Documentation/describe: improve one-line summary
[git.git] / refs.c
blob6664423f8d402b98a3aae90c932f64cff4d88cb2
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 /*
10 * How to handle various characters in refnames:
11 * 0: An acceptable character for refs
12 * 1: End-of-component
13 * 2: ., look for a preceding . to reject .. in refs
14 * 3: {, look for a preceding @ to reject @{ in refs
15 * 4: A bad character: ASCII control characters, "~", "^", ":" or SP
17 static unsigned char refname_disposition[256] = {
18 1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
19 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
20 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1,
21 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
22 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
23 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
24 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
25 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
29 * Used as a flag to ref_transaction_delete when a loose ref is being
30 * pruned.
32 #define REF_ISPRUNING 0x0100
34 * Try to read one refname component from the front of refname.
35 * Return the length of the component found, or -1 if the component is
36 * not legal. It is legal if it is something reasonable to have under
37 * ".git/refs/"; We do not like it if:
39 * - any path component of it begins with ".", or
40 * - it has double dots "..", or
41 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
42 * - it ends with a "/".
43 * - it ends with ".lock"
44 * - it contains a "\" (backslash)
46 static int check_refname_component(const char *refname, int flags)
48 const char *cp;
49 char last = '\0';
51 for (cp = refname; ; cp++) {
52 int ch = *cp & 255;
53 unsigned char disp = refname_disposition[ch];
54 switch (disp) {
55 case 1:
56 goto out;
57 case 2:
58 if (last == '.')
59 return -1; /* Refname contains "..". */
60 break;
61 case 3:
62 if (last == '@')
63 return -1; /* Refname contains "@{". */
64 break;
65 case 4:
66 return -1;
68 last = ch;
70 out:
71 if (cp == refname)
72 return 0; /* Component has zero length. */
73 if (refname[0] == '.')
74 return -1; /* Component starts with '.'. */
75 if (cp - refname >= LOCK_SUFFIX_LEN &&
76 !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
77 return -1; /* Refname ends with ".lock". */
78 return cp - refname;
81 int check_refname_format(const char *refname, int flags)
83 int component_len, component_count = 0;
85 if (!strcmp(refname, "@"))
86 /* Refname is a single character '@'. */
87 return -1;
89 while (1) {
90 /* We are at the start of a path component. */
91 component_len = check_refname_component(refname, flags);
92 if (component_len <= 0) {
93 if ((flags & REFNAME_REFSPEC_PATTERN) &&
94 refname[0] == '*' &&
95 (refname[1] == '\0' || refname[1] == '/')) {
96 /* Accept one wildcard as a full refname component. */
97 flags &= ~REFNAME_REFSPEC_PATTERN;
98 component_len = 1;
99 } else {
100 return -1;
103 component_count++;
104 if (refname[component_len] == '\0')
105 break;
106 /* Skip to next component. */
107 refname += component_len + 1;
110 if (refname[component_len - 1] == '.')
111 return -1; /* Refname ends with '.'. */
112 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
113 return -1; /* Refname has only one component. */
114 return 0;
117 struct ref_entry;
120 * Information used (along with the information in ref_entry) to
121 * describe a single cached reference. This data structure only
122 * occurs embedded in a union in struct ref_entry, and only when
123 * (ref_entry->flag & REF_DIR) is zero.
125 struct ref_value {
127 * The name of the object to which this reference resolves
128 * (which may be a tag object). If REF_ISBROKEN, this is
129 * null. If REF_ISSYMREF, then this is the name of the object
130 * referred to by the last reference in the symlink chain.
132 unsigned char sha1[20];
135 * If REF_KNOWS_PEELED, then this field holds the peeled value
136 * of this reference, or null if the reference is known not to
137 * be peelable. See the documentation for peel_ref() for an
138 * exact definition of "peelable".
140 unsigned char peeled[20];
143 struct ref_cache;
146 * Information used (along with the information in ref_entry) to
147 * describe a level in the hierarchy of references. This data
148 * structure only occurs embedded in a union in struct ref_entry, and
149 * only when (ref_entry.flag & REF_DIR) is set. In that case,
150 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
151 * in the directory have already been read:
153 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
154 * or packed references, already read.
156 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
157 * references that hasn't been read yet (nor has any of its
158 * subdirectories).
160 * Entries within a directory are stored within a growable array of
161 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
162 * sorted are sorted by their component name in strcmp() order and the
163 * remaining entries are unsorted.
165 * Loose references are read lazily, one directory at a time. When a
166 * directory of loose references is read, then all of the references
167 * in that directory are stored, and REF_INCOMPLETE stubs are created
168 * for any subdirectories, but the subdirectories themselves are not
169 * read. The reading is triggered by get_ref_dir().
171 struct ref_dir {
172 int nr, alloc;
175 * Entries with index 0 <= i < sorted are sorted by name. New
176 * entries are appended to the list unsorted, and are sorted
177 * only when required; thus we avoid the need to sort the list
178 * after the addition of every reference.
180 int sorted;
182 /* A pointer to the ref_cache that contains this ref_dir. */
183 struct ref_cache *ref_cache;
185 struct ref_entry **entries;
189 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
190 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are
191 * public values; see refs.h.
195 * The field ref_entry->u.value.peeled of this value entry contains
196 * the correct peeled value for the reference, which might be
197 * null_sha1 if the reference is not a tag or if it is broken.
199 #define REF_KNOWS_PEELED 0x10
201 /* ref_entry represents a directory of references */
202 #define REF_DIR 0x20
205 * Entry has not yet been read from disk (used only for REF_DIR
206 * entries representing loose references)
208 #define REF_INCOMPLETE 0x40
211 * A ref_entry represents either a reference or a "subdirectory" of
212 * references.
214 * Each directory in the reference namespace is represented by a
215 * ref_entry with (flags & REF_DIR) set and containing a subdir member
216 * that holds the entries in that directory that have been read so
217 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
218 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
219 * used for loose reference directories.
221 * References are represented by a ref_entry with (flags & REF_DIR)
222 * unset and a value member that describes the reference's value. The
223 * flag member is at the ref_entry level, but it is also needed to
224 * interpret the contents of the value field (in other words, a
225 * ref_value object is not very much use without the enclosing
226 * ref_entry).
228 * Reference names cannot end with slash and directories' names are
229 * always stored with a trailing slash (except for the top-level
230 * directory, which is always denoted by ""). This has two nice
231 * consequences: (1) when the entries in each subdir are sorted
232 * lexicographically by name (as they usually are), the references in
233 * a whole tree can be generated in lexicographic order by traversing
234 * the tree in left-to-right, depth-first order; (2) the names of
235 * references and subdirectories cannot conflict, and therefore the
236 * presence of an empty subdirectory does not block the creation of a
237 * similarly-named reference. (The fact that reference names with the
238 * same leading components can conflict *with each other* is a
239 * separate issue that is regulated by is_refname_available().)
241 * Please note that the name field contains the fully-qualified
242 * reference (or subdirectory) name. Space could be saved by only
243 * storing the relative names. But that would require the full names
244 * to be generated on the fly when iterating in do_for_each_ref(), and
245 * would break callback functions, who have always been able to assume
246 * that the name strings that they are passed will not be freed during
247 * the iteration.
249 struct ref_entry {
250 unsigned char flag; /* ISSYMREF? ISPACKED? */
251 union {
252 struct ref_value value; /* if not (flags&REF_DIR) */
253 struct ref_dir subdir; /* if (flags&REF_DIR) */
254 } u;
256 * The full name of the reference (e.g., "refs/heads/master")
257 * or the full name of the directory with a trailing slash
258 * (e.g., "refs/heads/"):
260 char name[FLEX_ARRAY];
263 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
265 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
267 struct ref_dir *dir;
268 assert(entry->flag & REF_DIR);
269 dir = &entry->u.subdir;
270 if (entry->flag & REF_INCOMPLETE) {
271 read_loose_refs(entry->name, dir);
272 entry->flag &= ~REF_INCOMPLETE;
274 return dir;
278 * Check if a refname is safe.
279 * For refs that start with "refs/" we consider it safe as long they do
280 * not try to resolve to outside of refs/.
282 * For all other refs we only consider them safe iff they only contain
283 * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like
284 * "config").
286 static int refname_is_safe(const char *refname)
288 if (starts_with(refname, "refs/")) {
289 char *buf;
290 int result;
292 buf = xmalloc(strlen(refname) + 1);
294 * Does the refname try to escape refs/?
295 * For example: refs/foo/../bar is safe but refs/foo/../../bar
296 * is not.
298 result = !normalize_path_copy(buf, refname + strlen("refs/"));
299 free(buf);
300 return result;
302 while (*refname) {
303 if (!isupper(*refname) && *refname != '_')
304 return 0;
305 refname++;
307 return 1;
310 static struct ref_entry *create_ref_entry(const char *refname,
311 const unsigned char *sha1, int flag,
312 int check_name)
314 int len;
315 struct ref_entry *ref;
317 if (check_name &&
318 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
319 die("Reference has invalid format: '%s'", refname);
320 if (!check_name && !refname_is_safe(refname))
321 die("Reference has invalid name: '%s'", refname);
322 len = strlen(refname) + 1;
323 ref = xmalloc(sizeof(struct ref_entry) + len);
324 hashcpy(ref->u.value.sha1, sha1);
325 hashclr(ref->u.value.peeled);
326 memcpy(ref->name, refname, len);
327 ref->flag = flag;
328 return ref;
331 static void clear_ref_dir(struct ref_dir *dir);
333 static void free_ref_entry(struct ref_entry *entry)
335 if (entry->flag & REF_DIR) {
337 * Do not use get_ref_dir() here, as that might
338 * trigger the reading of loose refs.
340 clear_ref_dir(&entry->u.subdir);
342 free(entry);
346 * Add a ref_entry to the end of dir (unsorted). Entry is always
347 * stored directly in dir; no recursion into subdirectories is
348 * done.
350 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
352 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
353 dir->entries[dir->nr++] = entry;
354 /* optimize for the case that entries are added in order */
355 if (dir->nr == 1 ||
356 (dir->nr == dir->sorted + 1 &&
357 strcmp(dir->entries[dir->nr - 2]->name,
358 dir->entries[dir->nr - 1]->name) < 0))
359 dir->sorted = dir->nr;
363 * Clear and free all entries in dir, recursively.
365 static void clear_ref_dir(struct ref_dir *dir)
367 int i;
368 for (i = 0; i < dir->nr; i++)
369 free_ref_entry(dir->entries[i]);
370 free(dir->entries);
371 dir->sorted = dir->nr = dir->alloc = 0;
372 dir->entries = NULL;
376 * Create a struct ref_entry object for the specified dirname.
377 * dirname is the name of the directory with a trailing slash (e.g.,
378 * "refs/heads/") or "" for the top-level directory.
380 static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
381 const char *dirname, size_t len,
382 int incomplete)
384 struct ref_entry *direntry;
385 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
386 memcpy(direntry->name, dirname, len);
387 direntry->name[len] = '\0';
388 direntry->u.subdir.ref_cache = ref_cache;
389 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
390 return direntry;
393 static int ref_entry_cmp(const void *a, const void *b)
395 struct ref_entry *one = *(struct ref_entry **)a;
396 struct ref_entry *two = *(struct ref_entry **)b;
397 return strcmp(one->name, two->name);
400 static void sort_ref_dir(struct ref_dir *dir);
402 struct string_slice {
403 size_t len;
404 const char *str;
407 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
409 const struct string_slice *key = key_;
410 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
411 int cmp = strncmp(key->str, ent->name, key->len);
412 if (cmp)
413 return cmp;
414 return '\0' - (unsigned char)ent->name[key->len];
418 * Return the index of the entry with the given refname from the
419 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
420 * no such entry is found. dir must already be complete.
422 static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
424 struct ref_entry **r;
425 struct string_slice key;
427 if (refname == NULL || !dir->nr)
428 return -1;
430 sort_ref_dir(dir);
431 key.len = len;
432 key.str = refname;
433 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
434 ref_entry_cmp_sslice);
436 if (r == NULL)
437 return -1;
439 return r - dir->entries;
443 * Search for a directory entry directly within dir (without
444 * recursing). Sort dir if necessary. subdirname must be a directory
445 * name (i.e., end in '/'). If mkdir is set, then create the
446 * directory if it is missing; otherwise, return NULL if the desired
447 * directory cannot be found. dir must already be complete.
449 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
450 const char *subdirname, size_t len,
451 int mkdir)
453 int entry_index = search_ref_dir(dir, subdirname, len);
454 struct ref_entry *entry;
455 if (entry_index == -1) {
456 if (!mkdir)
457 return NULL;
459 * Since dir is complete, the absence of a subdir
460 * means that the subdir really doesn't exist;
461 * therefore, create an empty record for it but mark
462 * the record complete.
464 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
465 add_entry_to_dir(dir, entry);
466 } else {
467 entry = dir->entries[entry_index];
469 return get_ref_dir(entry);
473 * If refname is a reference name, find the ref_dir within the dir
474 * tree that should hold refname. If refname is a directory name
475 * (i.e., ends in '/'), then return that ref_dir itself. dir must
476 * represent the top-level directory and must already be complete.
477 * Sort ref_dirs and recurse into subdirectories as necessary. If
478 * mkdir is set, then create any missing directories; otherwise,
479 * return NULL if the desired directory cannot be found.
481 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
482 const char *refname, int mkdir)
484 const char *slash;
485 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
486 size_t dirnamelen = slash - refname + 1;
487 struct ref_dir *subdir;
488 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
489 if (!subdir) {
490 dir = NULL;
491 break;
493 dir = subdir;
496 return dir;
500 * Find the value entry with the given name in dir, sorting ref_dirs
501 * and recursing into subdirectories as necessary. If the name is not
502 * found or it corresponds to a directory entry, return NULL.
504 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
506 int entry_index;
507 struct ref_entry *entry;
508 dir = find_containing_dir(dir, refname, 0);
509 if (!dir)
510 return NULL;
511 entry_index = search_ref_dir(dir, refname, strlen(refname));
512 if (entry_index == -1)
513 return NULL;
514 entry = dir->entries[entry_index];
515 return (entry->flag & REF_DIR) ? NULL : entry;
519 * Remove the entry with the given name from dir, recursing into
520 * subdirectories as necessary. If refname is the name of a directory
521 * (i.e., ends with '/'), then remove the directory and its contents.
522 * If the removal was successful, return the number of entries
523 * remaining in the directory entry that contained the deleted entry.
524 * If the name was not found, return -1. Please note that this
525 * function only deletes the entry from the cache; it does not delete
526 * it from the filesystem or ensure that other cache entries (which
527 * might be symbolic references to the removed entry) are updated.
528 * Nor does it remove any containing dir entries that might be made
529 * empty by the removal. dir must represent the top-level directory
530 * and must already be complete.
532 static int remove_entry(struct ref_dir *dir, const char *refname)
534 int refname_len = strlen(refname);
535 int entry_index;
536 struct ref_entry *entry;
537 int is_dir = refname[refname_len - 1] == '/';
538 if (is_dir) {
540 * refname represents a reference directory. Remove
541 * the trailing slash; otherwise we will get the
542 * directory *representing* refname rather than the
543 * one *containing* it.
545 char *dirname = xmemdupz(refname, refname_len - 1);
546 dir = find_containing_dir(dir, dirname, 0);
547 free(dirname);
548 } else {
549 dir = find_containing_dir(dir, refname, 0);
551 if (!dir)
552 return -1;
553 entry_index = search_ref_dir(dir, refname, refname_len);
554 if (entry_index == -1)
555 return -1;
556 entry = dir->entries[entry_index];
558 memmove(&dir->entries[entry_index],
559 &dir->entries[entry_index + 1],
560 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
562 dir->nr--;
563 if (dir->sorted > entry_index)
564 dir->sorted--;
565 free_ref_entry(entry);
566 return dir->nr;
570 * Add a ref_entry to the ref_dir (unsorted), recursing into
571 * subdirectories as necessary. dir must represent the top-level
572 * directory. Return 0 on success.
574 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
576 dir = find_containing_dir(dir, ref->name, 1);
577 if (!dir)
578 return -1;
579 add_entry_to_dir(dir, ref);
580 return 0;
584 * Emit a warning and return true iff ref1 and ref2 have the same name
585 * and the same sha1. Die if they have the same name but different
586 * sha1s.
588 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
590 if (strcmp(ref1->name, ref2->name))
591 return 0;
593 /* Duplicate name; make sure that they don't conflict: */
595 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
596 /* This is impossible by construction */
597 die("Reference directory conflict: %s", ref1->name);
599 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
600 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
602 warning("Duplicated ref: %s", ref1->name);
603 return 1;
607 * Sort the entries in dir non-recursively (if they are not already
608 * sorted) and remove any duplicate entries.
610 static void sort_ref_dir(struct ref_dir *dir)
612 int i, j;
613 struct ref_entry *last = NULL;
616 * This check also prevents passing a zero-length array to qsort(),
617 * which is a problem on some platforms.
619 if (dir->sorted == dir->nr)
620 return;
622 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
624 /* Remove any duplicates: */
625 for (i = 0, j = 0; j < dir->nr; j++) {
626 struct ref_entry *entry = dir->entries[j];
627 if (last && is_dup_ref(last, entry))
628 free_ref_entry(entry);
629 else
630 last = dir->entries[i++] = entry;
632 dir->sorted = dir->nr = i;
635 /* Include broken references in a do_for_each_ref*() iteration: */
636 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
639 * Return true iff the reference described by entry can be resolved to
640 * an object in the database. Emit a warning if the referred-to
641 * object does not exist.
643 static int ref_resolves_to_object(struct ref_entry *entry)
645 if (entry->flag & REF_ISBROKEN)
646 return 0;
647 if (!has_sha1_file(entry->u.value.sha1)) {
648 error("%s does not point to a valid object!", entry->name);
649 return 0;
651 return 1;
655 * current_ref is a performance hack: when iterating over references
656 * using the for_each_ref*() functions, current_ref is set to the
657 * current reference's entry before calling the callback function. If
658 * the callback function calls peel_ref(), then peel_ref() first
659 * checks whether the reference to be peeled is the current reference
660 * (it usually is) and if so, returns that reference's peeled version
661 * if it is available. This avoids a refname lookup in a common case.
663 static struct ref_entry *current_ref;
665 typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
667 struct ref_entry_cb {
668 const char *base;
669 int trim;
670 int flags;
671 each_ref_fn *fn;
672 void *cb_data;
676 * Handle one reference in a do_for_each_ref*()-style iteration,
677 * calling an each_ref_fn for each entry.
679 static int do_one_ref(struct ref_entry *entry, void *cb_data)
681 struct ref_entry_cb *data = cb_data;
682 struct ref_entry *old_current_ref;
683 int retval;
685 if (!starts_with(entry->name, data->base))
686 return 0;
688 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
689 !ref_resolves_to_object(entry))
690 return 0;
692 /* Store the old value, in case this is a recursive call: */
693 old_current_ref = current_ref;
694 current_ref = entry;
695 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
696 entry->flag, data->cb_data);
697 current_ref = old_current_ref;
698 return retval;
702 * Call fn for each reference in dir that has index in the range
703 * offset <= index < dir->nr. Recurse into subdirectories that are in
704 * that index range, sorting them before iterating. This function
705 * does not sort dir itself; it should be sorted beforehand. fn is
706 * called for all references, including broken ones.
708 static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
709 each_ref_entry_fn fn, void *cb_data)
711 int i;
712 assert(dir->sorted == dir->nr);
713 for (i = offset; i < dir->nr; i++) {
714 struct ref_entry *entry = dir->entries[i];
715 int retval;
716 if (entry->flag & REF_DIR) {
717 struct ref_dir *subdir = get_ref_dir(entry);
718 sort_ref_dir(subdir);
719 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
720 } else {
721 retval = fn(entry, cb_data);
723 if (retval)
724 return retval;
726 return 0;
730 * Call fn for each reference in the union of dir1 and dir2, in order
731 * by refname. Recurse into subdirectories. If a value entry appears
732 * in both dir1 and dir2, then only process the version that is in
733 * dir2. The input dirs must already be sorted, but subdirs will be
734 * sorted as needed. fn is called for all references, including
735 * broken ones.
737 static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
738 struct ref_dir *dir2,
739 each_ref_entry_fn fn, void *cb_data)
741 int retval;
742 int i1 = 0, i2 = 0;
744 assert(dir1->sorted == dir1->nr);
745 assert(dir2->sorted == dir2->nr);
746 while (1) {
747 struct ref_entry *e1, *e2;
748 int cmp;
749 if (i1 == dir1->nr) {
750 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
752 if (i2 == dir2->nr) {
753 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
755 e1 = dir1->entries[i1];
756 e2 = dir2->entries[i2];
757 cmp = strcmp(e1->name, e2->name);
758 if (cmp == 0) {
759 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
760 /* Both are directories; descend them in parallel. */
761 struct ref_dir *subdir1 = get_ref_dir(e1);
762 struct ref_dir *subdir2 = get_ref_dir(e2);
763 sort_ref_dir(subdir1);
764 sort_ref_dir(subdir2);
765 retval = do_for_each_entry_in_dirs(
766 subdir1, subdir2, fn, cb_data);
767 i1++;
768 i2++;
769 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
770 /* Both are references; ignore the one from dir1. */
771 retval = fn(e2, cb_data);
772 i1++;
773 i2++;
774 } else {
775 die("conflict between reference and directory: %s",
776 e1->name);
778 } else {
779 struct ref_entry *e;
780 if (cmp < 0) {
781 e = e1;
782 i1++;
783 } else {
784 e = e2;
785 i2++;
787 if (e->flag & REF_DIR) {
788 struct ref_dir *subdir = get_ref_dir(e);
789 sort_ref_dir(subdir);
790 retval = do_for_each_entry_in_dir(
791 subdir, 0, fn, cb_data);
792 } else {
793 retval = fn(e, cb_data);
796 if (retval)
797 return retval;
802 * Load all of the refs from the dir into our in-memory cache. The hard work
803 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
804 * through all of the sub-directories. We do not even need to care about
805 * sorting, as traversal order does not matter to us.
807 static void prime_ref_dir(struct ref_dir *dir)
809 int i;
810 for (i = 0; i < dir->nr; i++) {
811 struct ref_entry *entry = dir->entries[i];
812 if (entry->flag & REF_DIR)
813 prime_ref_dir(get_ref_dir(entry));
817 static int entry_matches(struct ref_entry *entry, const struct string_list *list)
819 return list && string_list_has_string(list, entry->name);
822 struct nonmatching_ref_data {
823 const struct string_list *skip;
824 struct ref_entry *found;
827 static int nonmatching_ref_fn(struct ref_entry *entry, void *vdata)
829 struct nonmatching_ref_data *data = vdata;
831 if (entry_matches(entry, data->skip))
832 return 0;
834 data->found = entry;
835 return 1;
838 static void report_refname_conflict(struct ref_entry *entry,
839 const char *refname)
841 error("'%s' exists; cannot create '%s'", entry->name, refname);
845 * Return true iff a reference named refname could be created without
846 * conflicting with the name of an existing reference in dir. If
847 * skip is non-NULL, ignore potential conflicts with refs in skip
848 * (e.g., because they are scheduled for deletion in the same
849 * operation).
851 * Two reference names conflict if one of them exactly matches the
852 * leading components of the other; e.g., "foo/bar" conflicts with
853 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
854 * "foo/barbados".
856 * skip must be sorted.
858 static int is_refname_available(const char *refname,
859 const struct string_list *skip,
860 struct ref_dir *dir)
862 const char *slash;
863 size_t len;
864 int pos;
865 char *dirname;
867 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
869 * We are still at a leading dir of the refname; we are
870 * looking for a conflict with a leaf entry.
872 * If we find one, we still must make sure it is
873 * not in "skip".
875 pos = search_ref_dir(dir, refname, slash - refname);
876 if (pos >= 0) {
877 struct ref_entry *entry = dir->entries[pos];
878 if (entry_matches(entry, skip))
879 return 1;
880 report_refname_conflict(entry, refname);
881 return 0;
886 * Otherwise, we can try to continue our search with
887 * the next component; if we come up empty, we know
888 * there is nothing under this whole prefix.
890 pos = search_ref_dir(dir, refname, slash + 1 - refname);
891 if (pos < 0)
892 return 1;
894 dir = get_ref_dir(dir->entries[pos]);
898 * We are at the leaf of our refname; we want to
899 * make sure there are no directories which match it.
901 len = strlen(refname);
902 dirname = xmallocz(len + 1);
903 sprintf(dirname, "%s/", refname);
904 pos = search_ref_dir(dir, dirname, len + 1);
905 free(dirname);
907 if (pos >= 0) {
909 * We found a directory named "refname". It is a
910 * problem iff it contains any ref that is not
911 * in "skip".
913 struct ref_entry *entry = dir->entries[pos];
914 struct ref_dir *dir = get_ref_dir(entry);
915 struct nonmatching_ref_data data;
917 data.skip = skip;
918 sort_ref_dir(dir);
919 if (!do_for_each_entry_in_dir(dir, 0, nonmatching_ref_fn, &data))
920 return 1;
922 report_refname_conflict(data.found, refname);
923 return 0;
927 * There is no point in searching for another leaf
928 * node which matches it; such an entry would be the
929 * ref we are looking for, not a conflict.
931 return 1;
934 struct packed_ref_cache {
935 struct ref_entry *root;
938 * Count of references to the data structure in this instance,
939 * including the pointer from ref_cache::packed if any. The
940 * data will not be freed as long as the reference count is
941 * nonzero.
943 unsigned int referrers;
946 * Iff the packed-refs file associated with this instance is
947 * currently locked for writing, this points at the associated
948 * lock (which is owned by somebody else). The referrer count
949 * is also incremented when the file is locked and decremented
950 * when it is unlocked.
952 struct lock_file *lock;
954 /* The metadata from when this packed-refs cache was read */
955 struct stat_validity validity;
959 * Future: need to be in "struct repository"
960 * when doing a full libification.
962 static struct ref_cache {
963 struct ref_cache *next;
964 struct ref_entry *loose;
965 struct packed_ref_cache *packed;
967 * The submodule name, or "" for the main repo. We allocate
968 * length 1 rather than FLEX_ARRAY so that the main ref_cache
969 * is initialized correctly.
971 char name[1];
972 } ref_cache, *submodule_ref_caches;
974 /* Lock used for the main packed-refs file: */
975 static struct lock_file packlock;
978 * Increment the reference count of *packed_refs.
980 static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
982 packed_refs->referrers++;
986 * Decrease the reference count of *packed_refs. If it goes to zero,
987 * free *packed_refs and return true; otherwise return false.
989 static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
991 if (!--packed_refs->referrers) {
992 free_ref_entry(packed_refs->root);
993 stat_validity_clear(&packed_refs->validity);
994 free(packed_refs);
995 return 1;
996 } else {
997 return 0;
1001 static void clear_packed_ref_cache(struct ref_cache *refs)
1003 if (refs->packed) {
1004 struct packed_ref_cache *packed_refs = refs->packed;
1006 if (packed_refs->lock)
1007 die("internal error: packed-ref cache cleared while locked");
1008 refs->packed = NULL;
1009 release_packed_ref_cache(packed_refs);
1013 static void clear_loose_ref_cache(struct ref_cache *refs)
1015 if (refs->loose) {
1016 free_ref_entry(refs->loose);
1017 refs->loose = NULL;
1021 static struct ref_cache *create_ref_cache(const char *submodule)
1023 int len;
1024 struct ref_cache *refs;
1025 if (!submodule)
1026 submodule = "";
1027 len = strlen(submodule) + 1;
1028 refs = xcalloc(1, sizeof(struct ref_cache) + len);
1029 memcpy(refs->name, submodule, len);
1030 return refs;
1034 * Return a pointer to a ref_cache for the specified submodule. For
1035 * the main repository, use submodule==NULL. The returned structure
1036 * will be allocated and initialized but not necessarily populated; it
1037 * should not be freed.
1039 static struct ref_cache *get_ref_cache(const char *submodule)
1041 struct ref_cache *refs;
1043 if (!submodule || !*submodule)
1044 return &ref_cache;
1046 for (refs = submodule_ref_caches; refs; refs = refs->next)
1047 if (!strcmp(submodule, refs->name))
1048 return refs;
1050 refs = create_ref_cache(submodule);
1051 refs->next = submodule_ref_caches;
1052 submodule_ref_caches = refs;
1053 return refs;
1056 /* The length of a peeled reference line in packed-refs, including EOL: */
1057 #define PEELED_LINE_LENGTH 42
1060 * The packed-refs header line that we write out. Perhaps other
1061 * traits will be added later. The trailing space is required.
1063 static const char PACKED_REFS_HEADER[] =
1064 "# pack-refs with: peeled fully-peeled \n";
1067 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
1068 * Return a pointer to the refname within the line (null-terminated),
1069 * or NULL if there was a problem.
1071 static const char *parse_ref_line(struct strbuf *line, unsigned char *sha1)
1073 const char *ref;
1076 * 42: the answer to everything.
1078 * In this case, it happens to be the answer to
1079 * 40 (length of sha1 hex representation)
1080 * +1 (space in between hex and name)
1081 * +1 (newline at the end of the line)
1083 if (line->len <= 42)
1084 return NULL;
1086 if (get_sha1_hex(line->buf, sha1) < 0)
1087 return NULL;
1088 if (!isspace(line->buf[40]))
1089 return NULL;
1091 ref = line->buf + 41;
1092 if (isspace(*ref))
1093 return NULL;
1095 if (line->buf[line->len - 1] != '\n')
1096 return NULL;
1097 line->buf[--line->len] = 0;
1099 return ref;
1103 * Read f, which is a packed-refs file, into dir.
1105 * A comment line of the form "# pack-refs with: " may contain zero or
1106 * more traits. We interpret the traits as follows:
1108 * No traits:
1110 * Probably no references are peeled. But if the file contains a
1111 * peeled value for a reference, we will use it.
1113 * peeled:
1115 * References under "refs/tags/", if they *can* be peeled, *are*
1116 * peeled in this file. References outside of "refs/tags/" are
1117 * probably not peeled even if they could have been, but if we find
1118 * a peeled value for such a reference we will use it.
1120 * fully-peeled:
1122 * All references in the file that can be peeled are peeled.
1123 * Inversely (and this is more important), any references in the
1124 * file for which no peeled value is recorded is not peelable. This
1125 * trait should typically be written alongside "peeled" for
1126 * compatibility with older clients, but we do not require it
1127 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1129 static void read_packed_refs(FILE *f, struct ref_dir *dir)
1131 struct ref_entry *last = NULL;
1132 struct strbuf line = STRBUF_INIT;
1133 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1135 while (strbuf_getwholeline(&line, f, '\n') != EOF) {
1136 unsigned char sha1[20];
1137 const char *refname;
1138 const char *traits;
1140 if (skip_prefix(line.buf, "# pack-refs with:", &traits)) {
1141 if (strstr(traits, " fully-peeled "))
1142 peeled = PEELED_FULLY;
1143 else if (strstr(traits, " peeled "))
1144 peeled = PEELED_TAGS;
1145 /* perhaps other traits later as well */
1146 continue;
1149 refname = parse_ref_line(&line, sha1);
1150 if (refname) {
1151 int flag = REF_ISPACKED;
1153 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1154 hashclr(sha1);
1155 flag |= REF_BAD_NAME | REF_ISBROKEN;
1157 last = create_ref_entry(refname, sha1, flag, 0);
1158 if (peeled == PEELED_FULLY ||
1159 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
1160 last->flag |= REF_KNOWS_PEELED;
1161 add_ref(dir, last);
1162 continue;
1164 if (last &&
1165 line.buf[0] == '^' &&
1166 line.len == PEELED_LINE_LENGTH &&
1167 line.buf[PEELED_LINE_LENGTH - 1] == '\n' &&
1168 !get_sha1_hex(line.buf + 1, sha1)) {
1169 hashcpy(last->u.value.peeled, sha1);
1171 * Regardless of what the file header said,
1172 * we definitely know the value of *this*
1173 * reference:
1175 last->flag |= REF_KNOWS_PEELED;
1179 strbuf_release(&line);
1183 * Get the packed_ref_cache for the specified ref_cache, creating it
1184 * if necessary.
1186 static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
1188 const char *packed_refs_file;
1190 if (*refs->name)
1191 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1192 else
1193 packed_refs_file = git_path("packed-refs");
1195 if (refs->packed &&
1196 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1197 clear_packed_ref_cache(refs);
1199 if (!refs->packed) {
1200 FILE *f;
1202 refs->packed = xcalloc(1, sizeof(*refs->packed));
1203 acquire_packed_ref_cache(refs->packed);
1204 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1205 f = fopen(packed_refs_file, "r");
1206 if (f) {
1207 stat_validity_update(&refs->packed->validity, fileno(f));
1208 read_packed_refs(f, get_ref_dir(refs->packed->root));
1209 fclose(f);
1212 return refs->packed;
1215 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1217 return get_ref_dir(packed_ref_cache->root);
1220 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1222 return get_packed_ref_dir(get_packed_ref_cache(refs));
1225 void add_packed_ref(const char *refname, const unsigned char *sha1)
1227 struct packed_ref_cache *packed_ref_cache =
1228 get_packed_ref_cache(&ref_cache);
1230 if (!packed_ref_cache->lock)
1231 die("internal error: packed refs not locked");
1232 add_ref(get_packed_ref_dir(packed_ref_cache),
1233 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1237 * Read the loose references from the namespace dirname into dir
1238 * (without recursing). dirname must end with '/'. dir must be the
1239 * directory entry corresponding to dirname.
1241 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1243 struct ref_cache *refs = dir->ref_cache;
1244 DIR *d;
1245 const char *path;
1246 struct dirent *de;
1247 int dirnamelen = strlen(dirname);
1248 struct strbuf refname;
1250 if (*refs->name)
1251 path = git_path_submodule(refs->name, "%s", dirname);
1252 else
1253 path = git_path("%s", dirname);
1255 d = opendir(path);
1256 if (!d)
1257 return;
1259 strbuf_init(&refname, dirnamelen + 257);
1260 strbuf_add(&refname, dirname, dirnamelen);
1262 while ((de = readdir(d)) != NULL) {
1263 unsigned char sha1[20];
1264 struct stat st;
1265 int flag;
1266 const char *refdir;
1268 if (de->d_name[0] == '.')
1269 continue;
1270 if (ends_with(de->d_name, ".lock"))
1271 continue;
1272 strbuf_addstr(&refname, de->d_name);
1273 refdir = *refs->name
1274 ? git_path_submodule(refs->name, "%s", refname.buf)
1275 : git_path("%s", refname.buf);
1276 if (stat(refdir, &st) < 0) {
1277 ; /* silently ignore */
1278 } else if (S_ISDIR(st.st_mode)) {
1279 strbuf_addch(&refname, '/');
1280 add_entry_to_dir(dir,
1281 create_dir_entry(refs, refname.buf,
1282 refname.len, 1));
1283 } else {
1284 if (*refs->name) {
1285 hashclr(sha1);
1286 flag = 0;
1287 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
1288 hashclr(sha1);
1289 flag |= REF_ISBROKEN;
1291 } else if (read_ref_full(refname.buf,
1292 RESOLVE_REF_READING,
1293 sha1, &flag)) {
1294 hashclr(sha1);
1295 flag |= REF_ISBROKEN;
1297 if (check_refname_format(refname.buf,
1298 REFNAME_ALLOW_ONELEVEL)) {
1299 hashclr(sha1);
1300 flag |= REF_BAD_NAME | REF_ISBROKEN;
1302 add_entry_to_dir(dir,
1303 create_ref_entry(refname.buf, sha1, flag, 0));
1305 strbuf_setlen(&refname, dirnamelen);
1307 strbuf_release(&refname);
1308 closedir(d);
1311 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
1313 if (!refs->loose) {
1315 * Mark the top-level directory complete because we
1316 * are about to read the only subdirectory that can
1317 * hold references:
1319 refs->loose = create_dir_entry(refs, "", 0, 0);
1321 * Create an incomplete entry for "refs/":
1323 add_entry_to_dir(get_ref_dir(refs->loose),
1324 create_dir_entry(refs, "refs/", 5, 1));
1326 return get_ref_dir(refs->loose);
1329 /* We allow "recursive" symbolic refs. Only within reason, though */
1330 #define MAXDEPTH 5
1331 #define MAXREFLEN (1024)
1334 * Called by resolve_gitlink_ref_recursive() after it failed to read
1335 * from the loose refs in ref_cache refs. Find <refname> in the
1336 * packed-refs file for the submodule.
1338 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
1339 const char *refname, unsigned char *sha1)
1341 struct ref_entry *ref;
1342 struct ref_dir *dir = get_packed_refs(refs);
1344 ref = find_ref(dir, refname);
1345 if (ref == NULL)
1346 return -1;
1348 hashcpy(sha1, ref->u.value.sha1);
1349 return 0;
1352 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
1353 const char *refname, unsigned char *sha1,
1354 int recursion)
1356 int fd, len;
1357 char buffer[128], *p;
1358 char *path;
1360 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
1361 return -1;
1362 path = *refs->name
1363 ? git_path_submodule(refs->name, "%s", refname)
1364 : git_path("%s", refname);
1365 fd = open(path, O_RDONLY);
1366 if (fd < 0)
1367 return resolve_gitlink_packed_ref(refs, refname, sha1);
1369 len = read(fd, buffer, sizeof(buffer)-1);
1370 close(fd);
1371 if (len < 0)
1372 return -1;
1373 while (len && isspace(buffer[len-1]))
1374 len--;
1375 buffer[len] = 0;
1377 /* Was it a detached head or an old-fashioned symlink? */
1378 if (!get_sha1_hex(buffer, sha1))
1379 return 0;
1381 /* Symref? */
1382 if (strncmp(buffer, "ref:", 4))
1383 return -1;
1384 p = buffer + 4;
1385 while (isspace(*p))
1386 p++;
1388 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1391 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1393 int len = strlen(path), retval;
1394 char *submodule;
1395 struct ref_cache *refs;
1397 while (len && path[len-1] == '/')
1398 len--;
1399 if (!len)
1400 return -1;
1401 submodule = xstrndup(path, len);
1402 refs = get_ref_cache(submodule);
1403 free(submodule);
1405 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1406 return retval;
1410 * Return the ref_entry for the given refname from the packed
1411 * references. If it does not exist, return NULL.
1413 static struct ref_entry *get_packed_ref(const char *refname)
1415 return find_ref(get_packed_refs(&ref_cache), refname);
1419 * A loose ref file doesn't exist; check for a packed ref. The
1420 * options are forwarded from resolve_safe_unsafe().
1422 static int resolve_missing_loose_ref(const char *refname,
1423 int resolve_flags,
1424 unsigned char *sha1,
1425 int *flags)
1427 struct ref_entry *entry;
1430 * The loose reference file does not exist; check for a packed
1431 * reference.
1433 entry = get_packed_ref(refname);
1434 if (entry) {
1435 hashcpy(sha1, entry->u.value.sha1);
1436 if (flags)
1437 *flags |= REF_ISPACKED;
1438 return 0;
1440 /* The reference is not a packed reference, either. */
1441 if (resolve_flags & RESOLVE_REF_READING) {
1442 errno = ENOENT;
1443 return -1;
1444 } else {
1445 hashclr(sha1);
1446 return 0;
1450 /* This function needs to return a meaningful errno on failure */
1451 const char *resolve_ref_unsafe(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
1453 int depth = MAXDEPTH;
1454 ssize_t len;
1455 char buffer[256];
1456 static char refname_buffer[256];
1457 int bad_name = 0;
1459 if (flags)
1460 *flags = 0;
1462 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1463 if (flags)
1464 *flags |= REF_BAD_NAME;
1466 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1467 !refname_is_safe(refname)) {
1468 errno = EINVAL;
1469 return NULL;
1472 * dwim_ref() uses REF_ISBROKEN to distinguish between
1473 * missing refs and refs that were present but invalid,
1474 * to complain about the latter to stderr.
1476 * We don't know whether the ref exists, so don't set
1477 * REF_ISBROKEN yet.
1479 bad_name = 1;
1481 for (;;) {
1482 char path[PATH_MAX];
1483 struct stat st;
1484 char *buf;
1485 int fd;
1487 if (--depth < 0) {
1488 errno = ELOOP;
1489 return NULL;
1492 git_snpath(path, sizeof(path), "%s", refname);
1495 * We might have to loop back here to avoid a race
1496 * condition: first we lstat() the file, then we try
1497 * to read it as a link or as a file. But if somebody
1498 * changes the type of the file (file <-> directory
1499 * <-> symlink) between the lstat() and reading, then
1500 * we don't want to report that as an error but rather
1501 * try again starting with the lstat().
1503 stat_ref:
1504 if (lstat(path, &st) < 0) {
1505 if (errno != ENOENT)
1506 return NULL;
1507 if (resolve_missing_loose_ref(refname, resolve_flags,
1508 sha1, flags))
1509 return NULL;
1510 if (bad_name) {
1511 hashclr(sha1);
1512 if (flags)
1513 *flags |= REF_ISBROKEN;
1515 return refname;
1518 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1519 if (S_ISLNK(st.st_mode)) {
1520 len = readlink(path, buffer, sizeof(buffer)-1);
1521 if (len < 0) {
1522 if (errno == ENOENT || errno == EINVAL)
1523 /* inconsistent with lstat; retry */
1524 goto stat_ref;
1525 else
1526 return NULL;
1528 buffer[len] = 0;
1529 if (starts_with(buffer, "refs/") &&
1530 !check_refname_format(buffer, 0)) {
1531 strcpy(refname_buffer, buffer);
1532 refname = refname_buffer;
1533 if (flags)
1534 *flags |= REF_ISSYMREF;
1535 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1536 hashclr(sha1);
1537 return refname;
1539 continue;
1543 /* Is it a directory? */
1544 if (S_ISDIR(st.st_mode)) {
1545 errno = EISDIR;
1546 return NULL;
1550 * Anything else, just open it and try to use it as
1551 * a ref
1553 fd = open(path, O_RDONLY);
1554 if (fd < 0) {
1555 if (errno == ENOENT)
1556 /* inconsistent with lstat; retry */
1557 goto stat_ref;
1558 else
1559 return NULL;
1561 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1562 if (len < 0) {
1563 int save_errno = errno;
1564 close(fd);
1565 errno = save_errno;
1566 return NULL;
1568 close(fd);
1569 while (len && isspace(buffer[len-1]))
1570 len--;
1571 buffer[len] = '\0';
1574 * Is it a symbolic ref?
1576 if (!starts_with(buffer, "ref:")) {
1578 * Please note that FETCH_HEAD has a second
1579 * line containing other data.
1581 if (get_sha1_hex(buffer, sha1) ||
1582 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1583 if (flags)
1584 *flags |= REF_ISBROKEN;
1585 errno = EINVAL;
1586 return NULL;
1588 if (bad_name) {
1589 hashclr(sha1);
1590 if (flags)
1591 *flags |= REF_ISBROKEN;
1593 return refname;
1595 if (flags)
1596 *flags |= REF_ISSYMREF;
1597 buf = buffer + 4;
1598 while (isspace(*buf))
1599 buf++;
1600 refname = strcpy(refname_buffer, buf);
1601 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1602 hashclr(sha1);
1603 return refname;
1605 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1606 if (flags)
1607 *flags |= REF_ISBROKEN;
1609 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1610 !refname_is_safe(buf)) {
1611 errno = EINVAL;
1612 return NULL;
1614 bad_name = 1;
1619 char *resolve_refdup(const char *ref, int resolve_flags, unsigned char *sha1, int *flags)
1621 const char *ret = resolve_ref_unsafe(ref, resolve_flags, sha1, flags);
1622 return ret ? xstrdup(ret) : NULL;
1625 /* The argument to filter_refs */
1626 struct ref_filter {
1627 const char *pattern;
1628 each_ref_fn *fn;
1629 void *cb_data;
1632 int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
1634 if (resolve_ref_unsafe(refname, resolve_flags, sha1, flags))
1635 return 0;
1636 return -1;
1639 int read_ref(const char *refname, unsigned char *sha1)
1641 return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);
1644 int ref_exists(const char *refname)
1646 unsigned char sha1[20];
1647 return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);
1650 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1651 void *data)
1653 struct ref_filter *filter = (struct ref_filter *)data;
1654 if (wildmatch(filter->pattern, refname, 0, NULL))
1655 return 0;
1656 return filter->fn(refname, sha1, flags, filter->cb_data);
1659 enum peel_status {
1660 /* object was peeled successfully: */
1661 PEEL_PEELED = 0,
1664 * object cannot be peeled because the named object (or an
1665 * object referred to by a tag in the peel chain), does not
1666 * exist.
1668 PEEL_INVALID = -1,
1670 /* object cannot be peeled because it is not a tag: */
1671 PEEL_NON_TAG = -2,
1673 /* ref_entry contains no peeled value because it is a symref: */
1674 PEEL_IS_SYMREF = -3,
1677 * ref_entry cannot be peeled because it is broken (i.e., the
1678 * symbolic reference cannot even be resolved to an object
1679 * name):
1681 PEEL_BROKEN = -4
1685 * Peel the named object; i.e., if the object is a tag, resolve the
1686 * tag recursively until a non-tag is found. If successful, store the
1687 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1688 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1689 * and leave sha1 unchanged.
1691 static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
1693 struct object *o = lookup_unknown_object(name);
1695 if (o->type == OBJ_NONE) {
1696 int type = sha1_object_info(name, NULL);
1697 if (type < 0 || !object_as_type(o, type, 0))
1698 return PEEL_INVALID;
1701 if (o->type != OBJ_TAG)
1702 return PEEL_NON_TAG;
1704 o = deref_tag_noverify(o);
1705 if (!o)
1706 return PEEL_INVALID;
1708 hashcpy(sha1, o->sha1);
1709 return PEEL_PEELED;
1713 * Peel the entry (if possible) and return its new peel_status. If
1714 * repeel is true, re-peel the entry even if there is an old peeled
1715 * value that is already stored in it.
1717 * It is OK to call this function with a packed reference entry that
1718 * might be stale and might even refer to an object that has since
1719 * been garbage-collected. In such a case, if the entry has
1720 * REF_KNOWS_PEELED then leave the status unchanged and return
1721 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1723 static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1725 enum peel_status status;
1727 if (entry->flag & REF_KNOWS_PEELED) {
1728 if (repeel) {
1729 entry->flag &= ~REF_KNOWS_PEELED;
1730 hashclr(entry->u.value.peeled);
1731 } else {
1732 return is_null_sha1(entry->u.value.peeled) ?
1733 PEEL_NON_TAG : PEEL_PEELED;
1736 if (entry->flag & REF_ISBROKEN)
1737 return PEEL_BROKEN;
1738 if (entry->flag & REF_ISSYMREF)
1739 return PEEL_IS_SYMREF;
1741 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1742 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1743 entry->flag |= REF_KNOWS_PEELED;
1744 return status;
1747 int peel_ref(const char *refname, unsigned char *sha1)
1749 int flag;
1750 unsigned char base[20];
1752 if (current_ref && (current_ref->name == refname
1753 || !strcmp(current_ref->name, refname))) {
1754 if (peel_entry(current_ref, 0))
1755 return -1;
1756 hashcpy(sha1, current_ref->u.value.peeled);
1757 return 0;
1760 if (read_ref_full(refname, RESOLVE_REF_READING, base, &flag))
1761 return -1;
1764 * If the reference is packed, read its ref_entry from the
1765 * cache in the hope that we already know its peeled value.
1766 * We only try this optimization on packed references because
1767 * (a) forcing the filling of the loose reference cache could
1768 * be expensive and (b) loose references anyway usually do not
1769 * have REF_KNOWS_PEELED.
1771 if (flag & REF_ISPACKED) {
1772 struct ref_entry *r = get_packed_ref(refname);
1773 if (r) {
1774 if (peel_entry(r, 0))
1775 return -1;
1776 hashcpy(sha1, r->u.value.peeled);
1777 return 0;
1781 return peel_object(base, sha1);
1784 struct warn_if_dangling_data {
1785 FILE *fp;
1786 const char *refname;
1787 const struct string_list *refnames;
1788 const char *msg_fmt;
1791 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1792 int flags, void *cb_data)
1794 struct warn_if_dangling_data *d = cb_data;
1795 const char *resolves_to;
1796 unsigned char junk[20];
1798 if (!(flags & REF_ISSYMREF))
1799 return 0;
1801 resolves_to = resolve_ref_unsafe(refname, 0, junk, NULL);
1802 if (!resolves_to
1803 || (d->refname
1804 ? strcmp(resolves_to, d->refname)
1805 : !string_list_has_string(d->refnames, resolves_to))) {
1806 return 0;
1809 fprintf(d->fp, d->msg_fmt, refname);
1810 fputc('\n', d->fp);
1811 return 0;
1814 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1816 struct warn_if_dangling_data data;
1818 data.fp = fp;
1819 data.refname = refname;
1820 data.refnames = NULL;
1821 data.msg_fmt = msg_fmt;
1822 for_each_rawref(warn_if_dangling_symref, &data);
1825 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
1827 struct warn_if_dangling_data data;
1829 data.fp = fp;
1830 data.refname = NULL;
1831 data.refnames = refnames;
1832 data.msg_fmt = msg_fmt;
1833 for_each_rawref(warn_if_dangling_symref, &data);
1837 * Call fn for each reference in the specified ref_cache, omitting
1838 * references not in the containing_dir of base. fn is called for all
1839 * references, including broken ones. If fn ever returns a non-zero
1840 * value, stop the iteration and return that value; otherwise, return
1841 * 0.
1843 static int do_for_each_entry(struct ref_cache *refs, const char *base,
1844 each_ref_entry_fn fn, void *cb_data)
1846 struct packed_ref_cache *packed_ref_cache;
1847 struct ref_dir *loose_dir;
1848 struct ref_dir *packed_dir;
1849 int retval = 0;
1852 * We must make sure that all loose refs are read before accessing the
1853 * packed-refs file; this avoids a race condition in which loose refs
1854 * are migrated to the packed-refs file by a simultaneous process, but
1855 * our in-memory view is from before the migration. get_packed_ref_cache()
1856 * takes care of making sure our view is up to date with what is on
1857 * disk.
1859 loose_dir = get_loose_refs(refs);
1860 if (base && *base) {
1861 loose_dir = find_containing_dir(loose_dir, base, 0);
1863 if (loose_dir)
1864 prime_ref_dir(loose_dir);
1866 packed_ref_cache = get_packed_ref_cache(refs);
1867 acquire_packed_ref_cache(packed_ref_cache);
1868 packed_dir = get_packed_ref_dir(packed_ref_cache);
1869 if (base && *base) {
1870 packed_dir = find_containing_dir(packed_dir, base, 0);
1873 if (packed_dir && loose_dir) {
1874 sort_ref_dir(packed_dir);
1875 sort_ref_dir(loose_dir);
1876 retval = do_for_each_entry_in_dirs(
1877 packed_dir, loose_dir, fn, cb_data);
1878 } else if (packed_dir) {
1879 sort_ref_dir(packed_dir);
1880 retval = do_for_each_entry_in_dir(
1881 packed_dir, 0, fn, cb_data);
1882 } else if (loose_dir) {
1883 sort_ref_dir(loose_dir);
1884 retval = do_for_each_entry_in_dir(
1885 loose_dir, 0, fn, cb_data);
1888 release_packed_ref_cache(packed_ref_cache);
1889 return retval;
1893 * Call fn for each reference in the specified ref_cache for which the
1894 * refname begins with base. If trim is non-zero, then trim that many
1895 * characters off the beginning of each refname before passing the
1896 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1897 * broken references in the iteration. If fn ever returns a non-zero
1898 * value, stop the iteration and return that value; otherwise, return
1899 * 0.
1901 static int do_for_each_ref(struct ref_cache *refs, const char *base,
1902 each_ref_fn fn, int trim, int flags, void *cb_data)
1904 struct ref_entry_cb data;
1905 data.base = base;
1906 data.trim = trim;
1907 data.flags = flags;
1908 data.fn = fn;
1909 data.cb_data = cb_data;
1911 return do_for_each_entry(refs, base, do_one_ref, &data);
1914 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1916 unsigned char sha1[20];
1917 int flag;
1919 if (submodule) {
1920 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1921 return fn("HEAD", sha1, 0, cb_data);
1923 return 0;
1926 if (!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag))
1927 return fn("HEAD", sha1, flag, cb_data);
1929 return 0;
1932 int head_ref(each_ref_fn fn, void *cb_data)
1934 return do_head_ref(NULL, fn, cb_data);
1937 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1939 return do_head_ref(submodule, fn, cb_data);
1942 int for_each_ref(each_ref_fn fn, void *cb_data)
1944 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1947 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1949 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
1952 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1954 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1957 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1958 each_ref_fn fn, void *cb_data)
1960 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
1963 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1965 return for_each_ref_in("refs/tags/", fn, cb_data);
1968 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1970 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1973 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1975 return for_each_ref_in("refs/heads/", fn, cb_data);
1978 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1980 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1983 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1985 return for_each_ref_in("refs/remotes/", fn, cb_data);
1988 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1990 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1993 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1995 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
1998 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
2000 struct strbuf buf = STRBUF_INIT;
2001 int ret = 0;
2002 unsigned char sha1[20];
2003 int flag;
2005 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
2006 if (!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag))
2007 ret = fn(buf.buf, sha1, flag, cb_data);
2008 strbuf_release(&buf);
2010 return ret;
2013 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
2015 struct strbuf buf = STRBUF_INIT;
2016 int ret;
2017 strbuf_addf(&buf, "%srefs/", get_git_namespace());
2018 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
2019 strbuf_release(&buf);
2020 return ret;
2023 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
2024 const char *prefix, void *cb_data)
2026 struct strbuf real_pattern = STRBUF_INIT;
2027 struct ref_filter filter;
2028 int ret;
2030 if (!prefix && !starts_with(pattern, "refs/"))
2031 strbuf_addstr(&real_pattern, "refs/");
2032 else if (prefix)
2033 strbuf_addstr(&real_pattern, prefix);
2034 strbuf_addstr(&real_pattern, pattern);
2036 if (!has_glob_specials(pattern)) {
2037 /* Append implied '/' '*' if not present. */
2038 if (real_pattern.buf[real_pattern.len - 1] != '/')
2039 strbuf_addch(&real_pattern, '/');
2040 /* No need to check for '*', there is none. */
2041 strbuf_addch(&real_pattern, '*');
2044 filter.pattern = real_pattern.buf;
2045 filter.fn = fn;
2046 filter.cb_data = cb_data;
2047 ret = for_each_ref(filter_refs, &filter);
2049 strbuf_release(&real_pattern);
2050 return ret;
2053 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
2055 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
2058 int for_each_rawref(each_ref_fn fn, void *cb_data)
2060 return do_for_each_ref(&ref_cache, "", fn, 0,
2061 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
2064 const char *prettify_refname(const char *name)
2066 return name + (
2067 starts_with(name, "refs/heads/") ? 11 :
2068 starts_with(name, "refs/tags/") ? 10 :
2069 starts_with(name, "refs/remotes/") ? 13 :
2073 static const char *ref_rev_parse_rules[] = {
2074 "%.*s",
2075 "refs/%.*s",
2076 "refs/tags/%.*s",
2077 "refs/heads/%.*s",
2078 "refs/remotes/%.*s",
2079 "refs/remotes/%.*s/HEAD",
2080 NULL
2083 int refname_match(const char *abbrev_name, const char *full_name)
2085 const char **p;
2086 const int abbrev_name_len = strlen(abbrev_name);
2088 for (p = ref_rev_parse_rules; *p; p++) {
2089 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
2090 return 1;
2094 return 0;
2097 /* This function should make sure errno is meaningful on error */
2098 static struct ref_lock *verify_lock(struct ref_lock *lock,
2099 const unsigned char *old_sha1, int mustexist)
2101 if (read_ref_full(lock->ref_name,
2102 mustexist ? RESOLVE_REF_READING : 0,
2103 lock->old_sha1, NULL)) {
2104 int save_errno = errno;
2105 error("Can't verify ref %s", lock->ref_name);
2106 unlock_ref(lock);
2107 errno = save_errno;
2108 return NULL;
2110 if (hashcmp(lock->old_sha1, old_sha1)) {
2111 error("Ref %s is at %s but expected %s", lock->ref_name,
2112 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
2113 unlock_ref(lock);
2114 errno = EBUSY;
2115 return NULL;
2117 return lock;
2120 static int remove_empty_directories(const char *file)
2122 /* we want to create a file but there is a directory there;
2123 * if that is an empty directory (or a directory that contains
2124 * only empty directories), remove them.
2126 struct strbuf path;
2127 int result, save_errno;
2129 strbuf_init(&path, 20);
2130 strbuf_addstr(&path, file);
2132 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
2133 save_errno = errno;
2135 strbuf_release(&path);
2136 errno = save_errno;
2138 return result;
2142 * *string and *len will only be substituted, and *string returned (for
2143 * later free()ing) if the string passed in is a magic short-hand form
2144 * to name a branch.
2146 static char *substitute_branch_name(const char **string, int *len)
2148 struct strbuf buf = STRBUF_INIT;
2149 int ret = interpret_branch_name(*string, *len, &buf);
2151 if (ret == *len) {
2152 size_t size;
2153 *string = strbuf_detach(&buf, &size);
2154 *len = size;
2155 return (char *)*string;
2158 return NULL;
2161 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
2163 char *last_branch = substitute_branch_name(&str, &len);
2164 const char **p, *r;
2165 int refs_found = 0;
2167 *ref = NULL;
2168 for (p = ref_rev_parse_rules; *p; p++) {
2169 char fullref[PATH_MAX];
2170 unsigned char sha1_from_ref[20];
2171 unsigned char *this_result;
2172 int flag;
2174 this_result = refs_found ? sha1_from_ref : sha1;
2175 mksnpath(fullref, sizeof(fullref), *p, len, str);
2176 r = resolve_ref_unsafe(fullref, RESOLVE_REF_READING,
2177 this_result, &flag);
2178 if (r) {
2179 if (!refs_found++)
2180 *ref = xstrdup(r);
2181 if (!warn_ambiguous_refs)
2182 break;
2183 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
2184 warning("ignoring dangling symref %s.", fullref);
2185 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
2186 warning("ignoring broken ref %s.", fullref);
2189 free(last_branch);
2190 return refs_found;
2193 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
2195 char *last_branch = substitute_branch_name(&str, &len);
2196 const char **p;
2197 int logs_found = 0;
2199 *log = NULL;
2200 for (p = ref_rev_parse_rules; *p; p++) {
2201 unsigned char hash[20];
2202 char path[PATH_MAX];
2203 const char *ref, *it;
2205 mksnpath(path, sizeof(path), *p, len, str);
2206 ref = resolve_ref_unsafe(path, RESOLVE_REF_READING,
2207 hash, NULL);
2208 if (!ref)
2209 continue;
2210 if (reflog_exists(path))
2211 it = path;
2212 else if (strcmp(ref, path) && reflog_exists(ref))
2213 it = ref;
2214 else
2215 continue;
2216 if (!logs_found++) {
2217 *log = xstrdup(it);
2218 hashcpy(sha1, hash);
2220 if (!warn_ambiguous_refs)
2221 break;
2223 free(last_branch);
2224 return logs_found;
2228 * Locks a ref returning the lock on success and NULL on failure.
2229 * On failure errno is set to something meaningful.
2231 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2232 const unsigned char *old_sha1,
2233 const struct string_list *skip,
2234 int flags, int *type_p)
2236 char *ref_file;
2237 const char *orig_refname = refname;
2238 struct ref_lock *lock;
2239 int last_errno = 0;
2240 int type, lflags;
2241 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
2242 int resolve_flags = 0;
2243 int missing = 0;
2244 int attempts_remaining = 3;
2246 lock = xcalloc(1, sizeof(struct ref_lock));
2247 lock->lock_fd = -1;
2249 if (mustexist)
2250 resolve_flags |= RESOLVE_REF_READING;
2251 if (flags & REF_DELETING) {
2252 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;
2253 if (flags & REF_NODEREF)
2254 resolve_flags |= RESOLVE_REF_NO_RECURSE;
2257 refname = resolve_ref_unsafe(refname, resolve_flags,
2258 lock->old_sha1, &type);
2259 if (!refname && errno == EISDIR) {
2260 /* we are trying to lock foo but we used to
2261 * have foo/bar which now does not exist;
2262 * it is normal for the empty directory 'foo'
2263 * to remain.
2265 ref_file = git_path("%s", orig_refname);
2266 if (remove_empty_directories(ref_file)) {
2267 last_errno = errno;
2268 error("there are still refs under '%s'", orig_refname);
2269 goto error_return;
2271 refname = resolve_ref_unsafe(orig_refname, resolve_flags,
2272 lock->old_sha1, &type);
2274 if (type_p)
2275 *type_p = type;
2276 if (!refname) {
2277 last_errno = errno;
2278 error("unable to resolve reference %s: %s",
2279 orig_refname, strerror(errno));
2280 goto error_return;
2282 missing = is_null_sha1(lock->old_sha1);
2283 /* When the ref did not exist and we are creating it,
2284 * make sure there is no existing ref that is packed
2285 * whose name begins with our refname, nor a ref whose
2286 * name is a proper prefix of our refname.
2288 if (missing &&
2289 !is_refname_available(refname, skip, get_packed_refs(&ref_cache))) {
2290 last_errno = ENOTDIR;
2291 goto error_return;
2294 lock->lk = xcalloc(1, sizeof(struct lock_file));
2296 lflags = 0;
2297 if (flags & REF_NODEREF) {
2298 refname = orig_refname;
2299 lflags |= LOCK_NO_DEREF;
2301 lock->ref_name = xstrdup(refname);
2302 lock->orig_ref_name = xstrdup(orig_refname);
2303 ref_file = git_path("%s", refname);
2304 if (missing)
2305 lock->force_write = 1;
2306 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2307 lock->force_write = 1;
2309 retry:
2310 switch (safe_create_leading_directories(ref_file)) {
2311 case SCLD_OK:
2312 break; /* success */
2313 case SCLD_VANISHED:
2314 if (--attempts_remaining > 0)
2315 goto retry;
2316 /* fall through */
2317 default:
2318 last_errno = errno;
2319 error("unable to create directory for %s", ref_file);
2320 goto error_return;
2323 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
2324 if (lock->lock_fd < 0) {
2325 if (errno == ENOENT && --attempts_remaining > 0)
2327 * Maybe somebody just deleted one of the
2328 * directories leading to ref_file. Try
2329 * again:
2331 goto retry;
2332 else
2333 unable_to_lock_die(ref_file, errno);
2335 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
2337 error_return:
2338 unlock_ref(lock);
2339 errno = last_errno;
2340 return NULL;
2343 struct ref_lock *lock_any_ref_for_update(const char *refname,
2344 const unsigned char *old_sha1,
2345 int flags, int *type_p)
2347 return lock_ref_sha1_basic(refname, old_sha1, NULL, flags, type_p);
2351 * Write an entry to the packed-refs file for the specified refname.
2352 * If peeled is non-NULL, write it as the entry's peeled value.
2354 static void write_packed_entry(FILE *fh, char *refname, unsigned char *sha1,
2355 unsigned char *peeled)
2357 fprintf_or_die(fh, "%s %s\n", sha1_to_hex(sha1), refname);
2358 if (peeled)
2359 fprintf_or_die(fh, "^%s\n", sha1_to_hex(peeled));
2363 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2365 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2367 enum peel_status peel_status = peel_entry(entry, 0);
2369 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2370 error("internal error: %s is not a valid packed reference!",
2371 entry->name);
2372 write_packed_entry(cb_data, entry->name, entry->u.value.sha1,
2373 peel_status == PEEL_PEELED ?
2374 entry->u.value.peeled : NULL);
2375 return 0;
2378 /* This should return a meaningful errno on failure */
2379 int lock_packed_refs(int flags)
2381 struct packed_ref_cache *packed_ref_cache;
2383 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2384 return -1;
2386 * Get the current packed-refs while holding the lock. If the
2387 * packed-refs file has been modified since we last read it,
2388 * this will automatically invalidate the cache and re-read
2389 * the packed-refs file.
2391 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2392 packed_ref_cache->lock = &packlock;
2393 /* Increment the reference count to prevent it from being freed: */
2394 acquire_packed_ref_cache(packed_ref_cache);
2395 return 0;
2399 * Commit the packed refs changes.
2400 * On error we must make sure that errno contains a meaningful value.
2402 int commit_packed_refs(void)
2404 struct packed_ref_cache *packed_ref_cache =
2405 get_packed_ref_cache(&ref_cache);
2406 int error = 0;
2407 int save_errno = 0;
2408 FILE *out;
2410 if (!packed_ref_cache->lock)
2411 die("internal error: packed-refs not locked");
2413 out = fdopen_lock_file(packed_ref_cache->lock, "w");
2414 if (!out)
2415 die_errno("unable to fdopen packed-refs descriptor");
2417 fprintf_or_die(out, "%s", PACKED_REFS_HEADER);
2418 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2419 0, write_packed_entry_fn, out);
2421 if (commit_lock_file(packed_ref_cache->lock)) {
2422 save_errno = errno;
2423 error = -1;
2425 packed_ref_cache->lock = NULL;
2426 release_packed_ref_cache(packed_ref_cache);
2427 errno = save_errno;
2428 return error;
2431 void rollback_packed_refs(void)
2433 struct packed_ref_cache *packed_ref_cache =
2434 get_packed_ref_cache(&ref_cache);
2436 if (!packed_ref_cache->lock)
2437 die("internal error: packed-refs not locked");
2438 rollback_lock_file(packed_ref_cache->lock);
2439 packed_ref_cache->lock = NULL;
2440 release_packed_ref_cache(packed_ref_cache);
2441 clear_packed_ref_cache(&ref_cache);
2444 struct ref_to_prune {
2445 struct ref_to_prune *next;
2446 unsigned char sha1[20];
2447 char name[FLEX_ARRAY];
2450 struct pack_refs_cb_data {
2451 unsigned int flags;
2452 struct ref_dir *packed_refs;
2453 struct ref_to_prune *ref_to_prune;
2457 * An each_ref_entry_fn that is run over loose references only. If
2458 * the loose reference can be packed, add an entry in the packed ref
2459 * cache. If the reference should be pruned, also add it to
2460 * ref_to_prune in the pack_refs_cb_data.
2462 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2464 struct pack_refs_cb_data *cb = cb_data;
2465 enum peel_status peel_status;
2466 struct ref_entry *packed_entry;
2467 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2469 /* ALWAYS pack tags */
2470 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2471 return 0;
2473 /* Do not pack symbolic or broken refs: */
2474 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2475 return 0;
2477 /* Add a packed ref cache entry equivalent to the loose entry. */
2478 peel_status = peel_entry(entry, 1);
2479 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2480 die("internal error peeling reference %s (%s)",
2481 entry->name, sha1_to_hex(entry->u.value.sha1));
2482 packed_entry = find_ref(cb->packed_refs, entry->name);
2483 if (packed_entry) {
2484 /* Overwrite existing packed entry with info from loose entry */
2485 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2486 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2487 } else {
2488 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2489 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2490 add_ref(cb->packed_refs, packed_entry);
2492 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
2494 /* Schedule the loose reference for pruning if requested. */
2495 if ((cb->flags & PACK_REFS_PRUNE)) {
2496 int namelen = strlen(entry->name) + 1;
2497 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
2498 hashcpy(n->sha1, entry->u.value.sha1);
2499 strcpy(n->name, entry->name);
2500 n->next = cb->ref_to_prune;
2501 cb->ref_to_prune = n;
2503 return 0;
2507 * Remove empty parents, but spare refs/ and immediate subdirs.
2508 * Note: munges *name.
2510 static void try_remove_empty_parents(char *name)
2512 char *p, *q;
2513 int i;
2514 p = name;
2515 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2516 while (*p && *p != '/')
2517 p++;
2518 /* tolerate duplicate slashes; see check_refname_format() */
2519 while (*p == '/')
2520 p++;
2522 for (q = p; *q; q++)
2524 while (1) {
2525 while (q > p && *q != '/')
2526 q--;
2527 while (q > p && *(q-1) == '/')
2528 q--;
2529 if (q == p)
2530 break;
2531 *q = '\0';
2532 if (rmdir(git_path("%s", name)))
2533 break;
2537 /* make sure nobody touched the ref, and unlink */
2538 static void prune_ref(struct ref_to_prune *r)
2540 struct ref_transaction *transaction;
2541 struct strbuf err = STRBUF_INIT;
2543 if (check_refname_format(r->name, 0))
2544 return;
2546 transaction = ref_transaction_begin(&err);
2547 if (!transaction ||
2548 ref_transaction_delete(transaction, r->name, r->sha1,
2549 REF_ISPRUNING, 1, NULL, &err) ||
2550 ref_transaction_commit(transaction, &err)) {
2551 ref_transaction_free(transaction);
2552 error("%s", err.buf);
2553 strbuf_release(&err);
2554 return;
2556 ref_transaction_free(transaction);
2557 strbuf_release(&err);
2558 try_remove_empty_parents(r->name);
2561 static void prune_refs(struct ref_to_prune *r)
2563 while (r) {
2564 prune_ref(r);
2565 r = r->next;
2569 int pack_refs(unsigned int flags)
2571 struct pack_refs_cb_data cbdata;
2573 memset(&cbdata, 0, sizeof(cbdata));
2574 cbdata.flags = flags;
2576 lock_packed_refs(LOCK_DIE_ON_ERROR);
2577 cbdata.packed_refs = get_packed_refs(&ref_cache);
2579 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2580 pack_if_possible_fn, &cbdata);
2582 if (commit_packed_refs())
2583 die_errno("unable to overwrite old ref-pack file");
2585 prune_refs(cbdata.ref_to_prune);
2586 return 0;
2590 * If entry is no longer needed in packed-refs, add it to the string
2591 * list pointed to by cb_data. Reasons for deleting entries:
2593 * - Entry is broken.
2594 * - Entry is overridden by a loose ref.
2595 * - Entry does not point at a valid object.
2597 * In the first and third cases, also emit an error message because these
2598 * are indications of repository corruption.
2600 static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
2602 struct string_list *refs_to_delete = cb_data;
2604 if (entry->flag & REF_ISBROKEN) {
2605 /* This shouldn't happen to packed refs. */
2606 error("%s is broken!", entry->name);
2607 string_list_append(refs_to_delete, entry->name);
2608 return 0;
2610 if (!has_sha1_file(entry->u.value.sha1)) {
2611 unsigned char sha1[20];
2612 int flags;
2614 if (read_ref_full(entry->name, 0, sha1, &flags))
2615 /* We should at least have found the packed ref. */
2616 die("Internal error");
2617 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
2619 * This packed reference is overridden by a
2620 * loose reference, so it is OK that its value
2621 * is no longer valid; for example, it might
2622 * refer to an object that has been garbage
2623 * collected. For this purpose we don't even
2624 * care whether the loose reference itself is
2625 * invalid, broken, symbolic, etc. Silently
2626 * remove the packed reference.
2628 string_list_append(refs_to_delete, entry->name);
2629 return 0;
2632 * There is no overriding loose reference, so the fact
2633 * that this reference doesn't refer to a valid object
2634 * indicates some kind of repository corruption.
2635 * Report the problem, then omit the reference from
2636 * the output.
2638 error("%s does not point to a valid object!", entry->name);
2639 string_list_append(refs_to_delete, entry->name);
2640 return 0;
2643 return 0;
2646 int repack_without_refs(const char **refnames, int n, struct strbuf *err)
2648 struct ref_dir *packed;
2649 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2650 struct string_list_item *ref_to_delete;
2651 int i, ret, removed = 0;
2653 assert(err);
2655 /* Look for a packed ref */
2656 for (i = 0; i < n; i++)
2657 if (get_packed_ref(refnames[i]))
2658 break;
2660 /* Avoid locking if we have nothing to do */
2661 if (i == n)
2662 return 0; /* no refname exists in packed refs */
2664 if (lock_packed_refs(0)) {
2665 unable_to_lock_message(git_path("packed-refs"), errno, err);
2666 return -1;
2668 packed = get_packed_refs(&ref_cache);
2670 /* Remove refnames from the cache */
2671 for (i = 0; i < n; i++)
2672 if (remove_entry(packed, refnames[i]) != -1)
2673 removed = 1;
2674 if (!removed) {
2676 * All packed entries disappeared while we were
2677 * acquiring the lock.
2679 rollback_packed_refs();
2680 return 0;
2683 /* Remove any other accumulated cruft */
2684 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2685 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2686 if (remove_entry(packed, ref_to_delete->string) == -1)
2687 die("internal error");
2690 /* Write what remains */
2691 ret = commit_packed_refs();
2692 if (ret)
2693 strbuf_addf(err, "unable to overwrite old ref-pack file: %s",
2694 strerror(errno));
2695 return ret;
2698 static int delete_ref_loose(struct ref_lock *lock, int flag, struct strbuf *err)
2700 assert(err);
2702 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2704 * loose. The loose file name is the same as the
2705 * lockfile name, minus ".lock":
2707 char *loose_filename = get_locked_file_path(lock->lk);
2708 int res = unlink_or_msg(loose_filename, err);
2709 free(loose_filename);
2710 if (res)
2711 return 1;
2713 return 0;
2716 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
2718 struct ref_transaction *transaction;
2719 struct strbuf err = STRBUF_INIT;
2721 transaction = ref_transaction_begin(&err);
2722 if (!transaction ||
2723 ref_transaction_delete(transaction, refname, sha1, delopt,
2724 sha1 && !is_null_sha1(sha1), NULL, &err) ||
2725 ref_transaction_commit(transaction, &err)) {
2726 error("%s", err.buf);
2727 ref_transaction_free(transaction);
2728 strbuf_release(&err);
2729 return 1;
2731 ref_transaction_free(transaction);
2732 strbuf_release(&err);
2733 return 0;
2737 * People using contrib's git-new-workdir have .git/logs/refs ->
2738 * /some/other/path/.git/logs/refs, and that may live on another device.
2740 * IOW, to avoid cross device rename errors, the temporary renamed log must
2741 * live into logs/refs.
2743 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2745 static int rename_tmp_log(const char *newrefname)
2747 int attempts_remaining = 4;
2749 retry:
2750 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2751 case SCLD_OK:
2752 break; /* success */
2753 case SCLD_VANISHED:
2754 if (--attempts_remaining > 0)
2755 goto retry;
2756 /* fall through */
2757 default:
2758 error("unable to create directory for %s", newrefname);
2759 return -1;
2762 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
2763 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
2765 * rename(a, b) when b is an existing
2766 * directory ought to result in ISDIR, but
2767 * Solaris 5.8 gives ENOTDIR. Sheesh.
2769 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2770 error("Directory not empty: logs/%s", newrefname);
2771 return -1;
2773 goto retry;
2774 } else if (errno == ENOENT && --attempts_remaining > 0) {
2776 * Maybe another process just deleted one of
2777 * the directories in the path to newrefname.
2778 * Try again from the beginning.
2780 goto retry;
2781 } else {
2782 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2783 newrefname, strerror(errno));
2784 return -1;
2787 return 0;
2790 static int rename_ref_available(const char *oldname, const char *newname)
2792 struct string_list skip = STRING_LIST_INIT_NODUP;
2793 int ret;
2795 string_list_insert(&skip, oldname);
2796 ret = is_refname_available(newname, &skip, get_packed_refs(&ref_cache))
2797 && is_refname_available(newname, &skip, get_loose_refs(&ref_cache));
2798 string_list_clear(&skip, 0);
2799 return ret;
2802 static int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1,
2803 const char *logmsg);
2805 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
2807 unsigned char sha1[20], orig_sha1[20];
2808 int flag = 0, logmoved = 0;
2809 struct ref_lock *lock;
2810 struct stat loginfo;
2811 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2812 const char *symref = NULL;
2814 if (log && S_ISLNK(loginfo.st_mode))
2815 return error("reflog for %s is a symlink", oldrefname);
2817 symref = resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,
2818 orig_sha1, &flag);
2819 if (flag & REF_ISSYMREF)
2820 return error("refname %s is a symbolic ref, renaming it is not supported",
2821 oldrefname);
2822 if (!symref)
2823 return error("refname %s not found", oldrefname);
2825 if (!rename_ref_available(oldrefname, newrefname))
2826 return 1;
2828 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2829 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2830 oldrefname, strerror(errno));
2832 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2833 error("unable to delete old %s", oldrefname);
2834 goto rollback;
2837 if (!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&
2838 delete_ref(newrefname, sha1, REF_NODEREF)) {
2839 if (errno==EISDIR) {
2840 if (remove_empty_directories(git_path("%s", newrefname))) {
2841 error("Directory not empty: %s", newrefname);
2842 goto rollback;
2844 } else {
2845 error("unable to delete existing %s", newrefname);
2846 goto rollback;
2850 if (log && rename_tmp_log(newrefname))
2851 goto rollback;
2853 logmoved = log;
2855 lock = lock_ref_sha1_basic(newrefname, NULL, NULL, 0, NULL);
2856 if (!lock) {
2857 error("unable to lock %s for update", newrefname);
2858 goto rollback;
2860 lock->force_write = 1;
2861 hashcpy(lock->old_sha1, orig_sha1);
2862 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
2863 error("unable to write current sha1 into %s", newrefname);
2864 goto rollback;
2867 return 0;
2869 rollback:
2870 lock = lock_ref_sha1_basic(oldrefname, NULL, NULL, 0, NULL);
2871 if (!lock) {
2872 error("unable to lock %s for rollback", oldrefname);
2873 goto rollbacklog;
2876 lock->force_write = 1;
2877 flag = log_all_ref_updates;
2878 log_all_ref_updates = 0;
2879 if (write_ref_sha1(lock, orig_sha1, NULL))
2880 error("unable to write current sha1 into %s", oldrefname);
2881 log_all_ref_updates = flag;
2883 rollbacklog:
2884 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2885 error("unable to restore logfile %s from %s: %s",
2886 oldrefname, newrefname, strerror(errno));
2887 if (!logmoved && log &&
2888 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2889 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2890 oldrefname, strerror(errno));
2892 return 1;
2895 int close_ref(struct ref_lock *lock)
2897 if (close_lock_file(lock->lk))
2898 return -1;
2899 lock->lock_fd = -1;
2900 return 0;
2903 int commit_ref(struct ref_lock *lock)
2905 if (commit_lock_file(lock->lk))
2906 return -1;
2907 lock->lock_fd = -1;
2908 return 0;
2911 void unlock_ref(struct ref_lock *lock)
2913 /* Do not free lock->lk -- atexit() still looks at them */
2914 if (lock->lk)
2915 rollback_lock_file(lock->lk);
2916 free(lock->ref_name);
2917 free(lock->orig_ref_name);
2918 free(lock);
2922 * copy the reflog message msg to buf, which has been allocated sufficiently
2923 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2924 * because reflog file is one line per entry.
2926 static int copy_msg(char *buf, const char *msg)
2928 char *cp = buf;
2929 char c;
2930 int wasspace = 1;
2932 *cp++ = '\t';
2933 while ((c = *msg++)) {
2934 if (wasspace && isspace(c))
2935 continue;
2936 wasspace = isspace(c);
2937 if (wasspace)
2938 c = ' ';
2939 *cp++ = c;
2941 while (buf < cp && isspace(cp[-1]))
2942 cp--;
2943 *cp++ = '\n';
2944 return cp - buf;
2947 /* This function must set a meaningful errno on failure */
2948 int log_ref_setup(const char *refname, char *logfile, int bufsize)
2950 int logfd, oflags = O_APPEND | O_WRONLY;
2952 git_snpath(logfile, bufsize, "logs/%s", refname);
2953 if (log_all_ref_updates &&
2954 (starts_with(refname, "refs/heads/") ||
2955 starts_with(refname, "refs/remotes/") ||
2956 starts_with(refname, "refs/notes/") ||
2957 !strcmp(refname, "HEAD"))) {
2958 if (safe_create_leading_directories(logfile) < 0) {
2959 int save_errno = errno;
2960 error("unable to create directory for %s", logfile);
2961 errno = save_errno;
2962 return -1;
2964 oflags |= O_CREAT;
2967 logfd = open(logfile, oflags, 0666);
2968 if (logfd < 0) {
2969 if (!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))
2970 return 0;
2972 if (errno == EISDIR) {
2973 if (remove_empty_directories(logfile)) {
2974 int save_errno = errno;
2975 error("There are still logs under '%s'",
2976 logfile);
2977 errno = save_errno;
2978 return -1;
2980 logfd = open(logfile, oflags, 0666);
2983 if (logfd < 0) {
2984 int save_errno = errno;
2985 error("Unable to append to %s: %s", logfile,
2986 strerror(errno));
2987 errno = save_errno;
2988 return -1;
2992 adjust_shared_perm(logfile);
2993 close(logfd);
2994 return 0;
2997 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2998 const unsigned char *new_sha1, const char *msg)
3000 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
3001 unsigned maxlen, len;
3002 int msglen;
3003 char log_file[PATH_MAX];
3004 char *logrec;
3005 const char *committer;
3007 if (log_all_ref_updates < 0)
3008 log_all_ref_updates = !is_bare_repository();
3010 result = log_ref_setup(refname, log_file, sizeof(log_file));
3011 if (result)
3012 return result;
3014 logfd = open(log_file, oflags);
3015 if (logfd < 0)
3016 return 0;
3017 msglen = msg ? strlen(msg) : 0;
3018 committer = git_committer_info(0);
3019 maxlen = strlen(committer) + msglen + 100;
3020 logrec = xmalloc(maxlen);
3021 len = sprintf(logrec, "%s %s %s\n",
3022 sha1_to_hex(old_sha1),
3023 sha1_to_hex(new_sha1),
3024 committer);
3025 if (msglen)
3026 len += copy_msg(logrec + len - 1, msg) - 1;
3027 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
3028 free(logrec);
3029 if (written != len) {
3030 int save_errno = errno;
3031 close(logfd);
3032 error("Unable to append to %s", log_file);
3033 errno = save_errno;
3034 return -1;
3036 if (close(logfd)) {
3037 int save_errno = errno;
3038 error("Unable to append to %s", log_file);
3039 errno = save_errno;
3040 return -1;
3042 return 0;
3045 int is_branch(const char *refname)
3047 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
3051 * Write sha1 into the ref specified by the lock. Make sure that errno
3052 * is sane on error.
3054 static int write_ref_sha1(struct ref_lock *lock,
3055 const unsigned char *sha1, const char *logmsg)
3057 static char term = '\n';
3058 struct object *o;
3060 if (!lock) {
3061 errno = EINVAL;
3062 return -1;
3064 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
3065 unlock_ref(lock);
3066 return 0;
3068 o = parse_object(sha1);
3069 if (!o) {
3070 error("Trying to write ref %s with nonexistent object %s",
3071 lock->ref_name, sha1_to_hex(sha1));
3072 unlock_ref(lock);
3073 errno = EINVAL;
3074 return -1;
3076 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
3077 error("Trying to write non-commit object %s to branch %s",
3078 sha1_to_hex(sha1), lock->ref_name);
3079 unlock_ref(lock);
3080 errno = EINVAL;
3081 return -1;
3083 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
3084 write_in_full(lock->lock_fd, &term, 1) != 1 ||
3085 close_ref(lock) < 0) {
3086 int save_errno = errno;
3087 error("Couldn't write %s", lock->lk->filename.buf);
3088 unlock_ref(lock);
3089 errno = save_errno;
3090 return -1;
3092 clear_loose_ref_cache(&ref_cache);
3093 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
3094 (strcmp(lock->ref_name, lock->orig_ref_name) &&
3095 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
3096 unlock_ref(lock);
3097 return -1;
3099 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
3101 * Special hack: If a branch is updated directly and HEAD
3102 * points to it (may happen on the remote side of a push
3103 * for example) then logically the HEAD reflog should be
3104 * updated too.
3105 * A generic solution implies reverse symref information,
3106 * but finding all symrefs pointing to the given branch
3107 * would be rather costly for this rare event (the direct
3108 * update of a branch) to be worth it. So let's cheat and
3109 * check with HEAD only which should cover 99% of all usage
3110 * scenarios (even 100% of the default ones).
3112 unsigned char head_sha1[20];
3113 int head_flag;
3114 const char *head_ref;
3115 head_ref = resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,
3116 head_sha1, &head_flag);
3117 if (head_ref && (head_flag & REF_ISSYMREF) &&
3118 !strcmp(head_ref, lock->ref_name))
3119 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
3121 if (commit_ref(lock)) {
3122 error("Couldn't set %s", lock->ref_name);
3123 unlock_ref(lock);
3124 return -1;
3126 unlock_ref(lock);
3127 return 0;
3130 int create_symref(const char *ref_target, const char *refs_heads_master,
3131 const char *logmsg)
3133 const char *lockpath;
3134 char ref[1000];
3135 int fd, len, written;
3136 char *git_HEAD = git_pathdup("%s", ref_target);
3137 unsigned char old_sha1[20], new_sha1[20];
3139 if (logmsg && read_ref(ref_target, old_sha1))
3140 hashclr(old_sha1);
3142 if (safe_create_leading_directories(git_HEAD) < 0)
3143 return error("unable to create directory for %s", git_HEAD);
3145 #ifndef NO_SYMLINK_HEAD
3146 if (prefer_symlink_refs) {
3147 unlink(git_HEAD);
3148 if (!symlink(refs_heads_master, git_HEAD))
3149 goto done;
3150 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
3152 #endif
3154 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
3155 if (sizeof(ref) <= len) {
3156 error("refname too long: %s", refs_heads_master);
3157 goto error_free_return;
3159 lockpath = mkpath("%s.lock", git_HEAD);
3160 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
3161 if (fd < 0) {
3162 error("Unable to open %s for writing", lockpath);
3163 goto error_free_return;
3165 written = write_in_full(fd, ref, len);
3166 if (close(fd) != 0 || written != len) {
3167 error("Unable to write to %s", lockpath);
3168 goto error_unlink_return;
3170 if (rename(lockpath, git_HEAD) < 0) {
3171 error("Unable to create %s", git_HEAD);
3172 goto error_unlink_return;
3174 if (adjust_shared_perm(git_HEAD)) {
3175 error("Unable to fix permissions on %s", lockpath);
3176 error_unlink_return:
3177 unlink_or_warn(lockpath);
3178 error_free_return:
3179 free(git_HEAD);
3180 return -1;
3183 #ifndef NO_SYMLINK_HEAD
3184 done:
3185 #endif
3186 if (logmsg && !read_ref(refs_heads_master, new_sha1))
3187 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
3189 free(git_HEAD);
3190 return 0;
3193 struct read_ref_at_cb {
3194 const char *refname;
3195 unsigned long at_time;
3196 int cnt;
3197 int reccnt;
3198 unsigned char *sha1;
3199 int found_it;
3201 unsigned char osha1[20];
3202 unsigned char nsha1[20];
3203 int tz;
3204 unsigned long date;
3205 char **msg;
3206 unsigned long *cutoff_time;
3207 int *cutoff_tz;
3208 int *cutoff_cnt;
3211 static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
3212 const char *email, unsigned long timestamp, int tz,
3213 const char *message, void *cb_data)
3215 struct read_ref_at_cb *cb = cb_data;
3217 cb->reccnt++;
3218 cb->tz = tz;
3219 cb->date = timestamp;
3221 if (timestamp <= cb->at_time || cb->cnt == 0) {
3222 if (cb->msg)
3223 *cb->msg = xstrdup(message);
3224 if (cb->cutoff_time)
3225 *cb->cutoff_time = timestamp;
3226 if (cb->cutoff_tz)
3227 *cb->cutoff_tz = tz;
3228 if (cb->cutoff_cnt)
3229 *cb->cutoff_cnt = cb->reccnt - 1;
3231 * we have not yet updated cb->[n|o]sha1 so they still
3232 * hold the values for the previous record.
3234 if (!is_null_sha1(cb->osha1)) {
3235 hashcpy(cb->sha1, nsha1);
3236 if (hashcmp(cb->osha1, nsha1))
3237 warning("Log for ref %s has gap after %s.",
3238 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));
3240 else if (cb->date == cb->at_time)
3241 hashcpy(cb->sha1, nsha1);
3242 else if (hashcmp(nsha1, cb->sha1))
3243 warning("Log for ref %s unexpectedly ended on %s.",
3244 cb->refname, show_date(cb->date, cb->tz,
3245 DATE_RFC2822));
3246 hashcpy(cb->osha1, osha1);
3247 hashcpy(cb->nsha1, nsha1);
3248 cb->found_it = 1;
3249 return 1;
3251 hashcpy(cb->osha1, osha1);
3252 hashcpy(cb->nsha1, nsha1);
3253 if (cb->cnt > 0)
3254 cb->cnt--;
3255 return 0;
3258 static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
3259 const char *email, unsigned long timestamp,
3260 int tz, const char *message, void *cb_data)
3262 struct read_ref_at_cb *cb = cb_data;
3264 if (cb->msg)
3265 *cb->msg = xstrdup(message);
3266 if (cb->cutoff_time)
3267 *cb->cutoff_time = timestamp;
3268 if (cb->cutoff_tz)
3269 *cb->cutoff_tz = tz;
3270 if (cb->cutoff_cnt)
3271 *cb->cutoff_cnt = cb->reccnt;
3272 hashcpy(cb->sha1, osha1);
3273 if (is_null_sha1(cb->sha1))
3274 hashcpy(cb->sha1, nsha1);
3275 /* We just want the first entry */
3276 return 1;
3279 int read_ref_at(const char *refname, unsigned int flags, unsigned long at_time, int cnt,
3280 unsigned char *sha1, char **msg,
3281 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
3283 struct read_ref_at_cb cb;
3285 memset(&cb, 0, sizeof(cb));
3286 cb.refname = refname;
3287 cb.at_time = at_time;
3288 cb.cnt = cnt;
3289 cb.msg = msg;
3290 cb.cutoff_time = cutoff_time;
3291 cb.cutoff_tz = cutoff_tz;
3292 cb.cutoff_cnt = cutoff_cnt;
3293 cb.sha1 = sha1;
3295 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
3297 if (!cb.reccnt) {
3298 if (flags & GET_SHA1_QUIETLY)
3299 exit(128);
3300 else
3301 die("Log for %s is empty.", refname);
3303 if (cb.found_it)
3304 return 0;
3306 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
3308 return 1;
3311 int reflog_exists(const char *refname)
3313 struct stat st;
3315 return !lstat(git_path("logs/%s", refname), &st) &&
3316 S_ISREG(st.st_mode);
3319 int delete_reflog(const char *refname)
3321 return remove_path(git_path("logs/%s", refname));
3324 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3326 unsigned char osha1[20], nsha1[20];
3327 char *email_end, *message;
3328 unsigned long timestamp;
3329 int tz;
3331 /* old SP new SP name <email> SP time TAB msg LF */
3332 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3333 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3334 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3335 !(email_end = strchr(sb->buf + 82, '>')) ||
3336 email_end[1] != ' ' ||
3337 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3338 !message || message[0] != ' ' ||
3339 (message[1] != '+' && message[1] != '-') ||
3340 !isdigit(message[2]) || !isdigit(message[3]) ||
3341 !isdigit(message[4]) || !isdigit(message[5]))
3342 return 0; /* corrupt? */
3343 email_end[1] = '\0';
3344 tz = strtol(message + 1, NULL, 10);
3345 if (message[6] != '\t')
3346 message += 6;
3347 else
3348 message += 7;
3349 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3352 static char *find_beginning_of_line(char *bob, char *scan)
3354 while (bob < scan && *(--scan) != '\n')
3355 ; /* keep scanning backwards */
3357 * Return either beginning of the buffer, or LF at the end of
3358 * the previous line.
3360 return scan;
3363 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3365 struct strbuf sb = STRBUF_INIT;
3366 FILE *logfp;
3367 long pos;
3368 int ret = 0, at_tail = 1;
3370 logfp = fopen(git_path("logs/%s", refname), "r");
3371 if (!logfp)
3372 return -1;
3374 /* Jump to the end */
3375 if (fseek(logfp, 0, SEEK_END) < 0)
3376 return error("cannot seek back reflog for %s: %s",
3377 refname, strerror(errno));
3378 pos = ftell(logfp);
3379 while (!ret && 0 < pos) {
3380 int cnt;
3381 size_t nread;
3382 char buf[BUFSIZ];
3383 char *endp, *scanp;
3385 /* Fill next block from the end */
3386 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3387 if (fseek(logfp, pos - cnt, SEEK_SET))
3388 return error("cannot seek back reflog for %s: %s",
3389 refname, strerror(errno));
3390 nread = fread(buf, cnt, 1, logfp);
3391 if (nread != 1)
3392 return error("cannot read %d bytes from reflog for %s: %s",
3393 cnt, refname, strerror(errno));
3394 pos -= cnt;
3396 scanp = endp = buf + cnt;
3397 if (at_tail && scanp[-1] == '\n')
3398 /* Looking at the final LF at the end of the file */
3399 scanp--;
3400 at_tail = 0;
3402 while (buf < scanp) {
3404 * terminating LF of the previous line, or the beginning
3405 * of the buffer.
3407 char *bp;
3409 bp = find_beginning_of_line(buf, scanp);
3411 if (*bp == '\n') {
3413 * The newline is the end of the previous line,
3414 * so we know we have complete line starting
3415 * at (bp + 1). Prefix it onto any prior data
3416 * we collected for the line and process it.
3418 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3419 scanp = bp;
3420 endp = bp + 1;
3421 ret = show_one_reflog_ent(&sb, fn, cb_data);
3422 strbuf_reset(&sb);
3423 if (ret)
3424 break;
3425 } else if (!pos) {
3427 * We are at the start of the buffer, and the
3428 * start of the file; there is no previous
3429 * line, and we have everything for this one.
3430 * Process it, and we can end the loop.
3432 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3433 ret = show_one_reflog_ent(&sb, fn, cb_data);
3434 strbuf_reset(&sb);
3435 break;
3438 if (bp == buf) {
3440 * We are at the start of the buffer, and there
3441 * is more file to read backwards. Which means
3442 * we are in the middle of a line. Note that we
3443 * may get here even if *bp was a newline; that
3444 * just means we are at the exact end of the
3445 * previous line, rather than some spot in the
3446 * middle.
3448 * Save away what we have to be combined with
3449 * the data from the next read.
3451 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3452 break;
3457 if (!ret && sb.len)
3458 die("BUG: reverse reflog parser had leftover data");
3460 fclose(logfp);
3461 strbuf_release(&sb);
3462 return ret;
3465 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3467 FILE *logfp;
3468 struct strbuf sb = STRBUF_INIT;
3469 int ret = 0;
3471 logfp = fopen(git_path("logs/%s", refname), "r");
3472 if (!logfp)
3473 return -1;
3475 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3476 ret = show_one_reflog_ent(&sb, fn, cb_data);
3477 fclose(logfp);
3478 strbuf_release(&sb);
3479 return ret;
3482 * Call fn for each reflog in the namespace indicated by name. name
3483 * must be empty or end with '/'. Name will be used as a scratch
3484 * space, but its contents will be restored before return.
3486 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
3488 DIR *d = opendir(git_path("logs/%s", name->buf));
3489 int retval = 0;
3490 struct dirent *de;
3491 int oldlen = name->len;
3493 if (!d)
3494 return name->len ? errno : 0;
3496 while ((de = readdir(d)) != NULL) {
3497 struct stat st;
3499 if (de->d_name[0] == '.')
3500 continue;
3501 if (ends_with(de->d_name, ".lock"))
3502 continue;
3503 strbuf_addstr(name, de->d_name);
3504 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3505 ; /* silently ignore */
3506 } else {
3507 if (S_ISDIR(st.st_mode)) {
3508 strbuf_addch(name, '/');
3509 retval = do_for_each_reflog(name, fn, cb_data);
3510 } else {
3511 unsigned char sha1[20];
3512 if (read_ref_full(name->buf, 0, sha1, NULL))
3513 retval = error("bad ref for %s", name->buf);
3514 else
3515 retval = fn(name->buf, sha1, 0, cb_data);
3517 if (retval)
3518 break;
3520 strbuf_setlen(name, oldlen);
3522 closedir(d);
3523 return retval;
3526 int for_each_reflog(each_ref_fn fn, void *cb_data)
3528 int retval;
3529 struct strbuf name;
3530 strbuf_init(&name, PATH_MAX);
3531 retval = do_for_each_reflog(&name, fn, cb_data);
3532 strbuf_release(&name);
3533 return retval;
3537 * Information needed for a single ref update. Set new_sha1 to the
3538 * new value or to zero to delete the ref. To check the old value
3539 * while locking the ref, set have_old to 1 and set old_sha1 to the
3540 * value or to zero to ensure the ref does not exist before update.
3542 struct ref_update {
3543 unsigned char new_sha1[20];
3544 unsigned char old_sha1[20];
3545 int flags; /* REF_NODEREF? */
3546 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
3547 struct ref_lock *lock;
3548 int type;
3549 char *msg;
3550 const char refname[FLEX_ARRAY];
3554 * Transaction states.
3555 * OPEN: The transaction is in a valid state and can accept new updates.
3556 * An OPEN transaction can be committed.
3557 * CLOSED: A closed transaction is no longer active and no other operations
3558 * than free can be used on it in this state.
3559 * A transaction can either become closed by successfully committing
3560 * an active transaction or if there is a failure while building
3561 * the transaction thus rendering it failed/inactive.
3563 enum ref_transaction_state {
3564 REF_TRANSACTION_OPEN = 0,
3565 REF_TRANSACTION_CLOSED = 1
3569 * Data structure for holding a reference transaction, which can
3570 * consist of checks and updates to multiple references, carried out
3571 * as atomically as possible. This structure is opaque to callers.
3573 struct ref_transaction {
3574 struct ref_update **updates;
3575 size_t alloc;
3576 size_t nr;
3577 enum ref_transaction_state state;
3580 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
3582 assert(err);
3584 return xcalloc(1, sizeof(struct ref_transaction));
3587 void ref_transaction_free(struct ref_transaction *transaction)
3589 int i;
3591 if (!transaction)
3592 return;
3594 for (i = 0; i < transaction->nr; i++) {
3595 free(transaction->updates[i]->msg);
3596 free(transaction->updates[i]);
3598 free(transaction->updates);
3599 free(transaction);
3602 static struct ref_update *add_update(struct ref_transaction *transaction,
3603 const char *refname)
3605 size_t len = strlen(refname);
3606 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
3608 strcpy((char *)update->refname, refname);
3609 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
3610 transaction->updates[transaction->nr++] = update;
3611 return update;
3614 int ref_transaction_update(struct ref_transaction *transaction,
3615 const char *refname,
3616 const unsigned char *new_sha1,
3617 const unsigned char *old_sha1,
3618 int flags, int have_old, const char *msg,
3619 struct strbuf *err)
3621 struct ref_update *update;
3623 assert(err);
3625 if (transaction->state != REF_TRANSACTION_OPEN)
3626 die("BUG: update called for transaction that is not open");
3628 if (have_old && !old_sha1)
3629 die("BUG: have_old is true but old_sha1 is NULL");
3631 if (!is_null_sha1(new_sha1) &&
3632 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
3633 strbuf_addf(err, "refusing to update ref with bad name %s",
3634 refname);
3635 return -1;
3638 update = add_update(transaction, refname);
3639 hashcpy(update->new_sha1, new_sha1);
3640 update->flags = flags;
3641 update->have_old = have_old;
3642 if (have_old)
3643 hashcpy(update->old_sha1, old_sha1);
3644 if (msg)
3645 update->msg = xstrdup(msg);
3646 return 0;
3649 int ref_transaction_create(struct ref_transaction *transaction,
3650 const char *refname,
3651 const unsigned char *new_sha1,
3652 int flags, const char *msg,
3653 struct strbuf *err)
3655 struct ref_update *update;
3657 assert(err);
3659 if (transaction->state != REF_TRANSACTION_OPEN)
3660 die("BUG: create called for transaction that is not open");
3662 if (!new_sha1 || is_null_sha1(new_sha1))
3663 die("BUG: create ref with null new_sha1");
3665 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
3666 strbuf_addf(err, "refusing to create ref with bad name %s",
3667 refname);
3668 return -1;
3671 update = add_update(transaction, refname);
3673 hashcpy(update->new_sha1, new_sha1);
3674 hashclr(update->old_sha1);
3675 update->flags = flags;
3676 update->have_old = 1;
3677 if (msg)
3678 update->msg = xstrdup(msg);
3679 return 0;
3682 int ref_transaction_delete(struct ref_transaction *transaction,
3683 const char *refname,
3684 const unsigned char *old_sha1,
3685 int flags, int have_old, const char *msg,
3686 struct strbuf *err)
3688 struct ref_update *update;
3690 assert(err);
3692 if (transaction->state != REF_TRANSACTION_OPEN)
3693 die("BUG: delete called for transaction that is not open");
3695 if (have_old && !old_sha1)
3696 die("BUG: have_old is true but old_sha1 is NULL");
3698 update = add_update(transaction, refname);
3699 update->flags = flags;
3700 update->have_old = have_old;
3701 if (have_old) {
3702 assert(!is_null_sha1(old_sha1));
3703 hashcpy(update->old_sha1, old_sha1);
3705 if (msg)
3706 update->msg = xstrdup(msg);
3707 return 0;
3710 int update_ref(const char *action, const char *refname,
3711 const unsigned char *sha1, const unsigned char *oldval,
3712 int flags, enum action_on_err onerr)
3714 struct ref_transaction *t;
3715 struct strbuf err = STRBUF_INIT;
3717 t = ref_transaction_begin(&err);
3718 if (!t ||
3719 ref_transaction_update(t, refname, sha1, oldval, flags,
3720 !!oldval, action, &err) ||
3721 ref_transaction_commit(t, &err)) {
3722 const char *str = "update_ref failed for ref '%s': %s";
3724 ref_transaction_free(t);
3725 switch (onerr) {
3726 case UPDATE_REFS_MSG_ON_ERR:
3727 error(str, refname, err.buf);
3728 break;
3729 case UPDATE_REFS_DIE_ON_ERR:
3730 die(str, refname, err.buf);
3731 break;
3732 case UPDATE_REFS_QUIET_ON_ERR:
3733 break;
3735 strbuf_release(&err);
3736 return 1;
3738 strbuf_release(&err);
3739 ref_transaction_free(t);
3740 return 0;
3743 static int ref_update_compare(const void *r1, const void *r2)
3745 const struct ref_update * const *u1 = r1;
3746 const struct ref_update * const *u2 = r2;
3747 return strcmp((*u1)->refname, (*u2)->refname);
3750 static int ref_update_reject_duplicates(struct ref_update **updates, int n,
3751 struct strbuf *err)
3753 int i;
3755 assert(err);
3757 for (i = 1; i < n; i++)
3758 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
3759 strbuf_addf(err,
3760 "Multiple updates for ref '%s' not allowed.",
3761 updates[i]->refname);
3762 return 1;
3764 return 0;
3767 int ref_transaction_commit(struct ref_transaction *transaction,
3768 struct strbuf *err)
3770 int ret = 0, delnum = 0, i;
3771 const char **delnames;
3772 int n = transaction->nr;
3773 struct ref_update **updates = transaction->updates;
3775 assert(err);
3777 if (transaction->state != REF_TRANSACTION_OPEN)
3778 die("BUG: commit called for transaction that is not open");
3780 if (!n) {
3781 transaction->state = REF_TRANSACTION_CLOSED;
3782 return 0;
3785 /* Allocate work space */
3786 delnames = xmalloc(sizeof(*delnames) * n);
3788 /* Copy, sort, and reject duplicate refs */
3789 qsort(updates, n, sizeof(*updates), ref_update_compare);
3790 if (ref_update_reject_duplicates(updates, n, err)) {
3791 ret = TRANSACTION_GENERIC_ERROR;
3792 goto cleanup;
3795 /* Acquire all locks while verifying old values */
3796 for (i = 0; i < n; i++) {
3797 struct ref_update *update = updates[i];
3798 int flags = update->flags;
3800 if (is_null_sha1(update->new_sha1))
3801 flags |= REF_DELETING;
3802 update->lock = lock_ref_sha1_basic(update->refname,
3803 (update->have_old ?
3804 update->old_sha1 :
3805 NULL),
3806 NULL,
3807 flags,
3808 &update->type);
3809 if (!update->lock) {
3810 ret = (errno == ENOTDIR)
3811 ? TRANSACTION_NAME_CONFLICT
3812 : TRANSACTION_GENERIC_ERROR;
3813 strbuf_addf(err, "Cannot lock the ref '%s'.",
3814 update->refname);
3815 goto cleanup;
3819 /* Perform updates first so live commits remain referenced */
3820 for (i = 0; i < n; i++) {
3821 struct ref_update *update = updates[i];
3823 if (!is_null_sha1(update->new_sha1)) {
3824 if (write_ref_sha1(update->lock, update->new_sha1,
3825 update->msg)) {
3826 update->lock = NULL; /* freed by write_ref_sha1 */
3827 strbuf_addf(err, "Cannot update the ref '%s'.",
3828 update->refname);
3829 ret = TRANSACTION_GENERIC_ERROR;
3830 goto cleanup;
3832 update->lock = NULL; /* freed by write_ref_sha1 */
3836 /* Perform deletes now that updates are safely completed */
3837 for (i = 0; i < n; i++) {
3838 struct ref_update *update = updates[i];
3840 if (update->lock) {
3841 if (delete_ref_loose(update->lock, update->type, err)) {
3842 ret = TRANSACTION_GENERIC_ERROR;
3843 goto cleanup;
3846 if (!(update->flags & REF_ISPRUNING))
3847 delnames[delnum++] = update->lock->ref_name;
3851 if (repack_without_refs(delnames, delnum, err)) {
3852 ret = TRANSACTION_GENERIC_ERROR;
3853 goto cleanup;
3855 for (i = 0; i < delnum; i++)
3856 unlink_or_warn(git_path("logs/%s", delnames[i]));
3857 clear_loose_ref_cache(&ref_cache);
3859 cleanup:
3860 transaction->state = REF_TRANSACTION_CLOSED;
3862 for (i = 0; i < n; i++)
3863 if (updates[i]->lock)
3864 unlock_ref(updates[i]->lock);
3865 free(delnames);
3866 return ret;
3869 char *shorten_unambiguous_ref(const char *refname, int strict)
3871 int i;
3872 static char **scanf_fmts;
3873 static int nr_rules;
3874 char *short_name;
3876 if (!nr_rules) {
3878 * Pre-generate scanf formats from ref_rev_parse_rules[].
3879 * Generate a format suitable for scanf from a
3880 * ref_rev_parse_rules rule by interpolating "%s" at the
3881 * location of the "%.*s".
3883 size_t total_len = 0;
3884 size_t offset = 0;
3886 /* the rule list is NULL terminated, count them first */
3887 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
3888 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
3889 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
3891 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3893 offset = 0;
3894 for (i = 0; i < nr_rules; i++) {
3895 assert(offset < total_len);
3896 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
3897 offset += snprintf(scanf_fmts[i], total_len - offset,
3898 ref_rev_parse_rules[i], 2, "%s") + 1;
3902 /* bail out if there are no rules */
3903 if (!nr_rules)
3904 return xstrdup(refname);
3906 /* buffer for scanf result, at most refname must fit */
3907 short_name = xstrdup(refname);
3909 /* skip first rule, it will always match */
3910 for (i = nr_rules - 1; i > 0 ; --i) {
3911 int j;
3912 int rules_to_fail = i;
3913 int short_name_len;
3915 if (1 != sscanf(refname, scanf_fmts[i], short_name))
3916 continue;
3918 short_name_len = strlen(short_name);
3921 * in strict mode, all (except the matched one) rules
3922 * must fail to resolve to a valid non-ambiguous ref
3924 if (strict)
3925 rules_to_fail = nr_rules;
3928 * check if the short name resolves to a valid ref,
3929 * but use only rules prior to the matched one
3931 for (j = 0; j < rules_to_fail; j++) {
3932 const char *rule = ref_rev_parse_rules[j];
3933 char refname[PATH_MAX];
3935 /* skip matched rule */
3936 if (i == j)
3937 continue;
3940 * the short name is ambiguous, if it resolves
3941 * (with this previous rule) to a valid ref
3942 * read_ref() returns 0 on success
3944 mksnpath(refname, sizeof(refname),
3945 rule, short_name_len, short_name);
3946 if (ref_exists(refname))
3947 break;
3951 * short name is non-ambiguous if all previous rules
3952 * haven't resolved to a valid ref
3954 if (j == rules_to_fail)
3955 return short_name;
3958 free(short_name);
3959 return xstrdup(refname);
3962 static struct string_list *hide_refs;
3964 int parse_hide_refs_config(const char *var, const char *value, const char *section)
3966 if (!strcmp("transfer.hiderefs", var) ||
3967 /* NEEDSWORK: use parse_config_key() once both are merged */
3968 (starts_with(var, section) && var[strlen(section)] == '.' &&
3969 !strcmp(var + strlen(section), ".hiderefs"))) {
3970 char *ref;
3971 int len;
3973 if (!value)
3974 return config_error_nonbool(var);
3975 ref = xstrdup(value);
3976 len = strlen(ref);
3977 while (len && ref[len - 1] == '/')
3978 ref[--len] = '\0';
3979 if (!hide_refs) {
3980 hide_refs = xcalloc(1, sizeof(*hide_refs));
3981 hide_refs->strdup_strings = 1;
3983 string_list_append(hide_refs, ref);
3985 return 0;
3988 int ref_is_hidden(const char *refname)
3990 struct string_list_item *item;
3992 if (!hide_refs)
3993 return 0;
3994 for_each_string_list_item(item, hide_refs) {
3995 int len;
3996 if (!starts_with(refname, item->string))
3997 continue;
3998 len = strlen(item->string);
3999 if (!refname[len] || refname[len] == '/')
4000 return 1;
4002 return 0;