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