Merge branch 'rs/fix-alt-odb-path-comparison' into maint
[git.git] / refs.c
blob59fb70087a438a763cdbfb2c4e75de36d533aead
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 if (!strcmp(refname, "@"))
76 /* Refname is a single character '@'. */
77 return -1;
79 while (1) {
80 /* We are at the start of a path component. */
81 component_len = check_refname_component(refname, flags);
82 if (component_len <= 0) {
83 if ((flags & REFNAME_REFSPEC_PATTERN) &&
84 refname[0] == '*' &&
85 (refname[1] == '\0' || refname[1] == '/')) {
86 /* Accept one wildcard as a full refname component. */
87 flags &= ~REFNAME_REFSPEC_PATTERN;
88 component_len = 1;
89 } else {
90 return -1;
93 component_count++;
94 if (refname[component_len] == '\0')
95 break;
96 /* Skip to next component. */
97 refname += component_len + 1;
100 if (refname[component_len - 1] == '.')
101 return -1; /* Refname ends with '.'. */
102 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
103 return -1; /* Refname has only one component. */
104 return 0;
107 struct ref_entry;
110 * Information used (along with the information in ref_entry) to
111 * describe a single cached reference. This data structure only
112 * occurs embedded in a union in struct ref_entry, and only when
113 * (ref_entry->flag & REF_DIR) is zero.
115 struct ref_value {
117 * The name of the object to which this reference resolves
118 * (which may be a tag object). If REF_ISBROKEN, this is
119 * null. If REF_ISSYMREF, then this is the name of the object
120 * referred to by the last reference in the symlink chain.
122 unsigned char sha1[20];
125 * If REF_KNOWS_PEELED, then this field holds the peeled value
126 * of this reference, or null if the reference is known not to
127 * be peelable. See the documentation for peel_ref() for an
128 * exact definition of "peelable".
130 unsigned char peeled[20];
133 struct ref_cache;
136 * Information used (along with the information in ref_entry) to
137 * describe a level in the hierarchy of references. This data
138 * structure only occurs embedded in a union in struct ref_entry, and
139 * only when (ref_entry.flag & REF_DIR) is set. In that case,
140 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
141 * in the directory have already been read:
143 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
144 * or packed references, already read.
146 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
147 * references that hasn't been read yet (nor has any of its
148 * subdirectories).
150 * Entries within a directory are stored within a growable array of
151 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
152 * sorted are sorted by their component name in strcmp() order and the
153 * remaining entries are unsorted.
155 * Loose references are read lazily, one directory at a time. When a
156 * directory of loose references is read, then all of the references
157 * in that directory are stored, and REF_INCOMPLETE stubs are created
158 * for any subdirectories, but the subdirectories themselves are not
159 * read. The reading is triggered by get_ref_dir().
161 struct ref_dir {
162 int nr, alloc;
165 * Entries with index 0 <= i < sorted are sorted by name. New
166 * entries are appended to the list unsorted, and are sorted
167 * only when required; thus we avoid the need to sort the list
168 * after the addition of every reference.
170 int sorted;
172 /* A pointer to the ref_cache that contains this ref_dir. */
173 struct ref_cache *ref_cache;
175 struct ref_entry **entries;
179 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
180 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
181 * refs.h.
185 * The field ref_entry->u.value.peeled of this value entry contains
186 * the correct peeled value for the reference, which might be
187 * null_sha1 if the reference is not a tag or if it is broken.
189 #define REF_KNOWS_PEELED 0x08
191 /* ref_entry represents a directory of references */
192 #define REF_DIR 0x10
195 * Entry has not yet been read from disk (used only for REF_DIR
196 * entries representing loose references)
198 #define REF_INCOMPLETE 0x20
201 * A ref_entry represents either a reference or a "subdirectory" of
202 * references.
204 * Each directory in the reference namespace is represented by a
205 * ref_entry with (flags & REF_DIR) set and containing a subdir member
206 * that holds the entries in that directory that have been read so
207 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
208 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
209 * used for loose reference directories.
211 * References are represented by a ref_entry with (flags & REF_DIR)
212 * unset and a value member that describes the reference's value. The
213 * flag member is at the ref_entry level, but it is also needed to
214 * interpret the contents of the value field (in other words, a
215 * ref_value object is not very much use without the enclosing
216 * ref_entry).
218 * Reference names cannot end with slash and directories' names are
219 * always stored with a trailing slash (except for the top-level
220 * directory, which is always denoted by ""). This has two nice
221 * consequences: (1) when the entries in each subdir are sorted
222 * lexicographically by name (as they usually are), the references in
223 * a whole tree can be generated in lexicographic order by traversing
224 * the tree in left-to-right, depth-first order; (2) the names of
225 * references and subdirectories cannot conflict, and therefore the
226 * presence of an empty subdirectory does not block the creation of a
227 * similarly-named reference. (The fact that reference names with the
228 * same leading components can conflict *with each other* is a
229 * separate issue that is regulated by is_refname_available().)
231 * Please note that the name field contains the fully-qualified
232 * reference (or subdirectory) name. Space could be saved by only
233 * storing the relative names. But that would require the full names
234 * to be generated on the fly when iterating in do_for_each_ref(), and
235 * would break callback functions, who have always been able to assume
236 * that the name strings that they are passed will not be freed during
237 * the iteration.
239 struct ref_entry {
240 unsigned char flag; /* ISSYMREF? ISPACKED? */
241 union {
242 struct ref_value value; /* if not (flags&REF_DIR) */
243 struct ref_dir subdir; /* if (flags&REF_DIR) */
244 } u;
246 * The full name of the reference (e.g., "refs/heads/master")
247 * or the full name of the directory with a trailing slash
248 * (e.g., "refs/heads/"):
250 char name[FLEX_ARRAY];
253 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
255 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
257 struct ref_dir *dir;
258 assert(entry->flag & REF_DIR);
259 dir = &entry->u.subdir;
260 if (entry->flag & REF_INCOMPLETE) {
261 read_loose_refs(entry->name, dir);
262 entry->flag &= ~REF_INCOMPLETE;
264 return dir;
267 static struct ref_entry *create_ref_entry(const char *refname,
268 const unsigned char *sha1, int flag,
269 int check_name)
271 int len;
272 struct ref_entry *ref;
274 if (check_name &&
275 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
276 die("Reference has invalid format: '%s'", refname);
277 len = strlen(refname) + 1;
278 ref = xmalloc(sizeof(struct ref_entry) + len);
279 hashcpy(ref->u.value.sha1, sha1);
280 hashclr(ref->u.value.peeled);
281 memcpy(ref->name, refname, len);
282 ref->flag = flag;
283 return ref;
286 static void clear_ref_dir(struct ref_dir *dir);
288 static void free_ref_entry(struct ref_entry *entry)
290 if (entry->flag & REF_DIR) {
292 * Do not use get_ref_dir() here, as that might
293 * trigger the reading of loose refs.
295 clear_ref_dir(&entry->u.subdir);
297 free(entry);
301 * Add a ref_entry to the end of dir (unsorted). Entry is always
302 * stored directly in dir; no recursion into subdirectories is
303 * done.
305 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
307 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
308 dir->entries[dir->nr++] = entry;
309 /* optimize for the case that entries are added in order */
310 if (dir->nr == 1 ||
311 (dir->nr == dir->sorted + 1 &&
312 strcmp(dir->entries[dir->nr - 2]->name,
313 dir->entries[dir->nr - 1]->name) < 0))
314 dir->sorted = dir->nr;
318 * Clear and free all entries in dir, recursively.
320 static void clear_ref_dir(struct ref_dir *dir)
322 int i;
323 for (i = 0; i < dir->nr; i++)
324 free_ref_entry(dir->entries[i]);
325 free(dir->entries);
326 dir->sorted = dir->nr = dir->alloc = 0;
327 dir->entries = NULL;
331 * Create a struct ref_entry object for the specified dirname.
332 * dirname is the name of the directory with a trailing slash (e.g.,
333 * "refs/heads/") or "" for the top-level directory.
335 static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
336 const char *dirname, size_t len,
337 int incomplete)
339 struct ref_entry *direntry;
340 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
341 memcpy(direntry->name, dirname, len);
342 direntry->name[len] = '\0';
343 direntry->u.subdir.ref_cache = ref_cache;
344 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
345 return direntry;
348 static int ref_entry_cmp(const void *a, const void *b)
350 struct ref_entry *one = *(struct ref_entry **)a;
351 struct ref_entry *two = *(struct ref_entry **)b;
352 return strcmp(one->name, two->name);
355 static void sort_ref_dir(struct ref_dir *dir);
357 struct string_slice {
358 size_t len;
359 const char *str;
362 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
364 const struct string_slice *key = key_;
365 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
366 int cmp = strncmp(key->str, ent->name, key->len);
367 if (cmp)
368 return cmp;
369 return '\0' - (unsigned char)ent->name[key->len];
373 * Return the index of the entry with the given refname from the
374 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
375 * no such entry is found. dir must already be complete.
377 static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
379 struct ref_entry **r;
380 struct string_slice key;
382 if (refname == NULL || !dir->nr)
383 return -1;
385 sort_ref_dir(dir);
386 key.len = len;
387 key.str = refname;
388 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
389 ref_entry_cmp_sslice);
391 if (r == NULL)
392 return -1;
394 return r - dir->entries;
398 * Search for a directory entry directly within dir (without
399 * recursing). Sort dir if necessary. subdirname must be a directory
400 * name (i.e., end in '/'). If mkdir is set, then create the
401 * directory if it is missing; otherwise, return NULL if the desired
402 * directory cannot be found. dir must already be complete.
404 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
405 const char *subdirname, size_t len,
406 int mkdir)
408 int entry_index = search_ref_dir(dir, subdirname, len);
409 struct ref_entry *entry;
410 if (entry_index == -1) {
411 if (!mkdir)
412 return NULL;
414 * Since dir is complete, the absence of a subdir
415 * means that the subdir really doesn't exist;
416 * therefore, create an empty record for it but mark
417 * the record complete.
419 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
420 add_entry_to_dir(dir, entry);
421 } else {
422 entry = dir->entries[entry_index];
424 return get_ref_dir(entry);
428 * If refname is a reference name, find the ref_dir within the dir
429 * tree that should hold refname. If refname is a directory name
430 * (i.e., ends in '/'), then return that ref_dir itself. dir must
431 * represent the top-level directory and must already be complete.
432 * Sort ref_dirs and recurse into subdirectories as necessary. If
433 * mkdir is set, then create any missing directories; otherwise,
434 * return NULL if the desired directory cannot be found.
436 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
437 const char *refname, int mkdir)
439 const char *slash;
440 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
441 size_t dirnamelen = slash - refname + 1;
442 struct ref_dir *subdir;
443 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
444 if (!subdir) {
445 dir = NULL;
446 break;
448 dir = subdir;
451 return dir;
455 * Find the value entry with the given name in dir, sorting ref_dirs
456 * and recursing into subdirectories as necessary. If the name is not
457 * found or it corresponds to a directory entry, return NULL.
459 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
461 int entry_index;
462 struct ref_entry *entry;
463 dir = find_containing_dir(dir, refname, 0);
464 if (!dir)
465 return NULL;
466 entry_index = search_ref_dir(dir, refname, strlen(refname));
467 if (entry_index == -1)
468 return NULL;
469 entry = dir->entries[entry_index];
470 return (entry->flag & REF_DIR) ? NULL : entry;
474 * Remove the entry with the given name from dir, recursing into
475 * subdirectories as necessary. If refname is the name of a directory
476 * (i.e., ends with '/'), then remove the directory and its contents.
477 * If the removal was successful, return the number of entries
478 * remaining in the directory entry that contained the deleted entry.
479 * If the name was not found, return -1. Please note that this
480 * function only deletes the entry from the cache; it does not delete
481 * it from the filesystem or ensure that other cache entries (which
482 * might be symbolic references to the removed entry) are updated.
483 * Nor does it remove any containing dir entries that might be made
484 * empty by the removal. dir must represent the top-level directory
485 * and must already be complete.
487 static int remove_entry(struct ref_dir *dir, const char *refname)
489 int refname_len = strlen(refname);
490 int entry_index;
491 struct ref_entry *entry;
492 int is_dir = refname[refname_len - 1] == '/';
493 if (is_dir) {
495 * refname represents a reference directory. Remove
496 * the trailing slash; otherwise we will get the
497 * directory *representing* refname rather than the
498 * one *containing* it.
500 char *dirname = xmemdupz(refname, refname_len - 1);
501 dir = find_containing_dir(dir, dirname, 0);
502 free(dirname);
503 } else {
504 dir = find_containing_dir(dir, refname, 0);
506 if (!dir)
507 return -1;
508 entry_index = search_ref_dir(dir, refname, refname_len);
509 if (entry_index == -1)
510 return -1;
511 entry = dir->entries[entry_index];
513 memmove(&dir->entries[entry_index],
514 &dir->entries[entry_index + 1],
515 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
517 dir->nr--;
518 if (dir->sorted > entry_index)
519 dir->sorted--;
520 free_ref_entry(entry);
521 return dir->nr;
525 * Add a ref_entry to the ref_dir (unsorted), recursing into
526 * subdirectories as necessary. dir must represent the top-level
527 * directory. Return 0 on success.
529 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
531 dir = find_containing_dir(dir, ref->name, 1);
532 if (!dir)
533 return -1;
534 add_entry_to_dir(dir, ref);
535 return 0;
539 * Emit a warning and return true iff ref1 and ref2 have the same name
540 * and the same sha1. Die if they have the same name but different
541 * sha1s.
543 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
545 if (strcmp(ref1->name, ref2->name))
546 return 0;
548 /* Duplicate name; make sure that they don't conflict: */
550 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
551 /* This is impossible by construction */
552 die("Reference directory conflict: %s", ref1->name);
554 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
555 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
557 warning("Duplicated ref: %s", ref1->name);
558 return 1;
562 * Sort the entries in dir non-recursively (if they are not already
563 * sorted) and remove any duplicate entries.
565 static void sort_ref_dir(struct ref_dir *dir)
567 int i, j;
568 struct ref_entry *last = NULL;
571 * This check also prevents passing a zero-length array to qsort(),
572 * which is a problem on some platforms.
574 if (dir->sorted == dir->nr)
575 return;
577 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
579 /* Remove any duplicates: */
580 for (i = 0, j = 0; j < dir->nr; j++) {
581 struct ref_entry *entry = dir->entries[j];
582 if (last && is_dup_ref(last, entry))
583 free_ref_entry(entry);
584 else
585 last = dir->entries[i++] = entry;
587 dir->sorted = dir->nr = i;
590 /* Include broken references in a do_for_each_ref*() iteration: */
591 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
594 * Return true iff the reference described by entry can be resolved to
595 * an object in the database. Emit a warning if the referred-to
596 * object does not exist.
598 static int ref_resolves_to_object(struct ref_entry *entry)
600 if (entry->flag & REF_ISBROKEN)
601 return 0;
602 if (!has_sha1_file(entry->u.value.sha1)) {
603 error("%s does not point to a valid object!", entry->name);
604 return 0;
606 return 1;
610 * current_ref is a performance hack: when iterating over references
611 * using the for_each_ref*() functions, current_ref is set to the
612 * current reference's entry before calling the callback function. If
613 * the callback function calls peel_ref(), then peel_ref() first
614 * checks whether the reference to be peeled is the current reference
615 * (it usually is) and if so, returns that reference's peeled version
616 * if it is available. This avoids a refname lookup in a common case.
618 static struct ref_entry *current_ref;
620 typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
622 struct ref_entry_cb {
623 const char *base;
624 int trim;
625 int flags;
626 each_ref_fn *fn;
627 void *cb_data;
631 * Handle one reference in a do_for_each_ref*()-style iteration,
632 * calling an each_ref_fn for each entry.
634 static int do_one_ref(struct ref_entry *entry, void *cb_data)
636 struct ref_entry_cb *data = cb_data;
637 struct ref_entry *old_current_ref;
638 int retval;
640 if (!starts_with(entry->name, data->base))
641 return 0;
643 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
644 !ref_resolves_to_object(entry))
645 return 0;
647 /* Store the old value, in case this is a recursive call: */
648 old_current_ref = current_ref;
649 current_ref = entry;
650 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
651 entry->flag, data->cb_data);
652 current_ref = old_current_ref;
653 return retval;
657 * Call fn for each reference in dir that has index in the range
658 * offset <= index < dir->nr. Recurse into subdirectories that are in
659 * that index range, sorting them before iterating. This function
660 * does not sort dir itself; it should be sorted beforehand. fn is
661 * called for all references, including broken ones.
663 static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
664 each_ref_entry_fn fn, void *cb_data)
666 int i;
667 assert(dir->sorted == dir->nr);
668 for (i = offset; i < dir->nr; i++) {
669 struct ref_entry *entry = dir->entries[i];
670 int retval;
671 if (entry->flag & REF_DIR) {
672 struct ref_dir *subdir = get_ref_dir(entry);
673 sort_ref_dir(subdir);
674 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
675 } else {
676 retval = fn(entry, cb_data);
678 if (retval)
679 return retval;
681 return 0;
685 * Call fn for each reference in the union of dir1 and dir2, in order
686 * by refname. Recurse into subdirectories. If a value entry appears
687 * in both dir1 and dir2, then only process the version that is in
688 * dir2. The input dirs must already be sorted, but subdirs will be
689 * sorted as needed. fn is called for all references, including
690 * broken ones.
692 static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
693 struct ref_dir *dir2,
694 each_ref_entry_fn fn, void *cb_data)
696 int retval;
697 int i1 = 0, i2 = 0;
699 assert(dir1->sorted == dir1->nr);
700 assert(dir2->sorted == dir2->nr);
701 while (1) {
702 struct ref_entry *e1, *e2;
703 int cmp;
704 if (i1 == dir1->nr) {
705 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
707 if (i2 == dir2->nr) {
708 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
710 e1 = dir1->entries[i1];
711 e2 = dir2->entries[i2];
712 cmp = strcmp(e1->name, e2->name);
713 if (cmp == 0) {
714 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
715 /* Both are directories; descend them in parallel. */
716 struct ref_dir *subdir1 = get_ref_dir(e1);
717 struct ref_dir *subdir2 = get_ref_dir(e2);
718 sort_ref_dir(subdir1);
719 sort_ref_dir(subdir2);
720 retval = do_for_each_entry_in_dirs(
721 subdir1, subdir2, fn, cb_data);
722 i1++;
723 i2++;
724 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
725 /* Both are references; ignore the one from dir1. */
726 retval = fn(e2, cb_data);
727 i1++;
728 i2++;
729 } else {
730 die("conflict between reference and directory: %s",
731 e1->name);
733 } else {
734 struct ref_entry *e;
735 if (cmp < 0) {
736 e = e1;
737 i1++;
738 } else {
739 e = e2;
740 i2++;
742 if (e->flag & REF_DIR) {
743 struct ref_dir *subdir = get_ref_dir(e);
744 sort_ref_dir(subdir);
745 retval = do_for_each_entry_in_dir(
746 subdir, 0, fn, cb_data);
747 } else {
748 retval = fn(e, cb_data);
751 if (retval)
752 return retval;
757 * Load all of the refs from the dir into our in-memory cache. The hard work
758 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
759 * through all of the sub-directories. We do not even need to care about
760 * sorting, as traversal order does not matter to us.
762 static void prime_ref_dir(struct ref_dir *dir)
764 int i;
765 for (i = 0; i < dir->nr; i++) {
766 struct ref_entry *entry = dir->entries[i];
767 if (entry->flag & REF_DIR)
768 prime_ref_dir(get_ref_dir(entry));
772 * Return true iff refname1 and refname2 conflict with each other.
773 * Two reference names conflict if one of them exactly matches the
774 * leading components of the other; e.g., "foo/bar" conflicts with
775 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
776 * "foo/barbados".
778 static int names_conflict(const char *refname1, const char *refname2)
780 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
782 return (*refname1 == '\0' && *refname2 == '/')
783 || (*refname1 == '/' && *refname2 == '\0');
786 struct name_conflict_cb {
787 const char *refname;
788 const char *oldrefname;
789 const char *conflicting_refname;
792 static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
794 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
795 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
796 return 0;
797 if (names_conflict(data->refname, entry->name)) {
798 data->conflicting_refname = entry->name;
799 return 1;
801 return 0;
805 * Return true iff a reference named refname could be created without
806 * conflicting with the name of an existing reference in dir. If
807 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
808 * (e.g., because oldrefname is scheduled for deletion in the same
809 * operation).
811 static int is_refname_available(const char *refname, const char *oldrefname,
812 struct ref_dir *dir)
814 struct name_conflict_cb data;
815 data.refname = refname;
816 data.oldrefname = oldrefname;
817 data.conflicting_refname = NULL;
819 sort_ref_dir(dir);
820 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
821 error("'%s' exists; cannot create '%s'",
822 data.conflicting_refname, refname);
823 return 0;
825 return 1;
828 struct packed_ref_cache {
829 struct ref_entry *root;
832 * Count of references to the data structure in this instance,
833 * including the pointer from ref_cache::packed if any. The
834 * data will not be freed as long as the reference count is
835 * nonzero.
837 unsigned int referrers;
840 * Iff the packed-refs file associated with this instance is
841 * currently locked for writing, this points at the associated
842 * lock (which is owned by somebody else). The referrer count
843 * is also incremented when the file is locked and decremented
844 * when it is unlocked.
846 struct lock_file *lock;
848 /* The metadata from when this packed-refs cache was read */
849 struct stat_validity validity;
853 * Future: need to be in "struct repository"
854 * when doing a full libification.
856 static struct ref_cache {
857 struct ref_cache *next;
858 struct ref_entry *loose;
859 struct packed_ref_cache *packed;
861 * The submodule name, or "" for the main repo. We allocate
862 * length 1 rather than FLEX_ARRAY so that the main ref_cache
863 * is initialized correctly.
865 char name[1];
866 } ref_cache, *submodule_ref_caches;
868 /* Lock used for the main packed-refs file: */
869 static struct lock_file packlock;
872 * Increment the reference count of *packed_refs.
874 static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
876 packed_refs->referrers++;
880 * Decrease the reference count of *packed_refs. If it goes to zero,
881 * free *packed_refs and return true; otherwise return false.
883 static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
885 if (!--packed_refs->referrers) {
886 free_ref_entry(packed_refs->root);
887 stat_validity_clear(&packed_refs->validity);
888 free(packed_refs);
889 return 1;
890 } else {
891 return 0;
895 static void clear_packed_ref_cache(struct ref_cache *refs)
897 if (refs->packed) {
898 struct packed_ref_cache *packed_refs = refs->packed;
900 if (packed_refs->lock)
901 die("internal error: packed-ref cache cleared while locked");
902 refs->packed = NULL;
903 release_packed_ref_cache(packed_refs);
907 static void clear_loose_ref_cache(struct ref_cache *refs)
909 if (refs->loose) {
910 free_ref_entry(refs->loose);
911 refs->loose = NULL;
915 static struct ref_cache *create_ref_cache(const char *submodule)
917 int len;
918 struct ref_cache *refs;
919 if (!submodule)
920 submodule = "";
921 len = strlen(submodule) + 1;
922 refs = xcalloc(1, sizeof(struct ref_cache) + len);
923 memcpy(refs->name, submodule, len);
924 return refs;
928 * Return a pointer to a ref_cache for the specified submodule. For
929 * the main repository, use submodule==NULL. The returned structure
930 * will be allocated and initialized but not necessarily populated; it
931 * should not be freed.
933 static struct ref_cache *get_ref_cache(const char *submodule)
935 struct ref_cache *refs;
937 if (!submodule || !*submodule)
938 return &ref_cache;
940 for (refs = submodule_ref_caches; refs; refs = refs->next)
941 if (!strcmp(submodule, refs->name))
942 return refs;
944 refs = create_ref_cache(submodule);
945 refs->next = submodule_ref_caches;
946 submodule_ref_caches = refs;
947 return refs;
950 /* The length of a peeled reference line in packed-refs, including EOL: */
951 #define PEELED_LINE_LENGTH 42
954 * The packed-refs header line that we write out. Perhaps other
955 * traits will be added later. The trailing space is required.
957 static const char PACKED_REFS_HEADER[] =
958 "# pack-refs with: peeled fully-peeled \n";
961 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
962 * Return a pointer to the refname within the line (null-terminated),
963 * or NULL if there was a problem.
965 static const char *parse_ref_line(char *line, unsigned char *sha1)
968 * 42: the answer to everything.
970 * In this case, it happens to be the answer to
971 * 40 (length of sha1 hex representation)
972 * +1 (space in between hex and name)
973 * +1 (newline at the end of the line)
975 int len = strlen(line) - 42;
977 if (len <= 0)
978 return NULL;
979 if (get_sha1_hex(line, sha1) < 0)
980 return NULL;
981 if (!isspace(line[40]))
982 return NULL;
983 line += 41;
984 if (isspace(*line))
985 return NULL;
986 if (line[len] != '\n')
987 return NULL;
988 line[len] = 0;
990 return line;
994 * Read f, which is a packed-refs file, into dir.
996 * A comment line of the form "# pack-refs with: " may contain zero or
997 * more traits. We interpret the traits as follows:
999 * No traits:
1001 * Probably no references are peeled. But if the file contains a
1002 * peeled value for a reference, we will use it.
1004 * peeled:
1006 * References under "refs/tags/", if they *can* be peeled, *are*
1007 * peeled in this file. References outside of "refs/tags/" are
1008 * probably not peeled even if they could have been, but if we find
1009 * a peeled value for such a reference we will use it.
1011 * fully-peeled:
1013 * All references in the file that can be peeled are peeled.
1014 * Inversely (and this is more important), any references in the
1015 * file for which no peeled value is recorded is not peelable. This
1016 * trait should typically be written alongside "peeled" for
1017 * compatibility with older clients, but we do not require it
1018 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1020 static void read_packed_refs(FILE *f, struct ref_dir *dir)
1022 struct ref_entry *last = NULL;
1023 char refline[PATH_MAX];
1024 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1026 while (fgets(refline, sizeof(refline), f)) {
1027 unsigned char sha1[20];
1028 const char *refname;
1029 static const char header[] = "# pack-refs with:";
1031 if (!strncmp(refline, header, sizeof(header)-1)) {
1032 const char *traits = refline + sizeof(header) - 1;
1033 if (strstr(traits, " fully-peeled "))
1034 peeled = PEELED_FULLY;
1035 else if (strstr(traits, " peeled "))
1036 peeled = PEELED_TAGS;
1037 /* perhaps other traits later as well */
1038 continue;
1041 refname = parse_ref_line(refline, sha1);
1042 if (refname) {
1043 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
1044 if (peeled == PEELED_FULLY ||
1045 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
1046 last->flag |= REF_KNOWS_PEELED;
1047 add_ref(dir, last);
1048 continue;
1050 if (last &&
1051 refline[0] == '^' &&
1052 strlen(refline) == PEELED_LINE_LENGTH &&
1053 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
1054 !get_sha1_hex(refline + 1, sha1)) {
1055 hashcpy(last->u.value.peeled, sha1);
1057 * Regardless of what the file header said,
1058 * we definitely know the value of *this*
1059 * reference:
1061 last->flag |= REF_KNOWS_PEELED;
1067 * Get the packed_ref_cache for the specified ref_cache, creating it
1068 * if necessary.
1070 static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
1072 const char *packed_refs_file;
1074 if (*refs->name)
1075 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1076 else
1077 packed_refs_file = git_path("packed-refs");
1079 if (refs->packed &&
1080 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1081 clear_packed_ref_cache(refs);
1083 if (!refs->packed) {
1084 FILE *f;
1086 refs->packed = xcalloc(1, sizeof(*refs->packed));
1087 acquire_packed_ref_cache(refs->packed);
1088 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1089 f = fopen(packed_refs_file, "r");
1090 if (f) {
1091 stat_validity_update(&refs->packed->validity, fileno(f));
1092 read_packed_refs(f, get_ref_dir(refs->packed->root));
1093 fclose(f);
1096 return refs->packed;
1099 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1101 return get_ref_dir(packed_ref_cache->root);
1104 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1106 return get_packed_ref_dir(get_packed_ref_cache(refs));
1109 void add_packed_ref(const char *refname, const unsigned char *sha1)
1111 struct packed_ref_cache *packed_ref_cache =
1112 get_packed_ref_cache(&ref_cache);
1114 if (!packed_ref_cache->lock)
1115 die("internal error: packed refs not locked");
1116 add_ref(get_packed_ref_dir(packed_ref_cache),
1117 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1121 * Read the loose references from the namespace dirname into dir
1122 * (without recursing). dirname must end with '/'. dir must be the
1123 * directory entry corresponding to dirname.
1125 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1127 struct ref_cache *refs = dir->ref_cache;
1128 DIR *d;
1129 const char *path;
1130 struct dirent *de;
1131 int dirnamelen = strlen(dirname);
1132 struct strbuf refname;
1134 if (*refs->name)
1135 path = git_path_submodule(refs->name, "%s", dirname);
1136 else
1137 path = git_path("%s", dirname);
1139 d = opendir(path);
1140 if (!d)
1141 return;
1143 strbuf_init(&refname, dirnamelen + 257);
1144 strbuf_add(&refname, dirname, dirnamelen);
1146 while ((de = readdir(d)) != NULL) {
1147 unsigned char sha1[20];
1148 struct stat st;
1149 int flag;
1150 const char *refdir;
1152 if (de->d_name[0] == '.')
1153 continue;
1154 if (has_extension(de->d_name, ".lock"))
1155 continue;
1156 strbuf_addstr(&refname, de->d_name);
1157 refdir = *refs->name
1158 ? git_path_submodule(refs->name, "%s", refname.buf)
1159 : git_path("%s", refname.buf);
1160 if (stat(refdir, &st) < 0) {
1161 ; /* silently ignore */
1162 } else if (S_ISDIR(st.st_mode)) {
1163 strbuf_addch(&refname, '/');
1164 add_entry_to_dir(dir,
1165 create_dir_entry(refs, refname.buf,
1166 refname.len, 1));
1167 } else {
1168 if (*refs->name) {
1169 hashclr(sha1);
1170 flag = 0;
1171 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
1172 hashclr(sha1);
1173 flag |= REF_ISBROKEN;
1175 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
1176 hashclr(sha1);
1177 flag |= REF_ISBROKEN;
1179 add_entry_to_dir(dir,
1180 create_ref_entry(refname.buf, sha1, flag, 1));
1182 strbuf_setlen(&refname, dirnamelen);
1184 strbuf_release(&refname);
1185 closedir(d);
1188 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
1190 if (!refs->loose) {
1192 * Mark the top-level directory complete because we
1193 * are about to read the only subdirectory that can
1194 * hold references:
1196 refs->loose = create_dir_entry(refs, "", 0, 0);
1198 * Create an incomplete entry for "refs/":
1200 add_entry_to_dir(get_ref_dir(refs->loose),
1201 create_dir_entry(refs, "refs/", 5, 1));
1203 return get_ref_dir(refs->loose);
1206 /* We allow "recursive" symbolic refs. Only within reason, though */
1207 #define MAXDEPTH 5
1208 #define MAXREFLEN (1024)
1211 * Called by resolve_gitlink_ref_recursive() after it failed to read
1212 * from the loose refs in ref_cache refs. Find <refname> in the
1213 * packed-refs file for the submodule.
1215 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
1216 const char *refname, unsigned char *sha1)
1218 struct ref_entry *ref;
1219 struct ref_dir *dir = get_packed_refs(refs);
1221 ref = find_ref(dir, refname);
1222 if (ref == NULL)
1223 return -1;
1225 hashcpy(sha1, ref->u.value.sha1);
1226 return 0;
1229 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
1230 const char *refname, unsigned char *sha1,
1231 int recursion)
1233 int fd, len;
1234 char buffer[128], *p;
1235 char *path;
1237 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
1238 return -1;
1239 path = *refs->name
1240 ? git_path_submodule(refs->name, "%s", refname)
1241 : git_path("%s", refname);
1242 fd = open(path, O_RDONLY);
1243 if (fd < 0)
1244 return resolve_gitlink_packed_ref(refs, refname, sha1);
1246 len = read(fd, buffer, sizeof(buffer)-1);
1247 close(fd);
1248 if (len < 0)
1249 return -1;
1250 while (len && isspace(buffer[len-1]))
1251 len--;
1252 buffer[len] = 0;
1254 /* Was it a detached head or an old-fashioned symlink? */
1255 if (!get_sha1_hex(buffer, sha1))
1256 return 0;
1258 /* Symref? */
1259 if (strncmp(buffer, "ref:", 4))
1260 return -1;
1261 p = buffer + 4;
1262 while (isspace(*p))
1263 p++;
1265 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1268 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1270 int len = strlen(path), retval;
1271 char *submodule;
1272 struct ref_cache *refs;
1274 while (len && path[len-1] == '/')
1275 len--;
1276 if (!len)
1277 return -1;
1278 submodule = xstrndup(path, len);
1279 refs = get_ref_cache(submodule);
1280 free(submodule);
1282 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1283 return retval;
1287 * Return the ref_entry for the given refname from the packed
1288 * references. If it does not exist, return NULL.
1290 static struct ref_entry *get_packed_ref(const char *refname)
1292 return find_ref(get_packed_refs(&ref_cache), refname);
1296 * A loose ref file doesn't exist; check for a packed ref. The
1297 * options are forwarded from resolve_safe_unsafe().
1299 static const char *handle_missing_loose_ref(const char *refname,
1300 unsigned char *sha1,
1301 int reading,
1302 int *flag)
1304 struct ref_entry *entry;
1307 * The loose reference file does not exist; check for a packed
1308 * reference.
1310 entry = get_packed_ref(refname);
1311 if (entry) {
1312 hashcpy(sha1, entry->u.value.sha1);
1313 if (flag)
1314 *flag |= REF_ISPACKED;
1315 return refname;
1317 /* The reference is not a packed reference, either. */
1318 if (reading) {
1319 return NULL;
1320 } else {
1321 hashclr(sha1);
1322 return refname;
1326 const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
1328 int depth = MAXDEPTH;
1329 ssize_t len;
1330 char buffer[256];
1331 static char refname_buffer[256];
1333 if (flag)
1334 *flag = 0;
1336 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1337 return NULL;
1339 for (;;) {
1340 char path[PATH_MAX];
1341 struct stat st;
1342 char *buf;
1343 int fd;
1345 if (--depth < 0)
1346 return NULL;
1348 git_snpath(path, sizeof(path), "%s", refname);
1351 * We might have to loop back here to avoid a race
1352 * condition: first we lstat() the file, then we try
1353 * to read it as a link or as a file. But if somebody
1354 * changes the type of the file (file <-> directory
1355 * <-> symlink) between the lstat() and reading, then
1356 * we don't want to report that as an error but rather
1357 * try again starting with the lstat().
1359 stat_ref:
1360 if (lstat(path, &st) < 0) {
1361 if (errno == ENOENT)
1362 return handle_missing_loose_ref(refname, sha1,
1363 reading, flag);
1364 else
1365 return NULL;
1368 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1369 if (S_ISLNK(st.st_mode)) {
1370 len = readlink(path, buffer, sizeof(buffer)-1);
1371 if (len < 0) {
1372 if (errno == ENOENT || errno == EINVAL)
1373 /* inconsistent with lstat; retry */
1374 goto stat_ref;
1375 else
1376 return NULL;
1378 buffer[len] = 0;
1379 if (starts_with(buffer, "refs/") &&
1380 !check_refname_format(buffer, 0)) {
1381 strcpy(refname_buffer, buffer);
1382 refname = refname_buffer;
1383 if (flag)
1384 *flag |= REF_ISSYMREF;
1385 continue;
1389 /* Is it a directory? */
1390 if (S_ISDIR(st.st_mode)) {
1391 errno = EISDIR;
1392 return NULL;
1396 * Anything else, just open it and try to use it as
1397 * a ref
1399 fd = open(path, O_RDONLY);
1400 if (fd < 0) {
1401 if (errno == ENOENT)
1402 /* inconsistent with lstat; retry */
1403 goto stat_ref;
1404 else
1405 return NULL;
1407 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1408 close(fd);
1409 if (len < 0)
1410 return NULL;
1411 while (len && isspace(buffer[len-1]))
1412 len--;
1413 buffer[len] = '\0';
1416 * Is it a symbolic ref?
1418 if (!starts_with(buffer, "ref:")) {
1420 * Please note that FETCH_HEAD has a second
1421 * line containing other data.
1423 if (get_sha1_hex(buffer, sha1) ||
1424 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1425 if (flag)
1426 *flag |= REF_ISBROKEN;
1427 return NULL;
1429 return refname;
1431 if (flag)
1432 *flag |= REF_ISSYMREF;
1433 buf = buffer + 4;
1434 while (isspace(*buf))
1435 buf++;
1436 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1437 if (flag)
1438 *flag |= REF_ISBROKEN;
1439 return NULL;
1441 refname = strcpy(refname_buffer, buf);
1445 char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1447 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
1448 return ret ? xstrdup(ret) : NULL;
1451 /* The argument to filter_refs */
1452 struct ref_filter {
1453 const char *pattern;
1454 each_ref_fn *fn;
1455 void *cb_data;
1458 int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
1460 if (resolve_ref_unsafe(refname, sha1, reading, flags))
1461 return 0;
1462 return -1;
1465 int read_ref(const char *refname, unsigned char *sha1)
1467 return read_ref_full(refname, sha1, 1, NULL);
1470 int ref_exists(const char *refname)
1472 unsigned char sha1[20];
1473 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
1476 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1477 void *data)
1479 struct ref_filter *filter = (struct ref_filter *)data;
1480 if (wildmatch(filter->pattern, refname, 0, NULL))
1481 return 0;
1482 return filter->fn(refname, sha1, flags, filter->cb_data);
1485 enum peel_status {
1486 /* object was peeled successfully: */
1487 PEEL_PEELED = 0,
1490 * object cannot be peeled because the named object (or an
1491 * object referred to by a tag in the peel chain), does not
1492 * exist.
1494 PEEL_INVALID = -1,
1496 /* object cannot be peeled because it is not a tag: */
1497 PEEL_NON_TAG = -2,
1499 /* ref_entry contains no peeled value because it is a symref: */
1500 PEEL_IS_SYMREF = -3,
1503 * ref_entry cannot be peeled because it is broken (i.e., the
1504 * symbolic reference cannot even be resolved to an object
1505 * name):
1507 PEEL_BROKEN = -4
1511 * Peel the named object; i.e., if the object is a tag, resolve the
1512 * tag recursively until a non-tag is found. If successful, store the
1513 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1514 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1515 * and leave sha1 unchanged.
1517 static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
1519 struct object *o = lookup_unknown_object(name);
1521 if (o->type == OBJ_NONE) {
1522 int type = sha1_object_info(name, NULL);
1523 if (type < 0)
1524 return PEEL_INVALID;
1525 o->type = type;
1528 if (o->type != OBJ_TAG)
1529 return PEEL_NON_TAG;
1531 o = deref_tag_noverify(o);
1532 if (!o)
1533 return PEEL_INVALID;
1535 hashcpy(sha1, o->sha1);
1536 return PEEL_PEELED;
1540 * Peel the entry (if possible) and return its new peel_status. If
1541 * repeel is true, re-peel the entry even if there is an old peeled
1542 * value that is already stored in it.
1544 * It is OK to call this function with a packed reference entry that
1545 * might be stale and might even refer to an object that has since
1546 * been garbage-collected. In such a case, if the entry has
1547 * REF_KNOWS_PEELED then leave the status unchanged and return
1548 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1550 static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1552 enum peel_status status;
1554 if (entry->flag & REF_KNOWS_PEELED) {
1555 if (repeel) {
1556 entry->flag &= ~REF_KNOWS_PEELED;
1557 hashclr(entry->u.value.peeled);
1558 } else {
1559 return is_null_sha1(entry->u.value.peeled) ?
1560 PEEL_NON_TAG : PEEL_PEELED;
1563 if (entry->flag & REF_ISBROKEN)
1564 return PEEL_BROKEN;
1565 if (entry->flag & REF_ISSYMREF)
1566 return PEEL_IS_SYMREF;
1568 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1569 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1570 entry->flag |= REF_KNOWS_PEELED;
1571 return status;
1574 int peel_ref(const char *refname, unsigned char *sha1)
1576 int flag;
1577 unsigned char base[20];
1579 if (current_ref && (current_ref->name == refname
1580 || !strcmp(current_ref->name, refname))) {
1581 if (peel_entry(current_ref, 0))
1582 return -1;
1583 hashcpy(sha1, current_ref->u.value.peeled);
1584 return 0;
1587 if (read_ref_full(refname, base, 1, &flag))
1588 return -1;
1591 * If the reference is packed, read its ref_entry from the
1592 * cache in the hope that we already know its peeled value.
1593 * We only try this optimization on packed references because
1594 * (a) forcing the filling of the loose reference cache could
1595 * be expensive and (b) loose references anyway usually do not
1596 * have REF_KNOWS_PEELED.
1598 if (flag & REF_ISPACKED) {
1599 struct ref_entry *r = get_packed_ref(refname);
1600 if (r) {
1601 if (peel_entry(r, 0))
1602 return -1;
1603 hashcpy(sha1, r->u.value.peeled);
1604 return 0;
1608 return peel_object(base, sha1);
1611 struct warn_if_dangling_data {
1612 FILE *fp;
1613 const char *refname;
1614 const struct string_list *refnames;
1615 const char *msg_fmt;
1618 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1619 int flags, void *cb_data)
1621 struct warn_if_dangling_data *d = cb_data;
1622 const char *resolves_to;
1623 unsigned char junk[20];
1625 if (!(flags & REF_ISSYMREF))
1626 return 0;
1628 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1629 if (!resolves_to
1630 || (d->refname
1631 ? strcmp(resolves_to, d->refname)
1632 : !string_list_has_string(d->refnames, resolves_to))) {
1633 return 0;
1636 fprintf(d->fp, d->msg_fmt, refname);
1637 fputc('\n', d->fp);
1638 return 0;
1641 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1643 struct warn_if_dangling_data data;
1645 data.fp = fp;
1646 data.refname = refname;
1647 data.refnames = NULL;
1648 data.msg_fmt = msg_fmt;
1649 for_each_rawref(warn_if_dangling_symref, &data);
1652 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
1654 struct warn_if_dangling_data data;
1656 data.fp = fp;
1657 data.refname = NULL;
1658 data.refnames = refnames;
1659 data.msg_fmt = msg_fmt;
1660 for_each_rawref(warn_if_dangling_symref, &data);
1664 * Call fn for each reference in the specified ref_cache, omitting
1665 * references not in the containing_dir of base. fn is called for all
1666 * references, including broken ones. If fn ever returns a non-zero
1667 * value, stop the iteration and return that value; otherwise, return
1668 * 0.
1670 static int do_for_each_entry(struct ref_cache *refs, const char *base,
1671 each_ref_entry_fn fn, void *cb_data)
1673 struct packed_ref_cache *packed_ref_cache;
1674 struct ref_dir *loose_dir;
1675 struct ref_dir *packed_dir;
1676 int retval = 0;
1679 * We must make sure that all loose refs are read before accessing the
1680 * packed-refs file; this avoids a race condition in which loose refs
1681 * are migrated to the packed-refs file by a simultaneous process, but
1682 * our in-memory view is from before the migration. get_packed_ref_cache()
1683 * takes care of making sure our view is up to date with what is on
1684 * disk.
1686 loose_dir = get_loose_refs(refs);
1687 if (base && *base) {
1688 loose_dir = find_containing_dir(loose_dir, base, 0);
1690 if (loose_dir)
1691 prime_ref_dir(loose_dir);
1693 packed_ref_cache = get_packed_ref_cache(refs);
1694 acquire_packed_ref_cache(packed_ref_cache);
1695 packed_dir = get_packed_ref_dir(packed_ref_cache);
1696 if (base && *base) {
1697 packed_dir = find_containing_dir(packed_dir, base, 0);
1700 if (packed_dir && loose_dir) {
1701 sort_ref_dir(packed_dir);
1702 sort_ref_dir(loose_dir);
1703 retval = do_for_each_entry_in_dirs(
1704 packed_dir, loose_dir, fn, cb_data);
1705 } else if (packed_dir) {
1706 sort_ref_dir(packed_dir);
1707 retval = do_for_each_entry_in_dir(
1708 packed_dir, 0, fn, cb_data);
1709 } else if (loose_dir) {
1710 sort_ref_dir(loose_dir);
1711 retval = do_for_each_entry_in_dir(
1712 loose_dir, 0, fn, cb_data);
1715 release_packed_ref_cache(packed_ref_cache);
1716 return retval;
1720 * Call fn for each reference in the specified ref_cache for which the
1721 * refname begins with base. If trim is non-zero, then trim that many
1722 * characters off the beginning of each refname before passing the
1723 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1724 * broken references in the iteration. If fn ever returns a non-zero
1725 * value, stop the iteration and return that value; otherwise, return
1726 * 0.
1728 static int do_for_each_ref(struct ref_cache *refs, const char *base,
1729 each_ref_fn fn, int trim, int flags, void *cb_data)
1731 struct ref_entry_cb data;
1732 data.base = base;
1733 data.trim = trim;
1734 data.flags = flags;
1735 data.fn = fn;
1736 data.cb_data = cb_data;
1738 return do_for_each_entry(refs, base, do_one_ref, &data);
1741 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1743 unsigned char sha1[20];
1744 int flag;
1746 if (submodule) {
1747 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1748 return fn("HEAD", sha1, 0, cb_data);
1750 return 0;
1753 if (!read_ref_full("HEAD", sha1, 1, &flag))
1754 return fn("HEAD", sha1, flag, cb_data);
1756 return 0;
1759 int head_ref(each_ref_fn fn, void *cb_data)
1761 return do_head_ref(NULL, fn, cb_data);
1764 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1766 return do_head_ref(submodule, fn, cb_data);
1769 int for_each_ref(each_ref_fn fn, void *cb_data)
1771 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1774 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1776 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
1779 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1781 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1784 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1785 each_ref_fn fn, void *cb_data)
1787 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
1790 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1792 return for_each_ref_in("refs/tags/", fn, cb_data);
1795 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1797 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1800 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1802 return for_each_ref_in("refs/heads/", fn, cb_data);
1805 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1807 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1810 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1812 return for_each_ref_in("refs/remotes/", fn, cb_data);
1815 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1817 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1820 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1822 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
1825 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1827 struct strbuf buf = STRBUF_INIT;
1828 int ret = 0;
1829 unsigned char sha1[20];
1830 int flag;
1832 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
1833 if (!read_ref_full(buf.buf, sha1, 1, &flag))
1834 ret = fn(buf.buf, sha1, flag, cb_data);
1835 strbuf_release(&buf);
1837 return ret;
1840 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1842 struct strbuf buf = STRBUF_INIT;
1843 int ret;
1844 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1845 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
1846 strbuf_release(&buf);
1847 return ret;
1850 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1851 const char *prefix, void *cb_data)
1853 struct strbuf real_pattern = STRBUF_INIT;
1854 struct ref_filter filter;
1855 int ret;
1857 if (!prefix && !starts_with(pattern, "refs/"))
1858 strbuf_addstr(&real_pattern, "refs/");
1859 else if (prefix)
1860 strbuf_addstr(&real_pattern, prefix);
1861 strbuf_addstr(&real_pattern, pattern);
1863 if (!has_glob_specials(pattern)) {
1864 /* Append implied '/' '*' if not present. */
1865 if (real_pattern.buf[real_pattern.len - 1] != '/')
1866 strbuf_addch(&real_pattern, '/');
1867 /* No need to check for '*', there is none. */
1868 strbuf_addch(&real_pattern, '*');
1871 filter.pattern = real_pattern.buf;
1872 filter.fn = fn;
1873 filter.cb_data = cb_data;
1874 ret = for_each_ref(filter_refs, &filter);
1876 strbuf_release(&real_pattern);
1877 return ret;
1880 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1882 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1885 int for_each_rawref(each_ref_fn fn, void *cb_data)
1887 return do_for_each_ref(&ref_cache, "", fn, 0,
1888 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1891 const char *prettify_refname(const char *name)
1893 return name + (
1894 starts_with(name, "refs/heads/") ? 11 :
1895 starts_with(name, "refs/tags/") ? 10 :
1896 starts_with(name, "refs/remotes/") ? 13 :
1900 static const char *ref_rev_parse_rules[] = {
1901 "%.*s",
1902 "refs/%.*s",
1903 "refs/tags/%.*s",
1904 "refs/heads/%.*s",
1905 "refs/remotes/%.*s",
1906 "refs/remotes/%.*s/HEAD",
1907 NULL
1910 int refname_match(const char *abbrev_name, const char *full_name)
1912 const char **p;
1913 const int abbrev_name_len = strlen(abbrev_name);
1915 for (p = ref_rev_parse_rules; *p; p++) {
1916 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1917 return 1;
1921 return 0;
1924 static struct ref_lock *verify_lock(struct ref_lock *lock,
1925 const unsigned char *old_sha1, int mustexist)
1927 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
1928 error("Can't verify ref %s", lock->ref_name);
1929 unlock_ref(lock);
1930 return NULL;
1932 if (hashcmp(lock->old_sha1, old_sha1)) {
1933 error("Ref %s is at %s but expected %s", lock->ref_name,
1934 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1935 unlock_ref(lock);
1936 return NULL;
1938 return lock;
1941 static int remove_empty_directories(const char *file)
1943 /* we want to create a file but there is a directory there;
1944 * if that is an empty directory (or a directory that contains
1945 * only empty directories), remove them.
1947 struct strbuf path;
1948 int result;
1950 strbuf_init(&path, 20);
1951 strbuf_addstr(&path, file);
1953 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
1955 strbuf_release(&path);
1957 return result;
1961 * *string and *len will only be substituted, and *string returned (for
1962 * later free()ing) if the string passed in is a magic short-hand form
1963 * to name a branch.
1965 static char *substitute_branch_name(const char **string, int *len)
1967 struct strbuf buf = STRBUF_INIT;
1968 int ret = interpret_branch_name(*string, *len, &buf);
1970 if (ret == *len) {
1971 size_t size;
1972 *string = strbuf_detach(&buf, &size);
1973 *len = size;
1974 return (char *)*string;
1977 return NULL;
1980 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1982 char *last_branch = substitute_branch_name(&str, &len);
1983 const char **p, *r;
1984 int refs_found = 0;
1986 *ref = NULL;
1987 for (p = ref_rev_parse_rules; *p; p++) {
1988 char fullref[PATH_MAX];
1989 unsigned char sha1_from_ref[20];
1990 unsigned char *this_result;
1991 int flag;
1993 this_result = refs_found ? sha1_from_ref : sha1;
1994 mksnpath(fullref, sizeof(fullref), *p, len, str);
1995 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
1996 if (r) {
1997 if (!refs_found++)
1998 *ref = xstrdup(r);
1999 if (!warn_ambiguous_refs)
2000 break;
2001 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
2002 warning("ignoring dangling symref %s.", fullref);
2003 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
2004 warning("ignoring broken ref %s.", fullref);
2007 free(last_branch);
2008 return refs_found;
2011 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
2013 char *last_branch = substitute_branch_name(&str, &len);
2014 const char **p;
2015 int logs_found = 0;
2017 *log = NULL;
2018 for (p = ref_rev_parse_rules; *p; p++) {
2019 struct stat st;
2020 unsigned char hash[20];
2021 char path[PATH_MAX];
2022 const char *ref, *it;
2024 mksnpath(path, sizeof(path), *p, len, str);
2025 ref = resolve_ref_unsafe(path, hash, 1, NULL);
2026 if (!ref)
2027 continue;
2028 if (!stat(git_path("logs/%s", path), &st) &&
2029 S_ISREG(st.st_mode))
2030 it = path;
2031 else if (strcmp(ref, path) &&
2032 !stat(git_path("logs/%s", ref), &st) &&
2033 S_ISREG(st.st_mode))
2034 it = ref;
2035 else
2036 continue;
2037 if (!logs_found++) {
2038 *log = xstrdup(it);
2039 hashcpy(sha1, hash);
2041 if (!warn_ambiguous_refs)
2042 break;
2044 free(last_branch);
2045 return logs_found;
2048 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2049 const unsigned char *old_sha1,
2050 int flags, int *type_p)
2052 char *ref_file;
2053 const char *orig_refname = refname;
2054 struct ref_lock *lock;
2055 int last_errno = 0;
2056 int type, lflags;
2057 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
2058 int missing = 0;
2059 int attempts_remaining = 3;
2061 lock = xcalloc(1, sizeof(struct ref_lock));
2062 lock->lock_fd = -1;
2064 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
2065 if (!refname && errno == EISDIR) {
2066 /* we are trying to lock foo but we used to
2067 * have foo/bar which now does not exist;
2068 * it is normal for the empty directory 'foo'
2069 * to remain.
2071 ref_file = git_path("%s", orig_refname);
2072 if (remove_empty_directories(ref_file)) {
2073 last_errno = errno;
2074 error("there are still refs under '%s'", orig_refname);
2075 goto error_return;
2077 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
2079 if (type_p)
2080 *type_p = type;
2081 if (!refname) {
2082 last_errno = errno;
2083 error("unable to resolve reference %s: %s",
2084 orig_refname, strerror(errno));
2085 goto error_return;
2087 missing = is_null_sha1(lock->old_sha1);
2088 /* When the ref did not exist and we are creating it,
2089 * make sure there is no existing ref that is packed
2090 * whose name begins with our refname, nor a ref whose
2091 * name is a proper prefix of our refname.
2093 if (missing &&
2094 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
2095 last_errno = ENOTDIR;
2096 goto error_return;
2099 lock->lk = xcalloc(1, sizeof(struct lock_file));
2101 lflags = 0;
2102 if (flags & REF_NODEREF) {
2103 refname = orig_refname;
2104 lflags |= LOCK_NODEREF;
2106 lock->ref_name = xstrdup(refname);
2107 lock->orig_ref_name = xstrdup(orig_refname);
2108 ref_file = git_path("%s", refname);
2109 if (missing)
2110 lock->force_write = 1;
2111 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2112 lock->force_write = 1;
2114 retry:
2115 switch (safe_create_leading_directories(ref_file)) {
2116 case SCLD_OK:
2117 break; /* success */
2118 case SCLD_VANISHED:
2119 if (--attempts_remaining > 0)
2120 goto retry;
2121 /* fall through */
2122 default:
2123 last_errno = errno;
2124 error("unable to create directory for %s", ref_file);
2125 goto error_return;
2128 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
2129 if (lock->lock_fd < 0) {
2130 if (errno == ENOENT && --attempts_remaining > 0)
2132 * Maybe somebody just deleted one of the
2133 * directories leading to ref_file. Try
2134 * again:
2136 goto retry;
2137 else
2138 unable_to_lock_index_die(ref_file, errno);
2140 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
2142 error_return:
2143 unlock_ref(lock);
2144 errno = last_errno;
2145 return NULL;
2148 struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
2150 char refpath[PATH_MAX];
2151 if (check_refname_format(refname, 0))
2152 return NULL;
2153 strcpy(refpath, mkpath("refs/%s", refname));
2154 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
2157 struct ref_lock *lock_any_ref_for_update(const char *refname,
2158 const unsigned char *old_sha1,
2159 int flags, int *type_p)
2161 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
2162 return NULL;
2163 return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
2167 * Write an entry to the packed-refs file for the specified refname.
2168 * If peeled is non-NULL, write it as the entry's peeled value.
2170 static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2171 unsigned char *peeled)
2173 char line[PATH_MAX + 100];
2174 int len;
2176 len = snprintf(line, sizeof(line), "%s %s\n",
2177 sha1_to_hex(sha1), refname);
2178 /* this should not happen but just being defensive */
2179 if (len > sizeof(line))
2180 die("too long a refname '%s'", refname);
2181 write_or_die(fd, line, len);
2183 if (peeled) {
2184 if (snprintf(line, sizeof(line), "^%s\n",
2185 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2186 die("internal error");
2187 write_or_die(fd, line, PEELED_LINE_LENGTH);
2192 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2194 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2196 int *fd = cb_data;
2197 enum peel_status peel_status = peel_entry(entry, 0);
2199 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2200 error("internal error: %s is not a valid packed reference!",
2201 entry->name);
2202 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2203 peel_status == PEEL_PEELED ?
2204 entry->u.value.peeled : NULL);
2205 return 0;
2208 int lock_packed_refs(int flags)
2210 struct packed_ref_cache *packed_ref_cache;
2212 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2213 return -1;
2215 * Get the current packed-refs while holding the lock. If the
2216 * packed-refs file has been modified since we last read it,
2217 * this will automatically invalidate the cache and re-read
2218 * the packed-refs file.
2220 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2221 packed_ref_cache->lock = &packlock;
2222 /* Increment the reference count to prevent it from being freed: */
2223 acquire_packed_ref_cache(packed_ref_cache);
2224 return 0;
2227 int commit_packed_refs(void)
2229 struct packed_ref_cache *packed_ref_cache =
2230 get_packed_ref_cache(&ref_cache);
2231 int error = 0;
2233 if (!packed_ref_cache->lock)
2234 die("internal error: packed-refs not locked");
2235 write_or_die(packed_ref_cache->lock->fd,
2236 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2238 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2239 0, write_packed_entry_fn,
2240 &packed_ref_cache->lock->fd);
2241 if (commit_lock_file(packed_ref_cache->lock))
2242 error = -1;
2243 packed_ref_cache->lock = NULL;
2244 release_packed_ref_cache(packed_ref_cache);
2245 return error;
2248 void rollback_packed_refs(void)
2250 struct packed_ref_cache *packed_ref_cache =
2251 get_packed_ref_cache(&ref_cache);
2253 if (!packed_ref_cache->lock)
2254 die("internal error: packed-refs not locked");
2255 rollback_lock_file(packed_ref_cache->lock);
2256 packed_ref_cache->lock = NULL;
2257 release_packed_ref_cache(packed_ref_cache);
2258 clear_packed_ref_cache(&ref_cache);
2261 struct ref_to_prune {
2262 struct ref_to_prune *next;
2263 unsigned char sha1[20];
2264 char name[FLEX_ARRAY];
2267 struct pack_refs_cb_data {
2268 unsigned int flags;
2269 struct ref_dir *packed_refs;
2270 struct ref_to_prune *ref_to_prune;
2274 * An each_ref_entry_fn that is run over loose references only. If
2275 * the loose reference can be packed, add an entry in the packed ref
2276 * cache. If the reference should be pruned, also add it to
2277 * ref_to_prune in the pack_refs_cb_data.
2279 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2281 struct pack_refs_cb_data *cb = cb_data;
2282 enum peel_status peel_status;
2283 struct ref_entry *packed_entry;
2284 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2286 /* ALWAYS pack tags */
2287 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2288 return 0;
2290 /* Do not pack symbolic or broken refs: */
2291 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2292 return 0;
2294 /* Add a packed ref cache entry equivalent to the loose entry. */
2295 peel_status = peel_entry(entry, 1);
2296 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2297 die("internal error peeling reference %s (%s)",
2298 entry->name, sha1_to_hex(entry->u.value.sha1));
2299 packed_entry = find_ref(cb->packed_refs, entry->name);
2300 if (packed_entry) {
2301 /* Overwrite existing packed entry with info from loose entry */
2302 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2303 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2304 } else {
2305 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2306 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2307 add_ref(cb->packed_refs, packed_entry);
2309 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
2311 /* Schedule the loose reference for pruning if requested. */
2312 if ((cb->flags & PACK_REFS_PRUNE)) {
2313 int namelen = strlen(entry->name) + 1;
2314 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
2315 hashcpy(n->sha1, entry->u.value.sha1);
2316 strcpy(n->name, entry->name);
2317 n->next = cb->ref_to_prune;
2318 cb->ref_to_prune = n;
2320 return 0;
2324 * Remove empty parents, but spare refs/ and immediate subdirs.
2325 * Note: munges *name.
2327 static void try_remove_empty_parents(char *name)
2329 char *p, *q;
2330 int i;
2331 p = name;
2332 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2333 while (*p && *p != '/')
2334 p++;
2335 /* tolerate duplicate slashes; see check_refname_format() */
2336 while (*p == '/')
2337 p++;
2339 for (q = p; *q; q++)
2341 while (1) {
2342 while (q > p && *q != '/')
2343 q--;
2344 while (q > p && *(q-1) == '/')
2345 q--;
2346 if (q == p)
2347 break;
2348 *q = '\0';
2349 if (rmdir(git_path("%s", name)))
2350 break;
2354 /* make sure nobody touched the ref, and unlink */
2355 static void prune_ref(struct ref_to_prune *r)
2357 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2359 if (lock) {
2360 unlink_or_warn(git_path("%s", r->name));
2361 unlock_ref(lock);
2362 try_remove_empty_parents(r->name);
2366 static void prune_refs(struct ref_to_prune *r)
2368 while (r) {
2369 prune_ref(r);
2370 r = r->next;
2374 int pack_refs(unsigned int flags)
2376 struct pack_refs_cb_data cbdata;
2378 memset(&cbdata, 0, sizeof(cbdata));
2379 cbdata.flags = flags;
2381 lock_packed_refs(LOCK_DIE_ON_ERROR);
2382 cbdata.packed_refs = get_packed_refs(&ref_cache);
2384 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2385 pack_if_possible_fn, &cbdata);
2387 if (commit_packed_refs())
2388 die_errno("unable to overwrite old ref-pack file");
2390 prune_refs(cbdata.ref_to_prune);
2391 return 0;
2395 * If entry is no longer needed in packed-refs, add it to the string
2396 * list pointed to by cb_data. Reasons for deleting entries:
2398 * - Entry is broken.
2399 * - Entry is overridden by a loose ref.
2400 * - Entry does not point at a valid object.
2402 * In the first and third cases, also emit an error message because these
2403 * are indications of repository corruption.
2405 static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
2407 struct string_list *refs_to_delete = cb_data;
2409 if (entry->flag & REF_ISBROKEN) {
2410 /* This shouldn't happen to packed refs. */
2411 error("%s is broken!", entry->name);
2412 string_list_append(refs_to_delete, entry->name);
2413 return 0;
2415 if (!has_sha1_file(entry->u.value.sha1)) {
2416 unsigned char sha1[20];
2417 int flags;
2419 if (read_ref_full(entry->name, sha1, 0, &flags))
2420 /* We should at least have found the packed ref. */
2421 die("Internal error");
2422 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
2424 * This packed reference is overridden by a
2425 * loose reference, so it is OK that its value
2426 * is no longer valid; for example, it might
2427 * refer to an object that has been garbage
2428 * collected. For this purpose we don't even
2429 * care whether the loose reference itself is
2430 * invalid, broken, symbolic, etc. Silently
2431 * remove the packed reference.
2433 string_list_append(refs_to_delete, entry->name);
2434 return 0;
2437 * There is no overriding loose reference, so the fact
2438 * that this reference doesn't refer to a valid object
2439 * indicates some kind of repository corruption.
2440 * Report the problem, then omit the reference from
2441 * the output.
2443 error("%s does not point to a valid object!", entry->name);
2444 string_list_append(refs_to_delete, entry->name);
2445 return 0;
2448 return 0;
2451 int repack_without_refs(const char **refnames, int n)
2453 struct ref_dir *packed;
2454 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2455 struct string_list_item *ref_to_delete;
2456 int i, removed = 0;
2458 /* Look for a packed ref */
2459 for (i = 0; i < n; i++)
2460 if (get_packed_ref(refnames[i]))
2461 break;
2463 /* Avoid locking if we have nothing to do */
2464 if (i == n)
2465 return 0; /* no refname exists in packed refs */
2467 if (lock_packed_refs(0)) {
2468 unable_to_lock_error(git_path("packed-refs"), errno);
2469 return error("cannot delete '%s' from packed refs", refnames[i]);
2471 packed = get_packed_refs(&ref_cache);
2473 /* Remove refnames from the cache */
2474 for (i = 0; i < n; i++)
2475 if (remove_entry(packed, refnames[i]) != -1)
2476 removed = 1;
2477 if (!removed) {
2479 * All packed entries disappeared while we were
2480 * acquiring the lock.
2482 rollback_packed_refs();
2483 return 0;
2486 /* Remove any other accumulated cruft */
2487 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2488 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2489 if (remove_entry(packed, ref_to_delete->string) == -1)
2490 die("internal error");
2493 /* Write what remains */
2494 return commit_packed_refs();
2497 static int repack_without_ref(const char *refname)
2499 return repack_without_refs(&refname, 1);
2502 static int delete_ref_loose(struct ref_lock *lock, int flag)
2504 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2505 /* loose */
2506 int err, i = strlen(lock->lk->filename) - 5; /* .lock */
2508 lock->lk->filename[i] = 0;
2509 err = unlink_or_warn(lock->lk->filename);
2510 lock->lk->filename[i] = '.';
2511 if (err && errno != ENOENT)
2512 return 1;
2514 return 0;
2517 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
2519 struct ref_lock *lock;
2520 int ret = 0, flag = 0;
2522 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
2523 if (!lock)
2524 return 1;
2525 ret |= delete_ref_loose(lock, flag);
2527 /* removing the loose one could have resurrected an earlier
2528 * packed one. Also, if it was not loose we need to repack
2529 * without it.
2531 ret |= repack_without_ref(lock->ref_name);
2533 unlink_or_warn(git_path("logs/%s", lock->ref_name));
2534 clear_loose_ref_cache(&ref_cache);
2535 unlock_ref(lock);
2536 return ret;
2540 * People using contrib's git-new-workdir have .git/logs/refs ->
2541 * /some/other/path/.git/logs/refs, and that may live on another device.
2543 * IOW, to avoid cross device rename errors, the temporary renamed log must
2544 * live into logs/refs.
2546 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2548 static int rename_tmp_log(const char *newrefname)
2550 int attempts_remaining = 4;
2552 retry:
2553 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2554 case SCLD_OK:
2555 break; /* success */
2556 case SCLD_VANISHED:
2557 if (--attempts_remaining > 0)
2558 goto retry;
2559 /* fall through */
2560 default:
2561 error("unable to create directory for %s", newrefname);
2562 return -1;
2565 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
2566 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
2568 * rename(a, b) when b is an existing
2569 * directory ought to result in ISDIR, but
2570 * Solaris 5.8 gives ENOTDIR. Sheesh.
2572 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2573 error("Directory not empty: logs/%s", newrefname);
2574 return -1;
2576 goto retry;
2577 } else if (errno == ENOENT && --attempts_remaining > 0) {
2579 * Maybe another process just deleted one of
2580 * the directories in the path to newrefname.
2581 * Try again from the beginning.
2583 goto retry;
2584 } else {
2585 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2586 newrefname, strerror(errno));
2587 return -1;
2590 return 0;
2593 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
2595 unsigned char sha1[20], orig_sha1[20];
2596 int flag = 0, logmoved = 0;
2597 struct ref_lock *lock;
2598 struct stat loginfo;
2599 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2600 const char *symref = NULL;
2602 if (log && S_ISLNK(loginfo.st_mode))
2603 return error("reflog for %s is a symlink", oldrefname);
2605 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
2606 if (flag & REF_ISSYMREF)
2607 return error("refname %s is a symbolic ref, renaming it is not supported",
2608 oldrefname);
2609 if (!symref)
2610 return error("refname %s not found", oldrefname);
2612 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
2613 return 1;
2615 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
2616 return 1;
2618 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2619 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2620 oldrefname, strerror(errno));
2622 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2623 error("unable to delete old %s", oldrefname);
2624 goto rollback;
2627 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2628 delete_ref(newrefname, sha1, REF_NODEREF)) {
2629 if (errno==EISDIR) {
2630 if (remove_empty_directories(git_path("%s", newrefname))) {
2631 error("Directory not empty: %s", newrefname);
2632 goto rollback;
2634 } else {
2635 error("unable to delete existing %s", newrefname);
2636 goto rollback;
2640 if (log && rename_tmp_log(newrefname))
2641 goto rollback;
2643 logmoved = log;
2645 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
2646 if (!lock) {
2647 error("unable to lock %s for update", newrefname);
2648 goto rollback;
2650 lock->force_write = 1;
2651 hashcpy(lock->old_sha1, orig_sha1);
2652 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
2653 error("unable to write current sha1 into %s", newrefname);
2654 goto rollback;
2657 return 0;
2659 rollback:
2660 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
2661 if (!lock) {
2662 error("unable to lock %s for rollback", oldrefname);
2663 goto rollbacklog;
2666 lock->force_write = 1;
2667 flag = log_all_ref_updates;
2668 log_all_ref_updates = 0;
2669 if (write_ref_sha1(lock, orig_sha1, NULL))
2670 error("unable to write current sha1 into %s", oldrefname);
2671 log_all_ref_updates = flag;
2673 rollbacklog:
2674 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2675 error("unable to restore logfile %s from %s: %s",
2676 oldrefname, newrefname, strerror(errno));
2677 if (!logmoved && log &&
2678 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2679 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2680 oldrefname, strerror(errno));
2682 return 1;
2685 int close_ref(struct ref_lock *lock)
2687 if (close_lock_file(lock->lk))
2688 return -1;
2689 lock->lock_fd = -1;
2690 return 0;
2693 int commit_ref(struct ref_lock *lock)
2695 if (commit_lock_file(lock->lk))
2696 return -1;
2697 lock->lock_fd = -1;
2698 return 0;
2701 void unlock_ref(struct ref_lock *lock)
2703 /* Do not free lock->lk -- atexit() still looks at them */
2704 if (lock->lk)
2705 rollback_lock_file(lock->lk);
2706 free(lock->ref_name);
2707 free(lock->orig_ref_name);
2708 free(lock);
2712 * copy the reflog message msg to buf, which has been allocated sufficiently
2713 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2714 * because reflog file is one line per entry.
2716 static int copy_msg(char *buf, const char *msg)
2718 char *cp = buf;
2719 char c;
2720 int wasspace = 1;
2722 *cp++ = '\t';
2723 while ((c = *msg++)) {
2724 if (wasspace && isspace(c))
2725 continue;
2726 wasspace = isspace(c);
2727 if (wasspace)
2728 c = ' ';
2729 *cp++ = c;
2731 while (buf < cp && isspace(cp[-1]))
2732 cp--;
2733 *cp++ = '\n';
2734 return cp - buf;
2737 int log_ref_setup(const char *refname, char *logfile, int bufsize)
2739 int logfd, oflags = O_APPEND | O_WRONLY;
2741 git_snpath(logfile, bufsize, "logs/%s", refname);
2742 if (log_all_ref_updates &&
2743 (starts_with(refname, "refs/heads/") ||
2744 starts_with(refname, "refs/remotes/") ||
2745 starts_with(refname, "refs/notes/") ||
2746 !strcmp(refname, "HEAD"))) {
2747 if (safe_create_leading_directories(logfile) < 0)
2748 return error("unable to create directory for %s",
2749 logfile);
2750 oflags |= O_CREAT;
2753 logfd = open(logfile, oflags, 0666);
2754 if (logfd < 0) {
2755 if (!(oflags & O_CREAT) && errno == ENOENT)
2756 return 0;
2758 if ((oflags & O_CREAT) && errno == EISDIR) {
2759 if (remove_empty_directories(logfile)) {
2760 return error("There are still logs under '%s'",
2761 logfile);
2763 logfd = open(logfile, oflags, 0666);
2766 if (logfd < 0)
2767 return error("Unable to append to %s: %s",
2768 logfile, strerror(errno));
2771 adjust_shared_perm(logfile);
2772 close(logfd);
2773 return 0;
2776 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2777 const unsigned char *new_sha1, const char *msg)
2779 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2780 unsigned maxlen, len;
2781 int msglen;
2782 char log_file[PATH_MAX];
2783 char *logrec;
2784 const char *committer;
2786 if (log_all_ref_updates < 0)
2787 log_all_ref_updates = !is_bare_repository();
2789 result = log_ref_setup(refname, log_file, sizeof(log_file));
2790 if (result)
2791 return result;
2793 logfd = open(log_file, oflags);
2794 if (logfd < 0)
2795 return 0;
2796 msglen = msg ? strlen(msg) : 0;
2797 committer = git_committer_info(0);
2798 maxlen = strlen(committer) + msglen + 100;
2799 logrec = xmalloc(maxlen);
2800 len = sprintf(logrec, "%s %s %s\n",
2801 sha1_to_hex(old_sha1),
2802 sha1_to_hex(new_sha1),
2803 committer);
2804 if (msglen)
2805 len += copy_msg(logrec + len - 1, msg) - 1;
2806 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
2807 free(logrec);
2808 if (close(logfd) != 0 || written != len)
2809 return error("Unable to append to %s", log_file);
2810 return 0;
2813 static int is_branch(const char *refname)
2815 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
2818 int write_ref_sha1(struct ref_lock *lock,
2819 const unsigned char *sha1, const char *logmsg)
2821 static char term = '\n';
2822 struct object *o;
2824 if (!lock)
2825 return -1;
2826 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
2827 unlock_ref(lock);
2828 return 0;
2830 o = parse_object(sha1);
2831 if (!o) {
2832 error("Trying to write ref %s with nonexistent object %s",
2833 lock->ref_name, sha1_to_hex(sha1));
2834 unlock_ref(lock);
2835 return -1;
2837 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2838 error("Trying to write non-commit object %s to branch %s",
2839 sha1_to_hex(sha1), lock->ref_name);
2840 unlock_ref(lock);
2841 return -1;
2843 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2844 write_in_full(lock->lock_fd, &term, 1) != 1
2845 || close_ref(lock) < 0) {
2846 error("Couldn't write %s", lock->lk->filename);
2847 unlock_ref(lock);
2848 return -1;
2850 clear_loose_ref_cache(&ref_cache);
2851 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2852 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2853 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
2854 unlock_ref(lock);
2855 return -1;
2857 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2859 * Special hack: If a branch is updated directly and HEAD
2860 * points to it (may happen on the remote side of a push
2861 * for example) then logically the HEAD reflog should be
2862 * updated too.
2863 * A generic solution implies reverse symref information,
2864 * but finding all symrefs pointing to the given branch
2865 * would be rather costly for this rare event (the direct
2866 * update of a branch) to be worth it. So let's cheat and
2867 * check with HEAD only which should cover 99% of all usage
2868 * scenarios (even 100% of the default ones).
2870 unsigned char head_sha1[20];
2871 int head_flag;
2872 const char *head_ref;
2873 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
2874 if (head_ref && (head_flag & REF_ISSYMREF) &&
2875 !strcmp(head_ref, lock->ref_name))
2876 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2878 if (commit_ref(lock)) {
2879 error("Couldn't set %s", lock->ref_name);
2880 unlock_ref(lock);
2881 return -1;
2883 unlock_ref(lock);
2884 return 0;
2887 int create_symref(const char *ref_target, const char *refs_heads_master,
2888 const char *logmsg)
2890 const char *lockpath;
2891 char ref[1000];
2892 int fd, len, written;
2893 char *git_HEAD = git_pathdup("%s", ref_target);
2894 unsigned char old_sha1[20], new_sha1[20];
2896 if (logmsg && read_ref(ref_target, old_sha1))
2897 hashclr(old_sha1);
2899 if (safe_create_leading_directories(git_HEAD) < 0)
2900 return error("unable to create directory for %s", git_HEAD);
2902 #ifndef NO_SYMLINK_HEAD
2903 if (prefer_symlink_refs) {
2904 unlink(git_HEAD);
2905 if (!symlink(refs_heads_master, git_HEAD))
2906 goto done;
2907 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2909 #endif
2911 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2912 if (sizeof(ref) <= len) {
2913 error("refname too long: %s", refs_heads_master);
2914 goto error_free_return;
2916 lockpath = mkpath("%s.lock", git_HEAD);
2917 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2918 if (fd < 0) {
2919 error("Unable to open %s for writing", lockpath);
2920 goto error_free_return;
2922 written = write_in_full(fd, ref, len);
2923 if (close(fd) != 0 || written != len) {
2924 error("Unable to write to %s", lockpath);
2925 goto error_unlink_return;
2927 if (rename(lockpath, git_HEAD) < 0) {
2928 error("Unable to create %s", git_HEAD);
2929 goto error_unlink_return;
2931 if (adjust_shared_perm(git_HEAD)) {
2932 error("Unable to fix permissions on %s", lockpath);
2933 error_unlink_return:
2934 unlink_or_warn(lockpath);
2935 error_free_return:
2936 free(git_HEAD);
2937 return -1;
2940 #ifndef NO_SYMLINK_HEAD
2941 done:
2942 #endif
2943 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2944 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2946 free(git_HEAD);
2947 return 0;
2950 static char *ref_msg(const char *line, const char *endp)
2952 const char *ep;
2953 line += 82;
2954 ep = memchr(line, '\n', endp - line);
2955 if (!ep)
2956 ep = endp;
2957 return xmemdupz(line, ep - line);
2960 int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2961 unsigned char *sha1, char **msg,
2962 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
2964 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
2965 char *tz_c;
2966 int logfd, tz, reccnt = 0;
2967 struct stat st;
2968 unsigned long date;
2969 unsigned char logged_sha1[20];
2970 void *log_mapped;
2971 size_t mapsz;
2973 logfile = git_path("logs/%s", refname);
2974 logfd = open(logfile, O_RDONLY, 0);
2975 if (logfd < 0)
2976 die_errno("Unable to read log '%s'", logfile);
2977 fstat(logfd, &st);
2978 if (!st.st_size)
2979 die("Log %s is empty.", logfile);
2980 mapsz = xsize_t(st.st_size);
2981 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
2982 logdata = log_mapped;
2983 close(logfd);
2985 lastrec = NULL;
2986 rec = logend = logdata + st.st_size;
2987 while (logdata < rec) {
2988 reccnt++;
2989 if (logdata < rec && *(rec-1) == '\n')
2990 rec--;
2991 lastgt = NULL;
2992 while (logdata < rec && *(rec-1) != '\n') {
2993 rec--;
2994 if (*rec == '>')
2995 lastgt = rec;
2997 if (!lastgt)
2998 die("Log %s is corrupt.", logfile);
2999 date = strtoul(lastgt + 1, &tz_c, 10);
3000 if (date <= at_time || cnt == 0) {
3001 tz = strtoul(tz_c, NULL, 10);
3002 if (msg)
3003 *msg = ref_msg(rec, logend);
3004 if (cutoff_time)
3005 *cutoff_time = date;
3006 if (cutoff_tz)
3007 *cutoff_tz = tz;
3008 if (cutoff_cnt)
3009 *cutoff_cnt = reccnt - 1;
3010 if (lastrec) {
3011 if (get_sha1_hex(lastrec, logged_sha1))
3012 die("Log %s is corrupt.", logfile);
3013 if (get_sha1_hex(rec + 41, sha1))
3014 die("Log %s is corrupt.", logfile);
3015 if (hashcmp(logged_sha1, sha1)) {
3016 warning("Log %s has gap after %s.",
3017 logfile, show_date(date, tz, DATE_RFC2822));
3020 else if (date == at_time) {
3021 if (get_sha1_hex(rec + 41, sha1))
3022 die("Log %s is corrupt.", logfile);
3024 else {
3025 if (get_sha1_hex(rec + 41, logged_sha1))
3026 die("Log %s is corrupt.", logfile);
3027 if (hashcmp(logged_sha1, sha1)) {
3028 warning("Log %s unexpectedly ended on %s.",
3029 logfile, show_date(date, tz, DATE_RFC2822));
3032 munmap(log_mapped, mapsz);
3033 return 0;
3035 lastrec = rec;
3036 if (cnt > 0)
3037 cnt--;
3040 rec = logdata;
3041 while (rec < logend && *rec != '>' && *rec != '\n')
3042 rec++;
3043 if (rec == logend || *rec == '\n')
3044 die("Log %s is corrupt.", logfile);
3045 date = strtoul(rec + 1, &tz_c, 10);
3046 tz = strtoul(tz_c, NULL, 10);
3047 if (get_sha1_hex(logdata, sha1))
3048 die("Log %s is corrupt.", logfile);
3049 if (is_null_sha1(sha1)) {
3050 if (get_sha1_hex(logdata + 41, sha1))
3051 die("Log %s is corrupt.", logfile);
3053 if (msg)
3054 *msg = ref_msg(logdata, logend);
3055 munmap(log_mapped, mapsz);
3057 if (cutoff_time)
3058 *cutoff_time = date;
3059 if (cutoff_tz)
3060 *cutoff_tz = tz;
3061 if (cutoff_cnt)
3062 *cutoff_cnt = reccnt;
3063 return 1;
3066 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3068 unsigned char osha1[20], nsha1[20];
3069 char *email_end, *message;
3070 unsigned long timestamp;
3071 int tz;
3073 /* old SP new SP name <email> SP time TAB msg LF */
3074 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3075 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3076 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3077 !(email_end = strchr(sb->buf + 82, '>')) ||
3078 email_end[1] != ' ' ||
3079 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3080 !message || message[0] != ' ' ||
3081 (message[1] != '+' && message[1] != '-') ||
3082 !isdigit(message[2]) || !isdigit(message[3]) ||
3083 !isdigit(message[4]) || !isdigit(message[5]))
3084 return 0; /* corrupt? */
3085 email_end[1] = '\0';
3086 tz = strtol(message + 1, NULL, 10);
3087 if (message[6] != '\t')
3088 message += 6;
3089 else
3090 message += 7;
3091 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3094 static char *find_beginning_of_line(char *bob, char *scan)
3096 while (bob < scan && *(--scan) != '\n')
3097 ; /* keep scanning backwards */
3099 * Return either beginning of the buffer, or LF at the end of
3100 * the previous line.
3102 return scan;
3105 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3107 struct strbuf sb = STRBUF_INIT;
3108 FILE *logfp;
3109 long pos;
3110 int ret = 0, at_tail = 1;
3112 logfp = fopen(git_path("logs/%s", refname), "r");
3113 if (!logfp)
3114 return -1;
3116 /* Jump to the end */
3117 if (fseek(logfp, 0, SEEK_END) < 0)
3118 return error("cannot seek back reflog for %s: %s",
3119 refname, strerror(errno));
3120 pos = ftell(logfp);
3121 while (!ret && 0 < pos) {
3122 int cnt;
3123 size_t nread;
3124 char buf[BUFSIZ];
3125 char *endp, *scanp;
3127 /* Fill next block from the end */
3128 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3129 if (fseek(logfp, pos - cnt, SEEK_SET))
3130 return error("cannot seek back reflog for %s: %s",
3131 refname, strerror(errno));
3132 nread = fread(buf, cnt, 1, logfp);
3133 if (nread != 1)
3134 return error("cannot read %d bytes from reflog for %s: %s",
3135 cnt, refname, strerror(errno));
3136 pos -= cnt;
3138 scanp = endp = buf + cnt;
3139 if (at_tail && scanp[-1] == '\n')
3140 /* Looking at the final LF at the end of the file */
3141 scanp--;
3142 at_tail = 0;
3144 while (buf < scanp) {
3146 * terminating LF of the previous line, or the beginning
3147 * of the buffer.
3149 char *bp;
3151 bp = find_beginning_of_line(buf, scanp);
3153 if (*bp != '\n') {
3154 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3155 if (pos)
3156 break; /* need to fill another block */
3157 scanp = buf - 1; /* leave loop */
3158 } else {
3160 * (bp + 1) thru endp is the beginning of the
3161 * current line we have in sb
3163 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3164 scanp = bp;
3165 endp = bp + 1;
3167 ret = show_one_reflog_ent(&sb, fn, cb_data);
3168 strbuf_reset(&sb);
3169 if (ret)
3170 break;
3174 if (!ret && sb.len)
3175 ret = show_one_reflog_ent(&sb, fn, cb_data);
3177 fclose(logfp);
3178 strbuf_release(&sb);
3179 return ret;
3182 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3184 FILE *logfp;
3185 struct strbuf sb = STRBUF_INIT;
3186 int ret = 0;
3188 logfp = fopen(git_path("logs/%s", refname), "r");
3189 if (!logfp)
3190 return -1;
3192 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3193 ret = show_one_reflog_ent(&sb, fn, cb_data);
3194 fclose(logfp);
3195 strbuf_release(&sb);
3196 return ret;
3199 * Call fn for each reflog in the namespace indicated by name. name
3200 * must be empty or end with '/'. Name will be used as a scratch
3201 * space, but its contents will be restored before return.
3203 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
3205 DIR *d = opendir(git_path("logs/%s", name->buf));
3206 int retval = 0;
3207 struct dirent *de;
3208 int oldlen = name->len;
3210 if (!d)
3211 return name->len ? errno : 0;
3213 while ((de = readdir(d)) != NULL) {
3214 struct stat st;
3216 if (de->d_name[0] == '.')
3217 continue;
3218 if (has_extension(de->d_name, ".lock"))
3219 continue;
3220 strbuf_addstr(name, de->d_name);
3221 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3222 ; /* silently ignore */
3223 } else {
3224 if (S_ISDIR(st.st_mode)) {
3225 strbuf_addch(name, '/');
3226 retval = do_for_each_reflog(name, fn, cb_data);
3227 } else {
3228 unsigned char sha1[20];
3229 if (read_ref_full(name->buf, sha1, 0, NULL))
3230 retval = error("bad ref for %s", name->buf);
3231 else
3232 retval = fn(name->buf, sha1, 0, cb_data);
3234 if (retval)
3235 break;
3237 strbuf_setlen(name, oldlen);
3239 closedir(d);
3240 return retval;
3243 int for_each_reflog(each_ref_fn fn, void *cb_data)
3245 int retval;
3246 struct strbuf name;
3247 strbuf_init(&name, PATH_MAX);
3248 retval = do_for_each_reflog(&name, fn, cb_data);
3249 strbuf_release(&name);
3250 return retval;
3253 static struct ref_lock *update_ref_lock(const char *refname,
3254 const unsigned char *oldval,
3255 int flags, int *type_p,
3256 enum action_on_err onerr)
3258 struct ref_lock *lock;
3259 lock = lock_any_ref_for_update(refname, oldval, flags, type_p);
3260 if (!lock) {
3261 const char *str = "Cannot lock the ref '%s'.";
3262 switch (onerr) {
3263 case MSG_ON_ERR: error(str, refname); break;
3264 case DIE_ON_ERR: die(str, refname); break;
3265 case QUIET_ON_ERR: break;
3268 return lock;
3271 static int update_ref_write(const char *action, const char *refname,
3272 const unsigned char *sha1, struct ref_lock *lock,
3273 enum action_on_err onerr)
3275 if (write_ref_sha1(lock, sha1, action) < 0) {
3276 const char *str = "Cannot update the ref '%s'.";
3277 switch (onerr) {
3278 case MSG_ON_ERR: error(str, refname); break;
3279 case DIE_ON_ERR: die(str, refname); break;
3280 case QUIET_ON_ERR: break;
3282 return 1;
3284 return 0;
3287 int update_ref(const char *action, const char *refname,
3288 const unsigned char *sha1, const unsigned char *oldval,
3289 int flags, enum action_on_err onerr)
3291 struct ref_lock *lock;
3292 lock = update_ref_lock(refname, oldval, flags, NULL, onerr);
3293 if (!lock)
3294 return 1;
3295 return update_ref_write(action, refname, sha1, lock, onerr);
3298 static int ref_update_compare(const void *r1, const void *r2)
3300 const struct ref_update * const *u1 = r1;
3301 const struct ref_update * const *u2 = r2;
3302 return strcmp((*u1)->ref_name, (*u2)->ref_name);
3305 static int ref_update_reject_duplicates(struct ref_update **updates, int n,
3306 enum action_on_err onerr)
3308 int i;
3309 for (i = 1; i < n; i++)
3310 if (!strcmp(updates[i - 1]->ref_name, updates[i]->ref_name)) {
3311 const char *str =
3312 "Multiple updates for ref '%s' not allowed.";
3313 switch (onerr) {
3314 case MSG_ON_ERR:
3315 error(str, updates[i]->ref_name); break;
3316 case DIE_ON_ERR:
3317 die(str, updates[i]->ref_name); break;
3318 case QUIET_ON_ERR:
3319 break;
3321 return 1;
3323 return 0;
3326 int update_refs(const char *action, const struct ref_update **updates_orig,
3327 int n, enum action_on_err onerr)
3329 int ret = 0, delnum = 0, i;
3330 struct ref_update **updates;
3331 int *types;
3332 struct ref_lock **locks;
3333 const char **delnames;
3335 if (!updates_orig || !n)
3336 return 0;
3338 /* Allocate work space */
3339 updates = xmalloc(sizeof(*updates) * n);
3340 types = xmalloc(sizeof(*types) * n);
3341 locks = xcalloc(n, sizeof(*locks));
3342 delnames = xmalloc(sizeof(*delnames) * n);
3344 /* Copy, sort, and reject duplicate refs */
3345 memcpy(updates, updates_orig, sizeof(*updates) * n);
3346 qsort(updates, n, sizeof(*updates), ref_update_compare);
3347 ret = ref_update_reject_duplicates(updates, n, onerr);
3348 if (ret)
3349 goto cleanup;
3351 /* Acquire all locks while verifying old values */
3352 for (i = 0; i < n; i++) {
3353 locks[i] = update_ref_lock(updates[i]->ref_name,
3354 (updates[i]->have_old ?
3355 updates[i]->old_sha1 : NULL),
3356 updates[i]->flags,
3357 &types[i], onerr);
3358 if (!locks[i]) {
3359 ret = 1;
3360 goto cleanup;
3364 /* Perform updates first so live commits remain referenced */
3365 for (i = 0; i < n; i++)
3366 if (!is_null_sha1(updates[i]->new_sha1)) {
3367 ret = update_ref_write(action,
3368 updates[i]->ref_name,
3369 updates[i]->new_sha1,
3370 locks[i], onerr);
3371 locks[i] = NULL; /* freed by update_ref_write */
3372 if (ret)
3373 goto cleanup;
3376 /* Perform deletes now that updates are safely completed */
3377 for (i = 0; i < n; i++)
3378 if (locks[i]) {
3379 delnames[delnum++] = locks[i]->ref_name;
3380 ret |= delete_ref_loose(locks[i], types[i]);
3382 ret |= repack_without_refs(delnames, delnum);
3383 for (i = 0; i < delnum; i++)
3384 unlink_or_warn(git_path("logs/%s", delnames[i]));
3385 clear_loose_ref_cache(&ref_cache);
3387 cleanup:
3388 for (i = 0; i < n; i++)
3389 if (locks[i])
3390 unlock_ref(locks[i]);
3391 free(updates);
3392 free(types);
3393 free(locks);
3394 free(delnames);
3395 return ret;
3398 char *shorten_unambiguous_ref(const char *refname, int strict)
3400 int i;
3401 static char **scanf_fmts;
3402 static int nr_rules;
3403 char *short_name;
3405 if (!nr_rules) {
3407 * Pre-generate scanf formats from ref_rev_parse_rules[].
3408 * Generate a format suitable for scanf from a
3409 * ref_rev_parse_rules rule by interpolating "%s" at the
3410 * location of the "%.*s".
3412 size_t total_len = 0;
3413 size_t offset = 0;
3415 /* the rule list is NULL terminated, count them first */
3416 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
3417 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
3418 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
3420 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3422 offset = 0;
3423 for (i = 0; i < nr_rules; i++) {
3424 assert(offset < total_len);
3425 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
3426 offset += snprintf(scanf_fmts[i], total_len - offset,
3427 ref_rev_parse_rules[i], 2, "%s") + 1;
3431 /* bail out if there are no rules */
3432 if (!nr_rules)
3433 return xstrdup(refname);
3435 /* buffer for scanf result, at most refname must fit */
3436 short_name = xstrdup(refname);
3438 /* skip first rule, it will always match */
3439 for (i = nr_rules - 1; i > 0 ; --i) {
3440 int j;
3441 int rules_to_fail = i;
3442 int short_name_len;
3444 if (1 != sscanf(refname, scanf_fmts[i], short_name))
3445 continue;
3447 short_name_len = strlen(short_name);
3450 * in strict mode, all (except the matched one) rules
3451 * must fail to resolve to a valid non-ambiguous ref
3453 if (strict)
3454 rules_to_fail = nr_rules;
3457 * check if the short name resolves to a valid ref,
3458 * but use only rules prior to the matched one
3460 for (j = 0; j < rules_to_fail; j++) {
3461 const char *rule = ref_rev_parse_rules[j];
3462 char refname[PATH_MAX];
3464 /* skip matched rule */
3465 if (i == j)
3466 continue;
3469 * the short name is ambiguous, if it resolves
3470 * (with this previous rule) to a valid ref
3471 * read_ref() returns 0 on success
3473 mksnpath(refname, sizeof(refname),
3474 rule, short_name_len, short_name);
3475 if (ref_exists(refname))
3476 break;
3480 * short name is non-ambiguous if all previous rules
3481 * haven't resolved to a valid ref
3483 if (j == rules_to_fail)
3484 return short_name;
3487 free(short_name);
3488 return xstrdup(refname);
3491 static struct string_list *hide_refs;
3493 int parse_hide_refs_config(const char *var, const char *value, const char *section)
3495 if (!strcmp("transfer.hiderefs", var) ||
3496 /* NEEDSWORK: use parse_config_key() once both are merged */
3497 (starts_with(var, section) && var[strlen(section)] == '.' &&
3498 !strcmp(var + strlen(section), ".hiderefs"))) {
3499 char *ref;
3500 int len;
3502 if (!value)
3503 return config_error_nonbool(var);
3504 ref = xstrdup(value);
3505 len = strlen(ref);
3506 while (len && ref[len - 1] == '/')
3507 ref[--len] = '\0';
3508 if (!hide_refs) {
3509 hide_refs = xcalloc(1, sizeof(*hide_refs));
3510 hide_refs->strdup_strings = 1;
3512 string_list_append(hide_refs, ref);
3514 return 0;
3517 int ref_is_hidden(const char *refname)
3519 struct string_list_item *item;
3521 if (!hide_refs)
3522 return 0;
3523 for_each_string_list_item(item, hide_refs) {
3524 int len;
3525 if (!starts_with(refname, item->string))
3526 continue;
3527 len = strlen(item->string);
3528 if (!refname[len] || refname[len] == '/')
3529 return 1;
3531 return 0;