Move setup_diff_pager to libgit.a
[git/jnareb-git.git] / refs.c
blob02e47b1157c367f9233ae88870b9a43cbe1a7d52
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;
105 * Information used (along with the information in ref_entry) to
106 * describe a single cached reference. This data structure only
107 * occurs embedded in a union in struct ref_entry, and only when
108 * (ref_entry->flag & REF_DIR) is zero.
110 struct ref_value {
111 unsigned char sha1[20];
112 unsigned char peeled[20];
115 struct ref_cache;
118 * Information used (along with the information in ref_entry) to
119 * describe a level in the hierarchy of references. This data
120 * structure only occurs embedded in a union in struct ref_entry, and
121 * only when (ref_entry.flag & REF_DIR) is set. In that case,
122 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
123 * in the directory have already been read:
125 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
126 * or packed references, already read.
128 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
129 * references that hasn't been read yet (nor has any of its
130 * subdirectories).
132 * Entries within a directory are stored within a growable array of
133 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
134 * sorted are sorted by their component name in strcmp() order and the
135 * remaining entries are unsorted.
137 * Loose references are read lazily, one directory at a time. When a
138 * directory of loose references is read, then all of the references
139 * in that directory are stored, and REF_INCOMPLETE stubs are created
140 * for any subdirectories, but the subdirectories themselves are not
141 * read. The reading is triggered by get_ref_dir().
143 struct ref_dir {
144 int nr, alloc;
147 * Entries with index 0 <= i < sorted are sorted by name. New
148 * entries are appended to the list unsorted, and are sorted
149 * only when required; thus we avoid the need to sort the list
150 * after the addition of every reference.
152 int sorted;
154 /* A pointer to the ref_cache that contains this ref_dir. */
155 struct ref_cache *ref_cache;
157 struct ref_entry **entries;
160 /* ISSYMREF=0x01, ISPACKED=0x02, and ISBROKEN=0x04 are public interfaces */
161 #define REF_KNOWS_PEELED 0x08
163 /* ref_entry represents a directory of references */
164 #define REF_DIR 0x10
167 * Entry has not yet been read from disk (used only for REF_DIR
168 * entries representing loose references)
170 #define REF_INCOMPLETE 0x20
173 * A ref_entry represents either a reference or a "subdirectory" of
174 * references.
176 * Each directory in the reference namespace is represented by a
177 * ref_entry with (flags & REF_DIR) set and containing a subdir member
178 * that holds the entries in that directory that have been read so
179 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
180 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
181 * used for loose reference directories.
183 * References are represented by a ref_entry with (flags & REF_DIR)
184 * unset and a value member that describes the reference's value. The
185 * flag member is at the ref_entry level, but it is also needed to
186 * interpret the contents of the value field (in other words, a
187 * ref_value object is not very much use without the enclosing
188 * ref_entry).
190 * Reference names cannot end with slash and directories' names are
191 * always stored with a trailing slash (except for the top-level
192 * directory, which is always denoted by ""). This has two nice
193 * consequences: (1) when the entries in each subdir are sorted
194 * lexicographically by name (as they usually are), the references in
195 * a whole tree can be generated in lexicographic order by traversing
196 * the tree in left-to-right, depth-first order; (2) the names of
197 * references and subdirectories cannot conflict, and therefore the
198 * presence of an empty subdirectory does not block the creation of a
199 * similarly-named reference. (The fact that reference names with the
200 * same leading components can conflict *with each other* is a
201 * separate issue that is regulated by is_refname_available().)
203 * Please note that the name field contains the fully-qualified
204 * reference (or subdirectory) name. Space could be saved by only
205 * storing the relative names. But that would require the full names
206 * to be generated on the fly when iterating in do_for_each_ref(), and
207 * would break callback functions, who have always been able to assume
208 * that the name strings that they are passed will not be freed during
209 * the iteration.
211 struct ref_entry {
212 unsigned char flag; /* ISSYMREF? ISPACKED? */
213 union {
214 struct ref_value value; /* if not (flags&REF_DIR) */
215 struct ref_dir subdir; /* if (flags&REF_DIR) */
216 } u;
218 * The full name of the reference (e.g., "refs/heads/master")
219 * or the full name of the directory with a trailing slash
220 * (e.g., "refs/heads/"):
222 char name[FLEX_ARRAY];
225 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
227 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
229 struct ref_dir *dir;
230 assert(entry->flag & REF_DIR);
231 dir = &entry->u.subdir;
232 if (entry->flag & REF_INCOMPLETE) {
233 read_loose_refs(entry->name, dir);
234 entry->flag &= ~REF_INCOMPLETE;
236 return dir;
239 static struct ref_entry *create_ref_entry(const char *refname,
240 const unsigned char *sha1, int flag,
241 int check_name)
243 int len;
244 struct ref_entry *ref;
246 if (check_name &&
247 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
248 die("Reference has invalid format: '%s'", refname);
249 len = strlen(refname) + 1;
250 ref = xmalloc(sizeof(struct ref_entry) + len);
251 hashcpy(ref->u.value.sha1, sha1);
252 hashclr(ref->u.value.peeled);
253 memcpy(ref->name, refname, len);
254 ref->flag = flag;
255 return ref;
258 static void clear_ref_dir(struct ref_dir *dir);
260 static void free_ref_entry(struct ref_entry *entry)
262 if (entry->flag & REF_DIR) {
264 * Do not use get_ref_dir() here, as that might
265 * trigger the reading of loose refs.
267 clear_ref_dir(&entry->u.subdir);
269 free(entry);
273 * Add a ref_entry to the end of dir (unsorted). Entry is always
274 * stored directly in dir; no recursion into subdirectories is
275 * done.
277 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
279 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
280 dir->entries[dir->nr++] = entry;
281 /* optimize for the case that entries are added in order */
282 if (dir->nr == 1 ||
283 (dir->nr == dir->sorted + 1 &&
284 strcmp(dir->entries[dir->nr - 2]->name,
285 dir->entries[dir->nr - 1]->name) < 0))
286 dir->sorted = dir->nr;
290 * Clear and free all entries in dir, recursively.
292 static void clear_ref_dir(struct ref_dir *dir)
294 int i;
295 for (i = 0; i < dir->nr; i++)
296 free_ref_entry(dir->entries[i]);
297 free(dir->entries);
298 dir->sorted = dir->nr = dir->alloc = 0;
299 dir->entries = NULL;
303 * Create a struct ref_entry object for the specified dirname.
304 * dirname is the name of the directory with a trailing slash (e.g.,
305 * "refs/heads/") or "" for the top-level directory.
307 static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
308 const char *dirname, size_t len,
309 int incomplete)
311 struct ref_entry *direntry;
312 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
313 memcpy(direntry->name, dirname, len);
314 direntry->name[len] = '\0';
315 direntry->u.subdir.ref_cache = ref_cache;
316 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
317 return direntry;
320 static int ref_entry_cmp(const void *a, const void *b)
322 struct ref_entry *one = *(struct ref_entry **)a;
323 struct ref_entry *two = *(struct ref_entry **)b;
324 return strcmp(one->name, two->name);
327 static void sort_ref_dir(struct ref_dir *dir);
329 struct string_slice {
330 size_t len;
331 const char *str;
334 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
336 struct string_slice *key = (struct string_slice *)key_;
337 struct ref_entry *ent = *(struct ref_entry **)ent_;
338 int entlen = strlen(ent->name);
339 int cmplen = key->len < entlen ? key->len : entlen;
340 int cmp = memcmp(key->str, ent->name, cmplen);
341 if (cmp)
342 return cmp;
343 return key->len - entlen;
347 * Return the entry with the given refname from the ref_dir
348 * (non-recursively), sorting dir if necessary. Return NULL if no
349 * such entry is found. dir must already be complete.
351 static struct ref_entry *search_ref_dir(struct ref_dir *dir,
352 const char *refname, size_t len)
354 struct ref_entry **r;
355 struct string_slice key;
357 if (refname == NULL || !dir->nr)
358 return NULL;
360 sort_ref_dir(dir);
361 key.len = len;
362 key.str = refname;
363 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
364 ref_entry_cmp_sslice);
366 if (r == NULL)
367 return NULL;
369 return *r;
373 * Search for a directory entry directly within dir (without
374 * recursing). Sort dir if necessary. subdirname must be a directory
375 * name (i.e., end in '/'). If mkdir is set, then create the
376 * directory if it is missing; otherwise, return NULL if the desired
377 * directory cannot be found. dir must already be complete.
379 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
380 const char *subdirname, size_t len,
381 int mkdir)
383 struct ref_entry *entry = search_ref_dir(dir, subdirname, len);
384 if (!entry) {
385 if (!mkdir)
386 return NULL;
388 * Since dir is complete, the absence of a subdir
389 * means that the subdir really doesn't exist;
390 * therefore, create an empty record for it but mark
391 * the record complete.
393 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
394 add_entry_to_dir(dir, entry);
396 return get_ref_dir(entry);
400 * If refname is a reference name, find the ref_dir within the dir
401 * tree that should hold refname. If refname is a directory name
402 * (i.e., ends in '/'), then return that ref_dir itself. dir must
403 * represent the top-level directory and must already be complete.
404 * Sort ref_dirs and recurse into subdirectories as necessary. If
405 * mkdir is set, then create any missing directories; otherwise,
406 * return NULL if the desired directory cannot be found.
408 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
409 const char *refname, int mkdir)
411 const char *slash;
412 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
413 size_t dirnamelen = slash - refname + 1;
414 struct ref_dir *subdir;
415 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
416 if (!subdir) {
417 dir = NULL;
418 break;
420 dir = subdir;
423 return dir;
427 * Find the value entry with the given name in dir, sorting ref_dirs
428 * and recursing into subdirectories as necessary. If the name is not
429 * found or it corresponds to a directory entry, return NULL.
431 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
433 struct ref_entry *entry;
434 dir = find_containing_dir(dir, refname, 0);
435 if (!dir)
436 return NULL;
437 entry = search_ref_dir(dir, refname, strlen(refname));
438 return (entry && !(entry->flag & REF_DIR)) ? entry : NULL;
442 * Add a ref_entry to the ref_dir (unsorted), recursing into
443 * subdirectories as necessary. dir must represent the top-level
444 * directory. Return 0 on success.
446 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
448 dir = find_containing_dir(dir, ref->name, 1);
449 if (!dir)
450 return -1;
451 add_entry_to_dir(dir, ref);
452 return 0;
456 * Emit a warning and return true iff ref1 and ref2 have the same name
457 * and the same sha1. Die if they have the same name but different
458 * sha1s.
460 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
462 if (strcmp(ref1->name, ref2->name))
463 return 0;
465 /* Duplicate name; make sure that they don't conflict: */
467 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
468 /* This is impossible by construction */
469 die("Reference directory conflict: %s", ref1->name);
471 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
472 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
474 warning("Duplicated ref: %s", ref1->name);
475 return 1;
479 * Sort the entries in dir non-recursively (if they are not already
480 * sorted) and remove any duplicate entries.
482 static void sort_ref_dir(struct ref_dir *dir)
484 int i, j;
485 struct ref_entry *last = NULL;
488 * This check also prevents passing a zero-length array to qsort(),
489 * which is a problem on some platforms.
491 if (dir->sorted == dir->nr)
492 return;
494 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
496 /* Remove any duplicates: */
497 for (i = 0, j = 0; j < dir->nr; j++) {
498 struct ref_entry *entry = dir->entries[j];
499 if (last && is_dup_ref(last, entry))
500 free_ref_entry(entry);
501 else
502 last = dir->entries[i++] = entry;
504 dir->sorted = dir->nr = i;
507 #define DO_FOR_EACH_INCLUDE_BROKEN 01
509 static struct ref_entry *current_ref;
511 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
512 int flags, void *cb_data, struct ref_entry *entry)
514 int retval;
515 if (prefixcmp(entry->name, base))
516 return 0;
518 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
519 if (entry->flag & REF_ISBROKEN)
520 return 0; /* ignore broken refs e.g. dangling symref */
521 if (!has_sha1_file(entry->u.value.sha1)) {
522 error("%s does not point to a valid object!", entry->name);
523 return 0;
526 current_ref = entry;
527 retval = fn(entry->name + trim, entry->u.value.sha1, entry->flag, cb_data);
528 current_ref = NULL;
529 return retval;
533 * Call fn for each reference in dir that has index in the range
534 * offset <= index < dir->nr. Recurse into subdirectories that are in
535 * that index range, sorting them before iterating. This function
536 * does not sort dir itself; it should be sorted beforehand.
538 static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
539 const char *base,
540 each_ref_fn fn, int trim, int flags, void *cb_data)
542 int i;
543 assert(dir->sorted == dir->nr);
544 for (i = offset; i < dir->nr; i++) {
545 struct ref_entry *entry = dir->entries[i];
546 int retval;
547 if (entry->flag & REF_DIR) {
548 struct ref_dir *subdir = get_ref_dir(entry);
549 sort_ref_dir(subdir);
550 retval = do_for_each_ref_in_dir(subdir, 0,
551 base, fn, trim, flags, cb_data);
552 } else {
553 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
555 if (retval)
556 return retval;
558 return 0;
562 * Call fn for each reference in the union of dir1 and dir2, in order
563 * by refname. Recurse into subdirectories. If a value entry appears
564 * in both dir1 and dir2, then only process the version that is in
565 * dir2. The input dirs must already be sorted, but subdirs will be
566 * sorted as needed.
568 static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
569 struct ref_dir *dir2,
570 const char *base, each_ref_fn fn, int trim,
571 int flags, void *cb_data)
573 int retval;
574 int i1 = 0, i2 = 0;
576 assert(dir1->sorted == dir1->nr);
577 assert(dir2->sorted == dir2->nr);
578 while (1) {
579 struct ref_entry *e1, *e2;
580 int cmp;
581 if (i1 == dir1->nr) {
582 return do_for_each_ref_in_dir(dir2, i2,
583 base, fn, trim, flags, cb_data);
585 if (i2 == dir2->nr) {
586 return do_for_each_ref_in_dir(dir1, i1,
587 base, fn, trim, flags, cb_data);
589 e1 = dir1->entries[i1];
590 e2 = dir2->entries[i2];
591 cmp = strcmp(e1->name, e2->name);
592 if (cmp == 0) {
593 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
594 /* Both are directories; descend them in parallel. */
595 struct ref_dir *subdir1 = get_ref_dir(e1);
596 struct ref_dir *subdir2 = get_ref_dir(e2);
597 sort_ref_dir(subdir1);
598 sort_ref_dir(subdir2);
599 retval = do_for_each_ref_in_dirs(
600 subdir1, subdir2,
601 base, fn, trim, flags, cb_data);
602 i1++;
603 i2++;
604 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
605 /* Both are references; ignore the one from dir1. */
606 retval = do_one_ref(base, fn, trim, flags, cb_data, e2);
607 i1++;
608 i2++;
609 } else {
610 die("conflict between reference and directory: %s",
611 e1->name);
613 } else {
614 struct ref_entry *e;
615 if (cmp < 0) {
616 e = e1;
617 i1++;
618 } else {
619 e = e2;
620 i2++;
622 if (e->flag & REF_DIR) {
623 struct ref_dir *subdir = get_ref_dir(e);
624 sort_ref_dir(subdir);
625 retval = do_for_each_ref_in_dir(
626 subdir, 0,
627 base, fn, trim, flags, cb_data);
628 } else {
629 retval = do_one_ref(base, fn, trim, flags, cb_data, e);
632 if (retval)
633 return retval;
635 if (i1 < dir1->nr)
636 return do_for_each_ref_in_dir(dir1, i1,
637 base, fn, trim, flags, cb_data);
638 if (i2 < dir2->nr)
639 return do_for_each_ref_in_dir(dir2, i2,
640 base, fn, trim, flags, cb_data);
641 return 0;
645 * Return true iff refname1 and refname2 conflict with each other.
646 * Two reference names conflict if one of them exactly matches the
647 * leading components of the other; e.g., "foo/bar" conflicts with
648 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
649 * "foo/barbados".
651 static int names_conflict(const char *refname1, const char *refname2)
653 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
655 return (*refname1 == '\0' && *refname2 == '/')
656 || (*refname1 == '/' && *refname2 == '\0');
659 struct name_conflict_cb {
660 const char *refname;
661 const char *oldrefname;
662 const char *conflicting_refname;
665 static int name_conflict_fn(const char *existingrefname, const unsigned char *sha1,
666 int flags, void *cb_data)
668 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
669 if (data->oldrefname && !strcmp(data->oldrefname, existingrefname))
670 return 0;
671 if (names_conflict(data->refname, existingrefname)) {
672 data->conflicting_refname = existingrefname;
673 return 1;
675 return 0;
679 * Return true iff a reference named refname could be created without
680 * conflicting with the name of an existing reference in array. If
681 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
682 * (e.g., because oldrefname is scheduled for deletion in the same
683 * operation).
685 static int is_refname_available(const char *refname, const char *oldrefname,
686 struct ref_dir *dir)
688 struct name_conflict_cb data;
689 data.refname = refname;
690 data.oldrefname = oldrefname;
691 data.conflicting_refname = NULL;
693 sort_ref_dir(dir);
694 if (do_for_each_ref_in_dir(dir, 0, "", name_conflict_fn,
695 0, DO_FOR_EACH_INCLUDE_BROKEN,
696 &data)) {
697 error("'%s' exists; cannot create '%s'",
698 data.conflicting_refname, refname);
699 return 0;
701 return 1;
705 * Future: need to be in "struct repository"
706 * when doing a full libification.
708 static struct ref_cache {
709 struct ref_cache *next;
710 struct ref_entry *loose;
711 struct ref_entry *packed;
712 /* The submodule name, or "" for the main repo. */
713 char name[FLEX_ARRAY];
714 } *ref_cache;
716 static void clear_packed_ref_cache(struct ref_cache *refs)
718 if (refs->packed) {
719 free_ref_entry(refs->packed);
720 refs->packed = NULL;
724 static void clear_loose_ref_cache(struct ref_cache *refs)
726 if (refs->loose) {
727 free_ref_entry(refs->loose);
728 refs->loose = NULL;
732 static struct ref_cache *create_ref_cache(const char *submodule)
734 int len;
735 struct ref_cache *refs;
736 if (!submodule)
737 submodule = "";
738 len = strlen(submodule) + 1;
739 refs = xcalloc(1, sizeof(struct ref_cache) + len);
740 memcpy(refs->name, submodule, len);
741 return refs;
745 * Return a pointer to a ref_cache for the specified submodule. For
746 * the main repository, use submodule==NULL. The returned structure
747 * will be allocated and initialized but not necessarily populated; it
748 * should not be freed.
750 static struct ref_cache *get_ref_cache(const char *submodule)
752 struct ref_cache *refs = ref_cache;
753 if (!submodule)
754 submodule = "";
755 while (refs) {
756 if (!strcmp(submodule, refs->name))
757 return refs;
758 refs = refs->next;
761 refs = create_ref_cache(submodule);
762 refs->next = ref_cache;
763 ref_cache = refs;
764 return refs;
767 void invalidate_ref_cache(const char *submodule)
769 struct ref_cache *refs = get_ref_cache(submodule);
770 clear_packed_ref_cache(refs);
771 clear_loose_ref_cache(refs);
775 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
776 * Return a pointer to the refname within the line (null-terminated),
777 * or NULL if there was a problem.
779 static const char *parse_ref_line(char *line, unsigned char *sha1)
782 * 42: the answer to everything.
784 * In this case, it happens to be the answer to
785 * 40 (length of sha1 hex representation)
786 * +1 (space in between hex and name)
787 * +1 (newline at the end of the line)
789 int len = strlen(line) - 42;
791 if (len <= 0)
792 return NULL;
793 if (get_sha1_hex(line, sha1) < 0)
794 return NULL;
795 if (!isspace(line[40]))
796 return NULL;
797 line += 41;
798 if (isspace(*line))
799 return NULL;
800 if (line[len] != '\n')
801 return NULL;
802 line[len] = 0;
804 return line;
807 static void read_packed_refs(FILE *f, struct ref_dir *dir)
809 struct ref_entry *last = NULL;
810 char refline[PATH_MAX];
811 int flag = REF_ISPACKED;
813 while (fgets(refline, sizeof(refline), f)) {
814 unsigned char sha1[20];
815 const char *refname;
816 static const char header[] = "# pack-refs with:";
818 if (!strncmp(refline, header, sizeof(header)-1)) {
819 const char *traits = refline + sizeof(header) - 1;
820 if (strstr(traits, " peeled "))
821 flag |= REF_KNOWS_PEELED;
822 /* perhaps other traits later as well */
823 continue;
826 refname = parse_ref_line(refline, sha1);
827 if (refname) {
828 last = create_ref_entry(refname, sha1, flag, 1);
829 add_ref(dir, last);
830 continue;
832 if (last &&
833 refline[0] == '^' &&
834 strlen(refline) == 42 &&
835 refline[41] == '\n' &&
836 !get_sha1_hex(refline + 1, sha1))
837 hashcpy(last->u.value.peeled, sha1);
841 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
843 if (!refs->packed) {
844 const char *packed_refs_file;
845 FILE *f;
847 refs->packed = create_dir_entry(refs, "", 0, 0);
848 if (*refs->name)
849 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
850 else
851 packed_refs_file = git_path("packed-refs");
852 f = fopen(packed_refs_file, "r");
853 if (f) {
854 read_packed_refs(f, get_ref_dir(refs->packed));
855 fclose(f);
858 return get_ref_dir(refs->packed);
861 void add_packed_ref(const char *refname, const unsigned char *sha1)
863 add_ref(get_packed_refs(get_ref_cache(NULL)),
864 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
868 * Read the loose references from the namespace dirname into dir
869 * (without recursing). dirname must end with '/'. dir must be the
870 * directory entry corresponding to dirname.
872 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
874 struct ref_cache *refs = dir->ref_cache;
875 DIR *d;
876 const char *path;
877 struct dirent *de;
878 int dirnamelen = strlen(dirname);
879 struct strbuf refname;
881 if (*refs->name)
882 path = git_path_submodule(refs->name, "%s", dirname);
883 else
884 path = git_path("%s", dirname);
886 d = opendir(path);
887 if (!d)
888 return;
890 strbuf_init(&refname, dirnamelen + 257);
891 strbuf_add(&refname, dirname, dirnamelen);
893 while ((de = readdir(d)) != NULL) {
894 unsigned char sha1[20];
895 struct stat st;
896 int flag;
897 const char *refdir;
899 if (de->d_name[0] == '.')
900 continue;
901 if (has_extension(de->d_name, ".lock"))
902 continue;
903 strbuf_addstr(&refname, de->d_name);
904 refdir = *refs->name
905 ? git_path_submodule(refs->name, "%s", refname.buf)
906 : git_path("%s", refname.buf);
907 if (stat(refdir, &st) < 0) {
908 ; /* silently ignore */
909 } else if (S_ISDIR(st.st_mode)) {
910 strbuf_addch(&refname, '/');
911 add_entry_to_dir(dir,
912 create_dir_entry(refs, refname.buf,
913 refname.len, 1));
914 } else {
915 if (*refs->name) {
916 hashclr(sha1);
917 flag = 0;
918 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
919 hashclr(sha1);
920 flag |= REF_ISBROKEN;
922 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
923 hashclr(sha1);
924 flag |= REF_ISBROKEN;
926 add_entry_to_dir(dir,
927 create_ref_entry(refname.buf, sha1, flag, 1));
929 strbuf_setlen(&refname, dirnamelen);
931 strbuf_release(&refname);
932 closedir(d);
935 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
937 if (!refs->loose) {
939 * Mark the top-level directory complete because we
940 * are about to read the only subdirectory that can
941 * hold references:
943 refs->loose = create_dir_entry(refs, "", 0, 0);
945 * Create an incomplete entry for "refs/":
947 add_entry_to_dir(get_ref_dir(refs->loose),
948 create_dir_entry(refs, "refs/", 5, 1));
950 return get_ref_dir(refs->loose);
953 /* We allow "recursive" symbolic refs. Only within reason, though */
954 #define MAXDEPTH 5
955 #define MAXREFLEN (1024)
958 * Called by resolve_gitlink_ref_recursive() after it failed to read
959 * from the loose refs in ref_cache refs. Find <refname> in the
960 * packed-refs file for the submodule.
962 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
963 const char *refname, unsigned char *sha1)
965 struct ref_entry *ref;
966 struct ref_dir *dir = get_packed_refs(refs);
968 ref = find_ref(dir, refname);
969 if (ref == NULL)
970 return -1;
972 memcpy(sha1, ref->u.value.sha1, 20);
973 return 0;
976 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
977 const char *refname, unsigned char *sha1,
978 int recursion)
980 int fd, len;
981 char buffer[128], *p;
982 char *path;
984 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
985 return -1;
986 path = *refs->name
987 ? git_path_submodule(refs->name, "%s", refname)
988 : git_path("%s", refname);
989 fd = open(path, O_RDONLY);
990 if (fd < 0)
991 return resolve_gitlink_packed_ref(refs, refname, sha1);
993 len = read(fd, buffer, sizeof(buffer)-1);
994 close(fd);
995 if (len < 0)
996 return -1;
997 while (len && isspace(buffer[len-1]))
998 len--;
999 buffer[len] = 0;
1001 /* Was it a detached head or an old-fashioned symlink? */
1002 if (!get_sha1_hex(buffer, sha1))
1003 return 0;
1005 /* Symref? */
1006 if (strncmp(buffer, "ref:", 4))
1007 return -1;
1008 p = buffer + 4;
1009 while (isspace(*p))
1010 p++;
1012 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1015 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1017 int len = strlen(path), retval;
1018 char *submodule;
1019 struct ref_cache *refs;
1021 while (len && path[len-1] == '/')
1022 len--;
1023 if (!len)
1024 return -1;
1025 submodule = xstrndup(path, len);
1026 refs = get_ref_cache(submodule);
1027 free(submodule);
1029 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1030 return retval;
1034 * Try to read ref from the packed references. On success, set sha1
1035 * and return 0; otherwise, return -1.
1037 static int get_packed_ref(const char *refname, unsigned char *sha1)
1039 struct ref_dir *packed = get_packed_refs(get_ref_cache(NULL));
1040 struct ref_entry *entry = find_ref(packed, refname);
1041 if (entry) {
1042 hashcpy(sha1, entry->u.value.sha1);
1043 return 0;
1045 return -1;
1048 const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
1050 int depth = MAXDEPTH;
1051 ssize_t len;
1052 char buffer[256];
1053 static char refname_buffer[256];
1055 if (flag)
1056 *flag = 0;
1058 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1059 return NULL;
1061 for (;;) {
1062 char path[PATH_MAX];
1063 struct stat st;
1064 char *buf;
1065 int fd;
1067 if (--depth < 0)
1068 return NULL;
1070 git_snpath(path, sizeof(path), "%s", refname);
1072 if (lstat(path, &st) < 0) {
1073 if (errno != ENOENT)
1074 return NULL;
1076 * The loose reference file does not exist;
1077 * check for a packed reference.
1079 if (!get_packed_ref(refname, sha1)) {
1080 if (flag)
1081 *flag |= REF_ISPACKED;
1082 return refname;
1084 /* The reference is not a packed reference, either. */
1085 if (reading) {
1086 return NULL;
1087 } else {
1088 hashclr(sha1);
1089 return refname;
1093 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1094 if (S_ISLNK(st.st_mode)) {
1095 len = readlink(path, buffer, sizeof(buffer)-1);
1096 if (len < 0)
1097 return NULL;
1098 buffer[len] = 0;
1099 if (!prefixcmp(buffer, "refs/") &&
1100 !check_refname_format(buffer, 0)) {
1101 strcpy(refname_buffer, buffer);
1102 refname = refname_buffer;
1103 if (flag)
1104 *flag |= REF_ISSYMREF;
1105 continue;
1109 /* Is it a directory? */
1110 if (S_ISDIR(st.st_mode)) {
1111 errno = EISDIR;
1112 return NULL;
1116 * Anything else, just open it and try to use it as
1117 * a ref
1119 fd = open(path, O_RDONLY);
1120 if (fd < 0)
1121 return NULL;
1122 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1123 close(fd);
1124 if (len < 0)
1125 return NULL;
1126 while (len && isspace(buffer[len-1]))
1127 len--;
1128 buffer[len] = '\0';
1131 * Is it a symbolic ref?
1133 if (prefixcmp(buffer, "ref:"))
1134 break;
1135 if (flag)
1136 *flag |= REF_ISSYMREF;
1137 buf = buffer + 4;
1138 while (isspace(*buf))
1139 buf++;
1140 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1141 if (flag)
1142 *flag |= REF_ISBROKEN;
1143 return NULL;
1145 refname = strcpy(refname_buffer, buf);
1147 /* Please note that FETCH_HEAD has a second line containing other data. */
1148 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
1149 if (flag)
1150 *flag |= REF_ISBROKEN;
1151 return NULL;
1153 return refname;
1156 char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1158 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
1159 return ret ? xstrdup(ret) : NULL;
1162 /* The argument to filter_refs */
1163 struct ref_filter {
1164 const char *pattern;
1165 each_ref_fn *fn;
1166 void *cb_data;
1169 int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
1171 if (resolve_ref_unsafe(refname, sha1, reading, flags))
1172 return 0;
1173 return -1;
1176 int read_ref(const char *refname, unsigned char *sha1)
1178 return read_ref_full(refname, sha1, 1, NULL);
1181 int ref_exists(const char *refname)
1183 unsigned char sha1[20];
1184 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
1187 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1188 void *data)
1190 struct ref_filter *filter = (struct ref_filter *)data;
1191 if (fnmatch(filter->pattern, refname, 0))
1192 return 0;
1193 return filter->fn(refname, sha1, flags, filter->cb_data);
1196 int peel_ref(const char *refname, unsigned char *sha1)
1198 int flag;
1199 unsigned char base[20];
1200 struct object *o;
1202 if (current_ref && (current_ref->name == refname
1203 || !strcmp(current_ref->name, refname))) {
1204 if (current_ref->flag & REF_KNOWS_PEELED) {
1205 if (is_null_sha1(current_ref->u.value.peeled))
1206 return -1;
1207 hashcpy(sha1, current_ref->u.value.peeled);
1208 return 0;
1210 hashcpy(base, current_ref->u.value.sha1);
1211 goto fallback;
1214 if (read_ref_full(refname, base, 1, &flag))
1215 return -1;
1217 if ((flag & REF_ISPACKED)) {
1218 struct ref_dir *dir = get_packed_refs(get_ref_cache(NULL));
1219 struct ref_entry *r = find_ref(dir, refname);
1221 if (r != NULL && r->flag & REF_KNOWS_PEELED) {
1222 hashcpy(sha1, r->u.value.peeled);
1223 return 0;
1227 fallback:
1228 o = lookup_unknown_object(base);
1229 if (o->type == OBJ_NONE) {
1230 int type = sha1_object_info(base, NULL);
1231 if (type < 0)
1232 return -1;
1233 o->type = type;
1236 if (o->type == OBJ_TAG) {
1237 o = deref_tag_noverify(o);
1238 if (o) {
1239 hashcpy(sha1, o->sha1);
1240 return 0;
1243 return -1;
1246 struct warn_if_dangling_data {
1247 FILE *fp;
1248 const char *refname;
1249 const char *msg_fmt;
1252 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1253 int flags, void *cb_data)
1255 struct warn_if_dangling_data *d = cb_data;
1256 const char *resolves_to;
1257 unsigned char junk[20];
1259 if (!(flags & REF_ISSYMREF))
1260 return 0;
1262 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1263 if (!resolves_to || strcmp(resolves_to, d->refname))
1264 return 0;
1266 fprintf(d->fp, d->msg_fmt, refname);
1267 fputc('\n', d->fp);
1268 return 0;
1271 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1273 struct warn_if_dangling_data data;
1275 data.fp = fp;
1276 data.refname = refname;
1277 data.msg_fmt = msg_fmt;
1278 for_each_rawref(warn_if_dangling_symref, &data);
1281 static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
1282 int trim, int flags, void *cb_data)
1284 struct ref_cache *refs = get_ref_cache(submodule);
1285 struct ref_dir *packed_dir = get_packed_refs(refs);
1286 struct ref_dir *loose_dir = get_loose_refs(refs);
1287 int retval = 0;
1289 if (base && *base) {
1290 packed_dir = find_containing_dir(packed_dir, base, 0);
1291 loose_dir = find_containing_dir(loose_dir, base, 0);
1294 if (packed_dir && loose_dir) {
1295 sort_ref_dir(packed_dir);
1296 sort_ref_dir(loose_dir);
1297 retval = do_for_each_ref_in_dirs(
1298 packed_dir, loose_dir,
1299 base, fn, trim, flags, cb_data);
1300 } else if (packed_dir) {
1301 sort_ref_dir(packed_dir);
1302 retval = do_for_each_ref_in_dir(
1303 packed_dir, 0,
1304 base, fn, trim, flags, cb_data);
1305 } else if (loose_dir) {
1306 sort_ref_dir(loose_dir);
1307 retval = do_for_each_ref_in_dir(
1308 loose_dir, 0,
1309 base, fn, trim, flags, cb_data);
1312 return retval;
1315 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1317 unsigned char sha1[20];
1318 int flag;
1320 if (submodule) {
1321 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1322 return fn("HEAD", sha1, 0, cb_data);
1324 return 0;
1327 if (!read_ref_full("HEAD", sha1, 1, &flag))
1328 return fn("HEAD", sha1, flag, cb_data);
1330 return 0;
1333 int head_ref(each_ref_fn fn, void *cb_data)
1335 return do_head_ref(NULL, fn, cb_data);
1338 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1340 return do_head_ref(submodule, fn, cb_data);
1343 int for_each_ref(each_ref_fn fn, void *cb_data)
1345 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
1348 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1350 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
1353 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1355 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
1358 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1359 each_ref_fn fn, void *cb_data)
1361 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
1364 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1366 return for_each_ref_in("refs/tags/", fn, cb_data);
1369 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1371 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1374 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1376 return for_each_ref_in("refs/heads/", fn, cb_data);
1379 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1381 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1384 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1386 return for_each_ref_in("refs/remotes/", fn, cb_data);
1389 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1391 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1394 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1396 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
1399 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1401 struct strbuf buf = STRBUF_INIT;
1402 int ret = 0;
1403 unsigned char sha1[20];
1404 int flag;
1406 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
1407 if (!read_ref_full(buf.buf, sha1, 1, &flag))
1408 ret = fn(buf.buf, sha1, flag, cb_data);
1409 strbuf_release(&buf);
1411 return ret;
1414 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1416 struct strbuf buf = STRBUF_INIT;
1417 int ret;
1418 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1419 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1420 strbuf_release(&buf);
1421 return ret;
1424 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1425 const char *prefix, void *cb_data)
1427 struct strbuf real_pattern = STRBUF_INIT;
1428 struct ref_filter filter;
1429 int ret;
1431 if (!prefix && prefixcmp(pattern, "refs/"))
1432 strbuf_addstr(&real_pattern, "refs/");
1433 else if (prefix)
1434 strbuf_addstr(&real_pattern, prefix);
1435 strbuf_addstr(&real_pattern, pattern);
1437 if (!has_glob_specials(pattern)) {
1438 /* Append implied '/' '*' if not present. */
1439 if (real_pattern.buf[real_pattern.len - 1] != '/')
1440 strbuf_addch(&real_pattern, '/');
1441 /* No need to check for '*', there is none. */
1442 strbuf_addch(&real_pattern, '*');
1445 filter.pattern = real_pattern.buf;
1446 filter.fn = fn;
1447 filter.cb_data = cb_data;
1448 ret = for_each_ref(filter_refs, &filter);
1450 strbuf_release(&real_pattern);
1451 return ret;
1454 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1456 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1459 int for_each_rawref(each_ref_fn fn, void *cb_data)
1461 return do_for_each_ref(NULL, "", fn, 0,
1462 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1465 const char *prettify_refname(const char *name)
1467 return name + (
1468 !prefixcmp(name, "refs/heads/") ? 11 :
1469 !prefixcmp(name, "refs/tags/") ? 10 :
1470 !prefixcmp(name, "refs/remotes/") ? 13 :
1474 const char *ref_rev_parse_rules[] = {
1475 "%.*s",
1476 "refs/%.*s",
1477 "refs/tags/%.*s",
1478 "refs/heads/%.*s",
1479 "refs/remotes/%.*s",
1480 "refs/remotes/%.*s/HEAD",
1481 NULL
1484 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1486 const char **p;
1487 const int abbrev_name_len = strlen(abbrev_name);
1489 for (p = rules; *p; p++) {
1490 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1491 return 1;
1495 return 0;
1498 static struct ref_lock *verify_lock(struct ref_lock *lock,
1499 const unsigned char *old_sha1, int mustexist)
1501 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
1502 error("Can't verify ref %s", lock->ref_name);
1503 unlock_ref(lock);
1504 return NULL;
1506 if (hashcmp(lock->old_sha1, old_sha1)) {
1507 error("Ref %s is at %s but expected %s", lock->ref_name,
1508 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1509 unlock_ref(lock);
1510 return NULL;
1512 return lock;
1515 static int remove_empty_directories(const char *file)
1517 /* we want to create a file but there is a directory there;
1518 * if that is an empty directory (or a directory that contains
1519 * only empty directories), remove them.
1521 struct strbuf path;
1522 int result;
1524 strbuf_init(&path, 20);
1525 strbuf_addstr(&path, file);
1527 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
1529 strbuf_release(&path);
1531 return result;
1535 * *string and *len will only be substituted, and *string returned (for
1536 * later free()ing) if the string passed in is a magic short-hand form
1537 * to name a branch.
1539 static char *substitute_branch_name(const char **string, int *len)
1541 struct strbuf buf = STRBUF_INIT;
1542 int ret = interpret_branch_name(*string, &buf);
1544 if (ret == *len) {
1545 size_t size;
1546 *string = strbuf_detach(&buf, &size);
1547 *len = size;
1548 return (char *)*string;
1551 return NULL;
1554 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1556 char *last_branch = substitute_branch_name(&str, &len);
1557 const char **p, *r;
1558 int refs_found = 0;
1560 *ref = NULL;
1561 for (p = ref_rev_parse_rules; *p; p++) {
1562 char fullref[PATH_MAX];
1563 unsigned char sha1_from_ref[20];
1564 unsigned char *this_result;
1565 int flag;
1567 this_result = refs_found ? sha1_from_ref : sha1;
1568 mksnpath(fullref, sizeof(fullref), *p, len, str);
1569 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
1570 if (r) {
1571 if (!refs_found++)
1572 *ref = xstrdup(r);
1573 if (!warn_ambiguous_refs)
1574 break;
1575 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
1576 warning("ignoring dangling symref %s.", fullref);
1577 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1578 warning("ignoring broken ref %s.", fullref);
1581 free(last_branch);
1582 return refs_found;
1585 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1587 char *last_branch = substitute_branch_name(&str, &len);
1588 const char **p;
1589 int logs_found = 0;
1591 *log = NULL;
1592 for (p = ref_rev_parse_rules; *p; p++) {
1593 struct stat st;
1594 unsigned char hash[20];
1595 char path[PATH_MAX];
1596 const char *ref, *it;
1598 mksnpath(path, sizeof(path), *p, len, str);
1599 ref = resolve_ref_unsafe(path, hash, 1, NULL);
1600 if (!ref)
1601 continue;
1602 if (!stat(git_path("logs/%s", path), &st) &&
1603 S_ISREG(st.st_mode))
1604 it = path;
1605 else if (strcmp(ref, path) &&
1606 !stat(git_path("logs/%s", ref), &st) &&
1607 S_ISREG(st.st_mode))
1608 it = ref;
1609 else
1610 continue;
1611 if (!logs_found++) {
1612 *log = xstrdup(it);
1613 hashcpy(sha1, hash);
1615 if (!warn_ambiguous_refs)
1616 break;
1618 free(last_branch);
1619 return logs_found;
1622 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1623 const unsigned char *old_sha1,
1624 int flags, int *type_p)
1626 char *ref_file;
1627 const char *orig_refname = refname;
1628 struct ref_lock *lock;
1629 int last_errno = 0;
1630 int type, lflags;
1631 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1632 int missing = 0;
1634 lock = xcalloc(1, sizeof(struct ref_lock));
1635 lock->lock_fd = -1;
1637 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
1638 if (!refname && errno == EISDIR) {
1639 /* we are trying to lock foo but we used to
1640 * have foo/bar which now does not exist;
1641 * it is normal for the empty directory 'foo'
1642 * to remain.
1644 ref_file = git_path("%s", orig_refname);
1645 if (remove_empty_directories(ref_file)) {
1646 last_errno = errno;
1647 error("there are still refs under '%s'", orig_refname);
1648 goto error_return;
1650 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
1652 if (type_p)
1653 *type_p = type;
1654 if (!refname) {
1655 last_errno = errno;
1656 error("unable to resolve reference %s: %s",
1657 orig_refname, strerror(errno));
1658 goto error_return;
1660 missing = is_null_sha1(lock->old_sha1);
1661 /* When the ref did not exist and we are creating it,
1662 * make sure there is no existing ref that is packed
1663 * whose name begins with our refname, nor a ref whose
1664 * name is a proper prefix of our refname.
1666 if (missing &&
1667 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
1668 last_errno = ENOTDIR;
1669 goto error_return;
1672 lock->lk = xcalloc(1, sizeof(struct lock_file));
1674 lflags = LOCK_DIE_ON_ERROR;
1675 if (flags & REF_NODEREF) {
1676 refname = orig_refname;
1677 lflags |= LOCK_NODEREF;
1679 lock->ref_name = xstrdup(refname);
1680 lock->orig_ref_name = xstrdup(orig_refname);
1681 ref_file = git_path("%s", refname);
1682 if (missing)
1683 lock->force_write = 1;
1684 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1685 lock->force_write = 1;
1687 if (safe_create_leading_directories(ref_file)) {
1688 last_errno = errno;
1689 error("unable to create directory for %s", ref_file);
1690 goto error_return;
1693 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
1694 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
1696 error_return:
1697 unlock_ref(lock);
1698 errno = last_errno;
1699 return NULL;
1702 struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
1704 char refpath[PATH_MAX];
1705 if (check_refname_format(refname, 0))
1706 return NULL;
1707 strcpy(refpath, mkpath("refs/%s", refname));
1708 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
1711 struct ref_lock *lock_any_ref_for_update(const char *refname,
1712 const unsigned char *old_sha1, int flags)
1714 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1715 return NULL;
1716 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
1719 struct repack_without_ref_sb {
1720 const char *refname;
1721 int fd;
1724 static int repack_without_ref_fn(const char *refname, const unsigned char *sha1,
1725 int flags, void *cb_data)
1727 struct repack_without_ref_sb *data = cb_data;
1728 char line[PATH_MAX + 100];
1729 int len;
1731 if (!strcmp(data->refname, refname))
1732 return 0;
1733 len = snprintf(line, sizeof(line), "%s %s\n",
1734 sha1_to_hex(sha1), refname);
1735 /* this should not happen but just being defensive */
1736 if (len > sizeof(line))
1737 die("too long a refname '%s'", refname);
1738 write_or_die(data->fd, line, len);
1739 return 0;
1742 static struct lock_file packlock;
1744 static int repack_without_ref(const char *refname)
1746 struct repack_without_ref_sb data;
1747 struct ref_dir *packed = get_packed_refs(get_ref_cache(NULL));
1748 if (find_ref(packed, refname) == NULL)
1749 return 0;
1750 data.refname = refname;
1751 data.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1752 if (data.fd < 0) {
1753 unable_to_lock_error(git_path("packed-refs"), errno);
1754 return error("cannot delete '%s' from packed refs", refname);
1756 do_for_each_ref_in_dir(packed, 0, "", repack_without_ref_fn, 0, 0, &data);
1757 return commit_lock_file(&packlock);
1760 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
1762 struct ref_lock *lock;
1763 int err, i = 0, ret = 0, flag = 0;
1765 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
1766 if (!lock)
1767 return 1;
1768 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
1769 /* loose */
1770 const char *path;
1772 if (!(delopt & REF_NODEREF)) {
1773 i = strlen(lock->lk->filename) - 5; /* .lock */
1774 lock->lk->filename[i] = 0;
1775 path = lock->lk->filename;
1776 } else {
1777 path = git_path("%s", refname);
1779 err = unlink_or_warn(path);
1780 if (err && errno != ENOENT)
1781 ret = 1;
1783 if (!(delopt & REF_NODEREF))
1784 lock->lk->filename[i] = '.';
1786 /* removing the loose one could have resurrected an earlier
1787 * packed one. Also, if it was not loose we need to repack
1788 * without it.
1790 ret |= repack_without_ref(refname);
1792 unlink_or_warn(git_path("logs/%s", lock->ref_name));
1793 invalidate_ref_cache(NULL);
1794 unlock_ref(lock);
1795 return ret;
1799 * People using contrib's git-new-workdir have .git/logs/refs ->
1800 * /some/other/path/.git/logs/refs, and that may live on another device.
1802 * IOW, to avoid cross device rename errors, the temporary renamed log must
1803 * live into logs/refs.
1805 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1807 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
1809 unsigned char sha1[20], orig_sha1[20];
1810 int flag = 0, logmoved = 0;
1811 struct ref_lock *lock;
1812 struct stat loginfo;
1813 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
1814 const char *symref = NULL;
1815 struct ref_cache *refs = get_ref_cache(NULL);
1817 if (log && S_ISLNK(loginfo.st_mode))
1818 return error("reflog for %s is a symlink", oldrefname);
1820 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
1821 if (flag & REF_ISSYMREF)
1822 return error("refname %s is a symbolic ref, renaming it is not supported",
1823 oldrefname);
1824 if (!symref)
1825 return error("refname %s not found", oldrefname);
1827 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
1828 return 1;
1830 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
1831 return 1;
1833 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
1834 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
1835 oldrefname, strerror(errno));
1837 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
1838 error("unable to delete old %s", oldrefname);
1839 goto rollback;
1842 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
1843 delete_ref(newrefname, sha1, REF_NODEREF)) {
1844 if (errno==EISDIR) {
1845 if (remove_empty_directories(git_path("%s", newrefname))) {
1846 error("Directory not empty: %s", newrefname);
1847 goto rollback;
1849 } else {
1850 error("unable to delete existing %s", newrefname);
1851 goto rollback;
1855 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
1856 error("unable to create directory for %s", newrefname);
1857 goto rollback;
1860 retry:
1861 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
1862 if (errno==EISDIR || errno==ENOTDIR) {
1864 * rename(a, b) when b is an existing
1865 * directory ought to result in ISDIR, but
1866 * Solaris 5.8 gives ENOTDIR. Sheesh.
1868 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
1869 error("Directory not empty: logs/%s", newrefname);
1870 goto rollback;
1872 goto retry;
1873 } else {
1874 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
1875 newrefname, strerror(errno));
1876 goto rollback;
1879 logmoved = log;
1881 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
1882 if (!lock) {
1883 error("unable to lock %s for update", newrefname);
1884 goto rollback;
1886 lock->force_write = 1;
1887 hashcpy(lock->old_sha1, orig_sha1);
1888 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1889 error("unable to write current sha1 into %s", newrefname);
1890 goto rollback;
1893 return 0;
1895 rollback:
1896 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
1897 if (!lock) {
1898 error("unable to lock %s for rollback", oldrefname);
1899 goto rollbacklog;
1902 lock->force_write = 1;
1903 flag = log_all_ref_updates;
1904 log_all_ref_updates = 0;
1905 if (write_ref_sha1(lock, orig_sha1, NULL))
1906 error("unable to write current sha1 into %s", oldrefname);
1907 log_all_ref_updates = flag;
1909 rollbacklog:
1910 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
1911 error("unable to restore logfile %s from %s: %s",
1912 oldrefname, newrefname, strerror(errno));
1913 if (!logmoved && log &&
1914 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
1915 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
1916 oldrefname, strerror(errno));
1918 return 1;
1921 int close_ref(struct ref_lock *lock)
1923 if (close_lock_file(lock->lk))
1924 return -1;
1925 lock->lock_fd = -1;
1926 return 0;
1929 int commit_ref(struct ref_lock *lock)
1931 if (commit_lock_file(lock->lk))
1932 return -1;
1933 lock->lock_fd = -1;
1934 return 0;
1937 void unlock_ref(struct ref_lock *lock)
1939 /* Do not free lock->lk -- atexit() still looks at them */
1940 if (lock->lk)
1941 rollback_lock_file(lock->lk);
1942 free(lock->ref_name);
1943 free(lock->orig_ref_name);
1944 free(lock);
1948 * copy the reflog message msg to buf, which has been allocated sufficiently
1949 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1950 * because reflog file is one line per entry.
1952 static int copy_msg(char *buf, const char *msg)
1954 char *cp = buf;
1955 char c;
1956 int wasspace = 1;
1958 *cp++ = '\t';
1959 while ((c = *msg++)) {
1960 if (wasspace && isspace(c))
1961 continue;
1962 wasspace = isspace(c);
1963 if (wasspace)
1964 c = ' ';
1965 *cp++ = c;
1967 while (buf < cp && isspace(cp[-1]))
1968 cp--;
1969 *cp++ = '\n';
1970 return cp - buf;
1973 int log_ref_setup(const char *refname, char *logfile, int bufsize)
1975 int logfd, oflags = O_APPEND | O_WRONLY;
1977 git_snpath(logfile, bufsize, "logs/%s", refname);
1978 if (log_all_ref_updates &&
1979 (!prefixcmp(refname, "refs/heads/") ||
1980 !prefixcmp(refname, "refs/remotes/") ||
1981 !prefixcmp(refname, "refs/notes/") ||
1982 !strcmp(refname, "HEAD"))) {
1983 if (safe_create_leading_directories(logfile) < 0)
1984 return error("unable to create directory for %s",
1985 logfile);
1986 oflags |= O_CREAT;
1989 logfd = open(logfile, oflags, 0666);
1990 if (logfd < 0) {
1991 if (!(oflags & O_CREAT) && errno == ENOENT)
1992 return 0;
1994 if ((oflags & O_CREAT) && errno == EISDIR) {
1995 if (remove_empty_directories(logfile)) {
1996 return error("There are still logs under '%s'",
1997 logfile);
1999 logfd = open(logfile, oflags, 0666);
2002 if (logfd < 0)
2003 return error("Unable to append to %s: %s",
2004 logfile, strerror(errno));
2007 adjust_shared_perm(logfile);
2008 close(logfd);
2009 return 0;
2012 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2013 const unsigned char *new_sha1, const char *msg)
2015 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2016 unsigned maxlen, len;
2017 int msglen;
2018 char log_file[PATH_MAX];
2019 char *logrec;
2020 const char *committer;
2022 if (log_all_ref_updates < 0)
2023 log_all_ref_updates = !is_bare_repository();
2025 result = log_ref_setup(refname, log_file, sizeof(log_file));
2026 if (result)
2027 return result;
2029 logfd = open(log_file, oflags);
2030 if (logfd < 0)
2031 return 0;
2032 msglen = msg ? strlen(msg) : 0;
2033 committer = git_committer_info(0);
2034 maxlen = strlen(committer) + msglen + 100;
2035 logrec = xmalloc(maxlen);
2036 len = sprintf(logrec, "%s %s %s\n",
2037 sha1_to_hex(old_sha1),
2038 sha1_to_hex(new_sha1),
2039 committer);
2040 if (msglen)
2041 len += copy_msg(logrec + len - 1, msg) - 1;
2042 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
2043 free(logrec);
2044 if (close(logfd) != 0 || written != len)
2045 return error("Unable to append to %s", log_file);
2046 return 0;
2049 static int is_branch(const char *refname)
2051 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2054 int write_ref_sha1(struct ref_lock *lock,
2055 const unsigned char *sha1, const char *logmsg)
2057 static char term = '\n';
2058 struct object *o;
2060 if (!lock)
2061 return -1;
2062 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
2063 unlock_ref(lock);
2064 return 0;
2066 o = parse_object(sha1);
2067 if (!o) {
2068 error("Trying to write ref %s with nonexistent object %s",
2069 lock->ref_name, sha1_to_hex(sha1));
2070 unlock_ref(lock);
2071 return -1;
2073 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2074 error("Trying to write non-commit object %s to branch %s",
2075 sha1_to_hex(sha1), lock->ref_name);
2076 unlock_ref(lock);
2077 return -1;
2079 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2080 write_in_full(lock->lock_fd, &term, 1) != 1
2081 || close_ref(lock) < 0) {
2082 error("Couldn't write %s", lock->lk->filename);
2083 unlock_ref(lock);
2084 return -1;
2086 clear_loose_ref_cache(get_ref_cache(NULL));
2087 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2088 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2089 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
2090 unlock_ref(lock);
2091 return -1;
2093 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2095 * Special hack: If a branch is updated directly and HEAD
2096 * points to it (may happen on the remote side of a push
2097 * for example) then logically the HEAD reflog should be
2098 * updated too.
2099 * A generic solution implies reverse symref information,
2100 * but finding all symrefs pointing to the given branch
2101 * would be rather costly for this rare event (the direct
2102 * update of a branch) to be worth it. So let's cheat and
2103 * check with HEAD only which should cover 99% of all usage
2104 * scenarios (even 100% of the default ones).
2106 unsigned char head_sha1[20];
2107 int head_flag;
2108 const char *head_ref;
2109 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
2110 if (head_ref && (head_flag & REF_ISSYMREF) &&
2111 !strcmp(head_ref, lock->ref_name))
2112 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2114 if (commit_ref(lock)) {
2115 error("Couldn't set %s", lock->ref_name);
2116 unlock_ref(lock);
2117 return -1;
2119 unlock_ref(lock);
2120 return 0;
2123 int create_symref(const char *ref_target, const char *refs_heads_master,
2124 const char *logmsg)
2126 const char *lockpath;
2127 char ref[1000];
2128 int fd, len, written;
2129 char *git_HEAD = git_pathdup("%s", ref_target);
2130 unsigned char old_sha1[20], new_sha1[20];
2132 if (logmsg && read_ref(ref_target, old_sha1))
2133 hashclr(old_sha1);
2135 if (safe_create_leading_directories(git_HEAD) < 0)
2136 return error("unable to create directory for %s", git_HEAD);
2138 #ifndef NO_SYMLINK_HEAD
2139 if (prefer_symlink_refs) {
2140 unlink(git_HEAD);
2141 if (!symlink(refs_heads_master, git_HEAD))
2142 goto done;
2143 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2145 #endif
2147 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2148 if (sizeof(ref) <= len) {
2149 error("refname too long: %s", refs_heads_master);
2150 goto error_free_return;
2152 lockpath = mkpath("%s.lock", git_HEAD);
2153 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2154 if (fd < 0) {
2155 error("Unable to open %s for writing", lockpath);
2156 goto error_free_return;
2158 written = write_in_full(fd, ref, len);
2159 if (close(fd) != 0 || written != len) {
2160 error("Unable to write to %s", lockpath);
2161 goto error_unlink_return;
2163 if (rename(lockpath, git_HEAD) < 0) {
2164 error("Unable to create %s", git_HEAD);
2165 goto error_unlink_return;
2167 if (adjust_shared_perm(git_HEAD)) {
2168 error("Unable to fix permissions on %s", lockpath);
2169 error_unlink_return:
2170 unlink_or_warn(lockpath);
2171 error_free_return:
2172 free(git_HEAD);
2173 return -1;
2176 #ifndef NO_SYMLINK_HEAD
2177 done:
2178 #endif
2179 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2180 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2182 free(git_HEAD);
2183 return 0;
2186 static char *ref_msg(const char *line, const char *endp)
2188 const char *ep;
2189 line += 82;
2190 ep = memchr(line, '\n', endp - line);
2191 if (!ep)
2192 ep = endp;
2193 return xmemdupz(line, ep - line);
2196 int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2197 unsigned char *sha1, char **msg,
2198 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
2200 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
2201 char *tz_c;
2202 int logfd, tz, reccnt = 0;
2203 struct stat st;
2204 unsigned long date;
2205 unsigned char logged_sha1[20];
2206 void *log_mapped;
2207 size_t mapsz;
2209 logfile = git_path("logs/%s", refname);
2210 logfd = open(logfile, O_RDONLY, 0);
2211 if (logfd < 0)
2212 die_errno("Unable to read log '%s'", logfile);
2213 fstat(logfd, &st);
2214 if (!st.st_size)
2215 die("Log %s is empty.", logfile);
2216 mapsz = xsize_t(st.st_size);
2217 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
2218 logdata = log_mapped;
2219 close(logfd);
2221 lastrec = NULL;
2222 rec = logend = logdata + st.st_size;
2223 while (logdata < rec) {
2224 reccnt++;
2225 if (logdata < rec && *(rec-1) == '\n')
2226 rec--;
2227 lastgt = NULL;
2228 while (logdata < rec && *(rec-1) != '\n') {
2229 rec--;
2230 if (*rec == '>')
2231 lastgt = rec;
2233 if (!lastgt)
2234 die("Log %s is corrupt.", logfile);
2235 date = strtoul(lastgt + 1, &tz_c, 10);
2236 if (date <= at_time || cnt == 0) {
2237 tz = strtoul(tz_c, NULL, 10);
2238 if (msg)
2239 *msg = ref_msg(rec, logend);
2240 if (cutoff_time)
2241 *cutoff_time = date;
2242 if (cutoff_tz)
2243 *cutoff_tz = tz;
2244 if (cutoff_cnt)
2245 *cutoff_cnt = reccnt - 1;
2246 if (lastrec) {
2247 if (get_sha1_hex(lastrec, logged_sha1))
2248 die("Log %s is corrupt.", logfile);
2249 if (get_sha1_hex(rec + 41, sha1))
2250 die("Log %s is corrupt.", logfile);
2251 if (hashcmp(logged_sha1, sha1)) {
2252 warning("Log %s has gap after %s.",
2253 logfile, show_date(date, tz, DATE_RFC2822));
2256 else if (date == at_time) {
2257 if (get_sha1_hex(rec + 41, sha1))
2258 die("Log %s is corrupt.", logfile);
2260 else {
2261 if (get_sha1_hex(rec + 41, logged_sha1))
2262 die("Log %s is corrupt.", logfile);
2263 if (hashcmp(logged_sha1, sha1)) {
2264 warning("Log %s unexpectedly ended on %s.",
2265 logfile, show_date(date, tz, DATE_RFC2822));
2268 munmap(log_mapped, mapsz);
2269 return 0;
2271 lastrec = rec;
2272 if (cnt > 0)
2273 cnt--;
2276 rec = logdata;
2277 while (rec < logend && *rec != '>' && *rec != '\n')
2278 rec++;
2279 if (rec == logend || *rec == '\n')
2280 die("Log %s is corrupt.", logfile);
2281 date = strtoul(rec + 1, &tz_c, 10);
2282 tz = strtoul(tz_c, NULL, 10);
2283 if (get_sha1_hex(logdata, sha1))
2284 die("Log %s is corrupt.", logfile);
2285 if (is_null_sha1(sha1)) {
2286 if (get_sha1_hex(logdata + 41, sha1))
2287 die("Log %s is corrupt.", logfile);
2289 if (msg)
2290 *msg = ref_msg(logdata, logend);
2291 munmap(log_mapped, mapsz);
2293 if (cutoff_time)
2294 *cutoff_time = date;
2295 if (cutoff_tz)
2296 *cutoff_tz = tz;
2297 if (cutoff_cnt)
2298 *cutoff_cnt = reccnt;
2299 return 1;
2302 int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
2304 const char *logfile;
2305 FILE *logfp;
2306 struct strbuf sb = STRBUF_INIT;
2307 int ret = 0;
2309 logfile = git_path("logs/%s", refname);
2310 logfp = fopen(logfile, "r");
2311 if (!logfp)
2312 return -1;
2314 if (ofs) {
2315 struct stat statbuf;
2316 if (fstat(fileno(logfp), &statbuf) ||
2317 statbuf.st_size < ofs ||
2318 fseek(logfp, -ofs, SEEK_END) ||
2319 strbuf_getwholeline(&sb, logfp, '\n')) {
2320 fclose(logfp);
2321 strbuf_release(&sb);
2322 return -1;
2326 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2327 unsigned char osha1[20], nsha1[20];
2328 char *email_end, *message;
2329 unsigned long timestamp;
2330 int tz;
2332 /* old SP new SP name <email> SP time TAB msg LF */
2333 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
2334 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
2335 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
2336 !(email_end = strchr(sb.buf + 82, '>')) ||
2337 email_end[1] != ' ' ||
2338 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2339 !message || message[0] != ' ' ||
2340 (message[1] != '+' && message[1] != '-') ||
2341 !isdigit(message[2]) || !isdigit(message[3]) ||
2342 !isdigit(message[4]) || !isdigit(message[5]))
2343 continue; /* corrupt? */
2344 email_end[1] = '\0';
2345 tz = strtol(message + 1, NULL, 10);
2346 if (message[6] != '\t')
2347 message += 6;
2348 else
2349 message += 7;
2350 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
2351 cb_data);
2352 if (ret)
2353 break;
2355 fclose(logfp);
2356 strbuf_release(&sb);
2357 return ret;
2360 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2362 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
2366 * Call fn for each reflog in the namespace indicated by name. name
2367 * must be empty or end with '/'. Name will be used as a scratch
2368 * space, but its contents will be restored before return.
2370 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
2372 DIR *d = opendir(git_path("logs/%s", name->buf));
2373 int retval = 0;
2374 struct dirent *de;
2375 int oldlen = name->len;
2377 if (!d)
2378 return name->len ? errno : 0;
2380 while ((de = readdir(d)) != NULL) {
2381 struct stat st;
2383 if (de->d_name[0] == '.')
2384 continue;
2385 if (has_extension(de->d_name, ".lock"))
2386 continue;
2387 strbuf_addstr(name, de->d_name);
2388 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2389 ; /* silently ignore */
2390 } else {
2391 if (S_ISDIR(st.st_mode)) {
2392 strbuf_addch(name, '/');
2393 retval = do_for_each_reflog(name, fn, cb_data);
2394 } else {
2395 unsigned char sha1[20];
2396 if (read_ref_full(name->buf, sha1, 0, NULL))
2397 retval = error("bad ref for %s", name->buf);
2398 else
2399 retval = fn(name->buf, sha1, 0, cb_data);
2401 if (retval)
2402 break;
2404 strbuf_setlen(name, oldlen);
2406 closedir(d);
2407 return retval;
2410 int for_each_reflog(each_ref_fn fn, void *cb_data)
2412 int retval;
2413 struct strbuf name;
2414 strbuf_init(&name, PATH_MAX);
2415 retval = do_for_each_reflog(&name, fn, cb_data);
2416 strbuf_release(&name);
2417 return retval;
2420 int update_ref(const char *action, const char *refname,
2421 const unsigned char *sha1, const unsigned char *oldval,
2422 int flags, enum action_on_err onerr)
2424 static struct ref_lock *lock;
2425 lock = lock_any_ref_for_update(refname, oldval, flags);
2426 if (!lock) {
2427 const char *str = "Cannot lock the ref '%s'.";
2428 switch (onerr) {
2429 case MSG_ON_ERR: error(str, refname); break;
2430 case DIE_ON_ERR: die(str, refname); break;
2431 case QUIET_ON_ERR: break;
2433 return 1;
2435 if (write_ref_sha1(lock, sha1, action) < 0) {
2436 const char *str = "Cannot update the ref '%s'.";
2437 switch (onerr) {
2438 case MSG_ON_ERR: error(str, refname); break;
2439 case DIE_ON_ERR: die(str, refname); break;
2440 case QUIET_ON_ERR: break;
2442 return 1;
2444 return 0;
2447 struct ref *find_ref_by_name(const struct ref *list, const char *name)
2449 for ( ; list; list = list->next)
2450 if (!strcmp(list->name, name))
2451 return (struct ref *)list;
2452 return NULL;
2456 * generate a format suitable for scanf from a ref_rev_parse_rules
2457 * rule, that is replace the "%.*s" spec with a "%s" spec
2459 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2461 char *spec;
2463 spec = strstr(rule, "%.*s");
2464 if (!spec || strstr(spec + 4, "%.*s"))
2465 die("invalid rule in ref_rev_parse_rules: %s", rule);
2467 /* copy all until spec */
2468 strncpy(scanf_fmt, rule, spec - rule);
2469 scanf_fmt[spec - rule] = '\0';
2470 /* copy new spec */
2471 strcat(scanf_fmt, "%s");
2472 /* copy remaining rule */
2473 strcat(scanf_fmt, spec + 4);
2475 return;
2478 char *shorten_unambiguous_ref(const char *refname, int strict)
2480 int i;
2481 static char **scanf_fmts;
2482 static int nr_rules;
2483 char *short_name;
2485 /* pre generate scanf formats from ref_rev_parse_rules[] */
2486 if (!nr_rules) {
2487 size_t total_len = 0;
2489 /* the rule list is NULL terminated, count them first */
2490 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2491 /* no +1 because strlen("%s") < strlen("%.*s") */
2492 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2494 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2496 total_len = 0;
2497 for (i = 0; i < nr_rules; i++) {
2498 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2499 + total_len;
2500 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2501 total_len += strlen(ref_rev_parse_rules[i]);
2505 /* bail out if there are no rules */
2506 if (!nr_rules)
2507 return xstrdup(refname);
2509 /* buffer for scanf result, at most refname must fit */
2510 short_name = xstrdup(refname);
2512 /* skip first rule, it will always match */
2513 for (i = nr_rules - 1; i > 0 ; --i) {
2514 int j;
2515 int rules_to_fail = i;
2516 int short_name_len;
2518 if (1 != sscanf(refname, scanf_fmts[i], short_name))
2519 continue;
2521 short_name_len = strlen(short_name);
2524 * in strict mode, all (except the matched one) rules
2525 * must fail to resolve to a valid non-ambiguous ref
2527 if (strict)
2528 rules_to_fail = nr_rules;
2531 * check if the short name resolves to a valid ref,
2532 * but use only rules prior to the matched one
2534 for (j = 0; j < rules_to_fail; j++) {
2535 const char *rule = ref_rev_parse_rules[j];
2536 char refname[PATH_MAX];
2538 /* skip matched rule */
2539 if (i == j)
2540 continue;
2543 * the short name is ambiguous, if it resolves
2544 * (with this previous rule) to a valid ref
2545 * read_ref() returns 0 on success
2547 mksnpath(refname, sizeof(refname),
2548 rule, short_name_len, short_name);
2549 if (ref_exists(refname))
2550 break;
2554 * short name is non-ambiguous if all previous rules
2555 * haven't resolved to a valid ref
2557 if (j == rules_to_fail)
2558 return short_name;
2561 free(short_name);
2562 return xstrdup(refname);