Merge branch 'mh/reflife'
[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"
daebaa78 6#include "string-list.h"
95fc7512 7
bc5fd6d3
MH
8/*
9 * Make sure "ref" is something reasonable to have under ".git/refs/";
10 * We do not like it if:
11 *
12 * - any path component of it begins with ".", or
13 * - it has double dots "..", or
14 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
15 * - it ends with a "/".
16 * - it ends with ".lock"
17 * - it contains a "\" (backslash)
18 */
f4204ab9 19
bc5fd6d3
MH
20/* Return true iff ch is not allowed in reference names. */
21static inline int bad_ref_char(int ch)
22{
23 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
24 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
25 return 1;
26 /* 2.13 Pattern Matching Notation */
27 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
28 return 1;
29 return 0;
30}
31
32/*
33 * Try to read one refname component from the front of refname. Return
34 * the length of the component found, or -1 if the component is not
35 * legal.
36 */
37static int check_refname_component(const char *refname, int flags)
38{
39 const char *cp;
40 char last = '\0';
41
42 for (cp = refname; ; cp++) {
43 char ch = *cp;
44 if (ch == '\0' || ch == '/')
45 break;
46 if (bad_ref_char(ch))
47 return -1; /* Illegal character in refname. */
48 if (last == '.' && ch == '.')
49 return -1; /* Refname contains "..". */
50 if (last == '@' && ch == '{')
51 return -1; /* Refname contains "@{". */
52 last = ch;
53 }
54 if (cp == refname)
dac529e4 55 return 0; /* Component has zero length. */
bc5fd6d3
MH
56 if (refname[0] == '.') {
57 if (!(flags & REFNAME_DOT_COMPONENT))
58 return -1; /* Component starts with '.'. */
59 /*
60 * Even if leading dots are allowed, don't allow "."
61 * as a component (".." is prevented by a rule above).
62 */
63 if (refname[1] == '\0')
64 return -1; /* Component equals ".". */
65 }
66 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
67 return -1; /* Refname ends with ".lock". */
68 return cp - refname;
69}
70
71int check_refname_format(const char *refname, int flags)
72{
73 int component_len, component_count = 0;
74
cdfd9483
FC
75 if (!strcmp(refname, "@"))
76 /* Refname is a single character '@'. */
77 return -1;
78
bc5fd6d3
MH
79 while (1) {
80 /* We are at the start of a path component. */
81 component_len = check_refname_component(refname, flags);
dac529e4 82 if (component_len <= 0) {
bc5fd6d3
MH
83 if ((flags & REFNAME_REFSPEC_PATTERN) &&
84 refname[0] == '*' &&
85 (refname[1] == '\0' || refname[1] == '/')) {
86 /* Accept one wildcard as a full refname component. */
87 flags &= ~REFNAME_REFSPEC_PATTERN;
88 component_len = 1;
89 } else {
90 return -1;
91 }
92 }
93 component_count++;
94 if (refname[component_len] == '\0')
95 break;
96 /* Skip to next component. */
97 refname += component_len + 1;
98 }
99
100 if (refname[component_len - 1] == '.')
101 return -1; /* Refname ends with '.'. */
102 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
103 return -1; /* Refname has only one component. */
104 return 0;
105}
106
107struct ref_entry;
e1e22e37 108
28e6a34e
MH
109/*
110 * Information used (along with the information in ref_entry) to
111 * describe a single cached reference. This data structure only
112 * occurs embedded in a union in struct ref_entry, and only when
113 * (ref_entry->flag & REF_DIR) is zero.
114 */
593f1bb8 115struct ref_value {
6c6f58df
MH
116 /*
117 * The name of the object to which this reference resolves
118 * (which may be a tag object). If REF_ISBROKEN, this is
119 * null. If REF_ISSYMREF, then this is the name of the object
120 * referred to by the last reference in the symlink chain.
121 */
593f1bb8 122 unsigned char sha1[20];
6c6f58df
MH
123
124 /*
125 * If REF_KNOWS_PEELED, then this field holds the peeled value
126 * of this reference, or null if the reference is known not to
2312a793
MH
127 * be peelable. See the documentation for peel_ref() for an
128 * exact definition of "peelable".
6c6f58df 129 */
593f1bb8
MH
130 unsigned char peeled[20];
131};
132
f006c42a
MH
133struct ref_cache;
134
28e6a34e
MH
135/*
136 * Information used (along with the information in ref_entry) to
137 * describe a level in the hierarchy of references. This data
138 * structure only occurs embedded in a union in struct ref_entry, and
139 * only when (ref_entry.flag & REF_DIR) is set. In that case,
140 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
141 * in the directory have already been read:
142 *
143 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
144 * or packed references, already read.
145 *
146 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
147 * references that hasn't been read yet (nor has any of its
148 * subdirectories).
149 *
150 * Entries within a directory are stored within a growable array of
151 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
152 * sorted are sorted by their component name in strcmp() order and the
153 * remaining entries are unsorted.
154 *
155 * Loose references are read lazily, one directory at a time. When a
156 * directory of loose references is read, then all of the references
157 * in that directory are stored, and REF_INCOMPLETE stubs are created
158 * for any subdirectories, but the subdirectories themselves are not
159 * read. The reading is triggered by get_ref_dir().
160 */
d3177275 161struct ref_dir {
e9c4c111 162 int nr, alloc;
e6ed3ca6
MH
163
164 /*
165 * Entries with index 0 <= i < sorted are sorted by name. New
166 * entries are appended to the list unsorted, and are sorted
167 * only when required; thus we avoid the need to sort the list
168 * after the addition of every reference.
169 */
170 int sorted;
171
f006c42a
MH
172 /* A pointer to the ref_cache that contains this ref_dir. */
173 struct ref_cache *ref_cache;
174
d3177275 175 struct ref_entry **entries;
e9c4c111
JP
176};
177
89df9c84
MH
178/*
179 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
180 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
181 * refs.h.
182 */
183
184/*
185 * The field ref_entry->u.value.peeled of this value entry contains
186 * the correct peeled value for the reference, which might be
187 * null_sha1 if the reference is not a tag or if it is broken.
188 */
432ad41e 189#define REF_KNOWS_PEELED 0x08
28e6a34e
MH
190
191/* ref_entry represents a directory of references */
432ad41e 192#define REF_DIR 0x10
cf0adba7 193
28e6a34e
MH
194/*
195 * Entry has not yet been read from disk (used only for REF_DIR
196 * entries representing loose references)
197 */
198#define REF_INCOMPLETE 0x20
199
432ad41e
MH
200/*
201 * A ref_entry represents either a reference or a "subdirectory" of
28e6a34e
MH
202 * references.
203 *
204 * Each directory in the reference namespace is represented by a
205 * ref_entry with (flags & REF_DIR) set and containing a subdir member
206 * that holds the entries in that directory that have been read so
207 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
208 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
209 * used for loose reference directories.
210 *
211 * References are represented by a ref_entry with (flags & REF_DIR)
212 * unset and a value member that describes the reference's value. The
213 * flag member is at the ref_entry level, but it is also needed to
214 * interpret the contents of the value field (in other words, a
215 * ref_value object is not very much use without the enclosing
216 * ref_entry).
432ad41e
MH
217 *
218 * Reference names cannot end with slash and directories' names are
219 * always stored with a trailing slash (except for the top-level
220 * directory, which is always denoted by ""). This has two nice
221 * consequences: (1) when the entries in each subdir are sorted
222 * lexicographically by name (as they usually are), the references in
223 * a whole tree can be generated in lexicographic order by traversing
224 * the tree in left-to-right, depth-first order; (2) the names of
225 * references and subdirectories cannot conflict, and therefore the
226 * presence of an empty subdirectory does not block the creation of a
227 * similarly-named reference. (The fact that reference names with the
228 * same leading components can conflict *with each other* is a
229 * separate issue that is regulated by is_refname_available().)
230 *
231 * Please note that the name field contains the fully-qualified
232 * reference (or subdirectory) name. Space could be saved by only
233 * storing the relative names. But that would require the full names
234 * to be generated on the fly when iterating in do_for_each_ref(), and
235 * would break callback functions, who have always been able to assume
236 * that the name strings that they are passed will not be freed during
237 * the iteration.
238 */
bc5fd6d3
MH
239struct ref_entry {
240 unsigned char flag; /* ISSYMREF? ISPACKED? */
593f1bb8 241 union {
432ad41e
MH
242 struct ref_value value; /* if not (flags&REF_DIR) */
243 struct ref_dir subdir; /* if (flags&REF_DIR) */
593f1bb8 244 } u;
432ad41e
MH
245 /*
246 * The full name of the reference (e.g., "refs/heads/master")
247 * or the full name of the directory with a trailing slash
248 * (e.g., "refs/heads/"):
249 */
bc5fd6d3
MH
250 char name[FLEX_ARRAY];
251};
e1e22e37 252
28e6a34e
MH
253static void read_loose_refs(const char *dirname, struct ref_dir *dir);
254
d7826d54
MH
255static struct ref_dir *get_ref_dir(struct ref_entry *entry)
256{
28e6a34e 257 struct ref_dir *dir;
d7826d54 258 assert(entry->flag & REF_DIR);
28e6a34e
MH
259 dir = &entry->u.subdir;
260 if (entry->flag & REF_INCOMPLETE) {
261 read_loose_refs(entry->name, dir);
262 entry->flag &= ~REF_INCOMPLETE;
263 }
264 return dir;
d7826d54
MH
265}
266
cddc4258
MH
267static struct ref_entry *create_ref_entry(const char *refname,
268 const unsigned char *sha1, int flag,
269 int check_name)
e1e22e37
LT
270{
271 int len;
cddc4258 272 struct ref_entry *ref;
e1e22e37 273
09116a1c 274 if (check_name &&
dfefa935
MH
275 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
276 die("Reference has invalid format: '%s'", refname);
cddc4258
MH
277 len = strlen(refname) + 1;
278 ref = xmalloc(sizeof(struct ref_entry) + len);
593f1bb8
MH
279 hashcpy(ref->u.value.sha1, sha1);
280 hashclr(ref->u.value.peeled);
cddc4258
MH
281 memcpy(ref->name, refname, len);
282 ref->flag = flag;
283 return ref;
284}
285
432ad41e
MH
286static void clear_ref_dir(struct ref_dir *dir);
287
732134ed
MH
288static void free_ref_entry(struct ref_entry *entry)
289{
27b5587c
MH
290 if (entry->flag & REF_DIR) {
291 /*
292 * Do not use get_ref_dir() here, as that might
293 * trigger the reading of loose refs.
294 */
295 clear_ref_dir(&entry->u.subdir);
296 }
732134ed
MH
297 free(entry);
298}
299
432ad41e
MH
300/*
301 * Add a ref_entry to the end of dir (unsorted). Entry is always
302 * stored directly in dir; no recursion into subdirectories is
303 * done.
304 */
305static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
cddc4258 306{
432ad41e
MH
307 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
308 dir->entries[dir->nr++] = entry;
654ad400
MH
309 /* optimize for the case that entries are added in order */
310 if (dir->nr == 1 ||
311 (dir->nr == dir->sorted + 1 &&
312 strcmp(dir->entries[dir->nr - 2]->name,
313 dir->entries[dir->nr - 1]->name) < 0))
314 dir->sorted = dir->nr;
c774aab9
JP
315}
316
432ad41e
MH
317/*
318 * Clear and free all entries in dir, recursively.
319 */
d3177275 320static void clear_ref_dir(struct ref_dir *dir)
bc5fd6d3
MH
321{
322 int i;
d3177275
MH
323 for (i = 0; i < dir->nr; i++)
324 free_ref_entry(dir->entries[i]);
325 free(dir->entries);
326 dir->sorted = dir->nr = dir->alloc = 0;
327 dir->entries = NULL;
bc5fd6d3
MH
328}
329
432ad41e
MH
330/*
331 * Create a struct ref_entry object for the specified dirname.
332 * dirname is the name of the directory with a trailing slash (e.g.,
333 * "refs/heads/") or "" for the top-level directory.
334 */
f006c42a 335static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
b9146f51
RS
336 const char *dirname, size_t len,
337 int incomplete)
432ad41e
MH
338{
339 struct ref_entry *direntry;
432ad41e 340 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
b9146f51
RS
341 memcpy(direntry->name, dirname, len);
342 direntry->name[len] = '\0';
f006c42a 343 direntry->u.subdir.ref_cache = ref_cache;
28e6a34e 344 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
432ad41e
MH
345 return direntry;
346}
347
e9c4c111 348static int ref_entry_cmp(const void *a, const void *b)
c774aab9 349{
e9c4c111
JP
350 struct ref_entry *one = *(struct ref_entry **)a;
351 struct ref_entry *two = *(struct ref_entry **)b;
352 return strcmp(one->name, two->name);
353}
c774aab9 354
d3177275 355static void sort_ref_dir(struct ref_dir *dir);
bc5fd6d3 356
e1980c9d
JH
357struct string_slice {
358 size_t len;
359 const char *str;
360};
361
362static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
363{
c971ddfd
RS
364 const struct string_slice *key = key_;
365 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
366 int cmp = strncmp(key->str, ent->name, key->len);
e1980c9d
JH
367 if (cmp)
368 return cmp;
c971ddfd 369 return '\0' - (unsigned char)ent->name[key->len];
e1980c9d
JH
370}
371
432ad41e 372/*
9fc0a648
MH
373 * Return the index of the entry with the given refname from the
374 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
375 * no such entry is found. dir must already be complete.
432ad41e 376 */
9fc0a648 377static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
bc5fd6d3 378{
e1980c9d
JH
379 struct ref_entry **r;
380 struct string_slice key;
bc5fd6d3 381
432ad41e 382 if (refname == NULL || !dir->nr)
9fc0a648 383 return -1;
bc5fd6d3 384
d3177275 385 sort_ref_dir(dir);
e1980c9d
JH
386 key.len = len;
387 key.str = refname;
388 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
389 ref_entry_cmp_sslice);
bc5fd6d3
MH
390
391 if (r == NULL)
9fc0a648 392 return -1;
bc5fd6d3 393
9fc0a648 394 return r - dir->entries;
bc5fd6d3
MH
395}
396
f348ac92
MH
397/*
398 * Search for a directory entry directly within dir (without
399 * recursing). Sort dir if necessary. subdirname must be a directory
400 * name (i.e., end in '/'). If mkdir is set, then create the
401 * directory if it is missing; otherwise, return NULL if the desired
28e6a34e 402 * directory cannot be found. dir must already be complete.
f348ac92 403 */
3f3aa1bc 404static struct ref_dir *search_for_subdir(struct ref_dir *dir,
dd02e728
RS
405 const char *subdirname, size_t len,
406 int mkdir)
f348ac92 407{
9fc0a648
MH
408 int entry_index = search_ref_dir(dir, subdirname, len);
409 struct ref_entry *entry;
410 if (entry_index == -1) {
f348ac92
MH
411 if (!mkdir)
412 return NULL;
28e6a34e
MH
413 /*
414 * Since dir is complete, the absence of a subdir
415 * means that the subdir really doesn't exist;
416 * therefore, create an empty record for it but mark
417 * the record complete.
418 */
b9146f51 419 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
f348ac92 420 add_entry_to_dir(dir, entry);
9fc0a648
MH
421 } else {
422 entry = dir->entries[entry_index];
f348ac92 423 }
3f3aa1bc 424 return get_ref_dir(entry);
f348ac92
MH
425}
426
432ad41e
MH
427/*
428 * If refname is a reference name, find the ref_dir within the dir
429 * tree that should hold refname. If refname is a directory name
430 * (i.e., ends in '/'), then return that ref_dir itself. dir must
28e6a34e
MH
431 * represent the top-level directory and must already be complete.
432 * Sort ref_dirs and recurse into subdirectories as necessary. If
433 * mkdir is set, then create any missing directories; otherwise,
434 * return NULL if the desired directory cannot be found.
432ad41e
MH
435 */
436static struct ref_dir *find_containing_dir(struct ref_dir *dir,
437 const char *refname, int mkdir)
438{
5fa04418 439 const char *slash;
5fa04418 440 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
dd02e728 441 size_t dirnamelen = slash - refname + 1;
3f3aa1bc 442 struct ref_dir *subdir;
dd02e728 443 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
663c1295
JH
444 if (!subdir) {
445 dir = NULL;
f348ac92 446 break;
432ad41e 447 }
3f3aa1bc 448 dir = subdir;
432ad41e
MH
449 }
450
432ad41e
MH
451 return dir;
452}
453
454/*
455 * Find the value entry with the given name in dir, sorting ref_dirs
456 * and recursing into subdirectories as necessary. If the name is not
457 * found or it corresponds to a directory entry, return NULL.
458 */
459static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
460{
9fc0a648 461 int entry_index;
432ad41e
MH
462 struct ref_entry *entry;
463 dir = find_containing_dir(dir, refname, 0);
464 if (!dir)
465 return NULL;
9fc0a648
MH
466 entry_index = search_ref_dir(dir, refname, strlen(refname));
467 if (entry_index == -1)
468 return NULL;
469 entry = dir->entries[entry_index];
470 return (entry->flag & REF_DIR) ? NULL : entry;
432ad41e
MH
471}
472
506a760d
MH
473/*
474 * Remove the entry with the given name from dir, recursing into
475 * subdirectories as necessary. If refname is the name of a directory
476 * (i.e., ends with '/'), then remove the directory and its contents.
477 * If the removal was successful, return the number of entries
478 * remaining in the directory entry that contained the deleted entry.
479 * If the name was not found, return -1. Please note that this
480 * function only deletes the entry from the cache; it does not delete
481 * it from the filesystem or ensure that other cache entries (which
482 * might be symbolic references to the removed entry) are updated.
483 * Nor does it remove any containing dir entries that might be made
484 * empty by the removal. dir must represent the top-level directory
485 * and must already be complete.
486 */
487static int remove_entry(struct ref_dir *dir, const char *refname)
488{
489 int refname_len = strlen(refname);
490 int entry_index;
491 struct ref_entry *entry;
492 int is_dir = refname[refname_len - 1] == '/';
493 if (is_dir) {
494 /*
495 * refname represents a reference directory. Remove
496 * the trailing slash; otherwise we will get the
497 * directory *representing* refname rather than the
498 * one *containing* it.
499 */
500 char *dirname = xmemdupz(refname, refname_len - 1);
501 dir = find_containing_dir(dir, dirname, 0);
502 free(dirname);
503 } else {
504 dir = find_containing_dir(dir, refname, 0);
505 }
506 if (!dir)
507 return -1;
508 entry_index = search_ref_dir(dir, refname, refname_len);
509 if (entry_index == -1)
510 return -1;
511 entry = dir->entries[entry_index];
512
513 memmove(&dir->entries[entry_index],
514 &dir->entries[entry_index + 1],
515 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
516 );
517 dir->nr--;
518 if (dir->sorted > entry_index)
519 dir->sorted--;
520 free_ref_entry(entry);
521 return dir->nr;
432ad41e
MH
522}
523
524/*
525 * Add a ref_entry to the ref_dir (unsorted), recursing into
526 * subdirectories as necessary. dir must represent the top-level
527 * directory. Return 0 on success.
528 */
529static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
530{
531 dir = find_containing_dir(dir, ref->name, 1);
532 if (!dir)
533 return -1;
534 add_entry_to_dir(dir, ref);
535 return 0;
536}
537
202a56a9
MH
538/*
539 * Emit a warning and return true iff ref1 and ref2 have the same name
540 * and the same sha1. Die if they have the same name but different
541 * sha1s.
542 */
543static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
544{
432ad41e 545 if (strcmp(ref1->name, ref2->name))
202a56a9 546 return 0;
432ad41e
MH
547
548 /* Duplicate name; make sure that they don't conflict: */
549
550 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
551 /* This is impossible by construction */
552 die("Reference directory conflict: %s", ref1->name);
553
554 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
555 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
556
557 warning("Duplicated ref: %s", ref1->name);
558 return 1;
202a56a9
MH
559}
560
e6ed3ca6 561/*
432ad41e
MH
562 * Sort the entries in dir non-recursively (if they are not already
563 * sorted) and remove any duplicate entries.
e6ed3ca6 564 */
d3177275 565static void sort_ref_dir(struct ref_dir *dir)
e9c4c111 566{
202a56a9 567 int i, j;
81a79d8e 568 struct ref_entry *last = NULL;
c774aab9 569
e6ed3ca6
MH
570 /*
571 * This check also prevents passing a zero-length array to qsort(),
572 * which is a problem on some platforms.
573 */
d3177275 574 if (dir->sorted == dir->nr)
e9c4c111 575 return;
c774aab9 576
d3177275 577 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
c774aab9 578
81a79d8e
MH
579 /* Remove any duplicates: */
580 for (i = 0, j = 0; j < dir->nr; j++) {
581 struct ref_entry *entry = dir->entries[j];
582 if (last && is_dup_ref(last, entry))
583 free_ref_entry(entry);
584 else
585 last = dir->entries[i++] = entry;
e9c4c111 586 }
81a79d8e 587 dir->sorted = dir->nr = i;
e9c4c111 588}
c774aab9 589
fcce1703
MH
590/* Include broken references in a do_for_each_ref*() iteration: */
591#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
c774aab9 592
662428f4
MH
593/*
594 * Return true iff the reference described by entry can be resolved to
595 * an object in the database. Emit a warning if the referred-to
596 * object does not exist.
597 */
598static int ref_resolves_to_object(struct ref_entry *entry)
599{
600 if (entry->flag & REF_ISBROKEN)
601 return 0;
602 if (!has_sha1_file(entry->u.value.sha1)) {
603 error("%s does not point to a valid object!", entry->name);
604 return 0;
605 }
606 return 1;
607}
c774aab9 608
7d76fdc8
MH
609/*
610 * current_ref is a performance hack: when iterating over references
611 * using the for_each_ref*() functions, current_ref is set to the
612 * current reference's entry before calling the callback function. If
613 * the callback function calls peel_ref(), then peel_ref() first
614 * checks whether the reference to be peeled is the current reference
615 * (it usually is) and if so, returns that reference's peeled version
616 * if it is available. This avoids a refname lookup in a common case.
617 */
bc5fd6d3 618static struct ref_entry *current_ref;
c774aab9 619
624cac35
MH
620typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
621
622struct ref_entry_cb {
623 const char *base;
624 int trim;
625 int flags;
626 each_ref_fn *fn;
627 void *cb_data;
628};
629
fcce1703 630/*
624cac35
MH
631 * Handle one reference in a do_for_each_ref*()-style iteration,
632 * calling an each_ref_fn for each entry.
fcce1703 633 */
624cac35 634static int do_one_ref(struct ref_entry *entry, void *cb_data)
bc5fd6d3 635{
624cac35 636 struct ref_entry_cb *data = cb_data;
429213e4 637 int retval;
624cac35 638 if (prefixcmp(entry->name, data->base))
bc5fd6d3 639 return 0;
c774aab9 640
624cac35 641 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
662428f4 642 !ref_resolves_to_object(entry))
bc5fd6d3 643 return 0;
c774aab9 644
bc5fd6d3 645 current_ref = entry;
624cac35
MH
646 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
647 entry->flag, data->cb_data);
429213e4
MH
648 current_ref = NULL;
649 return retval;
bc5fd6d3 650}
c774aab9 651
c36b5bc2 652/*
d3177275 653 * Call fn for each reference in dir that has index in the range
432ad41e
MH
654 * offset <= index < dir->nr. Recurse into subdirectories that are in
655 * that index range, sorting them before iterating. This function
624cac35
MH
656 * does not sort dir itself; it should be sorted beforehand. fn is
657 * called for all references, including broken ones.
c36b5bc2 658 */
624cac35
MH
659static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
660 each_ref_entry_fn fn, void *cb_data)
c36b5bc2
MH
661{
662 int i;
d3177275
MH
663 assert(dir->sorted == dir->nr);
664 for (i = offset; i < dir->nr; i++) {
432ad41e
MH
665 struct ref_entry *entry = dir->entries[i];
666 int retval;
667 if (entry->flag & REF_DIR) {
d7826d54
MH
668 struct ref_dir *subdir = get_ref_dir(entry);
669 sort_ref_dir(subdir);
624cac35 670 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
432ad41e 671 } else {
624cac35 672 retval = fn(entry, cb_data);
432ad41e 673 }
c36b5bc2
MH
674 if (retval)
675 return retval;
676 }
677 return 0;
678}
679
b3fd060f 680/*
d3177275 681 * Call fn for each reference in the union of dir1 and dir2, in order
432ad41e
MH
682 * by refname. Recurse into subdirectories. If a value entry appears
683 * in both dir1 and dir2, then only process the version that is in
684 * dir2. The input dirs must already be sorted, but subdirs will be
624cac35
MH
685 * sorted as needed. fn is called for all references, including
686 * broken ones.
b3fd060f 687 */
624cac35
MH
688static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
689 struct ref_dir *dir2,
690 each_ref_entry_fn fn, void *cb_data)
b3fd060f
MH
691{
692 int retval;
693 int i1 = 0, i2 = 0;
694
d3177275
MH
695 assert(dir1->sorted == dir1->nr);
696 assert(dir2->sorted == dir2->nr);
432ad41e
MH
697 while (1) {
698 struct ref_entry *e1, *e2;
699 int cmp;
700 if (i1 == dir1->nr) {
624cac35 701 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
432ad41e
MH
702 }
703 if (i2 == dir2->nr) {
624cac35 704 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
432ad41e
MH
705 }
706 e1 = dir1->entries[i1];
707 e2 = dir2->entries[i2];
708 cmp = strcmp(e1->name, e2->name);
709 if (cmp == 0) {
710 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
711 /* Both are directories; descend them in parallel. */
d7826d54
MH
712 struct ref_dir *subdir1 = get_ref_dir(e1);
713 struct ref_dir *subdir2 = get_ref_dir(e2);
714 sort_ref_dir(subdir1);
715 sort_ref_dir(subdir2);
624cac35
MH
716 retval = do_for_each_entry_in_dirs(
717 subdir1, subdir2, fn, cb_data);
432ad41e
MH
718 i1++;
719 i2++;
720 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
721 /* Both are references; ignore the one from dir1. */
624cac35 722 retval = fn(e2, cb_data);
432ad41e
MH
723 i1++;
724 i2++;
725 } else {
726 die("conflict between reference and directory: %s",
727 e1->name);
728 }
b3fd060f 729 } else {
432ad41e
MH
730 struct ref_entry *e;
731 if (cmp < 0) {
732 e = e1;
b3fd060f 733 i1++;
432ad41e
MH
734 } else {
735 e = e2;
736 i2++;
737 }
738 if (e->flag & REF_DIR) {
d7826d54
MH
739 struct ref_dir *subdir = get_ref_dir(e);
740 sort_ref_dir(subdir);
624cac35
MH
741 retval = do_for_each_entry_in_dir(
742 subdir, 0, fn, cb_data);
432ad41e 743 } else {
624cac35 744 retval = fn(e, cb_data);
b3fd060f
MH
745 }
746 }
747 if (retval)
748 return retval;
749 }
b3fd060f
MH
750}
751
d66da478
MH
752/*
753 * Return true iff refname1 and refname2 conflict with each other.
754 * Two reference names conflict if one of them exactly matches the
755 * leading components of the other; e.g., "foo/bar" conflicts with
756 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
757 * "foo/barbados".
758 */
759static int names_conflict(const char *refname1, const char *refname2)
760{
5a4d4947
MH
761 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
762 ;
763 return (*refname1 == '\0' && *refname2 == '/')
764 || (*refname1 == '/' && *refname2 == '\0');
765}
766
767struct name_conflict_cb {
768 const char *refname;
769 const char *oldrefname;
770 const char *conflicting_refname;
771};
772
624cac35 773static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
5a4d4947
MH
774{
775 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
624cac35 776 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
5a4d4947 777 return 0;
624cac35
MH
778 if (names_conflict(data->refname, entry->name)) {
779 data->conflicting_refname = entry->name;
5a4d4947 780 return 1;
d66da478 781 }
5a4d4947 782 return 0;
d66da478
MH
783}
784
bc5fd6d3
MH
785/*
786 * Return true iff a reference named refname could be created without
624cac35 787 * conflicting with the name of an existing reference in dir. If
5a4d4947
MH
788 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
789 * (e.g., because oldrefname is scheduled for deletion in the same
bc5fd6d3
MH
790 * operation).
791 */
792static int is_refname_available(const char *refname, const char *oldrefname,
d3177275 793 struct ref_dir *dir)
bc5fd6d3 794{
5a4d4947
MH
795 struct name_conflict_cb data;
796 data.refname = refname;
797 data.oldrefname = oldrefname;
798 data.conflicting_refname = NULL;
799
d3177275 800 sort_ref_dir(dir);
624cac35 801 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
5a4d4947
MH
802 error("'%s' exists; cannot create '%s'",
803 data.conflicting_refname, refname);
804 return 0;
bc5fd6d3
MH
805 }
806 return 1;
e1e22e37
LT
807}
808
5e290ff7
JH
809/*
810 * Future: need to be in "struct repository"
811 * when doing a full libification.
812 */
79c7ca54
MH
813static struct ref_cache {
814 struct ref_cache *next;
d12229f5
MH
815 struct ref_entry *loose;
816 struct ref_entry *packed;
9da31cb0
MH
817 /*
818 * The submodule name, or "" for the main repo. We allocate
819 * length 1 rather than FLEX_ARRAY so that the main ref_cache
820 * is initialized correctly.
821 */
822 char name[1];
823} ref_cache, *submodule_ref_caches;
0e88c130 824
760c4512 825static void clear_packed_ref_cache(struct ref_cache *refs)
e1e22e37 826{
d12229f5
MH
827 if (refs->packed) {
828 free_ref_entry(refs->packed);
829 refs->packed = NULL;
830 }
5e290ff7 831}
e1e22e37 832
760c4512
MH
833static void clear_loose_ref_cache(struct ref_cache *refs)
834{
d12229f5
MH
835 if (refs->loose) {
836 free_ref_entry(refs->loose);
837 refs->loose = NULL;
838 }
760c4512
MH
839}
840
79c7ca54 841static struct ref_cache *create_ref_cache(const char *submodule)
e5dbf605 842{
ce40979c 843 int len;
79c7ca54 844 struct ref_cache *refs;
ce40979c
MH
845 if (!submodule)
846 submodule = "";
847 len = strlen(submodule) + 1;
79c7ca54 848 refs = xcalloc(1, sizeof(struct ref_cache) + len);
ce40979c 849 memcpy(refs->name, submodule, len);
e5dbf605
MH
850 return refs;
851}
852
4349a668 853/*
79c7ca54 854 * Return a pointer to a ref_cache for the specified submodule. For
4349a668
MH
855 * the main repository, use submodule==NULL. The returned structure
856 * will be allocated and initialized but not necessarily populated; it
857 * should not be freed.
858 */
79c7ca54 859static struct ref_cache *get_ref_cache(const char *submodule)
4349a668 860{
9da31cb0
MH
861 struct ref_cache *refs;
862
863 if (!submodule || !*submodule)
864 return &ref_cache;
865
866 for (refs = submodule_ref_caches; refs; refs = refs->next)
0e88c130
MH
867 if (!strcmp(submodule, refs->name))
868 return refs;
0e88c130 869
79c7ca54 870 refs = create_ref_cache(submodule);
9da31cb0
MH
871 refs->next = submodule_ref_caches;
872 submodule_ref_caches = refs;
0e88c130 873 return refs;
4349a668
MH
874}
875
8be8bde7 876void invalidate_ref_cache(const char *submodule)
f130b116 877{
c5f29abd
MH
878 struct ref_cache *refs = get_ref_cache(submodule);
879 clear_packed_ref_cache(refs);
880 clear_loose_ref_cache(refs);
5e290ff7 881}
e1e22e37 882
3feb4f0c
MH
883/* The length of a peeled reference line in packed-refs, including EOL: */
884#define PEELED_LINE_LENGTH 42
885
694b7a19
MH
886/*
887 * The packed-refs header line that we write out. Perhaps other
888 * traits will be added later. The trailing space is required.
889 */
890static const char PACKED_REFS_HEADER[] =
891 "# pack-refs with: peeled fully-peeled \n";
892
bc5fd6d3
MH
893/*
894 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
895 * Return a pointer to the refname within the line (null-terminated),
896 * or NULL if there was a problem.
897 */
898static const char *parse_ref_line(char *line, unsigned char *sha1)
899{
900 /*
901 * 42: the answer to everything.
902 *
903 * In this case, it happens to be the answer to
904 * 40 (length of sha1 hex representation)
905 * +1 (space in between hex and name)
906 * +1 (newline at the end of the line)
907 */
908 int len = strlen(line) - 42;
909
910 if (len <= 0)
911 return NULL;
912 if (get_sha1_hex(line, sha1) < 0)
913 return NULL;
914 if (!isspace(line[40]))
915 return NULL;
916 line += 41;
917 if (isspace(*line))
918 return NULL;
919 if (line[len] != '\n')
920 return NULL;
921 line[len] = 0;
922
923 return line;
924}
925
c29c46fa
MH
926/*
927 * Read f, which is a packed-refs file, into dir.
928 *
929 * A comment line of the form "# pack-refs with: " may contain zero or
930 * more traits. We interpret the traits as follows:
931 *
932 * No traits:
933 *
934 * Probably no references are peeled. But if the file contains a
935 * peeled value for a reference, we will use it.
936 *
937 * peeled:
938 *
939 * References under "refs/tags/", if they *can* be peeled, *are*
940 * peeled in this file. References outside of "refs/tags/" are
941 * probably not peeled even if they could have been, but if we find
942 * a peeled value for such a reference we will use it.
943 *
944 * fully-peeled:
945 *
946 * All references in the file that can be peeled are peeled.
947 * Inversely (and this is more important), any references in the
948 * file for which no peeled value is recorded is not peelable. This
949 * trait should typically be written alongside "peeled" for
950 * compatibility with older clients, but we do not require it
951 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
952 */
d3177275 953static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 954{
e9c4c111 955 struct ref_entry *last = NULL;
f4204ab9 956 char refline[PATH_MAX];
c29c46fa 957 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
958
959 while (fgets(refline, sizeof(refline), f)) {
960 unsigned char sha1[20];
dfefa935 961 const char *refname;
f4204ab9
JH
962 static const char header[] = "# pack-refs with:";
963
964 if (!strncmp(refline, header, sizeof(header)-1)) {
965 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
966 if (strstr(traits, " fully-peeled "))
967 peeled = PEELED_FULLY;
968 else if (strstr(traits, " peeled "))
969 peeled = PEELED_TAGS;
f4204ab9
JH
970 /* perhaps other traits later as well */
971 continue;
972 }
973
dfefa935
MH
974 refname = parse_ref_line(refline, sha1);
975 if (refname) {
c29c46fa
MH
976 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
977 if (peeled == PEELED_FULLY ||
978 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
979 last->flag |= REF_KNOWS_PEELED;
d3177275 980 add_ref(dir, last);
f4204ab9
JH
981 continue;
982 }
983 if (last &&
984 refline[0] == '^' &&
3feb4f0c
MH
985 strlen(refline) == PEELED_LINE_LENGTH &&
986 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 987 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 988 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
989 /*
990 * Regardless of what the file header said,
991 * we definitely know the value of *this*
992 * reference:
993 */
994 last->flag |= REF_KNOWS_PEELED;
995 }
f4204ab9 996 }
f4204ab9
JH
997}
998
d3177275 999static struct ref_dir *get_packed_refs(struct ref_cache *refs)
5e290ff7 1000{
d12229f5 1001 if (!refs->packed) {
4349a668
MH
1002 const char *packed_refs_file;
1003 FILE *f;
0bad611b 1004
b9146f51 1005 refs->packed = create_dir_entry(refs, "", 0, 0);
316b097a
MH
1006 if (*refs->name)
1007 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
4349a668
MH
1008 else
1009 packed_refs_file = git_path("packed-refs");
1010 f = fopen(packed_refs_file, "r");
e1e22e37 1011 if (f) {
d7826d54 1012 read_packed_refs(f, get_ref_dir(refs->packed));
e1e22e37 1013 fclose(f);
e1e22e37 1014 }
e1e22e37 1015 }
d7826d54 1016 return get_ref_dir(refs->packed);
e1e22e37
LT
1017}
1018
30249ee6
MH
1019void add_packed_ref(const char *refname, const unsigned char *sha1)
1020{
9da31cb0
MH
1021 add_ref(get_packed_refs(&ref_cache),
1022 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
30249ee6
MH
1023}
1024
abc39098 1025/*
28e6a34e
MH
1026 * Read the loose references from the namespace dirname into dir
1027 * (without recursing). dirname must end with '/'. dir must be the
1028 * directory entry corresponding to dirname.
abc39098 1029 */
423a1afc 1030static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 1031{
423a1afc 1032 struct ref_cache *refs = dir->ref_cache;
d3177275 1033 DIR *d;
0bad611b 1034 const char *path;
d5fdae67 1035 struct dirent *de;
abc39098 1036 int dirnamelen = strlen(dirname);
72b64b44 1037 struct strbuf refname;
0bad611b 1038
3b124823 1039 if (*refs->name)
66a3d20b 1040 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 1041 else
66a3d20b 1042 path = git_path("%s", dirname);
0bad611b 1043
d3177275 1044 d = opendir(path);
d5fdae67
MH
1045 if (!d)
1046 return;
1047
66a3d20b
MH
1048 strbuf_init(&refname, dirnamelen + 257);
1049 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
1050
1051 while ((de = readdir(d)) != NULL) {
1052 unsigned char sha1[20];
1053 struct stat st;
1054 int flag;
d5fdae67
MH
1055 const char *refdir;
1056
1057 if (de->d_name[0] == '.')
1058 continue;
d5fdae67
MH
1059 if (has_extension(de->d_name, ".lock"))
1060 continue;
72b64b44 1061 strbuf_addstr(&refname, de->d_name);
d5fdae67 1062 refdir = *refs->name
72b64b44
MH
1063 ? git_path_submodule(refs->name, "%s", refname.buf)
1064 : git_path("%s", refname.buf);
1065 if (stat(refdir, &st) < 0) {
1066 ; /* silently ignore */
1067 } else if (S_ISDIR(st.st_mode)) {
abc39098 1068 strbuf_addch(&refname, '/');
28e6a34e 1069 add_entry_to_dir(dir,
b9146f51
RS
1070 create_dir_entry(refs, refname.buf,
1071 refname.len, 1));
72b64b44 1072 } else {
3b124823 1073 if (*refs->name) {
f8948e2f 1074 hashclr(sha1);
0bad611b 1075 flag = 0;
72b64b44 1076 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1077 hashclr(sha1);
98ac34b2 1078 flag |= REF_ISBROKEN;
0bad611b 1079 }
72b64b44 1080 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1081 hashclr(sha1);
1082 flag |= REF_ISBROKEN;
1083 }
9f2fb4a3
MH
1084 add_entry_to_dir(dir,
1085 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1086 }
66a3d20b 1087 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1088 }
72b64b44 1089 strbuf_release(&refname);
d5fdae67 1090 closedir(d);
e1e22e37
LT
1091}
1092
d3177275 1093static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1094{
d12229f5 1095 if (!refs->loose) {
28e6a34e
MH
1096 /*
1097 * Mark the top-level directory complete because we
1098 * are about to read the only subdirectory that can
1099 * hold references:
1100 */
b9146f51 1101 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1102 /*
1103 * Create an incomplete entry for "refs/":
1104 */
1105 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1106 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1107 }
d7826d54 1108 return get_ref_dir(refs->loose);
e1e22e37
LT
1109}
1110
ca8db142
LT
1111/* We allow "recursive" symbolic refs. Only within reason, though */
1112#define MAXDEPTH 5
0ebde32c
LT
1113#define MAXREFLEN (1024)
1114
e5fa45c1
JH
1115/*
1116 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1117 * from the loose refs in ref_cache refs. Find <refname> in the
1118 * packed-refs file for the submodule.
e5fa45c1 1119 */
b0626608 1120static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1121 const char *refname, unsigned char *sha1)
0ebde32c 1122{
2c5c66be 1123 struct ref_entry *ref;
d3177275 1124 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1125
432ad41e 1126 ref = find_ref(dir, refname);
b0626608
MH
1127 if (ref == NULL)
1128 return -1;
1129
593f1bb8 1130 memcpy(sha1, ref->u.value.sha1, 20);
b0626608 1131 return 0;
0ebde32c
LT
1132}
1133
b0626608 1134static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1135 const char *refname, unsigned char *sha1,
dfefa935 1136 int recursion)
0ebde32c 1137{
064d51dc 1138 int fd, len;
0ebde32c 1139 char buffer[128], *p;
064d51dc 1140 char *path;
0ebde32c 1141
064d51dc 1142 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1143 return -1;
064d51dc
MH
1144 path = *refs->name
1145 ? git_path_submodule(refs->name, "%s", refname)
1146 : git_path("%s", refname);
1147 fd = open(path, O_RDONLY);
0ebde32c 1148 if (fd < 0)
b0626608 1149 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1150
1151 len = read(fd, buffer, sizeof(buffer)-1);
1152 close(fd);
1153 if (len < 0)
1154 return -1;
1155 while (len && isspace(buffer[len-1]))
1156 len--;
1157 buffer[len] = 0;
1158
1159 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1160 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1161 return 0;
1162
1163 /* Symref? */
1164 if (strncmp(buffer, "ref:", 4))
1165 return -1;
1166 p = buffer + 4;
1167 while (isspace(*p))
1168 p++;
1169
064d51dc 1170 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1171}
1172
85be1fe3 1173int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1174{
1175 int len = strlen(path), retval;
064d51dc 1176 char *submodule;
b0626608 1177 struct ref_cache *refs;
0ebde32c
LT
1178
1179 while (len && path[len-1] == '/')
1180 len--;
1181 if (!len)
1182 return -1;
b0626608
MH
1183 submodule = xstrndup(path, len);
1184 refs = get_ref_cache(submodule);
1185 free(submodule);
1186
064d51dc 1187 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1188 return retval;
1189}
ca8db142 1190
4886b89f 1191/*
63331581
MH
1192 * Return the ref_entry for the given refname from the packed
1193 * references. If it does not exist, return NULL.
4886b89f 1194 */
63331581 1195static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1196{
9da31cb0 1197 return find_ref(get_packed_refs(&ref_cache), refname);
c224ca7f
MH
1198}
1199
8d68493f 1200const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1201{
0104ca09
HO
1202 int depth = MAXDEPTH;
1203 ssize_t len;
a876ed83 1204 char buffer[256];
dfefa935 1205 static char refname_buffer[256];
ca8db142 1206
8da19775
JH
1207 if (flag)
1208 *flag = 0;
1209
dfefa935 1210 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
8384d788
MH
1211 return NULL;
1212
a876ed83 1213 for (;;) {
55956350 1214 char path[PATH_MAX];
a876ed83
JH
1215 struct stat st;
1216 char *buf;
1217 int fd;
8a65ff76 1218
a876ed83
JH
1219 if (--depth < 0)
1220 return NULL;
ca8db142 1221
dfefa935 1222 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1223
a876ed83 1224 if (lstat(path, &st) < 0) {
63331581
MH
1225 struct ref_entry *entry;
1226
c224ca7f
MH
1227 if (errno != ENOENT)
1228 return NULL;
1229 /*
1230 * The loose reference file does not exist;
1231 * check for a packed reference.
1232 */
63331581
MH
1233 entry = get_packed_ref(refname);
1234 if (entry) {
1235 hashcpy(sha1, entry->u.value.sha1);
c224ca7f
MH
1236 if (flag)
1237 *flag |= REF_ISPACKED;
dfefa935 1238 return refname;
434cd0cd 1239 }
c224ca7f
MH
1240 /* The reference is not a packed reference, either. */
1241 if (reading) {
a876ed83 1242 return NULL;
c224ca7f
MH
1243 } else {
1244 hashclr(sha1);
dfefa935 1245 return refname;
c224ca7f 1246 }
a876ed83 1247 }
ca8db142 1248
a876ed83
JH
1249 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1250 if (S_ISLNK(st.st_mode)) {
1251 len = readlink(path, buffer, sizeof(buffer)-1);
7bb2bf8e
MH
1252 if (len < 0)
1253 return NULL;
b54cb795 1254 buffer[len] = 0;
1f58a038
MH
1255 if (!prefixcmp(buffer, "refs/") &&
1256 !check_refname_format(buffer, 0)) {
dfefa935
MH
1257 strcpy(refname_buffer, buffer);
1258 refname = refname_buffer;
8da19775
JH
1259 if (flag)
1260 *flag |= REF_ISSYMREF;
a876ed83
JH
1261 continue;
1262 }
ca8db142 1263 }
a876ed83 1264
7a21632f
DS
1265 /* Is it a directory? */
1266 if (S_ISDIR(st.st_mode)) {
1267 errno = EISDIR;
1268 return NULL;
1269 }
1270
a876ed83
JH
1271 /*
1272 * Anything else, just open it and try to use it as
1273 * a ref
1274 */
1275 fd = open(path, O_RDONLY);
1276 if (fd < 0)
1277 return NULL;
93d26e4c 1278 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83 1279 close(fd);
28775050
MH
1280 if (len < 0)
1281 return NULL;
1282 while (len && isspace(buffer[len-1]))
1283 len--;
1284 buffer[len] = '\0';
a876ed83
JH
1285
1286 /*
1287 * Is it a symbolic ref?
1288 */
28775050 1289 if (prefixcmp(buffer, "ref:"))
a876ed83 1290 break;
55956350
JH
1291 if (flag)
1292 *flag |= REF_ISSYMREF;
a876ed83 1293 buf = buffer + 4;
28775050
MH
1294 while (isspace(*buf))
1295 buf++;
313fb010 1296 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1297 if (flag)
1298 *flag |= REF_ISBROKEN;
313fb010
MH
1299 return NULL;
1300 }
dfefa935 1301 refname = strcpy(refname_buffer, buf);
8a65ff76 1302 }
f989fea0
MH
1303 /* Please note that FETCH_HEAD has a second line containing other data. */
1304 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
55956350
JH
1305 if (flag)
1306 *flag |= REF_ISBROKEN;
a876ed83 1307 return NULL;
629cd3ac 1308 }
dfefa935 1309 return refname;
a876ed83
JH
1310}
1311
96ec7b1e
NTND
1312char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1313{
8cad4744 1314 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1315 return ret ? xstrdup(ret) : NULL;
1316}
1317
d08bae7e
IL
1318/* The argument to filter_refs */
1319struct ref_filter {
1320 const char *pattern;
1321 each_ref_fn *fn;
1322 void *cb_data;
1323};
1324
dfefa935 1325int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1326{
8d68493f 1327 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1328 return 0;
1329 return -1;
8a65ff76
LT
1330}
1331
dfefa935 1332int read_ref(const char *refname, unsigned char *sha1)
c6893323 1333{
dfefa935 1334 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1335}
1336
bc5fd6d3 1337int ref_exists(const char *refname)
ef06b918 1338{
bc5fd6d3
MH
1339 unsigned char sha1[20];
1340 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1341}
1342
85be1fe3 1343static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1344 void *data)
d08bae7e
IL
1345{
1346 struct ref_filter *filter = (struct ref_filter *)data;
dfefa935 1347 if (fnmatch(filter->pattern, refname, 0))
d08bae7e 1348 return 0;
85be1fe3 1349 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1350}
1351
68cf8703
MH
1352enum peel_status {
1353 /* object was peeled successfully: */
1354 PEEL_PEELED = 0,
1355
1356 /*
1357 * object cannot be peeled because the named object (or an
1358 * object referred to by a tag in the peel chain), does not
1359 * exist.
1360 */
1361 PEEL_INVALID = -1,
1362
1363 /* object cannot be peeled because it is not a tag: */
9a489f3c
MH
1364 PEEL_NON_TAG = -2,
1365
1366 /* ref_entry contains no peeled value because it is a symref: */
1367 PEEL_IS_SYMREF = -3,
1368
1369 /*
1370 * ref_entry cannot be peeled because it is broken (i.e., the
1371 * symbolic reference cannot even be resolved to an object
1372 * name):
1373 */
1374 PEEL_BROKEN = -4
68cf8703
MH
1375};
1376
cb2ae1c4
MH
1377/*
1378 * Peel the named object; i.e., if the object is a tag, resolve the
68cf8703
MH
1379 * tag recursively until a non-tag is found. If successful, store the
1380 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1381 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1382 * and leave sha1 unchanged.
cb2ae1c4 1383 */
68cf8703 1384static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
cb2ae1c4
MH
1385{
1386 struct object *o = lookup_unknown_object(name);
1387
1388 if (o->type == OBJ_NONE) {
1389 int type = sha1_object_info(name, NULL);
1390 if (type < 0)
68cf8703 1391 return PEEL_INVALID;
cb2ae1c4
MH
1392 o->type = type;
1393 }
1394
1395 if (o->type != OBJ_TAG)
68cf8703 1396 return PEEL_NON_TAG;
cb2ae1c4
MH
1397
1398 o = deref_tag_noverify(o);
1399 if (!o)
68cf8703 1400 return PEEL_INVALID;
cb2ae1c4
MH
1401
1402 hashcpy(sha1, o->sha1);
68cf8703 1403 return PEEL_PEELED;
cb2ae1c4
MH
1404}
1405
9a489f3c 1406/*
f85354b5
MH
1407 * Peel the entry (if possible) and return its new peel_status. If
1408 * repeel is true, re-peel the entry even if there is an old peeled
1409 * value that is already stored in it.
694b7a19
MH
1410 *
1411 * It is OK to call this function with a packed reference entry that
1412 * might be stale and might even refer to an object that has since
1413 * been garbage-collected. In such a case, if the entry has
1414 * REF_KNOWS_PEELED then leave the status unchanged and return
1415 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
9a489f3c 1416 */
f85354b5 1417static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
9a489f3c
MH
1418{
1419 enum peel_status status;
1420
f85354b5
MH
1421 if (entry->flag & REF_KNOWS_PEELED) {
1422 if (repeel) {
1423 entry->flag &= ~REF_KNOWS_PEELED;
1424 hashclr(entry->u.value.peeled);
1425 } else {
1426 return is_null_sha1(entry->u.value.peeled) ?
1427 PEEL_NON_TAG : PEEL_PEELED;
1428 }
1429 }
9a489f3c
MH
1430 if (entry->flag & REF_ISBROKEN)
1431 return PEEL_BROKEN;
1432 if (entry->flag & REF_ISSYMREF)
1433 return PEEL_IS_SYMREF;
1434
1435 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1436 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1437 entry->flag |= REF_KNOWS_PEELED;
1438 return status;
1439}
1440
dfefa935 1441int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1442{
1443 int flag;
1444 unsigned char base[20];
cf0adba7 1445
dfefa935 1446 if (current_ref && (current_ref->name == refname
9a489f3c 1447 || !strcmp(current_ref->name, refname))) {
f85354b5 1448 if (peel_entry(current_ref, 0))
9a489f3c
MH
1449 return -1;
1450 hashcpy(sha1, current_ref->u.value.peeled);
1451 return 0;
0ae91be0
SP
1452 }
1453
dfefa935 1454 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1455 return -1;
1456
9a489f3c
MH
1457 /*
1458 * If the reference is packed, read its ref_entry from the
1459 * cache in the hope that we already know its peeled value.
1460 * We only try this optimization on packed references because
1461 * (a) forcing the filling of the loose reference cache could
1462 * be expensive and (b) loose references anyway usually do not
1463 * have REF_KNOWS_PEELED.
1464 */
1465 if (flag & REF_ISPACKED) {
f361baeb 1466 struct ref_entry *r = get_packed_ref(refname);
9a489f3c 1467 if (r) {
f85354b5 1468 if (peel_entry(r, 0))
9a489f3c 1469 return -1;
593f1bb8 1470 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1471 return 0;
cf0adba7 1472 }
cf0adba7
JH
1473 }
1474
cb2ae1c4 1475 return peel_object(base, sha1);
cf0adba7
JH
1476}
1477
bc5fd6d3
MH
1478struct warn_if_dangling_data {
1479 FILE *fp;
1480 const char *refname;
1481 const char *msg_fmt;
1482};
1483
1484static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1485 int flags, void *cb_data)
1486{
1487 struct warn_if_dangling_data *d = cb_data;
1488 const char *resolves_to;
1489 unsigned char junk[20];
1490
1491 if (!(flags & REF_ISSYMREF))
1492 return 0;
1493
1494 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1495 if (!resolves_to || strcmp(resolves_to, d->refname))
1496 return 0;
1497
1498 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1499 fputc('\n', d->fp);
bc5fd6d3
MH
1500 return 0;
1501}
1502
1503void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1504{
1505 struct warn_if_dangling_data data;
1506
1507 data.fp = fp;
1508 data.refname = refname;
1509 data.msg_fmt = msg_fmt;
1510 for_each_rawref(warn_if_dangling_symref, &data);
1511}
1512
fcce1703 1513/*
65cf102b 1514 * Call fn for each reference in the specified ref_cache, omitting
624cac35
MH
1515 * references not in the containing_dir of base. fn is called for all
1516 * references, including broken ones. If fn ever returns a non-zero
fcce1703
MH
1517 * value, stop the iteration and return that value; otherwise, return
1518 * 0.
1519 */
65cf102b 1520static int do_for_each_entry(struct ref_cache *refs, const char *base,
624cac35 1521 each_ref_entry_fn fn, void *cb_data)
8a65ff76 1522{
933ac036
MH
1523 struct ref_dir *packed_dir = get_packed_refs(refs);
1524 struct ref_dir *loose_dir = get_loose_refs(refs);
1525 int retval = 0;
1526
1527 if (base && *base) {
1528 packed_dir = find_containing_dir(packed_dir, base, 0);
1529 loose_dir = find_containing_dir(loose_dir, base, 0);
1530 }
1531
1532 if (packed_dir && loose_dir) {
1533 sort_ref_dir(packed_dir);
1534 sort_ref_dir(loose_dir);
624cac35
MH
1535 retval = do_for_each_entry_in_dirs(
1536 packed_dir, loose_dir, fn, cb_data);
933ac036
MH
1537 } else if (packed_dir) {
1538 sort_ref_dir(packed_dir);
624cac35
MH
1539 retval = do_for_each_entry_in_dir(
1540 packed_dir, 0, fn, cb_data);
933ac036
MH
1541 } else if (loose_dir) {
1542 sort_ref_dir(loose_dir);
624cac35
MH
1543 retval = do_for_each_entry_in_dir(
1544 loose_dir, 0, fn, cb_data);
933ac036
MH
1545 }
1546
1547 return retval;
8a65ff76
LT
1548}
1549
624cac35 1550/*
65cf102b 1551 * Call fn for each reference in the specified ref_cache for which the
624cac35
MH
1552 * refname begins with base. If trim is non-zero, then trim that many
1553 * characters off the beginning of each refname before passing the
1554 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1555 * broken references in the iteration. If fn ever returns a non-zero
1556 * value, stop the iteration and return that value; otherwise, return
1557 * 0.
1558 */
65cf102b
MH
1559static int do_for_each_ref(struct ref_cache *refs, const char *base,
1560 each_ref_fn fn, int trim, int flags, void *cb_data)
624cac35
MH
1561{
1562 struct ref_entry_cb data;
1563 data.base = base;
1564 data.trim = trim;
1565 data.flags = flags;
1566 data.fn = fn;
1567 data.cb_data = cb_data;
1568
65cf102b 1569 return do_for_each_entry(refs, base, do_one_ref, &data);
624cac35
MH
1570}
1571
0bad611b 1572static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1573{
1574 unsigned char sha1[20];
8da19775
JH
1575 int flag;
1576
0bad611b
HV
1577 if (submodule) {
1578 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1579 return fn("HEAD", sha1, 0, cb_data);
1580
1581 return 0;
1582 }
1583
c6893323 1584 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1585 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1586
2f34ba32 1587 return 0;
723c31fe
LT
1588}
1589
0bad611b
HV
1590int head_ref(each_ref_fn fn, void *cb_data)
1591{
1592 return do_head_ref(NULL, fn, cb_data);
1593}
1594
9ef6aeb0
HV
1595int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1596{
1597 return do_head_ref(submodule, fn, cb_data);
1598}
1599
cb5d709f 1600int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1601{
9da31cb0 1602 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
a62be77f
SE
1603}
1604
9ef6aeb0
HV
1605int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1606{
65cf102b 1607 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
a62be77f
SE
1608}
1609
2a8177b6
CC
1610int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1611{
9da31cb0 1612 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1613}
1614
9ef6aeb0
HV
1615int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1616 each_ref_fn fn, void *cb_data)
1617{
65cf102b 1618 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1619}
1620
cb5d709f 1621int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1622{
2a8177b6 1623 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1624}
1625
9ef6aeb0
HV
1626int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1627{
1628 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1629}
1630
cb5d709f 1631int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1632{
2a8177b6 1633 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1634}
1635
9ef6aeb0
HV
1636int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1637{
1638 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1639}
1640
cb5d709f 1641int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1642{
2a8177b6 1643 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1644}
1645
9ef6aeb0
HV
1646int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1647{
1648 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1649}
1650
29268700
CC
1651int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1652{
9da31cb0 1653 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1654}
1655
a1bea2c1
JT
1656int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1657{
1658 struct strbuf buf = STRBUF_INIT;
1659 int ret = 0;
1660 unsigned char sha1[20];
1661 int flag;
1662
1663 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1664 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1665 ret = fn(buf.buf, sha1, flag, cb_data);
1666 strbuf_release(&buf);
1667
1668 return ret;
1669}
1670
1671int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1672{
1673 struct strbuf buf = STRBUF_INIT;
1674 int ret;
1675 strbuf_addf(&buf, "%srefs/", get_git_namespace());
9da31cb0 1676 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
a1bea2c1
JT
1677 strbuf_release(&buf);
1678 return ret;
1679}
1680
b09fe971
IL
1681int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1682 const char *prefix, void *cb_data)
d08bae7e
IL
1683{
1684 struct strbuf real_pattern = STRBUF_INIT;
1685 struct ref_filter filter;
d08bae7e
IL
1686 int ret;
1687
b09fe971 1688 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 1689 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1690 else if (prefix)
1691 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1692 strbuf_addstr(&real_pattern, pattern);
1693
894a9d33 1694 if (!has_glob_specials(pattern)) {
9517e6b8 1695 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1696 if (real_pattern.buf[real_pattern.len - 1] != '/')
1697 strbuf_addch(&real_pattern, '/');
1698 /* No need to check for '*', there is none. */
1699 strbuf_addch(&real_pattern, '*');
1700 }
1701
1702 filter.pattern = real_pattern.buf;
1703 filter.fn = fn;
1704 filter.cb_data = cb_data;
1705 ret = for_each_ref(filter_refs, &filter);
1706
1707 strbuf_release(&real_pattern);
1708 return ret;
1709}
1710
b09fe971
IL
1711int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1712{
1713 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1714}
1715
f8948e2f
JH
1716int for_each_rawref(each_ref_fn fn, void *cb_data)
1717{
9da31cb0 1718 return do_for_each_ref(&ref_cache, "", fn, 0,
f8948e2f 1719 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1720}
1721
4577e483 1722const char *prettify_refname(const char *name)
a9c37a72 1723{
a9c37a72
DB
1724 return name + (
1725 !prefixcmp(name, "refs/heads/") ? 11 :
1726 !prefixcmp(name, "refs/tags/") ? 10 :
1727 !prefixcmp(name, "refs/remotes/") ? 13 :
1728 0);
1729}
1730
79803322
SP
1731const char *ref_rev_parse_rules[] = {
1732 "%.*s",
1733 "refs/%.*s",
1734 "refs/tags/%.*s",
1735 "refs/heads/%.*s",
1736 "refs/remotes/%.*s",
1737 "refs/remotes/%.*s/HEAD",
1738 NULL
1739};
1740
1741int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1742{
1743 const char **p;
1744 const int abbrev_name_len = strlen(abbrev_name);
1745
1746 for (p = rules; *p; p++) {
1747 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1748 return 1;
1749 }
1750 }
1751
1752 return 0;
1753}
1754
e5f38ec3 1755static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1756 const unsigned char *old_sha1, int mustexist)
1757{
c6893323 1758 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1759 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1760 unlock_ref(lock);
1761 return NULL;
1762 }
a89fccd2 1763 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1764 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1765 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1766 unlock_ref(lock);
1767 return NULL;
1768 }
1769 return lock;
1770}
1771
7155b727 1772static int remove_empty_directories(const char *file)
bc7127ef
JH
1773{
1774 /* we want to create a file but there is a directory there;
1775 * if that is an empty directory (or a directory that contains
1776 * only empty directories), remove them.
1777 */
7155b727
JS
1778 struct strbuf path;
1779 int result;
bc7127ef 1780
7155b727
JS
1781 strbuf_init(&path, 20);
1782 strbuf_addstr(&path, file);
1783
a0f4afbe 1784 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1785
1786 strbuf_release(&path);
1787
1788 return result;
bc7127ef
JH
1789}
1790
ff74f7f1
JH
1791/*
1792 * *string and *len will only be substituted, and *string returned (for
1793 * later free()ing) if the string passed in is a magic short-hand form
1794 * to name a branch.
1795 */
1796static char *substitute_branch_name(const char **string, int *len)
1797{
1798 struct strbuf buf = STRBUF_INIT;
1799 int ret = interpret_branch_name(*string, &buf);
1800
1801 if (ret == *len) {
1802 size_t size;
1803 *string = strbuf_detach(&buf, &size);
1804 *len = size;
1805 return (char *)*string;
1806 }
1807
1808 return NULL;
1809}
1810
1811int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1812{
1813 char *last_branch = substitute_branch_name(&str, &len);
1814 const char **p, *r;
1815 int refs_found = 0;
1816
1817 *ref = NULL;
1818 for (p = ref_rev_parse_rules; *p; p++) {
1819 char fullref[PATH_MAX];
1820 unsigned char sha1_from_ref[20];
1821 unsigned char *this_result;
1822 int flag;
1823
1824 this_result = refs_found ? sha1_from_ref : sha1;
1825 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1826 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1827 if (r) {
1828 if (!refs_found++)
1829 *ref = xstrdup(r);
1830 if (!warn_ambiguous_refs)
1831 break;
55956350 1832 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1833 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1834 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1835 warning("ignoring broken ref %s.", fullref);
1836 }
ff74f7f1
JH
1837 }
1838 free(last_branch);
1839 return refs_found;
1840}
1841
1842int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1843{
1844 char *last_branch = substitute_branch_name(&str, &len);
1845 const char **p;
1846 int logs_found = 0;
1847
1848 *log = NULL;
1849 for (p = ref_rev_parse_rules; *p; p++) {
1850 struct stat st;
1851 unsigned char hash[20];
1852 char path[PATH_MAX];
1853 const char *ref, *it;
1854
1855 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 1856 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
1857 if (!ref)
1858 continue;
1859 if (!stat(git_path("logs/%s", path), &st) &&
1860 S_ISREG(st.st_mode))
1861 it = path;
1862 else if (strcmp(ref, path) &&
1863 !stat(git_path("logs/%s", ref), &st) &&
1864 S_ISREG(st.st_mode))
1865 it = ref;
1866 else
1867 continue;
1868 if (!logs_found++) {
1869 *log = xstrdup(it);
1870 hashcpy(sha1, hash);
1871 }
1872 if (!warn_ambiguous_refs)
1873 break;
1874 }
1875 free(last_branch);
1876 return logs_found;
1877}
1878
dfefa935
MH
1879static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1880 const unsigned char *old_sha1,
1881 int flags, int *type_p)
4bd18c43 1882{
434cd0cd 1883 char *ref_file;
dfefa935 1884 const char *orig_refname = refname;
4bd18c43 1885 struct ref_lock *lock;
5cc3cef9 1886 int last_errno = 0;
acd3b9ec 1887 int type, lflags;
4431fcc4 1888 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1889 int missing = 0;
4bd18c43
SP
1890
1891 lock = xcalloc(1, sizeof(struct ref_lock));
1892 lock->lock_fd = -1;
1893
8d68493f 1894 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 1895 if (!refname && errno == EISDIR) {
bc7127ef
JH
1896 /* we are trying to lock foo but we used to
1897 * have foo/bar which now does not exist;
1898 * it is normal for the empty directory 'foo'
1899 * to remain.
1900 */
dfefa935 1901 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
1902 if (remove_empty_directories(ref_file)) {
1903 last_errno = errno;
dfefa935 1904 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
1905 goto error_return;
1906 }
8d68493f 1907 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 1908 }
68db31cc
SV
1909 if (type_p)
1910 *type_p = type;
dfefa935 1911 if (!refname) {
5cc3cef9 1912 last_errno = errno;
818f477c 1913 error("unable to resolve reference %s: %s",
dfefa935 1914 orig_refname, strerror(errno));
5cc3cef9 1915 goto error_return;
4bd18c43 1916 }
5bdd8d4a 1917 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1918 /* When the ref did not exist and we are creating it,
1919 * make sure there is no existing ref that is packed
1920 * whose name begins with our refname, nor a ref whose
1921 * name is a proper prefix of our refname.
1922 */
5bdd8d4a 1923 if (missing &&
9da31cb0 1924 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
f475e08e 1925 last_errno = ENOTDIR;
c976d415 1926 goto error_return;
f475e08e 1927 }
22a3844e 1928
c33d5174 1929 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1930
acd3b9ec
JH
1931 lflags = LOCK_DIE_ON_ERROR;
1932 if (flags & REF_NODEREF) {
dfefa935 1933 refname = orig_refname;
acd3b9ec
JH
1934 lflags |= LOCK_NODEREF;
1935 }
dfefa935
MH
1936 lock->ref_name = xstrdup(refname);
1937 lock->orig_ref_name = xstrdup(orig_refname);
1938 ref_file = git_path("%s", refname);
5bdd8d4a 1939 if (missing)
68db31cc
SV
1940 lock->force_write = 1;
1941 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1942 lock->force_write = 1;
4bd18c43 1943
5cc3cef9
JH
1944 if (safe_create_leading_directories(ref_file)) {
1945 last_errno = errno;
1946 error("unable to create directory for %s", ref_file);
1947 goto error_return;
1948 }
4bd18c43 1949
acd3b9ec 1950 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1951 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1952
1953 error_return:
1954 unlock_ref(lock);
1955 errno = last_errno;
1956 return NULL;
4bd18c43
SP
1957}
1958
dfefa935 1959struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 1960{
53cce84c 1961 char refpath[PATH_MAX];
dfefa935 1962 if (check_refname_format(refname, 0))
4bd18c43 1963 return NULL;
dfefa935 1964 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 1965 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1966}
1967
dfefa935
MH
1968struct ref_lock *lock_any_ref_for_update(const char *refname,
1969 const unsigned char *old_sha1, int flags)
4bd18c43 1970{
dfefa935 1971 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 1972 return NULL;
dfefa935 1973 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
c0277d15
JH
1974}
1975
fec3137f
MH
1976/*
1977 * Write an entry to the packed-refs file for the specified refname.
1978 * If peeled is non-NULL, write it as the entry's peeled value.
1979 */
1980static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
1981 unsigned char *peeled)
d66da478 1982{
d66da478
MH
1983 char line[PATH_MAX + 100];
1984 int len;
1985
d66da478
MH
1986 len = snprintf(line, sizeof(line), "%s %s\n",
1987 sha1_to_hex(sha1), refname);
1988 /* this should not happen but just being defensive */
1989 if (len > sizeof(line))
1990 die("too long a refname '%s'", refname);
fec3137f
MH
1991 write_or_die(fd, line, len);
1992
1993 if (peeled) {
1994 if (snprintf(line, sizeof(line), "^%s\n",
1995 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
1996 die("internal error");
1997 write_or_die(fd, line, PEELED_LINE_LENGTH);
1998 }
1999}
2000
32d462ce
MH
2001struct ref_to_prune {
2002 struct ref_to_prune *next;
2003 unsigned char sha1[20];
2004 char name[FLEX_ARRAY];
2005};
2006
2007struct pack_refs_cb_data {
2008 unsigned int flags;
2009 struct ref_to_prune *ref_to_prune;
0f29920f 2010 int fd;
32d462ce
MH
2011};
2012
12e77559 2013static int pack_one_ref(struct ref_entry *entry, void *cb_data)
32d462ce
MH
2014{
2015 struct pack_refs_cb_data *cb = cb_data;
f85354b5 2016 enum peel_status peel_status;
b2a8226d 2017 int is_tag_ref = !prefixcmp(entry->name, "refs/tags/");
32d462ce
MH
2018
2019 /* ALWAYS pack refs that were already packed or are tags */
12e77559
MH
2020 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref &&
2021 !(entry->flag & REF_ISPACKED))
32d462ce
MH
2022 return 0;
2023
b2a8226d
MH
2024 /* Do not pack symbolic or broken refs: */
2025 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2026 return 0;
2027
f85354b5 2028 peel_status = peel_entry(entry, 1);
0f29920f 2029 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
f85354b5
MH
2030 die("internal error peeling reference %s (%s)",
2031 entry->name, sha1_to_hex(entry->u.value.sha1));
0f29920f
MH
2032 write_packed_entry(cb->fd, entry->name, entry->u.value.sha1,
2033 peel_status == PEEL_PEELED ?
2034 entry->u.value.peeled : NULL);
32d462ce 2035
8d3725b9
MH
2036 /* If the ref was already packed, there is no need to prune it. */
2037 if ((cb->flags & PACK_REFS_PRUNE) && !(entry->flag & REF_ISPACKED)) {
12e77559 2038 int namelen = strlen(entry->name) + 1;
32d462ce 2039 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
12e77559
MH
2040 hashcpy(n->sha1, entry->u.value.sha1);
2041 strcpy(n->name, entry->name);
32d462ce
MH
2042 n->next = cb->ref_to_prune;
2043 cb->ref_to_prune = n;
2044 }
d66da478
MH
2045 return 0;
2046}
2047
32d462ce
MH
2048/*
2049 * Remove empty parents, but spare refs/ and immediate subdirs.
2050 * Note: munges *name.
2051 */
2052static void try_remove_empty_parents(char *name)
2053{
2054 char *p, *q;
2055 int i;
2056 p = name;
2057 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2058 while (*p && *p != '/')
2059 p++;
2060 /* tolerate duplicate slashes; see check_refname_format() */
2061 while (*p == '/')
2062 p++;
2063 }
2064 for (q = p; *q; q++)
2065 ;
2066 while (1) {
2067 while (q > p && *q != '/')
2068 q--;
2069 while (q > p && *(q-1) == '/')
2070 q--;
2071 if (q == p)
2072 break;
2073 *q = '\0';
2074 if (rmdir(git_path("%s", name)))
2075 break;
2076 }
2077}
2078
2079/* make sure nobody touched the ref, and unlink */
2080static void prune_ref(struct ref_to_prune *r)
2081{
2082 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2083
2084 if (lock) {
2085 unlink_or_warn(git_path("%s", r->name));
2086 unlock_ref(lock);
2087 try_remove_empty_parents(r->name);
2088 }
2089}
2090
2091static void prune_refs(struct ref_to_prune *r)
2092{
2093 while (r) {
2094 prune_ref(r);
2095 r = r->next;
2096 }
2097}
2098
26a063a1
JH
2099static struct lock_file packlock;
2100
32d462ce
MH
2101int pack_refs(unsigned int flags)
2102{
32d462ce
MH
2103 struct pack_refs_cb_data cbdata;
2104
2105 memset(&cbdata, 0, sizeof(cbdata));
2106 cbdata.flags = flags;
2107
0f29920f
MH
2108 cbdata.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"),
2109 LOCK_DIE_ON_ERROR);
32d462ce 2110
0f29920f 2111 write_or_die(cbdata.fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
32d462ce 2112
9da31cb0 2113 do_for_each_entry(&ref_cache, "", pack_one_ref, &cbdata);
d9470330 2114 if (commit_lock_file(&packlock) < 0)
32d462ce
MH
2115 die_errno("unable to overwrite old ref-pack file");
2116 prune_refs(cbdata.ref_to_prune);
2117 return 0;
2118}
2119
fec3137f 2120static int repack_ref_fn(struct ref_entry *entry, void *cb_data)
c0277d15 2121{
fec3137f
MH
2122 int *fd = cb_data;
2123 enum peel_status peel_status;
2124
ab292bc4
MH
2125 if (entry->flag & REF_ISBROKEN) {
2126 /* This shouldn't happen to packed refs. */
2127 error("%s is broken!", entry->name);
c0277d15 2128 return 0;
ab292bc4
MH
2129 }
2130 if (!has_sha1_file(entry->u.value.sha1)) {
2131 unsigned char sha1[20];
2132 int flags;
2133
2134 if (read_ref_full(entry->name, sha1, 0, &flags))
2135 /* We should at least have found the packed ref. */
2136 die("Internal error");
2137 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED))
2138 /*
2139 * This packed reference is overridden by a
2140 * loose reference, so it is OK that its value
2141 * is no longer valid; for example, it might
2142 * refer to an object that has been garbage
2143 * collected. For this purpose we don't even
2144 * care whether the loose reference itself is
2145 * invalid, broken, symbolic, etc. Silently
2146 * omit the packed reference from the output.
2147 */
2148 return 0;
2149 /*
2150 * There is no overriding loose reference, so the fact
2151 * that this reference doesn't refer to a valid object
2152 * indicates some kind of repository corruption.
2153 * Report the problem, then omit the reference from
2154 * the output.
2155 */
2156 error("%s does not point to a valid object!", entry->name);
2157 return 0;
2158 }
2159
f85354b5 2160 peel_status = peel_entry(entry, 0);
fec3137f
MH
2161 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2162 peel_status == PEEL_PEELED ?
2163 entry->u.value.peeled : NULL);
694b7a19 2164
d66da478
MH
2165 return 0;
2166}
2167
c0277d15
JH
2168static int repack_without_ref(const char *refname)
2169{
506a760d 2170 int fd;
7618fd80
MH
2171 struct ref_dir *packed;
2172
2173 if (!get_packed_ref(refname))
2174 return 0; /* refname does not exist in packed refs */
2175
506a760d
MH
2176 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
2177 if (fd < 0) {
1b018fd9 2178 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 2179 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 2180 }
9da31cb0
MH
2181 clear_packed_ref_cache(&ref_cache);
2182 packed = get_packed_refs(&ref_cache);
506a760d
MH
2183 /* Remove refname from the cache. */
2184 if (remove_entry(packed, refname) == -1) {
2185 /*
2186 * The packed entry disappeared while we were
2187 * acquiring the lock.
2188 */
2189 rollback_lock_file(&packlock);
2190 return 0;
2191 }
694b7a19 2192 write_or_die(fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
506a760d 2193 do_for_each_entry_in_dir(packed, 0, repack_ref_fn, &fd);
c0277d15
JH
2194 return commit_lock_file(&packlock);
2195}
2196
eca35a25 2197int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
2198{
2199 struct ref_lock *lock;
eca35a25 2200 int err, i = 0, ret = 0, flag = 0;
c0277d15 2201
547d058f 2202 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
2203 if (!lock)
2204 return 1;
045a476f 2205 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 2206 /* loose */
547d058f
RS
2207 i = strlen(lock->lk->filename) - 5; /* .lock */
2208 lock->lk->filename[i] = 0;
2209 err = unlink_or_warn(lock->lk->filename);
691f1a28 2210 if (err && errno != ENOENT)
c0277d15 2211 ret = 1;
691f1a28 2212
547d058f 2213 lock->lk->filename[i] = '.';
c0277d15
JH
2214 }
2215 /* removing the loose one could have resurrected an earlier
2216 * packed one. Also, if it was not loose we need to repack
2217 * without it.
2218 */
b274a714 2219 ret |= repack_without_ref(lock->ref_name);
c0277d15 2220
691f1a28 2221 unlink_or_warn(git_path("logs/%s", lock->ref_name));
9da31cb0 2222 clear_loose_ref_cache(&ref_cache);
c0277d15
JH
2223 unlock_ref(lock);
2224 return ret;
4bd18c43
SP
2225}
2226
765c2258
PH
2227/*
2228 * People using contrib's git-new-workdir have .git/logs/refs ->
2229 * /some/other/path/.git/logs/refs, and that may live on another device.
2230 *
2231 * IOW, to avoid cross device rename errors, the temporary renamed log must
2232 * live into logs/refs.
2233 */
2234#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2235
dfefa935 2236int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 2237{
c976d415
LH
2238 unsigned char sha1[20], orig_sha1[20];
2239 int flag = 0, logmoved = 0;
2240 struct ref_lock *lock;
c976d415 2241 struct stat loginfo;
dfefa935 2242 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 2243 const char *symref = NULL;
c976d415 2244
450d4c0f 2245 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 2246 return error("reflog for %s is a symlink", oldrefname);
c976d415 2247
8d68493f 2248 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 2249 if (flag & REF_ISSYMREF)
fa58186c 2250 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 2251 oldrefname);
eca35a25 2252 if (!symref)
dfefa935 2253 return error("refname %s not found", oldrefname);
c976d415 2254
9da31cb0 2255 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
c976d415
LH
2256 return 1;
2257
9da31cb0 2258 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
c976d415
LH
2259 return 1;
2260
dfefa935 2261 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 2262 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 2263 oldrefname, strerror(errno));
c976d415 2264
dfefa935
MH
2265 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2266 error("unable to delete old %s", oldrefname);
c976d415
LH
2267 goto rollback;
2268 }
2269
dfefa935
MH
2270 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2271 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 2272 if (errno==EISDIR) {
dfefa935
MH
2273 if (remove_empty_directories(git_path("%s", newrefname))) {
2274 error("Directory not empty: %s", newrefname);
c976d415
LH
2275 goto rollback;
2276 }
2277 } else {
dfefa935 2278 error("unable to delete existing %s", newrefname);
c976d415
LH
2279 goto rollback;
2280 }
2281 }
2282
dfefa935
MH
2283 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2284 error("unable to create directory for %s", newrefname);
c976d415
LH
2285 goto rollback;
2286 }
2287
2288 retry:
dfefa935 2289 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
d9e74d57
JR
2290 if (errno==EISDIR || errno==ENOTDIR) {
2291 /*
2292 * rename(a, b) when b is an existing
2293 * directory ought to result in ISDIR, but
2294 * Solaris 5.8 gives ENOTDIR. Sheesh.
2295 */
dfefa935
MH
2296 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2297 error("Directory not empty: logs/%s", newrefname);
c976d415
LH
2298 goto rollback;
2299 }
2300 goto retry;
2301 } else {
765c2258 2302 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
dfefa935 2303 newrefname, strerror(errno));
c976d415
LH
2304 goto rollback;
2305 }
2306 }
2307 logmoved = log;
2308
dfefa935 2309 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2310 if (!lock) {
dfefa935 2311 error("unable to lock %s for update", newrefname);
c976d415
LH
2312 goto rollback;
2313 }
c976d415
LH
2314 lock->force_write = 1;
2315 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2316 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2317 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2318 goto rollback;
2319 }
2320
2321 return 0;
2322
2323 rollback:
dfefa935 2324 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2325 if (!lock) {
dfefa935 2326 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2327 goto rollbacklog;
2328 }
2329
2330 lock->force_write = 1;
2331 flag = log_all_ref_updates;
2332 log_all_ref_updates = 0;
2333 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2334 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2335 log_all_ref_updates = flag;
2336
2337 rollbacklog:
dfefa935 2338 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2339 error("unable to restore logfile %s from %s: %s",
dfefa935 2340 oldrefname, newrefname, strerror(errno));
c976d415 2341 if (!logmoved && log &&
dfefa935 2342 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2343 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2344 oldrefname, strerror(errno));
c976d415
LH
2345
2346 return 1;
2347}
2348
435fc852 2349int close_ref(struct ref_lock *lock)
b531394d
BC
2350{
2351 if (close_lock_file(lock->lk))
2352 return -1;
2353 lock->lock_fd = -1;
2354 return 0;
2355}
2356
435fc852 2357int commit_ref(struct ref_lock *lock)
b531394d
BC
2358{
2359 if (commit_lock_file(lock->lk))
2360 return -1;
2361 lock->lock_fd = -1;
2362 return 0;
2363}
2364
e5f38ec3 2365void unlock_ref(struct ref_lock *lock)
4bd18c43 2366{
4ed7cd3a
BC
2367 /* Do not free lock->lk -- atexit() still looks at them */
2368 if (lock->lk)
2369 rollback_lock_file(lock->lk);
434cd0cd 2370 free(lock->ref_name);
1655707c 2371 free(lock->orig_ref_name);
4bd18c43
SP
2372 free(lock);
2373}
2374
0ec29a47
JH
2375/*
2376 * copy the reflog message msg to buf, which has been allocated sufficiently
2377 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2378 * because reflog file is one line per entry.
2379 */
2380static int copy_msg(char *buf, const char *msg)
2381{
2382 char *cp = buf;
2383 char c;
2384 int wasspace = 1;
2385
2386 *cp++ = '\t';
2387 while ((c = *msg++)) {
2388 if (wasspace && isspace(c))
2389 continue;
2390 wasspace = isspace(c);
2391 if (wasspace)
2392 c = ' ';
2393 *cp++ = c;
2394 }
2395 while (buf < cp && isspace(cp[-1]))
2396 cp--;
2397 *cp++ = '\n';
2398 return cp - buf;
2399}
2400
dfefa935 2401int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2402{
859c3017 2403 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2404
dfefa935 2405 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2406 if (log_all_ref_updates &&
dfefa935
MH
2407 (!prefixcmp(refname, "refs/heads/") ||
2408 !prefixcmp(refname, "refs/remotes/") ||
2409 !prefixcmp(refname, "refs/notes/") ||
2410 !strcmp(refname, "HEAD"))) {
157aaea5 2411 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2412 return error("unable to create directory for %s",
157aaea5 2413 logfile);
6de08ae6
SP
2414 oflags |= O_CREAT;
2415 }
2416
157aaea5 2417 logfd = open(logfile, oflags, 0666);
6de08ae6 2418 if (logfd < 0) {
1974bf62 2419 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2420 return 0;
3b463c3f
JH
2421
2422 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2423 if (remove_empty_directories(logfile)) {
3b463c3f 2424 return error("There are still logs under '%s'",
157aaea5 2425 logfile);
3b463c3f 2426 }
157aaea5 2427 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2428 }
2429
2430 if (logfd < 0)
2431 return error("Unable to append to %s: %s",
157aaea5 2432 logfile, strerror(errno));
6de08ae6
SP
2433 }
2434
157aaea5 2435 adjust_shared_perm(logfile);
859c3017
EM
2436 close(logfd);
2437 return 0;
2438}
443b92b6 2439
dfefa935 2440static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2441 const unsigned char *new_sha1, const char *msg)
2442{
2443 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2444 unsigned maxlen, len;
2445 int msglen;
157aaea5 2446 char log_file[PATH_MAX];
859c3017
EM
2447 char *logrec;
2448 const char *committer;
2449
2450 if (log_all_ref_updates < 0)
2451 log_all_ref_updates = !is_bare_repository();
2452
dfefa935 2453 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2454 if (result)
2455 return result;
2456
2457 logfd = open(log_file, oflags);
2458 if (logfd < 0)
2459 return 0;
0ec29a47 2460 msglen = msg ? strlen(msg) : 0;
774751a8 2461 committer = git_committer_info(0);
8ac65937
JH
2462 maxlen = strlen(committer) + msglen + 100;
2463 logrec = xmalloc(maxlen);
2464 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2465 sha1_to_hex(old_sha1),
2466 sha1_to_hex(new_sha1),
8ac65937
JH
2467 committer);
2468 if (msglen)
0ec29a47 2469 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2470 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2471 free(logrec);
91c8d590 2472 if (close(logfd) != 0 || written != len)
9a13f0b7 2473 return error("Unable to append to %s", log_file);
6de08ae6
SP
2474 return 0;
2475}
2476
c3b0dec5
LT
2477static int is_branch(const char *refname)
2478{
2479 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2480}
2481
4bd18c43
SP
2482int write_ref_sha1(struct ref_lock *lock,
2483 const unsigned char *sha1, const char *logmsg)
2484{
2485 static char term = '\n';
c3b0dec5 2486 struct object *o;
4bd18c43
SP
2487
2488 if (!lock)
95fc7512 2489 return -1;
a89fccd2 2490 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2491 unlock_ref(lock);
2492 return 0;
95fc7512 2493 }
c3b0dec5
LT
2494 o = parse_object(sha1);
2495 if (!o) {
7be8b3ba 2496 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2497 lock->ref_name, sha1_to_hex(sha1));
2498 unlock_ref(lock);
2499 return -1;
2500 }
2501 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2502 error("Trying to write non-commit object %s to branch %s",
2503 sha1_to_hex(sha1), lock->ref_name);
2504 unlock_ref(lock);
2505 return -1;
2506 }
93822c22
AW
2507 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2508 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2509 || close_ref(lock) < 0) {
c33d5174 2510 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2511 unlock_ref(lock);
2512 return -1;
2513 }
9da31cb0 2514 clear_loose_ref_cache(&ref_cache);
bd104db1
NP
2515 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2516 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2517 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2518 unlock_ref(lock);
2519 return -1;
2520 }
605fac8b
NP
2521 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2522 /*
2523 * Special hack: If a branch is updated directly and HEAD
2524 * points to it (may happen on the remote side of a push
2525 * for example) then logically the HEAD reflog should be
2526 * updated too.
2527 * A generic solution implies reverse symref information,
2528 * but finding all symrefs pointing to the given branch
2529 * would be rather costly for this rare event (the direct
2530 * update of a branch) to be worth it. So let's cheat and
2531 * check with HEAD only which should cover 99% of all usage
2532 * scenarios (even 100% of the default ones).
2533 */
2534 unsigned char head_sha1[20];
2535 int head_flag;
2536 const char *head_ref;
8cad4744 2537 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2538 if (head_ref && (head_flag & REF_ISSYMREF) &&
2539 !strcmp(head_ref, lock->ref_name))
2540 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2541 }
b531394d 2542 if (commit_ref(lock)) {
434cd0cd 2543 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2544 unlock_ref(lock);
2545 return -1;
2546 }
4bd18c43
SP
2547 unlock_ref(lock);
2548 return 0;
95fc7512 2549}
d556fae2 2550
8b5157e4
NP
2551int create_symref(const char *ref_target, const char *refs_heads_master,
2552 const char *logmsg)
41b625b0
NP
2553{
2554 const char *lockpath;
2555 char ref[1000];
2556 int fd, len, written;
a4f34cbb 2557 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2558 unsigned char old_sha1[20], new_sha1[20];
2559
2560 if (logmsg && read_ref(ref_target, old_sha1))
2561 hashclr(old_sha1);
41b625b0 2562
d48744d1
JH
2563 if (safe_create_leading_directories(git_HEAD) < 0)
2564 return error("unable to create directory for %s", git_HEAD);
2565
41b625b0
NP
2566#ifndef NO_SYMLINK_HEAD
2567 if (prefer_symlink_refs) {
2568 unlink(git_HEAD);
2569 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2570 goto done;
41b625b0
NP
2571 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2572 }
2573#endif
2574
2575 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2576 if (sizeof(ref) <= len) {
2577 error("refname too long: %s", refs_heads_master);
47fc52e2 2578 goto error_free_return;
41b625b0
NP
2579 }
2580 lockpath = mkpath("%s.lock", git_HEAD);
2581 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2582 if (fd < 0) {
2583 error("Unable to open %s for writing", lockpath);
47fc52e2 2584 goto error_free_return;
41b625b0
NP
2585 }
2586 written = write_in_full(fd, ref, len);
91c8d590 2587 if (close(fd) != 0 || written != len) {
41b625b0 2588 error("Unable to write to %s", lockpath);
47fc52e2 2589 goto error_unlink_return;
41b625b0
NP
2590 }
2591 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2592 error("Unable to create %s", git_HEAD);
47fc52e2 2593 goto error_unlink_return;
41b625b0
NP
2594 }
2595 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2596 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2597 error_unlink_return:
691f1a28 2598 unlink_or_warn(lockpath);
47fc52e2
JH
2599 error_free_return:
2600 free(git_HEAD);
2601 return -1;
41b625b0 2602 }
8b5157e4 2603
ee96d11b 2604#ifndef NO_SYMLINK_HEAD
8b5157e4 2605 done:
ee96d11b 2606#endif
8b5157e4
NP
2607 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2608 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2609
47fc52e2 2610 free(git_HEAD);
41b625b0
NP
2611 return 0;
2612}
2613
16d7cc90
JH
2614static char *ref_msg(const char *line, const char *endp)
2615{
2616 const char *ep;
16d7cc90 2617 line += 82;
182af834
PH
2618 ep = memchr(line, '\n', endp - line);
2619 if (!ep)
2620 ep = endp;
2621 return xmemdupz(line, ep - line);
16d7cc90
JH
2622}
2623
dfefa935
MH
2624int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2625 unsigned char *sha1, char **msg,
2626 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2627{
e5229042 2628 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2629 char *tz_c;
e29cb53a 2630 int logfd, tz, reccnt = 0;
d556fae2
SP
2631 struct stat st;
2632 unsigned long date;
e5229042 2633 unsigned char logged_sha1[20];
cb48cb58 2634 void *log_mapped;
dc49cd76 2635 size_t mapsz;
d556fae2 2636
dfefa935 2637 logfile = git_path("logs/%s", refname);
d556fae2
SP
2638 logfd = open(logfile, O_RDONLY, 0);
2639 if (logfd < 0)
d824cbba 2640 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2641 fstat(logfd, &st);
2642 if (!st.st_size)
2643 die("Log %s is empty.", logfile);
dc49cd76
SP
2644 mapsz = xsize_t(st.st_size);
2645 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2646 logdata = log_mapped;
d556fae2
SP
2647 close(logfd);
2648
e5229042 2649 lastrec = NULL;
d556fae2
SP
2650 rec = logend = logdata + st.st_size;
2651 while (logdata < rec) {
e29cb53a 2652 reccnt++;
d556fae2
SP
2653 if (logdata < rec && *(rec-1) == '\n')
2654 rec--;
e5229042
SP
2655 lastgt = NULL;
2656 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2657 rec--;
e5229042
SP
2658 if (*rec == '>')
2659 lastgt = rec;
2660 }
2661 if (!lastgt)
d556fae2 2662 die("Log %s is corrupt.", logfile);
e5229042 2663 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2664 if (date <= at_time || cnt == 0) {
76a44c5c 2665 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2666 if (msg)
2667 *msg = ref_msg(rec, logend);
2668 if (cutoff_time)
2669 *cutoff_time = date;
2670 if (cutoff_tz)
2671 *cutoff_tz = tz;
2672 if (cutoff_cnt)
76a44c5c 2673 *cutoff_cnt = reccnt - 1;
e5229042
SP
2674 if (lastrec) {
2675 if (get_sha1_hex(lastrec, logged_sha1))
2676 die("Log %s is corrupt.", logfile);
2677 if (get_sha1_hex(rec + 41, sha1))
2678 die("Log %s is corrupt.", logfile);
a89fccd2 2679 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2680 warning("Log %s has gap after %s.",
73013afd 2681 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 2682 }
e5f38ec3
JH
2683 }
2684 else if (date == at_time) {
e5229042
SP
2685 if (get_sha1_hex(rec + 41, sha1))
2686 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
2687 }
2688 else {
e5229042
SP
2689 if (get_sha1_hex(rec + 41, logged_sha1))
2690 die("Log %s is corrupt.", logfile);
a89fccd2 2691 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2692 warning("Log %s unexpectedly ended on %s.",
73013afd 2693 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
2694 }
2695 }
dc49cd76 2696 munmap(log_mapped, mapsz);
d556fae2
SP
2697 return 0;
2698 }
e5229042 2699 lastrec = rec;
ab2a1a32
JH
2700 if (cnt > 0)
2701 cnt--;
d556fae2
SP
2702 }
2703
e5229042
SP
2704 rec = logdata;
2705 while (rec < logend && *rec != '>' && *rec != '\n')
2706 rec++;
2707 if (rec == logend || *rec == '\n')
d556fae2 2708 die("Log %s is corrupt.", logfile);
e5229042 2709 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
2710 tz = strtoul(tz_c, NULL, 10);
2711 if (get_sha1_hex(logdata, sha1))
2712 die("Log %s is corrupt.", logfile);
d1a4489a
JK
2713 if (is_null_sha1(sha1)) {
2714 if (get_sha1_hex(logdata + 41, sha1))
2715 die("Log %s is corrupt.", logfile);
2716 }
16d7cc90
JH
2717 if (msg)
2718 *msg = ref_msg(logdata, logend);
dc49cd76 2719 munmap(log_mapped, mapsz);
16d7cc90
JH
2720
2721 if (cutoff_time)
2722 *cutoff_time = date;
2723 if (cutoff_tz)
2724 *cutoff_tz = tz;
2725 if (cutoff_cnt)
2726 *cutoff_cnt = reccnt;
2727 return 1;
d556fae2 2728}
2ff81662 2729
9a7a183b
JH
2730static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
2731{
2732 unsigned char osha1[20], nsha1[20];
2733 char *email_end, *message;
2734 unsigned long timestamp;
2735 int tz;
2736
2737 /* old SP new SP name <email> SP time TAB msg LF */
2738 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
2739 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
2740 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
2741 !(email_end = strchr(sb->buf + 82, '>')) ||
2742 email_end[1] != ' ' ||
2743 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2744 !message || message[0] != ' ' ||
2745 (message[1] != '+' && message[1] != '-') ||
2746 !isdigit(message[2]) || !isdigit(message[3]) ||
2747 !isdigit(message[4]) || !isdigit(message[5]))
2748 return 0; /* corrupt? */
2749 email_end[1] = '\0';
2750 tz = strtol(message + 1, NULL, 10);
2751 if (message[6] != '\t')
2752 message += 6;
2753 else
2754 message += 7;
2755 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
2756}
2757
98f85ff4
JH
2758static char *find_beginning_of_line(char *bob, char *scan)
2759{
2760 while (bob < scan && *(--scan) != '\n')
2761 ; /* keep scanning backwards */
2762 /*
2763 * Return either beginning of the buffer, or LF at the end of
2764 * the previous line.
2765 */
2766 return scan;
2767}
2768
2769int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2ff81662 2770{
8ca78803 2771 struct strbuf sb = STRBUF_INIT;
98f85ff4
JH
2772 FILE *logfp;
2773 long pos;
2774 int ret = 0, at_tail = 1;
2ff81662 2775
7ae07c1b 2776 logfp = fopen(git_path("logs/%s", refname), "r");
2ff81662 2777 if (!logfp)
883d60fa 2778 return -1;
101d15e0 2779
98f85ff4
JH
2780 /* Jump to the end */
2781 if (fseek(logfp, 0, SEEK_END) < 0)
2782 return error("cannot seek back reflog for %s: %s",
2783 refname, strerror(errno));
2784 pos = ftell(logfp);
2785 while (!ret && 0 < pos) {
2786 int cnt;
2787 size_t nread;
2788 char buf[BUFSIZ];
2789 char *endp, *scanp;
2790
2791 /* Fill next block from the end */
2792 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
2793 if (fseek(logfp, pos - cnt, SEEK_SET))
2794 return error("cannot seek back reflog for %s: %s",
2795 refname, strerror(errno));
2796 nread = fread(buf, cnt, 1, logfp);
e4ca819a 2797 if (nread != 1)
98f85ff4
JH
2798 return error("cannot read %d bytes from reflog for %s: %s",
2799 cnt, refname, strerror(errno));
2800 pos -= cnt;
2801
2802 scanp = endp = buf + cnt;
2803 if (at_tail && scanp[-1] == '\n')
2804 /* Looking at the final LF at the end of the file */
2805 scanp--;
2806 at_tail = 0;
2807
2808 while (buf < scanp) {
2809 /*
2810 * terminating LF of the previous line, or the beginning
2811 * of the buffer.
2812 */
2813 char *bp;
2814
2815 bp = find_beginning_of_line(buf, scanp);
2816
2817 if (*bp != '\n') {
2818 strbuf_splice(&sb, 0, 0, buf, endp - buf);
2819 if (pos)
2820 break; /* need to fill another block */
2821 scanp = buf - 1; /* leave loop */
2822 } else {
2823 /*
2824 * (bp + 1) thru endp is the beginning of the
2825 * current line we have in sb
2826 */
2827 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
2828 scanp = bp;
2829 endp = bp + 1;
2830 }
2831 ret = show_one_reflog_ent(&sb, fn, cb_data);
2832 strbuf_reset(&sb);
2833 if (ret)
2834 break;
9d33f7c2 2835 }
101d15e0 2836
2ff81662 2837 }
98f85ff4 2838 if (!ret && sb.len)
9a7a183b 2839 ret = show_one_reflog_ent(&sb, fn, cb_data);
98f85ff4 2840
2ff81662 2841 fclose(logfp);
8ca78803 2842 strbuf_release(&sb);
2266bf27 2843 return ret;
2ff81662 2844}
e29cb53a 2845
dfefa935 2846int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 2847{
98f85ff4
JH
2848 FILE *logfp;
2849 struct strbuf sb = STRBUF_INIT;
2850 int ret = 0;
2851
2852 logfp = fopen(git_path("logs/%s", refname), "r");
2853 if (!logfp)
2854 return -1;
101d15e0 2855
98f85ff4
JH
2856 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
2857 ret = show_one_reflog_ent(&sb, fn, cb_data);
2858 fclose(logfp);
2859 strbuf_release(&sb);
2860 return ret;
2861}
989c0e5d
MH
2862/*
2863 * Call fn for each reflog in the namespace indicated by name. name
2864 * must be empty or end with '/'. Name will be used as a scratch
2865 * space, but its contents will be restored before return.
2866 */
2867static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 2868{
989c0e5d 2869 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 2870 int retval = 0;
93c603fc 2871 struct dirent *de;
989c0e5d 2872 int oldlen = name->len;
eb8381c8 2873
93c603fc 2874 if (!d)
989c0e5d 2875 return name->len ? errno : 0;
eb8381c8 2876
93c603fc
MH
2877 while ((de = readdir(d)) != NULL) {
2878 struct stat st;
eb8381c8 2879
93c603fc
MH
2880 if (de->d_name[0] == '.')
2881 continue;
93c603fc
MH
2882 if (has_extension(de->d_name, ".lock"))
2883 continue;
989c0e5d
MH
2884 strbuf_addstr(name, de->d_name);
2885 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2886 ; /* silently ignore */
93c603fc 2887 } else {
eb8381c8 2888 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
2889 strbuf_addch(name, '/');
2890 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
2891 } else {
2892 unsigned char sha1[20];
989c0e5d
MH
2893 if (read_ref_full(name->buf, sha1, 0, NULL))
2894 retval = error("bad ref for %s", name->buf);
eb8381c8 2895 else
989c0e5d 2896 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
2897 }
2898 if (retval)
2899 break;
2900 }
989c0e5d 2901 strbuf_setlen(name, oldlen);
eb8381c8 2902 }
93c603fc 2903 closedir(d);
eb8381c8
NP
2904 return retval;
2905}
2906
2907int for_each_reflog(each_ref_fn fn, void *cb_data)
2908{
989c0e5d
MH
2909 int retval;
2910 struct strbuf name;
2911 strbuf_init(&name, PATH_MAX);
2912 retval = do_for_each_reflog(&name, fn, cb_data);
2913 strbuf_release(&name);
2914 return retval;
eb8381c8 2915}
3d9f037c
CR
2916
2917int update_ref(const char *action, const char *refname,
2918 const unsigned char *sha1, const unsigned char *oldval,
2919 int flags, enum action_on_err onerr)
2920{
2921 static struct ref_lock *lock;
2922 lock = lock_any_ref_for_update(refname, oldval, flags);
2923 if (!lock) {
2924 const char *str = "Cannot lock the ref '%s'.";
2925 switch (onerr) {
2926 case MSG_ON_ERR: error(str, refname); break;
2927 case DIE_ON_ERR: die(str, refname); break;
2928 case QUIET_ON_ERR: break;
2929 }
2930 return 1;
2931 }
2932 if (write_ref_sha1(lock, sha1, action) < 0) {
2933 const char *str = "Cannot update the ref '%s'.";
2934 switch (onerr) {
2935 case MSG_ON_ERR: error(str, refname); break;
2936 case DIE_ON_ERR: die(str, refname); break;
2937 case QUIET_ON_ERR: break;
2938 }
2939 return 1;
2940 }
2941 return 0;
2942}
cda69f48 2943
5483f799 2944struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
2945{
2946 for ( ; list; list = list->next)
2947 if (!strcmp(list->name, name))
5483f799 2948 return (struct ref *)list;
cda69f48
JK
2949 return NULL;
2950}
7c2b3029
JK
2951
2952/*
2953 * generate a format suitable for scanf from a ref_rev_parse_rules
2954 * rule, that is replace the "%.*s" spec with a "%s" spec
2955 */
2956static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2957{
2958 char *spec;
2959
2960 spec = strstr(rule, "%.*s");
2961 if (!spec || strstr(spec + 4, "%.*s"))
2962 die("invalid rule in ref_rev_parse_rules: %s", rule);
2963
2964 /* copy all until spec */
2965 strncpy(scanf_fmt, rule, spec - rule);
2966 scanf_fmt[spec - rule] = '\0';
2967 /* copy new spec */
2968 strcat(scanf_fmt, "%s");
2969 /* copy remaining rule */
2970 strcat(scanf_fmt, spec + 4);
2971
2972 return;
2973}
2974
dfefa935 2975char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
2976{
2977 int i;
2978 static char **scanf_fmts;
2979 static int nr_rules;
2980 char *short_name;
2981
2982 /* pre generate scanf formats from ref_rev_parse_rules[] */
2983 if (!nr_rules) {
2984 size_t total_len = 0;
2985
2986 /* the rule list is NULL terminated, count them first */
2987 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2988 /* no +1 because strlen("%s") < strlen("%.*s") */
2989 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2990
2991 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2992
2993 total_len = 0;
2994 for (i = 0; i < nr_rules; i++) {
2995 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2996 + total_len;
2997 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2998 total_len += strlen(ref_rev_parse_rules[i]);
2999 }
3000 }
3001
3002 /* bail out if there are no rules */
3003 if (!nr_rules)
dfefa935 3004 return xstrdup(refname);
7c2b3029 3005
dfefa935
MH
3006 /* buffer for scanf result, at most refname must fit */
3007 short_name = xstrdup(refname);
7c2b3029
JK
3008
3009 /* skip first rule, it will always match */
3010 for (i = nr_rules - 1; i > 0 ; --i) {
3011 int j;
6e7b3309 3012 int rules_to_fail = i;
7c2b3029
JK
3013 int short_name_len;
3014
dfefa935 3015 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
3016 continue;
3017
3018 short_name_len = strlen(short_name);
3019
6e7b3309
BW
3020 /*
3021 * in strict mode, all (except the matched one) rules
3022 * must fail to resolve to a valid non-ambiguous ref
3023 */
3024 if (strict)
3025 rules_to_fail = nr_rules;
3026
7c2b3029
JK
3027 /*
3028 * check if the short name resolves to a valid ref,
3029 * but use only rules prior to the matched one
3030 */
6e7b3309 3031 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 3032 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
3033 char refname[PATH_MAX];
3034
6e7b3309
BW
3035 /* skip matched rule */
3036 if (i == j)
3037 continue;
3038
7c2b3029
JK
3039 /*
3040 * the short name is ambiguous, if it resolves
3041 * (with this previous rule) to a valid ref
3042 * read_ref() returns 0 on success
3043 */
3044 mksnpath(refname, sizeof(refname),
3045 rule, short_name_len, short_name);
c6893323 3046 if (ref_exists(refname))
7c2b3029
JK
3047 break;
3048 }
3049
3050 /*
3051 * short name is non-ambiguous if all previous rules
3052 * haven't resolved to a valid ref
3053 */
6e7b3309 3054 if (j == rules_to_fail)
7c2b3029
JK
3055 return short_name;
3056 }
3057
3058 free(short_name);
dfefa935 3059 return xstrdup(refname);
7c2b3029 3060}
daebaa78
JH
3061
3062static struct string_list *hide_refs;
3063
3064int parse_hide_refs_config(const char *var, const char *value, const char *section)
3065{
3066 if (!strcmp("transfer.hiderefs", var) ||
3067 /* NEEDSWORK: use parse_config_key() once both are merged */
3068 (!prefixcmp(var, section) && var[strlen(section)] == '.' &&
3069 !strcmp(var + strlen(section), ".hiderefs"))) {
3070 char *ref;
3071 int len;
3072
3073 if (!value)
3074 return config_error_nonbool(var);
3075 ref = xstrdup(value);
3076 len = strlen(ref);
3077 while (len && ref[len - 1] == '/')
3078 ref[--len] = '\0';
3079 if (!hide_refs) {
3080 hide_refs = xcalloc(1, sizeof(*hide_refs));
3081 hide_refs->strdup_strings = 1;
3082 }
3083 string_list_append(hide_refs, ref);
3084 }
3085 return 0;
3086}
3087
3088int ref_is_hidden(const char *refname)
3089{
3090 struct string_list_item *item;
3091
3092 if (!hide_refs)
3093 return 0;
3094 for_each_string_list_item(item, hide_refs) {
3095 int len;
3096 if (prefixcmp(refname, item->string))
3097 continue;
3098 len = strlen(item->string);
3099 if (!refname[len] || refname[len] == '/')
3100 return 1;
3101 }
3102 return 0;
3103}