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[git/mjg.git] / refs.c
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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(struct strbuf *line, unsigned char *sha1)
1082 const char *ref;
1085 * 42: the answer to everything.
1087 * In this case, it happens to be the answer to
1088 * 40 (length of sha1 hex representation)
1089 * +1 (space in between hex and name)
1090 * +1 (newline at the end of the line)
1092 if (line->len <= 42)
1093 return NULL;
1095 if (get_sha1_hex(line->buf, sha1) < 0)
1096 return NULL;
1097 if (!isspace(line->buf[40]))
1098 return NULL;
1100 ref = line->buf + 41;
1101 if (isspace(*ref))
1102 return NULL;
1104 if (line->buf[line->len - 1] != '\n')
1105 return NULL;
1106 line->buf[--line->len] = 0;
1108 return ref;
1112 * Read f, which is a packed-refs file, into dir.
1114 * A comment line of the form "# pack-refs with: " may contain zero or
1115 * more traits. We interpret the traits as follows:
1117 * No traits:
1119 * Probably no references are peeled. But if the file contains a
1120 * peeled value for a reference, we will use it.
1122 * peeled:
1124 * References under "refs/tags/", if they *can* be peeled, *are*
1125 * peeled in this file. References outside of "refs/tags/" are
1126 * probably not peeled even if they could have been, but if we find
1127 * a peeled value for such a reference we will use it.
1129 * fully-peeled:
1131 * All references in the file that can be peeled are peeled.
1132 * Inversely (and this is more important), any references in the
1133 * file for which no peeled value is recorded is not peelable. This
1134 * trait should typically be written alongside "peeled" for
1135 * compatibility with older clients, but we do not require it
1136 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1138 static void read_packed_refs(FILE *f, struct ref_dir *dir)
1140 struct ref_entry *last = NULL;
1141 struct strbuf line = STRBUF_INIT;
1142 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1144 while (strbuf_getwholeline(&line, f, '\n') != EOF) {
1145 unsigned char sha1[20];
1146 const char *refname;
1147 const char *traits;
1149 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {
1150 if (strstr(traits, " fully-peeled "))
1151 peeled = PEELED_FULLY;
1152 else if (strstr(traits, " peeled "))
1153 peeled = PEELED_TAGS;
1154 /* perhaps other traits later as well */
1155 continue;
1158 refname = parse_ref_line(&line, sha1);
1159 if (refname) {
1160 int flag = REF_ISPACKED;
1162 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1163 hashclr(sha1);
1164 flag |= REF_BAD_NAME | REF_ISBROKEN;
1166 last = create_ref_entry(refname, sha1, flag, 0);
1167 if (peeled == PEELED_FULLY ||
1168 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
1169 last->flag |= REF_KNOWS_PEELED;
1170 add_ref(dir, last);
1171 continue;
1173 if (last &&
1174 line.buf[0] == '^' &&
1175 line.len == PEELED_LINE_LENGTH &&
1176 line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&
1177 !get_sha1_hex(line.buf + 1, sha1)) {
1178 hashcpy(last->u.value.peeled, sha1);
1180 * Regardless of what the file header said,
1181 * we definitely know the value of *this*
1182 * reference:
1184 last->flag |= REF_KNOWS_PEELED;
1188 strbuf_release(&line);
1192 * Get the packed_ref_cache for the specified ref_cache, creating it
1193 * if necessary.
1195 static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
1197 const char *packed_refs_file;
1199 if (*refs->name)
1200 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1201 else
1202 packed_refs_file = git_path("packed-refs");
1204 if (refs->packed &&
1205 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1206 clear_packed_ref_cache(refs);
1208 if (!refs->packed) {
1209 FILE *f;
1211 refs->packed = xcalloc(1, sizeof(*refs->packed));
1212 acquire_packed_ref_cache(refs->packed);
1213 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1214 f = fopen(packed_refs_file, "r");
1215 if (f) {
1216 stat_validity_update(&refs->packed->validity, fileno(f));
1217 read_packed_refs(f, get_ref_dir(refs->packed->root));
1218 fclose(f);
1221 return refs->packed;
1224 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1226 return get_ref_dir(packed_ref_cache->root);
1229 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1231 return get_packed_ref_dir(get_packed_ref_cache(refs));
1234 void add_packed_ref(const char *refname, const unsigned char *sha1)
1236 struct packed_ref_cache *packed_ref_cache =
1237 get_packed_ref_cache(&ref_cache);
1239 if (!packed_ref_cache->lock)
1240 die("internal error: packed refs not locked");
1241 add_ref(get_packed_ref_dir(packed_ref_cache),
1242 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1246 * Read the loose references from the namespace dirname into dir
1247 * (without recursing). dirname must end with '/'. dir must be the
1248 * directory entry corresponding to dirname.
1250 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1252 struct ref_cache *refs = dir->ref_cache;
1253 DIR *d;
1254 const char *path;
1255 struct dirent *de;
1256 int dirnamelen = strlen(dirname);
1257 struct strbuf refname;
1259 if (*refs->name)
1260 path = git_path_submodule(refs->name, "%s", dirname);
1261 else
1262 path = git_path("%s", dirname);
1264 d = opendir(path);
1265 if (!d)
1266 return;
1268 strbuf_init(&refname, dirnamelen + 257);
1269 strbuf_add(&refname, dirname, dirnamelen);
1271 while ((de = readdir(d)) != NULL) {
1272 unsigned char sha1[20];
1273 struct stat st;
1274 int flag;
1275 const char *refdir;
1277 if (de->d_name[0] == '.')
1278 continue;
1279 if (ends_with(de->d_name, ".lock"))
1280 continue;
1281 strbuf_addstr(&refname, de->d_name);
1282 refdir = *refs->name
1283 ? git_path_submodule(refs->name, "%s", refname.buf)
1284 : git_path("%s", refname.buf);
1285 if (stat(refdir, &st) < 0) {
1286 ; /* silently ignore */
1287 } else if (S_ISDIR(st.st_mode)) {
1288 strbuf_addch(&refname, '/');
1289 add_entry_to_dir(dir,
1290 create_dir_entry(refs, refname.buf,
1291 refname.len, 1));
1292 } else {
1293 if (*refs->name) {
1294 hashclr(sha1);
1295 flag = 0;
1296 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
1297 hashclr(sha1);
1298 flag |= REF_ISBROKEN;
1300 } else if (read_ref_full(refname.buf,
1301 RESOLVE_REF_READING,
1302 sha1, &flag)) {
1303 hashclr(sha1);
1304 flag |= REF_ISBROKEN;
1306 if (check_refname_format(refname.buf,
1307 REFNAME_ALLOW_ONELEVEL)) {
1308 hashclr(sha1);
1309 flag |= REF_BAD_NAME | REF_ISBROKEN;
1311 add_entry_to_dir(dir,
1312 create_ref_entry(refname.buf, sha1, flag, 0));
1314 strbuf_setlen(&refname, dirnamelen);
1316 strbuf_release(&refname);
1317 closedir(d);
1320 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
1322 if (!refs->loose) {
1324 * Mark the top-level directory complete because we
1325 * are about to read the only subdirectory that can
1326 * hold references:
1328 refs->loose = create_dir_entry(refs, "", 0, 0);
1330 * Create an incomplete entry for "refs/":
1332 add_entry_to_dir(get_ref_dir(refs->loose),
1333 create_dir_entry(refs, "refs/", 5, 1));
1335 return get_ref_dir(refs->loose);
1338 /* We allow "recursive" symbolic refs. Only within reason, though */
1339 #define MAXDEPTH 5
1340 #define MAXREFLEN (1024)
1343 * Called by resolve_gitlink_ref_recursive() after it failed to read
1344 * from the loose refs in ref_cache refs. Find <refname> in the
1345 * packed-refs file for the submodule.
1347 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
1348 const char *refname, unsigned char *sha1)
1350 struct ref_entry *ref;
1351 struct ref_dir *dir = get_packed_refs(refs);
1353 ref = find_ref(dir, refname);
1354 if (ref == NULL)
1355 return -1;
1357 hashcpy(sha1, ref->u.value.sha1);
1358 return 0;
1361 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
1362 const char *refname, unsigned char *sha1,
1363 int recursion)
1365 int fd, len;
1366 char buffer[128], *p;
1367 char *path;
1369 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
1370 return -1;
1371 path = *refs->name
1372 ? git_path_submodule(refs->name, "%s", refname)
1373 : git_path("%s", refname);
1374 fd = open(path, O_RDONLY);
1375 if (fd < 0)
1376 return resolve_gitlink_packed_ref(refs, refname, sha1);
1378 len = read(fd, buffer, sizeof(buffer)-1);
1379 close(fd);
1380 if (len < 0)
1381 return -1;
1382 while (len && isspace(buffer[len-1]))
1383 len--;
1384 buffer[len] = 0;
1386 /* Was it a detached head or an old-fashioned symlink? */
1387 if (!get_sha1_hex(buffer, sha1))
1388 return 0;
1390 /* Symref? */
1391 if (strncmp(buffer, "ref:", 4))
1392 return -1;
1393 p = buffer + 4;
1394 while (isspace(*p))
1395 p++;
1397 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1400 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1402 int len = strlen(path), retval;
1403 char *submodule;
1404 struct ref_cache *refs;
1406 while (len && path[len-1] == '/')
1407 len--;
1408 if (!len)
1409 return -1;
1410 submodule = xstrndup(path, len);
1411 refs = get_ref_cache(submodule);
1412 free(submodule);
1414 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1415 return retval;
1419 * Return the ref_entry for the given refname from the packed
1420 * references. If it does not exist, return NULL.
1422 static struct ref_entry *get_packed_ref(const char *refname)
1424 return find_ref(get_packed_refs(&ref_cache), refname);
1428 * A loose ref file doesn't exist; check for a packed ref. The
1429 * options are forwarded from resolve_safe_unsafe().
1431 static int resolve_missing_loose_ref(const char *refname,
1432 int resolve_flags,
1433 unsigned char *sha1,
1434 int *flags)
1436 struct ref_entry *entry;
1439 * The loose reference file does not exist; check for a packed
1440 * reference.
1442 entry = get_packed_ref(refname);
1443 if (entry) {
1444 hashcpy(sha1, entry->u.value.sha1);
1445 if (flags)
1446 *flags |= REF_ISPACKED;
1447 return 0;
1449 /* The reference is not a packed reference, either. */
1450 if (resolve_flags & RESOLVE_REF_READING) {
1451 errno = ENOENT;
1452 return -1;
1453 } else {
1454 hashclr(sha1);
1455 return 0;
1459 /* This function needs to return a meaningful errno on failure */
1460 const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
1462 int depth = MAXDEPTH;
1463 ssize_t len;
1464 char buffer[256];
1465 static char refname_buffer[256];
1466 int bad_name = 0;
1468 if (flags)
1469 *flags = 0;
1471 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1472 if (flags)
1473 *flags |= REF_BAD_NAME;
1475 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1476 !refname_is_safe(refname)) {
1477 errno = EINVAL;
1478 return NULL;
1481 * dwim_ref() uses REF_ISBROKEN to distinguish between
1482 * missing refs and refs that were present but invalid,
1483 * to complain about the latter to stderr.
1485 * We don't know whether the ref exists, so don't set
1486 * REF_ISBROKEN yet.
1488 bad_name = 1;
1490 for (;;) {
1491 char path[PATH_MAX];
1492 struct stat st;
1493 char *buf;
1494 int fd;
1496 if (--depth < 0) {
1497 errno = ELOOP;
1498 return NULL;
1501 git_snpath(path, sizeof(path), "%s", refname);
1504 * We might have to loop back here to avoid a race
1505 * condition: first we lstat() the file, then we try
1506 * to read it as a link or as a file. But if somebody
1507 * changes the type of the file (file <-> directory
1508 * <-> symlink) between the lstat() and reading, then
1509 * we don't want to report that as an error but rather
1510 * try again starting with the lstat().
1512 stat_ref:
1513 if (lstat(path, &st) < 0) {
1514 if (errno != ENOENT)
1515 return NULL;
1516 if (resolve_missing_loose_ref(refname, resolve_flags,
1517 sha1, flags))
1518 return NULL;
1519 if (bad_name) {
1520 hashclr(sha1);
1521 if (flags)
1522 *flags |= REF_ISBROKEN;
1524 return refname;
1527 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1528 if (S_ISLNK(st.st_mode)) {
1529 len = readlink(path, buffer, sizeof(buffer)-1);
1530 if (len < 0) {
1531 if (errno == ENOENT || errno == EINVAL)
1532 /* inconsistent with lstat; retry */
1533 goto stat_ref;
1534 else
1535 return NULL;
1537 buffer[len] = 0;
1538 if (starts_with(buffer, "refs/") &&
1539 !check_refname_format(buffer, 0)) {
1540 strcpy(refname_buffer, buffer);
1541 refname = refname_buffer;
1542 if (flags)
1543 *flags |= REF_ISSYMREF;
1544 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1545 hashclr(sha1);
1546 return refname;
1548 continue;
1552 /* Is it a directory? */
1553 if (S_ISDIR(st.st_mode)) {
1554 errno = EISDIR;
1555 return NULL;
1559 * Anything else, just open it and try to use it as
1560 * a ref
1562 fd = open(path, O_RDONLY);
1563 if (fd < 0) {
1564 if (errno == ENOENT)
1565 /* inconsistent with lstat; retry */
1566 goto stat_ref;
1567 else
1568 return NULL;
1570 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1571 if (len < 0) {
1572 int save_errno = errno;
1573 close(fd);
1574 errno = save_errno;
1575 return NULL;
1577 close(fd);
1578 while (len && isspace(buffer[len-1]))
1579 len--;
1580 buffer[len] = '\0';
1583 * Is it a symbolic ref?
1585 if (!starts_with(buffer, "ref:")) {
1587 * Please note that FETCH_HEAD has a second
1588 * line containing other data.
1590 if (get_sha1_hex(buffer, sha1) ||
1591 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1592 if (flags)
1593 *flags |= REF_ISBROKEN;
1594 errno = EINVAL;
1595 return NULL;
1597 if (bad_name) {
1598 hashclr(sha1);
1599 if (flags)
1600 *flags |= REF_ISBROKEN;
1602 return refname;
1604 if (flags)
1605 *flags |= REF_ISSYMREF;
1606 buf = buffer + 4;
1607 while (isspace(*buf))
1608 buf++;
1609 refname = strcpy(refname_buffer, buf);
1610 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1611 hashclr(sha1);
1612 return refname;
1614 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1615 if (flags)
1616 *flags |= REF_ISBROKEN;
1618 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1619 !refname_is_safe(buf)) {
1620 errno = EINVAL;
1621 return NULL;
1623 bad_name = 1;
1628 char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags)
1630 return xstrdup_or_null(resolve_ref_unsafe(ref, resolve_flags, sha1, flags));
1633 /* The argument to filter_refs */
1634 struct ref_filter {
1635 const char *pattern;
1636 each_ref_fn *fn;
1637 void *cb_data;
1640 int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
1642 if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags))
1643 return 0;
1644 return -1;
1647 int read_ref(const char *refname, unsigned char *sha1)
1649 return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);
1652 int ref_exists(const char *refname)
1654 unsigned char sha1[20];
1655 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);
1658 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1659 void *data)
1661 struct ref_filter *filter = (struct ref_filter *)data;
1662 if (wildmatch(filter->pattern, refname, 0, NULL))
1663 return 0;
1664 return filter->fn(refname, sha1, flags, filter->cb_data);
1667 enum peel_status {
1668 /* object was peeled successfully: */
1669 PEEL_PEELED = 0,
1672 * object cannot be peeled because the named object (or an
1673 * object referred to by a tag in the peel chain), does not
1674 * exist.
1676 PEEL_INVALID = -1,
1678 /* object cannot be peeled because it is not a tag: */
1679 PEEL_NON_TAG = -2,
1681 /* ref_entry contains no peeled value because it is a symref: */
1682 PEEL_IS_SYMREF = -3,
1685 * ref_entry cannot be peeled because it is broken (i.e., the
1686 * symbolic reference cannot even be resolved to an object
1687 * name):
1689 PEEL_BROKEN = -4
1693 * Peel the named object; i.e., if the object is a tag, resolve the
1694 * tag recursively until a non-tag is found. If successful, store the
1695 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1696 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1697 * and leave sha1 unchanged.
1699 static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
1701 struct object *o = lookup_unknown_object(name);
1703 if (o->type == OBJ_NONE) {
1704 int type = sha1_object_info(name, NULL);
1705 if (type < 0 || !object_as_type(o, type, 0))
1706 return PEEL_INVALID;
1709 if (o->type != OBJ_TAG)
1710 return PEEL_NON_TAG;
1712 o = deref_tag_noverify(o);
1713 if (!o)
1714 return PEEL_INVALID;
1716 hashcpy(sha1, o->sha1);
1717 return PEEL_PEELED;
1721 * Peel the entry (if possible) and return its new peel_status. If
1722 * repeel is true, re-peel the entry even if there is an old peeled
1723 * value that is already stored in it.
1725 * It is OK to call this function with a packed reference entry that
1726 * might be stale and might even refer to an object that has since
1727 * been garbage-collected. In such a case, if the entry has
1728 * REF_KNOWS_PEELED then leave the status unchanged and return
1729 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1731 static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1733 enum peel_status status;
1735 if (entry->flag & REF_KNOWS_PEELED) {
1736 if (repeel) {
1737 entry->flag &= ~REF_KNOWS_PEELED;
1738 hashclr(entry->u.value.peeled);
1739 } else {
1740 return is_null_sha1(entry->u.value.peeled) ?
1741 PEEL_NON_TAG : PEEL_PEELED;
1744 if (entry->flag & REF_ISBROKEN)
1745 return PEEL_BROKEN;
1746 if (entry->flag & REF_ISSYMREF)
1747 return PEEL_IS_SYMREF;
1749 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1750 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1751 entry->flag |= REF_KNOWS_PEELED;
1752 return status;
1755 int peel_ref(const char *refname, unsigned char *sha1)
1757 int flag;
1758 unsigned char base[20];
1760 if (current_ref && (current_ref->name == refname
1761 || !strcmp(current_ref->name, refname))) {
1762 if (peel_entry(current_ref, 0))
1763 return -1;
1764 hashcpy(sha1, current_ref->u.value.peeled);
1765 return 0;
1768 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))
1769 return -1;
1772 * If the reference is packed, read its ref_entry from the
1773 * cache in the hope that we already know its peeled value.
1774 * We only try this optimization on packed references because
1775 * (a) forcing the filling of the loose reference cache could
1776 * be expensive and (b) loose references anyway usually do not
1777 * have REF_KNOWS_PEELED.
1779 if (flag & REF_ISPACKED) {
1780 struct ref_entry *r = get_packed_ref(refname);
1781 if (r) {
1782 if (peel_entry(r, 0))
1783 return -1;
1784 hashcpy(sha1, r->u.value.peeled);
1785 return 0;
1789 return peel_object(base, sha1);
1792 struct warn_if_dangling_data {
1793 FILE *fp;
1794 const char *refname;
1795 const struct string_list *refnames;
1796 const char *msg_fmt;
1799 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1800 int flags, void *cb_data)
1802 struct warn_if_dangling_data *d = cb_data;
1803 const char *resolves_to;
1804 unsigned char junk[20];
1806 if (!(flags & REF_ISSYMREF))
1807 return 0;
1809 resolves_to = resolve_ref_unsafe(refname, 0, junk, NULL);
1810 if (!resolves_to
1811 || (d->refname
1812 ? strcmp(resolves_to, d->refname)
1813 : !string_list_has_string(d->refnames, resolves_to))) {
1814 return 0;
1817 fprintf(d->fp, d->msg_fmt, refname);
1818 fputc('\n', d->fp);
1819 return 0;
1822 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1824 struct warn_if_dangling_data data;
1826 data.fp = fp;
1827 data.refname = refname;
1828 data.refnames = NULL;
1829 data.msg_fmt = msg_fmt;
1830 for_each_rawref(warn_if_dangling_symref, &data);
1833 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
1835 struct warn_if_dangling_data data;
1837 data.fp = fp;
1838 data.refname = NULL;
1839 data.refnames = refnames;
1840 data.msg_fmt = msg_fmt;
1841 for_each_rawref(warn_if_dangling_symref, &data);
1845 * Call fn for each reference in the specified ref_cache, omitting
1846 * references not in the containing_dir of base. fn is called for all
1847 * references, including broken ones. If fn ever returns a non-zero
1848 * value, stop the iteration and return that value; otherwise, return
1849 * 0.
1851 static int do_for_each_entry(struct ref_cache *refs, const char *base,
1852 each_ref_entry_fn fn, void *cb_data)
1854 struct packed_ref_cache *packed_ref_cache;
1855 struct ref_dir *loose_dir;
1856 struct ref_dir *packed_dir;
1857 int retval = 0;
1860 * We must make sure that all loose refs are read before accessing the
1861 * packed-refs file; this avoids a race condition in which loose refs
1862 * are migrated to the packed-refs file by a simultaneous process, but
1863 * our in-memory view is from before the migration. get_packed_ref_cache()
1864 * takes care of making sure our view is up to date with what is on
1865 * disk.
1867 loose_dir = get_loose_refs(refs);
1868 if (base && *base) {
1869 loose_dir = find_containing_dir(loose_dir, base, 0);
1871 if (loose_dir)
1872 prime_ref_dir(loose_dir);
1874 packed_ref_cache = get_packed_ref_cache(refs);
1875 acquire_packed_ref_cache(packed_ref_cache);
1876 packed_dir = get_packed_ref_dir(packed_ref_cache);
1877 if (base && *base) {
1878 packed_dir = find_containing_dir(packed_dir, base, 0);
1881 if (packed_dir && loose_dir) {
1882 sort_ref_dir(packed_dir);
1883 sort_ref_dir(loose_dir);
1884 retval = do_for_each_entry_in_dirs(
1885 packed_dir, loose_dir, fn, cb_data);
1886 } else if (packed_dir) {
1887 sort_ref_dir(packed_dir);
1888 retval = do_for_each_entry_in_dir(
1889 packed_dir, 0, fn, cb_data);
1890 } else if (loose_dir) {
1891 sort_ref_dir(loose_dir);
1892 retval = do_for_each_entry_in_dir(
1893 loose_dir, 0, fn, cb_data);
1896 release_packed_ref_cache(packed_ref_cache);
1897 return retval;
1901 * Call fn for each reference in the specified ref_cache for which the
1902 * refname begins with base. If trim is non-zero, then trim that many
1903 * characters off the beginning of each refname before passing the
1904 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1905 * broken references in the iteration. If fn ever returns a non-zero
1906 * value, stop the iteration and return that value; otherwise, return
1907 * 0.
1909 static int do_for_each_ref(struct ref_cache *refs, const char *base,
1910 each_ref_fn fn, int trim, int flags, void *cb_data)
1912 struct ref_entry_cb data;
1913 data.base = base;
1914 data.trim = trim;
1915 data.flags = flags;
1916 data.fn = fn;
1917 data.cb_data = cb_data;
1919 return do_for_each_entry(refs, base, do_one_ref, &data);
1922 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1924 unsigned char sha1[20];
1925 int flag;
1927 if (submodule) {
1928 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1929 return fn("HEAD", sha1, 0, cb_data);
1931 return 0;
1934 if (!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag))
1935 return fn("HEAD", sha1, flag, cb_data);
1937 return 0;
1940 int head_ref(each_ref_fn fn, void *cb_data)
1942 return do_head_ref(NULL, fn, cb_data);
1945 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1947 return do_head_ref(submodule, fn, cb_data);
1950 int for_each_ref(each_ref_fn fn, void *cb_data)
1952 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1955 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1957 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
1960 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1962 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1965 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1966 each_ref_fn fn, void *cb_data)
1968 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
1971 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1973 return for_each_ref_in("refs/tags/", fn, cb_data);
1976 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1978 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1981 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1983 return for_each_ref_in("refs/heads/", fn, cb_data);
1986 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1988 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1991 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1993 return for_each_ref_in("refs/remotes/", fn, cb_data);
1996 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1998 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
2001 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
2003 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
2006 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
2008 struct strbuf buf = STRBUF_INIT;
2009 int ret = 0;
2010 unsigned char sha1[20];
2011 int flag;
2013 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
2014 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag))
2015 ret = fn(buf.buf, sha1, flag, cb_data);
2016 strbuf_release(&buf);
2018 return ret;
2021 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
2023 struct strbuf buf = STRBUF_INIT;
2024 int ret;
2025 strbuf_addf(&buf, "%srefs/", get_git_namespace());
2026 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
2027 strbuf_release(&buf);
2028 return ret;
2031 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
2032 const char *prefix, void *cb_data)
2034 struct strbuf real_pattern = STRBUF_INIT;
2035 struct ref_filter filter;
2036 int ret;
2038 if (!prefix && !starts_with(pattern, "refs/"))
2039 strbuf_addstr(&real_pattern, "refs/");
2040 else if (prefix)
2041 strbuf_addstr(&real_pattern, prefix);
2042 strbuf_addstr(&real_pattern, pattern);
2044 if (!has_glob_specials(pattern)) {
2045 /* Append implied '/' '*' if not present. */
2046 if (real_pattern.buf[real_pattern.len - 1] != '/')
2047 strbuf_addch(&real_pattern, '/');
2048 /* No need to check for '*', there is none. */
2049 strbuf_addch(&real_pattern, '*');
2052 filter.pattern = real_pattern.buf;
2053 filter.fn = fn;
2054 filter.cb_data = cb_data;
2055 ret = for_each_ref(filter_refs, &filter);
2057 strbuf_release(&real_pattern);
2058 return ret;
2061 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
2063 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
2066 int for_each_rawref(each_ref_fn fn, void *cb_data)
2068 return do_for_each_ref(&ref_cache, "", fn, 0,
2069 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
2072 const char *prettify_refname(const char *name)
2074 return name + (
2075 starts_with(name, "refs/heads/") ? 11 :
2076 starts_with(name, "refs/tags/") ? 10 :
2077 starts_with(name, "refs/remotes/") ? 13 :
2081 static const char *ref_rev_parse_rules[] = {
2082 "%.*s",
2083 "refs/%.*s",
2084 "refs/tags/%.*s",
2085 "refs/heads/%.*s",
2086 "refs/remotes/%.*s",
2087 "refs/remotes/%.*s/HEAD",
2088 NULL
2091 int refname_match(const char *abbrev_name, const char *full_name)
2093 const char **p;
2094 const int abbrev_name_len = strlen(abbrev_name);
2096 for (p = ref_rev_parse_rules; *p; p++) {
2097 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
2098 return 1;
2102 return 0;
2105 static void unlock_ref(struct ref_lock *lock)
2107 /* Do not free lock->lk -- atexit() still looks at them */
2108 if (lock->lk)
2109 rollback_lock_file(lock->lk);
2110 free(lock->ref_name);
2111 free(lock->orig_ref_name);
2112 free(lock);
2115 /* This function should make sure errno is meaningful on error */
2116 static struct ref_lock *verify_lock(struct ref_lock *lock,
2117 const unsigned char *old_sha1, int mustexist)
2119 if (read_ref_full(lock->ref_name,
2120 mustexist ? RESOLVE_REF_READING : 0,
2121 lock->old_sha1, NULL)) {
2122 int save_errno = errno;
2123 error("Can't verify ref %s", lock->ref_name);
2124 unlock_ref(lock);
2125 errno = save_errno;
2126 return NULL;
2128 if (hashcmp(lock->old_sha1, old_sha1)) {
2129 error("Ref %s is at %s but expected %s", lock->ref_name,
2130 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
2131 unlock_ref(lock);
2132 errno = EBUSY;
2133 return NULL;
2135 return lock;
2138 static int remove_empty_directories(const char *file)
2140 /* we want to create a file but there is a directory there;
2141 * if that is an empty directory (or a directory that contains
2142 * only empty directories), remove them.
2144 struct strbuf path;
2145 int result, save_errno;
2147 strbuf_init(&path, 20);
2148 strbuf_addstr(&path, file);
2150 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
2151 save_errno = errno;
2153 strbuf_release(&path);
2154 errno = save_errno;
2156 return result;
2160 * *string and *len will only be substituted, and *string returned (for
2161 * later free()ing) if the string passed in is a magic short-hand form
2162 * to name a branch.
2164 static char *substitute_branch_name(const char **string, int *len)
2166 struct strbuf buf = STRBUF_INIT;
2167 int ret = interpret_branch_name(*string, *len, &buf);
2169 if (ret == *len) {
2170 size_t size;
2171 *string = strbuf_detach(&buf, &size);
2172 *len = size;
2173 return (char *)*string;
2176 return NULL;
2179 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
2181 char *last_branch = substitute_branch_name(&str, &len);
2182 const char **p, *r;
2183 int refs_found = 0;
2185 *ref = NULL;
2186 for (p = ref_rev_parse_rules; *p; p++) {
2187 char fullref[PATH_MAX];
2188 unsigned char sha1_from_ref[20];
2189 unsigned char *this_result;
2190 int flag;
2192 this_result = refs_found ? sha1_from_ref : sha1;
2193 mksnpath(fullref, sizeof(fullref), *p, len, str);
2194 r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING,
2195 this_result, &flag);
2196 if (r) {
2197 if (!refs_found++)
2198 *ref = xstrdup(r);
2199 if (!warn_ambiguous_refs)
2200 break;
2201 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
2202 warning("ignoring dangling symref %s.", fullref);
2203 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
2204 warning("ignoring broken ref %s.", fullref);
2207 free(last_branch);
2208 return refs_found;
2211 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
2213 char *last_branch = substitute_branch_name(&str, &len);
2214 const char **p;
2215 int logs_found = 0;
2217 *log = NULL;
2218 for (p = ref_rev_parse_rules; *p; p++) {
2219 unsigned char hash[20];
2220 char path[PATH_MAX];
2221 const char *ref, *it;
2223 mksnpath(path, sizeof(path), *p, len, str);
2224 ref = resolve_ref_unsafe(path, RESOLVE_REF_READING,
2225 hash, NULL);
2226 if (!ref)
2227 continue;
2228 if (reflog_exists(path))
2229 it = path;
2230 else if (strcmp(ref, path) && reflog_exists(ref))
2231 it = ref;
2232 else
2233 continue;
2234 if (!logs_found++) {
2235 *log = xstrdup(it);
2236 hashcpy(sha1, hash);
2238 if (!warn_ambiguous_refs)
2239 break;
2241 free(last_branch);
2242 return logs_found;
2246 * Locks a ref returning the lock on success and NULL on failure.
2247 * On failure errno is set to something meaningful.
2249 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2250 const unsigned char *old_sha1,
2251 const struct string_list *skip,
2252 int flags, int *type_p)
2254 char *ref_file;
2255 const char *orig_refname = refname;
2256 struct ref_lock *lock;
2257 int last_errno = 0;
2258 int type, lflags;
2259 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
2260 int resolve_flags = 0;
2261 int missing = 0;
2262 int attempts_remaining = 3;
2264 lock = xcalloc(1, sizeof(struct ref_lock));
2265 lock->lock_fd = -1;
2267 if (mustexist)
2268 resolve_flags |= RESOLVE_REF_READING;
2269 if (flags & REF_DELETING) {
2270 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
2271 if (flags & REF_NODEREF)
2272 resolve_flags |= RESOLVE_REF_NO_RECURSE;
2275 refname = resolve_ref_unsafe(refname, resolve_flags,
2276 lock->old_sha1, &type);
2277 if (!refname && errno == EISDIR) {
2278 /* we are trying to lock foo but we used to
2279 * have foo/bar which now does not exist;
2280 * it is normal for the empty directory 'foo'
2281 * to remain.
2283 ref_file = git_path("%s", orig_refname);
2284 if (remove_empty_directories(ref_file)) {
2285 last_errno = errno;
2286 error("there are still refs under '%s'", orig_refname);
2287 goto error_return;
2289 refname = resolve_ref_unsafe(orig_refname, resolve_flags,
2290 lock->old_sha1, &type);
2292 if (type_p)
2293 *type_p = type;
2294 if (!refname) {
2295 last_errno = errno;
2296 error("unable to resolve reference %s: %s",
2297 orig_refname, strerror(errno));
2298 goto error_return;
2300 missing = is_null_sha1(lock->old_sha1);
2301 /* When the ref did not exist and we are creating it,
2302 * make sure there is no existing ref that is packed
2303 * whose name begins with our refname, nor a ref whose
2304 * name is a proper prefix of our refname.
2306 if (missing &&
2307 !is_refname_available(refname, skip, get_packed_refs(&ref_cache))) {
2308 last_errno = ENOTDIR;
2309 goto error_return;
2312 lock->lk = xcalloc(1, sizeof(struct lock_file));
2314 lflags = 0;
2315 if (flags & REF_NODEREF) {
2316 refname = orig_refname;
2317 lflags |= LOCK_NO_DEREF;
2319 lock->ref_name = xstrdup(refname);
2320 lock->orig_ref_name = xstrdup(orig_refname);
2321 ref_file = git_path("%s", refname);
2322 if (missing)
2323 lock->force_write = 1;
2324 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2325 lock->force_write = 1;
2327 retry:
2328 switch (safe_create_leading_directories(ref_file)) {
2329 case SCLD_OK:
2330 break; /* success */
2331 case SCLD_VANISHED:
2332 if (--attempts_remaining > 0)
2333 goto retry;
2334 /* fall through */
2335 default:
2336 last_errno = errno;
2337 error("unable to create directory for %s", ref_file);
2338 goto error_return;
2341 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
2342 if (lock->lock_fd < 0) {
2343 last_errno = errno;
2344 if (errno == ENOENT && --attempts_remaining > 0)
2346 * Maybe somebody just deleted one of the
2347 * directories leading to ref_file. Try
2348 * again:
2350 goto retry;
2351 else {
2352 struct strbuf err = STRBUF_INIT;
2353 unable_to_lock_message(ref_file, errno, &err);
2354 error("%s", err.buf);
2355 strbuf_release(&err);
2356 goto error_return;
2359 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
2361 error_return:
2362 unlock_ref(lock);
2363 errno = last_errno;
2364 return NULL;
2368 * Write an entry to the packed-refs file for the specified refname.
2369 * If peeled is non-NULL, write it as the entry's peeled value.
2371 static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,
2372 unsigned char *peeled)
2374 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);
2375 if (peeled)
2376 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));
2380 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2382 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2384 enum peel_status peel_status = peel_entry(entry, 0);
2386 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2387 error("internal error: %s is not a valid packed reference!",
2388 entry->name);
2389 write_packed_entry(cb_data, entry->name, entry->u.value.sha1,
2390 peel_status == PEEL_PEELED ?
2391 entry->u.value.peeled : NULL);
2392 return 0;
2395 /* This should return a meaningful errno on failure */
2396 int lock_packed_refs(int flags)
2398 struct packed_ref_cache *packed_ref_cache;
2400 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2401 return -1;
2403 * Get the current packed-refs while holding the lock. If the
2404 * packed-refs file has been modified since we last read it,
2405 * this will automatically invalidate the cache and re-read
2406 * the packed-refs file.
2408 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2409 packed_ref_cache->lock = &packlock;
2410 /* Increment the reference count to prevent it from being freed: */
2411 acquire_packed_ref_cache(packed_ref_cache);
2412 return 0;
2416 * Commit the packed refs changes.
2417 * On error we must make sure that errno contains a meaningful value.
2419 int commit_packed_refs(void)
2421 struct packed_ref_cache *packed_ref_cache =
2422 get_packed_ref_cache(&ref_cache);
2423 int error = 0;
2424 int save_errno = 0;
2425 FILE *out;
2427 if (!packed_ref_cache->lock)
2428 die("internal error: packed-refs not locked");
2430 out = fdopen_lock_file(packed_ref_cache->lock, "w");
2431 if (!out)
2432 die_errno("unable to fdopen packed-refs descriptor");
2434 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);
2435 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2436 0, write_packed_entry_fn, out);
2438 if (commit_lock_file(packed_ref_cache->lock)) {
2439 save_errno = errno;
2440 error = -1;
2442 packed_ref_cache->lock = NULL;
2443 release_packed_ref_cache(packed_ref_cache);
2444 errno = save_errno;
2445 return error;
2448 void rollback_packed_refs(void)
2450 struct packed_ref_cache *packed_ref_cache =
2451 get_packed_ref_cache(&ref_cache);
2453 if (!packed_ref_cache->lock)
2454 die("internal error: packed-refs not locked");
2455 rollback_lock_file(packed_ref_cache->lock);
2456 packed_ref_cache->lock = NULL;
2457 release_packed_ref_cache(packed_ref_cache);
2458 clear_packed_ref_cache(&ref_cache);
2461 struct ref_to_prune {
2462 struct ref_to_prune *next;
2463 unsigned char sha1[20];
2464 char name[FLEX_ARRAY];
2467 struct pack_refs_cb_data {
2468 unsigned int flags;
2469 struct ref_dir *packed_refs;
2470 struct ref_to_prune *ref_to_prune;
2474 * An each_ref_entry_fn that is run over loose references only. If
2475 * the loose reference can be packed, add an entry in the packed ref
2476 * cache. If the reference should be pruned, also add it to
2477 * ref_to_prune in the pack_refs_cb_data.
2479 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2481 struct pack_refs_cb_data *cb = cb_data;
2482 enum peel_status peel_status;
2483 struct ref_entry *packed_entry;
2484 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2486 /* ALWAYS pack tags */
2487 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2488 return 0;
2490 /* Do not pack symbolic or broken refs: */
2491 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2492 return 0;
2494 /* Add a packed ref cache entry equivalent to the loose entry. */
2495 peel_status = peel_entry(entry, 1);
2496 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2497 die("internal error peeling reference %s (%s)",
2498 entry->name, sha1_to_hex(entry->u.value.sha1));
2499 packed_entry = find_ref(cb->packed_refs, entry->name);
2500 if (packed_entry) {
2501 /* Overwrite existing packed entry with info from loose entry */
2502 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2503 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2504 } else {
2505 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2506 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2507 add_ref(cb->packed_refs, packed_entry);
2509 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
2511 /* Schedule the loose reference for pruning if requested. */
2512 if ((cb->flags & PACK_REFS_PRUNE)) {
2513 int namelen = strlen(entry->name) + 1;
2514 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
2515 hashcpy(n->sha1, entry->u.value.sha1);
2516 strcpy(n->name, entry->name);
2517 n->next = cb->ref_to_prune;
2518 cb->ref_to_prune = n;
2520 return 0;
2524 * Remove empty parents, but spare refs/ and immediate subdirs.
2525 * Note: munges *name.
2527 static void try_remove_empty_parents(char *name)
2529 char *p, *q;
2530 int i;
2531 p = name;
2532 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2533 while (*p && *p != '/')
2534 p++;
2535 /* tolerate duplicate slashes; see check_refname_format() */
2536 while (*p == '/')
2537 p++;
2539 for (q = p; *q; q++)
2541 while (1) {
2542 while (q > p && *q != '/')
2543 q--;
2544 while (q > p && *(q-1) == '/')
2545 q--;
2546 if (q == p)
2547 break;
2548 *q = '\0';
2549 if (rmdir(git_path("%s", name)))
2550 break;
2554 /* make sure nobody touched the ref, and unlink */
2555 static void prune_ref(struct ref_to_prune *r)
2557 struct ref_transaction *transaction;
2558 struct strbuf err = STRBUF_INIT;
2560 if (check_refname_format(r->name, 0))
2561 return;
2563 transaction = ref_transaction_begin(&err);
2564 if (!transaction ||
2565 ref_transaction_delete(transaction, r->name, r->sha1,
2566 REF_ISPRUNING, 1, NULL, &err) ||
2567 ref_transaction_commit(transaction, &err)) {
2568 ref_transaction_free(transaction);
2569 error("%s", err.buf);
2570 strbuf_release(&err);
2571 return;
2573 ref_transaction_free(transaction);
2574 strbuf_release(&err);
2575 try_remove_empty_parents(r->name);
2578 static void prune_refs(struct ref_to_prune *r)
2580 while (r) {
2581 prune_ref(r);
2582 r = r->next;
2586 int pack_refs(unsigned int flags)
2588 struct pack_refs_cb_data cbdata;
2590 memset(&cbdata, 0, sizeof(cbdata));
2591 cbdata.flags = flags;
2593 lock_packed_refs(LOCK_DIE_ON_ERROR);
2594 cbdata.packed_refs = get_packed_refs(&ref_cache);
2596 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2597 pack_if_possible_fn, &cbdata);
2599 if (commit_packed_refs())
2600 die_errno("unable to overwrite old ref-pack file");
2602 prune_refs(cbdata.ref_to_prune);
2603 return 0;
2607 * If entry is no longer needed in packed-refs, add it to the string
2608 * list pointed to by cb_data. Reasons for deleting entries:
2610 * - Entry is broken.
2611 * - Entry is overridden by a loose ref.
2612 * - Entry does not point at a valid object.
2614 * In the first and third cases, also emit an error message because these
2615 * are indications of repository corruption.
2617 static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
2619 struct string_list *refs_to_delete = cb_data;
2621 if (entry->flag & REF_ISBROKEN) {
2622 /* This shouldn't happen to packed refs. */
2623 error("%s is broken!", entry->name);
2624 string_list_append(refs_to_delete, entry->name);
2625 return 0;
2627 if (!has_sha1_file(entry->u.value.sha1)) {
2628 unsigned char sha1[20];
2629 int flags;
2631 if (read_ref_full(entry->name, 0, sha1, &flags))
2632 /* We should at least have found the packed ref. */
2633 die("Internal error");
2634 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
2636 * This packed reference is overridden by a
2637 * loose reference, so it is OK that its value
2638 * is no longer valid; for example, it might
2639 * refer to an object that has been garbage
2640 * collected. For this purpose we don't even
2641 * care whether the loose reference itself is
2642 * invalid, broken, symbolic, etc. Silently
2643 * remove the packed reference.
2645 string_list_append(refs_to_delete, entry->name);
2646 return 0;
2649 * There is no overriding loose reference, so the fact
2650 * that this reference doesn't refer to a valid object
2651 * indicates some kind of repository corruption.
2652 * Report the problem, then omit the reference from
2653 * the output.
2655 error("%s does not point to a valid object!", entry->name);
2656 string_list_append(refs_to_delete, entry->name);
2657 return 0;
2660 return 0;
2663 int repack_without_refs(struct string_list *refnames, struct strbuf *err)
2665 struct ref_dir *packed;
2666 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2667 struct string_list_item *refname, *ref_to_delete;
2668 int ret, needs_repacking = 0, removed = 0;
2670 assert(err);
2672 /* Look for a packed ref */
2673 for_each_string_list_item(refname, refnames) {
2674 if (get_packed_ref(refname->string)) {
2675 needs_repacking = 1;
2676 break;
2680 /* Avoid locking if we have nothing to do */
2681 if (!needs_repacking)
2682 return 0; /* no refname exists in packed refs */
2684 if (lock_packed_refs(0)) {
2685 unable_to_lock_message(git_path("packed-refs"), errno, err);
2686 return -1;
2688 packed = get_packed_refs(&ref_cache);
2690 /* Remove refnames from the cache */
2691 for_each_string_list_item(refname, refnames)
2692 if (remove_entry(packed, refname->string) != -1)
2693 removed = 1;
2694 if (!removed) {
2696 * All packed entries disappeared while we were
2697 * acquiring the lock.
2699 rollback_packed_refs();
2700 return 0;
2703 /* Remove any other accumulated cruft */
2704 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2705 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2706 if (remove_entry(packed, ref_to_delete->string) == -1)
2707 die("internal error");
2710 /* Write what remains */
2711 ret = commit_packed_refs();
2712 if (ret)
2713 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",
2714 strerror(errno));
2715 return ret;
2718 static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)
2720 assert(err);
2722 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2724 * loose. The loose file name is the same as the
2725 * lockfile name, minus ".lock":
2727 char *loose_filename = get_locked_file_path(lock->lk);
2728 int res = unlink_or_msg(loose_filename, err);
2729 free(loose_filename);
2730 if (res)
2731 return 1;
2733 return 0;
2736 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
2738 struct ref_transaction *transaction;
2739 struct strbuf err = STRBUF_INIT;
2741 transaction = ref_transaction_begin(&err);
2742 if (!transaction ||
2743 ref_transaction_delete(transaction, refname, sha1, delopt,
2744 sha1 && !is_null_sha1(sha1), NULL, &err) ||
2745 ref_transaction_commit(transaction, &err)) {
2746 error("%s", err.buf);
2747 ref_transaction_free(transaction);
2748 strbuf_release(&err);
2749 return 1;
2751 ref_transaction_free(transaction);
2752 strbuf_release(&err);
2753 return 0;
2757 * People using contrib's git-new-workdir have .git/logs/refs ->
2758 * /some/other/path/.git/logs/refs, and that may live on another device.
2760 * IOW, to avoid cross device rename errors, the temporary renamed log must
2761 * live into logs/refs.
2763 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2765 static int rename_tmp_log(const char *newrefname)
2767 int attempts_remaining = 4;
2769 retry:
2770 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2771 case SCLD_OK:
2772 break; /* success */
2773 case SCLD_VANISHED:
2774 if (--attempts_remaining > 0)
2775 goto retry;
2776 /* fall through */
2777 default:
2778 error("unable to create directory for %s", newrefname);
2779 return -1;
2782 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
2783 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
2785 * rename(a, b) when b is an existing
2786 * directory ought to result in ISDIR, but
2787 * Solaris 5.8 gives ENOTDIR. Sheesh.
2789 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2790 error("Directory not empty: logs/%s", newrefname);
2791 return -1;
2793 goto retry;
2794 } else if (errno == ENOENT && --attempts_remaining > 0) {
2796 * Maybe another process just deleted one of
2797 * the directories in the path to newrefname.
2798 * Try again from the beginning.
2800 goto retry;
2801 } else {
2802 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2803 newrefname, strerror(errno));
2804 return -1;
2807 return 0;
2810 static int rename_ref_available(const char *oldname, const char *newname)
2812 struct string_list skip = STRING_LIST_INIT_NODUP;
2813 int ret;
2815 string_list_insert(&skip, oldname);
2816 ret = is_refname_available(newname, &skip, get_packed_refs(&ref_cache))
2817 && is_refname_available(newname, &skip, get_loose_refs(&ref_cache));
2818 string_list_clear(&skip, 0);
2819 return ret;
2822 static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1,
2823 const char *logmsg);
2825 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
2827 unsigned char sha1[20], orig_sha1[20];
2828 int flag = 0, logmoved = 0;
2829 struct ref_lock *lock;
2830 struct stat loginfo;
2831 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2832 const char *symref = NULL;
2834 if (log && S_ISLNK(loginfo.st_mode))
2835 return error("reflog for %s is a symlink", oldrefname);
2837 symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,
2838 orig_sha1, &flag);
2839 if (flag & REF_ISSYMREF)
2840 return error("refname %s is a symbolic ref, renaming it is not supported",
2841 oldrefname);
2842 if (!symref)
2843 return error("refname %s not found", oldrefname);
2845 if (!rename_ref_available(oldrefname, newrefname))
2846 return 1;
2848 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2849 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2850 oldrefname, strerror(errno));
2852 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2853 error("unable to delete old %s", oldrefname);
2854 goto rollback;
2857 if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&
2858 delete_ref(newrefname, sha1, REF_NODEREF)) {
2859 if (errno==EISDIR) {
2860 if (remove_empty_directories(git_path("%s", newrefname))) {
2861 error("Directory not empty: %s", newrefname);
2862 goto rollback;
2864 } else {
2865 error("unable to delete existing %s", newrefname);
2866 goto rollback;
2870 if (log && rename_tmp_log(newrefname))
2871 goto rollback;
2873 logmoved = log;
2875 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, 0, NULL);
2876 if (!lock) {
2877 error("unable to lock %s for update", newrefname);
2878 goto rollback;
2880 lock->force_write = 1;
2881 hashcpy(lock->old_sha1, orig_sha1);
2882 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
2883 error("unable to write current sha1 into %s", newrefname);
2884 goto rollback;
2887 return 0;
2889 rollback:
2890 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, 0, NULL);
2891 if (!lock) {
2892 error("unable to lock %s for rollback", oldrefname);
2893 goto rollbacklog;
2896 lock->force_write = 1;
2897 flag = log_all_ref_updates;
2898 log_all_ref_updates = 0;
2899 if (write_ref_sha1(lock, orig_sha1, NULL))
2900 error("unable to write current sha1 into %s", oldrefname);
2901 log_all_ref_updates = flag;
2903 rollbacklog:
2904 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2905 error("unable to restore logfile %s from %s: %s",
2906 oldrefname, newrefname, strerror(errno));
2907 if (!logmoved && log &&
2908 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2909 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2910 oldrefname, strerror(errno));
2912 return 1;
2915 static int close_ref(struct ref_lock *lock)
2917 if (close_lock_file(lock->lk))
2918 return -1;
2919 lock->lock_fd = -1;
2920 return 0;
2923 static int commit_ref(struct ref_lock *lock)
2925 if (commit_lock_file(lock->lk))
2926 return -1;
2927 lock->lock_fd = -1;
2928 return 0;
2932 * copy the reflog message msg to buf, which has been allocated sufficiently
2933 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2934 * because reflog file is one line per entry.
2936 static int copy_msg(char *buf, const char *msg)
2938 char *cp = buf;
2939 char c;
2940 int wasspace = 1;
2942 *cp++ = '\t';
2943 while ((c = *msg++)) {
2944 if (wasspace && isspace(c))
2945 continue;
2946 wasspace = isspace(c);
2947 if (wasspace)
2948 c = ' ';
2949 *cp++ = c;
2951 while (buf < cp && isspace(cp[-1]))
2952 cp--;
2953 *cp++ = '\n';
2954 return cp - buf;
2957 /* This function must set a meaningful errno on failure */
2958 int log_ref_setup(const char *refname, char *logfile, int bufsize)
2960 int logfd, oflags = O_APPEND | O_WRONLY;
2962 git_snpath(logfile, bufsize, "logs/%s", refname);
2963 if (log_all_ref_updates &&
2964 (starts_with(refname, "refs/heads/") ||
2965 starts_with(refname, "refs/remotes/") ||
2966 starts_with(refname, "refs/notes/") ||
2967 !strcmp(refname, "HEAD"))) {
2968 if (safe_create_leading_directories(logfile) < 0) {
2969 int save_errno = errno;
2970 error("unable to create directory for %s", logfile);
2971 errno = save_errno;
2972 return -1;
2974 oflags |= O_CREAT;
2977 logfd = open(logfile, oflags, 0666);
2978 if (logfd < 0) {
2979 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))
2980 return 0;
2982 if (errno == EISDIR) {
2983 if (remove_empty_directories(logfile)) {
2984 int save_errno = errno;
2985 error("There are still logs under '%s'",
2986 logfile);
2987 errno = save_errno;
2988 return -1;
2990 logfd = open(logfile, oflags, 0666);
2993 if (logfd < 0) {
2994 int save_errno = errno;
2995 error("Unable to append to %s: %s", logfile,
2996 strerror(errno));
2997 errno = save_errno;
2998 return -1;
3002 adjust_shared_perm(logfile);
3003 close(logfd);
3004 return 0;
3007 static int log_ref_write_fd(int fd, const unsigned char *old_sha1,
3008 const unsigned char *new_sha1,
3009 const char *committer, const char *msg)
3011 int msglen, written;
3012 unsigned maxlen, len;
3013 char *logrec;
3015 msglen = msg ? strlen(msg) : 0;
3016 maxlen = strlen(committer) + msglen + 100;
3017 logrec = xmalloc(maxlen);
3018 len = sprintf(logrec, "%s %s %s\n",
3019 sha1_to_hex(old_sha1),
3020 sha1_to_hex(new_sha1),
3021 committer);
3022 if (msglen)
3023 len += copy_msg(logrec + len - 1, msg) - 1;
3025 written = len <= maxlen ? write_in_full(fd, logrec, len) : -1;
3026 free(logrec);
3027 if (written != len)
3028 return -1;
3030 return 0;
3033 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
3034 const unsigned char *new_sha1, const char *msg)
3036 int logfd, result, oflags = O_APPEND | O_WRONLY;
3037 char log_file[PATH_MAX];
3039 if (log_all_ref_updates < 0)
3040 log_all_ref_updates = !is_bare_repository();
3042 result = log_ref_setup(refname, log_file, sizeof(log_file));
3043 if (result)
3044 return result;
3046 logfd = open(log_file, oflags);
3047 if (logfd < 0)
3048 return 0;
3049 result = log_ref_write_fd(logfd, old_sha1, new_sha1,
3050 git_committer_info(0), msg);
3051 if (result) {
3052 int save_errno = errno;
3053 close(logfd);
3054 error("Unable to append to %s", log_file);
3055 errno = save_errno;
3056 return -1;
3058 if (close(logfd)) {
3059 int save_errno = errno;
3060 error("Unable to append to %s", log_file);
3061 errno = save_errno;
3062 return -1;
3064 return 0;
3067 int is_branch(const char *refname)
3069 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
3073 * Write sha1 into the ref specified by the lock. Make sure that errno
3074 * is sane on error.
3076 static int write_ref_sha1(struct ref_lock *lock,
3077 const unsigned char *sha1, const char *logmsg)
3079 static char term = '\n';
3080 struct object *o;
3082 if (!lock) {
3083 errno = EINVAL;
3084 return -1;
3086 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
3087 unlock_ref(lock);
3088 return 0;
3090 o = parse_object(sha1);
3091 if (!o) {
3092 error("Trying to write ref %s with nonexistent object %s",
3093 lock->ref_name, sha1_to_hex(sha1));
3094 unlock_ref(lock);
3095 errno = EINVAL;
3096 return -1;
3098 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
3099 error("Trying to write non-commit object %s to branch %s",
3100 sha1_to_hex(sha1), lock->ref_name);
3101 unlock_ref(lock);
3102 errno = EINVAL;
3103 return -1;
3105 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
3106 write_in_full(lock->lock_fd, &term, 1) != 1 ||
3107 close_ref(lock) < 0) {
3108 int save_errno = errno;
3109 error("Couldn't write %s", lock->lk->filename.buf);
3110 unlock_ref(lock);
3111 errno = save_errno;
3112 return -1;
3114 clear_loose_ref_cache(&ref_cache);
3115 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
3116 (strcmp(lock->ref_name, lock->orig_ref_name) &&
3117 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
3118 unlock_ref(lock);
3119 return -1;
3121 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
3123 * Special hack: If a branch is updated directly and HEAD
3124 * points to it (may happen on the remote side of a push
3125 * for example) then logically the HEAD reflog should be
3126 * updated too.
3127 * A generic solution implies reverse symref information,
3128 * but finding all symrefs pointing to the given branch
3129 * would be rather costly for this rare event (the direct
3130 * update of a branch) to be worth it. So let's cheat and
3131 * check with HEAD only which should cover 99% of all usage
3132 * scenarios (even 100% of the default ones).
3134 unsigned char head_sha1[20];
3135 int head_flag;
3136 const char *head_ref;
3137 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
3138 head_sha1, &head_flag);
3139 if (head_ref && (head_flag & REF_ISSYMREF) &&
3140 !strcmp(head_ref, lock->ref_name))
3141 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
3143 if (commit_ref(lock)) {
3144 error("Couldn't set %s", lock->ref_name);
3145 unlock_ref(lock);
3146 return -1;
3148 unlock_ref(lock);
3149 return 0;
3152 int create_symref(const char *ref_target, const char *refs_heads_master,
3153 const char *logmsg)
3155 const char *lockpath;
3156 char ref[1000];
3157 int fd, len, written;
3158 char *git_HEAD = git_pathdup("%s", ref_target);
3159 unsigned char old_sha1[20], new_sha1[20];
3161 if (logmsg && read_ref(ref_target, old_sha1))
3162 hashclr(old_sha1);
3164 if (safe_create_leading_directories(git_HEAD) < 0)
3165 return error("unable to create directory for %s", git_HEAD);
3167 #ifndef NO_SYMLINK_HEAD
3168 if (prefer_symlink_refs) {
3169 unlink(git_HEAD);
3170 if (!symlink(refs_heads_master, git_HEAD))
3171 goto done;
3172 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
3174 #endif
3176 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
3177 if (sizeof(ref) <= len) {
3178 error("refname too long: %s", refs_heads_master);
3179 goto error_free_return;
3181 lockpath = mkpath("%s.lock", git_HEAD);
3182 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
3183 if (fd < 0) {
3184 error("Unable to open %s for writing", lockpath);
3185 goto error_free_return;
3187 written = write_in_full(fd, ref, len);
3188 if (close(fd) != 0 || written != len) {
3189 error("Unable to write to %s", lockpath);
3190 goto error_unlink_return;
3192 if (rename(lockpath, git_HEAD) < 0) {
3193 error("Unable to create %s", git_HEAD);
3194 goto error_unlink_return;
3196 if (adjust_shared_perm(git_HEAD)) {
3197 error("Unable to fix permissions on %s", lockpath);
3198 error_unlink_return:
3199 unlink_or_warn(lockpath);
3200 error_free_return:
3201 free(git_HEAD);
3202 return -1;
3205 #ifndef NO_SYMLINK_HEAD
3206 done:
3207 #endif
3208 if (logmsg && !read_ref(refs_heads_master, new_sha1))
3209 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
3211 free(git_HEAD);
3212 return 0;
3215 struct read_ref_at_cb {
3216 const char *refname;
3217 unsigned long at_time;
3218 int cnt;
3219 int reccnt;
3220 unsigned char *sha1;
3221 int found_it;
3223 unsigned char osha1[20];
3224 unsigned char nsha1[20];
3225 int tz;
3226 unsigned long date;
3227 char **msg;
3228 unsigned long *cutoff_time;
3229 int *cutoff_tz;
3230 int *cutoff_cnt;
3233 static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
3234 const char *email, unsigned long timestamp, int tz,
3235 const char *message, void *cb_data)
3237 struct read_ref_at_cb *cb = cb_data;
3239 cb->reccnt++;
3240 cb->tz = tz;
3241 cb->date = timestamp;
3243 if (timestamp <= cb->at_time || cb->cnt == 0) {
3244 if (cb->msg)
3245 *cb->msg = xstrdup(message);
3246 if (cb->cutoff_time)
3247 *cb->cutoff_time = timestamp;
3248 if (cb->cutoff_tz)
3249 *cb->cutoff_tz = tz;
3250 if (cb->cutoff_cnt)
3251 *cb->cutoff_cnt = cb->reccnt - 1;
3253 * we have not yet updated cb->[n|o]sha1 so they still
3254 * hold the values for the previous record.
3256 if (!is_null_sha1(cb->osha1)) {
3257 hashcpy(cb->sha1, nsha1);
3258 if (hashcmp(cb->osha1, nsha1))
3259 warning("Log for ref %s has gap after %s.",
3260 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));
3262 else if (cb->date == cb->at_time)
3263 hashcpy(cb->sha1, nsha1);
3264 else if (hashcmp(nsha1, cb->sha1))
3265 warning("Log for ref %s unexpectedly ended on %s.",
3266 cb->refname, show_date(cb->date, cb->tz,
3267 DATE_RFC2822));
3268 hashcpy(cb->osha1, osha1);
3269 hashcpy(cb->nsha1, nsha1);
3270 cb->found_it = 1;
3271 return 1;
3273 hashcpy(cb->osha1, osha1);
3274 hashcpy(cb->nsha1, nsha1);
3275 if (cb->cnt > 0)
3276 cb->cnt--;
3277 return 0;
3280 static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
3281 const char *email, unsigned long timestamp,
3282 int tz, const char *message, void *cb_data)
3284 struct read_ref_at_cb *cb = cb_data;
3286 if (cb->msg)
3287 *cb->msg = xstrdup(message);
3288 if (cb->cutoff_time)
3289 *cb->cutoff_time = timestamp;
3290 if (cb->cutoff_tz)
3291 *cb->cutoff_tz = tz;
3292 if (cb->cutoff_cnt)
3293 *cb->cutoff_cnt = cb->reccnt;
3294 hashcpy(cb->sha1, osha1);
3295 if (is_null_sha1(cb->sha1))
3296 hashcpy(cb->sha1, nsha1);
3297 /* We just want the first entry */
3298 return 1;
3301 int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt,
3302 unsigned char *sha1, char **msg,
3303 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
3305 struct read_ref_at_cb cb;
3307 memset(&cb, 0, sizeof(cb));
3308 cb.refname = refname;
3309 cb.at_time = at_time;
3310 cb.cnt = cnt;
3311 cb.msg = msg;
3312 cb.cutoff_time = cutoff_time;
3313 cb.cutoff_tz = cutoff_tz;
3314 cb.cutoff_cnt = cutoff_cnt;
3315 cb.sha1 = sha1;
3317 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
3319 if (!cb.reccnt) {
3320 if (flags & GET_SHA1_QUIETLY)
3321 exit(128);
3322 else
3323 die("Log for %s is empty.", refname);
3325 if (cb.found_it)
3326 return 0;
3328 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
3330 return 1;
3333 int reflog_exists(const char *refname)
3335 struct stat st;
3337 return !lstat(git_path("logs/%s", refname), &st) &&
3338 S_ISREG(st.st_mode);
3341 int delete_reflog(const char *refname)
3343 return remove_path(git_path("logs/%s", refname));
3346 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3348 unsigned char osha1[20], nsha1[20];
3349 char *email_end, *message;
3350 unsigned long timestamp;
3351 int tz;
3353 /* old SP new SP name <email> SP time TAB msg LF */
3354 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3355 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3356 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3357 !(email_end = strchr(sb->buf + 82, '>')) ||
3358 email_end[1] != ' ' ||
3359 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3360 !message || message[0] != ' ' ||
3361 (message[1] != '+' && message[1] != '-') ||
3362 !isdigit(message[2]) || !isdigit(message[3]) ||
3363 !isdigit(message[4]) || !isdigit(message[5]))
3364 return 0; /* corrupt? */
3365 email_end[1] = '\0';
3366 tz = strtol(message + 1, NULL, 10);
3367 if (message[6] != '\t')
3368 message += 6;
3369 else
3370 message += 7;
3371 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3374 static char *find_beginning_of_line(char *bob, char *scan)
3376 while (bob < scan && *(--scan) != '\n')
3377 ; /* keep scanning backwards */
3379 * Return either beginning of the buffer, or LF at the end of
3380 * the previous line.
3382 return scan;
3385 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3387 struct strbuf sb = STRBUF_INIT;
3388 FILE *logfp;
3389 long pos;
3390 int ret = 0, at_tail = 1;
3392 logfp = fopen(git_path("logs/%s", refname), "r");
3393 if (!logfp)
3394 return -1;
3396 /* Jump to the end */
3397 if (fseek(logfp, 0, SEEK_END) < 0)
3398 return error("cannot seek back reflog for %s: %s",
3399 refname, strerror(errno));
3400 pos = ftell(logfp);
3401 while (!ret && 0 < pos) {
3402 int cnt;
3403 size_t nread;
3404 char buf[BUFSIZ];
3405 char *endp, *scanp;
3407 /* Fill next block from the end */
3408 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3409 if (fseek(logfp, pos - cnt, SEEK_SET))
3410 return error("cannot seek back reflog for %s: %s",
3411 refname, strerror(errno));
3412 nread = fread(buf, cnt, 1, logfp);
3413 if (nread != 1)
3414 return error("cannot read %d bytes from reflog for %s: %s",
3415 cnt, refname, strerror(errno));
3416 pos -= cnt;
3418 scanp = endp = buf + cnt;
3419 if (at_tail && scanp[-1] == '\n')
3420 /* Looking at the final LF at the end of the file */
3421 scanp--;
3422 at_tail = 0;
3424 while (buf < scanp) {
3426 * terminating LF of the previous line, or the beginning
3427 * of the buffer.
3429 char *bp;
3431 bp = find_beginning_of_line(buf, scanp);
3433 if (*bp == '\n') {
3435 * The newline is the end of the previous line,
3436 * so we know we have complete line starting
3437 * at (bp + 1). Prefix it onto any prior data
3438 * we collected for the line and process it.
3440 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3441 scanp = bp;
3442 endp = bp + 1;
3443 ret = show_one_reflog_ent(&sb, fn, cb_data);
3444 strbuf_reset(&sb);
3445 if (ret)
3446 break;
3447 } else if (!pos) {
3449 * We are at the start of the buffer, and the
3450 * start of the file; there is no previous
3451 * line, and we have everything for this one.
3452 * Process it, and we can end the loop.
3454 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3455 ret = show_one_reflog_ent(&sb, fn, cb_data);
3456 strbuf_reset(&sb);
3457 break;
3460 if (bp == buf) {
3462 * We are at the start of the buffer, and there
3463 * is more file to read backwards. Which means
3464 * we are in the middle of a line. Note that we
3465 * may get here even if *bp was a newline; that
3466 * just means we are at the exact end of the
3467 * previous line, rather than some spot in the
3468 * middle.
3470 * Save away what we have to be combined with
3471 * the data from the next read.
3473 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3474 break;
3479 if (!ret && sb.len)
3480 die("BUG: reverse reflog parser had leftover data");
3482 fclose(logfp);
3483 strbuf_release(&sb);
3484 return ret;
3487 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3489 FILE *logfp;
3490 struct strbuf sb = STRBUF_INIT;
3491 int ret = 0;
3493 logfp = fopen(git_path("logs/%s", refname), "r");
3494 if (!logfp)
3495 return -1;
3497 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3498 ret = show_one_reflog_ent(&sb, fn, cb_data);
3499 fclose(logfp);
3500 strbuf_release(&sb);
3501 return ret;
3504 * Call fn for each reflog in the namespace indicated by name. name
3505 * must be empty or end with '/'. Name will be used as a scratch
3506 * space, but its contents will be restored before return.
3508 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
3510 DIR *d = opendir(git_path("logs/%s", name->buf));
3511 int retval = 0;
3512 struct dirent *de;
3513 int oldlen = name->len;
3515 if (!d)
3516 return name->len ? errno : 0;
3518 while ((de = readdir(d)) != NULL) {
3519 struct stat st;
3521 if (de->d_name[0] == '.')
3522 continue;
3523 if (ends_with(de->d_name, ".lock"))
3524 continue;
3525 strbuf_addstr(name, de->d_name);
3526 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3527 ; /* silently ignore */
3528 } else {
3529 if (S_ISDIR(st.st_mode)) {
3530 strbuf_addch(name, '/');
3531 retval = do_for_each_reflog(name, fn, cb_data);
3532 } else {
3533 unsigned char sha1[20];
3534 if (read_ref_full(name->buf, 0, sha1, NULL))
3535 retval = error("bad ref for %s", name->buf);
3536 else
3537 retval = fn(name->buf, sha1, 0, cb_data);
3539 if (retval)
3540 break;
3542 strbuf_setlen(name, oldlen);
3544 closedir(d);
3545 return retval;
3548 int for_each_reflog(each_ref_fn fn, void *cb_data)
3550 int retval;
3551 struct strbuf name;
3552 strbuf_init(&name, PATH_MAX);
3553 retval = do_for_each_reflog(&name, fn, cb_data);
3554 strbuf_release(&name);
3555 return retval;
3559 * Information needed for a single ref update. Set new_sha1 to the
3560 * new value or to zero to delete the ref. To check the old value
3561 * while locking the ref, set have_old to 1 and set old_sha1 to the
3562 * value or to zero to ensure the ref does not exist before update.
3564 struct ref_update {
3565 unsigned char new_sha1[20];
3566 unsigned char old_sha1[20];
3567 int flags; /* REF_NODEREF? */
3568 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
3569 struct ref_lock *lock;
3570 int type;
3571 char *msg;
3572 const char refname[FLEX_ARRAY];
3576 * Transaction states.
3577 * OPEN: The transaction is in a valid state and can accept new updates.
3578 * An OPEN transaction can be committed.
3579 * CLOSED: A closed transaction is no longer active and no other operations
3580 * than free can be used on it in this state.
3581 * A transaction can either become closed by successfully committing
3582 * an active transaction or if there is a failure while building
3583 * the transaction thus rendering it failed/inactive.
3585 enum ref_transaction_state {
3586 REF_TRANSACTION_OPEN = 0,
3587 REF_TRANSACTION_CLOSED = 1
3591 * Data structure for holding a reference transaction, which can
3592 * consist of checks and updates to multiple references, carried out
3593 * as atomically as possible. This structure is opaque to callers.
3595 struct ref_transaction {
3596 struct ref_update **updates;
3597 size_t alloc;
3598 size_t nr;
3599 enum ref_transaction_state state;
3602 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
3604 assert(err);
3606 return xcalloc(1, sizeof(struct ref_transaction));
3609 void ref_transaction_free(struct ref_transaction *transaction)
3611 int i;
3613 if (!transaction)
3614 return;
3616 for (i = 0; i < transaction->nr; i++) {
3617 free(transaction->updates[i]->msg);
3618 free(transaction->updates[i]);
3620 free(transaction->updates);
3621 free(transaction);
3624 static struct ref_update *add_update(struct ref_transaction *transaction,
3625 const char *refname)
3627 size_t len = strlen(refname);
3628 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
3630 strcpy((char *)update->refname, refname);
3631 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
3632 transaction->updates[transaction->nr++] = update;
3633 return update;
3636 int ref_transaction_update(struct ref_transaction *transaction,
3637 const char *refname,
3638 const unsigned char *new_sha1,
3639 const unsigned char *old_sha1,
3640 int flags, int have_old, const char *msg,
3641 struct strbuf *err)
3643 struct ref_update *update;
3645 assert(err);
3647 if (transaction->state != REF_TRANSACTION_OPEN)
3648 die("BUG: update called for transaction that is not open");
3650 if (have_old && !old_sha1)
3651 die("BUG: have_old is true but old_sha1 is NULL");
3653 if (!is_null_sha1(new_sha1) &&
3654 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
3655 strbuf_addf(err, "refusing to update ref with bad name %s",
3656 refname);
3657 return -1;
3660 update = add_update(transaction, refname);
3661 hashcpy(update->new_sha1, new_sha1);
3662 update->flags = flags;
3663 update->have_old = have_old;
3664 if (have_old)
3665 hashcpy(update->old_sha1, old_sha1);
3666 if (msg)
3667 update->msg = xstrdup(msg);
3668 return 0;
3671 int ref_transaction_create(struct ref_transaction *transaction,
3672 const char *refname,
3673 const unsigned char *new_sha1,
3674 int flags, const char *msg,
3675 struct strbuf *err)
3677 return ref_transaction_update(transaction, refname, new_sha1,
3678 null_sha1, flags, 1, msg, err);
3681 int ref_transaction_delete(struct ref_transaction *transaction,
3682 const char *refname,
3683 const unsigned char *old_sha1,
3684 int flags, int have_old, const char *msg,
3685 struct strbuf *err)
3687 return ref_transaction_update(transaction, refname, null_sha1,
3688 old_sha1, flags, have_old, msg, err);
3691 int update_ref(const char *action, const char *refname,
3692 const unsigned char *sha1, const unsigned char *oldval,
3693 int flags, enum action_on_err onerr)
3695 struct ref_transaction *t;
3696 struct strbuf err = STRBUF_INIT;
3698 t = ref_transaction_begin(&err);
3699 if (!t ||
3700 ref_transaction_update(t, refname, sha1, oldval, flags,
3701 !!oldval, action, &err) ||
3702 ref_transaction_commit(t, &err)) {
3703 const char *str = "update_ref failed for ref '%s': %s";
3705 ref_transaction_free(t);
3706 switch (onerr) {
3707 case UPDATE_REFS_MSG_ON_ERR:
3708 error(str, refname, err.buf);
3709 break;
3710 case UPDATE_REFS_DIE_ON_ERR:
3711 die(str, refname, err.buf);
3712 break;
3713 case UPDATE_REFS_QUIET_ON_ERR:
3714 break;
3716 strbuf_release(&err);
3717 return 1;
3719 strbuf_release(&err);
3720 ref_transaction_free(t);
3721 return 0;
3724 static int ref_update_compare(const void *r1, const void *r2)
3726 const struct ref_update * const *u1 = r1;
3727 const struct ref_update * const *u2 = r2;
3728 return strcmp((*u1)->refname, (*u2)->refname);
3731 static int ref_update_reject_duplicates(struct ref_update **updates, int n,
3732 struct strbuf *err)
3734 int i;
3736 assert(err);
3738 for (i = 1; i < n; i++)
3739 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
3740 strbuf_addf(err,
3741 "Multiple updates for ref '%s' not allowed.",
3742 updates[i]->refname);
3743 return 1;
3745 return 0;
3748 int ref_transaction_commit(struct ref_transaction *transaction,
3749 struct strbuf *err)
3751 int ret = 0, i;
3752 int n = transaction->nr;
3753 struct ref_update **updates = transaction->updates;
3754 struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;
3755 struct string_list_item *ref_to_delete;
3757 assert(err);
3759 if (transaction->state != REF_TRANSACTION_OPEN)
3760 die("BUG: commit called for transaction that is not open");
3762 if (!n) {
3763 transaction->state = REF_TRANSACTION_CLOSED;
3764 return 0;
3767 /* Copy, sort, and reject duplicate refs */
3768 qsort(updates, n, sizeof(*updates), ref_update_compare);
3769 if (ref_update_reject_duplicates(updates, n, err)) {
3770 ret = TRANSACTION_GENERIC_ERROR;
3771 goto cleanup;
3774 /* Acquire all locks while verifying old values */
3775 for (i = 0; i < n; i++) {
3776 struct ref_update *update = updates[i];
3777 int flags = update->flags;
3779 if (is_null_sha1(update->new_sha1))
3780 flags |= REF_DELETING;
3781 update->lock = lock_ref_sha1_basic(update->refname,
3782 (update->have_old ?
3783 update->old_sha1 :
3784 NULL),
3785 NULL,
3786 flags,
3787 &update->type);
3788 if (!update->lock) {
3789 ret = (errno == ENOTDIR)
3790 ? TRANSACTION_NAME_CONFLICT
3791 : TRANSACTION_GENERIC_ERROR;
3792 strbuf_addf(err, "Cannot lock the ref '%s'.",
3793 update->refname);
3794 goto cleanup;
3798 /* Perform updates first so live commits remain referenced */
3799 for (i = 0; i < n; i++) {
3800 struct ref_update *update = updates[i];
3802 if (!is_null_sha1(update->new_sha1)) {
3803 if (write_ref_sha1(update->lock, update->new_sha1,
3804 update->msg)) {
3805 update->lock = NULL; /* freed by write_ref_sha1 */
3806 strbuf_addf(err, "Cannot update the ref '%s'.",
3807 update->refname);
3808 ret = TRANSACTION_GENERIC_ERROR;
3809 goto cleanup;
3811 update->lock = NULL; /* freed by write_ref_sha1 */
3815 /* Perform deletes now that updates are safely completed */
3816 for (i = 0; i < n; i++) {
3817 struct ref_update *update = updates[i];
3819 if (update->lock) {
3820 if (delete_ref_loose(update->lock, update->type, err)) {
3821 ret = TRANSACTION_GENERIC_ERROR;
3822 goto cleanup;
3825 if (!(update->flags & REF_ISPRUNING))
3826 string_list_append(&refs_to_delete,
3827 update->lock->ref_name);
3831 if (repack_without_refs(&refs_to_delete, err)) {
3832 ret = TRANSACTION_GENERIC_ERROR;
3833 goto cleanup;
3835 for_each_string_list_item(ref_to_delete, &refs_to_delete)
3836 unlink_or_warn(git_path("logs/%s", ref_to_delete->string));
3837 clear_loose_ref_cache(&ref_cache);
3839 cleanup:
3840 transaction->state = REF_TRANSACTION_CLOSED;
3842 for (i = 0; i < n; i++)
3843 if (updates[i]->lock)
3844 unlock_ref(updates[i]->lock);
3845 string_list_clear(&refs_to_delete, 0);
3846 return ret;
3849 char *shorten_unambiguous_ref(const char *refname, int strict)
3851 int i;
3852 static char **scanf_fmts;
3853 static int nr_rules;
3854 char *short_name;
3856 if (!nr_rules) {
3858 * Pre-generate scanf formats from ref_rev_parse_rules[].
3859 * Generate a format suitable for scanf from a
3860 * ref_rev_parse_rules rule by interpolating "%s" at the
3861 * location of the "%.*s".
3863 size_t total_len = 0;
3864 size_t offset = 0;
3866 /* the rule list is NULL terminated, count them first */
3867 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
3868 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
3869 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
3871 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3873 offset = 0;
3874 for (i = 0; i < nr_rules; i++) {
3875 assert(offset < total_len);
3876 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
3877 offset += snprintf(scanf_fmts[i], total_len - offset,
3878 ref_rev_parse_rules[i], 2, "%s") + 1;
3882 /* bail out if there are no rules */
3883 if (!nr_rules)
3884 return xstrdup(refname);
3886 /* buffer for scanf result, at most refname must fit */
3887 short_name = xstrdup(refname);
3889 /* skip first rule, it will always match */
3890 for (i = nr_rules - 1; i > 0 ; --i) {
3891 int j;
3892 int rules_to_fail = i;
3893 int short_name_len;
3895 if (1 != sscanf(refname, scanf_fmts[i], short_name))
3896 continue;
3898 short_name_len = strlen(short_name);
3901 * in strict mode, all (except the matched one) rules
3902 * must fail to resolve to a valid non-ambiguous ref
3904 if (strict)
3905 rules_to_fail = nr_rules;
3908 * check if the short name resolves to a valid ref,
3909 * but use only rules prior to the matched one
3911 for (j = 0; j < rules_to_fail; j++) {
3912 const char *rule = ref_rev_parse_rules[j];
3913 char refname[PATH_MAX];
3915 /* skip matched rule */
3916 if (i == j)
3917 continue;
3920 * the short name is ambiguous, if it resolves
3921 * (with this previous rule) to a valid ref
3922 * read_ref() returns 0 on success
3924 mksnpath(refname, sizeof(refname),
3925 rule, short_name_len, short_name);
3926 if (ref_exists(refname))
3927 break;
3931 * short name is non-ambiguous if all previous rules
3932 * haven't resolved to a valid ref
3934 if (j == rules_to_fail)
3935 return short_name;
3938 free(short_name);
3939 return xstrdup(refname);
3942 static struct string_list *hide_refs;
3944 int parse_hide_refs_config(const char *var, const char *value, const char *section)
3946 if (!strcmp("transfer.hiderefs", var) ||
3947 /* NEEDSWORK: use parse_config_key() once both are merged */
3948 (starts_with(var, section) && var[strlen(section)] == '.' &&
3949 !strcmp(var + strlen(section), ".hiderefs"))) {
3950 char *ref;
3951 int len;
3953 if (!value)
3954 return config_error_nonbool(var);
3955 ref = xstrdup(value);
3956 len = strlen(ref);
3957 while (len && ref[len - 1] == '/')
3958 ref[--len] = '\0';
3959 if (!hide_refs) {
3960 hide_refs = xcalloc(1, sizeof(*hide_refs));
3961 hide_refs->strdup_strings = 1;
3963 string_list_append(hide_refs, ref);
3965 return 0;
3968 int ref_is_hidden(const char *refname)
3970 struct string_list_item *item;
3972 if (!hide_refs)
3973 return 0;
3974 for_each_string_list_item(item, hide_refs) {
3975 int len;
3976 if (!starts_with(refname, item->string))
3977 continue;
3978 len = strlen(item->string);
3979 if (!refname[len] || refname[len] == '/')
3980 return 1;
3982 return 0;
3985 struct expire_reflog_cb {
3986 unsigned int flags;
3987 reflog_expiry_should_prune_fn *should_prune_fn;
3988 void *policy_cb;
3989 FILE *newlog;
3990 unsigned char last_kept_sha1[20];
3993 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
3994 const char *email, unsigned long timestamp, int tz,
3995 const char *message, void *cb_data)
3997 struct expire_reflog_cb *cb = cb_data;
3998 struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;
4000 if (cb->flags & EXPIRE_REFLOGS_REWRITE)
4001 osha1 = cb->last_kept_sha1;
4003 if ((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,
4004 message, policy_cb)) {
4005 if (!cb->newlog)
4006 printf("would prune %s", message);
4007 else if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
4008 printf("prune %s", message);
4009 } else {
4010 if (cb->newlog) {
4011 fprintf(cb->newlog, "%s %s %s %lu %+05d\t%s",
4012 sha1_to_hex(osha1), sha1_to_hex(nsha1),
4013 email, timestamp, tz, message);
4014 hashcpy(cb->last_kept_sha1, nsha1);
4016 if (cb->flags & EXPIRE_REFLOGS_VERBOSE)
4017 printf("keep %s", message);
4019 return 0;
4022 int reflog_expire(const char *refname, const unsigned char *sha1,
4023 unsigned int flags,
4024 reflog_expiry_prepare_fn prepare_fn,
4025 reflog_expiry_should_prune_fn should_prune_fn,
4026 reflog_expiry_cleanup_fn cleanup_fn,
4027 void *policy_cb_data)
4029 static struct lock_file reflog_lock;
4030 struct expire_reflog_cb cb;
4031 struct ref_lock *lock;
4032 char *log_file;
4033 int status = 0;
4035 memset(&cb, 0, sizeof(cb));
4036 cb.flags = flags;
4037 cb.policy_cb = policy_cb_data;
4038 cb.should_prune_fn = should_prune_fn;
4041 * The reflog file is locked by holding the lock on the
4042 * reference itself, plus we might need to update the
4043 * reference if --updateref was specified:
4045 lock = lock_ref_sha1_basic(refname, sha1, NULL, 0, NULL);
4046 if (!lock)
4047 return error("cannot lock ref '%s'", refname);
4048 if (!reflog_exists(refname)) {
4049 unlock_ref(lock);
4050 return 0;
4053 log_file = git_pathdup("logs/%s", refname);
4054 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
4056 * Even though holding $GIT_DIR/logs/$reflog.lock has
4057 * no locking implications, we use the lock_file
4058 * machinery here anyway because it does a lot of the
4059 * work we need, including cleaning up if the program
4060 * exits unexpectedly.
4062 if (hold_lock_file_for_update(&reflog_lock, log_file, 0) < 0) {
4063 struct strbuf err = STRBUF_INIT;
4064 unable_to_lock_message(log_file, errno, &err);
4065 error("%s", err.buf);
4066 strbuf_release(&err);
4067 goto failure;
4069 cb.newlog = fdopen_lock_file(&reflog_lock, "w");
4070 if (!cb.newlog) {
4071 error("cannot fdopen %s (%s)",
4072 reflog_lock.filename.buf, strerror(errno));
4073 goto failure;
4077 (*prepare_fn)(refname, sha1, cb.policy_cb);
4078 for_each_reflog_ent(refname, expire_reflog_ent, &cb);
4079 (*cleanup_fn)(cb.policy_cb);
4081 if (!(flags & EXPIRE_REFLOGS_DRY_RUN)) {
4082 if (close_lock_file(&reflog_lock)) {
4083 status |= error("couldn't write %s: %s", log_file,
4084 strerror(errno));
4085 } else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) &&
4086 (write_in_full(lock->lock_fd,
4087 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
4088 write_str_in_full(lock->lock_fd, "\n") != 1 ||
4089 close_ref(lock) < 0)) {
4090 status |= error("couldn't write %s",
4091 lock->lk->filename.buf);
4092 rollback_lock_file(&reflog_lock);
4093 } else if (commit_lock_file(&reflog_lock)) {
4094 status |= error("unable to commit reflog '%s' (%s)",
4095 log_file, strerror(errno));
4096 } else if ((flags & EXPIRE_REFLOGS_UPDATE_REF) && commit_ref(lock)) {
4097 status |= error("couldn't set %s", lock->ref_name);
4100 free(log_file);
4101 unlock_ref(lock);
4102 return status;
4104 failure:
4105 rollback_lock_file(&reflog_lock);
4106 free(log_file);
4107 unlock_ref(lock);
4108 return -1;