clone: test the new HEAD detection logic
[alt-git.git] / refs.c
blob7922261580515859bc89005c4c69e8623c50c728
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
6 #include "string-list.h"
8 /*
9 * Make sure "ref" is something reasonable to have under ".git/refs/";
10 * We do not like it if:
12 * - any path component of it begins with ".", or
13 * - it has double dots "..", or
14 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
15 * - it ends with a "/".
16 * - it ends with ".lock"
17 * - it contains a "\" (backslash)
20 /* Return true iff ch is not allowed in reference names. */
21 static inline int bad_ref_char(int ch)
23 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
24 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
25 return 1;
26 /* 2.13 Pattern Matching Notation */
27 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
28 return 1;
29 return 0;
33 * Try to read one refname component from the front of refname. Return
34 * the length of the component found, or -1 if the component is not
35 * legal.
37 static int check_refname_component(const char *refname, int flags)
39 const char *cp;
40 char last = '\0';
42 for (cp = refname; ; cp++) {
43 char ch = *cp;
44 if (ch == '\0' || ch == '/')
45 break;
46 if (bad_ref_char(ch))
47 return -1; /* Illegal character in refname. */
48 if (last == '.' && ch == '.')
49 return -1; /* Refname contains "..". */
50 if (last == '@' && ch == '{')
51 return -1; /* Refname contains "@{". */
52 last = ch;
54 if (cp == refname)
55 return 0; /* Component has zero length. */
56 if (refname[0] == '.') {
57 if (!(flags & REFNAME_DOT_COMPONENT))
58 return -1; /* Component starts with '.'. */
60 * Even if leading dots are allowed, don't allow "."
61 * as a component (".." is prevented by a rule above).
63 if (refname[1] == '\0')
64 return -1; /* Component equals ".". */
66 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
67 return -1; /* Refname ends with ".lock". */
68 return cp - refname;
71 int check_refname_format(const char *refname, int flags)
73 int component_len, component_count = 0;
75 while (1) {
76 /* We are at the start of a path component. */
77 component_len = check_refname_component(refname, flags);
78 if (component_len <= 0) {
79 if ((flags & REFNAME_REFSPEC_PATTERN) &&
80 refname[0] == '*' &&
81 (refname[1] == '\0' || refname[1] == '/')) {
82 /* Accept one wildcard as a full refname component. */
83 flags &= ~REFNAME_REFSPEC_PATTERN;
84 component_len = 1;
85 } else {
86 return -1;
89 component_count++;
90 if (refname[component_len] == '\0')
91 break;
92 /* Skip to next component. */
93 refname += component_len + 1;
96 if (refname[component_len - 1] == '.')
97 return -1; /* Refname ends with '.'. */
98 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
99 return -1; /* Refname has only one component. */
100 return 0;
103 struct ref_entry;
106 * Information used (along with the information in ref_entry) to
107 * describe a single cached reference. This data structure only
108 * occurs embedded in a union in struct ref_entry, and only when
109 * (ref_entry->flag & REF_DIR) is zero.
111 struct ref_value {
113 * The name of the object to which this reference resolves
114 * (which may be a tag object). If REF_ISBROKEN, this is
115 * null. If REF_ISSYMREF, then this is the name of the object
116 * referred to by the last reference in the symlink chain.
118 unsigned char sha1[20];
121 * If REF_KNOWS_PEELED, then this field holds the peeled value
122 * of this reference, or null if the reference is known not to
123 * be peelable. See the documentation for peel_ref() for an
124 * exact definition of "peelable".
126 unsigned char peeled[20];
129 struct ref_cache;
132 * Information used (along with the information in ref_entry) to
133 * describe a level in the hierarchy of references. This data
134 * structure only occurs embedded in a union in struct ref_entry, and
135 * only when (ref_entry.flag & REF_DIR) is set. In that case,
136 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
137 * in the directory have already been read:
139 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
140 * or packed references, already read.
142 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
143 * references that hasn't been read yet (nor has any of its
144 * subdirectories).
146 * Entries within a directory are stored within a growable array of
147 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
148 * sorted are sorted by their component name in strcmp() order and the
149 * remaining entries are unsorted.
151 * Loose references are read lazily, one directory at a time. When a
152 * directory of loose references is read, then all of the references
153 * in that directory are stored, and REF_INCOMPLETE stubs are created
154 * for any subdirectories, but the subdirectories themselves are not
155 * read. The reading is triggered by get_ref_dir().
157 struct ref_dir {
158 int nr, alloc;
161 * Entries with index 0 <= i < sorted are sorted by name. New
162 * entries are appended to the list unsorted, and are sorted
163 * only when required; thus we avoid the need to sort the list
164 * after the addition of every reference.
166 int sorted;
168 /* A pointer to the ref_cache that contains this ref_dir. */
169 struct ref_cache *ref_cache;
171 struct ref_entry **entries;
175 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
176 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
177 * refs.h.
181 * The field ref_entry->u.value.peeled of this value entry contains
182 * the correct peeled value for the reference, which might be
183 * null_sha1 if the reference is not a tag or if it is broken.
185 #define REF_KNOWS_PEELED 0x08
187 /* ref_entry represents a directory of references */
188 #define REF_DIR 0x10
191 * Entry has not yet been read from disk (used only for REF_DIR
192 * entries representing loose references)
194 #define REF_INCOMPLETE 0x20
197 * A ref_entry represents either a reference or a "subdirectory" of
198 * references.
200 * Each directory in the reference namespace is represented by a
201 * ref_entry with (flags & REF_DIR) set and containing a subdir member
202 * that holds the entries in that directory that have been read so
203 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
204 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
205 * used for loose reference directories.
207 * References are represented by a ref_entry with (flags & REF_DIR)
208 * unset and a value member that describes the reference's value. The
209 * flag member is at the ref_entry level, but it is also needed to
210 * interpret the contents of the value field (in other words, a
211 * ref_value object is not very much use without the enclosing
212 * ref_entry).
214 * Reference names cannot end with slash and directories' names are
215 * always stored with a trailing slash (except for the top-level
216 * directory, which is always denoted by ""). This has two nice
217 * consequences: (1) when the entries in each subdir are sorted
218 * lexicographically by name (as they usually are), the references in
219 * a whole tree can be generated in lexicographic order by traversing
220 * the tree in left-to-right, depth-first order; (2) the names of
221 * references and subdirectories cannot conflict, and therefore the
222 * presence of an empty subdirectory does not block the creation of a
223 * similarly-named reference. (The fact that reference names with the
224 * same leading components can conflict *with each other* is a
225 * separate issue that is regulated by is_refname_available().)
227 * Please note that the name field contains the fully-qualified
228 * reference (or subdirectory) name. Space could be saved by only
229 * storing the relative names. But that would require the full names
230 * to be generated on the fly when iterating in do_for_each_ref(), and
231 * would break callback functions, who have always been able to assume
232 * that the name strings that they are passed will not be freed during
233 * the iteration.
235 struct ref_entry {
236 unsigned char flag; /* ISSYMREF? ISPACKED? */
237 union {
238 struct ref_value value; /* if not (flags&REF_DIR) */
239 struct ref_dir subdir; /* if (flags&REF_DIR) */
240 } u;
242 * The full name of the reference (e.g., "refs/heads/master")
243 * or the full name of the directory with a trailing slash
244 * (e.g., "refs/heads/"):
246 char name[FLEX_ARRAY];
249 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
251 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
253 struct ref_dir *dir;
254 assert(entry->flag & REF_DIR);
255 dir = &entry->u.subdir;
256 if (entry->flag & REF_INCOMPLETE) {
257 read_loose_refs(entry->name, dir);
258 entry->flag &= ~REF_INCOMPLETE;
260 return dir;
263 static struct ref_entry *create_ref_entry(const char *refname,
264 const unsigned char *sha1, int flag,
265 int check_name)
267 int len;
268 struct ref_entry *ref;
270 if (check_name &&
271 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
272 die("Reference has invalid format: '%s'", refname);
273 len = strlen(refname) + 1;
274 ref = xmalloc(sizeof(struct ref_entry) + len);
275 hashcpy(ref->u.value.sha1, sha1);
276 hashclr(ref->u.value.peeled);
277 memcpy(ref->name, refname, len);
278 ref->flag = flag;
279 return ref;
282 static void clear_ref_dir(struct ref_dir *dir);
284 static void free_ref_entry(struct ref_entry *entry)
286 if (entry->flag & REF_DIR) {
288 * Do not use get_ref_dir() here, as that might
289 * trigger the reading of loose refs.
291 clear_ref_dir(&entry->u.subdir);
293 free(entry);
297 * Add a ref_entry to the end of dir (unsorted). Entry is always
298 * stored directly in dir; no recursion into subdirectories is
299 * done.
301 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
303 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
304 dir->entries[dir->nr++] = entry;
305 /* optimize for the case that entries are added in order */
306 if (dir->nr == 1 ||
307 (dir->nr == dir->sorted + 1 &&
308 strcmp(dir->entries[dir->nr - 2]->name,
309 dir->entries[dir->nr - 1]->name) < 0))
310 dir->sorted = dir->nr;
314 * Clear and free all entries in dir, recursively.
316 static void clear_ref_dir(struct ref_dir *dir)
318 int i;
319 for (i = 0; i < dir->nr; i++)
320 free_ref_entry(dir->entries[i]);
321 free(dir->entries);
322 dir->sorted = dir->nr = dir->alloc = 0;
323 dir->entries = NULL;
327 * Create a struct ref_entry object for the specified dirname.
328 * dirname is the name of the directory with a trailing slash (e.g.,
329 * "refs/heads/") or "" for the top-level directory.
331 static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
332 const char *dirname, size_t len,
333 int incomplete)
335 struct ref_entry *direntry;
336 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
337 memcpy(direntry->name, dirname, len);
338 direntry->name[len] = '\0';
339 direntry->u.subdir.ref_cache = ref_cache;
340 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
341 return direntry;
344 static int ref_entry_cmp(const void *a, const void *b)
346 struct ref_entry *one = *(struct ref_entry **)a;
347 struct ref_entry *two = *(struct ref_entry **)b;
348 return strcmp(one->name, two->name);
351 static void sort_ref_dir(struct ref_dir *dir);
353 struct string_slice {
354 size_t len;
355 const char *str;
358 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
360 const struct string_slice *key = key_;
361 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
362 int cmp = strncmp(key->str, ent->name, key->len);
363 if (cmp)
364 return cmp;
365 return '\0' - (unsigned char)ent->name[key->len];
369 * Return the index of the entry with the given refname from the
370 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
371 * no such entry is found. dir must already be complete.
373 static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
375 struct ref_entry **r;
376 struct string_slice key;
378 if (refname == NULL || !dir->nr)
379 return -1;
381 sort_ref_dir(dir);
382 key.len = len;
383 key.str = refname;
384 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
385 ref_entry_cmp_sslice);
387 if (r == NULL)
388 return -1;
390 return r - dir->entries;
394 * Search for a directory entry directly within dir (without
395 * recursing). Sort dir if necessary. subdirname must be a directory
396 * name (i.e., end in '/'). If mkdir is set, then create the
397 * directory if it is missing; otherwise, return NULL if the desired
398 * directory cannot be found. dir must already be complete.
400 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
401 const char *subdirname, size_t len,
402 int mkdir)
404 int entry_index = search_ref_dir(dir, subdirname, len);
405 struct ref_entry *entry;
406 if (entry_index == -1) {
407 if (!mkdir)
408 return NULL;
410 * Since dir is complete, the absence of a subdir
411 * means that the subdir really doesn't exist;
412 * therefore, create an empty record for it but mark
413 * the record complete.
415 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
416 add_entry_to_dir(dir, entry);
417 } else {
418 entry = dir->entries[entry_index];
420 return get_ref_dir(entry);
424 * If refname is a reference name, find the ref_dir within the dir
425 * tree that should hold refname. If refname is a directory name
426 * (i.e., ends in '/'), then return that ref_dir itself. dir must
427 * represent the top-level directory and must already be complete.
428 * Sort ref_dirs and recurse into subdirectories as necessary. If
429 * mkdir is set, then create any missing directories; otherwise,
430 * return NULL if the desired directory cannot be found.
432 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
433 const char *refname, int mkdir)
435 const char *slash;
436 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
437 size_t dirnamelen = slash - refname + 1;
438 struct ref_dir *subdir;
439 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
440 if (!subdir) {
441 dir = NULL;
442 break;
444 dir = subdir;
447 return dir;
451 * Find the value entry with the given name in dir, sorting ref_dirs
452 * and recursing into subdirectories as necessary. If the name is not
453 * found or it corresponds to a directory entry, return NULL.
455 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
457 int entry_index;
458 struct ref_entry *entry;
459 dir = find_containing_dir(dir, refname, 0);
460 if (!dir)
461 return NULL;
462 entry_index = search_ref_dir(dir, refname, strlen(refname));
463 if (entry_index == -1)
464 return NULL;
465 entry = dir->entries[entry_index];
466 return (entry->flag & REF_DIR) ? NULL : entry;
470 * Remove the entry with the given name from dir, recursing into
471 * subdirectories as necessary. If refname is the name of a directory
472 * (i.e., ends with '/'), then remove the directory and its contents.
473 * If the removal was successful, return the number of entries
474 * remaining in the directory entry that contained the deleted entry.
475 * If the name was not found, return -1. Please note that this
476 * function only deletes the entry from the cache; it does not delete
477 * it from the filesystem or ensure that other cache entries (which
478 * might be symbolic references to the removed entry) are updated.
479 * Nor does it remove any containing dir entries that might be made
480 * empty by the removal. dir must represent the top-level directory
481 * and must already be complete.
483 static int remove_entry(struct ref_dir *dir, const char *refname)
485 int refname_len = strlen(refname);
486 int entry_index;
487 struct ref_entry *entry;
488 int is_dir = refname[refname_len - 1] == '/';
489 if (is_dir) {
491 * refname represents a reference directory. Remove
492 * the trailing slash; otherwise we will get the
493 * directory *representing* refname rather than the
494 * one *containing* it.
496 char *dirname = xmemdupz(refname, refname_len - 1);
497 dir = find_containing_dir(dir, dirname, 0);
498 free(dirname);
499 } else {
500 dir = find_containing_dir(dir, refname, 0);
502 if (!dir)
503 return -1;
504 entry_index = search_ref_dir(dir, refname, refname_len);
505 if (entry_index == -1)
506 return -1;
507 entry = dir->entries[entry_index];
509 memmove(&dir->entries[entry_index],
510 &dir->entries[entry_index + 1],
511 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
513 dir->nr--;
514 if (dir->sorted > entry_index)
515 dir->sorted--;
516 free_ref_entry(entry);
517 return dir->nr;
521 * Add a ref_entry to the ref_dir (unsorted), recursing into
522 * subdirectories as necessary. dir must represent the top-level
523 * directory. Return 0 on success.
525 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
527 dir = find_containing_dir(dir, ref->name, 1);
528 if (!dir)
529 return -1;
530 add_entry_to_dir(dir, ref);
531 return 0;
535 * Emit a warning and return true iff ref1 and ref2 have the same name
536 * and the same sha1. Die if they have the same name but different
537 * sha1s.
539 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
541 if (strcmp(ref1->name, ref2->name))
542 return 0;
544 /* Duplicate name; make sure that they don't conflict: */
546 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
547 /* This is impossible by construction */
548 die("Reference directory conflict: %s", ref1->name);
550 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
551 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
553 warning("Duplicated ref: %s", ref1->name);
554 return 1;
558 * Sort the entries in dir non-recursively (if they are not already
559 * sorted) and remove any duplicate entries.
561 static void sort_ref_dir(struct ref_dir *dir)
563 int i, j;
564 struct ref_entry *last = NULL;
567 * This check also prevents passing a zero-length array to qsort(),
568 * which is a problem on some platforms.
570 if (dir->sorted == dir->nr)
571 return;
573 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
575 /* Remove any duplicates: */
576 for (i = 0, j = 0; j < dir->nr; j++) {
577 struct ref_entry *entry = dir->entries[j];
578 if (last && is_dup_ref(last, entry))
579 free_ref_entry(entry);
580 else
581 last = dir->entries[i++] = entry;
583 dir->sorted = dir->nr = i;
586 /* Include broken references in a do_for_each_ref*() iteration: */
587 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
590 * Return true iff the reference described by entry can be resolved to
591 * an object in the database. Emit a warning if the referred-to
592 * object does not exist.
594 static int ref_resolves_to_object(struct ref_entry *entry)
596 if (entry->flag & REF_ISBROKEN)
597 return 0;
598 if (!has_sha1_file(entry->u.value.sha1)) {
599 error("%s does not point to a valid object!", entry->name);
600 return 0;
602 return 1;
606 * current_ref is a performance hack: when iterating over references
607 * using the for_each_ref*() functions, current_ref is set to the
608 * current reference's entry before calling the callback function. If
609 * the callback function calls peel_ref(), then peel_ref() first
610 * checks whether the reference to be peeled is the current reference
611 * (it usually is) and if so, returns that reference's peeled version
612 * if it is available. This avoids a refname lookup in a common case.
614 static struct ref_entry *current_ref;
616 typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
618 struct ref_entry_cb {
619 const char *base;
620 int trim;
621 int flags;
622 each_ref_fn *fn;
623 void *cb_data;
627 * Handle one reference in a do_for_each_ref*()-style iteration,
628 * calling an each_ref_fn for each entry.
630 static int do_one_ref(struct ref_entry *entry, void *cb_data)
632 struct ref_entry_cb *data = cb_data;
633 struct ref_entry *old_current_ref;
634 int retval;
636 if (prefixcmp(entry->name, data->base))
637 return 0;
639 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
640 !ref_resolves_to_object(entry))
641 return 0;
643 /* Store the old value, in case this is a recursive call: */
644 old_current_ref = current_ref;
645 current_ref = entry;
646 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
647 entry->flag, data->cb_data);
648 current_ref = old_current_ref;
649 return retval;
653 * Call fn for each reference in dir that has index in the range
654 * offset <= index < dir->nr. Recurse into subdirectories that are in
655 * that index range, sorting them before iterating. This function
656 * does not sort dir itself; it should be sorted beforehand. fn is
657 * called for all references, including broken ones.
659 static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
660 each_ref_entry_fn fn, void *cb_data)
662 int i;
663 assert(dir->sorted == dir->nr);
664 for (i = offset; i < dir->nr; i++) {
665 struct ref_entry *entry = dir->entries[i];
666 int retval;
667 if (entry->flag & REF_DIR) {
668 struct ref_dir *subdir = get_ref_dir(entry);
669 sort_ref_dir(subdir);
670 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
671 } else {
672 retval = fn(entry, cb_data);
674 if (retval)
675 return retval;
677 return 0;
681 * Call fn for each reference in the union of dir1 and dir2, in order
682 * by refname. Recurse into subdirectories. If a value entry appears
683 * in both dir1 and dir2, then only process the version that is in
684 * dir2. The input dirs must already be sorted, but subdirs will be
685 * sorted as needed. fn is called for all references, including
686 * broken ones.
688 static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
689 struct ref_dir *dir2,
690 each_ref_entry_fn fn, void *cb_data)
692 int retval;
693 int i1 = 0, i2 = 0;
695 assert(dir1->sorted == dir1->nr);
696 assert(dir2->sorted == dir2->nr);
697 while (1) {
698 struct ref_entry *e1, *e2;
699 int cmp;
700 if (i1 == dir1->nr) {
701 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
703 if (i2 == dir2->nr) {
704 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
706 e1 = dir1->entries[i1];
707 e2 = dir2->entries[i2];
708 cmp = strcmp(e1->name, e2->name);
709 if (cmp == 0) {
710 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
711 /* Both are directories; descend them in parallel. */
712 struct ref_dir *subdir1 = get_ref_dir(e1);
713 struct ref_dir *subdir2 = get_ref_dir(e2);
714 sort_ref_dir(subdir1);
715 sort_ref_dir(subdir2);
716 retval = do_for_each_entry_in_dirs(
717 subdir1, subdir2, fn, cb_data);
718 i1++;
719 i2++;
720 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
721 /* Both are references; ignore the one from dir1. */
722 retval = fn(e2, cb_data);
723 i1++;
724 i2++;
725 } else {
726 die("conflict between reference and directory: %s",
727 e1->name);
729 } else {
730 struct ref_entry *e;
731 if (cmp < 0) {
732 e = e1;
733 i1++;
734 } else {
735 e = e2;
736 i2++;
738 if (e->flag & REF_DIR) {
739 struct ref_dir *subdir = get_ref_dir(e);
740 sort_ref_dir(subdir);
741 retval = do_for_each_entry_in_dir(
742 subdir, 0, fn, cb_data);
743 } else {
744 retval = fn(e, cb_data);
747 if (retval)
748 return retval;
753 * Load all of the refs from the dir into our in-memory cache. The hard work
754 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
755 * through all of the sub-directories. We do not even need to care about
756 * sorting, as traversal order does not matter to us.
758 static void prime_ref_dir(struct ref_dir *dir)
760 int i;
761 for (i = 0; i < dir->nr; i++) {
762 struct ref_entry *entry = dir->entries[i];
763 if (entry->flag & REF_DIR)
764 prime_ref_dir(get_ref_dir(entry));
768 * Return true iff refname1 and refname2 conflict with each other.
769 * Two reference names conflict if one of them exactly matches the
770 * leading components of the other; e.g., "foo/bar" conflicts with
771 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
772 * "foo/barbados".
774 static int names_conflict(const char *refname1, const char *refname2)
776 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
778 return (*refname1 == '\0' && *refname2 == '/')
779 || (*refname1 == '/' && *refname2 == '\0');
782 struct name_conflict_cb {
783 const char *refname;
784 const char *oldrefname;
785 const char *conflicting_refname;
788 static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
790 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
791 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
792 return 0;
793 if (names_conflict(data->refname, entry->name)) {
794 data->conflicting_refname = entry->name;
795 return 1;
797 return 0;
801 * Return true iff a reference named refname could be created without
802 * conflicting with the name of an existing reference in dir. If
803 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
804 * (e.g., because oldrefname is scheduled for deletion in the same
805 * operation).
807 static int is_refname_available(const char *refname, const char *oldrefname,
808 struct ref_dir *dir)
810 struct name_conflict_cb data;
811 data.refname = refname;
812 data.oldrefname = oldrefname;
813 data.conflicting_refname = NULL;
815 sort_ref_dir(dir);
816 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
817 error("'%s' exists; cannot create '%s'",
818 data.conflicting_refname, refname);
819 return 0;
821 return 1;
824 struct packed_ref_cache {
825 struct ref_entry *root;
828 * Count of references to the data structure in this instance,
829 * including the pointer from ref_cache::packed if any. The
830 * data will not be freed as long as the reference count is
831 * nonzero.
833 unsigned int referrers;
836 * Iff the packed-refs file associated with this instance is
837 * currently locked for writing, this points at the associated
838 * lock (which is owned by somebody else). The referrer count
839 * is also incremented when the file is locked and decremented
840 * when it is unlocked.
842 struct lock_file *lock;
844 /* The metadata from when this packed-refs cache was read */
845 struct stat_validity validity;
849 * Future: need to be in "struct repository"
850 * when doing a full libification.
852 static struct ref_cache {
853 struct ref_cache *next;
854 struct ref_entry *loose;
855 struct packed_ref_cache *packed;
857 * The submodule name, or "" for the main repo. We allocate
858 * length 1 rather than FLEX_ARRAY so that the main ref_cache
859 * is initialized correctly.
861 char name[1];
862 } ref_cache, *submodule_ref_caches;
864 /* Lock used for the main packed-refs file: */
865 static struct lock_file packlock;
868 * Increment the reference count of *packed_refs.
870 static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
872 packed_refs->referrers++;
876 * Decrease the reference count of *packed_refs. If it goes to zero,
877 * free *packed_refs and return true; otherwise return false.
879 static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
881 if (!--packed_refs->referrers) {
882 free_ref_entry(packed_refs->root);
883 stat_validity_clear(&packed_refs->validity);
884 free(packed_refs);
885 return 1;
886 } else {
887 return 0;
891 static void clear_packed_ref_cache(struct ref_cache *refs)
893 if (refs->packed) {
894 struct packed_ref_cache *packed_refs = refs->packed;
896 if (packed_refs->lock)
897 die("internal error: packed-ref cache cleared while locked");
898 refs->packed = NULL;
899 release_packed_ref_cache(packed_refs);
903 static void clear_loose_ref_cache(struct ref_cache *refs)
905 if (refs->loose) {
906 free_ref_entry(refs->loose);
907 refs->loose = NULL;
911 static struct ref_cache *create_ref_cache(const char *submodule)
913 int len;
914 struct ref_cache *refs;
915 if (!submodule)
916 submodule = "";
917 len = strlen(submodule) + 1;
918 refs = xcalloc(1, sizeof(struct ref_cache) + len);
919 memcpy(refs->name, submodule, len);
920 return refs;
924 * Return a pointer to a ref_cache for the specified submodule. For
925 * the main repository, use submodule==NULL. The returned structure
926 * will be allocated and initialized but not necessarily populated; it
927 * should not be freed.
929 static struct ref_cache *get_ref_cache(const char *submodule)
931 struct ref_cache *refs;
933 if (!submodule || !*submodule)
934 return &ref_cache;
936 for (refs = submodule_ref_caches; refs; refs = refs->next)
937 if (!strcmp(submodule, refs->name))
938 return refs;
940 refs = create_ref_cache(submodule);
941 refs->next = submodule_ref_caches;
942 submodule_ref_caches = refs;
943 return refs;
946 void invalidate_ref_cache(const char *submodule)
948 struct ref_cache *refs = get_ref_cache(submodule);
949 clear_packed_ref_cache(refs);
950 clear_loose_ref_cache(refs);
953 /* The length of a peeled reference line in packed-refs, including EOL: */
954 #define PEELED_LINE_LENGTH 42
957 * The packed-refs header line that we write out. Perhaps other
958 * traits will be added later. The trailing space is required.
960 static const char PACKED_REFS_HEADER[] =
961 "# pack-refs with: peeled fully-peeled \n";
964 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
965 * Return a pointer to the refname within the line (null-terminated),
966 * or NULL if there was a problem.
968 static const char *parse_ref_line(char *line, unsigned char *sha1)
971 * 42: the answer to everything.
973 * In this case, it happens to be the answer to
974 * 40 (length of sha1 hex representation)
975 * +1 (space in between hex and name)
976 * +1 (newline at the end of the line)
978 int len = strlen(line) - 42;
980 if (len <= 0)
981 return NULL;
982 if (get_sha1_hex(line, sha1) < 0)
983 return NULL;
984 if (!isspace(line[40]))
985 return NULL;
986 line += 41;
987 if (isspace(*line))
988 return NULL;
989 if (line[len] != '\n')
990 return NULL;
991 line[len] = 0;
993 return line;
997 * Read f, which is a packed-refs file, into dir.
999 * A comment line of the form "# pack-refs with: " may contain zero or
1000 * more traits. We interpret the traits as follows:
1002 * No traits:
1004 * Probably no references are peeled. But if the file contains a
1005 * peeled value for a reference, we will use it.
1007 * peeled:
1009 * References under "refs/tags/", if they *can* be peeled, *are*
1010 * peeled in this file. References outside of "refs/tags/" are
1011 * probably not peeled even if they could have been, but if we find
1012 * a peeled value for such a reference we will use it.
1014 * fully-peeled:
1016 * All references in the file that can be peeled are peeled.
1017 * Inversely (and this is more important), any references in the
1018 * file for which no peeled value is recorded is not peelable. This
1019 * trait should typically be written alongside "peeled" for
1020 * compatibility with older clients, but we do not require it
1021 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1023 static void read_packed_refs(FILE *f, struct ref_dir *dir)
1025 struct ref_entry *last = NULL;
1026 char refline[PATH_MAX];
1027 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1029 while (fgets(refline, sizeof(refline), f)) {
1030 unsigned char sha1[20];
1031 const char *refname;
1032 static const char header[] = "# pack-refs with:";
1034 if (!strncmp(refline, header, sizeof(header)-1)) {
1035 const char *traits = refline + sizeof(header) - 1;
1036 if (strstr(traits, " fully-peeled "))
1037 peeled = PEELED_FULLY;
1038 else if (strstr(traits, " peeled "))
1039 peeled = PEELED_TAGS;
1040 /* perhaps other traits later as well */
1041 continue;
1044 refname = parse_ref_line(refline, sha1);
1045 if (refname) {
1046 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
1047 if (peeled == PEELED_FULLY ||
1048 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
1049 last->flag |= REF_KNOWS_PEELED;
1050 add_ref(dir, last);
1051 continue;
1053 if (last &&
1054 refline[0] == '^' &&
1055 strlen(refline) == PEELED_LINE_LENGTH &&
1056 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
1057 !get_sha1_hex(refline + 1, sha1)) {
1058 hashcpy(last->u.value.peeled, sha1);
1060 * Regardless of what the file header said,
1061 * we definitely know the value of *this*
1062 * reference:
1064 last->flag |= REF_KNOWS_PEELED;
1070 * Get the packed_ref_cache for the specified ref_cache, creating it
1071 * if necessary.
1073 static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
1075 const char *packed_refs_file;
1077 if (*refs->name)
1078 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1079 else
1080 packed_refs_file = git_path("packed-refs");
1082 if (refs->packed &&
1083 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1084 clear_packed_ref_cache(refs);
1086 if (!refs->packed) {
1087 FILE *f;
1089 refs->packed = xcalloc(1, sizeof(*refs->packed));
1090 acquire_packed_ref_cache(refs->packed);
1091 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1092 f = fopen(packed_refs_file, "r");
1093 if (f) {
1094 stat_validity_update(&refs->packed->validity, fileno(f));
1095 read_packed_refs(f, get_ref_dir(refs->packed->root));
1096 fclose(f);
1099 return refs->packed;
1102 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1104 return get_ref_dir(packed_ref_cache->root);
1107 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1109 return get_packed_ref_dir(get_packed_ref_cache(refs));
1112 void add_packed_ref(const char *refname, const unsigned char *sha1)
1114 struct packed_ref_cache *packed_ref_cache =
1115 get_packed_ref_cache(&ref_cache);
1117 if (!packed_ref_cache->lock)
1118 die("internal error: packed refs not locked");
1119 add_ref(get_packed_ref_dir(packed_ref_cache),
1120 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1124 * Read the loose references from the namespace dirname into dir
1125 * (without recursing). dirname must end with '/'. dir must be the
1126 * directory entry corresponding to dirname.
1128 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1130 struct ref_cache *refs = dir->ref_cache;
1131 DIR *d;
1132 const char *path;
1133 struct dirent *de;
1134 int dirnamelen = strlen(dirname);
1135 struct strbuf refname;
1137 if (*refs->name)
1138 path = git_path_submodule(refs->name, "%s", dirname);
1139 else
1140 path = git_path("%s", dirname);
1142 d = opendir(path);
1143 if (!d)
1144 return;
1146 strbuf_init(&refname, dirnamelen + 257);
1147 strbuf_add(&refname, dirname, dirnamelen);
1149 while ((de = readdir(d)) != NULL) {
1150 unsigned char sha1[20];
1151 struct stat st;
1152 int flag;
1153 const char *refdir;
1155 if (de->d_name[0] == '.')
1156 continue;
1157 if (has_extension(de->d_name, ".lock"))
1158 continue;
1159 strbuf_addstr(&refname, de->d_name);
1160 refdir = *refs->name
1161 ? git_path_submodule(refs->name, "%s", refname.buf)
1162 : git_path("%s", refname.buf);
1163 if (stat(refdir, &st) < 0) {
1164 ; /* silently ignore */
1165 } else if (S_ISDIR(st.st_mode)) {
1166 strbuf_addch(&refname, '/');
1167 add_entry_to_dir(dir,
1168 create_dir_entry(refs, refname.buf,
1169 refname.len, 1));
1170 } else {
1171 if (*refs->name) {
1172 hashclr(sha1);
1173 flag = 0;
1174 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
1175 hashclr(sha1);
1176 flag |= REF_ISBROKEN;
1178 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
1179 hashclr(sha1);
1180 flag |= REF_ISBROKEN;
1182 add_entry_to_dir(dir,
1183 create_ref_entry(refname.buf, sha1, flag, 1));
1185 strbuf_setlen(&refname, dirnamelen);
1187 strbuf_release(&refname);
1188 closedir(d);
1191 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
1193 if (!refs->loose) {
1195 * Mark the top-level directory complete because we
1196 * are about to read the only subdirectory that can
1197 * hold references:
1199 refs->loose = create_dir_entry(refs, "", 0, 0);
1201 * Create an incomplete entry for "refs/":
1203 add_entry_to_dir(get_ref_dir(refs->loose),
1204 create_dir_entry(refs, "refs/", 5, 1));
1206 return get_ref_dir(refs->loose);
1209 /* We allow "recursive" symbolic refs. Only within reason, though */
1210 #define MAXDEPTH 5
1211 #define MAXREFLEN (1024)
1214 * Called by resolve_gitlink_ref_recursive() after it failed to read
1215 * from the loose refs in ref_cache refs. Find <refname> in the
1216 * packed-refs file for the submodule.
1218 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
1219 const char *refname, unsigned char *sha1)
1221 struct ref_entry *ref;
1222 struct ref_dir *dir = get_packed_refs(refs);
1224 ref = find_ref(dir, refname);
1225 if (ref == NULL)
1226 return -1;
1228 memcpy(sha1, ref->u.value.sha1, 20);
1229 return 0;
1232 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
1233 const char *refname, unsigned char *sha1,
1234 int recursion)
1236 int fd, len;
1237 char buffer[128], *p;
1238 char *path;
1240 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
1241 return -1;
1242 path = *refs->name
1243 ? git_path_submodule(refs->name, "%s", refname)
1244 : git_path("%s", refname);
1245 fd = open(path, O_RDONLY);
1246 if (fd < 0)
1247 return resolve_gitlink_packed_ref(refs, refname, sha1);
1249 len = read(fd, buffer, sizeof(buffer)-1);
1250 close(fd);
1251 if (len < 0)
1252 return -1;
1253 while (len && isspace(buffer[len-1]))
1254 len--;
1255 buffer[len] = 0;
1257 /* Was it a detached head or an old-fashioned symlink? */
1258 if (!get_sha1_hex(buffer, sha1))
1259 return 0;
1261 /* Symref? */
1262 if (strncmp(buffer, "ref:", 4))
1263 return -1;
1264 p = buffer + 4;
1265 while (isspace(*p))
1266 p++;
1268 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1271 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1273 int len = strlen(path), retval;
1274 char *submodule;
1275 struct ref_cache *refs;
1277 while (len && path[len-1] == '/')
1278 len--;
1279 if (!len)
1280 return -1;
1281 submodule = xstrndup(path, len);
1282 refs = get_ref_cache(submodule);
1283 free(submodule);
1285 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1286 return retval;
1290 * Return the ref_entry for the given refname from the packed
1291 * references. If it does not exist, return NULL.
1293 static struct ref_entry *get_packed_ref(const char *refname)
1295 return find_ref(get_packed_refs(&ref_cache), refname);
1299 * A loose ref file doesn't exist; check for a packed ref. The
1300 * options are forwarded from resolve_safe_unsafe().
1302 static const char *handle_missing_loose_ref(const char *refname,
1303 unsigned char *sha1,
1304 int reading,
1305 int *flag)
1307 struct ref_entry *entry;
1310 * The loose reference file does not exist; check for a packed
1311 * reference.
1313 entry = get_packed_ref(refname);
1314 if (entry) {
1315 hashcpy(sha1, entry->u.value.sha1);
1316 if (flag)
1317 *flag |= REF_ISPACKED;
1318 return refname;
1320 /* The reference is not a packed reference, either. */
1321 if (reading) {
1322 return NULL;
1323 } else {
1324 hashclr(sha1);
1325 return refname;
1329 const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
1331 int depth = MAXDEPTH;
1332 ssize_t len;
1333 char buffer[256];
1334 static char refname_buffer[256];
1336 if (flag)
1337 *flag = 0;
1339 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1340 return NULL;
1342 for (;;) {
1343 char path[PATH_MAX];
1344 struct stat st;
1345 char *buf;
1346 int fd;
1348 if (--depth < 0)
1349 return NULL;
1351 git_snpath(path, sizeof(path), "%s", refname);
1354 * We might have to loop back here to avoid a race
1355 * condition: first we lstat() the file, then we try
1356 * to read it as a link or as a file. But if somebody
1357 * changes the type of the file (file <-> directory
1358 * <-> symlink) between the lstat() and reading, then
1359 * we don't want to report that as an error but rather
1360 * try again starting with the lstat().
1362 stat_ref:
1363 if (lstat(path, &st) < 0) {
1364 if (errno == ENOENT)
1365 return handle_missing_loose_ref(refname, sha1,
1366 reading, flag);
1367 else
1368 return NULL;
1371 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1372 if (S_ISLNK(st.st_mode)) {
1373 len = readlink(path, buffer, sizeof(buffer)-1);
1374 if (len < 0) {
1375 if (errno == ENOENT || errno == EINVAL)
1376 /* inconsistent with lstat; retry */
1377 goto stat_ref;
1378 else
1379 return NULL;
1381 buffer[len] = 0;
1382 if (!prefixcmp(buffer, "refs/") &&
1383 !check_refname_format(buffer, 0)) {
1384 strcpy(refname_buffer, buffer);
1385 refname = refname_buffer;
1386 if (flag)
1387 *flag |= REF_ISSYMREF;
1388 continue;
1392 /* Is it a directory? */
1393 if (S_ISDIR(st.st_mode)) {
1394 errno = EISDIR;
1395 return NULL;
1399 * Anything else, just open it and try to use it as
1400 * a ref
1402 fd = open(path, O_RDONLY);
1403 if (fd < 0) {
1404 if (errno == ENOENT)
1405 /* inconsistent with lstat; retry */
1406 goto stat_ref;
1407 else
1408 return NULL;
1410 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1411 close(fd);
1412 if (len < 0)
1413 return NULL;
1414 while (len && isspace(buffer[len-1]))
1415 len--;
1416 buffer[len] = '\0';
1419 * Is it a symbolic ref?
1421 if (prefixcmp(buffer, "ref:")) {
1423 * Please note that FETCH_HEAD has a second
1424 * line containing other data.
1426 if (get_sha1_hex(buffer, sha1) ||
1427 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1428 if (flag)
1429 *flag |= REF_ISBROKEN;
1430 return NULL;
1432 return refname;
1434 if (flag)
1435 *flag |= REF_ISSYMREF;
1436 buf = buffer + 4;
1437 while (isspace(*buf))
1438 buf++;
1439 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1440 if (flag)
1441 *flag |= REF_ISBROKEN;
1442 return NULL;
1444 refname = strcpy(refname_buffer, buf);
1448 char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1450 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
1451 return ret ? xstrdup(ret) : NULL;
1454 /* The argument to filter_refs */
1455 struct ref_filter {
1456 const char *pattern;
1457 each_ref_fn *fn;
1458 void *cb_data;
1461 int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
1463 if (resolve_ref_unsafe(refname, sha1, reading, flags))
1464 return 0;
1465 return -1;
1468 int read_ref(const char *refname, unsigned char *sha1)
1470 return read_ref_full(refname, sha1, 1, NULL);
1473 int ref_exists(const char *refname)
1475 unsigned char sha1[20];
1476 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
1479 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1480 void *data)
1482 struct ref_filter *filter = (struct ref_filter *)data;
1483 if (fnmatch(filter->pattern, refname, 0))
1484 return 0;
1485 return filter->fn(refname, sha1, flags, filter->cb_data);
1488 enum peel_status {
1489 /* object was peeled successfully: */
1490 PEEL_PEELED = 0,
1493 * object cannot be peeled because the named object (or an
1494 * object referred to by a tag in the peel chain), does not
1495 * exist.
1497 PEEL_INVALID = -1,
1499 /* object cannot be peeled because it is not a tag: */
1500 PEEL_NON_TAG = -2,
1502 /* ref_entry contains no peeled value because it is a symref: */
1503 PEEL_IS_SYMREF = -3,
1506 * ref_entry cannot be peeled because it is broken (i.e., the
1507 * symbolic reference cannot even be resolved to an object
1508 * name):
1510 PEEL_BROKEN = -4
1514 * Peel the named object; i.e., if the object is a tag, resolve the
1515 * tag recursively until a non-tag is found. If successful, store the
1516 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1517 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1518 * and leave sha1 unchanged.
1520 static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
1522 struct object *o = lookup_unknown_object(name);
1524 if (o->type == OBJ_NONE) {
1525 int type = sha1_object_info(name, NULL);
1526 if (type < 0)
1527 return PEEL_INVALID;
1528 o->type = type;
1531 if (o->type != OBJ_TAG)
1532 return PEEL_NON_TAG;
1534 o = deref_tag_noverify(o);
1535 if (!o)
1536 return PEEL_INVALID;
1538 hashcpy(sha1, o->sha1);
1539 return PEEL_PEELED;
1543 * Peel the entry (if possible) and return its new peel_status. If
1544 * repeel is true, re-peel the entry even if there is an old peeled
1545 * value that is already stored in it.
1547 * It is OK to call this function with a packed reference entry that
1548 * might be stale and might even refer to an object that has since
1549 * been garbage-collected. In such a case, if the entry has
1550 * REF_KNOWS_PEELED then leave the status unchanged and return
1551 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1553 static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1555 enum peel_status status;
1557 if (entry->flag & REF_KNOWS_PEELED) {
1558 if (repeel) {
1559 entry->flag &= ~REF_KNOWS_PEELED;
1560 hashclr(entry->u.value.peeled);
1561 } else {
1562 return is_null_sha1(entry->u.value.peeled) ?
1563 PEEL_NON_TAG : PEEL_PEELED;
1566 if (entry->flag & REF_ISBROKEN)
1567 return PEEL_BROKEN;
1568 if (entry->flag & REF_ISSYMREF)
1569 return PEEL_IS_SYMREF;
1571 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1572 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1573 entry->flag |= REF_KNOWS_PEELED;
1574 return status;
1577 int peel_ref(const char *refname, unsigned char *sha1)
1579 int flag;
1580 unsigned char base[20];
1582 if (current_ref && (current_ref->name == refname
1583 || !strcmp(current_ref->name, refname))) {
1584 if (peel_entry(current_ref, 0))
1585 return -1;
1586 hashcpy(sha1, current_ref->u.value.peeled);
1587 return 0;
1590 if (read_ref_full(refname, base, 1, &flag))
1591 return -1;
1594 * If the reference is packed, read its ref_entry from the
1595 * cache in the hope that we already know its peeled value.
1596 * We only try this optimization on packed references because
1597 * (a) forcing the filling of the loose reference cache could
1598 * be expensive and (b) loose references anyway usually do not
1599 * have REF_KNOWS_PEELED.
1601 if (flag & REF_ISPACKED) {
1602 struct ref_entry *r = get_packed_ref(refname);
1603 if (r) {
1604 if (peel_entry(r, 0))
1605 return -1;
1606 hashcpy(sha1, r->u.value.peeled);
1607 return 0;
1611 return peel_object(base, sha1);
1614 struct warn_if_dangling_data {
1615 FILE *fp;
1616 const char *refname;
1617 const char *msg_fmt;
1620 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1621 int flags, void *cb_data)
1623 struct warn_if_dangling_data *d = cb_data;
1624 const char *resolves_to;
1625 unsigned char junk[20];
1627 if (!(flags & REF_ISSYMREF))
1628 return 0;
1630 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1631 if (!resolves_to || strcmp(resolves_to, d->refname))
1632 return 0;
1634 fprintf(d->fp, d->msg_fmt, refname);
1635 fputc('\n', d->fp);
1636 return 0;
1639 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1641 struct warn_if_dangling_data data;
1643 data.fp = fp;
1644 data.refname = refname;
1645 data.msg_fmt = msg_fmt;
1646 for_each_rawref(warn_if_dangling_symref, &data);
1650 * Call fn for each reference in the specified ref_cache, omitting
1651 * references not in the containing_dir of base. fn is called for all
1652 * references, including broken ones. If fn ever returns a non-zero
1653 * value, stop the iteration and return that value; otherwise, return
1654 * 0.
1656 static int do_for_each_entry(struct ref_cache *refs, const char *base,
1657 each_ref_entry_fn fn, void *cb_data)
1659 struct packed_ref_cache *packed_ref_cache;
1660 struct ref_dir *loose_dir;
1661 struct ref_dir *packed_dir;
1662 int retval = 0;
1665 * We must make sure that all loose refs are read before accessing the
1666 * packed-refs file; this avoids a race condition in which loose refs
1667 * are migrated to the packed-refs file by a simultaneous process, but
1668 * our in-memory view is from before the migration. get_packed_ref_cache()
1669 * takes care of making sure our view is up to date with what is on
1670 * disk.
1672 loose_dir = get_loose_refs(refs);
1673 if (base && *base) {
1674 loose_dir = find_containing_dir(loose_dir, base, 0);
1676 if (loose_dir)
1677 prime_ref_dir(loose_dir);
1679 packed_ref_cache = get_packed_ref_cache(refs);
1680 acquire_packed_ref_cache(packed_ref_cache);
1681 packed_dir = get_packed_ref_dir(packed_ref_cache);
1682 if (base && *base) {
1683 packed_dir = find_containing_dir(packed_dir, base, 0);
1686 if (packed_dir && loose_dir) {
1687 sort_ref_dir(packed_dir);
1688 sort_ref_dir(loose_dir);
1689 retval = do_for_each_entry_in_dirs(
1690 packed_dir, loose_dir, fn, cb_data);
1691 } else if (packed_dir) {
1692 sort_ref_dir(packed_dir);
1693 retval = do_for_each_entry_in_dir(
1694 packed_dir, 0, fn, cb_data);
1695 } else if (loose_dir) {
1696 sort_ref_dir(loose_dir);
1697 retval = do_for_each_entry_in_dir(
1698 loose_dir, 0, fn, cb_data);
1701 release_packed_ref_cache(packed_ref_cache);
1702 return retval;
1706 * Call fn for each reference in the specified ref_cache for which the
1707 * refname begins with base. If trim is non-zero, then trim that many
1708 * characters off the beginning of each refname before passing the
1709 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1710 * broken references in the iteration. If fn ever returns a non-zero
1711 * value, stop the iteration and return that value; otherwise, return
1712 * 0.
1714 static int do_for_each_ref(struct ref_cache *refs, const char *base,
1715 each_ref_fn fn, int trim, int flags, void *cb_data)
1717 struct ref_entry_cb data;
1718 data.base = base;
1719 data.trim = trim;
1720 data.flags = flags;
1721 data.fn = fn;
1722 data.cb_data = cb_data;
1724 return do_for_each_entry(refs, base, do_one_ref, &data);
1727 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1729 unsigned char sha1[20];
1730 int flag;
1732 if (submodule) {
1733 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1734 return fn("HEAD", sha1, 0, cb_data);
1736 return 0;
1739 if (!read_ref_full("HEAD", sha1, 1, &flag))
1740 return fn("HEAD", sha1, flag, cb_data);
1742 return 0;
1745 int head_ref(each_ref_fn fn, void *cb_data)
1747 return do_head_ref(NULL, fn, cb_data);
1750 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1752 return do_head_ref(submodule, fn, cb_data);
1755 int for_each_ref(each_ref_fn fn, void *cb_data)
1757 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1760 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1762 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
1765 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1767 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1770 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1771 each_ref_fn fn, void *cb_data)
1773 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
1776 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1778 return for_each_ref_in("refs/tags/", fn, cb_data);
1781 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1783 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1786 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1788 return for_each_ref_in("refs/heads/", fn, cb_data);
1791 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1793 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1796 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1798 return for_each_ref_in("refs/remotes/", fn, cb_data);
1801 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1803 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1806 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1808 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
1811 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1813 struct strbuf buf = STRBUF_INIT;
1814 int ret = 0;
1815 unsigned char sha1[20];
1816 int flag;
1818 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
1819 if (!read_ref_full(buf.buf, sha1, 1, &flag))
1820 ret = fn(buf.buf, sha1, flag, cb_data);
1821 strbuf_release(&buf);
1823 return ret;
1826 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1828 struct strbuf buf = STRBUF_INIT;
1829 int ret;
1830 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1831 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
1832 strbuf_release(&buf);
1833 return ret;
1836 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1837 const char *prefix, void *cb_data)
1839 struct strbuf real_pattern = STRBUF_INIT;
1840 struct ref_filter filter;
1841 int ret;
1843 if (!prefix && prefixcmp(pattern, "refs/"))
1844 strbuf_addstr(&real_pattern, "refs/");
1845 else if (prefix)
1846 strbuf_addstr(&real_pattern, prefix);
1847 strbuf_addstr(&real_pattern, pattern);
1849 if (!has_glob_specials(pattern)) {
1850 /* Append implied '/' '*' if not present. */
1851 if (real_pattern.buf[real_pattern.len - 1] != '/')
1852 strbuf_addch(&real_pattern, '/');
1853 /* No need to check for '*', there is none. */
1854 strbuf_addch(&real_pattern, '*');
1857 filter.pattern = real_pattern.buf;
1858 filter.fn = fn;
1859 filter.cb_data = cb_data;
1860 ret = for_each_ref(filter_refs, &filter);
1862 strbuf_release(&real_pattern);
1863 return ret;
1866 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1868 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1871 int for_each_rawref(each_ref_fn fn, void *cb_data)
1873 return do_for_each_ref(&ref_cache, "", fn, 0,
1874 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1877 const char *prettify_refname(const char *name)
1879 return name + (
1880 !prefixcmp(name, "refs/heads/") ? 11 :
1881 !prefixcmp(name, "refs/tags/") ? 10 :
1882 !prefixcmp(name, "refs/remotes/") ? 13 :
1886 const char *ref_rev_parse_rules[] = {
1887 "%.*s",
1888 "refs/%.*s",
1889 "refs/tags/%.*s",
1890 "refs/heads/%.*s",
1891 "refs/remotes/%.*s",
1892 "refs/remotes/%.*s/HEAD",
1893 NULL
1896 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1898 const char **p;
1899 const int abbrev_name_len = strlen(abbrev_name);
1901 for (p = rules; *p; p++) {
1902 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1903 return 1;
1907 return 0;
1910 static struct ref_lock *verify_lock(struct ref_lock *lock,
1911 const unsigned char *old_sha1, int mustexist)
1913 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
1914 error("Can't verify ref %s", lock->ref_name);
1915 unlock_ref(lock);
1916 return NULL;
1918 if (hashcmp(lock->old_sha1, old_sha1)) {
1919 error("Ref %s is at %s but expected %s", lock->ref_name,
1920 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1921 unlock_ref(lock);
1922 return NULL;
1924 return lock;
1927 static int remove_empty_directories(const char *file)
1929 /* we want to create a file but there is a directory there;
1930 * if that is an empty directory (or a directory that contains
1931 * only empty directories), remove them.
1933 struct strbuf path;
1934 int result;
1936 strbuf_init(&path, 20);
1937 strbuf_addstr(&path, file);
1939 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
1941 strbuf_release(&path);
1943 return result;
1947 * *string and *len will only be substituted, and *string returned (for
1948 * later free()ing) if the string passed in is a magic short-hand form
1949 * to name a branch.
1951 static char *substitute_branch_name(const char **string, int *len)
1953 struct strbuf buf = STRBUF_INIT;
1954 int ret = interpret_branch_name(*string, &buf);
1956 if (ret == *len) {
1957 size_t size;
1958 *string = strbuf_detach(&buf, &size);
1959 *len = size;
1960 return (char *)*string;
1963 return NULL;
1966 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1968 char *last_branch = substitute_branch_name(&str, &len);
1969 const char **p, *r;
1970 int refs_found = 0;
1972 *ref = NULL;
1973 for (p = ref_rev_parse_rules; *p; p++) {
1974 char fullref[PATH_MAX];
1975 unsigned char sha1_from_ref[20];
1976 unsigned char *this_result;
1977 int flag;
1979 this_result = refs_found ? sha1_from_ref : sha1;
1980 mksnpath(fullref, sizeof(fullref), *p, len, str);
1981 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
1982 if (r) {
1983 if (!refs_found++)
1984 *ref = xstrdup(r);
1985 if (!warn_ambiguous_refs)
1986 break;
1987 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
1988 warning("ignoring dangling symref %s.", fullref);
1989 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1990 warning("ignoring broken ref %s.", fullref);
1993 free(last_branch);
1994 return refs_found;
1997 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1999 char *last_branch = substitute_branch_name(&str, &len);
2000 const char **p;
2001 int logs_found = 0;
2003 *log = NULL;
2004 for (p = ref_rev_parse_rules; *p; p++) {
2005 struct stat st;
2006 unsigned char hash[20];
2007 char path[PATH_MAX];
2008 const char *ref, *it;
2010 mksnpath(path, sizeof(path), *p, len, str);
2011 ref = resolve_ref_unsafe(path, hash, 1, NULL);
2012 if (!ref)
2013 continue;
2014 if (!stat(git_path("logs/%s", path), &st) &&
2015 S_ISREG(st.st_mode))
2016 it = path;
2017 else if (strcmp(ref, path) &&
2018 !stat(git_path("logs/%s", ref), &st) &&
2019 S_ISREG(st.st_mode))
2020 it = ref;
2021 else
2022 continue;
2023 if (!logs_found++) {
2024 *log = xstrdup(it);
2025 hashcpy(sha1, hash);
2027 if (!warn_ambiguous_refs)
2028 break;
2030 free(last_branch);
2031 return logs_found;
2034 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2035 const unsigned char *old_sha1,
2036 int flags, int *type_p)
2038 char *ref_file;
2039 const char *orig_refname = refname;
2040 struct ref_lock *lock;
2041 int last_errno = 0;
2042 int type, lflags;
2043 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
2044 int missing = 0;
2046 lock = xcalloc(1, sizeof(struct ref_lock));
2047 lock->lock_fd = -1;
2049 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
2050 if (!refname && errno == EISDIR) {
2051 /* we are trying to lock foo but we used to
2052 * have foo/bar which now does not exist;
2053 * it is normal for the empty directory 'foo'
2054 * to remain.
2056 ref_file = git_path("%s", orig_refname);
2057 if (remove_empty_directories(ref_file)) {
2058 last_errno = errno;
2059 error("there are still refs under '%s'", orig_refname);
2060 goto error_return;
2062 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
2064 if (type_p)
2065 *type_p = type;
2066 if (!refname) {
2067 last_errno = errno;
2068 error("unable to resolve reference %s: %s",
2069 orig_refname, strerror(errno));
2070 goto error_return;
2072 missing = is_null_sha1(lock->old_sha1);
2073 /* When the ref did not exist and we are creating it,
2074 * make sure there is no existing ref that is packed
2075 * whose name begins with our refname, nor a ref whose
2076 * name is a proper prefix of our refname.
2078 if (missing &&
2079 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
2080 last_errno = ENOTDIR;
2081 goto error_return;
2084 lock->lk = xcalloc(1, sizeof(struct lock_file));
2086 lflags = LOCK_DIE_ON_ERROR;
2087 if (flags & REF_NODEREF) {
2088 refname = orig_refname;
2089 lflags |= LOCK_NODEREF;
2091 lock->ref_name = xstrdup(refname);
2092 lock->orig_ref_name = xstrdup(orig_refname);
2093 ref_file = git_path("%s", refname);
2094 if (missing)
2095 lock->force_write = 1;
2096 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2097 lock->force_write = 1;
2099 if (safe_create_leading_directories(ref_file)) {
2100 last_errno = errno;
2101 error("unable to create directory for %s", ref_file);
2102 goto error_return;
2105 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
2106 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
2108 error_return:
2109 unlock_ref(lock);
2110 errno = last_errno;
2111 return NULL;
2114 struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
2116 char refpath[PATH_MAX];
2117 if (check_refname_format(refname, 0))
2118 return NULL;
2119 strcpy(refpath, mkpath("refs/%s", refname));
2120 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
2123 struct ref_lock *lock_any_ref_for_update(const char *refname,
2124 const unsigned char *old_sha1, int flags)
2126 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
2127 return NULL;
2128 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
2132 * Write an entry to the packed-refs file for the specified refname.
2133 * If peeled is non-NULL, write it as the entry's peeled value.
2135 static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2136 unsigned char *peeled)
2138 char line[PATH_MAX + 100];
2139 int len;
2141 len = snprintf(line, sizeof(line), "%s %s\n",
2142 sha1_to_hex(sha1), refname);
2143 /* this should not happen but just being defensive */
2144 if (len > sizeof(line))
2145 die("too long a refname '%s'", refname);
2146 write_or_die(fd, line, len);
2148 if (peeled) {
2149 if (snprintf(line, sizeof(line), "^%s\n",
2150 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2151 die("internal error");
2152 write_or_die(fd, line, PEELED_LINE_LENGTH);
2157 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2159 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2161 int *fd = cb_data;
2162 enum peel_status peel_status = peel_entry(entry, 0);
2164 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2165 error("internal error: %s is not a valid packed reference!",
2166 entry->name);
2167 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2168 peel_status == PEEL_PEELED ?
2169 entry->u.value.peeled : NULL);
2170 return 0;
2173 int lock_packed_refs(int flags)
2175 struct packed_ref_cache *packed_ref_cache;
2177 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2178 return -1;
2180 * Get the current packed-refs while holding the lock. If the
2181 * packed-refs file has been modified since we last read it,
2182 * this will automatically invalidate the cache and re-read
2183 * the packed-refs file.
2185 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2186 packed_ref_cache->lock = &packlock;
2187 /* Increment the reference count to prevent it from being freed: */
2188 acquire_packed_ref_cache(packed_ref_cache);
2189 return 0;
2192 int commit_packed_refs(void)
2194 struct packed_ref_cache *packed_ref_cache =
2195 get_packed_ref_cache(&ref_cache);
2196 int error = 0;
2198 if (!packed_ref_cache->lock)
2199 die("internal error: packed-refs not locked");
2200 write_or_die(packed_ref_cache->lock->fd,
2201 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2203 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2204 0, write_packed_entry_fn,
2205 &packed_ref_cache->lock->fd);
2206 if (commit_lock_file(packed_ref_cache->lock))
2207 error = -1;
2208 packed_ref_cache->lock = NULL;
2209 release_packed_ref_cache(packed_ref_cache);
2210 return error;
2213 void rollback_packed_refs(void)
2215 struct packed_ref_cache *packed_ref_cache =
2216 get_packed_ref_cache(&ref_cache);
2218 if (!packed_ref_cache->lock)
2219 die("internal error: packed-refs not locked");
2220 rollback_lock_file(packed_ref_cache->lock);
2221 packed_ref_cache->lock = NULL;
2222 release_packed_ref_cache(packed_ref_cache);
2223 clear_packed_ref_cache(&ref_cache);
2226 struct ref_to_prune {
2227 struct ref_to_prune *next;
2228 unsigned char sha1[20];
2229 char name[FLEX_ARRAY];
2232 struct pack_refs_cb_data {
2233 unsigned int flags;
2234 struct ref_dir *packed_refs;
2235 struct ref_to_prune *ref_to_prune;
2239 * An each_ref_entry_fn that is run over loose references only. If
2240 * the loose reference can be packed, add an entry in the packed ref
2241 * cache. If the reference should be pruned, also add it to
2242 * ref_to_prune in the pack_refs_cb_data.
2244 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2246 struct pack_refs_cb_data *cb = cb_data;
2247 enum peel_status peel_status;
2248 struct ref_entry *packed_entry;
2249 int is_tag_ref = !prefixcmp(entry->name, "refs/tags/");
2251 /* ALWAYS pack tags */
2252 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2253 return 0;
2255 /* Do not pack symbolic or broken refs: */
2256 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2257 return 0;
2259 /* Add a packed ref cache entry equivalent to the loose entry. */
2260 peel_status = peel_entry(entry, 1);
2261 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2262 die("internal error peeling reference %s (%s)",
2263 entry->name, sha1_to_hex(entry->u.value.sha1));
2264 packed_entry = find_ref(cb->packed_refs, entry->name);
2265 if (packed_entry) {
2266 /* Overwrite existing packed entry with info from loose entry */
2267 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2268 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2269 } else {
2270 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2271 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2272 add_ref(cb->packed_refs, packed_entry);
2274 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
2276 /* Schedule the loose reference for pruning if requested. */
2277 if ((cb->flags & PACK_REFS_PRUNE)) {
2278 int namelen = strlen(entry->name) + 1;
2279 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
2280 hashcpy(n->sha1, entry->u.value.sha1);
2281 strcpy(n->name, entry->name);
2282 n->next = cb->ref_to_prune;
2283 cb->ref_to_prune = n;
2285 return 0;
2289 * Remove empty parents, but spare refs/ and immediate subdirs.
2290 * Note: munges *name.
2292 static void try_remove_empty_parents(char *name)
2294 char *p, *q;
2295 int i;
2296 p = name;
2297 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2298 while (*p && *p != '/')
2299 p++;
2300 /* tolerate duplicate slashes; see check_refname_format() */
2301 while (*p == '/')
2302 p++;
2304 for (q = p; *q; q++)
2306 while (1) {
2307 while (q > p && *q != '/')
2308 q--;
2309 while (q > p && *(q-1) == '/')
2310 q--;
2311 if (q == p)
2312 break;
2313 *q = '\0';
2314 if (rmdir(git_path("%s", name)))
2315 break;
2319 /* make sure nobody touched the ref, and unlink */
2320 static void prune_ref(struct ref_to_prune *r)
2322 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2324 if (lock) {
2325 unlink_or_warn(git_path("%s", r->name));
2326 unlock_ref(lock);
2327 try_remove_empty_parents(r->name);
2331 static void prune_refs(struct ref_to_prune *r)
2333 while (r) {
2334 prune_ref(r);
2335 r = r->next;
2339 int pack_refs(unsigned int flags)
2341 struct pack_refs_cb_data cbdata;
2343 memset(&cbdata, 0, sizeof(cbdata));
2344 cbdata.flags = flags;
2346 lock_packed_refs(LOCK_DIE_ON_ERROR);
2347 cbdata.packed_refs = get_packed_refs(&ref_cache);
2349 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2350 pack_if_possible_fn, &cbdata);
2352 if (commit_packed_refs())
2353 die_errno("unable to overwrite old ref-pack file");
2355 prune_refs(cbdata.ref_to_prune);
2356 return 0;
2360 * If entry is no longer needed in packed-refs, add it to the string
2361 * list pointed to by cb_data. Reasons for deleting entries:
2363 * - Entry is broken.
2364 * - Entry is overridden by a loose ref.
2365 * - Entry does not point at a valid object.
2367 * In the first and third cases, also emit an error message because these
2368 * are indications of repository corruption.
2370 static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
2372 struct string_list *refs_to_delete = cb_data;
2374 if (entry->flag & REF_ISBROKEN) {
2375 /* This shouldn't happen to packed refs. */
2376 error("%s is broken!", entry->name);
2377 string_list_append(refs_to_delete, entry->name);
2378 return 0;
2380 if (!has_sha1_file(entry->u.value.sha1)) {
2381 unsigned char sha1[20];
2382 int flags;
2384 if (read_ref_full(entry->name, sha1, 0, &flags))
2385 /* We should at least have found the packed ref. */
2386 die("Internal error");
2387 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
2389 * This packed reference is overridden by a
2390 * loose reference, so it is OK that its value
2391 * is no longer valid; for example, it might
2392 * refer to an object that has been garbage
2393 * collected. For this purpose we don't even
2394 * care whether the loose reference itself is
2395 * invalid, broken, symbolic, etc. Silently
2396 * remove the packed reference.
2398 string_list_append(refs_to_delete, entry->name);
2399 return 0;
2402 * There is no overriding loose reference, so the fact
2403 * that this reference doesn't refer to a valid object
2404 * indicates some kind of repository corruption.
2405 * Report the problem, then omit the reference from
2406 * the output.
2408 error("%s does not point to a valid object!", entry->name);
2409 string_list_append(refs_to_delete, entry->name);
2410 return 0;
2413 return 0;
2416 static int repack_without_ref(const char *refname)
2418 struct ref_dir *packed;
2419 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2420 struct string_list_item *ref_to_delete;
2422 if (!get_packed_ref(refname))
2423 return 0; /* refname does not exist in packed refs */
2425 if (lock_packed_refs(0)) {
2426 unable_to_lock_error(git_path("packed-refs"), errno);
2427 return error("cannot delete '%s' from packed refs", refname);
2429 packed = get_packed_refs(&ref_cache);
2431 /* Remove refname from the cache: */
2432 if (remove_entry(packed, refname) == -1) {
2434 * The packed entry disappeared while we were
2435 * acquiring the lock.
2437 rollback_packed_refs();
2438 return 0;
2441 /* Remove any other accumulated cruft: */
2442 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2443 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2444 if (remove_entry(packed, ref_to_delete->string) == -1)
2445 die("internal error");
2448 /* Write what remains: */
2449 return commit_packed_refs();
2452 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
2454 struct ref_lock *lock;
2455 int err, i = 0, ret = 0, flag = 0;
2457 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
2458 if (!lock)
2459 return 1;
2460 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2461 /* loose */
2462 i = strlen(lock->lk->filename) - 5; /* .lock */
2463 lock->lk->filename[i] = 0;
2464 err = unlink_or_warn(lock->lk->filename);
2465 if (err && errno != ENOENT)
2466 ret = 1;
2468 lock->lk->filename[i] = '.';
2470 /* removing the loose one could have resurrected an earlier
2471 * packed one. Also, if it was not loose we need to repack
2472 * without it.
2474 ret |= repack_without_ref(lock->ref_name);
2476 unlink_or_warn(git_path("logs/%s", lock->ref_name));
2477 clear_loose_ref_cache(&ref_cache);
2478 unlock_ref(lock);
2479 return ret;
2483 * People using contrib's git-new-workdir have .git/logs/refs ->
2484 * /some/other/path/.git/logs/refs, and that may live on another device.
2486 * IOW, to avoid cross device rename errors, the temporary renamed log must
2487 * live into logs/refs.
2489 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2491 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
2493 unsigned char sha1[20], orig_sha1[20];
2494 int flag = 0, logmoved = 0;
2495 struct ref_lock *lock;
2496 struct stat loginfo;
2497 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2498 const char *symref = NULL;
2500 if (log && S_ISLNK(loginfo.st_mode))
2501 return error("reflog for %s is a symlink", oldrefname);
2503 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
2504 if (flag & REF_ISSYMREF)
2505 return error("refname %s is a symbolic ref, renaming it is not supported",
2506 oldrefname);
2507 if (!symref)
2508 return error("refname %s not found", oldrefname);
2510 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
2511 return 1;
2513 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
2514 return 1;
2516 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2517 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2518 oldrefname, strerror(errno));
2520 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2521 error("unable to delete old %s", oldrefname);
2522 goto rollback;
2525 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2526 delete_ref(newrefname, sha1, REF_NODEREF)) {
2527 if (errno==EISDIR) {
2528 if (remove_empty_directories(git_path("%s", newrefname))) {
2529 error("Directory not empty: %s", newrefname);
2530 goto rollback;
2532 } else {
2533 error("unable to delete existing %s", newrefname);
2534 goto rollback;
2538 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2539 error("unable to create directory for %s", newrefname);
2540 goto rollback;
2543 retry:
2544 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
2545 if (errno==EISDIR || errno==ENOTDIR) {
2547 * rename(a, b) when b is an existing
2548 * directory ought to result in ISDIR, but
2549 * Solaris 5.8 gives ENOTDIR. Sheesh.
2551 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2552 error("Directory not empty: logs/%s", newrefname);
2553 goto rollback;
2555 goto retry;
2556 } else {
2557 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2558 newrefname, strerror(errno));
2559 goto rollback;
2562 logmoved = log;
2564 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
2565 if (!lock) {
2566 error("unable to lock %s for update", newrefname);
2567 goto rollback;
2569 lock->force_write = 1;
2570 hashcpy(lock->old_sha1, orig_sha1);
2571 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
2572 error("unable to write current sha1 into %s", newrefname);
2573 goto rollback;
2576 return 0;
2578 rollback:
2579 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
2580 if (!lock) {
2581 error("unable to lock %s for rollback", oldrefname);
2582 goto rollbacklog;
2585 lock->force_write = 1;
2586 flag = log_all_ref_updates;
2587 log_all_ref_updates = 0;
2588 if (write_ref_sha1(lock, orig_sha1, NULL))
2589 error("unable to write current sha1 into %s", oldrefname);
2590 log_all_ref_updates = flag;
2592 rollbacklog:
2593 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2594 error("unable to restore logfile %s from %s: %s",
2595 oldrefname, newrefname, strerror(errno));
2596 if (!logmoved && log &&
2597 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2598 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2599 oldrefname, strerror(errno));
2601 return 1;
2604 int close_ref(struct ref_lock *lock)
2606 if (close_lock_file(lock->lk))
2607 return -1;
2608 lock->lock_fd = -1;
2609 return 0;
2612 int commit_ref(struct ref_lock *lock)
2614 if (commit_lock_file(lock->lk))
2615 return -1;
2616 lock->lock_fd = -1;
2617 return 0;
2620 void unlock_ref(struct ref_lock *lock)
2622 /* Do not free lock->lk -- atexit() still looks at them */
2623 if (lock->lk)
2624 rollback_lock_file(lock->lk);
2625 free(lock->ref_name);
2626 free(lock->orig_ref_name);
2627 free(lock);
2631 * copy the reflog message msg to buf, which has been allocated sufficiently
2632 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2633 * because reflog file is one line per entry.
2635 static int copy_msg(char *buf, const char *msg)
2637 char *cp = buf;
2638 char c;
2639 int wasspace = 1;
2641 *cp++ = '\t';
2642 while ((c = *msg++)) {
2643 if (wasspace && isspace(c))
2644 continue;
2645 wasspace = isspace(c);
2646 if (wasspace)
2647 c = ' ';
2648 *cp++ = c;
2650 while (buf < cp && isspace(cp[-1]))
2651 cp--;
2652 *cp++ = '\n';
2653 return cp - buf;
2656 int log_ref_setup(const char *refname, char *logfile, int bufsize)
2658 int logfd, oflags = O_APPEND | O_WRONLY;
2660 git_snpath(logfile, bufsize, "logs/%s", refname);
2661 if (log_all_ref_updates &&
2662 (!prefixcmp(refname, "refs/heads/") ||
2663 !prefixcmp(refname, "refs/remotes/") ||
2664 !prefixcmp(refname, "refs/notes/") ||
2665 !strcmp(refname, "HEAD"))) {
2666 if (safe_create_leading_directories(logfile) < 0)
2667 return error("unable to create directory for %s",
2668 logfile);
2669 oflags |= O_CREAT;
2672 logfd = open(logfile, oflags, 0666);
2673 if (logfd < 0) {
2674 if (!(oflags & O_CREAT) && errno == ENOENT)
2675 return 0;
2677 if ((oflags & O_CREAT) && errno == EISDIR) {
2678 if (remove_empty_directories(logfile)) {
2679 return error("There are still logs under '%s'",
2680 logfile);
2682 logfd = open(logfile, oflags, 0666);
2685 if (logfd < 0)
2686 return error("Unable to append to %s: %s",
2687 logfile, strerror(errno));
2690 adjust_shared_perm(logfile);
2691 close(logfd);
2692 return 0;
2695 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2696 const unsigned char *new_sha1, const char *msg)
2698 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2699 unsigned maxlen, len;
2700 int msglen;
2701 char log_file[PATH_MAX];
2702 char *logrec;
2703 const char *committer;
2705 if (log_all_ref_updates < 0)
2706 log_all_ref_updates = !is_bare_repository();
2708 result = log_ref_setup(refname, log_file, sizeof(log_file));
2709 if (result)
2710 return result;
2712 logfd = open(log_file, oflags);
2713 if (logfd < 0)
2714 return 0;
2715 msglen = msg ? strlen(msg) : 0;
2716 committer = git_committer_info(0);
2717 maxlen = strlen(committer) + msglen + 100;
2718 logrec = xmalloc(maxlen);
2719 len = sprintf(logrec, "%s %s %s\n",
2720 sha1_to_hex(old_sha1),
2721 sha1_to_hex(new_sha1),
2722 committer);
2723 if (msglen)
2724 len += copy_msg(logrec + len - 1, msg) - 1;
2725 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
2726 free(logrec);
2727 if (close(logfd) != 0 || written != len)
2728 return error("Unable to append to %s", log_file);
2729 return 0;
2732 static int is_branch(const char *refname)
2734 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2737 int write_ref_sha1(struct ref_lock *lock,
2738 const unsigned char *sha1, const char *logmsg)
2740 static char term = '\n';
2741 struct object *o;
2743 if (!lock)
2744 return -1;
2745 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
2746 unlock_ref(lock);
2747 return 0;
2749 o = parse_object(sha1);
2750 if (!o) {
2751 error("Trying to write ref %s with nonexistent object %s",
2752 lock->ref_name, sha1_to_hex(sha1));
2753 unlock_ref(lock);
2754 return -1;
2756 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2757 error("Trying to write non-commit object %s to branch %s",
2758 sha1_to_hex(sha1), lock->ref_name);
2759 unlock_ref(lock);
2760 return -1;
2762 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2763 write_in_full(lock->lock_fd, &term, 1) != 1
2764 || close_ref(lock) < 0) {
2765 error("Couldn't write %s", lock->lk->filename);
2766 unlock_ref(lock);
2767 return -1;
2769 clear_loose_ref_cache(&ref_cache);
2770 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2771 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2772 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
2773 unlock_ref(lock);
2774 return -1;
2776 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2778 * Special hack: If a branch is updated directly and HEAD
2779 * points to it (may happen on the remote side of a push
2780 * for example) then logically the HEAD reflog should be
2781 * updated too.
2782 * A generic solution implies reverse symref information,
2783 * but finding all symrefs pointing to the given branch
2784 * would be rather costly for this rare event (the direct
2785 * update of a branch) to be worth it. So let's cheat and
2786 * check with HEAD only which should cover 99% of all usage
2787 * scenarios (even 100% of the default ones).
2789 unsigned char head_sha1[20];
2790 int head_flag;
2791 const char *head_ref;
2792 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
2793 if (head_ref && (head_flag & REF_ISSYMREF) &&
2794 !strcmp(head_ref, lock->ref_name))
2795 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2797 if (commit_ref(lock)) {
2798 error("Couldn't set %s", lock->ref_name);
2799 unlock_ref(lock);
2800 return -1;
2802 unlock_ref(lock);
2803 return 0;
2806 int create_symref(const char *ref_target, const char *refs_heads_master,
2807 const char *logmsg)
2809 const char *lockpath;
2810 char ref[1000];
2811 int fd, len, written;
2812 char *git_HEAD = git_pathdup("%s", ref_target);
2813 unsigned char old_sha1[20], new_sha1[20];
2815 if (logmsg && read_ref(ref_target, old_sha1))
2816 hashclr(old_sha1);
2818 if (safe_create_leading_directories(git_HEAD) < 0)
2819 return error("unable to create directory for %s", git_HEAD);
2821 #ifndef NO_SYMLINK_HEAD
2822 if (prefer_symlink_refs) {
2823 unlink(git_HEAD);
2824 if (!symlink(refs_heads_master, git_HEAD))
2825 goto done;
2826 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2828 #endif
2830 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2831 if (sizeof(ref) <= len) {
2832 error("refname too long: %s", refs_heads_master);
2833 goto error_free_return;
2835 lockpath = mkpath("%s.lock", git_HEAD);
2836 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2837 if (fd < 0) {
2838 error("Unable to open %s for writing", lockpath);
2839 goto error_free_return;
2841 written = write_in_full(fd, ref, len);
2842 if (close(fd) != 0 || written != len) {
2843 error("Unable to write to %s", lockpath);
2844 goto error_unlink_return;
2846 if (rename(lockpath, git_HEAD) < 0) {
2847 error("Unable to create %s", git_HEAD);
2848 goto error_unlink_return;
2850 if (adjust_shared_perm(git_HEAD)) {
2851 error("Unable to fix permissions on %s", lockpath);
2852 error_unlink_return:
2853 unlink_or_warn(lockpath);
2854 error_free_return:
2855 free(git_HEAD);
2856 return -1;
2859 #ifndef NO_SYMLINK_HEAD
2860 done:
2861 #endif
2862 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2863 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2865 free(git_HEAD);
2866 return 0;
2869 static char *ref_msg(const char *line, const char *endp)
2871 const char *ep;
2872 line += 82;
2873 ep = memchr(line, '\n', endp - line);
2874 if (!ep)
2875 ep = endp;
2876 return xmemdupz(line, ep - line);
2879 int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2880 unsigned char *sha1, char **msg,
2881 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
2883 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
2884 char *tz_c;
2885 int logfd, tz, reccnt = 0;
2886 struct stat st;
2887 unsigned long date;
2888 unsigned char logged_sha1[20];
2889 void *log_mapped;
2890 size_t mapsz;
2892 logfile = git_path("logs/%s", refname);
2893 logfd = open(logfile, O_RDONLY, 0);
2894 if (logfd < 0)
2895 die_errno("Unable to read log '%s'", logfile);
2896 fstat(logfd, &st);
2897 if (!st.st_size)
2898 die("Log %s is empty.", logfile);
2899 mapsz = xsize_t(st.st_size);
2900 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
2901 logdata = log_mapped;
2902 close(logfd);
2904 lastrec = NULL;
2905 rec = logend = logdata + st.st_size;
2906 while (logdata < rec) {
2907 reccnt++;
2908 if (logdata < rec && *(rec-1) == '\n')
2909 rec--;
2910 lastgt = NULL;
2911 while (logdata < rec && *(rec-1) != '\n') {
2912 rec--;
2913 if (*rec == '>')
2914 lastgt = rec;
2916 if (!lastgt)
2917 die("Log %s is corrupt.", logfile);
2918 date = strtoul(lastgt + 1, &tz_c, 10);
2919 if (date <= at_time || cnt == 0) {
2920 tz = strtoul(tz_c, NULL, 10);
2921 if (msg)
2922 *msg = ref_msg(rec, logend);
2923 if (cutoff_time)
2924 *cutoff_time = date;
2925 if (cutoff_tz)
2926 *cutoff_tz = tz;
2927 if (cutoff_cnt)
2928 *cutoff_cnt = reccnt - 1;
2929 if (lastrec) {
2930 if (get_sha1_hex(lastrec, logged_sha1))
2931 die("Log %s is corrupt.", logfile);
2932 if (get_sha1_hex(rec + 41, sha1))
2933 die("Log %s is corrupt.", logfile);
2934 if (hashcmp(logged_sha1, sha1)) {
2935 warning("Log %s has gap after %s.",
2936 logfile, show_date(date, tz, DATE_RFC2822));
2939 else if (date == at_time) {
2940 if (get_sha1_hex(rec + 41, sha1))
2941 die("Log %s is corrupt.", logfile);
2943 else {
2944 if (get_sha1_hex(rec + 41, logged_sha1))
2945 die("Log %s is corrupt.", logfile);
2946 if (hashcmp(logged_sha1, sha1)) {
2947 warning("Log %s unexpectedly ended on %s.",
2948 logfile, show_date(date, tz, DATE_RFC2822));
2951 munmap(log_mapped, mapsz);
2952 return 0;
2954 lastrec = rec;
2955 if (cnt > 0)
2956 cnt--;
2959 rec = logdata;
2960 while (rec < logend && *rec != '>' && *rec != '\n')
2961 rec++;
2962 if (rec == logend || *rec == '\n')
2963 die("Log %s is corrupt.", logfile);
2964 date = strtoul(rec + 1, &tz_c, 10);
2965 tz = strtoul(tz_c, NULL, 10);
2966 if (get_sha1_hex(logdata, sha1))
2967 die("Log %s is corrupt.", logfile);
2968 if (is_null_sha1(sha1)) {
2969 if (get_sha1_hex(logdata + 41, sha1))
2970 die("Log %s is corrupt.", logfile);
2972 if (msg)
2973 *msg = ref_msg(logdata, logend);
2974 munmap(log_mapped, mapsz);
2976 if (cutoff_time)
2977 *cutoff_time = date;
2978 if (cutoff_tz)
2979 *cutoff_tz = tz;
2980 if (cutoff_cnt)
2981 *cutoff_cnt = reccnt;
2982 return 1;
2985 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
2987 unsigned char osha1[20], nsha1[20];
2988 char *email_end, *message;
2989 unsigned long timestamp;
2990 int tz;
2992 /* old SP new SP name <email> SP time TAB msg LF */
2993 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
2994 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
2995 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
2996 !(email_end = strchr(sb->buf + 82, '>')) ||
2997 email_end[1] != ' ' ||
2998 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2999 !message || message[0] != ' ' ||
3000 (message[1] != '+' && message[1] != '-') ||
3001 !isdigit(message[2]) || !isdigit(message[3]) ||
3002 !isdigit(message[4]) || !isdigit(message[5]))
3003 return 0; /* corrupt? */
3004 email_end[1] = '\0';
3005 tz = strtol(message + 1, NULL, 10);
3006 if (message[6] != '\t')
3007 message += 6;
3008 else
3009 message += 7;
3010 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3013 static char *find_beginning_of_line(char *bob, char *scan)
3015 while (bob < scan && *(--scan) != '\n')
3016 ; /* keep scanning backwards */
3018 * Return either beginning of the buffer, or LF at the end of
3019 * the previous line.
3021 return scan;
3024 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3026 struct strbuf sb = STRBUF_INIT;
3027 FILE *logfp;
3028 long pos;
3029 int ret = 0, at_tail = 1;
3031 logfp = fopen(git_path("logs/%s", refname), "r");
3032 if (!logfp)
3033 return -1;
3035 /* Jump to the end */
3036 if (fseek(logfp, 0, SEEK_END) < 0)
3037 return error("cannot seek back reflog for %s: %s",
3038 refname, strerror(errno));
3039 pos = ftell(logfp);
3040 while (!ret && 0 < pos) {
3041 int cnt;
3042 size_t nread;
3043 char buf[BUFSIZ];
3044 char *endp, *scanp;
3046 /* Fill next block from the end */
3047 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3048 if (fseek(logfp, pos - cnt, SEEK_SET))
3049 return error("cannot seek back reflog for %s: %s",
3050 refname, strerror(errno));
3051 nread = fread(buf, cnt, 1, logfp);
3052 if (nread != 1)
3053 return error("cannot read %d bytes from reflog for %s: %s",
3054 cnt, refname, strerror(errno));
3055 pos -= cnt;
3057 scanp = endp = buf + cnt;
3058 if (at_tail && scanp[-1] == '\n')
3059 /* Looking at the final LF at the end of the file */
3060 scanp--;
3061 at_tail = 0;
3063 while (buf < scanp) {
3065 * terminating LF of the previous line, or the beginning
3066 * of the buffer.
3068 char *bp;
3070 bp = find_beginning_of_line(buf, scanp);
3072 if (*bp != '\n') {
3073 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3074 if (pos)
3075 break; /* need to fill another block */
3076 scanp = buf - 1; /* leave loop */
3077 } else {
3079 * (bp + 1) thru endp is the beginning of the
3080 * current line we have in sb
3082 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3083 scanp = bp;
3084 endp = bp + 1;
3086 ret = show_one_reflog_ent(&sb, fn, cb_data);
3087 strbuf_reset(&sb);
3088 if (ret)
3089 break;
3093 if (!ret && sb.len)
3094 ret = show_one_reflog_ent(&sb, fn, cb_data);
3096 fclose(logfp);
3097 strbuf_release(&sb);
3098 return ret;
3101 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3103 FILE *logfp;
3104 struct strbuf sb = STRBUF_INIT;
3105 int ret = 0;
3107 logfp = fopen(git_path("logs/%s", refname), "r");
3108 if (!logfp)
3109 return -1;
3111 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3112 ret = show_one_reflog_ent(&sb, fn, cb_data);
3113 fclose(logfp);
3114 strbuf_release(&sb);
3115 return ret;
3118 * Call fn for each reflog in the namespace indicated by name. name
3119 * must be empty or end with '/'. Name will be used as a scratch
3120 * space, but its contents will be restored before return.
3122 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
3124 DIR *d = opendir(git_path("logs/%s", name->buf));
3125 int retval = 0;
3126 struct dirent *de;
3127 int oldlen = name->len;
3129 if (!d)
3130 return name->len ? errno : 0;
3132 while ((de = readdir(d)) != NULL) {
3133 struct stat st;
3135 if (de->d_name[0] == '.')
3136 continue;
3137 if (has_extension(de->d_name, ".lock"))
3138 continue;
3139 strbuf_addstr(name, de->d_name);
3140 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3141 ; /* silently ignore */
3142 } else {
3143 if (S_ISDIR(st.st_mode)) {
3144 strbuf_addch(name, '/');
3145 retval = do_for_each_reflog(name, fn, cb_data);
3146 } else {
3147 unsigned char sha1[20];
3148 if (read_ref_full(name->buf, sha1, 0, NULL))
3149 retval = error("bad ref for %s", name->buf);
3150 else
3151 retval = fn(name->buf, sha1, 0, cb_data);
3153 if (retval)
3154 break;
3156 strbuf_setlen(name, oldlen);
3158 closedir(d);
3159 return retval;
3162 int for_each_reflog(each_ref_fn fn, void *cb_data)
3164 int retval;
3165 struct strbuf name;
3166 strbuf_init(&name, PATH_MAX);
3167 retval = do_for_each_reflog(&name, fn, cb_data);
3168 strbuf_release(&name);
3169 return retval;
3172 int update_ref(const char *action, const char *refname,
3173 const unsigned char *sha1, const unsigned char *oldval,
3174 int flags, enum action_on_err onerr)
3176 static struct ref_lock *lock;
3177 lock = lock_any_ref_for_update(refname, oldval, flags);
3178 if (!lock) {
3179 const char *str = "Cannot lock the ref '%s'.";
3180 switch (onerr) {
3181 case MSG_ON_ERR: error(str, refname); break;
3182 case DIE_ON_ERR: die(str, refname); break;
3183 case QUIET_ON_ERR: break;
3185 return 1;
3187 if (write_ref_sha1(lock, sha1, action) < 0) {
3188 const char *str = "Cannot update the ref '%s'.";
3189 switch (onerr) {
3190 case MSG_ON_ERR: error(str, refname); break;
3191 case DIE_ON_ERR: die(str, refname); break;
3192 case QUIET_ON_ERR: break;
3194 return 1;
3196 return 0;
3199 struct ref *find_ref_by_name(const struct ref *list, const char *name)
3201 for ( ; list; list = list->next)
3202 if (!strcmp(list->name, name))
3203 return (struct ref *)list;
3204 return NULL;
3208 * generate a format suitable for scanf from a ref_rev_parse_rules
3209 * rule, that is replace the "%.*s" spec with a "%s" spec
3211 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
3213 char *spec;
3215 spec = strstr(rule, "%.*s");
3216 if (!spec || strstr(spec + 4, "%.*s"))
3217 die("invalid rule in ref_rev_parse_rules: %s", rule);
3219 /* copy all until spec */
3220 strncpy(scanf_fmt, rule, spec - rule);
3221 scanf_fmt[spec - rule] = '\0';
3222 /* copy new spec */
3223 strcat(scanf_fmt, "%s");
3224 /* copy remaining rule */
3225 strcat(scanf_fmt, spec + 4);
3227 return;
3230 char *shorten_unambiguous_ref(const char *refname, int strict)
3232 int i;
3233 static char **scanf_fmts;
3234 static int nr_rules;
3235 char *short_name;
3237 /* pre generate scanf formats from ref_rev_parse_rules[] */
3238 if (!nr_rules) {
3239 size_t total_len = 0;
3241 /* the rule list is NULL terminated, count them first */
3242 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
3243 /* no +1 because strlen("%s") < strlen("%.*s") */
3244 total_len += strlen(ref_rev_parse_rules[nr_rules]);
3246 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3248 total_len = 0;
3249 for (i = 0; i < nr_rules; i++) {
3250 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
3251 + total_len;
3252 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
3253 total_len += strlen(ref_rev_parse_rules[i]);
3257 /* bail out if there are no rules */
3258 if (!nr_rules)
3259 return xstrdup(refname);
3261 /* buffer for scanf result, at most refname must fit */
3262 short_name = xstrdup(refname);
3264 /* skip first rule, it will always match */
3265 for (i = nr_rules - 1; i > 0 ; --i) {
3266 int j;
3267 int rules_to_fail = i;
3268 int short_name_len;
3270 if (1 != sscanf(refname, scanf_fmts[i], short_name))
3271 continue;
3273 short_name_len = strlen(short_name);
3276 * in strict mode, all (except the matched one) rules
3277 * must fail to resolve to a valid non-ambiguous ref
3279 if (strict)
3280 rules_to_fail = nr_rules;
3283 * check if the short name resolves to a valid ref,
3284 * but use only rules prior to the matched one
3286 for (j = 0; j < rules_to_fail; j++) {
3287 const char *rule = ref_rev_parse_rules[j];
3288 char refname[PATH_MAX];
3290 /* skip matched rule */
3291 if (i == j)
3292 continue;
3295 * the short name is ambiguous, if it resolves
3296 * (with this previous rule) to a valid ref
3297 * read_ref() returns 0 on success
3299 mksnpath(refname, sizeof(refname),
3300 rule, short_name_len, short_name);
3301 if (ref_exists(refname))
3302 break;
3306 * short name is non-ambiguous if all previous rules
3307 * haven't resolved to a valid ref
3309 if (j == rules_to_fail)
3310 return short_name;
3313 free(short_name);
3314 return xstrdup(refname);
3317 static struct string_list *hide_refs;
3319 int parse_hide_refs_config(const char *var, const char *value, const char *section)
3321 if (!strcmp("transfer.hiderefs", var) ||
3322 /* NEEDSWORK: use parse_config_key() once both are merged */
3323 (!prefixcmp(var, section) && var[strlen(section)] == '.' &&
3324 !strcmp(var + strlen(section), ".hiderefs"))) {
3325 char *ref;
3326 int len;
3328 if (!value)
3329 return config_error_nonbool(var);
3330 ref = xstrdup(value);
3331 len = strlen(ref);
3332 while (len && ref[len - 1] == '/')
3333 ref[--len] = '\0';
3334 if (!hide_refs) {
3335 hide_refs = xcalloc(1, sizeof(*hide_refs));
3336 hide_refs->strdup_strings = 1;
3338 string_list_append(hide_refs, ref);
3340 return 0;
3343 int ref_is_hidden(const char *refname)
3345 struct string_list_item *item;
3347 if (!hide_refs)
3348 return 0;
3349 for_each_string_list_item(item, hide_refs) {
3350 int len;
3351 if (prefixcmp(refname, item->string))
3352 continue;
3353 len = strlen(item->string);
3354 if (!refname[len] || refname[len] == '/')
3355 return 1;
3357 return 0;