contrib: add convert-grafts-to-replace-refs.sh
[alt-git.git] / refs.c
blob20e2bf18c9da51904d53ec594022eb75e7cefcf0
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
6 #include "string-list.h"
8 /*
9 * How to handle various characters in refnames:
10 * This table is used by both the SIMD and non-SIMD code. It has
11 * some cases that are only useful for the SIMD; these are handled
12 * equivalently to the listed disposition in the non-SIMD code.
13 * 0: An acceptable character for refs
14 * 1: @, look for a following { to reject @{ in refs (SIMD or = 0)
15 * 2: \0: End-of-component and string
16 * 3: /: End-of-component (SIMD or = 2)
17 * 4: ., look for a preceding . to reject .. in refs
18 * 5: {, look for a preceding @ to reject @{ in refs
19 * 6: *, usually a bad character except, once as a wildcard (SIMD or = 7)
20 * 7: A bad character except * (see check_refname_component below)
22 static unsigned char refname_disposition[256] = {
23 2, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
24 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
25 7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 4, 3,
26 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 7,
27 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
28 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 7, 0, 7, 0,
29 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
30 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 7, 7
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 has pattern-matching notation "*", "?", "[", anywhere, or
43 * - it ends with a "/", or
44 * - it ends with ".lock", or
45 * - it contains a "\" (backslash)
47 static int check_refname_component(const char *refname, int flags)
49 const char *cp;
50 char last = '\0';
52 for (cp = refname; ; cp++) {
53 int ch = *cp & 255;
54 unsigned char disp = refname_disposition[ch];
55 switch (disp) {
56 case 2: /* fall-through */
57 case 3:
58 goto out;
59 case 4:
60 if (last == '.')
61 return -1; /* Refname contains "..". */
62 break;
63 case 5:
64 if (last == '@')
65 return -1; /* Refname contains "@{". */
66 break;
67 case 6: /* fall-through */
68 case 7:
69 return -1;
71 last = ch;
73 out:
74 if (cp == refname)
75 return 0; /* Component has zero length. */
76 if (refname[0] == '.') {
77 if (!(flags & REFNAME_DOT_COMPONENT))
78 return -1; /* Component starts with '.'. */
80 * Even if leading dots are allowed, don't allow "."
81 * as a component (".." is prevented by a rule above).
83 if (refname[1] == '\0')
84 return -1; /* Component equals ".". */
86 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
87 return -1; /* Refname ends with ".lock". */
88 return cp - refname;
91 static int check_refname_format_bytewise(const char *refname, int flags)
93 int component_len, component_count = 0;
95 if (!strcmp(refname, "@"))
96 /* Refname is a single character '@'. */
97 return -1;
99 while (1) {
100 /* We are at the start of a path component. */
101 component_len = check_refname_component(refname, flags);
102 if (component_len <= 0) {
103 if ((flags & REFNAME_REFSPEC_PATTERN) &&
104 refname[0] == '*' &&
105 (refname[1] == '\0' || refname[1] == '/')) {
106 /* Accept one wildcard as a full refname component. */
107 flags &= ~REFNAME_REFSPEC_PATTERN;
108 component_len = 1;
109 } else {
110 return -1;
113 component_count++;
114 if (refname[component_len] == '\0')
115 break;
116 /* Skip to next component. */
117 refname += component_len + 1;
120 if (refname[component_len - 1] == '.')
121 return -1; /* Refname ends with '.'. */
122 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
123 return -1; /* Refname has only one component. */
124 return 0;
127 #if defined(__GNUC__) && defined(__x86_64__)
128 #define SSE_VECTOR_BYTES 16
130 /* Vectorized version of check_refname_format. */
131 int check_refname_format(const char *refname, int flags)
133 const char *cp = refname;
135 const __m128i dot = _mm_set1_epi8('.');
136 const __m128i at = _mm_set1_epi8('@');
137 const __m128i curly = _mm_set1_epi8('{');
138 const __m128i slash = _mm_set1_epi8('/');
139 const __m128i zero = _mm_set1_epi8('\000');
140 const __m128i el = _mm_set1_epi8('l');
142 /* below '*', all characters are forbidden or rare */
143 const __m128i star_ub = _mm_set1_epi8('*' + 1);
145 const __m128i colon = _mm_set1_epi8(':');
146 const __m128i question = _mm_set1_epi8('?');
148 /* '['..'^' contains 4 characters: 3 forbidden and 1 rare */
149 const __m128i bracket_lb = _mm_set1_epi8('[' - 1);
150 const __m128i caret_ub = _mm_set1_epi8('^' + 1);
152 /* '~' and above are forbidden */
153 const __m128i tilde_lb = _mm_set1_epi8('~' - 1);
155 int component_count = 0;
157 if (refname[0] == 0 || refname[0] == '/') {
158 /* entirely empty ref or initial ref component */
159 return -1;
163 * Initial ref component of '.'; below we look for /. so we'll
164 * miss this.
166 if (refname[0] == '.') {
167 if (refname[1] == '/' || refname[1] == '\0')
168 return -1;
169 if (!(flags & REFNAME_DOT_COMPONENT))
170 return -1;
172 while(1) {
173 __m128i tmp, tmp1, result;
174 uint64_t mask;
176 if ((uintptr_t) cp % PAGE_SIZE > PAGE_SIZE - SSE_VECTOR_BYTES - 1)
178 * End-of-page; fall back to slow method for
179 * this entire ref.
181 return check_refname_format_bytewise(refname, flags);
183 tmp = _mm_loadu_si128((__m128i *)cp);
184 tmp1 = _mm_loadu_si128((__m128i *)(cp + 1));
187 * This range (note the lt) contains some
188 * permissible-but-rare characters (including all
189 * characters >= 128), which we handle later. It also
190 * includes \000.
192 result = _mm_cmplt_epi8(tmp, star_ub);
194 result = _mm_or_si128(result, _mm_cmpeq_epi8(tmp, question));
195 result = _mm_or_si128(result, _mm_cmpeq_epi8(tmp, colon));
197 /* This range contains the permissible ] as bycatch */
198 result = _mm_or_si128(result, _mm_and_si128(
199 _mm_cmpgt_epi8(tmp, bracket_lb),
200 _mm_cmplt_epi8(tmp, caret_ub)));
202 result = _mm_or_si128(result, _mm_cmpgt_epi8(tmp, tilde_lb));
204 /* .. */
205 result = _mm_or_si128(result, _mm_and_si128(
206 _mm_cmpeq_epi8(tmp, dot),
207 _mm_cmpeq_epi8(tmp1, dot)));
208 /* @{ */
209 result = _mm_or_si128(result, _mm_and_si128(
210 _mm_cmpeq_epi8(tmp, at),
211 _mm_cmpeq_epi8(tmp1, curly)));
212 /* // */
213 result = _mm_or_si128(result, _mm_and_si128(
214 _mm_cmpeq_epi8(tmp, slash),
215 _mm_cmpeq_epi8(tmp1, slash)));
216 /* trailing / */
217 result = _mm_or_si128(result, _mm_and_si128(
218 _mm_cmpeq_epi8(tmp, slash),
219 _mm_cmpeq_epi8(tmp1, zero)));
220 /* .l, beginning of .lock */
221 result = _mm_or_si128(result, _mm_and_si128(
222 _mm_cmpeq_epi8(tmp, dot),
223 _mm_cmpeq_epi8(tmp1, el)));
225 * Even though /. is not necessarily an error, we flag
226 * it anyway. If we find it, we'll check if it's valid
227 * and if so we'll advance just past it.
229 result = _mm_or_si128(result, _mm_and_si128(
230 _mm_cmpeq_epi8(tmp, slash),
231 _mm_cmpeq_epi8(tmp1, dot)));
233 mask = _mm_movemask_epi8(result);
234 if (mask) {
236 * We've found either end-of-string, or some
237 * probably-bad character or substring.
239 int i = __builtin_ctz(mask);
240 switch (refname_disposition[cp[i] & 255]) {
241 case 0: /* fall-through */
242 case 5:
244 * bycatch: a good character that's in
245 * one of the ranges of mostly-forbidden
246 * characters
248 cp += i + 1;
249 break;
250 case 1:
251 if (cp[i + 1] == '{')
252 return -1;
253 cp += i + 1;
254 break;
255 case 2:
256 if (!(flags & REFNAME_ALLOW_ONELEVEL)
257 && !component_count && !strchr(refname, '/'))
258 /* Refname has only one component. */
259 return -1;
260 return 0;
261 case 3:
262 component_count ++;
264 * Even if leading dots are allowed, don't
265 * allow "." as a component (".." is
266 * prevented by case 4 below).
268 if (cp[i + 1] == '.') {
269 if (cp[i + 2] == '\0')
270 return -1;
271 if (flags & REFNAME_DOT_COMPONENT) {
272 /* skip to just after the /. */
273 cp += i + 2;
274 break;
276 return -1;
277 } else if (cp[i + 1] == '/' || cp[i + 1] == '\0')
278 return -1;
279 break;
280 case 4:
281 if (cp[i + 1] == '.' || cp[i + 1] == '\0')
282 return -1;
283 /* .lock as end-of-component or end-of-string */
284 if ((!strncmp(cp + i, ".lock", 5))
285 && (cp[i + 5] == '/' || cp[i + 5] == 0))
286 return -1;
287 cp += 1;
288 break;
289 case 6:
290 if (((cp == refname + i) || cp[i - 1] == '/')
291 && (cp[i + 1] == '/' || cp[i + 1] == 0))
292 if (flags & REFNAME_REFSPEC_PATTERN) {
293 flags &= ~REFNAME_REFSPEC_PATTERN;
294 /* restart after the * */
295 cp += i + 1;
296 continue;
298 /* fall-through */
299 case 7:
300 return -1;
302 } else
303 cp += SSE_VECTOR_BYTES;
307 #else
309 int check_refname_format (const char *refname, int flags)
311 return check_refname_format_bytewise(refname, flags);
314 #endif
316 struct ref_entry;
319 * Information used (along with the information in ref_entry) to
320 * describe a single cached reference. This data structure only
321 * occurs embedded in a union in struct ref_entry, and only when
322 * (ref_entry->flag & REF_DIR) is zero.
324 struct ref_value {
326 * The name of the object to which this reference resolves
327 * (which may be a tag object). If REF_ISBROKEN, this is
328 * null. If REF_ISSYMREF, then this is the name of the object
329 * referred to by the last reference in the symlink chain.
331 unsigned char sha1[20];
334 * If REF_KNOWS_PEELED, then this field holds the peeled value
335 * of this reference, or null if the reference is known not to
336 * be peelable. See the documentation for peel_ref() for an
337 * exact definition of "peelable".
339 unsigned char peeled[20];
342 struct ref_cache;
345 * Information used (along with the information in ref_entry) to
346 * describe a level in the hierarchy of references. This data
347 * structure only occurs embedded in a union in struct ref_entry, and
348 * only when (ref_entry.flag & REF_DIR) is set. In that case,
349 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
350 * in the directory have already been read:
352 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
353 * or packed references, already read.
355 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
356 * references that hasn't been read yet (nor has any of its
357 * subdirectories).
359 * Entries within a directory are stored within a growable array of
360 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
361 * sorted are sorted by their component name in strcmp() order and the
362 * remaining entries are unsorted.
364 * Loose references are read lazily, one directory at a time. When a
365 * directory of loose references is read, then all of the references
366 * in that directory are stored, and REF_INCOMPLETE stubs are created
367 * for any subdirectories, but the subdirectories themselves are not
368 * read. The reading is triggered by get_ref_dir().
370 struct ref_dir {
371 int nr, alloc;
374 * Entries with index 0 <= i < sorted are sorted by name. New
375 * entries are appended to the list unsorted, and are sorted
376 * only when required; thus we avoid the need to sort the list
377 * after the addition of every reference.
379 int sorted;
381 /* A pointer to the ref_cache that contains this ref_dir. */
382 struct ref_cache *ref_cache;
384 struct ref_entry **entries;
388 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
389 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
390 * refs.h.
394 * The field ref_entry->u.value.peeled of this value entry contains
395 * the correct peeled value for the reference, which might be
396 * null_sha1 if the reference is not a tag or if it is broken.
398 #define REF_KNOWS_PEELED 0x08
400 /* ref_entry represents a directory of references */
401 #define REF_DIR 0x10
404 * Entry has not yet been read from disk (used only for REF_DIR
405 * entries representing loose references)
407 #define REF_INCOMPLETE 0x20
410 * A ref_entry represents either a reference or a "subdirectory" of
411 * references.
413 * Each directory in the reference namespace is represented by a
414 * ref_entry with (flags & REF_DIR) set and containing a subdir member
415 * that holds the entries in that directory that have been read so
416 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
417 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
418 * used for loose reference directories.
420 * References are represented by a ref_entry with (flags & REF_DIR)
421 * unset and a value member that describes the reference's value. The
422 * flag member is at the ref_entry level, but it is also needed to
423 * interpret the contents of the value field (in other words, a
424 * ref_value object is not very much use without the enclosing
425 * ref_entry).
427 * Reference names cannot end with slash and directories' names are
428 * always stored with a trailing slash (except for the top-level
429 * directory, which is always denoted by ""). This has two nice
430 * consequences: (1) when the entries in each subdir are sorted
431 * lexicographically by name (as they usually are), the references in
432 * a whole tree can be generated in lexicographic order by traversing
433 * the tree in left-to-right, depth-first order; (2) the names of
434 * references and subdirectories cannot conflict, and therefore the
435 * presence of an empty subdirectory does not block the creation of a
436 * similarly-named reference. (The fact that reference names with the
437 * same leading components can conflict *with each other* is a
438 * separate issue that is regulated by is_refname_available().)
440 * Please note that the name field contains the fully-qualified
441 * reference (or subdirectory) name. Space could be saved by only
442 * storing the relative names. But that would require the full names
443 * to be generated on the fly when iterating in do_for_each_ref(), and
444 * would break callback functions, who have always been able to assume
445 * that the name strings that they are passed will not be freed during
446 * the iteration.
448 struct ref_entry {
449 unsigned char flag; /* ISSYMREF? ISPACKED? */
450 union {
451 struct ref_value value; /* if not (flags&REF_DIR) */
452 struct ref_dir subdir; /* if (flags&REF_DIR) */
453 } u;
455 * The full name of the reference (e.g., "refs/heads/master")
456 * or the full name of the directory with a trailing slash
457 * (e.g., "refs/heads/"):
459 char name[FLEX_ARRAY];
462 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
464 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
466 struct ref_dir *dir;
467 assert(entry->flag & REF_DIR);
468 dir = &entry->u.subdir;
469 if (entry->flag & REF_INCOMPLETE) {
470 read_loose_refs(entry->name, dir);
471 entry->flag &= ~REF_INCOMPLETE;
473 return dir;
476 static struct ref_entry *create_ref_entry(const char *refname,
477 const unsigned char *sha1, int flag,
478 int check_name)
480 int len;
481 struct ref_entry *ref;
483 if (check_name &&
484 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
485 die("Reference has invalid format: '%s'", refname);
486 len = strlen(refname) + 1;
487 ref = xmalloc(sizeof(struct ref_entry) + len);
488 hashcpy(ref->u.value.sha1, sha1);
489 hashclr(ref->u.value.peeled);
490 memcpy(ref->name, refname, len);
491 ref->flag = flag;
492 return ref;
495 static void clear_ref_dir(struct ref_dir *dir);
497 static void free_ref_entry(struct ref_entry *entry)
499 if (entry->flag & REF_DIR) {
501 * Do not use get_ref_dir() here, as that might
502 * trigger the reading of loose refs.
504 clear_ref_dir(&entry->u.subdir);
506 free(entry);
510 * Add a ref_entry to the end of dir (unsorted). Entry is always
511 * stored directly in dir; no recursion into subdirectories is
512 * done.
514 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
516 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
517 dir->entries[dir->nr++] = entry;
518 /* optimize for the case that entries are added in order */
519 if (dir->nr == 1 ||
520 (dir->nr == dir->sorted + 1 &&
521 strcmp(dir->entries[dir->nr - 2]->name,
522 dir->entries[dir->nr - 1]->name) < 0))
523 dir->sorted = dir->nr;
527 * Clear and free all entries in dir, recursively.
529 static void clear_ref_dir(struct ref_dir *dir)
531 int i;
532 for (i = 0; i < dir->nr; i++)
533 free_ref_entry(dir->entries[i]);
534 free(dir->entries);
535 dir->sorted = dir->nr = dir->alloc = 0;
536 dir->entries = NULL;
540 * Create a struct ref_entry object for the specified dirname.
541 * dirname is the name of the directory with a trailing slash (e.g.,
542 * "refs/heads/") or "" for the top-level directory.
544 static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
545 const char *dirname, size_t len,
546 int incomplete)
548 struct ref_entry *direntry;
549 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
550 memcpy(direntry->name, dirname, len);
551 direntry->name[len] = '\0';
552 direntry->u.subdir.ref_cache = ref_cache;
553 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
554 return direntry;
557 static int ref_entry_cmp(const void *a, const void *b)
559 struct ref_entry *one = *(struct ref_entry **)a;
560 struct ref_entry *two = *(struct ref_entry **)b;
561 return strcmp(one->name, two->name);
564 static void sort_ref_dir(struct ref_dir *dir);
566 struct string_slice {
567 size_t len;
568 const char *str;
571 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
573 const struct string_slice *key = key_;
574 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
575 int cmp = strncmp(key->str, ent->name, key->len);
576 if (cmp)
577 return cmp;
578 return '\0' - (unsigned char)ent->name[key->len];
582 * Return the index of the entry with the given refname from the
583 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
584 * no such entry is found. dir must already be complete.
586 static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
588 struct ref_entry **r;
589 struct string_slice key;
591 if (refname == NULL || !dir->nr)
592 return -1;
594 sort_ref_dir(dir);
595 key.len = len;
596 key.str = refname;
597 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
598 ref_entry_cmp_sslice);
600 if (r == NULL)
601 return -1;
603 return r - dir->entries;
607 * Search for a directory entry directly within dir (without
608 * recursing). Sort dir if necessary. subdirname must be a directory
609 * name (i.e., end in '/'). If mkdir is set, then create the
610 * directory if it is missing; otherwise, return NULL if the desired
611 * directory cannot be found. dir must already be complete.
613 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
614 const char *subdirname, size_t len,
615 int mkdir)
617 int entry_index = search_ref_dir(dir, subdirname, len);
618 struct ref_entry *entry;
619 if (entry_index == -1) {
620 if (!mkdir)
621 return NULL;
623 * Since dir is complete, the absence of a subdir
624 * means that the subdir really doesn't exist;
625 * therefore, create an empty record for it but mark
626 * the record complete.
628 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
629 add_entry_to_dir(dir, entry);
630 } else {
631 entry = dir->entries[entry_index];
633 return get_ref_dir(entry);
637 * If refname is a reference name, find the ref_dir within the dir
638 * tree that should hold refname. If refname is a directory name
639 * (i.e., ends in '/'), then return that ref_dir itself. dir must
640 * represent the top-level directory and must already be complete.
641 * Sort ref_dirs and recurse into subdirectories as necessary. If
642 * mkdir is set, then create any missing directories; otherwise,
643 * return NULL if the desired directory cannot be found.
645 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
646 const char *refname, int mkdir)
648 const char *slash;
649 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
650 size_t dirnamelen = slash - refname + 1;
651 struct ref_dir *subdir;
652 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
653 if (!subdir) {
654 dir = NULL;
655 break;
657 dir = subdir;
660 return dir;
664 * Find the value entry with the given name in dir, sorting ref_dirs
665 * and recursing into subdirectories as necessary. If the name is not
666 * found or it corresponds to a directory entry, return NULL.
668 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
670 int entry_index;
671 struct ref_entry *entry;
672 dir = find_containing_dir(dir, refname, 0);
673 if (!dir)
674 return NULL;
675 entry_index = search_ref_dir(dir, refname, strlen(refname));
676 if (entry_index == -1)
677 return NULL;
678 entry = dir->entries[entry_index];
679 return (entry->flag & REF_DIR) ? NULL : entry;
683 * Remove the entry with the given name from dir, recursing into
684 * subdirectories as necessary. If refname is the name of a directory
685 * (i.e., ends with '/'), then remove the directory and its contents.
686 * If the removal was successful, return the number of entries
687 * remaining in the directory entry that contained the deleted entry.
688 * If the name was not found, return -1. Please note that this
689 * function only deletes the entry from the cache; it does not delete
690 * it from the filesystem or ensure that other cache entries (which
691 * might be symbolic references to the removed entry) are updated.
692 * Nor does it remove any containing dir entries that might be made
693 * empty by the removal. dir must represent the top-level directory
694 * and must already be complete.
696 static int remove_entry(struct ref_dir *dir, const char *refname)
698 int refname_len = strlen(refname);
699 int entry_index;
700 struct ref_entry *entry;
701 int is_dir = refname[refname_len - 1] == '/';
702 if (is_dir) {
704 * refname represents a reference directory. Remove
705 * the trailing slash; otherwise we will get the
706 * directory *representing* refname rather than the
707 * one *containing* it.
709 char *dirname = xmemdupz(refname, refname_len - 1);
710 dir = find_containing_dir(dir, dirname, 0);
711 free(dirname);
712 } else {
713 dir = find_containing_dir(dir, refname, 0);
715 if (!dir)
716 return -1;
717 entry_index = search_ref_dir(dir, refname, refname_len);
718 if (entry_index == -1)
719 return -1;
720 entry = dir->entries[entry_index];
722 memmove(&dir->entries[entry_index],
723 &dir->entries[entry_index + 1],
724 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
726 dir->nr--;
727 if (dir->sorted > entry_index)
728 dir->sorted--;
729 free_ref_entry(entry);
730 return dir->nr;
734 * Add a ref_entry to the ref_dir (unsorted), recursing into
735 * subdirectories as necessary. dir must represent the top-level
736 * directory. Return 0 on success.
738 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
740 dir = find_containing_dir(dir, ref->name, 1);
741 if (!dir)
742 return -1;
743 add_entry_to_dir(dir, ref);
744 return 0;
748 * Emit a warning and return true iff ref1 and ref2 have the same name
749 * and the same sha1. Die if they have the same name but different
750 * sha1s.
752 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
754 if (strcmp(ref1->name, ref2->name))
755 return 0;
757 /* Duplicate name; make sure that they don't conflict: */
759 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
760 /* This is impossible by construction */
761 die("Reference directory conflict: %s", ref1->name);
763 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
764 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
766 warning("Duplicated ref: %s", ref1->name);
767 return 1;
771 * Sort the entries in dir non-recursively (if they are not already
772 * sorted) and remove any duplicate entries.
774 static void sort_ref_dir(struct ref_dir *dir)
776 int i, j;
777 struct ref_entry *last = NULL;
780 * This check also prevents passing a zero-length array to qsort(),
781 * which is a problem on some platforms.
783 if (dir->sorted == dir->nr)
784 return;
786 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
788 /* Remove any duplicates: */
789 for (i = 0, j = 0; j < dir->nr; j++) {
790 struct ref_entry *entry = dir->entries[j];
791 if (last && is_dup_ref(last, entry))
792 free_ref_entry(entry);
793 else
794 last = dir->entries[i++] = entry;
796 dir->sorted = dir->nr = i;
799 /* Include broken references in a do_for_each_ref*() iteration: */
800 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
803 * Return true iff the reference described by entry can be resolved to
804 * an object in the database. Emit a warning if the referred-to
805 * object does not exist.
807 static int ref_resolves_to_object(struct ref_entry *entry)
809 if (entry->flag & REF_ISBROKEN)
810 return 0;
811 if (!has_sha1_file(entry->u.value.sha1)) {
812 error("%s does not point to a valid object!", entry->name);
813 return 0;
815 return 1;
819 * current_ref is a performance hack: when iterating over references
820 * using the for_each_ref*() functions, current_ref is set to the
821 * current reference's entry before calling the callback function. If
822 * the callback function calls peel_ref(), then peel_ref() first
823 * checks whether the reference to be peeled is the current reference
824 * (it usually is) and if so, returns that reference's peeled version
825 * if it is available. This avoids a refname lookup in a common case.
827 static struct ref_entry *current_ref;
829 typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
831 struct ref_entry_cb {
832 const char *base;
833 int trim;
834 int flags;
835 each_ref_fn *fn;
836 void *cb_data;
840 * Handle one reference in a do_for_each_ref*()-style iteration,
841 * calling an each_ref_fn for each entry.
843 static int do_one_ref(struct ref_entry *entry, void *cb_data)
845 struct ref_entry_cb *data = cb_data;
846 struct ref_entry *old_current_ref;
847 int retval;
849 if (!starts_with(entry->name, data->base))
850 return 0;
852 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
853 !ref_resolves_to_object(entry))
854 return 0;
856 /* Store the old value, in case this is a recursive call: */
857 old_current_ref = current_ref;
858 current_ref = entry;
859 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
860 entry->flag, data->cb_data);
861 current_ref = old_current_ref;
862 return retval;
866 * Call fn for each reference in dir that has index in the range
867 * offset <= index < dir->nr. Recurse into subdirectories that are in
868 * that index range, sorting them before iterating. This function
869 * does not sort dir itself; it should be sorted beforehand. fn is
870 * called for all references, including broken ones.
872 static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
873 each_ref_entry_fn fn, void *cb_data)
875 int i;
876 assert(dir->sorted == dir->nr);
877 for (i = offset; i < dir->nr; i++) {
878 struct ref_entry *entry = dir->entries[i];
879 int retval;
880 if (entry->flag & REF_DIR) {
881 struct ref_dir *subdir = get_ref_dir(entry);
882 sort_ref_dir(subdir);
883 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
884 } else {
885 retval = fn(entry, cb_data);
887 if (retval)
888 return retval;
890 return 0;
894 * Call fn for each reference in the union of dir1 and dir2, in order
895 * by refname. Recurse into subdirectories. If a value entry appears
896 * in both dir1 and dir2, then only process the version that is in
897 * dir2. The input dirs must already be sorted, but subdirs will be
898 * sorted as needed. fn is called for all references, including
899 * broken ones.
901 static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
902 struct ref_dir *dir2,
903 each_ref_entry_fn fn, void *cb_data)
905 int retval;
906 int i1 = 0, i2 = 0;
908 assert(dir1->sorted == dir1->nr);
909 assert(dir2->sorted == dir2->nr);
910 while (1) {
911 struct ref_entry *e1, *e2;
912 int cmp;
913 if (i1 == dir1->nr) {
914 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
916 if (i2 == dir2->nr) {
917 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
919 e1 = dir1->entries[i1];
920 e2 = dir2->entries[i2];
921 cmp = strcmp(e1->name, e2->name);
922 if (cmp == 0) {
923 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
924 /* Both are directories; descend them in parallel. */
925 struct ref_dir *subdir1 = get_ref_dir(e1);
926 struct ref_dir *subdir2 = get_ref_dir(e2);
927 sort_ref_dir(subdir1);
928 sort_ref_dir(subdir2);
929 retval = do_for_each_entry_in_dirs(
930 subdir1, subdir2, fn, cb_data);
931 i1++;
932 i2++;
933 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
934 /* Both are references; ignore the one from dir1. */
935 retval = fn(e2, cb_data);
936 i1++;
937 i2++;
938 } else {
939 die("conflict between reference and directory: %s",
940 e1->name);
942 } else {
943 struct ref_entry *e;
944 if (cmp < 0) {
945 e = e1;
946 i1++;
947 } else {
948 e = e2;
949 i2++;
951 if (e->flag & REF_DIR) {
952 struct ref_dir *subdir = get_ref_dir(e);
953 sort_ref_dir(subdir);
954 retval = do_for_each_entry_in_dir(
955 subdir, 0, fn, cb_data);
956 } else {
957 retval = fn(e, cb_data);
960 if (retval)
961 return retval;
966 * Load all of the refs from the dir into our in-memory cache. The hard work
967 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
968 * through all of the sub-directories. We do not even need to care about
969 * sorting, as traversal order does not matter to us.
971 static void prime_ref_dir(struct ref_dir *dir)
973 int i;
974 for (i = 0; i < dir->nr; i++) {
975 struct ref_entry *entry = dir->entries[i];
976 if (entry->flag & REF_DIR)
977 prime_ref_dir(get_ref_dir(entry));
981 * Return true iff refname1 and refname2 conflict with each other.
982 * Two reference names conflict if one of them exactly matches the
983 * leading components of the other; e.g., "foo/bar" conflicts with
984 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
985 * "foo/barbados".
987 static int names_conflict(const char *refname1, const char *refname2)
989 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
991 return (*refname1 == '\0' && *refname2 == '/')
992 || (*refname1 == '/' && *refname2 == '\0');
995 struct name_conflict_cb {
996 const char *refname;
997 const char *oldrefname;
998 const char *conflicting_refname;
1001 static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
1003 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
1004 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
1005 return 0;
1006 if (names_conflict(data->refname, entry->name)) {
1007 data->conflicting_refname = entry->name;
1008 return 1;
1010 return 0;
1014 * Return true iff a reference named refname could be created without
1015 * conflicting with the name of an existing reference in dir. If
1016 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
1017 * (e.g., because oldrefname is scheduled for deletion in the same
1018 * operation).
1020 static int is_refname_available(const char *refname, const char *oldrefname,
1021 struct ref_dir *dir)
1023 struct name_conflict_cb data;
1024 data.refname = refname;
1025 data.oldrefname = oldrefname;
1026 data.conflicting_refname = NULL;
1028 sort_ref_dir(dir);
1029 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
1030 error("'%s' exists; cannot create '%s'",
1031 data.conflicting_refname, refname);
1032 return 0;
1034 return 1;
1037 struct packed_ref_cache {
1038 struct ref_entry *root;
1041 * Count of references to the data structure in this instance,
1042 * including the pointer from ref_cache::packed if any. The
1043 * data will not be freed as long as the reference count is
1044 * nonzero.
1046 unsigned int referrers;
1049 * Iff the packed-refs file associated with this instance is
1050 * currently locked for writing, this points at the associated
1051 * lock (which is owned by somebody else). The referrer count
1052 * is also incremented when the file is locked and decremented
1053 * when it is unlocked.
1055 struct lock_file *lock;
1057 /* The metadata from when this packed-refs cache was read */
1058 struct stat_validity validity;
1062 * Future: need to be in "struct repository"
1063 * when doing a full libification.
1065 static struct ref_cache {
1066 struct ref_cache *next;
1067 struct ref_entry *loose;
1068 struct packed_ref_cache *packed;
1070 * The submodule name, or "" for the main repo. We allocate
1071 * length 1 rather than FLEX_ARRAY so that the main ref_cache
1072 * is initialized correctly.
1074 char name[1];
1075 } ref_cache, *submodule_ref_caches;
1077 /* Lock used for the main packed-refs file: */
1078 static struct lock_file packlock;
1081 * Increment the reference count of *packed_refs.
1083 static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
1085 packed_refs->referrers++;
1089 * Decrease the reference count of *packed_refs. If it goes to zero,
1090 * free *packed_refs and return true; otherwise return false.
1092 static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
1094 if (!--packed_refs->referrers) {
1095 free_ref_entry(packed_refs->root);
1096 stat_validity_clear(&packed_refs->validity);
1097 free(packed_refs);
1098 return 1;
1099 } else {
1100 return 0;
1104 static void clear_packed_ref_cache(struct ref_cache *refs)
1106 if (refs->packed) {
1107 struct packed_ref_cache *packed_refs = refs->packed;
1109 if (packed_refs->lock)
1110 die("internal error: packed-ref cache cleared while locked");
1111 refs->packed = NULL;
1112 release_packed_ref_cache(packed_refs);
1116 static void clear_loose_ref_cache(struct ref_cache *refs)
1118 if (refs->loose) {
1119 free_ref_entry(refs->loose);
1120 refs->loose = NULL;
1124 static struct ref_cache *create_ref_cache(const char *submodule)
1126 int len;
1127 struct ref_cache *refs;
1128 if (!submodule)
1129 submodule = "";
1130 len = strlen(submodule) + 1;
1131 refs = xcalloc(1, sizeof(struct ref_cache) + len);
1132 memcpy(refs->name, submodule, len);
1133 return refs;
1137 * Return a pointer to a ref_cache for the specified submodule. For
1138 * the main repository, use submodule==NULL. The returned structure
1139 * will be allocated and initialized but not necessarily populated; it
1140 * should not be freed.
1142 static struct ref_cache *get_ref_cache(const char *submodule)
1144 struct ref_cache *refs;
1146 if (!submodule || !*submodule)
1147 return &ref_cache;
1149 for (refs = submodule_ref_caches; refs; refs = refs->next)
1150 if (!strcmp(submodule, refs->name))
1151 return refs;
1153 refs = create_ref_cache(submodule);
1154 refs->next = submodule_ref_caches;
1155 submodule_ref_caches = refs;
1156 return refs;
1159 /* The length of a peeled reference line in packed-refs, including EOL: */
1160 #define PEELED_LINE_LENGTH 42
1163 * The packed-refs header line that we write out. Perhaps other
1164 * traits will be added later. The trailing space is required.
1166 static const char PACKED_REFS_HEADER[] =
1167 "# pack-refs with: peeled fully-peeled \n";
1170 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
1171 * Return a pointer to the refname within the line (null-terminated),
1172 * or NULL if there was a problem.
1174 static const char *parse_ref_line(char *line, unsigned char *sha1)
1177 * 42: the answer to everything.
1179 * In this case, it happens to be the answer to
1180 * 40 (length of sha1 hex representation)
1181 * +1 (space in between hex and name)
1182 * +1 (newline at the end of the line)
1184 int len = strlen(line) - 42;
1186 if (len <= 0)
1187 return NULL;
1188 if (get_sha1_hex(line, sha1) < 0)
1189 return NULL;
1190 if (!isspace(line[40]))
1191 return NULL;
1192 line += 41;
1193 if (isspace(*line))
1194 return NULL;
1195 if (line[len] != '\n')
1196 return NULL;
1197 line[len] = 0;
1199 return line;
1203 * Read f, which is a packed-refs file, into dir.
1205 * A comment line of the form "# pack-refs with: " may contain zero or
1206 * more traits. We interpret the traits as follows:
1208 * No traits:
1210 * Probably no references are peeled. But if the file contains a
1211 * peeled value for a reference, we will use it.
1213 * peeled:
1215 * References under "refs/tags/", if they *can* be peeled, *are*
1216 * peeled in this file. References outside of "refs/tags/" are
1217 * probably not peeled even if they could have been, but if we find
1218 * a peeled value for such a reference we will use it.
1220 * fully-peeled:
1222 * All references in the file that can be peeled are peeled.
1223 * Inversely (and this is more important), any references in the
1224 * file for which no peeled value is recorded is not peelable. This
1225 * trait should typically be written alongside "peeled" for
1226 * compatibility with older clients, but we do not require it
1227 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1229 static void read_packed_refs(FILE *f, struct ref_dir *dir)
1231 struct ref_entry *last = NULL;
1232 char refline[PATH_MAX];
1233 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1235 while (fgets(refline, sizeof(refline), f)) {
1236 unsigned char sha1[20];
1237 const char *refname;
1238 static const char header[] = "# pack-refs with:";
1240 if (!strncmp(refline, header, sizeof(header)-1)) {
1241 const char *traits = refline + sizeof(header) - 1;
1242 if (strstr(traits, " fully-peeled "))
1243 peeled = PEELED_FULLY;
1244 else if (strstr(traits, " peeled "))
1245 peeled = PEELED_TAGS;
1246 /* perhaps other traits later as well */
1247 continue;
1250 refname = parse_ref_line(refline, sha1);
1251 if (refname) {
1252 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
1253 if (peeled == PEELED_FULLY ||
1254 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
1255 last->flag |= REF_KNOWS_PEELED;
1256 add_ref(dir, last);
1257 continue;
1259 if (last &&
1260 refline[0] == '^' &&
1261 strlen(refline) == PEELED_LINE_LENGTH &&
1262 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
1263 !get_sha1_hex(refline + 1, sha1)) {
1264 hashcpy(last->u.value.peeled, sha1);
1266 * Regardless of what the file header said,
1267 * we definitely know the value of *this*
1268 * reference:
1270 last->flag |= REF_KNOWS_PEELED;
1276 * Get the packed_ref_cache for the specified ref_cache, creating it
1277 * if necessary.
1279 static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
1281 const char *packed_refs_file;
1283 if (*refs->name)
1284 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1285 else
1286 packed_refs_file = git_path("packed-refs");
1288 if (refs->packed &&
1289 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1290 clear_packed_ref_cache(refs);
1292 if (!refs->packed) {
1293 FILE *f;
1295 refs->packed = xcalloc(1, sizeof(*refs->packed));
1296 acquire_packed_ref_cache(refs->packed);
1297 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1298 f = fopen(packed_refs_file, "r");
1299 if (f) {
1300 stat_validity_update(&refs->packed->validity, fileno(f));
1301 read_packed_refs(f, get_ref_dir(refs->packed->root));
1302 fclose(f);
1305 return refs->packed;
1308 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1310 return get_ref_dir(packed_ref_cache->root);
1313 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1315 return get_packed_ref_dir(get_packed_ref_cache(refs));
1318 void add_packed_ref(const char *refname, const unsigned char *sha1)
1320 struct packed_ref_cache *packed_ref_cache =
1321 get_packed_ref_cache(&ref_cache);
1323 if (!packed_ref_cache->lock)
1324 die("internal error: packed refs not locked");
1325 add_ref(get_packed_ref_dir(packed_ref_cache),
1326 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1330 * Read the loose references from the namespace dirname into dir
1331 * (without recursing). dirname must end with '/'. dir must be the
1332 * directory entry corresponding to dirname.
1334 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1336 struct ref_cache *refs = dir->ref_cache;
1337 DIR *d;
1338 const char *path;
1339 struct dirent *de;
1340 int dirnamelen = strlen(dirname);
1341 struct strbuf refname;
1343 if (*refs->name)
1344 path = git_path_submodule(refs->name, "%s", dirname);
1345 else
1346 path = git_path("%s", dirname);
1348 d = opendir(path);
1349 if (!d)
1350 return;
1352 strbuf_init(&refname, dirnamelen + 257);
1353 strbuf_add(&refname, dirname, dirnamelen);
1355 while ((de = readdir(d)) != NULL) {
1356 unsigned char sha1[20];
1357 struct stat st;
1358 int flag;
1359 const char *refdir;
1361 if (de->d_name[0] == '.')
1362 continue;
1363 if (has_extension(de->d_name, ".lock"))
1364 continue;
1365 strbuf_addstr(&refname, de->d_name);
1366 refdir = *refs->name
1367 ? git_path_submodule(refs->name, "%s", refname.buf)
1368 : git_path("%s", refname.buf);
1369 if (stat(refdir, &st) < 0) {
1370 ; /* silently ignore */
1371 } else if (S_ISDIR(st.st_mode)) {
1372 strbuf_addch(&refname, '/');
1373 add_entry_to_dir(dir,
1374 create_dir_entry(refs, refname.buf,
1375 refname.len, 1));
1376 } else {
1377 if (*refs->name) {
1378 hashclr(sha1);
1379 flag = 0;
1380 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
1381 hashclr(sha1);
1382 flag |= REF_ISBROKEN;
1384 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
1385 hashclr(sha1);
1386 flag |= REF_ISBROKEN;
1388 add_entry_to_dir(dir,
1389 create_ref_entry(refname.buf, sha1, flag, 1));
1391 strbuf_setlen(&refname, dirnamelen);
1393 strbuf_release(&refname);
1394 closedir(d);
1397 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
1399 if (!refs->loose) {
1401 * Mark the top-level directory complete because we
1402 * are about to read the only subdirectory that can
1403 * hold references:
1405 refs->loose = create_dir_entry(refs, "", 0, 0);
1407 * Create an incomplete entry for "refs/":
1409 add_entry_to_dir(get_ref_dir(refs->loose),
1410 create_dir_entry(refs, "refs/", 5, 1));
1412 return get_ref_dir(refs->loose);
1415 /* We allow "recursive" symbolic refs. Only within reason, though */
1416 #define MAXDEPTH 5
1417 #define MAXREFLEN (1024)
1420 * Called by resolve_gitlink_ref_recursive() after it failed to read
1421 * from the loose refs in ref_cache refs. Find <refname> in the
1422 * packed-refs file for the submodule.
1424 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
1425 const char *refname, unsigned char *sha1)
1427 struct ref_entry *ref;
1428 struct ref_dir *dir = get_packed_refs(refs);
1430 ref = find_ref(dir, refname);
1431 if (ref == NULL)
1432 return -1;
1434 hashcpy(sha1, ref->u.value.sha1);
1435 return 0;
1438 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
1439 const char *refname, unsigned char *sha1,
1440 int recursion)
1442 int fd, len;
1443 char buffer[128], *p;
1444 char *path;
1446 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
1447 return -1;
1448 path = *refs->name
1449 ? git_path_submodule(refs->name, "%s", refname)
1450 : git_path("%s", refname);
1451 fd = open(path, O_RDONLY);
1452 if (fd < 0)
1453 return resolve_gitlink_packed_ref(refs, refname, sha1);
1455 len = read(fd, buffer, sizeof(buffer)-1);
1456 close(fd);
1457 if (len < 0)
1458 return -1;
1459 while (len && isspace(buffer[len-1]))
1460 len--;
1461 buffer[len] = 0;
1463 /* Was it a detached head or an old-fashioned symlink? */
1464 if (!get_sha1_hex(buffer, sha1))
1465 return 0;
1467 /* Symref? */
1468 if (strncmp(buffer, "ref:", 4))
1469 return -1;
1470 p = buffer + 4;
1471 while (isspace(*p))
1472 p++;
1474 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1477 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1479 int len = strlen(path), retval;
1480 char *submodule;
1481 struct ref_cache *refs;
1483 while (len && path[len-1] == '/')
1484 len--;
1485 if (!len)
1486 return -1;
1487 submodule = xstrndup(path, len);
1488 refs = get_ref_cache(submodule);
1489 free(submodule);
1491 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1492 return retval;
1496 * Return the ref_entry for the given refname from the packed
1497 * references. If it does not exist, return NULL.
1499 static struct ref_entry *get_packed_ref(const char *refname)
1501 return find_ref(get_packed_refs(&ref_cache), refname);
1505 * A loose ref file doesn't exist; check for a packed ref. The
1506 * options are forwarded from resolve_safe_unsafe().
1508 static const char *handle_missing_loose_ref(const char *refname,
1509 unsigned char *sha1,
1510 int reading,
1511 int *flag)
1513 struct ref_entry *entry;
1516 * The loose reference file does not exist; check for a packed
1517 * reference.
1519 entry = get_packed_ref(refname);
1520 if (entry) {
1521 hashcpy(sha1, entry->u.value.sha1);
1522 if (flag)
1523 *flag |= REF_ISPACKED;
1524 return refname;
1526 /* The reference is not a packed reference, either. */
1527 if (reading) {
1528 return NULL;
1529 } else {
1530 hashclr(sha1);
1531 return refname;
1535 const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
1537 int depth = MAXDEPTH;
1538 ssize_t len;
1539 char buffer[256];
1540 static char refname_buffer[256];
1542 if (flag)
1543 *flag = 0;
1545 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1546 return NULL;
1548 for (;;) {
1549 char path[PATH_MAX];
1550 struct stat st;
1551 char *buf;
1552 int fd;
1554 if (--depth < 0)
1555 return NULL;
1557 git_snpath(path, sizeof(path), "%s", refname);
1560 * We might have to loop back here to avoid a race
1561 * condition: first we lstat() the file, then we try
1562 * to read it as a link or as a file. But if somebody
1563 * changes the type of the file (file <-> directory
1564 * <-> symlink) between the lstat() and reading, then
1565 * we don't want to report that as an error but rather
1566 * try again starting with the lstat().
1568 stat_ref:
1569 if (lstat(path, &st) < 0) {
1570 if (errno == ENOENT)
1571 return handle_missing_loose_ref(refname, sha1,
1572 reading, flag);
1573 else
1574 return NULL;
1577 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1578 if (S_ISLNK(st.st_mode)) {
1579 len = readlink(path, buffer, sizeof(buffer)-1);
1580 if (len < 0) {
1581 if (errno == ENOENT || errno == EINVAL)
1582 /* inconsistent with lstat; retry */
1583 goto stat_ref;
1584 else
1585 return NULL;
1587 buffer[len] = 0;
1588 if (starts_with(buffer, "refs/") &&
1589 !check_refname_format(buffer, 0)) {
1590 strcpy(refname_buffer, buffer);
1591 refname = refname_buffer;
1592 if (flag)
1593 *flag |= REF_ISSYMREF;
1594 continue;
1598 /* Is it a directory? */
1599 if (S_ISDIR(st.st_mode)) {
1600 errno = EISDIR;
1601 return NULL;
1605 * Anything else, just open it and try to use it as
1606 * a ref
1608 fd = open(path, O_RDONLY);
1609 if (fd < 0) {
1610 if (errno == ENOENT)
1611 /* inconsistent with lstat; retry */
1612 goto stat_ref;
1613 else
1614 return NULL;
1616 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1617 close(fd);
1618 if (len < 0)
1619 return NULL;
1620 while (len && isspace(buffer[len-1]))
1621 len--;
1622 buffer[len] = '\0';
1625 * Is it a symbolic ref?
1627 if (!starts_with(buffer, "ref:")) {
1629 * Please note that FETCH_HEAD has a second
1630 * line containing other data.
1632 if (get_sha1_hex(buffer, sha1) ||
1633 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1634 if (flag)
1635 *flag |= REF_ISBROKEN;
1636 return NULL;
1638 return refname;
1640 if (flag)
1641 *flag |= REF_ISSYMREF;
1642 buf = buffer + 4;
1643 while (isspace(*buf))
1644 buf++;
1645 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1646 if (flag)
1647 *flag |= REF_ISBROKEN;
1648 return NULL;
1650 refname = strcpy(refname_buffer, buf);
1654 char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1656 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
1657 return ret ? xstrdup(ret) : NULL;
1660 /* The argument to filter_refs */
1661 struct ref_filter {
1662 const char *pattern;
1663 each_ref_fn *fn;
1664 void *cb_data;
1667 int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
1669 if (resolve_ref_unsafe(refname, sha1, reading, flags))
1670 return 0;
1671 return -1;
1674 int read_ref(const char *refname, unsigned char *sha1)
1676 return read_ref_full(refname, sha1, 1, NULL);
1679 int ref_exists(const char *refname)
1681 unsigned char sha1[20];
1682 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
1685 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1686 void *data)
1688 struct ref_filter *filter = (struct ref_filter *)data;
1689 if (wildmatch(filter->pattern, refname, 0, NULL))
1690 return 0;
1691 return filter->fn(refname, sha1, flags, filter->cb_data);
1694 enum peel_status {
1695 /* object was peeled successfully: */
1696 PEEL_PEELED = 0,
1699 * object cannot be peeled because the named object (or an
1700 * object referred to by a tag in the peel chain), does not
1701 * exist.
1703 PEEL_INVALID = -1,
1705 /* object cannot be peeled because it is not a tag: */
1706 PEEL_NON_TAG = -2,
1708 /* ref_entry contains no peeled value because it is a symref: */
1709 PEEL_IS_SYMREF = -3,
1712 * ref_entry cannot be peeled because it is broken (i.e., the
1713 * symbolic reference cannot even be resolved to an object
1714 * name):
1716 PEEL_BROKEN = -4
1720 * Peel the named object; i.e., if the object is a tag, resolve the
1721 * tag recursively until a non-tag is found. If successful, store the
1722 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1723 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1724 * and leave sha1 unchanged.
1726 static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
1728 struct object *o = lookup_unknown_object(name);
1730 if (o->type == OBJ_NONE) {
1731 int type = sha1_object_info(name, NULL);
1732 if (type < 0)
1733 return PEEL_INVALID;
1734 o->type = type;
1737 if (o->type != OBJ_TAG)
1738 return PEEL_NON_TAG;
1740 o = deref_tag_noverify(o);
1741 if (!o)
1742 return PEEL_INVALID;
1744 hashcpy(sha1, o->sha1);
1745 return PEEL_PEELED;
1749 * Peel the entry (if possible) and return its new peel_status. If
1750 * repeel is true, re-peel the entry even if there is an old peeled
1751 * value that is already stored in it.
1753 * It is OK to call this function with a packed reference entry that
1754 * might be stale and might even refer to an object that has since
1755 * been garbage-collected. In such a case, if the entry has
1756 * REF_KNOWS_PEELED then leave the status unchanged and return
1757 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1759 static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1761 enum peel_status status;
1763 if (entry->flag & REF_KNOWS_PEELED) {
1764 if (repeel) {
1765 entry->flag &= ~REF_KNOWS_PEELED;
1766 hashclr(entry->u.value.peeled);
1767 } else {
1768 return is_null_sha1(entry->u.value.peeled) ?
1769 PEEL_NON_TAG : PEEL_PEELED;
1772 if (entry->flag & REF_ISBROKEN)
1773 return PEEL_BROKEN;
1774 if (entry->flag & REF_ISSYMREF)
1775 return PEEL_IS_SYMREF;
1777 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1778 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1779 entry->flag |= REF_KNOWS_PEELED;
1780 return status;
1783 int peel_ref(const char *refname, unsigned char *sha1)
1785 int flag;
1786 unsigned char base[20];
1788 if (current_ref && (current_ref->name == refname
1789 || !strcmp(current_ref->name, refname))) {
1790 if (peel_entry(current_ref, 0))
1791 return -1;
1792 hashcpy(sha1, current_ref->u.value.peeled);
1793 return 0;
1796 if (read_ref_full(refname, base, 1, &flag))
1797 return -1;
1800 * If the reference is packed, read its ref_entry from the
1801 * cache in the hope that we already know its peeled value.
1802 * We only try this optimization on packed references because
1803 * (a) forcing the filling of the loose reference cache could
1804 * be expensive and (b) loose references anyway usually do not
1805 * have REF_KNOWS_PEELED.
1807 if (flag & REF_ISPACKED) {
1808 struct ref_entry *r = get_packed_ref(refname);
1809 if (r) {
1810 if (peel_entry(r, 0))
1811 return -1;
1812 hashcpy(sha1, r->u.value.peeled);
1813 return 0;
1817 return peel_object(base, sha1);
1820 struct warn_if_dangling_data {
1821 FILE *fp;
1822 const char *refname;
1823 const struct string_list *refnames;
1824 const char *msg_fmt;
1827 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1828 int flags, void *cb_data)
1830 struct warn_if_dangling_data *d = cb_data;
1831 const char *resolves_to;
1832 unsigned char junk[20];
1834 if (!(flags & REF_ISSYMREF))
1835 return 0;
1837 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1838 if (!resolves_to
1839 || (d->refname
1840 ? strcmp(resolves_to, d->refname)
1841 : !string_list_has_string(d->refnames, resolves_to))) {
1842 return 0;
1845 fprintf(d->fp, d->msg_fmt, refname);
1846 fputc('\n', d->fp);
1847 return 0;
1850 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1852 struct warn_if_dangling_data data;
1854 data.fp = fp;
1855 data.refname = refname;
1856 data.refnames = NULL;
1857 data.msg_fmt = msg_fmt;
1858 for_each_rawref(warn_if_dangling_symref, &data);
1861 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
1863 struct warn_if_dangling_data data;
1865 data.fp = fp;
1866 data.refname = NULL;
1867 data.refnames = refnames;
1868 data.msg_fmt = msg_fmt;
1869 for_each_rawref(warn_if_dangling_symref, &data);
1873 * Call fn for each reference in the specified ref_cache, omitting
1874 * references not in the containing_dir of base. fn is called for all
1875 * references, including broken ones. If fn ever returns a non-zero
1876 * value, stop the iteration and return that value; otherwise, return
1877 * 0.
1879 static int do_for_each_entry(struct ref_cache *refs, const char *base,
1880 each_ref_entry_fn fn, void *cb_data)
1882 struct packed_ref_cache *packed_ref_cache;
1883 struct ref_dir *loose_dir;
1884 struct ref_dir *packed_dir;
1885 int retval = 0;
1888 * We must make sure that all loose refs are read before accessing the
1889 * packed-refs file; this avoids a race condition in which loose refs
1890 * are migrated to the packed-refs file by a simultaneous process, but
1891 * our in-memory view is from before the migration. get_packed_ref_cache()
1892 * takes care of making sure our view is up to date with what is on
1893 * disk.
1895 loose_dir = get_loose_refs(refs);
1896 if (base && *base) {
1897 loose_dir = find_containing_dir(loose_dir, base, 0);
1899 if (loose_dir)
1900 prime_ref_dir(loose_dir);
1902 packed_ref_cache = get_packed_ref_cache(refs);
1903 acquire_packed_ref_cache(packed_ref_cache);
1904 packed_dir = get_packed_ref_dir(packed_ref_cache);
1905 if (base && *base) {
1906 packed_dir = find_containing_dir(packed_dir, base, 0);
1909 if (packed_dir && loose_dir) {
1910 sort_ref_dir(packed_dir);
1911 sort_ref_dir(loose_dir);
1912 retval = do_for_each_entry_in_dirs(
1913 packed_dir, loose_dir, fn, cb_data);
1914 } else if (packed_dir) {
1915 sort_ref_dir(packed_dir);
1916 retval = do_for_each_entry_in_dir(
1917 packed_dir, 0, fn, cb_data);
1918 } else if (loose_dir) {
1919 sort_ref_dir(loose_dir);
1920 retval = do_for_each_entry_in_dir(
1921 loose_dir, 0, fn, cb_data);
1924 release_packed_ref_cache(packed_ref_cache);
1925 return retval;
1929 * Call fn for each reference in the specified ref_cache for which the
1930 * refname begins with base. If trim is non-zero, then trim that many
1931 * characters off the beginning of each refname before passing the
1932 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1933 * broken references in the iteration. If fn ever returns a non-zero
1934 * value, stop the iteration and return that value; otherwise, return
1935 * 0.
1937 static int do_for_each_ref(struct ref_cache *refs, const char *base,
1938 each_ref_fn fn, int trim, int flags, void *cb_data)
1940 struct ref_entry_cb data;
1941 data.base = base;
1942 data.trim = trim;
1943 data.flags = flags;
1944 data.fn = fn;
1945 data.cb_data = cb_data;
1947 return do_for_each_entry(refs, base, do_one_ref, &data);
1950 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1952 unsigned char sha1[20];
1953 int flag;
1955 if (submodule) {
1956 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1957 return fn("HEAD", sha1, 0, cb_data);
1959 return 0;
1962 if (!read_ref_full("HEAD", sha1, 1, &flag))
1963 return fn("HEAD", sha1, flag, cb_data);
1965 return 0;
1968 int head_ref(each_ref_fn fn, void *cb_data)
1970 return do_head_ref(NULL, fn, cb_data);
1973 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1975 return do_head_ref(submodule, fn, cb_data);
1978 int for_each_ref(each_ref_fn fn, void *cb_data)
1980 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1983 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1985 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
1988 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1990 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1993 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1994 each_ref_fn fn, void *cb_data)
1996 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
1999 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
2001 return for_each_ref_in("refs/tags/", fn, cb_data);
2004 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
2006 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
2009 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
2011 return for_each_ref_in("refs/heads/", fn, cb_data);
2014 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
2016 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
2019 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
2021 return for_each_ref_in("refs/remotes/", fn, cb_data);
2024 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
2026 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
2029 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
2031 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
2034 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
2036 struct strbuf buf = STRBUF_INIT;
2037 int ret = 0;
2038 unsigned char sha1[20];
2039 int flag;
2041 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
2042 if (!read_ref_full(buf.buf, sha1, 1, &flag))
2043 ret = fn(buf.buf, sha1, flag, cb_data);
2044 strbuf_release(&buf);
2046 return ret;
2049 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
2051 struct strbuf buf = STRBUF_INIT;
2052 int ret;
2053 strbuf_addf(&buf, "%srefs/", get_git_namespace());
2054 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
2055 strbuf_release(&buf);
2056 return ret;
2059 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
2060 const char *prefix, void *cb_data)
2062 struct strbuf real_pattern = STRBUF_INIT;
2063 struct ref_filter filter;
2064 int ret;
2066 if (!prefix && !starts_with(pattern, "refs/"))
2067 strbuf_addstr(&real_pattern, "refs/");
2068 else if (prefix)
2069 strbuf_addstr(&real_pattern, prefix);
2070 strbuf_addstr(&real_pattern, pattern);
2072 if (!has_glob_specials(pattern)) {
2073 /* Append implied '/' '*' if not present. */
2074 if (real_pattern.buf[real_pattern.len - 1] != '/')
2075 strbuf_addch(&real_pattern, '/');
2076 /* No need to check for '*', there is none. */
2077 strbuf_addch(&real_pattern, '*');
2080 filter.pattern = real_pattern.buf;
2081 filter.fn = fn;
2082 filter.cb_data = cb_data;
2083 ret = for_each_ref(filter_refs, &filter);
2085 strbuf_release(&real_pattern);
2086 return ret;
2089 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
2091 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
2094 int for_each_rawref(each_ref_fn fn, void *cb_data)
2096 return do_for_each_ref(&ref_cache, "", fn, 0,
2097 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
2100 const char *prettify_refname(const char *name)
2102 return name + (
2103 starts_with(name, "refs/heads/") ? 11 :
2104 starts_with(name, "refs/tags/") ? 10 :
2105 starts_with(name, "refs/remotes/") ? 13 :
2109 static const char *ref_rev_parse_rules[] = {
2110 "%.*s",
2111 "refs/%.*s",
2112 "refs/tags/%.*s",
2113 "refs/heads/%.*s",
2114 "refs/remotes/%.*s",
2115 "refs/remotes/%.*s/HEAD",
2116 NULL
2119 int refname_match(const char *abbrev_name, const char *full_name)
2121 const char **p;
2122 const int abbrev_name_len = strlen(abbrev_name);
2124 for (p = ref_rev_parse_rules; *p; p++) {
2125 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
2126 return 1;
2130 return 0;
2133 static struct ref_lock *verify_lock(struct ref_lock *lock,
2134 const unsigned char *old_sha1, int mustexist)
2136 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
2137 error("Can't verify ref %s", lock->ref_name);
2138 unlock_ref(lock);
2139 return NULL;
2141 if (hashcmp(lock->old_sha1, old_sha1)) {
2142 error("Ref %s is at %s but expected %s", lock->ref_name,
2143 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
2144 unlock_ref(lock);
2145 return NULL;
2147 return lock;
2150 static int remove_empty_directories(const char *file)
2152 /* we want to create a file but there is a directory there;
2153 * if that is an empty directory (or a directory that contains
2154 * only empty directories), remove them.
2156 struct strbuf path;
2157 int result;
2159 strbuf_init(&path, 20);
2160 strbuf_addstr(&path, file);
2162 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
2164 strbuf_release(&path);
2166 return result;
2170 * *string and *len will only be substituted, and *string returned (for
2171 * later free()ing) if the string passed in is a magic short-hand form
2172 * to name a branch.
2174 static char *substitute_branch_name(const char **string, int *len)
2176 struct strbuf buf = STRBUF_INIT;
2177 int ret = interpret_branch_name(*string, *len, &buf);
2179 if (ret == *len) {
2180 size_t size;
2181 *string = strbuf_detach(&buf, &size);
2182 *len = size;
2183 return (char *)*string;
2186 return NULL;
2189 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
2191 char *last_branch = substitute_branch_name(&str, &len);
2192 const char **p, *r;
2193 int refs_found = 0;
2195 *ref = NULL;
2196 for (p = ref_rev_parse_rules; *p; p++) {
2197 char fullref[PATH_MAX];
2198 unsigned char sha1_from_ref[20];
2199 unsigned char *this_result;
2200 int flag;
2202 this_result = refs_found ? sha1_from_ref : sha1;
2203 mksnpath(fullref, sizeof(fullref), *p, len, str);
2204 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
2205 if (r) {
2206 if (!refs_found++)
2207 *ref = xstrdup(r);
2208 if (!warn_ambiguous_refs)
2209 break;
2210 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
2211 warning("ignoring dangling symref %s.", fullref);
2212 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
2213 warning("ignoring broken ref %s.", fullref);
2216 free(last_branch);
2217 return refs_found;
2220 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
2222 char *last_branch = substitute_branch_name(&str, &len);
2223 const char **p;
2224 int logs_found = 0;
2226 *log = NULL;
2227 for (p = ref_rev_parse_rules; *p; p++) {
2228 unsigned char hash[20];
2229 char path[PATH_MAX];
2230 const char *ref, *it;
2232 mksnpath(path, sizeof(path), *p, len, str);
2233 ref = resolve_ref_unsafe(path, hash, 1, NULL);
2234 if (!ref)
2235 continue;
2236 if (reflog_exists(path))
2237 it = path;
2238 else if (strcmp(ref, path) && reflog_exists(ref))
2239 it = ref;
2240 else
2241 continue;
2242 if (!logs_found++) {
2243 *log = xstrdup(it);
2244 hashcpy(sha1, hash);
2246 if (!warn_ambiguous_refs)
2247 break;
2249 free(last_branch);
2250 return logs_found;
2253 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2254 const unsigned char *old_sha1,
2255 int flags, int *type_p)
2257 char *ref_file;
2258 const char *orig_refname = refname;
2259 struct ref_lock *lock;
2260 int last_errno = 0;
2261 int type, lflags;
2262 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
2263 int missing = 0;
2264 int attempts_remaining = 3;
2266 lock = xcalloc(1, sizeof(struct ref_lock));
2267 lock->lock_fd = -1;
2269 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
2270 if (!refname && errno == EISDIR) {
2271 /* we are trying to lock foo but we used to
2272 * have foo/bar which now does not exist;
2273 * it is normal for the empty directory 'foo'
2274 * to remain.
2276 ref_file = git_path("%s", orig_refname);
2277 if (remove_empty_directories(ref_file)) {
2278 last_errno = errno;
2279 error("there are still refs under '%s'", orig_refname);
2280 goto error_return;
2282 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
2284 if (type_p)
2285 *type_p = type;
2286 if (!refname) {
2287 last_errno = errno;
2288 error("unable to resolve reference %s: %s",
2289 orig_refname, strerror(errno));
2290 goto error_return;
2292 missing = is_null_sha1(lock->old_sha1);
2293 /* When the ref did not exist and we are creating it,
2294 * make sure there is no existing ref that is packed
2295 * whose name begins with our refname, nor a ref whose
2296 * name is a proper prefix of our refname.
2298 if (missing &&
2299 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
2300 last_errno = ENOTDIR;
2301 goto error_return;
2304 lock->lk = xcalloc(1, sizeof(struct lock_file));
2306 lflags = 0;
2307 if (flags & REF_NODEREF) {
2308 refname = orig_refname;
2309 lflags |= LOCK_NODEREF;
2311 lock->ref_name = xstrdup(refname);
2312 lock->orig_ref_name = xstrdup(orig_refname);
2313 ref_file = git_path("%s", refname);
2314 if (missing)
2315 lock->force_write = 1;
2316 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2317 lock->force_write = 1;
2319 retry:
2320 switch (safe_create_leading_directories(ref_file)) {
2321 case SCLD_OK:
2322 break; /* success */
2323 case SCLD_VANISHED:
2324 if (--attempts_remaining > 0)
2325 goto retry;
2326 /* fall through */
2327 default:
2328 last_errno = errno;
2329 error("unable to create directory for %s", ref_file);
2330 goto error_return;
2333 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
2334 if (lock->lock_fd < 0) {
2335 if (errno == ENOENT && --attempts_remaining > 0)
2337 * Maybe somebody just deleted one of the
2338 * directories leading to ref_file. Try
2339 * again:
2341 goto retry;
2342 else
2343 unable_to_lock_index_die(ref_file, errno);
2345 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
2347 error_return:
2348 unlock_ref(lock);
2349 errno = last_errno;
2350 return NULL;
2353 struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
2355 char refpath[PATH_MAX];
2356 if (check_refname_format(refname, 0))
2357 return NULL;
2358 strcpy(refpath, mkpath("refs/%s", refname));
2359 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
2362 struct ref_lock *lock_any_ref_for_update(const char *refname,
2363 const unsigned char *old_sha1,
2364 int flags, int *type_p)
2366 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
2367 return NULL;
2368 return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
2372 * Write an entry to the packed-refs file for the specified refname.
2373 * If peeled is non-NULL, write it as the entry's peeled value.
2375 static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2376 unsigned char *peeled)
2378 char line[PATH_MAX + 100];
2379 int len;
2381 len = snprintf(line, sizeof(line), "%s %s\n",
2382 sha1_to_hex(sha1), refname);
2383 /* this should not happen but just being defensive */
2384 if (len > sizeof(line))
2385 die("too long a refname '%s'", refname);
2386 write_or_die(fd, line, len);
2388 if (peeled) {
2389 if (snprintf(line, sizeof(line), "^%s\n",
2390 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2391 die("internal error");
2392 write_or_die(fd, line, PEELED_LINE_LENGTH);
2397 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2399 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2401 int *fd = cb_data;
2402 enum peel_status peel_status = peel_entry(entry, 0);
2404 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2405 error("internal error: %s is not a valid packed reference!",
2406 entry->name);
2407 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2408 peel_status == PEEL_PEELED ?
2409 entry->u.value.peeled : NULL);
2410 return 0;
2413 int lock_packed_refs(int flags)
2415 struct packed_ref_cache *packed_ref_cache;
2417 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2418 return -1;
2420 * Get the current packed-refs while holding the lock. If the
2421 * packed-refs file has been modified since we last read it,
2422 * this will automatically invalidate the cache and re-read
2423 * the packed-refs file.
2425 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2426 packed_ref_cache->lock = &packlock;
2427 /* Increment the reference count to prevent it from being freed: */
2428 acquire_packed_ref_cache(packed_ref_cache);
2429 return 0;
2432 int commit_packed_refs(void)
2434 struct packed_ref_cache *packed_ref_cache =
2435 get_packed_ref_cache(&ref_cache);
2436 int error = 0;
2438 if (!packed_ref_cache->lock)
2439 die("internal error: packed-refs not locked");
2440 write_or_die(packed_ref_cache->lock->fd,
2441 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2443 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2444 0, write_packed_entry_fn,
2445 &packed_ref_cache->lock->fd);
2446 if (commit_lock_file(packed_ref_cache->lock))
2447 error = -1;
2448 packed_ref_cache->lock = NULL;
2449 release_packed_ref_cache(packed_ref_cache);
2450 return error;
2453 void rollback_packed_refs(void)
2455 struct packed_ref_cache *packed_ref_cache =
2456 get_packed_ref_cache(&ref_cache);
2458 if (!packed_ref_cache->lock)
2459 die("internal error: packed-refs not locked");
2460 rollback_lock_file(packed_ref_cache->lock);
2461 packed_ref_cache->lock = NULL;
2462 release_packed_ref_cache(packed_ref_cache);
2463 clear_packed_ref_cache(&ref_cache);
2466 struct ref_to_prune {
2467 struct ref_to_prune *next;
2468 unsigned char sha1[20];
2469 char name[FLEX_ARRAY];
2472 struct pack_refs_cb_data {
2473 unsigned int flags;
2474 struct ref_dir *packed_refs;
2475 struct ref_to_prune *ref_to_prune;
2479 * An each_ref_entry_fn that is run over loose references only. If
2480 * the loose reference can be packed, add an entry in the packed ref
2481 * cache. If the reference should be pruned, also add it to
2482 * ref_to_prune in the pack_refs_cb_data.
2484 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2486 struct pack_refs_cb_data *cb = cb_data;
2487 enum peel_status peel_status;
2488 struct ref_entry *packed_entry;
2489 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2491 /* ALWAYS pack tags */
2492 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2493 return 0;
2495 /* Do not pack symbolic or broken refs: */
2496 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2497 return 0;
2499 /* Add a packed ref cache entry equivalent to the loose entry. */
2500 peel_status = peel_entry(entry, 1);
2501 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2502 die("internal error peeling reference %s (%s)",
2503 entry->name, sha1_to_hex(entry->u.value.sha1));
2504 packed_entry = find_ref(cb->packed_refs, entry->name);
2505 if (packed_entry) {
2506 /* Overwrite existing packed entry with info from loose entry */
2507 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2508 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2509 } else {
2510 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2511 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2512 add_ref(cb->packed_refs, packed_entry);
2514 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
2516 /* Schedule the loose reference for pruning if requested. */
2517 if ((cb->flags & PACK_REFS_PRUNE)) {
2518 int namelen = strlen(entry->name) + 1;
2519 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
2520 hashcpy(n->sha1, entry->u.value.sha1);
2521 strcpy(n->name, entry->name);
2522 n->next = cb->ref_to_prune;
2523 cb->ref_to_prune = n;
2525 return 0;
2529 * Remove empty parents, but spare refs/ and immediate subdirs.
2530 * Note: munges *name.
2532 static void try_remove_empty_parents(char *name)
2534 char *p, *q;
2535 int i;
2536 p = name;
2537 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2538 while (*p && *p != '/')
2539 p++;
2540 /* tolerate duplicate slashes; see check_refname_format() */
2541 while (*p == '/')
2542 p++;
2544 for (q = p; *q; q++)
2546 while (1) {
2547 while (q > p && *q != '/')
2548 q--;
2549 while (q > p && *(q-1) == '/')
2550 q--;
2551 if (q == p)
2552 break;
2553 *q = '\0';
2554 if (rmdir(git_path("%s", name)))
2555 break;
2559 /* make sure nobody touched the ref, and unlink */
2560 static void prune_ref(struct ref_to_prune *r)
2562 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2564 if (lock) {
2565 unlink_or_warn(git_path("%s", r->name));
2566 unlock_ref(lock);
2567 try_remove_empty_parents(r->name);
2571 static void prune_refs(struct ref_to_prune *r)
2573 while (r) {
2574 prune_ref(r);
2575 r = r->next;
2579 int pack_refs(unsigned int flags)
2581 struct pack_refs_cb_data cbdata;
2583 memset(&cbdata, 0, sizeof(cbdata));
2584 cbdata.flags = flags;
2586 lock_packed_refs(LOCK_DIE_ON_ERROR);
2587 cbdata.packed_refs = get_packed_refs(&ref_cache);
2589 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2590 pack_if_possible_fn, &cbdata);
2592 if (commit_packed_refs())
2593 die_errno("unable to overwrite old ref-pack file");
2595 prune_refs(cbdata.ref_to_prune);
2596 return 0;
2600 * If entry is no longer needed in packed-refs, add it to the string
2601 * list pointed to by cb_data. Reasons for deleting entries:
2603 * - Entry is broken.
2604 * - Entry is overridden by a loose ref.
2605 * - Entry does not point at a valid object.
2607 * In the first and third cases, also emit an error message because these
2608 * are indications of repository corruption.
2610 static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
2612 struct string_list *refs_to_delete = cb_data;
2614 if (entry->flag & REF_ISBROKEN) {
2615 /* This shouldn't happen to packed refs. */
2616 error("%s is broken!", entry->name);
2617 string_list_append(refs_to_delete, entry->name);
2618 return 0;
2620 if (!has_sha1_file(entry->u.value.sha1)) {
2621 unsigned char sha1[20];
2622 int flags;
2624 if (read_ref_full(entry->name, sha1, 0, &flags))
2625 /* We should at least have found the packed ref. */
2626 die("Internal error");
2627 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
2629 * This packed reference is overridden by a
2630 * loose reference, so it is OK that its value
2631 * is no longer valid; for example, it might
2632 * refer to an object that has been garbage
2633 * collected. For this purpose we don't even
2634 * care whether the loose reference itself is
2635 * invalid, broken, symbolic, etc. Silently
2636 * remove the packed reference.
2638 string_list_append(refs_to_delete, entry->name);
2639 return 0;
2642 * There is no overriding loose reference, so the fact
2643 * that this reference doesn't refer to a valid object
2644 * indicates some kind of repository corruption.
2645 * Report the problem, then omit the reference from
2646 * the output.
2648 error("%s does not point to a valid object!", entry->name);
2649 string_list_append(refs_to_delete, entry->name);
2650 return 0;
2653 return 0;
2656 int repack_without_refs(const char **refnames, int n)
2658 struct ref_dir *packed;
2659 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2660 struct string_list_item *ref_to_delete;
2661 int i, removed = 0;
2663 /* Look for a packed ref */
2664 for (i = 0; i < n; i++)
2665 if (get_packed_ref(refnames[i]))
2666 break;
2668 /* Avoid locking if we have nothing to do */
2669 if (i == n)
2670 return 0; /* no refname exists in packed refs */
2672 if (lock_packed_refs(0)) {
2673 unable_to_lock_error(git_path("packed-refs"), errno);
2674 return error("cannot delete '%s' from packed refs", refnames[i]);
2676 packed = get_packed_refs(&ref_cache);
2678 /* Remove refnames from the cache */
2679 for (i = 0; i < n; i++)
2680 if (remove_entry(packed, refnames[i]) != -1)
2681 removed = 1;
2682 if (!removed) {
2684 * All packed entries disappeared while we were
2685 * acquiring the lock.
2687 rollback_packed_refs();
2688 return 0;
2691 /* Remove any other accumulated cruft */
2692 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2693 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2694 if (remove_entry(packed, ref_to_delete->string) == -1)
2695 die("internal error");
2698 /* Write what remains */
2699 return commit_packed_refs();
2702 static int repack_without_ref(const char *refname)
2704 return repack_without_refs(&refname, 1);
2707 static int delete_ref_loose(struct ref_lock *lock, int flag)
2709 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2710 /* loose */
2711 int err, i = strlen(lock->lk->filename) - 5; /* .lock */
2713 lock->lk->filename[i] = 0;
2714 err = unlink_or_warn(lock->lk->filename);
2715 lock->lk->filename[i] = '.';
2716 if (err && errno != ENOENT)
2717 return 1;
2719 return 0;
2722 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
2724 struct ref_lock *lock;
2725 int ret = 0, flag = 0;
2727 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
2728 if (!lock)
2729 return 1;
2730 ret |= delete_ref_loose(lock, flag);
2732 /* removing the loose one could have resurrected an earlier
2733 * packed one. Also, if it was not loose we need to repack
2734 * without it.
2736 ret |= repack_without_ref(lock->ref_name);
2738 unlink_or_warn(git_path("logs/%s", lock->ref_name));
2739 clear_loose_ref_cache(&ref_cache);
2740 unlock_ref(lock);
2741 return ret;
2745 * People using contrib's git-new-workdir have .git/logs/refs ->
2746 * /some/other/path/.git/logs/refs, and that may live on another device.
2748 * IOW, to avoid cross device rename errors, the temporary renamed log must
2749 * live into logs/refs.
2751 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2753 static int rename_tmp_log(const char *newrefname)
2755 int attempts_remaining = 4;
2757 retry:
2758 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2759 case SCLD_OK:
2760 break; /* success */
2761 case SCLD_VANISHED:
2762 if (--attempts_remaining > 0)
2763 goto retry;
2764 /* fall through */
2765 default:
2766 error("unable to create directory for %s", newrefname);
2767 return -1;
2770 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
2771 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
2773 * rename(a, b) when b is an existing
2774 * directory ought to result in ISDIR, but
2775 * Solaris 5.8 gives ENOTDIR. Sheesh.
2777 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2778 error("Directory not empty: logs/%s", newrefname);
2779 return -1;
2781 goto retry;
2782 } else if (errno == ENOENT && --attempts_remaining > 0) {
2784 * Maybe another process just deleted one of
2785 * the directories in the path to newrefname.
2786 * Try again from the beginning.
2788 goto retry;
2789 } else {
2790 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2791 newrefname, strerror(errno));
2792 return -1;
2795 return 0;
2798 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
2800 unsigned char sha1[20], orig_sha1[20];
2801 int flag = 0, logmoved = 0;
2802 struct ref_lock *lock;
2803 struct stat loginfo;
2804 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2805 const char *symref = NULL;
2807 if (log && S_ISLNK(loginfo.st_mode))
2808 return error("reflog for %s is a symlink", oldrefname);
2810 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
2811 if (flag & REF_ISSYMREF)
2812 return error("refname %s is a symbolic ref, renaming it is not supported",
2813 oldrefname);
2814 if (!symref)
2815 return error("refname %s not found", oldrefname);
2817 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
2818 return 1;
2820 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
2821 return 1;
2823 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2824 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2825 oldrefname, strerror(errno));
2827 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2828 error("unable to delete old %s", oldrefname);
2829 goto rollback;
2832 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2833 delete_ref(newrefname, sha1, REF_NODEREF)) {
2834 if (errno==EISDIR) {
2835 if (remove_empty_directories(git_path("%s", newrefname))) {
2836 error("Directory not empty: %s", newrefname);
2837 goto rollback;
2839 } else {
2840 error("unable to delete existing %s", newrefname);
2841 goto rollback;
2845 if (log && rename_tmp_log(newrefname))
2846 goto rollback;
2848 logmoved = log;
2850 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
2851 if (!lock) {
2852 error("unable to lock %s for update", newrefname);
2853 goto rollback;
2855 lock->force_write = 1;
2856 hashcpy(lock->old_sha1, orig_sha1);
2857 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
2858 error("unable to write current sha1 into %s", newrefname);
2859 goto rollback;
2862 return 0;
2864 rollback:
2865 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
2866 if (!lock) {
2867 error("unable to lock %s for rollback", oldrefname);
2868 goto rollbacklog;
2871 lock->force_write = 1;
2872 flag = log_all_ref_updates;
2873 log_all_ref_updates = 0;
2874 if (write_ref_sha1(lock, orig_sha1, NULL))
2875 error("unable to write current sha1 into %s", oldrefname);
2876 log_all_ref_updates = flag;
2878 rollbacklog:
2879 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2880 error("unable to restore logfile %s from %s: %s",
2881 oldrefname, newrefname, strerror(errno));
2882 if (!logmoved && log &&
2883 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2884 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2885 oldrefname, strerror(errno));
2887 return 1;
2890 int close_ref(struct ref_lock *lock)
2892 if (close_lock_file(lock->lk))
2893 return -1;
2894 lock->lock_fd = -1;
2895 return 0;
2898 int commit_ref(struct ref_lock *lock)
2900 if (commit_lock_file(lock->lk))
2901 return -1;
2902 lock->lock_fd = -1;
2903 return 0;
2906 void unlock_ref(struct ref_lock *lock)
2908 /* Do not free lock->lk -- atexit() still looks at them */
2909 if (lock->lk)
2910 rollback_lock_file(lock->lk);
2911 free(lock->ref_name);
2912 free(lock->orig_ref_name);
2913 free(lock);
2917 * copy the reflog message msg to buf, which has been allocated sufficiently
2918 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2919 * because reflog file is one line per entry.
2921 static int copy_msg(char *buf, const char *msg)
2923 char *cp = buf;
2924 char c;
2925 int wasspace = 1;
2927 *cp++ = '\t';
2928 while ((c = *msg++)) {
2929 if (wasspace && isspace(c))
2930 continue;
2931 wasspace = isspace(c);
2932 if (wasspace)
2933 c = ' ';
2934 *cp++ = c;
2936 while (buf < cp && isspace(cp[-1]))
2937 cp--;
2938 *cp++ = '\n';
2939 return cp - buf;
2942 int log_ref_setup(const char *refname, char *logfile, int bufsize)
2944 int logfd, oflags = O_APPEND | O_WRONLY;
2946 git_snpath(logfile, bufsize, "logs/%s", refname);
2947 if (log_all_ref_updates &&
2948 (starts_with(refname, "refs/heads/") ||
2949 starts_with(refname, "refs/remotes/") ||
2950 starts_with(refname, "refs/notes/") ||
2951 !strcmp(refname, "HEAD"))) {
2952 if (safe_create_leading_directories(logfile) < 0)
2953 return error("unable to create directory for %s",
2954 logfile);
2955 oflags |= O_CREAT;
2958 logfd = open(logfile, oflags, 0666);
2959 if (logfd < 0) {
2960 if (!(oflags & O_CREAT) && errno == ENOENT)
2961 return 0;
2963 if ((oflags & O_CREAT) && errno == EISDIR) {
2964 if (remove_empty_directories(logfile)) {
2965 return error("There are still logs under '%s'",
2966 logfile);
2968 logfd = open(logfile, oflags, 0666);
2971 if (logfd < 0)
2972 return error("Unable to append to %s: %s",
2973 logfile, strerror(errno));
2976 adjust_shared_perm(logfile);
2977 close(logfd);
2978 return 0;
2981 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2982 const unsigned char *new_sha1, const char *msg)
2984 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2985 unsigned maxlen, len;
2986 int msglen;
2987 char log_file[PATH_MAX];
2988 char *logrec;
2989 const char *committer;
2991 if (log_all_ref_updates < 0)
2992 log_all_ref_updates = !is_bare_repository();
2994 result = log_ref_setup(refname, log_file, sizeof(log_file));
2995 if (result)
2996 return result;
2998 logfd = open(log_file, oflags);
2999 if (logfd < 0)
3000 return 0;
3001 msglen = msg ? strlen(msg) : 0;
3002 committer = git_committer_info(0);
3003 maxlen = strlen(committer) + msglen + 100;
3004 logrec = xmalloc(maxlen);
3005 len = sprintf(logrec, "%s %s %s\n",
3006 sha1_to_hex(old_sha1),
3007 sha1_to_hex(new_sha1),
3008 committer);
3009 if (msglen)
3010 len += copy_msg(logrec + len - 1, msg) - 1;
3011 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
3012 free(logrec);
3013 if (close(logfd) != 0 || written != len)
3014 return error("Unable to append to %s", log_file);
3015 return 0;
3018 static int is_branch(const char *refname)
3020 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
3023 int write_ref_sha1(struct ref_lock *lock,
3024 const unsigned char *sha1, const char *logmsg)
3026 static char term = '\n';
3027 struct object *o;
3029 if (!lock)
3030 return -1;
3031 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
3032 unlock_ref(lock);
3033 return 0;
3035 o = parse_object(sha1);
3036 if (!o) {
3037 error("Trying to write ref %s with nonexistent object %s",
3038 lock->ref_name, sha1_to_hex(sha1));
3039 unlock_ref(lock);
3040 return -1;
3042 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
3043 error("Trying to write non-commit object %s to branch %s",
3044 sha1_to_hex(sha1), lock->ref_name);
3045 unlock_ref(lock);
3046 return -1;
3048 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
3049 write_in_full(lock->lock_fd, &term, 1) != 1
3050 || close_ref(lock) < 0) {
3051 error("Couldn't write %s", lock->lk->filename);
3052 unlock_ref(lock);
3053 return -1;
3055 clear_loose_ref_cache(&ref_cache);
3056 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
3057 (strcmp(lock->ref_name, lock->orig_ref_name) &&
3058 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
3059 unlock_ref(lock);
3060 return -1;
3062 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
3064 * Special hack: If a branch is updated directly and HEAD
3065 * points to it (may happen on the remote side of a push
3066 * for example) then logically the HEAD reflog should be
3067 * updated too.
3068 * A generic solution implies reverse symref information,
3069 * but finding all symrefs pointing to the given branch
3070 * would be rather costly for this rare event (the direct
3071 * update of a branch) to be worth it. So let's cheat and
3072 * check with HEAD only which should cover 99% of all usage
3073 * scenarios (even 100% of the default ones).
3075 unsigned char head_sha1[20];
3076 int head_flag;
3077 const char *head_ref;
3078 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
3079 if (head_ref && (head_flag & REF_ISSYMREF) &&
3080 !strcmp(head_ref, lock->ref_name))
3081 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
3083 if (commit_ref(lock)) {
3084 error("Couldn't set %s", lock->ref_name);
3085 unlock_ref(lock);
3086 return -1;
3088 unlock_ref(lock);
3089 return 0;
3092 int create_symref(const char *ref_target, const char *refs_heads_master,
3093 const char *logmsg)
3095 const char *lockpath;
3096 char ref[1000];
3097 int fd, len, written;
3098 char *git_HEAD = git_pathdup("%s", ref_target);
3099 unsigned char old_sha1[20], new_sha1[20];
3101 if (logmsg && read_ref(ref_target, old_sha1))
3102 hashclr(old_sha1);
3104 if (safe_create_leading_directories(git_HEAD) < 0)
3105 return error("unable to create directory for %s", git_HEAD);
3107 #ifndef NO_SYMLINK_HEAD
3108 if (prefer_symlink_refs) {
3109 unlink(git_HEAD);
3110 if (!symlink(refs_heads_master, git_HEAD))
3111 goto done;
3112 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
3114 #endif
3116 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
3117 if (sizeof(ref) <= len) {
3118 error("refname too long: %s", refs_heads_master);
3119 goto error_free_return;
3121 lockpath = mkpath("%s.lock", git_HEAD);
3122 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
3123 if (fd < 0) {
3124 error("Unable to open %s for writing", lockpath);
3125 goto error_free_return;
3127 written = write_in_full(fd, ref, len);
3128 if (close(fd) != 0 || written != len) {
3129 error("Unable to write to %s", lockpath);
3130 goto error_unlink_return;
3132 if (rename(lockpath, git_HEAD) < 0) {
3133 error("Unable to create %s", git_HEAD);
3134 goto error_unlink_return;
3136 if (adjust_shared_perm(git_HEAD)) {
3137 error("Unable to fix permissions on %s", lockpath);
3138 error_unlink_return:
3139 unlink_or_warn(lockpath);
3140 error_free_return:
3141 free(git_HEAD);
3142 return -1;
3145 #ifndef NO_SYMLINK_HEAD
3146 done:
3147 #endif
3148 if (logmsg && !read_ref(refs_heads_master, new_sha1))
3149 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
3151 free(git_HEAD);
3152 return 0;
3155 struct read_ref_at_cb {
3156 const char *refname;
3157 unsigned long at_time;
3158 int cnt;
3159 int reccnt;
3160 unsigned char *sha1;
3161 int found_it;
3163 unsigned char osha1[20];
3164 unsigned char nsha1[20];
3165 int tz;
3166 unsigned long date;
3167 char **msg;
3168 unsigned long *cutoff_time;
3169 int *cutoff_tz;
3170 int *cutoff_cnt;
3173 static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
3174 const char *email, unsigned long timestamp, int tz,
3175 const char *message, void *cb_data)
3177 struct read_ref_at_cb *cb = cb_data;
3179 cb->reccnt++;
3180 cb->tz = tz;
3181 cb->date = timestamp;
3183 if (timestamp <= cb->at_time || cb->cnt == 0) {
3184 if (cb->msg)
3185 *cb->msg = xstrdup(message);
3186 if (cb->cutoff_time)
3187 *cb->cutoff_time = timestamp;
3188 if (cb->cutoff_tz)
3189 *cb->cutoff_tz = tz;
3190 if (cb->cutoff_cnt)
3191 *cb->cutoff_cnt = cb->reccnt - 1;
3193 * we have not yet updated cb->[n|o]sha1 so they still
3194 * hold the values for the previous record.
3196 if (!is_null_sha1(cb->osha1)) {
3197 hashcpy(cb->sha1, nsha1);
3198 if (hashcmp(cb->osha1, nsha1))
3199 warning("Log for ref %s has gap after %s.",
3200 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));
3202 else if (cb->date == cb->at_time)
3203 hashcpy(cb->sha1, nsha1);
3204 else if (hashcmp(nsha1, cb->sha1))
3205 warning("Log for ref %s unexpectedly ended on %s.",
3206 cb->refname, show_date(cb->date, cb->tz,
3207 DATE_RFC2822));
3208 hashcpy(cb->osha1, osha1);
3209 hashcpy(cb->nsha1, nsha1);
3210 cb->found_it = 1;
3211 return 1;
3213 hashcpy(cb->osha1, osha1);
3214 hashcpy(cb->nsha1, nsha1);
3215 if (cb->cnt > 0)
3216 cb->cnt--;
3217 return 0;
3220 static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
3221 const char *email, unsigned long timestamp,
3222 int tz, const char *message, void *cb_data)
3224 struct read_ref_at_cb *cb = cb_data;
3226 if (cb->msg)
3227 *cb->msg = xstrdup(message);
3228 if (cb->cutoff_time)
3229 *cb->cutoff_time = timestamp;
3230 if (cb->cutoff_tz)
3231 *cb->cutoff_tz = tz;
3232 if (cb->cutoff_cnt)
3233 *cb->cutoff_cnt = cb->reccnt;
3234 hashcpy(cb->sha1, osha1);
3235 if (is_null_sha1(cb->sha1))
3236 hashcpy(cb->sha1, nsha1);
3237 /* We just want the first entry */
3238 return 1;
3241 int read_ref_at(const char *refname, unsigned long at_time, int cnt,
3242 unsigned char *sha1, char **msg,
3243 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
3245 struct read_ref_at_cb cb;
3247 memset(&cb, 0, sizeof(cb));
3248 cb.refname = refname;
3249 cb.at_time = at_time;
3250 cb.cnt = cnt;
3251 cb.msg = msg;
3252 cb.cutoff_time = cutoff_time;
3253 cb.cutoff_tz = cutoff_tz;
3254 cb.cutoff_cnt = cutoff_cnt;
3255 cb.sha1 = sha1;
3257 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
3259 if (!cb.reccnt)
3260 die("Log for %s is empty.", refname);
3261 if (cb.found_it)
3262 return 0;
3264 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
3266 return 1;
3269 int reflog_exists(const char *refname)
3271 struct stat st;
3273 return !lstat(git_path("logs/%s", refname), &st) &&
3274 S_ISREG(st.st_mode);
3277 int delete_reflog(const char *refname)
3279 return remove_path(git_path("logs/%s", refname));
3282 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3284 unsigned char osha1[20], nsha1[20];
3285 char *email_end, *message;
3286 unsigned long timestamp;
3287 int tz;
3289 /* old SP new SP name <email> SP time TAB msg LF */
3290 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3291 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3292 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3293 !(email_end = strchr(sb->buf + 82, '>')) ||
3294 email_end[1] != ' ' ||
3295 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3296 !message || message[0] != ' ' ||
3297 (message[1] != '+' && message[1] != '-') ||
3298 !isdigit(message[2]) || !isdigit(message[3]) ||
3299 !isdigit(message[4]) || !isdigit(message[5]))
3300 return 0; /* corrupt? */
3301 email_end[1] = '\0';
3302 tz = strtol(message + 1, NULL, 10);
3303 if (message[6] != '\t')
3304 message += 6;
3305 else
3306 message += 7;
3307 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3310 static char *find_beginning_of_line(char *bob, char *scan)
3312 while (bob < scan && *(--scan) != '\n')
3313 ; /* keep scanning backwards */
3315 * Return either beginning of the buffer, or LF at the end of
3316 * the previous line.
3318 return scan;
3321 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3323 struct strbuf sb = STRBUF_INIT;
3324 FILE *logfp;
3325 long pos;
3326 int ret = 0, at_tail = 1;
3328 logfp = fopen(git_path("logs/%s", refname), "r");
3329 if (!logfp)
3330 return -1;
3332 /* Jump to the end */
3333 if (fseek(logfp, 0, SEEK_END) < 0)
3334 return error("cannot seek back reflog for %s: %s",
3335 refname, strerror(errno));
3336 pos = ftell(logfp);
3337 while (!ret && 0 < pos) {
3338 int cnt;
3339 size_t nread;
3340 char buf[BUFSIZ];
3341 char *endp, *scanp;
3343 /* Fill next block from the end */
3344 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3345 if (fseek(logfp, pos - cnt, SEEK_SET))
3346 return error("cannot seek back reflog for %s: %s",
3347 refname, strerror(errno));
3348 nread = fread(buf, cnt, 1, logfp);
3349 if (nread != 1)
3350 return error("cannot read %d bytes from reflog for %s: %s",
3351 cnt, refname, strerror(errno));
3352 pos -= cnt;
3354 scanp = endp = buf + cnt;
3355 if (at_tail && scanp[-1] == '\n')
3356 /* Looking at the final LF at the end of the file */
3357 scanp--;
3358 at_tail = 0;
3360 while (buf < scanp) {
3362 * terminating LF of the previous line, or the beginning
3363 * of the buffer.
3365 char *bp;
3367 bp = find_beginning_of_line(buf, scanp);
3369 if (*bp != '\n') {
3370 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3371 if (pos)
3372 break; /* need to fill another block */
3373 scanp = buf - 1; /* leave loop */
3374 } else {
3376 * (bp + 1) thru endp is the beginning of the
3377 * current line we have in sb
3379 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3380 scanp = bp;
3381 endp = bp + 1;
3383 ret = show_one_reflog_ent(&sb, fn, cb_data);
3384 strbuf_reset(&sb);
3385 if (ret)
3386 break;
3390 if (!ret && sb.len)
3391 ret = show_one_reflog_ent(&sb, fn, cb_data);
3393 fclose(logfp);
3394 strbuf_release(&sb);
3395 return ret;
3398 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3400 FILE *logfp;
3401 struct strbuf sb = STRBUF_INIT;
3402 int ret = 0;
3404 logfp = fopen(git_path("logs/%s", refname), "r");
3405 if (!logfp)
3406 return -1;
3408 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3409 ret = show_one_reflog_ent(&sb, fn, cb_data);
3410 fclose(logfp);
3411 strbuf_release(&sb);
3412 return ret;
3415 * Call fn for each reflog in the namespace indicated by name. name
3416 * must be empty or end with '/'. Name will be used as a scratch
3417 * space, but its contents will be restored before return.
3419 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
3421 DIR *d = opendir(git_path("logs/%s", name->buf));
3422 int retval = 0;
3423 struct dirent *de;
3424 int oldlen = name->len;
3426 if (!d)
3427 return name->len ? errno : 0;
3429 while ((de = readdir(d)) != NULL) {
3430 struct stat st;
3432 if (de->d_name[0] == '.')
3433 continue;
3434 if (has_extension(de->d_name, ".lock"))
3435 continue;
3436 strbuf_addstr(name, de->d_name);
3437 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3438 ; /* silently ignore */
3439 } else {
3440 if (S_ISDIR(st.st_mode)) {
3441 strbuf_addch(name, '/');
3442 retval = do_for_each_reflog(name, fn, cb_data);
3443 } else {
3444 unsigned char sha1[20];
3445 if (read_ref_full(name->buf, sha1, 0, NULL))
3446 retval = error("bad ref for %s", name->buf);
3447 else
3448 retval = fn(name->buf, sha1, 0, cb_data);
3450 if (retval)
3451 break;
3453 strbuf_setlen(name, oldlen);
3455 closedir(d);
3456 return retval;
3459 int for_each_reflog(each_ref_fn fn, void *cb_data)
3461 int retval;
3462 struct strbuf name;
3463 strbuf_init(&name, PATH_MAX);
3464 retval = do_for_each_reflog(&name, fn, cb_data);
3465 strbuf_release(&name);
3466 return retval;
3469 static struct ref_lock *update_ref_lock(const char *refname,
3470 const unsigned char *oldval,
3471 int flags, int *type_p,
3472 enum action_on_err onerr)
3474 struct ref_lock *lock;
3475 lock = lock_any_ref_for_update(refname, oldval, flags, type_p);
3476 if (!lock) {
3477 const char *str = "Cannot lock the ref '%s'.";
3478 switch (onerr) {
3479 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
3480 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
3481 case UPDATE_REFS_QUIET_ON_ERR: break;
3484 return lock;
3487 static int update_ref_write(const char *action, const char *refname,
3488 const unsigned char *sha1, struct ref_lock *lock,
3489 enum action_on_err onerr)
3491 if (write_ref_sha1(lock, sha1, action) < 0) {
3492 const char *str = "Cannot update the ref '%s'.";
3493 switch (onerr) {
3494 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
3495 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
3496 case UPDATE_REFS_QUIET_ON_ERR: break;
3498 return 1;
3500 return 0;
3504 * Information needed for a single ref update. Set new_sha1 to the
3505 * new value or to zero to delete the ref. To check the old value
3506 * while locking the ref, set have_old to 1 and set old_sha1 to the
3507 * value or to zero to ensure the ref does not exist before update.
3509 struct ref_update {
3510 unsigned char new_sha1[20];
3511 unsigned char old_sha1[20];
3512 int flags; /* REF_NODEREF? */
3513 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
3514 struct ref_lock *lock;
3515 int type;
3516 const char refname[FLEX_ARRAY];
3520 * Data structure for holding a reference transaction, which can
3521 * consist of checks and updates to multiple references, carried out
3522 * as atomically as possible. This structure is opaque to callers.
3524 struct ref_transaction {
3525 struct ref_update **updates;
3526 size_t alloc;
3527 size_t nr;
3530 struct ref_transaction *ref_transaction_begin(void)
3532 return xcalloc(1, sizeof(struct ref_transaction));
3535 static void ref_transaction_free(struct ref_transaction *transaction)
3537 int i;
3539 for (i = 0; i < transaction->nr; i++)
3540 free(transaction->updates[i]);
3542 free(transaction->updates);
3543 free(transaction);
3546 void ref_transaction_rollback(struct ref_transaction *transaction)
3548 ref_transaction_free(transaction);
3551 static struct ref_update *add_update(struct ref_transaction *transaction,
3552 const char *refname)
3554 size_t len = strlen(refname);
3555 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
3557 strcpy((char *)update->refname, refname);
3558 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
3559 transaction->updates[transaction->nr++] = update;
3560 return update;
3563 void ref_transaction_update(struct ref_transaction *transaction,
3564 const char *refname,
3565 unsigned char *new_sha1, unsigned char *old_sha1,
3566 int flags, int have_old)
3568 struct ref_update *update = add_update(transaction, refname);
3570 hashcpy(update->new_sha1, new_sha1);
3571 update->flags = flags;
3572 update->have_old = have_old;
3573 if (have_old)
3574 hashcpy(update->old_sha1, old_sha1);
3577 void ref_transaction_create(struct ref_transaction *transaction,
3578 const char *refname,
3579 unsigned char *new_sha1,
3580 int flags)
3582 struct ref_update *update = add_update(transaction, refname);
3584 assert(!is_null_sha1(new_sha1));
3585 hashcpy(update->new_sha1, new_sha1);
3586 hashclr(update->old_sha1);
3587 update->flags = flags;
3588 update->have_old = 1;
3591 void ref_transaction_delete(struct ref_transaction *transaction,
3592 const char *refname,
3593 unsigned char *old_sha1,
3594 int flags, int have_old)
3596 struct ref_update *update = add_update(transaction, refname);
3598 update->flags = flags;
3599 update->have_old = have_old;
3600 if (have_old) {
3601 assert(!is_null_sha1(old_sha1));
3602 hashcpy(update->old_sha1, old_sha1);
3606 int update_ref(const char *action, const char *refname,
3607 const unsigned char *sha1, const unsigned char *oldval,
3608 int flags, enum action_on_err onerr)
3610 struct ref_lock *lock;
3611 lock = update_ref_lock(refname, oldval, flags, NULL, onerr);
3612 if (!lock)
3613 return 1;
3614 return update_ref_write(action, refname, sha1, lock, onerr);
3617 static int ref_update_compare(const void *r1, const void *r2)
3619 const struct ref_update * const *u1 = r1;
3620 const struct ref_update * const *u2 = r2;
3621 return strcmp((*u1)->refname, (*u2)->refname);
3624 static int ref_update_reject_duplicates(struct ref_update **updates, int n,
3625 enum action_on_err onerr)
3627 int i;
3628 for (i = 1; i < n; i++)
3629 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
3630 const char *str =
3631 "Multiple updates for ref '%s' not allowed.";
3632 switch (onerr) {
3633 case UPDATE_REFS_MSG_ON_ERR:
3634 error(str, updates[i]->refname); break;
3635 case UPDATE_REFS_DIE_ON_ERR:
3636 die(str, updates[i]->refname); break;
3637 case UPDATE_REFS_QUIET_ON_ERR:
3638 break;
3640 return 1;
3642 return 0;
3645 int ref_transaction_commit(struct ref_transaction *transaction,
3646 const char *msg, enum action_on_err onerr)
3648 int ret = 0, delnum = 0, i;
3649 const char **delnames;
3650 int n = transaction->nr;
3651 struct ref_update **updates = transaction->updates;
3653 if (!n)
3654 return 0;
3656 /* Allocate work space */
3657 delnames = xmalloc(sizeof(*delnames) * n);
3659 /* Copy, sort, and reject duplicate refs */
3660 qsort(updates, n, sizeof(*updates), ref_update_compare);
3661 ret = ref_update_reject_duplicates(updates, n, onerr);
3662 if (ret)
3663 goto cleanup;
3665 /* Acquire all locks while verifying old values */
3666 for (i = 0; i < n; i++) {
3667 struct ref_update *update = updates[i];
3669 update->lock = update_ref_lock(update->refname,
3670 (update->have_old ?
3671 update->old_sha1 : NULL),
3672 update->flags,
3673 &update->type, onerr);
3674 if (!update->lock) {
3675 ret = 1;
3676 goto cleanup;
3680 /* Perform updates first so live commits remain referenced */
3681 for (i = 0; i < n; i++) {
3682 struct ref_update *update = updates[i];
3684 if (!is_null_sha1(update->new_sha1)) {
3685 ret = update_ref_write(msg,
3686 update->refname,
3687 update->new_sha1,
3688 update->lock, onerr);
3689 update->lock = NULL; /* freed by update_ref_write */
3690 if (ret)
3691 goto cleanup;
3695 /* Perform deletes now that updates are safely completed */
3696 for (i = 0; i < n; i++) {
3697 struct ref_update *update = updates[i];
3699 if (update->lock) {
3700 delnames[delnum++] = update->lock->ref_name;
3701 ret |= delete_ref_loose(update->lock, update->type);
3705 ret |= repack_without_refs(delnames, delnum);
3706 for (i = 0; i < delnum; i++)
3707 unlink_or_warn(git_path("logs/%s", delnames[i]));
3708 clear_loose_ref_cache(&ref_cache);
3710 cleanup:
3711 for (i = 0; i < n; i++)
3712 if (updates[i]->lock)
3713 unlock_ref(updates[i]->lock);
3714 free(delnames);
3715 ref_transaction_free(transaction);
3716 return ret;
3719 char *shorten_unambiguous_ref(const char *refname, int strict)
3721 int i;
3722 static char **scanf_fmts;
3723 static int nr_rules;
3724 char *short_name;
3726 if (!nr_rules) {
3728 * Pre-generate scanf formats from ref_rev_parse_rules[].
3729 * Generate a format suitable for scanf from a
3730 * ref_rev_parse_rules rule by interpolating "%s" at the
3731 * location of the "%.*s".
3733 size_t total_len = 0;
3734 size_t offset = 0;
3736 /* the rule list is NULL terminated, count them first */
3737 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
3738 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
3739 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
3741 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3743 offset = 0;
3744 for (i = 0; i < nr_rules; i++) {
3745 assert(offset < total_len);
3746 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
3747 offset += snprintf(scanf_fmts[i], total_len - offset,
3748 ref_rev_parse_rules[i], 2, "%s") + 1;
3752 /* bail out if there are no rules */
3753 if (!nr_rules)
3754 return xstrdup(refname);
3756 /* buffer for scanf result, at most refname must fit */
3757 short_name = xstrdup(refname);
3759 /* skip first rule, it will always match */
3760 for (i = nr_rules - 1; i > 0 ; --i) {
3761 int j;
3762 int rules_to_fail = i;
3763 int short_name_len;
3765 if (1 != sscanf(refname, scanf_fmts[i], short_name))
3766 continue;
3768 short_name_len = strlen(short_name);
3771 * in strict mode, all (except the matched one) rules
3772 * must fail to resolve to a valid non-ambiguous ref
3774 if (strict)
3775 rules_to_fail = nr_rules;
3778 * check if the short name resolves to a valid ref,
3779 * but use only rules prior to the matched one
3781 for (j = 0; j < rules_to_fail; j++) {
3782 const char *rule = ref_rev_parse_rules[j];
3783 char refname[PATH_MAX];
3785 /* skip matched rule */
3786 if (i == j)
3787 continue;
3790 * the short name is ambiguous, if it resolves
3791 * (with this previous rule) to a valid ref
3792 * read_ref() returns 0 on success
3794 mksnpath(refname, sizeof(refname),
3795 rule, short_name_len, short_name);
3796 if (ref_exists(refname))
3797 break;
3801 * short name is non-ambiguous if all previous rules
3802 * haven't resolved to a valid ref
3804 if (j == rules_to_fail)
3805 return short_name;
3808 free(short_name);
3809 return xstrdup(refname);
3812 static struct string_list *hide_refs;
3814 int parse_hide_refs_config(const char *var, const char *value, const char *section)
3816 if (!strcmp("transfer.hiderefs", var) ||
3817 /* NEEDSWORK: use parse_config_key() once both are merged */
3818 (starts_with(var, section) && var[strlen(section)] == '.' &&
3819 !strcmp(var + strlen(section), ".hiderefs"))) {
3820 char *ref;
3821 int len;
3823 if (!value)
3824 return config_error_nonbool(var);
3825 ref = xstrdup(value);
3826 len = strlen(ref);
3827 while (len && ref[len - 1] == '/')
3828 ref[--len] = '\0';
3829 if (!hide_refs) {
3830 hide_refs = xcalloc(1, sizeof(*hide_refs));
3831 hide_refs->strdup_strings = 1;
3833 string_list_append(hide_refs, ref);
3835 return 0;
3838 int ref_is_hidden(const char *refname)
3840 struct string_list_item *item;
3842 if (!hide_refs)
3843 return 0;
3844 for_each_string_list_item(item, hide_refs) {
3845 int len;
3846 if (!starts_with(refname, item->string))
3847 continue;
3848 len = strlen(item->string);
3849 if (!refname[len] || refname[len] == '/')
3850 return 1;
3852 return 0;