gitweb: use new Git::Repo API, and add optional caching
[git/gitweb-caching.git] / refs.c
blob39a3b23804d2da715c564459bf320be23d41c1bf
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
7 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
8 #define REF_KNOWS_PEELED 04
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];
18 static const char *parse_ref_line(char *line, unsigned char *sha1)
21 * 42: the answer to everything.
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)
28 int len = strlen(line) - 42;
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;
43 return line;
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)
50 int len;
51 struct ref_list *entry;
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;
66 /* merge sort the ref list */
67 static struct ref_list *sort_ref_list(struct ref_list *list)
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;
75 if (!list)
76 return list;
78 do {
79 last_merge_count = merge_count;
80 merge_count = 0;
82 psize = 0;
84 p = new_list;
85 q = new_list;
86 new_list = NULL;
87 l = NULL;
89 while (p) {
90 merge_count++;
92 while (psize < k && q->next) {
93 q = q->next;
94 psize++;
96 qsize = k;
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--;
132 e->next = NULL;
134 if (l)
135 l->next = e;
136 if (!new_list)
137 new_list = e;
138 l = e;
141 p = q;
144 k = k * 2;
145 } while ((last_merge_count != merge_count) || (last_merge_count != 1));
147 return new_list;
151 * Future: need to be in "struct repository"
152 * when doing a full libification.
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;
162 static struct ref_list *extra_refs;
164 static void free_ref_list(struct ref_list *list)
166 struct ref_list *next;
167 for ( ; list; list = next) {
168 next = list->next;
169 free(list);
173 static void invalidate_cached_refs(void)
175 struct cached_refs *ca = &cached_refs;
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;
185 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
187 struct ref_list *list = NULL;
188 struct ref_list *last = NULL;
189 char refline[PATH_MAX];
190 int flag = REF_ISPACKED;
192 while (fgets(refline, sizeof(refline), f)) {
193 unsigned char sha1[20];
194 const char *name;
195 static const char header[] = "# pack-refs with:";
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;
205 name = parse_ref_line(refline, sha1);
206 if (name) {
207 list = add_ref(name, sha1, flag, list, &last);
208 continue;
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);
217 cached_refs->packed = sort_ref_list(list);
220 void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
222 extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
225 void clear_extra_refs(void)
227 free_ref_list(extra_refs);
228 extra_refs = NULL;
231 static struct ref_list *get_packed_refs(void)
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);
240 cached_refs.did_packed = 1;
242 return cached_refs.packed;
245 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
247 DIR *dir = opendir(git_path("%s", base));
249 if (dir) {
250 struct dirent *de;
251 int baselen = strlen(base);
252 char *ref = xmalloc(baselen + 257);
254 memcpy(ref, base, baselen);
255 if (baselen && base[baselen-1] != '/')
256 ref[baselen++] = '/';
258 while ((de = readdir(dir)) != NULL) {
259 unsigned char sha1[20];
260 struct stat st;
261 int flag;
262 int namelen;
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;
278 if (!resolve_ref(ref, sha1, 1, &flag)) {
279 error("%s points nowhere!", ref);
280 continue;
282 list = add_ref(ref, sha1, flag, list, NULL);
284 free(ref);
285 closedir(dir);
287 return sort_ref_list(list);
290 static struct ref_list *get_loose_refs(void)
292 if (!cached_refs.did_loose) {
293 cached_refs.loose = get_ref_dir("refs", NULL);
294 cached_refs.did_loose = 1;
296 return cached_refs.loose;
299 /* We allow "recursive" symbolic refs. Only within reason, though */
300 #define MAXDEPTH 5
301 #define MAXREFLEN (1024)
303 static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
305 FILE *f;
306 struct cached_refs refs;
307 struct ref_list *ref;
308 int retval;
310 strcpy(name + pathlen, "packed-refs");
311 f = fopen(name, "r");
312 if (!f)
313 return -1;
314 read_packed_refs(f, &refs);
315 fclose(f);
316 ref = refs.packed;
317 retval = -1;
318 while (ref) {
319 if (!strcmp(ref->name, refname)) {
320 retval = 0;
321 memcpy(result, ref->sha1, 20);
322 break;
324 ref = ref->next;
326 free_ref_list(refs.packed);
327 return retval;
330 static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
332 int fd, len = strlen(refname);
333 char buffer[128], *p;
335 if (recursion > MAXDEPTH || len > MAXREFLEN)
336 return -1;
337 memcpy(name + pathlen, refname, len+1);
338 fd = open(name, O_RDONLY);
339 if (fd < 0)
340 return resolve_gitlink_packed_ref(name, pathlen, refname, result);
342 len = read(fd, buffer, sizeof(buffer)-1);
343 close(fd);
344 if (len < 0)
345 return -1;
346 while (len && isspace(buffer[len-1]))
347 len--;
348 buffer[len] = 0;
350 /* Was it a detached head or an old-fashioned symlink? */
351 if (!get_sha1_hex(buffer, result))
352 return 0;
354 /* Symref? */
355 if (strncmp(buffer, "ref:", 4))
356 return -1;
357 p = buffer + 4;
358 while (isspace(*p))
359 p++;
361 return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
364 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
366 int len = strlen(path), retval;
367 char *gitdir;
368 const char *tmp;
370 while (len && path[len-1] == '/')
371 len--;
372 if (!len)
373 return -1;
374 gitdir = xmalloc(len + MAXREFLEN + 8);
375 memcpy(gitdir, path, len);
376 memcpy(gitdir + len, "/.git", 6);
377 len += 5;
379 tmp = read_gitfile_gently(gitdir);
380 if (tmp) {
381 free(gitdir);
382 len = strlen(tmp);
383 gitdir = xmalloc(len + MAXREFLEN + 3);
384 memcpy(gitdir, tmp, len);
386 gitdir[len] = '/';
387 gitdir[++len] = '\0';
388 retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
389 free(gitdir);
390 return retval;
393 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
395 int depth = MAXDEPTH;
396 ssize_t len;
397 char buffer[256];
398 static char ref_buffer[256];
400 if (flag)
401 *flag = 0;
403 for (;;) {
404 const char *path = git_path("%s", ref);
405 struct stat st;
406 char *buf;
407 int fd;
409 if (--depth < 0)
410 return NULL;
412 /* Special case: non-existing file.
413 * Not having the refs/heads/new-branch is OK
414 * if we are writing into it, so is .git/HEAD
415 * that points at refs/heads/master still to be
416 * born. It is NOT OK if we are resolving for
417 * reading.
419 if (lstat(path, &st) < 0) {
420 struct ref_list *list = get_packed_refs();
421 while (list) {
422 if (!strcmp(ref, list->name)) {
423 hashcpy(sha1, list->sha1);
424 if (flag)
425 *flag |= REF_ISPACKED;
426 return ref;
428 list = list->next;
430 if (reading || errno != ENOENT)
431 return NULL;
432 hashclr(sha1);
433 return ref;
436 /* Follow "normalized" - ie "refs/.." symlinks by hand */
437 if (S_ISLNK(st.st_mode)) {
438 len = readlink(path, buffer, sizeof(buffer)-1);
439 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
440 buffer[len] = 0;
441 strcpy(ref_buffer, buffer);
442 ref = ref_buffer;
443 if (flag)
444 *flag |= REF_ISSYMREF;
445 continue;
449 /* Is it a directory? */
450 if (S_ISDIR(st.st_mode)) {
451 errno = EISDIR;
452 return NULL;
456 * Anything else, just open it and try to use it as
457 * a ref
459 fd = open(path, O_RDONLY);
460 if (fd < 0)
461 return NULL;
462 len = read_in_full(fd, buffer, sizeof(buffer)-1);
463 close(fd);
466 * Is it a symbolic ref?
468 if (len < 4 || memcmp("ref:", buffer, 4))
469 break;
470 buf = buffer + 4;
471 len -= 4;
472 while (len && isspace(*buf))
473 buf++, len--;
474 while (len && isspace(buf[len-1]))
475 len--;
476 buf[len] = 0;
477 memcpy(ref_buffer, buf, len + 1);
478 ref = ref_buffer;
479 if (flag)
480 *flag |= REF_ISSYMREF;
482 if (len < 40 || get_sha1_hex(buffer, sha1))
483 return NULL;
484 return ref;
487 int read_ref(const char *ref, unsigned char *sha1)
489 if (resolve_ref(ref, sha1, 1, NULL))
490 return 0;
491 return -1;
494 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
495 void *cb_data, struct ref_list *entry)
497 if (strncmp(base, entry->name, trim))
498 return 0;
499 if (is_null_sha1(entry->sha1))
500 return 0;
501 if (!has_sha1_file(entry->sha1)) {
502 error("%s does not point to a valid object!", entry->name);
503 return 0;
505 current_ref = entry;
506 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
509 int peel_ref(const char *ref, unsigned char *sha1)
511 int flag;
512 unsigned char base[20];
513 struct object *o;
515 if (current_ref && (current_ref->name == ref
516 || !strcmp(current_ref->name, ref))) {
517 if (current_ref->flag & REF_KNOWS_PEELED) {
518 hashcpy(sha1, current_ref->peeled);
519 return 0;
521 hashcpy(base, current_ref->sha1);
522 goto fallback;
525 if (!resolve_ref(ref, base, 1, &flag))
526 return -1;
528 if ((flag & REF_ISPACKED)) {
529 struct ref_list *list = get_packed_refs();
531 while (list) {
532 if (!strcmp(list->name, ref)) {
533 if (list->flag & REF_KNOWS_PEELED) {
534 hashcpy(sha1, list->peeled);
535 return 0;
537 /* older pack-refs did not leave peeled ones */
538 break;
540 list = list->next;
544 fallback:
545 o = parse_object(base);
546 if (o && o->type == OBJ_TAG) {
547 o = deref_tag(o, ref, 0);
548 if (o) {
549 hashcpy(sha1, o->sha1);
550 return 0;
553 return -1;
556 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
557 void *cb_data)
559 int retval = 0;
560 struct ref_list *packed = get_packed_refs();
561 struct ref_list *loose = get_loose_refs();
563 struct ref_list *extra;
565 for (extra = extra_refs; extra; extra = extra->next)
566 retval = do_one_ref(base, fn, trim, cb_data, extra);
568 while (packed && loose) {
569 struct ref_list *entry;
570 int cmp = strcmp(packed->name, loose->name);
571 if (!cmp) {
572 packed = packed->next;
573 continue;
575 if (cmp > 0) {
576 entry = loose;
577 loose = loose->next;
578 } else {
579 entry = packed;
580 packed = packed->next;
582 retval = do_one_ref(base, fn, trim, cb_data, entry);
583 if (retval)
584 goto end_each;
587 for (packed = packed ? packed : loose; packed; packed = packed->next) {
588 retval = do_one_ref(base, fn, trim, cb_data, packed);
589 if (retval)
590 goto end_each;
593 end_each:
594 current_ref = NULL;
595 return retval;
598 int head_ref(each_ref_fn fn, void *cb_data)
600 unsigned char sha1[20];
601 int flag;
603 if (resolve_ref("HEAD", sha1, 1, &flag))
604 return fn("HEAD", sha1, flag, cb_data);
605 return 0;
608 int for_each_ref(each_ref_fn fn, void *cb_data)
610 return do_for_each_ref("refs/", fn, 0, cb_data);
613 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
615 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
618 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
620 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
623 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
625 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
629 * Make sure "ref" is something reasonable to have under ".git/refs/";
630 * We do not like it if:
632 * - any path component of it begins with ".", or
633 * - it has double dots "..", or
634 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
635 * - it ends with a "/".
638 static inline int bad_ref_char(int ch)
640 if (((unsigned) ch) <= ' ' ||
641 ch == '~' || ch == '^' || ch == ':')
642 return 1;
643 /* 2.13 Pattern Matching Notation */
644 if (ch == '?' || ch == '[') /* Unsupported */
645 return 1;
646 if (ch == '*') /* Supported at the end */
647 return 2;
648 return 0;
651 int check_ref_format(const char *ref)
653 int ch, level, bad_type;
654 const char *cp = ref;
656 level = 0;
657 while (1) {
658 while ((ch = *cp++) == '/')
659 ; /* tolerate duplicated slashes */
660 if (!ch)
661 /* should not end with slashes */
662 return CHECK_REF_FORMAT_ERROR;
664 /* we are at the beginning of the path component */
665 if (ch == '.')
666 return CHECK_REF_FORMAT_ERROR;
667 bad_type = bad_ref_char(ch);
668 if (bad_type) {
669 return (bad_type == 2 && !*cp)
670 ? CHECK_REF_FORMAT_WILDCARD
671 : CHECK_REF_FORMAT_ERROR;
674 /* scan the rest of the path component */
675 while ((ch = *cp++) != 0) {
676 bad_type = bad_ref_char(ch);
677 if (bad_type) {
678 return (bad_type == 2 && !*cp)
679 ? CHECK_REF_FORMAT_WILDCARD
680 : CHECK_REF_FORMAT_ERROR;
682 if (ch == '/')
683 break;
684 if (ch == '.' && *cp == '.')
685 return CHECK_REF_FORMAT_ERROR;
687 level++;
688 if (!ch) {
689 if (level < 2)
690 return CHECK_REF_FORMAT_ONELEVEL;
691 return CHECK_REF_FORMAT_OK;
696 const char *ref_rev_parse_rules[] = {
697 "%.*s",
698 "refs/%.*s",
699 "refs/tags/%.*s",
700 "refs/heads/%.*s",
701 "refs/remotes/%.*s",
702 "refs/remotes/%.*s/HEAD",
703 NULL
706 const char *ref_fetch_rules[] = {
707 "%.*s",
708 "refs/%.*s",
709 "refs/heads/%.*s",
710 NULL
713 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
715 const char **p;
716 const int abbrev_name_len = strlen(abbrev_name);
718 for (p = rules; *p; p++) {
719 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
720 return 1;
724 return 0;
727 static struct ref_lock *verify_lock(struct ref_lock *lock,
728 const unsigned char *old_sha1, int mustexist)
730 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
731 error("Can't verify ref %s", lock->ref_name);
732 unlock_ref(lock);
733 return NULL;
735 if (hashcmp(lock->old_sha1, old_sha1)) {
736 error("Ref %s is at %s but expected %s", lock->ref_name,
737 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
738 unlock_ref(lock);
739 return NULL;
741 return lock;
744 static int remove_empty_directories(const char *file)
746 /* we want to create a file but there is a directory there;
747 * if that is an empty directory (or a directory that contains
748 * only empty directories), remove them.
750 struct strbuf path;
751 int result;
753 strbuf_init(&path, 20);
754 strbuf_addstr(&path, file);
756 result = remove_dir_recursively(&path, 1);
758 strbuf_release(&path);
760 return result;
763 static int is_refname_available(const char *ref, const char *oldref,
764 struct ref_list *list, int quiet)
766 int namlen = strlen(ref); /* e.g. 'foo/bar' */
767 while (list) {
768 /* list->name could be 'foo' or 'foo/bar/baz' */
769 if (!oldref || strcmp(oldref, list->name)) {
770 int len = strlen(list->name);
771 int cmplen = (namlen < len) ? namlen : len;
772 const char *lead = (namlen < len) ? list->name : ref;
773 if (!strncmp(ref, list->name, cmplen) &&
774 lead[cmplen] == '/') {
775 if (!quiet)
776 error("'%s' exists; cannot create '%s'",
777 list->name, ref);
778 return 0;
781 list = list->next;
783 return 1;
786 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
788 char *ref_file;
789 const char *orig_ref = ref;
790 struct ref_lock *lock;
791 struct stat st;
792 int last_errno = 0;
793 int type;
794 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
796 lock = xcalloc(1, sizeof(struct ref_lock));
797 lock->lock_fd = -1;
799 ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
800 if (!ref && errno == EISDIR) {
801 /* we are trying to lock foo but we used to
802 * have foo/bar which now does not exist;
803 * it is normal for the empty directory 'foo'
804 * to remain.
806 ref_file = git_path("%s", orig_ref);
807 if (remove_empty_directories(ref_file)) {
808 last_errno = errno;
809 error("there are still refs under '%s'", orig_ref);
810 goto error_return;
812 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
814 if (type_p)
815 *type_p = type;
816 if (!ref) {
817 last_errno = errno;
818 error("unable to resolve reference %s: %s",
819 orig_ref, strerror(errno));
820 goto error_return;
822 /* When the ref did not exist and we are creating it,
823 * make sure there is no existing ref that is packed
824 * whose name begins with our refname, nor a ref whose
825 * name is a proper prefix of our refname.
827 if (is_null_sha1(lock->old_sha1) &&
828 !is_refname_available(ref, NULL, get_packed_refs(), 0))
829 goto error_return;
831 lock->lk = xcalloc(1, sizeof(struct lock_file));
833 if (flags & REF_NODEREF)
834 ref = orig_ref;
835 lock->ref_name = xstrdup(ref);
836 lock->orig_ref_name = xstrdup(orig_ref);
837 ref_file = git_path("%s", ref);
838 if (lstat(ref_file, &st) && errno == ENOENT)
839 lock->force_write = 1;
840 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
841 lock->force_write = 1;
843 if (safe_create_leading_directories(ref_file)) {
844 last_errno = errno;
845 error("unable to create directory for %s", ref_file);
846 goto error_return;
848 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
850 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
852 error_return:
853 unlock_ref(lock);
854 errno = last_errno;
855 return NULL;
858 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
860 char refpath[PATH_MAX];
861 if (check_ref_format(ref))
862 return NULL;
863 strcpy(refpath, mkpath("refs/%s", ref));
864 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
867 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
869 switch (check_ref_format(ref)) {
870 default:
871 return NULL;
872 case 0:
873 case CHECK_REF_FORMAT_ONELEVEL:
874 return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
878 static struct lock_file packlock;
880 static int repack_without_ref(const char *refname)
882 struct ref_list *list, *packed_ref_list;
883 int fd;
884 int found = 0;
886 packed_ref_list = get_packed_refs();
887 for (list = packed_ref_list; list; list = list->next) {
888 if (!strcmp(refname, list->name)) {
889 found = 1;
890 break;
893 if (!found)
894 return 0;
895 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
896 if (fd < 0)
897 return error("cannot delete '%s' from packed refs", refname);
899 for (list = packed_ref_list; list; list = list->next) {
900 char line[PATH_MAX + 100];
901 int len;
903 if (!strcmp(refname, list->name))
904 continue;
905 len = snprintf(line, sizeof(line), "%s %s\n",
906 sha1_to_hex(list->sha1), list->name);
907 /* this should not happen but just being defensive */
908 if (len > sizeof(line))
909 die("too long a refname '%s'", list->name);
910 write_or_die(fd, line, len);
912 return commit_lock_file(&packlock);
915 int delete_ref(const char *refname, const unsigned char *sha1)
917 struct ref_lock *lock;
918 int err, i, ret = 0, flag = 0;
920 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
921 if (!lock)
922 return 1;
923 if (!(flag & REF_ISPACKED)) {
924 /* loose */
925 i = strlen(lock->lk->filename) - 5; /* .lock */
926 lock->lk->filename[i] = 0;
927 err = unlink(lock->lk->filename);
928 if (err && errno != ENOENT) {
929 ret = 1;
930 error("unlink(%s) failed: %s",
931 lock->lk->filename, strerror(errno));
933 lock->lk->filename[i] = '.';
935 /* removing the loose one could have resurrected an earlier
936 * packed one. Also, if it was not loose we need to repack
937 * without it.
939 ret |= repack_without_ref(refname);
941 err = unlink(git_path("logs/%s", lock->ref_name));
942 if (err && errno != ENOENT)
943 fprintf(stderr, "warning: unlink(%s) failed: %s",
944 git_path("logs/%s", lock->ref_name), strerror(errno));
945 invalidate_cached_refs();
946 unlock_ref(lock);
947 return ret;
950 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
952 static const char renamed_ref[] = "RENAMED-REF";
953 unsigned char sha1[20], orig_sha1[20];
954 int flag = 0, logmoved = 0;
955 struct ref_lock *lock;
956 struct stat loginfo;
957 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
959 if (S_ISLNK(loginfo.st_mode))
960 return error("reflog for %s is a symlink", oldref);
962 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
963 return error("refname %s not found", oldref);
965 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
966 return 1;
968 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
969 return 1;
971 lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
972 if (!lock)
973 return error("unable to lock %s", renamed_ref);
974 lock->force_write = 1;
975 if (write_ref_sha1(lock, orig_sha1, logmsg))
976 return error("unable to save current sha1 in %s", renamed_ref);
978 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
979 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
980 oldref, strerror(errno));
982 if (delete_ref(oldref, orig_sha1)) {
983 error("unable to delete old %s", oldref);
984 goto rollback;
987 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
988 if (errno==EISDIR) {
989 if (remove_empty_directories(git_path("%s", newref))) {
990 error("Directory not empty: %s", newref);
991 goto rollback;
993 } else {
994 error("unable to delete existing %s", newref);
995 goto rollback;
999 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1000 error("unable to create directory for %s", newref);
1001 goto rollback;
1004 retry:
1005 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
1006 if (errno==EISDIR || errno==ENOTDIR) {
1008 * rename(a, b) when b is an existing
1009 * directory ought to result in ISDIR, but
1010 * Solaris 5.8 gives ENOTDIR. Sheesh.
1012 if (remove_empty_directories(git_path("logs/%s", newref))) {
1013 error("Directory not empty: logs/%s", newref);
1014 goto rollback;
1016 goto retry;
1017 } else {
1018 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
1019 newref, strerror(errno));
1020 goto rollback;
1023 logmoved = log;
1025 lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
1026 if (!lock) {
1027 error("unable to lock %s for update", newref);
1028 goto rollback;
1031 lock->force_write = 1;
1032 hashcpy(lock->old_sha1, orig_sha1);
1033 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1034 error("unable to write current sha1 into %s", newref);
1035 goto rollback;
1038 return 0;
1040 rollback:
1041 lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1042 if (!lock) {
1043 error("unable to lock %s for rollback", oldref);
1044 goto rollbacklog;
1047 lock->force_write = 1;
1048 flag = log_all_ref_updates;
1049 log_all_ref_updates = 0;
1050 if (write_ref_sha1(lock, orig_sha1, NULL))
1051 error("unable to write current sha1 into %s", oldref);
1052 log_all_ref_updates = flag;
1054 rollbacklog:
1055 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1056 error("unable to restore logfile %s from %s: %s",
1057 oldref, newref, strerror(errno));
1058 if (!logmoved && log &&
1059 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1060 error("unable to restore logfile %s from tmp-renamed-log: %s",
1061 oldref, strerror(errno));
1063 return 1;
1066 int close_ref(struct ref_lock *lock)
1068 if (close_lock_file(lock->lk))
1069 return -1;
1070 lock->lock_fd = -1;
1071 return 0;
1074 int commit_ref(struct ref_lock *lock)
1076 if (commit_lock_file(lock->lk))
1077 return -1;
1078 lock->lock_fd = -1;
1079 return 0;
1082 void unlock_ref(struct ref_lock *lock)
1084 /* Do not free lock->lk -- atexit() still looks at them */
1085 if (lock->lk)
1086 rollback_lock_file(lock->lk);
1087 free(lock->ref_name);
1088 free(lock->orig_ref_name);
1089 free(lock);
1093 * copy the reflog message msg to buf, which has been allocated sufficiently
1094 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1095 * because reflog file is one line per entry.
1097 static int copy_msg(char *buf, const char *msg)
1099 char *cp = buf;
1100 char c;
1101 int wasspace = 1;
1103 *cp++ = '\t';
1104 while ((c = *msg++)) {
1105 if (wasspace && isspace(c))
1106 continue;
1107 wasspace = isspace(c);
1108 if (wasspace)
1109 c = ' ';
1110 *cp++ = c;
1112 while (buf < cp && isspace(cp[-1]))
1113 cp--;
1114 *cp++ = '\n';
1115 return cp - buf;
1118 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1119 const unsigned char *new_sha1, const char *msg)
1121 int logfd, written, oflags = O_APPEND | O_WRONLY;
1122 unsigned maxlen, len;
1123 int msglen;
1124 char *log_file, *logrec;
1125 const char *committer;
1127 if (log_all_ref_updates < 0)
1128 log_all_ref_updates = !is_bare_repository();
1130 log_file = git_path("logs/%s", ref_name);
1132 if (log_all_ref_updates &&
1133 (!prefixcmp(ref_name, "refs/heads/") ||
1134 !prefixcmp(ref_name, "refs/remotes/") ||
1135 !strcmp(ref_name, "HEAD"))) {
1136 if (safe_create_leading_directories(log_file) < 0)
1137 return error("unable to create directory for %s",
1138 log_file);
1139 oflags |= O_CREAT;
1142 logfd = open(log_file, oflags, 0666);
1143 if (logfd < 0) {
1144 if (!(oflags & O_CREAT) && errno == ENOENT)
1145 return 0;
1147 if ((oflags & O_CREAT) && errno == EISDIR) {
1148 if (remove_empty_directories(log_file)) {
1149 return error("There are still logs under '%s'",
1150 log_file);
1152 logfd = open(log_file, oflags, 0666);
1155 if (logfd < 0)
1156 return error("Unable to append to %s: %s",
1157 log_file, strerror(errno));
1160 adjust_shared_perm(log_file);
1162 msglen = msg ? strlen(msg) : 0;
1163 committer = git_committer_info(0);
1164 maxlen = strlen(committer) + msglen + 100;
1165 logrec = xmalloc(maxlen);
1166 len = sprintf(logrec, "%s %s %s\n",
1167 sha1_to_hex(old_sha1),
1168 sha1_to_hex(new_sha1),
1169 committer);
1170 if (msglen)
1171 len += copy_msg(logrec + len - 1, msg) - 1;
1172 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1173 free(logrec);
1174 if (close(logfd) != 0 || written != len)
1175 return error("Unable to append to %s", log_file);
1176 return 0;
1179 static int is_branch(const char *refname)
1181 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1184 int write_ref_sha1(struct ref_lock *lock,
1185 const unsigned char *sha1, const char *logmsg)
1187 static char term = '\n';
1188 struct object *o;
1190 if (!lock)
1191 return -1;
1192 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1193 unlock_ref(lock);
1194 return 0;
1196 o = parse_object(sha1);
1197 if (!o) {
1198 error("Trying to write ref %s with nonexistant object %s",
1199 lock->ref_name, sha1_to_hex(sha1));
1200 unlock_ref(lock);
1201 return -1;
1203 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1204 error("Trying to write non-commit object %s to branch %s",
1205 sha1_to_hex(sha1), lock->ref_name);
1206 unlock_ref(lock);
1207 return -1;
1209 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1210 write_in_full(lock->lock_fd, &term, 1) != 1
1211 || close_ref(lock) < 0) {
1212 error("Couldn't write %s", lock->lk->filename);
1213 unlock_ref(lock);
1214 return -1;
1216 invalidate_cached_refs();
1217 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1218 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1219 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1220 unlock_ref(lock);
1221 return -1;
1223 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1225 * Special hack: If a branch is updated directly and HEAD
1226 * points to it (may happen on the remote side of a push
1227 * for example) then logically the HEAD reflog should be
1228 * updated too.
1229 * A generic solution implies reverse symref information,
1230 * but finding all symrefs pointing to the given branch
1231 * would be rather costly for this rare event (the direct
1232 * update of a branch) to be worth it. So let's cheat and
1233 * check with HEAD only which should cover 99% of all usage
1234 * scenarios (even 100% of the default ones).
1236 unsigned char head_sha1[20];
1237 int head_flag;
1238 const char *head_ref;
1239 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1240 if (head_ref && (head_flag & REF_ISSYMREF) &&
1241 !strcmp(head_ref, lock->ref_name))
1242 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1244 if (commit_ref(lock)) {
1245 error("Couldn't set %s", lock->ref_name);
1246 unlock_ref(lock);
1247 return -1;
1249 unlock_ref(lock);
1250 return 0;
1253 int create_symref(const char *ref_target, const char *refs_heads_master,
1254 const char *logmsg)
1256 const char *lockpath;
1257 char ref[1000];
1258 int fd, len, written;
1259 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1260 unsigned char old_sha1[20], new_sha1[20];
1262 if (logmsg && read_ref(ref_target, old_sha1))
1263 hashclr(old_sha1);
1265 if (safe_create_leading_directories(git_HEAD) < 0)
1266 return error("unable to create directory for %s", git_HEAD);
1268 #ifndef NO_SYMLINK_HEAD
1269 if (prefer_symlink_refs) {
1270 unlink(git_HEAD);
1271 if (!symlink(refs_heads_master, git_HEAD))
1272 goto done;
1273 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1275 #endif
1277 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1278 if (sizeof(ref) <= len) {
1279 error("refname too long: %s", refs_heads_master);
1280 goto error_free_return;
1282 lockpath = mkpath("%s.lock", git_HEAD);
1283 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1284 if (fd < 0) {
1285 error("Unable to open %s for writing", lockpath);
1286 goto error_free_return;
1288 written = write_in_full(fd, ref, len);
1289 if (close(fd) != 0 || written != len) {
1290 error("Unable to write to %s", lockpath);
1291 goto error_unlink_return;
1293 if (rename(lockpath, git_HEAD) < 0) {
1294 error("Unable to create %s", git_HEAD);
1295 goto error_unlink_return;
1297 if (adjust_shared_perm(git_HEAD)) {
1298 error("Unable to fix permissions on %s", lockpath);
1299 error_unlink_return:
1300 unlink(lockpath);
1301 error_free_return:
1302 free(git_HEAD);
1303 return -1;
1306 #ifndef NO_SYMLINK_HEAD
1307 done:
1308 #endif
1309 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1310 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1312 free(git_HEAD);
1313 return 0;
1316 static char *ref_msg(const char *line, const char *endp)
1318 const char *ep;
1319 line += 82;
1320 ep = memchr(line, '\n', endp - line);
1321 if (!ep)
1322 ep = endp;
1323 return xmemdupz(line, ep - line);
1326 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)
1328 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1329 char *tz_c;
1330 int logfd, tz, reccnt = 0;
1331 struct stat st;
1332 unsigned long date;
1333 unsigned char logged_sha1[20];
1334 void *log_mapped;
1335 size_t mapsz;
1337 logfile = git_path("logs/%s", ref);
1338 logfd = open(logfile, O_RDONLY, 0);
1339 if (logfd < 0)
1340 die("Unable to read log %s: %s", logfile, strerror(errno));
1341 fstat(logfd, &st);
1342 if (!st.st_size)
1343 die("Log %s is empty.", logfile);
1344 mapsz = xsize_t(st.st_size);
1345 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1346 logdata = log_mapped;
1347 close(logfd);
1349 lastrec = NULL;
1350 rec = logend = logdata + st.st_size;
1351 while (logdata < rec) {
1352 reccnt++;
1353 if (logdata < rec && *(rec-1) == '\n')
1354 rec--;
1355 lastgt = NULL;
1356 while (logdata < rec && *(rec-1) != '\n') {
1357 rec--;
1358 if (*rec == '>')
1359 lastgt = rec;
1361 if (!lastgt)
1362 die("Log %s is corrupt.", logfile);
1363 date = strtoul(lastgt + 1, &tz_c, 10);
1364 if (date <= at_time || cnt == 0) {
1365 tz = strtoul(tz_c, NULL, 10);
1366 if (msg)
1367 *msg = ref_msg(rec, logend);
1368 if (cutoff_time)
1369 *cutoff_time = date;
1370 if (cutoff_tz)
1371 *cutoff_tz = tz;
1372 if (cutoff_cnt)
1373 *cutoff_cnt = reccnt - 1;
1374 if (lastrec) {
1375 if (get_sha1_hex(lastrec, logged_sha1))
1376 die("Log %s is corrupt.", logfile);
1377 if (get_sha1_hex(rec + 41, sha1))
1378 die("Log %s is corrupt.", logfile);
1379 if (hashcmp(logged_sha1, sha1)) {
1380 fprintf(stderr,
1381 "warning: Log %s has gap after %s.\n",
1382 logfile, show_date(date, tz, DATE_RFC2822));
1385 else if (date == at_time) {
1386 if (get_sha1_hex(rec + 41, sha1))
1387 die("Log %s is corrupt.", logfile);
1389 else {
1390 if (get_sha1_hex(rec + 41, logged_sha1))
1391 die("Log %s is corrupt.", logfile);
1392 if (hashcmp(logged_sha1, sha1)) {
1393 fprintf(stderr,
1394 "warning: Log %s unexpectedly ended on %s.\n",
1395 logfile, show_date(date, tz, DATE_RFC2822));
1398 munmap(log_mapped, mapsz);
1399 return 0;
1401 lastrec = rec;
1402 if (cnt > 0)
1403 cnt--;
1406 rec = logdata;
1407 while (rec < logend && *rec != '>' && *rec != '\n')
1408 rec++;
1409 if (rec == logend || *rec == '\n')
1410 die("Log %s is corrupt.", logfile);
1411 date = strtoul(rec + 1, &tz_c, 10);
1412 tz = strtoul(tz_c, NULL, 10);
1413 if (get_sha1_hex(logdata, sha1))
1414 die("Log %s is corrupt.", logfile);
1415 if (is_null_sha1(sha1)) {
1416 if (get_sha1_hex(logdata + 41, sha1))
1417 die("Log %s is corrupt.", logfile);
1419 if (msg)
1420 *msg = ref_msg(logdata, logend);
1421 munmap(log_mapped, mapsz);
1423 if (cutoff_time)
1424 *cutoff_time = date;
1425 if (cutoff_tz)
1426 *cutoff_tz = tz;
1427 if (cutoff_cnt)
1428 *cutoff_cnt = reccnt;
1429 return 1;
1432 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1434 const char *logfile;
1435 FILE *logfp;
1436 char buf[1024];
1437 int ret = 0;
1439 logfile = git_path("logs/%s", ref);
1440 logfp = fopen(logfile, "r");
1441 if (!logfp)
1442 return -1;
1443 while (fgets(buf, sizeof(buf), logfp)) {
1444 unsigned char osha1[20], nsha1[20];
1445 char *email_end, *message;
1446 unsigned long timestamp;
1447 int len, tz;
1449 /* old SP new SP name <email> SP time TAB msg LF */
1450 len = strlen(buf);
1451 if (len < 83 || buf[len-1] != '\n' ||
1452 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1453 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1454 !(email_end = strchr(buf + 82, '>')) ||
1455 email_end[1] != ' ' ||
1456 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1457 !message || message[0] != ' ' ||
1458 (message[1] != '+' && message[1] != '-') ||
1459 !isdigit(message[2]) || !isdigit(message[3]) ||
1460 !isdigit(message[4]) || !isdigit(message[5]))
1461 continue; /* corrupt? */
1462 email_end[1] = '\0';
1463 tz = strtol(message + 1, NULL, 10);
1464 if (message[6] != '\t')
1465 message += 6;
1466 else
1467 message += 7;
1468 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1469 if (ret)
1470 break;
1472 fclose(logfp);
1473 return ret;
1476 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1478 DIR *dir = opendir(git_path("logs/%s", base));
1479 int retval = 0;
1481 if (dir) {
1482 struct dirent *de;
1483 int baselen = strlen(base);
1484 char *log = xmalloc(baselen + 257);
1486 memcpy(log, base, baselen);
1487 if (baselen && base[baselen-1] != '/')
1488 log[baselen++] = '/';
1490 while ((de = readdir(dir)) != NULL) {
1491 struct stat st;
1492 int namelen;
1494 if (de->d_name[0] == '.')
1495 continue;
1496 namelen = strlen(de->d_name);
1497 if (namelen > 255)
1498 continue;
1499 if (has_extension(de->d_name, ".lock"))
1500 continue;
1501 memcpy(log + baselen, de->d_name, namelen+1);
1502 if (stat(git_path("logs/%s", log), &st) < 0)
1503 continue;
1504 if (S_ISDIR(st.st_mode)) {
1505 retval = do_for_each_reflog(log, fn, cb_data);
1506 } else {
1507 unsigned char sha1[20];
1508 if (!resolve_ref(log, sha1, 0, NULL))
1509 retval = error("bad ref for %s", log);
1510 else
1511 retval = fn(log, sha1, 0, cb_data);
1513 if (retval)
1514 break;
1516 free(log);
1517 closedir(dir);
1519 else if (*base)
1520 return errno;
1521 return retval;
1524 int for_each_reflog(each_ref_fn fn, void *cb_data)
1526 return do_for_each_reflog("", fn, cb_data);
1529 int update_ref(const char *action, const char *refname,
1530 const unsigned char *sha1, const unsigned char *oldval,
1531 int flags, enum action_on_err onerr)
1533 static struct ref_lock *lock;
1534 lock = lock_any_ref_for_update(refname, oldval, flags);
1535 if (!lock) {
1536 const char *str = "Cannot lock the ref '%s'.";
1537 switch (onerr) {
1538 case MSG_ON_ERR: error(str, refname); break;
1539 case DIE_ON_ERR: die(str, refname); break;
1540 case QUIET_ON_ERR: break;
1542 return 1;
1544 if (write_ref_sha1(lock, sha1, action) < 0) {
1545 const char *str = "Cannot update the ref '%s'.";
1546 switch (onerr) {
1547 case MSG_ON_ERR: error(str, refname); break;
1548 case DIE_ON_ERR: die(str, refname); break;
1549 case QUIET_ON_ERR: break;
1551 return 1;
1553 return 0;
1556 struct ref *find_ref_by_name(struct ref *list, const char *name)
1558 for ( ; list; list = list->next)
1559 if (!strcmp(list->name, name))
1560 return list;
1561 return NULL;