user-manual: fix discussion of default clone
[git/jrn.git] / refs.c
blobd2b7b7fb56f76294bb48526496429968d86e49b2
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
6 /* ISSYMREF=01 and ISPACKED=02 are public interfaces */
7 #define REF_KNOWS_PEELED 04
9 struct ref_list {
10 struct ref_list *next;
11 unsigned char flag; /* ISSYMREF? ISPACKED? */
12 unsigned char sha1[20];
13 unsigned char peeled[20];
14 char name[FLEX_ARRAY];
17 static const char *parse_ref_line(char *line, unsigned char *sha1)
20 * 42: the answer to everything.
22 * In this case, it happens to be the answer to
23 * 40 (length of sha1 hex representation)
24 * +1 (space in between hex and name)
25 * +1 (newline at the end of the line)
27 int len = strlen(line) - 42;
29 if (len <= 0)
30 return NULL;
31 if (get_sha1_hex(line, sha1) < 0)
32 return NULL;
33 if (!isspace(line[40]))
34 return NULL;
35 line += 41;
36 if (isspace(*line))
37 return NULL;
38 if (line[len] != '\n')
39 return NULL;
40 line[len] = 0;
42 return line;
45 static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
46 int flag, struct ref_list *list,
47 struct ref_list **new_entry)
49 int len;
50 struct ref_list **p = &list, *entry;
52 /* Find the place to insert the ref into.. */
53 while ((entry = *p) != NULL) {
54 int cmp = strcmp(entry->name, name);
55 if (cmp > 0)
56 break;
58 /* Same as existing entry? */
59 if (!cmp) {
60 if (new_entry)
61 *new_entry = entry;
62 return list;
64 p = &entry->next;
67 /* Allocate it and add it in.. */
68 len = strlen(name) + 1;
69 entry = xmalloc(sizeof(struct ref_list) + len);
70 hashcpy(entry->sha1, sha1);
71 hashclr(entry->peeled);
72 memcpy(entry->name, name, len);
73 entry->flag = flag;
74 entry->next = *p;
75 *p = entry;
76 if (new_entry)
77 *new_entry = entry;
78 return list;
82 * Future: need to be in "struct repository"
83 * when doing a full libification.
85 struct cached_refs {
86 char did_loose;
87 char did_packed;
88 struct ref_list *loose;
89 struct ref_list *packed;
90 } cached_refs;
92 static void free_ref_list(struct ref_list *list)
94 struct ref_list *next;
95 for ( ; list; list = next) {
96 next = list->next;
97 free(list);
101 static void invalidate_cached_refs(void)
103 struct cached_refs *ca = &cached_refs;
105 if (ca->did_loose && ca->loose)
106 free_ref_list(ca->loose);
107 if (ca->did_packed && ca->packed)
108 free_ref_list(ca->packed);
109 ca->loose = ca->packed = NULL;
110 ca->did_loose = ca->did_packed = 0;
113 static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
115 struct ref_list *list = NULL;
116 struct ref_list *last = NULL;
117 char refline[PATH_MAX];
118 int flag = REF_ISPACKED;
120 while (fgets(refline, sizeof(refline), f)) {
121 unsigned char sha1[20];
122 const char *name;
123 static const char header[] = "# pack-refs with:";
125 if (!strncmp(refline, header, sizeof(header)-1)) {
126 const char *traits = refline + sizeof(header) - 1;
127 if (strstr(traits, " peeled "))
128 flag |= REF_KNOWS_PEELED;
129 /* perhaps other traits later as well */
130 continue;
133 name = parse_ref_line(refline, sha1);
134 if (name) {
135 list = add_ref(name, sha1, flag, list, &last);
136 continue;
138 if (last &&
139 refline[0] == '^' &&
140 strlen(refline) == 42 &&
141 refline[41] == '\n' &&
142 !get_sha1_hex(refline + 1, sha1))
143 hashcpy(last->peeled, sha1);
145 cached_refs->packed = list;
148 static struct ref_list *get_packed_refs(void)
150 if (!cached_refs.did_packed) {
151 FILE *f = fopen(git_path("packed-refs"), "r");
152 cached_refs.packed = NULL;
153 if (f) {
154 read_packed_refs(f, &cached_refs);
155 fclose(f);
157 cached_refs.did_packed = 1;
159 return cached_refs.packed;
162 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
164 DIR *dir = opendir(git_path("%s", base));
166 if (dir) {
167 struct dirent *de;
168 int baselen = strlen(base);
169 char *ref = xmalloc(baselen + 257);
171 memcpy(ref, base, baselen);
172 if (baselen && base[baselen-1] != '/')
173 ref[baselen++] = '/';
175 while ((de = readdir(dir)) != NULL) {
176 unsigned char sha1[20];
177 struct stat st;
178 int flag;
179 int namelen;
181 if (de->d_name[0] == '.')
182 continue;
183 namelen = strlen(de->d_name);
184 if (namelen > 255)
185 continue;
186 if (has_extension(de->d_name, ".lock"))
187 continue;
188 memcpy(ref + baselen, de->d_name, namelen+1);
189 if (stat(git_path("%s", ref), &st) < 0)
190 continue;
191 if (S_ISDIR(st.st_mode)) {
192 list = get_ref_dir(ref, list);
193 continue;
195 if (!resolve_ref(ref, sha1, 1, &flag)) {
196 error("%s points nowhere!", ref);
197 continue;
199 list = add_ref(ref, sha1, flag, list, NULL);
201 free(ref);
202 closedir(dir);
204 return list;
207 static struct ref_list *get_loose_refs(void)
209 if (!cached_refs.did_loose) {
210 cached_refs.loose = get_ref_dir("refs", NULL);
211 cached_refs.did_loose = 1;
213 return cached_refs.loose;
216 /* We allow "recursive" symbolic refs. Only within reason, though */
217 #define MAXDEPTH 5
219 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
221 int depth = MAXDEPTH, len;
222 char buffer[256];
223 static char ref_buffer[256];
225 if (flag)
226 *flag = 0;
228 for (;;) {
229 const char *path = git_path("%s", ref);
230 struct stat st;
231 char *buf;
232 int fd;
234 if (--depth < 0)
235 return NULL;
237 /* Special case: non-existing file.
238 * Not having the refs/heads/new-branch is OK
239 * if we are writing into it, so is .git/HEAD
240 * that points at refs/heads/master still to be
241 * born. It is NOT OK if we are resolving for
242 * reading.
244 if (lstat(path, &st) < 0) {
245 struct ref_list *list = get_packed_refs();
246 while (list) {
247 if (!strcmp(ref, list->name)) {
248 hashcpy(sha1, list->sha1);
249 if (flag)
250 *flag |= REF_ISPACKED;
251 return ref;
253 list = list->next;
255 if (reading || errno != ENOENT)
256 return NULL;
257 hashclr(sha1);
258 return ref;
261 /* Follow "normalized" - ie "refs/.." symlinks by hand */
262 if (S_ISLNK(st.st_mode)) {
263 len = readlink(path, buffer, sizeof(buffer)-1);
264 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
265 buffer[len] = 0;
266 strcpy(ref_buffer, buffer);
267 ref = ref_buffer;
268 if (flag)
269 *flag |= REF_ISSYMREF;
270 continue;
274 /* Is it a directory? */
275 if (S_ISDIR(st.st_mode)) {
276 errno = EISDIR;
277 return NULL;
281 * Anything else, just open it and try to use it as
282 * a ref
284 fd = open(path, O_RDONLY);
285 if (fd < 0)
286 return NULL;
287 len = read_in_full(fd, buffer, sizeof(buffer)-1);
288 close(fd);
291 * Is it a symbolic ref?
293 if (len < 4 || memcmp("ref:", buffer, 4))
294 break;
295 buf = buffer + 4;
296 len -= 4;
297 while (len && isspace(*buf))
298 buf++, len--;
299 while (len && isspace(buf[len-1]))
300 len--;
301 buf[len] = 0;
302 memcpy(ref_buffer, buf, len + 1);
303 ref = ref_buffer;
304 if (flag)
305 *flag |= REF_ISSYMREF;
307 if (len < 40 || get_sha1_hex(buffer, sha1))
308 return NULL;
309 return ref;
312 int read_ref(const char *ref, unsigned char *sha1)
314 if (resolve_ref(ref, sha1, 1, NULL))
315 return 0;
316 return -1;
319 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
320 void *cb_data, struct ref_list *entry)
322 if (strncmp(base, entry->name, trim))
323 return 0;
324 if (is_null_sha1(entry->sha1))
325 return 0;
326 if (!has_sha1_file(entry->sha1)) {
327 error("%s does not point to a valid object!", entry->name);
328 return 0;
330 return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
333 int peel_ref(const char *ref, unsigned char *sha1)
335 int flag;
336 unsigned char base[20];
337 struct object *o;
339 if (!resolve_ref(ref, base, 1, &flag))
340 return -1;
342 if ((flag & REF_ISPACKED)) {
343 struct ref_list *list = get_packed_refs();
345 while (list) {
346 if (!strcmp(list->name, ref)) {
347 if (list->flag & REF_KNOWS_PEELED) {
348 hashcpy(sha1, list->peeled);
349 return 0;
351 /* older pack-refs did not leave peeled ones */
352 break;
354 list = list->next;
358 /* fallback - callers should not call this for unpacked refs */
359 o = parse_object(base);
360 if (o->type == OBJ_TAG) {
361 o = deref_tag(o, ref, 0);
362 if (o) {
363 hashcpy(sha1, o->sha1);
364 return 0;
367 return -1;
370 static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
371 void *cb_data)
373 int retval;
374 struct ref_list *packed = get_packed_refs();
375 struct ref_list *loose = get_loose_refs();
377 while (packed && loose) {
378 struct ref_list *entry;
379 int cmp = strcmp(packed->name, loose->name);
380 if (!cmp) {
381 packed = packed->next;
382 continue;
384 if (cmp > 0) {
385 entry = loose;
386 loose = loose->next;
387 } else {
388 entry = packed;
389 packed = packed->next;
391 retval = do_one_ref(base, fn, trim, cb_data, entry);
392 if (retval)
393 return retval;
396 for (packed = packed ? packed : loose; packed; packed = packed->next) {
397 retval = do_one_ref(base, fn, trim, cb_data, packed);
398 if (retval)
399 return retval;
401 return 0;
404 int head_ref(each_ref_fn fn, void *cb_data)
406 unsigned char sha1[20];
407 int flag;
409 if (resolve_ref("HEAD", sha1, 1, &flag))
410 return fn("HEAD", sha1, flag, cb_data);
411 return 0;
414 int for_each_ref(each_ref_fn fn, void *cb_data)
416 return do_for_each_ref("refs/", fn, 0, cb_data);
419 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
421 return do_for_each_ref("refs/tags/", fn, 10, cb_data);
424 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
426 return do_for_each_ref("refs/heads/", fn, 11, cb_data);
429 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
431 return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
434 /* NEEDSWORK: This is only used by ssh-upload and it should go; the
435 * caller should do resolve_ref or read_ref like everybody else. Or
436 * maybe everybody else should use get_ref_sha1() instead of doing
437 * read_ref().
439 int get_ref_sha1(const char *ref, unsigned char *sha1)
441 if (check_ref_format(ref))
442 return -1;
443 return read_ref(mkpath("refs/%s", ref), sha1);
447 * Make sure "ref" is something reasonable to have under ".git/refs/";
448 * We do not like it if:
450 * - any path component of it begins with ".", or
451 * - it has double dots "..", or
452 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
453 * - it ends with a "/".
456 static inline int bad_ref_char(int ch)
458 return (((unsigned) ch) <= ' ' ||
459 ch == '~' || ch == '^' || ch == ':' ||
460 /* 2.13 Pattern Matching Notation */
461 ch == '?' || ch == '*' || ch == '[');
464 int check_ref_format(const char *ref)
466 int ch, level;
467 const char *cp = ref;
469 level = 0;
470 while (1) {
471 while ((ch = *cp++) == '/')
472 ; /* tolerate duplicated slashes */
473 if (!ch)
474 return -1; /* should not end with slashes */
476 /* we are at the beginning of the path component */
477 if (ch == '.' || bad_ref_char(ch))
478 return -1;
480 /* scan the rest of the path component */
481 while ((ch = *cp++) != 0) {
482 if (bad_ref_char(ch))
483 return -1;
484 if (ch == '/')
485 break;
486 if (ch == '.' && *cp == '.')
487 return -1;
489 level++;
490 if (!ch) {
491 if (level < 2)
492 return -2; /* at least of form "heads/blah" */
493 return 0;
498 static struct ref_lock *verify_lock(struct ref_lock *lock,
499 const unsigned char *old_sha1, int mustexist)
501 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
502 error("Can't verify ref %s", lock->ref_name);
503 unlock_ref(lock);
504 return NULL;
506 if (hashcmp(lock->old_sha1, old_sha1)) {
507 error("Ref %s is at %s but expected %s", lock->ref_name,
508 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
509 unlock_ref(lock);
510 return NULL;
512 return lock;
515 static int remove_empty_dir_recursive(char *path, int len)
517 DIR *dir = opendir(path);
518 struct dirent *e;
519 int ret = 0;
521 if (!dir)
522 return -1;
523 if (path[len-1] != '/')
524 path[len++] = '/';
525 while ((e = readdir(dir)) != NULL) {
526 struct stat st;
527 int namlen;
528 if ((e->d_name[0] == '.') &&
529 ((e->d_name[1] == 0) ||
530 ((e->d_name[1] == '.') && e->d_name[2] == 0)))
531 continue; /* "." and ".." */
533 namlen = strlen(e->d_name);
534 if ((len + namlen < PATH_MAX) &&
535 strcpy(path + len, e->d_name) &&
536 !lstat(path, &st) &&
537 S_ISDIR(st.st_mode) &&
538 !remove_empty_dir_recursive(path, len + namlen))
539 continue; /* happy */
541 /* path too long, stat fails, or non-directory still exists */
542 ret = -1;
543 break;
545 closedir(dir);
546 if (!ret) {
547 path[len] = 0;
548 ret = rmdir(path);
550 return ret;
553 static int remove_empty_directories(char *file)
555 /* we want to create a file but there is a directory there;
556 * if that is an empty directory (or a directory that contains
557 * only empty directories), remove them.
559 char path[PATH_MAX];
560 int len = strlen(file);
562 if (len >= PATH_MAX) /* path too long ;-) */
563 return -1;
564 strcpy(path, file);
565 return remove_empty_dir_recursive(path, len);
568 static int is_refname_available(const char *ref, const char *oldref,
569 struct ref_list *list, int quiet)
571 int namlen = strlen(ref); /* e.g. 'foo/bar' */
572 while (list) {
573 /* list->name could be 'foo' or 'foo/bar/baz' */
574 if (!oldref || strcmp(oldref, list->name)) {
575 int len = strlen(list->name);
576 int cmplen = (namlen < len) ? namlen : len;
577 const char *lead = (namlen < len) ? list->name : ref;
578 if (!strncmp(ref, list->name, cmplen) &&
579 lead[cmplen] == '/') {
580 if (!quiet)
581 error("'%s' exists; cannot create '%s'",
582 list->name, ref);
583 return 0;
586 list = list->next;
588 return 1;
591 static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int *flag)
593 char *ref_file;
594 const char *orig_ref = ref;
595 struct ref_lock *lock;
596 struct stat st;
597 int last_errno = 0;
598 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
600 lock = xcalloc(1, sizeof(struct ref_lock));
601 lock->lock_fd = -1;
603 ref = resolve_ref(ref, lock->old_sha1, mustexist, flag);
604 if (!ref && errno == EISDIR) {
605 /* we are trying to lock foo but we used to
606 * have foo/bar which now does not exist;
607 * it is normal for the empty directory 'foo'
608 * to remain.
610 ref_file = git_path("%s", orig_ref);
611 if (remove_empty_directories(ref_file)) {
612 last_errno = errno;
613 error("there are still refs under '%s'", orig_ref);
614 goto error_return;
616 ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, flag);
618 if (!ref) {
619 last_errno = errno;
620 error("unable to resolve reference %s: %s",
621 orig_ref, strerror(errno));
622 goto error_return;
624 /* When the ref did not exist and we are creating it,
625 * make sure there is no existing ref that is packed
626 * whose name begins with our refname, nor a ref whose
627 * name is a proper prefix of our refname.
629 if (is_null_sha1(lock->old_sha1) &&
630 !is_refname_available(ref, NULL, get_packed_refs(), 0))
631 goto error_return;
633 lock->lk = xcalloc(1, sizeof(struct lock_file));
635 lock->ref_name = xstrdup(ref);
636 lock->orig_ref_name = xstrdup(orig_ref);
637 ref_file = git_path("%s", ref);
638 lock->force_write = lstat(ref_file, &st) && errno == ENOENT;
640 if (safe_create_leading_directories(ref_file)) {
641 last_errno = errno;
642 error("unable to create directory for %s", ref_file);
643 goto error_return;
645 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
647 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
649 error_return:
650 unlock_ref(lock);
651 errno = last_errno;
652 return NULL;
655 struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
657 char refpath[PATH_MAX];
658 if (check_ref_format(ref))
659 return NULL;
660 strcpy(refpath, mkpath("refs/%s", ref));
661 return lock_ref_sha1_basic(refpath, old_sha1, NULL);
664 struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1)
666 if (check_ref_format(ref) == -1)
667 return NULL;
668 return lock_ref_sha1_basic(ref, old_sha1, NULL);
671 static struct lock_file packlock;
673 static int repack_without_ref(const char *refname)
675 struct ref_list *list, *packed_ref_list;
676 int fd;
677 int found = 0;
679 packed_ref_list = get_packed_refs();
680 for (list = packed_ref_list; list; list = list->next) {
681 if (!strcmp(refname, list->name)) {
682 found = 1;
683 break;
686 if (!found)
687 return 0;
688 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
689 if (fd < 0)
690 return error("cannot delete '%s' from packed refs", refname);
692 for (list = packed_ref_list; list; list = list->next) {
693 char line[PATH_MAX + 100];
694 int len;
696 if (!strcmp(refname, list->name))
697 continue;
698 len = snprintf(line, sizeof(line), "%s %s\n",
699 sha1_to_hex(list->sha1), list->name);
700 /* this should not happen but just being defensive */
701 if (len > sizeof(line))
702 die("too long a refname '%s'", list->name);
703 write_or_die(fd, line, len);
705 return commit_lock_file(&packlock);
708 int delete_ref(const char *refname, unsigned char *sha1)
710 struct ref_lock *lock;
711 int err, i, ret = 0, flag = 0;
713 lock = lock_ref_sha1_basic(refname, sha1, &flag);
714 if (!lock)
715 return 1;
716 if (!(flag & REF_ISPACKED)) {
717 /* loose */
718 i = strlen(lock->lk->filename) - 5; /* .lock */
719 lock->lk->filename[i] = 0;
720 err = unlink(lock->lk->filename);
721 if (err) {
722 ret = 1;
723 error("unlink(%s) failed: %s",
724 lock->lk->filename, strerror(errno));
726 lock->lk->filename[i] = '.';
728 /* removing the loose one could have resurrected an earlier
729 * packed one. Also, if it was not loose we need to repack
730 * without it.
732 ret |= repack_without_ref(refname);
734 err = unlink(git_path("logs/%s", lock->ref_name));
735 if (err && errno != ENOENT)
736 fprintf(stderr, "warning: unlink(%s) failed: %s",
737 git_path("logs/%s", lock->ref_name), strerror(errno));
738 invalidate_cached_refs();
739 unlock_ref(lock);
740 return ret;
743 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
745 static const char renamed_ref[] = "RENAMED-REF";
746 unsigned char sha1[20], orig_sha1[20];
747 int flag = 0, logmoved = 0;
748 struct ref_lock *lock;
749 struct stat loginfo;
750 int log = !lstat(git_path("logs/%s", oldref), &loginfo);
752 if (S_ISLNK(loginfo.st_mode))
753 return error("reflog for %s is a symlink", oldref);
755 if (!resolve_ref(oldref, orig_sha1, 1, &flag))
756 return error("refname %s not found", oldref);
758 if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
759 return 1;
761 if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
762 return 1;
764 lock = lock_ref_sha1_basic(renamed_ref, NULL, NULL);
765 if (!lock)
766 return error("unable to lock %s", renamed_ref);
767 lock->force_write = 1;
768 if (write_ref_sha1(lock, orig_sha1, logmsg))
769 return error("unable to save current sha1 in %s", renamed_ref);
771 if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
772 return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
773 oldref, strerror(errno));
775 if (delete_ref(oldref, orig_sha1)) {
776 error("unable to delete old %s", oldref);
777 goto rollback;
780 if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
781 if (errno==EISDIR) {
782 if (remove_empty_directories(git_path("%s", newref))) {
783 error("Directory not empty: %s", newref);
784 goto rollback;
786 } else {
787 error("unable to delete existing %s", newref);
788 goto rollback;
792 if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
793 error("unable to create directory for %s", newref);
794 goto rollback;
797 retry:
798 if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
799 if (errno==EISDIR || errno==ENOTDIR) {
801 * rename(a, b) when b is an existing
802 * directory ought to result in ISDIR, but
803 * Solaris 5.8 gives ENOTDIR. Sheesh.
805 if (remove_empty_directories(git_path("logs/%s", newref))) {
806 error("Directory not empty: logs/%s", newref);
807 goto rollback;
809 goto retry;
810 } else {
811 error("unable to move logfile tmp-renamed-log to logs/%s: %s",
812 newref, strerror(errno));
813 goto rollback;
816 logmoved = log;
818 lock = lock_ref_sha1_basic(newref, NULL, NULL);
819 if (!lock) {
820 error("unable to lock %s for update", newref);
821 goto rollback;
824 lock->force_write = 1;
825 hashcpy(lock->old_sha1, orig_sha1);
826 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
827 error("unable to write current sha1 into %s", newref);
828 goto rollback;
831 return 0;
833 rollback:
834 lock = lock_ref_sha1_basic(oldref, NULL, NULL);
835 if (!lock) {
836 error("unable to lock %s for rollback", oldref);
837 goto rollbacklog;
840 lock->force_write = 1;
841 flag = log_all_ref_updates;
842 log_all_ref_updates = 0;
843 if (write_ref_sha1(lock, orig_sha1, NULL))
844 error("unable to write current sha1 into %s", oldref);
845 log_all_ref_updates = flag;
847 rollbacklog:
848 if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
849 error("unable to restore logfile %s from %s: %s",
850 oldref, newref, strerror(errno));
851 if (!logmoved && log &&
852 rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
853 error("unable to restore logfile %s from tmp-renamed-log: %s",
854 oldref, strerror(errno));
856 return 1;
859 void unlock_ref(struct ref_lock *lock)
861 if (lock->lock_fd >= 0) {
862 close(lock->lock_fd);
863 /* Do not free lock->lk -- atexit() still looks at them */
864 if (lock->lk)
865 rollback_lock_file(lock->lk);
867 free(lock->ref_name);
868 free(lock->orig_ref_name);
869 free(lock);
872 static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
873 const unsigned char *new_sha1, const char *msg)
875 int logfd, written, oflags = O_APPEND | O_WRONLY;
876 unsigned maxlen, len;
877 int msglen;
878 char *log_file, *logrec;
879 const char *committer;
881 if (log_all_ref_updates < 0)
882 log_all_ref_updates = !is_bare_repository();
884 log_file = git_path("logs/%s", ref_name);
886 if (log_all_ref_updates &&
887 (!prefixcmp(ref_name, "refs/heads/") ||
888 !prefixcmp(ref_name, "refs/remotes/") ||
889 !strcmp(ref_name, "HEAD"))) {
890 if (safe_create_leading_directories(log_file) < 0)
891 return error("unable to create directory for %s",
892 log_file);
893 oflags |= O_CREAT;
896 logfd = open(log_file, oflags, 0666);
897 if (logfd < 0) {
898 if (!(oflags & O_CREAT) && errno == ENOENT)
899 return 0;
901 if ((oflags & O_CREAT) && errno == EISDIR) {
902 if (remove_empty_directories(log_file)) {
903 return error("There are still logs under '%s'",
904 log_file);
906 logfd = open(log_file, oflags, 0666);
909 if (logfd < 0)
910 return error("Unable to append to %s: %s",
911 log_file, strerror(errno));
914 adjust_shared_perm(log_file);
916 msglen = 0;
917 if (msg) {
918 /* clean up the message and make sure it is a single line */
919 for ( ; *msg; msg++)
920 if (!isspace(*msg))
921 break;
922 if (*msg) {
923 const char *ep = strchr(msg, '\n');
924 if (ep)
925 msglen = ep - msg;
926 else
927 msglen = strlen(msg);
931 committer = git_committer_info(-1);
932 maxlen = strlen(committer) + msglen + 100;
933 logrec = xmalloc(maxlen);
934 len = sprintf(logrec, "%s %s %s\n",
935 sha1_to_hex(old_sha1),
936 sha1_to_hex(new_sha1),
937 committer);
938 if (msglen)
939 len += sprintf(logrec + len - 1, "\t%.*s\n", msglen, msg) - 1;
940 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
941 free(logrec);
942 close(logfd);
943 if (written != len)
944 return error("Unable to append to %s", log_file);
945 return 0;
948 int write_ref_sha1(struct ref_lock *lock,
949 const unsigned char *sha1, const char *logmsg)
951 static char term = '\n';
953 if (!lock)
954 return -1;
955 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
956 unlock_ref(lock);
957 return 0;
959 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
960 write_in_full(lock->lock_fd, &term, 1) != 1
961 || close(lock->lock_fd) < 0) {
962 error("Couldn't write %s", lock->lk->filename);
963 unlock_ref(lock);
964 return -1;
966 invalidate_cached_refs();
967 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
968 (strcmp(lock->ref_name, lock->orig_ref_name) &&
969 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
970 unlock_ref(lock);
971 return -1;
973 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
975 * Special hack: If a branch is updated directly and HEAD
976 * points to it (may happen on the remote side of a push
977 * for example) then logically the HEAD reflog should be
978 * updated too.
979 * A generic solution implies reverse symref information,
980 * but finding all symrefs pointing to the given branch
981 * would be rather costly for this rare event (the direct
982 * update of a branch) to be worth it. So let's cheat and
983 * check with HEAD only which should cover 99% of all usage
984 * scenarios (even 100% of the default ones).
986 unsigned char head_sha1[20];
987 int head_flag;
988 const char *head_ref;
989 head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
990 if (head_ref && (head_flag & REF_ISSYMREF) &&
991 !strcmp(head_ref, lock->ref_name))
992 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
994 if (commit_lock_file(lock->lk)) {
995 error("Couldn't set %s", lock->ref_name);
996 unlock_ref(lock);
997 return -1;
999 lock->lock_fd = -1;
1000 unlock_ref(lock);
1001 return 0;
1004 int create_symref(const char *ref_target, const char *refs_heads_master,
1005 const char *logmsg)
1007 const char *lockpath;
1008 char ref[1000];
1009 int fd, len, written;
1010 char *git_HEAD = xstrdup(git_path("%s", ref_target));
1011 unsigned char old_sha1[20], new_sha1[20];
1013 if (logmsg && read_ref(ref_target, old_sha1))
1014 hashclr(old_sha1);
1016 if (safe_create_leading_directories(git_HEAD) < 0)
1017 return error("unable to create directory for %s", git_HEAD);
1019 #ifndef NO_SYMLINK_HEAD
1020 if (prefer_symlink_refs) {
1021 unlink(git_HEAD);
1022 if (!symlink(refs_heads_master, git_HEAD))
1023 goto done;
1024 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1026 #endif
1028 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1029 if (sizeof(ref) <= len) {
1030 error("refname too long: %s", refs_heads_master);
1031 goto error_free_return;
1033 lockpath = mkpath("%s.lock", git_HEAD);
1034 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1035 if (fd < 0) {
1036 error("Unable to open %s for writing", lockpath);
1037 goto error_free_return;
1039 written = write_in_full(fd, ref, len);
1040 close(fd);
1041 if (written != len) {
1042 error("Unable to write to %s", lockpath);
1043 goto error_unlink_return;
1045 if (rename(lockpath, git_HEAD) < 0) {
1046 error("Unable to create %s", git_HEAD);
1047 goto error_unlink_return;
1049 if (adjust_shared_perm(git_HEAD)) {
1050 error("Unable to fix permissions on %s", lockpath);
1051 error_unlink_return:
1052 unlink(lockpath);
1053 error_free_return:
1054 free(git_HEAD);
1055 return -1;
1058 #ifndef NO_SYMLINK_HEAD
1059 done:
1060 #endif
1061 if (logmsg && !read_ref(refs_heads_master, new_sha1))
1062 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1064 free(git_HEAD);
1065 return 0;
1068 static char *ref_msg(const char *line, const char *endp)
1070 const char *ep;
1071 char *msg;
1073 line += 82;
1074 for (ep = line; ep < endp && *ep != '\n'; ep++)
1076 msg = xmalloc(ep - line + 1);
1077 memcpy(msg, line, ep - line);
1078 msg[ep - line] = 0;
1079 return msg;
1082 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)
1084 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1085 char *tz_c;
1086 int logfd, tz, reccnt = 0;
1087 struct stat st;
1088 unsigned long date;
1089 unsigned char logged_sha1[20];
1090 void *log_mapped;
1091 size_t mapsz;
1093 logfile = git_path("logs/%s", ref);
1094 logfd = open(logfile, O_RDONLY, 0);
1095 if (logfd < 0)
1096 die("Unable to read log %s: %s", logfile, strerror(errno));
1097 fstat(logfd, &st);
1098 if (!st.st_size)
1099 die("Log %s is empty.", logfile);
1100 mapsz = xsize_t(st.st_size);
1101 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1102 logdata = log_mapped;
1103 close(logfd);
1105 lastrec = NULL;
1106 rec = logend = logdata + st.st_size;
1107 while (logdata < rec) {
1108 reccnt++;
1109 if (logdata < rec && *(rec-1) == '\n')
1110 rec--;
1111 lastgt = NULL;
1112 while (logdata < rec && *(rec-1) != '\n') {
1113 rec--;
1114 if (*rec == '>')
1115 lastgt = rec;
1117 if (!lastgt)
1118 die("Log %s is corrupt.", logfile);
1119 date = strtoul(lastgt + 1, &tz_c, 10);
1120 if (date <= at_time || cnt == 0) {
1121 tz = strtoul(tz_c, NULL, 10);
1122 if (msg)
1123 *msg = ref_msg(rec, logend);
1124 if (cutoff_time)
1125 *cutoff_time = date;
1126 if (cutoff_tz)
1127 *cutoff_tz = tz;
1128 if (cutoff_cnt)
1129 *cutoff_cnt = reccnt - 1;
1130 if (lastrec) {
1131 if (get_sha1_hex(lastrec, logged_sha1))
1132 die("Log %s is corrupt.", logfile);
1133 if (get_sha1_hex(rec + 41, sha1))
1134 die("Log %s is corrupt.", logfile);
1135 if (hashcmp(logged_sha1, sha1)) {
1136 fprintf(stderr,
1137 "warning: Log %s has gap after %s.\n",
1138 logfile, show_rfc2822_date(date, tz));
1141 else if (date == at_time) {
1142 if (get_sha1_hex(rec + 41, sha1))
1143 die("Log %s is corrupt.", logfile);
1145 else {
1146 if (get_sha1_hex(rec + 41, logged_sha1))
1147 die("Log %s is corrupt.", logfile);
1148 if (hashcmp(logged_sha1, sha1)) {
1149 fprintf(stderr,
1150 "warning: Log %s unexpectedly ended on %s.\n",
1151 logfile, show_rfc2822_date(date, tz));
1154 munmap(log_mapped, mapsz);
1155 return 0;
1157 lastrec = rec;
1158 if (cnt > 0)
1159 cnt--;
1162 rec = logdata;
1163 while (rec < logend && *rec != '>' && *rec != '\n')
1164 rec++;
1165 if (rec == logend || *rec == '\n')
1166 die("Log %s is corrupt.", logfile);
1167 date = strtoul(rec + 1, &tz_c, 10);
1168 tz = strtoul(tz_c, NULL, 10);
1169 if (get_sha1_hex(logdata, sha1))
1170 die("Log %s is corrupt.", logfile);
1171 if (msg)
1172 *msg = ref_msg(logdata, logend);
1173 munmap(log_mapped, mapsz);
1175 if (cutoff_time)
1176 *cutoff_time = date;
1177 if (cutoff_tz)
1178 *cutoff_tz = tz;
1179 if (cutoff_cnt)
1180 *cutoff_cnt = reccnt;
1181 return 1;
1184 int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1186 const char *logfile;
1187 FILE *logfp;
1188 char buf[1024];
1189 int ret = 0;
1191 logfile = git_path("logs/%s", ref);
1192 logfp = fopen(logfile, "r");
1193 if (!logfp)
1194 return -1;
1195 while (fgets(buf, sizeof(buf), logfp)) {
1196 unsigned char osha1[20], nsha1[20];
1197 char *email_end, *message;
1198 unsigned long timestamp;
1199 int len, tz;
1201 /* old SP new SP name <email> SP time TAB msg LF */
1202 len = strlen(buf);
1203 if (len < 83 || buf[len-1] != '\n' ||
1204 get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1205 get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1206 !(email_end = strchr(buf + 82, '>')) ||
1207 email_end[1] != ' ' ||
1208 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1209 !message || message[0] != ' ' ||
1210 (message[1] != '+' && message[1] != '-') ||
1211 !isdigit(message[2]) || !isdigit(message[3]) ||
1212 !isdigit(message[4]) || !isdigit(message[5]))
1213 continue; /* corrupt? */
1214 email_end[1] = '\0';
1215 tz = strtol(message + 1, NULL, 10);
1216 if (message[6] != '\t')
1217 message += 6;
1218 else
1219 message += 7;
1220 ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1221 if (ret)
1222 break;
1224 fclose(logfp);
1225 return ret;
1228 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1230 DIR *dir = opendir(git_path("logs/%s", base));
1231 int retval = 0;
1233 if (dir) {
1234 struct dirent *de;
1235 int baselen = strlen(base);
1236 char *log = xmalloc(baselen + 257);
1238 memcpy(log, base, baselen);
1239 if (baselen && base[baselen-1] != '/')
1240 log[baselen++] = '/';
1242 while ((de = readdir(dir)) != NULL) {
1243 struct stat st;
1244 int namelen;
1246 if (de->d_name[0] == '.')
1247 continue;
1248 namelen = strlen(de->d_name);
1249 if (namelen > 255)
1250 continue;
1251 if (has_extension(de->d_name, ".lock"))
1252 continue;
1253 memcpy(log + baselen, de->d_name, namelen+1);
1254 if (stat(git_path("logs/%s", log), &st) < 0)
1255 continue;
1256 if (S_ISDIR(st.st_mode)) {
1257 retval = do_for_each_reflog(log, fn, cb_data);
1258 } else {
1259 unsigned char sha1[20];
1260 if (!resolve_ref(log, sha1, 0, NULL))
1261 retval = error("bad ref for %s", log);
1262 else
1263 retval = fn(log, sha1, 0, cb_data);
1265 if (retval)
1266 break;
1268 free(log);
1269 closedir(dir);
1271 else if (*base)
1272 return errno;
1273 return retval;
1276 int for_each_reflog(each_ref_fn fn, void *cb_data)
1278 return do_for_each_reflog("", fn, cb_data);