pack_one_ref(): do some cheap tests before a more expensive one
[git/git.git] / refs.c
CommitLineData
95fc7512 1#include "cache.h"
85023577 2#include "refs.h"
cf0adba7
JH
3#include "object.h"
4#include "tag.h"
7155b727 5#include "dir.h"
95fc7512 6
bc5fd6d3
MH
7/*
8 * Make sure "ref" is something reasonable to have under ".git/refs/";
9 * We do not like it if:
10 *
11 * - any path component of it begins with ".", or
12 * - it has double dots "..", or
13 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
14 * - it ends with a "/".
15 * - it ends with ".lock"
16 * - it contains a "\" (backslash)
17 */
f4204ab9 18
bc5fd6d3
MH
19/* Return true iff ch is not allowed in reference names. */
20static inline int bad_ref_char(int ch)
21{
22 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
23 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
24 return 1;
25 /* 2.13 Pattern Matching Notation */
26 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
27 return 1;
28 return 0;
29}
30
31/*
32 * Try to read one refname component from the front of refname. Return
33 * the length of the component found, or -1 if the component is not
34 * legal.
35 */
36static int check_refname_component(const char *refname, int flags)
37{
38 const char *cp;
39 char last = '\0';
40
41 for (cp = refname; ; cp++) {
42 char ch = *cp;
43 if (ch == '\0' || ch == '/')
44 break;
45 if (bad_ref_char(ch))
46 return -1; /* Illegal character in refname. */
47 if (last == '.' && ch == '.')
48 return -1; /* Refname contains "..". */
49 if (last == '@' && ch == '{')
50 return -1; /* Refname contains "@{". */
51 last = ch;
52 }
53 if (cp == refname)
dac529e4 54 return 0; /* Component has zero length. */
bc5fd6d3
MH
55 if (refname[0] == '.') {
56 if (!(flags & REFNAME_DOT_COMPONENT))
57 return -1; /* Component starts with '.'. */
58 /*
59 * Even if leading dots are allowed, don't allow "."
60 * as a component (".." is prevented by a rule above).
61 */
62 if (refname[1] == '\0')
63 return -1; /* Component equals ".". */
64 }
65 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
66 return -1; /* Refname ends with ".lock". */
67 return cp - refname;
68}
69
70int check_refname_format(const char *refname, int flags)
71{
72 int component_len, component_count = 0;
73
74 while (1) {
75 /* We are at the start of a path component. */
76 component_len = check_refname_component(refname, flags);
dac529e4 77 if (component_len <= 0) {
bc5fd6d3
MH
78 if ((flags & REFNAME_REFSPEC_PATTERN) &&
79 refname[0] == '*' &&
80 (refname[1] == '\0' || refname[1] == '/')) {
81 /* Accept one wildcard as a full refname component. */
82 flags &= ~REFNAME_REFSPEC_PATTERN;
83 component_len = 1;
84 } else {
85 return -1;
86 }
87 }
88 component_count++;
89 if (refname[component_len] == '\0')
90 break;
91 /* Skip to next component. */
92 refname += component_len + 1;
93 }
94
95 if (refname[component_len - 1] == '.')
96 return -1; /* Refname ends with '.'. */
97 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
98 return -1; /* Refname has only one component. */
99 return 0;
100}
101
102struct ref_entry;
e1e22e37 103
28e6a34e
MH
104/*
105 * Information used (along with the information in ref_entry) to
106 * describe a single cached reference. This data structure only
107 * occurs embedded in a union in struct ref_entry, and only when
108 * (ref_entry->flag & REF_DIR) is zero.
109 */
593f1bb8 110struct ref_value {
6c6f58df
MH
111 /*
112 * The name of the object to which this reference resolves
113 * (which may be a tag object). If REF_ISBROKEN, this is
114 * null. If REF_ISSYMREF, then this is the name of the object
115 * referred to by the last reference in the symlink chain.
116 */
593f1bb8 117 unsigned char sha1[20];
6c6f58df
MH
118
119 /*
120 * If REF_KNOWS_PEELED, then this field holds the peeled value
121 * of this reference, or null if the reference is known not to
2312a793
MH
122 * be peelable. See the documentation for peel_ref() for an
123 * exact definition of "peelable".
6c6f58df 124 */
593f1bb8
MH
125 unsigned char peeled[20];
126};
127
f006c42a
MH
128struct ref_cache;
129
28e6a34e
MH
130/*
131 * Information used (along with the information in ref_entry) to
132 * describe a level in the hierarchy of references. This data
133 * structure only occurs embedded in a union in struct ref_entry, and
134 * only when (ref_entry.flag & REF_DIR) is set. In that case,
135 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
136 * in the directory have already been read:
137 *
138 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
139 * or packed references, already read.
140 *
141 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
142 * references that hasn't been read yet (nor has any of its
143 * subdirectories).
144 *
145 * Entries within a directory are stored within a growable array of
146 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
147 * sorted are sorted by their component name in strcmp() order and the
148 * remaining entries are unsorted.
149 *
150 * Loose references are read lazily, one directory at a time. When a
151 * directory of loose references is read, then all of the references
152 * in that directory are stored, and REF_INCOMPLETE stubs are created
153 * for any subdirectories, but the subdirectories themselves are not
154 * read. The reading is triggered by get_ref_dir().
155 */
d3177275 156struct ref_dir {
e9c4c111 157 int nr, alloc;
e6ed3ca6
MH
158
159 /*
160 * Entries with index 0 <= i < sorted are sorted by name. New
161 * entries are appended to the list unsorted, and are sorted
162 * only when required; thus we avoid the need to sort the list
163 * after the addition of every reference.
164 */
165 int sorted;
166
f006c42a
MH
167 /* A pointer to the ref_cache that contains this ref_dir. */
168 struct ref_cache *ref_cache;
169
d3177275 170 struct ref_entry **entries;
e9c4c111
JP
171};
172
89df9c84
MH
173/*
174 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
175 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
176 * refs.h.
177 */
178
179/*
180 * The field ref_entry->u.value.peeled of this value entry contains
181 * the correct peeled value for the reference, which might be
182 * null_sha1 if the reference is not a tag or if it is broken.
183 */
432ad41e 184#define REF_KNOWS_PEELED 0x08
28e6a34e
MH
185
186/* ref_entry represents a directory of references */
432ad41e 187#define REF_DIR 0x10
cf0adba7 188
28e6a34e
MH
189/*
190 * Entry has not yet been read from disk (used only for REF_DIR
191 * entries representing loose references)
192 */
193#define REF_INCOMPLETE 0x20
194
432ad41e
MH
195/*
196 * A ref_entry represents either a reference or a "subdirectory" of
28e6a34e
MH
197 * references.
198 *
199 * Each directory in the reference namespace is represented by a
200 * ref_entry with (flags & REF_DIR) set and containing a subdir member
201 * that holds the entries in that directory that have been read so
202 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
203 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
204 * used for loose reference directories.
205 *
206 * References are represented by a ref_entry with (flags & REF_DIR)
207 * unset and a value member that describes the reference's value. The
208 * flag member is at the ref_entry level, but it is also needed to
209 * interpret the contents of the value field (in other words, a
210 * ref_value object is not very much use without the enclosing
211 * ref_entry).
432ad41e
MH
212 *
213 * Reference names cannot end with slash and directories' names are
214 * always stored with a trailing slash (except for the top-level
215 * directory, which is always denoted by ""). This has two nice
216 * consequences: (1) when the entries in each subdir are sorted
217 * lexicographically by name (as they usually are), the references in
218 * a whole tree can be generated in lexicographic order by traversing
219 * the tree in left-to-right, depth-first order; (2) the names of
220 * references and subdirectories cannot conflict, and therefore the
221 * presence of an empty subdirectory does not block the creation of a
222 * similarly-named reference. (The fact that reference names with the
223 * same leading components can conflict *with each other* is a
224 * separate issue that is regulated by is_refname_available().)
225 *
226 * Please note that the name field contains the fully-qualified
227 * reference (or subdirectory) name. Space could be saved by only
228 * storing the relative names. But that would require the full names
229 * to be generated on the fly when iterating in do_for_each_ref(), and
230 * would break callback functions, who have always been able to assume
231 * that the name strings that they are passed will not be freed during
232 * the iteration.
233 */
bc5fd6d3
MH
234struct ref_entry {
235 unsigned char flag; /* ISSYMREF? ISPACKED? */
593f1bb8 236 union {
432ad41e
MH
237 struct ref_value value; /* if not (flags&REF_DIR) */
238 struct ref_dir subdir; /* if (flags&REF_DIR) */
593f1bb8 239 } u;
432ad41e
MH
240 /*
241 * The full name of the reference (e.g., "refs/heads/master")
242 * or the full name of the directory with a trailing slash
243 * (e.g., "refs/heads/"):
244 */
bc5fd6d3
MH
245 char name[FLEX_ARRAY];
246};
e1e22e37 247
28e6a34e
MH
248static void read_loose_refs(const char *dirname, struct ref_dir *dir);
249
d7826d54
MH
250static struct ref_dir *get_ref_dir(struct ref_entry *entry)
251{
28e6a34e 252 struct ref_dir *dir;
d7826d54 253 assert(entry->flag & REF_DIR);
28e6a34e
MH
254 dir = &entry->u.subdir;
255 if (entry->flag & REF_INCOMPLETE) {
256 read_loose_refs(entry->name, dir);
257 entry->flag &= ~REF_INCOMPLETE;
258 }
259 return dir;
d7826d54
MH
260}
261
cddc4258
MH
262static struct ref_entry *create_ref_entry(const char *refname,
263 const unsigned char *sha1, int flag,
264 int check_name)
e1e22e37
LT
265{
266 int len;
cddc4258 267 struct ref_entry *ref;
e1e22e37 268
09116a1c 269 if (check_name &&
dfefa935
MH
270 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
271 die("Reference has invalid format: '%s'", refname);
cddc4258
MH
272 len = strlen(refname) + 1;
273 ref = xmalloc(sizeof(struct ref_entry) + len);
593f1bb8
MH
274 hashcpy(ref->u.value.sha1, sha1);
275 hashclr(ref->u.value.peeled);
cddc4258
MH
276 memcpy(ref->name, refname, len);
277 ref->flag = flag;
278 return ref;
279}
280
432ad41e
MH
281static void clear_ref_dir(struct ref_dir *dir);
282
732134ed
MH
283static void free_ref_entry(struct ref_entry *entry)
284{
27b5587c
MH
285 if (entry->flag & REF_DIR) {
286 /*
287 * Do not use get_ref_dir() here, as that might
288 * trigger the reading of loose refs.
289 */
290 clear_ref_dir(&entry->u.subdir);
291 }
732134ed
MH
292 free(entry);
293}
294
432ad41e
MH
295/*
296 * Add a ref_entry to the end of dir (unsorted). Entry is always
297 * stored directly in dir; no recursion into subdirectories is
298 * done.
299 */
300static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
cddc4258 301{
432ad41e
MH
302 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
303 dir->entries[dir->nr++] = entry;
654ad400
MH
304 /* optimize for the case that entries are added in order */
305 if (dir->nr == 1 ||
306 (dir->nr == dir->sorted + 1 &&
307 strcmp(dir->entries[dir->nr - 2]->name,
308 dir->entries[dir->nr - 1]->name) < 0))
309 dir->sorted = dir->nr;
c774aab9
JP
310}
311
432ad41e
MH
312/*
313 * Clear and free all entries in dir, recursively.
314 */
d3177275 315static void clear_ref_dir(struct ref_dir *dir)
bc5fd6d3
MH
316{
317 int i;
d3177275
MH
318 for (i = 0; i < dir->nr; i++)
319 free_ref_entry(dir->entries[i]);
320 free(dir->entries);
321 dir->sorted = dir->nr = dir->alloc = 0;
322 dir->entries = NULL;
bc5fd6d3
MH
323}
324
432ad41e
MH
325/*
326 * Create a struct ref_entry object for the specified dirname.
327 * dirname is the name of the directory with a trailing slash (e.g.,
328 * "refs/heads/") or "" for the top-level directory.
329 */
f006c42a 330static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
b9146f51
RS
331 const char *dirname, size_t len,
332 int incomplete)
432ad41e
MH
333{
334 struct ref_entry *direntry;
432ad41e 335 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
b9146f51
RS
336 memcpy(direntry->name, dirname, len);
337 direntry->name[len] = '\0';
f006c42a 338 direntry->u.subdir.ref_cache = ref_cache;
28e6a34e 339 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
432ad41e
MH
340 return direntry;
341}
342
e9c4c111 343static int ref_entry_cmp(const void *a, const void *b)
c774aab9 344{
e9c4c111
JP
345 struct ref_entry *one = *(struct ref_entry **)a;
346 struct ref_entry *two = *(struct ref_entry **)b;
347 return strcmp(one->name, two->name);
348}
c774aab9 349
d3177275 350static void sort_ref_dir(struct ref_dir *dir);
bc5fd6d3 351
e1980c9d
JH
352struct string_slice {
353 size_t len;
354 const char *str;
355};
356
357static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
358{
359 struct string_slice *key = (struct string_slice *)key_;
360 struct ref_entry *ent = *(struct ref_entry **)ent_;
361 int entlen = strlen(ent->name);
362 int cmplen = key->len < entlen ? key->len : entlen;
363 int cmp = memcmp(key->str, ent->name, cmplen);
364 if (cmp)
365 return cmp;
366 return key->len - entlen;
367}
368
432ad41e 369/*
9fc0a648
MH
370 * Return the index of the entry with the given refname from the
371 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
372 * no such entry is found. dir must already be complete.
432ad41e 373 */
9fc0a648 374static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
bc5fd6d3 375{
e1980c9d
JH
376 struct ref_entry **r;
377 struct string_slice key;
bc5fd6d3 378
432ad41e 379 if (refname == NULL || !dir->nr)
9fc0a648 380 return -1;
bc5fd6d3 381
d3177275 382 sort_ref_dir(dir);
e1980c9d
JH
383 key.len = len;
384 key.str = refname;
385 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
386 ref_entry_cmp_sslice);
bc5fd6d3
MH
387
388 if (r == NULL)
9fc0a648 389 return -1;
bc5fd6d3 390
9fc0a648 391 return r - dir->entries;
bc5fd6d3
MH
392}
393
f348ac92
MH
394/*
395 * Search for a directory entry directly within dir (without
396 * recursing). Sort dir if necessary. subdirname must be a directory
397 * name (i.e., end in '/'). If mkdir is set, then create the
398 * directory if it is missing; otherwise, return NULL if the desired
28e6a34e 399 * directory cannot be found. dir must already be complete.
f348ac92 400 */
3f3aa1bc 401static struct ref_dir *search_for_subdir(struct ref_dir *dir,
dd02e728
RS
402 const char *subdirname, size_t len,
403 int mkdir)
f348ac92 404{
9fc0a648
MH
405 int entry_index = search_ref_dir(dir, subdirname, len);
406 struct ref_entry *entry;
407 if (entry_index == -1) {
f348ac92
MH
408 if (!mkdir)
409 return NULL;
28e6a34e
MH
410 /*
411 * Since dir is complete, the absence of a subdir
412 * means that the subdir really doesn't exist;
413 * therefore, create an empty record for it but mark
414 * the record complete.
415 */
b9146f51 416 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
f348ac92 417 add_entry_to_dir(dir, entry);
9fc0a648
MH
418 } else {
419 entry = dir->entries[entry_index];
f348ac92 420 }
3f3aa1bc 421 return get_ref_dir(entry);
f348ac92
MH
422}
423
432ad41e
MH
424/*
425 * If refname is a reference name, find the ref_dir within the dir
426 * tree that should hold refname. If refname is a directory name
427 * (i.e., ends in '/'), then return that ref_dir itself. dir must
28e6a34e
MH
428 * represent the top-level directory and must already be complete.
429 * Sort ref_dirs and recurse into subdirectories as necessary. If
430 * mkdir is set, then create any missing directories; otherwise,
431 * return NULL if the desired directory cannot be found.
432ad41e
MH
432 */
433static struct ref_dir *find_containing_dir(struct ref_dir *dir,
434 const char *refname, int mkdir)
435{
5fa04418 436 const char *slash;
5fa04418 437 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
dd02e728 438 size_t dirnamelen = slash - refname + 1;
3f3aa1bc 439 struct ref_dir *subdir;
dd02e728 440 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
663c1295
JH
441 if (!subdir) {
442 dir = NULL;
f348ac92 443 break;
432ad41e 444 }
3f3aa1bc 445 dir = subdir;
432ad41e
MH
446 }
447
432ad41e
MH
448 return dir;
449}
450
451/*
452 * Find the value entry with the given name in dir, sorting ref_dirs
453 * and recursing into subdirectories as necessary. If the name is not
454 * found or it corresponds to a directory entry, return NULL.
455 */
456static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
457{
9fc0a648 458 int entry_index;
432ad41e
MH
459 struct ref_entry *entry;
460 dir = find_containing_dir(dir, refname, 0);
461 if (!dir)
462 return NULL;
9fc0a648
MH
463 entry_index = search_ref_dir(dir, refname, strlen(refname));
464 if (entry_index == -1)
465 return NULL;
466 entry = dir->entries[entry_index];
467 return (entry->flag & REF_DIR) ? NULL : entry;
432ad41e
MH
468}
469
506a760d
MH
470/*
471 * Remove the entry with the given name from dir, recursing into
472 * subdirectories as necessary. If refname is the name of a directory
473 * (i.e., ends with '/'), then remove the directory and its contents.
474 * If the removal was successful, return the number of entries
475 * remaining in the directory entry that contained the deleted entry.
476 * If the name was not found, return -1. Please note that this
477 * function only deletes the entry from the cache; it does not delete
478 * it from the filesystem or ensure that other cache entries (which
479 * might be symbolic references to the removed entry) are updated.
480 * Nor does it remove any containing dir entries that might be made
481 * empty by the removal. dir must represent the top-level directory
482 * and must already be complete.
483 */
484static int remove_entry(struct ref_dir *dir, const char *refname)
485{
486 int refname_len = strlen(refname);
487 int entry_index;
488 struct ref_entry *entry;
489 int is_dir = refname[refname_len - 1] == '/';
490 if (is_dir) {
491 /*
492 * refname represents a reference directory. Remove
493 * the trailing slash; otherwise we will get the
494 * directory *representing* refname rather than the
495 * one *containing* it.
496 */
497 char *dirname = xmemdupz(refname, refname_len - 1);
498 dir = find_containing_dir(dir, dirname, 0);
499 free(dirname);
500 } else {
501 dir = find_containing_dir(dir, refname, 0);
502 }
503 if (!dir)
504 return -1;
505 entry_index = search_ref_dir(dir, refname, refname_len);
506 if (entry_index == -1)
507 return -1;
508 entry = dir->entries[entry_index];
509
510 memmove(&dir->entries[entry_index],
511 &dir->entries[entry_index + 1],
512 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
513 );
514 dir->nr--;
515 if (dir->sorted > entry_index)
516 dir->sorted--;
517 free_ref_entry(entry);
518 return dir->nr;
519}
520
432ad41e
MH
521/*
522 * Add a ref_entry to the ref_dir (unsorted), recursing into
523 * subdirectories as necessary. dir must represent the top-level
524 * directory. Return 0 on success.
525 */
526static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
527{
528 dir = find_containing_dir(dir, ref->name, 1);
529 if (!dir)
530 return -1;
531 add_entry_to_dir(dir, ref);
532 return 0;
533}
534
202a56a9
MH
535/*
536 * Emit a warning and return true iff ref1 and ref2 have the same name
537 * and the same sha1. Die if they have the same name but different
538 * sha1s.
539 */
540static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
541{
432ad41e 542 if (strcmp(ref1->name, ref2->name))
202a56a9 543 return 0;
432ad41e
MH
544
545 /* Duplicate name; make sure that they don't conflict: */
546
547 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
548 /* This is impossible by construction */
549 die("Reference directory conflict: %s", ref1->name);
550
551 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
552 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
553
554 warning("Duplicated ref: %s", ref1->name);
555 return 1;
202a56a9
MH
556}
557
e6ed3ca6 558/*
432ad41e
MH
559 * Sort the entries in dir non-recursively (if they are not already
560 * sorted) and remove any duplicate entries.
e6ed3ca6 561 */
d3177275 562static void sort_ref_dir(struct ref_dir *dir)
e9c4c111 563{
202a56a9 564 int i, j;
81a79d8e 565 struct ref_entry *last = NULL;
c774aab9 566
e6ed3ca6
MH
567 /*
568 * This check also prevents passing a zero-length array to qsort(),
569 * which is a problem on some platforms.
570 */
d3177275 571 if (dir->sorted == dir->nr)
e9c4c111 572 return;
c774aab9 573
d3177275 574 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
c774aab9 575
81a79d8e
MH
576 /* Remove any duplicates: */
577 for (i = 0, j = 0; j < dir->nr; j++) {
578 struct ref_entry *entry = dir->entries[j];
579 if (last && is_dup_ref(last, entry))
580 free_ref_entry(entry);
581 else
582 last = dir->entries[i++] = entry;
e9c4c111 583 }
81a79d8e 584 dir->sorted = dir->nr = i;
e9c4c111 585}
c774aab9 586
fcce1703
MH
587/* Include broken references in a do_for_each_ref*() iteration: */
588#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
c774aab9 589
662428f4
MH
590/*
591 * Return true iff the reference described by entry can be resolved to
592 * an object in the database. Emit a warning if the referred-to
593 * object does not exist.
594 */
595static int ref_resolves_to_object(struct ref_entry *entry)
596{
597 if (entry->flag & REF_ISBROKEN)
598 return 0;
599 if (!has_sha1_file(entry->u.value.sha1)) {
600 error("%s does not point to a valid object!", entry->name);
601 return 0;
602 }
603 return 1;
604}
605
7d76fdc8
MH
606/*
607 * current_ref is a performance hack: when iterating over references
608 * using the for_each_ref*() functions, current_ref is set to the
609 * current reference's entry before calling the callback function. If
610 * the callback function calls peel_ref(), then peel_ref() first
611 * checks whether the reference to be peeled is the current reference
612 * (it usually is) and if so, returns that reference's peeled version
613 * if it is available. This avoids a refname lookup in a common case.
614 */
bc5fd6d3 615static struct ref_entry *current_ref;
c774aab9 616
624cac35
MH
617typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
618
619struct ref_entry_cb {
620 const char *base;
621 int trim;
622 int flags;
623 each_ref_fn *fn;
624 void *cb_data;
625};
626
fcce1703 627/*
624cac35
MH
628 * Handle one reference in a do_for_each_ref*()-style iteration,
629 * calling an each_ref_fn for each entry.
fcce1703 630 */
624cac35 631static int do_one_ref(struct ref_entry *entry, void *cb_data)
bc5fd6d3 632{
624cac35 633 struct ref_entry_cb *data = cb_data;
429213e4 634 int retval;
624cac35 635 if (prefixcmp(entry->name, data->base))
bc5fd6d3 636 return 0;
c774aab9 637
624cac35 638 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
662428f4
MH
639 !ref_resolves_to_object(entry))
640 return 0;
641
bc5fd6d3 642 current_ref = entry;
624cac35
MH
643 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
644 entry->flag, data->cb_data);
429213e4
MH
645 current_ref = NULL;
646 return retval;
bc5fd6d3 647}
c774aab9 648
c36b5bc2 649/*
d3177275 650 * Call fn for each reference in dir that has index in the range
432ad41e
MH
651 * offset <= index < dir->nr. Recurse into subdirectories that are in
652 * that index range, sorting them before iterating. This function
624cac35
MH
653 * does not sort dir itself; it should be sorted beforehand. fn is
654 * called for all references, including broken ones.
c36b5bc2 655 */
624cac35
MH
656static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
657 each_ref_entry_fn fn, void *cb_data)
c36b5bc2
MH
658{
659 int i;
d3177275
MH
660 assert(dir->sorted == dir->nr);
661 for (i = offset; i < dir->nr; i++) {
432ad41e
MH
662 struct ref_entry *entry = dir->entries[i];
663 int retval;
664 if (entry->flag & REF_DIR) {
d7826d54
MH
665 struct ref_dir *subdir = get_ref_dir(entry);
666 sort_ref_dir(subdir);
624cac35 667 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
432ad41e 668 } else {
624cac35 669 retval = fn(entry, cb_data);
432ad41e 670 }
c36b5bc2
MH
671 if (retval)
672 return retval;
673 }
674 return 0;
675}
676
b3fd060f 677/*
d3177275 678 * Call fn for each reference in the union of dir1 and dir2, in order
432ad41e
MH
679 * by refname. Recurse into subdirectories. If a value entry appears
680 * in both dir1 and dir2, then only process the version that is in
681 * dir2. The input dirs must already be sorted, but subdirs will be
624cac35
MH
682 * sorted as needed. fn is called for all references, including
683 * broken ones.
b3fd060f 684 */
624cac35
MH
685static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
686 struct ref_dir *dir2,
687 each_ref_entry_fn fn, void *cb_data)
b3fd060f
MH
688{
689 int retval;
690 int i1 = 0, i2 = 0;
691
d3177275
MH
692 assert(dir1->sorted == dir1->nr);
693 assert(dir2->sorted == dir2->nr);
432ad41e
MH
694 while (1) {
695 struct ref_entry *e1, *e2;
696 int cmp;
697 if (i1 == dir1->nr) {
624cac35 698 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
432ad41e
MH
699 }
700 if (i2 == dir2->nr) {
624cac35 701 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
432ad41e
MH
702 }
703 e1 = dir1->entries[i1];
704 e2 = dir2->entries[i2];
705 cmp = strcmp(e1->name, e2->name);
706 if (cmp == 0) {
707 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
708 /* Both are directories; descend them in parallel. */
d7826d54
MH
709 struct ref_dir *subdir1 = get_ref_dir(e1);
710 struct ref_dir *subdir2 = get_ref_dir(e2);
711 sort_ref_dir(subdir1);
712 sort_ref_dir(subdir2);
624cac35
MH
713 retval = do_for_each_entry_in_dirs(
714 subdir1, subdir2, fn, cb_data);
432ad41e
MH
715 i1++;
716 i2++;
717 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
718 /* Both are references; ignore the one from dir1. */
624cac35 719 retval = fn(e2, cb_data);
432ad41e
MH
720 i1++;
721 i2++;
722 } else {
723 die("conflict between reference and directory: %s",
724 e1->name);
725 }
b3fd060f 726 } else {
432ad41e
MH
727 struct ref_entry *e;
728 if (cmp < 0) {
729 e = e1;
b3fd060f 730 i1++;
432ad41e
MH
731 } else {
732 e = e2;
733 i2++;
734 }
735 if (e->flag & REF_DIR) {
d7826d54
MH
736 struct ref_dir *subdir = get_ref_dir(e);
737 sort_ref_dir(subdir);
624cac35
MH
738 retval = do_for_each_entry_in_dir(
739 subdir, 0, fn, cb_data);
432ad41e 740 } else {
624cac35 741 retval = fn(e, cb_data);
b3fd060f
MH
742 }
743 }
744 if (retval)
745 return retval;
746 }
b3fd060f
MH
747}
748
d66da478
MH
749/*
750 * Return true iff refname1 and refname2 conflict with each other.
751 * Two reference names conflict if one of them exactly matches the
752 * leading components of the other; e.g., "foo/bar" conflicts with
753 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
754 * "foo/barbados".
755 */
756static int names_conflict(const char *refname1, const char *refname2)
757{
5a4d4947
MH
758 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
759 ;
760 return (*refname1 == '\0' && *refname2 == '/')
761 || (*refname1 == '/' && *refname2 == '\0');
762}
763
764struct name_conflict_cb {
765 const char *refname;
766 const char *oldrefname;
767 const char *conflicting_refname;
768};
769
624cac35 770static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
5a4d4947
MH
771{
772 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
624cac35 773 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
5a4d4947 774 return 0;
624cac35
MH
775 if (names_conflict(data->refname, entry->name)) {
776 data->conflicting_refname = entry->name;
5a4d4947 777 return 1;
d66da478 778 }
5a4d4947 779 return 0;
d66da478
MH
780}
781
bc5fd6d3
MH
782/*
783 * Return true iff a reference named refname could be created without
624cac35 784 * conflicting with the name of an existing reference in dir. If
5a4d4947
MH
785 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
786 * (e.g., because oldrefname is scheduled for deletion in the same
bc5fd6d3
MH
787 * operation).
788 */
789static int is_refname_available(const char *refname, const char *oldrefname,
d3177275 790 struct ref_dir *dir)
bc5fd6d3 791{
5a4d4947
MH
792 struct name_conflict_cb data;
793 data.refname = refname;
794 data.oldrefname = oldrefname;
795 data.conflicting_refname = NULL;
796
d3177275 797 sort_ref_dir(dir);
624cac35 798 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
5a4d4947
MH
799 error("'%s' exists; cannot create '%s'",
800 data.conflicting_refname, refname);
801 return 0;
bc5fd6d3
MH
802 }
803 return 1;
e1e22e37
LT
804}
805
5e290ff7
JH
806/*
807 * Future: need to be in "struct repository"
808 * when doing a full libification.
809 */
79c7ca54
MH
810static struct ref_cache {
811 struct ref_cache *next;
d12229f5
MH
812 struct ref_entry *loose;
813 struct ref_entry *packed;
ce40979c
MH
814 /* The submodule name, or "" for the main repo. */
815 char name[FLEX_ARRAY];
79c7ca54 816} *ref_cache;
0e88c130 817
760c4512 818static void clear_packed_ref_cache(struct ref_cache *refs)
e1e22e37 819{
d12229f5
MH
820 if (refs->packed) {
821 free_ref_entry(refs->packed);
822 refs->packed = NULL;
823 }
5e290ff7 824}
e1e22e37 825
760c4512
MH
826static void clear_loose_ref_cache(struct ref_cache *refs)
827{
d12229f5
MH
828 if (refs->loose) {
829 free_ref_entry(refs->loose);
830 refs->loose = NULL;
831 }
760c4512
MH
832}
833
79c7ca54 834static struct ref_cache *create_ref_cache(const char *submodule)
e5dbf605 835{
ce40979c 836 int len;
79c7ca54 837 struct ref_cache *refs;
ce40979c
MH
838 if (!submodule)
839 submodule = "";
840 len = strlen(submodule) + 1;
79c7ca54 841 refs = xcalloc(1, sizeof(struct ref_cache) + len);
ce40979c 842 memcpy(refs->name, submodule, len);
e5dbf605
MH
843 return refs;
844}
845
4349a668 846/*
79c7ca54 847 * Return a pointer to a ref_cache for the specified submodule. For
4349a668
MH
848 * the main repository, use submodule==NULL. The returned structure
849 * will be allocated and initialized but not necessarily populated; it
850 * should not be freed.
851 */
79c7ca54 852static struct ref_cache *get_ref_cache(const char *submodule)
4349a668 853{
79c7ca54 854 struct ref_cache *refs = ref_cache;
0e88c130
MH
855 if (!submodule)
856 submodule = "";
857 while (refs) {
858 if (!strcmp(submodule, refs->name))
859 return refs;
860 refs = refs->next;
4349a668 861 }
0e88c130 862
79c7ca54
MH
863 refs = create_ref_cache(submodule);
864 refs->next = ref_cache;
865 ref_cache = refs;
0e88c130 866 return refs;
4349a668
MH
867}
868
8be8bde7 869void invalidate_ref_cache(const char *submodule)
f130b116 870{
c5f29abd
MH
871 struct ref_cache *refs = get_ref_cache(submodule);
872 clear_packed_ref_cache(refs);
873 clear_loose_ref_cache(refs);
5e290ff7 874}
e1e22e37 875
3feb4f0c
MH
876/* The length of a peeled reference line in packed-refs, including EOL: */
877#define PEELED_LINE_LENGTH 42
878
694b7a19
MH
879/*
880 * The packed-refs header line that we write out. Perhaps other
881 * traits will be added later. The trailing space is required.
882 */
883static const char PACKED_REFS_HEADER[] =
884 "# pack-refs with: peeled fully-peeled \n";
885
bc5fd6d3
MH
886/*
887 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
888 * Return a pointer to the refname within the line (null-terminated),
889 * or NULL if there was a problem.
890 */
891static const char *parse_ref_line(char *line, unsigned char *sha1)
892{
893 /*
894 * 42: the answer to everything.
895 *
896 * In this case, it happens to be the answer to
897 * 40 (length of sha1 hex representation)
898 * +1 (space in between hex and name)
899 * +1 (newline at the end of the line)
900 */
901 int len = strlen(line) - 42;
902
903 if (len <= 0)
904 return NULL;
905 if (get_sha1_hex(line, sha1) < 0)
906 return NULL;
907 if (!isspace(line[40]))
908 return NULL;
909 line += 41;
910 if (isspace(*line))
911 return NULL;
912 if (line[len] != '\n')
913 return NULL;
914 line[len] = 0;
915
916 return line;
917}
918
c29c46fa
MH
919/*
920 * Read f, which is a packed-refs file, into dir.
921 *
922 * A comment line of the form "# pack-refs with: " may contain zero or
923 * more traits. We interpret the traits as follows:
924 *
925 * No traits:
926 *
927 * Probably no references are peeled. But if the file contains a
928 * peeled value for a reference, we will use it.
929 *
930 * peeled:
931 *
932 * References under "refs/tags/", if they *can* be peeled, *are*
933 * peeled in this file. References outside of "refs/tags/" are
934 * probably not peeled even if they could have been, but if we find
935 * a peeled value for such a reference we will use it.
936 *
937 * fully-peeled:
938 *
939 * All references in the file that can be peeled are peeled.
940 * Inversely (and this is more important), any references in the
941 * file for which no peeled value is recorded is not peelable. This
942 * trait should typically be written alongside "peeled" for
943 * compatibility with older clients, but we do not require it
944 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
945 */
d3177275 946static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 947{
e9c4c111 948 struct ref_entry *last = NULL;
f4204ab9 949 char refline[PATH_MAX];
c29c46fa 950 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
951
952 while (fgets(refline, sizeof(refline), f)) {
953 unsigned char sha1[20];
dfefa935 954 const char *refname;
f4204ab9
JH
955 static const char header[] = "# pack-refs with:";
956
957 if (!strncmp(refline, header, sizeof(header)-1)) {
958 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
959 if (strstr(traits, " fully-peeled "))
960 peeled = PEELED_FULLY;
961 else if (strstr(traits, " peeled "))
962 peeled = PEELED_TAGS;
f4204ab9
JH
963 /* perhaps other traits later as well */
964 continue;
965 }
966
dfefa935
MH
967 refname = parse_ref_line(refline, sha1);
968 if (refname) {
c29c46fa
MH
969 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
970 if (peeled == PEELED_FULLY ||
971 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
972 last->flag |= REF_KNOWS_PEELED;
d3177275 973 add_ref(dir, last);
f4204ab9
JH
974 continue;
975 }
976 if (last &&
977 refline[0] == '^' &&
3feb4f0c
MH
978 strlen(refline) == PEELED_LINE_LENGTH &&
979 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 980 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 981 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
982 /*
983 * Regardless of what the file header said,
984 * we definitely know the value of *this*
985 * reference:
986 */
987 last->flag |= REF_KNOWS_PEELED;
988 }
f4204ab9 989 }
f4204ab9
JH
990}
991
d3177275 992static struct ref_dir *get_packed_refs(struct ref_cache *refs)
5e290ff7 993{
d12229f5 994 if (!refs->packed) {
4349a668
MH
995 const char *packed_refs_file;
996 FILE *f;
0bad611b 997
b9146f51 998 refs->packed = create_dir_entry(refs, "", 0, 0);
316b097a
MH
999 if (*refs->name)
1000 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
4349a668
MH
1001 else
1002 packed_refs_file = git_path("packed-refs");
1003 f = fopen(packed_refs_file, "r");
e1e22e37 1004 if (f) {
d7826d54 1005 read_packed_refs(f, get_ref_dir(refs->packed));
e1e22e37 1006 fclose(f);
e1e22e37 1007 }
e1e22e37 1008 }
d7826d54 1009 return get_ref_dir(refs->packed);
e1e22e37
LT
1010}
1011
30249ee6
MH
1012void add_packed_ref(const char *refname, const unsigned char *sha1)
1013{
1014 add_ref(get_packed_refs(get_ref_cache(NULL)),
1015 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
1016}
1017
abc39098 1018/*
28e6a34e
MH
1019 * Read the loose references from the namespace dirname into dir
1020 * (without recursing). dirname must end with '/'. dir must be the
1021 * directory entry corresponding to dirname.
abc39098 1022 */
423a1afc 1023static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 1024{
423a1afc 1025 struct ref_cache *refs = dir->ref_cache;
d3177275 1026 DIR *d;
0bad611b 1027 const char *path;
d5fdae67 1028 struct dirent *de;
abc39098 1029 int dirnamelen = strlen(dirname);
72b64b44 1030 struct strbuf refname;
0bad611b 1031
3b124823 1032 if (*refs->name)
66a3d20b 1033 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 1034 else
66a3d20b 1035 path = git_path("%s", dirname);
0bad611b 1036
d3177275 1037 d = opendir(path);
d5fdae67
MH
1038 if (!d)
1039 return;
1040
66a3d20b
MH
1041 strbuf_init(&refname, dirnamelen + 257);
1042 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
1043
1044 while ((de = readdir(d)) != NULL) {
1045 unsigned char sha1[20];
1046 struct stat st;
1047 int flag;
d5fdae67
MH
1048 const char *refdir;
1049
1050 if (de->d_name[0] == '.')
1051 continue;
d5fdae67
MH
1052 if (has_extension(de->d_name, ".lock"))
1053 continue;
72b64b44 1054 strbuf_addstr(&refname, de->d_name);
d5fdae67 1055 refdir = *refs->name
72b64b44
MH
1056 ? git_path_submodule(refs->name, "%s", refname.buf)
1057 : git_path("%s", refname.buf);
1058 if (stat(refdir, &st) < 0) {
1059 ; /* silently ignore */
1060 } else if (S_ISDIR(st.st_mode)) {
abc39098 1061 strbuf_addch(&refname, '/');
28e6a34e 1062 add_entry_to_dir(dir,
b9146f51
RS
1063 create_dir_entry(refs, refname.buf,
1064 refname.len, 1));
72b64b44 1065 } else {
3b124823 1066 if (*refs->name) {
f8948e2f 1067 hashclr(sha1);
0bad611b 1068 flag = 0;
72b64b44 1069 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1070 hashclr(sha1);
98ac34b2 1071 flag |= REF_ISBROKEN;
0bad611b 1072 }
72b64b44 1073 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1074 hashclr(sha1);
1075 flag |= REF_ISBROKEN;
1076 }
9f2fb4a3
MH
1077 add_entry_to_dir(dir,
1078 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1079 }
66a3d20b 1080 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1081 }
72b64b44 1082 strbuf_release(&refname);
d5fdae67 1083 closedir(d);
e1e22e37
LT
1084}
1085
d3177275 1086static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1087{
d12229f5 1088 if (!refs->loose) {
28e6a34e
MH
1089 /*
1090 * Mark the top-level directory complete because we
1091 * are about to read the only subdirectory that can
1092 * hold references:
1093 */
b9146f51 1094 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1095 /*
1096 * Create an incomplete entry for "refs/":
1097 */
1098 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1099 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1100 }
d7826d54 1101 return get_ref_dir(refs->loose);
e1e22e37
LT
1102}
1103
ca8db142
LT
1104/* We allow "recursive" symbolic refs. Only within reason, though */
1105#define MAXDEPTH 5
0ebde32c
LT
1106#define MAXREFLEN (1024)
1107
e5fa45c1
JH
1108/*
1109 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1110 * from the loose refs in ref_cache refs. Find <refname> in the
1111 * packed-refs file for the submodule.
e5fa45c1 1112 */
b0626608 1113static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1114 const char *refname, unsigned char *sha1)
0ebde32c 1115{
2c5c66be 1116 struct ref_entry *ref;
d3177275 1117 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1118
432ad41e 1119 ref = find_ref(dir, refname);
b0626608
MH
1120 if (ref == NULL)
1121 return -1;
1122
593f1bb8 1123 memcpy(sha1, ref->u.value.sha1, 20);
b0626608 1124 return 0;
0ebde32c
LT
1125}
1126
b0626608 1127static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1128 const char *refname, unsigned char *sha1,
dfefa935 1129 int recursion)
0ebde32c 1130{
064d51dc 1131 int fd, len;
0ebde32c 1132 char buffer[128], *p;
064d51dc 1133 char *path;
0ebde32c 1134
064d51dc 1135 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1136 return -1;
064d51dc
MH
1137 path = *refs->name
1138 ? git_path_submodule(refs->name, "%s", refname)
1139 : git_path("%s", refname);
1140 fd = open(path, O_RDONLY);
0ebde32c 1141 if (fd < 0)
b0626608 1142 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1143
1144 len = read(fd, buffer, sizeof(buffer)-1);
1145 close(fd);
1146 if (len < 0)
1147 return -1;
1148 while (len && isspace(buffer[len-1]))
1149 len--;
1150 buffer[len] = 0;
1151
1152 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1153 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1154 return 0;
1155
1156 /* Symref? */
1157 if (strncmp(buffer, "ref:", 4))
1158 return -1;
1159 p = buffer + 4;
1160 while (isspace(*p))
1161 p++;
1162
064d51dc 1163 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1164}
1165
85be1fe3 1166int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1167{
1168 int len = strlen(path), retval;
064d51dc 1169 char *submodule;
b0626608 1170 struct ref_cache *refs;
0ebde32c
LT
1171
1172 while (len && path[len-1] == '/')
1173 len--;
1174 if (!len)
1175 return -1;
b0626608
MH
1176 submodule = xstrndup(path, len);
1177 refs = get_ref_cache(submodule);
1178 free(submodule);
1179
064d51dc 1180 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1181 return retval;
1182}
ca8db142 1183
4886b89f 1184/*
63331581
MH
1185 * Return the ref_entry for the given refname from the packed
1186 * references. If it does not exist, return NULL.
4886b89f 1187 */
63331581 1188static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1189{
63331581 1190 return find_ref(get_packed_refs(get_ref_cache(NULL)), refname);
c224ca7f
MH
1191}
1192
8d68493f 1193const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1194{
0104ca09
HO
1195 int depth = MAXDEPTH;
1196 ssize_t len;
a876ed83 1197 char buffer[256];
dfefa935 1198 static char refname_buffer[256];
ca8db142 1199
8da19775
JH
1200 if (flag)
1201 *flag = 0;
1202
dfefa935 1203 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
8384d788
MH
1204 return NULL;
1205
a876ed83 1206 for (;;) {
55956350 1207 char path[PATH_MAX];
a876ed83
JH
1208 struct stat st;
1209 char *buf;
1210 int fd;
8a65ff76 1211
a876ed83
JH
1212 if (--depth < 0)
1213 return NULL;
ca8db142 1214
dfefa935 1215 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1216
a876ed83 1217 if (lstat(path, &st) < 0) {
63331581
MH
1218 struct ref_entry *entry;
1219
c224ca7f
MH
1220 if (errno != ENOENT)
1221 return NULL;
1222 /*
1223 * The loose reference file does not exist;
1224 * check for a packed reference.
1225 */
63331581
MH
1226 entry = get_packed_ref(refname);
1227 if (entry) {
1228 hashcpy(sha1, entry->u.value.sha1);
c224ca7f
MH
1229 if (flag)
1230 *flag |= REF_ISPACKED;
dfefa935 1231 return refname;
434cd0cd 1232 }
c224ca7f
MH
1233 /* The reference is not a packed reference, either. */
1234 if (reading) {
a876ed83 1235 return NULL;
c224ca7f
MH
1236 } else {
1237 hashclr(sha1);
dfefa935 1238 return refname;
c224ca7f 1239 }
a876ed83 1240 }
ca8db142 1241
a876ed83
JH
1242 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1243 if (S_ISLNK(st.st_mode)) {
1244 len = readlink(path, buffer, sizeof(buffer)-1);
7bb2bf8e
MH
1245 if (len < 0)
1246 return NULL;
b54cb795 1247 buffer[len] = 0;
1f58a038
MH
1248 if (!prefixcmp(buffer, "refs/") &&
1249 !check_refname_format(buffer, 0)) {
dfefa935
MH
1250 strcpy(refname_buffer, buffer);
1251 refname = refname_buffer;
8da19775
JH
1252 if (flag)
1253 *flag |= REF_ISSYMREF;
a876ed83
JH
1254 continue;
1255 }
ca8db142 1256 }
a876ed83 1257
7a21632f
DS
1258 /* Is it a directory? */
1259 if (S_ISDIR(st.st_mode)) {
1260 errno = EISDIR;
1261 return NULL;
1262 }
1263
a876ed83
JH
1264 /*
1265 * Anything else, just open it and try to use it as
1266 * a ref
1267 */
1268 fd = open(path, O_RDONLY);
1269 if (fd < 0)
1270 return NULL;
93d26e4c 1271 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83 1272 close(fd);
28775050
MH
1273 if (len < 0)
1274 return NULL;
1275 while (len && isspace(buffer[len-1]))
1276 len--;
1277 buffer[len] = '\0';
a876ed83
JH
1278
1279 /*
1280 * Is it a symbolic ref?
1281 */
28775050 1282 if (prefixcmp(buffer, "ref:"))
a876ed83 1283 break;
55956350
JH
1284 if (flag)
1285 *flag |= REF_ISSYMREF;
a876ed83 1286 buf = buffer + 4;
28775050
MH
1287 while (isspace(*buf))
1288 buf++;
313fb010 1289 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1290 if (flag)
1291 *flag |= REF_ISBROKEN;
313fb010
MH
1292 return NULL;
1293 }
dfefa935 1294 refname = strcpy(refname_buffer, buf);
8a65ff76 1295 }
f989fea0
MH
1296 /* Please note that FETCH_HEAD has a second line containing other data. */
1297 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
55956350
JH
1298 if (flag)
1299 *flag |= REF_ISBROKEN;
a876ed83 1300 return NULL;
629cd3ac 1301 }
dfefa935 1302 return refname;
a876ed83
JH
1303}
1304
96ec7b1e
NTND
1305char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1306{
8cad4744 1307 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1308 return ret ? xstrdup(ret) : NULL;
1309}
1310
d08bae7e
IL
1311/* The argument to filter_refs */
1312struct ref_filter {
1313 const char *pattern;
1314 each_ref_fn *fn;
1315 void *cb_data;
1316};
1317
dfefa935 1318int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1319{
8d68493f 1320 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1321 return 0;
1322 return -1;
8a65ff76
LT
1323}
1324
dfefa935 1325int read_ref(const char *refname, unsigned char *sha1)
c6893323 1326{
dfefa935 1327 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1328}
1329
bc5fd6d3 1330int ref_exists(const char *refname)
ef06b918 1331{
bc5fd6d3
MH
1332 unsigned char sha1[20];
1333 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1334}
1335
85be1fe3 1336static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1337 void *data)
d08bae7e
IL
1338{
1339 struct ref_filter *filter = (struct ref_filter *)data;
dfefa935 1340 if (fnmatch(filter->pattern, refname, 0))
d08bae7e 1341 return 0;
85be1fe3 1342 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1343}
1344
68cf8703
MH
1345enum peel_status {
1346 /* object was peeled successfully: */
1347 PEEL_PEELED = 0,
1348
1349 /*
1350 * object cannot be peeled because the named object (or an
1351 * object referred to by a tag in the peel chain), does not
1352 * exist.
1353 */
1354 PEEL_INVALID = -1,
1355
1356 /* object cannot be peeled because it is not a tag: */
9a489f3c
MH
1357 PEEL_NON_TAG = -2,
1358
1359 /* ref_entry contains no peeled value because it is a symref: */
1360 PEEL_IS_SYMREF = -3,
1361
1362 /*
1363 * ref_entry cannot be peeled because it is broken (i.e., the
1364 * symbolic reference cannot even be resolved to an object
1365 * name):
1366 */
1367 PEEL_BROKEN = -4
68cf8703
MH
1368};
1369
cb2ae1c4
MH
1370/*
1371 * Peel the named object; i.e., if the object is a tag, resolve the
68cf8703
MH
1372 * tag recursively until a non-tag is found. If successful, store the
1373 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1374 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1375 * and leave sha1 unchanged.
cb2ae1c4 1376 */
68cf8703 1377static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
cb2ae1c4
MH
1378{
1379 struct object *o = lookup_unknown_object(name);
1380
1381 if (o->type == OBJ_NONE) {
1382 int type = sha1_object_info(name, NULL);
1383 if (type < 0)
68cf8703 1384 return PEEL_INVALID;
cb2ae1c4
MH
1385 o->type = type;
1386 }
1387
1388 if (o->type != OBJ_TAG)
68cf8703 1389 return PEEL_NON_TAG;
cb2ae1c4
MH
1390
1391 o = deref_tag_noverify(o);
1392 if (!o)
68cf8703 1393 return PEEL_INVALID;
cb2ae1c4
MH
1394
1395 hashcpy(sha1, o->sha1);
68cf8703 1396 return PEEL_PEELED;
cb2ae1c4
MH
1397}
1398
9a489f3c 1399/*
f85354b5
MH
1400 * Peel the entry (if possible) and return its new peel_status. If
1401 * repeel is true, re-peel the entry even if there is an old peeled
1402 * value that is already stored in it.
694b7a19
MH
1403 *
1404 * It is OK to call this function with a packed reference entry that
1405 * might be stale and might even refer to an object that has since
1406 * been garbage-collected. In such a case, if the entry has
1407 * REF_KNOWS_PEELED then leave the status unchanged and return
1408 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
9a489f3c 1409 */
f85354b5 1410static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
9a489f3c
MH
1411{
1412 enum peel_status status;
1413
f85354b5
MH
1414 if (entry->flag & REF_KNOWS_PEELED) {
1415 if (repeel) {
1416 entry->flag &= ~REF_KNOWS_PEELED;
1417 hashclr(entry->u.value.peeled);
1418 } else {
1419 return is_null_sha1(entry->u.value.peeled) ?
1420 PEEL_NON_TAG : PEEL_PEELED;
1421 }
1422 }
9a489f3c
MH
1423 if (entry->flag & REF_ISBROKEN)
1424 return PEEL_BROKEN;
1425 if (entry->flag & REF_ISSYMREF)
1426 return PEEL_IS_SYMREF;
1427
1428 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1429 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1430 entry->flag |= REF_KNOWS_PEELED;
1431 return status;
1432}
1433
dfefa935 1434int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1435{
1436 int flag;
1437 unsigned char base[20];
cf0adba7 1438
dfefa935 1439 if (current_ref && (current_ref->name == refname
9a489f3c 1440 || !strcmp(current_ref->name, refname))) {
f85354b5 1441 if (peel_entry(current_ref, 0))
9a489f3c
MH
1442 return -1;
1443 hashcpy(sha1, current_ref->u.value.peeled);
1444 return 0;
0ae91be0
SP
1445 }
1446
dfefa935 1447 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1448 return -1;
1449
9a489f3c
MH
1450 /*
1451 * If the reference is packed, read its ref_entry from the
1452 * cache in the hope that we already know its peeled value.
1453 * We only try this optimization on packed references because
1454 * (a) forcing the filling of the loose reference cache could
1455 * be expensive and (b) loose references anyway usually do not
1456 * have REF_KNOWS_PEELED.
1457 */
1458 if (flag & REF_ISPACKED) {
f361baeb 1459 struct ref_entry *r = get_packed_ref(refname);
9a489f3c 1460 if (r) {
f85354b5 1461 if (peel_entry(r, 0))
9a489f3c 1462 return -1;
593f1bb8 1463 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1464 return 0;
cf0adba7 1465 }
cf0adba7
JH
1466 }
1467
cb2ae1c4 1468 return peel_object(base, sha1);
cf0adba7
JH
1469}
1470
bc5fd6d3
MH
1471struct warn_if_dangling_data {
1472 FILE *fp;
1473 const char *refname;
1474 const char *msg_fmt;
1475};
1476
1477static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1478 int flags, void *cb_data)
1479{
1480 struct warn_if_dangling_data *d = cb_data;
1481 const char *resolves_to;
1482 unsigned char junk[20];
1483
1484 if (!(flags & REF_ISSYMREF))
1485 return 0;
1486
1487 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1488 if (!resolves_to || strcmp(resolves_to, d->refname))
1489 return 0;
1490
1491 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1492 fputc('\n', d->fp);
bc5fd6d3
MH
1493 return 0;
1494}
1495
1496void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1497{
1498 struct warn_if_dangling_data data;
1499
1500 data.fp = fp;
1501 data.refname = refname;
1502 data.msg_fmt = msg_fmt;
1503 for_each_rawref(warn_if_dangling_symref, &data);
1504}
1505
fcce1703 1506/*
624cac35
MH
1507 * Call fn for each reference in the specified submodule, omitting
1508 * references not in the containing_dir of base. fn is called for all
1509 * references, including broken ones. If fn ever returns a non-zero
fcce1703
MH
1510 * value, stop the iteration and return that value; otherwise, return
1511 * 0.
1512 */
624cac35
MH
1513static int do_for_each_entry(const char *submodule, const char *base,
1514 each_ref_entry_fn fn, void *cb_data)
8a65ff76 1515{
316b097a 1516 struct ref_cache *refs = get_ref_cache(submodule);
933ac036
MH
1517 struct ref_dir *packed_dir = get_packed_refs(refs);
1518 struct ref_dir *loose_dir = get_loose_refs(refs);
1519 int retval = 0;
1520
1521 if (base && *base) {
1522 packed_dir = find_containing_dir(packed_dir, base, 0);
1523 loose_dir = find_containing_dir(loose_dir, base, 0);
1524 }
1525
1526 if (packed_dir && loose_dir) {
1527 sort_ref_dir(packed_dir);
1528 sort_ref_dir(loose_dir);
624cac35
MH
1529 retval = do_for_each_entry_in_dirs(
1530 packed_dir, loose_dir, fn, cb_data);
933ac036
MH
1531 } else if (packed_dir) {
1532 sort_ref_dir(packed_dir);
624cac35
MH
1533 retval = do_for_each_entry_in_dir(
1534 packed_dir, 0, fn, cb_data);
933ac036
MH
1535 } else if (loose_dir) {
1536 sort_ref_dir(loose_dir);
624cac35
MH
1537 retval = do_for_each_entry_in_dir(
1538 loose_dir, 0, fn, cb_data);
933ac036
MH
1539 }
1540
1541 return retval;
8a65ff76
LT
1542}
1543
624cac35
MH
1544/*
1545 * Call fn for each reference in the specified submodule for which the
1546 * refname begins with base. If trim is non-zero, then trim that many
1547 * characters off the beginning of each refname before passing the
1548 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1549 * broken references in the iteration. If fn ever returns a non-zero
1550 * value, stop the iteration and return that value; otherwise, return
1551 * 0.
1552 */
1553static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
1554 int trim, int flags, void *cb_data)
1555{
1556 struct ref_entry_cb data;
1557 data.base = base;
1558 data.trim = trim;
1559 data.flags = flags;
1560 data.fn = fn;
1561 data.cb_data = cb_data;
1562
1563 return do_for_each_entry(submodule, base, do_one_ref, &data);
1564}
1565
0bad611b 1566static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1567{
1568 unsigned char sha1[20];
8da19775
JH
1569 int flag;
1570
0bad611b
HV
1571 if (submodule) {
1572 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1573 return fn("HEAD", sha1, 0, cb_data);
1574
1575 return 0;
1576 }
1577
c6893323 1578 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1579 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1580
2f34ba32 1581 return 0;
723c31fe
LT
1582}
1583
0bad611b
HV
1584int head_ref(each_ref_fn fn, void *cb_data)
1585{
1586 return do_head_ref(NULL, fn, cb_data);
1587}
1588
9ef6aeb0
HV
1589int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1590{
1591 return do_head_ref(submodule, fn, cb_data);
1592}
1593
cb5d709f 1594int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1595{
b3cfc406 1596 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
a62be77f
SE
1597}
1598
9ef6aeb0
HV
1599int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1600{
b3cfc406 1601 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
a62be77f
SE
1602}
1603
2a8177b6
CC
1604int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1605{
0bad611b 1606 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1607}
1608
9ef6aeb0
HV
1609int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1610 each_ref_fn fn, void *cb_data)
1611{
1612 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1613}
1614
cb5d709f 1615int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1616{
2a8177b6 1617 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1618}
1619
9ef6aeb0
HV
1620int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1621{
1622 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1623}
1624
cb5d709f 1625int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1626{
2a8177b6 1627 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1628}
1629
9ef6aeb0
HV
1630int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1631{
1632 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1633}
1634
cb5d709f 1635int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1636{
2a8177b6 1637 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1638}
1639
9ef6aeb0
HV
1640int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1641{
1642 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1643}
1644
29268700
CC
1645int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1646{
0bad611b 1647 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1648}
1649
a1bea2c1
JT
1650int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1651{
1652 struct strbuf buf = STRBUF_INIT;
1653 int ret = 0;
1654 unsigned char sha1[20];
1655 int flag;
1656
1657 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1658 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1659 ret = fn(buf.buf, sha1, flag, cb_data);
1660 strbuf_release(&buf);
1661
1662 return ret;
1663}
1664
1665int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1666{
1667 struct strbuf buf = STRBUF_INIT;
1668 int ret;
1669 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1670 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1671 strbuf_release(&buf);
1672 return ret;
1673}
1674
b09fe971
IL
1675int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1676 const char *prefix, void *cb_data)
d08bae7e
IL
1677{
1678 struct strbuf real_pattern = STRBUF_INIT;
1679 struct ref_filter filter;
d08bae7e
IL
1680 int ret;
1681
b09fe971 1682 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 1683 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1684 else if (prefix)
1685 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1686 strbuf_addstr(&real_pattern, pattern);
1687
894a9d33 1688 if (!has_glob_specials(pattern)) {
9517e6b8 1689 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1690 if (real_pattern.buf[real_pattern.len - 1] != '/')
1691 strbuf_addch(&real_pattern, '/');
1692 /* No need to check for '*', there is none. */
1693 strbuf_addch(&real_pattern, '*');
1694 }
1695
1696 filter.pattern = real_pattern.buf;
1697 filter.fn = fn;
1698 filter.cb_data = cb_data;
1699 ret = for_each_ref(filter_refs, &filter);
1700
1701 strbuf_release(&real_pattern);
1702 return ret;
1703}
1704
b09fe971
IL
1705int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1706{
1707 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1708}
1709
f8948e2f
JH
1710int for_each_rawref(each_ref_fn fn, void *cb_data)
1711{
b3cfc406 1712 return do_for_each_ref(NULL, "", fn, 0,
f8948e2f 1713 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1714}
1715
4577e483 1716const char *prettify_refname(const char *name)
a9c37a72 1717{
a9c37a72
DB
1718 return name + (
1719 !prefixcmp(name, "refs/heads/") ? 11 :
1720 !prefixcmp(name, "refs/tags/") ? 10 :
1721 !prefixcmp(name, "refs/remotes/") ? 13 :
1722 0);
1723}
1724
79803322
SP
1725const char *ref_rev_parse_rules[] = {
1726 "%.*s",
1727 "refs/%.*s",
1728 "refs/tags/%.*s",
1729 "refs/heads/%.*s",
1730 "refs/remotes/%.*s",
1731 "refs/remotes/%.*s/HEAD",
1732 NULL
1733};
1734
1735int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1736{
1737 const char **p;
1738 const int abbrev_name_len = strlen(abbrev_name);
1739
1740 for (p = rules; *p; p++) {
1741 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1742 return 1;
1743 }
1744 }
1745
1746 return 0;
1747}
1748
e5f38ec3 1749static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1750 const unsigned char *old_sha1, int mustexist)
1751{
c6893323 1752 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1753 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1754 unlock_ref(lock);
1755 return NULL;
1756 }
a89fccd2 1757 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1758 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1759 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1760 unlock_ref(lock);
1761 return NULL;
1762 }
1763 return lock;
1764}
1765
7155b727 1766static int remove_empty_directories(const char *file)
bc7127ef
JH
1767{
1768 /* we want to create a file but there is a directory there;
1769 * if that is an empty directory (or a directory that contains
1770 * only empty directories), remove them.
1771 */
7155b727
JS
1772 struct strbuf path;
1773 int result;
bc7127ef 1774
7155b727
JS
1775 strbuf_init(&path, 20);
1776 strbuf_addstr(&path, file);
1777
a0f4afbe 1778 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1779
1780 strbuf_release(&path);
1781
1782 return result;
bc7127ef
JH
1783}
1784
ff74f7f1
JH
1785/*
1786 * *string and *len will only be substituted, and *string returned (for
1787 * later free()ing) if the string passed in is a magic short-hand form
1788 * to name a branch.
1789 */
1790static char *substitute_branch_name(const char **string, int *len)
1791{
1792 struct strbuf buf = STRBUF_INIT;
1793 int ret = interpret_branch_name(*string, &buf);
1794
1795 if (ret == *len) {
1796 size_t size;
1797 *string = strbuf_detach(&buf, &size);
1798 *len = size;
1799 return (char *)*string;
1800 }
1801
1802 return NULL;
1803}
1804
1805int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1806{
1807 char *last_branch = substitute_branch_name(&str, &len);
1808 const char **p, *r;
1809 int refs_found = 0;
1810
1811 *ref = NULL;
1812 for (p = ref_rev_parse_rules; *p; p++) {
1813 char fullref[PATH_MAX];
1814 unsigned char sha1_from_ref[20];
1815 unsigned char *this_result;
1816 int flag;
1817
1818 this_result = refs_found ? sha1_from_ref : sha1;
1819 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1820 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1821 if (r) {
1822 if (!refs_found++)
1823 *ref = xstrdup(r);
1824 if (!warn_ambiguous_refs)
1825 break;
55956350 1826 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1827 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1828 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1829 warning("ignoring broken ref %s.", fullref);
1830 }
ff74f7f1
JH
1831 }
1832 free(last_branch);
1833 return refs_found;
1834}
1835
1836int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1837{
1838 char *last_branch = substitute_branch_name(&str, &len);
1839 const char **p;
1840 int logs_found = 0;
1841
1842 *log = NULL;
1843 for (p = ref_rev_parse_rules; *p; p++) {
1844 struct stat st;
1845 unsigned char hash[20];
1846 char path[PATH_MAX];
1847 const char *ref, *it;
1848
1849 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 1850 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
1851 if (!ref)
1852 continue;
1853 if (!stat(git_path("logs/%s", path), &st) &&
1854 S_ISREG(st.st_mode))
1855 it = path;
1856 else if (strcmp(ref, path) &&
1857 !stat(git_path("logs/%s", ref), &st) &&
1858 S_ISREG(st.st_mode))
1859 it = ref;
1860 else
1861 continue;
1862 if (!logs_found++) {
1863 *log = xstrdup(it);
1864 hashcpy(sha1, hash);
1865 }
1866 if (!warn_ambiguous_refs)
1867 break;
1868 }
1869 free(last_branch);
1870 return logs_found;
1871}
1872
dfefa935
MH
1873static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1874 const unsigned char *old_sha1,
1875 int flags, int *type_p)
4bd18c43 1876{
434cd0cd 1877 char *ref_file;
dfefa935 1878 const char *orig_refname = refname;
4bd18c43 1879 struct ref_lock *lock;
5cc3cef9 1880 int last_errno = 0;
acd3b9ec 1881 int type, lflags;
4431fcc4 1882 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1883 int missing = 0;
4bd18c43
SP
1884
1885 lock = xcalloc(1, sizeof(struct ref_lock));
1886 lock->lock_fd = -1;
1887
8d68493f 1888 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 1889 if (!refname && errno == EISDIR) {
bc7127ef
JH
1890 /* we are trying to lock foo but we used to
1891 * have foo/bar which now does not exist;
1892 * it is normal for the empty directory 'foo'
1893 * to remain.
1894 */
dfefa935 1895 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
1896 if (remove_empty_directories(ref_file)) {
1897 last_errno = errno;
dfefa935 1898 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
1899 goto error_return;
1900 }
8d68493f 1901 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 1902 }
68db31cc
SV
1903 if (type_p)
1904 *type_p = type;
dfefa935 1905 if (!refname) {
5cc3cef9 1906 last_errno = errno;
818f477c 1907 error("unable to resolve reference %s: %s",
dfefa935 1908 orig_refname, strerror(errno));
5cc3cef9 1909 goto error_return;
4bd18c43 1910 }
5bdd8d4a 1911 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1912 /* When the ref did not exist and we are creating it,
1913 * make sure there is no existing ref that is packed
1914 * whose name begins with our refname, nor a ref whose
1915 * name is a proper prefix of our refname.
1916 */
5bdd8d4a 1917 if (missing &&
316b097a 1918 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
f475e08e 1919 last_errno = ENOTDIR;
c976d415 1920 goto error_return;
f475e08e 1921 }
22a3844e 1922
c33d5174 1923 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1924
acd3b9ec
JH
1925 lflags = LOCK_DIE_ON_ERROR;
1926 if (flags & REF_NODEREF) {
dfefa935 1927 refname = orig_refname;
acd3b9ec
JH
1928 lflags |= LOCK_NODEREF;
1929 }
dfefa935
MH
1930 lock->ref_name = xstrdup(refname);
1931 lock->orig_ref_name = xstrdup(orig_refname);
1932 ref_file = git_path("%s", refname);
5bdd8d4a 1933 if (missing)
68db31cc
SV
1934 lock->force_write = 1;
1935 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1936 lock->force_write = 1;
4bd18c43 1937
5cc3cef9
JH
1938 if (safe_create_leading_directories(ref_file)) {
1939 last_errno = errno;
1940 error("unable to create directory for %s", ref_file);
1941 goto error_return;
1942 }
4bd18c43 1943
acd3b9ec 1944 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1945 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1946
1947 error_return:
1948 unlock_ref(lock);
1949 errno = last_errno;
1950 return NULL;
4bd18c43
SP
1951}
1952
dfefa935 1953struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 1954{
53cce84c 1955 char refpath[PATH_MAX];
dfefa935 1956 if (check_refname_format(refname, 0))
4bd18c43 1957 return NULL;
dfefa935 1958 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 1959 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1960}
1961
dfefa935
MH
1962struct ref_lock *lock_any_ref_for_update(const char *refname,
1963 const unsigned char *old_sha1, int flags)
4bd18c43 1964{
dfefa935 1965 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 1966 return NULL;
dfefa935 1967 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
c0277d15
JH
1968}
1969
fec3137f
MH
1970/*
1971 * Write an entry to the packed-refs file for the specified refname.
1972 * If peeled is non-NULL, write it as the entry's peeled value.
1973 */
1974static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
1975 unsigned char *peeled)
d66da478 1976{
d66da478
MH
1977 char line[PATH_MAX + 100];
1978 int len;
1979
fec3137f
MH
1980 len = snprintf(line, sizeof(line), "%s %s\n",
1981 sha1_to_hex(sha1), refname);
1982 /* this should not happen but just being defensive */
1983 if (len > sizeof(line))
1984 die("too long a refname '%s'", refname);
1985 write_or_die(fd, line, len);
1986
1987 if (peeled) {
1988 if (snprintf(line, sizeof(line), "^%s\n",
1989 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
1990 die("internal error");
1991 write_or_die(fd, line, PEELED_LINE_LENGTH);
1992 }
1993}
1994
32d462ce
MH
1995struct ref_to_prune {
1996 struct ref_to_prune *next;
1997 unsigned char sha1[20];
1998 char name[FLEX_ARRAY];
1999};
2000
2001struct pack_refs_cb_data {
2002 unsigned int flags;
2003 struct ref_to_prune *ref_to_prune;
0f29920f 2004 int fd;
32d462ce
MH
2005};
2006
12e77559 2007static int pack_one_ref(struct ref_entry *entry, void *cb_data)
32d462ce
MH
2008{
2009 struct pack_refs_cb_data *cb = cb_data;
f85354b5 2010 enum peel_status peel_status;
b2a8226d 2011 int is_tag_ref = !prefixcmp(entry->name, "refs/tags/");
32d462ce
MH
2012
2013 /* ALWAYS pack refs that were already packed or are tags */
12e77559
MH
2014 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref &&
2015 !(entry->flag & REF_ISPACKED))
32d462ce
MH
2016 return 0;
2017
b2a8226d
MH
2018 /* Do not pack symbolic or broken refs: */
2019 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2020 return 0;
2021
f85354b5 2022 peel_status = peel_entry(entry, 1);
0f29920f 2023 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
f85354b5
MH
2024 die("internal error peeling reference %s (%s)",
2025 entry->name, sha1_to_hex(entry->u.value.sha1));
0f29920f
MH
2026 write_packed_entry(cb->fd, entry->name, entry->u.value.sha1,
2027 peel_status == PEEL_PEELED ?
2028 entry->u.value.peeled : NULL);
32d462ce 2029
8d3725b9
MH
2030 /* If the ref was already packed, there is no need to prune it. */
2031 if ((cb->flags & PACK_REFS_PRUNE) && !(entry->flag & REF_ISPACKED)) {
12e77559 2032 int namelen = strlen(entry->name) + 1;
32d462ce 2033 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
12e77559
MH
2034 hashcpy(n->sha1, entry->u.value.sha1);
2035 strcpy(n->name, entry->name);
32d462ce
MH
2036 n->next = cb->ref_to_prune;
2037 cb->ref_to_prune = n;
2038 }
2039 return 0;
2040}
2041
2042/*
2043 * Remove empty parents, but spare refs/ and immediate subdirs.
2044 * Note: munges *name.
2045 */
2046static void try_remove_empty_parents(char *name)
2047{
2048 char *p, *q;
2049 int i;
2050 p = name;
2051 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2052 while (*p && *p != '/')
2053 p++;
2054 /* tolerate duplicate slashes; see check_refname_format() */
2055 while (*p == '/')
2056 p++;
2057 }
2058 for (q = p; *q; q++)
2059 ;
2060 while (1) {
2061 while (q > p && *q != '/')
2062 q--;
2063 while (q > p && *(q-1) == '/')
2064 q--;
2065 if (q == p)
2066 break;
2067 *q = '\0';
2068 if (rmdir(git_path("%s", name)))
2069 break;
2070 }
2071}
2072
2073/* make sure nobody touched the ref, and unlink */
2074static void prune_ref(struct ref_to_prune *r)
2075{
2076 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2077
2078 if (lock) {
2079 unlink_or_warn(git_path("%s", r->name));
2080 unlock_ref(lock);
2081 try_remove_empty_parents(r->name);
2082 }
2083}
2084
2085static void prune_refs(struct ref_to_prune *r)
2086{
2087 while (r) {
2088 prune_ref(r);
2089 r = r->next;
2090 }
2091}
2092
d9470330 2093static struct lock_file packlock;
32d462ce
MH
2094
2095int pack_refs(unsigned int flags)
2096{
32d462ce
MH
2097 struct pack_refs_cb_data cbdata;
2098
2099 memset(&cbdata, 0, sizeof(cbdata));
2100 cbdata.flags = flags;
2101
0f29920f
MH
2102 cbdata.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"),
2103 LOCK_DIE_ON_ERROR);
32d462ce 2104
0f29920f 2105 write_or_die(cbdata.fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
32d462ce 2106
12e77559 2107 do_for_each_entry(NULL, "", pack_one_ref, &cbdata);
d9470330 2108 if (commit_lock_file(&packlock) < 0)
32d462ce
MH
2109 die_errno("unable to overwrite old ref-pack file");
2110 prune_refs(cbdata.ref_to_prune);
2111 return 0;
2112}
2113
fec3137f
MH
2114static int repack_ref_fn(struct ref_entry *entry, void *cb_data)
2115{
2116 int *fd = cb_data;
2117 enum peel_status peel_status;
2118
ab292bc4
MH
2119 if (entry->flag & REF_ISBROKEN) {
2120 /* This shouldn't happen to packed refs. */
2121 error("%s is broken!", entry->name);
2122 return 0;
2123 }
2124 if (!has_sha1_file(entry->u.value.sha1)) {
2125 unsigned char sha1[20];
2126 int flags;
2127
2128 if (read_ref_full(entry->name, sha1, 0, &flags))
2129 /* We should at least have found the packed ref. */
2130 die("Internal error");
2131 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED))
2132 /*
2133 * This packed reference is overridden by a
2134 * loose reference, so it is OK that its value
2135 * is no longer valid; for example, it might
2136 * refer to an object that has been garbage
2137 * collected. For this purpose we don't even
2138 * care whether the loose reference itself is
2139 * invalid, broken, symbolic, etc. Silently
2140 * omit the packed reference from the output.
2141 */
2142 return 0;
2143 /*
2144 * There is no overriding loose reference, so the fact
2145 * that this reference doesn't refer to a valid object
2146 * indicates some kind of repository corruption.
2147 * Report the problem, then omit the reference from
2148 * the output.
2149 */
2150 error("%s does not point to a valid object!", entry->name);
2151 return 0;
2152 }
2153
f85354b5 2154 peel_status = peel_entry(entry, 0);
fec3137f
MH
2155 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2156 peel_status == PEEL_PEELED ?
2157 entry->u.value.peeled : NULL);
694b7a19 2158
d66da478
MH
2159 return 0;
2160}
2161
c0277d15
JH
2162static int repack_without_ref(const char *refname)
2163{
506a760d 2164 int fd;
b3f1280e 2165 struct ref_cache *refs = get_ref_cache(NULL);
7618fd80
MH
2166 struct ref_dir *packed;
2167
2168 if (!get_packed_ref(refname))
2169 return 0; /* refname does not exist in packed refs */
2170
506a760d
MH
2171 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
2172 if (fd < 0) {
1b018fd9 2173 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 2174 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 2175 }
b3f1280e
JK
2176 clear_packed_ref_cache(refs);
2177 packed = get_packed_refs(refs);
506a760d
MH
2178 /* Remove refname from the cache. */
2179 if (remove_entry(packed, refname) == -1) {
2180 /*
2181 * The packed entry disappeared while we were
2182 * acquiring the lock.
2183 */
2184 rollback_lock_file(&packlock);
2185 return 0;
2186 }
694b7a19 2187 write_or_die(fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
506a760d 2188 do_for_each_entry_in_dir(packed, 0, repack_ref_fn, &fd);
c0277d15
JH
2189 return commit_lock_file(&packlock);
2190}
2191
eca35a25 2192int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
2193{
2194 struct ref_lock *lock;
eca35a25 2195 int err, i = 0, ret = 0, flag = 0;
c0277d15 2196
547d058f 2197 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
2198 if (!lock)
2199 return 1;
045a476f 2200 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 2201 /* loose */
547d058f
RS
2202 i = strlen(lock->lk->filename) - 5; /* .lock */
2203 lock->lk->filename[i] = 0;
2204 err = unlink_or_warn(lock->lk->filename);
691f1a28 2205 if (err && errno != ENOENT)
c0277d15 2206 ret = 1;
691f1a28 2207
547d058f 2208 lock->lk->filename[i] = '.';
c0277d15
JH
2209 }
2210 /* removing the loose one could have resurrected an earlier
2211 * packed one. Also, if it was not loose we need to repack
2212 * without it.
2213 */
b274a714 2214 ret |= repack_without_ref(lock->ref_name);
c0277d15 2215
691f1a28 2216 unlink_or_warn(git_path("logs/%s", lock->ref_name));
506a760d 2217 clear_loose_ref_cache(get_ref_cache(NULL));
c0277d15
JH
2218 unlock_ref(lock);
2219 return ret;
4bd18c43
SP
2220}
2221
765c2258
PH
2222/*
2223 * People using contrib's git-new-workdir have .git/logs/refs ->
2224 * /some/other/path/.git/logs/refs, and that may live on another device.
2225 *
2226 * IOW, to avoid cross device rename errors, the temporary renamed log must
2227 * live into logs/refs.
2228 */
2229#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2230
dfefa935 2231int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 2232{
c976d415
LH
2233 unsigned char sha1[20], orig_sha1[20];
2234 int flag = 0, logmoved = 0;
2235 struct ref_lock *lock;
c976d415 2236 struct stat loginfo;
dfefa935 2237 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 2238 const char *symref = NULL;
316b097a 2239 struct ref_cache *refs = get_ref_cache(NULL);
c976d415 2240
450d4c0f 2241 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 2242 return error("reflog for %s is a symlink", oldrefname);
c976d415 2243
8d68493f 2244 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 2245 if (flag & REF_ISSYMREF)
fa58186c 2246 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 2247 oldrefname);
eca35a25 2248 if (!symref)
dfefa935 2249 return error("refname %s not found", oldrefname);
c976d415 2250
316b097a 2251 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
c976d415
LH
2252 return 1;
2253
316b097a 2254 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
c976d415
LH
2255 return 1;
2256
dfefa935 2257 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 2258 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 2259 oldrefname, strerror(errno));
c976d415 2260
dfefa935
MH
2261 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2262 error("unable to delete old %s", oldrefname);
c976d415
LH
2263 goto rollback;
2264 }
2265
dfefa935
MH
2266 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2267 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 2268 if (errno==EISDIR) {
dfefa935
MH
2269 if (remove_empty_directories(git_path("%s", newrefname))) {
2270 error("Directory not empty: %s", newrefname);
c976d415
LH
2271 goto rollback;
2272 }
2273 } else {
dfefa935 2274 error("unable to delete existing %s", newrefname);
c976d415
LH
2275 goto rollback;
2276 }
2277 }
2278
dfefa935
MH
2279 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2280 error("unable to create directory for %s", newrefname);
c976d415
LH
2281 goto rollback;
2282 }
2283
2284 retry:
dfefa935 2285 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
d9e74d57
JR
2286 if (errno==EISDIR || errno==ENOTDIR) {
2287 /*
2288 * rename(a, b) when b is an existing
2289 * directory ought to result in ISDIR, but
2290 * Solaris 5.8 gives ENOTDIR. Sheesh.
2291 */
dfefa935
MH
2292 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2293 error("Directory not empty: logs/%s", newrefname);
c976d415
LH
2294 goto rollback;
2295 }
2296 goto retry;
2297 } else {
765c2258 2298 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
dfefa935 2299 newrefname, strerror(errno));
c976d415
LH
2300 goto rollback;
2301 }
2302 }
2303 logmoved = log;
2304
dfefa935 2305 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2306 if (!lock) {
dfefa935 2307 error("unable to lock %s for update", newrefname);
c976d415
LH
2308 goto rollback;
2309 }
c976d415
LH
2310 lock->force_write = 1;
2311 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2312 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2313 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2314 goto rollback;
2315 }
2316
2317 return 0;
2318
2319 rollback:
dfefa935 2320 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2321 if (!lock) {
dfefa935 2322 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2323 goto rollbacklog;
2324 }
2325
2326 lock->force_write = 1;
2327 flag = log_all_ref_updates;
2328 log_all_ref_updates = 0;
2329 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2330 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2331 log_all_ref_updates = flag;
2332
2333 rollbacklog:
dfefa935 2334 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2335 error("unable to restore logfile %s from %s: %s",
dfefa935 2336 oldrefname, newrefname, strerror(errno));
c976d415 2337 if (!logmoved && log &&
dfefa935 2338 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2339 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2340 oldrefname, strerror(errno));
c976d415
LH
2341
2342 return 1;
2343}
2344
435fc852 2345int close_ref(struct ref_lock *lock)
b531394d
BC
2346{
2347 if (close_lock_file(lock->lk))
2348 return -1;
2349 lock->lock_fd = -1;
2350 return 0;
2351}
2352
435fc852 2353int commit_ref(struct ref_lock *lock)
b531394d
BC
2354{
2355 if (commit_lock_file(lock->lk))
2356 return -1;
2357 lock->lock_fd = -1;
2358 return 0;
2359}
2360
e5f38ec3 2361void unlock_ref(struct ref_lock *lock)
4bd18c43 2362{
4ed7cd3a
BC
2363 /* Do not free lock->lk -- atexit() still looks at them */
2364 if (lock->lk)
2365 rollback_lock_file(lock->lk);
434cd0cd 2366 free(lock->ref_name);
1655707c 2367 free(lock->orig_ref_name);
4bd18c43
SP
2368 free(lock);
2369}
2370
0ec29a47
JH
2371/*
2372 * copy the reflog message msg to buf, which has been allocated sufficiently
2373 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2374 * because reflog file is one line per entry.
2375 */
2376static int copy_msg(char *buf, const char *msg)
2377{
2378 char *cp = buf;
2379 char c;
2380 int wasspace = 1;
2381
2382 *cp++ = '\t';
2383 while ((c = *msg++)) {
2384 if (wasspace && isspace(c))
2385 continue;
2386 wasspace = isspace(c);
2387 if (wasspace)
2388 c = ' ';
2389 *cp++ = c;
2390 }
2391 while (buf < cp && isspace(cp[-1]))
2392 cp--;
2393 *cp++ = '\n';
2394 return cp - buf;
2395}
2396
dfefa935 2397int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2398{
859c3017 2399 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2400
dfefa935 2401 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2402 if (log_all_ref_updates &&
dfefa935
MH
2403 (!prefixcmp(refname, "refs/heads/") ||
2404 !prefixcmp(refname, "refs/remotes/") ||
2405 !prefixcmp(refname, "refs/notes/") ||
2406 !strcmp(refname, "HEAD"))) {
157aaea5 2407 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2408 return error("unable to create directory for %s",
157aaea5 2409 logfile);
6de08ae6
SP
2410 oflags |= O_CREAT;
2411 }
2412
157aaea5 2413 logfd = open(logfile, oflags, 0666);
6de08ae6 2414 if (logfd < 0) {
1974bf62 2415 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2416 return 0;
3b463c3f
JH
2417
2418 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2419 if (remove_empty_directories(logfile)) {
3b463c3f 2420 return error("There are still logs under '%s'",
157aaea5 2421 logfile);
3b463c3f 2422 }
157aaea5 2423 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2424 }
2425
2426 if (logfd < 0)
2427 return error("Unable to append to %s: %s",
157aaea5 2428 logfile, strerror(errno));
6de08ae6
SP
2429 }
2430
157aaea5 2431 adjust_shared_perm(logfile);
859c3017
EM
2432 close(logfd);
2433 return 0;
2434}
443b92b6 2435
dfefa935 2436static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2437 const unsigned char *new_sha1, const char *msg)
2438{
2439 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2440 unsigned maxlen, len;
2441 int msglen;
157aaea5 2442 char log_file[PATH_MAX];
859c3017
EM
2443 char *logrec;
2444 const char *committer;
2445
2446 if (log_all_ref_updates < 0)
2447 log_all_ref_updates = !is_bare_repository();
2448
dfefa935 2449 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2450 if (result)
2451 return result;
2452
2453 logfd = open(log_file, oflags);
2454 if (logfd < 0)
2455 return 0;
0ec29a47 2456 msglen = msg ? strlen(msg) : 0;
774751a8 2457 committer = git_committer_info(0);
8ac65937
JH
2458 maxlen = strlen(committer) + msglen + 100;
2459 logrec = xmalloc(maxlen);
2460 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2461 sha1_to_hex(old_sha1),
2462 sha1_to_hex(new_sha1),
8ac65937
JH
2463 committer);
2464 if (msglen)
0ec29a47 2465 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2466 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2467 free(logrec);
91c8d590 2468 if (close(logfd) != 0 || written != len)
9a13f0b7 2469 return error("Unable to append to %s", log_file);
6de08ae6
SP
2470 return 0;
2471}
2472
c3b0dec5
LT
2473static int is_branch(const char *refname)
2474{
2475 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2476}
2477
4bd18c43
SP
2478int write_ref_sha1(struct ref_lock *lock,
2479 const unsigned char *sha1, const char *logmsg)
2480{
2481 static char term = '\n';
c3b0dec5 2482 struct object *o;
4bd18c43
SP
2483
2484 if (!lock)
95fc7512 2485 return -1;
a89fccd2 2486 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2487 unlock_ref(lock);
2488 return 0;
95fc7512 2489 }
c3b0dec5
LT
2490 o = parse_object(sha1);
2491 if (!o) {
7be8b3ba 2492 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2493 lock->ref_name, sha1_to_hex(sha1));
2494 unlock_ref(lock);
2495 return -1;
2496 }
2497 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2498 error("Trying to write non-commit object %s to branch %s",
2499 sha1_to_hex(sha1), lock->ref_name);
2500 unlock_ref(lock);
2501 return -1;
2502 }
93822c22
AW
2503 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2504 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2505 || close_ref(lock) < 0) {
c33d5174 2506 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2507 unlock_ref(lock);
2508 return -1;
2509 }
8bf90dc9 2510 clear_loose_ref_cache(get_ref_cache(NULL));
bd104db1
NP
2511 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2512 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2513 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2514 unlock_ref(lock);
2515 return -1;
2516 }
605fac8b
NP
2517 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2518 /*
2519 * Special hack: If a branch is updated directly and HEAD
2520 * points to it (may happen on the remote side of a push
2521 * for example) then logically the HEAD reflog should be
2522 * updated too.
2523 * A generic solution implies reverse symref information,
2524 * but finding all symrefs pointing to the given branch
2525 * would be rather costly for this rare event (the direct
2526 * update of a branch) to be worth it. So let's cheat and
2527 * check with HEAD only which should cover 99% of all usage
2528 * scenarios (even 100% of the default ones).
2529 */
2530 unsigned char head_sha1[20];
2531 int head_flag;
2532 const char *head_ref;
8cad4744 2533 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2534 if (head_ref && (head_flag & REF_ISSYMREF) &&
2535 !strcmp(head_ref, lock->ref_name))
2536 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2537 }
b531394d 2538 if (commit_ref(lock)) {
434cd0cd 2539 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2540 unlock_ref(lock);
2541 return -1;
2542 }
4bd18c43
SP
2543 unlock_ref(lock);
2544 return 0;
95fc7512 2545}
d556fae2 2546
8b5157e4
NP
2547int create_symref(const char *ref_target, const char *refs_heads_master,
2548 const char *logmsg)
41b625b0
NP
2549{
2550 const char *lockpath;
2551 char ref[1000];
2552 int fd, len, written;
a4f34cbb 2553 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2554 unsigned char old_sha1[20], new_sha1[20];
2555
2556 if (logmsg && read_ref(ref_target, old_sha1))
2557 hashclr(old_sha1);
41b625b0 2558
d48744d1
JH
2559 if (safe_create_leading_directories(git_HEAD) < 0)
2560 return error("unable to create directory for %s", git_HEAD);
2561
41b625b0
NP
2562#ifndef NO_SYMLINK_HEAD
2563 if (prefer_symlink_refs) {
2564 unlink(git_HEAD);
2565 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2566 goto done;
41b625b0
NP
2567 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2568 }
2569#endif
2570
2571 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2572 if (sizeof(ref) <= len) {
2573 error("refname too long: %s", refs_heads_master);
47fc52e2 2574 goto error_free_return;
41b625b0
NP
2575 }
2576 lockpath = mkpath("%s.lock", git_HEAD);
2577 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2578 if (fd < 0) {
2579 error("Unable to open %s for writing", lockpath);
47fc52e2 2580 goto error_free_return;
41b625b0
NP
2581 }
2582 written = write_in_full(fd, ref, len);
91c8d590 2583 if (close(fd) != 0 || written != len) {
41b625b0 2584 error("Unable to write to %s", lockpath);
47fc52e2 2585 goto error_unlink_return;
41b625b0
NP
2586 }
2587 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2588 error("Unable to create %s", git_HEAD);
47fc52e2 2589 goto error_unlink_return;
41b625b0
NP
2590 }
2591 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2592 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2593 error_unlink_return:
691f1a28 2594 unlink_or_warn(lockpath);
47fc52e2
JH
2595 error_free_return:
2596 free(git_HEAD);
2597 return -1;
41b625b0 2598 }
8b5157e4 2599
ee96d11b 2600#ifndef NO_SYMLINK_HEAD
8b5157e4 2601 done:
ee96d11b 2602#endif
8b5157e4
NP
2603 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2604 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2605
47fc52e2 2606 free(git_HEAD);
41b625b0
NP
2607 return 0;
2608}
2609
16d7cc90
JH
2610static char *ref_msg(const char *line, const char *endp)
2611{
2612 const char *ep;
16d7cc90 2613 line += 82;
182af834
PH
2614 ep = memchr(line, '\n', endp - line);
2615 if (!ep)
2616 ep = endp;
2617 return xmemdupz(line, ep - line);
16d7cc90
JH
2618}
2619
dfefa935
MH
2620int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2621 unsigned char *sha1, char **msg,
2622 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2623{
e5229042 2624 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2625 char *tz_c;
e29cb53a 2626 int logfd, tz, reccnt = 0;
d556fae2
SP
2627 struct stat st;
2628 unsigned long date;
e5229042 2629 unsigned char logged_sha1[20];
cb48cb58 2630 void *log_mapped;
dc49cd76 2631 size_t mapsz;
d556fae2 2632
dfefa935 2633 logfile = git_path("logs/%s", refname);
d556fae2
SP
2634 logfd = open(logfile, O_RDONLY, 0);
2635 if (logfd < 0)
d824cbba 2636 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2637 fstat(logfd, &st);
2638 if (!st.st_size)
2639 die("Log %s is empty.", logfile);
dc49cd76
SP
2640 mapsz = xsize_t(st.st_size);
2641 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2642 logdata = log_mapped;
d556fae2
SP
2643 close(logfd);
2644
e5229042 2645 lastrec = NULL;
d556fae2
SP
2646 rec = logend = logdata + st.st_size;
2647 while (logdata < rec) {
e29cb53a 2648 reccnt++;
d556fae2
SP
2649 if (logdata < rec && *(rec-1) == '\n')
2650 rec--;
e5229042
SP
2651 lastgt = NULL;
2652 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2653 rec--;
e5229042
SP
2654 if (*rec == '>')
2655 lastgt = rec;
2656 }
2657 if (!lastgt)
d556fae2 2658 die("Log %s is corrupt.", logfile);
e5229042 2659 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2660 if (date <= at_time || cnt == 0) {
76a44c5c 2661 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2662 if (msg)
2663 *msg = ref_msg(rec, logend);
2664 if (cutoff_time)
2665 *cutoff_time = date;
2666 if (cutoff_tz)
2667 *cutoff_tz = tz;
2668 if (cutoff_cnt)
76a44c5c 2669 *cutoff_cnt = reccnt - 1;
e5229042
SP
2670 if (lastrec) {
2671 if (get_sha1_hex(lastrec, logged_sha1))
2672 die("Log %s is corrupt.", logfile);
2673 if (get_sha1_hex(rec + 41, sha1))
2674 die("Log %s is corrupt.", logfile);
a89fccd2 2675 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2676 warning("Log %s has gap after %s.",
73013afd 2677 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 2678 }
e5f38ec3
JH
2679 }
2680 else if (date == at_time) {
e5229042
SP
2681 if (get_sha1_hex(rec + 41, sha1))
2682 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
2683 }
2684 else {
e5229042
SP
2685 if (get_sha1_hex(rec + 41, logged_sha1))
2686 die("Log %s is corrupt.", logfile);
a89fccd2 2687 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2688 warning("Log %s unexpectedly ended on %s.",
73013afd 2689 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
2690 }
2691 }
dc49cd76 2692 munmap(log_mapped, mapsz);
d556fae2
SP
2693 return 0;
2694 }
e5229042 2695 lastrec = rec;
ab2a1a32
JH
2696 if (cnt > 0)
2697 cnt--;
d556fae2
SP
2698 }
2699
e5229042
SP
2700 rec = logdata;
2701 while (rec < logend && *rec != '>' && *rec != '\n')
2702 rec++;
2703 if (rec == logend || *rec == '\n')
d556fae2 2704 die("Log %s is corrupt.", logfile);
e5229042 2705 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
2706 tz = strtoul(tz_c, NULL, 10);
2707 if (get_sha1_hex(logdata, sha1))
2708 die("Log %s is corrupt.", logfile);
d1a4489a
JK
2709 if (is_null_sha1(sha1)) {
2710 if (get_sha1_hex(logdata + 41, sha1))
2711 die("Log %s is corrupt.", logfile);
2712 }
16d7cc90
JH
2713 if (msg)
2714 *msg = ref_msg(logdata, logend);
dc49cd76 2715 munmap(log_mapped, mapsz);
16d7cc90
JH
2716
2717 if (cutoff_time)
2718 *cutoff_time = date;
2719 if (cutoff_tz)
2720 *cutoff_tz = tz;
2721 if (cutoff_cnt)
2722 *cutoff_cnt = reccnt;
2723 return 1;
d556fae2 2724}
2ff81662 2725
dfefa935 2726int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
2727{
2728 const char *logfile;
2729 FILE *logfp;
8ca78803 2730 struct strbuf sb = STRBUF_INIT;
2266bf27 2731 int ret = 0;
2ff81662 2732
dfefa935 2733 logfile = git_path("logs/%s", refname);
2ff81662
JH
2734 logfp = fopen(logfile, "r");
2735 if (!logfp)
883d60fa 2736 return -1;
101d15e0
JH
2737
2738 if (ofs) {
2739 struct stat statbuf;
2740 if (fstat(fileno(logfp), &statbuf) ||
2741 statbuf.st_size < ofs ||
2742 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 2743 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 2744 fclose(logfp);
8ca78803 2745 strbuf_release(&sb);
101d15e0 2746 return -1;
9d33f7c2 2747 }
101d15e0
JH
2748 }
2749
8ca78803 2750 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 2751 unsigned char osha1[20], nsha1[20];
883d60fa
JS
2752 char *email_end, *message;
2753 unsigned long timestamp;
8ca78803 2754 int tz;
2ff81662
JH
2755
2756 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
2757 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
2758 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
2759 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
2760 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
2761 email_end[1] != ' ' ||
2762 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2763 !message || message[0] != ' ' ||
2764 (message[1] != '+' && message[1] != '-') ||
2765 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 2766 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 2767 continue; /* corrupt? */
883d60fa
JS
2768 email_end[1] = '\0';
2769 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
2770 if (message[6] != '\t')
2771 message += 6;
2772 else
2773 message += 7;
8ca78803
RS
2774 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
2775 cb_data);
883d60fa 2776 if (ret)
2266bf27 2777 break;
2ff81662
JH
2778 }
2779 fclose(logfp);
8ca78803 2780 strbuf_release(&sb);
2266bf27 2781 return ret;
2ff81662 2782}
e29cb53a 2783
dfefa935 2784int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 2785{
dfefa935 2786 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
101d15e0
JH
2787}
2788
989c0e5d
MH
2789/*
2790 * Call fn for each reflog in the namespace indicated by name. name
2791 * must be empty or end with '/'. Name will be used as a scratch
2792 * space, but its contents will be restored before return.
2793 */
2794static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 2795{
989c0e5d 2796 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 2797 int retval = 0;
93c603fc 2798 struct dirent *de;
989c0e5d 2799 int oldlen = name->len;
eb8381c8 2800
93c603fc 2801 if (!d)
989c0e5d 2802 return name->len ? errno : 0;
eb8381c8 2803
93c603fc
MH
2804 while ((de = readdir(d)) != NULL) {
2805 struct stat st;
eb8381c8 2806
93c603fc
MH
2807 if (de->d_name[0] == '.')
2808 continue;
93c603fc
MH
2809 if (has_extension(de->d_name, ".lock"))
2810 continue;
989c0e5d
MH
2811 strbuf_addstr(name, de->d_name);
2812 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2813 ; /* silently ignore */
93c603fc 2814 } else {
eb8381c8 2815 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
2816 strbuf_addch(name, '/');
2817 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
2818 } else {
2819 unsigned char sha1[20];
989c0e5d
MH
2820 if (read_ref_full(name->buf, sha1, 0, NULL))
2821 retval = error("bad ref for %s", name->buf);
eb8381c8 2822 else
989c0e5d 2823 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
2824 }
2825 if (retval)
2826 break;
2827 }
989c0e5d 2828 strbuf_setlen(name, oldlen);
eb8381c8 2829 }
93c603fc 2830 closedir(d);
eb8381c8
NP
2831 return retval;
2832}
2833
2834int for_each_reflog(each_ref_fn fn, void *cb_data)
2835{
989c0e5d
MH
2836 int retval;
2837 struct strbuf name;
2838 strbuf_init(&name, PATH_MAX);
2839 retval = do_for_each_reflog(&name, fn, cb_data);
2840 strbuf_release(&name);
2841 return retval;
eb8381c8 2842}
3d9f037c
CR
2843
2844int update_ref(const char *action, const char *refname,
2845 const unsigned char *sha1, const unsigned char *oldval,
2846 int flags, enum action_on_err onerr)
2847{
2848 static struct ref_lock *lock;
2849 lock = lock_any_ref_for_update(refname, oldval, flags);
2850 if (!lock) {
2851 const char *str = "Cannot lock the ref '%s'.";
2852 switch (onerr) {
2853 case MSG_ON_ERR: error(str, refname); break;
2854 case DIE_ON_ERR: die(str, refname); break;
2855 case QUIET_ON_ERR: break;
2856 }
2857 return 1;
2858 }
2859 if (write_ref_sha1(lock, sha1, action) < 0) {
2860 const char *str = "Cannot update the ref '%s'.";
2861 switch (onerr) {
2862 case MSG_ON_ERR: error(str, refname); break;
2863 case DIE_ON_ERR: die(str, refname); break;
2864 case QUIET_ON_ERR: break;
2865 }
2866 return 1;
2867 }
2868 return 0;
2869}
cda69f48 2870
5483f799 2871struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
2872{
2873 for ( ; list; list = list->next)
2874 if (!strcmp(list->name, name))
5483f799 2875 return (struct ref *)list;
cda69f48
JK
2876 return NULL;
2877}
7c2b3029
JK
2878
2879/*
2880 * generate a format suitable for scanf from a ref_rev_parse_rules
2881 * rule, that is replace the "%.*s" spec with a "%s" spec
2882 */
2883static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2884{
2885 char *spec;
2886
2887 spec = strstr(rule, "%.*s");
2888 if (!spec || strstr(spec + 4, "%.*s"))
2889 die("invalid rule in ref_rev_parse_rules: %s", rule);
2890
2891 /* copy all until spec */
2892 strncpy(scanf_fmt, rule, spec - rule);
2893 scanf_fmt[spec - rule] = '\0';
2894 /* copy new spec */
2895 strcat(scanf_fmt, "%s");
2896 /* copy remaining rule */
2897 strcat(scanf_fmt, spec + 4);
2898
2899 return;
2900}
2901
dfefa935 2902char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
2903{
2904 int i;
2905 static char **scanf_fmts;
2906 static int nr_rules;
2907 char *short_name;
2908
2909 /* pre generate scanf formats from ref_rev_parse_rules[] */
2910 if (!nr_rules) {
2911 size_t total_len = 0;
2912
2913 /* the rule list is NULL terminated, count them first */
2914 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2915 /* no +1 because strlen("%s") < strlen("%.*s") */
2916 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2917
2918 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2919
2920 total_len = 0;
2921 for (i = 0; i < nr_rules; i++) {
2922 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2923 + total_len;
2924 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2925 total_len += strlen(ref_rev_parse_rules[i]);
2926 }
2927 }
2928
2929 /* bail out if there are no rules */
2930 if (!nr_rules)
dfefa935 2931 return xstrdup(refname);
7c2b3029 2932
dfefa935
MH
2933 /* buffer for scanf result, at most refname must fit */
2934 short_name = xstrdup(refname);
7c2b3029
JK
2935
2936 /* skip first rule, it will always match */
2937 for (i = nr_rules - 1; i > 0 ; --i) {
2938 int j;
6e7b3309 2939 int rules_to_fail = i;
7c2b3029
JK
2940 int short_name_len;
2941
dfefa935 2942 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
2943 continue;
2944
2945 short_name_len = strlen(short_name);
2946
6e7b3309
BW
2947 /*
2948 * in strict mode, all (except the matched one) rules
2949 * must fail to resolve to a valid non-ambiguous ref
2950 */
2951 if (strict)
2952 rules_to_fail = nr_rules;
2953
7c2b3029
JK
2954 /*
2955 * check if the short name resolves to a valid ref,
2956 * but use only rules prior to the matched one
2957 */
6e7b3309 2958 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 2959 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
2960 char refname[PATH_MAX];
2961
6e7b3309
BW
2962 /* skip matched rule */
2963 if (i == j)
2964 continue;
2965
7c2b3029
JK
2966 /*
2967 * the short name is ambiguous, if it resolves
2968 * (with this previous rule) to a valid ref
2969 * read_ref() returns 0 on success
2970 */
2971 mksnpath(refname, sizeof(refname),
2972 rule, short_name_len, short_name);
c6893323 2973 if (ref_exists(refname))
7c2b3029
JK
2974 break;
2975 }
2976
2977 /*
2978 * short name is non-ambiguous if all previous rules
2979 * haven't resolved to a valid ref
2980 */
6e7b3309 2981 if (j == rules_to_fail)
7c2b3029
JK
2982 return short_name;
2983 }
2984
2985 free(short_name);
dfefa935 2986 return xstrdup(refname);
7c2b3029 2987}