Merge branch 'tc/commit-dry-run-exit-status-tests'
[git.git] / refs.c
blob28d5eca8eaff7be48a4b89e6217886b8c96eb3b2
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 char *msg_fmt;
1617 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1618 int flags, void *cb_data)
1620 struct warn_if_dangling_data *d = cb_data;
1621 const char *resolves_to;
1622 unsigned char junk[20];
1624 if (!(flags & REF_ISSYMREF))
1625 return 0;
1627 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1628 if (!resolves_to || strcmp(resolves_to, d->refname))
1629 return 0;
1631 fprintf(d->fp, d->msg_fmt, refname);
1632 fputc('\n', d->fp);
1633 return 0;
1636 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1638 struct warn_if_dangling_data data;
1640 data.fp = fp;
1641 data.refname = refname;
1642 data.msg_fmt = msg_fmt;
1643 for_each_rawref(warn_if_dangling_symref, &data);
1647 * Call fn for each reference in the specified ref_cache, omitting
1648 * references not in the containing_dir of base. fn is called for all
1649 * references, including broken ones. If fn ever returns a non-zero
1650 * value, stop the iteration and return that value; otherwise, return
1651 * 0.
1653 static int do_for_each_entry(struct ref_cache *refs, const char *base,
1654 each_ref_entry_fn fn, void *cb_data)
1656 struct packed_ref_cache *packed_ref_cache;
1657 struct ref_dir *loose_dir;
1658 struct ref_dir *packed_dir;
1659 int retval = 0;
1662 * We must make sure that all loose refs are read before accessing the
1663 * packed-refs file; this avoids a race condition in which loose refs
1664 * are migrated to the packed-refs file by a simultaneous process, but
1665 * our in-memory view is from before the migration. get_packed_ref_cache()
1666 * takes care of making sure our view is up to date with what is on
1667 * disk.
1669 loose_dir = get_loose_refs(refs);
1670 if (base && *base) {
1671 loose_dir = find_containing_dir(loose_dir, base, 0);
1673 if (loose_dir)
1674 prime_ref_dir(loose_dir);
1676 packed_ref_cache = get_packed_ref_cache(refs);
1677 acquire_packed_ref_cache(packed_ref_cache);
1678 packed_dir = get_packed_ref_dir(packed_ref_cache);
1679 if (base && *base) {
1680 packed_dir = find_containing_dir(packed_dir, base, 0);
1683 if (packed_dir && loose_dir) {
1684 sort_ref_dir(packed_dir);
1685 sort_ref_dir(loose_dir);
1686 retval = do_for_each_entry_in_dirs(
1687 packed_dir, loose_dir, fn, cb_data);
1688 } else if (packed_dir) {
1689 sort_ref_dir(packed_dir);
1690 retval = do_for_each_entry_in_dir(
1691 packed_dir, 0, fn, cb_data);
1692 } else if (loose_dir) {
1693 sort_ref_dir(loose_dir);
1694 retval = do_for_each_entry_in_dir(
1695 loose_dir, 0, fn, cb_data);
1698 release_packed_ref_cache(packed_ref_cache);
1699 return retval;
1703 * Call fn for each reference in the specified ref_cache for which the
1704 * refname begins with base. If trim is non-zero, then trim that many
1705 * characters off the beginning of each refname before passing the
1706 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1707 * broken references in the iteration. If fn ever returns a non-zero
1708 * value, stop the iteration and return that value; otherwise, return
1709 * 0.
1711 static int do_for_each_ref(struct ref_cache *refs, const char *base,
1712 each_ref_fn fn, int trim, int flags, void *cb_data)
1714 struct ref_entry_cb data;
1715 data.base = base;
1716 data.trim = trim;
1717 data.flags = flags;
1718 data.fn = fn;
1719 data.cb_data = cb_data;
1721 return do_for_each_entry(refs, base, do_one_ref, &data);
1724 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1726 unsigned char sha1[20];
1727 int flag;
1729 if (submodule) {
1730 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1731 return fn("HEAD", sha1, 0, cb_data);
1733 return 0;
1736 if (!read_ref_full("HEAD", sha1, 1, &flag))
1737 return fn("HEAD", sha1, flag, cb_data);
1739 return 0;
1742 int head_ref(each_ref_fn fn, void *cb_data)
1744 return do_head_ref(NULL, fn, cb_data);
1747 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1749 return do_head_ref(submodule, fn, cb_data);
1752 int for_each_ref(each_ref_fn fn, void *cb_data)
1754 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1757 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1759 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
1762 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1764 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1767 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1768 each_ref_fn fn, void *cb_data)
1770 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
1773 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1775 return for_each_ref_in("refs/tags/", fn, cb_data);
1778 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1780 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1783 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1785 return for_each_ref_in("refs/heads/", fn, cb_data);
1788 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1790 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1793 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1795 return for_each_ref_in("refs/remotes/", fn, cb_data);
1798 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1800 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1803 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1805 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
1808 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1810 struct strbuf buf = STRBUF_INIT;
1811 int ret = 0;
1812 unsigned char sha1[20];
1813 int flag;
1815 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
1816 if (!read_ref_full(buf.buf, sha1, 1, &flag))
1817 ret = fn(buf.buf, sha1, flag, cb_data);
1818 strbuf_release(&buf);
1820 return ret;
1823 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1825 struct strbuf buf = STRBUF_INIT;
1826 int ret;
1827 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1828 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
1829 strbuf_release(&buf);
1830 return ret;
1833 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1834 const char *prefix, void *cb_data)
1836 struct strbuf real_pattern = STRBUF_INIT;
1837 struct ref_filter filter;
1838 int ret;
1840 if (!prefix && !starts_with(pattern, "refs/"))
1841 strbuf_addstr(&real_pattern, "refs/");
1842 else if (prefix)
1843 strbuf_addstr(&real_pattern, prefix);
1844 strbuf_addstr(&real_pattern, pattern);
1846 if (!has_glob_specials(pattern)) {
1847 /* Append implied '/' '*' if not present. */
1848 if (real_pattern.buf[real_pattern.len - 1] != '/')
1849 strbuf_addch(&real_pattern, '/');
1850 /* No need to check for '*', there is none. */
1851 strbuf_addch(&real_pattern, '*');
1854 filter.pattern = real_pattern.buf;
1855 filter.fn = fn;
1856 filter.cb_data = cb_data;
1857 ret = for_each_ref(filter_refs, &filter);
1859 strbuf_release(&real_pattern);
1860 return ret;
1863 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1865 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1868 int for_each_rawref(each_ref_fn fn, void *cb_data)
1870 return do_for_each_ref(&ref_cache, "", fn, 0,
1871 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1874 const char *prettify_refname(const char *name)
1876 return name + (
1877 starts_with(name, "refs/heads/") ? 11 :
1878 starts_with(name, "refs/tags/") ? 10 :
1879 starts_with(name, "refs/remotes/") ? 13 :
1883 static const char *ref_rev_parse_rules[] = {
1884 "%.*s",
1885 "refs/%.*s",
1886 "refs/tags/%.*s",
1887 "refs/heads/%.*s",
1888 "refs/remotes/%.*s",
1889 "refs/remotes/%.*s/HEAD",
1890 NULL
1893 int refname_match(const char *abbrev_name, const char *full_name)
1895 const char **p;
1896 const int abbrev_name_len = strlen(abbrev_name);
1898 for (p = ref_rev_parse_rules; *p; p++) {
1899 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1900 return 1;
1904 return 0;
1907 static struct ref_lock *verify_lock(struct ref_lock *lock,
1908 const unsigned char *old_sha1, int mustexist)
1910 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
1911 error("Can't verify ref %s", lock->ref_name);
1912 unlock_ref(lock);
1913 return NULL;
1915 if (hashcmp(lock->old_sha1, old_sha1)) {
1916 error("Ref %s is at %s but expected %s", lock->ref_name,
1917 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1918 unlock_ref(lock);
1919 return NULL;
1921 return lock;
1924 static int remove_empty_directories(const char *file)
1926 /* we want to create a file but there is a directory there;
1927 * if that is an empty directory (or a directory that contains
1928 * only empty directories), remove them.
1930 struct strbuf path;
1931 int result;
1933 strbuf_init(&path, 20);
1934 strbuf_addstr(&path, file);
1936 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
1938 strbuf_release(&path);
1940 return result;
1944 * *string and *len will only be substituted, and *string returned (for
1945 * later free()ing) if the string passed in is a magic short-hand form
1946 * to name a branch.
1948 static char *substitute_branch_name(const char **string, int *len)
1950 struct strbuf buf = STRBUF_INIT;
1951 int ret = interpret_branch_name(*string, *len, &buf);
1953 if (ret == *len) {
1954 size_t size;
1955 *string = strbuf_detach(&buf, &size);
1956 *len = size;
1957 return (char *)*string;
1960 return NULL;
1963 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1965 char *last_branch = substitute_branch_name(&str, &len);
1966 const char **p, *r;
1967 int refs_found = 0;
1969 *ref = NULL;
1970 for (p = ref_rev_parse_rules; *p; p++) {
1971 char fullref[PATH_MAX];
1972 unsigned char sha1_from_ref[20];
1973 unsigned char *this_result;
1974 int flag;
1976 this_result = refs_found ? sha1_from_ref : sha1;
1977 mksnpath(fullref, sizeof(fullref), *p, len, str);
1978 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
1979 if (r) {
1980 if (!refs_found++)
1981 *ref = xstrdup(r);
1982 if (!warn_ambiguous_refs)
1983 break;
1984 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
1985 warning("ignoring dangling symref %s.", fullref);
1986 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1987 warning("ignoring broken ref %s.", fullref);
1990 free(last_branch);
1991 return refs_found;
1994 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1996 char *last_branch = substitute_branch_name(&str, &len);
1997 const char **p;
1998 int logs_found = 0;
2000 *log = NULL;
2001 for (p = ref_rev_parse_rules; *p; p++) {
2002 struct stat st;
2003 unsigned char hash[20];
2004 char path[PATH_MAX];
2005 const char *ref, *it;
2007 mksnpath(path, sizeof(path), *p, len, str);
2008 ref = resolve_ref_unsafe(path, hash, 1, NULL);
2009 if (!ref)
2010 continue;
2011 if (!stat(git_path("logs/%s", path), &st) &&
2012 S_ISREG(st.st_mode))
2013 it = path;
2014 else if (strcmp(ref, path) &&
2015 !stat(git_path("logs/%s", ref), &st) &&
2016 S_ISREG(st.st_mode))
2017 it = ref;
2018 else
2019 continue;
2020 if (!logs_found++) {
2021 *log = xstrdup(it);
2022 hashcpy(sha1, hash);
2024 if (!warn_ambiguous_refs)
2025 break;
2027 free(last_branch);
2028 return logs_found;
2031 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2032 const unsigned char *old_sha1,
2033 int flags, int *type_p)
2035 char *ref_file;
2036 const char *orig_refname = refname;
2037 struct ref_lock *lock;
2038 int last_errno = 0;
2039 int type, lflags;
2040 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
2041 int missing = 0;
2042 int attempts_remaining = 3;
2044 lock = xcalloc(1, sizeof(struct ref_lock));
2045 lock->lock_fd = -1;
2047 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
2048 if (!refname && errno == EISDIR) {
2049 /* we are trying to lock foo but we used to
2050 * have foo/bar which now does not exist;
2051 * it is normal for the empty directory 'foo'
2052 * to remain.
2054 ref_file = git_path("%s", orig_refname);
2055 if (remove_empty_directories(ref_file)) {
2056 last_errno = errno;
2057 error("there are still refs under '%s'", orig_refname);
2058 goto error_return;
2060 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
2062 if (type_p)
2063 *type_p = type;
2064 if (!refname) {
2065 last_errno = errno;
2066 error("unable to resolve reference %s: %s",
2067 orig_refname, strerror(errno));
2068 goto error_return;
2070 missing = is_null_sha1(lock->old_sha1);
2071 /* When the ref did not exist and we are creating it,
2072 * make sure there is no existing ref that is packed
2073 * whose name begins with our refname, nor a ref whose
2074 * name is a proper prefix of our refname.
2076 if (missing &&
2077 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
2078 last_errno = ENOTDIR;
2079 goto error_return;
2082 lock->lk = xcalloc(1, sizeof(struct lock_file));
2084 lflags = 0;
2085 if (flags & REF_NODEREF) {
2086 refname = orig_refname;
2087 lflags |= LOCK_NODEREF;
2089 lock->ref_name = xstrdup(refname);
2090 lock->orig_ref_name = xstrdup(orig_refname);
2091 ref_file = git_path("%s", refname);
2092 if (missing)
2093 lock->force_write = 1;
2094 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2095 lock->force_write = 1;
2097 retry:
2098 switch (safe_create_leading_directories(ref_file)) {
2099 case SCLD_OK:
2100 break; /* success */
2101 case SCLD_VANISHED:
2102 if (--attempts_remaining > 0)
2103 goto retry;
2104 /* fall through */
2105 default:
2106 last_errno = errno;
2107 error("unable to create directory for %s", ref_file);
2108 goto error_return;
2111 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
2112 if (lock->lock_fd < 0) {
2113 if (errno == ENOENT && --attempts_remaining > 0)
2115 * Maybe somebody just deleted one of the
2116 * directories leading to ref_file. Try
2117 * again:
2119 goto retry;
2120 else
2121 unable_to_lock_index_die(ref_file, errno);
2123 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
2125 error_return:
2126 unlock_ref(lock);
2127 errno = last_errno;
2128 return NULL;
2131 struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
2133 char refpath[PATH_MAX];
2134 if (check_refname_format(refname, 0))
2135 return NULL;
2136 strcpy(refpath, mkpath("refs/%s", refname));
2137 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
2140 struct ref_lock *lock_any_ref_for_update(const char *refname,
2141 const unsigned char *old_sha1,
2142 int flags, int *type_p)
2144 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
2145 return NULL;
2146 return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
2150 * Write an entry to the packed-refs file for the specified refname.
2151 * If peeled is non-NULL, write it as the entry's peeled value.
2153 static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2154 unsigned char *peeled)
2156 char line[PATH_MAX + 100];
2157 int len;
2159 len = snprintf(line, sizeof(line), "%s %s\n",
2160 sha1_to_hex(sha1), refname);
2161 /* this should not happen but just being defensive */
2162 if (len > sizeof(line))
2163 die("too long a refname '%s'", refname);
2164 write_or_die(fd, line, len);
2166 if (peeled) {
2167 if (snprintf(line, sizeof(line), "^%s\n",
2168 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2169 die("internal error");
2170 write_or_die(fd, line, PEELED_LINE_LENGTH);
2175 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2177 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2179 int *fd = cb_data;
2180 enum peel_status peel_status = peel_entry(entry, 0);
2182 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2183 error("internal error: %s is not a valid packed reference!",
2184 entry->name);
2185 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2186 peel_status == PEEL_PEELED ?
2187 entry->u.value.peeled : NULL);
2188 return 0;
2191 int lock_packed_refs(int flags)
2193 struct packed_ref_cache *packed_ref_cache;
2195 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2196 return -1;
2198 * Get the current packed-refs while holding the lock. If the
2199 * packed-refs file has been modified since we last read it,
2200 * this will automatically invalidate the cache and re-read
2201 * the packed-refs file.
2203 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2204 packed_ref_cache->lock = &packlock;
2205 /* Increment the reference count to prevent it from being freed: */
2206 acquire_packed_ref_cache(packed_ref_cache);
2207 return 0;
2210 int commit_packed_refs(void)
2212 struct packed_ref_cache *packed_ref_cache =
2213 get_packed_ref_cache(&ref_cache);
2214 int error = 0;
2216 if (!packed_ref_cache->lock)
2217 die("internal error: packed-refs not locked");
2218 write_or_die(packed_ref_cache->lock->fd,
2219 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2221 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2222 0, write_packed_entry_fn,
2223 &packed_ref_cache->lock->fd);
2224 if (commit_lock_file(packed_ref_cache->lock))
2225 error = -1;
2226 packed_ref_cache->lock = NULL;
2227 release_packed_ref_cache(packed_ref_cache);
2228 return error;
2231 void rollback_packed_refs(void)
2233 struct packed_ref_cache *packed_ref_cache =
2234 get_packed_ref_cache(&ref_cache);
2236 if (!packed_ref_cache->lock)
2237 die("internal error: packed-refs not locked");
2238 rollback_lock_file(packed_ref_cache->lock);
2239 packed_ref_cache->lock = NULL;
2240 release_packed_ref_cache(packed_ref_cache);
2241 clear_packed_ref_cache(&ref_cache);
2244 struct ref_to_prune {
2245 struct ref_to_prune *next;
2246 unsigned char sha1[20];
2247 char name[FLEX_ARRAY];
2250 struct pack_refs_cb_data {
2251 unsigned int flags;
2252 struct ref_dir *packed_refs;
2253 struct ref_to_prune *ref_to_prune;
2257 * An each_ref_entry_fn that is run over loose references only. If
2258 * the loose reference can be packed, add an entry in the packed ref
2259 * cache. If the reference should be pruned, also add it to
2260 * ref_to_prune in the pack_refs_cb_data.
2262 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2264 struct pack_refs_cb_data *cb = cb_data;
2265 enum peel_status peel_status;
2266 struct ref_entry *packed_entry;
2267 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2269 /* ALWAYS pack tags */
2270 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2271 return 0;
2273 /* Do not pack symbolic or broken refs: */
2274 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2275 return 0;
2277 /* Add a packed ref cache entry equivalent to the loose entry. */
2278 peel_status = peel_entry(entry, 1);
2279 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2280 die("internal error peeling reference %s (%s)",
2281 entry->name, sha1_to_hex(entry->u.value.sha1));
2282 packed_entry = find_ref(cb->packed_refs, entry->name);
2283 if (packed_entry) {
2284 /* Overwrite existing packed entry with info from loose entry */
2285 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2286 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2287 } else {
2288 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2289 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2290 add_ref(cb->packed_refs, packed_entry);
2292 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
2294 /* Schedule the loose reference for pruning if requested. */
2295 if ((cb->flags & PACK_REFS_PRUNE)) {
2296 int namelen = strlen(entry->name) + 1;
2297 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
2298 hashcpy(n->sha1, entry->u.value.sha1);
2299 strcpy(n->name, entry->name);
2300 n->next = cb->ref_to_prune;
2301 cb->ref_to_prune = n;
2303 return 0;
2307 * Remove empty parents, but spare refs/ and immediate subdirs.
2308 * Note: munges *name.
2310 static void try_remove_empty_parents(char *name)
2312 char *p, *q;
2313 int i;
2314 p = name;
2315 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2316 while (*p && *p != '/')
2317 p++;
2318 /* tolerate duplicate slashes; see check_refname_format() */
2319 while (*p == '/')
2320 p++;
2322 for (q = p; *q; q++)
2324 while (1) {
2325 while (q > p && *q != '/')
2326 q--;
2327 while (q > p && *(q-1) == '/')
2328 q--;
2329 if (q == p)
2330 break;
2331 *q = '\0';
2332 if (rmdir(git_path("%s", name)))
2333 break;
2337 /* make sure nobody touched the ref, and unlink */
2338 static void prune_ref(struct ref_to_prune *r)
2340 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2342 if (lock) {
2343 unlink_or_warn(git_path("%s", r->name));
2344 unlock_ref(lock);
2345 try_remove_empty_parents(r->name);
2349 static void prune_refs(struct ref_to_prune *r)
2351 while (r) {
2352 prune_ref(r);
2353 r = r->next;
2357 int pack_refs(unsigned int flags)
2359 struct pack_refs_cb_data cbdata;
2361 memset(&cbdata, 0, sizeof(cbdata));
2362 cbdata.flags = flags;
2364 lock_packed_refs(LOCK_DIE_ON_ERROR);
2365 cbdata.packed_refs = get_packed_refs(&ref_cache);
2367 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2368 pack_if_possible_fn, &cbdata);
2370 if (commit_packed_refs())
2371 die_errno("unable to overwrite old ref-pack file");
2373 prune_refs(cbdata.ref_to_prune);
2374 return 0;
2378 * If entry is no longer needed in packed-refs, add it to the string
2379 * list pointed to by cb_data. Reasons for deleting entries:
2381 * - Entry is broken.
2382 * - Entry is overridden by a loose ref.
2383 * - Entry does not point at a valid object.
2385 * In the first and third cases, also emit an error message because these
2386 * are indications of repository corruption.
2388 static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
2390 struct string_list *refs_to_delete = cb_data;
2392 if (entry->flag & REF_ISBROKEN) {
2393 /* This shouldn't happen to packed refs. */
2394 error("%s is broken!", entry->name);
2395 string_list_append(refs_to_delete, entry->name);
2396 return 0;
2398 if (!has_sha1_file(entry->u.value.sha1)) {
2399 unsigned char sha1[20];
2400 int flags;
2402 if (read_ref_full(entry->name, sha1, 0, &flags))
2403 /* We should at least have found the packed ref. */
2404 die("Internal error");
2405 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
2407 * This packed reference is overridden by a
2408 * loose reference, so it is OK that its value
2409 * is no longer valid; for example, it might
2410 * refer to an object that has been garbage
2411 * collected. For this purpose we don't even
2412 * care whether the loose reference itself is
2413 * invalid, broken, symbolic, etc. Silently
2414 * remove the packed reference.
2416 string_list_append(refs_to_delete, entry->name);
2417 return 0;
2420 * There is no overriding loose reference, so the fact
2421 * that this reference doesn't refer to a valid object
2422 * indicates some kind of repository corruption.
2423 * Report the problem, then omit the reference from
2424 * the output.
2426 error("%s does not point to a valid object!", entry->name);
2427 string_list_append(refs_to_delete, entry->name);
2428 return 0;
2431 return 0;
2434 static int repack_without_refs(const char **refnames, int n)
2436 struct ref_dir *packed;
2437 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2438 struct string_list_item *ref_to_delete;
2439 int i, removed = 0;
2441 /* Look for a packed ref */
2442 for (i = 0; i < n; i++)
2443 if (get_packed_ref(refnames[i]))
2444 break;
2446 /* Avoid locking if we have nothing to do */
2447 if (i == n)
2448 return 0; /* no refname exists in packed refs */
2450 if (lock_packed_refs(0)) {
2451 unable_to_lock_error(git_path("packed-refs"), errno);
2452 return error("cannot delete '%s' from packed refs", refnames[i]);
2454 packed = get_packed_refs(&ref_cache);
2456 /* Remove refnames from the cache */
2457 for (i = 0; i < n; i++)
2458 if (remove_entry(packed, refnames[i]) != -1)
2459 removed = 1;
2460 if (!removed) {
2462 * All packed entries disappeared while we were
2463 * acquiring the lock.
2465 rollback_packed_refs();
2466 return 0;
2469 /* Remove any other accumulated cruft */
2470 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2471 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2472 if (remove_entry(packed, ref_to_delete->string) == -1)
2473 die("internal error");
2476 /* Write what remains */
2477 return commit_packed_refs();
2480 static int repack_without_ref(const char *refname)
2482 return repack_without_refs(&refname, 1);
2485 static int delete_ref_loose(struct ref_lock *lock, int flag)
2487 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2488 /* loose */
2489 int err, i = strlen(lock->lk->filename) - 5; /* .lock */
2491 lock->lk->filename[i] = 0;
2492 err = unlink_or_warn(lock->lk->filename);
2493 lock->lk->filename[i] = '.';
2494 if (err && errno != ENOENT)
2495 return 1;
2497 return 0;
2500 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
2502 struct ref_lock *lock;
2503 int ret = 0, flag = 0;
2505 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
2506 if (!lock)
2507 return 1;
2508 ret |= delete_ref_loose(lock, flag);
2510 /* removing the loose one could have resurrected an earlier
2511 * packed one. Also, if it was not loose we need to repack
2512 * without it.
2514 ret |= repack_without_ref(lock->ref_name);
2516 unlink_or_warn(git_path("logs/%s", lock->ref_name));
2517 clear_loose_ref_cache(&ref_cache);
2518 unlock_ref(lock);
2519 return ret;
2523 * People using contrib's git-new-workdir have .git/logs/refs ->
2524 * /some/other/path/.git/logs/refs, and that may live on another device.
2526 * IOW, to avoid cross device rename errors, the temporary renamed log must
2527 * live into logs/refs.
2529 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2531 static int rename_tmp_log(const char *newrefname)
2533 int attempts_remaining = 4;
2535 retry:
2536 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2537 case SCLD_OK:
2538 break; /* success */
2539 case SCLD_VANISHED:
2540 if (--attempts_remaining > 0)
2541 goto retry;
2542 /* fall through */
2543 default:
2544 error("unable to create directory for %s", newrefname);
2545 return -1;
2548 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
2549 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
2551 * rename(a, b) when b is an existing
2552 * directory ought to result in ISDIR, but
2553 * Solaris 5.8 gives ENOTDIR. Sheesh.
2555 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2556 error("Directory not empty: logs/%s", newrefname);
2557 return -1;
2559 goto retry;
2560 } else if (errno == ENOENT && --attempts_remaining > 0) {
2562 * Maybe another process just deleted one of
2563 * the directories in the path to newrefname.
2564 * Try again from the beginning.
2566 goto retry;
2567 } else {
2568 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2569 newrefname, strerror(errno));
2570 return -1;
2573 return 0;
2576 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
2578 unsigned char sha1[20], orig_sha1[20];
2579 int flag = 0, logmoved = 0;
2580 struct ref_lock *lock;
2581 struct stat loginfo;
2582 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2583 const char *symref = NULL;
2585 if (log && S_ISLNK(loginfo.st_mode))
2586 return error("reflog for %s is a symlink", oldrefname);
2588 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
2589 if (flag & REF_ISSYMREF)
2590 return error("refname %s is a symbolic ref, renaming it is not supported",
2591 oldrefname);
2592 if (!symref)
2593 return error("refname %s not found", oldrefname);
2595 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
2596 return 1;
2598 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
2599 return 1;
2601 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2602 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2603 oldrefname, strerror(errno));
2605 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2606 error("unable to delete old %s", oldrefname);
2607 goto rollback;
2610 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2611 delete_ref(newrefname, sha1, REF_NODEREF)) {
2612 if (errno==EISDIR) {
2613 if (remove_empty_directories(git_path("%s", newrefname))) {
2614 error("Directory not empty: %s", newrefname);
2615 goto rollback;
2617 } else {
2618 error("unable to delete existing %s", newrefname);
2619 goto rollback;
2623 if (log && rename_tmp_log(newrefname))
2624 goto rollback;
2626 logmoved = log;
2628 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
2629 if (!lock) {
2630 error("unable to lock %s for update", newrefname);
2631 goto rollback;
2633 lock->force_write = 1;
2634 hashcpy(lock->old_sha1, orig_sha1);
2635 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
2636 error("unable to write current sha1 into %s", newrefname);
2637 goto rollback;
2640 return 0;
2642 rollback:
2643 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
2644 if (!lock) {
2645 error("unable to lock %s for rollback", oldrefname);
2646 goto rollbacklog;
2649 lock->force_write = 1;
2650 flag = log_all_ref_updates;
2651 log_all_ref_updates = 0;
2652 if (write_ref_sha1(lock, orig_sha1, NULL))
2653 error("unable to write current sha1 into %s", oldrefname);
2654 log_all_ref_updates = flag;
2656 rollbacklog:
2657 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2658 error("unable to restore logfile %s from %s: %s",
2659 oldrefname, newrefname, strerror(errno));
2660 if (!logmoved && log &&
2661 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2662 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2663 oldrefname, strerror(errno));
2665 return 1;
2668 int close_ref(struct ref_lock *lock)
2670 if (close_lock_file(lock->lk))
2671 return -1;
2672 lock->lock_fd = -1;
2673 return 0;
2676 int commit_ref(struct ref_lock *lock)
2678 if (commit_lock_file(lock->lk))
2679 return -1;
2680 lock->lock_fd = -1;
2681 return 0;
2684 void unlock_ref(struct ref_lock *lock)
2686 /* Do not free lock->lk -- atexit() still looks at them */
2687 if (lock->lk)
2688 rollback_lock_file(lock->lk);
2689 free(lock->ref_name);
2690 free(lock->orig_ref_name);
2691 free(lock);
2695 * copy the reflog message msg to buf, which has been allocated sufficiently
2696 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2697 * because reflog file is one line per entry.
2699 static int copy_msg(char *buf, const char *msg)
2701 char *cp = buf;
2702 char c;
2703 int wasspace = 1;
2705 *cp++ = '\t';
2706 while ((c = *msg++)) {
2707 if (wasspace && isspace(c))
2708 continue;
2709 wasspace = isspace(c);
2710 if (wasspace)
2711 c = ' ';
2712 *cp++ = c;
2714 while (buf < cp && isspace(cp[-1]))
2715 cp--;
2716 *cp++ = '\n';
2717 return cp - buf;
2720 int log_ref_setup(const char *refname, char *logfile, int bufsize)
2722 int logfd, oflags = O_APPEND | O_WRONLY;
2724 git_snpath(logfile, bufsize, "logs/%s", refname);
2725 if (log_all_ref_updates &&
2726 (starts_with(refname, "refs/heads/") ||
2727 starts_with(refname, "refs/remotes/") ||
2728 starts_with(refname, "refs/notes/") ||
2729 !strcmp(refname, "HEAD"))) {
2730 if (safe_create_leading_directories(logfile) < 0)
2731 return error("unable to create directory for %s",
2732 logfile);
2733 oflags |= O_CREAT;
2736 logfd = open(logfile, oflags, 0666);
2737 if (logfd < 0) {
2738 if (!(oflags & O_CREAT) && errno == ENOENT)
2739 return 0;
2741 if ((oflags & O_CREAT) && errno == EISDIR) {
2742 if (remove_empty_directories(logfile)) {
2743 return error("There are still logs under '%s'",
2744 logfile);
2746 logfd = open(logfile, oflags, 0666);
2749 if (logfd < 0)
2750 return error("Unable to append to %s: %s",
2751 logfile, strerror(errno));
2754 adjust_shared_perm(logfile);
2755 close(logfd);
2756 return 0;
2759 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2760 const unsigned char *new_sha1, const char *msg)
2762 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2763 unsigned maxlen, len;
2764 int msglen;
2765 char log_file[PATH_MAX];
2766 char *logrec;
2767 const char *committer;
2769 if (log_all_ref_updates < 0)
2770 log_all_ref_updates = !is_bare_repository();
2772 result = log_ref_setup(refname, log_file, sizeof(log_file));
2773 if (result)
2774 return result;
2776 logfd = open(log_file, oflags);
2777 if (logfd < 0)
2778 return 0;
2779 msglen = msg ? strlen(msg) : 0;
2780 committer = git_committer_info(0);
2781 maxlen = strlen(committer) + msglen + 100;
2782 logrec = xmalloc(maxlen);
2783 len = sprintf(logrec, "%s %s %s\n",
2784 sha1_to_hex(old_sha1),
2785 sha1_to_hex(new_sha1),
2786 committer);
2787 if (msglen)
2788 len += copy_msg(logrec + len - 1, msg) - 1;
2789 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
2790 free(logrec);
2791 if (close(logfd) != 0 || written != len)
2792 return error("Unable to append to %s", log_file);
2793 return 0;
2796 static int is_branch(const char *refname)
2798 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
2801 int write_ref_sha1(struct ref_lock *lock,
2802 const unsigned char *sha1, const char *logmsg)
2804 static char term = '\n';
2805 struct object *o;
2807 if (!lock)
2808 return -1;
2809 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
2810 unlock_ref(lock);
2811 return 0;
2813 o = parse_object(sha1);
2814 if (!o) {
2815 error("Trying to write ref %s with nonexistent object %s",
2816 lock->ref_name, sha1_to_hex(sha1));
2817 unlock_ref(lock);
2818 return -1;
2820 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2821 error("Trying to write non-commit object %s to branch %s",
2822 sha1_to_hex(sha1), lock->ref_name);
2823 unlock_ref(lock);
2824 return -1;
2826 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2827 write_in_full(lock->lock_fd, &term, 1) != 1
2828 || close_ref(lock) < 0) {
2829 error("Couldn't write %s", lock->lk->filename);
2830 unlock_ref(lock);
2831 return -1;
2833 clear_loose_ref_cache(&ref_cache);
2834 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2835 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2836 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
2837 unlock_ref(lock);
2838 return -1;
2840 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2842 * Special hack: If a branch is updated directly and HEAD
2843 * points to it (may happen on the remote side of a push
2844 * for example) then logically the HEAD reflog should be
2845 * updated too.
2846 * A generic solution implies reverse symref information,
2847 * but finding all symrefs pointing to the given branch
2848 * would be rather costly for this rare event (the direct
2849 * update of a branch) to be worth it. So let's cheat and
2850 * check with HEAD only which should cover 99% of all usage
2851 * scenarios (even 100% of the default ones).
2853 unsigned char head_sha1[20];
2854 int head_flag;
2855 const char *head_ref;
2856 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
2857 if (head_ref && (head_flag & REF_ISSYMREF) &&
2858 !strcmp(head_ref, lock->ref_name))
2859 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2861 if (commit_ref(lock)) {
2862 error("Couldn't set %s", lock->ref_name);
2863 unlock_ref(lock);
2864 return -1;
2866 unlock_ref(lock);
2867 return 0;
2870 int create_symref(const char *ref_target, const char *refs_heads_master,
2871 const char *logmsg)
2873 const char *lockpath;
2874 char ref[1000];
2875 int fd, len, written;
2876 char *git_HEAD = git_pathdup("%s", ref_target);
2877 unsigned char old_sha1[20], new_sha1[20];
2879 if (logmsg && read_ref(ref_target, old_sha1))
2880 hashclr(old_sha1);
2882 if (safe_create_leading_directories(git_HEAD) < 0)
2883 return error("unable to create directory for %s", git_HEAD);
2885 #ifndef NO_SYMLINK_HEAD
2886 if (prefer_symlink_refs) {
2887 unlink(git_HEAD);
2888 if (!symlink(refs_heads_master, git_HEAD))
2889 goto done;
2890 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2892 #endif
2894 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2895 if (sizeof(ref) <= len) {
2896 error("refname too long: %s", refs_heads_master);
2897 goto error_free_return;
2899 lockpath = mkpath("%s.lock", git_HEAD);
2900 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2901 if (fd < 0) {
2902 error("Unable to open %s for writing", lockpath);
2903 goto error_free_return;
2905 written = write_in_full(fd, ref, len);
2906 if (close(fd) != 0 || written != len) {
2907 error("Unable to write to %s", lockpath);
2908 goto error_unlink_return;
2910 if (rename(lockpath, git_HEAD) < 0) {
2911 error("Unable to create %s", git_HEAD);
2912 goto error_unlink_return;
2914 if (adjust_shared_perm(git_HEAD)) {
2915 error("Unable to fix permissions on %s", lockpath);
2916 error_unlink_return:
2917 unlink_or_warn(lockpath);
2918 error_free_return:
2919 free(git_HEAD);
2920 return -1;
2923 #ifndef NO_SYMLINK_HEAD
2924 done:
2925 #endif
2926 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2927 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2929 free(git_HEAD);
2930 return 0;
2933 static char *ref_msg(const char *line, const char *endp)
2935 const char *ep;
2936 line += 82;
2937 ep = memchr(line, '\n', endp - line);
2938 if (!ep)
2939 ep = endp;
2940 return xmemdupz(line, ep - line);
2943 int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2944 unsigned char *sha1, char **msg,
2945 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
2947 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
2948 char *tz_c;
2949 int logfd, tz, reccnt = 0;
2950 struct stat st;
2951 unsigned long date;
2952 unsigned char logged_sha1[20];
2953 void *log_mapped;
2954 size_t mapsz;
2956 logfile = git_path("logs/%s", refname);
2957 logfd = open(logfile, O_RDONLY, 0);
2958 if (logfd < 0)
2959 die_errno("Unable to read log '%s'", logfile);
2960 fstat(logfd, &st);
2961 if (!st.st_size)
2962 die("Log %s is empty.", logfile);
2963 mapsz = xsize_t(st.st_size);
2964 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
2965 logdata = log_mapped;
2966 close(logfd);
2968 lastrec = NULL;
2969 rec = logend = logdata + st.st_size;
2970 while (logdata < rec) {
2971 reccnt++;
2972 if (logdata < rec && *(rec-1) == '\n')
2973 rec--;
2974 lastgt = NULL;
2975 while (logdata < rec && *(rec-1) != '\n') {
2976 rec--;
2977 if (*rec == '>')
2978 lastgt = rec;
2980 if (!lastgt)
2981 die("Log %s is corrupt.", logfile);
2982 date = strtoul(lastgt + 1, &tz_c, 10);
2983 if (date <= at_time || cnt == 0) {
2984 tz = strtoul(tz_c, NULL, 10);
2985 if (msg)
2986 *msg = ref_msg(rec, logend);
2987 if (cutoff_time)
2988 *cutoff_time = date;
2989 if (cutoff_tz)
2990 *cutoff_tz = tz;
2991 if (cutoff_cnt)
2992 *cutoff_cnt = reccnt - 1;
2993 if (lastrec) {
2994 if (get_sha1_hex(lastrec, logged_sha1))
2995 die("Log %s is corrupt.", logfile);
2996 if (get_sha1_hex(rec + 41, sha1))
2997 die("Log %s is corrupt.", logfile);
2998 if (hashcmp(logged_sha1, sha1)) {
2999 warning("Log %s has gap after %s.",
3000 logfile, show_date(date, tz, DATE_RFC2822));
3003 else if (date == at_time) {
3004 if (get_sha1_hex(rec + 41, sha1))
3005 die("Log %s is corrupt.", logfile);
3007 else {
3008 if (get_sha1_hex(rec + 41, logged_sha1))
3009 die("Log %s is corrupt.", logfile);
3010 if (hashcmp(logged_sha1, sha1)) {
3011 warning("Log %s unexpectedly ended on %s.",
3012 logfile, show_date(date, tz, DATE_RFC2822));
3015 munmap(log_mapped, mapsz);
3016 return 0;
3018 lastrec = rec;
3019 if (cnt > 0)
3020 cnt--;
3023 rec = logdata;
3024 while (rec < logend && *rec != '>' && *rec != '\n')
3025 rec++;
3026 if (rec == logend || *rec == '\n')
3027 die("Log %s is corrupt.", logfile);
3028 date = strtoul(rec + 1, &tz_c, 10);
3029 tz = strtoul(tz_c, NULL, 10);
3030 if (get_sha1_hex(logdata, sha1))
3031 die("Log %s is corrupt.", logfile);
3032 if (is_null_sha1(sha1)) {
3033 if (get_sha1_hex(logdata + 41, sha1))
3034 die("Log %s is corrupt.", logfile);
3036 if (msg)
3037 *msg = ref_msg(logdata, logend);
3038 munmap(log_mapped, mapsz);
3040 if (cutoff_time)
3041 *cutoff_time = date;
3042 if (cutoff_tz)
3043 *cutoff_tz = tz;
3044 if (cutoff_cnt)
3045 *cutoff_cnt = reccnt;
3046 return 1;
3049 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3051 unsigned char osha1[20], nsha1[20];
3052 char *email_end, *message;
3053 unsigned long timestamp;
3054 int tz;
3056 /* old SP new SP name <email> SP time TAB msg LF */
3057 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3058 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3059 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3060 !(email_end = strchr(sb->buf + 82, '>')) ||
3061 email_end[1] != ' ' ||
3062 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3063 !message || message[0] != ' ' ||
3064 (message[1] != '+' && message[1] != '-') ||
3065 !isdigit(message[2]) || !isdigit(message[3]) ||
3066 !isdigit(message[4]) || !isdigit(message[5]))
3067 return 0; /* corrupt? */
3068 email_end[1] = '\0';
3069 tz = strtol(message + 1, NULL, 10);
3070 if (message[6] != '\t')
3071 message += 6;
3072 else
3073 message += 7;
3074 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3077 static char *find_beginning_of_line(char *bob, char *scan)
3079 while (bob < scan && *(--scan) != '\n')
3080 ; /* keep scanning backwards */
3082 * Return either beginning of the buffer, or LF at the end of
3083 * the previous line.
3085 return scan;
3088 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3090 struct strbuf sb = STRBUF_INIT;
3091 FILE *logfp;
3092 long pos;
3093 int ret = 0, at_tail = 1;
3095 logfp = fopen(git_path("logs/%s", refname), "r");
3096 if (!logfp)
3097 return -1;
3099 /* Jump to the end */
3100 if (fseek(logfp, 0, SEEK_END) < 0)
3101 return error("cannot seek back reflog for %s: %s",
3102 refname, strerror(errno));
3103 pos = ftell(logfp);
3104 while (!ret && 0 < pos) {
3105 int cnt;
3106 size_t nread;
3107 char buf[BUFSIZ];
3108 char *endp, *scanp;
3110 /* Fill next block from the end */
3111 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3112 if (fseek(logfp, pos - cnt, SEEK_SET))
3113 return error("cannot seek back reflog for %s: %s",
3114 refname, strerror(errno));
3115 nread = fread(buf, cnt, 1, logfp);
3116 if (nread != 1)
3117 return error("cannot read %d bytes from reflog for %s: %s",
3118 cnt, refname, strerror(errno));
3119 pos -= cnt;
3121 scanp = endp = buf + cnt;
3122 if (at_tail && scanp[-1] == '\n')
3123 /* Looking at the final LF at the end of the file */
3124 scanp--;
3125 at_tail = 0;
3127 while (buf < scanp) {
3129 * terminating LF of the previous line, or the beginning
3130 * of the buffer.
3132 char *bp;
3134 bp = find_beginning_of_line(buf, scanp);
3136 if (*bp != '\n') {
3137 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3138 if (pos)
3139 break; /* need to fill another block */
3140 scanp = buf - 1; /* leave loop */
3141 } else {
3143 * (bp + 1) thru endp is the beginning of the
3144 * current line we have in sb
3146 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3147 scanp = bp;
3148 endp = bp + 1;
3150 ret = show_one_reflog_ent(&sb, fn, cb_data);
3151 strbuf_reset(&sb);
3152 if (ret)
3153 break;
3157 if (!ret && sb.len)
3158 ret = show_one_reflog_ent(&sb, fn, cb_data);
3160 fclose(logfp);
3161 strbuf_release(&sb);
3162 return ret;
3165 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3167 FILE *logfp;
3168 struct strbuf sb = STRBUF_INIT;
3169 int ret = 0;
3171 logfp = fopen(git_path("logs/%s", refname), "r");
3172 if (!logfp)
3173 return -1;
3175 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3176 ret = show_one_reflog_ent(&sb, fn, cb_data);
3177 fclose(logfp);
3178 strbuf_release(&sb);
3179 return ret;
3182 * Call fn for each reflog in the namespace indicated by name. name
3183 * must be empty or end with '/'. Name will be used as a scratch
3184 * space, but its contents will be restored before return.
3186 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
3188 DIR *d = opendir(git_path("logs/%s", name->buf));
3189 int retval = 0;
3190 struct dirent *de;
3191 int oldlen = name->len;
3193 if (!d)
3194 return name->len ? errno : 0;
3196 while ((de = readdir(d)) != NULL) {
3197 struct stat st;
3199 if (de->d_name[0] == '.')
3200 continue;
3201 if (has_extension(de->d_name, ".lock"))
3202 continue;
3203 strbuf_addstr(name, de->d_name);
3204 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3205 ; /* silently ignore */
3206 } else {
3207 if (S_ISDIR(st.st_mode)) {
3208 strbuf_addch(name, '/');
3209 retval = do_for_each_reflog(name, fn, cb_data);
3210 } else {
3211 unsigned char sha1[20];
3212 if (read_ref_full(name->buf, sha1, 0, NULL))
3213 retval = error("bad ref for %s", name->buf);
3214 else
3215 retval = fn(name->buf, sha1, 0, cb_data);
3217 if (retval)
3218 break;
3220 strbuf_setlen(name, oldlen);
3222 closedir(d);
3223 return retval;
3226 int for_each_reflog(each_ref_fn fn, void *cb_data)
3228 int retval;
3229 struct strbuf name;
3230 strbuf_init(&name, PATH_MAX);
3231 retval = do_for_each_reflog(&name, fn, cb_data);
3232 strbuf_release(&name);
3233 return retval;
3236 static struct ref_lock *update_ref_lock(const char *refname,
3237 const unsigned char *oldval,
3238 int flags, int *type_p,
3239 enum action_on_err onerr)
3241 struct ref_lock *lock;
3242 lock = lock_any_ref_for_update(refname, oldval, flags, type_p);
3243 if (!lock) {
3244 const char *str = "Cannot lock the ref '%s'.";
3245 switch (onerr) {
3246 case MSG_ON_ERR: error(str, refname); break;
3247 case DIE_ON_ERR: die(str, refname); break;
3248 case QUIET_ON_ERR: break;
3251 return lock;
3254 static int update_ref_write(const char *action, const char *refname,
3255 const unsigned char *sha1, struct ref_lock *lock,
3256 enum action_on_err onerr)
3258 if (write_ref_sha1(lock, sha1, action) < 0) {
3259 const char *str = "Cannot update the ref '%s'.";
3260 switch (onerr) {
3261 case MSG_ON_ERR: error(str, refname); break;
3262 case DIE_ON_ERR: die(str, refname); break;
3263 case QUIET_ON_ERR: break;
3265 return 1;
3267 return 0;
3270 int update_ref(const char *action, const char *refname,
3271 const unsigned char *sha1, const unsigned char *oldval,
3272 int flags, enum action_on_err onerr)
3274 struct ref_lock *lock;
3275 lock = update_ref_lock(refname, oldval, flags, NULL, onerr);
3276 if (!lock)
3277 return 1;
3278 return update_ref_write(action, refname, sha1, lock, onerr);
3281 static int ref_update_compare(const void *r1, const void *r2)
3283 const struct ref_update * const *u1 = r1;
3284 const struct ref_update * const *u2 = r2;
3285 return strcmp((*u1)->ref_name, (*u2)->ref_name);
3288 static int ref_update_reject_duplicates(struct ref_update **updates, int n,
3289 enum action_on_err onerr)
3291 int i;
3292 for (i = 1; i < n; i++)
3293 if (!strcmp(updates[i - 1]->ref_name, updates[i]->ref_name)) {
3294 const char *str =
3295 "Multiple updates for ref '%s' not allowed.";
3296 switch (onerr) {
3297 case MSG_ON_ERR:
3298 error(str, updates[i]->ref_name); break;
3299 case DIE_ON_ERR:
3300 die(str, updates[i]->ref_name); break;
3301 case QUIET_ON_ERR:
3302 break;
3304 return 1;
3306 return 0;
3309 int update_refs(const char *action, const struct ref_update **updates_orig,
3310 int n, enum action_on_err onerr)
3312 int ret = 0, delnum = 0, i;
3313 struct ref_update **updates;
3314 int *types;
3315 struct ref_lock **locks;
3316 const char **delnames;
3318 if (!updates_orig || !n)
3319 return 0;
3321 /* Allocate work space */
3322 updates = xmalloc(sizeof(*updates) * n);
3323 types = xmalloc(sizeof(*types) * n);
3324 locks = xcalloc(n, sizeof(*locks));
3325 delnames = xmalloc(sizeof(*delnames) * n);
3327 /* Copy, sort, and reject duplicate refs */
3328 memcpy(updates, updates_orig, sizeof(*updates) * n);
3329 qsort(updates, n, sizeof(*updates), ref_update_compare);
3330 ret = ref_update_reject_duplicates(updates, n, onerr);
3331 if (ret)
3332 goto cleanup;
3334 /* Acquire all locks while verifying old values */
3335 for (i = 0; i < n; i++) {
3336 locks[i] = update_ref_lock(updates[i]->ref_name,
3337 (updates[i]->have_old ?
3338 updates[i]->old_sha1 : NULL),
3339 updates[i]->flags,
3340 &types[i], onerr);
3341 if (!locks[i]) {
3342 ret = 1;
3343 goto cleanup;
3347 /* Perform updates first so live commits remain referenced */
3348 for (i = 0; i < n; i++)
3349 if (!is_null_sha1(updates[i]->new_sha1)) {
3350 ret = update_ref_write(action,
3351 updates[i]->ref_name,
3352 updates[i]->new_sha1,
3353 locks[i], onerr);
3354 locks[i] = NULL; /* freed by update_ref_write */
3355 if (ret)
3356 goto cleanup;
3359 /* Perform deletes now that updates are safely completed */
3360 for (i = 0; i < n; i++)
3361 if (locks[i]) {
3362 delnames[delnum++] = locks[i]->ref_name;
3363 ret |= delete_ref_loose(locks[i], types[i]);
3365 ret |= repack_without_refs(delnames, delnum);
3366 for (i = 0; i < delnum; i++)
3367 unlink_or_warn(git_path("logs/%s", delnames[i]));
3368 clear_loose_ref_cache(&ref_cache);
3370 cleanup:
3371 for (i = 0; i < n; i++)
3372 if (locks[i])
3373 unlock_ref(locks[i]);
3374 free(updates);
3375 free(types);
3376 free(locks);
3377 free(delnames);
3378 return ret;
3381 char *shorten_unambiguous_ref(const char *refname, int strict)
3383 int i;
3384 static char **scanf_fmts;
3385 static int nr_rules;
3386 char *short_name;
3388 if (!nr_rules) {
3390 * Pre-generate scanf formats from ref_rev_parse_rules[].
3391 * Generate a format suitable for scanf from a
3392 * ref_rev_parse_rules rule by interpolating "%s" at the
3393 * location of the "%.*s".
3395 size_t total_len = 0;
3396 size_t offset = 0;
3398 /* the rule list is NULL terminated, count them first */
3399 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
3400 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
3401 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
3403 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3405 offset = 0;
3406 for (i = 0; i < nr_rules; i++) {
3407 assert(offset < total_len);
3408 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
3409 offset += snprintf(scanf_fmts[i], total_len - offset,
3410 ref_rev_parse_rules[i], 2, "%s") + 1;
3414 /* bail out if there are no rules */
3415 if (!nr_rules)
3416 return xstrdup(refname);
3418 /* buffer for scanf result, at most refname must fit */
3419 short_name = xstrdup(refname);
3421 /* skip first rule, it will always match */
3422 for (i = nr_rules - 1; i > 0 ; --i) {
3423 int j;
3424 int rules_to_fail = i;
3425 int short_name_len;
3427 if (1 != sscanf(refname, scanf_fmts[i], short_name))
3428 continue;
3430 short_name_len = strlen(short_name);
3433 * in strict mode, all (except the matched one) rules
3434 * must fail to resolve to a valid non-ambiguous ref
3436 if (strict)
3437 rules_to_fail = nr_rules;
3440 * check if the short name resolves to a valid ref,
3441 * but use only rules prior to the matched one
3443 for (j = 0; j < rules_to_fail; j++) {
3444 const char *rule = ref_rev_parse_rules[j];
3445 char refname[PATH_MAX];
3447 /* skip matched rule */
3448 if (i == j)
3449 continue;
3452 * the short name is ambiguous, if it resolves
3453 * (with this previous rule) to a valid ref
3454 * read_ref() returns 0 on success
3456 mksnpath(refname, sizeof(refname),
3457 rule, short_name_len, short_name);
3458 if (ref_exists(refname))
3459 break;
3463 * short name is non-ambiguous if all previous rules
3464 * haven't resolved to a valid ref
3466 if (j == rules_to_fail)
3467 return short_name;
3470 free(short_name);
3471 return xstrdup(refname);
3474 static struct string_list *hide_refs;
3476 int parse_hide_refs_config(const char *var, const char *value, const char *section)
3478 if (!strcmp("transfer.hiderefs", var) ||
3479 /* NEEDSWORK: use parse_config_key() once both are merged */
3480 (starts_with(var, section) && var[strlen(section)] == '.' &&
3481 !strcmp(var + strlen(section), ".hiderefs"))) {
3482 char *ref;
3483 int len;
3485 if (!value)
3486 return config_error_nonbool(var);
3487 ref = xstrdup(value);
3488 len = strlen(ref);
3489 while (len && ref[len - 1] == '/')
3490 ref[--len] = '\0';
3491 if (!hide_refs) {
3492 hide_refs = xcalloc(1, sizeof(*hide_refs));
3493 hide_refs->strdup_strings = 1;
3495 string_list_append(hide_refs, ref);
3497 return 0;
3500 int ref_is_hidden(const char *refname)
3502 struct string_list_item *item;
3504 if (!hide_refs)
3505 return 0;
3506 for_each_string_list_item(item, hide_refs) {
3507 int len;
3508 if (!starts_with(refname, item->string))
3509 continue;
3510 len = strlen(item->string);
3511 if (!refname[len] || refname[len] == '/')
3512 return 1;
3514 return 0;