parse_color: drop COLOR_BACKGROUND macro
[git.git] / refs.c
blob82e5b1b14f7a6e7341dfcf8fbf61ae3982851e18
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 * How to handle various characters in refnames:
10 * 0: An acceptable character for refs
11 * 1: End-of-component
12 * 2: ., look for a preceding . to reject .. in refs
13 * 3: {, look for a preceding @ to reject @{ in refs
14 * 4: A bad character: ASCII control characters, "~", "^", ":" or SP
16 static unsigned char refname_disposition[256] = {
17 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
18 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
19 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1,
20 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
21 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
22 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
23 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
24 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
28 * Try to read one refname component from the front of refname.
29 * Return the length of the component found, or -1 if the component is
30 * not legal. It is legal if it is something reasonable to have under
31 * ".git/refs/"; We do not like it if:
33 * - any path component of it begins with ".", or
34 * - it has double dots "..", or
35 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
36 * - it ends with a "/".
37 * - it ends with ".lock"
38 * - it contains a "\" (backslash)
40 static int check_refname_component(const char *refname, int flags)
42 const char *cp;
43 char last = '\0';
45 for (cp = refname; ; cp++) {
46 int ch = *cp & 255;
47 unsigned char disp = refname_disposition[ch];
48 switch (disp) {
49 case 1:
50 goto out;
51 case 2:
52 if (last == '.')
53 return -1; /* Refname contains "..". */
54 break;
55 case 3:
56 if (last == '@')
57 return -1; /* Refname contains "@{". */
58 break;
59 case 4:
60 return -1;
62 last = ch;
64 out:
65 if (cp == refname)
66 return 0; /* Component has zero length. */
67 if (refname[0] == '.') {
68 if (!(flags & REFNAME_DOT_COMPONENT))
69 return -1; /* Component starts with '.'. */
71 * Even if leading dots are allowed, don't allow "."
72 * as a component (".." is prevented by a rule above).
74 if (refname[1] == '\0')
75 return -1; /* Component equals ".". */
77 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
78 return -1; /* Refname ends with ".lock". */
79 return cp - refname;
82 int check_refname_format(const char *refname, int flags)
84 int component_len, component_count = 0;
86 if (!strcmp(refname, "@"))
87 /* Refname is a single character '@'. */
88 return -1;
90 while (1) {
91 /* We are at the start of a path component. */
92 component_len = check_refname_component(refname, flags);
93 if (component_len <= 0) {
94 if ((flags & REFNAME_REFSPEC_PATTERN) &&
95 refname[0] == '*' &&
96 (refname[1] == '\0' || refname[1] == '/')) {
97 /* Accept one wildcard as a full refname component. */
98 flags &= ~REFNAME_REFSPEC_PATTERN;
99 component_len = 1;
100 } else {
101 return -1;
104 component_count++;
105 if (refname[component_len] == '\0')
106 break;
107 /* Skip to next component. */
108 refname += component_len + 1;
111 if (refname[component_len - 1] == '.')
112 return -1; /* Refname ends with '.'. */
113 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
114 return -1; /* Refname has only one component. */
115 return 0;
118 struct ref_entry;
121 * Information used (along with the information in ref_entry) to
122 * describe a single cached reference. This data structure only
123 * occurs embedded in a union in struct ref_entry, and only when
124 * (ref_entry->flag & REF_DIR) is zero.
126 struct ref_value {
128 * The name of the object to which this reference resolves
129 * (which may be a tag object). If REF_ISBROKEN, this is
130 * null. If REF_ISSYMREF, then this is the name of the object
131 * referred to by the last reference in the symlink chain.
133 unsigned char sha1[20];
136 * If REF_KNOWS_PEELED, then this field holds the peeled value
137 * of this reference, or null if the reference is known not to
138 * be peelable. See the documentation for peel_ref() for an
139 * exact definition of "peelable".
141 unsigned char peeled[20];
144 struct ref_cache;
147 * Information used (along with the information in ref_entry) to
148 * describe a level in the hierarchy of references. This data
149 * structure only occurs embedded in a union in struct ref_entry, and
150 * only when (ref_entry.flag & REF_DIR) is set. In that case,
151 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
152 * in the directory have already been read:
154 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
155 * or packed references, already read.
157 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
158 * references that hasn't been read yet (nor has any of its
159 * subdirectories).
161 * Entries within a directory are stored within a growable array of
162 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
163 * sorted are sorted by their component name in strcmp() order and the
164 * remaining entries are unsorted.
166 * Loose references are read lazily, one directory at a time. When a
167 * directory of loose references is read, then all of the references
168 * in that directory are stored, and REF_INCOMPLETE stubs are created
169 * for any subdirectories, but the subdirectories themselves are not
170 * read. The reading is triggered by get_ref_dir().
172 struct ref_dir {
173 int nr, alloc;
176 * Entries with index 0 <= i < sorted are sorted by name. New
177 * entries are appended to the list unsorted, and are sorted
178 * only when required; thus we avoid the need to sort the list
179 * after the addition of every reference.
181 int sorted;
183 /* A pointer to the ref_cache that contains this ref_dir. */
184 struct ref_cache *ref_cache;
186 struct ref_entry **entries;
190 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
191 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
192 * refs.h.
196 * The field ref_entry->u.value.peeled of this value entry contains
197 * the correct peeled value for the reference, which might be
198 * null_sha1 if the reference is not a tag or if it is broken.
200 #define REF_KNOWS_PEELED 0x08
202 /* ref_entry represents a directory of references */
203 #define REF_DIR 0x10
206 * Entry has not yet been read from disk (used only for REF_DIR
207 * entries representing loose references)
209 #define REF_INCOMPLETE 0x20
212 * A ref_entry represents either a reference or a "subdirectory" of
213 * references.
215 * Each directory in the reference namespace is represented by a
216 * ref_entry with (flags & REF_DIR) set and containing a subdir member
217 * that holds the entries in that directory that have been read so
218 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
219 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
220 * used for loose reference directories.
222 * References are represented by a ref_entry with (flags & REF_DIR)
223 * unset and a value member that describes the reference's value. The
224 * flag member is at the ref_entry level, but it is also needed to
225 * interpret the contents of the value field (in other words, a
226 * ref_value object is not very much use without the enclosing
227 * ref_entry).
229 * Reference names cannot end with slash and directories' names are
230 * always stored with a trailing slash (except for the top-level
231 * directory, which is always denoted by ""). This has two nice
232 * consequences: (1) when the entries in each subdir are sorted
233 * lexicographically by name (as they usually are), the references in
234 * a whole tree can be generated in lexicographic order by traversing
235 * the tree in left-to-right, depth-first order; (2) the names of
236 * references and subdirectories cannot conflict, and therefore the
237 * presence of an empty subdirectory does not block the creation of a
238 * similarly-named reference. (The fact that reference names with the
239 * same leading components can conflict *with each other* is a
240 * separate issue that is regulated by is_refname_available().)
242 * Please note that the name field contains the fully-qualified
243 * reference (or subdirectory) name. Space could be saved by only
244 * storing the relative names. But that would require the full names
245 * to be generated on the fly when iterating in do_for_each_ref(), and
246 * would break callback functions, who have always been able to assume
247 * that the name strings that they are passed will not be freed during
248 * the iteration.
250 struct ref_entry {
251 unsigned char flag; /* ISSYMREF? ISPACKED? */
252 union {
253 struct ref_value value; /* if not (flags&REF_DIR) */
254 struct ref_dir subdir; /* if (flags&REF_DIR) */
255 } u;
257 * The full name of the reference (e.g., "refs/heads/master")
258 * or the full name of the directory with a trailing slash
259 * (e.g., "refs/heads/"):
261 char name[FLEX_ARRAY];
264 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
266 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
268 struct ref_dir *dir;
269 assert(entry->flag & REF_DIR);
270 dir = &entry->u.subdir;
271 if (entry->flag & REF_INCOMPLETE) {
272 read_loose_refs(entry->name, dir);
273 entry->flag &= ~REF_INCOMPLETE;
275 return dir;
278 static struct ref_entry *create_ref_entry(const char *refname,
279 const unsigned char *sha1, int flag,
280 int check_name)
282 int len;
283 struct ref_entry *ref;
285 if (check_name &&
286 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
287 die("Reference has invalid format: '%s'", refname);
288 len = strlen(refname) + 1;
289 ref = xmalloc(sizeof(struct ref_entry) + len);
290 hashcpy(ref->u.value.sha1, sha1);
291 hashclr(ref->u.value.peeled);
292 memcpy(ref->name, refname, len);
293 ref->flag = flag;
294 return ref;
297 static void clear_ref_dir(struct ref_dir *dir);
299 static void free_ref_entry(struct ref_entry *entry)
301 if (entry->flag & REF_DIR) {
303 * Do not use get_ref_dir() here, as that might
304 * trigger the reading of loose refs.
306 clear_ref_dir(&entry->u.subdir);
308 free(entry);
312 * Add a ref_entry to the end of dir (unsorted). Entry is always
313 * stored directly in dir; no recursion into subdirectories is
314 * done.
316 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
318 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
319 dir->entries[dir->nr++] = entry;
320 /* optimize for the case that entries are added in order */
321 if (dir->nr == 1 ||
322 (dir->nr == dir->sorted + 1 &&
323 strcmp(dir->entries[dir->nr - 2]->name,
324 dir->entries[dir->nr - 1]->name) < 0))
325 dir->sorted = dir->nr;
329 * Clear and free all entries in dir, recursively.
331 static void clear_ref_dir(struct ref_dir *dir)
333 int i;
334 for (i = 0; i < dir->nr; i++)
335 free_ref_entry(dir->entries[i]);
336 free(dir->entries);
337 dir->sorted = dir->nr = dir->alloc = 0;
338 dir->entries = NULL;
342 * Create a struct ref_entry object for the specified dirname.
343 * dirname is the name of the directory with a trailing slash (e.g.,
344 * "refs/heads/") or "" for the top-level directory.
346 static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
347 const char *dirname, size_t len,
348 int incomplete)
350 struct ref_entry *direntry;
351 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
352 memcpy(direntry->name, dirname, len);
353 direntry->name[len] = '\0';
354 direntry->u.subdir.ref_cache = ref_cache;
355 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
356 return direntry;
359 static int ref_entry_cmp(const void *a, const void *b)
361 struct ref_entry *one = *(struct ref_entry **)a;
362 struct ref_entry *two = *(struct ref_entry **)b;
363 return strcmp(one->name, two->name);
366 static void sort_ref_dir(struct ref_dir *dir);
368 struct string_slice {
369 size_t len;
370 const char *str;
373 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
375 const struct string_slice *key = key_;
376 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
377 int cmp = strncmp(key->str, ent->name, key->len);
378 if (cmp)
379 return cmp;
380 return '\0' - (unsigned char)ent->name[key->len];
384 * Return the index of the entry with the given refname from the
385 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
386 * no such entry is found. dir must already be complete.
388 static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
390 struct ref_entry **r;
391 struct string_slice key;
393 if (refname == NULL || !dir->nr)
394 return -1;
396 sort_ref_dir(dir);
397 key.len = len;
398 key.str = refname;
399 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
400 ref_entry_cmp_sslice);
402 if (r == NULL)
403 return -1;
405 return r - dir->entries;
409 * Search for a directory entry directly within dir (without
410 * recursing). Sort dir if necessary. subdirname must be a directory
411 * name (i.e., end in '/'). If mkdir is set, then create the
412 * directory if it is missing; otherwise, return NULL if the desired
413 * directory cannot be found. dir must already be complete.
415 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
416 const char *subdirname, size_t len,
417 int mkdir)
419 int entry_index = search_ref_dir(dir, subdirname, len);
420 struct ref_entry *entry;
421 if (entry_index == -1) {
422 if (!mkdir)
423 return NULL;
425 * Since dir is complete, the absence of a subdir
426 * means that the subdir really doesn't exist;
427 * therefore, create an empty record for it but mark
428 * the record complete.
430 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
431 add_entry_to_dir(dir, entry);
432 } else {
433 entry = dir->entries[entry_index];
435 return get_ref_dir(entry);
439 * If refname is a reference name, find the ref_dir within the dir
440 * tree that should hold refname. If refname is a directory name
441 * (i.e., ends in '/'), then return that ref_dir itself. dir must
442 * represent the top-level directory and must already be complete.
443 * Sort ref_dirs and recurse into subdirectories as necessary. If
444 * mkdir is set, then create any missing directories; otherwise,
445 * return NULL if the desired directory cannot be found.
447 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
448 const char *refname, int mkdir)
450 const char *slash;
451 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
452 size_t dirnamelen = slash - refname + 1;
453 struct ref_dir *subdir;
454 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
455 if (!subdir) {
456 dir = NULL;
457 break;
459 dir = subdir;
462 return dir;
466 * Find the value entry with the given name in dir, sorting ref_dirs
467 * and recursing into subdirectories as necessary. If the name is not
468 * found or it corresponds to a directory entry, return NULL.
470 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
472 int entry_index;
473 struct ref_entry *entry;
474 dir = find_containing_dir(dir, refname, 0);
475 if (!dir)
476 return NULL;
477 entry_index = search_ref_dir(dir, refname, strlen(refname));
478 if (entry_index == -1)
479 return NULL;
480 entry = dir->entries[entry_index];
481 return (entry->flag & REF_DIR) ? NULL : entry;
485 * Remove the entry with the given name from dir, recursing into
486 * subdirectories as necessary. If refname is the name of a directory
487 * (i.e., ends with '/'), then remove the directory and its contents.
488 * If the removal was successful, return the number of entries
489 * remaining in the directory entry that contained the deleted entry.
490 * If the name was not found, return -1. Please note that this
491 * function only deletes the entry from the cache; it does not delete
492 * it from the filesystem or ensure that other cache entries (which
493 * might be symbolic references to the removed entry) are updated.
494 * Nor does it remove any containing dir entries that might be made
495 * empty by the removal. dir must represent the top-level directory
496 * and must already be complete.
498 static int remove_entry(struct ref_dir *dir, const char *refname)
500 int refname_len = strlen(refname);
501 int entry_index;
502 struct ref_entry *entry;
503 int is_dir = refname[refname_len - 1] == '/';
504 if (is_dir) {
506 * refname represents a reference directory. Remove
507 * the trailing slash; otherwise we will get the
508 * directory *representing* refname rather than the
509 * one *containing* it.
511 char *dirname = xmemdupz(refname, refname_len - 1);
512 dir = find_containing_dir(dir, dirname, 0);
513 free(dirname);
514 } else {
515 dir = find_containing_dir(dir, refname, 0);
517 if (!dir)
518 return -1;
519 entry_index = search_ref_dir(dir, refname, refname_len);
520 if (entry_index == -1)
521 return -1;
522 entry = dir->entries[entry_index];
524 memmove(&dir->entries[entry_index],
525 &dir->entries[entry_index + 1],
526 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
528 dir->nr--;
529 if (dir->sorted > entry_index)
530 dir->sorted--;
531 free_ref_entry(entry);
532 return dir->nr;
536 * Add a ref_entry to the ref_dir (unsorted), recursing into
537 * subdirectories as necessary. dir must represent the top-level
538 * directory. Return 0 on success.
540 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
542 dir = find_containing_dir(dir, ref->name, 1);
543 if (!dir)
544 return -1;
545 add_entry_to_dir(dir, ref);
546 return 0;
550 * Emit a warning and return true iff ref1 and ref2 have the same name
551 * and the same sha1. Die if they have the same name but different
552 * sha1s.
554 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
556 if (strcmp(ref1->name, ref2->name))
557 return 0;
559 /* Duplicate name; make sure that they don't conflict: */
561 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
562 /* This is impossible by construction */
563 die("Reference directory conflict: %s", ref1->name);
565 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
566 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
568 warning("Duplicated ref: %s", ref1->name);
569 return 1;
573 * Sort the entries in dir non-recursively (if they are not already
574 * sorted) and remove any duplicate entries.
576 static void sort_ref_dir(struct ref_dir *dir)
578 int i, j;
579 struct ref_entry *last = NULL;
582 * This check also prevents passing a zero-length array to qsort(),
583 * which is a problem on some platforms.
585 if (dir->sorted == dir->nr)
586 return;
588 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
590 /* Remove any duplicates: */
591 for (i = 0, j = 0; j < dir->nr; j++) {
592 struct ref_entry *entry = dir->entries[j];
593 if (last && is_dup_ref(last, entry))
594 free_ref_entry(entry);
595 else
596 last = dir->entries[i++] = entry;
598 dir->sorted = dir->nr = i;
601 /* Include broken references in a do_for_each_ref*() iteration: */
602 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
605 * Return true iff the reference described by entry can be resolved to
606 * an object in the database. Emit a warning if the referred-to
607 * object does not exist.
609 static int ref_resolves_to_object(struct ref_entry *entry)
611 if (entry->flag & REF_ISBROKEN)
612 return 0;
613 if (!has_sha1_file(entry->u.value.sha1)) {
614 error("%s does not point to a valid object!", entry->name);
615 return 0;
617 return 1;
621 * current_ref is a performance hack: when iterating over references
622 * using the for_each_ref*() functions, current_ref is set to the
623 * current reference's entry before calling the callback function. If
624 * the callback function calls peel_ref(), then peel_ref() first
625 * checks whether the reference to be peeled is the current reference
626 * (it usually is) and if so, returns that reference's peeled version
627 * if it is available. This avoids a refname lookup in a common case.
629 static struct ref_entry *current_ref;
631 typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
633 struct ref_entry_cb {
634 const char *base;
635 int trim;
636 int flags;
637 each_ref_fn *fn;
638 void *cb_data;
642 * Handle one reference in a do_for_each_ref*()-style iteration,
643 * calling an each_ref_fn for each entry.
645 static int do_one_ref(struct ref_entry *entry, void *cb_data)
647 struct ref_entry_cb *data = cb_data;
648 struct ref_entry *old_current_ref;
649 int retval;
651 if (!starts_with(entry->name, data->base))
652 return 0;
654 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
655 !ref_resolves_to_object(entry))
656 return 0;
658 /* Store the old value, in case this is a recursive call: */
659 old_current_ref = current_ref;
660 current_ref = entry;
661 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
662 entry->flag, data->cb_data);
663 current_ref = old_current_ref;
664 return retval;
668 * Call fn for each reference in dir that has index in the range
669 * offset <= index < dir->nr. Recurse into subdirectories that are in
670 * that index range, sorting them before iterating. This function
671 * does not sort dir itself; it should be sorted beforehand. fn is
672 * called for all references, including broken ones.
674 static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
675 each_ref_entry_fn fn, void *cb_data)
677 int i;
678 assert(dir->sorted == dir->nr);
679 for (i = offset; i < dir->nr; i++) {
680 struct ref_entry *entry = dir->entries[i];
681 int retval;
682 if (entry->flag & REF_DIR) {
683 struct ref_dir *subdir = get_ref_dir(entry);
684 sort_ref_dir(subdir);
685 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
686 } else {
687 retval = fn(entry, cb_data);
689 if (retval)
690 return retval;
692 return 0;
696 * Call fn for each reference in the union of dir1 and dir2, in order
697 * by refname. Recurse into subdirectories. If a value entry appears
698 * in both dir1 and dir2, then only process the version that is in
699 * dir2. The input dirs must already be sorted, but subdirs will be
700 * sorted as needed. fn is called for all references, including
701 * broken ones.
703 static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
704 struct ref_dir *dir2,
705 each_ref_entry_fn fn, void *cb_data)
707 int retval;
708 int i1 = 0, i2 = 0;
710 assert(dir1->sorted == dir1->nr);
711 assert(dir2->sorted == dir2->nr);
712 while (1) {
713 struct ref_entry *e1, *e2;
714 int cmp;
715 if (i1 == dir1->nr) {
716 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
718 if (i2 == dir2->nr) {
719 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
721 e1 = dir1->entries[i1];
722 e2 = dir2->entries[i2];
723 cmp = strcmp(e1->name, e2->name);
724 if (cmp == 0) {
725 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
726 /* Both are directories; descend them in parallel. */
727 struct ref_dir *subdir1 = get_ref_dir(e1);
728 struct ref_dir *subdir2 = get_ref_dir(e2);
729 sort_ref_dir(subdir1);
730 sort_ref_dir(subdir2);
731 retval = do_for_each_entry_in_dirs(
732 subdir1, subdir2, fn, cb_data);
733 i1++;
734 i2++;
735 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
736 /* Both are references; ignore the one from dir1. */
737 retval = fn(e2, cb_data);
738 i1++;
739 i2++;
740 } else {
741 die("conflict between reference and directory: %s",
742 e1->name);
744 } else {
745 struct ref_entry *e;
746 if (cmp < 0) {
747 e = e1;
748 i1++;
749 } else {
750 e = e2;
751 i2++;
753 if (e->flag & REF_DIR) {
754 struct ref_dir *subdir = get_ref_dir(e);
755 sort_ref_dir(subdir);
756 retval = do_for_each_entry_in_dir(
757 subdir, 0, fn, cb_data);
758 } else {
759 retval = fn(e, cb_data);
762 if (retval)
763 return retval;
768 * Load all of the refs from the dir into our in-memory cache. The hard work
769 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
770 * through all of the sub-directories. We do not even need to care about
771 * sorting, as traversal order does not matter to us.
773 static void prime_ref_dir(struct ref_dir *dir)
775 int i;
776 for (i = 0; i < dir->nr; i++) {
777 struct ref_entry *entry = dir->entries[i];
778 if (entry->flag & REF_DIR)
779 prime_ref_dir(get_ref_dir(entry));
783 * Return true iff refname1 and refname2 conflict with each other.
784 * Two reference names conflict if one of them exactly matches the
785 * leading components of the other; e.g., "foo/bar" conflicts with
786 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
787 * "foo/barbados".
789 static int names_conflict(const char *refname1, const char *refname2)
791 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
793 return (*refname1 == '\0' && *refname2 == '/')
794 || (*refname1 == '/' && *refname2 == '\0');
797 struct name_conflict_cb {
798 const char *refname;
799 const char *oldrefname;
800 const char *conflicting_refname;
803 static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
805 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
806 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
807 return 0;
808 if (names_conflict(data->refname, entry->name)) {
809 data->conflicting_refname = entry->name;
810 return 1;
812 return 0;
816 * Return true iff a reference named refname could be created without
817 * conflicting with the name of an existing reference in dir. If
818 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
819 * (e.g., because oldrefname is scheduled for deletion in the same
820 * operation).
822 static int is_refname_available(const char *refname, const char *oldrefname,
823 struct ref_dir *dir)
825 struct name_conflict_cb data;
826 data.refname = refname;
827 data.oldrefname = oldrefname;
828 data.conflicting_refname = NULL;
830 sort_ref_dir(dir);
831 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
832 error("'%s' exists; cannot create '%s'",
833 data.conflicting_refname, refname);
834 return 0;
836 return 1;
839 struct packed_ref_cache {
840 struct ref_entry *root;
843 * Count of references to the data structure in this instance,
844 * including the pointer from ref_cache::packed if any. The
845 * data will not be freed as long as the reference count is
846 * nonzero.
848 unsigned int referrers;
851 * Iff the packed-refs file associated with this instance is
852 * currently locked for writing, this points at the associated
853 * lock (which is owned by somebody else). The referrer count
854 * is also incremented when the file is locked and decremented
855 * when it is unlocked.
857 struct lock_file *lock;
859 /* The metadata from when this packed-refs cache was read */
860 struct stat_validity validity;
864 * Future: need to be in "struct repository"
865 * when doing a full libification.
867 static struct ref_cache {
868 struct ref_cache *next;
869 struct ref_entry *loose;
870 struct packed_ref_cache *packed;
872 * The submodule name, or "" for the main repo. We allocate
873 * length 1 rather than FLEX_ARRAY so that the main ref_cache
874 * is initialized correctly.
876 char name[1];
877 } ref_cache, *submodule_ref_caches;
879 /* Lock used for the main packed-refs file: */
880 static struct lock_file packlock;
883 * Increment the reference count of *packed_refs.
885 static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
887 packed_refs->referrers++;
891 * Decrease the reference count of *packed_refs. If it goes to zero,
892 * free *packed_refs and return true; otherwise return false.
894 static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
896 if (!--packed_refs->referrers) {
897 free_ref_entry(packed_refs->root);
898 stat_validity_clear(&packed_refs->validity);
899 free(packed_refs);
900 return 1;
901 } else {
902 return 0;
906 static void clear_packed_ref_cache(struct ref_cache *refs)
908 if (refs->packed) {
909 struct packed_ref_cache *packed_refs = refs->packed;
911 if (packed_refs->lock)
912 die("internal error: packed-ref cache cleared while locked");
913 refs->packed = NULL;
914 release_packed_ref_cache(packed_refs);
918 static void clear_loose_ref_cache(struct ref_cache *refs)
920 if (refs->loose) {
921 free_ref_entry(refs->loose);
922 refs->loose = NULL;
926 static struct ref_cache *create_ref_cache(const char *submodule)
928 int len;
929 struct ref_cache *refs;
930 if (!submodule)
931 submodule = "";
932 len = strlen(submodule) + 1;
933 refs = xcalloc(1, sizeof(struct ref_cache) + len);
934 memcpy(refs->name, submodule, len);
935 return refs;
939 * Return a pointer to a ref_cache for the specified submodule. For
940 * the main repository, use submodule==NULL. The returned structure
941 * will be allocated and initialized but not necessarily populated; it
942 * should not be freed.
944 static struct ref_cache *get_ref_cache(const char *submodule)
946 struct ref_cache *refs;
948 if (!submodule || !*submodule)
949 return &ref_cache;
951 for (refs = submodule_ref_caches; refs; refs = refs->next)
952 if (!strcmp(submodule, refs->name))
953 return refs;
955 refs = create_ref_cache(submodule);
956 refs->next = submodule_ref_caches;
957 submodule_ref_caches = refs;
958 return refs;
961 /* The length of a peeled reference line in packed-refs, including EOL: */
962 #define PEELED_LINE_LENGTH 42
965 * The packed-refs header line that we write out. Perhaps other
966 * traits will be added later. The trailing space is required.
968 static const char PACKED_REFS_HEADER[] =
969 "# pack-refs with: peeled fully-peeled \n";
972 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
973 * Return a pointer to the refname within the line (null-terminated),
974 * or NULL if there was a problem.
976 static const char *parse_ref_line(char *line, unsigned char *sha1)
979 * 42: the answer to everything.
981 * In this case, it happens to be the answer to
982 * 40 (length of sha1 hex representation)
983 * +1 (space in between hex and name)
984 * +1 (newline at the end of the line)
986 int len = strlen(line) - 42;
988 if (len <= 0)
989 return NULL;
990 if (get_sha1_hex(line, sha1) < 0)
991 return NULL;
992 if (!isspace(line[40]))
993 return NULL;
994 line += 41;
995 if (isspace(*line))
996 return NULL;
997 if (line[len] != '\n')
998 return NULL;
999 line[len] = 0;
1001 return line;
1005 * Read f, which is a packed-refs file, into dir.
1007 * A comment line of the form "# pack-refs with: " may contain zero or
1008 * more traits. We interpret the traits as follows:
1010 * No traits:
1012 * Probably no references are peeled. But if the file contains a
1013 * peeled value for a reference, we will use it.
1015 * peeled:
1017 * References under "refs/tags/", if they *can* be peeled, *are*
1018 * peeled in this file. References outside of "refs/tags/" are
1019 * probably not peeled even if they could have been, but if we find
1020 * a peeled value for such a reference we will use it.
1022 * fully-peeled:
1024 * All references in the file that can be peeled are peeled.
1025 * Inversely (and this is more important), any references in the
1026 * file for which no peeled value is recorded is not peelable. This
1027 * trait should typically be written alongside "peeled" for
1028 * compatibility with older clients, but we do not require it
1029 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1031 static void read_packed_refs(FILE *f, struct ref_dir *dir)
1033 struct ref_entry *last = NULL;
1034 char refline[PATH_MAX];
1035 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1037 while (fgets(refline, sizeof(refline), f)) {
1038 unsigned char sha1[20];
1039 const char *refname;
1040 static const char header[] = "# pack-refs with:";
1042 if (!strncmp(refline, header, sizeof(header)-1)) {
1043 const char *traits = refline + sizeof(header) - 1;
1044 if (strstr(traits, " fully-peeled "))
1045 peeled = PEELED_FULLY;
1046 else if (strstr(traits, " peeled "))
1047 peeled = PEELED_TAGS;
1048 /* perhaps other traits later as well */
1049 continue;
1052 refname = parse_ref_line(refline, sha1);
1053 if (refname) {
1054 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
1055 if (peeled == PEELED_FULLY ||
1056 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
1057 last->flag |= REF_KNOWS_PEELED;
1058 add_ref(dir, last);
1059 continue;
1061 if (last &&
1062 refline[0] == '^' &&
1063 strlen(refline) == PEELED_LINE_LENGTH &&
1064 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
1065 !get_sha1_hex(refline + 1, sha1)) {
1066 hashcpy(last->u.value.peeled, sha1);
1068 * Regardless of what the file header said,
1069 * we definitely know the value of *this*
1070 * reference:
1072 last->flag |= REF_KNOWS_PEELED;
1078 * Get the packed_ref_cache for the specified ref_cache, creating it
1079 * if necessary.
1081 static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
1083 const char *packed_refs_file;
1085 if (*refs->name)
1086 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1087 else
1088 packed_refs_file = git_path("packed-refs");
1090 if (refs->packed &&
1091 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1092 clear_packed_ref_cache(refs);
1094 if (!refs->packed) {
1095 FILE *f;
1097 refs->packed = xcalloc(1, sizeof(*refs->packed));
1098 acquire_packed_ref_cache(refs->packed);
1099 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1100 f = fopen(packed_refs_file, "r");
1101 if (f) {
1102 stat_validity_update(&refs->packed->validity, fileno(f));
1103 read_packed_refs(f, get_ref_dir(refs->packed->root));
1104 fclose(f);
1107 return refs->packed;
1110 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1112 return get_ref_dir(packed_ref_cache->root);
1115 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1117 return get_packed_ref_dir(get_packed_ref_cache(refs));
1120 void add_packed_ref(const char *refname, const unsigned char *sha1)
1122 struct packed_ref_cache *packed_ref_cache =
1123 get_packed_ref_cache(&ref_cache);
1125 if (!packed_ref_cache->lock)
1126 die("internal error: packed refs not locked");
1127 add_ref(get_packed_ref_dir(packed_ref_cache),
1128 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1132 * Read the loose references from the namespace dirname into dir
1133 * (without recursing). dirname must end with '/'. dir must be the
1134 * directory entry corresponding to dirname.
1136 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1138 struct ref_cache *refs = dir->ref_cache;
1139 DIR *d;
1140 const char *path;
1141 struct dirent *de;
1142 int dirnamelen = strlen(dirname);
1143 struct strbuf refname;
1145 if (*refs->name)
1146 path = git_path_submodule(refs->name, "%s", dirname);
1147 else
1148 path = git_path("%s", dirname);
1150 d = opendir(path);
1151 if (!d)
1152 return;
1154 strbuf_init(&refname, dirnamelen + 257);
1155 strbuf_add(&refname, dirname, dirnamelen);
1157 while ((de = readdir(d)) != NULL) {
1158 unsigned char sha1[20];
1159 struct stat st;
1160 int flag;
1161 const char *refdir;
1163 if (de->d_name[0] == '.')
1164 continue;
1165 if (ends_with(de->d_name, ".lock"))
1166 continue;
1167 strbuf_addstr(&refname, de->d_name);
1168 refdir = *refs->name
1169 ? git_path_submodule(refs->name, "%s", refname.buf)
1170 : git_path("%s", refname.buf);
1171 if (stat(refdir, &st) < 0) {
1172 ; /* silently ignore */
1173 } else if (S_ISDIR(st.st_mode)) {
1174 strbuf_addch(&refname, '/');
1175 add_entry_to_dir(dir,
1176 create_dir_entry(refs, refname.buf,
1177 refname.len, 1));
1178 } else {
1179 if (*refs->name) {
1180 hashclr(sha1);
1181 flag = 0;
1182 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
1183 hashclr(sha1);
1184 flag |= REF_ISBROKEN;
1186 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
1187 hashclr(sha1);
1188 flag |= REF_ISBROKEN;
1190 add_entry_to_dir(dir,
1191 create_ref_entry(refname.buf, sha1, flag, 1));
1193 strbuf_setlen(&refname, dirnamelen);
1195 strbuf_release(&refname);
1196 closedir(d);
1199 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
1201 if (!refs->loose) {
1203 * Mark the top-level directory complete because we
1204 * are about to read the only subdirectory that can
1205 * hold references:
1207 refs->loose = create_dir_entry(refs, "", 0, 0);
1209 * Create an incomplete entry for "refs/":
1211 add_entry_to_dir(get_ref_dir(refs->loose),
1212 create_dir_entry(refs, "refs/", 5, 1));
1214 return get_ref_dir(refs->loose);
1217 /* We allow "recursive" symbolic refs. Only within reason, though */
1218 #define MAXDEPTH 5
1219 #define MAXREFLEN (1024)
1222 * Called by resolve_gitlink_ref_recursive() after it failed to read
1223 * from the loose refs in ref_cache refs. Find <refname> in the
1224 * packed-refs file for the submodule.
1226 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
1227 const char *refname, unsigned char *sha1)
1229 struct ref_entry *ref;
1230 struct ref_dir *dir = get_packed_refs(refs);
1232 ref = find_ref(dir, refname);
1233 if (ref == NULL)
1234 return -1;
1236 hashcpy(sha1, ref->u.value.sha1);
1237 return 0;
1240 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
1241 const char *refname, unsigned char *sha1,
1242 int recursion)
1244 int fd, len;
1245 char buffer[128], *p;
1246 char *path;
1248 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
1249 return -1;
1250 path = *refs->name
1251 ? git_path_submodule(refs->name, "%s", refname)
1252 : git_path("%s", refname);
1253 fd = open(path, O_RDONLY);
1254 if (fd < 0)
1255 return resolve_gitlink_packed_ref(refs, refname, sha1);
1257 len = read(fd, buffer, sizeof(buffer)-1);
1258 close(fd);
1259 if (len < 0)
1260 return -1;
1261 while (len && isspace(buffer[len-1]))
1262 len--;
1263 buffer[len] = 0;
1265 /* Was it a detached head or an old-fashioned symlink? */
1266 if (!get_sha1_hex(buffer, sha1))
1267 return 0;
1269 /* Symref? */
1270 if (strncmp(buffer, "ref:", 4))
1271 return -1;
1272 p = buffer + 4;
1273 while (isspace(*p))
1274 p++;
1276 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1279 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1281 int len = strlen(path), retval;
1282 char *submodule;
1283 struct ref_cache *refs;
1285 while (len && path[len-1] == '/')
1286 len--;
1287 if (!len)
1288 return -1;
1289 submodule = xstrndup(path, len);
1290 refs = get_ref_cache(submodule);
1291 free(submodule);
1293 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1294 return retval;
1298 * Return the ref_entry for the given refname from the packed
1299 * references. If it does not exist, return NULL.
1301 static struct ref_entry *get_packed_ref(const char *refname)
1303 return find_ref(get_packed_refs(&ref_cache), refname);
1307 * A loose ref file doesn't exist; check for a packed ref. The
1308 * options are forwarded from resolve_safe_unsafe().
1310 static const char *handle_missing_loose_ref(const char *refname,
1311 unsigned char *sha1,
1312 int reading,
1313 int *flag)
1315 struct ref_entry *entry;
1318 * The loose reference file does not exist; check for a packed
1319 * reference.
1321 entry = get_packed_ref(refname);
1322 if (entry) {
1323 hashcpy(sha1, entry->u.value.sha1);
1324 if (flag)
1325 *flag |= REF_ISPACKED;
1326 return refname;
1328 /* The reference is not a packed reference, either. */
1329 if (reading) {
1330 return NULL;
1331 } else {
1332 hashclr(sha1);
1333 return refname;
1337 /* This function needs to return a meaningful errno on failure */
1338 const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
1340 int depth = MAXDEPTH;
1341 ssize_t len;
1342 char buffer[256];
1343 static char refname_buffer[256];
1345 if (flag)
1346 *flag = 0;
1348 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1349 errno = EINVAL;
1350 return NULL;
1353 for (;;) {
1354 char path[PATH_MAX];
1355 struct stat st;
1356 char *buf;
1357 int fd;
1359 if (--depth < 0) {
1360 errno = ELOOP;
1361 return NULL;
1364 git_snpath(path, sizeof(path), "%s", refname);
1367 * We might have to loop back here to avoid a race
1368 * condition: first we lstat() the file, then we try
1369 * to read it as a link or as a file. But if somebody
1370 * changes the type of the file (file <-> directory
1371 * <-> symlink) between the lstat() and reading, then
1372 * we don't want to report that as an error but rather
1373 * try again starting with the lstat().
1375 stat_ref:
1376 if (lstat(path, &st) < 0) {
1377 if (errno == ENOENT)
1378 return handle_missing_loose_ref(refname, sha1,
1379 reading, flag);
1380 else
1381 return NULL;
1384 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1385 if (S_ISLNK(st.st_mode)) {
1386 len = readlink(path, buffer, sizeof(buffer)-1);
1387 if (len < 0) {
1388 if (errno == ENOENT || errno == EINVAL)
1389 /* inconsistent with lstat; retry */
1390 goto stat_ref;
1391 else
1392 return NULL;
1394 buffer[len] = 0;
1395 if (starts_with(buffer, "refs/") &&
1396 !check_refname_format(buffer, 0)) {
1397 strcpy(refname_buffer, buffer);
1398 refname = refname_buffer;
1399 if (flag)
1400 *flag |= REF_ISSYMREF;
1401 continue;
1405 /* Is it a directory? */
1406 if (S_ISDIR(st.st_mode)) {
1407 errno = EISDIR;
1408 return NULL;
1412 * Anything else, just open it and try to use it as
1413 * a ref
1415 fd = open(path, O_RDONLY);
1416 if (fd < 0) {
1417 if (errno == ENOENT)
1418 /* inconsistent with lstat; retry */
1419 goto stat_ref;
1420 else
1421 return NULL;
1423 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1424 if (len < 0) {
1425 int save_errno = errno;
1426 close(fd);
1427 errno = save_errno;
1428 return NULL;
1430 close(fd);
1431 while (len && isspace(buffer[len-1]))
1432 len--;
1433 buffer[len] = '\0';
1436 * Is it a symbolic ref?
1438 if (!starts_with(buffer, "ref:")) {
1440 * Please note that FETCH_HEAD has a second
1441 * line containing other data.
1443 if (get_sha1_hex(buffer, sha1) ||
1444 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1445 if (flag)
1446 *flag |= REF_ISBROKEN;
1447 errno = EINVAL;
1448 return NULL;
1450 return refname;
1452 if (flag)
1453 *flag |= REF_ISSYMREF;
1454 buf = buffer + 4;
1455 while (isspace(*buf))
1456 buf++;
1457 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1458 if (flag)
1459 *flag |= REF_ISBROKEN;
1460 errno = EINVAL;
1461 return NULL;
1463 refname = strcpy(refname_buffer, buf);
1467 char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1469 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
1470 return ret ? xstrdup(ret) : NULL;
1473 /* The argument to filter_refs */
1474 struct ref_filter {
1475 const char *pattern;
1476 each_ref_fn *fn;
1477 void *cb_data;
1480 int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
1482 if (resolve_ref_unsafe(refname, sha1, reading, flags))
1483 return 0;
1484 return -1;
1487 int read_ref(const char *refname, unsigned char *sha1)
1489 return read_ref_full(refname, sha1, 1, NULL);
1492 int ref_exists(const char *refname)
1494 unsigned char sha1[20];
1495 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
1498 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1499 void *data)
1501 struct ref_filter *filter = (struct ref_filter *)data;
1502 if (wildmatch(filter->pattern, refname, 0, NULL))
1503 return 0;
1504 return filter->fn(refname, sha1, flags, filter->cb_data);
1507 enum peel_status {
1508 /* object was peeled successfully: */
1509 PEEL_PEELED = 0,
1512 * object cannot be peeled because the named object (or an
1513 * object referred to by a tag in the peel chain), does not
1514 * exist.
1516 PEEL_INVALID = -1,
1518 /* object cannot be peeled because it is not a tag: */
1519 PEEL_NON_TAG = -2,
1521 /* ref_entry contains no peeled value because it is a symref: */
1522 PEEL_IS_SYMREF = -3,
1525 * ref_entry cannot be peeled because it is broken (i.e., the
1526 * symbolic reference cannot even be resolved to an object
1527 * name):
1529 PEEL_BROKEN = -4
1533 * Peel the named object; i.e., if the object is a tag, resolve the
1534 * tag recursively until a non-tag is found. If successful, store the
1535 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1536 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1537 * and leave sha1 unchanged.
1539 static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
1541 struct object *o = lookup_unknown_object(name);
1543 if (o->type == OBJ_NONE) {
1544 int type = sha1_object_info(name, NULL);
1545 if (type < 0 || !object_as_type(o, type, 0))
1546 return PEEL_INVALID;
1549 if (o->type != OBJ_TAG)
1550 return PEEL_NON_TAG;
1552 o = deref_tag_noverify(o);
1553 if (!o)
1554 return PEEL_INVALID;
1556 hashcpy(sha1, o->sha1);
1557 return PEEL_PEELED;
1561 * Peel the entry (if possible) and return its new peel_status. If
1562 * repeel is true, re-peel the entry even if there is an old peeled
1563 * value that is already stored in it.
1565 * It is OK to call this function with a packed reference entry that
1566 * might be stale and might even refer to an object that has since
1567 * been garbage-collected. In such a case, if the entry has
1568 * REF_KNOWS_PEELED then leave the status unchanged and return
1569 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1571 static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1573 enum peel_status status;
1575 if (entry->flag & REF_KNOWS_PEELED) {
1576 if (repeel) {
1577 entry->flag &= ~REF_KNOWS_PEELED;
1578 hashclr(entry->u.value.peeled);
1579 } else {
1580 return is_null_sha1(entry->u.value.peeled) ?
1581 PEEL_NON_TAG : PEEL_PEELED;
1584 if (entry->flag & REF_ISBROKEN)
1585 return PEEL_BROKEN;
1586 if (entry->flag & REF_ISSYMREF)
1587 return PEEL_IS_SYMREF;
1589 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1590 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1591 entry->flag |= REF_KNOWS_PEELED;
1592 return status;
1595 int peel_ref(const char *refname, unsigned char *sha1)
1597 int flag;
1598 unsigned char base[20];
1600 if (current_ref && (current_ref->name == refname
1601 || !strcmp(current_ref->name, refname))) {
1602 if (peel_entry(current_ref, 0))
1603 return -1;
1604 hashcpy(sha1, current_ref->u.value.peeled);
1605 return 0;
1608 if (read_ref_full(refname, base, 1, &flag))
1609 return -1;
1612 * If the reference is packed, read its ref_entry from the
1613 * cache in the hope that we already know its peeled value.
1614 * We only try this optimization on packed references because
1615 * (a) forcing the filling of the loose reference cache could
1616 * be expensive and (b) loose references anyway usually do not
1617 * have REF_KNOWS_PEELED.
1619 if (flag & REF_ISPACKED) {
1620 struct ref_entry *r = get_packed_ref(refname);
1621 if (r) {
1622 if (peel_entry(r, 0))
1623 return -1;
1624 hashcpy(sha1, r->u.value.peeled);
1625 return 0;
1629 return peel_object(base, sha1);
1632 struct warn_if_dangling_data {
1633 FILE *fp;
1634 const char *refname;
1635 const struct string_list *refnames;
1636 const char *msg_fmt;
1639 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1640 int flags, void *cb_data)
1642 struct warn_if_dangling_data *d = cb_data;
1643 const char *resolves_to;
1644 unsigned char junk[20];
1646 if (!(flags & REF_ISSYMREF))
1647 return 0;
1649 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1650 if (!resolves_to
1651 || (d->refname
1652 ? strcmp(resolves_to, d->refname)
1653 : !string_list_has_string(d->refnames, resolves_to))) {
1654 return 0;
1657 fprintf(d->fp, d->msg_fmt, refname);
1658 fputc('\n', d->fp);
1659 return 0;
1662 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1664 struct warn_if_dangling_data data;
1666 data.fp = fp;
1667 data.refname = refname;
1668 data.refnames = NULL;
1669 data.msg_fmt = msg_fmt;
1670 for_each_rawref(warn_if_dangling_symref, &data);
1673 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
1675 struct warn_if_dangling_data data;
1677 data.fp = fp;
1678 data.refname = NULL;
1679 data.refnames = refnames;
1680 data.msg_fmt = msg_fmt;
1681 for_each_rawref(warn_if_dangling_symref, &data);
1685 * Call fn for each reference in the specified ref_cache, omitting
1686 * references not in the containing_dir of base. fn is called for all
1687 * references, including broken ones. If fn ever returns a non-zero
1688 * value, stop the iteration and return that value; otherwise, return
1689 * 0.
1691 static int do_for_each_entry(struct ref_cache *refs, const char *base,
1692 each_ref_entry_fn fn, void *cb_data)
1694 struct packed_ref_cache *packed_ref_cache;
1695 struct ref_dir *loose_dir;
1696 struct ref_dir *packed_dir;
1697 int retval = 0;
1700 * We must make sure that all loose refs are read before accessing the
1701 * packed-refs file; this avoids a race condition in which loose refs
1702 * are migrated to the packed-refs file by a simultaneous process, but
1703 * our in-memory view is from before the migration. get_packed_ref_cache()
1704 * takes care of making sure our view is up to date with what is on
1705 * disk.
1707 loose_dir = get_loose_refs(refs);
1708 if (base && *base) {
1709 loose_dir = find_containing_dir(loose_dir, base, 0);
1711 if (loose_dir)
1712 prime_ref_dir(loose_dir);
1714 packed_ref_cache = get_packed_ref_cache(refs);
1715 acquire_packed_ref_cache(packed_ref_cache);
1716 packed_dir = get_packed_ref_dir(packed_ref_cache);
1717 if (base && *base) {
1718 packed_dir = find_containing_dir(packed_dir, base, 0);
1721 if (packed_dir && loose_dir) {
1722 sort_ref_dir(packed_dir);
1723 sort_ref_dir(loose_dir);
1724 retval = do_for_each_entry_in_dirs(
1725 packed_dir, loose_dir, fn, cb_data);
1726 } else if (packed_dir) {
1727 sort_ref_dir(packed_dir);
1728 retval = do_for_each_entry_in_dir(
1729 packed_dir, 0, fn, cb_data);
1730 } else if (loose_dir) {
1731 sort_ref_dir(loose_dir);
1732 retval = do_for_each_entry_in_dir(
1733 loose_dir, 0, fn, cb_data);
1736 release_packed_ref_cache(packed_ref_cache);
1737 return retval;
1741 * Call fn for each reference in the specified ref_cache for which the
1742 * refname begins with base. If trim is non-zero, then trim that many
1743 * characters off the beginning of each refname before passing the
1744 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1745 * broken references in the iteration. If fn ever returns a non-zero
1746 * value, stop the iteration and return that value; otherwise, return
1747 * 0.
1749 static int do_for_each_ref(struct ref_cache *refs, const char *base,
1750 each_ref_fn fn, int trim, int flags, void *cb_data)
1752 struct ref_entry_cb data;
1753 data.base = base;
1754 data.trim = trim;
1755 data.flags = flags;
1756 data.fn = fn;
1757 data.cb_data = cb_data;
1759 return do_for_each_entry(refs, base, do_one_ref, &data);
1762 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1764 unsigned char sha1[20];
1765 int flag;
1767 if (submodule) {
1768 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1769 return fn("HEAD", sha1, 0, cb_data);
1771 return 0;
1774 if (!read_ref_full("HEAD", sha1, 1, &flag))
1775 return fn("HEAD", sha1, flag, cb_data);
1777 return 0;
1780 int head_ref(each_ref_fn fn, void *cb_data)
1782 return do_head_ref(NULL, fn, cb_data);
1785 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1787 return do_head_ref(submodule, fn, cb_data);
1790 int for_each_ref(each_ref_fn fn, void *cb_data)
1792 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1795 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1797 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
1800 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1802 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1805 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1806 each_ref_fn fn, void *cb_data)
1808 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
1811 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1813 return for_each_ref_in("refs/tags/", fn, cb_data);
1816 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1818 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1821 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1823 return for_each_ref_in("refs/heads/", fn, cb_data);
1826 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1828 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1831 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1833 return for_each_ref_in("refs/remotes/", fn, cb_data);
1836 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1838 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1841 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1843 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
1846 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1848 struct strbuf buf = STRBUF_INIT;
1849 int ret = 0;
1850 unsigned char sha1[20];
1851 int flag;
1853 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
1854 if (!read_ref_full(buf.buf, sha1, 1, &flag))
1855 ret = fn(buf.buf, sha1, flag, cb_data);
1856 strbuf_release(&buf);
1858 return ret;
1861 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1863 struct strbuf buf = STRBUF_INIT;
1864 int ret;
1865 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1866 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
1867 strbuf_release(&buf);
1868 return ret;
1871 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1872 const char *prefix, void *cb_data)
1874 struct strbuf real_pattern = STRBUF_INIT;
1875 struct ref_filter filter;
1876 int ret;
1878 if (!prefix && !starts_with(pattern, "refs/"))
1879 strbuf_addstr(&real_pattern, "refs/");
1880 else if (prefix)
1881 strbuf_addstr(&real_pattern, prefix);
1882 strbuf_addstr(&real_pattern, pattern);
1884 if (!has_glob_specials(pattern)) {
1885 /* Append implied '/' '*' if not present. */
1886 if (real_pattern.buf[real_pattern.len - 1] != '/')
1887 strbuf_addch(&real_pattern, '/');
1888 /* No need to check for '*', there is none. */
1889 strbuf_addch(&real_pattern, '*');
1892 filter.pattern = real_pattern.buf;
1893 filter.fn = fn;
1894 filter.cb_data = cb_data;
1895 ret = for_each_ref(filter_refs, &filter);
1897 strbuf_release(&real_pattern);
1898 return ret;
1901 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1903 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1906 int for_each_rawref(each_ref_fn fn, void *cb_data)
1908 return do_for_each_ref(&ref_cache, "", fn, 0,
1909 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1912 const char *prettify_refname(const char *name)
1914 return name + (
1915 starts_with(name, "refs/heads/") ? 11 :
1916 starts_with(name, "refs/tags/") ? 10 :
1917 starts_with(name, "refs/remotes/") ? 13 :
1921 static const char *ref_rev_parse_rules[] = {
1922 "%.*s",
1923 "refs/%.*s",
1924 "refs/tags/%.*s",
1925 "refs/heads/%.*s",
1926 "refs/remotes/%.*s",
1927 "refs/remotes/%.*s/HEAD",
1928 NULL
1931 int refname_match(const char *abbrev_name, const char *full_name)
1933 const char **p;
1934 const int abbrev_name_len = strlen(abbrev_name);
1936 for (p = ref_rev_parse_rules; *p; p++) {
1937 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1938 return 1;
1942 return 0;
1945 /* This function should make sure errno is meaningful on error */
1946 static struct ref_lock *verify_lock(struct ref_lock *lock,
1947 const unsigned char *old_sha1, int mustexist)
1949 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
1950 int save_errno = errno;
1951 error("Can't verify ref %s", lock->ref_name);
1952 unlock_ref(lock);
1953 errno = save_errno;
1954 return NULL;
1956 if (hashcmp(lock->old_sha1, old_sha1)) {
1957 error("Ref %s is at %s but expected %s", lock->ref_name,
1958 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1959 unlock_ref(lock);
1960 errno = EBUSY;
1961 return NULL;
1963 return lock;
1966 static int remove_empty_directories(const char *file)
1968 /* we want to create a file but there is a directory there;
1969 * if that is an empty directory (or a directory that contains
1970 * only empty directories), remove them.
1972 struct strbuf path;
1973 int result, save_errno;
1975 strbuf_init(&path, 20);
1976 strbuf_addstr(&path, file);
1978 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
1979 save_errno = errno;
1981 strbuf_release(&path);
1982 errno = save_errno;
1984 return result;
1988 * *string and *len will only be substituted, and *string returned (for
1989 * later free()ing) if the string passed in is a magic short-hand form
1990 * to name a branch.
1992 static char *substitute_branch_name(const char **string, int *len)
1994 struct strbuf buf = STRBUF_INIT;
1995 int ret = interpret_branch_name(*string, *len, &buf);
1997 if (ret == *len) {
1998 size_t size;
1999 *string = strbuf_detach(&buf, &size);
2000 *len = size;
2001 return (char *)*string;
2004 return NULL;
2007 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
2009 char *last_branch = substitute_branch_name(&str, &len);
2010 const char **p, *r;
2011 int refs_found = 0;
2013 *ref = NULL;
2014 for (p = ref_rev_parse_rules; *p; p++) {
2015 char fullref[PATH_MAX];
2016 unsigned char sha1_from_ref[20];
2017 unsigned char *this_result;
2018 int flag;
2020 this_result = refs_found ? sha1_from_ref : sha1;
2021 mksnpath(fullref, sizeof(fullref), *p, len, str);
2022 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
2023 if (r) {
2024 if (!refs_found++)
2025 *ref = xstrdup(r);
2026 if (!warn_ambiguous_refs)
2027 break;
2028 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
2029 warning("ignoring dangling symref %s.", fullref);
2030 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
2031 warning("ignoring broken ref %s.", fullref);
2034 free(last_branch);
2035 return refs_found;
2038 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
2040 char *last_branch = substitute_branch_name(&str, &len);
2041 const char **p;
2042 int logs_found = 0;
2044 *log = NULL;
2045 for (p = ref_rev_parse_rules; *p; p++) {
2046 unsigned char hash[20];
2047 char path[PATH_MAX];
2048 const char *ref, *it;
2050 mksnpath(path, sizeof(path), *p, len, str);
2051 ref = resolve_ref_unsafe(path, hash, 1, NULL);
2052 if (!ref)
2053 continue;
2054 if (reflog_exists(path))
2055 it = path;
2056 else if (strcmp(ref, path) && reflog_exists(ref))
2057 it = ref;
2058 else
2059 continue;
2060 if (!logs_found++) {
2061 *log = xstrdup(it);
2062 hashcpy(sha1, hash);
2064 if (!warn_ambiguous_refs)
2065 break;
2067 free(last_branch);
2068 return logs_found;
2071 /* This function should make sure errno is meaningful on error */
2072 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2073 const unsigned char *old_sha1,
2074 int flags, int *type_p)
2076 char *ref_file;
2077 const char *orig_refname = refname;
2078 struct ref_lock *lock;
2079 int last_errno = 0;
2080 int type, lflags;
2081 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
2082 int missing = 0;
2083 int attempts_remaining = 3;
2085 lock = xcalloc(1, sizeof(struct ref_lock));
2086 lock->lock_fd = -1;
2088 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
2089 if (!refname && errno == EISDIR) {
2090 /* we are trying to lock foo but we used to
2091 * have foo/bar which now does not exist;
2092 * it is normal for the empty directory 'foo'
2093 * to remain.
2095 ref_file = git_path("%s", orig_refname);
2096 if (remove_empty_directories(ref_file)) {
2097 last_errno = errno;
2098 error("there are still refs under '%s'", orig_refname);
2099 goto error_return;
2101 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
2103 if (type_p)
2104 *type_p = type;
2105 if (!refname) {
2106 last_errno = errno;
2107 error("unable to resolve reference %s: %s",
2108 orig_refname, strerror(errno));
2109 goto error_return;
2111 missing = is_null_sha1(lock->old_sha1);
2112 /* When the ref did not exist and we are creating it,
2113 * make sure there is no existing ref that is packed
2114 * whose name begins with our refname, nor a ref whose
2115 * name is a proper prefix of our refname.
2117 if (missing &&
2118 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
2119 last_errno = ENOTDIR;
2120 goto error_return;
2123 lock->lk = xcalloc(1, sizeof(struct lock_file));
2125 lflags = 0;
2126 if (flags & REF_NODEREF) {
2127 refname = orig_refname;
2128 lflags |= LOCK_NODEREF;
2130 lock->ref_name = xstrdup(refname);
2131 lock->orig_ref_name = xstrdup(orig_refname);
2132 ref_file = git_path("%s", refname);
2133 if (missing)
2134 lock->force_write = 1;
2135 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2136 lock->force_write = 1;
2138 retry:
2139 switch (safe_create_leading_directories(ref_file)) {
2140 case SCLD_OK:
2141 break; /* success */
2142 case SCLD_VANISHED:
2143 if (--attempts_remaining > 0)
2144 goto retry;
2145 /* fall through */
2146 default:
2147 last_errno = errno;
2148 error("unable to create directory for %s", ref_file);
2149 goto error_return;
2152 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
2153 if (lock->lock_fd < 0) {
2154 if (errno == ENOENT && --attempts_remaining > 0)
2156 * Maybe somebody just deleted one of the
2157 * directories leading to ref_file. Try
2158 * again:
2160 goto retry;
2161 else
2162 unable_to_lock_index_die(ref_file, errno);
2164 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
2166 error_return:
2167 unlock_ref(lock);
2168 errno = last_errno;
2169 return NULL;
2172 struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
2174 char refpath[PATH_MAX];
2175 if (check_refname_format(refname, 0))
2176 return NULL;
2177 strcpy(refpath, mkpath("refs/%s", refname));
2178 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
2181 struct ref_lock *lock_any_ref_for_update(const char *refname,
2182 const unsigned char *old_sha1,
2183 int flags, int *type_p)
2185 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
2186 return NULL;
2187 return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
2191 * Write an entry to the packed-refs file for the specified refname.
2192 * If peeled is non-NULL, write it as the entry's peeled value.
2194 static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2195 unsigned char *peeled)
2197 char line[PATH_MAX + 100];
2198 int len;
2200 len = snprintf(line, sizeof(line), "%s %s\n",
2201 sha1_to_hex(sha1), refname);
2202 /* this should not happen but just being defensive */
2203 if (len > sizeof(line))
2204 die("too long a refname '%s'", refname);
2205 write_or_die(fd, line, len);
2207 if (peeled) {
2208 if (snprintf(line, sizeof(line), "^%s\n",
2209 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2210 die("internal error");
2211 write_or_die(fd, line, PEELED_LINE_LENGTH);
2216 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2218 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2220 int *fd = cb_data;
2221 enum peel_status peel_status = peel_entry(entry, 0);
2223 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2224 error("internal error: %s is not a valid packed reference!",
2225 entry->name);
2226 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2227 peel_status == PEEL_PEELED ?
2228 entry->u.value.peeled : NULL);
2229 return 0;
2232 /* This should return a meaningful errno on failure */
2233 int lock_packed_refs(int flags)
2235 struct packed_ref_cache *packed_ref_cache;
2237 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2238 return -1;
2240 * Get the current packed-refs while holding the lock. If the
2241 * packed-refs file has been modified since we last read it,
2242 * this will automatically invalidate the cache and re-read
2243 * the packed-refs file.
2245 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2246 packed_ref_cache->lock = &packlock;
2247 /* Increment the reference count to prevent it from being freed: */
2248 acquire_packed_ref_cache(packed_ref_cache);
2249 return 0;
2253 * Commit the packed refs changes.
2254 * On error we must make sure that errno contains a meaningful value.
2256 int commit_packed_refs(void)
2258 struct packed_ref_cache *packed_ref_cache =
2259 get_packed_ref_cache(&ref_cache);
2260 int error = 0;
2261 int save_errno = 0;
2263 if (!packed_ref_cache->lock)
2264 die("internal error: packed-refs not locked");
2265 write_or_die(packed_ref_cache->lock->fd,
2266 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2268 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2269 0, write_packed_entry_fn,
2270 &packed_ref_cache->lock->fd);
2271 if (commit_lock_file(packed_ref_cache->lock)) {
2272 save_errno = errno;
2273 error = -1;
2275 packed_ref_cache->lock = NULL;
2276 release_packed_ref_cache(packed_ref_cache);
2277 errno = save_errno;
2278 return error;
2281 void rollback_packed_refs(void)
2283 struct packed_ref_cache *packed_ref_cache =
2284 get_packed_ref_cache(&ref_cache);
2286 if (!packed_ref_cache->lock)
2287 die("internal error: packed-refs not locked");
2288 rollback_lock_file(packed_ref_cache->lock);
2289 packed_ref_cache->lock = NULL;
2290 release_packed_ref_cache(packed_ref_cache);
2291 clear_packed_ref_cache(&ref_cache);
2294 struct ref_to_prune {
2295 struct ref_to_prune *next;
2296 unsigned char sha1[20];
2297 char name[FLEX_ARRAY];
2300 struct pack_refs_cb_data {
2301 unsigned int flags;
2302 struct ref_dir *packed_refs;
2303 struct ref_to_prune *ref_to_prune;
2307 * An each_ref_entry_fn that is run over loose references only. If
2308 * the loose reference can be packed, add an entry in the packed ref
2309 * cache. If the reference should be pruned, also add it to
2310 * ref_to_prune in the pack_refs_cb_data.
2312 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2314 struct pack_refs_cb_data *cb = cb_data;
2315 enum peel_status peel_status;
2316 struct ref_entry *packed_entry;
2317 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2319 /* ALWAYS pack tags */
2320 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2321 return 0;
2323 /* Do not pack symbolic or broken refs: */
2324 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2325 return 0;
2327 /* Add a packed ref cache entry equivalent to the loose entry. */
2328 peel_status = peel_entry(entry, 1);
2329 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2330 die("internal error peeling reference %s (%s)",
2331 entry->name, sha1_to_hex(entry->u.value.sha1));
2332 packed_entry = find_ref(cb->packed_refs, entry->name);
2333 if (packed_entry) {
2334 /* Overwrite existing packed entry with info from loose entry */
2335 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2336 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2337 } else {
2338 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2339 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2340 add_ref(cb->packed_refs, packed_entry);
2342 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
2344 /* Schedule the loose reference for pruning if requested. */
2345 if ((cb->flags & PACK_REFS_PRUNE)) {
2346 int namelen = strlen(entry->name) + 1;
2347 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
2348 hashcpy(n->sha1, entry->u.value.sha1);
2349 strcpy(n->name, entry->name);
2350 n->next = cb->ref_to_prune;
2351 cb->ref_to_prune = n;
2353 return 0;
2357 * Remove empty parents, but spare refs/ and immediate subdirs.
2358 * Note: munges *name.
2360 static void try_remove_empty_parents(char *name)
2362 char *p, *q;
2363 int i;
2364 p = name;
2365 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2366 while (*p && *p != '/')
2367 p++;
2368 /* tolerate duplicate slashes; see check_refname_format() */
2369 while (*p == '/')
2370 p++;
2372 for (q = p; *q; q++)
2374 while (1) {
2375 while (q > p && *q != '/')
2376 q--;
2377 while (q > p && *(q-1) == '/')
2378 q--;
2379 if (q == p)
2380 break;
2381 *q = '\0';
2382 if (rmdir(git_path("%s", name)))
2383 break;
2387 /* make sure nobody touched the ref, and unlink */
2388 static void prune_ref(struct ref_to_prune *r)
2390 struct ref_lock *lock = lock_any_ref_for_update(r->name, r->sha1,
2391 0, NULL);
2393 if (lock) {
2394 unlink_or_warn(git_path("%s", r->name));
2395 unlock_ref(lock);
2396 try_remove_empty_parents(r->name);
2400 static void prune_refs(struct ref_to_prune *r)
2402 while (r) {
2403 prune_ref(r);
2404 r = r->next;
2408 int pack_refs(unsigned int flags)
2410 struct pack_refs_cb_data cbdata;
2412 memset(&cbdata, 0, sizeof(cbdata));
2413 cbdata.flags = flags;
2415 lock_packed_refs(LOCK_DIE_ON_ERROR);
2416 cbdata.packed_refs = get_packed_refs(&ref_cache);
2418 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2419 pack_if_possible_fn, &cbdata);
2421 if (commit_packed_refs())
2422 die_errno("unable to overwrite old ref-pack file");
2424 prune_refs(cbdata.ref_to_prune);
2425 return 0;
2429 * If entry is no longer needed in packed-refs, add it to the string
2430 * list pointed to by cb_data. Reasons for deleting entries:
2432 * - Entry is broken.
2433 * - Entry is overridden by a loose ref.
2434 * - Entry does not point at a valid object.
2436 * In the first and third cases, also emit an error message because these
2437 * are indications of repository corruption.
2439 static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
2441 struct string_list *refs_to_delete = cb_data;
2443 if (entry->flag & REF_ISBROKEN) {
2444 /* This shouldn't happen to packed refs. */
2445 error("%s is broken!", entry->name);
2446 string_list_append(refs_to_delete, entry->name);
2447 return 0;
2449 if (!has_sha1_file(entry->u.value.sha1)) {
2450 unsigned char sha1[20];
2451 int flags;
2453 if (read_ref_full(entry->name, sha1, 0, &flags))
2454 /* We should at least have found the packed ref. */
2455 die("Internal error");
2456 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
2458 * This packed reference is overridden by a
2459 * loose reference, so it is OK that its value
2460 * is no longer valid; for example, it might
2461 * refer to an object that has been garbage
2462 * collected. For this purpose we don't even
2463 * care whether the loose reference itself is
2464 * invalid, broken, symbolic, etc. Silently
2465 * remove the packed reference.
2467 string_list_append(refs_to_delete, entry->name);
2468 return 0;
2471 * There is no overriding loose reference, so the fact
2472 * that this reference doesn't refer to a valid object
2473 * indicates some kind of repository corruption.
2474 * Report the problem, then omit the reference from
2475 * the output.
2477 error("%s does not point to a valid object!", entry->name);
2478 string_list_append(refs_to_delete, entry->name);
2479 return 0;
2482 return 0;
2485 int repack_without_refs(const char **refnames, int n, struct strbuf *err)
2487 struct ref_dir *packed;
2488 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2489 struct string_list_item *ref_to_delete;
2490 int i, ret, removed = 0;
2492 /* Look for a packed ref */
2493 for (i = 0; i < n; i++)
2494 if (get_packed_ref(refnames[i]))
2495 break;
2497 /* Avoid locking if we have nothing to do */
2498 if (i == n)
2499 return 0; /* no refname exists in packed refs */
2501 if (lock_packed_refs(0)) {
2502 if (err) {
2503 unable_to_lock_message(git_path("packed-refs"), errno,
2504 err);
2505 return -1;
2507 unable_to_lock_error(git_path("packed-refs"), errno);
2508 return error("cannot delete '%s' from packed refs", refnames[i]);
2510 packed = get_packed_refs(&ref_cache);
2512 /* Remove refnames from the cache */
2513 for (i = 0; i < n; i++)
2514 if (remove_entry(packed, refnames[i]) != -1)
2515 removed = 1;
2516 if (!removed) {
2518 * All packed entries disappeared while we were
2519 * acquiring the lock.
2521 rollback_packed_refs();
2522 return 0;
2525 /* Remove any other accumulated cruft */
2526 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2527 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2528 if (remove_entry(packed, ref_to_delete->string) == -1)
2529 die("internal error");
2532 /* Write what remains */
2533 ret = commit_packed_refs();
2534 if (ret && err)
2535 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",
2536 strerror(errno));
2537 return ret;
2540 static int repack_without_ref(const char *refname)
2542 return repack_without_refs(&refname, 1, NULL);
2545 static int delete_ref_loose(struct ref_lock *lock, int flag)
2547 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2548 /* loose */
2549 int err, i = strlen(lock->lk->filename) - 5; /* .lock */
2551 lock->lk->filename[i] = 0;
2552 err = unlink_or_warn(lock->lk->filename);
2553 lock->lk->filename[i] = '.';
2554 if (err && errno != ENOENT)
2555 return 1;
2557 return 0;
2560 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
2562 struct ref_lock *lock;
2563 int ret = 0, flag = 0;
2565 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
2566 if (!lock)
2567 return 1;
2568 ret |= delete_ref_loose(lock, flag);
2570 /* removing the loose one could have resurrected an earlier
2571 * packed one. Also, if it was not loose we need to repack
2572 * without it.
2574 ret |= repack_without_ref(lock->ref_name);
2576 unlink_or_warn(git_path("logs/%s", lock->ref_name));
2577 clear_loose_ref_cache(&ref_cache);
2578 unlock_ref(lock);
2579 return ret;
2583 * People using contrib's git-new-workdir have .git/logs/refs ->
2584 * /some/other/path/.git/logs/refs, and that may live on another device.
2586 * IOW, to avoid cross device rename errors, the temporary renamed log must
2587 * live into logs/refs.
2589 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2591 static int rename_tmp_log(const char *newrefname)
2593 int attempts_remaining = 4;
2595 retry:
2596 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2597 case SCLD_OK:
2598 break; /* success */
2599 case SCLD_VANISHED:
2600 if (--attempts_remaining > 0)
2601 goto retry;
2602 /* fall through */
2603 default:
2604 error("unable to create directory for %s", newrefname);
2605 return -1;
2608 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
2609 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
2611 * rename(a, b) when b is an existing
2612 * directory ought to result in ISDIR, but
2613 * Solaris 5.8 gives ENOTDIR. Sheesh.
2615 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2616 error("Directory not empty: logs/%s", newrefname);
2617 return -1;
2619 goto retry;
2620 } else if (errno == ENOENT && --attempts_remaining > 0) {
2622 * Maybe another process just deleted one of
2623 * the directories in the path to newrefname.
2624 * Try again from the beginning.
2626 goto retry;
2627 } else {
2628 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2629 newrefname, strerror(errno));
2630 return -1;
2633 return 0;
2636 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
2638 unsigned char sha1[20], orig_sha1[20];
2639 int flag = 0, logmoved = 0;
2640 struct ref_lock *lock;
2641 struct stat loginfo;
2642 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2643 const char *symref = NULL;
2645 if (log && S_ISLNK(loginfo.st_mode))
2646 return error("reflog for %s is a symlink", oldrefname);
2648 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
2649 if (flag & REF_ISSYMREF)
2650 return error("refname %s is a symbolic ref, renaming it is not supported",
2651 oldrefname);
2652 if (!symref)
2653 return error("refname %s not found", oldrefname);
2655 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
2656 return 1;
2658 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
2659 return 1;
2661 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2662 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2663 oldrefname, strerror(errno));
2665 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2666 error("unable to delete old %s", oldrefname);
2667 goto rollback;
2670 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2671 delete_ref(newrefname, sha1, REF_NODEREF)) {
2672 if (errno==EISDIR) {
2673 if (remove_empty_directories(git_path("%s", newrefname))) {
2674 error("Directory not empty: %s", newrefname);
2675 goto rollback;
2677 } else {
2678 error("unable to delete existing %s", newrefname);
2679 goto rollback;
2683 if (log && rename_tmp_log(newrefname))
2684 goto rollback;
2686 logmoved = log;
2688 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
2689 if (!lock) {
2690 error("unable to lock %s for update", newrefname);
2691 goto rollback;
2693 lock->force_write = 1;
2694 hashcpy(lock->old_sha1, orig_sha1);
2695 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
2696 error("unable to write current sha1 into %s", newrefname);
2697 goto rollback;
2700 return 0;
2702 rollback:
2703 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
2704 if (!lock) {
2705 error("unable to lock %s for rollback", oldrefname);
2706 goto rollbacklog;
2709 lock->force_write = 1;
2710 flag = log_all_ref_updates;
2711 log_all_ref_updates = 0;
2712 if (write_ref_sha1(lock, orig_sha1, NULL))
2713 error("unable to write current sha1 into %s", oldrefname);
2714 log_all_ref_updates = flag;
2716 rollbacklog:
2717 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2718 error("unable to restore logfile %s from %s: %s",
2719 oldrefname, newrefname, strerror(errno));
2720 if (!logmoved && log &&
2721 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2722 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2723 oldrefname, strerror(errno));
2725 return 1;
2728 int close_ref(struct ref_lock *lock)
2730 if (close_lock_file(lock->lk))
2731 return -1;
2732 lock->lock_fd = -1;
2733 return 0;
2736 int commit_ref(struct ref_lock *lock)
2738 if (commit_lock_file(lock->lk))
2739 return -1;
2740 lock->lock_fd = -1;
2741 return 0;
2744 void unlock_ref(struct ref_lock *lock)
2746 /* Do not free lock->lk -- atexit() still looks at them */
2747 if (lock->lk)
2748 rollback_lock_file(lock->lk);
2749 free(lock->ref_name);
2750 free(lock->orig_ref_name);
2751 free(lock);
2755 * copy the reflog message msg to buf, which has been allocated sufficiently
2756 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2757 * because reflog file is one line per entry.
2759 static int copy_msg(char *buf, const char *msg)
2761 char *cp = buf;
2762 char c;
2763 int wasspace = 1;
2765 *cp++ = '\t';
2766 while ((c = *msg++)) {
2767 if (wasspace && isspace(c))
2768 continue;
2769 wasspace = isspace(c);
2770 if (wasspace)
2771 c = ' ';
2772 *cp++ = c;
2774 while (buf < cp && isspace(cp[-1]))
2775 cp--;
2776 *cp++ = '\n';
2777 return cp - buf;
2780 /* This function must set a meaningful errno on failure */
2781 int log_ref_setup(const char *refname, char *logfile, int bufsize)
2783 int logfd, oflags = O_APPEND | O_WRONLY;
2785 git_snpath(logfile, bufsize, "logs/%s", refname);
2786 if (log_all_ref_updates &&
2787 (starts_with(refname, "refs/heads/") ||
2788 starts_with(refname, "refs/remotes/") ||
2789 starts_with(refname, "refs/notes/") ||
2790 !strcmp(refname, "HEAD"))) {
2791 if (safe_create_leading_directories(logfile) < 0) {
2792 int save_errno = errno;
2793 error("unable to create directory for %s", logfile);
2794 errno = save_errno;
2795 return -1;
2797 oflags |= O_CREAT;
2800 logfd = open(logfile, oflags, 0666);
2801 if (logfd < 0) {
2802 if (!(oflags & O_CREAT) && errno == ENOENT)
2803 return 0;
2805 if ((oflags & O_CREAT) && errno == EISDIR) {
2806 if (remove_empty_directories(logfile)) {
2807 int save_errno = errno;
2808 error("There are still logs under '%s'",
2809 logfile);
2810 errno = save_errno;
2811 return -1;
2813 logfd = open(logfile, oflags, 0666);
2816 if (logfd < 0) {
2817 int save_errno = errno;
2818 error("Unable to append to %s: %s", logfile,
2819 strerror(errno));
2820 errno = save_errno;
2821 return -1;
2825 adjust_shared_perm(logfile);
2826 close(logfd);
2827 return 0;
2830 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2831 const unsigned char *new_sha1, const char *msg)
2833 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2834 unsigned maxlen, len;
2835 int msglen;
2836 char log_file[PATH_MAX];
2837 char *logrec;
2838 const char *committer;
2840 if (log_all_ref_updates < 0)
2841 log_all_ref_updates = !is_bare_repository();
2843 result = log_ref_setup(refname, log_file, sizeof(log_file));
2844 if (result)
2845 return result;
2847 logfd = open(log_file, oflags);
2848 if (logfd < 0)
2849 return 0;
2850 msglen = msg ? strlen(msg) : 0;
2851 committer = git_committer_info(0);
2852 maxlen = strlen(committer) + msglen + 100;
2853 logrec = xmalloc(maxlen);
2854 len = sprintf(logrec, "%s %s %s\n",
2855 sha1_to_hex(old_sha1),
2856 sha1_to_hex(new_sha1),
2857 committer);
2858 if (msglen)
2859 len += copy_msg(logrec + len - 1, msg) - 1;
2860 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
2861 free(logrec);
2862 if (written != len) {
2863 int save_errno = errno;
2864 close(logfd);
2865 error("Unable to append to %s", log_file);
2866 errno = save_errno;
2867 return -1;
2869 if (close(logfd)) {
2870 int save_errno = errno;
2871 error("Unable to append to %s", log_file);
2872 errno = save_errno;
2873 return -1;
2875 return 0;
2878 int is_branch(const char *refname)
2880 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
2883 /* This function must return a meaningful errno */
2884 int write_ref_sha1(struct ref_lock *lock,
2885 const unsigned char *sha1, const char *logmsg)
2887 static char term = '\n';
2888 struct object *o;
2890 if (!lock) {
2891 errno = EINVAL;
2892 return -1;
2894 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
2895 unlock_ref(lock);
2896 return 0;
2898 o = parse_object(sha1);
2899 if (!o) {
2900 error("Trying to write ref %s with nonexistent object %s",
2901 lock->ref_name, sha1_to_hex(sha1));
2902 unlock_ref(lock);
2903 errno = EINVAL;
2904 return -1;
2906 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2907 error("Trying to write non-commit object %s to branch %s",
2908 sha1_to_hex(sha1), lock->ref_name);
2909 unlock_ref(lock);
2910 errno = EINVAL;
2911 return -1;
2913 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2914 write_in_full(lock->lock_fd, &term, 1) != 1 ||
2915 close_ref(lock) < 0) {
2916 int save_errno = errno;
2917 error("Couldn't write %s", lock->lk->filename);
2918 unlock_ref(lock);
2919 errno = save_errno;
2920 return -1;
2922 clear_loose_ref_cache(&ref_cache);
2923 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2924 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2925 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
2926 unlock_ref(lock);
2927 return -1;
2929 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2931 * Special hack: If a branch is updated directly and HEAD
2932 * points to it (may happen on the remote side of a push
2933 * for example) then logically the HEAD reflog should be
2934 * updated too.
2935 * A generic solution implies reverse symref information,
2936 * but finding all symrefs pointing to the given branch
2937 * would be rather costly for this rare event (the direct
2938 * update of a branch) to be worth it. So let's cheat and
2939 * check with HEAD only which should cover 99% of all usage
2940 * scenarios (even 100% of the default ones).
2942 unsigned char head_sha1[20];
2943 int head_flag;
2944 const char *head_ref;
2945 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
2946 if (head_ref && (head_flag & REF_ISSYMREF) &&
2947 !strcmp(head_ref, lock->ref_name))
2948 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2950 if (commit_ref(lock)) {
2951 error("Couldn't set %s", lock->ref_name);
2952 unlock_ref(lock);
2953 return -1;
2955 unlock_ref(lock);
2956 return 0;
2959 int create_symref(const char *ref_target, const char *refs_heads_master,
2960 const char *logmsg)
2962 const char *lockpath;
2963 char ref[1000];
2964 int fd, len, written;
2965 char *git_HEAD = git_pathdup("%s", ref_target);
2966 unsigned char old_sha1[20], new_sha1[20];
2968 if (logmsg && read_ref(ref_target, old_sha1))
2969 hashclr(old_sha1);
2971 if (safe_create_leading_directories(git_HEAD) < 0)
2972 return error("unable to create directory for %s", git_HEAD);
2974 #ifndef NO_SYMLINK_HEAD
2975 if (prefer_symlink_refs) {
2976 unlink(git_HEAD);
2977 if (!symlink(refs_heads_master, git_HEAD))
2978 goto done;
2979 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2981 #endif
2983 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2984 if (sizeof(ref) <= len) {
2985 error("refname too long: %s", refs_heads_master);
2986 goto error_free_return;
2988 lockpath = mkpath("%s.lock", git_HEAD);
2989 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2990 if (fd < 0) {
2991 error("Unable to open %s for writing", lockpath);
2992 goto error_free_return;
2994 written = write_in_full(fd, ref, len);
2995 if (close(fd) != 0 || written != len) {
2996 error("Unable to write to %s", lockpath);
2997 goto error_unlink_return;
2999 if (rename(lockpath, git_HEAD) < 0) {
3000 error("Unable to create %s", git_HEAD);
3001 goto error_unlink_return;
3003 if (adjust_shared_perm(git_HEAD)) {
3004 error("Unable to fix permissions on %s", lockpath);
3005 error_unlink_return:
3006 unlink_or_warn(lockpath);
3007 error_free_return:
3008 free(git_HEAD);
3009 return -1;
3012 #ifndef NO_SYMLINK_HEAD
3013 done:
3014 #endif
3015 if (logmsg && !read_ref(refs_heads_master, new_sha1))
3016 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
3018 free(git_HEAD);
3019 return 0;
3022 struct read_ref_at_cb {
3023 const char *refname;
3024 unsigned long at_time;
3025 int cnt;
3026 int reccnt;
3027 unsigned char *sha1;
3028 int found_it;
3030 unsigned char osha1[20];
3031 unsigned char nsha1[20];
3032 int tz;
3033 unsigned long date;
3034 char **msg;
3035 unsigned long *cutoff_time;
3036 int *cutoff_tz;
3037 int *cutoff_cnt;
3040 static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
3041 const char *email, unsigned long timestamp, int tz,
3042 const char *message, void *cb_data)
3044 struct read_ref_at_cb *cb = cb_data;
3046 cb->reccnt++;
3047 cb->tz = tz;
3048 cb->date = timestamp;
3050 if (timestamp <= cb->at_time || cb->cnt == 0) {
3051 if (cb->msg)
3052 *cb->msg = xstrdup(message);
3053 if (cb->cutoff_time)
3054 *cb->cutoff_time = timestamp;
3055 if (cb->cutoff_tz)
3056 *cb->cutoff_tz = tz;
3057 if (cb->cutoff_cnt)
3058 *cb->cutoff_cnt = cb->reccnt - 1;
3060 * we have not yet updated cb->[n|o]sha1 so they still
3061 * hold the values for the previous record.
3063 if (!is_null_sha1(cb->osha1)) {
3064 hashcpy(cb->sha1, nsha1);
3065 if (hashcmp(cb->osha1, nsha1))
3066 warning("Log for ref %s has gap after %s.",
3067 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));
3069 else if (cb->date == cb->at_time)
3070 hashcpy(cb->sha1, nsha1);
3071 else if (hashcmp(nsha1, cb->sha1))
3072 warning("Log for ref %s unexpectedly ended on %s.",
3073 cb->refname, show_date(cb->date, cb->tz,
3074 DATE_RFC2822));
3075 hashcpy(cb->osha1, osha1);
3076 hashcpy(cb->nsha1, nsha1);
3077 cb->found_it = 1;
3078 return 1;
3080 hashcpy(cb->osha1, osha1);
3081 hashcpy(cb->nsha1, nsha1);
3082 if (cb->cnt > 0)
3083 cb->cnt--;
3084 return 0;
3087 static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
3088 const char *email, unsigned long timestamp,
3089 int tz, const char *message, void *cb_data)
3091 struct read_ref_at_cb *cb = cb_data;
3093 if (cb->msg)
3094 *cb->msg = xstrdup(message);
3095 if (cb->cutoff_time)
3096 *cb->cutoff_time = timestamp;
3097 if (cb->cutoff_tz)
3098 *cb->cutoff_tz = tz;
3099 if (cb->cutoff_cnt)
3100 *cb->cutoff_cnt = cb->reccnt;
3101 hashcpy(cb->sha1, osha1);
3102 if (is_null_sha1(cb->sha1))
3103 hashcpy(cb->sha1, nsha1);
3104 /* We just want the first entry */
3105 return 1;
3108 int read_ref_at(const char *refname, unsigned long at_time, int cnt,
3109 unsigned char *sha1, char **msg,
3110 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
3112 struct read_ref_at_cb cb;
3114 memset(&cb, 0, sizeof(cb));
3115 cb.refname = refname;
3116 cb.at_time = at_time;
3117 cb.cnt = cnt;
3118 cb.msg = msg;
3119 cb.cutoff_time = cutoff_time;
3120 cb.cutoff_tz = cutoff_tz;
3121 cb.cutoff_cnt = cutoff_cnt;
3122 cb.sha1 = sha1;
3124 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
3126 if (!cb.reccnt)
3127 die("Log for %s is empty.", refname);
3128 if (cb.found_it)
3129 return 0;
3131 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
3133 return 1;
3136 int reflog_exists(const char *refname)
3138 struct stat st;
3140 return !lstat(git_path("logs/%s", refname), &st) &&
3141 S_ISREG(st.st_mode);
3144 int delete_reflog(const char *refname)
3146 return remove_path(git_path("logs/%s", refname));
3149 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3151 unsigned char osha1[20], nsha1[20];
3152 char *email_end, *message;
3153 unsigned long timestamp;
3154 int tz;
3156 /* old SP new SP name <email> SP time TAB msg LF */
3157 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3158 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3159 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3160 !(email_end = strchr(sb->buf + 82, '>')) ||
3161 email_end[1] != ' ' ||
3162 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3163 !message || message[0] != ' ' ||
3164 (message[1] != '+' && message[1] != '-') ||
3165 !isdigit(message[2]) || !isdigit(message[3]) ||
3166 !isdigit(message[4]) || !isdigit(message[5]))
3167 return 0; /* corrupt? */
3168 email_end[1] = '\0';
3169 tz = strtol(message + 1, NULL, 10);
3170 if (message[6] != '\t')
3171 message += 6;
3172 else
3173 message += 7;
3174 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3177 static char *find_beginning_of_line(char *bob, char *scan)
3179 while (bob < scan && *(--scan) != '\n')
3180 ; /* keep scanning backwards */
3182 * Return either beginning of the buffer, or LF at the end of
3183 * the previous line.
3185 return scan;
3188 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3190 struct strbuf sb = STRBUF_INIT;
3191 FILE *logfp;
3192 long pos;
3193 int ret = 0, at_tail = 1;
3195 logfp = fopen(git_path("logs/%s", refname), "r");
3196 if (!logfp)
3197 return -1;
3199 /* Jump to the end */
3200 if (fseek(logfp, 0, SEEK_END) < 0)
3201 return error("cannot seek back reflog for %s: %s",
3202 refname, strerror(errno));
3203 pos = ftell(logfp);
3204 while (!ret && 0 < pos) {
3205 int cnt;
3206 size_t nread;
3207 char buf[BUFSIZ];
3208 char *endp, *scanp;
3210 /* Fill next block from the end */
3211 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3212 if (fseek(logfp, pos - cnt, SEEK_SET))
3213 return error("cannot seek back reflog for %s: %s",
3214 refname, strerror(errno));
3215 nread = fread(buf, cnt, 1, logfp);
3216 if (nread != 1)
3217 return error("cannot read %d bytes from reflog for %s: %s",
3218 cnt, refname, strerror(errno));
3219 pos -= cnt;
3221 scanp = endp = buf + cnt;
3222 if (at_tail && scanp[-1] == '\n')
3223 /* Looking at the final LF at the end of the file */
3224 scanp--;
3225 at_tail = 0;
3227 while (buf < scanp) {
3229 * terminating LF of the previous line, or the beginning
3230 * of the buffer.
3232 char *bp;
3234 bp = find_beginning_of_line(buf, scanp);
3236 if (*bp != '\n') {
3237 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3238 if (pos)
3239 break; /* need to fill another block */
3240 scanp = buf - 1; /* leave loop */
3241 } else {
3243 * (bp + 1) thru endp is the beginning of the
3244 * current line we have in sb
3246 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3247 scanp = bp;
3248 endp = bp + 1;
3250 ret = show_one_reflog_ent(&sb, fn, cb_data);
3251 strbuf_reset(&sb);
3252 if (ret)
3253 break;
3257 if (!ret && sb.len)
3258 ret = show_one_reflog_ent(&sb, fn, cb_data);
3260 fclose(logfp);
3261 strbuf_release(&sb);
3262 return ret;
3265 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3267 FILE *logfp;
3268 struct strbuf sb = STRBUF_INIT;
3269 int ret = 0;
3271 logfp = fopen(git_path("logs/%s", refname), "r");
3272 if (!logfp)
3273 return -1;
3275 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3276 ret = show_one_reflog_ent(&sb, fn, cb_data);
3277 fclose(logfp);
3278 strbuf_release(&sb);
3279 return ret;
3282 * Call fn for each reflog in the namespace indicated by name. name
3283 * must be empty or end with '/'. Name will be used as a scratch
3284 * space, but its contents will be restored before return.
3286 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
3288 DIR *d = opendir(git_path("logs/%s", name->buf));
3289 int retval = 0;
3290 struct dirent *de;
3291 int oldlen = name->len;
3293 if (!d)
3294 return name->len ? errno : 0;
3296 while ((de = readdir(d)) != NULL) {
3297 struct stat st;
3299 if (de->d_name[0] == '.')
3300 continue;
3301 if (ends_with(de->d_name, ".lock"))
3302 continue;
3303 strbuf_addstr(name, de->d_name);
3304 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3305 ; /* silently ignore */
3306 } else {
3307 if (S_ISDIR(st.st_mode)) {
3308 strbuf_addch(name, '/');
3309 retval = do_for_each_reflog(name, fn, cb_data);
3310 } else {
3311 unsigned char sha1[20];
3312 if (read_ref_full(name->buf, sha1, 0, NULL))
3313 retval = error("bad ref for %s", name->buf);
3314 else
3315 retval = fn(name->buf, sha1, 0, cb_data);
3317 if (retval)
3318 break;
3320 strbuf_setlen(name, oldlen);
3322 closedir(d);
3323 return retval;
3326 int for_each_reflog(each_ref_fn fn, void *cb_data)
3328 int retval;
3329 struct strbuf name;
3330 strbuf_init(&name, PATH_MAX);
3331 retval = do_for_each_reflog(&name, fn, cb_data);
3332 strbuf_release(&name);
3333 return retval;
3336 static struct ref_lock *update_ref_lock(const char *refname,
3337 const unsigned char *oldval,
3338 int flags, int *type_p,
3339 enum action_on_err onerr)
3341 struct ref_lock *lock;
3342 lock = lock_any_ref_for_update(refname, oldval, flags, type_p);
3343 if (!lock) {
3344 const char *str = "Cannot lock the ref '%s'.";
3345 switch (onerr) {
3346 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
3347 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
3348 case UPDATE_REFS_QUIET_ON_ERR: break;
3351 return lock;
3354 static int update_ref_write(const char *action, const char *refname,
3355 const unsigned char *sha1, struct ref_lock *lock,
3356 struct strbuf *err, enum action_on_err onerr)
3358 if (write_ref_sha1(lock, sha1, action) < 0) {
3359 const char *str = "Cannot update the ref '%s'.";
3360 if (err)
3361 strbuf_addf(err, str, refname);
3363 switch (onerr) {
3364 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
3365 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
3366 case UPDATE_REFS_QUIET_ON_ERR: break;
3368 return 1;
3370 return 0;
3374 * Information needed for a single ref update. Set new_sha1 to the
3375 * new value or to zero to delete the ref. To check the old value
3376 * while locking the ref, set have_old to 1 and set old_sha1 to the
3377 * value or to zero to ensure the ref does not exist before update.
3379 struct ref_update {
3380 unsigned char new_sha1[20];
3381 unsigned char old_sha1[20];
3382 int flags; /* REF_NODEREF? */
3383 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
3384 struct ref_lock *lock;
3385 int type;
3386 const char refname[FLEX_ARRAY];
3390 * Data structure for holding a reference transaction, which can
3391 * consist of checks and updates to multiple references, carried out
3392 * as atomically as possible. This structure is opaque to callers.
3394 struct ref_transaction {
3395 struct ref_update **updates;
3396 size_t alloc;
3397 size_t nr;
3400 struct ref_transaction *ref_transaction_begin(void)
3402 return xcalloc(1, sizeof(struct ref_transaction));
3405 void ref_transaction_free(struct ref_transaction *transaction)
3407 int i;
3409 if (!transaction)
3410 return;
3412 for (i = 0; i < transaction->nr; i++)
3413 free(transaction->updates[i]);
3415 free(transaction->updates);
3416 free(transaction);
3419 static struct ref_update *add_update(struct ref_transaction *transaction,
3420 const char *refname)
3422 size_t len = strlen(refname);
3423 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
3425 strcpy((char *)update->refname, refname);
3426 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
3427 transaction->updates[transaction->nr++] = update;
3428 return update;
3431 int ref_transaction_update(struct ref_transaction *transaction,
3432 const char *refname,
3433 const unsigned char *new_sha1,
3434 const unsigned char *old_sha1,
3435 int flags, int have_old,
3436 struct strbuf *err)
3438 struct ref_update *update;
3440 if (have_old && !old_sha1)
3441 die("BUG: have_old is true but old_sha1 is NULL");
3443 update = add_update(transaction, refname);
3444 hashcpy(update->new_sha1, new_sha1);
3445 update->flags = flags;
3446 update->have_old = have_old;
3447 if (have_old)
3448 hashcpy(update->old_sha1, old_sha1);
3449 return 0;
3452 void ref_transaction_create(struct ref_transaction *transaction,
3453 const char *refname,
3454 const unsigned char *new_sha1,
3455 int flags)
3457 struct ref_update *update = add_update(transaction, refname);
3459 assert(!is_null_sha1(new_sha1));
3460 hashcpy(update->new_sha1, new_sha1);
3461 hashclr(update->old_sha1);
3462 update->flags = flags;
3463 update->have_old = 1;
3466 void ref_transaction_delete(struct ref_transaction *transaction,
3467 const char *refname,
3468 const unsigned char *old_sha1,
3469 int flags, int have_old)
3471 struct ref_update *update = add_update(transaction, refname);
3473 update->flags = flags;
3474 update->have_old = have_old;
3475 if (have_old) {
3476 assert(!is_null_sha1(old_sha1));
3477 hashcpy(update->old_sha1, old_sha1);
3481 int update_ref(const char *action, const char *refname,
3482 const unsigned char *sha1, const unsigned char *oldval,
3483 int flags, enum action_on_err onerr)
3485 struct ref_lock *lock;
3486 lock = update_ref_lock(refname, oldval, flags, NULL, onerr);
3487 if (!lock)
3488 return 1;
3489 return update_ref_write(action, refname, sha1, lock, NULL, onerr);
3492 static int ref_update_compare(const void *r1, const void *r2)
3494 const struct ref_update * const *u1 = r1;
3495 const struct ref_update * const *u2 = r2;
3496 return strcmp((*u1)->refname, (*u2)->refname);
3499 static int ref_update_reject_duplicates(struct ref_update **updates, int n,
3500 struct strbuf *err)
3502 int i;
3503 for (i = 1; i < n; i++)
3504 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
3505 const char *str =
3506 "Multiple updates for ref '%s' not allowed.";
3507 if (err)
3508 strbuf_addf(err, str, updates[i]->refname);
3510 return 1;
3512 return 0;
3515 int ref_transaction_commit(struct ref_transaction *transaction,
3516 const char *msg, struct strbuf *err)
3518 int ret = 0, delnum = 0, i;
3519 const char **delnames;
3520 int n = transaction->nr;
3521 struct ref_update **updates = transaction->updates;
3523 if (!n)
3524 return 0;
3526 /* Allocate work space */
3527 delnames = xmalloc(sizeof(*delnames) * n);
3529 /* Copy, sort, and reject duplicate refs */
3530 qsort(updates, n, sizeof(*updates), ref_update_compare);
3531 ret = ref_update_reject_duplicates(updates, n, err);
3532 if (ret)
3533 goto cleanup;
3535 /* Acquire all locks while verifying old values */
3536 for (i = 0; i < n; i++) {
3537 struct ref_update *update = updates[i];
3539 update->lock = update_ref_lock(update->refname,
3540 (update->have_old ?
3541 update->old_sha1 : NULL),
3542 update->flags,
3543 &update->type,
3544 UPDATE_REFS_QUIET_ON_ERR);
3545 if (!update->lock) {
3546 if (err)
3547 strbuf_addf(err, "Cannot lock the ref '%s'.",
3548 update->refname);
3549 ret = 1;
3550 goto cleanup;
3554 /* Perform updates first so live commits remain referenced */
3555 for (i = 0; i < n; i++) {
3556 struct ref_update *update = updates[i];
3558 if (!is_null_sha1(update->new_sha1)) {
3559 ret = update_ref_write(msg,
3560 update->refname,
3561 update->new_sha1,
3562 update->lock, err,
3563 UPDATE_REFS_QUIET_ON_ERR);
3564 update->lock = NULL; /* freed by update_ref_write */
3565 if (ret)
3566 goto cleanup;
3570 /* Perform deletes now that updates are safely completed */
3571 for (i = 0; i < n; i++) {
3572 struct ref_update *update = updates[i];
3574 if (update->lock) {
3575 delnames[delnum++] = update->lock->ref_name;
3576 ret |= delete_ref_loose(update->lock, update->type);
3580 ret |= repack_without_refs(delnames, delnum, err);
3581 for (i = 0; i < delnum; i++)
3582 unlink_or_warn(git_path("logs/%s", delnames[i]));
3583 clear_loose_ref_cache(&ref_cache);
3585 cleanup:
3586 for (i = 0; i < n; i++)
3587 if (updates[i]->lock)
3588 unlock_ref(updates[i]->lock);
3589 free(delnames);
3590 return ret;
3593 char *shorten_unambiguous_ref(const char *refname, int strict)
3595 int i;
3596 static char **scanf_fmts;
3597 static int nr_rules;
3598 char *short_name;
3600 if (!nr_rules) {
3602 * Pre-generate scanf formats from ref_rev_parse_rules[].
3603 * Generate a format suitable for scanf from a
3604 * ref_rev_parse_rules rule by interpolating "%s" at the
3605 * location of the "%.*s".
3607 size_t total_len = 0;
3608 size_t offset = 0;
3610 /* the rule list is NULL terminated, count them first */
3611 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
3612 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
3613 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
3615 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3617 offset = 0;
3618 for (i = 0; i < nr_rules; i++) {
3619 assert(offset < total_len);
3620 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
3621 offset += snprintf(scanf_fmts[i], total_len - offset,
3622 ref_rev_parse_rules[i], 2, "%s") + 1;
3626 /* bail out if there are no rules */
3627 if (!nr_rules)
3628 return xstrdup(refname);
3630 /* buffer for scanf result, at most refname must fit */
3631 short_name = xstrdup(refname);
3633 /* skip first rule, it will always match */
3634 for (i = nr_rules - 1; i > 0 ; --i) {
3635 int j;
3636 int rules_to_fail = i;
3637 int short_name_len;
3639 if (1 != sscanf(refname, scanf_fmts[i], short_name))
3640 continue;
3642 short_name_len = strlen(short_name);
3645 * in strict mode, all (except the matched one) rules
3646 * must fail to resolve to a valid non-ambiguous ref
3648 if (strict)
3649 rules_to_fail = nr_rules;
3652 * check if the short name resolves to a valid ref,
3653 * but use only rules prior to the matched one
3655 for (j = 0; j < rules_to_fail; j++) {
3656 const char *rule = ref_rev_parse_rules[j];
3657 char refname[PATH_MAX];
3659 /* skip matched rule */
3660 if (i == j)
3661 continue;
3664 * the short name is ambiguous, if it resolves
3665 * (with this previous rule) to a valid ref
3666 * read_ref() returns 0 on success
3668 mksnpath(refname, sizeof(refname),
3669 rule, short_name_len, short_name);
3670 if (ref_exists(refname))
3671 break;
3675 * short name is non-ambiguous if all previous rules
3676 * haven't resolved to a valid ref
3678 if (j == rules_to_fail)
3679 return short_name;
3682 free(short_name);
3683 return xstrdup(refname);
3686 static struct string_list *hide_refs;
3688 int parse_hide_refs_config(const char *var, const char *value, const char *section)
3690 if (!strcmp("transfer.hiderefs", var) ||
3691 /* NEEDSWORK: use parse_config_key() once both are merged */
3692 (starts_with(var, section) && var[strlen(section)] == '.' &&
3693 !strcmp(var + strlen(section), ".hiderefs"))) {
3694 char *ref;
3695 int len;
3697 if (!value)
3698 return config_error_nonbool(var);
3699 ref = xstrdup(value);
3700 len = strlen(ref);
3701 while (len && ref[len - 1] == '/')
3702 ref[--len] = '\0';
3703 if (!hide_refs) {
3704 hide_refs = xcalloc(1, sizeof(*hide_refs));
3705 hide_refs->strdup_strings = 1;
3707 string_list_append(hide_refs, ref);
3709 return 0;
3712 int ref_is_hidden(const char *refname)
3714 struct string_list_item *item;
3716 if (!hide_refs)
3717 return 0;
3718 for_each_string_list_item(item, hide_refs) {
3719 int len;
3720 if (!starts_with(refname, item->string))
3721 continue;
3722 len = strlen(item->string);
3723 if (!refname[len] || refname[len] == '/')
3724 return 1;
3726 return 0;