 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
1088 if (errno==EISDIR || errno==ENOTDIR) {
1089 /*
1090 * rename(a, b) when b is an existing
1091 * directory ought to result in ISDIR, but
1092 * Solaris 5.8 gives ENOTDIR. Sheesh.
1093 */
1094 if (remove_empty_directories(git_path("logs/%s", newref))) {
1095 error("Directory not empty: logs/%s", newref);
1096 goto rollback;
1097 }
1098 goto retry;
1099 } else {
1100 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
1101 newref, strerror(errno));
1102 goto rollback;
1103 }
1104 }
1105 logmoved = log;
1106
1107 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
1108 if (!lock) {
1109 error("unable to lock %s for update", newref);
1110 goto rollback;
1111 }
1112 lock->force_write = 1;
1113 hashcpy(lock->old_sha1, orig_sha1);
1114 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1115 error("unable to write current sha1 into %s", newref);
1116 goto rollback;
1117 }
1118
1119 return 0;
1120
1121 rollback:
1122 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1123 if (!lock) {
1124 error("unable to lock %s for rollback", oldref);
1125 goto rollbacklog;
1126 }
1127
1128 lock->force_write = 1;
1129 flag = log_all_ref_updates;
1130 log_all_ref_updates = 0;
1131 if (write_ref_sha1(lock, orig_sha1, NULL))
1132 error("unable to write current sha1 into %s", oldref);
1133 log_all_ref_updates = flag;
1134
1135 rollbacklog:
1136 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1137 error("unable to restore logfile %s from %s: %s",
1138 oldref, newref, strerror(errno));
1139 if (!logmoved && log &&
1140 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1141 error("unable to restore logfile %s from tmp-renamed-log: %s",
1142 oldref, strerror(errno));
1143
1144 return 1;
1145 }
1146
1147 int close_ref(struct ref_lock *lock)
1148 {
1149 if (close_lock_file(lock->lk))
1150 return -1;
1151 lock->lock_fd = -1;
1152 return 0;
1153 }
1154
1155 int commit_ref(struct ref_lock *lock)
1156 {
1157 if (commit_lock_file(lock->lk))
1158 return -1;
1159 lock->lock_fd = -1;
1160 return 0;
1161 }
1162
1163 void unlock_ref(struct ref_lock *lock)
1164 {
1165 /* Do not free lock->lk -- atexit() still looks at them */
1166 if (lock->lk)
1167 rollback_lock_file(lock->lk);
1168 free(lock->ref_name);
1169 free(lock->orig_ref_name);
1170 free(lock);
1171 }
1172
1173 /*
1174 * copy the reflog message msg to buf, which has been allocated sufficiently
1175 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1176 * because reflog file is one line per entry.
1177 */
1178 static int copy_msg(char *buf, const char *msg)
1179 {
1180 char *cp = buf;
1181 char c;
1182 int wasspace = 1;
1183
1184 *cp++ = '\t';
1185 while ((c = *msg++)) {
1186 if (wasspace && isspace(c))
1187 continue;
1188 wasspace = isspace(c);
1189 if (wasspace)
1190 c = ' ';
1191 *cp++ = c;
1192 }
1193 while (buf < cp && isspace(cp[-1]))
1194 cp--;
1195 *cp++ = '\n';
1196 return cp - buf;
1197 }
1198
1199 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1200 const unsigned char *new_sha1, const char *msg)
1201 {
1202 int logfd, written, oflags = O_APPEND | O_WRONLY;
1203 unsigned maxlen, len;
1204 int msglen;
1205 char log_file[PATH_MAX];
1206 char *logrec;
1207 const char *committer;
1208
1209 if (log_all_ref_updates < 0)
1210 log_all_ref_updates = !is_bare_repository();
1211
1212 git_snpath(log_file, sizeof(log_file), "logs/%s", ref_name);
1213
1214 if (log_all_ref_updates &&
1215 (!prefixcmp(ref_name, "refs/heads/") ||
1216 !prefixcmp(ref_name, "refs/remotes/") ||
1217 !strcmp(ref_name, "HEAD"))) {
1218 if (safe_create_leading_directories(log_file) < 0)
1219 return error("unable to create directory for %s",
1220 log_file);
1221 oflags |= O_CREAT;
1222 }
1223
1224 logfd = open(log_file, oflags, 0666);
1225 if (logfd < 0) {
1226 if (!(oflags & O_CREAT) && errno == ENOENT)
1227 return 0;
1228
1229 if ((oflags & O_CREAT) && errno == EISDIR) {
1230 if (remove_empty_directories(log_file)) {
1231 return error("There are still logs under '%s'",
1232 log_file);
1233 }
1234 logfd = open(log_file, oflags, 0666);
1235 }
1236
1237 if (logfd < 0)
1238 return error("Unable to append to %s: %s",
1239 log_file, strerror(errno));
1240 }
1241
1242 adjust_shared_perm(log_file);
1243
1244 msglen = msg ? strlen(msg) : 0;
1245 committer = git_committer_info(0);
1246 maxlen = strlen(committer) + msglen + 100;
1247 logrec = xmalloc(maxlen);
1248 len = sprintf(logrec, "%s %s %s\n",
1249 sha1_to_hex(old_sha1),
1250 sha1_to_hex(new_sha1),
1251 committer);
1252 if (msglen)
1253 len += copy_msg(logrec + len - 1, msg) - 1;
1254 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1255 free(logrec);
1256 if (close(logfd) != 0 || written != len)
1257 return error("Unable to append to %s", log_file);
1258 return 0;
1259 }
1260
1261 static int is_branch(const char *refname)
1262 {
1263 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1264 }
1265
1266 int write_ref_sha1(struct ref_lock *lock,
1267 const unsigned char *sha1, const char *logmsg)
1268 {
1269 static char term = '\n';
1270 struct object *o;
1271
1272 if (!lock)
1273 return -1;
1274 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1275 unlock_ref(lock);
1276 return 0;
1277 }
1278 o = parse_object(sha1);
1279 if (!o) {
1280 error("Trying to write ref %s with nonexistant object %s",
1281 lock->ref_name, sha1_to_hex(sha1));
1282 unlock_ref(lock);
1283 return -1;
1284 }
1285 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1286 error("Trying to write non-commit object %s to branch %s",
1287 sha1_to_hex(sha1), lock->ref_name);
1288 unlock_ref(lock);
1289 return -1;
1290 }
1291 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1292 write_in_full(lock->lock_fd, &term, 1) != 1
1293 || close_ref(lock) < 0) {
1294 error("Couldn't write %s", lock->lk->filename);
1295 unlock_ref(lock);
1296 return -1;
1297 }
1298 invalidate_cached_refs();
1299 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1300 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1301 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1302 unlock_ref(lock);
1303 return -1;
1304 }
1305 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1306 /*
1307 * Special hack: If a branch is updated directly and HEAD
1308 * points to it (may happen on the remote side of a push
1309 * for example) then logically the HEAD reflog should be
1310 * updated too.
1311 * A generic solution implies reverse symref information,
1312 * but finding all symrefs pointing to the given branch
1313 * would be rather costly for this rare event (the direct
1314 * update of a branch) to be worth it. So let's cheat and
1315 * check with HEAD only which should cover 99% of all usage
1316 * scenarios (even 100% of the default ones).
1317 */
1318 unsigned char head_sha1[20];
1319 int head_flag;
1320 const char *head_ref;
1321 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1322 if (head_ref && (head_flag & REF_ISSYMREF) &&
1323 !strcmp(head_ref, lock->ref_name))
1324 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1325 }
1326 if (commit_ref(lock)) {
1327 error("Couldn't set %s", lock->ref_name);
1328 unlock_ref(lock);
1329 return -1;
1330 }
1331 unlock_ref(lock);
1332 return 0;
1333 }
1334
1335 int create_symref(const char *ref_target, const char *refs_heads_master,
1336 const char *logmsg)
1337 {
1338 const char *lockpath;
1339 char ref[1000];
1340 int fd, len, written;
1341 char *git_HEAD = git_pathdup("%s", ref_target);
1342 unsigned char old_sha1[20], new_sha1[20];
1343
1344 if (logmsg && read_ref(ref_target, old_sha1))
1345 hashclr(old_sha1);
1346
1347 if (safe_create_leading_directories(git_HEAD) < 0)
1348 return error("unable to create directory for %s", git_HEAD);
1349
1350 #ifndef NO_SYMLINK_HEAD
1351 if (prefer_symlink_refs) {
1352 unlink(git_HEAD);
1353 if (!symlink(refs_heads_master, git_HEAD))
1354 goto done;
1355 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1356 }
1357 #endif
1358
1359 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1360 if (sizeof(ref) <= len) {
1361 error("refname too long: %s", refs_heads_master);
1362 goto error_free_return;
1363 }
1364 lockpath = mkpath("%s.lock", git_HEAD);
1365 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1366 if (fd < 0) {
1367 error("Unable to open %s for writing", lockpath);
1368 goto error_free_return;
1369 }
1370 written = write_in_full(fd, ref, len);
1371 if (close(fd) != 0 || written != len) {
1372 error("Unable to write to %s", lockpath);
1373 goto error_unlink_return;
1374 }
1375 if (rename(lockpath, git_HEAD) < 0) {
1376 error("Unable to create %s", git_HEAD);
1377 goto error_unlink_return;
1378 }
1379 if (adjust_shared_perm(git_HEAD)) {
1380 error("Unable to fix permissions on %s", lockpath);
1381 error_unlink_return:
1382 unlink_or_warn(lockpath);
1383 error_free_return:
1384 free(git_HEAD);
1385 return -1;
1386 }
1387
1388 #ifndef NO_SYMLINK_HEAD
1389 done:
1390 #endif
1391 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1392 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1393
1394 free(git_HEAD);
1395 return 0;
1396 }
1397
1398 static char *ref_msg(const char *line, const char *endp)
1399 {
1400 const char *ep;
1401 line += 82;
1402 ep = memchr(line, '\n', endp - line);
1403 if (!ep)
1404 ep = endp;
1405 return xmemdupz(line, ep - line);
1406 }
1407
1408 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)
1409 {
1410 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1411 char *tz_c;
1412 int logfd, tz, reccnt = 0;
1413 struct stat st;
1414 unsigned long date;
1415 unsigned char logged_sha1[20];
1416 void *log_mapped;
1417 size_t mapsz;
1418
1419 logfile = git_path("logs/%s", ref);
1420 logfd = open(logfile, O_RDONLY, 0);
1421 if (logfd < 0)
1422 die_errno("Unable to read log '%s'", logfile);
1423 fstat(logfd, &st);
1424 if (!st.st_size)
1425 die("Log %s is empty.", logfile);
1426 mapsz = xsize_t(st.st_size);
1427 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1428 logdata = log_mapped;
1429 close(logfd);
1430
1431 lastrec = NULL;
1432 rec = logend = logdata + st.st_size;
1433 while (logdata < rec) {
1434 reccnt++;
1435 if (logdata < rec && *(rec-1) == '\n')
1436 rec--;
1437 lastgt = NULL;
1438 while (logdata < rec && *(rec-1) != '\n') {
1439 rec--;
1440 if (*rec == '>')
1441 lastgt = rec;
1442 }
1443 if (!lastgt)
1444 die("Log %s is corrupt.", logfile);
1445 date = strtoul(lastgt + 1, &tz_c, 10);
1446 if (date <= at_time || cnt == 0) {
1447 tz = strtoul(tz_c, NULL, 10);
1448 if (msg)
1449 *msg = ref_msg(rec, logend);
1450 if (cutoff_time)
1451 *cutoff_time = date;
1452 if (cutoff_tz)
1453 *cutoff_tz = tz;
1454 if (cutoff_cnt)
1455 *cutoff_cnt = reccnt - 1;
1456 if (lastrec) {
1457 if (get_sha1_hex(lastrec, logged_sha1))
1458 die("Log %s is corrupt.", logfile);
1459 if (get_sha1_hex(rec + 41, sha1))
1460 die("Log %s is corrupt.", logfile);
1461 if (hashcmp(logged_sha1, sha1)) {
1462 warning("Log %s has gap after %s.",
1463 logfile, show_date(date, tz, DATE_RFC2822));
1464 }
1465 }
1466 else if (date == at_time) {
1467 if (get_sha1_hex(rec + 41, sha1))
1468 die("Log %s is corrupt.", logfile);
1469 }
1470 else {
1471 if (get_sha1_hex(rec + 41, logged_sha1))
1472 die("Log %s is corrupt.", logfile);
1473 if (hashcmp(logged_sha1, sha1)) {
1474 warning("Log %s unexpectedly ended on %s.",
1475 logfile, show_date(date, tz, DATE_RFC2822));
1476 }
1477 }
1478 munmap(log_mapped, mapsz);
1479 return 0;
1480 }
1481 lastrec = rec;
1482 if (cnt > 0)
1483 cnt--;
1484 }
1485
1486 rec = logdata;
1487 while (rec < logend && *rec != '>' && *rec != '\n')
1488 rec++;
1489 if (rec == logend || *rec == '\n')
1490 die("Log %s is corrupt.", logfile);
1491 date = strtoul(rec + 1, &tz_c, 10);
1492 tz = strtoul(tz_c, NULL, 10);
1493 if (get_sha1_hex(logdata, sha1))
1494 die("Log %s is corrupt.", logfile);
1495 if (is_null_sha1(sha1)) {
1496 if (get_sha1_hex(logdata + 41, sha1))
1497 die("Log %s is corrupt.", logfile);
1498 }
1499 if (msg)
1500 *msg = ref_msg(logdata, logend);
1501 munmap(log_mapped, mapsz);
1502
1503 if (cutoff_time)
1504 *cutoff_time = date;
1505 if (cutoff_tz)
1506 *cutoff_tz = tz;
1507 if (cutoff_cnt)
1508 *cutoff_cnt = reccnt;
1509 return 1;
1510 }
1511
1512 int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
1513 {
1514 const char *logfile;
1515 FILE *logfp;
1516 char buf[1024];
1517 int ret = 0;
1518
1519 logfile = git_path("logs/%s", ref);
1520 logfp = fopen(logfile, "r");
1521 if (!logfp)
1522 return -1;
1523
1524 if (ofs) {
1525 struct stat statbuf;
1526 if (fstat(fileno(logfp), &statbuf) ||
1527 statbuf.st_size < ofs ||
1528 fseek(logfp, -ofs, SEEK_END) ||
1529 fgets(buf, sizeof(buf), logfp)) {
1530 fclose(logfp);
1531 return -1;
1532 }
1533 }
1534
1535 while (fgets(buf, sizeof(buf), logfp)) {
1536 unsigned char osha1[20], nsha1[20];
1537 char *email_end, *message;
1538 unsigned long timestamp;
1539 int len, tz;
1540
1541 /* old SP new SP name <email> SP time TAB msg LF */
1542 len = strlen(buf);
1543 if (len < 83 || buf[len-1] != '\n' ||
1544 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1545 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1546 !(email_end = strchr(buf + 82, '>')) ||
1547 email_end[1] != ' ' ||
1548 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1549 !message || message[0] != ' ' ||
1550 (message[1] != '+' && message[1] != '-') ||
1551 !isdigit(message[2]) || !isdigit(message[3]) ||
1552 !isdigit(message[4]) || !isdigit(message[5]))
1553 continue; /* corrupt? */
1554 email_end[1] = '\0';
1555 tz = strtol(message + 1, NULL, 10);
1556 if (message[6] != '\t')
1557 message += 6;
1558 else
1559 message += 7;
1560 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1561 if (ret)
1562 break;
1563 }
1564 fclose(logfp);
1565 return ret;
1566 }
1567
1568 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1569 {
1570 return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1571 }
1572
1573 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1574 {
1575 DIR *dir = opendir(git_path("logs/%s", base));
1576 int retval = 0;
1577
1578 if (dir) {
1579 struct dirent *de;
1580 int baselen = strlen(base);
1581 char *log = xmalloc(baselen + 257);
1582
1583 memcpy(log, base, baselen);
1584 if (baselen && base[baselen-1] != '/')
1585 log[baselen++] = '/';
1586
1587 while ((de = readdir(dir)) != NULL) {
1588 struct stat st;
1589 int namelen;
1590
1591 if (de->d_name[0] == '.')
1592 continue;
1593 namelen = strlen(de->d_name);
1594 if (namelen > 255)
1595 continue;
1596 if (has_extension(de->d_name, ".lock"))
1597 continue;
1598 memcpy(log + baselen, de->d_name, namelen+1);
1599 if (stat(git_path("logs/%s", log), &st) < 0)
1600 continue;
1601 if (S_ISDIR(st.st_mode)) {
1602 retval = do_for_each_reflog(log, fn, cb_data);
1603 } else {
1604 unsigned char sha1[20];
1605 if (!resolve_ref(log, sha1, 0, NULL))
1606 retval = error("bad ref for %s", log);
1607 else
1608 retval = fn(log, sha1, 0, cb_data);
1609 }
1610 if (retval)
1611 break;
1612 }
1613 free(log);
1614 closedir(dir);
1615 }
1616 else if (*base)
1617 return errno;
1618 return retval;
1619 }
1620
1621 int for_each_reflog(each_ref_fn fn, void *cb_data)
1622 {
1623 return do_for_each_reflog("", fn, cb_data);
1624 }
1625
1626 int update_ref(const char *action, const char *refname,
1627 const unsigned char *sha1, const unsigned char *oldval,
1628 int flags, enum action_on_err onerr)
1629 {
1630 static struct ref_lock *lock;
1631 lock = lock_any_ref_for_update(refname, oldval, flags);
1632 if (!lock) {
1633 const char *str = "Cannot lock the ref '%s'.";
1634 switch (onerr) {
1635 case MSG_ON_ERR: error(str, refname); break;
1636 case DIE_ON_ERR: die(str, refname); break;
1637 case QUIET_ON_ERR: break;
1638 }
1639 return 1;
1640 }
1641 if (write_ref_sha1(lock, sha1, action) < 0) {
1642 const char *str = "Cannot update the ref '%s'.";
1643 switch (onerr) {
1644 case MSG_ON_ERR: error(str, refname); break;
1645 case DIE_ON_ERR: die(str, refname); break;
1646 case QUIET_ON_ERR: break;
1647 }
1648 return 1;
1649 }
1650 return 0;
1651 }
1652
1653 struct ref *find_ref_by_name(const struct ref *list, const char *name)
1654 {
1655 for ( ; list; list = list->next)
1656 if (!strcmp(list->name, name))
1657 return (struct ref *)list;
1658 return NULL;
1659 }
1660
1661 /*
1662 * generate a format suitable for scanf from a ref_rev_parse_rules
1663 * rule, that is replace the "%.*s" spec with a "%s" spec
1664 */
1665 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
1666 {
1667 char *spec;
1668
1669 spec = strstr(rule, "%.*s");
1670 if (!spec || strstr(spec + 4, "%.*s"))
1671 die("invalid rule in ref_rev_parse_rules: %s", rule);
1672
1673 /* copy all until spec */
1674 strncpy(scanf_fmt, rule, spec - rule);
1675 scanf_fmt[spec - rule] = '\0';
1676 /* copy new spec */
1677 strcat(scanf_fmt, "%s");
1678 /* copy remaining rule */
1679 strcat(scanf_fmt, spec + 4);
1680
1681 return;
1682 }
1683
1684 char *shorten_unambiguous_ref(const char *ref, int strict)
1685 {
1686 int i;
1687 static char **scanf_fmts;
1688 static int nr_rules;
1689 char *short_name;
1690
1691 /* pre generate scanf formats from ref_rev_parse_rules[] */
1692 if (!nr_rules) {
1693 size_t total_len = 0;
1694
1695 /* the rule list is NULL terminated, count them first */
1696 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
1697 /* no +1 because strlen("%s") < strlen("%.*s") */
1698 total_len += strlen(ref_rev_parse_rules[nr_rules]);
1699
1700 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
1701
1702 total_len = 0;
1703 for (i = 0; i < nr_rules; i++) {
1704 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
1705 + total_len;
1706 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
1707 total_len += strlen(ref_rev_parse_rules[i]);
1708 }
1709 }
1710
1711 /* bail out if there are no rules */
1712 if (!nr_rules)
1713 return xstrdup(ref);
1714
1715 /* buffer for scanf result, at most ref must fit */
1716 short_name = xstrdup(ref);
1717
1718 /* skip first rule, it will always match */
1719 for (i = nr_rules - 1; i > 0 ; --i) {
1720 int j;
1721 int rules_to_fail = i;
1722 int short_name_len;
1723
1724 if (1 != sscanf(ref, scanf_fmts[i], short_name))
1725 continue;
1726
1727 short_name_len = strlen(short_name);
1728
1729 /*
1730 * in strict mode, all (except the matched one) rules
1731 * must fail to resolve to a valid non-ambiguous ref
1732 */
1733 if (strict)
1734 rules_to_fail = nr_rules;
1735
1736 /*
1737 * check if the short name resolves to a valid ref,
1738 * but use only rules prior to the matched one
1739 */
1740 for (j = 0; j < rules_to_fail; j++) {
1741 const char *rule = ref_rev_parse_rules[j];
1742 unsigned char short_objectname[20];
1743 char refname[PATH_MAX];
1744
1745 /* skip matched rule */
1746 if (i == j)
1747 continue;
1748
1749 /*
1750 * the short name is ambiguous, if it resolves
1751 * (with this previous rule) to a valid ref
1752 * read_ref() returns 0 on success
1753 */
1754 mksnpath(refname, sizeof(refname),
1755 rule, short_name_len, short_name);
1756 if (!read_ref(refname, short_objectname))
1757 break;
1758 }
1759
1760 /*
1761 * short name is non-ambiguous if all previous rules
1762 * haven't resolved to a valid ref
1763 */
1764 if (j == rules_to_fail)
1765 return short_name;
1766 }
1767
1768 free(short_name);
1769 return xstrdup(ref);
1770 }