refs.c: don't expose the internal struct ref_lock in the header file
[git/mingw/j6t.git] / refs.c
blob048fbbf50f6dab1742f6b82b71ae6fa33f0134e1
1 #include "cache.h"
2 #include "lockfile.h"
3 #include "refs.h"
4 #include "object.h"
5 #include "tag.h"
6 #include "dir.h"
7 #include "string-list.h"
9 struct ref_lock {
10 char *ref_name;
11 char *orig_ref_name;
12 struct lock_file *lk;
13 unsigned char old_sha1[20];
14 int lock_fd;
15 int force_write;
19 * How to handle various characters in refnames:
20 * 0: An acceptable character for refs
21 * 1: End-of-component
22 * 2: ., look for a preceding . to reject .. in refs
23 * 3: {, look for a preceding @ to reject @{ in refs
24 * 4: A bad character: ASCII control characters, "~", "^", ":" or SP
26 static unsigned char refname_disposition[256] = {
27 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
28 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
29 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1,
30 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
31 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
32 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
33 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
34 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
38 * Used as a flag to ref_transaction_delete when a loose ref is being
39 * pruned.
41 #define REF_ISPRUNING 0x0100
43 * Try to read one refname component from the front of refname.
44 * Return the length of the component found, or -1 if the component is
45 * not legal. It is legal if it is something reasonable to have under
46 * ".git/refs/"; We do not like it if:
48 * - any path component of it begins with ".", or
49 * - it has double dots "..", or
50 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
51 * - it ends with a "/".
52 * - it ends with ".lock"
53 * - it contains a "\" (backslash)
55 static int check_refname_component(const char *refname, int flags)
57 const char *cp;
58 char last = '\0';
60 for (cp = refname; ; cp++) {
61 int ch = *cp & 255;
62 unsigned char disp = refname_disposition[ch];
63 switch (disp) {
64 case 1:
65 goto out;
66 case 2:
67 if (last == '.')
68 return -1; /* Refname contains "..". */
69 break;
70 case 3:
71 if (last == '@')
72 return -1; /* Refname contains "@{". */
73 break;
74 case 4:
75 return -1;
77 last = ch;
79 out:
80 if (cp == refname)
81 return 0; /* Component has zero length. */
82 if (refname[0] == '.')
83 return -1; /* Component starts with '.'. */
84 if (cp - refname >= LOCK_SUFFIX_LEN &&
85 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
86 return -1; /* Refname ends with ".lock". */
87 return cp - refname;
90 int check_refname_format(const char *refname, int flags)
92 int component_len, component_count = 0;
94 if (!strcmp(refname, "@"))
95 /* Refname is a single character '@'. */
96 return -1;
98 while (1) {
99 /* We are at the start of a path component. */
100 component_len = check_refname_component(refname, flags);
101 if (component_len <= 0) {
102 if ((flags & REFNAME_REFSPEC_PATTERN) &&
103 refname[0] == '*' &&
104 (refname[1] == '\0' || refname[1] == '/')) {
105 /* Accept one wildcard as a full refname component. */
106 flags &= ~REFNAME_REFSPEC_PATTERN;
107 component_len = 1;
108 } else {
109 return -1;
112 component_count++;
113 if (refname[component_len] == '\0')
114 break;
115 /* Skip to next component. */
116 refname += component_len + 1;
119 if (refname[component_len - 1] == '.')
120 return -1; /* Refname ends with '.'. */
121 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
122 return -1; /* Refname has only one component. */
123 return 0;
126 struct ref_entry;
129 * Information used (along with the information in ref_entry) to
130 * describe a single cached reference. This data structure only
131 * occurs embedded in a union in struct ref_entry, and only when
132 * (ref_entry->flag & REF_DIR) is zero.
134 struct ref_value {
136 * The name of the object to which this reference resolves
137 * (which may be a tag object). If REF_ISBROKEN, this is
138 * null. If REF_ISSYMREF, then this is the name of the object
139 * referred to by the last reference in the symlink chain.
141 unsigned char sha1[20];
144 * If REF_KNOWS_PEELED, then this field holds the peeled value
145 * of this reference, or null if the reference is known not to
146 * be peelable. See the documentation for peel_ref() for an
147 * exact definition of "peelable".
149 unsigned char peeled[20];
152 struct ref_cache;
155 * Information used (along with the information in ref_entry) to
156 * describe a level in the hierarchy of references. This data
157 * structure only occurs embedded in a union in struct ref_entry, and
158 * only when (ref_entry.flag & REF_DIR) is set. In that case,
159 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
160 * in the directory have already been read:
162 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
163 * or packed references, already read.
165 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
166 * references that hasn't been read yet (nor has any of its
167 * subdirectories).
169 * Entries within a directory are stored within a growable array of
170 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
171 * sorted are sorted by their component name in strcmp() order and the
172 * remaining entries are unsorted.
174 * Loose references are read lazily, one directory at a time. When a
175 * directory of loose references is read, then all of the references
176 * in that directory are stored, and REF_INCOMPLETE stubs are created
177 * for any subdirectories, but the subdirectories themselves are not
178 * read. The reading is triggered by get_ref_dir().
180 struct ref_dir {
181 int nr, alloc;
184 * Entries with index 0 <= i < sorted are sorted by name. New
185 * entries are appended to the list unsorted, and are sorted
186 * only when required; thus we avoid the need to sort the list
187 * after the addition of every reference.
189 int sorted;
191 /* A pointer to the ref_cache that contains this ref_dir. */
192 struct ref_cache *ref_cache;
194 struct ref_entry **entries;
198 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
199 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are
200 * public values; see refs.h.
204 * The field ref_entry->u.value.peeled of this value entry contains
205 * the correct peeled value for the reference, which might be
206 * null_sha1 if the reference is not a tag or if it is broken.
208 #define REF_KNOWS_PEELED 0x10
210 /* ref_entry represents a directory of references */
211 #define REF_DIR 0x20
214 * Entry has not yet been read from disk (used only for REF_DIR
215 * entries representing loose references)
217 #define REF_INCOMPLETE 0x40
220 * A ref_entry represents either a reference or a "subdirectory" of
221 * references.
223 * Each directory in the reference namespace is represented by a
224 * ref_entry with (flags & REF_DIR) set and containing a subdir member
225 * that holds the entries in that directory that have been read so
226 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
227 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
228 * used for loose reference directories.
230 * References are represented by a ref_entry with (flags & REF_DIR)
231 * unset and a value member that describes the reference's value. The
232 * flag member is at the ref_entry level, but it is also needed to
233 * interpret the contents of the value field (in other words, a
234 * ref_value object is not very much use without the enclosing
235 * ref_entry).
237 * Reference names cannot end with slash and directories' names are
238 * always stored with a trailing slash (except for the top-level
239 * directory, which is always denoted by ""). This has two nice
240 * consequences: (1) when the entries in each subdir are sorted
241 * lexicographically by name (as they usually are), the references in
242 * a whole tree can be generated in lexicographic order by traversing
243 * the tree in left-to-right, depth-first order; (2) the names of
244 * references and subdirectories cannot conflict, and therefore the
245 * presence of an empty subdirectory does not block the creation of a
246 * similarly-named reference. (The fact that reference names with the
247 * same leading components can conflict *with each other* is a
248 * separate issue that is regulated by is_refname_available().)
250 * Please note that the name field contains the fully-qualified
251 * reference (or subdirectory) name. Space could be saved by only
252 * storing the relative names. But that would require the full names
253 * to be generated on the fly when iterating in do_for_each_ref(), and
254 * would break callback functions, who have always been able to assume
255 * that the name strings that they are passed will not be freed during
256 * the iteration.
258 struct ref_entry {
259 unsigned char flag; /* ISSYMREF? ISPACKED? */
260 union {
261 struct ref_value value; /* if not (flags&REF_DIR) */
262 struct ref_dir subdir; /* if (flags&REF_DIR) */
263 } u;
265 * The full name of the reference (e.g., "refs/heads/master")
266 * or the full name of the directory with a trailing slash
267 * (e.g., "refs/heads/"):
269 char name[FLEX_ARRAY];
272 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
274 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
276 struct ref_dir *dir;
277 assert(entry->flag & REF_DIR);
278 dir = &entry->u.subdir;
279 if (entry->flag & REF_INCOMPLETE) {
280 read_loose_refs(entry->name, dir);
281 entry->flag &= ~REF_INCOMPLETE;
283 return dir;
287 * Check if a refname is safe.
288 * For refs that start with "refs/" we consider it safe as long they do
289 * not try to resolve to outside of refs/.
291 * For all other refs we only consider them safe iff they only contain
292 * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like
293 * "config").
295 static int refname_is_safe(const char *refname)
297 if (starts_with(refname, "refs/")) {
298 char *buf;
299 int result;
301 buf = xmalloc(strlen(refname) + 1);
303 * Does the refname try to escape refs/?
304 * For example: refs/foo/../bar is safe but refs/foo/../../bar
305 * is not.
307 result = !normalize_path_copy(buf, refname + strlen("refs/"));
308 free(buf);
309 return result;
311 while (*refname) {
312 if (!isupper(*refname) && *refname != '_')
313 return 0;
314 refname++;
316 return 1;
319 static struct ref_entry *create_ref_entry(const char *refname,
320 const unsigned char *sha1, int flag,
321 int check_name)
323 int len;
324 struct ref_entry *ref;
326 if (check_name &&
327 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
328 die("Reference has invalid format: '%s'", refname);
329 if (!check_name && !refname_is_safe(refname))
330 die("Reference has invalid name: '%s'", refname);
331 len = strlen(refname) + 1;
332 ref = xmalloc(sizeof(struct ref_entry) + len);
333 hashcpy(ref->u.value.sha1, sha1);
334 hashclr(ref->u.value.peeled);
335 memcpy(ref->name, refname, len);
336 ref->flag = flag;
337 return ref;
340 static void clear_ref_dir(struct ref_dir *dir);
342 static void free_ref_entry(struct ref_entry *entry)
344 if (entry->flag & REF_DIR) {
346 * Do not use get_ref_dir() here, as that might
347 * trigger the reading of loose refs.
349 clear_ref_dir(&entry->u.subdir);
351 free(entry);
355 * Add a ref_entry to the end of dir (unsorted). Entry is always
356 * stored directly in dir; no recursion into subdirectories is
357 * done.
359 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
361 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
362 dir->entries[dir->nr++] = entry;
363 /* optimize for the case that entries are added in order */
364 if (dir->nr == 1 ||
365 (dir->nr == dir->sorted + 1 &&
366 strcmp(dir->entries[dir->nr - 2]->name,
367 dir->entries[dir->nr - 1]->name) < 0))
368 dir->sorted = dir->nr;
372 * Clear and free all entries in dir, recursively.
374 static void clear_ref_dir(struct ref_dir *dir)
376 int i;
377 for (i = 0; i < dir->nr; i++)
378 free_ref_entry(dir->entries[i]);
379 free(dir->entries);
380 dir->sorted = dir->nr = dir->alloc = 0;
381 dir->entries = NULL;
385 * Create a struct ref_entry object for the specified dirname.
386 * dirname is the name of the directory with a trailing slash (e.g.,
387 * "refs/heads/") or "" for the top-level directory.
389 static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
390 const char *dirname, size_t len,
391 int incomplete)
393 struct ref_entry *direntry;
394 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
395 memcpy(direntry->name, dirname, len);
396 direntry->name[len] = '\0';
397 direntry->u.subdir.ref_cache = ref_cache;
398 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
399 return direntry;
402 static int ref_entry_cmp(const void *a, const void *b)
404 struct ref_entry *one = *(struct ref_entry **)a;
405 struct ref_entry *two = *(struct ref_entry **)b;
406 return strcmp(one->name, two->name);
409 static void sort_ref_dir(struct ref_dir *dir);
411 struct string_slice {
412 size_t len;
413 const char *str;
416 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
418 const struct string_slice *key = key_;
419 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
420 int cmp = strncmp(key->str, ent->name, key->len);
421 if (cmp)
422 return cmp;
423 return '\0' - (unsigned char)ent->name[key->len];
427 * Return the index of the entry with the given refname from the
428 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
429 * no such entry is found. dir must already be complete.
431 static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
433 struct ref_entry **r;
434 struct string_slice key;
436 if (refname == NULL || !dir->nr)
437 return -1;
439 sort_ref_dir(dir);
440 key.len = len;
441 key.str = refname;
442 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
443 ref_entry_cmp_sslice);
445 if (r == NULL)
446 return -1;
448 return r - dir->entries;
452 * Search for a directory entry directly within dir (without
453 * recursing). Sort dir if necessary. subdirname must be a directory
454 * name (i.e., end in '/'). If mkdir is set, then create the
455 * directory if it is missing; otherwise, return NULL if the desired
456 * directory cannot be found. dir must already be complete.
458 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
459 const char *subdirname, size_t len,
460 int mkdir)
462 int entry_index = search_ref_dir(dir, subdirname, len);
463 struct ref_entry *entry;
464 if (entry_index == -1) {
465 if (!mkdir)
466 return NULL;
468 * Since dir is complete, the absence of a subdir
469 * means that the subdir really doesn't exist;
470 * therefore, create an empty record for it but mark
471 * the record complete.
473 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
474 add_entry_to_dir(dir, entry);
475 } else {
476 entry = dir->entries[entry_index];
478 return get_ref_dir(entry);
482 * If refname is a reference name, find the ref_dir within the dir
483 * tree that should hold refname. If refname is a directory name
484 * (i.e., ends in '/'), then return that ref_dir itself. dir must
485 * represent the top-level directory and must already be complete.
486 * Sort ref_dirs and recurse into subdirectories as necessary. If
487 * mkdir is set, then create any missing directories; otherwise,
488 * return NULL if the desired directory cannot be found.
490 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
491 const char *refname, int mkdir)
493 const char *slash;
494 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
495 size_t dirnamelen = slash - refname + 1;
496 struct ref_dir *subdir;
497 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
498 if (!subdir) {
499 dir = NULL;
500 break;
502 dir = subdir;
505 return dir;
509 * Find the value entry with the given name in dir, sorting ref_dirs
510 * and recursing into subdirectories as necessary. If the name is not
511 * found or it corresponds to a directory entry, return NULL.
513 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
515 int entry_index;
516 struct ref_entry *entry;
517 dir = find_containing_dir(dir, refname, 0);
518 if (!dir)
519 return NULL;
520 entry_index = search_ref_dir(dir, refname, strlen(refname));
521 if (entry_index == -1)
522 return NULL;
523 entry = dir->entries[entry_index];
524 return (entry->flag & REF_DIR) ? NULL : entry;
528 * Remove the entry with the given name from dir, recursing into
529 * subdirectories as necessary. If refname is the name of a directory
530 * (i.e., ends with '/'), then remove the directory and its contents.
531 * If the removal was successful, return the number of entries
532 * remaining in the directory entry that contained the deleted entry.
533 * If the name was not found, return -1. Please note that this
534 * function only deletes the entry from the cache; it does not delete
535 * it from the filesystem or ensure that other cache entries (which
536 * might be symbolic references to the removed entry) are updated.
537 * Nor does it remove any containing dir entries that might be made
538 * empty by the removal. dir must represent the top-level directory
539 * and must already be complete.
541 static int remove_entry(struct ref_dir *dir, const char *refname)
543 int refname_len = strlen(refname);
544 int entry_index;
545 struct ref_entry *entry;
546 int is_dir = refname[refname_len - 1] == '/';
547 if (is_dir) {
549 * refname represents a reference directory. Remove
550 * the trailing slash; otherwise we will get the
551 * directory *representing* refname rather than the
552 * one *containing* it.
554 char *dirname = xmemdupz(refname, refname_len - 1);
555 dir = find_containing_dir(dir, dirname, 0);
556 free(dirname);
557 } else {
558 dir = find_containing_dir(dir, refname, 0);
560 if (!dir)
561 return -1;
562 entry_index = search_ref_dir(dir, refname, refname_len);
563 if (entry_index == -1)
564 return -1;
565 entry = dir->entries[entry_index];
567 memmove(&dir->entries[entry_index],
568 &dir->entries[entry_index + 1],
569 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
571 dir->nr--;
572 if (dir->sorted > entry_index)
573 dir->sorted--;
574 free_ref_entry(entry);
575 return dir->nr;
579 * Add a ref_entry to the ref_dir (unsorted), recursing into
580 * subdirectories as necessary. dir must represent the top-level
581 * directory. Return 0 on success.
583 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
585 dir = find_containing_dir(dir, ref->name, 1);
586 if (!dir)
587 return -1;
588 add_entry_to_dir(dir, ref);
589 return 0;
593 * Emit a warning and return true iff ref1 and ref2 have the same name
594 * and the same sha1. Die if they have the same name but different
595 * sha1s.
597 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
599 if (strcmp(ref1->name, ref2->name))
600 return 0;
602 /* Duplicate name; make sure that they don't conflict: */
604 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
605 /* This is impossible by construction */
606 die("Reference directory conflict: %s", ref1->name);
608 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
609 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
611 warning("Duplicated ref: %s", ref1->name);
612 return 1;
616 * Sort the entries in dir non-recursively (if they are not already
617 * sorted) and remove any duplicate entries.
619 static void sort_ref_dir(struct ref_dir *dir)
621 int i, j;
622 struct ref_entry *last = NULL;
625 * This check also prevents passing a zero-length array to qsort(),
626 * which is a problem on some platforms.
628 if (dir->sorted == dir->nr)
629 return;
631 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
633 /* Remove any duplicates: */
634 for (i = 0, j = 0; j < dir->nr; j++) {
635 struct ref_entry *entry = dir->entries[j];
636 if (last && is_dup_ref(last, entry))
637 free_ref_entry(entry);
638 else
639 last = dir->entries[i++] = entry;
641 dir->sorted = dir->nr = i;
644 /* Include broken references in a do_for_each_ref*() iteration: */
645 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
648 * Return true iff the reference described by entry can be resolved to
649 * an object in the database. Emit a warning if the referred-to
650 * object does not exist.
652 static int ref_resolves_to_object(struct ref_entry *entry)
654 if (entry->flag & REF_ISBROKEN)
655 return 0;
656 if (!has_sha1_file(entry->u.value.sha1)) {
657 error("%s does not point to a valid object!", entry->name);
658 return 0;
660 return 1;
664 * current_ref is a performance hack: when iterating over references
665 * using the for_each_ref*() functions, current_ref is set to the
666 * current reference's entry before calling the callback function. If
667 * the callback function calls peel_ref(), then peel_ref() first
668 * checks whether the reference to be peeled is the current reference
669 * (it usually is) and if so, returns that reference's peeled version
670 * if it is available. This avoids a refname lookup in a common case.
672 static struct ref_entry *current_ref;
674 typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
676 struct ref_entry_cb {
677 const char *base;
678 int trim;
679 int flags;
680 each_ref_fn *fn;
681 void *cb_data;
685 * Handle one reference in a do_for_each_ref*()-style iteration,
686 * calling an each_ref_fn for each entry.
688 static int do_one_ref(struct ref_entry *entry, void *cb_data)
690 struct ref_entry_cb *data = cb_data;
691 struct ref_entry *old_current_ref;
692 int retval;
694 if (!starts_with(entry->name, data->base))
695 return 0;
697 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
698 !ref_resolves_to_object(entry))
699 return 0;
701 /* Store the old value, in case this is a recursive call: */
702 old_current_ref = current_ref;
703 current_ref = entry;
704 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
705 entry->flag, data->cb_data);
706 current_ref = old_current_ref;
707 return retval;
711 * Call fn for each reference in dir that has index in the range
712 * offset <= index < dir->nr. Recurse into subdirectories that are in
713 * that index range, sorting them before iterating. This function
714 * does not sort dir itself; it should be sorted beforehand. fn is
715 * called for all references, including broken ones.
717 static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
718 each_ref_entry_fn fn, void *cb_data)
720 int i;
721 assert(dir->sorted == dir->nr);
722 for (i = offset; i < dir->nr; i++) {
723 struct ref_entry *entry = dir->entries[i];
724 int retval;
725 if (entry->flag & REF_DIR) {
726 struct ref_dir *subdir = get_ref_dir(entry);
727 sort_ref_dir(subdir);
728 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
729 } else {
730 retval = fn(entry, cb_data);
732 if (retval)
733 return retval;
735 return 0;
739 * Call fn for each reference in the union of dir1 and dir2, in order
740 * by refname. Recurse into subdirectories. If a value entry appears
741 * in both dir1 and dir2, then only process the version that is in
742 * dir2. The input dirs must already be sorted, but subdirs will be
743 * sorted as needed. fn is called for all references, including
744 * broken ones.
746 static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
747 struct ref_dir *dir2,
748 each_ref_entry_fn fn, void *cb_data)
750 int retval;
751 int i1 = 0, i2 = 0;
753 assert(dir1->sorted == dir1->nr);
754 assert(dir2->sorted == dir2->nr);
755 while (1) {
756 struct ref_entry *e1, *e2;
757 int cmp;
758 if (i1 == dir1->nr) {
759 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
761 if (i2 == dir2->nr) {
762 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
764 e1 = dir1->entries[i1];
765 e2 = dir2->entries[i2];
766 cmp = strcmp(e1->name, e2->name);
767 if (cmp == 0) {
768 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
769 /* Both are directories; descend them in parallel. */
770 struct ref_dir *subdir1 = get_ref_dir(e1);
771 struct ref_dir *subdir2 = get_ref_dir(e2);
772 sort_ref_dir(subdir1);
773 sort_ref_dir(subdir2);
774 retval = do_for_each_entry_in_dirs(
775 subdir1, subdir2, fn, cb_data);
776 i1++;
777 i2++;
778 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
779 /* Both are references; ignore the one from dir1. */
780 retval = fn(e2, cb_data);
781 i1++;
782 i2++;
783 } else {
784 die("conflict between reference and directory: %s",
785 e1->name);
787 } else {
788 struct ref_entry *e;
789 if (cmp < 0) {
790 e = e1;
791 i1++;
792 } else {
793 e = e2;
794 i2++;
796 if (e->flag & REF_DIR) {
797 struct ref_dir *subdir = get_ref_dir(e);
798 sort_ref_dir(subdir);
799 retval = do_for_each_entry_in_dir(
800 subdir, 0, fn, cb_data);
801 } else {
802 retval = fn(e, cb_data);
805 if (retval)
806 return retval;
811 * Load all of the refs from the dir into our in-memory cache. The hard work
812 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
813 * through all of the sub-directories. We do not even need to care about
814 * sorting, as traversal order does not matter to us.
816 static void prime_ref_dir(struct ref_dir *dir)
818 int i;
819 for (i = 0; i < dir->nr; i++) {
820 struct ref_entry *entry = dir->entries[i];
821 if (entry->flag & REF_DIR)
822 prime_ref_dir(get_ref_dir(entry));
826 static int entry_matches(struct ref_entry *entry, const struct string_list *list)
828 return list && string_list_has_string(list, entry->name);
831 struct nonmatching_ref_data {
832 const struct string_list *skip;
833 struct ref_entry *found;
836 static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata)
838 struct nonmatching_ref_data *data = vdata;
840 if (entry_matches(entry, data->skip))
841 return 0;
843 data->found = entry;
844 return 1;
847 static void report_refname_conflict(struct ref_entry *entry,
848 const char *refname)
850 error("'%s' exists; cannot create '%s'", entry->name, refname);
854 * Return true iff a reference named refname could be created without
855 * conflicting with the name of an existing reference in dir. If
856 * skip is non-NULL, ignore potential conflicts with refs in skip
857 * (e.g., because they are scheduled for deletion in the same
858 * operation).
860 * Two reference names conflict if one of them exactly matches the
861 * leading components of the other; e.g., "foo/bar" conflicts with
862 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
863 * "foo/barbados".
865 * skip must be sorted.
867 static int is_refname_available(const char *refname,
868 const struct string_list *skip,
869 struct ref_dir *dir)
871 const char *slash;
872 size_t len;
873 int pos;
874 char *dirname;
876 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
878 * We are still at a leading dir of the refname; we are
879 * looking for a conflict with a leaf entry.
881 * If we find one, we still must make sure it is
882 * not in "skip".
884 pos = search_ref_dir(dir, refname, slash - refname);
885 if (pos >= 0) {
886 struct ref_entry *entry = dir->entries[pos];
887 if (entry_matches(entry, skip))
888 return 1;
889 report_refname_conflict(entry, refname);
890 return 0;
895 * Otherwise, we can try to continue our search with
896 * the next component; if we come up empty, we know
897 * there is nothing under this whole prefix.
899 pos = search_ref_dir(dir, refname, slash + 1 - refname);
900 if (pos < 0)
901 return 1;
903 dir = get_ref_dir(dir->entries[pos]);
907 * We are at the leaf of our refname; we want to
908 * make sure there are no directories which match it.
910 len = strlen(refname);
911 dirname = xmallocz(len + 1);
912 sprintf(dirname, "%s/", refname);
913 pos = search_ref_dir(dir, dirname, len + 1);
914 free(dirname);
916 if (pos >= 0) {
918 * We found a directory named "refname". It is a
919 * problem iff it contains any ref that is not
920 * in "skip".
922 struct ref_entry *entry = dir->entries[pos];
923 struct ref_dir *dir = get_ref_dir(entry);
924 struct nonmatching_ref_data data;
926 data.skip = skip;
927 sort_ref_dir(dir);
928 if (!do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data))
929 return 1;
931 report_refname_conflict(data.found, refname);
932 return 0;
936 * There is no point in searching for another leaf
937 * node which matches it; such an entry would be the
938 * ref we are looking for, not a conflict.
940 return 1;
943 struct packed_ref_cache {
944 struct ref_entry *root;
947 * Count of references to the data structure in this instance,
948 * including the pointer from ref_cache::packed if any. The
949 * data will not be freed as long as the reference count is
950 * nonzero.
952 unsigned int referrers;
955 * Iff the packed-refs file associated with this instance is
956 * currently locked for writing, this points at the associated
957 * lock (which is owned by somebody else). The referrer count
958 * is also incremented when the file is locked and decremented
959 * when it is unlocked.
961 struct lock_file *lock;
963 /* The metadata from when this packed-refs cache was read */
964 struct stat_validity validity;
968 * Future: need to be in "struct repository"
969 * when doing a full libification.
971 static struct ref_cache {
972 struct ref_cache *next;
973 struct ref_entry *loose;
974 struct packed_ref_cache *packed;
976 * The submodule name, or "" for the main repo. We allocate
977 * length 1 rather than FLEX_ARRAY so that the main ref_cache
978 * is initialized correctly.
980 char name[1];
981 } ref_cache, *submodule_ref_caches;
983 /* Lock used for the main packed-refs file: */
984 static struct lock_file packlock;
987 * Increment the reference count of *packed_refs.
989 static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
991 packed_refs->referrers++;
995 * Decrease the reference count of *packed_refs. If it goes to zero,
996 * free *packed_refs and return true; otherwise return false.
998 static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
1000 if (!--packed_refs->referrers) {
1001 free_ref_entry(packed_refs->root);
1002 stat_validity_clear(&packed_refs->validity);
1003 free(packed_refs);
1004 return 1;
1005 } else {
1006 return 0;
1010 static void clear_packed_ref_cache(struct ref_cache *refs)
1012 if (refs->packed) {
1013 struct packed_ref_cache *packed_refs = refs->packed;
1015 if (packed_refs->lock)
1016 die("internal error: packed-ref cache cleared while locked");
1017 refs->packed = NULL;
1018 release_packed_ref_cache(packed_refs);
1022 static void clear_loose_ref_cache(struct ref_cache *refs)
1024 if (refs->loose) {
1025 free_ref_entry(refs->loose);
1026 refs->loose = NULL;
1030 static struct ref_cache *create_ref_cache(const char *submodule)
1032 int len;
1033 struct ref_cache *refs;
1034 if (!submodule)
1035 submodule = "";
1036 len = strlen(submodule) + 1;
1037 refs = xcalloc(1, sizeof(struct ref_cache) + len);
1038 memcpy(refs->name, submodule, len);
1039 return refs;
1043 * Return a pointer to a ref_cache for the specified submodule. For
1044 * the main repository, use submodule==NULL. The returned structure
1045 * will be allocated and initialized but not necessarily populated; it
1046 * should not be freed.
1048 static struct ref_cache *get_ref_cache(const char *submodule)
1050 struct ref_cache *refs;
1052 if (!submodule || !*submodule)
1053 return &ref_cache;
1055 for (refs = submodule_ref_caches; refs; refs = refs->next)
1056 if (!strcmp(submodule, refs->name))
1057 return refs;
1059 refs = create_ref_cache(submodule);
1060 refs->next = submodule_ref_caches;
1061 submodule_ref_caches = refs;
1062 return refs;
1065 /* The length of a peeled reference line in packed-refs, including EOL: */
1066 #define PEELED_LINE_LENGTH 42
1069 * The packed-refs header line that we write out. Perhaps other
1070 * traits will be added later. The trailing space is required.
1072 static const char PACKED_REFS_HEADER[] =
1073 "# pack-refs with: peeled fully-peeled \n";
1076 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
1077 * Return a pointer to the refname within the line (null-terminated),
1078 * or NULL if there was a problem.
1080 static const char *parse_ref_line(char *line, unsigned char *sha1)
1083 * 42: the answer to everything.
1085 * In this case, it happens to be the answer to
1086 * 40 (length of sha1 hex representation)
1087 * +1 (space in between hex and name)
1088 * +1 (newline at the end of the line)
1090 int len = strlen(line) - 42;
1092 if (len <= 0)
1093 return NULL;
1094 if (get_sha1_hex(line, sha1) < 0)
1095 return NULL;
1096 if (!isspace(line[40]))
1097 return NULL;
1098 line += 41;
1099 if (isspace(*line))
1100 return NULL;
1101 if (line[len] != '\n')
1102 return NULL;
1103 line[len] = 0;
1105 return line;
1109 * Read f, which is a packed-refs file, into dir.
1111 * A comment line of the form "# pack-refs with: " may contain zero or
1112 * more traits. We interpret the traits as follows:
1114 * No traits:
1116 * Probably no references are peeled. But if the file contains a
1117 * peeled value for a reference, we will use it.
1119 * peeled:
1121 * References under "refs/tags/", if they *can* be peeled, *are*
1122 * peeled in this file. References outside of "refs/tags/" are
1123 * probably not peeled even if they could have been, but if we find
1124 * a peeled value for such a reference we will use it.
1126 * fully-peeled:
1128 * All references in the file that can be peeled are peeled.
1129 * Inversely (and this is more important), any references in the
1130 * file for which no peeled value is recorded is not peelable. This
1131 * trait should typically be written alongside "peeled" for
1132 * compatibility with older clients, but we do not require it
1133 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1135 static void read_packed_refs(FILE *f, struct ref_dir *dir)
1137 struct ref_entry *last = NULL;
1138 char refline[PATH_MAX];
1139 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1141 while (fgets(refline, sizeof(refline), f)) {
1142 unsigned char sha1[20];
1143 const char *refname;
1144 static const char header[] = "# pack-refs with:";
1146 if (!strncmp(refline, header, sizeof(header)-1)) {
1147 const char *traits = refline + sizeof(header) - 1;
1148 if (strstr(traits, " fully-peeled "))
1149 peeled = PEELED_FULLY;
1150 else if (strstr(traits, " peeled "))
1151 peeled = PEELED_TAGS;
1152 /* perhaps other traits later as well */
1153 continue;
1156 refname = parse_ref_line(refline, sha1);
1157 if (refname) {
1158 int flag = REF_ISPACKED;
1160 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1161 hashclr(sha1);
1162 flag |= REF_BAD_NAME | REF_ISBROKEN;
1164 last = create_ref_entry(refname, sha1, flag, 0);
1165 if (peeled == PEELED_FULLY ||
1166 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
1167 last->flag |= REF_KNOWS_PEELED;
1168 add_ref(dir, last);
1169 continue;
1171 if (last &&
1172 refline[0] == '^' &&
1173 strlen(refline) == PEELED_LINE_LENGTH &&
1174 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
1175 !get_sha1_hex(refline + 1, sha1)) {
1176 hashcpy(last->u.value.peeled, sha1);
1178 * Regardless of what the file header said,
1179 * we definitely know the value of *this*
1180 * reference:
1182 last->flag |= REF_KNOWS_PEELED;
1188 * Get the packed_ref_cache for the specified ref_cache, creating it
1189 * if necessary.
1191 static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
1193 const char *packed_refs_file;
1195 if (*refs->name)
1196 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1197 else
1198 packed_refs_file = git_path("packed-refs");
1200 if (refs->packed &&
1201 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1202 clear_packed_ref_cache(refs);
1204 if (!refs->packed) {
1205 FILE *f;
1207 refs->packed = xcalloc(1, sizeof(*refs->packed));
1208 acquire_packed_ref_cache(refs->packed);
1209 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1210 f = fopen(packed_refs_file, "r");
1211 if (f) {
1212 stat_validity_update(&refs->packed->validity, fileno(f));
1213 read_packed_refs(f, get_ref_dir(refs->packed->root));
1214 fclose(f);
1217 return refs->packed;
1220 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1222 return get_ref_dir(packed_ref_cache->root);
1225 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1227 return get_packed_ref_dir(get_packed_ref_cache(refs));
1230 void add_packed_ref(const char *refname, const unsigned char *sha1)
1232 struct packed_ref_cache *packed_ref_cache =
1233 get_packed_ref_cache(&ref_cache);
1235 if (!packed_ref_cache->lock)
1236 die("internal error: packed refs not locked");
1237 add_ref(get_packed_ref_dir(packed_ref_cache),
1238 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1242 * Read the loose references from the namespace dirname into dir
1243 * (without recursing). dirname must end with '/'. dir must be the
1244 * directory entry corresponding to dirname.
1246 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1248 struct ref_cache *refs = dir->ref_cache;
1249 DIR *d;
1250 const char *path;
1251 struct dirent *de;
1252 int dirnamelen = strlen(dirname);
1253 struct strbuf refname;
1255 if (*refs->name)
1256 path = git_path_submodule(refs->name, "%s", dirname);
1257 else
1258 path = git_path("%s", dirname);
1260 d = opendir(path);
1261 if (!d)
1262 return;
1264 strbuf_init(&refname, dirnamelen + 257);
1265 strbuf_add(&refname, dirname, dirnamelen);
1267 while ((de = readdir(d)) != NULL) {
1268 unsigned char sha1[20];
1269 struct stat st;
1270 int flag;
1271 const char *refdir;
1273 if (de->d_name[0] == '.')
1274 continue;
1275 if (ends_with(de->d_name, ".lock"))
1276 continue;
1277 strbuf_addstr(&refname, de->d_name);
1278 refdir = *refs->name
1279 ? git_path_submodule(refs->name, "%s", refname.buf)
1280 : git_path("%s", refname.buf);
1281 if (stat(refdir, &st) < 0) {
1282 ; /* silently ignore */
1283 } else if (S_ISDIR(st.st_mode)) {
1284 strbuf_addch(&refname, '/');
1285 add_entry_to_dir(dir,
1286 create_dir_entry(refs, refname.buf,
1287 refname.len, 1));
1288 } else {
1289 if (*refs->name) {
1290 hashclr(sha1);
1291 flag = 0;
1292 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
1293 hashclr(sha1);
1294 flag |= REF_ISBROKEN;
1296 } else if (read_ref_full(refname.buf,
1297 RESOLVE_REF_READING,
1298 sha1, &flag)) {
1299 hashclr(sha1);
1300 flag |= REF_ISBROKEN;
1302 if (check_refname_format(refname.buf,
1303 REFNAME_ALLOW_ONELEVEL)) {
1304 hashclr(sha1);
1305 flag |= REF_BAD_NAME | REF_ISBROKEN;
1307 add_entry_to_dir(dir,
1308 create_ref_entry(refname.buf, sha1, flag, 0));
1310 strbuf_setlen(&refname, dirnamelen);
1312 strbuf_release(&refname);
1313 closedir(d);
1316 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
1318 if (!refs->loose) {
1320 * Mark the top-level directory complete because we
1321 * are about to read the only subdirectory that can
1322 * hold references:
1324 refs->loose = create_dir_entry(refs, "", 0, 0);
1326 * Create an incomplete entry for "refs/":
1328 add_entry_to_dir(get_ref_dir(refs->loose),
1329 create_dir_entry(refs, "refs/", 5, 1));
1331 return get_ref_dir(refs->loose);
1334 /* We allow "recursive" symbolic refs. Only within reason, though */
1335 #define MAXDEPTH 5
1336 #define MAXREFLEN (1024)
1339 * Called by resolve_gitlink_ref_recursive() after it failed to read
1340 * from the loose refs in ref_cache refs. Find <refname> in the
1341 * packed-refs file for the submodule.
1343 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
1344 const char *refname, unsigned char *sha1)
1346 struct ref_entry *ref;
1347 struct ref_dir *dir = get_packed_refs(refs);
1349 ref = find_ref(dir, refname);
1350 if (ref == NULL)
1351 return -1;
1353 hashcpy(sha1, ref->u.value.sha1);
1354 return 0;
1357 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
1358 const char *refname, unsigned char *sha1,
1359 int recursion)
1361 int fd, len;
1362 char buffer[128], *p;
1363 char *path;
1365 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
1366 return -1;
1367 path = *refs->name
1368 ? git_path_submodule(refs->name, "%s", refname)
1369 : git_path("%s", refname);
1370 fd = open(path, O_RDONLY);
1371 if (fd < 0)
1372 return resolve_gitlink_packed_ref(refs, refname, sha1);
1374 len = read(fd, buffer, sizeof(buffer)-1);
1375 close(fd);
1376 if (len < 0)
1377 return -1;
1378 while (len && isspace(buffer[len-1]))
1379 len--;
1380 buffer[len] = 0;
1382 /* Was it a detached head or an old-fashioned symlink? */
1383 if (!get_sha1_hex(buffer, sha1))
1384 return 0;
1386 /* Symref? */
1387 if (strncmp(buffer, "ref:", 4))
1388 return -1;
1389 p = buffer + 4;
1390 while (isspace(*p))
1391 p++;
1393 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1396 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1398 int len = strlen(path), retval;
1399 char *submodule;
1400 struct ref_cache *refs;
1402 while (len && path[len-1] == '/')
1403 len--;
1404 if (!len)
1405 return -1;
1406 submodule = xstrndup(path, len);
1407 refs = get_ref_cache(submodule);
1408 free(submodule);
1410 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1411 return retval;
1415 * Return the ref_entry for the given refname from the packed
1416 * references. If it does not exist, return NULL.
1418 static struct ref_entry *get_packed_ref(const char *refname)
1420 return find_ref(get_packed_refs(&ref_cache), refname);
1424 * A loose ref file doesn't exist; check for a packed ref. The
1425 * options are forwarded from resolve_safe_unsafe().
1427 static int resolve_missing_loose_ref(const char *refname,
1428 int resolve_flags,
1429 unsigned char *sha1,
1430 int *flags)
1432 struct ref_entry *entry;
1435 * The loose reference file does not exist; check for a packed
1436 * reference.
1438 entry = get_packed_ref(refname);
1439 if (entry) {
1440 hashcpy(sha1, entry->u.value.sha1);
1441 if (flags)
1442 *flags |= REF_ISPACKED;
1443 return 0;
1445 /* The reference is not a packed reference, either. */
1446 if (resolve_flags & RESOLVE_REF_READING) {
1447 errno = ENOENT;
1448 return -1;
1449 } else {
1450 hashclr(sha1);
1451 return 0;
1455 /* This function needs to return a meaningful errno on failure */
1456 const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
1458 int depth = MAXDEPTH;
1459 ssize_t len;
1460 char buffer[256];
1461 static char refname_buffer[256];
1462 int bad_name = 0;
1464 if (flags)
1465 *flags = 0;
1467 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1468 if (flags)
1469 *flags |= REF_BAD_NAME;
1471 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1472 !refname_is_safe(refname)) {
1473 errno = EINVAL;
1474 return NULL;
1477 * dwim_ref() uses REF_ISBROKEN to distinguish between
1478 * missing refs and refs that were present but invalid,
1479 * to complain about the latter to stderr.
1481 * We don't know whether the ref exists, so don't set
1482 * REF_ISBROKEN yet.
1484 bad_name = 1;
1486 for (;;) {
1487 char path[PATH_MAX];
1488 struct stat st;
1489 char *buf;
1490 int fd;
1492 if (--depth < 0) {
1493 errno = ELOOP;
1494 return NULL;
1497 git_snpath(path, sizeof(path), "%s", refname);
1500 * We might have to loop back here to avoid a race
1501 * condition: first we lstat() the file, then we try
1502 * to read it as a link or as a file. But if somebody
1503 * changes the type of the file (file <-> directory
1504 * <-> symlink) between the lstat() and reading, then
1505 * we don't want to report that as an error but rather
1506 * try again starting with the lstat().
1508 stat_ref:
1509 if (lstat(path, &st) < 0) {
1510 if (errno != ENOENT)
1511 return NULL;
1512 if (resolve_missing_loose_ref(refname, resolve_flags,
1513 sha1, flags))
1514 return NULL;
1515 if (bad_name) {
1516 hashclr(sha1);
1517 if (flags)
1518 *flags |= REF_ISBROKEN;
1520 return refname;
1523 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1524 if (S_ISLNK(st.st_mode)) {
1525 len = readlink(path, buffer, sizeof(buffer)-1);
1526 if (len < 0) {
1527 if (errno == ENOENT || errno == EINVAL)
1528 /* inconsistent with lstat; retry */
1529 goto stat_ref;
1530 else
1531 return NULL;
1533 buffer[len] = 0;
1534 if (starts_with(buffer, "refs/") &&
1535 !check_refname_format(buffer, 0)) {
1536 strcpy(refname_buffer, buffer);
1537 refname = refname_buffer;
1538 if (flags)
1539 *flags |= REF_ISSYMREF;
1540 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1541 hashclr(sha1);
1542 return refname;
1544 continue;
1548 /* Is it a directory? */
1549 if (S_ISDIR(st.st_mode)) {
1550 errno = EISDIR;
1551 return NULL;
1555 * Anything else, just open it and try to use it as
1556 * a ref
1558 fd = open(path, O_RDONLY);
1559 if (fd < 0) {
1560 if (errno == ENOENT)
1561 /* inconsistent with lstat; retry */
1562 goto stat_ref;
1563 else
1564 return NULL;
1566 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1567 if (len < 0) {
1568 int save_errno = errno;
1569 close(fd);
1570 errno = save_errno;
1571 return NULL;
1573 close(fd);
1574 while (len && isspace(buffer[len-1]))
1575 len--;
1576 buffer[len] = '\0';
1579 * Is it a symbolic ref?
1581 if (!starts_with(buffer, "ref:")) {
1583 * Please note that FETCH_HEAD has a second
1584 * line containing other data.
1586 if (get_sha1_hex(buffer, sha1) ||
1587 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1588 if (flags)
1589 *flags |= REF_ISBROKEN;
1590 errno = EINVAL;
1591 return NULL;
1593 if (bad_name) {
1594 hashclr(sha1);
1595 if (flags)
1596 *flags |= REF_ISBROKEN;
1598 return refname;
1600 if (flags)
1601 *flags |= REF_ISSYMREF;
1602 buf = buffer + 4;
1603 while (isspace(*buf))
1604 buf++;
1605 refname = strcpy(refname_buffer, buf);
1606 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1607 hashclr(sha1);
1608 return refname;
1610 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1611 if (flags)
1612 *flags |= REF_ISBROKEN;
1614 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1615 !refname_is_safe(buf)) {
1616 errno = EINVAL;
1617 return NULL;
1619 bad_name = 1;
1624 char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags)
1626 const char *ret = resolve_ref_unsafe(ref, resolve_flags, sha1, flags);
1627 return ret ? xstrdup(ret) : NULL;
1630 /* The argument to filter_refs */
1631 struct ref_filter {
1632 const char *pattern;
1633 each_ref_fn *fn;
1634 void *cb_data;
1637 int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
1639 if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags))
1640 return 0;
1641 return -1;
1644 int read_ref(const char *refname, unsigned char *sha1)
1646 return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);
1649 int ref_exists(const char *refname)
1651 unsigned char sha1[20];
1652 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);
1655 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1656 void *data)
1658 struct ref_filter *filter = (struct ref_filter *)data;
1659 if (wildmatch(filter->pattern, refname, 0, NULL))
1660 return 0;
1661 return filter->fn(refname, sha1, flags, filter->cb_data);
1664 enum peel_status {
1665 /* object was peeled successfully: */
1666 PEEL_PEELED = 0,
1669 * object cannot be peeled because the named object (or an
1670 * object referred to by a tag in the peel chain), does not
1671 * exist.
1673 PEEL_INVALID = -1,
1675 /* object cannot be peeled because it is not a tag: */
1676 PEEL_NON_TAG = -2,
1678 /* ref_entry contains no peeled value because it is a symref: */
1679 PEEL_IS_SYMREF = -3,
1682 * ref_entry cannot be peeled because it is broken (i.e., the
1683 * symbolic reference cannot even be resolved to an object
1684 * name):
1686 PEEL_BROKEN = -4
1690 * Peel the named object; i.e., if the object is a tag, resolve the
1691 * tag recursively until a non-tag is found. If successful, store the
1692 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1693 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1694 * and leave sha1 unchanged.
1696 static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
1698 struct object *o = lookup_unknown_object(name);
1700 if (o->type == OBJ_NONE) {
1701 int type = sha1_object_info(name, NULL);
1702 if (type < 0 || !object_as_type(o, type, 0))
1703 return PEEL_INVALID;
1706 if (o->type != OBJ_TAG)
1707 return PEEL_NON_TAG;
1709 o = deref_tag_noverify(o);
1710 if (!o)
1711 return PEEL_INVALID;
1713 hashcpy(sha1, o->sha1);
1714 return PEEL_PEELED;
1718 * Peel the entry (if possible) and return its new peel_status. If
1719 * repeel is true, re-peel the entry even if there is an old peeled
1720 * value that is already stored in it.
1722 * It is OK to call this function with a packed reference entry that
1723 * might be stale and might even refer to an object that has since
1724 * been garbage-collected. In such a case, if the entry has
1725 * REF_KNOWS_PEELED then leave the status unchanged and return
1726 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1728 static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1730 enum peel_status status;
1732 if (entry->flag & REF_KNOWS_PEELED) {
1733 if (repeel) {
1734 entry->flag &= ~REF_KNOWS_PEELED;
1735 hashclr(entry->u.value.peeled);
1736 } else {
1737 return is_null_sha1(entry->u.value.peeled) ?
1738 PEEL_NON_TAG : PEEL_PEELED;
1741 if (entry->flag & REF_ISBROKEN)
1742 return PEEL_BROKEN;
1743 if (entry->flag & REF_ISSYMREF)
1744 return PEEL_IS_SYMREF;
1746 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1747 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1748 entry->flag |= REF_KNOWS_PEELED;
1749 return status;
1752 int peel_ref(const char *refname, unsigned char *sha1)
1754 int flag;
1755 unsigned char base[20];
1757 if (current_ref && (current_ref->name == refname
1758 || !strcmp(current_ref->name, refname))) {
1759 if (peel_entry(current_ref, 0))
1760 return -1;
1761 hashcpy(sha1, current_ref->u.value.peeled);
1762 return 0;
1765 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))
1766 return -1;
1769 * If the reference is packed, read its ref_entry from the
1770 * cache in the hope that we already know its peeled value.
1771 * We only try this optimization on packed references because
1772 * (a) forcing the filling of the loose reference cache could
1773 * be expensive and (b) loose references anyway usually do not
1774 * have REF_KNOWS_PEELED.
1776 if (flag & REF_ISPACKED) {
1777 struct ref_entry *r = get_packed_ref(refname);
1778 if (r) {
1779 if (peel_entry(r, 0))
1780 return -1;
1781 hashcpy(sha1, r->u.value.peeled);
1782 return 0;
1786 return peel_object(base, sha1);
1789 struct warn_if_dangling_data {
1790 FILE *fp;
1791 const char *refname;
1792 const struct string_list *refnames;
1793 const char *msg_fmt;
1796 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1797 int flags, void *cb_data)
1799 struct warn_if_dangling_data *d = cb_data;
1800 const char *resolves_to;
1801 unsigned char junk[20];
1803 if (!(flags & REF_ISSYMREF))
1804 return 0;
1806 resolves_to = resolve_ref_unsafe(refname, 0, junk, NULL);
1807 if (!resolves_to
1808 || (d->refname
1809 ? strcmp(resolves_to, d->refname)
1810 : !string_list_has_string(d->refnames, resolves_to))) {
1811 return 0;
1814 fprintf(d->fp, d->msg_fmt, refname);
1815 fputc('\n', d->fp);
1816 return 0;
1819 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1821 struct warn_if_dangling_data data;
1823 data.fp = fp;
1824 data.refname = refname;
1825 data.refnames = NULL;
1826 data.msg_fmt = msg_fmt;
1827 for_each_rawref(warn_if_dangling_symref, &data);
1830 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
1832 struct warn_if_dangling_data data;
1834 data.fp = fp;
1835 data.refname = NULL;
1836 data.refnames = refnames;
1837 data.msg_fmt = msg_fmt;
1838 for_each_rawref(warn_if_dangling_symref, &data);
1842 * Call fn for each reference in the specified ref_cache, omitting
1843 * references not in the containing_dir of base. fn is called for all
1844 * references, including broken ones. If fn ever returns a non-zero
1845 * value, stop the iteration and return that value; otherwise, return
1846 * 0.
1848 static int do_for_each_entry(struct ref_cache *refs, const char *base,
1849 each_ref_entry_fn fn, void *cb_data)
1851 struct packed_ref_cache *packed_ref_cache;
1852 struct ref_dir *loose_dir;
1853 struct ref_dir *packed_dir;
1854 int retval = 0;
1857 * We must make sure that all loose refs are read before accessing the
1858 * packed-refs file; this avoids a race condition in which loose refs
1859 * are migrated to the packed-refs file by a simultaneous process, but
1860 * our in-memory view is from before the migration. get_packed_ref_cache()
1861 * takes care of making sure our view is up to date with what is on
1862 * disk.
1864 loose_dir = get_loose_refs(refs);
1865 if (base && *base) {
1866 loose_dir = find_containing_dir(loose_dir, base, 0);
1868 if (loose_dir)
1869 prime_ref_dir(loose_dir);
1871 packed_ref_cache = get_packed_ref_cache(refs);
1872 acquire_packed_ref_cache(packed_ref_cache);
1873 packed_dir = get_packed_ref_dir(packed_ref_cache);
1874 if (base && *base) {
1875 packed_dir = find_containing_dir(packed_dir, base, 0);
1878 if (packed_dir && loose_dir) {
1879 sort_ref_dir(packed_dir);
1880 sort_ref_dir(loose_dir);
1881 retval = do_for_each_entry_in_dirs(
1882 packed_dir, loose_dir, fn, cb_data);
1883 } else if (packed_dir) {
1884 sort_ref_dir(packed_dir);
1885 retval = do_for_each_entry_in_dir(
1886 packed_dir, 0, fn, cb_data);
1887 } else if (loose_dir) {
1888 sort_ref_dir(loose_dir);
1889 retval = do_for_each_entry_in_dir(
1890 loose_dir, 0, fn, cb_data);
1893 release_packed_ref_cache(packed_ref_cache);
1894 return retval;
1898 * Call fn for each reference in the specified ref_cache for which the
1899 * refname begins with base. If trim is non-zero, then trim that many
1900 * characters off the beginning of each refname before passing the
1901 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1902 * broken references in the iteration. If fn ever returns a non-zero
1903 * value, stop the iteration and return that value; otherwise, return
1904 * 0.
1906 static int do_for_each_ref(struct ref_cache *refs, const char *base,
1907 each_ref_fn fn, int trim, int flags, void *cb_data)
1909 struct ref_entry_cb data;
1910 data.base = base;
1911 data.trim = trim;
1912 data.flags = flags;
1913 data.fn = fn;
1914 data.cb_data = cb_data;
1916 return do_for_each_entry(refs, base, do_one_ref, &data);
1919 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1921 unsigned char sha1[20];
1922 int flag;
1924 if (submodule) {
1925 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1926 return fn("HEAD", sha1, 0, cb_data);
1928 return 0;
1931 if (!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag))
1932 return fn("HEAD", sha1, flag, cb_data);
1934 return 0;
1937 int head_ref(each_ref_fn fn, void *cb_data)
1939 return do_head_ref(NULL, fn, cb_data);
1942 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1944 return do_head_ref(submodule, fn, cb_data);
1947 int for_each_ref(each_ref_fn fn, void *cb_data)
1949 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1952 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1954 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
1957 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1959 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1962 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1963 each_ref_fn fn, void *cb_data)
1965 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
1968 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1970 return for_each_ref_in("refs/tags/", fn, cb_data);
1973 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1975 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1978 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1980 return for_each_ref_in("refs/heads/", fn, cb_data);
1983 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1985 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1988 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1990 return for_each_ref_in("refs/remotes/", fn, cb_data);
1993 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1995 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1998 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
2000 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
2003 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
2005 struct strbuf buf = STRBUF_INIT;
2006 int ret = 0;
2007 unsigned char sha1[20];
2008 int flag;
2010 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
2011 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag))
2012 ret = fn(buf.buf, sha1, flag, cb_data);
2013 strbuf_release(&buf);
2015 return ret;
2018 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
2020 struct strbuf buf = STRBUF_INIT;
2021 int ret;
2022 strbuf_addf(&buf, "%srefs/", get_git_namespace());
2023 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
2024 strbuf_release(&buf);
2025 return ret;
2028 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
2029 const char *prefix, void *cb_data)
2031 struct strbuf real_pattern = STRBUF_INIT;
2032 struct ref_filter filter;
2033 int ret;
2035 if (!prefix && !starts_with(pattern, "refs/"))
2036 strbuf_addstr(&real_pattern, "refs/");
2037 else if (prefix)
2038 strbuf_addstr(&real_pattern, prefix);
2039 strbuf_addstr(&real_pattern, pattern);
2041 if (!has_glob_specials(pattern)) {
2042 /* Append implied '/' '*' if not present. */
2043 if (real_pattern.buf[real_pattern.len - 1] != '/')
2044 strbuf_addch(&real_pattern, '/');
2045 /* No need to check for '*', there is none. */
2046 strbuf_addch(&real_pattern, '*');
2049 filter.pattern = real_pattern.buf;
2050 filter.fn = fn;
2051 filter.cb_data = cb_data;
2052 ret = for_each_ref(filter_refs, &filter);
2054 strbuf_release(&real_pattern);
2055 return ret;
2058 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
2060 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
2063 int for_each_rawref(each_ref_fn fn, void *cb_data)
2065 return do_for_each_ref(&ref_cache, "", fn, 0,
2066 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
2069 const char *prettify_refname(const char *name)
2071 return name + (
2072 starts_with(name, "refs/heads/") ? 11 :
2073 starts_with(name, "refs/tags/") ? 10 :
2074 starts_with(name, "refs/remotes/") ? 13 :
2078 static const char *ref_rev_parse_rules[] = {
2079 "%.*s",
2080 "refs/%.*s",
2081 "refs/tags/%.*s",
2082 "refs/heads/%.*s",
2083 "refs/remotes/%.*s",
2084 "refs/remotes/%.*s/HEAD",
2085 NULL
2088 int refname_match(const char *abbrev_name, const char *full_name)
2090 const char **p;
2091 const int abbrev_name_len = strlen(abbrev_name);
2093 for (p = ref_rev_parse_rules; *p; p++) {
2094 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
2095 return 1;
2099 return 0;
2102 static void unlock_ref(struct ref_lock *lock)
2104 /* Do not free lock->lk -- atexit() still looks at them */
2105 if (lock->lk)
2106 rollback_lock_file(lock->lk);
2107 free(lock->ref_name);
2108 free(lock->orig_ref_name);
2109 free(lock);
2112 /* This function should make sure errno is meaningful on error */
2113 static struct ref_lock *verify_lock(struct ref_lock *lock,
2114 const unsigned char *old_sha1, int mustexist)
2116 if (read_ref_full(lock->ref_name,
2117 mustexist ? RESOLVE_REF_READING : 0,
2118 lock->old_sha1, NULL)) {
2119 int save_errno = errno;
2120 error("Can't verify ref %s", lock->ref_name);
2121 unlock_ref(lock);
2122 errno = save_errno;
2123 return NULL;
2125 if (hashcmp(lock->old_sha1, old_sha1)) {
2126 error("Ref %s is at %s but expected %s", lock->ref_name,
2127 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
2128 unlock_ref(lock);
2129 errno = EBUSY;
2130 return NULL;
2132 return lock;
2135 static int remove_empty_directories(const char *file)
2137 /* we want to create a file but there is a directory there;
2138 * if that is an empty directory (or a directory that contains
2139 * only empty directories), remove them.
2141 struct strbuf path;
2142 int result, save_errno;
2144 strbuf_init(&path, 20);
2145 strbuf_addstr(&path, file);
2147 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
2148 save_errno = errno;
2150 strbuf_release(&path);
2151 errno = save_errno;
2153 return result;
2157 * *string and *len will only be substituted, and *string returned (for
2158 * later free()ing) if the string passed in is a magic short-hand form
2159 * to name a branch.
2161 static char *substitute_branch_name(const char **string, int *len)
2163 struct strbuf buf = STRBUF_INIT;
2164 int ret = interpret_branch_name(*string, *len, &buf);
2166 if (ret == *len) {
2167 size_t size;
2168 *string = strbuf_detach(&buf, &size);
2169 *len = size;
2170 return (char *)*string;
2173 return NULL;
2176 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
2178 char *last_branch = substitute_branch_name(&str, &len);
2179 const char **p, *r;
2180 int refs_found = 0;
2182 *ref = NULL;
2183 for (p = ref_rev_parse_rules; *p; p++) {
2184 char fullref[PATH_MAX];
2185 unsigned char sha1_from_ref[20];
2186 unsigned char *this_result;
2187 int flag;
2189 this_result = refs_found ? sha1_from_ref : sha1;
2190 mksnpath(fullref, sizeof(fullref), *p, len, str);
2191 r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING,
2192 this_result, &flag);
2193 if (r) {
2194 if (!refs_found++)
2195 *ref = xstrdup(r);
2196 if (!warn_ambiguous_refs)
2197 break;
2198 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
2199 warning("ignoring dangling symref %s.", fullref);
2200 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
2201 warning("ignoring broken ref %s.", fullref);
2204 free(last_branch);
2205 return refs_found;
2208 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
2210 char *last_branch = substitute_branch_name(&str, &len);
2211 const char **p;
2212 int logs_found = 0;
2214 *log = NULL;
2215 for (p = ref_rev_parse_rules; *p; p++) {
2216 unsigned char hash[20];
2217 char path[PATH_MAX];
2218 const char *ref, *it;
2220 mksnpath(path, sizeof(path), *p, len, str);
2221 ref = resolve_ref_unsafe(path, RESOLVE_REF_READING,
2222 hash, NULL);
2223 if (!ref)
2224 continue;
2225 if (reflog_exists(path))
2226 it = path;
2227 else if (strcmp(ref, path) && reflog_exists(ref))
2228 it = ref;
2229 else
2230 continue;
2231 if (!logs_found++) {
2232 *log = xstrdup(it);
2233 hashcpy(sha1, hash);
2235 if (!warn_ambiguous_refs)
2236 break;
2238 free(last_branch);
2239 return logs_found;
2243 * Locks a ref returning the lock on success and NULL on failure.
2244 * On failure errno is set to something meaningful.
2246 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2247 const unsigned char *old_sha1,
2248 const struct string_list *skip,
2249 int flags, int *type_p)
2251 char *ref_file;
2252 const char *orig_refname = refname;
2253 struct ref_lock *lock;
2254 int last_errno = 0;
2255 int type, lflags;
2256 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
2257 int resolve_flags = 0;
2258 int missing = 0;
2259 int attempts_remaining = 3;
2261 lock = xcalloc(1, sizeof(struct ref_lock));
2262 lock->lock_fd = -1;
2264 if (mustexist)
2265 resolve_flags |= RESOLVE_REF_READING;
2266 if (flags & REF_DELETING) {
2267 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
2268 if (flags & REF_NODEREF)
2269 resolve_flags |= RESOLVE_REF_NO_RECURSE;
2272 refname = resolve_ref_unsafe(refname, resolve_flags,
2273 lock->old_sha1, &type);
2274 if (!refname && errno == EISDIR) {
2275 /* we are trying to lock foo but we used to
2276 * have foo/bar which now does not exist;
2277 * it is normal for the empty directory 'foo'
2278 * to remain.
2280 ref_file = git_path("%s", orig_refname);
2281 if (remove_empty_directories(ref_file)) {
2282 last_errno = errno;
2283 error("there are still refs under '%s'", orig_refname);
2284 goto error_return;
2286 refname = resolve_ref_unsafe(orig_refname, resolve_flags,
2287 lock->old_sha1, &type);
2289 if (type_p)
2290 *type_p = type;
2291 if (!refname) {
2292 last_errno = errno;
2293 error("unable to resolve reference %s: %s",
2294 orig_refname, strerror(errno));
2295 goto error_return;
2297 missing = is_null_sha1(lock->old_sha1);
2298 /* When the ref did not exist and we are creating it,
2299 * make sure there is no existing ref that is packed
2300 * whose name begins with our refname, nor a ref whose
2301 * name is a proper prefix of our refname.
2303 if (missing &&
2304 !is_refname_available(refname, skip, get_packed_refs(&ref_cache))) {
2305 last_errno = ENOTDIR;
2306 goto error_return;
2309 lock->lk = xcalloc(1, sizeof(struct lock_file));
2311 lflags = 0;
2312 if (flags & REF_NODEREF) {
2313 refname = orig_refname;
2314 lflags |= LOCK_NO_DEREF;
2316 lock->ref_name = xstrdup(refname);
2317 lock->orig_ref_name = xstrdup(orig_refname);
2318 ref_file = git_path("%s", refname);
2319 if (missing)
2320 lock->force_write = 1;
2321 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2322 lock->force_write = 1;
2324 retry:
2325 switch (safe_create_leading_directories(ref_file)) {
2326 case SCLD_OK:
2327 break; /* success */
2328 case SCLD_VANISHED:
2329 if (--attempts_remaining > 0)
2330 goto retry;
2331 /* fall through */
2332 default:
2333 last_errno = errno;
2334 error("unable to create directory for %s", ref_file);
2335 goto error_return;
2338 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
2339 if (lock->lock_fd < 0) {
2340 if (errno == ENOENT && --attempts_remaining > 0)
2342 * Maybe somebody just deleted one of the
2343 * directories leading to ref_file. Try
2344 * again:
2346 goto retry;
2347 else
2348 unable_to_lock_die(ref_file, errno);
2350 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
2352 error_return:
2353 unlock_ref(lock);
2354 errno = last_errno;
2355 return NULL;
2359 * Write an entry to the packed-refs file for the specified refname.
2360 * If peeled is non-NULL, write it as the entry's peeled value.
2362 static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,
2363 unsigned char *peeled)
2365 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);
2366 if (peeled)
2367 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));
2371 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2373 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2375 enum peel_status peel_status = peel_entry(entry, 0);
2377 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2378 error("internal error: %s is not a valid packed reference!",
2379 entry->name);
2380 write_packed_entry(cb_data, entry->name, entry->u.value.sha1,
2381 peel_status == PEEL_PEELED ?
2382 entry->u.value.peeled : NULL);
2383 return 0;
2386 /* This should return a meaningful errno on failure */
2387 int lock_packed_refs(int flags)
2389 struct packed_ref_cache *packed_ref_cache;
2391 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2392 return -1;
2394 * Get the current packed-refs while holding the lock. If the
2395 * packed-refs file has been modified since we last read it,
2396 * this will automatically invalidate the cache and re-read
2397 * the packed-refs file.
2399 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2400 packed_ref_cache->lock = &packlock;
2401 /* Increment the reference count to prevent it from being freed: */
2402 acquire_packed_ref_cache(packed_ref_cache);
2403 return 0;
2407 * Commit the packed refs changes.
2408 * On error we must make sure that errno contains a meaningful value.
2410 int commit_packed_refs(void)
2412 struct packed_ref_cache *packed_ref_cache =
2413 get_packed_ref_cache(&ref_cache);
2414 int error = 0;
2415 int save_errno = 0;
2416 FILE *out;
2418 if (!packed_ref_cache->lock)
2419 die("internal error: packed-refs not locked");
2421 out = fdopen_lock_file(packed_ref_cache->lock, "w");
2422 if (!out)
2423 die_errno("unable to fdopen packed-refs descriptor");
2425 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);
2426 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2427 0, write_packed_entry_fn, out);
2429 if (commit_lock_file(packed_ref_cache->lock)) {
2430 save_errno = errno;
2431 error = -1;
2433 packed_ref_cache->lock = NULL;
2434 release_packed_ref_cache(packed_ref_cache);
2435 errno = save_errno;
2436 return error;
2439 void rollback_packed_refs(void)
2441 struct packed_ref_cache *packed_ref_cache =
2442 get_packed_ref_cache(&ref_cache);
2444 if (!packed_ref_cache->lock)
2445 die("internal error: packed-refs not locked");
2446 rollback_lock_file(packed_ref_cache->lock);
2447 packed_ref_cache->lock = NULL;
2448 release_packed_ref_cache(packed_ref_cache);
2449 clear_packed_ref_cache(&ref_cache);
2452 struct ref_to_prune {
2453 struct ref_to_prune *next;
2454 unsigned char sha1[20];
2455 char name[FLEX_ARRAY];
2458 struct pack_refs_cb_data {
2459 unsigned int flags;
2460 struct ref_dir *packed_refs;
2461 struct ref_to_prune *ref_to_prune;
2465 * An each_ref_entry_fn that is run over loose references only. If
2466 * the loose reference can be packed, add an entry in the packed ref
2467 * cache. If the reference should be pruned, also add it to
2468 * ref_to_prune in the pack_refs_cb_data.
2470 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2472 struct pack_refs_cb_data *cb = cb_data;
2473 enum peel_status peel_status;
2474 struct ref_entry *packed_entry;
2475 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2477 /* ALWAYS pack tags */
2478 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2479 return 0;
2481 /* Do not pack symbolic or broken refs: */
2482 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2483 return 0;
2485 /* Add a packed ref cache entry equivalent to the loose entry. */
2486 peel_status = peel_entry(entry, 1);
2487 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2488 die("internal error peeling reference %s (%s)",
2489 entry->name, sha1_to_hex(entry->u.value.sha1));
2490 packed_entry = find_ref(cb->packed_refs, entry->name);
2491 if (packed_entry) {
2492 /* Overwrite existing packed entry with info from loose entry */
2493 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2494 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2495 } else {
2496 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2497 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2498 add_ref(cb->packed_refs, packed_entry);
2500 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
2502 /* Schedule the loose reference for pruning if requested. */
2503 if ((cb->flags & PACK_REFS_PRUNE)) {
2504 int namelen = strlen(entry->name) + 1;
2505 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
2506 hashcpy(n->sha1, entry->u.value.sha1);
2507 strcpy(n->name, entry->name);
2508 n->next = cb->ref_to_prune;
2509 cb->ref_to_prune = n;
2511 return 0;
2515 * Remove empty parents, but spare refs/ and immediate subdirs.
2516 * Note: munges *name.
2518 static void try_remove_empty_parents(char *name)
2520 char *p, *q;
2521 int i;
2522 p = name;
2523 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2524 while (*p && *p != '/')
2525 p++;
2526 /* tolerate duplicate slashes; see check_refname_format() */
2527 while (*p == '/')
2528 p++;
2530 for (q = p; *q; q++)
2532 while (1) {
2533 while (q > p && *q != '/')
2534 q--;
2535 while (q > p && *(q-1) == '/')
2536 q--;
2537 if (q == p)
2538 break;
2539 *q = '\0';
2540 if (rmdir(git_path("%s", name)))
2541 break;
2545 /* make sure nobody touched the ref, and unlink */
2546 static void prune_ref(struct ref_to_prune *r)
2548 struct ref_transaction *transaction;
2549 struct strbuf err = STRBUF_INIT;
2551 if (check_refname_format(r->name, 0))
2552 return;
2554 transaction = ref_transaction_begin(&err);
2555 if (!transaction ||
2556 ref_transaction_delete(transaction, r->name, r->sha1,
2557 REF_ISPRUNING, 1, NULL, &err) ||
2558 ref_transaction_commit(transaction, &err)) {
2559 ref_transaction_free(transaction);
2560 error("%s", err.buf);
2561 strbuf_release(&err);
2562 return;
2564 ref_transaction_free(transaction);
2565 strbuf_release(&err);
2566 try_remove_empty_parents(r->name);
2569 static void prune_refs(struct ref_to_prune *r)
2571 while (r) {
2572 prune_ref(r);
2573 r = r->next;
2577 int pack_refs(unsigned int flags)
2579 struct pack_refs_cb_data cbdata;
2581 memset(&cbdata, 0, sizeof(cbdata));
2582 cbdata.flags = flags;
2584 lock_packed_refs(LOCK_DIE_ON_ERROR);
2585 cbdata.packed_refs = get_packed_refs(&ref_cache);
2587 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2588 pack_if_possible_fn, &cbdata);
2590 if (commit_packed_refs())
2591 die_errno("unable to overwrite old ref-pack file");
2593 prune_refs(cbdata.ref_to_prune);
2594 return 0;
2598 * If entry is no longer needed in packed-refs, add it to the string
2599 * list pointed to by cb_data. Reasons for deleting entries:
2601 * - Entry is broken.
2602 * - Entry is overridden by a loose ref.
2603 * - Entry does not point at a valid object.
2605 * In the first and third cases, also emit an error message because these
2606 * are indications of repository corruption.
2608 static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
2610 struct string_list *refs_to_delete = cb_data;
2612 if (entry->flag & REF_ISBROKEN) {
2613 /* This shouldn't happen to packed refs. */
2614 error("%s is broken!", entry->name);
2615 string_list_append(refs_to_delete, entry->name);
2616 return 0;
2618 if (!has_sha1_file(entry->u.value.sha1)) {
2619 unsigned char sha1[20];
2620 int flags;
2622 if (read_ref_full(entry->name, 0, sha1, &flags))
2623 /* We should at least have found the packed ref. */
2624 die("Internal error");
2625 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
2627 * This packed reference is overridden by a
2628 * loose reference, so it is OK that its value
2629 * is no longer valid; for example, it might
2630 * refer to an object that has been garbage
2631 * collected. For this purpose we don't even
2632 * care whether the loose reference itself is
2633 * invalid, broken, symbolic, etc. Silently
2634 * remove the packed reference.
2636 string_list_append(refs_to_delete, entry->name);
2637 return 0;
2640 * There is no overriding loose reference, so the fact
2641 * that this reference doesn't refer to a valid object
2642 * indicates some kind of repository corruption.
2643 * Report the problem, then omit the reference from
2644 * the output.
2646 error("%s does not point to a valid object!", entry->name);
2647 string_list_append(refs_to_delete, entry->name);
2648 return 0;
2651 return 0;
2654 int repack_without_refs(const char **refnames, int n, struct strbuf *err)
2656 struct ref_dir *packed;
2657 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2658 struct string_list_item *ref_to_delete;
2659 int i, ret, removed = 0;
2661 assert(err);
2663 /* Look for a packed ref */
2664 for (i = 0; i < n; i++)
2665 if (get_packed_ref(refnames[i]))
2666 break;
2668 /* Avoid locking if we have nothing to do */
2669 if (i == n)
2670 return 0; /* no refname exists in packed refs */
2672 if (lock_packed_refs(0)) {
2673 unable_to_lock_message(git_path("packed-refs"), errno, err);
2674 return -1;
2676 packed = get_packed_refs(&ref_cache);
2678 /* Remove refnames from the cache */
2679 for (i = 0; i < n; i++)
2680 if (remove_entry(packed, refnames[i]) != -1)
2681 removed = 1;
2682 if (!removed) {
2684 * All packed entries disappeared while we were
2685 * acquiring the lock.
2687 rollback_packed_refs();
2688 return 0;
2691 /* Remove any other accumulated cruft */
2692 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2693 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2694 if (remove_entry(packed, ref_to_delete->string) == -1)
2695 die("internal error");
2698 /* Write what remains */
2699 ret = commit_packed_refs();
2700 if (ret)
2701 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",
2702 strerror(errno));
2703 return ret;
2706 static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)
2708 assert(err);
2710 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2712 * loose. The loose file name is the same as the
2713 * lockfile name, minus ".lock":
2715 char *loose_filename = get_locked_file_path(lock->lk);
2716 int res = unlink_or_msg(loose_filename, err);
2717 free(loose_filename);
2718 if (res)
2719 return 1;
2721 return 0;
2724 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
2726 struct ref_transaction *transaction;
2727 struct strbuf err = STRBUF_INIT;
2729 transaction = ref_transaction_begin(&err);
2730 if (!transaction ||
2731 ref_transaction_delete(transaction, refname, sha1, delopt,
2732 sha1 && !is_null_sha1(sha1), NULL, &err) ||
2733 ref_transaction_commit(transaction, &err)) {
2734 error("%s", err.buf);
2735 ref_transaction_free(transaction);
2736 strbuf_release(&err);
2737 return 1;
2739 ref_transaction_free(transaction);
2740 strbuf_release(&err);
2741 return 0;
2745 * People using contrib's git-new-workdir have .git/logs/refs ->
2746 * /some/other/path/.git/logs/refs, and that may live on another device.
2748 * IOW, to avoid cross device rename errors, the temporary renamed log must
2749 * live into logs/refs.
2751 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2753 static int rename_tmp_log(const char *newrefname)
2755 int attempts_remaining = 4;
2757 retry:
2758 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2759 case SCLD_OK:
2760 break; /* success */
2761 case SCLD_VANISHED:
2762 if (--attempts_remaining > 0)
2763 goto retry;
2764 /* fall through */
2765 default:
2766 error("unable to create directory for %s", newrefname);
2767 return -1;
2770 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
2771 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
2773 * rename(a, b) when b is an existing
2774 * directory ought to result in ISDIR, but
2775 * Solaris 5.8 gives ENOTDIR. Sheesh.
2777 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2778 error("Directory not empty: logs/%s", newrefname);
2779 return -1;
2781 goto retry;
2782 } else if (errno == ENOENT && --attempts_remaining > 0) {
2784 * Maybe another process just deleted one of
2785 * the directories in the path to newrefname.
2786 * Try again from the beginning.
2788 goto retry;
2789 } else {
2790 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2791 newrefname, strerror(errno));
2792 return -1;
2795 return 0;
2798 static int rename_ref_available(const char *oldname, const char *newname)
2800 struct string_list skip = STRING_LIST_INIT_NODUP;
2801 int ret;
2803 string_list_insert(&skip, oldname);
2804 ret = is_refname_available(newname, &skip, get_packed_refs(&ref_cache))
2805 && is_refname_available(newname, &skip, get_loose_refs(&ref_cache));
2806 string_list_clear(&skip, 0);
2807 return ret;
2810 static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1,
2811 const char *logmsg);
2813 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
2815 unsigned char sha1[20], orig_sha1[20];
2816 int flag = 0, logmoved = 0;
2817 struct ref_lock *lock;
2818 struct stat loginfo;
2819 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2820 const char *symref = NULL;
2822 if (log && S_ISLNK(loginfo.st_mode))
2823 return error("reflog for %s is a symlink", oldrefname);
2825 symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,
2826 orig_sha1, &flag);
2827 if (flag & REF_ISSYMREF)
2828 return error("refname %s is a symbolic ref, renaming it is not supported",
2829 oldrefname);
2830 if (!symref)
2831 return error("refname %s not found", oldrefname);
2833 if (!rename_ref_available(oldrefname, newrefname))
2834 return 1;
2836 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2837 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2838 oldrefname, strerror(errno));
2840 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2841 error("unable to delete old %s", oldrefname);
2842 goto rollback;
2845 if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&
2846 delete_ref(newrefname, sha1, REF_NODEREF)) {
2847 if (errno==EISDIR) {
2848 if (remove_empty_directories(git_path("%s", newrefname))) {
2849 error("Directory not empty: %s", newrefname);
2850 goto rollback;
2852 } else {
2853 error("unable to delete existing %s", newrefname);
2854 goto rollback;
2858 if (log && rename_tmp_log(newrefname))
2859 goto rollback;
2861 logmoved = log;
2863 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, 0, NULL);
2864 if (!lock) {
2865 error("unable to lock %s for update", newrefname);
2866 goto rollback;
2868 lock->force_write = 1;
2869 hashcpy(lock->old_sha1, orig_sha1);
2870 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
2871 error("unable to write current sha1 into %s", newrefname);
2872 goto rollback;
2875 return 0;
2877 rollback:
2878 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, 0, NULL);
2879 if (!lock) {
2880 error("unable to lock %s for rollback", oldrefname);
2881 goto rollbacklog;
2884 lock->force_write = 1;
2885 flag = log_all_ref_updates;
2886 log_all_ref_updates = 0;
2887 if (write_ref_sha1(lock, orig_sha1, NULL))
2888 error("unable to write current sha1 into %s", oldrefname);
2889 log_all_ref_updates = flag;
2891 rollbacklog:
2892 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2893 error("unable to restore logfile %s from %s: %s",
2894 oldrefname, newrefname, strerror(errno));
2895 if (!logmoved && log &&
2896 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2897 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2898 oldrefname, strerror(errno));
2900 return 1;
2903 static int close_ref(struct ref_lock *lock)
2905 if (close_lock_file(lock->lk))
2906 return -1;
2907 lock->lock_fd = -1;
2908 return 0;
2911 static int commit_ref(struct ref_lock *lock)
2913 if (commit_lock_file(lock->lk))
2914 return -1;
2915 lock->lock_fd = -1;
2916 return 0;
2920 * copy the reflog message msg to buf, which has been allocated sufficiently
2921 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2922 * because reflog file is one line per entry.
2924 static int copy_msg(char *buf, const char *msg)
2926 char *cp = buf;
2927 char c;
2928 int wasspace = 1;
2930 *cp++ = '\t';
2931 while ((c = *msg++)) {
2932 if (wasspace && isspace(c))
2933 continue;
2934 wasspace = isspace(c);
2935 if (wasspace)
2936 c = ' ';
2937 *cp++ = c;
2939 while (buf < cp && isspace(cp[-1]))
2940 cp--;
2941 *cp++ = '\n';
2942 return cp - buf;
2945 /* This function must set a meaningful errno on failure */
2946 int log_ref_setup(const char *refname, char *logfile, int bufsize)
2948 int logfd, oflags = O_APPEND | O_WRONLY;
2950 git_snpath(logfile, bufsize, "logs/%s", refname);
2951 if (log_all_ref_updates &&
2952 (starts_with(refname, "refs/heads/") ||
2953 starts_with(refname, "refs/remotes/") ||
2954 starts_with(refname, "refs/notes/") ||
2955 !strcmp(refname, "HEAD"))) {
2956 if (safe_create_leading_directories(logfile) < 0) {
2957 int save_errno = errno;
2958 error("unable to create directory for %s", logfile);
2959 errno = save_errno;
2960 return -1;
2962 oflags |= O_CREAT;
2965 logfd = open(logfile, oflags, 0666);
2966 if (logfd < 0) {
2967 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))
2968 return 0;
2970 if (errno == EISDIR) {
2971 if (remove_empty_directories(logfile)) {
2972 int save_errno = errno;
2973 error("There are still logs under '%s'",
2974 logfile);
2975 errno = save_errno;
2976 return -1;
2978 logfd = open(logfile, oflags, 0666);
2981 if (logfd < 0) {
2982 int save_errno = errno;
2983 error("Unable to append to %s: %s", logfile,
2984 strerror(errno));
2985 errno = save_errno;
2986 return -1;
2990 adjust_shared_perm(logfile);
2991 close(logfd);
2992 return 0;
2995 static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
2996 const unsigned char *new_sha1,
2997 const char *committer, const char *msg)
2999 int msglen, written;
3000 unsigned maxlen, len;
3001 char *logrec;
3003 msglen = msg ? strlen(msg) : 0;
3004 maxlen = strlen(committer) + msglen + 100;
3005 logrec = xmalloc(maxlen);
3006 len = sprintf(logrec, "%s %s %s\n",
3007 sha1_to_hex(old_sha1),
3008 sha1_to_hex(new_sha1),
3009 committer);
3010 if (msglen)
3011 len += copy_msg(logrec + len - 1, msg) - 1;
3013 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;
3014 free(logrec);
3015 if (written != len)
3016 return -1;
3018 return 0;
3021 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
3022 const unsigned char *new_sha1, const char *msg)
3024 int logfd, result, oflags = O_APPEND | O_WRONLY;
3025 char log_file[PATH_MAX];
3027 if (log_all_ref_updates < 0)
3028 log_all_ref_updates = !is_bare_repository();
3030 result = log_ref_setup(refname, log_file, sizeof(log_file));
3031 if (result)
3032 return result;
3034 logfd = open(log_file, oflags);
3035 if (logfd < 0)
3036 return 0;
3037 result = log_ref_write_fd(logfd, old_sha1, new_sha1,
3038 git_committer_info(0), msg);
3039 if (result) {
3040 int save_errno = errno;
3041 close(logfd);
3042 error("Unable to append to %s", log_file);
3043 errno = save_errno;
3044 return -1;
3046 if (close(logfd)) {
3047 int save_errno = errno;
3048 error("Unable to append to %s", log_file);
3049 errno = save_errno;
3050 return -1;
3052 return 0;
3055 int is_branch(const char *refname)
3057 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
3061 * Write sha1 into the ref specified by the lock. Make sure that errno
3062 * is sane on error.
3064 static int write_ref_sha1(struct ref_lock *lock,
3065 const unsigned char *sha1, const char *logmsg)
3067 static char term = '\n';
3068 struct object *o;
3070 if (!lock) {
3071 errno = EINVAL;
3072 return -1;
3074 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
3075 unlock_ref(lock);
3076 return 0;
3078 o = parse_object(sha1);
3079 if (!o) {
3080 error("Trying to write ref %s with nonexistent object %s",
3081 lock->ref_name, sha1_to_hex(sha1));
3082 unlock_ref(lock);
3083 errno = EINVAL;
3084 return -1;
3086 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
3087 error("Trying to write non-commit object %s to branch %s",
3088 sha1_to_hex(sha1), lock->ref_name);
3089 unlock_ref(lock);
3090 errno = EINVAL;
3091 return -1;
3093 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
3094 write_in_full(lock->lock_fd, &term, 1) != 1 ||
3095 close_ref(lock) < 0) {
3096 int save_errno = errno;
3097 error("Couldn't write %s", lock->lk->filename.buf);
3098 unlock_ref(lock);
3099 errno = save_errno;
3100 return -1;
3102 clear_loose_ref_cache(&ref_cache);
3103 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
3104 (strcmp(lock->ref_name, lock->orig_ref_name) &&
3105 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
3106 unlock_ref(lock);
3107 return -1;
3109 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
3111 * Special hack: If a branch is updated directly and HEAD
3112 * points to it (may happen on the remote side of a push
3113 * for example) then logically the HEAD reflog should be
3114 * updated too.
3115 * A generic solution implies reverse symref information,
3116 * but finding all symrefs pointing to the given branch
3117 * would be rather costly for this rare event (the direct
3118 * update of a branch) to be worth it. So let's cheat and
3119 * check with HEAD only which should cover 99% of all usage
3120 * scenarios (even 100% of the default ones).
3122 unsigned char head_sha1[20];
3123 int head_flag;
3124 const char *head_ref;
3125 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
3126 head_sha1, &head_flag);
3127 if (head_ref && (head_flag & REF_ISSYMREF) &&
3128 !strcmp(head_ref, lock->ref_name))
3129 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
3131 if (commit_ref(lock)) {
3132 error("Couldn't set %s", lock->ref_name);
3133 unlock_ref(lock);
3134 return -1;
3136 unlock_ref(lock);
3137 return 0;
3140 int create_symref(const char *ref_target, const char *refs_heads_master,
3141 const char *logmsg)
3143 const char *lockpath;
3144 char ref[1000];
3145 int fd, len, written;
3146 char *git_HEAD = git_pathdup("%s", ref_target);
3147 unsigned char old_sha1[20], new_sha1[20];
3149 if (logmsg && read_ref(ref_target, old_sha1))
3150 hashclr(old_sha1);
3152 if (safe_create_leading_directories(git_HEAD) < 0)
3153 return error("unable to create directory for %s", git_HEAD);
3155 #ifndef NO_SYMLINK_HEAD
3156 if (prefer_symlink_refs) {
3157 unlink(git_HEAD);
3158 if (!symlink(refs_heads_master, git_HEAD))
3159 goto done;
3160 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
3162 #endif
3164 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
3165 if (sizeof(ref) <= len) {
3166 error("refname too long: %s", refs_heads_master);
3167 goto error_free_return;
3169 lockpath = mkpath("%s.lock", git_HEAD);
3170 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
3171 if (fd < 0) {
3172 error("Unable to open %s for writing", lockpath);
3173 goto error_free_return;
3175 written = write_in_full(fd, ref, len);
3176 if (close(fd) != 0 || written != len) {
3177 error("Unable to write to %s", lockpath);
3178 goto error_unlink_return;
3180 if (rename(lockpath, git_HEAD) < 0) {
3181 error("Unable to create %s", git_HEAD);
3182 goto error_unlink_return;
3184 if (adjust_shared_perm(git_HEAD)) {
3185 error("Unable to fix permissions on %s", lockpath);
3186 error_unlink_return:
3187 unlink_or_warn(lockpath);
3188 error_free_return:
3189 free(git_HEAD);
3190 return -1;
3193 #ifndef NO_SYMLINK_HEAD
3194 done:
3195 #endif
3196 if (logmsg && !read_ref(refs_heads_master, new_sha1))
3197 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
3199 free(git_HEAD);
3200 return 0;
3203 struct read_ref_at_cb {
3204 const char *refname;
3205 unsigned long at_time;
3206 int cnt;
3207 int reccnt;
3208 unsigned char *sha1;
3209 int found_it;
3211 unsigned char osha1[20];
3212 unsigned char nsha1[20];
3213 int tz;
3214 unsigned long date;
3215 char **msg;
3216 unsigned long *cutoff_time;
3217 int *cutoff_tz;
3218 int *cutoff_cnt;
3221 static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
3222 const char *email, unsigned long timestamp, int tz,
3223 const char *message, void *cb_data)
3225 struct read_ref_at_cb *cb = cb_data;
3227 cb->reccnt++;
3228 cb->tz = tz;
3229 cb->date = timestamp;
3231 if (timestamp <= cb->at_time || cb->cnt == 0) {
3232 if (cb->msg)
3233 *cb->msg = xstrdup(message);
3234 if (cb->cutoff_time)
3235 *cb->cutoff_time = timestamp;
3236 if (cb->cutoff_tz)
3237 *cb->cutoff_tz = tz;
3238 if (cb->cutoff_cnt)
3239 *cb->cutoff_cnt = cb->reccnt - 1;
3241 * we have not yet updated cb->[n|o]sha1 so they still
3242 * hold the values for the previous record.
3244 if (!is_null_sha1(cb->osha1)) {
3245 hashcpy(cb->sha1, nsha1);
3246 if (hashcmp(cb->osha1, nsha1))
3247 warning("Log for ref %s has gap after %s.",
3248 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));
3250 else if (cb->date == cb->at_time)
3251 hashcpy(cb->sha1, nsha1);
3252 else if (hashcmp(nsha1, cb->sha1))
3253 warning("Log for ref %s unexpectedly ended on %s.",
3254 cb->refname, show_date(cb->date, cb->tz,
3255 DATE_RFC2822));
3256 hashcpy(cb->osha1, osha1);
3257 hashcpy(cb->nsha1, nsha1);
3258 cb->found_it = 1;
3259 return 1;
3261 hashcpy(cb->osha1, osha1);
3262 hashcpy(cb->nsha1, nsha1);
3263 if (cb->cnt > 0)
3264 cb->cnt--;
3265 return 0;
3268 static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
3269 const char *email, unsigned long timestamp,
3270 int tz, const char *message, void *cb_data)
3272 struct read_ref_at_cb *cb = cb_data;
3274 if (cb->msg)
3275 *cb->msg = xstrdup(message);
3276 if (cb->cutoff_time)
3277 *cb->cutoff_time = timestamp;
3278 if (cb->cutoff_tz)
3279 *cb->cutoff_tz = tz;
3280 if (cb->cutoff_cnt)
3281 *cb->cutoff_cnt = cb->reccnt;
3282 hashcpy(cb->sha1, osha1);
3283 if (is_null_sha1(cb->sha1))
3284 hashcpy(cb->sha1, nsha1);
3285 /* We just want the first entry */
3286 return 1;
3289 int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt,
3290 unsigned char *sha1, char **msg,
3291 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
3293 struct read_ref_at_cb cb;
3295 memset(&cb, 0, sizeof(cb));
3296 cb.refname = refname;
3297 cb.at_time = at_time;
3298 cb.cnt = cnt;
3299 cb.msg = msg;
3300 cb.cutoff_time = cutoff_time;
3301 cb.cutoff_tz = cutoff_tz;
3302 cb.cutoff_cnt = cutoff_cnt;
3303 cb.sha1 = sha1;
3305 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
3307 if (!cb.reccnt) {
3308 if (flags & GET_SHA1_QUIETLY)
3309 exit(128);
3310 else
3311 die("Log for %s is empty.", refname);
3313 if (cb.found_it)
3314 return 0;
3316 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
3318 return 1;
3321 int reflog_exists(const char *refname)
3323 struct stat st;
3325 return !lstat(git_path("logs/%s", refname), &st) &&
3326 S_ISREG(st.st_mode);
3329 int delete_reflog(const char *refname)
3331 return remove_path(git_path("logs/%s", refname));
3334 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3336 unsigned char osha1[20], nsha1[20];
3337 char *email_end, *message;
3338 unsigned long timestamp;
3339 int tz;
3341 /* old SP new SP name <email> SP time TAB msg LF */
3342 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3343 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3344 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3345 !(email_end = strchr(sb->buf + 82, '>')) ||
3346 email_end[1] != ' ' ||
3347 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3348 !message || message[0] != ' ' ||
3349 (message[1] != '+' && message[1] != '-') ||
3350 !isdigit(message[2]) || !isdigit(message[3]) ||
3351 !isdigit(message[4]) || !isdigit(message[5]))
3352 return 0; /* corrupt? */
3353 email_end[1] = '\0';
3354 tz = strtol(message + 1, NULL, 10);
3355 if (message[6] != '\t')
3356 message += 6;
3357 else
3358 message += 7;
3359 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3362 static char *find_beginning_of_line(char *bob, char *scan)
3364 while (bob < scan && *(--scan) != '\n')
3365 ; /* keep scanning backwards */
3367 * Return either beginning of the buffer, or LF at the end of
3368 * the previous line.
3370 return scan;
3373 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3375 struct strbuf sb = STRBUF_INIT;
3376 FILE *logfp;
3377 long pos;
3378 int ret = 0, at_tail = 1;
3380 logfp = fopen(git_path("logs/%s", refname), "r");
3381 if (!logfp)
3382 return -1;
3384 /* Jump to the end */
3385 if (fseek(logfp, 0, SEEK_END) < 0)
3386 return error("cannot seek back reflog for %s: %s",
3387 refname, strerror(errno));
3388 pos = ftell(logfp);
3389 while (!ret && 0 < pos) {
3390 int cnt;
3391 size_t nread;
3392 char buf[BUFSIZ];
3393 char *endp, *scanp;
3395 /* Fill next block from the end */
3396 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3397 if (fseek(logfp, pos - cnt, SEEK_SET))
3398 return error("cannot seek back reflog for %s: %s",
3399 refname, strerror(errno));
3400 nread = fread(buf, cnt, 1, logfp);
3401 if (nread != 1)
3402 return error("cannot read %d bytes from reflog for %s: %s",
3403 cnt, refname, strerror(errno));
3404 pos -= cnt;
3406 scanp = endp = buf + cnt;
3407 if (at_tail && scanp[-1] == '\n')
3408 /* Looking at the final LF at the end of the file */
3409 scanp--;
3410 at_tail = 0;
3412 while (buf < scanp) {
3414 * terminating LF of the previous line, or the beginning
3415 * of the buffer.
3417 char *bp;
3419 bp = find_beginning_of_line(buf, scanp);
3421 if (*bp != '\n') {
3422 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3423 if (pos)
3424 break; /* need to fill another block */
3425 scanp = buf - 1; /* leave loop */
3426 } else {
3428 * (bp + 1) thru endp is the beginning of the
3429 * current line we have in sb
3431 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3432 scanp = bp;
3433 endp = bp + 1;
3435 ret = show_one_reflog_ent(&sb, fn, cb_data);
3436 strbuf_reset(&sb);
3437 if (ret)
3438 break;
3442 if (!ret && sb.len)
3443 ret = show_one_reflog_ent(&sb, fn, cb_data);
3445 fclose(logfp);
3446 strbuf_release(&sb);
3447 return ret;
3450 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3452 FILE *logfp;
3453 struct strbuf sb = STRBUF_INIT;
3454 int ret = 0;
3456 logfp = fopen(git_path("logs/%s", refname), "r");
3457 if (!logfp)
3458 return -1;
3460 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3461 ret = show_one_reflog_ent(&sb, fn, cb_data);
3462 fclose(logfp);
3463 strbuf_release(&sb);
3464 return ret;
3467 * Call fn for each reflog in the namespace indicated by name. name
3468 * must be empty or end with '/'. Name will be used as a scratch
3469 * space, but its contents will be restored before return.
3471 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
3473 DIR *d = opendir(git_path("logs/%s", name->buf));
3474 int retval = 0;
3475 struct dirent *de;
3476 int oldlen = name->len;
3478 if (!d)
3479 return name->len ? errno : 0;
3481 while ((de = readdir(d)) != NULL) {
3482 struct stat st;
3484 if (de->d_name[0] == '.')
3485 continue;
3486 if (ends_with(de->d_name, ".lock"))
3487 continue;
3488 strbuf_addstr(name, de->d_name);
3489 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3490 ; /* silently ignore */
3491 } else {
3492 if (S_ISDIR(st.st_mode)) {
3493 strbuf_addch(name, '/');
3494 retval = do_for_each_reflog(name, fn, cb_data);
3495 } else {
3496 unsigned char sha1[20];
3497 if (read_ref_full(name->buf, 0, sha1, NULL))
3498 retval = error("bad ref for %s", name->buf);
3499 else
3500 retval = fn(name->buf, sha1, 0, cb_data);
3502 if (retval)
3503 break;
3505 strbuf_setlen(name, oldlen);
3507 closedir(d);
3508 return retval;
3511 int for_each_reflog(each_ref_fn fn, void *cb_data)
3513 int retval;
3514 struct strbuf name;
3515 strbuf_init(&name, PATH_MAX);
3516 retval = do_for_each_reflog(&name, fn, cb_data);
3517 strbuf_release(&name);
3518 return retval;
3522 * Information needed for a single ref update. Set new_sha1 to the
3523 * new value or to zero to delete the ref. To check the old value
3524 * while locking the ref, set have_old to 1 and set old_sha1 to the
3525 * value or to zero to ensure the ref does not exist before update.
3527 struct ref_update {
3528 unsigned char new_sha1[20];
3529 unsigned char old_sha1[20];
3530 int flags; /* REF_NODEREF? */
3531 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
3532 struct ref_lock *lock;
3533 int type;
3534 char *msg;
3535 const char refname[FLEX_ARRAY];
3539 * Transaction states.
3540 * OPEN: The transaction is in a valid state and can accept new updates.
3541 * An OPEN transaction can be committed.
3542 * CLOSED: A closed transaction is no longer active and no other operations
3543 * than free can be used on it in this state.
3544 * A transaction can either become closed by successfully committing
3545 * an active transaction or if there is a failure while building
3546 * the transaction thus rendering it failed/inactive.
3548 enum ref_transaction_state {
3549 REF_TRANSACTION_OPEN = 0,
3550 REF_TRANSACTION_CLOSED = 1
3554 * Data structure for holding a reference transaction, which can
3555 * consist of checks and updates to multiple references, carried out
3556 * as atomically as possible. This structure is opaque to callers.
3558 struct ref_transaction {
3559 struct ref_update **updates;
3560 size_t alloc;
3561 size_t nr;
3562 enum ref_transaction_state state;
3565 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
3567 assert(err);
3569 return xcalloc(1, sizeof(struct ref_transaction));
3572 void ref_transaction_free(struct ref_transaction *transaction)
3574 int i;
3576 if (!transaction)
3577 return;
3579 for (i = 0; i < transaction->nr; i++) {
3580 free(transaction->updates[i]->msg);
3581 free(transaction->updates[i]);
3583 free(transaction->updates);
3584 free(transaction);
3587 static struct ref_update *add_update(struct ref_transaction *transaction,
3588 const char *refname)
3590 size_t len = strlen(refname);
3591 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
3593 strcpy((char *)update->refname, refname);
3594 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
3595 transaction->updates[transaction->nr++] = update;
3596 return update;
3599 int ref_transaction_update(struct ref_transaction *transaction,
3600 const char *refname,
3601 const unsigned char *new_sha1,
3602 const unsigned char *old_sha1,
3603 int flags, int have_old, const char *msg,
3604 struct strbuf *err)
3606 struct ref_update *update;
3608 assert(err);
3610 if (transaction->state != REF_TRANSACTION_OPEN)
3611 die("BUG: update called for transaction that is not open");
3613 if (have_old && !old_sha1)
3614 die("BUG: have_old is true but old_sha1 is NULL");
3616 if (!is_null_sha1(new_sha1) &&
3617 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
3618 strbuf_addf(err, "refusing to update ref with bad name %s",
3619 refname);
3620 return -1;
3623 update = add_update(transaction, refname);
3624 hashcpy(update->new_sha1, new_sha1);
3625 update->flags = flags;
3626 update->have_old = have_old;
3627 if (have_old)
3628 hashcpy(update->old_sha1, old_sha1);
3629 if (msg)
3630 update->msg = xstrdup(msg);
3631 return 0;
3634 int ref_transaction_create(struct ref_transaction *transaction,
3635 const char *refname,
3636 const unsigned char *new_sha1,
3637 int flags, const char *msg,
3638 struct strbuf *err)
3640 return ref_transaction_update(transaction, refname, new_sha1,
3641 null_sha1, flags, 1, msg, err);
3644 int ref_transaction_delete(struct ref_transaction *transaction,
3645 const char *refname,
3646 const unsigned char *old_sha1,
3647 int flags, int have_old, const char *msg,
3648 struct strbuf *err)
3650 return ref_transaction_update(transaction, refname, null_sha1,
3651 old_sha1, flags, have_old, msg, err);
3654 int update_ref(const char *action, const char *refname,
3655 const unsigned char *sha1, const unsigned char *oldval,
3656 int flags, enum action_on_err onerr)
3658 struct ref_transaction *t;
3659 struct strbuf err = STRBUF_INIT;
3661 t = ref_transaction_begin(&err);
3662 if (!t ||
3663 ref_transaction_update(t, refname, sha1, oldval, flags,
3664 !!oldval, action, &err) ||
3665 ref_transaction_commit(t, &err)) {
3666 const char *str = "update_ref failed for ref '%s': %s";
3668 ref_transaction_free(t);
3669 switch (onerr) {
3670 case UPDATE_REFS_MSG_ON_ERR:
3671 error(str, refname, err.buf);
3672 break;
3673 case UPDATE_REFS_DIE_ON_ERR:
3674 die(str, refname, err.buf);
3675 break;
3676 case UPDATE_REFS_QUIET_ON_ERR:
3677 break;
3679 strbuf_release(&err);
3680 return 1;
3682 strbuf_release(&err);
3683 ref_transaction_free(t);
3684 return 0;
3687 static int ref_update_compare(const void *r1, const void *r2)
3689 const struct ref_update * const *u1 = r1;
3690 const struct ref_update * const *u2 = r2;
3691 return strcmp((*u1)->refname, (*u2)->refname);
3694 static int ref_update_reject_duplicates(struct ref_update **updates, int n,
3695 struct strbuf *err)
3697 int i;
3699 assert(err);
3701 for (i = 1; i < n; i++)
3702 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
3703 strbuf_addf(err,
3704 "Multiple updates for ref '%s' not allowed.",
3705 updates[i]->refname);
3706 return 1;
3708 return 0;
3711 int ref_transaction_commit(struct ref_transaction *transaction,
3712 struct strbuf *err)
3714 int ret = 0, delnum = 0, i;
3715 const char **delnames;
3716 int n = transaction->nr;
3717 struct ref_update **updates = transaction->updates;
3719 assert(err);
3721 if (transaction->state != REF_TRANSACTION_OPEN)
3722 die("BUG: commit called for transaction that is not open");
3724 if (!n) {
3725 transaction->state = REF_TRANSACTION_CLOSED;
3726 return 0;
3729 /* Allocate work space */
3730 delnames = xmalloc(sizeof(*delnames) * n);
3732 /* Copy, sort, and reject duplicate refs */
3733 qsort(updates, n, sizeof(*updates), ref_update_compare);
3734 if (ref_update_reject_duplicates(updates, n, err)) {
3735 ret = TRANSACTION_GENERIC_ERROR;
3736 goto cleanup;
3739 /* Acquire all locks while verifying old values */
3740 for (i = 0; i < n; i++) {
3741 struct ref_update *update = updates[i];
3742 int flags = update->flags;
3744 if (is_null_sha1(update->new_sha1))
3745 flags |= REF_DELETING;
3746 update->lock = lock_ref_sha1_basic(update->refname,
3747 (update->have_old ?
3748 update->old_sha1 :
3749 NULL),
3750 NULL,
3751 flags,
3752 &update->type);
3753 if (!update->lock) {
3754 ret = (errno == ENOTDIR)
3755 ? TRANSACTION_NAME_CONFLICT
3756 : TRANSACTION_GENERIC_ERROR;
3757 strbuf_addf(err, "Cannot lock the ref '%s'.",
3758 update->refname);
3759 goto cleanup;
3763 /* Perform updates first so live commits remain referenced */
3764 for (i = 0; i < n; i++) {
3765 struct ref_update *update = updates[i];
3767 if (!is_null_sha1(update->new_sha1)) {
3768 if (write_ref_sha1(update->lock, update->new_sha1,
3769 update->msg)) {
3770 update->lock = NULL; /* freed by write_ref_sha1 */
3771 strbuf_addf(err, "Cannot update the ref '%s'.",
3772 update->refname);
3773 ret = TRANSACTION_GENERIC_ERROR;
3774 goto cleanup;
3776 update->lock = NULL; /* freed by write_ref_sha1 */
3780 /* Perform deletes now that updates are safely completed */
3781 for (i = 0; i < n; i++) {
3782 struct ref_update *update = updates[i];
3784 if (update->lock) {
3785 if (delete_ref_loose(update->lock, update->type, err)) {
3786 ret = TRANSACTION_GENERIC_ERROR;
3787 goto cleanup;
3790 if (!(update->flags & REF_ISPRUNING))
3791 delnames[delnum++] = update->lock->ref_name;
3795 if (repack_without_refs(delnames, delnum, err)) {
3796 ret = TRANSACTION_GENERIC_ERROR;
3797 goto cleanup;
3799 for (i = 0; i < delnum; i++)
3800 unlink_or_warn(git_path("logs/%s", delnames[i]));
3801 clear_loose_ref_cache(&ref_cache);
3803 cleanup:
3804 transaction->state = REF_TRANSACTION_CLOSED;
3806 for (i = 0; i < n; i++)
3807 if (updates[i]->lock)
3808 unlock_ref(updates[i]->lock);
3809 free(delnames);
3810 return ret;
3813 char *shorten_unambiguous_ref(const char *refname, int strict)
3815 int i;
3816 static char **scanf_fmts;
3817 static int nr_rules;
3818 char *short_name;
3820 if (!nr_rules) {
3822 * Pre-generate scanf formats from ref_rev_parse_rules[].
3823 * Generate a format suitable for scanf from a
3824 * ref_rev_parse_rules rule by interpolating "%s" at the
3825 * location of the "%.*s".
3827 size_t total_len = 0;
3828 size_t offset = 0;
3830 /* the rule list is NULL terminated, count them first */
3831 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
3832 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
3833 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
3835 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3837 offset = 0;
3838 for (i = 0; i < nr_rules; i++) {
3839 assert(offset < total_len);
3840 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
3841 offset += snprintf(scanf_fmts[i], total_len - offset,
3842 ref_rev_parse_rules[i], 2, "%s") + 1;
3846 /* bail out if there are no rules */
3847 if (!nr_rules)
3848 return xstrdup(refname);
3850 /* buffer for scanf result, at most refname must fit */
3851 short_name = xstrdup(refname);
3853 /* skip first rule, it will always match */
3854 for (i = nr_rules - 1; i > 0 ; --i) {
3855 int j;
3856 int rules_to_fail = i;
3857 int short_name_len;
3859 if (1 != sscanf(refname, scanf_fmts[i], short_name))
3860 continue;
3862 short_name_len = strlen(short_name);
3865 * in strict mode, all (except the matched one) rules
3866 * must fail to resolve to a valid non-ambiguous ref
3868 if (strict)
3869 rules_to_fail = nr_rules;
3872 * check if the short name resolves to a valid ref,
3873 * but use only rules prior to the matched one
3875 for (j = 0; j < rules_to_fail; j++) {
3876 const char *rule = ref_rev_parse_rules[j];
3877 char refname[PATH_MAX];
3879 /* skip matched rule */
3880 if (i == j)
3881 continue;
3884 * the short name is ambiguous, if it resolves
3885 * (with this previous rule) to a valid ref
3886 * read_ref() returns 0 on success
3888 mksnpath(refname, sizeof(refname),
3889 rule, short_name_len, short_name);
3890 if (ref_exists(refname))
3891 break;
3895 * short name is non-ambiguous if all previous rules
3896 * haven't resolved to a valid ref
3898 if (j == rules_to_fail)
3899 return short_name;
3902 free(short_name);
3903 return xstrdup(refname);
3906 static struct string_list *hide_refs;
3908 int parse_hide_refs_config(const char *var, const char *value, const char *section)
3910 if (!strcmp("transfer.hiderefs", var) ||
3911 /* NEEDSWORK: use parse_config_key() once both are merged */
3912 (starts_with(var, section) && var[strlen(section)] == '.' &&
3913 !strcmp(var + strlen(section), ".hiderefs"))) {
3914 char *ref;
3915 int len;
3917 if (!value)
3918 return config_error_nonbool(var);
3919 ref = xstrdup(value);
3920 len = strlen(ref);
3921 while (len && ref[len - 1] == '/')
3922 ref[--len] = '\0';
3923 if (!hide_refs) {
3924 hide_refs = xcalloc(1, sizeof(*hide_refs));
3925 hide_refs->strdup_strings = 1;
3927 string_list_append(hide_refs, ref);
3929 return 0;
3932 int ref_is_hidden(const char *refname)
3934 struct string_list_item *item;
3936 if (!hide_refs)
3937 return 0;
3938 for_each_string_list_item(item, hide_refs) {
3939 int len;
3940 if (!starts_with(refname, item->string))
3941 continue;
3942 len = strlen(item->string);
3943 if (!refname[len] || refname[len] == '/')
3944 return 1;
3946 return 0;
3949 struct expire_reflog_cb {
3950 unsigned int flags;
3951 reflog_expiry_should_prune_fn *should_prune_fn;
3952 void *policy_cb;
3953 FILE *newlog;
3954 unsigned char last_kept_sha1[20];
3957 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
3958 const char *email, unsigned long timestamp, int tz,
3959 const char *message, void *cb_data)
3961 struct expire_reflog_cb *cb = cb_data;
3962 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
3964 if (cb->flags & EXPIRE_REFLOGS_REWRITE)
3965 osha1 = cb->last_kept_sha1;
3967 if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,
3968 message, policy_cb)) {
3969 if (!cb->newlog)
3970 printf("would prune %s", message);
3971 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3972 printf("prune %s", message);
3973 } else {
3974 if (cb->newlog) {
3975 char sign = (tz < 0) ? '-' : '+';
3976 int zone = (tz < 0) ? (-tz) : tz;
3977 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
3978 sha1_to_hex(osha1), sha1_to_hex(nsha1),
3979 email, timestamp, sign, zone,
3980 message);
3981 hashcpy(cb->last_kept_sha1, nsha1);
3983 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
3984 printf("keep %s", message);
3986 return 0;
3989 int reflog_expire(const char *refname, const unsigned char *sha1,
3990 unsigned int flags,
3991 reflog_expiry_prepare_fn prepare_fn,
3992 reflog_expiry_should_prune_fn should_prune_fn,
3993 reflog_expiry_cleanup_fn cleanup_fn,
3994 void *policy_cb_data)
3996 static struct lock_file reflog_lock;
3997 struct expire_reflog_cb cb;
3998 struct ref_lock *lock;
3999 char *log_file;
4000 int status = 0;
4002 memset(&cb, 0, sizeof(cb));
4003 cb.flags = flags;
4004 cb.policy_cb = policy_cb_data;
4005 cb.should_prune_fn = should_prune_fn;
4008 * The reflog file is locked by holding the lock on the
4009 * reference itself, plus we might need to update the
4010 * reference if --updateref was specified:
4012 lock = lock_ref_sha1_basic(refname, sha1, NULL, 0, NULL);
4013 if (!lock)
4014 return error("cannot lock ref '%s'", refname);
4015 if (!reflog_exists(refname)) {
4016 unlock_ref(lock);
4017 return 0;
4020 log_file = git_pathdup("logs/%s", refname);
4021 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
4023 * Even though holding $GIT_DIR/logs/$reflog.lock has
4024 * no locking implications, we use the lock_file
4025 * machinery here anyway because it does a lot of the
4026 * work we need, including cleaning up if the program
4027 * exits unexpectedly.
4029 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
4030 struct strbuf err = STRBUF_INIT;
4031 unable_to_lock_message(log_file, errno, &err);
4032 error("%s", err.buf);
4033 strbuf_release(&err);
4034 goto failure;
4036 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
4037 if (!cb.newlog) {
4038 error("cannot fdopen %s (%s)",
4039 reflog_lock.filename.buf, strerror(errno));
4040 goto failure;
4044 (*prepare_fn)(refname, sha1, cb.policy_cb);
4045 for_each_reflog_ent(refname, expire_reflog_ent, &cb);
4046 (*cleanup_fn)(cb.policy_cb);
4048 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
4049 if (close_lock_file(&reflog_lock)) {
4050 status |= error("couldn't write %s: %s", log_file,
4051 strerror(errno));
4052 } else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) &&
4053 (write_in_full(lock->lock_fd,
4054 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
4055 write_str_in_full(lock->lock_fd, "\n") != 1 ||
4056 close_ref(lock) < 0)) {
4057 status |= error("couldn't write %s",
4058 lock->lk->filename.buf);
4059 rollback_lock_file(&reflog_lock);
4060 } else if (commit_lock_file(&reflog_lock)) {
4061 status |= error("unable to commit reflog '%s' (%s)",
4062 log_file, strerror(errno));
4063 } else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) && commit_ref(lock)) {
4064 status |= error("couldn't set %s", lock->ref_name);
4067 free(log_file);
4068 unlock_ref(lock);
4069 return status;
4071 failure:
4072 rollback_lock_file(&reflog_lock);
4073 free(log_file);
4074 unlock_ref(lock);
4075 return -1;