refs: inline function do_not_prune()
[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
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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
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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
MH
1399/*
1400 * Peel the entry (if possible) and return its new peel_status.
694b7a19
MH
1401 *
1402 * It is OK to call this function with a packed reference entry that
1403 * might be stale and might even refer to an object that has since
1404 * been garbage-collected. In such a case, if the entry has
1405 * REF_KNOWS_PEELED then leave the status unchanged and return
1406 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
9a489f3c
MH
1407 */
1408static enum peel_status peel_entry(struct ref_entry *entry)
1409{
1410 enum peel_status status;
1411
1412 if (entry->flag & REF_KNOWS_PEELED)
1413 return is_null_sha1(entry->u.value.peeled) ?
1414 PEEL_NON_TAG : PEEL_PEELED;
1415 if (entry->flag & REF_ISBROKEN)
1416 return PEEL_BROKEN;
1417 if (entry->flag & REF_ISSYMREF)
1418 return PEEL_IS_SYMREF;
1419
1420 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1421 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1422 entry->flag |= REF_KNOWS_PEELED;
1423 return status;
1424}
1425
dfefa935 1426int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1427{
1428 int flag;
1429 unsigned char base[20];
cf0adba7 1430
dfefa935 1431 if (current_ref && (current_ref->name == refname
9a489f3c
MH
1432 || !strcmp(current_ref->name, refname))) {
1433 if (peel_entry(current_ref))
1434 return -1;
1435 hashcpy(sha1, current_ref->u.value.peeled);
1436 return 0;
0ae91be0
SP
1437 }
1438
dfefa935 1439 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1440 return -1;
1441
9a489f3c
MH
1442 /*
1443 * If the reference is packed, read its ref_entry from the
1444 * cache in the hope that we already know its peeled value.
1445 * We only try this optimization on packed references because
1446 * (a) forcing the filling of the loose reference cache could
1447 * be expensive and (b) loose references anyway usually do not
1448 * have REF_KNOWS_PEELED.
1449 */
1450 if (flag & REF_ISPACKED) {
f361baeb 1451 struct ref_entry *r = get_packed_ref(refname);
9a489f3c
MH
1452 if (r) {
1453 if (peel_entry(r))
1454 return -1;
593f1bb8 1455 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1456 return 0;
cf0adba7 1457 }
cf0adba7
JH
1458 }
1459
cb2ae1c4 1460 return peel_object(base, sha1);
cf0adba7
JH
1461}
1462
bc5fd6d3
MH
1463struct warn_if_dangling_data {
1464 FILE *fp;
1465 const char *refname;
1466 const char *msg_fmt;
1467};
1468
1469static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1470 int flags, void *cb_data)
1471{
1472 struct warn_if_dangling_data *d = cb_data;
1473 const char *resolves_to;
1474 unsigned char junk[20];
1475
1476 if (!(flags & REF_ISSYMREF))
1477 return 0;
1478
1479 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1480 if (!resolves_to || strcmp(resolves_to, d->refname))
1481 return 0;
1482
1483 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1484 fputc('\n', d->fp);
bc5fd6d3
MH
1485 return 0;
1486}
1487
1488void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1489{
1490 struct warn_if_dangling_data data;
1491
1492 data.fp = fp;
1493 data.refname = refname;
1494 data.msg_fmt = msg_fmt;
1495 for_each_rawref(warn_if_dangling_symref, &data);
1496}
1497
fcce1703 1498/*
624cac35
MH
1499 * Call fn for each reference in the specified submodule, omitting
1500 * references not in the containing_dir of base. fn is called for all
1501 * references, including broken ones. If fn ever returns a non-zero
fcce1703
MH
1502 * value, stop the iteration and return that value; otherwise, return
1503 * 0.
1504 */
624cac35
MH
1505static int do_for_each_entry(const char *submodule, const char *base,
1506 each_ref_entry_fn fn, void *cb_data)
8a65ff76 1507{
316b097a 1508 struct ref_cache *refs = get_ref_cache(submodule);
933ac036
MH
1509 struct ref_dir *packed_dir = get_packed_refs(refs);
1510 struct ref_dir *loose_dir = get_loose_refs(refs);
1511 int retval = 0;
1512
1513 if (base && *base) {
1514 packed_dir = find_containing_dir(packed_dir, base, 0);
1515 loose_dir = find_containing_dir(loose_dir, base, 0);
1516 }
1517
1518 if (packed_dir && loose_dir) {
1519 sort_ref_dir(packed_dir);
1520 sort_ref_dir(loose_dir);
624cac35
MH
1521 retval = do_for_each_entry_in_dirs(
1522 packed_dir, loose_dir, fn, cb_data);
933ac036
MH
1523 } else if (packed_dir) {
1524 sort_ref_dir(packed_dir);
624cac35
MH
1525 retval = do_for_each_entry_in_dir(
1526 packed_dir, 0, fn, cb_data);
933ac036
MH
1527 } else if (loose_dir) {
1528 sort_ref_dir(loose_dir);
624cac35
MH
1529 retval = do_for_each_entry_in_dir(
1530 loose_dir, 0, fn, cb_data);
933ac036
MH
1531 }
1532
1533 return retval;
8a65ff76
LT
1534}
1535
624cac35
MH
1536/*
1537 * Call fn for each reference in the specified submodule for which the
1538 * refname begins with base. If trim is non-zero, then trim that many
1539 * characters off the beginning of each refname before passing the
1540 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1541 * broken references in the iteration. If fn ever returns a non-zero
1542 * value, stop the iteration and return that value; otherwise, return
1543 * 0.
1544 */
1545static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
1546 int trim, int flags, void *cb_data)
1547{
1548 struct ref_entry_cb data;
1549 data.base = base;
1550 data.trim = trim;
1551 data.flags = flags;
1552 data.fn = fn;
1553 data.cb_data = cb_data;
1554
1555 return do_for_each_entry(submodule, base, do_one_ref, &data);
1556}
1557
0bad611b 1558static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1559{
1560 unsigned char sha1[20];
8da19775
JH
1561 int flag;
1562
0bad611b
HV
1563 if (submodule) {
1564 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1565 return fn("HEAD", sha1, 0, cb_data);
1566
1567 return 0;
1568 }
1569
c6893323 1570 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1571 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1572
2f34ba32 1573 return 0;
723c31fe
LT
1574}
1575
0bad611b
HV
1576int head_ref(each_ref_fn fn, void *cb_data)
1577{
1578 return do_head_ref(NULL, fn, cb_data);
1579}
1580
9ef6aeb0
HV
1581int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1582{
1583 return do_head_ref(submodule, fn, cb_data);
1584}
1585
cb5d709f 1586int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1587{
b3cfc406 1588 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
a62be77f
SE
1589}
1590
9ef6aeb0
HV
1591int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1592{
b3cfc406 1593 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
a62be77f
SE
1594}
1595
2a8177b6
CC
1596int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1597{
0bad611b 1598 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1599}
1600
9ef6aeb0
HV
1601int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1602 each_ref_fn fn, void *cb_data)
1603{
1604 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1605}
1606
cb5d709f 1607int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1608{
2a8177b6 1609 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1610}
1611
9ef6aeb0
HV
1612int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1613{
1614 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1615}
1616
cb5d709f 1617int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1618{
2a8177b6 1619 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1620}
1621
9ef6aeb0
HV
1622int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1623{
1624 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1625}
1626
cb5d709f 1627int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1628{
2a8177b6 1629 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1630}
1631
9ef6aeb0
HV
1632int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1633{
1634 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1635}
1636
29268700
CC
1637int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1638{
0bad611b 1639 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1640}
1641
a1bea2c1
JT
1642int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1643{
1644 struct strbuf buf = STRBUF_INIT;
1645 int ret = 0;
1646 unsigned char sha1[20];
1647 int flag;
1648
1649 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1650 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1651 ret = fn(buf.buf, sha1, flag, cb_data);
1652 strbuf_release(&buf);
1653
1654 return ret;
1655}
1656
1657int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1658{
1659 struct strbuf buf = STRBUF_INIT;
1660 int ret;
1661 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1662 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1663 strbuf_release(&buf);
1664 return ret;
1665}
1666
b09fe971
IL
1667int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1668 const char *prefix, void *cb_data)
d08bae7e
IL
1669{
1670 struct strbuf real_pattern = STRBUF_INIT;
1671 struct ref_filter filter;
d08bae7e
IL
1672 int ret;
1673
b09fe971 1674 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 1675 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1676 else if (prefix)
1677 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1678 strbuf_addstr(&real_pattern, pattern);
1679
894a9d33 1680 if (!has_glob_specials(pattern)) {
9517e6b8 1681 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1682 if (real_pattern.buf[real_pattern.len - 1] != '/')
1683 strbuf_addch(&real_pattern, '/');
1684 /* No need to check for '*', there is none. */
1685 strbuf_addch(&real_pattern, '*');
1686 }
1687
1688 filter.pattern = real_pattern.buf;
1689 filter.fn = fn;
1690 filter.cb_data = cb_data;
1691 ret = for_each_ref(filter_refs, &filter);
1692
1693 strbuf_release(&real_pattern);
1694 return ret;
1695}
1696
b09fe971
IL
1697int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1698{
1699 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1700}
1701
f8948e2f
JH
1702int for_each_rawref(each_ref_fn fn, void *cb_data)
1703{
b3cfc406 1704 return do_for_each_ref(NULL, "", fn, 0,
f8948e2f 1705 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1706}
1707
4577e483 1708const char *prettify_refname(const char *name)
a9c37a72 1709{
a9c37a72
DB
1710 return name + (
1711 !prefixcmp(name, "refs/heads/") ? 11 :
1712 !prefixcmp(name, "refs/tags/") ? 10 :
1713 !prefixcmp(name, "refs/remotes/") ? 13 :
1714 0);
1715}
1716
79803322
SP
1717const char *ref_rev_parse_rules[] = {
1718 "%.*s",
1719 "refs/%.*s",
1720 "refs/tags/%.*s",
1721 "refs/heads/%.*s",
1722 "refs/remotes/%.*s",
1723 "refs/remotes/%.*s/HEAD",
1724 NULL
1725};
1726
1727int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1728{
1729 const char **p;
1730 const int abbrev_name_len = strlen(abbrev_name);
1731
1732 for (p = rules; *p; p++) {
1733 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1734 return 1;
1735 }
1736 }
1737
1738 return 0;
1739}
1740
e5f38ec3 1741static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1742 const unsigned char *old_sha1, int mustexist)
1743{
c6893323 1744 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1745 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1746 unlock_ref(lock);
1747 return NULL;
1748 }
a89fccd2 1749 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1750 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1751 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1752 unlock_ref(lock);
1753 return NULL;
1754 }
1755 return lock;
1756}
1757
7155b727 1758static int remove_empty_directories(const char *file)
bc7127ef
JH
1759{
1760 /* we want to create a file but there is a directory there;
1761 * if that is an empty directory (or a directory that contains
1762 * only empty directories), remove them.
1763 */
7155b727
JS
1764 struct strbuf path;
1765 int result;
bc7127ef 1766
7155b727
JS
1767 strbuf_init(&path, 20);
1768 strbuf_addstr(&path, file);
1769
a0f4afbe 1770 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1771
1772 strbuf_release(&path);
1773
1774 return result;
bc7127ef
JH
1775}
1776
ff74f7f1
JH
1777/*
1778 * *string and *len will only be substituted, and *string returned (for
1779 * later free()ing) if the string passed in is a magic short-hand form
1780 * to name a branch.
1781 */
1782static char *substitute_branch_name(const char **string, int *len)
1783{
1784 struct strbuf buf = STRBUF_INIT;
1785 int ret = interpret_branch_name(*string, &buf);
1786
1787 if (ret == *len) {
1788 size_t size;
1789 *string = strbuf_detach(&buf, &size);
1790 *len = size;
1791 return (char *)*string;
1792 }
1793
1794 return NULL;
1795}
1796
1797int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1798{
1799 char *last_branch = substitute_branch_name(&str, &len);
1800 const char **p, *r;
1801 int refs_found = 0;
1802
1803 *ref = NULL;
1804 for (p = ref_rev_parse_rules; *p; p++) {
1805 char fullref[PATH_MAX];
1806 unsigned char sha1_from_ref[20];
1807 unsigned char *this_result;
1808 int flag;
1809
1810 this_result = refs_found ? sha1_from_ref : sha1;
1811 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1812 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1813 if (r) {
1814 if (!refs_found++)
1815 *ref = xstrdup(r);
1816 if (!warn_ambiguous_refs)
1817 break;
55956350 1818 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1819 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1820 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1821 warning("ignoring broken ref %s.", fullref);
1822 }
ff74f7f1
JH
1823 }
1824 free(last_branch);
1825 return refs_found;
1826}
1827
1828int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1829{
1830 char *last_branch = substitute_branch_name(&str, &len);
1831 const char **p;
1832 int logs_found = 0;
1833
1834 *log = NULL;
1835 for (p = ref_rev_parse_rules; *p; p++) {
1836 struct stat st;
1837 unsigned char hash[20];
1838 char path[PATH_MAX];
1839 const char *ref, *it;
1840
1841 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 1842 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
1843 if (!ref)
1844 continue;
1845 if (!stat(git_path("logs/%s", path), &st) &&
1846 S_ISREG(st.st_mode))
1847 it = path;
1848 else if (strcmp(ref, path) &&
1849 !stat(git_path("logs/%s", ref), &st) &&
1850 S_ISREG(st.st_mode))
1851 it = ref;
1852 else
1853 continue;
1854 if (!logs_found++) {
1855 *log = xstrdup(it);
1856 hashcpy(sha1, hash);
1857 }
1858 if (!warn_ambiguous_refs)
1859 break;
1860 }
1861 free(last_branch);
1862 return logs_found;
1863}
1864
dfefa935
MH
1865static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1866 const unsigned char *old_sha1,
1867 int flags, int *type_p)
4bd18c43 1868{
434cd0cd 1869 char *ref_file;
dfefa935 1870 const char *orig_refname = refname;
4bd18c43 1871 struct ref_lock *lock;
5cc3cef9 1872 int last_errno = 0;
acd3b9ec 1873 int type, lflags;
4431fcc4 1874 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1875 int missing = 0;
4bd18c43
SP
1876
1877 lock = xcalloc(1, sizeof(struct ref_lock));
1878 lock->lock_fd = -1;
1879
8d68493f 1880 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 1881 if (!refname && errno == EISDIR) {
bc7127ef
JH
1882 /* we are trying to lock foo but we used to
1883 * have foo/bar which now does not exist;
1884 * it is normal for the empty directory 'foo'
1885 * to remain.
1886 */
dfefa935 1887 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
1888 if (remove_empty_directories(ref_file)) {
1889 last_errno = errno;
dfefa935 1890 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
1891 goto error_return;
1892 }
8d68493f 1893 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 1894 }
68db31cc
SV
1895 if (type_p)
1896 *type_p = type;
dfefa935 1897 if (!refname) {
5cc3cef9 1898 last_errno = errno;
818f477c 1899 error("unable to resolve reference %s: %s",
dfefa935 1900 orig_refname, strerror(errno));
5cc3cef9 1901 goto error_return;
4bd18c43 1902 }
5bdd8d4a 1903 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1904 /* When the ref did not exist and we are creating it,
1905 * make sure there is no existing ref that is packed
1906 * whose name begins with our refname, nor a ref whose
1907 * name is a proper prefix of our refname.
1908 */
5bdd8d4a 1909 if (missing &&
316b097a 1910 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
f475e08e 1911 last_errno = ENOTDIR;
c976d415 1912 goto error_return;
f475e08e 1913 }
22a3844e 1914
c33d5174 1915 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1916
acd3b9ec
JH
1917 lflags = LOCK_DIE_ON_ERROR;
1918 if (flags & REF_NODEREF) {
dfefa935 1919 refname = orig_refname;
acd3b9ec
JH
1920 lflags |= LOCK_NODEREF;
1921 }
dfefa935
MH
1922 lock->ref_name = xstrdup(refname);
1923 lock->orig_ref_name = xstrdup(orig_refname);
1924 ref_file = git_path("%s", refname);
5bdd8d4a 1925 if (missing)
68db31cc
SV
1926 lock->force_write = 1;
1927 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1928 lock->force_write = 1;
4bd18c43 1929
5cc3cef9
JH
1930 if (safe_create_leading_directories(ref_file)) {
1931 last_errno = errno;
1932 error("unable to create directory for %s", ref_file);
1933 goto error_return;
1934 }
4bd18c43 1935
acd3b9ec 1936 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1937 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1938
1939 error_return:
1940 unlock_ref(lock);
1941 errno = last_errno;
1942 return NULL;
4bd18c43
SP
1943}
1944
dfefa935 1945struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 1946{
53cce84c 1947 char refpath[PATH_MAX];
dfefa935 1948 if (check_refname_format(refname, 0))
4bd18c43 1949 return NULL;
dfefa935 1950 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 1951 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1952}
1953
dfefa935
MH
1954struct ref_lock *lock_any_ref_for_update(const char *refname,
1955 const unsigned char *old_sha1, int flags)
4bd18c43 1956{
dfefa935 1957 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 1958 return NULL;
dfefa935 1959 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
c0277d15
JH
1960}
1961
fec3137f
MH
1962/*
1963 * Write an entry to the packed-refs file for the specified refname.
1964 * If peeled is non-NULL, write it as the entry's peeled value.
1965 */
1966static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
1967 unsigned char *peeled)
d66da478 1968{
d66da478
MH
1969 char line[PATH_MAX + 100];
1970 int len;
1971
fec3137f
MH
1972 len = snprintf(line, sizeof(line), "%s %s\n",
1973 sha1_to_hex(sha1), refname);
1974 /* this should not happen but just being defensive */
1975 if (len > sizeof(line))
1976 die("too long a refname '%s'", refname);
1977 write_or_die(fd, line, len);
1978
1979 if (peeled) {
1980 if (snprintf(line, sizeof(line), "^%s\n",
1981 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
1982 die("internal error");
1983 write_or_die(fd, line, PEELED_LINE_LENGTH);
1984 }
1985}
1986
32d462ce
MH
1987struct ref_to_prune {
1988 struct ref_to_prune *next;
1989 unsigned char sha1[20];
1990 char name[FLEX_ARRAY];
1991};
1992
1993struct pack_refs_cb_data {
1994 unsigned int flags;
1995 struct ref_to_prune *ref_to_prune;
1996 FILE *refs_file;
1997};
1998
12e77559 1999static int pack_one_ref(struct ref_entry *entry, void *cb_data)
32d462ce
MH
2000{
2001 struct pack_refs_cb_data *cb = cb_data;
2002 struct object *o;
2003 int is_tag_ref;
2004
12e77559
MH
2005 /* Do not pack symbolic or broken refs: */
2006 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
32d462ce 2007 return 0;
12e77559 2008 is_tag_ref = !prefixcmp(entry->name, "refs/tags/");
32d462ce
MH
2009
2010 /* ALWAYS pack refs that were already packed or are tags */
12e77559
MH
2011 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref &&
2012 !(entry->flag & REF_ISPACKED))
32d462ce
MH
2013 return 0;
2014
12e77559
MH
2015 fprintf(cb->refs_file, "%s %s\n", sha1_to_hex(entry->u.value.sha1),
2016 entry->name);
32d462ce 2017
12e77559 2018 o = parse_object_or_die(entry->u.value.sha1, entry->name);
32d462ce 2019 if (o->type == OBJ_TAG) {
12e77559 2020 o = deref_tag(o, entry->name, 0);
32d462ce
MH
2021 if (o)
2022 fprintf(cb->refs_file, "^%s\n",
2023 sha1_to_hex(o->sha1));
2024 }
2025
8d3725b9
MH
2026 /* If the ref was already packed, there is no need to prune it. */
2027 if ((cb->flags & PACK_REFS_PRUNE) && !(entry->flag & REF_ISPACKED)) {
12e77559 2028 int namelen = strlen(entry->name) + 1;
32d462ce 2029 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
12e77559
MH
2030 hashcpy(n->sha1, entry->u.value.sha1);
2031 strcpy(n->name, entry->name);
32d462ce
MH
2032 n->next = cb->ref_to_prune;
2033 cb->ref_to_prune = n;
2034 }
2035 return 0;
2036}
2037
2038/*
2039 * Remove empty parents, but spare refs/ and immediate subdirs.
2040 * Note: munges *name.
2041 */
2042static void try_remove_empty_parents(char *name)
2043{
2044 char *p, *q;
2045 int i;
2046 p = name;
2047 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2048 while (*p && *p != '/')
2049 p++;
2050 /* tolerate duplicate slashes; see check_refname_format() */
2051 while (*p == '/')
2052 p++;
2053 }
2054 for (q = p; *q; q++)
2055 ;
2056 while (1) {
2057 while (q > p && *q != '/')
2058 q--;
2059 while (q > p && *(q-1) == '/')
2060 q--;
2061 if (q == p)
2062 break;
2063 *q = '\0';
2064 if (rmdir(git_path("%s", name)))
2065 break;
2066 }
2067}
2068
2069/* make sure nobody touched the ref, and unlink */
2070static void prune_ref(struct ref_to_prune *r)
2071{
2072 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2073
2074 if (lock) {
2075 unlink_or_warn(git_path("%s", r->name));
2076 unlock_ref(lock);
2077 try_remove_empty_parents(r->name);
2078 }
2079}
2080
2081static void prune_refs(struct ref_to_prune *r)
2082{
2083 while (r) {
2084 prune_ref(r);
2085 r = r->next;
2086 }
2087}
2088
d9470330 2089static struct lock_file packlock;
32d462ce
MH
2090
2091int pack_refs(unsigned int flags)
2092{
2093 int fd;
2094 struct pack_refs_cb_data cbdata;
2095
2096 memset(&cbdata, 0, sizeof(cbdata));
2097 cbdata.flags = flags;
2098
d9470330 2099 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"),
32d462ce
MH
2100 LOCK_DIE_ON_ERROR);
2101 cbdata.refs_file = fdopen(fd, "w");
2102 if (!cbdata.refs_file)
2103 die_errno("unable to create ref-pack file structure");
2104
2105 /* perhaps other traits later as well */
2106 fprintf(cbdata.refs_file, "# pack-refs with: peeled fully-peeled \n");
2107
12e77559 2108 do_for_each_entry(NULL, "", pack_one_ref, &cbdata);
32d462ce
MH
2109 if (ferror(cbdata.refs_file))
2110 die("failed to write ref-pack file");
2111 if (fflush(cbdata.refs_file) || fsync(fd) || fclose(cbdata.refs_file))
2112 die_errno("failed to write ref-pack file");
2113 /*
2114 * Since the lock file was fdopen()'ed and then fclose()'ed above,
2115 * assign -1 to the lock file descriptor so that commit_lock_file()
2116 * won't try to close() it.
2117 */
d9470330
MH
2118 packlock.fd = -1;
2119 if (commit_lock_file(&packlock) < 0)
32d462ce
MH
2120 die_errno("unable to overwrite old ref-pack file");
2121 prune_refs(cbdata.ref_to_prune);
2122 return 0;
2123}
2124
fec3137f
MH
2125static int repack_ref_fn(struct ref_entry *entry, void *cb_data)
2126{
2127 int *fd = cb_data;
2128 enum peel_status peel_status;
2129
ab292bc4
MH
2130 if (entry->flag & REF_ISBROKEN) {
2131 /* This shouldn't happen to packed refs. */
2132 error("%s is broken!", entry->name);
2133 return 0;
2134 }
2135 if (!has_sha1_file(entry->u.value.sha1)) {
2136 unsigned char sha1[20];
2137 int flags;
2138
2139 if (read_ref_full(entry->name, sha1, 0, &flags))
2140 /* We should at least have found the packed ref. */
2141 die("Internal error");
2142 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED))
2143 /*
2144 * This packed reference is overridden by a
2145 * loose reference, so it is OK that its value
2146 * is no longer valid; for example, it might
2147 * refer to an object that has been garbage
2148 * collected. For this purpose we don't even
2149 * care whether the loose reference itself is
2150 * invalid, broken, symbolic, etc. Silently
2151 * omit the packed reference from the output.
2152 */
2153 return 0;
2154 /*
2155 * There is no overriding loose reference, so the fact
2156 * that this reference doesn't refer to a valid object
2157 * indicates some kind of repository corruption.
2158 * Report the problem, then omit the reference from
2159 * the output.
2160 */
2161 error("%s does not point to a valid object!", entry->name);
2162 return 0;
2163 }
2164
fec3137f
MH
2165 peel_status = peel_entry(entry);
2166 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2167 peel_status == PEEL_PEELED ?
2168 entry->u.value.peeled : NULL);
694b7a19 2169
d66da478
MH
2170 return 0;
2171}
2172
c0277d15
JH
2173static int repack_without_ref(const char *refname)
2174{
506a760d 2175 int fd;
b3f1280e 2176 struct ref_cache *refs = get_ref_cache(NULL);
7618fd80
MH
2177 struct ref_dir *packed;
2178
2179 if (!get_packed_ref(refname))
2180 return 0; /* refname does not exist in packed refs */
2181
506a760d
MH
2182 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
2183 if (fd < 0) {
1b018fd9 2184 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 2185 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 2186 }
b3f1280e
JK
2187 clear_packed_ref_cache(refs);
2188 packed = get_packed_refs(refs);
506a760d
MH
2189 /* Remove refname from the cache. */
2190 if (remove_entry(packed, refname) == -1) {
2191 /*
2192 * The packed entry disappeared while we were
2193 * acquiring the lock.
2194 */
2195 rollback_lock_file(&packlock);
2196 return 0;
2197 }
694b7a19 2198 write_or_die(fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
506a760d 2199 do_for_each_entry_in_dir(packed, 0, repack_ref_fn, &fd);
c0277d15
JH
2200 return commit_lock_file(&packlock);
2201}
2202
eca35a25 2203int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
2204{
2205 struct ref_lock *lock;
eca35a25 2206 int err, i = 0, ret = 0, flag = 0;
c0277d15 2207
547d058f 2208 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
2209 if (!lock)
2210 return 1;
045a476f 2211 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 2212 /* loose */
547d058f
RS
2213 i = strlen(lock->lk->filename) - 5; /* .lock */
2214 lock->lk->filename[i] = 0;
2215 err = unlink_or_warn(lock->lk->filename);
691f1a28 2216 if (err && errno != ENOENT)
c0277d15 2217 ret = 1;
691f1a28 2218
547d058f 2219 lock->lk->filename[i] = '.';
c0277d15
JH
2220 }
2221 /* removing the loose one could have resurrected an earlier
2222 * packed one. Also, if it was not loose we need to repack
2223 * without it.
2224 */
b274a714 2225 ret |= repack_without_ref(lock->ref_name);
c0277d15 2226
691f1a28 2227 unlink_or_warn(git_path("logs/%s", lock->ref_name));
506a760d 2228 clear_loose_ref_cache(get_ref_cache(NULL));
c0277d15
JH
2229 unlock_ref(lock);
2230 return ret;
4bd18c43
SP
2231}
2232
765c2258
PH
2233/*
2234 * People using contrib's git-new-workdir have .git/logs/refs ->
2235 * /some/other/path/.git/logs/refs, and that may live on another device.
2236 *
2237 * IOW, to avoid cross device rename errors, the temporary renamed log must
2238 * live into logs/refs.
2239 */
2240#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2241
dfefa935 2242int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 2243{
c976d415
LH
2244 unsigned char sha1[20], orig_sha1[20];
2245 int flag = 0, logmoved = 0;
2246 struct ref_lock *lock;
c976d415 2247 struct stat loginfo;
dfefa935 2248 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 2249 const char *symref = NULL;
316b097a 2250 struct ref_cache *refs = get_ref_cache(NULL);
c976d415 2251
450d4c0f 2252 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 2253 return error("reflog for %s is a symlink", oldrefname);
c976d415 2254
8d68493f 2255 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 2256 if (flag & REF_ISSYMREF)
fa58186c 2257 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 2258 oldrefname);
eca35a25 2259 if (!symref)
dfefa935 2260 return error("refname %s not found", oldrefname);
c976d415 2261
316b097a 2262 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
c976d415
LH
2263 return 1;
2264
316b097a 2265 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
c976d415
LH
2266 return 1;
2267
dfefa935 2268 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 2269 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 2270 oldrefname, strerror(errno));
c976d415 2271
dfefa935
MH
2272 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2273 error("unable to delete old %s", oldrefname);
c976d415
LH
2274 goto rollback;
2275 }
2276
dfefa935
MH
2277 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2278 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 2279 if (errno==EISDIR) {
dfefa935
MH
2280 if (remove_empty_directories(git_path("%s", newrefname))) {
2281 error("Directory not empty: %s", newrefname);
c976d415
LH
2282 goto rollback;
2283 }
2284 } else {
dfefa935 2285 error("unable to delete existing %s", newrefname);
c976d415
LH
2286 goto rollback;
2287 }
2288 }
2289
dfefa935
MH
2290 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2291 error("unable to create directory for %s", newrefname);
c976d415
LH
2292 goto rollback;
2293 }
2294
2295 retry:
dfefa935 2296 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
d9e74d57
JR
2297 if (errno==EISDIR || errno==ENOTDIR) {
2298 /*
2299 * rename(a, b) when b is an existing
2300 * directory ought to result in ISDIR, but
2301 * Solaris 5.8 gives ENOTDIR. Sheesh.
2302 */
dfefa935
MH
2303 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2304 error("Directory not empty: logs/%s", newrefname);
c976d415
LH
2305 goto rollback;
2306 }
2307 goto retry;
2308 } else {
765c2258 2309 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
dfefa935 2310 newrefname, strerror(errno));
c976d415
LH
2311 goto rollback;
2312 }
2313 }
2314 logmoved = log;
2315
dfefa935 2316 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2317 if (!lock) {
dfefa935 2318 error("unable to lock %s for update", newrefname);
c976d415
LH
2319 goto rollback;
2320 }
c976d415
LH
2321 lock->force_write = 1;
2322 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2323 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2324 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2325 goto rollback;
2326 }
2327
2328 return 0;
2329
2330 rollback:
dfefa935 2331 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2332 if (!lock) {
dfefa935 2333 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2334 goto rollbacklog;
2335 }
2336
2337 lock->force_write = 1;
2338 flag = log_all_ref_updates;
2339 log_all_ref_updates = 0;
2340 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2341 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2342 log_all_ref_updates = flag;
2343
2344 rollbacklog:
dfefa935 2345 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2346 error("unable to restore logfile %s from %s: %s",
dfefa935 2347 oldrefname, newrefname, strerror(errno));
c976d415 2348 if (!logmoved && log &&
dfefa935 2349 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2350 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2351 oldrefname, strerror(errno));
c976d415
LH
2352
2353 return 1;
2354}
2355
435fc852 2356int close_ref(struct ref_lock *lock)
b531394d
BC
2357{
2358 if (close_lock_file(lock->lk))
2359 return -1;
2360 lock->lock_fd = -1;
2361 return 0;
2362}
2363
435fc852 2364int commit_ref(struct ref_lock *lock)
b531394d
BC
2365{
2366 if (commit_lock_file(lock->lk))
2367 return -1;
2368 lock->lock_fd = -1;
2369 return 0;
2370}
2371
e5f38ec3 2372void unlock_ref(struct ref_lock *lock)
4bd18c43 2373{
4ed7cd3a
BC
2374 /* Do not free lock->lk -- atexit() still looks at them */
2375 if (lock->lk)
2376 rollback_lock_file(lock->lk);
434cd0cd 2377 free(lock->ref_name);
1655707c 2378 free(lock->orig_ref_name);
4bd18c43
SP
2379 free(lock);
2380}
2381
0ec29a47
JH
2382/*
2383 * copy the reflog message msg to buf, which has been allocated sufficiently
2384 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2385 * because reflog file is one line per entry.
2386 */
2387static int copy_msg(char *buf, const char *msg)
2388{
2389 char *cp = buf;
2390 char c;
2391 int wasspace = 1;
2392
2393 *cp++ = '\t';
2394 while ((c = *msg++)) {
2395 if (wasspace && isspace(c))
2396 continue;
2397 wasspace = isspace(c);
2398 if (wasspace)
2399 c = ' ';
2400 *cp++ = c;
2401 }
2402 while (buf < cp && isspace(cp[-1]))
2403 cp--;
2404 *cp++ = '\n';
2405 return cp - buf;
2406}
2407
dfefa935 2408int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2409{
859c3017 2410 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2411
dfefa935 2412 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2413 if (log_all_ref_updates &&
dfefa935
MH
2414 (!prefixcmp(refname, "refs/heads/") ||
2415 !prefixcmp(refname, "refs/remotes/") ||
2416 !prefixcmp(refname, "refs/notes/") ||
2417 !strcmp(refname, "HEAD"))) {
157aaea5 2418 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2419 return error("unable to create directory for %s",
157aaea5 2420 logfile);
6de08ae6
SP
2421 oflags |= O_CREAT;
2422 }
2423
157aaea5 2424 logfd = open(logfile, oflags, 0666);
6de08ae6 2425 if (logfd < 0) {
1974bf62 2426 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2427 return 0;
3b463c3f
JH
2428
2429 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2430 if (remove_empty_directories(logfile)) {
3b463c3f 2431 return error("There are still logs under '%s'",
157aaea5 2432 logfile);
3b463c3f 2433 }
157aaea5 2434 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2435 }
2436
2437 if (logfd < 0)
2438 return error("Unable to append to %s: %s",
157aaea5 2439 logfile, strerror(errno));
6de08ae6
SP
2440 }
2441
157aaea5 2442 adjust_shared_perm(logfile);
859c3017
EM
2443 close(logfd);
2444 return 0;
2445}
443b92b6 2446
dfefa935 2447static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2448 const unsigned char *new_sha1, const char *msg)
2449{
2450 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2451 unsigned maxlen, len;
2452 int msglen;
157aaea5 2453 char log_file[PATH_MAX];
859c3017
EM
2454 char *logrec;
2455 const char *committer;
2456
2457 if (log_all_ref_updates < 0)
2458 log_all_ref_updates = !is_bare_repository();
2459
dfefa935 2460 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2461 if (result)
2462 return result;
2463
2464 logfd = open(log_file, oflags);
2465 if (logfd < 0)
2466 return 0;
0ec29a47 2467 msglen = msg ? strlen(msg) : 0;
774751a8 2468 committer = git_committer_info(0);
8ac65937
JH
2469 maxlen = strlen(committer) + msglen + 100;
2470 logrec = xmalloc(maxlen);
2471 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2472 sha1_to_hex(old_sha1),
2473 sha1_to_hex(new_sha1),
8ac65937
JH
2474 committer);
2475 if (msglen)
0ec29a47 2476 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2477 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2478 free(logrec);
91c8d590 2479 if (close(logfd) != 0 || written != len)
9a13f0b7 2480 return error("Unable to append to %s", log_file);
6de08ae6
SP
2481 return 0;
2482}
2483
c3b0dec5
LT
2484static int is_branch(const char *refname)
2485{
2486 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2487}
2488
4bd18c43
SP
2489int write_ref_sha1(struct ref_lock *lock,
2490 const unsigned char *sha1, const char *logmsg)
2491{
2492 static char term = '\n';
c3b0dec5 2493 struct object *o;
4bd18c43
SP
2494
2495 if (!lock)
95fc7512 2496 return -1;
a89fccd2 2497 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2498 unlock_ref(lock);
2499 return 0;
95fc7512 2500 }
c3b0dec5
LT
2501 o = parse_object(sha1);
2502 if (!o) {
7be8b3ba 2503 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2504 lock->ref_name, sha1_to_hex(sha1));
2505 unlock_ref(lock);
2506 return -1;
2507 }
2508 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2509 error("Trying to write non-commit object %s to branch %s",
2510 sha1_to_hex(sha1), lock->ref_name);
2511 unlock_ref(lock);
2512 return -1;
2513 }
93822c22
AW
2514 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2515 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2516 || close_ref(lock) < 0) {
c33d5174 2517 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2518 unlock_ref(lock);
2519 return -1;
2520 }
8bf90dc9 2521 clear_loose_ref_cache(get_ref_cache(NULL));
bd104db1
NP
2522 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2523 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2524 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2525 unlock_ref(lock);
2526 return -1;
2527 }
605fac8b
NP
2528 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2529 /*
2530 * Special hack: If a branch is updated directly and HEAD
2531 * points to it (may happen on the remote side of a push
2532 * for example) then logically the HEAD reflog should be
2533 * updated too.
2534 * A generic solution implies reverse symref information,
2535 * but finding all symrefs pointing to the given branch
2536 * would be rather costly for this rare event (the direct
2537 * update of a branch) to be worth it. So let's cheat and
2538 * check with HEAD only which should cover 99% of all usage
2539 * scenarios (even 100% of the default ones).
2540 */
2541 unsigned char head_sha1[20];
2542 int head_flag;
2543 const char *head_ref;
8cad4744 2544 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2545 if (head_ref && (head_flag & REF_ISSYMREF) &&
2546 !strcmp(head_ref, lock->ref_name))
2547 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2548 }
b531394d 2549 if (commit_ref(lock)) {
434cd0cd 2550 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2551 unlock_ref(lock);
2552 return -1;
2553 }
4bd18c43
SP
2554 unlock_ref(lock);
2555 return 0;
95fc7512 2556}
d556fae2 2557
8b5157e4
NP
2558int create_symref(const char *ref_target, const char *refs_heads_master,
2559 const char *logmsg)
41b625b0
NP
2560{
2561 const char *lockpath;
2562 char ref[1000];
2563 int fd, len, written;
a4f34cbb 2564 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2565 unsigned char old_sha1[20], new_sha1[20];
2566
2567 if (logmsg && read_ref(ref_target, old_sha1))
2568 hashclr(old_sha1);
41b625b0 2569
d48744d1
JH
2570 if (safe_create_leading_directories(git_HEAD) < 0)
2571 return error("unable to create directory for %s", git_HEAD);
2572
41b625b0
NP
2573#ifndef NO_SYMLINK_HEAD
2574 if (prefer_symlink_refs) {
2575 unlink(git_HEAD);
2576 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2577 goto done;
41b625b0
NP
2578 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2579 }
2580#endif
2581
2582 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2583 if (sizeof(ref) <= len) {
2584 error("refname too long: %s", refs_heads_master);
47fc52e2 2585 goto error_free_return;
41b625b0
NP
2586 }
2587 lockpath = mkpath("%s.lock", git_HEAD);
2588 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2589 if (fd < 0) {
2590 error("Unable to open %s for writing", lockpath);
47fc52e2 2591 goto error_free_return;
41b625b0
NP
2592 }
2593 written = write_in_full(fd, ref, len);
91c8d590 2594 if (close(fd) != 0 || written != len) {
41b625b0 2595 error("Unable to write to %s", lockpath);
47fc52e2 2596 goto error_unlink_return;
41b625b0
NP
2597 }
2598 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2599 error("Unable to create %s", git_HEAD);
47fc52e2 2600 goto error_unlink_return;
41b625b0
NP
2601 }
2602 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2603 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2604 error_unlink_return:
691f1a28 2605 unlink_or_warn(lockpath);
47fc52e2
JH
2606 error_free_return:
2607 free(git_HEAD);
2608 return -1;
41b625b0 2609 }
8b5157e4 2610
ee96d11b 2611#ifndef NO_SYMLINK_HEAD
8b5157e4 2612 done:
ee96d11b 2613#endif
8b5157e4
NP
2614 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2615 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2616
47fc52e2 2617 free(git_HEAD);
41b625b0
NP
2618 return 0;
2619}
2620
16d7cc90
JH
2621static char *ref_msg(const char *line, const char *endp)
2622{
2623 const char *ep;
16d7cc90 2624 line += 82;
182af834
PH
2625 ep = memchr(line, '\n', endp - line);
2626 if (!ep)
2627 ep = endp;
2628 return xmemdupz(line, ep - line);
16d7cc90
JH
2629}
2630
dfefa935
MH
2631int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2632 unsigned char *sha1, char **msg,
2633 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2634{
e5229042 2635 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2636 char *tz_c;
e29cb53a 2637 int logfd, tz, reccnt = 0;
d556fae2
SP
2638 struct stat st;
2639 unsigned long date;
e5229042 2640 unsigned char logged_sha1[20];
cb48cb58 2641 void *log_mapped;
dc49cd76 2642 size_t mapsz;
d556fae2 2643
dfefa935 2644 logfile = git_path("logs/%s", refname);
d556fae2
SP
2645 logfd = open(logfile, O_RDONLY, 0);
2646 if (logfd < 0)
d824cbba 2647 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2648 fstat(logfd, &st);
2649 if (!st.st_size)
2650 die("Log %s is empty.", logfile);
dc49cd76
SP
2651 mapsz = xsize_t(st.st_size);
2652 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2653 logdata = log_mapped;
d556fae2
SP
2654 close(logfd);
2655
e5229042 2656 lastrec = NULL;
d556fae2
SP
2657 rec = logend = logdata + st.st_size;
2658 while (logdata < rec) {
e29cb53a 2659 reccnt++;
d556fae2
SP
2660 if (logdata < rec && *(rec-1) == '\n')
2661 rec--;
e5229042
SP
2662 lastgt = NULL;
2663 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2664 rec--;
e5229042
SP
2665 if (*rec == '>')
2666 lastgt = rec;
2667 }
2668 if (!lastgt)
d556fae2 2669 die("Log %s is corrupt.", logfile);
e5229042 2670 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2671 if (date <= at_time || cnt == 0) {
76a44c5c 2672 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2673 if (msg)
2674 *msg = ref_msg(rec, logend);
2675 if (cutoff_time)
2676 *cutoff_time = date;
2677 if (cutoff_tz)
2678 *cutoff_tz = tz;
2679 if (cutoff_cnt)
76a44c5c 2680 *cutoff_cnt = reccnt - 1;
e5229042
SP
2681 if (lastrec) {
2682 if (get_sha1_hex(lastrec, logged_sha1))
2683 die("Log %s is corrupt.", logfile);
2684 if (get_sha1_hex(rec + 41, sha1))
2685 die("Log %s is corrupt.", logfile);
a89fccd2 2686 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2687 warning("Log %s has gap after %s.",
73013afd 2688 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 2689 }
e5f38ec3
JH
2690 }
2691 else if (date == at_time) {
e5229042
SP
2692 if (get_sha1_hex(rec + 41, sha1))
2693 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
2694 }
2695 else {
e5229042
SP
2696 if (get_sha1_hex(rec + 41, logged_sha1))
2697 die("Log %s is corrupt.", logfile);
a89fccd2 2698 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2699 warning("Log %s unexpectedly ended on %s.",
73013afd 2700 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
2701 }
2702 }
dc49cd76 2703 munmap(log_mapped, mapsz);
d556fae2
SP
2704 return 0;
2705 }
e5229042 2706 lastrec = rec;
ab2a1a32
JH
2707 if (cnt > 0)
2708 cnt--;
d556fae2
SP
2709 }
2710
e5229042
SP
2711 rec = logdata;
2712 while (rec < logend && *rec != '>' && *rec != '\n')
2713 rec++;
2714 if (rec == logend || *rec == '\n')
d556fae2 2715 die("Log %s is corrupt.", logfile);
e5229042 2716 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
2717 tz = strtoul(tz_c, NULL, 10);
2718 if (get_sha1_hex(logdata, sha1))
2719 die("Log %s is corrupt.", logfile);
d1a4489a
JK
2720 if (is_null_sha1(sha1)) {
2721 if (get_sha1_hex(logdata + 41, sha1))
2722 die("Log %s is corrupt.", logfile);
2723 }
16d7cc90
JH
2724 if (msg)
2725 *msg = ref_msg(logdata, logend);
dc49cd76 2726 munmap(log_mapped, mapsz);
16d7cc90
JH
2727
2728 if (cutoff_time)
2729 *cutoff_time = date;
2730 if (cutoff_tz)
2731 *cutoff_tz = tz;
2732 if (cutoff_cnt)
2733 *cutoff_cnt = reccnt;
2734 return 1;
d556fae2 2735}
2ff81662 2736
dfefa935 2737int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
2738{
2739 const char *logfile;
2740 FILE *logfp;
8ca78803 2741 struct strbuf sb = STRBUF_INIT;
2266bf27 2742 int ret = 0;
2ff81662 2743
dfefa935 2744 logfile = git_path("logs/%s", refname);
2ff81662
JH
2745 logfp = fopen(logfile, "r");
2746 if (!logfp)
883d60fa 2747 return -1;
101d15e0
JH
2748
2749 if (ofs) {
2750 struct stat statbuf;
2751 if (fstat(fileno(logfp), &statbuf) ||
2752 statbuf.st_size < ofs ||
2753 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 2754 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 2755 fclose(logfp);
8ca78803 2756 strbuf_release(&sb);
101d15e0 2757 return -1;
9d33f7c2 2758 }
101d15e0
JH
2759 }
2760
8ca78803 2761 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 2762 unsigned char osha1[20], nsha1[20];
883d60fa
JS
2763 char *email_end, *message;
2764 unsigned long timestamp;
8ca78803 2765 int tz;
2ff81662
JH
2766
2767 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
2768 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
2769 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
2770 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
2771 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
2772 email_end[1] != ' ' ||
2773 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2774 !message || message[0] != ' ' ||
2775 (message[1] != '+' && message[1] != '-') ||
2776 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 2777 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 2778 continue; /* corrupt? */
883d60fa
JS
2779 email_end[1] = '\0';
2780 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
2781 if (message[6] != '\t')
2782 message += 6;
2783 else
2784 message += 7;
8ca78803
RS
2785 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
2786 cb_data);
883d60fa 2787 if (ret)
2266bf27 2788 break;
2ff81662
JH
2789 }
2790 fclose(logfp);
8ca78803 2791 strbuf_release(&sb);
2266bf27 2792 return ret;
2ff81662 2793}
e29cb53a 2794
dfefa935 2795int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 2796{
dfefa935 2797 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
101d15e0
JH
2798}
2799
989c0e5d
MH
2800/*
2801 * Call fn for each reflog in the namespace indicated by name. name
2802 * must be empty or end with '/'. Name will be used as a scratch
2803 * space, but its contents will be restored before return.
2804 */
2805static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 2806{
989c0e5d 2807 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 2808 int retval = 0;
93c603fc 2809 struct dirent *de;
989c0e5d 2810 int oldlen = name->len;
eb8381c8 2811
93c603fc 2812 if (!d)
989c0e5d 2813 return name->len ? errno : 0;
eb8381c8 2814
93c603fc
MH
2815 while ((de = readdir(d)) != NULL) {
2816 struct stat st;
eb8381c8 2817
93c603fc
MH
2818 if (de->d_name[0] == '.')
2819 continue;
93c603fc
MH
2820 if (has_extension(de->d_name, ".lock"))
2821 continue;
989c0e5d
MH
2822 strbuf_addstr(name, de->d_name);
2823 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2824 ; /* silently ignore */
93c603fc 2825 } else {
eb8381c8 2826 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
2827 strbuf_addch(name, '/');
2828 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
2829 } else {
2830 unsigned char sha1[20];
989c0e5d
MH
2831 if (read_ref_full(name->buf, sha1, 0, NULL))
2832 retval = error("bad ref for %s", name->buf);
eb8381c8 2833 else
989c0e5d 2834 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
2835 }
2836 if (retval)
2837 break;
2838 }
989c0e5d 2839 strbuf_setlen(name, oldlen);
eb8381c8 2840 }
93c603fc 2841 closedir(d);
eb8381c8
NP
2842 return retval;
2843}
2844
2845int for_each_reflog(each_ref_fn fn, void *cb_data)
2846{
989c0e5d
MH
2847 int retval;
2848 struct strbuf name;
2849 strbuf_init(&name, PATH_MAX);
2850 retval = do_for_each_reflog(&name, fn, cb_data);
2851 strbuf_release(&name);
2852 return retval;
eb8381c8 2853}
3d9f037c
CR
2854
2855int update_ref(const char *action, const char *refname,
2856 const unsigned char *sha1, const unsigned char *oldval,
2857 int flags, enum action_on_err onerr)
2858{
2859 static struct ref_lock *lock;
2860 lock = lock_any_ref_for_update(refname, oldval, flags);
2861 if (!lock) {
2862 const char *str = "Cannot lock the ref '%s'.";
2863 switch (onerr) {
2864 case MSG_ON_ERR: error(str, refname); break;
2865 case DIE_ON_ERR: die(str, refname); break;
2866 case QUIET_ON_ERR: break;
2867 }
2868 return 1;
2869 }
2870 if (write_ref_sha1(lock, sha1, action) < 0) {
2871 const char *str = "Cannot update the ref '%s'.";
2872 switch (onerr) {
2873 case MSG_ON_ERR: error(str, refname); break;
2874 case DIE_ON_ERR: die(str, refname); break;
2875 case QUIET_ON_ERR: break;
2876 }
2877 return 1;
2878 }
2879 return 0;
2880}
cda69f48 2881
5483f799 2882struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
2883{
2884 for ( ; list; list = list->next)
2885 if (!strcmp(list->name, name))
5483f799 2886 return (struct ref *)list;
cda69f48
JK
2887 return NULL;
2888}
7c2b3029
JK
2889
2890/*
2891 * generate a format suitable for scanf from a ref_rev_parse_rules
2892 * rule, that is replace the "%.*s" spec with a "%s" spec
2893 */
2894static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2895{
2896 char *spec;
2897
2898 spec = strstr(rule, "%.*s");
2899 if (!spec || strstr(spec + 4, "%.*s"))
2900 die("invalid rule in ref_rev_parse_rules: %s", rule);
2901
2902 /* copy all until spec */
2903 strncpy(scanf_fmt, rule, spec - rule);
2904 scanf_fmt[spec - rule] = '\0';
2905 /* copy new spec */
2906 strcat(scanf_fmt, "%s");
2907 /* copy remaining rule */
2908 strcat(scanf_fmt, spec + 4);
2909
2910 return;
2911}
2912
dfefa935 2913char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
2914{
2915 int i;
2916 static char **scanf_fmts;
2917 static int nr_rules;
2918 char *short_name;
2919
2920 /* pre generate scanf formats from ref_rev_parse_rules[] */
2921 if (!nr_rules) {
2922 size_t total_len = 0;
2923
2924 /* the rule list is NULL terminated, count them first */
2925 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2926 /* no +1 because strlen("%s") < strlen("%.*s") */
2927 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2928
2929 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2930
2931 total_len = 0;
2932 for (i = 0; i < nr_rules; i++) {
2933 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2934 + total_len;
2935 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2936 total_len += strlen(ref_rev_parse_rules[i]);
2937 }
2938 }
2939
2940 /* bail out if there are no rules */
2941 if (!nr_rules)
dfefa935 2942 return xstrdup(refname);
7c2b3029 2943
dfefa935
MH
2944 /* buffer for scanf result, at most refname must fit */
2945 short_name = xstrdup(refname);
7c2b3029
JK
2946
2947 /* skip first rule, it will always match */
2948 for (i = nr_rules - 1; i > 0 ; --i) {
2949 int j;
6e7b3309 2950 int rules_to_fail = i;
7c2b3029
JK
2951 int short_name_len;
2952
dfefa935 2953 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
2954 continue;
2955
2956 short_name_len = strlen(short_name);
2957
6e7b3309
BW
2958 /*
2959 * in strict mode, all (except the matched one) rules
2960 * must fail to resolve to a valid non-ambiguous ref
2961 */
2962 if (strict)
2963 rules_to_fail = nr_rules;
2964
7c2b3029
JK
2965 /*
2966 * check if the short name resolves to a valid ref,
2967 * but use only rules prior to the matched one
2968 */
6e7b3309 2969 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 2970 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
2971 char refname[PATH_MAX];
2972
6e7b3309
BW
2973 /* skip matched rule */
2974 if (i == j)
2975 continue;
2976
7c2b3029
JK
2977 /*
2978 * the short name is ambiguous, if it resolves
2979 * (with this previous rule) to a valid ref
2980 * read_ref() returns 0 on success
2981 */
2982 mksnpath(refname, sizeof(refname),
2983 rule, short_name_len, short_name);
c6893323 2984 if (ref_exists(refname))
7c2b3029
JK
2985 break;
2986 }
2987
2988 /*
2989 * short name is non-ambiguous if all previous rules
2990 * haven't resolved to a valid ref
2991 */
6e7b3309 2992 if (j == rules_to_fail)
7c2b3029
JK
2993 return short_name;
2994 }
2995
2996 free(short_name);
dfefa935 2997 return xstrdup(refname);
7c2b3029 2998}