am: Use cat instead of echo to avoid DOS line-endings (fixes t4150)
[git/dscho.git] / refs.c
bloba5802e19029747fc95939bc9110ea151c080c30c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
7 /*
8 * Make sure "ref" is something reasonable to have under ".git/refs/";
9 * We do not like it if:
11 * - any path component of it begins with ".", or
12 * - it has double dots "..", or
13 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
14 * - it ends with a "/".
15 * - it ends with ".lock"
16 * - it contains a "\" (backslash)
19 /* Return true iff ch is not allowed in reference names. */
20 static inline int bad_ref_char(int ch)
22 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
23 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
24 return 1;
25 /* 2.13 Pattern Matching Notation */
26 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
27 return 1;
28 return 0;
32 * Try to read one refname component from the front of refname. Return
33 * the length of the component found, or -1 if the component is not
34 * legal.
36 static int check_refname_component(const char *refname, int flags)
38 const char *cp;
39 char last = '\0';
41 for (cp = refname; ; cp++) {
42 char ch = *cp;
43 if (ch == '\0' || ch == '/')
44 break;
45 if (bad_ref_char(ch))
46 return -1; /* Illegal character in refname. */
47 if (last == '.' && ch == '.')
48 return -1; /* Refname contains "..". */
49 if (last == '@' && ch == '{')
50 return -1; /* Refname contains "@{". */
51 last = ch;
53 if (cp == refname)
54 return 0; /* Component has zero length. */
55 if (refname[0] == '.') {
56 if (!(flags & REFNAME_DOT_COMPONENT))
57 return -1; /* Component starts with '.'. */
59 * Even if leading dots are allowed, don't allow "."
60 * as a component (".." is prevented by a rule above).
62 if (refname[1] == '\0')
63 return -1; /* Component equals ".". */
65 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
66 return -1; /* Refname ends with ".lock". */
67 return cp - refname;
70 int check_refname_format(const char *refname, int flags)
72 int component_len, component_count = 0;
74 while (1) {
75 /* We are at the start of a path component. */
76 component_len = check_refname_component(refname, flags);
77 if (component_len <= 0) {
78 if ((flags & REFNAME_REFSPEC_PATTERN) &&
79 refname[0] == '*' &&
80 (refname[1] == '\0' || refname[1] == '/')) {
81 /* Accept one wildcard as a full refname component. */
82 flags &= ~REFNAME_REFSPEC_PATTERN;
83 component_len = 1;
84 } else {
85 return -1;
88 component_count++;
89 if (refname[component_len] == '\0')
90 break;
91 /* Skip to next component. */
92 refname += component_len + 1;
95 if (refname[component_len - 1] == '.')
96 return -1; /* Refname ends with '.'. */
97 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
98 return -1; /* Refname has only one component. */
99 return 0;
102 struct ref_entry;
104 struct ref_value {
105 unsigned char sha1[20];
106 unsigned char peeled[20];
109 struct ref_dir {
110 int nr, alloc;
113 * Entries with index 0 <= i < sorted are sorted by name. New
114 * entries are appended to the list unsorted, and are sorted
115 * only when required; thus we avoid the need to sort the list
116 * after the addition of every reference.
118 int sorted;
120 struct ref_entry **entries;
123 /* ISSYMREF=0x01, ISPACKED=0x02, and ISBROKEN=0x04 are public interfaces */
124 #define REF_KNOWS_PEELED 0x08
125 #define REF_DIR 0x10
128 * A ref_entry represents either a reference or a "subdirectory" of
129 * references. Each directory in the reference namespace is
130 * represented by a ref_entry with (flags & REF_DIR) set and
131 * containing a subdir member that holds the entries in that
132 * directory. References are represented by a ref_entry with (flags &
133 * REF_DIR) unset and a value member that describes the reference's
134 * value. The flag member is at the ref_entry level, but it is also
135 * needed to interpret the contents of the value field (in other
136 * words, a ref_value object is not very much use without the
137 * enclosing ref_entry).
139 * Reference names cannot end with slash and directories' names are
140 * always stored with a trailing slash (except for the top-level
141 * directory, which is always denoted by ""). This has two nice
142 * consequences: (1) when the entries in each subdir are sorted
143 * lexicographically by name (as they usually are), the references in
144 * a whole tree can be generated in lexicographic order by traversing
145 * the tree in left-to-right, depth-first order; (2) the names of
146 * references and subdirectories cannot conflict, and therefore the
147 * presence of an empty subdirectory does not block the creation of a
148 * similarly-named reference. (The fact that reference names with the
149 * same leading components can conflict *with each other* is a
150 * separate issue that is regulated by is_refname_available().)
152 * Please note that the name field contains the fully-qualified
153 * reference (or subdirectory) name. Space could be saved by only
154 * storing the relative names. But that would require the full names
155 * to be generated on the fly when iterating in do_for_each_ref(), and
156 * would break callback functions, who have always been able to assume
157 * that the name strings that they are passed will not be freed during
158 * the iteration.
160 struct ref_entry {
161 unsigned char flag; /* ISSYMREF? ISPACKED? */
162 union {
163 struct ref_value value; /* if not (flags&REF_DIR) */
164 struct ref_dir subdir; /* if (flags&REF_DIR) */
165 } u;
167 * The full name of the reference (e.g., "refs/heads/master")
168 * or the full name of the directory with a trailing slash
169 * (e.g., "refs/heads/"):
171 char name[FLEX_ARRAY];
174 static struct ref_entry *create_ref_entry(const char *refname,
175 const unsigned char *sha1, int flag,
176 int check_name)
178 int len;
179 struct ref_entry *ref;
181 if (check_name &&
182 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
183 die("Reference has invalid format: '%s'", refname);
184 len = strlen(refname) + 1;
185 ref = xmalloc(sizeof(struct ref_entry) + len);
186 hashcpy(ref->u.value.sha1, sha1);
187 hashclr(ref->u.value.peeled);
188 memcpy(ref->name, refname, len);
189 ref->flag = flag;
190 return ref;
193 static void clear_ref_dir(struct ref_dir *dir);
195 static void free_ref_entry(struct ref_entry *entry)
197 if (entry->flag & REF_DIR)
198 clear_ref_dir(&entry->u.subdir);
199 free(entry);
203 * Add a ref_entry to the end of dir (unsorted). Entry is always
204 * stored directly in dir; no recursion into subdirectories is
205 * done.
207 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
209 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
210 dir->entries[dir->nr++] = entry;
214 * Clear and free all entries in dir, recursively.
216 static void clear_ref_dir(struct ref_dir *dir)
218 int i;
219 for (i = 0; i < dir->nr; i++)
220 free_ref_entry(dir->entries[i]);
221 free(dir->entries);
222 dir->sorted = dir->nr = dir->alloc = 0;
223 dir->entries = NULL;
227 * Create a struct ref_entry object for the specified dirname.
228 * dirname is the name of the directory with a trailing slash (e.g.,
229 * "refs/heads/") or "" for the top-level directory.
231 static struct ref_entry *create_dir_entry(const char *dirname)
233 struct ref_entry *direntry;
234 int len = strlen(dirname);
235 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
236 memcpy(direntry->name, dirname, len + 1);
237 direntry->flag = REF_DIR;
238 return direntry;
241 static int ref_entry_cmp(const void *a, const void *b)
243 struct ref_entry *one = *(struct ref_entry **)a;
244 struct ref_entry *two = *(struct ref_entry **)b;
245 return strcmp(one->name, two->name);
248 static void sort_ref_dir(struct ref_dir *dir);
251 * Return the entry with the given refname from the ref_dir
252 * (non-recursively), sorting dir if necessary. Return NULL if no
253 * such entry is found.
255 static struct ref_entry *search_ref_dir(struct ref_dir *dir, const char *refname)
257 struct ref_entry *e, **r;
258 int len;
260 if (refname == NULL || !dir->nr)
261 return NULL;
263 sort_ref_dir(dir);
265 len = strlen(refname) + 1;
266 e = xmalloc(sizeof(struct ref_entry) + len);
267 memcpy(e->name, refname, len);
269 r = bsearch(&e, dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
271 free(e);
273 if (r == NULL)
274 return NULL;
276 return *r;
280 * If refname is a reference name, find the ref_dir within the dir
281 * tree that should hold refname. If refname is a directory name
282 * (i.e., ends in '/'), then return that ref_dir itself. dir must
283 * represent the top-level directory. Sort ref_dirs and recurse into
284 * subdirectories as necessary. If mkdir is set, then create any
285 * missing directories; otherwise, return NULL if the desired
286 * directory cannot be found.
288 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
289 const char *refname, int mkdir)
291 char *refname_copy = xstrdup(refname);
292 char *slash;
293 struct ref_entry *entry;
294 for (slash = strchr(refname_copy, '/'); slash; slash = strchr(slash + 1, '/')) {
295 char tmp = slash[1];
296 slash[1] = '\0';
297 entry = search_ref_dir(dir, refname_copy);
298 if (!entry) {
299 if (!mkdir) {
300 dir = NULL;
301 break;
303 entry = create_dir_entry(refname_copy);
304 add_entry_to_dir(dir, entry);
306 slash[1] = tmp;
307 assert(entry->flag & REF_DIR);
308 dir = &entry->u.subdir;
311 free(refname_copy);
312 return dir;
316 * Find the value entry with the given name in dir, sorting ref_dirs
317 * and recursing into subdirectories as necessary. If the name is not
318 * found or it corresponds to a directory entry, return NULL.
320 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
322 struct ref_entry *entry;
323 dir = find_containing_dir(dir, refname, 0);
324 if (!dir)
325 return NULL;
326 entry = search_ref_dir(dir, refname);
327 return (entry && !(entry->flag & REF_DIR)) ? entry : NULL;
331 * Add a ref_entry to the ref_dir (unsorted), recursing into
332 * subdirectories as necessary. dir must represent the top-level
333 * directory. Return 0 on success.
335 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
337 dir = find_containing_dir(dir, ref->name, 1);
338 if (!dir)
339 return -1;
340 add_entry_to_dir(dir, ref);
341 return 0;
345 * Emit a warning and return true iff ref1 and ref2 have the same name
346 * and the same sha1. Die if they have the same name but different
347 * sha1s.
349 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
351 if (strcmp(ref1->name, ref2->name))
352 return 0;
354 /* Duplicate name; make sure that they don't conflict: */
356 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
357 /* This is impossible by construction */
358 die("Reference directory conflict: %s", ref1->name);
360 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
361 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
363 warning("Duplicated ref: %s", ref1->name);
364 return 1;
368 * Sort the entries in dir non-recursively (if they are not already
369 * sorted) and remove any duplicate entries.
371 static void sort_ref_dir(struct ref_dir *dir)
373 int i, j;
374 struct ref_entry *last = NULL;
377 * This check also prevents passing a zero-length array to qsort(),
378 * which is a problem on some platforms.
380 if (dir->sorted == dir->nr)
381 return;
383 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
385 /* Remove any duplicates: */
386 for (i = 0, j = 0; j < dir->nr; j++) {
387 struct ref_entry *entry = dir->entries[j];
388 if (last && is_dup_ref(last, entry))
389 free_ref_entry(entry);
390 else
391 last = dir->entries[i++] = entry;
393 dir->sorted = dir->nr = i;
396 #define DO_FOR_EACH_INCLUDE_BROKEN 01
398 static struct ref_entry *current_ref;
400 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
401 int flags, void *cb_data, struct ref_entry *entry)
403 int retval;
404 if (prefixcmp(entry->name, base))
405 return 0;
407 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
408 if (entry->flag & REF_ISBROKEN)
409 return 0; /* ignore broken refs e.g. dangling symref */
410 if (!has_sha1_file(entry->u.value.sha1)) {
411 error("%s does not point to a valid object!", entry->name);
412 return 0;
415 current_ref = entry;
416 retval = fn(entry->name + trim, entry->u.value.sha1, entry->flag, cb_data);
417 current_ref = NULL;
418 return retval;
422 * Call fn for each reference in dir that has index in the range
423 * offset <= index < dir->nr. Recurse into subdirectories that are in
424 * that index range, sorting them before iterating. This function
425 * does not sort dir itself; it should be sorted beforehand.
427 static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
428 const char *base,
429 each_ref_fn fn, int trim, int flags, void *cb_data)
431 int i;
432 assert(dir->sorted == dir->nr);
433 for (i = offset; i < dir->nr; i++) {
434 struct ref_entry *entry = dir->entries[i];
435 int retval;
436 if (entry->flag & REF_DIR) {
437 sort_ref_dir(&entry->u.subdir);
438 retval = do_for_each_ref_in_dir(&entry->u.subdir, 0,
439 base, fn, trim, flags, cb_data);
440 } else {
441 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
443 if (retval)
444 return retval;
446 return 0;
450 * Call fn for each reference in the union of dir1 and dir2, in order
451 * by refname. Recurse into subdirectories. If a value entry appears
452 * in both dir1 and dir2, then only process the version that is in
453 * dir2. The input dirs must already be sorted, but subdirs will be
454 * sorted as needed.
456 static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
457 struct ref_dir *dir2,
458 const char *base, each_ref_fn fn, int trim,
459 int flags, void *cb_data)
461 int retval;
462 int i1 = 0, i2 = 0;
464 assert(dir1->sorted == dir1->nr);
465 assert(dir2->sorted == dir2->nr);
466 while (1) {
467 struct ref_entry *e1, *e2;
468 int cmp;
469 if (i1 == dir1->nr) {
470 return do_for_each_ref_in_dir(dir2, i2,
471 base, fn, trim, flags, cb_data);
473 if (i2 == dir2->nr) {
474 return do_for_each_ref_in_dir(dir1, i1,
475 base, fn, trim, flags, cb_data);
477 e1 = dir1->entries[i1];
478 e2 = dir2->entries[i2];
479 cmp = strcmp(e1->name, e2->name);
480 if (cmp == 0) {
481 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
482 /* Both are directories; descend them in parallel. */
483 sort_ref_dir(&e1->u.subdir);
484 sort_ref_dir(&e2->u.subdir);
485 retval = do_for_each_ref_in_dirs(
486 &e1->u.subdir, &e2->u.subdir,
487 base, fn, trim, flags, cb_data);
488 i1++;
489 i2++;
490 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
491 /* Both are references; ignore the one from dir1. */
492 retval = do_one_ref(base, fn, trim, flags, cb_data, e2);
493 i1++;
494 i2++;
495 } else {
496 die("conflict between reference and directory: %s",
497 e1->name);
499 } else {
500 struct ref_entry *e;
501 if (cmp < 0) {
502 e = e1;
503 i1++;
504 } else {
505 e = e2;
506 i2++;
508 if (e->flag & REF_DIR) {
509 sort_ref_dir(&e->u.subdir);
510 retval = do_for_each_ref_in_dir(
511 &e->u.subdir, 0,
512 base, fn, trim, flags, cb_data);
513 } else {
514 retval = do_one_ref(base, fn, trim, flags, cb_data, e);
517 if (retval)
518 return retval;
520 if (i1 < dir1->nr)
521 return do_for_each_ref_in_dir(dir1, i1,
522 base, fn, trim, flags, cb_data);
523 if (i2 < dir2->nr)
524 return do_for_each_ref_in_dir(dir2, i2,
525 base, fn, trim, flags, cb_data);
526 return 0;
530 * Return true iff refname1 and refname2 conflict with each other.
531 * Two reference names conflict if one of them exactly matches the
532 * leading components of the other; e.g., "foo/bar" conflicts with
533 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
534 * "foo/barbados".
536 static int names_conflict(const char *refname1, const char *refname2)
538 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
540 return (*refname1 == '\0' && *refname2 == '/')
541 || (*refname1 == '/' && *refname2 == '\0');
544 struct name_conflict_cb {
545 const char *refname;
546 const char *oldrefname;
547 const char *conflicting_refname;
550 static int name_conflict_fn(const char *existingrefname, const unsigned char *sha1,
551 int flags, void *cb_data)
553 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
554 if (data->oldrefname && !strcmp(data->oldrefname, existingrefname))
555 return 0;
556 if (names_conflict(data->refname, existingrefname)) {
557 data->conflicting_refname = existingrefname;
558 return 1;
560 return 0;
564 * Return true iff a reference named refname could be created without
565 * conflicting with the name of an existing reference in array. If
566 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
567 * (e.g., because oldrefname is scheduled for deletion in the same
568 * operation).
570 static int is_refname_available(const char *refname, const char *oldrefname,
571 struct ref_dir *dir)
573 struct name_conflict_cb data;
574 data.refname = refname;
575 data.oldrefname = oldrefname;
576 data.conflicting_refname = NULL;
578 sort_ref_dir(dir);
579 if (do_for_each_ref_in_dir(dir, 0, "", name_conflict_fn,
580 0, DO_FOR_EACH_INCLUDE_BROKEN,
581 &data)) {
582 error("'%s' exists; cannot create '%s'",
583 data.conflicting_refname, refname);
584 return 0;
586 return 1;
590 * Future: need to be in "struct repository"
591 * when doing a full libification.
593 static struct ref_cache {
594 struct ref_cache *next;
595 char did_loose;
596 char did_packed;
597 struct ref_dir loose;
598 struct ref_dir packed;
599 /* The submodule name, or "" for the main repo. */
600 char name[FLEX_ARRAY];
601 } *ref_cache;
603 static void clear_packed_ref_cache(struct ref_cache *refs)
605 if (refs->did_packed)
606 clear_ref_dir(&refs->packed);
607 refs->did_packed = 0;
610 static void clear_loose_ref_cache(struct ref_cache *refs)
612 if (refs->did_loose)
613 clear_ref_dir(&refs->loose);
614 refs->did_loose = 0;
617 static struct ref_cache *create_ref_cache(const char *submodule)
619 int len;
620 struct ref_cache *refs;
621 if (!submodule)
622 submodule = "";
623 len = strlen(submodule) + 1;
624 refs = xcalloc(1, sizeof(struct ref_cache) + len);
625 memcpy(refs->name, submodule, len);
626 return refs;
630 * Return a pointer to a ref_cache for the specified submodule. For
631 * the main repository, use submodule==NULL. The returned structure
632 * will be allocated and initialized but not necessarily populated; it
633 * should not be freed.
635 static struct ref_cache *get_ref_cache(const char *submodule)
637 struct ref_cache *refs = ref_cache;
638 if (!submodule)
639 submodule = "";
640 while (refs) {
641 if (!strcmp(submodule, refs->name))
642 return refs;
643 refs = refs->next;
646 refs = create_ref_cache(submodule);
647 refs->next = ref_cache;
648 ref_cache = refs;
649 return refs;
652 void invalidate_ref_cache(const char *submodule)
654 struct ref_cache *refs = get_ref_cache(submodule);
655 clear_packed_ref_cache(refs);
656 clear_loose_ref_cache(refs);
660 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
661 * Return a pointer to the refname within the line (null-terminated),
662 * or NULL if there was a problem.
664 static const char *parse_ref_line(char *line, unsigned char *sha1)
667 * 42: the answer to everything.
669 * In this case, it happens to be the answer to
670 * 40 (length of sha1 hex representation)
671 * +1 (space in between hex and name)
672 * +1 (newline at the end of the line)
674 int len = strlen(line) - 42;
676 if (len <= 0)
677 return NULL;
678 if (get_sha1_hex(line, sha1) < 0)
679 return NULL;
680 if (!isspace(line[40]))
681 return NULL;
682 line += 41;
683 if (isspace(*line))
684 return NULL;
685 if (line[len] != '\n')
686 return NULL;
687 line[len] = 0;
689 return line;
692 static void read_packed_refs(FILE *f, struct ref_dir *dir)
694 struct ref_entry *last = NULL;
695 char refline[PATH_MAX];
696 int flag = REF_ISPACKED;
698 while (fgets(refline, sizeof(refline), f)) {
699 unsigned char sha1[20];
700 const char *refname;
701 static const char header[] = "# pack-refs with:";
703 if (!strncmp(refline, header, sizeof(header)-1)) {
704 const char *traits = refline + sizeof(header) - 1;
705 if (strstr(traits, " peeled "))
706 flag |= REF_KNOWS_PEELED;
707 /* perhaps other traits later as well */
708 continue;
711 refname = parse_ref_line(refline, sha1);
712 if (refname) {
713 last = create_ref_entry(refname, sha1, flag, 1);
714 add_ref(dir, last);
715 continue;
717 if (last &&
718 refline[0] == '^' &&
719 strlen(refline) == 42 &&
720 refline[41] == '\n' &&
721 !get_sha1_hex(refline + 1, sha1))
722 hashcpy(last->u.value.peeled, sha1);
726 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
728 if (!refs->did_packed) {
729 const char *packed_refs_file;
730 FILE *f;
732 if (*refs->name)
733 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
734 else
735 packed_refs_file = git_path("packed-refs");
736 f = fopen(packed_refs_file, "r");
737 if (f) {
738 read_packed_refs(f, &refs->packed);
739 fclose(f);
741 refs->did_packed = 1;
743 return &refs->packed;
746 void add_packed_ref(const char *refname, const unsigned char *sha1)
748 add_ref(get_packed_refs(get_ref_cache(NULL)),
749 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
752 static void get_ref_dir(struct ref_cache *refs, const char *base,
753 struct ref_dir *dir)
755 DIR *d;
756 const char *path;
758 if (*refs->name)
759 path = git_path_submodule(refs->name, "%s", base);
760 else
761 path = git_path("%s", base);
763 d = opendir(path);
764 if (d) {
765 struct dirent *de;
766 int baselen = strlen(base);
767 char *refname = xmalloc(baselen + 257);
769 memcpy(refname, base, baselen);
770 if (baselen && base[baselen-1] != '/')
771 refname[baselen++] = '/';
773 while ((de = readdir(d)) != NULL) {
774 unsigned char sha1[20];
775 struct stat st;
776 int flag;
777 int namelen;
778 const char *refdir;
780 if (de->d_name[0] == '.')
781 continue;
782 namelen = strlen(de->d_name);
783 if (namelen > 255)
784 continue;
785 if (has_extension(de->d_name, ".lock"))
786 continue;
787 memcpy(refname + baselen, de->d_name, namelen+1);
788 refdir = *refs->name
789 ? git_path_submodule(refs->name, "%s", refname)
790 : git_path("%s", refname);
791 if (stat(refdir, &st) < 0)
792 continue;
793 if (S_ISDIR(st.st_mode)) {
794 get_ref_dir(refs, refname, dir);
795 continue;
797 if (*refs->name) {
798 hashclr(sha1);
799 flag = 0;
800 if (resolve_gitlink_ref(refs->name, refname, sha1) < 0) {
801 hashclr(sha1);
802 flag |= REF_ISBROKEN;
804 } else if (read_ref_full(refname, sha1, 1, &flag)) {
805 hashclr(sha1);
806 flag |= REF_ISBROKEN;
808 add_ref(dir, create_ref_entry(refname, sha1, flag, 1));
810 free(refname);
811 closedir(d);
815 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
817 if (!refs->did_loose) {
818 get_ref_dir(refs, "refs", &refs->loose);
819 refs->did_loose = 1;
821 return &refs->loose;
824 /* We allow "recursive" symbolic refs. Only within reason, though */
825 #define MAXDEPTH 5
826 #define MAXREFLEN (1024)
829 * Called by resolve_gitlink_ref_recursive() after it failed to read
830 * from the loose refs in ref_cache refs. Find <refname> in the
831 * packed-refs file for the submodule.
833 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
834 const char *refname, unsigned char *sha1)
836 struct ref_entry *ref;
837 struct ref_dir *dir = get_packed_refs(refs);
839 ref = find_ref(dir, refname);
840 if (ref == NULL)
841 return -1;
843 memcpy(sha1, ref->u.value.sha1, 20);
844 return 0;
847 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
848 const char *refname, unsigned char *sha1,
849 int recursion)
851 int fd, len;
852 char buffer[128], *p;
853 char *path;
855 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
856 return -1;
857 path = *refs->name
858 ? git_path_submodule(refs->name, "%s", refname)
859 : git_path("%s", refname);
860 fd = open(path, O_RDONLY);
861 if (fd < 0)
862 return resolve_gitlink_packed_ref(refs, refname, sha1);
864 len = read(fd, buffer, sizeof(buffer)-1);
865 close(fd);
866 if (len < 0)
867 return -1;
868 while (len && isspace(buffer[len-1]))
869 len--;
870 buffer[len] = 0;
872 /* Was it a detached head or an old-fashioned symlink? */
873 if (!get_sha1_hex(buffer, sha1))
874 return 0;
876 /* Symref? */
877 if (strncmp(buffer, "ref:", 4))
878 return -1;
879 p = buffer + 4;
880 while (isspace(*p))
881 p++;
883 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
886 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
888 int len = strlen(path), retval;
889 char *submodule;
890 struct ref_cache *refs;
892 while (len && path[len-1] == '/')
893 len--;
894 if (!len)
895 return -1;
896 submodule = xstrndup(path, len);
897 refs = get_ref_cache(submodule);
898 free(submodule);
900 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
901 return retval;
905 * Try to read ref from the packed references. On success, set sha1
906 * and return 0; otherwise, return -1.
908 static int get_packed_ref(const char *refname, unsigned char *sha1)
910 struct ref_dir *packed = get_packed_refs(get_ref_cache(NULL));
911 struct ref_entry *entry = find_ref(packed, refname);
912 if (entry) {
913 hashcpy(sha1, entry->u.value.sha1);
914 return 0;
916 return -1;
919 const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
921 int depth = MAXDEPTH;
922 ssize_t len;
923 char buffer[256];
924 static char refname_buffer[256];
926 if (flag)
927 *flag = 0;
929 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
930 return NULL;
932 for (;;) {
933 char path[PATH_MAX];
934 struct stat st;
935 char *buf;
936 int fd;
938 if (--depth < 0)
939 return NULL;
941 git_snpath(path, sizeof(path), "%s", refname);
943 if (lstat(path, &st) < 0) {
944 if (errno != ENOENT)
945 return NULL;
947 * The loose reference file does not exist;
948 * check for a packed reference.
950 if (!get_packed_ref(refname, sha1)) {
951 if (flag)
952 *flag |= REF_ISPACKED;
953 return refname;
955 /* The reference is not a packed reference, either. */
956 if (reading) {
957 return NULL;
958 } else {
959 hashclr(sha1);
960 return refname;
964 /* Follow "normalized" - ie "refs/.." symlinks by hand */
965 if (S_ISLNK(st.st_mode)) {
966 len = readlink(path, buffer, sizeof(buffer)-1);
967 if (len < 0)
968 return NULL;
969 buffer[len] = 0;
970 if (!prefixcmp(buffer, "refs/") &&
971 !check_refname_format(buffer, 0)) {
972 strcpy(refname_buffer, buffer);
973 refname = refname_buffer;
974 if (flag)
975 *flag |= REF_ISSYMREF;
976 continue;
980 /* Is it a directory? */
981 if (S_ISDIR(st.st_mode)) {
982 errno = EISDIR;
983 return NULL;
987 * Anything else, just open it and try to use it as
988 * a ref
990 fd = open(path, O_RDONLY);
991 if (fd < 0)
992 return NULL;
993 len = read_in_full(fd, buffer, sizeof(buffer)-1);
994 close(fd);
995 if (len < 0)
996 return NULL;
997 while (len && isspace(buffer[len-1]))
998 len--;
999 buffer[len] = '\0';
1002 * Is it a symbolic ref?
1004 if (prefixcmp(buffer, "ref:"))
1005 break;
1006 if (flag)
1007 *flag |= REF_ISSYMREF;
1008 buf = buffer + 4;
1009 while (isspace(*buf))
1010 buf++;
1011 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1012 if (flag)
1013 *flag |= REF_ISBROKEN;
1014 return NULL;
1016 refname = strcpy(refname_buffer, buf);
1018 /* Please note that FETCH_HEAD has a second line containing other data. */
1019 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
1020 if (flag)
1021 *flag |= REF_ISBROKEN;
1022 return NULL;
1024 return refname;
1027 char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1029 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
1030 return ret ? xstrdup(ret) : NULL;
1033 /* The argument to filter_refs */
1034 struct ref_filter {
1035 const char *pattern;
1036 each_ref_fn *fn;
1037 void *cb_data;
1040 int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
1042 if (resolve_ref_unsafe(refname, sha1, reading, flags))
1043 return 0;
1044 return -1;
1047 int read_ref(const char *refname, unsigned char *sha1)
1049 return read_ref_full(refname, sha1, 1, NULL);
1052 int ref_exists(const char *refname)
1054 unsigned char sha1[20];
1055 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
1058 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1059 void *data)
1061 struct ref_filter *filter = (struct ref_filter *)data;
1062 if (fnmatch(filter->pattern, refname, 0))
1063 return 0;
1064 return filter->fn(refname, sha1, flags, filter->cb_data);
1067 int peel_ref(const char *refname, unsigned char *sha1)
1069 int flag;
1070 unsigned char base[20];
1071 struct object *o;
1073 if (current_ref && (current_ref->name == refname
1074 || !strcmp(current_ref->name, refname))) {
1075 if (current_ref->flag & REF_KNOWS_PEELED) {
1076 hashcpy(sha1, current_ref->u.value.peeled);
1077 return 0;
1079 hashcpy(base, current_ref->u.value.sha1);
1080 goto fallback;
1083 if (read_ref_full(refname, base, 1, &flag))
1084 return -1;
1086 if ((flag & REF_ISPACKED)) {
1087 struct ref_dir *dir = get_packed_refs(get_ref_cache(NULL));
1088 struct ref_entry *r = find_ref(dir, refname);
1090 if (r != NULL && r->flag & REF_KNOWS_PEELED) {
1091 hashcpy(sha1, r->u.value.peeled);
1092 return 0;
1096 fallback:
1097 o = parse_object(base);
1098 if (o && o->type == OBJ_TAG) {
1099 o = deref_tag(o, refname, 0);
1100 if (o) {
1101 hashcpy(sha1, o->sha1);
1102 return 0;
1105 return -1;
1108 struct warn_if_dangling_data {
1109 FILE *fp;
1110 const char *refname;
1111 const char *msg_fmt;
1114 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1115 int flags, void *cb_data)
1117 struct warn_if_dangling_data *d = cb_data;
1118 const char *resolves_to;
1119 unsigned char junk[20];
1121 if (!(flags & REF_ISSYMREF))
1122 return 0;
1124 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1125 if (!resolves_to || strcmp(resolves_to, d->refname))
1126 return 0;
1128 fprintf(d->fp, d->msg_fmt, refname);
1129 fputc('\n', d->fp);
1130 return 0;
1133 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1135 struct warn_if_dangling_data data;
1137 data.fp = fp;
1138 data.refname = refname;
1139 data.msg_fmt = msg_fmt;
1140 for_each_rawref(warn_if_dangling_symref, &data);
1143 static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
1144 int trim, int flags, void *cb_data)
1146 struct ref_cache *refs = get_ref_cache(submodule);
1147 struct ref_dir *packed_dir = get_packed_refs(refs);
1148 struct ref_dir *loose_dir = get_loose_refs(refs);
1149 int retval = 0;
1151 if (base && *base) {
1152 packed_dir = find_containing_dir(packed_dir, base, 0);
1153 loose_dir = find_containing_dir(loose_dir, base, 0);
1156 if (packed_dir && loose_dir) {
1157 sort_ref_dir(packed_dir);
1158 sort_ref_dir(loose_dir);
1159 retval = do_for_each_ref_in_dirs(
1160 packed_dir, loose_dir,
1161 base, fn, trim, flags, cb_data);
1162 } else if (packed_dir) {
1163 sort_ref_dir(packed_dir);
1164 retval = do_for_each_ref_in_dir(
1165 packed_dir, 0,
1166 base, fn, trim, flags, cb_data);
1167 } else if (loose_dir) {
1168 sort_ref_dir(loose_dir);
1169 retval = do_for_each_ref_in_dir(
1170 loose_dir, 0,
1171 base, fn, trim, flags, cb_data);
1174 return retval;
1177 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1179 unsigned char sha1[20];
1180 int flag;
1182 if (submodule) {
1183 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1184 return fn("HEAD", sha1, 0, cb_data);
1186 return 0;
1189 if (!read_ref_full("HEAD", sha1, 1, &flag))
1190 return fn("HEAD", sha1, flag, cb_data);
1192 return 0;
1195 int head_ref(each_ref_fn fn, void *cb_data)
1197 return do_head_ref(NULL, fn, cb_data);
1200 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1202 return do_head_ref(submodule, fn, cb_data);
1205 int for_each_ref(each_ref_fn fn, void *cb_data)
1207 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
1210 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1212 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
1215 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1217 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
1220 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1221 each_ref_fn fn, void *cb_data)
1223 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
1226 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1228 return for_each_ref_in("refs/tags/", fn, cb_data);
1231 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1233 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1236 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1238 return for_each_ref_in("refs/heads/", fn, cb_data);
1241 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1243 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1246 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1248 return for_each_ref_in("refs/remotes/", fn, cb_data);
1251 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1253 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1256 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1258 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
1261 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1263 struct strbuf buf = STRBUF_INIT;
1264 int ret = 0;
1265 unsigned char sha1[20];
1266 int flag;
1268 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
1269 if (!read_ref_full(buf.buf, sha1, 1, &flag))
1270 ret = fn(buf.buf, sha1, flag, cb_data);
1271 strbuf_release(&buf);
1273 return ret;
1276 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1278 struct strbuf buf = STRBUF_INIT;
1279 int ret;
1280 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1281 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1282 strbuf_release(&buf);
1283 return ret;
1286 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1287 const char *prefix, void *cb_data)
1289 struct strbuf real_pattern = STRBUF_INIT;
1290 struct ref_filter filter;
1291 int ret;
1293 if (!prefix && prefixcmp(pattern, "refs/"))
1294 strbuf_addstr(&real_pattern, "refs/");
1295 else if (prefix)
1296 strbuf_addstr(&real_pattern, prefix);
1297 strbuf_addstr(&real_pattern, pattern);
1299 if (!has_glob_specials(pattern)) {
1300 /* Append implied '/' '*' if not present. */
1301 if (real_pattern.buf[real_pattern.len - 1] != '/')
1302 strbuf_addch(&real_pattern, '/');
1303 /* No need to check for '*', there is none. */
1304 strbuf_addch(&real_pattern, '*');
1307 filter.pattern = real_pattern.buf;
1308 filter.fn = fn;
1309 filter.cb_data = cb_data;
1310 ret = for_each_ref(filter_refs, &filter);
1312 strbuf_release(&real_pattern);
1313 return ret;
1316 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1318 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1321 int for_each_rawref(each_ref_fn fn, void *cb_data)
1323 return do_for_each_ref(NULL, "", fn, 0,
1324 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1327 const char *prettify_refname(const char *name)
1329 return name + (
1330 !prefixcmp(name, "refs/heads/") ? 11 :
1331 !prefixcmp(name, "refs/tags/") ? 10 :
1332 !prefixcmp(name, "refs/remotes/") ? 13 :
1336 const char *ref_rev_parse_rules[] = {
1337 "%.*s",
1338 "refs/%.*s",
1339 "refs/tags/%.*s",
1340 "refs/heads/%.*s",
1341 "refs/remotes/%.*s",
1342 "refs/remotes/%.*s/HEAD",
1343 NULL
1346 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1348 const char **p;
1349 const int abbrev_name_len = strlen(abbrev_name);
1351 for (p = rules; *p; p++) {
1352 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1353 return 1;
1357 return 0;
1360 static struct ref_lock *verify_lock(struct ref_lock *lock,
1361 const unsigned char *old_sha1, int mustexist)
1363 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
1364 error("Can't verify ref %s", lock->ref_name);
1365 unlock_ref(lock);
1366 return NULL;
1368 if (hashcmp(lock->old_sha1, old_sha1)) {
1369 error("Ref %s is at %s but expected %s", lock->ref_name,
1370 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1371 unlock_ref(lock);
1372 return NULL;
1374 return lock;
1377 static int remove_empty_directories(const char *file)
1379 /* we want to create a file but there is a directory there;
1380 * if that is an empty directory (or a directory that contains
1381 * only empty directories), remove them.
1383 struct strbuf path;
1384 int result;
1386 strbuf_init(&path, 20);
1387 strbuf_addstr(&path, file);
1389 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
1391 strbuf_release(&path);
1393 return result;
1397 * *string and *len will only be substituted, and *string returned (for
1398 * later free()ing) if the string passed in is a magic short-hand form
1399 * to name a branch.
1401 static char *substitute_branch_name(const char **string, int *len)
1403 struct strbuf buf = STRBUF_INIT;
1404 int ret = interpret_branch_name(*string, &buf);
1406 if (ret == *len) {
1407 size_t size;
1408 *string = strbuf_detach(&buf, &size);
1409 *len = size;
1410 return (char *)*string;
1413 return NULL;
1416 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1418 char *last_branch = substitute_branch_name(&str, &len);
1419 const char **p, *r;
1420 int refs_found = 0;
1422 *ref = NULL;
1423 for (p = ref_rev_parse_rules; *p; p++) {
1424 char fullref[PATH_MAX];
1425 unsigned char sha1_from_ref[20];
1426 unsigned char *this_result;
1427 int flag;
1429 this_result = refs_found ? sha1_from_ref : sha1;
1430 mksnpath(fullref, sizeof(fullref), *p, len, str);
1431 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
1432 if (r) {
1433 if (!refs_found++)
1434 *ref = xstrdup(r);
1435 if (!warn_ambiguous_refs)
1436 break;
1437 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
1438 warning("ignoring dangling symref %s.", fullref);
1439 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1440 warning("ignoring broken ref %s.", fullref);
1443 free(last_branch);
1444 return refs_found;
1447 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1449 char *last_branch = substitute_branch_name(&str, &len);
1450 const char **p;
1451 int logs_found = 0;
1453 *log = NULL;
1454 for (p = ref_rev_parse_rules; *p; p++) {
1455 struct stat st;
1456 unsigned char hash[20];
1457 char path[PATH_MAX];
1458 const char *ref, *it;
1460 mksnpath(path, sizeof(path), *p, len, str);
1461 ref = resolve_ref_unsafe(path, hash, 1, NULL);
1462 if (!ref)
1463 continue;
1464 if (!stat(git_path("logs/%s", path), &st) &&
1465 S_ISREG(st.st_mode))
1466 it = path;
1467 else if (strcmp(ref, path) &&
1468 !stat(git_path("logs/%s", ref), &st) &&
1469 S_ISREG(st.st_mode))
1470 it = ref;
1471 else
1472 continue;
1473 if (!logs_found++) {
1474 *log = xstrdup(it);
1475 hashcpy(sha1, hash);
1477 if (!warn_ambiguous_refs)
1478 break;
1480 free(last_branch);
1481 return logs_found;
1484 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1485 const unsigned char *old_sha1,
1486 int flags, int *type_p)
1488 char *ref_file;
1489 const char *orig_refname = refname;
1490 struct ref_lock *lock;
1491 int last_errno = 0;
1492 int type, lflags;
1493 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1494 int missing = 0;
1496 lock = xcalloc(1, sizeof(struct ref_lock));
1497 lock->lock_fd = -1;
1499 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
1500 if (!refname && errno == EISDIR) {
1501 /* we are trying to lock foo but we used to
1502 * have foo/bar which now does not exist;
1503 * it is normal for the empty directory 'foo'
1504 * to remain.
1506 ref_file = git_path("%s", orig_refname);
1507 if (remove_empty_directories(ref_file)) {
1508 last_errno = errno;
1509 error("there are still refs under '%s'", orig_refname);
1510 goto error_return;
1512 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
1514 if (type_p)
1515 *type_p = type;
1516 if (!refname) {
1517 last_errno = errno;
1518 error("unable to resolve reference %s: %s",
1519 orig_refname, strerror(errno));
1520 goto error_return;
1522 missing = is_null_sha1(lock->old_sha1);
1523 /* When the ref did not exist and we are creating it,
1524 * make sure there is no existing ref that is packed
1525 * whose name begins with our refname, nor a ref whose
1526 * name is a proper prefix of our refname.
1528 if (missing &&
1529 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
1530 last_errno = ENOTDIR;
1531 goto error_return;
1534 lock->lk = xcalloc(1, sizeof(struct lock_file));
1536 lflags = LOCK_DIE_ON_ERROR;
1537 if (flags & REF_NODEREF) {
1538 refname = orig_refname;
1539 lflags |= LOCK_NODEREF;
1541 lock->ref_name = xstrdup(refname);
1542 lock->orig_ref_name = xstrdup(orig_refname);
1543 ref_file = git_path("%s", refname);
1544 if (missing)
1545 lock->force_write = 1;
1546 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1547 lock->force_write = 1;
1549 if (safe_create_leading_directories(ref_file)) {
1550 last_errno = errno;
1551 error("unable to create directory for %s", ref_file);
1552 goto error_return;
1555 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
1556 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
1558 error_return:
1559 unlock_ref(lock);
1560 errno = last_errno;
1561 return NULL;
1564 struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
1566 char refpath[PATH_MAX];
1567 if (check_refname_format(refname, 0))
1568 return NULL;
1569 strcpy(refpath, mkpath("refs/%s", refname));
1570 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
1573 struct ref_lock *lock_any_ref_for_update(const char *refname,
1574 const unsigned char *old_sha1, int flags)
1576 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1577 return NULL;
1578 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
1581 struct repack_without_ref_sb {
1582 const char *refname;
1583 int fd;
1586 static int repack_without_ref_fn(const char *refname, const unsigned char *sha1,
1587 int flags, void *cb_data)
1589 struct repack_without_ref_sb *data = cb_data;
1590 char line[PATH_MAX + 100];
1591 int len;
1593 if (!strcmp(data->refname, refname))
1594 return 0;
1595 len = snprintf(line, sizeof(line), "%s %s\n",
1596 sha1_to_hex(sha1), refname);
1597 /* this should not happen but just being defensive */
1598 if (len > sizeof(line))
1599 die("too long a refname '%s'", refname);
1600 write_or_die(data->fd, line, len);
1601 return 0;
1604 static struct lock_file packlock;
1606 static int repack_without_ref(const char *refname)
1608 struct repack_without_ref_sb data;
1609 struct ref_dir *packed = get_packed_refs(get_ref_cache(NULL));
1610 if (find_ref(packed, refname) == NULL)
1611 return 0;
1612 data.refname = refname;
1613 data.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1614 if (data.fd < 0) {
1615 unable_to_lock_error(git_path("packed-refs"), errno);
1616 return error("cannot delete '%s' from packed refs", refname);
1618 do_for_each_ref_in_dir(packed, 0, "", repack_without_ref_fn, 0, 0, &data);
1619 return commit_lock_file(&packlock);
1622 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
1624 struct ref_lock *lock;
1625 int err, i = 0, ret = 0, flag = 0;
1627 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
1628 if (!lock)
1629 return 1;
1630 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
1631 /* loose */
1632 const char *path;
1634 if (!(delopt & REF_NODEREF)) {
1635 i = strlen(lock->lk->filename) - 5; /* .lock */
1636 lock->lk->filename[i] = 0;
1637 path = lock->lk->filename;
1638 } else {
1639 path = git_path("%s", refname);
1641 err = unlink_or_warn(path);
1642 if (err && errno != ENOENT)
1643 ret = 1;
1645 if (!(delopt & REF_NODEREF))
1646 lock->lk->filename[i] = '.';
1648 /* removing the loose one could have resurrected an earlier
1649 * packed one. Also, if it was not loose we need to repack
1650 * without it.
1652 ret |= repack_without_ref(refname);
1654 unlink_or_warn(git_path("logs/%s", lock->ref_name));
1655 invalidate_ref_cache(NULL);
1656 unlock_ref(lock);
1657 return ret;
1661 * People using contrib's git-new-workdir have .git/logs/refs ->
1662 * /some/other/path/.git/logs/refs, and that may live on another device.
1664 * IOW, to avoid cross device rename errors, the temporary renamed log must
1665 * live into logs/refs.
1667 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1669 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
1671 unsigned char sha1[20], orig_sha1[20];
1672 int flag = 0, logmoved = 0;
1673 struct ref_lock *lock;
1674 struct stat loginfo;
1675 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
1676 const char *symref = NULL;
1677 struct ref_cache *refs = get_ref_cache(NULL);
1679 if (log && S_ISLNK(loginfo.st_mode))
1680 return error("reflog for %s is a symlink", oldrefname);
1682 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
1683 if (flag & REF_ISSYMREF)
1684 return error("refname %s is a symbolic ref, renaming it is not supported",
1685 oldrefname);
1686 if (!symref)
1687 return error("refname %s not found", oldrefname);
1689 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
1690 return 1;
1692 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
1693 return 1;
1695 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
1696 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
1697 oldrefname, strerror(errno));
1699 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
1700 error("unable to delete old %s", oldrefname);
1701 goto rollback;
1704 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
1705 delete_ref(newrefname, sha1, REF_NODEREF)) {
1706 if (errno==EISDIR) {
1707 if (remove_empty_directories(git_path("%s", newrefname))) {
1708 error("Directory not empty: %s", newrefname);
1709 goto rollback;
1711 } else {
1712 error("unable to delete existing %s", newrefname);
1713 goto rollback;
1717 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
1718 error("unable to create directory for %s", newrefname);
1719 goto rollback;
1722 retry:
1723 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
1724 if (errno==EISDIR || errno==ENOTDIR) {
1726 * rename(a, b) when b is an existing
1727 * directory ought to result in ISDIR, but
1728 * Solaris 5.8 gives ENOTDIR. Sheesh.
1730 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
1731 error("Directory not empty: logs/%s", newrefname);
1732 goto rollback;
1734 goto retry;
1735 } else {
1736 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
1737 newrefname, strerror(errno));
1738 goto rollback;
1741 logmoved = log;
1743 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
1744 if (!lock) {
1745 error("unable to lock %s for update", newrefname);
1746 goto rollback;
1748 lock->force_write = 1;
1749 hashcpy(lock->old_sha1, orig_sha1);
1750 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1751 error("unable to write current sha1 into %s", newrefname);
1752 goto rollback;
1755 return 0;
1757 rollback:
1758 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
1759 if (!lock) {
1760 error("unable to lock %s for rollback", oldrefname);
1761 goto rollbacklog;
1764 lock->force_write = 1;
1765 flag = log_all_ref_updates;
1766 log_all_ref_updates = 0;
1767 if (write_ref_sha1(lock, orig_sha1, NULL))
1768 error("unable to write current sha1 into %s", oldrefname);
1769 log_all_ref_updates = flag;
1771 rollbacklog:
1772 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
1773 error("unable to restore logfile %s from %s: %s",
1774 oldrefname, newrefname, strerror(errno));
1775 if (!logmoved && log &&
1776 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
1777 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
1778 oldrefname, strerror(errno));
1780 return 1;
1783 int close_ref(struct ref_lock *lock)
1785 if (close_lock_file(lock->lk))
1786 return -1;
1787 lock->lock_fd = -1;
1788 return 0;
1791 int commit_ref(struct ref_lock *lock)
1793 if (commit_lock_file(lock->lk))
1794 return -1;
1795 lock->lock_fd = -1;
1796 return 0;
1799 void unlock_ref(struct ref_lock *lock)
1801 /* Do not free lock->lk -- atexit() still looks at them */
1802 if (lock->lk)
1803 rollback_lock_file(lock->lk);
1804 free(lock->ref_name);
1805 free(lock->orig_ref_name);
1806 free(lock);
1810 * copy the reflog message msg to buf, which has been allocated sufficiently
1811 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1812 * because reflog file is one line per entry.
1814 static int copy_msg(char *buf, const char *msg)
1816 char *cp = buf;
1817 char c;
1818 int wasspace = 1;
1820 *cp++ = '\t';
1821 while ((c = *msg++)) {
1822 if (wasspace && isspace(c))
1823 continue;
1824 wasspace = isspace(c);
1825 if (wasspace)
1826 c = ' ';
1827 *cp++ = c;
1829 while (buf < cp && isspace(cp[-1]))
1830 cp--;
1831 *cp++ = '\n';
1832 return cp - buf;
1835 int log_ref_setup(const char *refname, char *logfile, int bufsize)
1837 int logfd, oflags = O_APPEND | O_WRONLY;
1839 git_snpath(logfile, bufsize, "logs/%s", refname);
1840 if (log_all_ref_updates &&
1841 (!prefixcmp(refname, "refs/heads/") ||
1842 !prefixcmp(refname, "refs/remotes/") ||
1843 !prefixcmp(refname, "refs/notes/") ||
1844 !strcmp(refname, "HEAD"))) {
1845 if (safe_create_leading_directories(logfile) < 0)
1846 return error("unable to create directory for %s",
1847 logfile);
1848 oflags |= O_CREAT;
1851 logfd = open(logfile, oflags, 0666);
1852 if (logfd < 0) {
1853 if (!(oflags & O_CREAT) && errno == ENOENT)
1854 return 0;
1856 if ((oflags & O_CREAT) && errno == EISDIR) {
1857 if (remove_empty_directories(logfile)) {
1858 return error("There are still logs under '%s'",
1859 logfile);
1861 logfd = open(logfile, oflags, 0666);
1864 if (logfd < 0)
1865 return error("Unable to append to %s: %s",
1866 logfile, strerror(errno));
1869 adjust_shared_perm(logfile);
1870 close(logfd);
1871 return 0;
1874 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
1875 const unsigned char *new_sha1, const char *msg)
1877 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1878 unsigned maxlen, len;
1879 int msglen;
1880 char log_file[PATH_MAX];
1881 char *logrec;
1882 const char *committer;
1884 if (log_all_ref_updates < 0)
1885 log_all_ref_updates = !is_bare_repository();
1887 result = log_ref_setup(refname, log_file, sizeof(log_file));
1888 if (result)
1889 return result;
1891 logfd = open(log_file, oflags);
1892 if (logfd < 0)
1893 return 0;
1894 msglen = msg ? strlen(msg) : 0;
1895 committer = git_committer_info(0);
1896 maxlen = strlen(committer) + msglen + 100;
1897 logrec = xmalloc(maxlen);
1898 len = sprintf(logrec, "%s %s %s\n",
1899 sha1_to_hex(old_sha1),
1900 sha1_to_hex(new_sha1),
1901 committer);
1902 if (msglen)
1903 len += copy_msg(logrec + len - 1, msg) - 1;
1904 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1905 free(logrec);
1906 if (close(logfd) != 0 || written != len)
1907 return error("Unable to append to %s", log_file);
1908 return 0;
1911 static int is_branch(const char *refname)
1913 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1916 int write_ref_sha1(struct ref_lock *lock,
1917 const unsigned char *sha1, const char *logmsg)
1919 static char term = '\n';
1920 struct object *o;
1922 if (!lock)
1923 return -1;
1924 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1925 unlock_ref(lock);
1926 return 0;
1928 o = parse_object(sha1);
1929 if (!o) {
1930 error("Trying to write ref %s with nonexistent object %s",
1931 lock->ref_name, sha1_to_hex(sha1));
1932 unlock_ref(lock);
1933 return -1;
1935 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1936 error("Trying to write non-commit object %s to branch %s",
1937 sha1_to_hex(sha1), lock->ref_name);
1938 unlock_ref(lock);
1939 return -1;
1941 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1942 write_in_full(lock->lock_fd, &term, 1) != 1
1943 || close_ref(lock) < 0) {
1944 error("Couldn't write %s", lock->lk->filename);
1945 unlock_ref(lock);
1946 return -1;
1948 clear_loose_ref_cache(get_ref_cache(NULL));
1949 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1950 (strcmp(lock->ref_name, lock->orig_ref_name) &&
1951 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1952 unlock_ref(lock);
1953 return -1;
1955 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1957 * Special hack: If a branch is updated directly and HEAD
1958 * points to it (may happen on the remote side of a push
1959 * for example) then logically the HEAD reflog should be
1960 * updated too.
1961 * A generic solution implies reverse symref information,
1962 * but finding all symrefs pointing to the given branch
1963 * would be rather costly for this rare event (the direct
1964 * update of a branch) to be worth it. So let's cheat and
1965 * check with HEAD only which should cover 99% of all usage
1966 * scenarios (even 100% of the default ones).
1968 unsigned char head_sha1[20];
1969 int head_flag;
1970 const char *head_ref;
1971 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
1972 if (head_ref && (head_flag & REF_ISSYMREF) &&
1973 !strcmp(head_ref, lock->ref_name))
1974 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1976 if (commit_ref(lock)) {
1977 error("Couldn't set %s", lock->ref_name);
1978 unlock_ref(lock);
1979 return -1;
1981 unlock_ref(lock);
1982 return 0;
1985 int create_symref(const char *ref_target, const char *refs_heads_master,
1986 const char *logmsg)
1988 const char *lockpath;
1989 char ref[1000];
1990 int fd, len, written;
1991 char *git_HEAD = git_pathdup("%s", ref_target);
1992 unsigned char old_sha1[20], new_sha1[20];
1994 if (logmsg && read_ref(ref_target, old_sha1))
1995 hashclr(old_sha1);
1997 if (safe_create_leading_directories(git_HEAD) < 0)
1998 return error("unable to create directory for %s", git_HEAD);
2000 #ifndef NO_SYMLINK_HEAD
2001 if (prefer_symlink_refs) {
2002 unlink(git_HEAD);
2003 if (!symlink(refs_heads_master, git_HEAD))
2004 goto done;
2005 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2007 #endif
2009 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2010 if (sizeof(ref) <= len) {
2011 error("refname too long: %s", refs_heads_master);
2012 goto error_free_return;
2014 lockpath = mkpath("%s.lock", git_HEAD);
2015 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2016 if (fd < 0) {
2017 error("Unable to open %s for writing", lockpath);
2018 goto error_free_return;
2020 written = write_in_full(fd, ref, len);
2021 if (close(fd) != 0 || written != len) {
2022 error("Unable to write to %s", lockpath);
2023 goto error_unlink_return;
2025 if (rename(lockpath, git_HEAD) < 0) {
2026 error("Unable to create %s", git_HEAD);
2027 goto error_unlink_return;
2029 if (adjust_shared_perm(git_HEAD)) {
2030 error("Unable to fix permissions on %s", lockpath);
2031 error_unlink_return:
2032 unlink_or_warn(lockpath);
2033 error_free_return:
2034 free(git_HEAD);
2035 return -1;
2038 #ifndef NO_SYMLINK_HEAD
2039 done:
2040 #endif
2041 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2042 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2044 free(git_HEAD);
2045 return 0;
2048 static char *ref_msg(const char *line, const char *endp)
2050 const char *ep;
2051 line += 82;
2052 ep = memchr(line, '\n', endp - line);
2053 if (!ep)
2054 ep = endp;
2055 return xmemdupz(line, ep - line);
2058 int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2059 unsigned char *sha1, char **msg,
2060 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
2062 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
2063 char *tz_c;
2064 int logfd, tz, reccnt = 0;
2065 struct stat st;
2066 unsigned long date;
2067 unsigned char logged_sha1[20];
2068 void *log_mapped;
2069 size_t mapsz;
2071 logfile = git_path("logs/%s", refname);
2072 logfd = open(logfile, O_RDONLY, 0);
2073 if (logfd < 0)
2074 die_errno("Unable to read log '%s'", logfile);
2075 fstat(logfd, &st);
2076 if (!st.st_size)
2077 die("Log %s is empty.", logfile);
2078 mapsz = xsize_t(st.st_size);
2079 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
2080 logdata = log_mapped;
2081 close(logfd);
2083 lastrec = NULL;
2084 rec = logend = logdata + st.st_size;
2085 while (logdata < rec) {
2086 reccnt++;
2087 if (logdata < rec && *(rec-1) == '\n')
2088 rec--;
2089 lastgt = NULL;
2090 while (logdata < rec && *(rec-1) != '\n') {
2091 rec--;
2092 if (*rec == '>')
2093 lastgt = rec;
2095 if (!lastgt)
2096 die("Log %s is corrupt.", logfile);
2097 date = strtoul(lastgt + 1, &tz_c, 10);
2098 if (date <= at_time || cnt == 0) {
2099 tz = strtoul(tz_c, NULL, 10);
2100 if (msg)
2101 *msg = ref_msg(rec, logend);
2102 if (cutoff_time)
2103 *cutoff_time = date;
2104 if (cutoff_tz)
2105 *cutoff_tz = tz;
2106 if (cutoff_cnt)
2107 *cutoff_cnt = reccnt - 1;
2108 if (lastrec) {
2109 if (get_sha1_hex(lastrec, logged_sha1))
2110 die("Log %s is corrupt.", logfile);
2111 if (get_sha1_hex(rec + 41, sha1))
2112 die("Log %s is corrupt.", logfile);
2113 if (hashcmp(logged_sha1, sha1)) {
2114 warning("Log %s has gap after %s.",
2115 logfile, show_date(date, tz, DATE_RFC2822));
2118 else if (date == at_time) {
2119 if (get_sha1_hex(rec + 41, sha1))
2120 die("Log %s is corrupt.", logfile);
2122 else {
2123 if (get_sha1_hex(rec + 41, logged_sha1))
2124 die("Log %s is corrupt.", logfile);
2125 if (hashcmp(logged_sha1, sha1)) {
2126 warning("Log %s unexpectedly ended on %s.",
2127 logfile, show_date(date, tz, DATE_RFC2822));
2130 munmap(log_mapped, mapsz);
2131 return 0;
2133 lastrec = rec;
2134 if (cnt > 0)
2135 cnt--;
2138 rec = logdata;
2139 while (rec < logend && *rec != '>' && *rec != '\n')
2140 rec++;
2141 if (rec == logend || *rec == '\n')
2142 die("Log %s is corrupt.", logfile);
2143 date = strtoul(rec + 1, &tz_c, 10);
2144 tz = strtoul(tz_c, NULL, 10);
2145 if (get_sha1_hex(logdata, sha1))
2146 die("Log %s is corrupt.", logfile);
2147 if (is_null_sha1(sha1)) {
2148 if (get_sha1_hex(logdata + 41, sha1))
2149 die("Log %s is corrupt.", logfile);
2151 if (msg)
2152 *msg = ref_msg(logdata, logend);
2153 munmap(log_mapped, mapsz);
2155 if (cutoff_time)
2156 *cutoff_time = date;
2157 if (cutoff_tz)
2158 *cutoff_tz = tz;
2159 if (cutoff_cnt)
2160 *cutoff_cnt = reccnt;
2161 return 1;
2164 int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
2166 const char *logfile;
2167 FILE *logfp;
2168 struct strbuf sb = STRBUF_INIT;
2169 int ret = 0;
2171 logfile = git_path("logs/%s", refname);
2172 logfp = fopen(logfile, "r");
2173 if (!logfp)
2174 return -1;
2176 if (ofs) {
2177 struct stat statbuf;
2178 if (fstat(fileno(logfp), &statbuf) ||
2179 statbuf.st_size < ofs ||
2180 fseek(logfp, -ofs, SEEK_END) ||
2181 strbuf_getwholeline(&sb, logfp, '\n')) {
2182 fclose(logfp);
2183 strbuf_release(&sb);
2184 return -1;
2188 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2189 unsigned char osha1[20], nsha1[20];
2190 char *email_end, *message;
2191 unsigned long timestamp;
2192 int tz;
2194 /* old SP new SP name <email> SP time TAB msg LF */
2195 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
2196 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
2197 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
2198 !(email_end = strchr(sb.buf + 82, '>')) ||
2199 email_end[1] != ' ' ||
2200 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2201 !message || message[0] != ' ' ||
2202 (message[1] != '+' && message[1] != '-') ||
2203 !isdigit(message[2]) || !isdigit(message[3]) ||
2204 !isdigit(message[4]) || !isdigit(message[5]))
2205 continue; /* corrupt? */
2206 email_end[1] = '\0';
2207 tz = strtol(message + 1, NULL, 10);
2208 if (message[6] != '\t')
2209 message += 6;
2210 else
2211 message += 7;
2212 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
2213 cb_data);
2214 if (ret)
2215 break;
2217 fclose(logfp);
2218 strbuf_release(&sb);
2219 return ret;
2222 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2224 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
2227 static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
2229 DIR *d = opendir(git_path("logs/%s", base));
2230 int retval = 0;
2232 if (d) {
2233 struct dirent *de;
2234 int baselen = strlen(base);
2235 char *log = xmalloc(baselen + 257);
2237 memcpy(log, base, baselen);
2238 if (baselen && base[baselen-1] != '/')
2239 log[baselen++] = '/';
2241 while ((de = readdir(d)) != NULL) {
2242 struct stat st;
2243 int namelen;
2245 if (de->d_name[0] == '.')
2246 continue;
2247 namelen = strlen(de->d_name);
2248 if (namelen > 255)
2249 continue;
2250 if (has_extension(de->d_name, ".lock"))
2251 continue;
2252 memcpy(log + baselen, de->d_name, namelen+1);
2253 if (stat(git_path("logs/%s", log), &st) < 0)
2254 continue;
2255 if (S_ISDIR(st.st_mode)) {
2256 retval = do_for_each_reflog(log, fn, cb_data);
2257 } else {
2258 unsigned char sha1[20];
2259 if (read_ref_full(log, sha1, 0, NULL))
2260 retval = error("bad ref for %s", log);
2261 else
2262 retval = fn(log, sha1, 0, cb_data);
2264 if (retval)
2265 break;
2267 free(log);
2268 closedir(d);
2270 else if (*base)
2271 return errno;
2272 return retval;
2275 int for_each_reflog(each_ref_fn fn, void *cb_data)
2277 return do_for_each_reflog("", fn, cb_data);
2280 int update_ref(const char *action, const char *refname,
2281 const unsigned char *sha1, const unsigned char *oldval,
2282 int flags, enum action_on_err onerr)
2284 static struct ref_lock *lock;
2285 lock = lock_any_ref_for_update(refname, oldval, flags);
2286 if (!lock) {
2287 const char *str = "Cannot lock the ref '%s'.";
2288 switch (onerr) {
2289 case MSG_ON_ERR: error(str, refname); break;
2290 case DIE_ON_ERR: die(str, refname); break;
2291 case QUIET_ON_ERR: break;
2293 return 1;
2295 if (write_ref_sha1(lock, sha1, action) < 0) {
2296 const char *str = "Cannot update the ref '%s'.";
2297 switch (onerr) {
2298 case MSG_ON_ERR: error(str, refname); break;
2299 case DIE_ON_ERR: die(str, refname); break;
2300 case QUIET_ON_ERR: break;
2302 return 1;
2304 return 0;
2307 struct ref *find_ref_by_name(const struct ref *list, const char *name)
2309 for ( ; list; list = list->next)
2310 if (!strcmp(list->name, name))
2311 return (struct ref *)list;
2312 return NULL;
2316 * generate a format suitable for scanf from a ref_rev_parse_rules
2317 * rule, that is replace the "%.*s" spec with a "%s" spec
2319 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2321 char *spec;
2323 spec = strstr(rule, "%.*s");
2324 if (!spec || strstr(spec + 4, "%.*s"))
2325 die("invalid rule in ref_rev_parse_rules: %s", rule);
2327 /* copy all until spec */
2328 strncpy(scanf_fmt, rule, spec - rule);
2329 scanf_fmt[spec - rule] = '\0';
2330 /* copy new spec */
2331 strcat(scanf_fmt, "%s");
2332 /* copy remaining rule */
2333 strcat(scanf_fmt, spec + 4);
2335 return;
2338 char *shorten_unambiguous_ref(const char *refname, int strict)
2340 int i;
2341 static char **scanf_fmts;
2342 static int nr_rules;
2343 char *short_name;
2345 /* pre generate scanf formats from ref_rev_parse_rules[] */
2346 if (!nr_rules) {
2347 size_t total_len = 0;
2349 /* the rule list is NULL terminated, count them first */
2350 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2351 /* no +1 because strlen("%s") < strlen("%.*s") */
2352 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2354 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2356 total_len = 0;
2357 for (i = 0; i < nr_rules; i++) {
2358 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2359 + total_len;
2360 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2361 total_len += strlen(ref_rev_parse_rules[i]);
2365 /* bail out if there are no rules */
2366 if (!nr_rules)
2367 return xstrdup(refname);
2369 /* buffer for scanf result, at most refname must fit */
2370 short_name = xstrdup(refname);
2372 /* skip first rule, it will always match */
2373 for (i = nr_rules - 1; i > 0 ; --i) {
2374 int j;
2375 int rules_to_fail = i;
2376 int short_name_len;
2378 if (1 != sscanf(refname, scanf_fmts[i], short_name))
2379 continue;
2381 short_name_len = strlen(short_name);
2384 * in strict mode, all (except the matched one) rules
2385 * must fail to resolve to a valid non-ambiguous ref
2387 if (strict)
2388 rules_to_fail = nr_rules;
2391 * check if the short name resolves to a valid ref,
2392 * but use only rules prior to the matched one
2394 for (j = 0; j < rules_to_fail; j++) {
2395 const char *rule = ref_rev_parse_rules[j];
2396 char refname[PATH_MAX];
2398 /* skip matched rule */
2399 if (i == j)
2400 continue;
2403 * the short name is ambiguous, if it resolves
2404 * (with this previous rule) to a valid ref
2405 * read_ref() returns 0 on success
2407 mksnpath(refname, sizeof(refname),
2408 rule, short_name_len, short_name);
2409 if (ref_exists(refname))
2410 break;
2414 * short name is non-ambiguous if all previous rules
2415 * haven't resolved to a valid ref
2417 if (j == rules_to_fail)
2418 return short_name;
2421 free(short_name);
2422 return xstrdup(refname);