First batch for 2.1
[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
9ba89f48
FC
75 if (!strcmp(refname, "@"))
76 /* Refname is a single character '@'. */
77 return -1;
78
bc5fd6d3
MH
79 while (1) {
80 /* We are at the start of a path component. */
81 component_len = check_refname_component(refname, flags);
dac529e4 82 if (component_len <= 0) {
bc5fd6d3
MH
83 if ((flags & REFNAME_REFSPEC_PATTERN) &&
84 refname[0] == '*' &&
85 (refname[1] == '\0' || refname[1] == '/')) {
86 /* Accept one wildcard as a full refname component. */
87 flags &= ~REFNAME_REFSPEC_PATTERN;
88 component_len = 1;
89 } else {
90 return -1;
91 }
92 }
93 component_count++;
94 if (refname[component_len] == '\0')
95 break;
96 /* Skip to next component. */
97 refname += component_len + 1;
98 }
99
100 if (refname[component_len - 1] == '.')
101 return -1; /* Refname ends with '.'. */
102 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
103 return -1; /* Refname has only one component. */
104 return 0;
105}
106
107struct ref_entry;
e1e22e37 108
28e6a34e
MH
109/*
110 * Information used (along with the information in ref_entry) to
111 * describe a single cached reference. This data structure only
112 * occurs embedded in a union in struct ref_entry, and only when
113 * (ref_entry->flag & REF_DIR) is zero.
114 */
593f1bb8 115struct ref_value {
6c6f58df
MH
116 /*
117 * The name of the object to which this reference resolves
118 * (which may be a tag object). If REF_ISBROKEN, this is
119 * null. If REF_ISSYMREF, then this is the name of the object
120 * referred to by the last reference in the symlink chain.
121 */
593f1bb8 122 unsigned char sha1[20];
6c6f58df
MH
123
124 /*
125 * If REF_KNOWS_PEELED, then this field holds the peeled value
126 * of this reference, or null if the reference is known not to
2312a793
MH
127 * be peelable. See the documentation for peel_ref() for an
128 * exact definition of "peelable".
6c6f58df 129 */
593f1bb8
MH
130 unsigned char peeled[20];
131};
132
f006c42a
MH
133struct ref_cache;
134
28e6a34e
MH
135/*
136 * Information used (along with the information in ref_entry) to
137 * describe a level in the hierarchy of references. This data
138 * structure only occurs embedded in a union in struct ref_entry, and
139 * only when (ref_entry.flag & REF_DIR) is set. In that case,
140 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
141 * in the directory have already been read:
142 *
143 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
144 * or packed references, already read.
145 *
146 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
147 * references that hasn't been read yet (nor has any of its
148 * subdirectories).
149 *
150 * Entries within a directory are stored within a growable array of
151 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
152 * sorted are sorted by their component name in strcmp() order and the
153 * remaining entries are unsorted.
154 *
155 * Loose references are read lazily, one directory at a time. When a
156 * directory of loose references is read, then all of the references
157 * in that directory are stored, and REF_INCOMPLETE stubs are created
158 * for any subdirectories, but the subdirectories themselves are not
159 * read. The reading is triggered by get_ref_dir().
160 */
d3177275 161struct ref_dir {
e9c4c111 162 int nr, alloc;
e6ed3ca6
MH
163
164 /*
165 * Entries with index 0 <= i < sorted are sorted by name. New
166 * entries are appended to the list unsorted, and are sorted
167 * only when required; thus we avoid the need to sort the list
168 * after the addition of every reference.
169 */
170 int sorted;
171
f006c42a
MH
172 /* A pointer to the ref_cache that contains this ref_dir. */
173 struct ref_cache *ref_cache;
174
d3177275 175 struct ref_entry **entries;
e9c4c111
JP
176};
177
89df9c84
MH
178/*
179 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
180 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
181 * refs.h.
182 */
183
184/*
185 * The field ref_entry->u.value.peeled of this value entry contains
186 * the correct peeled value for the reference, which might be
187 * null_sha1 if the reference is not a tag or if it is broken.
188 */
432ad41e 189#define REF_KNOWS_PEELED 0x08
28e6a34e
MH
190
191/* ref_entry represents a directory of references */
432ad41e 192#define REF_DIR 0x10
cf0adba7 193
28e6a34e
MH
194/*
195 * Entry has not yet been read from disk (used only for REF_DIR
196 * entries representing loose references)
197 */
198#define REF_INCOMPLETE 0x20
199
432ad41e
MH
200/*
201 * A ref_entry represents either a reference or a "subdirectory" of
28e6a34e
MH
202 * references.
203 *
204 * Each directory in the reference namespace is represented by a
205 * ref_entry with (flags & REF_DIR) set and containing a subdir member
206 * that holds the entries in that directory that have been read so
207 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
208 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
209 * used for loose reference directories.
210 *
211 * References are represented by a ref_entry with (flags & REF_DIR)
212 * unset and a value member that describes the reference's value. The
213 * flag member is at the ref_entry level, but it is also needed to
214 * interpret the contents of the value field (in other words, a
215 * ref_value object is not very much use without the enclosing
216 * ref_entry).
432ad41e
MH
217 *
218 * Reference names cannot end with slash and directories' names are
219 * always stored with a trailing slash (except for the top-level
220 * directory, which is always denoted by ""). This has two nice
221 * consequences: (1) when the entries in each subdir are sorted
222 * lexicographically by name (as they usually are), the references in
223 * a whole tree can be generated in lexicographic order by traversing
224 * the tree in left-to-right, depth-first order; (2) the names of
225 * references and subdirectories cannot conflict, and therefore the
226 * presence of an empty subdirectory does not block the creation of a
227 * similarly-named reference. (The fact that reference names with the
228 * same leading components can conflict *with each other* is a
229 * separate issue that is regulated by is_refname_available().)
230 *
231 * Please note that the name field contains the fully-qualified
232 * reference (or subdirectory) name. Space could be saved by only
233 * storing the relative names. But that would require the full names
234 * to be generated on the fly when iterating in do_for_each_ref(), and
235 * would break callback functions, who have always been able to assume
236 * that the name strings that they are passed will not be freed during
237 * the iteration.
238 */
bc5fd6d3
MH
239struct ref_entry {
240 unsigned char flag; /* ISSYMREF? ISPACKED? */
593f1bb8 241 union {
432ad41e
MH
242 struct ref_value value; /* if not (flags&REF_DIR) */
243 struct ref_dir subdir; /* if (flags&REF_DIR) */
593f1bb8 244 } u;
432ad41e
MH
245 /*
246 * The full name of the reference (e.g., "refs/heads/master")
247 * or the full name of the directory with a trailing slash
248 * (e.g., "refs/heads/"):
249 */
bc5fd6d3
MH
250 char name[FLEX_ARRAY];
251};
e1e22e37 252
28e6a34e
MH
253static void read_loose_refs(const char *dirname, struct ref_dir *dir);
254
d7826d54
MH
255static struct ref_dir *get_ref_dir(struct ref_entry *entry)
256{
28e6a34e 257 struct ref_dir *dir;
d7826d54 258 assert(entry->flag & REF_DIR);
28e6a34e
MH
259 dir = &entry->u.subdir;
260 if (entry->flag & REF_INCOMPLETE) {
261 read_loose_refs(entry->name, dir);
262 entry->flag &= ~REF_INCOMPLETE;
263 }
264 return dir;
d7826d54
MH
265}
266
cddc4258
MH
267static struct ref_entry *create_ref_entry(const char *refname,
268 const unsigned char *sha1, int flag,
269 int check_name)
e1e22e37
LT
270{
271 int len;
cddc4258 272 struct ref_entry *ref;
e1e22e37 273
09116a1c 274 if (check_name &&
dfefa935
MH
275 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
276 die("Reference has invalid format: '%s'", refname);
cddc4258
MH
277 len = strlen(refname) + 1;
278 ref = xmalloc(sizeof(struct ref_entry) + len);
593f1bb8
MH
279 hashcpy(ref->u.value.sha1, sha1);
280 hashclr(ref->u.value.peeled);
cddc4258
MH
281 memcpy(ref->name, refname, len);
282 ref->flag = flag;
283 return ref;
284}
285
432ad41e
MH
286static void clear_ref_dir(struct ref_dir *dir);
287
732134ed
MH
288static void free_ref_entry(struct ref_entry *entry)
289{
27b5587c
MH
290 if (entry->flag & REF_DIR) {
291 /*
292 * Do not use get_ref_dir() here, as that might
293 * trigger the reading of loose refs.
294 */
295 clear_ref_dir(&entry->u.subdir);
296 }
732134ed
MH
297 free(entry);
298}
299
432ad41e
MH
300/*
301 * Add a ref_entry to the end of dir (unsorted). Entry is always
302 * stored directly in dir; no recursion into subdirectories is
303 * done.
304 */
305static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
cddc4258 306{
432ad41e
MH
307 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
308 dir->entries[dir->nr++] = entry;
654ad400
MH
309 /* optimize for the case that entries are added in order */
310 if (dir->nr == 1 ||
311 (dir->nr == dir->sorted + 1 &&
312 strcmp(dir->entries[dir->nr - 2]->name,
313 dir->entries[dir->nr - 1]->name) < 0))
314 dir->sorted = dir->nr;
c774aab9
JP
315}
316
432ad41e
MH
317/*
318 * Clear and free all entries in dir, recursively.
319 */
d3177275 320static void clear_ref_dir(struct ref_dir *dir)
bc5fd6d3
MH
321{
322 int i;
d3177275
MH
323 for (i = 0; i < dir->nr; i++)
324 free_ref_entry(dir->entries[i]);
325 free(dir->entries);
326 dir->sorted = dir->nr = dir->alloc = 0;
327 dir->entries = NULL;
bc5fd6d3
MH
328}
329
432ad41e
MH
330/*
331 * Create a struct ref_entry object for the specified dirname.
332 * dirname is the name of the directory with a trailing slash (e.g.,
333 * "refs/heads/") or "" for the top-level directory.
334 */
f006c42a 335static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
b9146f51
RS
336 const char *dirname, size_t len,
337 int incomplete)
432ad41e
MH
338{
339 struct ref_entry *direntry;
432ad41e 340 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
b9146f51
RS
341 memcpy(direntry->name, dirname, len);
342 direntry->name[len] = '\0';
f006c42a 343 direntry->u.subdir.ref_cache = ref_cache;
28e6a34e 344 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
432ad41e
MH
345 return direntry;
346}
347
e9c4c111 348static int ref_entry_cmp(const void *a, const void *b)
c774aab9 349{
e9c4c111
JP
350 struct ref_entry *one = *(struct ref_entry **)a;
351 struct ref_entry *two = *(struct ref_entry **)b;
352 return strcmp(one->name, two->name);
353}
c774aab9 354
d3177275 355static void sort_ref_dir(struct ref_dir *dir);
bc5fd6d3 356
e1980c9d
JH
357struct string_slice {
358 size_t len;
359 const char *str;
360};
361
362static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
363{
c971ddfd
RS
364 const struct string_slice *key = key_;
365 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
366 int cmp = strncmp(key->str, ent->name, key->len);
e1980c9d
JH
367 if (cmp)
368 return cmp;
c971ddfd 369 return '\0' - (unsigned char)ent->name[key->len];
e1980c9d
JH
370}
371
432ad41e 372/*
9fc0a648
MH
373 * Return the index of the entry with the given refname from the
374 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
375 * no such entry is found. dir must already be complete.
432ad41e 376 */
9fc0a648 377static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
bc5fd6d3 378{
e1980c9d
JH
379 struct ref_entry **r;
380 struct string_slice key;
bc5fd6d3 381
432ad41e 382 if (refname == NULL || !dir->nr)
9fc0a648 383 return -1;
bc5fd6d3 384
d3177275 385 sort_ref_dir(dir);
e1980c9d
JH
386 key.len = len;
387 key.str = refname;
388 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
389 ref_entry_cmp_sslice);
bc5fd6d3
MH
390
391 if (r == NULL)
9fc0a648 392 return -1;
bc5fd6d3 393
9fc0a648 394 return r - dir->entries;
bc5fd6d3
MH
395}
396
f348ac92
MH
397/*
398 * Search for a directory entry directly within dir (without
399 * recursing). Sort dir if necessary. subdirname must be a directory
400 * name (i.e., end in '/'). If mkdir is set, then create the
401 * directory if it is missing; otherwise, return NULL if the desired
28e6a34e 402 * directory cannot be found. dir must already be complete.
f348ac92 403 */
3f3aa1bc 404static struct ref_dir *search_for_subdir(struct ref_dir *dir,
dd02e728
RS
405 const char *subdirname, size_t len,
406 int mkdir)
f348ac92 407{
9fc0a648
MH
408 int entry_index = search_ref_dir(dir, subdirname, len);
409 struct ref_entry *entry;
410 if (entry_index == -1) {
f348ac92
MH
411 if (!mkdir)
412 return NULL;
28e6a34e
MH
413 /*
414 * Since dir is complete, the absence of a subdir
415 * means that the subdir really doesn't exist;
416 * therefore, create an empty record for it but mark
417 * the record complete.
418 */
b9146f51 419 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
f348ac92 420 add_entry_to_dir(dir, entry);
9fc0a648
MH
421 } else {
422 entry = dir->entries[entry_index];
f348ac92 423 }
3f3aa1bc 424 return get_ref_dir(entry);
f348ac92
MH
425}
426
432ad41e
MH
427/*
428 * If refname is a reference name, find the ref_dir within the dir
429 * tree that should hold refname. If refname is a directory name
430 * (i.e., ends in '/'), then return that ref_dir itself. dir must
28e6a34e
MH
431 * represent the top-level directory and must already be complete.
432 * Sort ref_dirs and recurse into subdirectories as necessary. If
433 * mkdir is set, then create any missing directories; otherwise,
434 * return NULL if the desired directory cannot be found.
432ad41e
MH
435 */
436static struct ref_dir *find_containing_dir(struct ref_dir *dir,
437 const char *refname, int mkdir)
438{
5fa04418 439 const char *slash;
5fa04418 440 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
dd02e728 441 size_t dirnamelen = slash - refname + 1;
3f3aa1bc 442 struct ref_dir *subdir;
dd02e728 443 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
663c1295
JH
444 if (!subdir) {
445 dir = NULL;
f348ac92 446 break;
432ad41e 447 }
3f3aa1bc 448 dir = subdir;
432ad41e
MH
449 }
450
432ad41e
MH
451 return dir;
452}
453
454/*
455 * Find the value entry with the given name in dir, sorting ref_dirs
456 * and recursing into subdirectories as necessary. If the name is not
457 * found or it corresponds to a directory entry, return NULL.
458 */
459static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
460{
9fc0a648 461 int entry_index;
432ad41e
MH
462 struct ref_entry *entry;
463 dir = find_containing_dir(dir, refname, 0);
464 if (!dir)
465 return NULL;
9fc0a648
MH
466 entry_index = search_ref_dir(dir, refname, strlen(refname));
467 if (entry_index == -1)
468 return NULL;
469 entry = dir->entries[entry_index];
470 return (entry->flag & REF_DIR) ? NULL : entry;
432ad41e
MH
471}
472
506a760d
MH
473/*
474 * Remove the entry with the given name from dir, recursing into
475 * subdirectories as necessary. If refname is the name of a directory
476 * (i.e., ends with '/'), then remove the directory and its contents.
477 * If the removal was successful, return the number of entries
478 * remaining in the directory entry that contained the deleted entry.
479 * If the name was not found, return -1. Please note that this
480 * function only deletes the entry from the cache; it does not delete
481 * it from the filesystem or ensure that other cache entries (which
482 * might be symbolic references to the removed entry) are updated.
483 * Nor does it remove any containing dir entries that might be made
484 * empty by the removal. dir must represent the top-level directory
485 * and must already be complete.
486 */
487static int remove_entry(struct ref_dir *dir, const char *refname)
488{
489 int refname_len = strlen(refname);
490 int entry_index;
491 struct ref_entry *entry;
492 int is_dir = refname[refname_len - 1] == '/';
493 if (is_dir) {
494 /*
495 * refname represents a reference directory. Remove
496 * the trailing slash; otherwise we will get the
497 * directory *representing* refname rather than the
498 * one *containing* it.
499 */
500 char *dirname = xmemdupz(refname, refname_len - 1);
501 dir = find_containing_dir(dir, dirname, 0);
502 free(dirname);
503 } else {
504 dir = find_containing_dir(dir, refname, 0);
505 }
506 if (!dir)
507 return -1;
508 entry_index = search_ref_dir(dir, refname, refname_len);
509 if (entry_index == -1)
510 return -1;
511 entry = dir->entries[entry_index];
512
513 memmove(&dir->entries[entry_index],
514 &dir->entries[entry_index + 1],
515 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
516 );
517 dir->nr--;
518 if (dir->sorted > entry_index)
519 dir->sorted--;
520 free_ref_entry(entry);
521 return dir->nr;
432ad41e
MH
522}
523
524/*
525 * Add a ref_entry to the ref_dir (unsorted), recursing into
526 * subdirectories as necessary. dir must represent the top-level
527 * directory. Return 0 on success.
528 */
529static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
530{
531 dir = find_containing_dir(dir, ref->name, 1);
532 if (!dir)
533 return -1;
534 add_entry_to_dir(dir, ref);
535 return 0;
536}
537
202a56a9
MH
538/*
539 * Emit a warning and return true iff ref1 and ref2 have the same name
540 * and the same sha1. Die if they have the same name but different
541 * sha1s.
542 */
543static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
544{
432ad41e 545 if (strcmp(ref1->name, ref2->name))
202a56a9 546 return 0;
432ad41e
MH
547
548 /* Duplicate name; make sure that they don't conflict: */
549
550 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
551 /* This is impossible by construction */
552 die("Reference directory conflict: %s", ref1->name);
553
554 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
555 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
556
557 warning("Duplicated ref: %s", ref1->name);
558 return 1;
202a56a9
MH
559}
560
e6ed3ca6 561/*
432ad41e
MH
562 * Sort the entries in dir non-recursively (if they are not already
563 * sorted) and remove any duplicate entries.
e6ed3ca6 564 */
d3177275 565static void sort_ref_dir(struct ref_dir *dir)
e9c4c111 566{
202a56a9 567 int i, j;
81a79d8e 568 struct ref_entry *last = NULL;
c774aab9 569
e6ed3ca6
MH
570 /*
571 * This check also prevents passing a zero-length array to qsort(),
572 * which is a problem on some platforms.
573 */
d3177275 574 if (dir->sorted == dir->nr)
e9c4c111 575 return;
c774aab9 576
d3177275 577 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
c774aab9 578
81a79d8e
MH
579 /* Remove any duplicates: */
580 for (i = 0, j = 0; j < dir->nr; j++) {
581 struct ref_entry *entry = dir->entries[j];
582 if (last && is_dup_ref(last, entry))
583 free_ref_entry(entry);
584 else
585 last = dir->entries[i++] = entry;
e9c4c111 586 }
81a79d8e 587 dir->sorted = dir->nr = i;
e9c4c111 588}
c774aab9 589
fcce1703
MH
590/* Include broken references in a do_for_each_ref*() iteration: */
591#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
c774aab9 592
662428f4
MH
593/*
594 * Return true iff the reference described by entry can be resolved to
595 * an object in the database. Emit a warning if the referred-to
596 * object does not exist.
597 */
598static int ref_resolves_to_object(struct ref_entry *entry)
599{
600 if (entry->flag & REF_ISBROKEN)
601 return 0;
602 if (!has_sha1_file(entry->u.value.sha1)) {
603 error("%s does not point to a valid object!", entry->name);
604 return 0;
605 }
606 return 1;
607}
c774aab9 608
7d76fdc8
MH
609/*
610 * current_ref is a performance hack: when iterating over references
611 * using the for_each_ref*() functions, current_ref is set to the
612 * current reference's entry before calling the callback function. If
613 * the callback function calls peel_ref(), then peel_ref() first
614 * checks whether the reference to be peeled is the current reference
615 * (it usually is) and if so, returns that reference's peeled version
616 * if it is available. This avoids a refname lookup in a common case.
617 */
bc5fd6d3 618static struct ref_entry *current_ref;
c774aab9 619
624cac35
MH
620typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
621
622struct ref_entry_cb {
623 const char *base;
624 int trim;
625 int flags;
626 each_ref_fn *fn;
627 void *cb_data;
628};
629
fcce1703 630/*
624cac35
MH
631 * Handle one reference in a do_for_each_ref*()-style iteration,
632 * calling an each_ref_fn for each entry.
fcce1703 633 */
624cac35 634static int do_one_ref(struct ref_entry *entry, void *cb_data)
bc5fd6d3 635{
624cac35 636 struct ref_entry_cb *data = cb_data;
d0cf51e9 637 struct ref_entry *old_current_ref;
429213e4 638 int retval;
d0cf51e9 639
59556548 640 if (!starts_with(entry->name, data->base))
bc5fd6d3 641 return 0;
c774aab9 642
624cac35 643 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
662428f4 644 !ref_resolves_to_object(entry))
bc5fd6d3 645 return 0;
c774aab9 646
d0cf51e9
MH
647 /* Store the old value, in case this is a recursive call: */
648 old_current_ref = current_ref;
bc5fd6d3 649 current_ref = entry;
624cac35
MH
650 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
651 entry->flag, data->cb_data);
d0cf51e9 652 current_ref = old_current_ref;
429213e4 653 return retval;
bc5fd6d3 654}
c774aab9 655
c36b5bc2 656/*
d3177275 657 * Call fn for each reference in dir that has index in the range
432ad41e
MH
658 * offset <= index < dir->nr. Recurse into subdirectories that are in
659 * that index range, sorting them before iterating. This function
624cac35
MH
660 * does not sort dir itself; it should be sorted beforehand. fn is
661 * called for all references, including broken ones.
c36b5bc2 662 */
624cac35
MH
663static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
664 each_ref_entry_fn fn, void *cb_data)
c36b5bc2
MH
665{
666 int i;
d3177275
MH
667 assert(dir->sorted == dir->nr);
668 for (i = offset; i < dir->nr; i++) {
432ad41e
MH
669 struct ref_entry *entry = dir->entries[i];
670 int retval;
671 if (entry->flag & REF_DIR) {
d7826d54
MH
672 struct ref_dir *subdir = get_ref_dir(entry);
673 sort_ref_dir(subdir);
624cac35 674 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
432ad41e 675 } else {
624cac35 676 retval = fn(entry, cb_data);
432ad41e 677 }
c36b5bc2
MH
678 if (retval)
679 return retval;
680 }
681 return 0;
682}
683
b3fd060f 684/*
d3177275 685 * Call fn for each reference in the union of dir1 and dir2, in order
432ad41e
MH
686 * by refname. Recurse into subdirectories. If a value entry appears
687 * in both dir1 and dir2, then only process the version that is in
688 * dir2. The input dirs must already be sorted, but subdirs will be
624cac35
MH
689 * sorted as needed. fn is called for all references, including
690 * broken ones.
b3fd060f 691 */
624cac35
MH
692static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
693 struct ref_dir *dir2,
694 each_ref_entry_fn fn, void *cb_data)
b3fd060f
MH
695{
696 int retval;
697 int i1 = 0, i2 = 0;
698
d3177275
MH
699 assert(dir1->sorted == dir1->nr);
700 assert(dir2->sorted == dir2->nr);
432ad41e
MH
701 while (1) {
702 struct ref_entry *e1, *e2;
703 int cmp;
704 if (i1 == dir1->nr) {
624cac35 705 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
432ad41e
MH
706 }
707 if (i2 == dir2->nr) {
624cac35 708 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
432ad41e
MH
709 }
710 e1 = dir1->entries[i1];
711 e2 = dir2->entries[i2];
712 cmp = strcmp(e1->name, e2->name);
713 if (cmp == 0) {
714 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
715 /* Both are directories; descend them in parallel. */
d7826d54
MH
716 struct ref_dir *subdir1 = get_ref_dir(e1);
717 struct ref_dir *subdir2 = get_ref_dir(e2);
718 sort_ref_dir(subdir1);
719 sort_ref_dir(subdir2);
624cac35
MH
720 retval = do_for_each_entry_in_dirs(
721 subdir1, subdir2, fn, cb_data);
432ad41e
MH
722 i1++;
723 i2++;
724 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
725 /* Both are references; ignore the one from dir1. */
624cac35 726 retval = fn(e2, cb_data);
432ad41e
MH
727 i1++;
728 i2++;
729 } else {
730 die("conflict between reference and directory: %s",
731 e1->name);
732 }
b3fd060f 733 } else {
432ad41e
MH
734 struct ref_entry *e;
735 if (cmp < 0) {
736 e = e1;
b3fd060f 737 i1++;
432ad41e
MH
738 } else {
739 e = e2;
740 i2++;
741 }
742 if (e->flag & REF_DIR) {
d7826d54
MH
743 struct ref_dir *subdir = get_ref_dir(e);
744 sort_ref_dir(subdir);
624cac35
MH
745 retval = do_for_each_entry_in_dir(
746 subdir, 0, fn, cb_data);
432ad41e 747 } else {
624cac35 748 retval = fn(e, cb_data);
b3fd060f
MH
749 }
750 }
751 if (retval)
752 return retval;
753 }
b3fd060f
MH
754}
755
98eeb09e
JK
756/*
757 * Load all of the refs from the dir into our in-memory cache. The hard work
758 * of loading loose refs is done by get_ref_dir(), so we just need to recurse
759 * through all of the sub-directories. We do not even need to care about
760 * sorting, as traversal order does not matter to us.
761 */
762static void prime_ref_dir(struct ref_dir *dir)
763{
764 int i;
765 for (i = 0; i < dir->nr; i++) {
766 struct ref_entry *entry = dir->entries[i];
767 if (entry->flag & REF_DIR)
768 prime_ref_dir(get_ref_dir(entry));
769 }
770}
d66da478
MH
771/*
772 * Return true iff refname1 and refname2 conflict with each other.
773 * Two reference names conflict if one of them exactly matches the
774 * leading components of the other; e.g., "foo/bar" conflicts with
775 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
776 * "foo/barbados".
777 */
778static int names_conflict(const char *refname1, const char *refname2)
779{
5a4d4947
MH
780 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
781 ;
782 return (*refname1 == '\0' && *refname2 == '/')
783 || (*refname1 == '/' && *refname2 == '\0');
784}
785
786struct name_conflict_cb {
787 const char *refname;
788 const char *oldrefname;
789 const char *conflicting_refname;
790};
791
624cac35 792static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
5a4d4947
MH
793{
794 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
624cac35 795 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
5a4d4947 796 return 0;
624cac35
MH
797 if (names_conflict(data->refname, entry->name)) {
798 data->conflicting_refname = entry->name;
5a4d4947 799 return 1;
d66da478 800 }
5a4d4947 801 return 0;
d66da478
MH
802}
803
bc5fd6d3
MH
804/*
805 * Return true iff a reference named refname could be created without
624cac35 806 * conflicting with the name of an existing reference in dir. If
5a4d4947
MH
807 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
808 * (e.g., because oldrefname is scheduled for deletion in the same
bc5fd6d3
MH
809 * operation).
810 */
811static int is_refname_available(const char *refname, const char *oldrefname,
d3177275 812 struct ref_dir *dir)
bc5fd6d3 813{
5a4d4947
MH
814 struct name_conflict_cb data;
815 data.refname = refname;
816 data.oldrefname = oldrefname;
817 data.conflicting_refname = NULL;
818
d3177275 819 sort_ref_dir(dir);
624cac35 820 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
5a4d4947
MH
821 error("'%s' exists; cannot create '%s'",
822 data.conflicting_refname, refname);
823 return 0;
bc5fd6d3
MH
824 }
825 return 1;
e1e22e37
LT
826}
827
2fff7812
MH
828struct packed_ref_cache {
829 struct ref_entry *root;
9f69d297 830
5f5e2a88
MH
831 /*
832 * Count of references to the data structure in this instance,
833 * including the pointer from ref_cache::packed if any. The
834 * data will not be freed as long as the reference count is
835 * nonzero.
836 */
837 unsigned int referrers;
838
9f69d297
MH
839 /*
840 * Iff the packed-refs file associated with this instance is
841 * currently locked for writing, this points at the associated
4f6b83e3
MH
842 * lock (which is owned by somebody else). The referrer count
843 * is also incremented when the file is locked and decremented
844 * when it is unlocked.
9f69d297
MH
845 */
846 struct lock_file *lock;
ca919930
JK
847
848 /* The metadata from when this packed-refs cache was read */
849 struct stat_validity validity;
2fff7812
MH
850};
851
5e290ff7
JH
852/*
853 * Future: need to be in "struct repository"
854 * when doing a full libification.
855 */
79c7ca54
MH
856static struct ref_cache {
857 struct ref_cache *next;
d12229f5 858 struct ref_entry *loose;
2fff7812 859 struct packed_ref_cache *packed;
9da31cb0
MH
860 /*
861 * The submodule name, or "" for the main repo. We allocate
862 * length 1 rather than FLEX_ARRAY so that the main ref_cache
863 * is initialized correctly.
864 */
865 char name[1];
866} ref_cache, *submodule_ref_caches;
0e88c130 867
9f69d297
MH
868/* Lock used for the main packed-refs file: */
869static struct lock_file packlock;
870
5f5e2a88
MH
871/*
872 * Increment the reference count of *packed_refs.
873 */
874static void acquire_packed_ref_cache(struct packed_ref_cache *packed_refs)
875{
876 packed_refs->referrers++;
877}
878
879/*
880 * Decrease the reference count of *packed_refs. If it goes to zero,
881 * free *packed_refs and return true; otherwise return false.
882 */
883static int release_packed_ref_cache(struct packed_ref_cache *packed_refs)
884{
885 if (!--packed_refs->referrers) {
886 free_ref_entry(packed_refs->root);
ca919930 887 stat_validity_clear(&packed_refs->validity);
5f5e2a88
MH
888 free(packed_refs);
889 return 1;
890 } else {
891 return 0;
892 }
893}
894
760c4512 895static void clear_packed_ref_cache(struct ref_cache *refs)
e1e22e37 896{
d12229f5 897 if (refs->packed) {
5f5e2a88
MH
898 struct packed_ref_cache *packed_refs = refs->packed;
899
900 if (packed_refs->lock)
9f69d297 901 die("internal error: packed-ref cache cleared while locked");
d12229f5 902 refs->packed = NULL;
5f5e2a88 903 release_packed_ref_cache(packed_refs);
d12229f5 904 }
5e290ff7 905}
e1e22e37 906
760c4512
MH
907static void clear_loose_ref_cache(struct ref_cache *refs)
908{
d12229f5
MH
909 if (refs->loose) {
910 free_ref_entry(refs->loose);
911 refs->loose = NULL;
912 }
760c4512
MH
913}
914
79c7ca54 915static struct ref_cache *create_ref_cache(const char *submodule)
e5dbf605 916{
ce40979c 917 int len;
79c7ca54 918 struct ref_cache *refs;
ce40979c
MH
919 if (!submodule)
920 submodule = "";
921 len = strlen(submodule) + 1;
79c7ca54 922 refs = xcalloc(1, sizeof(struct ref_cache) + len);
ce40979c 923 memcpy(refs->name, submodule, len);
e5dbf605
MH
924 return refs;
925}
926
4349a668 927/*
79c7ca54 928 * Return a pointer to a ref_cache for the specified submodule. For
4349a668
MH
929 * the main repository, use submodule==NULL. The returned structure
930 * will be allocated and initialized but not necessarily populated; it
931 * should not be freed.
932 */
79c7ca54 933static struct ref_cache *get_ref_cache(const char *submodule)
4349a668 934{
9da31cb0
MH
935 struct ref_cache *refs;
936
937 if (!submodule || !*submodule)
938 return &ref_cache;
939
940 for (refs = submodule_ref_caches; refs; refs = refs->next)
0e88c130
MH
941 if (!strcmp(submodule, refs->name))
942 return refs;
0e88c130 943
79c7ca54 944 refs = create_ref_cache(submodule);
9da31cb0
MH
945 refs->next = submodule_ref_caches;
946 submodule_ref_caches = refs;
0e88c130 947 return refs;
4349a668
MH
948}
949
3feb4f0c
MH
950/* The length of a peeled reference line in packed-refs, including EOL: */
951#define PEELED_LINE_LENGTH 42
952
694b7a19
MH
953/*
954 * The packed-refs header line that we write out. Perhaps other
955 * traits will be added later. The trailing space is required.
956 */
957static const char PACKED_REFS_HEADER[] =
958 "# pack-refs with: peeled fully-peeled \n";
959
bc5fd6d3
MH
960/*
961 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
962 * Return a pointer to the refname within the line (null-terminated),
963 * or NULL if there was a problem.
964 */
965static const char *parse_ref_line(char *line, unsigned char *sha1)
966{
967 /*
968 * 42: the answer to everything.
969 *
970 * In this case, it happens to be the answer to
971 * 40 (length of sha1 hex representation)
972 * +1 (space in between hex and name)
973 * +1 (newline at the end of the line)
974 */
975 int len = strlen(line) - 42;
976
977 if (len <= 0)
978 return NULL;
979 if (get_sha1_hex(line, sha1) < 0)
980 return NULL;
981 if (!isspace(line[40]))
982 return NULL;
983 line += 41;
984 if (isspace(*line))
985 return NULL;
986 if (line[len] != '\n')
987 return NULL;
988 line[len] = 0;
989
990 return line;
991}
992
c29c46fa
MH
993/*
994 * Read f, which is a packed-refs file, into dir.
995 *
996 * A comment line of the form "# pack-refs with: " may contain zero or
997 * more traits. We interpret the traits as follows:
998 *
999 * No traits:
1000 *
1001 * Probably no references are peeled. But if the file contains a
1002 * peeled value for a reference, we will use it.
1003 *
1004 * peeled:
1005 *
1006 * References under "refs/tags/", if they *can* be peeled, *are*
1007 * peeled in this file. References outside of "refs/tags/" are
1008 * probably not peeled even if they could have been, but if we find
1009 * a peeled value for such a reference we will use it.
1010 *
1011 * fully-peeled:
1012 *
1013 * All references in the file that can be peeled are peeled.
1014 * Inversely (and this is more important), any references in the
1015 * file for which no peeled value is recorded is not peelable. This
1016 * trait should typically be written alongside "peeled" for
1017 * compatibility with older clients, but we do not require it
1018 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1019 */
d3177275 1020static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 1021{
e9c4c111 1022 struct ref_entry *last = NULL;
f4204ab9 1023 char refline[PATH_MAX];
c29c46fa 1024 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
1025
1026 while (fgets(refline, sizeof(refline), f)) {
1027 unsigned char sha1[20];
dfefa935 1028 const char *refname;
f4204ab9
JH
1029 static const char header[] = "# pack-refs with:";
1030
1031 if (!strncmp(refline, header, sizeof(header)-1)) {
1032 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
1033 if (strstr(traits, " fully-peeled "))
1034 peeled = PEELED_FULLY;
1035 else if (strstr(traits, " peeled "))
1036 peeled = PEELED_TAGS;
f4204ab9
JH
1037 /* perhaps other traits later as well */
1038 continue;
1039 }
1040
dfefa935
MH
1041 refname = parse_ref_line(refline, sha1);
1042 if (refname) {
c29c46fa
MH
1043 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
1044 if (peeled == PEELED_FULLY ||
59556548 1045 (peeled == PEELED_TAGS && starts_with(refname, "refs/tags/")))
c29c46fa 1046 last->flag |= REF_KNOWS_PEELED;
d3177275 1047 add_ref(dir, last);
f4204ab9
JH
1048 continue;
1049 }
1050 if (last &&
1051 refline[0] == '^' &&
3feb4f0c
MH
1052 strlen(refline) == PEELED_LINE_LENGTH &&
1053 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 1054 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 1055 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
1056 /*
1057 * Regardless of what the file header said,
1058 * we definitely know the value of *this*
1059 * reference:
1060 */
1061 last->flag |= REF_KNOWS_PEELED;
1062 }
f4204ab9 1063 }
f4204ab9
JH
1064}
1065
2fff7812
MH
1066/*
1067 * Get the packed_ref_cache for the specified ref_cache, creating it
1068 * if necessary.
1069 */
1070static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
5e290ff7 1071{
ca919930
JK
1072 const char *packed_refs_file;
1073
1074 if (*refs->name)
1075 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1076 else
1077 packed_refs_file = git_path("packed-refs");
1078
1079 if (refs->packed &&
1080 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1081 clear_packed_ref_cache(refs);
1082
d12229f5 1083 if (!refs->packed) {
4349a668 1084 FILE *f;
0bad611b 1085
2fff7812 1086 refs->packed = xcalloc(1, sizeof(*refs->packed));
5f5e2a88 1087 acquire_packed_ref_cache(refs->packed);
2fff7812 1088 refs->packed->root = create_dir_entry(refs, "", 0, 0);
4349a668 1089 f = fopen(packed_refs_file, "r");
e1e22e37 1090 if (f) {
ca919930 1091 stat_validity_update(&refs->packed->validity, fileno(f));
2fff7812 1092 read_packed_refs(f, get_ref_dir(refs->packed->root));
e1e22e37 1093 fclose(f);
e1e22e37 1094 }
e1e22e37 1095 }
2fff7812
MH
1096 return refs->packed;
1097}
1098
1099static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1100{
1101 return get_ref_dir(packed_ref_cache->root);
1102}
1103
1104static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1105{
1106 return get_packed_ref_dir(get_packed_ref_cache(refs));
e1e22e37
LT
1107}
1108
30249ee6
MH
1109void add_packed_ref(const char *refname, const unsigned char *sha1)
1110{
9f69d297
MH
1111 struct packed_ref_cache *packed_ref_cache =
1112 get_packed_ref_cache(&ref_cache);
1113
1114 if (!packed_ref_cache->lock)
1115 die("internal error: packed refs not locked");
1116 add_ref(get_packed_ref_dir(packed_ref_cache),
9da31cb0 1117 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
30249ee6
MH
1118}
1119
abc39098 1120/*
28e6a34e
MH
1121 * Read the loose references from the namespace dirname into dir
1122 * (without recursing). dirname must end with '/'. dir must be the
1123 * directory entry corresponding to dirname.
abc39098 1124 */
423a1afc 1125static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 1126{
423a1afc 1127 struct ref_cache *refs = dir->ref_cache;
d3177275 1128 DIR *d;
0bad611b 1129 const char *path;
d5fdae67 1130 struct dirent *de;
abc39098 1131 int dirnamelen = strlen(dirname);
72b64b44 1132 struct strbuf refname;
0bad611b 1133
3b124823 1134 if (*refs->name)
66a3d20b 1135 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 1136 else
66a3d20b 1137 path = git_path("%s", dirname);
0bad611b 1138
d3177275 1139 d = opendir(path);
d5fdae67
MH
1140 if (!d)
1141 return;
1142
66a3d20b
MH
1143 strbuf_init(&refname, dirnamelen + 257);
1144 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
1145
1146 while ((de = readdir(d)) != NULL) {
1147 unsigned char sha1[20];
1148 struct stat st;
1149 int flag;
d5fdae67
MH
1150 const char *refdir;
1151
1152 if (de->d_name[0] == '.')
1153 continue;
d5fdae67
MH
1154 if (has_extension(de->d_name, ".lock"))
1155 continue;
72b64b44 1156 strbuf_addstr(&refname, de->d_name);
d5fdae67 1157 refdir = *refs->name
72b64b44
MH
1158 ? git_path_submodule(refs->name, "%s", refname.buf)
1159 : git_path("%s", refname.buf);
1160 if (stat(refdir, &st) < 0) {
1161 ; /* silently ignore */
1162 } else if (S_ISDIR(st.st_mode)) {
abc39098 1163 strbuf_addch(&refname, '/');
28e6a34e 1164 add_entry_to_dir(dir,
b9146f51
RS
1165 create_dir_entry(refs, refname.buf,
1166 refname.len, 1));
72b64b44 1167 } else {
3b124823 1168 if (*refs->name) {
f8948e2f 1169 hashclr(sha1);
0bad611b 1170 flag = 0;
72b64b44 1171 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1172 hashclr(sha1);
98ac34b2 1173 flag |= REF_ISBROKEN;
0bad611b 1174 }
72b64b44 1175 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1176 hashclr(sha1);
1177 flag |= REF_ISBROKEN;
1178 }
9f2fb4a3
MH
1179 add_entry_to_dir(dir,
1180 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1181 }
66a3d20b 1182 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1183 }
72b64b44 1184 strbuf_release(&refname);
d5fdae67 1185 closedir(d);
e1e22e37
LT
1186}
1187
d3177275 1188static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1189{
d12229f5 1190 if (!refs->loose) {
28e6a34e
MH
1191 /*
1192 * Mark the top-level directory complete because we
1193 * are about to read the only subdirectory that can
1194 * hold references:
1195 */
b9146f51 1196 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1197 /*
1198 * Create an incomplete entry for "refs/":
1199 */
1200 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1201 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1202 }
d7826d54 1203 return get_ref_dir(refs->loose);
e1e22e37
LT
1204}
1205
ca8db142
LT
1206/* We allow "recursive" symbolic refs. Only within reason, though */
1207#define MAXDEPTH 5
0ebde32c
LT
1208#define MAXREFLEN (1024)
1209
e5fa45c1
JH
1210/*
1211 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1212 * from the loose refs in ref_cache refs. Find <refname> in the
1213 * packed-refs file for the submodule.
e5fa45c1 1214 */
b0626608 1215static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1216 const char *refname, unsigned char *sha1)
0ebde32c 1217{
2c5c66be 1218 struct ref_entry *ref;
d3177275 1219 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1220
432ad41e 1221 ref = find_ref(dir, refname);
b0626608
MH
1222 if (ref == NULL)
1223 return -1;
1224
50546b15 1225 hashcpy(sha1, ref->u.value.sha1);
b0626608 1226 return 0;
0ebde32c
LT
1227}
1228
b0626608 1229static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1230 const char *refname, unsigned char *sha1,
dfefa935 1231 int recursion)
0ebde32c 1232{
064d51dc 1233 int fd, len;
0ebde32c 1234 char buffer[128], *p;
064d51dc 1235 char *path;
0ebde32c 1236
064d51dc 1237 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1238 return -1;
064d51dc
MH
1239 path = *refs->name
1240 ? git_path_submodule(refs->name, "%s", refname)
1241 : git_path("%s", refname);
1242 fd = open(path, O_RDONLY);
0ebde32c 1243 if (fd < 0)
b0626608 1244 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1245
1246 len = read(fd, buffer, sizeof(buffer)-1);
1247 close(fd);
1248 if (len < 0)
1249 return -1;
1250 while (len && isspace(buffer[len-1]))
1251 len--;
1252 buffer[len] = 0;
1253
1254 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1255 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1256 return 0;
1257
1258 /* Symref? */
1259 if (strncmp(buffer, "ref:", 4))
1260 return -1;
1261 p = buffer + 4;
1262 while (isspace(*p))
1263 p++;
1264
064d51dc 1265 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1266}
1267
85be1fe3 1268int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1269{
1270 int len = strlen(path), retval;
064d51dc 1271 char *submodule;
b0626608 1272 struct ref_cache *refs;
0ebde32c
LT
1273
1274 while (len && path[len-1] == '/')
1275 len--;
1276 if (!len)
1277 return -1;
b0626608
MH
1278 submodule = xstrndup(path, len);
1279 refs = get_ref_cache(submodule);
1280 free(submodule);
1281
064d51dc 1282 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1283 return retval;
1284}
ca8db142 1285
4886b89f 1286/*
63331581
MH
1287 * Return the ref_entry for the given refname from the packed
1288 * references. If it does not exist, return NULL.
4886b89f 1289 */
63331581 1290static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1291{
9da31cb0 1292 return find_ref(get_packed_refs(&ref_cache), refname);
c224ca7f
MH
1293}
1294
47f534bf
MH
1295/*
1296 * A loose ref file doesn't exist; check for a packed ref. The
1297 * options are forwarded from resolve_safe_unsafe().
1298 */
1299static const char *handle_missing_loose_ref(const char *refname,
1300 unsigned char *sha1,
1301 int reading,
1302 int *flag)
1303{
1304 struct ref_entry *entry;
1305
1306 /*
1307 * The loose reference file does not exist; check for a packed
1308 * reference.
1309 */
1310 entry = get_packed_ref(refname);
1311 if (entry) {
1312 hashcpy(sha1, entry->u.value.sha1);
1313 if (flag)
1314 *flag |= REF_ISPACKED;
1315 return refname;
1316 }
1317 /* The reference is not a packed reference, either. */
1318 if (reading) {
1319 return NULL;
1320 } else {
1321 hashclr(sha1);
1322 return refname;
1323 }
1324}
1325
8d68493f 1326const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1327{
0104ca09
HO
1328 int depth = MAXDEPTH;
1329 ssize_t len;
a876ed83 1330 char buffer[256];
dfefa935 1331 static char refname_buffer[256];
ca8db142 1332
8da19775
JH
1333 if (flag)
1334 *flag = 0;
1335
dfefa935 1336 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
8384d788
MH
1337 return NULL;
1338
a876ed83 1339 for (;;) {
55956350 1340 char path[PATH_MAX];
a876ed83
JH
1341 struct stat st;
1342 char *buf;
1343 int fd;
8a65ff76 1344
a876ed83
JH
1345 if (--depth < 0)
1346 return NULL;
ca8db142 1347
dfefa935 1348 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1349
fcb7c762
MH
1350 /*
1351 * We might have to loop back here to avoid a race
1352 * condition: first we lstat() the file, then we try
1353 * to read it as a link or as a file. But if somebody
1354 * changes the type of the file (file <-> directory
1355 * <-> symlink) between the lstat() and reading, then
1356 * we don't want to report that as an error but rather
1357 * try again starting with the lstat().
1358 */
1359 stat_ref:
a876ed83 1360 if (lstat(path, &st) < 0) {
47f534bf
MH
1361 if (errno == ENOENT)
1362 return handle_missing_loose_ref(refname, sha1,
1363 reading, flag);
1364 else
a876ed83 1365 return NULL;
a876ed83 1366 }
ca8db142 1367
a876ed83
JH
1368 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1369 if (S_ISLNK(st.st_mode)) {
1370 len = readlink(path, buffer, sizeof(buffer)-1);
fcb7c762
MH
1371 if (len < 0) {
1372 if (errno == ENOENT || errno == EINVAL)
1373 /* inconsistent with lstat; retry */
1374 goto stat_ref;
1375 else
1376 return NULL;
1377 }
b54cb795 1378 buffer[len] = 0;
59556548 1379 if (starts_with(buffer, "refs/") &&
1f58a038 1380 !check_refname_format(buffer, 0)) {
dfefa935
MH
1381 strcpy(refname_buffer, buffer);
1382 refname = refname_buffer;
8da19775
JH
1383 if (flag)
1384 *flag |= REF_ISSYMREF;
a876ed83
JH
1385 continue;
1386 }
ca8db142 1387 }
a876ed83 1388
7a21632f
DS
1389 /* Is it a directory? */
1390 if (S_ISDIR(st.st_mode)) {
1391 errno = EISDIR;
1392 return NULL;
1393 }
1394
a876ed83
JH
1395 /*
1396 * Anything else, just open it and try to use it as
1397 * a ref
1398 */
1399 fd = open(path, O_RDONLY);
fcb7c762
MH
1400 if (fd < 0) {
1401 if (errno == ENOENT)
1402 /* inconsistent with lstat; retry */
1403 goto stat_ref;
1404 else
1405 return NULL;
1406 }
93d26e4c 1407 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83 1408 close(fd);
28775050
MH
1409 if (len < 0)
1410 return NULL;
1411 while (len && isspace(buffer[len-1]))
1412 len--;
1413 buffer[len] = '\0';
a876ed83
JH
1414
1415 /*
1416 * Is it a symbolic ref?
1417 */
59556548 1418 if (!starts_with(buffer, "ref:")) {
2884c06a
MH
1419 /*
1420 * Please note that FETCH_HEAD has a second
1421 * line containing other data.
1422 */
1423 if (get_sha1_hex(buffer, sha1) ||
1424 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1425 if (flag)
1426 *flag |= REF_ISBROKEN;
1427 return NULL;
1428 }
1429 return refname;
1430 }
55956350
JH
1431 if (flag)
1432 *flag |= REF_ISSYMREF;
a876ed83 1433 buf = buffer + 4;
28775050
MH
1434 while (isspace(*buf))
1435 buf++;
313fb010 1436 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1437 if (flag)
1438 *flag |= REF_ISBROKEN;
313fb010
MH
1439 return NULL;
1440 }
dfefa935 1441 refname = strcpy(refname_buffer, buf);
8a65ff76 1442 }
a876ed83
JH
1443}
1444
96ec7b1e
NTND
1445char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1446{
8cad4744 1447 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1448 return ret ? xstrdup(ret) : NULL;
1449}
1450
d08bae7e
IL
1451/* The argument to filter_refs */
1452struct ref_filter {
1453 const char *pattern;
1454 each_ref_fn *fn;
1455 void *cb_data;
1456};
1457
dfefa935 1458int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1459{
8d68493f 1460 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1461 return 0;
1462 return -1;
8a65ff76
LT
1463}
1464
dfefa935 1465int read_ref(const char *refname, unsigned char *sha1)
c6893323 1466{
dfefa935 1467 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1468}
1469
bc5fd6d3 1470int ref_exists(const char *refname)
ef06b918 1471{
bc5fd6d3
MH
1472 unsigned char sha1[20];
1473 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1474}
1475
85be1fe3 1476static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1477 void *data)
d08bae7e
IL
1478{
1479 struct ref_filter *filter = (struct ref_filter *)data;
eb07894f 1480 if (wildmatch(filter->pattern, refname, 0, NULL))
d08bae7e 1481 return 0;
85be1fe3 1482 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1483}
1484
68cf8703
MH
1485enum peel_status {
1486 /* object was peeled successfully: */
1487 PEEL_PEELED = 0,
1488
1489 /*
1490 * object cannot be peeled because the named object (or an
1491 * object referred to by a tag in the peel chain), does not
1492 * exist.
1493 */
1494 PEEL_INVALID = -1,
1495
1496 /* object cannot be peeled because it is not a tag: */
9a489f3c
MH
1497 PEEL_NON_TAG = -2,
1498
1499 /* ref_entry contains no peeled value because it is a symref: */
1500 PEEL_IS_SYMREF = -3,
1501
1502 /*
1503 * ref_entry cannot be peeled because it is broken (i.e., the
1504 * symbolic reference cannot even be resolved to an object
1505 * name):
1506 */
1507 PEEL_BROKEN = -4
68cf8703
MH
1508};
1509
cb2ae1c4
MH
1510/*
1511 * Peel the named object; i.e., if the object is a tag, resolve the
68cf8703
MH
1512 * tag recursively until a non-tag is found. If successful, store the
1513 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1514 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1515 * and leave sha1 unchanged.
cb2ae1c4 1516 */
68cf8703 1517static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
cb2ae1c4
MH
1518{
1519 struct object *o = lookup_unknown_object(name);
1520
1521 if (o->type == OBJ_NONE) {
1522 int type = sha1_object_info(name, NULL);
1523 if (type < 0)
68cf8703 1524 return PEEL_INVALID;
cb2ae1c4
MH
1525 o->type = type;
1526 }
1527
1528 if (o->type != OBJ_TAG)
68cf8703 1529 return PEEL_NON_TAG;
cb2ae1c4
MH
1530
1531 o = deref_tag_noverify(o);
1532 if (!o)
68cf8703 1533 return PEEL_INVALID;
cb2ae1c4
MH
1534
1535 hashcpy(sha1, o->sha1);
68cf8703 1536 return PEEL_PEELED;
cb2ae1c4
MH
1537}
1538
9a489f3c 1539/*
f85354b5
MH
1540 * Peel the entry (if possible) and return its new peel_status. If
1541 * repeel is true, re-peel the entry even if there is an old peeled
1542 * value that is already stored in it.
694b7a19
MH
1543 *
1544 * It is OK to call this function with a packed reference entry that
1545 * might be stale and might even refer to an object that has since
1546 * been garbage-collected. In such a case, if the entry has
1547 * REF_KNOWS_PEELED then leave the status unchanged and return
1548 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
9a489f3c 1549 */
f85354b5 1550static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
9a489f3c
MH
1551{
1552 enum peel_status status;
1553
f85354b5
MH
1554 if (entry->flag & REF_KNOWS_PEELED) {
1555 if (repeel) {
1556 entry->flag &= ~REF_KNOWS_PEELED;
1557 hashclr(entry->u.value.peeled);
1558 } else {
1559 return is_null_sha1(entry->u.value.peeled) ?
1560 PEEL_NON_TAG : PEEL_PEELED;
1561 }
1562 }
9a489f3c
MH
1563 if (entry->flag & REF_ISBROKEN)
1564 return PEEL_BROKEN;
1565 if (entry->flag & REF_ISSYMREF)
1566 return PEEL_IS_SYMREF;
1567
1568 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1569 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1570 entry->flag |= REF_KNOWS_PEELED;
1571 return status;
1572}
1573
dfefa935 1574int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1575{
1576 int flag;
1577 unsigned char base[20];
cf0adba7 1578
dfefa935 1579 if (current_ref && (current_ref->name == refname
9a489f3c 1580 || !strcmp(current_ref->name, refname))) {
f85354b5 1581 if (peel_entry(current_ref, 0))
9a489f3c
MH
1582 return -1;
1583 hashcpy(sha1, current_ref->u.value.peeled);
1584 return 0;
0ae91be0
SP
1585 }
1586
dfefa935 1587 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1588 return -1;
1589
9a489f3c
MH
1590 /*
1591 * If the reference is packed, read its ref_entry from the
1592 * cache in the hope that we already know its peeled value.
1593 * We only try this optimization on packed references because
1594 * (a) forcing the filling of the loose reference cache could
1595 * be expensive and (b) loose references anyway usually do not
1596 * have REF_KNOWS_PEELED.
1597 */
1598 if (flag & REF_ISPACKED) {
f361baeb 1599 struct ref_entry *r = get_packed_ref(refname);
9a489f3c 1600 if (r) {
f85354b5 1601 if (peel_entry(r, 0))
9a489f3c 1602 return -1;
593f1bb8 1603 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1604 return 0;
cf0adba7 1605 }
cf0adba7
JH
1606 }
1607
cb2ae1c4 1608 return peel_object(base, sha1);
cf0adba7
JH
1609}
1610
bc5fd6d3
MH
1611struct warn_if_dangling_data {
1612 FILE *fp;
1613 const char *refname;
1614 const char *msg_fmt;
1615};
1616
1617static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1618 int flags, void *cb_data)
1619{
1620 struct warn_if_dangling_data *d = cb_data;
1621 const char *resolves_to;
1622 unsigned char junk[20];
1623
1624 if (!(flags & REF_ISSYMREF))
1625 return 0;
1626
1627 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1628 if (!resolves_to || strcmp(resolves_to, d->refname))
1629 return 0;
1630
1631 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1632 fputc('\n', d->fp);
bc5fd6d3
MH
1633 return 0;
1634}
1635
1636void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1637{
1638 struct warn_if_dangling_data data;
1639
1640 data.fp = fp;
1641 data.refname = refname;
1642 data.msg_fmt = msg_fmt;
1643 for_each_rawref(warn_if_dangling_symref, &data);
1644}
1645
fcce1703 1646/*
65cf102b 1647 * Call fn for each reference in the specified ref_cache, omitting
624cac35
MH
1648 * references not in the containing_dir of base. fn is called for all
1649 * references, including broken ones. If fn ever returns a non-zero
fcce1703
MH
1650 * value, stop the iteration and return that value; otherwise, return
1651 * 0.
1652 */
65cf102b 1653static int do_for_each_entry(struct ref_cache *refs, const char *base,
624cac35 1654 each_ref_entry_fn fn, void *cb_data)
8a65ff76 1655{
98eeb09e
JK
1656 struct packed_ref_cache *packed_ref_cache;
1657 struct ref_dir *loose_dir;
1658 struct ref_dir *packed_dir;
933ac036
MH
1659 int retval = 0;
1660
98eeb09e
JK
1661 /*
1662 * We must make sure that all loose refs are read before accessing the
1663 * packed-refs file; this avoids a race condition in which loose refs
1664 * are migrated to the packed-refs file by a simultaneous process, but
1665 * our in-memory view is from before the migration. get_packed_ref_cache()
1666 * takes care of making sure our view is up to date with what is on
1667 * disk.
1668 */
1669 loose_dir = get_loose_refs(refs);
933ac036 1670 if (base && *base) {
933ac036
MH
1671 loose_dir = find_containing_dir(loose_dir, base, 0);
1672 }
98eeb09e
JK
1673 if (loose_dir)
1674 prime_ref_dir(loose_dir);
1675
1676 packed_ref_cache = get_packed_ref_cache(refs);
8baf2bb9 1677 acquire_packed_ref_cache(packed_ref_cache);
98eeb09e 1678 packed_dir = get_packed_ref_dir(packed_ref_cache);
933ac036
MH
1679 if (base && *base) {
1680 packed_dir = find_containing_dir(packed_dir, base, 0);
933ac036
MH
1681 }
1682
1683 if (packed_dir && loose_dir) {
1684 sort_ref_dir(packed_dir);
1685 sort_ref_dir(loose_dir);
624cac35
MH
1686 retval = do_for_each_entry_in_dirs(
1687 packed_dir, loose_dir, fn, cb_data);
933ac036
MH
1688 } else if (packed_dir) {
1689 sort_ref_dir(packed_dir);
624cac35
MH
1690 retval = do_for_each_entry_in_dir(
1691 packed_dir, 0, fn, cb_data);
933ac036
MH
1692 } else if (loose_dir) {
1693 sort_ref_dir(loose_dir);
624cac35
MH
1694 retval = do_for_each_entry_in_dir(
1695 loose_dir, 0, fn, cb_data);
933ac036
MH
1696 }
1697
8baf2bb9 1698 release_packed_ref_cache(packed_ref_cache);
933ac036 1699 return retval;
8a65ff76
LT
1700}
1701
624cac35 1702/*
65cf102b 1703 * Call fn for each reference in the specified ref_cache for which the
624cac35
MH
1704 * refname begins with base. If trim is non-zero, then trim that many
1705 * characters off the beginning of each refname before passing the
1706 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1707 * broken references in the iteration. If fn ever returns a non-zero
1708 * value, stop the iteration and return that value; otherwise, return
1709 * 0.
1710 */
65cf102b
MH
1711static int do_for_each_ref(struct ref_cache *refs, const char *base,
1712 each_ref_fn fn, int trim, int flags, void *cb_data)
624cac35
MH
1713{
1714 struct ref_entry_cb data;
1715 data.base = base;
1716 data.trim = trim;
1717 data.flags = flags;
1718 data.fn = fn;
1719 data.cb_data = cb_data;
1720
65cf102b 1721 return do_for_each_entry(refs, base, do_one_ref, &data);
624cac35
MH
1722}
1723
0bad611b 1724static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1725{
1726 unsigned char sha1[20];
8da19775
JH
1727 int flag;
1728
0bad611b
HV
1729 if (submodule) {
1730 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1731 return fn("HEAD", sha1, 0, cb_data);
1732
1733 return 0;
1734 }
1735
c6893323 1736 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1737 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1738
2f34ba32 1739 return 0;
723c31fe
LT
1740}
1741
0bad611b
HV
1742int head_ref(each_ref_fn fn, void *cb_data)
1743{
1744 return do_head_ref(NULL, fn, cb_data);
1745}
1746
9ef6aeb0
HV
1747int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1748{
1749 return do_head_ref(submodule, fn, cb_data);
1750}
1751
cb5d709f 1752int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1753{
9da31cb0 1754 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
a62be77f
SE
1755}
1756
9ef6aeb0
HV
1757int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1758{
65cf102b 1759 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
a62be77f
SE
1760}
1761
2a8177b6
CC
1762int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1763{
9da31cb0 1764 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1765}
1766
9ef6aeb0
HV
1767int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1768 each_ref_fn fn, void *cb_data)
1769{
65cf102b 1770 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1771}
1772
cb5d709f 1773int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1774{
2a8177b6 1775 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1776}
1777
9ef6aeb0
HV
1778int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1779{
1780 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1781}
1782
cb5d709f 1783int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1784{
2a8177b6 1785 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1786}
1787
9ef6aeb0
HV
1788int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1789{
1790 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1791}
1792
cb5d709f 1793int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1794{
2a8177b6 1795 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1796}
1797
9ef6aeb0
HV
1798int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1799{
1800 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1801}
1802
29268700
CC
1803int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1804{
9da31cb0 1805 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1806}
1807
a1bea2c1
JT
1808int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1809{
1810 struct strbuf buf = STRBUF_INIT;
1811 int ret = 0;
1812 unsigned char sha1[20];
1813 int flag;
1814
1815 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1816 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1817 ret = fn(buf.buf, sha1, flag, cb_data);
1818 strbuf_release(&buf);
1819
1820 return ret;
1821}
1822
1823int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1824{
1825 struct strbuf buf = STRBUF_INIT;
1826 int ret;
1827 strbuf_addf(&buf, "%srefs/", get_git_namespace());
9da31cb0 1828 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
a1bea2c1
JT
1829 strbuf_release(&buf);
1830 return ret;
1831}
1832
b09fe971
IL
1833int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1834 const char *prefix, void *cb_data)
d08bae7e
IL
1835{
1836 struct strbuf real_pattern = STRBUF_INIT;
1837 struct ref_filter filter;
d08bae7e
IL
1838 int ret;
1839
59556548 1840 if (!prefix && !starts_with(pattern, "refs/"))
d08bae7e 1841 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1842 else if (prefix)
1843 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1844 strbuf_addstr(&real_pattern, pattern);
1845
894a9d33 1846 if (!has_glob_specials(pattern)) {
9517e6b8 1847 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1848 if (real_pattern.buf[real_pattern.len - 1] != '/')
1849 strbuf_addch(&real_pattern, '/');
1850 /* No need to check for '*', there is none. */
1851 strbuf_addch(&real_pattern, '*');
1852 }
1853
1854 filter.pattern = real_pattern.buf;
1855 filter.fn = fn;
1856 filter.cb_data = cb_data;
1857 ret = for_each_ref(filter_refs, &filter);
1858
1859 strbuf_release(&real_pattern);
1860 return ret;
1861}
1862
b09fe971
IL
1863int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1864{
1865 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1866}
1867
f8948e2f
JH
1868int for_each_rawref(each_ref_fn fn, void *cb_data)
1869{
9da31cb0 1870 return do_for_each_ref(&ref_cache, "", fn, 0,
f8948e2f 1871 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1872}
1873
4577e483 1874const char *prettify_refname(const char *name)
a9c37a72 1875{
a9c37a72 1876 return name + (
59556548
CC
1877 starts_with(name, "refs/heads/") ? 11 :
1878 starts_with(name, "refs/tags/") ? 10 :
1879 starts_with(name, "refs/remotes/") ? 13 :
a9c37a72
DB
1880 0);
1881}
1882
54457fe5 1883static const char *ref_rev_parse_rules[] = {
79803322
SP
1884 "%.*s",
1885 "refs/%.*s",
1886 "refs/tags/%.*s",
1887 "refs/heads/%.*s",
1888 "refs/remotes/%.*s",
1889 "refs/remotes/%.*s/HEAD",
1890 NULL
1891};
1892
54457fe5 1893int refname_match(const char *abbrev_name, const char *full_name)
79803322
SP
1894{
1895 const char **p;
1896 const int abbrev_name_len = strlen(abbrev_name);
1897
54457fe5 1898 for (p = ref_rev_parse_rules; *p; p++) {
79803322
SP
1899 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1900 return 1;
1901 }
1902 }
1903
1904 return 0;
1905}
1906
e5f38ec3 1907static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1908 const unsigned char *old_sha1, int mustexist)
1909{
c6893323 1910 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1911 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1912 unlock_ref(lock);
1913 return NULL;
1914 }
a89fccd2 1915 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1916 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1917 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1918 unlock_ref(lock);
1919 return NULL;
1920 }
1921 return lock;
1922}
1923
7155b727 1924static int remove_empty_directories(const char *file)
bc7127ef
JH
1925{
1926 /* we want to create a file but there is a directory there;
1927 * if that is an empty directory (or a directory that contains
1928 * only empty directories), remove them.
1929 */
7155b727
JS
1930 struct strbuf path;
1931 int result;
bc7127ef 1932
7155b727
JS
1933 strbuf_init(&path, 20);
1934 strbuf_addstr(&path, file);
1935
a0f4afbe 1936 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1937
1938 strbuf_release(&path);
1939
1940 return result;
bc7127ef
JH
1941}
1942
ff74f7f1
JH
1943/*
1944 * *string and *len will only be substituted, and *string returned (for
1945 * later free()ing) if the string passed in is a magic short-hand form
1946 * to name a branch.
1947 */
1948static char *substitute_branch_name(const char **string, int *len)
1949{
1950 struct strbuf buf = STRBUF_INIT;
cf99a761 1951 int ret = interpret_branch_name(*string, *len, &buf);
ff74f7f1
JH
1952
1953 if (ret == *len) {
1954 size_t size;
1955 *string = strbuf_detach(&buf, &size);
1956 *len = size;
1957 return (char *)*string;
1958 }
1959
1960 return NULL;
1961}
1962
1963int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1964{
1965 char *last_branch = substitute_branch_name(&str, &len);
1966 const char **p, *r;
1967 int refs_found = 0;
1968
1969 *ref = NULL;
1970 for (p = ref_rev_parse_rules; *p; p++) {
1971 char fullref[PATH_MAX];
1972 unsigned char sha1_from_ref[20];
1973 unsigned char *this_result;
1974 int flag;
1975
1976 this_result = refs_found ? sha1_from_ref : sha1;
1977 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1978 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1979 if (r) {
1980 if (!refs_found++)
1981 *ref = xstrdup(r);
1982 if (!warn_ambiguous_refs)
1983 break;
55956350 1984 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1985 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1986 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1987 warning("ignoring broken ref %s.", fullref);
1988 }
ff74f7f1
JH
1989 }
1990 free(last_branch);
1991 return refs_found;
1992}
1993
1994int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1995{
1996 char *last_branch = substitute_branch_name(&str, &len);
1997 const char **p;
1998 int logs_found = 0;
1999
2000 *log = NULL;
2001 for (p = ref_rev_parse_rules; *p; p++) {
2002 struct stat st;
2003 unsigned char hash[20];
2004 char path[PATH_MAX];
2005 const char *ref, *it;
2006
2007 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 2008 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
2009 if (!ref)
2010 continue;
2011 if (!stat(git_path("logs/%s", path), &st) &&
2012 S_ISREG(st.st_mode))
2013 it = path;
2014 else if (strcmp(ref, path) &&
2015 !stat(git_path("logs/%s", ref), &st) &&
2016 S_ISREG(st.st_mode))
2017 it = ref;
2018 else
2019 continue;
2020 if (!logs_found++) {
2021 *log = xstrdup(it);
2022 hashcpy(sha1, hash);
2023 }
2024 if (!warn_ambiguous_refs)
2025 break;
2026 }
2027 free(last_branch);
2028 return logs_found;
2029}
2030
dfefa935
MH
2031static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2032 const unsigned char *old_sha1,
2033 int flags, int *type_p)
4bd18c43 2034{
434cd0cd 2035 char *ref_file;
dfefa935 2036 const char *orig_refname = refname;
4bd18c43 2037 struct ref_lock *lock;
5cc3cef9 2038 int last_errno = 0;
acd3b9ec 2039 int type, lflags;
4431fcc4 2040 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 2041 int missing = 0;
c4c61c76 2042 int attempts_remaining = 3;
4bd18c43
SP
2043
2044 lock = xcalloc(1, sizeof(struct ref_lock));
2045 lock->lock_fd = -1;
2046
8d68493f 2047 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 2048 if (!refname && errno == EISDIR) {
bc7127ef
JH
2049 /* we are trying to lock foo but we used to
2050 * have foo/bar which now does not exist;
2051 * it is normal for the empty directory 'foo'
2052 * to remain.
2053 */
dfefa935 2054 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
2055 if (remove_empty_directories(ref_file)) {
2056 last_errno = errno;
dfefa935 2057 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
2058 goto error_return;
2059 }
8d68493f 2060 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 2061 }
68db31cc
SV
2062 if (type_p)
2063 *type_p = type;
dfefa935 2064 if (!refname) {
5cc3cef9 2065 last_errno = errno;
818f477c 2066 error("unable to resolve reference %s: %s",
dfefa935 2067 orig_refname, strerror(errno));
5cc3cef9 2068 goto error_return;
4bd18c43 2069 }
5bdd8d4a 2070 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
2071 /* When the ref did not exist and we are creating it,
2072 * make sure there is no existing ref that is packed
2073 * whose name begins with our refname, nor a ref whose
2074 * name is a proper prefix of our refname.
2075 */
5bdd8d4a 2076 if (missing &&
9da31cb0 2077 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
f475e08e 2078 last_errno = ENOTDIR;
c976d415 2079 goto error_return;
f475e08e 2080 }
22a3844e 2081
c33d5174 2082 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 2083
e5c223e9 2084 lflags = 0;
acd3b9ec 2085 if (flags & REF_NODEREF) {
dfefa935 2086 refname = orig_refname;
acd3b9ec
JH
2087 lflags |= LOCK_NODEREF;
2088 }
dfefa935
MH
2089 lock->ref_name = xstrdup(refname);
2090 lock->orig_ref_name = xstrdup(orig_refname);
2091 ref_file = git_path("%s", refname);
5bdd8d4a 2092 if (missing)
68db31cc
SV
2093 lock->force_write = 1;
2094 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2095 lock->force_write = 1;
4bd18c43 2096
c4c61c76
MH
2097 retry:
2098 switch (safe_create_leading_directories(ref_file)) {
2099 case SCLD_OK:
2100 break; /* success */
2101 case SCLD_VANISHED:
2102 if (--attempts_remaining > 0)
2103 goto retry;
2104 /* fall through */
2105 default:
5cc3cef9
JH
2106 last_errno = errno;
2107 error("unable to create directory for %s", ref_file);
2108 goto error_return;
2109 }
4bd18c43 2110
acd3b9ec 2111 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
e5c223e9
MH
2112 if (lock->lock_fd < 0) {
2113 if (errno == ENOENT && --attempts_remaining > 0)
2114 /*
2115 * Maybe somebody just deleted one of the
2116 * directories leading to ref_file. Try
2117 * again:
2118 */
2119 goto retry;
2120 else
2121 unable_to_lock_index_die(ref_file, errno);
2122 }
4bd18c43 2123 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
2124
2125 error_return:
2126 unlock_ref(lock);
2127 errno = last_errno;
2128 return NULL;
4bd18c43
SP
2129}
2130
dfefa935 2131struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 2132{
53cce84c 2133 char refpath[PATH_MAX];
dfefa935 2134 if (check_refname_format(refname, 0))
4bd18c43 2135 return NULL;
dfefa935 2136 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 2137 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
2138}
2139
dfefa935 2140struct ref_lock *lock_any_ref_for_update(const char *refname,
9bbb0fa1
BK
2141 const unsigned char *old_sha1,
2142 int flags, int *type_p)
4bd18c43 2143{
dfefa935 2144 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 2145 return NULL;
9bbb0fa1 2146 return lock_ref_sha1_basic(refname, old_sha1, flags, type_p);
c0277d15
JH
2147}
2148
fec3137f
MH
2149/*
2150 * Write an entry to the packed-refs file for the specified refname.
2151 * If peeled is non-NULL, write it as the entry's peeled value.
2152 */
2153static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2154 unsigned char *peeled)
d66da478 2155{
d66da478
MH
2156 char line[PATH_MAX + 100];
2157 int len;
2158
d66da478
MH
2159 len = snprintf(line, sizeof(line), "%s %s\n",
2160 sha1_to_hex(sha1), refname);
2161 /* this should not happen but just being defensive */
2162 if (len > sizeof(line))
2163 die("too long a refname '%s'", refname);
fec3137f
MH
2164 write_or_die(fd, line, len);
2165
2166 if (peeled) {
2167 if (snprintf(line, sizeof(line), "^%s\n",
2168 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2169 die("internal error");
2170 write_or_die(fd, line, PEELED_LINE_LENGTH);
2171 }
2172}
2173
7b40d396
MH
2174/*
2175 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2176 */
2177static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2178{
2179 int *fd = cb_data;
2180 enum peel_status peel_status = peel_entry(entry, 0);
2181
2182 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2183 error("internal error: %s is not a valid packed reference!",
2184 entry->name);
2185 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2186 peel_status == PEEL_PEELED ?
2187 entry->u.value.peeled : NULL);
2188 return 0;
2189}
2190
9f69d297
MH
2191int lock_packed_refs(int flags)
2192{
2193 struct packed_ref_cache *packed_ref_cache;
2194
9f69d297
MH
2195 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2196 return -1;
5d478f5c
MH
2197 /*
2198 * Get the current packed-refs while holding the lock. If the
2199 * packed-refs file has been modified since we last read it,
2200 * this will automatically invalidate the cache and re-read
2201 * the packed-refs file.
2202 */
9f69d297
MH
2203 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2204 packed_ref_cache->lock = &packlock;
4f6b83e3
MH
2205 /* Increment the reference count to prevent it from being freed: */
2206 acquire_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2207 return 0;
2208}
2209
2210int commit_packed_refs(void)
2211{
2212 struct packed_ref_cache *packed_ref_cache =
2213 get_packed_ref_cache(&ref_cache);
2214 int error = 0;
2215
2216 if (!packed_ref_cache->lock)
2217 die("internal error: packed-refs not locked");
2218 write_or_die(packed_ref_cache->lock->fd,
2219 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2220
2221 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2222 0, write_packed_entry_fn,
2223 &packed_ref_cache->lock->fd);
2224 if (commit_lock_file(packed_ref_cache->lock))
2225 error = -1;
2226 packed_ref_cache->lock = NULL;
4f6b83e3 2227 release_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2228 return error;
2229}
2230
2231void rollback_packed_refs(void)
2232{
2233 struct packed_ref_cache *packed_ref_cache =
2234 get_packed_ref_cache(&ref_cache);
2235
2236 if (!packed_ref_cache->lock)
2237 die("internal error: packed-refs not locked");
2238 rollback_lock_file(packed_ref_cache->lock);
2239 packed_ref_cache->lock = NULL;
4f6b83e3 2240 release_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2241 clear_packed_ref_cache(&ref_cache);
2242}
2243
32d462ce
MH
2244struct ref_to_prune {
2245 struct ref_to_prune *next;
2246 unsigned char sha1[20];
2247 char name[FLEX_ARRAY];
2248};
2249
2250struct pack_refs_cb_data {
2251 unsigned int flags;
267f9a8c 2252 struct ref_dir *packed_refs;
32d462ce 2253 struct ref_to_prune *ref_to_prune;
32d462ce
MH
2254};
2255
267f9a8c
MH
2256/*
2257 * An each_ref_entry_fn that is run over loose references only. If
2258 * the loose reference can be packed, add an entry in the packed ref
2259 * cache. If the reference should be pruned, also add it to
2260 * ref_to_prune in the pack_refs_cb_data.
2261 */
2262static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
32d462ce
MH
2263{
2264 struct pack_refs_cb_data *cb = cb_data;
f85354b5 2265 enum peel_status peel_status;
267f9a8c 2266 struct ref_entry *packed_entry;
59556548 2267 int is_tag_ref = starts_with(entry->name, "refs/tags/");
32d462ce 2268
267f9a8c
MH
2269 /* ALWAYS pack tags */
2270 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
32d462ce
MH
2271 return 0;
2272
b2a8226d
MH
2273 /* Do not pack symbolic or broken refs: */
2274 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2275 return 0;
2276
267f9a8c 2277 /* Add a packed ref cache entry equivalent to the loose entry. */
f85354b5 2278 peel_status = peel_entry(entry, 1);
0f29920f 2279 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
f85354b5
MH
2280 die("internal error peeling reference %s (%s)",
2281 entry->name, sha1_to_hex(entry->u.value.sha1));
267f9a8c
MH
2282 packed_entry = find_ref(cb->packed_refs, entry->name);
2283 if (packed_entry) {
2284 /* Overwrite existing packed entry with info from loose entry */
2285 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2286 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2287 } else {
2288 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2289 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2290 add_ref(cb->packed_refs, packed_entry);
2291 }
2292 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
32d462ce 2293
267f9a8c
MH
2294 /* Schedule the loose reference for pruning if requested. */
2295 if ((cb->flags & PACK_REFS_PRUNE)) {
12e77559 2296 int namelen = strlen(entry->name) + 1;
32d462ce 2297 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
12e77559
MH
2298 hashcpy(n->sha1, entry->u.value.sha1);
2299 strcpy(n->name, entry->name);
32d462ce
MH
2300 n->next = cb->ref_to_prune;
2301 cb->ref_to_prune = n;
2302 }
d66da478
MH
2303 return 0;
2304}
2305
32d462ce
MH
2306/*
2307 * Remove empty parents, but spare refs/ and immediate subdirs.
2308 * Note: munges *name.
2309 */
2310static void try_remove_empty_parents(char *name)
2311{
2312 char *p, *q;
2313 int i;
2314 p = name;
2315 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2316 while (*p && *p != '/')
2317 p++;
2318 /* tolerate duplicate slashes; see check_refname_format() */
2319 while (*p == '/')
2320 p++;
2321 }
2322 for (q = p; *q; q++)
2323 ;
2324 while (1) {
2325 while (q > p && *q != '/')
2326 q--;
2327 while (q > p && *(q-1) == '/')
2328 q--;
2329 if (q == p)
2330 break;
2331 *q = '\0';
2332 if (rmdir(git_path("%s", name)))
2333 break;
2334 }
2335}
2336
2337/* make sure nobody touched the ref, and unlink */
2338static void prune_ref(struct ref_to_prune *r)
2339{
2340 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2341
2342 if (lock) {
2343 unlink_or_warn(git_path("%s", r->name));
2344 unlock_ref(lock);
2345 try_remove_empty_parents(r->name);
2346 }
2347}
2348
2349static void prune_refs(struct ref_to_prune *r)
2350{
2351 while (r) {
2352 prune_ref(r);
2353 r = r->next;
2354 }
2355}
2356
32d462ce
MH
2357int pack_refs(unsigned int flags)
2358{
32d462ce
MH
2359 struct pack_refs_cb_data cbdata;
2360
2361 memset(&cbdata, 0, sizeof(cbdata));
2362 cbdata.flags = flags;
2363
9f69d297 2364 lock_packed_refs(LOCK_DIE_ON_ERROR);
267f9a8c 2365 cbdata.packed_refs = get_packed_refs(&ref_cache);
32d462ce 2366
267f9a8c
MH
2367 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2368 pack_if_possible_fn, &cbdata);
32d462ce 2369
9f69d297 2370 if (commit_packed_refs())
32d462ce 2371 die_errno("unable to overwrite old ref-pack file");
9f69d297 2372
32d462ce
MH
2373 prune_refs(cbdata.ref_to_prune);
2374 return 0;
2375}
2376
7b40d396
MH
2377/*
2378 * If entry is no longer needed in packed-refs, add it to the string
2379 * list pointed to by cb_data. Reasons for deleting entries:
2380 *
2381 * - Entry is broken.
2382 * - Entry is overridden by a loose ref.
2383 * - Entry does not point at a valid object.
2384 *
2385 * In the first and third cases, also emit an error message because these
2386 * are indications of repository corruption.
2387 */
2388static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
c0277d15 2389{
7b40d396 2390 struct string_list *refs_to_delete = cb_data;
fec3137f 2391
ab292bc4
MH
2392 if (entry->flag & REF_ISBROKEN) {
2393 /* This shouldn't happen to packed refs. */
2394 error("%s is broken!", entry->name);
7b40d396 2395 string_list_append(refs_to_delete, entry->name);
c0277d15 2396 return 0;
ab292bc4
MH
2397 }
2398 if (!has_sha1_file(entry->u.value.sha1)) {
2399 unsigned char sha1[20];
2400 int flags;
2401
2402 if (read_ref_full(entry->name, sha1, 0, &flags))
2403 /* We should at least have found the packed ref. */
2404 die("Internal error");
7b40d396 2405 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
ab292bc4
MH
2406 /*
2407 * This packed reference is overridden by a
2408 * loose reference, so it is OK that its value
2409 * is no longer valid; for example, it might
2410 * refer to an object that has been garbage
2411 * collected. For this purpose we don't even
2412 * care whether the loose reference itself is
2413 * invalid, broken, symbolic, etc. Silently
7b40d396 2414 * remove the packed reference.
ab292bc4 2415 */
7b40d396 2416 string_list_append(refs_to_delete, entry->name);
ab292bc4 2417 return 0;
7b40d396 2418 }
ab292bc4
MH
2419 /*
2420 * There is no overriding loose reference, so the fact
2421 * that this reference doesn't refer to a valid object
2422 * indicates some kind of repository corruption.
2423 * Report the problem, then omit the reference from
2424 * the output.
2425 */
2426 error("%s does not point to a valid object!", entry->name);
7b40d396 2427 string_list_append(refs_to_delete, entry->name);
ab292bc4
MH
2428 return 0;
2429 }
2430
d66da478
MH
2431 return 0;
2432}
2433
61cee0db 2434static int repack_without_refs(const char **refnames, int n)
c0277d15 2435{
7618fd80 2436 struct ref_dir *packed;
7b40d396
MH
2437 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2438 struct string_list_item *ref_to_delete;
61cee0db
BK
2439 int i, removed = 0;
2440
2441 /* Look for a packed ref */
2442 for (i = 0; i < n; i++)
2443 if (get_packed_ref(refnames[i]))
2444 break;
7618fd80 2445
61cee0db
BK
2446 /* Avoid locking if we have nothing to do */
2447 if (i == n)
2448 return 0; /* no refname exists in packed refs */
7618fd80 2449
9f69d297 2450 if (lock_packed_refs(0)) {
1b018fd9 2451 unable_to_lock_error(git_path("packed-refs"), errno);
61cee0db 2452 return error("cannot delete '%s' from packed refs", refnames[i]);
1b018fd9 2453 }
9da31cb0 2454 packed = get_packed_refs(&ref_cache);
7b40d396 2455
61cee0db
BK
2456 /* Remove refnames from the cache */
2457 for (i = 0; i < n; i++)
2458 if (remove_entry(packed, refnames[i]) != -1)
2459 removed = 1;
2460 if (!removed) {
506a760d 2461 /*
61cee0db 2462 * All packed entries disappeared while we were
506a760d
MH
2463 * acquiring the lock.
2464 */
9f69d297 2465 rollback_packed_refs();
506a760d
MH
2466 return 0;
2467 }
7b40d396 2468
61cee0db 2469 /* Remove any other accumulated cruft */
7b40d396
MH
2470 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2471 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2472 if (remove_entry(packed, ref_to_delete->string) == -1)
2473 die("internal error");
2474 }
2475
61cee0db 2476 /* Write what remains */
9f69d297 2477 return commit_packed_refs();
c0277d15
JH
2478}
2479
61cee0db 2480static int repack_without_ref(const char *refname)
c0277d15 2481{
61cee0db
BK
2482 return repack_without_refs(&refname, 1);
2483}
c0277d15 2484
2ddb5d17
BK
2485static int delete_ref_loose(struct ref_lock *lock, int flag)
2486{
045a476f 2487 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 2488 /* loose */
2ddb5d17
BK
2489 int err, i = strlen(lock->lk->filename) - 5; /* .lock */
2490
547d058f
RS
2491 lock->lk->filename[i] = 0;
2492 err = unlink_or_warn(lock->lk->filename);
547d058f 2493 lock->lk->filename[i] = '.';
2ddb5d17
BK
2494 if (err && errno != ENOENT)
2495 return 1;
c0277d15 2496 }
2ddb5d17
BK
2497 return 0;
2498}
2499
eca35a25 2500int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
2501{
2502 struct ref_lock *lock;
2ddb5d17 2503 int ret = 0, flag = 0;
c0277d15 2504
547d058f 2505 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
2506 if (!lock)
2507 return 1;
2ddb5d17 2508 ret |= delete_ref_loose(lock, flag);
691f1a28 2509
c0277d15
JH
2510 /* removing the loose one could have resurrected an earlier
2511 * packed one. Also, if it was not loose we need to repack
2512 * without it.
2513 */
b274a714 2514 ret |= repack_without_ref(lock->ref_name);
c0277d15 2515
691f1a28 2516 unlink_or_warn(git_path("logs/%s", lock->ref_name));
9da31cb0 2517 clear_loose_ref_cache(&ref_cache);
c0277d15
JH
2518 unlock_ref(lock);
2519 return ret;
4bd18c43
SP
2520}
2521
765c2258
PH
2522/*
2523 * People using contrib's git-new-workdir have .git/logs/refs ->
2524 * /some/other/path/.git/logs/refs, and that may live on another device.
2525 *
2526 * IOW, to avoid cross device rename errors, the temporary renamed log must
2527 * live into logs/refs.
2528 */
2529#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2530
fa59ae79
MH
2531static int rename_tmp_log(const char *newrefname)
2532{
f1e9e9a4 2533 int attempts_remaining = 4;
ae4a283e
MH
2534
2535 retry:
08f555cb
MH
2536 switch (safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2537 case SCLD_OK:
2538 break; /* success */
2539 case SCLD_VANISHED:
2540 if (--attempts_remaining > 0)
2541 goto retry;
2542 /* fall through */
2543 default:
fa59ae79
MH
2544 error("unable to create directory for %s", newrefname);
2545 return -1;
2546 }
2547
fa59ae79 2548 if (rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
f1e9e9a4 2549 if ((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining > 0) {
fa59ae79
MH
2550 /*
2551 * rename(a, b) when b is an existing
2552 * directory ought to result in ISDIR, but
2553 * Solaris 5.8 gives ENOTDIR. Sheesh.
2554 */
2555 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2556 error("Directory not empty: logs/%s", newrefname);
2557 return -1;
2558 }
2559 goto retry;
ae4a283e
MH
2560 } else if (errno == ENOENT && --attempts_remaining > 0) {
2561 /*
2562 * Maybe another process just deleted one of
2563 * the directories in the path to newrefname.
2564 * Try again from the beginning.
2565 */
2566 goto retry;
fa59ae79
MH
2567 } else {
2568 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
2569 newrefname, strerror(errno));
2570 return -1;
2571 }
2572 }
2573 return 0;
2574}
2575
dfefa935 2576int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 2577{
c976d415
LH
2578 unsigned char sha1[20], orig_sha1[20];
2579 int flag = 0, logmoved = 0;
2580 struct ref_lock *lock;
c976d415 2581 struct stat loginfo;
dfefa935 2582 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 2583 const char *symref = NULL;
c976d415 2584
450d4c0f 2585 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 2586 return error("reflog for %s is a symlink", oldrefname);
c976d415 2587
8d68493f 2588 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 2589 if (flag & REF_ISSYMREF)
fa58186c 2590 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 2591 oldrefname);
eca35a25 2592 if (!symref)
dfefa935 2593 return error("refname %s not found", oldrefname);
c976d415 2594
9da31cb0 2595 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
c976d415
LH
2596 return 1;
2597
9da31cb0 2598 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
c976d415
LH
2599 return 1;
2600
dfefa935 2601 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 2602 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 2603 oldrefname, strerror(errno));
c976d415 2604
dfefa935
MH
2605 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2606 error("unable to delete old %s", oldrefname);
c976d415
LH
2607 goto rollback;
2608 }
2609
dfefa935
MH
2610 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2611 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 2612 if (errno==EISDIR) {
dfefa935
MH
2613 if (remove_empty_directories(git_path("%s", newrefname))) {
2614 error("Directory not empty: %s", newrefname);
c976d415
LH
2615 goto rollback;
2616 }
2617 } else {
dfefa935 2618 error("unable to delete existing %s", newrefname);
c976d415
LH
2619 goto rollback;
2620 }
2621 }
2622
fa59ae79 2623 if (log && rename_tmp_log(newrefname))
c976d415 2624 goto rollback;
c976d415 2625
c976d415
LH
2626 logmoved = log;
2627
dfefa935 2628 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2629 if (!lock) {
dfefa935 2630 error("unable to lock %s for update", newrefname);
c976d415
LH
2631 goto rollback;
2632 }
c976d415
LH
2633 lock->force_write = 1;
2634 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2635 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2636 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2637 goto rollback;
2638 }
2639
2640 return 0;
2641
2642 rollback:
dfefa935 2643 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2644 if (!lock) {
dfefa935 2645 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2646 goto rollbacklog;
2647 }
2648
2649 lock->force_write = 1;
2650 flag = log_all_ref_updates;
2651 log_all_ref_updates = 0;
2652 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2653 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2654 log_all_ref_updates = flag;
2655
2656 rollbacklog:
dfefa935 2657 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2658 error("unable to restore logfile %s from %s: %s",
dfefa935 2659 oldrefname, newrefname, strerror(errno));
c976d415 2660 if (!logmoved && log &&
dfefa935 2661 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2662 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2663 oldrefname, strerror(errno));
c976d415
LH
2664
2665 return 1;
2666}
2667
435fc852 2668int close_ref(struct ref_lock *lock)
b531394d
BC
2669{
2670 if (close_lock_file(lock->lk))
2671 return -1;
2672 lock->lock_fd = -1;
2673 return 0;
2674}
2675
435fc852 2676int commit_ref(struct ref_lock *lock)
b531394d
BC
2677{
2678 if (commit_lock_file(lock->lk))
2679 return -1;
2680 lock->lock_fd = -1;
2681 return 0;
2682}
2683
e5f38ec3 2684void unlock_ref(struct ref_lock *lock)
4bd18c43 2685{
4ed7cd3a
BC
2686 /* Do not free lock->lk -- atexit() still looks at them */
2687 if (lock->lk)
2688 rollback_lock_file(lock->lk);
434cd0cd 2689 free(lock->ref_name);
1655707c 2690 free(lock->orig_ref_name);
4bd18c43
SP
2691 free(lock);
2692}
2693
0ec29a47
JH
2694/*
2695 * copy the reflog message msg to buf, which has been allocated sufficiently
2696 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2697 * because reflog file is one line per entry.
2698 */
2699static int copy_msg(char *buf, const char *msg)
2700{
2701 char *cp = buf;
2702 char c;
2703 int wasspace = 1;
2704
2705 *cp++ = '\t';
2706 while ((c = *msg++)) {
2707 if (wasspace && isspace(c))
2708 continue;
2709 wasspace = isspace(c);
2710 if (wasspace)
2711 c = ' ';
2712 *cp++ = c;
2713 }
2714 while (buf < cp && isspace(cp[-1]))
2715 cp--;
2716 *cp++ = '\n';
2717 return cp - buf;
2718}
2719
dfefa935 2720int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2721{
859c3017 2722 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2723
dfefa935 2724 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2725 if (log_all_ref_updates &&
59556548
CC
2726 (starts_with(refname, "refs/heads/") ||
2727 starts_with(refname, "refs/remotes/") ||
2728 starts_with(refname, "refs/notes/") ||
dfefa935 2729 !strcmp(refname, "HEAD"))) {
157aaea5 2730 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2731 return error("unable to create directory for %s",
157aaea5 2732 logfile);
6de08ae6
SP
2733 oflags |= O_CREAT;
2734 }
2735
157aaea5 2736 logfd = open(logfile, oflags, 0666);
6de08ae6 2737 if (logfd < 0) {
1974bf62 2738 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2739 return 0;
3b463c3f
JH
2740
2741 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2742 if (remove_empty_directories(logfile)) {
3b463c3f 2743 return error("There are still logs under '%s'",
157aaea5 2744 logfile);
3b463c3f 2745 }
157aaea5 2746 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2747 }
2748
2749 if (logfd < 0)
2750 return error("Unable to append to %s: %s",
157aaea5 2751 logfile, strerror(errno));
6de08ae6
SP
2752 }
2753
157aaea5 2754 adjust_shared_perm(logfile);
859c3017
EM
2755 close(logfd);
2756 return 0;
2757}
443b92b6 2758
dfefa935 2759static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2760 const unsigned char *new_sha1, const char *msg)
2761{
2762 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2763 unsigned maxlen, len;
2764 int msglen;
157aaea5 2765 char log_file[PATH_MAX];
859c3017
EM
2766 char *logrec;
2767 const char *committer;
2768
2769 if (log_all_ref_updates < 0)
2770 log_all_ref_updates = !is_bare_repository();
2771
dfefa935 2772 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2773 if (result)
2774 return result;
2775
2776 logfd = open(log_file, oflags);
2777 if (logfd < 0)
2778 return 0;
0ec29a47 2779 msglen = msg ? strlen(msg) : 0;
774751a8 2780 committer = git_committer_info(0);
8ac65937
JH
2781 maxlen = strlen(committer) + msglen + 100;
2782 logrec = xmalloc(maxlen);
2783 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2784 sha1_to_hex(old_sha1),
2785 sha1_to_hex(new_sha1),
8ac65937
JH
2786 committer);
2787 if (msglen)
0ec29a47 2788 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2789 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2790 free(logrec);
91c8d590 2791 if (close(logfd) != 0 || written != len)
9a13f0b7 2792 return error("Unable to append to %s", log_file);
6de08ae6
SP
2793 return 0;
2794}
2795
c3b0dec5
LT
2796static int is_branch(const char *refname)
2797{
59556548 2798 return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
c3b0dec5
LT
2799}
2800
4bd18c43
SP
2801int write_ref_sha1(struct ref_lock *lock,
2802 const unsigned char *sha1, const char *logmsg)
2803{
2804 static char term = '\n';
c3b0dec5 2805 struct object *o;
4bd18c43
SP
2806
2807 if (!lock)
95fc7512 2808 return -1;
a89fccd2 2809 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2810 unlock_ref(lock);
2811 return 0;
95fc7512 2812 }
c3b0dec5
LT
2813 o = parse_object(sha1);
2814 if (!o) {
7be8b3ba 2815 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2816 lock->ref_name, sha1_to_hex(sha1));
2817 unlock_ref(lock);
2818 return -1;
2819 }
2820 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2821 error("Trying to write non-commit object %s to branch %s",
2822 sha1_to_hex(sha1), lock->ref_name);
2823 unlock_ref(lock);
2824 return -1;
2825 }
93822c22
AW
2826 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2827 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2828 || close_ref(lock) < 0) {
c33d5174 2829 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2830 unlock_ref(lock);
2831 return -1;
2832 }
9da31cb0 2833 clear_loose_ref_cache(&ref_cache);
bd104db1
NP
2834 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2835 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2836 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2837 unlock_ref(lock);
2838 return -1;
2839 }
605fac8b
NP
2840 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2841 /*
2842 * Special hack: If a branch is updated directly and HEAD
2843 * points to it (may happen on the remote side of a push
2844 * for example) then logically the HEAD reflog should be
2845 * updated too.
2846 * A generic solution implies reverse symref information,
2847 * but finding all symrefs pointing to the given branch
2848 * would be rather costly for this rare event (the direct
2849 * update of a branch) to be worth it. So let's cheat and
2850 * check with HEAD only which should cover 99% of all usage
2851 * scenarios (even 100% of the default ones).
2852 */
2853 unsigned char head_sha1[20];
2854 int head_flag;
2855 const char *head_ref;
8cad4744 2856 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2857 if (head_ref && (head_flag & REF_ISSYMREF) &&
2858 !strcmp(head_ref, lock->ref_name))
2859 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2860 }
b531394d 2861 if (commit_ref(lock)) {
434cd0cd 2862 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2863 unlock_ref(lock);
2864 return -1;
2865 }
4bd18c43
SP
2866 unlock_ref(lock);
2867 return 0;
95fc7512 2868}
d556fae2 2869
8b5157e4
NP
2870int create_symref(const char *ref_target, const char *refs_heads_master,
2871 const char *logmsg)
41b625b0
NP
2872{
2873 const char *lockpath;
2874 char ref[1000];
2875 int fd, len, written;
a4f34cbb 2876 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2877 unsigned char old_sha1[20], new_sha1[20];
2878
2879 if (logmsg && read_ref(ref_target, old_sha1))
2880 hashclr(old_sha1);
41b625b0 2881
d48744d1
JH
2882 if (safe_create_leading_directories(git_HEAD) < 0)
2883 return error("unable to create directory for %s", git_HEAD);
2884
41b625b0
NP
2885#ifndef NO_SYMLINK_HEAD
2886 if (prefer_symlink_refs) {
2887 unlink(git_HEAD);
2888 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2889 goto done;
41b625b0
NP
2890 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2891 }
2892#endif
2893
2894 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2895 if (sizeof(ref) <= len) {
2896 error("refname too long: %s", refs_heads_master);
47fc52e2 2897 goto error_free_return;
41b625b0
NP
2898 }
2899 lockpath = mkpath("%s.lock", git_HEAD);
2900 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2901 if (fd < 0) {
2902 error("Unable to open %s for writing", lockpath);
47fc52e2 2903 goto error_free_return;
41b625b0
NP
2904 }
2905 written = write_in_full(fd, ref, len);
91c8d590 2906 if (close(fd) != 0 || written != len) {
41b625b0 2907 error("Unable to write to %s", lockpath);
47fc52e2 2908 goto error_unlink_return;
41b625b0
NP
2909 }
2910 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2911 error("Unable to create %s", git_HEAD);
47fc52e2 2912 goto error_unlink_return;
41b625b0
NP
2913 }
2914 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2915 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2916 error_unlink_return:
691f1a28 2917 unlink_or_warn(lockpath);
47fc52e2
JH
2918 error_free_return:
2919 free(git_HEAD);
2920 return -1;
41b625b0 2921 }
8b5157e4 2922
ee96d11b 2923#ifndef NO_SYMLINK_HEAD
8b5157e4 2924 done:
ee96d11b 2925#endif
8b5157e4
NP
2926 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2927 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2928
47fc52e2 2929 free(git_HEAD);
41b625b0
NP
2930 return 0;
2931}
2932
16d7cc90
JH
2933static char *ref_msg(const char *line, const char *endp)
2934{
2935 const char *ep;
16d7cc90 2936 line += 82;
182af834
PH
2937 ep = memchr(line, '\n', endp - line);
2938 if (!ep)
2939 ep = endp;
2940 return xmemdupz(line, ep - line);
16d7cc90
JH
2941}
2942
dfefa935
MH
2943int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2944 unsigned char *sha1, char **msg,
2945 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2946{
e5229042 2947 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2948 char *tz_c;
e29cb53a 2949 int logfd, tz, reccnt = 0;
d556fae2
SP
2950 struct stat st;
2951 unsigned long date;
e5229042 2952 unsigned char logged_sha1[20];
cb48cb58 2953 void *log_mapped;
dc49cd76 2954 size_t mapsz;
d556fae2 2955
dfefa935 2956 logfile = git_path("logs/%s", refname);
d556fae2
SP
2957 logfd = open(logfile, O_RDONLY, 0);
2958 if (logfd < 0)
d824cbba 2959 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2960 fstat(logfd, &st);
2961 if (!st.st_size)
2962 die("Log %s is empty.", logfile);
dc49cd76
SP
2963 mapsz = xsize_t(st.st_size);
2964 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2965 logdata = log_mapped;
d556fae2
SP
2966 close(logfd);
2967
e5229042 2968 lastrec = NULL;
d556fae2
SP
2969 rec = logend = logdata + st.st_size;
2970 while (logdata < rec) {
e29cb53a 2971 reccnt++;
d556fae2
SP
2972 if (logdata < rec && *(rec-1) == '\n')
2973 rec--;
e5229042
SP
2974 lastgt = NULL;
2975 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2976 rec--;
e5229042
SP
2977 if (*rec == '>')
2978 lastgt = rec;
2979 }
2980 if (!lastgt)
d556fae2 2981 die("Log %s is corrupt.", logfile);
e5229042 2982 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2983 if (date <= at_time || cnt == 0) {
76a44c5c 2984 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2985 if (msg)
2986 *msg = ref_msg(rec, logend);
2987 if (cutoff_time)
2988 *cutoff_time = date;
2989 if (cutoff_tz)
2990 *cutoff_tz = tz;
2991 if (cutoff_cnt)
76a44c5c 2992 *cutoff_cnt = reccnt - 1;
e5229042
SP
2993 if (lastrec) {
2994 if (get_sha1_hex(lastrec, logged_sha1))
2995 die("Log %s is corrupt.", logfile);
2996 if (get_sha1_hex(rec + 41, sha1))
2997 die("Log %s is corrupt.", logfile);
a89fccd2 2998 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2999 warning("Log %s has gap after %s.",
73013afd 3000 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 3001 }
e5f38ec3
JH
3002 }
3003 else if (date == at_time) {
e5229042
SP
3004 if (get_sha1_hex(rec + 41, sha1))
3005 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
3006 }
3007 else {
e5229042
SP
3008 if (get_sha1_hex(rec + 41, logged_sha1))
3009 die("Log %s is corrupt.", logfile);
a89fccd2 3010 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 3011 warning("Log %s unexpectedly ended on %s.",
73013afd 3012 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
3013 }
3014 }
dc49cd76 3015 munmap(log_mapped, mapsz);
d556fae2
SP
3016 return 0;
3017 }
e5229042 3018 lastrec = rec;
ab2a1a32
JH
3019 if (cnt > 0)
3020 cnt--;
d556fae2
SP
3021 }
3022
e5229042
SP
3023 rec = logdata;
3024 while (rec < logend && *rec != '>' && *rec != '\n')
3025 rec++;
3026 if (rec == logend || *rec == '\n')
d556fae2 3027 die("Log %s is corrupt.", logfile);
e5229042 3028 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
3029 tz = strtoul(tz_c, NULL, 10);
3030 if (get_sha1_hex(logdata, sha1))
3031 die("Log %s is corrupt.", logfile);
d1a4489a
JK
3032 if (is_null_sha1(sha1)) {
3033 if (get_sha1_hex(logdata + 41, sha1))
3034 die("Log %s is corrupt.", logfile);
3035 }
16d7cc90
JH
3036 if (msg)
3037 *msg = ref_msg(logdata, logend);
dc49cd76 3038 munmap(log_mapped, mapsz);
16d7cc90
JH
3039
3040 if (cutoff_time)
3041 *cutoff_time = date;
3042 if (cutoff_tz)
3043 *cutoff_tz = tz;
3044 if (cutoff_cnt)
3045 *cutoff_cnt = reccnt;
3046 return 1;
d556fae2 3047}
2ff81662 3048
9a7a183b
JH
3049static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
3050{
3051 unsigned char osha1[20], nsha1[20];
3052 char *email_end, *message;
3053 unsigned long timestamp;
3054 int tz;
3055
3056 /* old SP new SP name <email> SP time TAB msg LF */
3057 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
3058 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
3059 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3060 !(email_end = strchr(sb->buf + 82, '>')) ||
3061 email_end[1] != ' ' ||
3062 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3063 !message || message[0] != ' ' ||
3064 (message[1] != '+' && message[1] != '-') ||
3065 !isdigit(message[2]) || !isdigit(message[3]) ||
3066 !isdigit(message[4]) || !isdigit(message[5]))
3067 return 0; /* corrupt? */
3068 email_end[1] = '\0';
3069 tz = strtol(message + 1, NULL, 10);
3070 if (message[6] != '\t')
3071 message += 6;
3072 else
3073 message += 7;
3074 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3075}
3076
98f85ff4
JH
3077static char *find_beginning_of_line(char *bob, char *scan)
3078{
3079 while (bob < scan && *(--scan) != '\n')
3080 ; /* keep scanning backwards */
3081 /*
3082 * Return either beginning of the buffer, or LF at the end of
3083 * the previous line.
3084 */
3085 return scan;
3086}
3087
3088int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2ff81662 3089{
8ca78803 3090 struct strbuf sb = STRBUF_INIT;
98f85ff4
JH
3091 FILE *logfp;
3092 long pos;
3093 int ret = 0, at_tail = 1;
2ff81662 3094
7ae07c1b 3095 logfp = fopen(git_path("logs/%s", refname), "r");
2ff81662 3096 if (!logfp)
883d60fa 3097 return -1;
101d15e0 3098
98f85ff4
JH
3099 /* Jump to the end */
3100 if (fseek(logfp, 0, SEEK_END) < 0)
3101 return error("cannot seek back reflog for %s: %s",
3102 refname, strerror(errno));
3103 pos = ftell(logfp);
3104 while (!ret && 0 < pos) {
3105 int cnt;
3106 size_t nread;
3107 char buf[BUFSIZ];
3108 char *endp, *scanp;
3109
3110 /* Fill next block from the end */
3111 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3112 if (fseek(logfp, pos - cnt, SEEK_SET))
3113 return error("cannot seek back reflog for %s: %s",
3114 refname, strerror(errno));
3115 nread = fread(buf, cnt, 1, logfp);
e4ca819a 3116 if (nread != 1)
98f85ff4
JH
3117 return error("cannot read %d bytes from reflog for %s: %s",
3118 cnt, refname, strerror(errno));
3119 pos -= cnt;
3120
3121 scanp = endp = buf + cnt;
3122 if (at_tail && scanp[-1] == '\n')
3123 /* Looking at the final LF at the end of the file */
3124 scanp--;
3125 at_tail = 0;
3126
3127 while (buf < scanp) {
3128 /*
3129 * terminating LF of the previous line, or the beginning
3130 * of the buffer.
3131 */
3132 char *bp;
3133
3134 bp = find_beginning_of_line(buf, scanp);
3135
3136 if (*bp != '\n') {
3137 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3138 if (pos)
3139 break; /* need to fill another block */
3140 scanp = buf - 1; /* leave loop */
3141 } else {
3142 /*
3143 * (bp + 1) thru endp is the beginning of the
3144 * current line we have in sb
3145 */
3146 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3147 scanp = bp;
3148 endp = bp + 1;
3149 }
3150 ret = show_one_reflog_ent(&sb, fn, cb_data);
3151 strbuf_reset(&sb);
3152 if (ret)
3153 break;
9d33f7c2 3154 }
101d15e0 3155
2ff81662 3156 }
98f85ff4 3157 if (!ret && sb.len)
9a7a183b 3158 ret = show_one_reflog_ent(&sb, fn, cb_data);
98f85ff4 3159
2ff81662 3160 fclose(logfp);
8ca78803 3161 strbuf_release(&sb);
2266bf27 3162 return ret;
2ff81662 3163}
e29cb53a 3164
dfefa935 3165int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 3166{
98f85ff4
JH
3167 FILE *logfp;
3168 struct strbuf sb = STRBUF_INIT;
3169 int ret = 0;
3170
3171 logfp = fopen(git_path("logs/%s", refname), "r");
3172 if (!logfp)
3173 return -1;
101d15e0 3174
98f85ff4
JH
3175 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3176 ret = show_one_reflog_ent(&sb, fn, cb_data);
3177 fclose(logfp);
3178 strbuf_release(&sb);
3179 return ret;
3180}
989c0e5d
MH
3181/*
3182 * Call fn for each reflog in the namespace indicated by name. name
3183 * must be empty or end with '/'. Name will be used as a scratch
3184 * space, but its contents will be restored before return.
3185 */
3186static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 3187{
989c0e5d 3188 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 3189 int retval = 0;
93c603fc 3190 struct dirent *de;
989c0e5d 3191 int oldlen = name->len;
eb8381c8 3192
93c603fc 3193 if (!d)
989c0e5d 3194 return name->len ? errno : 0;
eb8381c8 3195
93c603fc
MH
3196 while ((de = readdir(d)) != NULL) {
3197 struct stat st;
eb8381c8 3198
93c603fc
MH
3199 if (de->d_name[0] == '.')
3200 continue;
93c603fc
MH
3201 if (has_extension(de->d_name, ".lock"))
3202 continue;
989c0e5d
MH
3203 strbuf_addstr(name, de->d_name);
3204 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3205 ; /* silently ignore */
93c603fc 3206 } else {
eb8381c8 3207 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
3208 strbuf_addch(name, '/');
3209 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
3210 } else {
3211 unsigned char sha1[20];
989c0e5d
MH
3212 if (read_ref_full(name->buf, sha1, 0, NULL))
3213 retval = error("bad ref for %s", name->buf);
eb8381c8 3214 else
989c0e5d 3215 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
3216 }
3217 if (retval)
3218 break;
3219 }
989c0e5d 3220 strbuf_setlen(name, oldlen);
eb8381c8 3221 }
93c603fc 3222 closedir(d);
eb8381c8
NP
3223 return retval;
3224}
3225
3226int for_each_reflog(each_ref_fn fn, void *cb_data)
3227{
989c0e5d
MH
3228 int retval;
3229 struct strbuf name;
3230 strbuf_init(&name, PATH_MAX);
3231 retval = do_for_each_reflog(&name, fn, cb_data);
3232 strbuf_release(&name);
3233 return retval;
eb8381c8 3234}
3d9f037c 3235
4738a333
BK
3236static struct ref_lock *update_ref_lock(const char *refname,
3237 const unsigned char *oldval,
3238 int flags, int *type_p,
3239 enum action_on_err onerr)
3d9f037c 3240{
4738a333
BK
3241 struct ref_lock *lock;
3242 lock = lock_any_ref_for_update(refname, oldval, flags, type_p);
3d9f037c
CR
3243 if (!lock) {
3244 const char *str = "Cannot lock the ref '%s'.";
3245 switch (onerr) {
f4124112
MH
3246 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
3247 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
3248 case UPDATE_REFS_QUIET_ON_ERR: break;
3d9f037c 3249 }
3d9f037c 3250 }
4738a333
BK
3251 return lock;
3252}
3253
3254static int update_ref_write(const char *action, const char *refname,
3255 const unsigned char *sha1, struct ref_lock *lock,
3256 enum action_on_err onerr)
3257{
3d9f037c
CR
3258 if (write_ref_sha1(lock, sha1, action) < 0) {
3259 const char *str = "Cannot update the ref '%s'.";
3260 switch (onerr) {
f4124112
MH
3261 case UPDATE_REFS_MSG_ON_ERR: error(str, refname); break;
3262 case UPDATE_REFS_DIE_ON_ERR: die(str, refname); break;
3263 case UPDATE_REFS_QUIET_ON_ERR: break;
3d9f037c
CR
3264 }
3265 return 1;
3266 }
3267 return 0;
3268}
cda69f48 3269
b5c8ea2a
MH
3270/**
3271 * Information needed for a single ref update. Set new_sha1 to the
3272 * new value or to zero to delete the ref. To check the old value
3273 * while locking the ref, set have_old to 1 and set old_sha1 to the
3274 * value or to zero to ensure the ref does not exist before update.
3275 */
3276struct ref_update {
b5c8ea2a
MH
3277 unsigned char new_sha1[20];
3278 unsigned char old_sha1[20];
3279 int flags; /* REF_NODEREF? */
3280 int have_old; /* 1 if old_sha1 is valid, 0 otherwise */
81c960e4 3281 struct ref_lock *lock;
84178db7 3282 int type;
88615910 3283 const char refname[FLEX_ARRAY];
b5c8ea2a
MH
3284};
3285
caa4046c
MH
3286/*
3287 * Data structure for holding a reference transaction, which can
3288 * consist of checks and updates to multiple references, carried out
3289 * as atomically as possible. This structure is opaque to callers.
3290 */
3291struct ref_transaction {
3292 struct ref_update **updates;
3293 size_t alloc;
3294 size_t nr;
3295};
3296
3297struct ref_transaction *ref_transaction_begin(void)
3298{
3299 return xcalloc(1, sizeof(struct ref_transaction));
3300}
3301
3302static void ref_transaction_free(struct ref_transaction *transaction)
3303{
3304 int i;
3305
88615910
MH
3306 for (i = 0; i < transaction->nr; i++)
3307 free(transaction->updates[i]);
caa4046c
MH
3308
3309 free(transaction->updates);
3310 free(transaction);
3311}
3312
3313void ref_transaction_rollback(struct ref_transaction *transaction)
3314{
3315 ref_transaction_free(transaction);
3316}
3317
3318static struct ref_update *add_update(struct ref_transaction *transaction,
3319 const char *refname)
3320{
88615910
MH
3321 size_t len = strlen(refname);
3322 struct ref_update *update = xcalloc(1, sizeof(*update) + len + 1);
caa4046c 3323
88615910 3324 strcpy((char *)update->refname, refname);
caa4046c
MH
3325 ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
3326 transaction->updates[transaction->nr++] = update;
3327 return update;
3328}
3329
3330void ref_transaction_update(struct ref_transaction *transaction,
3331 const char *refname,
3332 unsigned char *new_sha1, unsigned char *old_sha1,
3333 int flags, int have_old)
3334{
3335 struct ref_update *update = add_update(transaction, refname);
3336
3337 hashcpy(update->new_sha1, new_sha1);
3338 update->flags = flags;
3339 update->have_old = have_old;
3340 if (have_old)
3341 hashcpy(update->old_sha1, old_sha1);
3342}
3343
3344void ref_transaction_create(struct ref_transaction *transaction,
3345 const char *refname,
3346 unsigned char *new_sha1,
3347 int flags)
3348{
3349 struct ref_update *update = add_update(transaction, refname);
3350
3351 assert(!is_null_sha1(new_sha1));
3352 hashcpy(update->new_sha1, new_sha1);
3353 hashclr(update->old_sha1);
3354 update->flags = flags;
3355 update->have_old = 1;
3356}
3357
3358void ref_transaction_delete(struct ref_transaction *transaction,
3359 const char *refname,
3360 unsigned char *old_sha1,
3361 int flags, int have_old)
3362{
3363 struct ref_update *update = add_update(transaction, refname);
3364
3365 update->flags = flags;
3366 update->have_old = have_old;
3367 if (have_old) {
3368 assert(!is_null_sha1(old_sha1));
3369 hashcpy(update->old_sha1, old_sha1);
3370 }
3371}
3372
4738a333
BK
3373int update_ref(const char *action, const char *refname,
3374 const unsigned char *sha1, const unsigned char *oldval,
3375 int flags, enum action_on_err onerr)
3376{
3377 struct ref_lock *lock;
ce1e8462 3378 lock = update_ref_lock(refname, oldval, flags, NULL, onerr);
4738a333
BK
3379 if (!lock)
3380 return 1;
3381 return update_ref_write(action, refname, sha1, lock, onerr);
3382}
3383
98aee92d
BK
3384static int ref_update_compare(const void *r1, const void *r2)
3385{
3386 const struct ref_update * const *u1 = r1;
3387 const struct ref_update * const *u2 = r2;
5524e241 3388 return strcmp((*u1)->refname, (*u2)->refname);
98aee92d
BK
3389}
3390
3391static int ref_update_reject_duplicates(struct ref_update **updates, int n,
3392 enum action_on_err onerr)
3393{
3394 int i;
3395 for (i = 1; i < n; i++)
5524e241 3396 if (!strcmp(updates[i - 1]->refname, updates[i]->refname)) {
98aee92d
BK
3397 const char *str =
3398 "Multiple updates for ref '%s' not allowed.";
3399 switch (onerr) {
f4124112 3400 case UPDATE_REFS_MSG_ON_ERR:
5524e241 3401 error(str, updates[i]->refname); break;
f4124112 3402 case UPDATE_REFS_DIE_ON_ERR:
5524e241 3403 die(str, updates[i]->refname); break;
f4124112 3404 case UPDATE_REFS_QUIET_ON_ERR:
98aee92d
BK
3405 break;
3406 }
3407 return 1;
3408 }
3409 return 0;
3410}
3411
b5c8ea2a
MH
3412int ref_transaction_commit(struct ref_transaction *transaction,
3413 const char *msg, enum action_on_err onerr)
98aee92d
BK
3414{
3415 int ret = 0, delnum = 0, i;
98aee92d 3416 const char **delnames;
b5c8ea2a 3417 int n = transaction->nr;
6a402338 3418 struct ref_update **updates = transaction->updates;
98aee92d 3419
b5c8ea2a 3420 if (!n)
98aee92d
BK
3421 return 0;
3422
3423 /* Allocate work space */
98aee92d
BK
3424 delnames = xmalloc(sizeof(*delnames) * n);
3425
3426 /* Copy, sort, and reject duplicate refs */
98aee92d
BK
3427 qsort(updates, n, sizeof(*updates), ref_update_compare);
3428 ret = ref_update_reject_duplicates(updates, n, onerr);
3429 if (ret)
3430 goto cleanup;
3431
3432 /* Acquire all locks while verifying old values */
3433 for (i = 0; i < n; i++) {
cb198d21
MH
3434 struct ref_update *update = updates[i];
3435
81c960e4
MH
3436 update->lock = update_ref_lock(update->refname,
3437 (update->have_old ?
3438 update->old_sha1 : NULL),
3439 update->flags,
84178db7 3440 &update->type, onerr);
81c960e4 3441 if (!update->lock) {
98aee92d
BK
3442 ret = 1;
3443 goto cleanup;
3444 }
3445 }
3446
3447 /* Perform updates first so live commits remain referenced */
cb198d21
MH
3448 for (i = 0; i < n; i++) {
3449 struct ref_update *update = updates[i];
3450
3451 if (!is_null_sha1(update->new_sha1)) {
b5c8ea2a 3452 ret = update_ref_write(msg,
cb198d21
MH
3453 update->refname,
3454 update->new_sha1,
81c960e4
MH
3455 update->lock, onerr);
3456 update->lock = NULL; /* freed by update_ref_write */
98aee92d
BK
3457 if (ret)
3458 goto cleanup;
3459 }
cb198d21 3460 }
98aee92d
BK
3461
3462 /* Perform deletes now that updates are safely completed */
81c960e4
MH
3463 for (i = 0; i < n; i++) {
3464 struct ref_update *update = updates[i];
3465
3466 if (update->lock) {
3467 delnames[delnum++] = update->lock->ref_name;
84178db7 3468 ret |= delete_ref_loose(update->lock, update->type);
98aee92d 3469 }
81c960e4
MH
3470 }
3471
98aee92d
BK
3472 ret |= repack_without_refs(delnames, delnum);
3473 for (i = 0; i < delnum; i++)
3474 unlink_or_warn(git_path("logs/%s", delnames[i]));
3475 clear_loose_ref_cache(&ref_cache);
3476
3477cleanup:
3478 for (i = 0; i < n; i++)
81c960e4
MH
3479 if (updates[i]->lock)
3480 unlock_ref(updates[i]->lock);
98aee92d 3481 free(delnames);
caa4046c
MH
3482 ref_transaction_free(transaction);
3483 return ret;
3484}
3485
dfefa935 3486char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
3487{
3488 int i;
3489 static char **scanf_fmts;
3490 static int nr_rules;
3491 char *short_name;
3492
7c2b3029 3493 if (!nr_rules) {
4346663a
MH
3494 /*
3495 * Pre-generate scanf formats from ref_rev_parse_rules[].
3496 * Generate a format suitable for scanf from a
3497 * ref_rev_parse_rules rule by interpolating "%s" at the
3498 * location of the "%.*s".
3499 */
7c2b3029 3500 size_t total_len = 0;
84d5633f 3501 size_t offset = 0;
7c2b3029
JK
3502
3503 /* the rule list is NULL terminated, count them first */
a4165851 3504 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
7902fe03
MH
3505 /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
3506 total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
7c2b3029
JK
3507
3508 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3509
84d5633f 3510 offset = 0;
7c2b3029 3511 for (i = 0; i < nr_rules; i++) {
4346663a 3512 assert(offset < total_len);
84d5633f 3513 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
4346663a
MH
3514 offset += snprintf(scanf_fmts[i], total_len - offset,
3515 ref_rev_parse_rules[i], 2, "%s") + 1;
7c2b3029
JK
3516 }
3517 }
3518
3519 /* bail out if there are no rules */
3520 if (!nr_rules)
dfefa935 3521 return xstrdup(refname);
7c2b3029 3522
dfefa935
MH
3523 /* buffer for scanf result, at most refname must fit */
3524 short_name = xstrdup(refname);
7c2b3029
JK
3525
3526 /* skip first rule, it will always match */
3527 for (i = nr_rules - 1; i > 0 ; --i) {
3528 int j;
6e7b3309 3529 int rules_to_fail = i;
7c2b3029
JK
3530 int short_name_len;
3531
dfefa935 3532 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
3533 continue;
3534
3535 short_name_len = strlen(short_name);
3536
6e7b3309
BW
3537 /*
3538 * in strict mode, all (except the matched one) rules
3539 * must fail to resolve to a valid non-ambiguous ref
3540 */
3541 if (strict)
3542 rules_to_fail = nr_rules;
3543
7c2b3029
JK
3544 /*
3545 * check if the short name resolves to a valid ref,
3546 * but use only rules prior to the matched one
3547 */
6e7b3309 3548 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 3549 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
3550 char refname[PATH_MAX];
3551
6e7b3309
BW
3552 /* skip matched rule */
3553 if (i == j)
3554 continue;
3555
7c2b3029
JK
3556 /*
3557 * the short name is ambiguous, if it resolves
3558 * (with this previous rule) to a valid ref
3559 * read_ref() returns 0 on success
3560 */
3561 mksnpath(refname, sizeof(refname),
3562 rule, short_name_len, short_name);
c6893323 3563 if (ref_exists(refname))
7c2b3029
JK
3564 break;
3565 }
3566
3567 /*
3568 * short name is non-ambiguous if all previous rules
3569 * haven't resolved to a valid ref
3570 */
6e7b3309 3571 if (j == rules_to_fail)
7c2b3029
JK
3572 return short_name;
3573 }
3574
3575 free(short_name);
dfefa935 3576 return xstrdup(refname);
7c2b3029 3577}
daebaa78
JH
3578
3579static struct string_list *hide_refs;
3580
3581int parse_hide_refs_config(const char *var, const char *value, const char *section)
3582{
3583 if (!strcmp("transfer.hiderefs", var) ||
3584 /* NEEDSWORK: use parse_config_key() once both are merged */
59556548 3585 (starts_with(var, section) && var[strlen(section)] == '.' &&
daebaa78
JH
3586 !strcmp(var + strlen(section), ".hiderefs"))) {
3587 char *ref;
3588 int len;
3589
3590 if (!value)
3591 return config_error_nonbool(var);
3592 ref = xstrdup(value);
3593 len = strlen(ref);
3594 while (len && ref[len - 1] == '/')
3595 ref[--len] = '\0';
3596 if (!hide_refs) {
3597 hide_refs = xcalloc(1, sizeof(*hide_refs));
3598 hide_refs->strdup_strings = 1;
3599 }
3600 string_list_append(hide_refs, ref);
3601 }
3602 return 0;
3603}
3604
3605int ref_is_hidden(const char *refname)
3606{
3607 struct string_list_item *item;
3608
3609 if (!hide_refs)
3610 return 0;
3611 for_each_string_list_item(item, hide_refs) {
3612 int len;
59556548 3613 if (!starts_with(refname, item->string))
daebaa78
JH
3614 continue;
3615 len = strlen(item->string);
3616 if (!refname[len] || refname[len] == '/')
3617 return 1;
3618 }
3619 return 0;
3620}