Merge branch '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
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
161 static void free_ref_list(struct ref_list *list)
162 {
163 struct ref_list *next;
164 for ( ; list; list = next) {
165 next = list->next;
166 free(list);
167 }
168 }
169
170 static void invalidate_cached_refs(void)
171 {
172 struct cached_refs *ca = &cached_refs;
173
174 if (ca->did_loose && ca->loose)
175 free_ref_list(ca->loose);
176 if (ca->did_packed && ca->packed)
177 free_ref_list(ca->packed);
178 ca->loose = ca->packed = NULL;
179 ca->did_loose = ca->did_packed = 0;
180 }
181
182 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
183 {
184 struct ref_list *list = NULL;
185 struct ref_list *last = NULL;
186 char refline[PATH_MAX];
187 int flag = REF_ISPACKED;
188
189 while (fgets(refline, sizeof(refline), f)) {
190 unsigned char sha1[20];
191 const char *name;
192 static const char header[] = "# pack-refs with:";
193
194 if (!strncmp(refline, header, sizeof(header)-1)) {
195 const char *traits = refline + sizeof(header) - 1;
196 if (strstr(traits, " peeled "))
197 flag |= REF_KNOWS_PEELED;
198 /* perhaps other traits later as well */
199 continue;
200 }
201
202 name = parse_ref_line(refline, sha1);
203 if (name) {
204 list = add_ref(name, sha1, flag, list, &last);
205 continue;
206 }
207 if (last &&
208 refline[0] == '^' &&
209 strlen(refline) == 42 &&
210 refline[41] == '\n' &&
211 !get_sha1_hex(refline + 1, sha1))
212 hashcpy(last->peeled, sha1);
213 }
214 cached_refs->packed = sort_ref_list(list);
215 }
216
217 static struct ref_list *get_packed_refs(void)
218 {
219 if (!cached_refs.did_packed) {
220 FILE *f = fopen(git_path("packed-refs"), "r");
221 cached_refs.packed = NULL;
222 if (f) {
223 read_packed_refs(f, &cached_refs);
224 fclose(f);
225 }
226 cached_refs.did_packed = 1;
227 }
228 return cached_refs.packed;
229 }
230
231 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
232 {
233 DIR *dir = opendir(git_path("%s", base));
234
235 if (dir) {
236 struct dirent *de;
237 int baselen = strlen(base);
238 char *ref = xmalloc(baselen + 257);
239
240 memcpy(ref, base, baselen);
241 if (baselen && base[baselen-1] != '/')
242 ref[baselen++] = '/';
243
244 while ((de = readdir(dir)) != NULL) {
245 unsigned char sha1[20];
246 struct stat st;
247 int flag;
248 int namelen;
249
250 if (de->d_name[0] == '.')
251 continue;
252 namelen = strlen(de->d_name);
253 if (namelen > 255)
254 continue;
255 if (has_extension(de->d_name, ".lock"))
256 continue;
257 memcpy(ref + baselen, de->d_name, namelen+1);
258 if (stat(git_path("%s", ref), &st) < 0)
259 continue;
260 if (S_ISDIR(st.st_mode)) {
261 list = get_ref_dir(ref, list);
262 continue;
263 }
264 if (!resolve_ref(ref, sha1, 1, &flag)) {
265 error("%s points nowhere!", ref);
266 continue;
267 }
268 list = add_ref(ref, sha1, flag, list, NULL);
269 }
270 free(ref);
271 closedir(dir);
272 }
273 return sort_ref_list(list);
274 }
275
276 static struct ref_list *get_loose_refs(void)
277 {
278 if (!cached_refs.did_loose) {
279 cached_refs.loose = get_ref_dir("refs", NULL);
280 cached_refs.did_loose = 1;
281 }
282 return cached_refs.loose;
283 }
284
285 /* We allow "recursive" symbolic refs. Only within reason, though */
286 #define MAXDEPTH 5
287 #define MAXREFLEN (1024)
288
289 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
290 {
291 FILE *f;
292 struct cached_refs refs;
293 struct ref_list *ref;
294 int retval;
295
296 strcpy(name + pathlen, "packed-refs");
297 f = fopen(name, "r");
298 if (!f)
299 return -1;
300 read_packed_refs(f, &refs);
301 fclose(f);
302 ref = refs.packed;
303 retval = -1;
304 while (ref) {
305 if (!strcmp(ref->name, refname)) {
306 retval = 0;
307 memcpy(result, ref->sha1, 20);
308 break;
309 }
310 ref = ref->next;
311 }
312 free_ref_list(refs.packed);
313 return retval;
314 }
315
316 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
317 {
318 int fd, len = strlen(refname);
319 char buffer[128], *p;
320
321 if (recursion > MAXDEPTH || len > MAXREFLEN)
322 return -1;
323 memcpy(name + pathlen, refname, len+1);
324 fd = open(name, O_RDONLY);
325 if (fd < 0)
326 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
327
328 len = read(fd, buffer, sizeof(buffer)-1);
329 close(fd);
330 if (len < 0)
331 return -1;
332 while (len && isspace(buffer[len-1]))
333 len--;
334 buffer[len] = 0;
335
336 /* Was it a detached head or an old-fashioned symlink? */
337 if (!get_sha1_hex(buffer, result))
338 return 0;
339
340 /* Symref? */
341 if (strncmp(buffer, "ref:", 4))
342 return -1;
343 p = buffer + 4;
344 while (isspace(*p))
345 p++;
346
347 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
348 }
349
350 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
351 {
352 int len = strlen(path), retval;
353 char *gitdir;
354
355 while (len && path[len-1] == '/')
356 len--;
357 if (!len)
358 return -1;
359 gitdir = xmalloc(len + MAXREFLEN + 8);
360 memcpy(gitdir, path, len);
361 memcpy(gitdir + len, "/.git/", 7);
362
363 retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
364 free(gitdir);
365 return retval;
366 }
367
368 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
369 {
370 int depth = MAXDEPTH, len;
371 char buffer[256];
372 static char ref_buffer[256];
373
374 if (flag)
375 *flag = 0;
376
377 for (;;) {
378 const char *path = git_path("%s", ref);
379 struct stat st;
380 char *buf;
381 int fd;
382
383 if (--depth < 0)
384 return NULL;
385
386 /* Special case: non-existing file.
387 * Not having the refs/heads/new-branch is OK
388 * if we are writing into it, so is .git/HEAD
389 * that points at refs/heads/master still to be
390 * born. It is NOT OK if we are resolving for
391 * reading.
392 */
393 if (lstat(path, &st) < 0) {
394 struct ref_list *list = get_packed_refs();
395 while (list) {
396 if (!strcmp(ref, list->name)) {
397 hashcpy(sha1, list->sha1);
398 if (flag)
399 *flag |= REF_ISPACKED;
400 return ref;
401 }
402 list = list->next;
403 }
404 if (reading || errno != ENOENT)
405 return NULL;
406 hashclr(sha1);
407 return ref;
408 }
409
410 /* Follow "normalized" - ie "refs/.." symlinks by hand */
411 if (S_ISLNK(st.st_mode)) {
412 len = readlink(path, buffer, sizeof(buffer)-1);
413 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
414 buffer[len] = 0;
415 strcpy(ref_buffer, buffer);
416 ref = ref_buffer;
417 if (flag)
418 *flag |= REF_ISSYMREF;
419 continue;
420 }
421 }
422
423 /* Is it a directory? */
424 if (S_ISDIR(st.st_mode)) {
425 errno = EISDIR;
426 return NULL;
427 }
428
429 /*
430 * Anything else, just open it and try to use it as
431 * a ref
432 */
433 fd = open(path, O_RDONLY);
434 if (fd < 0)
435 return NULL;
436 len = read_in_full(fd, buffer, sizeof(buffer)-1);
437 close(fd);
438
439 /*
440 * Is it a symbolic ref?
441 */
442 if (len < 4 || memcmp("ref:", buffer, 4))
443 break;
444 buf = buffer + 4;
445 len -= 4;
446 while (len && isspace(*buf))
447 buf++, len--;
448 while (len && isspace(buf[len-1]))
449 len--;
450 buf[len] = 0;
451 memcpy(ref_buffer, buf, len + 1);
452 ref = ref_buffer;
453 if (flag)
454 *flag |= REF_ISSYMREF;
455 }
456 if (len < 40 || get_sha1_hex(buffer, sha1))
457 return NULL;
458 return ref;
459 }
460
461 int read_ref(const char *ref, unsigned char *sha1)
462 {
463 if (resolve_ref(ref, sha1, 1, NULL))
464 return 0;
465 return -1;
466 }
467
468 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
469 void *cb_data, struct ref_list *entry)
470 {
471 if (strncmp(base, entry->name, trim))
472 return 0;
473 if (is_null_sha1(entry->sha1))
474 return 0;
475 if (!has_sha1_file(entry->sha1)) {
476 error("%s does not point to a valid object!", entry->name);
477 return 0;
478 }
479 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
480 }
481
482 int peel_ref(const char *ref, unsigned char *sha1)
483 {
484 int flag;
485 unsigned char base[20];
486 struct object *o;
487
488 if (!resolve_ref(ref, base, 1, &flag))
489 return -1;
490
491 if ((flag & REF_ISPACKED)) {
492 struct ref_list *list = get_packed_refs();
493
494 while (list) {
495 if (!strcmp(list->name, ref)) {
496 if (list->flag & REF_KNOWS_PEELED) {
497 hashcpy(sha1, list->peeled);
498 return 0;
499 }
500 /* older pack-refs did not leave peeled ones */
501 break;
502 }
503 list = list->next;
504 }
505 }
506
507 /* fallback - callers should not call this for unpacked refs */
508 o = parse_object(base);
509 if (o->type == OBJ_TAG) {
510 o = deref_tag(o, ref, 0);
511 if (o) {
512 hashcpy(sha1, o->sha1);
513 return 0;
514 }
515 }
516 return -1;
517 }
518
519 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
520 void *cb_data)
521 {
522 int retval;
523 struct ref_list *packed = get_packed_refs();
524 struct ref_list *loose = get_loose_refs();
525
526 while (packed && loose) {
527 struct ref_list *entry;
528 int cmp = strcmp(packed->name, loose->name);
529 if (!cmp) {
530 packed = packed->next;
531 continue;
532 }
533 if (cmp > 0) {
534 entry = loose;
535 loose = loose->next;
536 } else {
537 entry = packed;
538 packed = packed->next;
539 }
540 retval = do_one_ref(base, fn, trim, cb_data, entry);
541 if (retval)
542 return retval;
543 }
544
545 for (packed = packed ? packed : loose; packed; packed = packed->next) {
546 retval = do_one_ref(base, fn, trim, cb_data, packed);
547 if (retval)
548 return retval;
549 }
550 return 0;
551 }
552
553 int head_ref(each_ref_fn fn, void *cb_data)
554 {
555 unsigned char sha1[20];
556 int flag;
557
558 if (resolve_ref("HEAD", sha1, 1, &flag))
559 return fn("HEAD", sha1, flag, cb_data);
560 return 0;
561 }
562
563 int for_each_ref(each_ref_fn fn, void *cb_data)
564 {
565 return do_for_each_ref("refs/", fn, 0, cb_data);
566 }
567
568 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
569 {
570 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
571 }
572
573 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
574 {
575 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
576 }
577
578 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
579 {
580 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
581 }
582
583 /*
584 * Make sure "ref" is something reasonable to have under ".git/refs/";
585 * We do not like it if:
586 *
587 * - any path component of it begins with ".", or
588 * - it has double dots "..", or
589 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
590 * - it ends with a "/".
591 */
592
593 static inline int bad_ref_char(int ch)
594 {
595 if (((unsigned) ch) <= ' ' ||
596 ch == '~' || ch == '^' || ch == ':')
597 return 1;
598 /* 2.13 Pattern Matching Notation */
599 if (ch == '?' || ch == '[') /* Unsupported */
600 return 1;
601 if (ch == '*') /* Supported at the end */
602 return 2;
603 return 0;
604 }
605
606 int check_ref_format(const char *ref)
607 {
608 int ch, level, bad_type;
609 const char *cp = ref;
610
611 level = 0;
612 while (1) {
613 while ((ch = *cp++) == '/')
614 ; /* tolerate duplicated slashes */
615 if (!ch)
616 return -1; /* should not end with slashes */
617
618 /* we are at the beginning of the path component */
619 if (ch == '.')
620 return -1;
621 bad_type = bad_ref_char(ch);
622 if (bad_type) {
623 return (bad_type == 2 && !*cp) ? -3 : -1;
624 }
625
626 /* scan the rest of the path component */
627 while ((ch = *cp++) != 0) {
628 bad_type = bad_ref_char(ch);
629 if (bad_type) {
630 return (bad_type == 2 && !*cp) ? -3 : -1;
631 }
632 if (ch == '/')
633 break;
634 if (ch == '.' && *cp == '.')
635 return -1;
636 }
637 level++;
638 if (!ch) {
639 if (level < 2)
640 return -2; /* at least of form "heads/blah" */
641 return 0;
642 }
643 }
644 }
645
646 const char *ref_rev_parse_rules[] = {
647 "%.*s",
648 "refs/%.*s",
649 "refs/tags/%.*s",
650 "refs/heads/%.*s",
651 "refs/remotes/%.*s",
652 "refs/remotes/%.*s/HEAD",
653 NULL
654 };
655
656 const char *ref_fetch_rules[] = {
657 "%.*s",
658 "refs/%.*s",
659 "refs/heads/%.*s",
660 NULL
661 };
662
663 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
664 {
665 const char **p;
666 const int abbrev_name_len = strlen(abbrev_name);
667
668 for (p = rules; *p; p++) {
669 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
670 return 1;
671 }
672 }
673
674 return 0;
675 }
676
677 static struct ref_lock *verify_lock(struct ref_lock *lock,
678 const unsigned char *old_sha1, int mustexist)
679 {
680 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
681 error("Can't verify ref %s", lock->ref_name);
682 unlock_ref(lock);
683 return NULL;
684 }
685 if (hashcmp(lock->old_sha1, old_sha1)) {
686 error("Ref %s is at %s but expected %s", lock->ref_name,
687 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
688 unlock_ref(lock);
689 return NULL;
690 }
691 return lock;
692 }
693
694 static int remove_empty_directories(const char *file)
695 {
696 /* we want to create a file but there is a directory there;
697 * if that is an empty directory (or a directory that contains
698 * only empty directories), remove them.
699 */
700 struct strbuf path;
701 int result;
702
703 strbuf_init(&path, 20);
704 strbuf_addstr(&path, file);
705
706 result = remove_dir_recursively(&path, 1);
707
708 strbuf_release(&path);
709
710 return result;
711 }
712
713 static int is_refname_available(const char *ref, const char *oldref,
714 struct ref_list *list, int quiet)
715 {
716 int namlen = strlen(ref); /* e.g. 'foo/bar' */
717 while (list) {
718 /* list->name could be 'foo' or 'foo/bar/baz' */
719 if (!oldref || strcmp(oldref, list->name)) {
720 int len = strlen(list->name);
721 int cmplen = (namlen < len) ? namlen : len;
722 const char *lead = (namlen < len) ? list->name : ref;
723 if (!strncmp(ref, list->name, cmplen) &&
724 lead[cmplen] == '/') {
725 if (!quiet)
726 error("'%s' exists; cannot create '%s'",
727 list->name, ref);
728 return 0;
729 }
730 }
731 list = list->next;
732 }
733 return 1;
734 }
735
736 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
737 {
738 char *ref_file;
739 const char *orig_ref = ref;
740 struct ref_lock *lock;
741 struct stat st;
742 int last_errno = 0;
743 int type;
744 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
745
746 lock = xcalloc(1, sizeof(struct ref_lock));
747 lock->lock_fd = -1;
748
749 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
750 if (!ref && errno == EISDIR) {
751 /* we are trying to lock foo but we used to
752 * have foo/bar which now does not exist;
753 * it is normal for the empty directory 'foo'
754 * to remain.
755 */
756 ref_file = git_path("%s", orig_ref);
757 if (remove_empty_directories(ref_file)) {
758 last_errno = errno;
759 error("there are still refs under '%s'", orig_ref);
760 goto error_return;
761 }
762 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
763 }
764 if (type_p)
765 *type_p = type;
766 if (!ref) {
767 last_errno = errno;
768 error("unable to resolve reference %s: %s",
769 orig_ref, strerror(errno));
770 goto error_return;
771 }
772 /* When the ref did not exist and we are creating it,
773 * make sure there is no existing ref that is packed
774 * whose name begins with our refname, nor a ref whose
775 * name is a proper prefix of our refname.
776 */
777 if (is_null_sha1(lock->old_sha1) &&
778 !is_refname_available(ref, NULL, get_packed_refs(), 0))
779 goto error_return;
780
781 lock->lk = xcalloc(1, sizeof(struct lock_file));
782
783 if (flags & REF_NODEREF)
784 ref = orig_ref;
785 lock->ref_name = xstrdup(ref);
786 lock->orig_ref_name = xstrdup(orig_ref);
787 ref_file = git_path("%s", ref);
788 if (lstat(ref_file, &st) && errno == ENOENT)
789 lock->force_write = 1;
790 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
791 lock->force_write = 1;
792
793 if (safe_create_leading_directories(ref_file)) {
794 last_errno = errno;
795 error("unable to create directory for %s", ref_file);
796 goto error_return;
797 }
798 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
799
800 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
801
802 error_return:
803 unlock_ref(lock);
804 errno = last_errno;
805 return NULL;
806 }
807
808 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
809 {
810 char refpath[PATH_MAX];
811 if (check_ref_format(ref))
812 return NULL;
813 strcpy(refpath, mkpath("refs/%s", ref));
814 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
815 }
816
817 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
818 {
819 if (check_ref_format(ref) == -1)
820 return NULL;
821 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
822 }
823
824 static struct lock_file packlock;
825
826 static int repack_without_ref(const char *refname)
827 {
828 struct ref_list *list, *packed_ref_list;
829 int fd;
830 int found = 0;
831
832 packed_ref_list = get_packed_refs();
833 for (list = packed_ref_list; list; list = list->next) {
834 if (!strcmp(refname, list->name)) {
835 found = 1;
836 break;
837 }
838 }
839 if (!found)
840 return 0;
841 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
842 if (fd < 0)
843 return error("cannot delete '%s' from packed refs", refname);
844
845 for (list = packed_ref_list; list; list = list->next) {
846 char line[PATH_MAX + 100];
847 int len;
848
849 if (!strcmp(refname, list->name))
850 continue;
851 len = snprintf(line, sizeof(line), "%s %s\n",
852 sha1_to_hex(list->sha1), list->name);
853 /* this should not happen but just being defensive */
854 if (len > sizeof(line))
855 die("too long a refname '%s'", list->name);
856 write_or_die(fd, line, len);
857 }
858 close(fd);
859 return commit_lock_file(&packlock);
860 }
861
862 int delete_ref(const char *refname, const unsigned char *sha1)
863 {
864 struct ref_lock *lock;
865 int err, i, ret = 0, flag = 0;
866
867 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
868 if (!lock)
869 return 1;
870 if (!(flag & REF_ISPACKED)) {
871 /* loose */
872 i = strlen(lock->lk->filename) - 5; /* .lock */
873 lock->lk->filename[i] = 0;
874 err = unlink(lock->lk->filename);
875 if (err) {
876 ret = 1;
877 error("unlink(%s) failed: %s",
878 lock->lk->filename, strerror(errno));
879 }
880 lock->lk->filename[i] = '.';
881 }
882 /* removing the loose one could have resurrected an earlier
883 * packed one. Also, if it was not loose we need to repack
884 * without it.
885 */
886 ret |= repack_without_ref(refname);
887
888 err = unlink(git_path("logs/%s", lock->ref_name));
889 if (err && errno != ENOENT)
890 fprintf(stderr, "warning: unlink(%s) failed: %s",
891 git_path("logs/%s", lock->ref_name), strerror(errno));
892 invalidate_cached_refs();
893 unlock_ref(lock);
894 return ret;
895 }
896
897 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
898 {
899 static const char renamed_ref[] = "RENAMED-REF";
900 unsigned char sha1[20], orig_sha1[20];
901 int flag = 0, logmoved = 0;
902 struct ref_lock *lock;
903 struct stat loginfo;
904 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
905
906 if (S_ISLNK(loginfo.st_mode))
907 return error("reflog for %s is a symlink", oldref);
908
909 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
910 return error("refname %s not found", oldref);
911
912 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
913 return 1;
914
915 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
916 return 1;
917
918 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
919 if (!lock)
920 return error("unable to lock %s", renamed_ref);
921 lock->force_write = 1;
922 if (write_ref_sha1(lock, orig_sha1, logmsg))
923 return error("unable to save current sha1 in %s", renamed_ref);
924
925 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
926 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
927 oldref, strerror(errno));
928
929 if (delete_ref(oldref, orig_sha1)) {
930 error("unable to delete old %s", oldref);
931 goto rollback;
932 }
933
934 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
935 if (errno==EISDIR) {
936 if (remove_empty_directories(git_path("%s", newref))) {
937 error("Directory not empty: %s", newref);
938 goto rollback;
939 }
940 } else {
941 error("unable to delete existing %s", newref);
942 goto rollback;
943 }
944 }
945
946 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
947 error("unable to create directory for %s", newref);
948 goto rollback;
949 }
950
951 retry:
952 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
953 if (errno==EISDIR || errno==ENOTDIR) {
954 /*
955 * rename(a, b) when b is an existing
956 * directory ought to result in ISDIR, but
957 * Solaris 5.8 gives ENOTDIR. Sheesh.
958 */
959 if (remove_empty_directories(git_path("logs/%s", newref))) {
960 error("Directory not empty: logs/%s", newref);
961 goto rollback;
962 }
963 goto retry;
964 } else {
965 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
966 newref, strerror(errno));
967 goto rollback;
968 }
969 }
970 logmoved = log;
971
972 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
973 if (!lock) {
974 error("unable to lock %s for update", newref);
975 goto rollback;
976 }
977
978 lock->force_write = 1;
979 hashcpy(lock->old_sha1, orig_sha1);
980 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
981 error("unable to write current sha1 into %s", newref);
982 goto rollback;
983 }
984
985 return 0;
986
987 rollback:
988 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
989 if (!lock) {
990 error("unable to lock %s for rollback", oldref);
991 goto rollbacklog;
992 }
993
994 lock->force_write = 1;
995 flag = log_all_ref_updates;
996 log_all_ref_updates = 0;
997 if (write_ref_sha1(lock, orig_sha1, NULL))
998 error("unable to write current sha1 into %s", oldref);
999 log_all_ref_updates = flag;
1000
1001 rollbacklog:
1002 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1003 error("unable to restore logfile %s from %s: %s",
1004 oldref, newref, strerror(errno));
1005 if (!logmoved && log &&
1006 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1007 error("unable to restore logfile %s from tmp-renamed-log: %s",
1008 oldref, strerror(errno));
1009
1010 return 1;
1011 }
1012
1013 void unlock_ref(struct ref_lock *lock)
1014 {
1015 if (lock->lock_fd >= 0) {
1016 close(lock->lock_fd);
1017 /* Do not free lock->lk -- atexit() still looks at them */
1018 if (lock->lk)
1019 rollback_lock_file(lock->lk);
1020 }
1021 free(lock->ref_name);
1022 free(lock->orig_ref_name);
1023 free(lock);
1024 }
1025
1026 /*
1027 * copy the reflog message msg to buf, which has been allocated sufficiently
1028 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1029 * because reflog file is one line per entry.
1030 */
1031 static int copy_msg(char *buf, const char *msg)
1032 {
1033 char *cp = buf;
1034 char c;
1035 int wasspace = 1;
1036
1037 *cp++ = '\t';
1038 while ((c = *msg++)) {
1039 if (wasspace && isspace(c))
1040 continue;
1041 wasspace = isspace(c);
1042 if (wasspace)
1043 c = ' ';
1044 *cp++ = c;
1045 }
1046 while (buf < cp && isspace(cp[-1]))
1047 cp--;
1048 *cp++ = '\n';
1049 return cp - buf;
1050 }
1051
1052 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1053 const unsigned char *new_sha1, const char *msg)
1054 {
1055 int logfd, written, oflags = O_APPEND | O_WRONLY;
1056 unsigned maxlen, len;
1057 int msglen;
1058 char *log_file, *logrec;
1059 const char *committer;
1060
1061 if (log_all_ref_updates < 0)
1062 log_all_ref_updates = !is_bare_repository();
1063
1064 log_file = git_path("logs/%s", ref_name);
1065
1066 if (log_all_ref_updates &&
1067 (!prefixcmp(ref_name, "refs/heads/") ||
1068 !prefixcmp(ref_name, "refs/remotes/") ||
1069 !strcmp(ref_name, "HEAD"))) {
1070 if (safe_create_leading_directories(log_file) < 0)
1071 return error("unable to create directory for %s",
1072 log_file);
1073 oflags |= O_CREAT;
1074 }
1075
1076 logfd = open(log_file, oflags, 0666);
1077 if (logfd < 0) {
1078 if (!(oflags & O_CREAT) && errno == ENOENT)
1079 return 0;
1080
1081 if ((oflags & O_CREAT) && errno == EISDIR) {
1082 if (remove_empty_directories(log_file)) {
1083 return error("There are still logs under '%s'",
1084 log_file);
1085 }
1086 logfd = open(log_file, oflags, 0666);
1087 }
1088
1089 if (logfd < 0)
1090 return error("Unable to append to %s: %s",
1091 log_file, strerror(errno));
1092 }
1093
1094 adjust_shared_perm(log_file);
1095
1096 msglen = msg ? strlen(msg) : 0;
1097 committer = git_committer_info(-1);
1098 maxlen = strlen(committer) + msglen + 100;
1099 logrec = xmalloc(maxlen);
1100 len = sprintf(logrec, "%s %s %s\n",
1101 sha1_to_hex(old_sha1),
1102 sha1_to_hex(new_sha1),
1103 committer);
1104 if (msglen)
1105 len += copy_msg(logrec + len - 1, msg) - 1;
1106 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1107 free(logrec);
1108 if (close(logfd) != 0 || written != len)
1109 return error("Unable to append to %s", log_file);
1110 return 0;
1111 }
1112
1113 int write_ref_sha1(struct ref_lock *lock,
1114 const unsigned char *sha1, const char *logmsg)
1115 {
1116 static char term = '\n';
1117
1118 if (!lock)
1119 return -1;
1120 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1121 unlock_ref(lock);
1122 return 0;
1123 }
1124 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1125 write_in_full(lock->lock_fd, &term, 1) != 1
1126 || close(lock->lock_fd) < 0) {
1127 error("Couldn't write %s", lock->lk->filename);
1128 unlock_ref(lock);
1129 return -1;
1130 }
1131 invalidate_cached_refs();
1132 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1133 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1134 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1135 unlock_ref(lock);
1136 return -1;
1137 }
1138 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1139 /*
1140 * Special hack: If a branch is updated directly and HEAD
1141 * points to it (may happen on the remote side of a push
1142 * for example) then logically the HEAD reflog should be
1143 * updated too.
1144 * A generic solution implies reverse symref information,
1145 * but finding all symrefs pointing to the given branch
1146 * would be rather costly for this rare event (the direct
1147 * update of a branch) to be worth it. So let's cheat and
1148 * check with HEAD only which should cover 99% of all usage
1149 * scenarios (even 100% of the default ones).
1150 */
1151 unsigned char head_sha1[20];
1152 int head_flag;
1153 const char *head_ref;
1154 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1155 if (head_ref && (head_flag & REF_ISSYMREF) &&
1156 !strcmp(head_ref, lock->ref_name))
1157 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1158 }
1159 if (commit_lock_file(lock->lk)) {
1160 error("Couldn't set %s", lock->ref_name);
1161 unlock_ref(lock);
1162 return -1;
1163 }
1164 lock->lock_fd = -1;
1165 unlock_ref(lock);
1166 return 0;
1167 }
1168
1169 int create_symref(const char *ref_target, const char *refs_heads_master,
1170 const char *logmsg)
1171 {
1172 const char *lockpath;
1173 char ref[1000];
1174 int fd, len, written;
1175 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1176 unsigned char old_sha1[20], new_sha1[20];
1177
1178 if (logmsg && read_ref(ref_target, old_sha1))
1179 hashclr(old_sha1);
1180
1181 if (safe_create_leading_directories(git_HEAD) < 0)
1182 return error("unable to create directory for %s", git_HEAD);
1183
1184 #ifndef NO_SYMLINK_HEAD
1185 if (prefer_symlink_refs) {
1186 unlink(git_HEAD);
1187 if (!symlink(refs_heads_master, git_HEAD))
1188 goto done;
1189 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1190 }
1191 #endif
1192
1193 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1194 if (sizeof(ref) <= len) {
1195 error("refname too long: %s", refs_heads_master);
1196 goto error_free_return;
1197 }
1198 lockpath = mkpath("%s.lock", git_HEAD);
1199 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1200 if (fd < 0) {
1201 error("Unable to open %s for writing", lockpath);
1202 goto error_free_return;
1203 }
1204 written = write_in_full(fd, ref, len);
1205 if (close(fd) != 0 || written != len) {
1206 error("Unable to write to %s", lockpath);
1207 goto error_unlink_return;
1208 }
1209 if (rename(lockpath, git_HEAD) < 0) {
1210 error("Unable to create %s", git_HEAD);
1211 goto error_unlink_return;
1212 }
1213 if (adjust_shared_perm(git_HEAD)) {
1214 error("Unable to fix permissions on %s", lockpath);
1215 error_unlink_return:
1216 unlink(lockpath);
1217 error_free_return:
1218 free(git_HEAD);
1219 return -1;
1220 }
1221
1222 #ifndef NO_SYMLINK_HEAD
1223 done:
1224 #endif
1225 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1226 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1227
1228 free(git_HEAD);
1229 return 0;
1230 }
1231
1232 static char *ref_msg(const char *line, const char *endp)
1233 {
1234 const char *ep;
1235 line += 82;
1236 ep = memchr(line, '\n', endp - line);
1237 if (!ep)
1238 ep = endp;
1239 return xmemdupz(line, ep - line);
1240 }
1241
1242 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)
1243 {
1244 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1245 char *tz_c;
1246 int logfd, tz, reccnt = 0;
1247 struct stat st;
1248 unsigned long date;
1249 unsigned char logged_sha1[20];
1250 void *log_mapped;
1251 size_t mapsz;
1252
1253 logfile = git_path("logs/%s", ref);
1254 logfd = open(logfile, O_RDONLY, 0);
1255 if (logfd < 0)
1256 die("Unable to read log %s: %s", logfile, strerror(errno));
1257 fstat(logfd, &st);
1258 if (!st.st_size)
1259 die("Log %s is empty.", logfile);
1260 mapsz = xsize_t(st.st_size);
1261 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1262 logdata = log_mapped;
1263 close(logfd);
1264
1265 lastrec = NULL;
1266 rec = logend = logdata + st.st_size;
1267 while (logdata < rec) {
1268 reccnt++;
1269 if (logdata < rec && *(rec-1) == '\n')
1270 rec--;
1271 lastgt = NULL;
1272 while (logdata < rec && *(rec-1) != '\n') {
1273 rec--;
1274 if (*rec == '>')
1275 lastgt = rec;
1276 }
1277 if (!lastgt)
1278 die("Log %s is corrupt.", logfile);
1279 date = strtoul(lastgt + 1, &tz_c, 10);
1280 if (date <= at_time || cnt == 0) {
1281 tz = strtoul(tz_c, NULL, 10);
1282 if (msg)
1283 *msg = ref_msg(rec, logend);
1284 if (cutoff_time)
1285 *cutoff_time = date;
1286 if (cutoff_tz)
1287 *cutoff_tz = tz;
1288 if (cutoff_cnt)
1289 *cutoff_cnt = reccnt - 1;
1290 if (lastrec) {
1291 if (get_sha1_hex(lastrec, logged_sha1))
1292 die("Log %s is corrupt.", logfile);
1293 if (get_sha1_hex(rec + 41, sha1))
1294 die("Log %s is corrupt.", logfile);
1295 if (hashcmp(logged_sha1, sha1)) {
1296 fprintf(stderr,
1297 "warning: Log %s has gap after %s.\n",
1298 logfile, show_date(date, tz, DATE_RFC2822));
1299 }
1300 }
1301 else if (date == at_time) {
1302 if (get_sha1_hex(rec + 41, sha1))
1303 die("Log %s is corrupt.", logfile);
1304 }
1305 else {
1306 if (get_sha1_hex(rec + 41, logged_sha1))
1307 die("Log %s is corrupt.", logfile);
1308 if (hashcmp(logged_sha1, sha1)) {
1309 fprintf(stderr,
1310 "warning: Log %s unexpectedly ended on %s.\n",
1311 logfile, show_date(date, tz, DATE_RFC2822));
1312 }
1313 }
1314 munmap(log_mapped, mapsz);
1315 return 0;
1316 }
1317 lastrec = rec;
1318 if (cnt > 0)
1319 cnt--;
1320 }
1321
1322 rec = logdata;
1323 while (rec < logend && *rec != '>' && *rec != '\n')
1324 rec++;
1325 if (rec == logend || *rec == '\n')
1326 die("Log %s is corrupt.", logfile);
1327 date = strtoul(rec + 1, &tz_c, 10);
1328 tz = strtoul(tz_c, NULL, 10);
1329 if (get_sha1_hex(logdata, sha1))
1330 die("Log %s is corrupt.", logfile);
1331 if (msg)
1332 *msg = ref_msg(logdata, logend);
1333 munmap(log_mapped, mapsz);
1334
1335 if (cutoff_time)
1336 *cutoff_time = date;
1337 if (cutoff_tz)
1338 *cutoff_tz = tz;
1339 if (cutoff_cnt)
1340 *cutoff_cnt = reccnt;
1341 return 1;
1342 }
1343
1344 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1345 {
1346 const char *logfile;
1347 FILE *logfp;
1348 char buf[1024];
1349 int ret = 0;
1350
1351 logfile = git_path("logs/%s", ref);
1352 logfp = fopen(logfile, "r");
1353 if (!logfp)
1354 return -1;
1355 while (fgets(buf, sizeof(buf), logfp)) {
1356 unsigned char osha1[20], nsha1[20];
1357 char *email_end, *message;
1358 unsigned long timestamp;
1359 int len, tz;
1360
1361 /* old SP new SP name <email> SP time TAB msg LF */
1362 len = strlen(buf);
1363 if (len < 83 || buf[len-1] != '\n' ||
1364 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1365 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1366 !(email_end = strchr(buf + 82, '>')) ||
1367 email_end[1] != ' ' ||
1368 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1369 !message || message[0] != ' ' ||
1370 (message[1] != '+' && message[1] != '-') ||
1371 !isdigit(message[2]) || !isdigit(message[3]) ||
1372 !isdigit(message[4]) || !isdigit(message[5]))
1373 continue; /* corrupt? */
1374 email_end[1] = '\0';
1375 tz = strtol(message + 1, NULL, 10);
1376 if (message[6] != '\t')
1377 message += 6;
1378 else
1379 message += 7;
1380 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1381 if (ret)
1382 break;
1383 }
1384 fclose(logfp);
1385 return ret;
1386 }
1387
1388 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1389 {
1390 DIR *dir = opendir(git_path("logs/%s", base));
1391 int retval = 0;
1392
1393 if (dir) {
1394 struct dirent *de;
1395 int baselen = strlen(base);
1396 char *log = xmalloc(baselen + 257);
1397
1398 memcpy(log, base, baselen);
1399 if (baselen && base[baselen-1] != '/')
1400 log[baselen++] = '/';
1401
1402 while ((de = readdir(dir)) != NULL) {
1403 struct stat st;
1404 int namelen;
1405
1406 if (de->d_name[0] == '.')
1407 continue;
1408 namelen = strlen(de->d_name);
1409 if (namelen > 255)
1410 continue;
1411 if (has_extension(de->d_name, ".lock"))
1412 continue;
1413 memcpy(log + baselen, de->d_name, namelen+1);
1414 if (stat(git_path("logs/%s", log), &st) < 0)
1415 continue;
1416 if (S_ISDIR(st.st_mode)) {
1417 retval = do_for_each_reflog(log, fn, cb_data);
1418 } else {
1419 unsigned char sha1[20];
1420 if (!resolve_ref(log, sha1, 0, NULL))
1421 retval = error("bad ref for %s", log);
1422 else
1423 retval = fn(log, sha1, 0, cb_data);
1424 }
1425 if (retval)
1426 break;
1427 }
1428 free(log);
1429 closedir(dir);
1430 }
1431 else if (*base)
1432 return errno;
1433 return retval;
1434 }
1435
1436 int for_each_reflog(each_ref_fn fn, void *cb_data)
1437 {
1438 return do_for_each_reflog("", fn, cb_data);
1439 }
1440
1441 int update_ref(const char *action, const char *refname,
1442 const unsigned char *sha1, const unsigned char *oldval,
1443 int flags, enum action_on_err onerr)
1444 {
1445 static struct ref_lock *lock;
1446 lock = lock_any_ref_for_update(refname, oldval, flags);
1447 if (!lock) {
1448 const char *str = "Cannot lock the ref '%s'.";
1449 switch (onerr) {
1450 case MSG_ON_ERR: error(str, refname); break;
1451 case DIE_ON_ERR: die(str, refname); break;
1452 case QUIET_ON_ERR: break;
1453 }
1454 return 1;
1455 }
1456 if (write_ref_sha1(lock, sha1, action) < 0) {
1457 const char *str = "Cannot update the ref '%s'.";
1458 switch (onerr) {
1459 case MSG_ON_ERR: error(str, refname); break;
1460 case DIE_ON_ERR: die(str, refname); break;
1461 case QUIET_ON_ERR: break;
1462 }
1463 return 1;
1464 }
1465 return 0;
1466 }
1467
1468 struct ref *find_ref_by_name(struct ref *list, const char *name)
1469 {
1470 for ( ; list; list = list->next)
1471 if (!strcmp(list->name, name))
1472 return list;
1473 return NULL;
1474 }