test prerequisites: enumerate with commas
[alt-git.git] / refs.c
blob061d233e4b6404c57ff8d62715758b900d02e051
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;
156 int orig_flags = flags;
158 if (refname[0] == 0 || refname[0] == '/') {
159 /* entirely empty ref or initial ref component */
160 return -1;
164 * Initial ref component of '.'; below we look for /. so we'll
165 * miss this.
167 if (refname[0] == '.') {
168 if (refname[1] == '/' || refname[1] == '\0')
169 return -1;
170 if (!(flags & REFNAME_DOT_COMPONENT))
171 return -1;
173 while(1) {
174 __m128i tmp, tmp1, result;
175 uint64_t mask;
177 if ((uintptr_t) cp % PAGE_SIZE > PAGE_SIZE - SSE_VECTOR_BYTES - 1)
179 * End-of-page; fall back to slow method for
180 * this entire ref.
182 return check_refname_format_bytewise(refname, orig_flags);
184 tmp = _mm_loadu_si128((__m128i *)cp);
185 tmp1 = _mm_loadu_si128((__m128i *)(cp + 1));
188 * This range (note the lt) contains some
189 * permissible-but-rare characters (including all
190 * characters >= 128), which we handle later. It also
191 * includes \000.
193 result = _mm_cmplt_epi8(tmp, star_ub);
195 result = _mm_or_si128(result, _mm_cmpeq_epi8(tmp, question));
196 result = _mm_or_si128(result, _mm_cmpeq_epi8(tmp, colon));
198 /* This range contains the permissible ] as bycatch */
199 result = _mm_or_si128(result, _mm_and_si128(
200 _mm_cmpgt_epi8(tmp, bracket_lb),
201 _mm_cmplt_epi8(tmp, caret_ub)));
203 result = _mm_or_si128(result, _mm_cmpgt_epi8(tmp, tilde_lb));
205 /* .. */
206 result = _mm_or_si128(result, _mm_and_si128(
207 _mm_cmpeq_epi8(tmp, dot),
208 _mm_cmpeq_epi8(tmp1, dot)));
209 /* @{ */
210 result = _mm_or_si128(result, _mm_and_si128(
211 _mm_cmpeq_epi8(tmp, at),
212 _mm_cmpeq_epi8(tmp1, curly)));
213 /* // */
214 result = _mm_or_si128(result, _mm_and_si128(
215 _mm_cmpeq_epi8(tmp, slash),
216 _mm_cmpeq_epi8(tmp1, slash)));
217 /* trailing / */
218 result = _mm_or_si128(result, _mm_and_si128(
219 _mm_cmpeq_epi8(tmp, slash),
220 _mm_cmpeq_epi8(tmp1, zero)));
221 /* .l, beginning of .lock */
222 result = _mm_or_si128(result, _mm_and_si128(
223 _mm_cmpeq_epi8(tmp, dot),
224 _mm_cmpeq_epi8(tmp1, el)));
226 * Even though /. is not necessarily an error, we flag
227 * it anyway. If we find it, we'll check if it's valid
228 * and if so we'll advance just past it.
230 result = _mm_or_si128(result, _mm_and_si128(
231 _mm_cmpeq_epi8(tmp, slash),
232 _mm_cmpeq_epi8(tmp1, dot)));
234 mask = _mm_movemask_epi8(result);
235 if (mask) {
237 * We've found either end-of-string, or some
238 * probably-bad character or substring.
240 int i = __builtin_ctz(mask);
241 switch (refname_disposition[cp[i] & 255]) {
242 case 0: /* fall-through */
243 case 5:
245 * bycatch: a good character that's in
246 * one of the ranges of mostly-forbidden
247 * characters
249 cp += i + 1;
250 break;
251 case 1:
252 if (cp[i + 1] == '{')
253 return -1;
254 cp += i + 1;
255 break;
256 case 2:
257 if (!(flags & REFNAME_ALLOW_ONELEVEL)
258 && !component_count && !strchr(refname, '/'))
259 /* Refname has only one component. */
260 return -1;
261 return 0;
262 case 3:
263 component_count ++;
265 * Even if leading dots are allowed, don't
266 * allow "." as a component (".." is
267 * prevented by case 4 below).
269 if (cp[i + 1] == '.') {
270 if (cp[i + 2] == '\0')
271 return -1;
272 if (flags & REFNAME_DOT_COMPONENT) {
273 /* skip to just after the /. */
274 cp += i + 2;
275 break;
277 return -1;
278 } else if (cp[i + 1] == '/' || cp[i + 1] == '\0')
279 return -1;
280 break;
281 case 4:
282 if (cp[i + 1] == '.' || cp[i + 1] == '\0')
283 return -1;
284 /* .lock as end-of-component or end-of-string */
285 if ((!strncmp(cp + i, ".lock", 5))
286 && (cp[i + 5] == '/' || cp[i + 5] == 0))
287 return -1;
288 cp += 1;
289 break;
290 case 6:
291 if (((cp == refname + i) || cp[i - 1] == '/')
292 && (cp[i + 1] == '/' || cp[i + 1] == 0))
293 if (flags & REFNAME_REFSPEC_PATTERN) {
294 flags &= ~REFNAME_REFSPEC_PATTERN;
295 /* restart after the * */
296 cp += i + 1;
297 continue;
299 /* fall-through */
300 case 7:
301 return -1;
303 } else
304 cp += SSE_VECTOR_BYTES;
308 #else
310 int check_refname_format (const char *refname, int flags)
312 return check_refname_format_bytewise(refname, flags);
315 #endif
317 struct ref_entry;
320 * Information used (along with the information in ref_entry) to
321 * describe a single cached reference. This data structure only
322 * occurs embedded in a union in struct ref_entry, and only when
323 * (ref_entry->flag & REF_DIR) is zero.
325 struct ref_value {
327 * The name of the object to which this reference resolves
328 * (which may be a tag object). If REF_ISBROKEN, this is
329 * null. If REF_ISSYMREF, then this is the name of the object
330 * referred to by the last reference in the symlink chain.
332 unsigned char sha1[20];
335 * If REF_KNOWS_PEELED, then this field holds the peeled value
336 * of this reference, or null if the reference is known not to
337 * be peelable. See the documentation for peel_ref() for an
338 * exact definition of "peelable".
340 unsigned char peeled[20];
343 struct ref_cache;
346 * Information used (along with the information in ref_entry) to
347 * describe a level in the hierarchy of references. This data
348 * structure only occurs embedded in a union in struct ref_entry, and
349 * only when (ref_entry.flag & REF_DIR) is set. In that case,
350 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
351 * in the directory have already been read:
353 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
354 * or packed references, already read.
356 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
357 * references that hasn't been read yet (nor has any of its
358 * subdirectories).
360 * Entries within a directory are stored within a growable array of
361 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
362 * sorted are sorted by their component name in strcmp() order and the
363 * remaining entries are unsorted.
365 * Loose references are read lazily, one directory at a time. When a
366 * directory of loose references is read, then all of the references
367 * in that directory are stored, and REF_INCOMPLETE stubs are created
368 * for any subdirectories, but the subdirectories themselves are not
369 * read. The reading is triggered by get_ref_dir().
371 struct ref_dir {
372 int nr, alloc;
375 * Entries with index 0 <= i < sorted are sorted by name. New
376 * entries are appended to the list unsorted, and are sorted
377 * only when required; thus we avoid the need to sort the list
378 * after the addition of every reference.
380 int sorted;
382 /* A pointer to the ref_cache that contains this ref_dir. */
383 struct ref_cache *ref_cache;
385 struct ref_entry **entries;
389 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
390 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
391 * refs.h.
395 * The field ref_entry->u.value.peeled of this value entry contains
396 * the correct peeled value for the reference, which might be
397 * null_sha1 if the reference is not a tag or if it is broken.
399 #define REF_KNOWS_PEELED 0x08
401 /* ref_entry represents a directory of references */
402 #define REF_DIR 0x10
405 * Entry has not yet been read from disk (used only for REF_DIR
406 * entries representing loose references)
408 #define REF_INCOMPLETE 0x20
411 * A ref_entry represents either a reference or a "subdirectory" of
412 * references.
414 * Each directory in the reference namespace is represented by a
415 * ref_entry with (flags & REF_DIR) set and containing a subdir member
416 * that holds the entries in that directory that have been read so
417 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
418 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
419 * used for loose reference directories.
421 * References are represented by a ref_entry with (flags & REF_DIR)
422 * unset and a value member that describes the reference's value. The
423 * flag member is at the ref_entry level, but it is also needed to
424 * interpret the contents of the value field (in other words, a
425 * ref_value object is not very much use without the enclosing
426 * ref_entry).
428 * Reference names cannot end with slash and directories' names are
429 * always stored with a trailing slash (except for the top-level
430 * directory, which is always denoted by ""). This has two nice
431 * consequences: (1) when the entries in each subdir are sorted
432 * lexicographically by name (as they usually are), the references in
433 * a whole tree can be generated in lexicographic order by traversing
434 * the tree in left-to-right, depth-first order; (2) the names of
435 * references and subdirectories cannot conflict, and therefore the
436 * presence of an empty subdirectory does not block the creation of a
437 * similarly-named reference. (The fact that reference names with the
438 * same leading components can conflict *with each other* is a
439 * separate issue that is regulated by is_refname_available().)
441 * Please note that the name field contains the fully-qualified
442 * reference (or subdirectory) name. Space could be saved by only
443 * storing the relative names. But that would require the full names
444 * to be generated on the fly when iterating in do_for_each_ref(), and
445 * would break callback functions, who have always been able to assume
446 * that the name strings that they are passed will not be freed during
447 * the iteration.
449 struct ref_entry {
450 unsigned char flag; /* ISSYMREF? ISPACKED? */
451 union {
452 struct ref_value value; /* if not (flags&REF_DIR) */
453 struct ref_dir subdir; /* if (flags&REF_DIR) */
454 } u;
456 * The full name of the reference (e.g., "refs/heads/master")
457 * or the full name of the directory with a trailing slash
458 * (e.g., "refs/heads/"):
460 char name[FLEX_ARRAY];
463 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
465 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
467 struct ref_dir *dir;
468 assert(entry->flag & REF_DIR);
469 dir = &entry->u.subdir;
470 if (entry->flag & REF_INCOMPLETE) {
471 read_loose_refs(entry->name, dir);
472 entry->flag &= ~REF_INCOMPLETE;
474 return dir;
477 static struct ref_entry *create_ref_entry(const char *refname,
478 const unsigned char *sha1, int flag,
479 int check_name)
481 int len;
482 struct ref_entry *ref;
484 if (check_name &&
485 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
486 die("Reference has invalid format: '%s'", refname);
487 len = strlen(refname) + 1;
488 ref = xmalloc(sizeof(struct ref_entry) + len);
489 hashcpy(ref->u.value.sha1, sha1);
490 hashclr(ref->u.value.peeled);
491 memcpy(ref->name, refname, len);
492 ref->flag = flag;
493 return ref;
496 static void clear_ref_dir(struct ref_dir *dir);
498 static void free_ref_entry(struct ref_entry *entry)
500 if (entry->flag & REF_DIR) {
502 * Do not use get_ref_dir() here, as that might
503 * trigger the reading of loose refs.
505 clear_ref_dir(&entry->u.subdir);
507 free(entry);
511 * Add a ref_entry to the end of dir (unsorted). Entry is always
512 * stored directly in dir; no recursion into subdirectories is
513 * done.
515 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
517 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
518 dir->entries[dir->nr++] = entry;
519 /* optimize for the case that entries are added in order */
520 if (dir->nr == 1 ||
521 (dir->nr == dir->sorted + 1 &&
522 strcmp(dir->entries[dir->nr - 2]->name,
523 dir->entries[dir->nr - 1]->name) < 0))
524 dir->sorted = dir->nr;
528 * Clear and free all entries in dir, recursively.
530 static void clear_ref_dir(struct ref_dir *dir)
532 int i;
533 for (i = 0; i < dir->nr; i++)
534 free_ref_entry(dir->entries[i]);
535 free(dir->entries);
536 dir->sorted = dir->nr = dir->alloc = 0;
537 dir->entries = NULL;
541 * Create a struct ref_entry object for the specified dirname.
542 * dirname is the name of the directory with a trailing slash (e.g.,
543 * "refs/heads/") or "" for the top-level directory.
545 static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
546 const char *dirname, size_t len,
547 int incomplete)
549 struct ref_entry *direntry;
550 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
551 memcpy(direntry->name, dirname, len);
552 direntry->name[len] = '\0';
553 direntry->u.subdir.ref_cache = ref_cache;
554 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
555 return direntry;
558 static int ref_entry_cmp(const void *a, const void *b)
560 struct ref_entry *one = *(struct ref_entry **)a;
561 struct ref_entry *two = *(struct ref_entry **)b;
562 return strcmp(one->name, two->name);
565 static void sort_ref_dir(struct ref_dir *dir);
567 struct string_slice {
568 size_t len;
569 const char *str;
572 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
574 const struct string_slice *key = key_;
575 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
576 int cmp = strncmp(key->str, ent->name, key->len);
577 if (cmp)
578 return cmp;
579 return '\0' - (unsigned char)ent->name[key->len];
583 * Return the index of the entry with the given refname from the
584 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
585 * no such entry is found. dir must already be complete.
587 static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
589 struct ref_entry **r;
590 struct string_slice key;
592 if (refname == NULL || !dir->nr)
593 return -1;
595 sort_ref_dir(dir);
596 key.len = len;
597 key.str = refname;
598 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
599 ref_entry_cmp_sslice);
601 if (r == NULL)
602 return -1;
604 return r - dir->entries;
608 * Search for a directory entry directly within dir (without
609 * recursing). Sort dir if necessary. subdirname must be a directory
610 * name (i.e., end in '/'). If mkdir is set, then create the
611 * directory if it is missing; otherwise, return NULL if the desired
612 * directory cannot be found. dir must already be complete.
614 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
615 const char *subdirname, size_t len,
616 int mkdir)
618 int entry_index = search_ref_dir(dir, subdirname, len);
619 struct ref_entry *entry;
620 if (entry_index == -1) {
621 if (!mkdir)
622 return NULL;
624 * Since dir is complete, the absence of a subdir
625 * means that the subdir really doesn't exist;
626 * therefore, create an empty record for it but mark
627 * the record complete.
629 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
630 add_entry_to_dir(dir, entry);
631 } else {
632 entry = dir->entries[entry_index];
634 return get_ref_dir(entry);
638 * If refname is a reference name, find the ref_dir within the dir
639 * tree that should hold refname. If refname is a directory name
640 * (i.e., ends in '/'), then return that ref_dir itself. dir must
641 * represent the top-level directory and must already be complete.
642 * Sort ref_dirs and recurse into subdirectories as necessary. If
643 * mkdir is set, then create any missing directories; otherwise,
644 * return NULL if the desired directory cannot be found.
646 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
647 const char *refname, int mkdir)
649 const char *slash;
650 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
651 size_t dirnamelen = slash - refname + 1;
652 struct ref_dir *subdir;
653 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
654 if (!subdir) {
655 dir = NULL;
656 break;
658 dir = subdir;
661 return dir;
665 * Find the value entry with the given name in dir, sorting ref_dirs
666 * and recursing into subdirectories as necessary. If the name is not
667 * found or it corresponds to a directory entry, return NULL.
669 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
671 int entry_index;
672 struct ref_entry *entry;
673 dir = find_containing_dir(dir, refname, 0);
674 if (!dir)
675 return NULL;
676 entry_index = search_ref_dir(dir, refname, strlen(refname));
677 if (entry_index == -1)
678 return NULL;
679 entry = dir->entries[entry_index];
680 return (entry->flag & REF_DIR) ? NULL : entry;
684 * Remove the entry with the given name from dir, recursing into
685 * subdirectories as necessary. If refname is the name of a directory
686 * (i.e., ends with '/'), then remove the directory and its contents.
687 * If the removal was successful, return the number of entries
688 * remaining in the directory entry that contained the deleted entry.
689 * If the name was not found, return -1. Please note that this
690 * function only deletes the entry from the cache; it does not delete
691 * it from the filesystem or ensure that other cache entries (which
692 * might be symbolic references to the removed entry) are updated.
693 * Nor does it remove any containing dir entries that might be made
694 * empty by the removal. dir must represent the top-level directory
695 * and must already be complete.
697 static int remove_entry(struct ref_dir *dir, const char *refname)
699 int refname_len = strlen(refname);
700 int entry_index;
701 struct ref_entry *entry;
702 int is_dir = refname[refname_len - 1] == '/';
703 if (is_dir) {
705 * refname represents a reference directory. Remove
706 * the trailing slash; otherwise we will get the
707 * directory *representing* refname rather than the
708 * one *containing* it.
710 char *dirname = xmemdupz(refname, refname_len - 1);
711 dir = find_containing_dir(dir, dirname, 0);
712 free(dirname);
713 } else {
714 dir = find_containing_dir(dir, refname, 0);
716 if (!dir)
717 return -1;
718 entry_index = search_ref_dir(dir, refname, refname_len);
719 if (entry_index == -1)
720 return -1;
721 entry = dir->entries[entry_index];
723 memmove(&dir->entries[entry_index],
724 &dir->entries[entry_index + 1],
725 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
727 dir->nr--;
728 if (dir->sorted > entry_index)
729 dir->sorted--;
730 free_ref_entry(entry);
731 return dir->nr;
735 * Add a ref_entry to the ref_dir (unsorted), recursing into
736 * subdirectories as necessary. dir must represent the top-level
737 * directory. Return 0 on success.
739 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
741 dir = find_containing_dir(dir, ref->name, 1);
742 if (!dir)
743 return -1;
744 add_entry_to_dir(dir, ref);
745 return 0;
749 * Emit a warning and return true iff ref1 and ref2 have the same name
750 * and the same sha1. Die if they have the same name but different
751 * sha1s.
753 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
755 if (strcmp(ref1->name, ref2->name))
756 return 0;
758 /* Duplicate name; make sure that they don't conflict: */
760 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
761 /* This is impossible by construction */
762 die("Reference directory conflict: %s", ref1->name);
764 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
765 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
767 warning("Duplicated ref: %s", ref1->name);
768 return 1;
772 * Sort the entries in dir non-recursively (if they are not already
773 * sorted) and remove any duplicate entries.
775 static void sort_ref_dir(struct ref_dir *dir)
777 int i, j;
778 struct ref_entry *last = NULL;
781 * This check also prevents passing a zero-length array to qsort(),
782 * which is a problem on some platforms.
784 if (dir->sorted == dir->nr)
785 return;
787 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
789 /* Remove any duplicates: */
790 for (i = 0, j = 0; j < dir->nr; j++) {
791 struct ref_entry *entry = dir->entries[j];
792 if (last && is_dup_ref(last, entry))
793 free_ref_entry(entry);
794 else
795 last = dir->entries[i++] = entry;
797 dir->sorted = dir->nr = i;
800 /* Include broken references in a do_for_each_ref*() iteration: */
801 #define DO_FOR_EACH_INCLUDE_BROKEN 0x01
804 * Return true iff the reference described by entry can be resolved to
805 * an object in the database. Emit a warning if the referred-to
806 * object does not exist.
808 static int ref_resolves_to_object(struct ref_entry *entry)
810 if (entry->flag & REF_ISBROKEN)
811 return 0;
812 if (!has_sha1_file(entry->u.value.sha1)) {
813 error("%s does not point to a valid object!", entry->name);
814 return 0;
816 return 1;
820 * current_ref is a performance hack: when iterating over references
821 * using the for_each_ref*() functions, current_ref is set to the
822 * current reference's entry before calling the callback function. If
823 * the callback function calls peel_ref(), then peel_ref() first
824 * checks whether the reference to be peeled is the current reference
825 * (it usually is) and if so, returns that reference's peeled version
826 * if it is available. This avoids a refname lookup in a common case.
828 static struct ref_entry *current_ref;
830 typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
832 struct ref_entry_cb {
833 const char *base;
834 int trim;
835 int flags;
836 each_ref_fn *fn;
837 void *cb_data;
841 * Handle one reference in a do_for_each_ref*()-style iteration,
842 * calling an each_ref_fn for each entry.
844 static int do_one_ref(struct ref_entry *entry, void *cb_data)
846 struct ref_entry_cb *data = cb_data;
847 struct ref_entry *old_current_ref;
848 int retval;
850 if (!starts_with(entry->name, data->base))
851 return 0;
853 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
854 !ref_resolves_to_object(entry))
855 return 0;
857 /* Store the old value, in case this is a recursive call: */
858 old_current_ref = current_ref;
859 current_ref = entry;
860 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
861 entry->flag, data->cb_data);
862 current_ref = old_current_ref;
863 return retval;
867 * Call fn for each reference in dir that has index in the range
868 * offset <= index < dir->nr. Recurse into subdirectories that are in
869 * that index range, sorting them before iterating. This function
870 * does not sort dir itself; it should be sorted beforehand. fn is
871 * called for all references, including broken ones.
873 static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
874 each_ref_entry_fn fn, void *cb_data)
876 int i;
877 assert(dir->sorted == dir->nr);
878 for (i = offset; i < dir->nr; i++) {
879 struct ref_entry *entry = dir->entries[i];
880 int retval;
881 if (entry->flag & REF_DIR) {
882 struct ref_dir *subdir = get_ref_dir(entry);
883 sort_ref_dir(subdir);
884 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
885 } else {
886 retval = fn(entry, cb_data);
888 if (retval)
889 return retval;
891 return 0;
895 * Call fn for each reference in the union of dir1 and dir2, in order
896 * by refname. Recurse into subdirectories. If a value entry appears
897 * in both dir1 and dir2, then only process the version that is in
898 * dir2. The input dirs must already be sorted, but subdirs will be
899 * sorted as needed. fn is called for all references, including
900 * broken ones.
902 static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
903 struct ref_dir *dir2,
904 each_ref_entry_fn fn, void *cb_data)
906 int retval;
907 int i1 = 0, i2 = 0;
909 assert(dir1->sorted == dir1->nr);
910 assert(dir2->sorted == dir2->nr);
911 while (1) {
912 struct ref_entry *e1, *e2;
913 int cmp;
914 if (i1 == dir1->nr) {
915 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
917 if (i2 == dir2->nr) {
918 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
920 e1 = dir1->entries[i1];
921 e2 = dir2->entries[i2];
922 cmp = strcmp(e1->name, e2->name);
923 if (cmp == 0) {
924 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
925 /* Both are directories; descend them in parallel. */
926 struct ref_dir *subdir1 = get_ref_dir(e1);
927 struct ref_dir *subdir2 = get_ref_dir(e2);
928 sort_ref_dir(subdir1);
929 sort_ref_dir(subdir2);
930 retval = do_for_each_entry_in_dirs(
931 subdir1, subdir2, fn, cb_data);
932 i1++;
933 i2++;
934 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
935 /* Both are references; ignore the one from dir1. */
936 retval = fn(e2, cb_data);
937 i1++;
938 i2++;
939 } else {
940 die("conflict between reference and directory: %s",
941 e1->name);
943 } else {
944 struct ref_entry *e;
945 if (cmp < 0) {
946 e = e1;
947 i1++;
948 } else {
949 e = e2;
950 i2++;
952 if (e->flag & REF_DIR) {
953 struct ref_dir *subdir = get_ref_dir(e);
954 sort_ref_dir(subdir);
955 retval = do_for_each_entry_in_dir(
956 subdir, 0, fn, cb_data);
957 } else {
958 retval = fn(e, cb_data);
961 if (retval)
962 return retval;
967 * Load all of the refs from the dir into our in-memory cache. The hard work
968 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
969 * through all of the sub-directories. We do not even need to care about
970 * sorting, as traversal order does not matter to us.
972 static void prime_ref_dir(struct ref_dir *dir)
974 int i;
975 for (i = 0; i < dir->nr; i++) {
976 struct ref_entry *entry = dir->entries[i];
977 if (entry->flag & REF_DIR)
978 prime_ref_dir(get_ref_dir(entry));
982 * Return true iff refname1 and refname2 conflict with each other.
983 * Two reference names conflict if one of them exactly matches the
984 * leading components of the other; e.g., "foo/bar" conflicts with
985 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
986 * "foo/barbados".
988 static int names_conflict(const char *refname1, const char *refname2)
990 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
992 return (*refname1 == '\0' && *refname2 == '/')
993 || (*refname1 == '/' && *refname2 == '\0');
996 struct name_conflict_cb {
997 const char *refname;
998 const char *oldrefname;
999 const char *conflicting_refname;
1002 static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
1004 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
1005 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
1006 return 0;
1007 if (names_conflict(data->refname, entry->name)) {
1008 data->conflicting_refname = entry->name;
1009 return 1;
1011 return 0;
1015 * Return true iff a reference named refname could be created without
1016 * conflicting with the name of an existing reference in dir. If
1017 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
1018 * (e.g., because oldrefname is scheduled for deletion in the same
1019 * operation).
1021 static int is_refname_available(const char *refname, const char *oldrefname,
1022 struct ref_dir *dir)
1024 struct name_conflict_cb data;
1025 data.refname = refname;
1026 data.oldrefname = oldrefname;
1027 data.conflicting_refname = NULL;
1029 sort_ref_dir(dir);
1030 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
1031 error("'%s' exists; cannot create '%s'",
1032 data.conflicting_refname, refname);
1033 return 0;
1035 return 1;
1038 struct packed_ref_cache {
1039 struct ref_entry *root;
1042 * Count of references to the data structure in this instance,
1043 * including the pointer from ref_cache::packed if any. The
1044 * data will not be freed as long as the reference count is
1045 * nonzero.
1047 unsigned int referrers;
1050 * Iff the packed-refs file associated with this instance is
1051 * currently locked for writing, this points at the associated
1052 * lock (which is owned by somebody else). The referrer count
1053 * is also incremented when the file is locked and decremented
1054 * when it is unlocked.
1056 struct lock_file *lock;
1058 /* The metadata from when this packed-refs cache was read */
1059 struct stat_validity validity;
1063 * Future: need to be in "struct repository"
1064 * when doing a full libification.
1066 static struct ref_cache {
1067 struct ref_cache *next;
1068 struct ref_entry *loose;
1069 struct packed_ref_cache *packed;
1071 * The submodule name, or "" for the main repo. We allocate
1072 * length 1 rather than FLEX_ARRAY so that the main ref_cache
1073 * is initialized correctly.
1075 char name[1];
1076 } ref_cache, *submodule_ref_caches;
1078 /* Lock used for the main packed-refs file: */
1079 static struct lock_file packlock;
1082 * Increment the reference count of *packed_refs.
1084 static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
1086 packed_refs->referrers++;
1090 * Decrease the reference count of *packed_refs. If it goes to zero,
1091 * free *packed_refs and return true; otherwise return false.
1093 static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
1095 if (!--packed_refs->referrers) {
1096 free_ref_entry(packed_refs->root);
1097 stat_validity_clear(&packed_refs->validity);
1098 free(packed_refs);
1099 return 1;
1100 } else {
1101 return 0;
1105 static void clear_packed_ref_cache(struct ref_cache *refs)
1107 if (refs->packed) {
1108 struct packed_ref_cache *packed_refs = refs->packed;
1110 if (packed_refs->lock)
1111 die("internal error: packed-ref cache cleared while locked");
1112 refs->packed = NULL;
1113 release_packed_ref_cache(packed_refs);
1117 static void clear_loose_ref_cache(struct ref_cache *refs)
1119 if (refs->loose) {
1120 free_ref_entry(refs->loose);
1121 refs->loose = NULL;
1125 static struct ref_cache *create_ref_cache(const char *submodule)
1127 int len;
1128 struct ref_cache *refs;
1129 if (!submodule)
1130 submodule = "";
1131 len = strlen(submodule) + 1;
1132 refs = xcalloc(1, sizeof(struct ref_cache) + len);
1133 memcpy(refs->name, submodule, len);
1134 return refs;
1138 * Return a pointer to a ref_cache for the specified submodule. For
1139 * the main repository, use submodule==NULL. The returned structure
1140 * will be allocated and initialized but not necessarily populated; it
1141 * should not be freed.
1143 static struct ref_cache *get_ref_cache(const char *submodule)
1145 struct ref_cache *refs;
1147 if (!submodule || !*submodule)
1148 return &ref_cache;
1150 for (refs = submodule_ref_caches; refs; refs = refs->next)
1151 if (!strcmp(submodule, refs->name))
1152 return refs;
1154 refs = create_ref_cache(submodule);
1155 refs->next = submodule_ref_caches;
1156 submodule_ref_caches = refs;
1157 return refs;
1160 /* The length of a peeled reference line in packed-refs, including EOL: */
1161 #define PEELED_LINE_LENGTH 42
1164 * The packed-refs header line that we write out. Perhaps other
1165 * traits will be added later. The trailing space is required.
1167 static const char PACKED_REFS_HEADER[] =
1168 "# pack-refs with: peeled fully-peeled \n";
1171 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
1172 * Return a pointer to the refname within the line (null-terminated),
1173 * or NULL if there was a problem.
1175 static const char *parse_ref_line(char *line, unsigned char *sha1)
1178 * 42: the answer to everything.
1180 * In this case, it happens to be the answer to
1181 * 40 (length of sha1 hex representation)
1182 * +1 (space in between hex and name)
1183 * +1 (newline at the end of the line)
1185 int len = strlen(line) - 42;
1187 if (len <= 0)
1188 return NULL;
1189 if (get_sha1_hex(line, sha1) < 0)
1190 return NULL;
1191 if (!isspace(line[40]))
1192 return NULL;
1193 line += 41;
1194 if (isspace(*line))
1195 return NULL;
1196 if (line[len] != '\n')
1197 return NULL;
1198 line[len] = 0;
1200 return line;
1204 * Read f, which is a packed-refs file, into dir.
1206 * A comment line of the form "# pack-refs with: " may contain zero or
1207 * more traits. We interpret the traits as follows:
1209 * No traits:
1211 * Probably no references are peeled. But if the file contains a
1212 * peeled value for a reference, we will use it.
1214 * peeled:
1216 * References under "refs/tags/", if they *can* be peeled, *are*
1217 * peeled in this file. References outside of "refs/tags/" are
1218 * probably not peeled even if they could have been, but if we find
1219 * a peeled value for such a reference we will use it.
1221 * fully-peeled:
1223 * All references in the file that can be peeled are peeled.
1224 * Inversely (and this is more important), any references in the
1225 * file for which no peeled value is recorded is not peelable. This
1226 * trait should typically be written alongside "peeled" for
1227 * compatibility with older clients, but we do not require it
1228 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1230 static void read_packed_refs(FILE *f, struct ref_dir *dir)
1232 struct ref_entry *last = NULL;
1233 char refline[PATH_MAX];
1234 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
1236 while (fgets(refline, sizeof(refline), f)) {
1237 unsigned char sha1[20];
1238 const char *refname;
1239 static const char header[] = "# pack-refs with:";
1241 if (!strncmp(refline, header, sizeof(header)-1)) {
1242 const char *traits = refline + sizeof(header) - 1;
1243 if (strstr(traits, " fully-peeled "))
1244 peeled = PEELED_FULLY;
1245 else if (strstr(traits, " peeled "))
1246 peeled = PEELED_TAGS;
1247 /* perhaps other traits later as well */
1248 continue;
1251 refname = parse_ref_line(refline, sha1);
1252 if (refname) {
1253 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
1254 if (peeled == PEELED_FULLY ||
1255 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
1256 last->flag |= REF_KNOWS_PEELED;
1257 add_ref(dir, last);
1258 continue;
1260 if (last &&
1261 refline[0] == '^' &&
1262 strlen(refline) == PEELED_LINE_LENGTH &&
1263 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
1264 !get_sha1_hex(refline + 1, sha1)) {
1265 hashcpy(last->u.value.peeled, sha1);
1267 * Regardless of what the file header said,
1268 * we definitely know the value of *this*
1269 * reference:
1271 last->flag |= REF_KNOWS_PEELED;
1277 * Get the packed_ref_cache for the specified ref_cache, creating it
1278 * if necessary.
1280 static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
1282 const char *packed_refs_file;
1284 if (*refs->name)
1285 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1286 else
1287 packed_refs_file = git_path("packed-refs");
1289 if (refs->packed &&
1290 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1291 clear_packed_ref_cache(refs);
1293 if (!refs->packed) {
1294 FILE *f;
1296 refs->packed = xcalloc(1, sizeof(*refs->packed));
1297 acquire_packed_ref_cache(refs->packed);
1298 refs->packed->root = create_dir_entry(refs, "", 0, 0);
1299 f = fopen(packed_refs_file, "r");
1300 if (f) {
1301 stat_validity_update(&refs->packed->validity, fileno(f));
1302 read_packed_refs(f, get_ref_dir(refs->packed->root));
1303 fclose(f);
1306 return refs->packed;
1309 static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1311 return get_ref_dir(packed_ref_cache->root);
1314 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1316 return get_packed_ref_dir(get_packed_ref_cache(refs));
1319 void add_packed_ref(const char *refname, const unsigned char *sha1)
1321 struct packed_ref_cache *packed_ref_cache =
1322 get_packed_ref_cache(&ref_cache);
1324 if (!packed_ref_cache->lock)
1325 die("internal error: packed refs not locked");
1326 add_ref(get_packed_ref_dir(packed_ref_cache),
1327 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1331 * Read the loose references from the namespace dirname into dir
1332 * (without recursing). dirname must end with '/'. dir must be the
1333 * directory entry corresponding to dirname.
1335 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
1337 struct ref_cache *refs = dir->ref_cache;
1338 DIR *d;
1339 const char *path;
1340 struct dirent *de;
1341 int dirnamelen = strlen(dirname);
1342 struct strbuf refname;
1344 if (*refs->name)
1345 path = git_path_submodule(refs->name, "%s", dirname);
1346 else
1347 path = git_path("%s", dirname);
1349 d = opendir(path);
1350 if (!d)
1351 return;
1353 strbuf_init(&refname, dirnamelen + 257);
1354 strbuf_add(&refname, dirname, dirnamelen);
1356 while ((de = readdir(d)) != NULL) {
1357 unsigned char sha1[20];
1358 struct stat st;
1359 int flag;
1360 const char *refdir;
1362 if (de->d_name[0] == '.')
1363 continue;
1364 if (ends_with(de->d_name, ".lock"))
1365 continue;
1366 strbuf_addstr(&refname, de->d_name);
1367 refdir = *refs->name
1368 ? git_path_submodule(refs->name, "%s", refname.buf)
1369 : git_path("%s", refname.buf);
1370 if (stat(refdir, &st) < 0) {
1371 ; /* silently ignore */
1372 } else if (S_ISDIR(st.st_mode)) {
1373 strbuf_addch(&refname, '/');
1374 add_entry_to_dir(dir,
1375 create_dir_entry(refs, refname.buf,
1376 refname.len, 1));
1377 } else {
1378 if (*refs->name) {
1379 hashclr(sha1);
1380 flag = 0;
1381 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
1382 hashclr(sha1);
1383 flag |= REF_ISBROKEN;
1385 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
1386 hashclr(sha1);
1387 flag |= REF_ISBROKEN;
1389 add_entry_to_dir(dir,
1390 create_ref_entry(refname.buf, sha1, flag, 1));
1392 strbuf_setlen(&refname, dirnamelen);
1394 strbuf_release(&refname);
1395 closedir(d);
1398 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
1400 if (!refs->loose) {
1402 * Mark the top-level directory complete because we
1403 * are about to read the only subdirectory that can
1404 * hold references:
1406 refs->loose = create_dir_entry(refs, "", 0, 0);
1408 * Create an incomplete entry for "refs/":
1410 add_entry_to_dir(get_ref_dir(refs->loose),
1411 create_dir_entry(refs, "refs/", 5, 1));
1413 return get_ref_dir(refs->loose);
1416 /* We allow "recursive" symbolic refs. Only within reason, though */
1417 #define MAXDEPTH 5
1418 #define MAXREFLEN (1024)
1421 * Called by resolve_gitlink_ref_recursive() after it failed to read
1422 * from the loose refs in ref_cache refs. Find <refname> in the
1423 * packed-refs file for the submodule.
1425 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
1426 const char *refname, unsigned char *sha1)
1428 struct ref_entry *ref;
1429 struct ref_dir *dir = get_packed_refs(refs);
1431 ref = find_ref(dir, refname);
1432 if (ref == NULL)
1433 return -1;
1435 hashcpy(sha1, ref->u.value.sha1);
1436 return 0;
1439 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
1440 const char *refname, unsigned char *sha1,
1441 int recursion)
1443 int fd, len;
1444 char buffer[128], *p;
1445 char *path;
1447 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
1448 return -1;
1449 path = *refs->name
1450 ? git_path_submodule(refs->name, "%s", refname)
1451 : git_path("%s", refname);
1452 fd = open(path, O_RDONLY);
1453 if (fd < 0)
1454 return resolve_gitlink_packed_ref(refs, refname, sha1);
1456 len = read(fd, buffer, sizeof(buffer)-1);
1457 close(fd);
1458 if (len < 0)
1459 return -1;
1460 while (len && isspace(buffer[len-1]))
1461 len--;
1462 buffer[len] = 0;
1464 /* Was it a detached head or an old-fashioned symlink? */
1465 if (!get_sha1_hex(buffer, sha1))
1466 return 0;
1468 /* Symref? */
1469 if (strncmp(buffer, "ref:", 4))
1470 return -1;
1471 p = buffer + 4;
1472 while (isspace(*p))
1473 p++;
1475 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1478 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1480 int len = strlen(path), retval;
1481 char *submodule;
1482 struct ref_cache *refs;
1484 while (len && path[len-1] == '/')
1485 len--;
1486 if (!len)
1487 return -1;
1488 submodule = xstrndup(path, len);
1489 refs = get_ref_cache(submodule);
1490 free(submodule);
1492 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1493 return retval;
1497 * Return the ref_entry for the given refname from the packed
1498 * references. If it does not exist, return NULL.
1500 static struct ref_entry *get_packed_ref(const char *refname)
1502 return find_ref(get_packed_refs(&ref_cache), refname);
1506 * A loose ref file doesn't exist; check for a packed ref. The
1507 * options are forwarded from resolve_safe_unsafe().
1509 static const char *handle_missing_loose_ref(const char *refname,
1510 unsigned char *sha1,
1511 int reading,
1512 int *flag)
1514 struct ref_entry *entry;
1517 * The loose reference file does not exist; check for a packed
1518 * reference.
1520 entry = get_packed_ref(refname);
1521 if (entry) {
1522 hashcpy(sha1, entry->u.value.sha1);
1523 if (flag)
1524 *flag |= REF_ISPACKED;
1525 return refname;
1527 /* The reference is not a packed reference, either. */
1528 if (reading) {
1529 return NULL;
1530 } else {
1531 hashclr(sha1);
1532 return refname;
1536 const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
1538 int depth = MAXDEPTH;
1539 ssize_t len;
1540 char buffer[256];
1541 static char refname_buffer[256];
1543 if (flag)
1544 *flag = 0;
1546 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1547 return NULL;
1549 for (;;) {
1550 char path[PATH_MAX];
1551 struct stat st;
1552 char *buf;
1553 int fd;
1555 if (--depth < 0)
1556 return NULL;
1558 git_snpath(path, sizeof(path), "%s", refname);
1561 * We might have to loop back here to avoid a race
1562 * condition: first we lstat() the file, then we try
1563 * to read it as a link or as a file. But if somebody
1564 * changes the type of the file (file <-> directory
1565 * <-> symlink) between the lstat() and reading, then
1566 * we don't want to report that as an error but rather
1567 * try again starting with the lstat().
1569 stat_ref:
1570 if (lstat(path, &st) < 0) {
1571 if (errno == ENOENT)
1572 return handle_missing_loose_ref(refname, sha1,
1573 reading, flag);
1574 else
1575 return NULL;
1578 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1579 if (S_ISLNK(st.st_mode)) {
1580 len = readlink(path, buffer, sizeof(buffer)-1);
1581 if (len < 0) {
1582 if (errno == ENOENT || errno == EINVAL)
1583 /* inconsistent with lstat; retry */
1584 goto stat_ref;
1585 else
1586 return NULL;
1588 buffer[len] = 0;
1589 if (starts_with(buffer, "refs/") &&
1590 !check_refname_format(buffer, 0)) {
1591 strcpy(refname_buffer, buffer);
1592 refname = refname_buffer;
1593 if (flag)
1594 *flag |= REF_ISSYMREF;
1595 continue;
1599 /* Is it a directory? */
1600 if (S_ISDIR(st.st_mode)) {
1601 errno = EISDIR;
1602 return NULL;
1606 * Anything else, just open it and try to use it as
1607 * a ref
1609 fd = open(path, O_RDONLY);
1610 if (fd < 0) {
1611 if (errno == ENOENT)
1612 /* inconsistent with lstat; retry */
1613 goto stat_ref;
1614 else
1615 return NULL;
1617 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1618 close(fd);
1619 if (len < 0)
1620 return NULL;
1621 while (len && isspace(buffer[len-1]))
1622 len--;
1623 buffer[len] = '\0';
1626 * Is it a symbolic ref?
1628 if (!starts_with(buffer, "ref:")) {
1630 * Please note that FETCH_HEAD has a second
1631 * line containing other data.
1633 if (get_sha1_hex(buffer, sha1) ||
1634 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1635 if (flag)
1636 *flag |= REF_ISBROKEN;
1637 return NULL;
1639 return refname;
1641 if (flag)
1642 *flag |= REF_ISSYMREF;
1643 buf = buffer + 4;
1644 while (isspace(*buf))
1645 buf++;
1646 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1647 if (flag)
1648 *flag |= REF_ISBROKEN;
1649 return NULL;
1651 refname = strcpy(refname_buffer, buf);
1655 char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1657 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
1658 return ret ? xstrdup(ret) : NULL;
1661 /* The argument to filter_refs */
1662 struct ref_filter {
1663 const char *pattern;
1664 each_ref_fn *fn;
1665 void *cb_data;
1668 int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
1670 if (resolve_ref_unsafe(refname, sha1, reading, flags))
1671 return 0;
1672 return -1;
1675 int read_ref(const char *refname, unsigned char *sha1)
1677 return read_ref_full(refname, sha1, 1, NULL);
1680 int ref_exists(const char *refname)
1682 unsigned char sha1[20];
1683 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
1686 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1687 void *data)
1689 struct ref_filter *filter = (struct ref_filter *)data;
1690 if (wildmatch(filter->pattern, refname, 0, NULL))
1691 return 0;
1692 return filter->fn(refname, sha1, flags, filter->cb_data);
1695 enum peel_status {
1696 /* object was peeled successfully: */
1697 PEEL_PEELED = 0,
1700 * object cannot be peeled because the named object (or an
1701 * object referred to by a tag in the peel chain), does not
1702 * exist.
1704 PEEL_INVALID = -1,
1706 /* object cannot be peeled because it is not a tag: */
1707 PEEL_NON_TAG = -2,
1709 /* ref_entry contains no peeled value because it is a symref: */
1710 PEEL_IS_SYMREF = -3,
1713 * ref_entry cannot be peeled because it is broken (i.e., the
1714 * symbolic reference cannot even be resolved to an object
1715 * name):
1717 PEEL_BROKEN = -4
1721 * Peel the named object; i.e., if the object is a tag, resolve the
1722 * tag recursively until a non-tag is found. If successful, store the
1723 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1724 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1725 * and leave sha1 unchanged.
1727 static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
1729 struct object *o = lookup_unknown_object(name);
1731 if (o->type == OBJ_NONE) {
1732 int type = sha1_object_info(name, NULL);
1733 if (type < 0)
1734 return PEEL_INVALID;
1735 o->type = type;
1738 if (o->type != OBJ_TAG)
1739 return PEEL_NON_TAG;
1741 o = deref_tag_noverify(o);
1742 if (!o)
1743 return PEEL_INVALID;
1745 hashcpy(sha1, o->sha1);
1746 return PEEL_PEELED;
1750 * Peel the entry (if possible) and return its new peel_status. If
1751 * repeel is true, re-peel the entry even if there is an old peeled
1752 * value that is already stored in it.
1754 * It is OK to call this function with a packed reference entry that
1755 * might be stale and might even refer to an object that has since
1756 * been garbage-collected. In such a case, if the entry has
1757 * REF_KNOWS_PEELED then leave the status unchanged and return
1758 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
1760 static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
1762 enum peel_status status;
1764 if (entry->flag & REF_KNOWS_PEELED) {
1765 if (repeel) {
1766 entry->flag &= ~REF_KNOWS_PEELED;
1767 hashclr(entry->u.value.peeled);
1768 } else {
1769 return is_null_sha1(entry->u.value.peeled) ?
1770 PEEL_NON_TAG : PEEL_PEELED;
1773 if (entry->flag & REF_ISBROKEN)
1774 return PEEL_BROKEN;
1775 if (entry->flag & REF_ISSYMREF)
1776 return PEEL_IS_SYMREF;
1778 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1779 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1780 entry->flag |= REF_KNOWS_PEELED;
1781 return status;
1784 int peel_ref(const char *refname, unsigned char *sha1)
1786 int flag;
1787 unsigned char base[20];
1789 if (current_ref && (current_ref->name == refname
1790 || !strcmp(current_ref->name, refname))) {
1791 if (peel_entry(current_ref, 0))
1792 return -1;
1793 hashcpy(sha1, current_ref->u.value.peeled);
1794 return 0;
1797 if (read_ref_full(refname, base, 1, &flag))
1798 return -1;
1801 * If the reference is packed, read its ref_entry from the
1802 * cache in the hope that we already know its peeled value.
1803 * We only try this optimization on packed references because
1804 * (a) forcing the filling of the loose reference cache could
1805 * be expensive and (b) loose references anyway usually do not
1806 * have REF_KNOWS_PEELED.
1808 if (flag & REF_ISPACKED) {
1809 struct ref_entry *r = get_packed_ref(refname);
1810 if (r) {
1811 if (peel_entry(r, 0))
1812 return -1;
1813 hashcpy(sha1, r->u.value.peeled);
1814 return 0;
1818 return peel_object(base, sha1);
1821 struct warn_if_dangling_data {
1822 FILE *fp;
1823 const char *refname;
1824 const struct string_list *refnames;
1825 const char *msg_fmt;
1828 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1829 int flags, void *cb_data)
1831 struct warn_if_dangling_data *d = cb_data;
1832 const char *resolves_to;
1833 unsigned char junk[20];
1835 if (!(flags & REF_ISSYMREF))
1836 return 0;
1838 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1839 if (!resolves_to
1840 || (d->refname
1841 ? strcmp(resolves_to, d->refname)
1842 : !string_list_has_string(d->refnames, resolves_to))) {
1843 return 0;
1846 fprintf(d->fp, d->msg_fmt, refname);
1847 fputc('\n', d->fp);
1848 return 0;
1851 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1853 struct warn_if_dangling_data data;
1855 data.fp = fp;
1856 data.refname = refname;
1857 data.refnames = NULL;
1858 data.msg_fmt = msg_fmt;
1859 for_each_rawref(warn_if_dangling_symref, &data);
1862 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
1864 struct warn_if_dangling_data data;
1866 data.fp = fp;
1867 data.refname = NULL;
1868 data.refnames = refnames;
1869 data.msg_fmt = msg_fmt;
1870 for_each_rawref(warn_if_dangling_symref, &data);
1874 * Call fn for each reference in the specified ref_cache, omitting
1875 * references not in the containing_dir of base. fn is called for all
1876 * references, including broken ones. If fn ever returns a non-zero
1877 * value, stop the iteration and return that value; otherwise, return
1878 * 0.
1880 static int do_for_each_entry(struct ref_cache *refs, const char *base,
1881 each_ref_entry_fn fn, void *cb_data)
1883 struct packed_ref_cache *packed_ref_cache;
1884 struct ref_dir *loose_dir;
1885 struct ref_dir *packed_dir;
1886 int retval = 0;
1889 * We must make sure that all loose refs are read before accessing the
1890 * packed-refs file; this avoids a race condition in which loose refs
1891 * are migrated to the packed-refs file by a simultaneous process, but
1892 * our in-memory view is from before the migration. get_packed_ref_cache()
1893 * takes care of making sure our view is up to date with what is on
1894 * disk.
1896 loose_dir = get_loose_refs(refs);
1897 if (base && *base) {
1898 loose_dir = find_containing_dir(loose_dir, base, 0);
1900 if (loose_dir)
1901 prime_ref_dir(loose_dir);
1903 packed_ref_cache = get_packed_ref_cache(refs);
1904 acquire_packed_ref_cache(packed_ref_cache);
1905 packed_dir = get_packed_ref_dir(packed_ref_cache);
1906 if (base && *base) {
1907 packed_dir = find_containing_dir(packed_dir, base, 0);
1910 if (packed_dir && loose_dir) {
1911 sort_ref_dir(packed_dir);
1912 sort_ref_dir(loose_dir);
1913 retval = do_for_each_entry_in_dirs(
1914 packed_dir, loose_dir, fn, cb_data);
1915 } else if (packed_dir) {
1916 sort_ref_dir(packed_dir);
1917 retval = do_for_each_entry_in_dir(
1918 packed_dir, 0, fn, cb_data);
1919 } else if (loose_dir) {
1920 sort_ref_dir(loose_dir);
1921 retval = do_for_each_entry_in_dir(
1922 loose_dir, 0, fn, cb_data);
1925 release_packed_ref_cache(packed_ref_cache);
1926 return retval;
1930 * Call fn for each reference in the specified ref_cache for which the
1931 * refname begins with base. If trim is non-zero, then trim that many
1932 * characters off the beginning of each refname before passing the
1933 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1934 * broken references in the iteration. If fn ever returns a non-zero
1935 * value, stop the iteration and return that value; otherwise, return
1936 * 0.
1938 static int do_for_each_ref(struct ref_cache *refs, const char *base,
1939 each_ref_fn fn, int trim, int flags, void *cb_data)
1941 struct ref_entry_cb data;
1942 data.base = base;
1943 data.trim = trim;
1944 data.flags = flags;
1945 data.fn = fn;
1946 data.cb_data = cb_data;
1948 return do_for_each_entry(refs, base, do_one_ref, &data);
1951 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1953 unsigned char sha1[20];
1954 int flag;
1956 if (submodule) {
1957 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1958 return fn("HEAD", sha1, 0, cb_data);
1960 return 0;
1963 if (!read_ref_full("HEAD", sha1, 1, &flag))
1964 return fn("HEAD", sha1, flag, cb_data);
1966 return 0;
1969 int head_ref(each_ref_fn fn, void *cb_data)
1971 return do_head_ref(NULL, fn, cb_data);
1974 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1976 return do_head_ref(submodule, fn, cb_data);
1979 int for_each_ref(each_ref_fn fn, void *cb_data)
1981 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
1984 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1986 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
1989 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1991 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
1994 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1995 each_ref_fn fn, void *cb_data)
1997 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
2000 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
2002 return for_each_ref_in("refs/tags/", fn, cb_data);
2005 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
2007 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
2010 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
2012 return for_each_ref_in("refs/heads/", fn, cb_data);
2015 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
2017 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
2020 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
2022 return for_each_ref_in("refs/remotes/", fn, cb_data);
2025 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
2027 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
2030 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
2032 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
2035 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
2037 struct strbuf buf = STRBUF_INIT;
2038 int ret = 0;
2039 unsigned char sha1[20];
2040 int flag;
2042 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
2043 if (!read_ref_full(buf.buf, sha1, 1, &flag))
2044 ret = fn(buf.buf, sha1, flag, cb_data);
2045 strbuf_release(&buf);
2047 return ret;
2050 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
2052 struct strbuf buf = STRBUF_INIT;
2053 int ret;
2054 strbuf_addf(&buf, "%srefs/", get_git_namespace());
2055 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
2056 strbuf_release(&buf);
2057 return ret;
2060 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
2061 const char *prefix, void *cb_data)
2063 struct strbuf real_pattern = STRBUF_INIT;
2064 struct ref_filter filter;
2065 int ret;
2067 if (!prefix && !starts_with(pattern, "refs/"))
2068 strbuf_addstr(&real_pattern, "refs/");
2069 else if (prefix)
2070 strbuf_addstr(&real_pattern, prefix);
2071 strbuf_addstr(&real_pattern, pattern);
2073 if (!has_glob_specials(pattern)) {
2074 /* Append implied '/' '*' if not present. */
2075 if (real_pattern.buf[real_pattern.len - 1] != '/')
2076 strbuf_addch(&real_pattern, '/');
2077 /* No need to check for '*', there is none. */
2078 strbuf_addch(&real_pattern, '*');
2081 filter.pattern = real_pattern.buf;
2082 filter.fn = fn;
2083 filter.cb_data = cb_data;
2084 ret = for_each_ref(filter_refs, &filter);
2086 strbuf_release(&real_pattern);
2087 return ret;
2090 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
2092 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
2095 int for_each_rawref(each_ref_fn fn, void *cb_data)
2097 return do_for_each_ref(&ref_cache, "", fn, 0,
2098 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
2101 const char *prettify_refname(const char *name)
2103 return name + (
2104 starts_with(name, "refs/heads/") ? 11 :
2105 starts_with(name, "refs/tags/") ? 10 :
2106 starts_with(name, "refs/remotes/") ? 13 :
2110 static const char *ref_rev_parse_rules[] = {
2111 "%.*s",
2112 "refs/%.*s",
2113 "refs/tags/%.*s",
2114 "refs/heads/%.*s",
2115 "refs/remotes/%.*s",
2116 "refs/remotes/%.*s/HEAD",
2117 NULL
2120 int refname_match(const char *abbrev_name, const char *full_name)
2122 const char **p;
2123 const int abbrev_name_len = strlen(abbrev_name);
2125 for (p = ref_rev_parse_rules; *p; p++) {
2126 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
2127 return 1;
2131 return 0;
2134 static struct ref_lock *verify_lock(struct ref_lock *lock,
2135 const unsigned char *old_sha1, int mustexist)
2137 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
2138 error("Can't verify ref %s", lock->ref_name);
2139 unlock_ref(lock);
2140 return NULL;
2142 if (hashcmp(lock->old_sha1, old_sha1)) {
2143 error("Ref %s is at %s but expected %s", lock->ref_name,
2144 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
2145 unlock_ref(lock);
2146 return NULL;
2148 return lock;
2151 static int remove_empty_directories(const char *file)
2153 /* we want to create a file but there is a directory there;
2154 * if that is an empty directory (or a directory that contains
2155 * only empty directories), remove them.
2157 struct strbuf path;
2158 int result;
2160 strbuf_init(&path, 20);
2161 strbuf_addstr(&path, file);
2163 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
2165 strbuf_release(&path);
2167 return result;
2171 * *string and *len will only be substituted, and *string returned (for
2172 * later free()ing) if the string passed in is a magic short-hand form
2173 * to name a branch.
2175 static char *substitute_branch_name(const char **string, int *len)
2177 struct strbuf buf = STRBUF_INIT;
2178 int ret = interpret_branch_name(*string, *len, &buf);
2180 if (ret == *len) {
2181 size_t size;
2182 *string = strbuf_detach(&buf, &size);
2183 *len = size;
2184 return (char *)*string;
2187 return NULL;
2190 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
2192 char *last_branch = substitute_branch_name(&str, &len);
2193 const char **p, *r;
2194 int refs_found = 0;
2196 *ref = NULL;
2197 for (p = ref_rev_parse_rules; *p; p++) {
2198 char fullref[PATH_MAX];
2199 unsigned char sha1_from_ref[20];
2200 unsigned char *this_result;
2201 int flag;
2203 this_result = refs_found ? sha1_from_ref : sha1;
2204 mksnpath(fullref, sizeof(fullref), *p, len, str);
2205 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
2206 if (r) {
2207 if (!refs_found++)
2208 *ref = xstrdup(r);
2209 if (!warn_ambiguous_refs)
2210 break;
2211 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
2212 warning("ignoring dangling symref %s.", fullref);
2213 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
2214 warning("ignoring broken ref %s.", fullref);
2217 free(last_branch);
2218 return refs_found;
2221 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
2223 char *last_branch = substitute_branch_name(&str, &len);
2224 const char **p;
2225 int logs_found = 0;
2227 *log = NULL;
2228 for (p = ref_rev_parse_rules; *p; p++) {
2229 unsigned char hash[20];
2230 char path[PATH_MAX];
2231 const char *ref, *it;
2233 mksnpath(path, sizeof(path), *p, len, str);
2234 ref = resolve_ref_unsafe(path, hash, 1, NULL);
2235 if (!ref)
2236 continue;
2237 if (reflog_exists(path))
2238 it = path;
2239 else if (strcmp(ref, path) && reflog_exists(ref))
2240 it = ref;
2241 else
2242 continue;
2243 if (!logs_found++) {
2244 *log = xstrdup(it);
2245 hashcpy(sha1, hash);
2247 if (!warn_ambiguous_refs)
2248 break;
2250 free(last_branch);
2251 return logs_found;
2254 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2255 const unsigned char *old_sha1,
2256 int flags, int *type_p)
2258 char *ref_file;
2259 const char *orig_refname = refname;
2260 struct ref_lock *lock;
2261 int last_errno = 0;
2262 int type, lflags;
2263 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
2264 int missing = 0;
2265 int attempts_remaining = 3;
2267 lock = xcalloc(1, sizeof(struct ref_lock));
2268 lock->lock_fd = -1;
2270 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
2271 if (!refname && errno == EISDIR) {
2272 /* we are trying to lock foo but we used to
2273 * have foo/bar which now does not exist;
2274 * it is normal for the empty directory 'foo'
2275 * to remain.
2277 ref_file = git_path("%s", orig_refname);
2278 if (remove_empty_directories(ref_file)) {
2279 last_errno = errno;
2280 error("there are still refs under '%s'", orig_refname);
2281 goto error_return;
2283 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
2285 if (type_p)
2286 *type_p = type;
2287 if (!refname) {
2288 last_errno = errno;
2289 error("unable to resolve reference %s: %s",
2290 orig_refname, strerror(errno));
2291 goto error_return;
2293 missing = is_null_sha1(lock->old_sha1);
2294 /* When the ref did not exist and we are creating it,
2295 * make sure there is no existing ref that is packed
2296 * whose name begins with our refname, nor a ref whose
2297 * name is a proper prefix of our refname.
2299 if (missing &&
2300 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
2301 last_errno = ENOTDIR;
2302 goto error_return;
2305 lock->lk = xcalloc(1, sizeof(struct lock_file));
2307 lflags = 0;
2308 if (flags & REF_NODEREF) {
2309 refname = orig_refname;
2310 lflags |= LOCK_NODEREF;
2312 lock->ref_name = xstrdup(refname);
2313 lock->orig_ref_name = xstrdup(orig_refname);
2314 ref_file = git_path("%s", refname);
2315 if (missing)
2316 lock->force_write = 1;
2317 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2318 lock->force_write = 1;
2320 retry:
2321 switch (safe_create_leading_directories(ref_file)) {
2322 case SCLD_OK:
2323 break; /* success */
2324 case SCLD_VANISHED:
2325 if (--attempts_remaining > 0)
2326 goto retry;
2327 /* fall through */
2328 default:
2329 last_errno = errno;
2330 error("unable to create directory for %s", ref_file);
2331 goto error_return;
2334 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
2335 if (lock->lock_fd < 0) {
2336 if (errno == ENOENT && --attempts_remaining > 0)
2338 * Maybe somebody just deleted one of the
2339 * directories leading to ref_file. Try
2340 * again:
2342 goto retry;
2343 else
2344 unable_to_lock_index_die(ref_file, errno);
2346 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
2348 error_return:
2349 unlock_ref(lock);
2350 errno = last_errno;
2351 return NULL;
2354 struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
2356 char refpath[PATH_MAX];
2357 if (check_refname_format(refname, 0))
2358 return NULL;
2359 strcpy(refpath, mkpath("refs/%s", refname));
2360 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
2363 struct ref_lock *lock_any_ref_for_update(const char *refname,
2364 const unsigned char *old_sha1,
2365 int flags, int *type_p)
2367 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
2368 return NULL;
2369 return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
2373 * Write an entry to the packed-refs file for the specified refname.
2374 * If peeled is non-NULL, write it as the entry's peeled value.
2376 static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2377 unsigned char *peeled)
2379 char line[PATH_MAX + 100];
2380 int len;
2382 len = snprintf(line, sizeof(line), "%s %s\n",
2383 sha1_to_hex(sha1), refname);
2384 /* this should not happen but just being defensive */
2385 if (len > sizeof(line))
2386 die("too long a refname '%s'", refname);
2387 write_or_die(fd, line, len);
2389 if (peeled) {
2390 if (snprintf(line, sizeof(line), "^%s\n",
2391 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2392 die("internal error");
2393 write_or_die(fd, line, PEELED_LINE_LENGTH);
2398 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2400 static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2402 int *fd = cb_data;
2403 enum peel_status peel_status = peel_entry(entry, 0);
2405 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2406 error("internal error: %s is not a valid packed reference!",
2407 entry->name);
2408 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2409 peel_status == PEEL_PEELED ?
2410 entry->u.value.peeled : NULL);
2411 return 0;
2414 int lock_packed_refs(int flags)
2416 struct packed_ref_cache *packed_ref_cache;
2418 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2419 return -1;
2421 * Get the current packed-refs while holding the lock. If the
2422 * packed-refs file has been modified since we last read it,
2423 * this will automatically invalidate the cache and re-read
2424 * the packed-refs file.
2426 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2427 packed_ref_cache->lock = &packlock;
2428 /* Increment the reference count to prevent it from being freed: */
2429 acquire_packed_ref_cache(packed_ref_cache);
2430 return 0;
2433 int commit_packed_refs(void)
2435 struct packed_ref_cache *packed_ref_cache =
2436 get_packed_ref_cache(&ref_cache);
2437 int error = 0;
2439 if (!packed_ref_cache->lock)
2440 die("internal error: packed-refs not locked");
2441 write_or_die(packed_ref_cache->lock->fd,
2442 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2444 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2445 0, write_packed_entry_fn,
2446 &packed_ref_cache->lock->fd);
2447 if (commit_lock_file(packed_ref_cache->lock))
2448 error = -1;
2449 packed_ref_cache->lock = NULL;
2450 release_packed_ref_cache(packed_ref_cache);
2451 return error;
2454 void rollback_packed_refs(void)
2456 struct packed_ref_cache *packed_ref_cache =
2457 get_packed_ref_cache(&ref_cache);
2459 if (!packed_ref_cache->lock)
2460 die("internal error: packed-refs not locked");
2461 rollback_lock_file(packed_ref_cache->lock);
2462 packed_ref_cache->lock = NULL;
2463 release_packed_ref_cache(packed_ref_cache);
2464 clear_packed_ref_cache(&ref_cache);
2467 struct ref_to_prune {
2468 struct ref_to_prune *next;
2469 unsigned char sha1[20];
2470 char name[FLEX_ARRAY];
2473 struct pack_refs_cb_data {
2474 unsigned int flags;
2475 struct ref_dir *packed_refs;
2476 struct ref_to_prune *ref_to_prune;
2480 * An each_ref_entry_fn that is run over loose references only. If
2481 * the loose reference can be packed, add an entry in the packed ref
2482 * cache. If the reference should be pruned, also add it to
2483 * ref_to_prune in the pack_refs_cb_data.
2485 static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
2487 struct pack_refs_cb_data *cb = cb_data;
2488 enum peel_status peel_status;
2489 struct ref_entry *packed_entry;
2490 int is_tag_ref = starts_with(entry->name, "refs/tags/");
2492 /* ALWAYS pack tags */
2493 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
2494 return 0;
2496 /* Do not pack symbolic or broken refs: */
2497 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2498 return 0;
2500 /* Add a packed ref cache entry equivalent to the loose entry. */
2501 peel_status = peel_entry(entry, 1);
2502 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2503 die("internal error peeling reference %s (%s)",
2504 entry->name, sha1_to_hex(entry->u.value.sha1));
2505 packed_entry = find_ref(cb->packed_refs, entry->name);
2506 if (packed_entry) {
2507 /* Overwrite existing packed entry with info from loose entry */
2508 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2509 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2510 } else {
2511 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2512 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2513 add_ref(cb->packed_refs, packed_entry);
2515 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
2517 /* Schedule the loose reference for pruning if requested. */
2518 if ((cb->flags & PACK_REFS_PRUNE)) {
2519 int namelen = strlen(entry->name) + 1;
2520 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
2521 hashcpy(n->sha1, entry->u.value.sha1);
2522 strcpy(n->name, entry->name);
2523 n->next = cb->ref_to_prune;
2524 cb->ref_to_prune = n;
2526 return 0;
2530 * Remove empty parents, but spare refs/ and immediate subdirs.
2531 * Note: munges *name.
2533 static void try_remove_empty_parents(char *name)
2535 char *p, *q;
2536 int i;
2537 p = name;
2538 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2539 while (*p && *p != '/')
2540 p++;
2541 /* tolerate duplicate slashes; see check_refname_format() */
2542 while (*p == '/')
2543 p++;
2545 for (q = p; *q; q++)
2547 while (1) {
2548 while (q > p && *q != '/')
2549 q--;
2550 while (q > p && *(q-1) == '/')
2551 q--;
2552 if (q == p)
2553 break;
2554 *q = '\0';
2555 if (rmdir(git_path("%s", name)))
2556 break;
2560 /* make sure nobody touched the ref, and unlink */
2561 static void prune_ref(struct ref_to_prune *r)
2563 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2565 if (lock) {
2566 unlink_or_warn(git_path("%s", r->name));
2567 unlock_ref(lock);
2568 try_remove_empty_parents(r->name);
2572 static void prune_refs(struct ref_to_prune *r)
2574 while (r) {
2575 prune_ref(r);
2576 r = r->next;
2580 int pack_refs(unsigned int flags)
2582 struct pack_refs_cb_data cbdata;
2584 memset(&cbdata, 0, sizeof(cbdata));
2585 cbdata.flags = flags;
2587 lock_packed_refs(LOCK_DIE_ON_ERROR);
2588 cbdata.packed_refs = get_packed_refs(&ref_cache);
2590 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2591 pack_if_possible_fn, &cbdata);
2593 if (commit_packed_refs())
2594 die_errno("unable to overwrite old ref-pack file");
2596 prune_refs(cbdata.ref_to_prune);
2597 return 0;
2601 * If entry is no longer needed in packed-refs, add it to the string
2602 * list pointed to by cb_data. Reasons for deleting entries:
2604 * - Entry is broken.
2605 * - Entry is overridden by a loose ref.
2606 * - Entry does not point at a valid object.
2608 * In the first and third cases, also emit an error message because these
2609 * are indications of repository corruption.
2611 static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
2613 struct string_list *refs_to_delete = cb_data;
2615 if (entry->flag & REF_ISBROKEN) {
2616 /* This shouldn't happen to packed refs. */
2617 error("%s is broken!", entry->name);
2618 string_list_append(refs_to_delete, entry->name);
2619 return 0;
2621 if (!has_sha1_file(entry->u.value.sha1)) {
2622 unsigned char sha1[20];
2623 int flags;
2625 if (read_ref_full(entry->name, sha1, 0, &flags))
2626 /* We should at least have found the packed ref. */
2627 die("Internal error");
2628 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
2630 * This packed reference is overridden by a
2631 * loose reference, so it is OK that its value
2632 * is no longer valid; for example, it might
2633 * refer to an object that has been garbage
2634 * collected. For this purpose we don't even
2635 * care whether the loose reference itself is
2636 * invalid, broken, symbolic, etc. Silently
2637 * remove the packed reference.
2639 string_list_append(refs_to_delete, entry->name);
2640 return 0;
2643 * There is no overriding loose reference, so the fact
2644 * that this reference doesn't refer to a valid object
2645 * indicates some kind of repository corruption.
2646 * Report the problem, then omit the reference from
2647 * the output.
2649 error("%s does not point to a valid object!", entry->name);
2650 string_list_append(refs_to_delete, entry->name);
2651 return 0;
2654 return 0;
2657 int repack_without_refs(const char **refnames, int n)
2659 struct ref_dir *packed;
2660 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2661 struct string_list_item *ref_to_delete;
2662 int i, removed = 0;
2664 /* Look for a packed ref */
2665 for (i = 0; i < n; i++)
2666 if (get_packed_ref(refnames[i]))
2667 break;
2669 /* Avoid locking if we have nothing to do */
2670 if (i == n)
2671 return 0; /* no refname exists in packed refs */
2673 if (lock_packed_refs(0)) {
2674 unable_to_lock_error(git_path("packed-refs"), errno);
2675 return error("cannot delete '%s' from packed refs", refnames[i]);
2677 packed = get_packed_refs(&ref_cache);
2679 /* Remove refnames from the cache */
2680 for (i = 0; i < n; i++)
2681 if (remove_entry(packed, refnames[i]) != -1)
2682 removed = 1;
2683 if (!removed) {
2685 * All packed entries disappeared while we were
2686 * acquiring the lock.
2688 rollback_packed_refs();
2689 return 0;
2692 /* Remove any other accumulated cruft */
2693 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2694 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2695 if (remove_entry(packed, ref_to_delete->string) == -1)
2696 die("internal error");
2699 /* Write what remains */
2700 return commit_packed_refs();
2703 static int repack_without_ref(const char *refname)
2705 return repack_without_refs(&refname, 1);
2708 static int delete_ref_loose(struct ref_lock *lock, int flag)
2710 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
2711 /* loose */
2712 int err, i = strlen(lock->lk->filename) - 5; /* .lock */
2714 lock->lk->filename[i] = 0;
2715 err = unlink_or_warn(lock->lk->filename);
2716 lock->lk->filename[i] = '.';
2717 if (err && errno != ENOENT)
2718 return 1;
2720 return 0;
2723 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
2725 struct ref_lock *lock;
2726 int ret = 0, flag = 0;
2728 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
2729 if (!lock)
2730 return 1;
2731 ret |= delete_ref_loose(lock, flag);
2733 /* removing the loose one could have resurrected an earlier
2734 * packed one. Also, if it was not loose we need to repack
2735 * without it.
2737 ret |= repack_without_ref(lock->ref_name);
2739 unlink_or_warn(git_path("logs/%s", lock->ref_name));
2740 clear_loose_ref_cache(&ref_cache);
2741 unlock_ref(lock);
2742 return ret;
2746 * People using contrib's git-new-workdir have .git/logs/refs ->
2747 * /some/other/path/.git/logs/refs, and that may live on another device.
2749 * IOW, to avoid cross device rename errors, the temporary renamed log must
2750 * live into logs/refs.
2752 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2754 static int rename_tmp_log(const char *newrefname)
2756 int attempts_remaining = 4;
2758 retry:
2759 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2760 case SCLD_OK:
2761 break; /* success */
2762 case SCLD_VANISHED:
2763 if (--attempts_remaining > 0)
2764 goto retry;
2765 /* fall through */
2766 default:
2767 error("unable to create directory for %s", newrefname);
2768 return -1;
2771 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
2772 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
2774 * rename(a, b) when b is an existing
2775 * directory ought to result in ISDIR, but
2776 * Solaris 5.8 gives ENOTDIR. Sheesh.
2778 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2779 error("Directory not empty: logs/%s", newrefname);
2780 return -1;
2782 goto retry;
2783 } else if (errno == ENOENT && --attempts_remaining > 0) {
2785 * Maybe another process just deleted one of
2786 * the directories in the path to newrefname.
2787 * Try again from the beginning.
2789 goto retry;
2790 } else {
2791 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2792 newrefname, strerror(errno));
2793 return -1;
2796 return 0;
2799 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
2801 unsigned char sha1[20], orig_sha1[20];
2802 int flag = 0, logmoved = 0;
2803 struct ref_lock *lock;
2804 struct stat loginfo;
2805 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
2806 const char *symref = NULL;
2808 if (log && S_ISLNK(loginfo.st_mode))
2809 return error("reflog for %s is a symlink", oldrefname);
2811 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
2812 if (flag & REF_ISSYMREF)
2813 return error("refname %s is a symbolic ref, renaming it is not supported",
2814 oldrefname);
2815 if (!symref)
2816 return error("refname %s not found", oldrefname);
2818 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
2819 return 1;
2821 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
2822 return 1;
2824 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
2825 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
2826 oldrefname, strerror(errno));
2828 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2829 error("unable to delete old %s", oldrefname);
2830 goto rollback;
2833 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2834 delete_ref(newrefname, sha1, REF_NODEREF)) {
2835 if (errno==EISDIR) {
2836 if (remove_empty_directories(git_path("%s", newrefname))) {
2837 error("Directory not empty: %s", newrefname);
2838 goto rollback;
2840 } else {
2841 error("unable to delete existing %s", newrefname);
2842 goto rollback;
2846 if (log && rename_tmp_log(newrefname))
2847 goto rollback;
2849 logmoved = log;
2851 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
2852 if (!lock) {
2853 error("unable to lock %s for update", newrefname);
2854 goto rollback;
2856 lock->force_write = 1;
2857 hashcpy(lock->old_sha1, orig_sha1);
2858 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
2859 error("unable to write current sha1 into %s", newrefname);
2860 goto rollback;
2863 return 0;
2865 rollback:
2866 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
2867 if (!lock) {
2868 error("unable to lock %s for rollback", oldrefname);
2869 goto rollbacklog;
2872 lock->force_write = 1;
2873 flag = log_all_ref_updates;
2874 log_all_ref_updates = 0;
2875 if (write_ref_sha1(lock, orig_sha1, NULL))
2876 error("unable to write current sha1 into %s", oldrefname);
2877 log_all_ref_updates = flag;
2879 rollbacklog:
2880 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
2881 error("unable to restore logfile %s from %s: %s",
2882 oldrefname, newrefname, strerror(errno));
2883 if (!logmoved && log &&
2884 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
2885 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
2886 oldrefname, strerror(errno));
2888 return 1;
2891 int close_ref(struct ref_lock *lock)
2893 if (close_lock_file(lock->lk))
2894 return -1;
2895 lock->lock_fd = -1;
2896 return 0;
2899 int commit_ref(struct ref_lock *lock)
2901 if (commit_lock_file(lock->lk))
2902 return -1;
2903 lock->lock_fd = -1;
2904 return 0;
2907 void unlock_ref(struct ref_lock *lock)
2909 /* Do not free lock->lk -- atexit() still looks at them */
2910 if (lock->lk)
2911 rollback_lock_file(lock->lk);
2912 free(lock->ref_name);
2913 free(lock->orig_ref_name);
2914 free(lock);
2918 * copy the reflog message msg to buf, which has been allocated sufficiently
2919 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2920 * because reflog file is one line per entry.
2922 static int copy_msg(char *buf, const char *msg)
2924 char *cp = buf;
2925 char c;
2926 int wasspace = 1;
2928 *cp++ = '\t';
2929 while ((c = *msg++)) {
2930 if (wasspace && isspace(c))
2931 continue;
2932 wasspace = isspace(c);
2933 if (wasspace)
2934 c = ' ';
2935 *cp++ = c;
2937 while (buf < cp && isspace(cp[-1]))
2938 cp--;
2939 *cp++ = '\n';
2940 return cp - buf;
2943 int log_ref_setup(const char *refname, char *logfile, int bufsize)
2945 int logfd, oflags = O_APPEND | O_WRONLY;
2947 git_snpath(logfile, bufsize, "logs/%s", refname);
2948 if (log_all_ref_updates &&
2949 (starts_with(refname, "refs/heads/") ||
2950 starts_with(refname, "refs/remotes/") ||
2951 starts_with(refname, "refs/notes/") ||
2952 !strcmp(refname, "HEAD"))) {
2953 if (safe_create_leading_directories(logfile) < 0)
2954 return error("unable to create directory for %s",
2955 logfile);
2956 oflags |= O_CREAT;
2959 logfd = open(logfile, oflags, 0666);
2960 if (logfd < 0) {
2961 if (!(oflags & O_CREAT) && errno == ENOENT)
2962 return 0;
2964 if ((oflags & O_CREAT) && errno == EISDIR) {
2965 if (remove_empty_directories(logfile)) {
2966 return error("There are still logs under '%s'",
2967 logfile);
2969 logfd = open(logfile, oflags, 0666);
2972 if (logfd < 0)
2973 return error("Unable to append to %s: %s",
2974 logfile, strerror(errno));
2977 adjust_shared_perm(logfile);
2978 close(logfd);
2979 return 0;
2982 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2983 const unsigned char *new_sha1, const char *msg)
2985 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2986 unsigned maxlen, len;
2987 int msglen;
2988 char log_file[PATH_MAX];
2989 char *logrec;
2990 const char *committer;
2992 if (log_all_ref_updates < 0)
2993 log_all_ref_updates = !is_bare_repository();
2995 result = log_ref_setup(refname, log_file, sizeof(log_file));
2996 if (result)
2997 return result;
2999 logfd = open(log_file, oflags);
3000 if (logfd < 0)
3001 return 0;
3002 msglen = msg ? strlen(msg) : 0;
3003 committer = git_committer_info(0);
3004 maxlen = strlen(committer) + msglen + 100;
3005 logrec = xmalloc(maxlen);
3006 len = sprintf(logrec, "%s %s %s\n",
3007 sha1_to_hex(old_sha1),
3008 sha1_to_hex(new_sha1),
3009 committer);
3010 if (msglen)
3011 len += copy_msg(logrec + len - 1, msg) - 1;
3012 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
3013 free(logrec);
3014 if (close(logfd) != 0 || written != len)
3015 return error("Unable to append to %s", log_file);
3016 return 0;
3019 static int is_branch(const char *refname)
3021 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
3024 int write_ref_sha1(struct ref_lock *lock,
3025 const unsigned char *sha1, const char *logmsg)
3027 static char term = '\n';
3028 struct object *o;
3030 if (!lock)
3031 return -1;
3032 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
3033 unlock_ref(lock);
3034 return 0;
3036 o = parse_object(sha1);
3037 if (!o) {
3038 error("Trying to write ref %s with nonexistent object %s",
3039 lock->ref_name, sha1_to_hex(sha1));
3040 unlock_ref(lock);
3041 return -1;
3043 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
3044 error("Trying to write non-commit object %s to branch %s",
3045 sha1_to_hex(sha1), lock->ref_name);
3046 unlock_ref(lock);
3047 return -1;
3049 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
3050 write_in_full(lock->lock_fd, &term, 1) != 1
3051 || close_ref(lock) < 0) {
3052 error("Couldn't write %s", lock->lk->filename);
3053 unlock_ref(lock);
3054 return -1;
3056 clear_loose_ref_cache(&ref_cache);
3057 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
3058 (strcmp(lock->ref_name, lock->orig_ref_name) &&
3059 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
3060 unlock_ref(lock);
3061 return -1;
3063 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
3065 * Special hack: If a branch is updated directly and HEAD
3066 * points to it (may happen on the remote side of a push
3067 * for example) then logically the HEAD reflog should be
3068 * updated too.
3069 * A generic solution implies reverse symref information,
3070 * but finding all symrefs pointing to the given branch
3071 * would be rather costly for this rare event (the direct
3072 * update of a branch) to be worth it. So let's cheat and
3073 * check with HEAD only which should cover 99% of all usage
3074 * scenarios (even 100% of the default ones).
3076 unsigned char head_sha1[20];
3077 int head_flag;
3078 const char *head_ref;
3079 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
3080 if (head_ref && (head_flag & REF_ISSYMREF) &&
3081 !strcmp(head_ref, lock->ref_name))
3082 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
3084 if (commit_ref(lock)) {
3085 error("Couldn't set %s", lock->ref_name);
3086 unlock_ref(lock);
3087 return -1;
3089 unlock_ref(lock);
3090 return 0;
3093 int create_symref(const char *ref_target, const char *refs_heads_master,
3094 const char *logmsg)
3096 const char *lockpath;
3097 char ref[1000];
3098 int fd, len, written;
3099 char *git_HEAD = git_pathdup("%s", ref_target);
3100 unsigned char old_sha1[20], new_sha1[20];
3102 if (logmsg && read_ref(ref_target, old_sha1))
3103 hashclr(old_sha1);
3105 if (safe_create_leading_directories(git_HEAD) < 0)
3106 return error("unable to create directory for %s", git_HEAD);
3108 #ifndef NO_SYMLINK_HEAD
3109 if (prefer_symlink_refs) {
3110 unlink(git_HEAD);
3111 if (!symlink(refs_heads_master, git_HEAD))
3112 goto done;
3113 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
3115 #endif
3117 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
3118 if (sizeof(ref) <= len) {
3119 error("refname too long: %s", refs_heads_master);
3120 goto error_free_return;
3122 lockpath = mkpath("%s.lock", git_HEAD);
3123 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
3124 if (fd < 0) {
3125 error("Unable to open %s for writing", lockpath);
3126 goto error_free_return;
3128 written = write_in_full(fd, ref, len);
3129 if (close(fd) != 0 || written != len) {
3130 error("Unable to write to %s", lockpath);
3131 goto error_unlink_return;
3133 if (rename(lockpath, git_HEAD) < 0) {
3134 error("Unable to create %s", git_HEAD);
3135 goto error_unlink_return;
3137 if (adjust_shared_perm(git_HEAD)) {
3138 error("Unable to fix permissions on %s", lockpath);
3139 error_unlink_return:
3140 unlink_or_warn(lockpath);
3141 error_free_return:
3142 free(git_HEAD);
3143 return -1;
3146 #ifndef NO_SYMLINK_HEAD
3147 done:
3148 #endif
3149 if (logmsg && !read_ref(refs_heads_master, new_sha1))
3150 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
3152 free(git_HEAD);
3153 return 0;
3156 struct read_ref_at_cb {
3157 const char *refname;
3158 unsigned long at_time;
3159 int cnt;
3160 int reccnt;
3161 unsigned char *sha1;
3162 int found_it;
3164 unsigned char osha1[20];
3165 unsigned char nsha1[20];
3166 int tz;
3167 unsigned long date;
3168 char **msg;
3169 unsigned long *cutoff_time;
3170 int *cutoff_tz;
3171 int *cutoff_cnt;
3174 static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
3175 const char *email, unsigned long timestamp, int tz,
3176 const char *message, void *cb_data)
3178 struct read_ref_at_cb *cb = cb_data;
3180 cb->reccnt++;
3181 cb->tz = tz;
3182 cb->date = timestamp;
3184 if (timestamp <= cb->at_time || cb->cnt == 0) {
3185 if (cb->msg)
3186 *cb->msg = xstrdup(message);
3187 if (cb->cutoff_time)
3188 *cb->cutoff_time = timestamp;
3189 if (cb->cutoff_tz)
3190 *cb->cutoff_tz = tz;
3191 if (cb->cutoff_cnt)
3192 *cb->cutoff_cnt = cb->reccnt - 1;
3194 * we have not yet updated cb->[n|o]sha1 so they still
3195 * hold the values for the previous record.
3197 if (!is_null_sha1(cb->osha1)) {
3198 hashcpy(cb->sha1, nsha1);
3199 if (hashcmp(cb->osha1, nsha1))
3200 warning("Log for ref %s has gap after %s.",
3201 cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));
3203 else if (cb->date == cb->at_time)
3204 hashcpy(cb->sha1, nsha1);
3205 else if (hashcmp(nsha1, cb->sha1))
3206 warning("Log for ref %s unexpectedly ended on %s.",
3207 cb->refname, show_date(cb->date, cb->tz,
3208 DATE_RFC2822));
3209 hashcpy(cb->osha1, osha1);
3210 hashcpy(cb->nsha1, nsha1);
3211 cb->found_it = 1;
3212 return 1;
3214 hashcpy(cb->osha1, osha1);
3215 hashcpy(cb->nsha1, nsha1);
3216 if (cb->cnt > 0)
3217 cb->cnt--;
3218 return 0;
3221 static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
3222 const char *email, unsigned long timestamp,
3223 int tz, const char *message, void *cb_data)
3225 struct read_ref_at_cb *cb = cb_data;
3227 if (cb->msg)
3228 *cb->msg = xstrdup(message);
3229 if (cb->cutoff_time)
3230 *cb->cutoff_time = timestamp;
3231 if (cb->cutoff_tz)
3232 *cb->cutoff_tz = tz;
3233 if (cb->cutoff_cnt)
3234 *cb->cutoff_cnt = cb->reccnt;
3235 hashcpy(cb->sha1, osha1);
3236 if (is_null_sha1(cb->sha1))
3237 hashcpy(cb->sha1, nsha1);
3238 /* We just want the first entry */
3239 return 1;
3242 int read_ref_at(const char *refname, unsigned long at_time, int cnt,
3243 unsigned char *sha1, char **msg,
3244 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
3246 struct read_ref_at_cb cb;
3248 memset(&cb, 0, sizeof(cb));
3249 cb.refname = refname;
3250 cb.at_time = at_time;
3251 cb.cnt = cnt;
3252 cb.msg = msg;
3253 cb.cutoff_time = cutoff_time;
3254 cb.cutoff_tz = cutoff_tz;
3255 cb.cutoff_cnt = cutoff_cnt;
3256 cb.sha1 = sha1;
3258 for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
3260 if (!cb.reccnt)
3261 die("Log for %s is empty.", refname);
3262 if (cb.found_it)
3263 return 0;
3265 for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
3267 return 1;
3270 int reflog_exists(const char *refname)
3272 struct stat st;
3274 return !lstat(git_path("logs/%s", refname), &st) &&
3275 S_ISREG(st.st_mode);
3278 int delete_reflog(const char *refname)
3280 return remove_path(git_path("logs/%s", refname));
3283 static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3285 unsigned char osha1[20], nsha1[20];
3286 char *email_end, *message;
3287 unsigned long timestamp;
3288 int tz;
3290 /* old SP new SP name <email> SP time TAB msg LF */
3291 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3292 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3293 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3294 !(email_end = strchr(sb->buf + 82, '>')) ||
3295 email_end[1] != ' ' ||
3296 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3297 !message || message[0] != ' ' ||
3298 (message[1] != '+' && message[1] != '-') ||
3299 !isdigit(message[2]) || !isdigit(message[3]) ||
3300 !isdigit(message[4]) || !isdigit(message[5]))
3301 return 0; /* corrupt? */
3302 email_end[1] = '\0';
3303 tz = strtol(message + 1, NULL, 10);
3304 if (message[6] != '\t')
3305 message += 6;
3306 else
3307 message += 7;
3308 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3311 static char *find_beginning_of_line(char *bob, char *scan)
3313 while (bob < scan && *(--scan) != '\n')
3314 ; /* keep scanning backwards */
3316 * Return either beginning of the buffer, or LF at the end of
3317 * the previous line.
3319 return scan;
3322 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3324 struct strbuf sb = STRBUF_INIT;
3325 FILE *logfp;
3326 long pos;
3327 int ret = 0, at_tail = 1;
3329 logfp = fopen(git_path("logs/%s", refname), "r");
3330 if (!logfp)
3331 return -1;
3333 /* Jump to the end */
3334 if (fseek(logfp, 0, SEEK_END) < 0)
3335 return error("cannot seek back reflog for %s: %s",
3336 refname, strerror(errno));
3337 pos = ftell(logfp);
3338 while (!ret && 0 < pos) {
3339 int cnt;
3340 size_t nread;
3341 char buf[BUFSIZ];
3342 char *endp, *scanp;
3344 /* Fill next block from the end */
3345 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3346 if (fseek(logfp, pos - cnt, SEEK_SET))
3347 return error("cannot seek back reflog for %s: %s",
3348 refname, strerror(errno));
3349 nread = fread(buf, cnt, 1, logfp);
3350 if (nread != 1)
3351 return error("cannot read %d bytes from reflog for %s: %s",
3352 cnt, refname, strerror(errno));
3353 pos -= cnt;
3355 scanp = endp = buf + cnt;
3356 if (at_tail && scanp[-1] == '\n')
3357 /* Looking at the final LF at the end of the file */
3358 scanp--;
3359 at_tail = 0;
3361 while (buf < scanp) {
3363 * terminating LF of the previous line, or the beginning
3364 * of the buffer.
3366 char *bp;
3368 bp = find_beginning_of_line(buf, scanp);
3370 if (*bp != '\n') {
3371 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3372 if (pos)
3373 break; /* need to fill another block */
3374 scanp = buf - 1; /* leave loop */
3375 } else {
3377 * (bp + 1) thru endp is the beginning of the
3378 * current line we have in sb
3380 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3381 scanp = bp;
3382 endp = bp + 1;
3384 ret = show_one_reflog_ent(&sb, fn, cb_data);
3385 strbuf_reset(&sb);
3386 if (ret)
3387 break;
3391 if (!ret && sb.len)
3392 ret = show_one_reflog_ent(&sb, fn, cb_data);
3394 fclose(logfp);
3395 strbuf_release(&sb);
3396 return ret;
3399 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
3401 FILE *logfp;
3402 struct strbuf sb = STRBUF_INIT;
3403 int ret = 0;
3405 logfp = fopen(git_path("logs/%s", refname), "r");
3406 if (!logfp)
3407 return -1;
3409 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3410 ret = show_one_reflog_ent(&sb, fn, cb_data);
3411 fclose(logfp);
3412 strbuf_release(&sb);
3413 return ret;
3416 * Call fn for each reflog in the namespace indicated by name. name
3417 * must be empty or end with '/'. Name will be used as a scratch
3418 * space, but its contents will be restored before return.
3420 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
3422 DIR *d = opendir(git_path("logs/%s", name->buf));
3423 int retval = 0;
3424 struct dirent *de;
3425 int oldlen = name->len;
3427 if (!d)
3428 return name->len ? errno : 0;
3430 while ((de = readdir(d)) != NULL) {
3431 struct stat st;
3433 if (de->d_name[0] == '.')
3434 continue;
3435 if (ends_with(de->d_name, ".lock"))
3436 continue;
3437 strbuf_addstr(name, de->d_name);
3438 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3439 ; /* silently ignore */
3440 } else {
3441 if (S_ISDIR(st.st_mode)) {
3442 strbuf_addch(name, '/');
3443 retval = do_for_each_reflog(name, fn, cb_data);
3444 } else {
3445 unsigned char sha1[20];
3446 if (read_ref_full(name->buf, sha1, 0, NULL))
3447 retval = error("bad ref for %s", name->buf);
3448 else
3449 retval = fn(name->buf, sha1, 0, cb_data);
3451 if (retval)
3452 break;
3454 strbuf_setlen(name, oldlen);
3456 closedir(d);
3457 return retval;
3460 int for_each_reflog(each_ref_fn fn, void *cb_data)
3462 int retval;
3463 struct strbuf name;
3464 strbuf_init(&name, PATH_MAX);
3465 retval = do_for_each_reflog(&name, fn, cb_data);
3466 strbuf_release(&name);
3467 return retval;
3470 static struct ref_lock *update_ref_lock(const char *refname,
3471 const unsigned char *oldval,
3472 int flags, int *type_p,
3473 enum action_on_err onerr)
3475 struct ref_lock *lock;
3476 lock = lock_any_ref_for_update(refname, oldval, flags, type_p);
3477 if (!lock) {
3478 const char *str = "Cannot lock the ref '%s'.";
3479 switch (onerr) {
3480 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
3481 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
3482 case UPDATE_REFS_QUIET_ON_ERR: break;
3485 return lock;
3488 static int update_ref_write(const char *action, const char *refname,
3489 const unsigned char *sha1, struct ref_lock *lock,
3490 enum action_on_err onerr)
3492 if (write_ref_sha1(lock, sha1, action) < 0) {
3493 const char *str = "Cannot update the ref '%s'.";
3494 switch (onerr) {
3495 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
3496 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
3497 case UPDATE_REFS_QUIET_ON_ERR: break;
3499 return 1;
3501 return 0;
3505 * Information needed for a single ref update. Set new_sha1 to the
3506 * new value or to zero to delete the ref. To check the old value
3507 * while locking the ref, set have_old to 1 and set old_sha1 to the
3508 * value or to zero to ensure the ref does not exist before update.
3510 struct ref_update {
3511 unsigned char new_sha1[20];
3512 unsigned char old_sha1[20];
3513 int flags; /* REF_NODEREF? */
3514 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
3515 struct ref_lock *lock;
3516 int type;
3517 const char refname[FLEX_ARRAY];
3521 * Data structure for holding a reference transaction, which can
3522 * consist of checks and updates to multiple references, carried out
3523 * as atomically as possible. This structure is opaque to callers.
3525 struct ref_transaction {
3526 struct ref_update **updates;
3527 size_t alloc;
3528 size_t nr;
3531 struct ref_transaction *ref_transaction_begin(void)
3533 return xcalloc(1, sizeof(struct ref_transaction));
3536 static void ref_transaction_free(struct ref_transaction *transaction)
3538 int i;
3540 for (i = 0; i < transaction->nr; i++)
3541 free(transaction->updates[i]);
3543 free(transaction->updates);
3544 free(transaction);
3547 void ref_transaction_rollback(struct ref_transaction *transaction)
3549 ref_transaction_free(transaction);
3552 static struct ref_update *add_update(struct ref_transaction *transaction,
3553 const char *refname)
3555 size_t len = strlen(refname);
3556 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
3558 strcpy((char *)update->refname, refname);
3559 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
3560 transaction->updates[transaction->nr++] = update;
3561 return update;
3564 void ref_transaction_update(struct ref_transaction *transaction,
3565 const char *refname,
3566 unsigned char *new_sha1, unsigned char *old_sha1,
3567 int flags, int have_old)
3569 struct ref_update *update = add_update(transaction, refname);
3571 hashcpy(update->new_sha1, new_sha1);
3572 update->flags = flags;
3573 update->have_old = have_old;
3574 if (have_old)
3575 hashcpy(update->old_sha1, old_sha1);
3578 void ref_transaction_create(struct ref_transaction *transaction,
3579 const char *refname,
3580 unsigned char *new_sha1,
3581 int flags)
3583 struct ref_update *update = add_update(transaction, refname);
3585 assert(!is_null_sha1(new_sha1));
3586 hashcpy(update->new_sha1, new_sha1);
3587 hashclr(update->old_sha1);
3588 update->flags = flags;
3589 update->have_old = 1;
3592 void ref_transaction_delete(struct ref_transaction *transaction,
3593 const char *refname,
3594 unsigned char *old_sha1,
3595 int flags, int have_old)
3597 struct ref_update *update = add_update(transaction, refname);
3599 update->flags = flags;
3600 update->have_old = have_old;
3601 if (have_old) {
3602 assert(!is_null_sha1(old_sha1));
3603 hashcpy(update->old_sha1, old_sha1);
3607 int update_ref(const char *action, const char *refname,
3608 const unsigned char *sha1, const unsigned char *oldval,
3609 int flags, enum action_on_err onerr)
3611 struct ref_lock *lock;
3612 lock = update_ref_lock(refname, oldval, flags, NULL, onerr);
3613 if (!lock)
3614 return 1;
3615 return update_ref_write(action, refname, sha1, lock, onerr);
3618 static int ref_update_compare(const void *r1, const void *r2)
3620 const struct ref_update * const *u1 = r1;
3621 const struct ref_update * const *u2 = r2;
3622 return strcmp((*u1)->refname, (*u2)->refname);
3625 static int ref_update_reject_duplicates(struct ref_update **updates, int n,
3626 enum action_on_err onerr)
3628 int i;
3629 for (i = 1; i < n; i++)
3630 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
3631 const char *str =
3632 "Multiple updates for ref '%s' not allowed.";
3633 switch (onerr) {
3634 case UPDATE_REFS_MSG_ON_ERR:
3635 error(str, updates[i]->refname); break;
3636 case UPDATE_REFS_DIE_ON_ERR:
3637 die(str, updates[i]->refname); break;
3638 case UPDATE_REFS_QUIET_ON_ERR:
3639 break;
3641 return 1;
3643 return 0;
3646 int ref_transaction_commit(struct ref_transaction *transaction,
3647 const char *msg, enum action_on_err onerr)
3649 int ret = 0, delnum = 0, i;
3650 const char **delnames;
3651 int n = transaction->nr;
3652 struct ref_update **updates = transaction->updates;
3654 if (!n)
3655 return 0;
3657 /* Allocate work space */
3658 delnames = xmalloc(sizeof(*delnames) * n);
3660 /* Copy, sort, and reject duplicate refs */
3661 qsort(updates, n, sizeof(*updates), ref_update_compare);
3662 ret = ref_update_reject_duplicates(updates, n, onerr);
3663 if (ret)
3664 goto cleanup;
3666 /* Acquire all locks while verifying old values */
3667 for (i = 0; i < n; i++) {
3668 struct ref_update *update = updates[i];
3670 update->lock = update_ref_lock(update->refname,
3671 (update->have_old ?
3672 update->old_sha1 : NULL),
3673 update->flags,
3674 &update->type, onerr);
3675 if (!update->lock) {
3676 ret = 1;
3677 goto cleanup;
3681 /* Perform updates first so live commits remain referenced */
3682 for (i = 0; i < n; i++) {
3683 struct ref_update *update = updates[i];
3685 if (!is_null_sha1(update->new_sha1)) {
3686 ret = update_ref_write(msg,
3687 update->refname,
3688 update->new_sha1,
3689 update->lock, onerr);
3690 update->lock = NULL; /* freed by update_ref_write */
3691 if (ret)
3692 goto cleanup;
3696 /* Perform deletes now that updates are safely completed */
3697 for (i = 0; i < n; i++) {
3698 struct ref_update *update = updates[i];
3700 if (update->lock) {
3701 delnames[delnum++] = update->lock->ref_name;
3702 ret |= delete_ref_loose(update->lock, update->type);
3706 ret |= repack_without_refs(delnames, delnum);
3707 for (i = 0; i < delnum; i++)
3708 unlink_or_warn(git_path("logs/%s", delnames[i]));
3709 clear_loose_ref_cache(&ref_cache);
3711 cleanup:
3712 for (i = 0; i < n; i++)
3713 if (updates[i]->lock)
3714 unlock_ref(updates[i]->lock);
3715 free(delnames);
3716 ref_transaction_free(transaction);
3717 return ret;
3720 char *shorten_unambiguous_ref(const char *refname, int strict)
3722 int i;
3723 static char **scanf_fmts;
3724 static int nr_rules;
3725 char *short_name;
3727 if (!nr_rules) {
3729 * Pre-generate scanf formats from ref_rev_parse_rules[].
3730 * Generate a format suitable for scanf from a
3731 * ref_rev_parse_rules rule by interpolating "%s" at the
3732 * location of the "%.*s".
3734 size_t total_len = 0;
3735 size_t offset = 0;
3737 /* the rule list is NULL terminated, count them first */
3738 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
3739 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
3740 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
3742 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3744 offset = 0;
3745 for (i = 0; i < nr_rules; i++) {
3746 assert(offset < total_len);
3747 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
3748 offset += snprintf(scanf_fmts[i], total_len - offset,
3749 ref_rev_parse_rules[i], 2, "%s") + 1;
3753 /* bail out if there are no rules */
3754 if (!nr_rules)
3755 return xstrdup(refname);
3757 /* buffer for scanf result, at most refname must fit */
3758 short_name = xstrdup(refname);
3760 /* skip first rule, it will always match */
3761 for (i = nr_rules - 1; i > 0 ; --i) {
3762 int j;
3763 int rules_to_fail = i;
3764 int short_name_len;
3766 if (1 != sscanf(refname, scanf_fmts[i], short_name))
3767 continue;
3769 short_name_len = strlen(short_name);
3772 * in strict mode, all (except the matched one) rules
3773 * must fail to resolve to a valid non-ambiguous ref
3775 if (strict)
3776 rules_to_fail = nr_rules;
3779 * check if the short name resolves to a valid ref,
3780 * but use only rules prior to the matched one
3782 for (j = 0; j < rules_to_fail; j++) {
3783 const char *rule = ref_rev_parse_rules[j];
3784 char refname[PATH_MAX];
3786 /* skip matched rule */
3787 if (i == j)
3788 continue;
3791 * the short name is ambiguous, if it resolves
3792 * (with this previous rule) to a valid ref
3793 * read_ref() returns 0 on success
3795 mksnpath(refname, sizeof(refname),
3796 rule, short_name_len, short_name);
3797 if (ref_exists(refname))
3798 break;
3802 * short name is non-ambiguous if all previous rules
3803 * haven't resolved to a valid ref
3805 if (j == rules_to_fail)
3806 return short_name;
3809 free(short_name);
3810 return xstrdup(refname);
3813 static struct string_list *hide_refs;
3815 int parse_hide_refs_config(const char *var, const char *value, const char *section)
3817 if (!strcmp("transfer.hiderefs", var) ||
3818 /* NEEDSWORK: use parse_config_key() once both are merged */
3819 (starts_with(var, section) && var[strlen(section)] == '.' &&
3820 !strcmp(var + strlen(section), ".hiderefs"))) {
3821 char *ref;
3822 int len;
3824 if (!value)
3825 return config_error_nonbool(var);
3826 ref = xstrdup(value);
3827 len = strlen(ref);
3828 while (len && ref[len - 1] == '/')
3829 ref[--len] = '\0';
3830 if (!hide_refs) {
3831 hide_refs = xcalloc(1, sizeof(*hide_refs));
3832 hide_refs->strdup_strings = 1;
3834 string_list_append(hide_refs, ref);
3836 return 0;
3839 int ref_is_hidden(const char *refname)
3841 struct string_list_item *item;
3843 if (!hide_refs)
3844 return 0;
3845 for_each_string_list_item(item, hide_refs) {
3846 int len;
3847 if (!starts_with(refname, item->string))
3848 continue;
3849 len = strlen(item->string);
3850 if (!refname[len] || refname[len] == '/')
3851 return 1;
3853 return 0;