Add new @ shortcut for HEAD
[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
624cac35 640 if (prefixcmp(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
8be8bde7 950void invalidate_ref_cache(const char *submodule)
f130b116 951{
c5f29abd
MH
952 struct ref_cache *refs = get_ref_cache(submodule);
953 clear_packed_ref_cache(refs);
954 clear_loose_ref_cache(refs);
5e290ff7 955}
e1e22e37 956
3feb4f0c
MH
957/* The length of a peeled reference line in packed-refs, including EOL: */
958#define PEELED_LINE_LENGTH 42
959
694b7a19
MH
960/*
961 * The packed-refs header line that we write out. Perhaps other
962 * traits will be added later. The trailing space is required.
963 */
964static const char PACKED_REFS_HEADER[] =
965 "# pack-refs with: peeled fully-peeled \n";
966
bc5fd6d3
MH
967/*
968 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
969 * Return a pointer to the refname within the line (null-terminated),
970 * or NULL if there was a problem.
971 */
972static const char *parse_ref_line(char *line, unsigned char *sha1)
973{
974 /*
975 * 42: the answer to everything.
976 *
977 * In this case, it happens to be the answer to
978 * 40 (length of sha1 hex representation)
979 * +1 (space in between hex and name)
980 * +1 (newline at the end of the line)
981 */
982 int len = strlen(line) - 42;
983
984 if (len <= 0)
985 return NULL;
986 if (get_sha1_hex(line, sha1) < 0)
987 return NULL;
988 if (!isspace(line[40]))
989 return NULL;
990 line += 41;
991 if (isspace(*line))
992 return NULL;
993 if (line[len] != '\n')
994 return NULL;
995 line[len] = 0;
996
997 return line;
998}
999
c29c46fa
MH
1000/*
1001 * Read f, which is a packed-refs file, into dir.
1002 *
1003 * A comment line of the form "# pack-refs with: " may contain zero or
1004 * more traits. We interpret the traits as follows:
1005 *
1006 * No traits:
1007 *
1008 * Probably no references are peeled. But if the file contains a
1009 * peeled value for a reference, we will use it.
1010 *
1011 * peeled:
1012 *
1013 * References under "refs/tags/", if they *can* be peeled, *are*
1014 * peeled in this file. References outside of "refs/tags/" are
1015 * probably not peeled even if they could have been, but if we find
1016 * a peeled value for such a reference we will use it.
1017 *
1018 * fully-peeled:
1019 *
1020 * All references in the file that can be peeled are peeled.
1021 * Inversely (and this is more important), any references in the
1022 * file for which no peeled value is recorded is not peelable. This
1023 * trait should typically be written alongside "peeled" for
1024 * compatibility with older clients, but we do not require it
1025 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
1026 */
d3177275 1027static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 1028{
e9c4c111 1029 struct ref_entry *last = NULL;
f4204ab9 1030 char refline[PATH_MAX];
c29c46fa 1031 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
1032
1033 while (fgets(refline, sizeof(refline), f)) {
1034 unsigned char sha1[20];
dfefa935 1035 const char *refname;
f4204ab9
JH
1036 static const char header[] = "# pack-refs with:";
1037
1038 if (!strncmp(refline, header, sizeof(header)-1)) {
1039 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
1040 if (strstr(traits, " fully-peeled "))
1041 peeled = PEELED_FULLY;
1042 else if (strstr(traits, " peeled "))
1043 peeled = PEELED_TAGS;
f4204ab9
JH
1044 /* perhaps other traits later as well */
1045 continue;
1046 }
1047
dfefa935
MH
1048 refname = parse_ref_line(refline, sha1);
1049 if (refname) {
c29c46fa
MH
1050 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
1051 if (peeled == PEELED_FULLY ||
1052 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
1053 last->flag |= REF_KNOWS_PEELED;
d3177275 1054 add_ref(dir, last);
f4204ab9
JH
1055 continue;
1056 }
1057 if (last &&
1058 refline[0] == '^' &&
3feb4f0c
MH
1059 strlen(refline) == PEELED_LINE_LENGTH &&
1060 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 1061 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 1062 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
1063 /*
1064 * Regardless of what the file header said,
1065 * we definitely know the value of *this*
1066 * reference:
1067 */
1068 last->flag |= REF_KNOWS_PEELED;
1069 }
f4204ab9 1070 }
f4204ab9
JH
1071}
1072
2fff7812
MH
1073/*
1074 * Get the packed_ref_cache for the specified ref_cache, creating it
1075 * if necessary.
1076 */
1077static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
5e290ff7 1078{
ca919930
JK
1079 const char *packed_refs_file;
1080
1081 if (*refs->name)
1082 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
1083 else
1084 packed_refs_file = git_path("packed-refs");
1085
1086 if (refs->packed &&
1087 !stat_validity_check(&refs->packed->validity, packed_refs_file))
1088 clear_packed_ref_cache(refs);
1089
d12229f5 1090 if (!refs->packed) {
4349a668 1091 FILE *f;
0bad611b 1092
2fff7812 1093 refs->packed = xcalloc(1, sizeof(*refs->packed));
5f5e2a88 1094 acquire_packed_ref_cache(refs->packed);
2fff7812 1095 refs->packed->root = create_dir_entry(refs, "", 0, 0);
4349a668 1096 f = fopen(packed_refs_file, "r");
e1e22e37 1097 if (f) {
ca919930 1098 stat_validity_update(&refs->packed->validity, fileno(f));
2fff7812 1099 read_packed_refs(f, get_ref_dir(refs->packed->root));
e1e22e37 1100 fclose(f);
e1e22e37 1101 }
e1e22e37 1102 }
2fff7812
MH
1103 return refs->packed;
1104}
1105
1106static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1107{
1108 return get_ref_dir(packed_ref_cache->root);
1109}
1110
1111static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1112{
1113 return get_packed_ref_dir(get_packed_ref_cache(refs));
e1e22e37
LT
1114}
1115
30249ee6
MH
1116void add_packed_ref(const char *refname, const unsigned char *sha1)
1117{
9f69d297
MH
1118 struct packed_ref_cache *packed_ref_cache =
1119 get_packed_ref_cache(&ref_cache);
1120
1121 if (!packed_ref_cache->lock)
1122 die("internal error: packed refs not locked");
1123 add_ref(get_packed_ref_dir(packed_ref_cache),
9da31cb0 1124 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
30249ee6
MH
1125}
1126
abc39098 1127/*
28e6a34e
MH
1128 * Read the loose references from the namespace dirname into dir
1129 * (without recursing). dirname must end with '/'. dir must be the
1130 * directory entry corresponding to dirname.
abc39098 1131 */
423a1afc 1132static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 1133{
423a1afc 1134 struct ref_cache *refs = dir->ref_cache;
d3177275 1135 DIR *d;
0bad611b 1136 const char *path;
d5fdae67 1137 struct dirent *de;
abc39098 1138 int dirnamelen = strlen(dirname);
72b64b44 1139 struct strbuf refname;
0bad611b 1140
3b124823 1141 if (*refs->name)
66a3d20b 1142 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 1143 else
66a3d20b 1144 path = git_path("%s", dirname);
0bad611b 1145
d3177275 1146 d = opendir(path);
d5fdae67
MH
1147 if (!d)
1148 return;
1149
66a3d20b
MH
1150 strbuf_init(&refname, dirnamelen + 257);
1151 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
1152
1153 while ((de = readdir(d)) != NULL) {
1154 unsigned char sha1[20];
1155 struct stat st;
1156 int flag;
d5fdae67
MH
1157 const char *refdir;
1158
1159 if (de->d_name[0] == '.')
1160 continue;
d5fdae67
MH
1161 if (has_extension(de->d_name, ".lock"))
1162 continue;
72b64b44 1163 strbuf_addstr(&refname, de->d_name);
d5fdae67 1164 refdir = *refs->name
72b64b44
MH
1165 ? git_path_submodule(refs->name, "%s", refname.buf)
1166 : git_path("%s", refname.buf);
1167 if (stat(refdir, &st) < 0) {
1168 ; /* silently ignore */
1169 } else if (S_ISDIR(st.st_mode)) {
abc39098 1170 strbuf_addch(&refname, '/');
28e6a34e 1171 add_entry_to_dir(dir,
b9146f51
RS
1172 create_dir_entry(refs, refname.buf,
1173 refname.len, 1));
72b64b44 1174 } else {
3b124823 1175 if (*refs->name) {
f8948e2f 1176 hashclr(sha1);
0bad611b 1177 flag = 0;
72b64b44 1178 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1179 hashclr(sha1);
98ac34b2 1180 flag |= REF_ISBROKEN;
0bad611b 1181 }
72b64b44 1182 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1183 hashclr(sha1);
1184 flag |= REF_ISBROKEN;
1185 }
9f2fb4a3
MH
1186 add_entry_to_dir(dir,
1187 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1188 }
66a3d20b 1189 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1190 }
72b64b44 1191 strbuf_release(&refname);
d5fdae67 1192 closedir(d);
e1e22e37
LT
1193}
1194
d3177275 1195static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1196{
d12229f5 1197 if (!refs->loose) {
28e6a34e
MH
1198 /*
1199 * Mark the top-level directory complete because we
1200 * are about to read the only subdirectory that can
1201 * hold references:
1202 */
b9146f51 1203 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1204 /*
1205 * Create an incomplete entry for "refs/":
1206 */
1207 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1208 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1209 }
d7826d54 1210 return get_ref_dir(refs->loose);
e1e22e37
LT
1211}
1212
ca8db142
LT
1213/* We allow "recursive" symbolic refs. Only within reason, though */
1214#define MAXDEPTH 5
0ebde32c
LT
1215#define MAXREFLEN (1024)
1216
e5fa45c1
JH
1217/*
1218 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1219 * from the loose refs in ref_cache refs. Find <refname> in the
1220 * packed-refs file for the submodule.
e5fa45c1 1221 */
b0626608 1222static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1223 const char *refname, unsigned char *sha1)
0ebde32c 1224{
2c5c66be 1225 struct ref_entry *ref;
d3177275 1226 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1227
432ad41e 1228 ref = find_ref(dir, refname);
b0626608
MH
1229 if (ref == NULL)
1230 return -1;
1231
593f1bb8 1232 memcpy(sha1, ref->u.value.sha1, 20);
b0626608 1233 return 0;
0ebde32c
LT
1234}
1235
b0626608 1236static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1237 const char *refname, unsigned char *sha1,
dfefa935 1238 int recursion)
0ebde32c 1239{
064d51dc 1240 int fd, len;
0ebde32c 1241 char buffer[128], *p;
064d51dc 1242 char *path;
0ebde32c 1243
064d51dc 1244 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1245 return -1;
064d51dc
MH
1246 path = *refs->name
1247 ? git_path_submodule(refs->name, "%s", refname)
1248 : git_path("%s", refname);
1249 fd = open(path, O_RDONLY);
0ebde32c 1250 if (fd < 0)
b0626608 1251 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1252
1253 len = read(fd, buffer, sizeof(buffer)-1);
1254 close(fd);
1255 if (len < 0)
1256 return -1;
1257 while (len && isspace(buffer[len-1]))
1258 len--;
1259 buffer[len] = 0;
1260
1261 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1262 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1263 return 0;
1264
1265 /* Symref? */
1266 if (strncmp(buffer, "ref:", 4))
1267 return -1;
1268 p = buffer + 4;
1269 while (isspace(*p))
1270 p++;
1271
064d51dc 1272 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1273}
1274
85be1fe3 1275int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1276{
1277 int len = strlen(path), retval;
064d51dc 1278 char *submodule;
b0626608 1279 struct ref_cache *refs;
0ebde32c
LT
1280
1281 while (len && path[len-1] == '/')
1282 len--;
1283 if (!len)
1284 return -1;
b0626608
MH
1285 submodule = xstrndup(path, len);
1286 refs = get_ref_cache(submodule);
1287 free(submodule);
1288
064d51dc 1289 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1290 return retval;
1291}
ca8db142 1292
4886b89f 1293/*
63331581
MH
1294 * Return the ref_entry for the given refname from the packed
1295 * references. If it does not exist, return NULL.
4886b89f 1296 */
63331581 1297static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1298{
9da31cb0 1299 return find_ref(get_packed_refs(&ref_cache), refname);
c224ca7f
MH
1300}
1301
47f534bf
MH
1302/*
1303 * A loose ref file doesn't exist; check for a packed ref. The
1304 * options are forwarded from resolve_safe_unsafe().
1305 */
1306static const char *handle_missing_loose_ref(const char *refname,
1307 unsigned char *sha1,
1308 int reading,
1309 int *flag)
1310{
1311 struct ref_entry *entry;
1312
1313 /*
1314 * The loose reference file does not exist; check for a packed
1315 * reference.
1316 */
1317 entry = get_packed_ref(refname);
1318 if (entry) {
1319 hashcpy(sha1, entry->u.value.sha1);
1320 if (flag)
1321 *flag |= REF_ISPACKED;
1322 return refname;
1323 }
1324 /* The reference is not a packed reference, either. */
1325 if (reading) {
1326 return NULL;
1327 } else {
1328 hashclr(sha1);
1329 return refname;
1330 }
1331}
1332
8d68493f 1333const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1334{
0104ca09
HO
1335 int depth = MAXDEPTH;
1336 ssize_t len;
a876ed83 1337 char buffer[256];
dfefa935 1338 static char refname_buffer[256];
ca8db142 1339
8da19775
JH
1340 if (flag)
1341 *flag = 0;
1342
dfefa935 1343 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
8384d788
MH
1344 return NULL;
1345
a876ed83 1346 for (;;) {
55956350 1347 char path[PATH_MAX];
a876ed83
JH
1348 struct stat st;
1349 char *buf;
1350 int fd;
8a65ff76 1351
a876ed83
JH
1352 if (--depth < 0)
1353 return NULL;
ca8db142 1354
dfefa935 1355 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1356
fcb7c762
MH
1357 /*
1358 * We might have to loop back here to avoid a race
1359 * condition: first we lstat() the file, then we try
1360 * to read it as a link or as a file. But if somebody
1361 * changes the type of the file (file <-> directory
1362 * <-> symlink) between the lstat() and reading, then
1363 * we don't want to report that as an error but rather
1364 * try again starting with the lstat().
1365 */
1366 stat_ref:
a876ed83 1367 if (lstat(path, &st) < 0) {
47f534bf
MH
1368 if (errno == ENOENT)
1369 return handle_missing_loose_ref(refname, sha1,
1370 reading, flag);
1371 else
a876ed83 1372 return NULL;
a876ed83 1373 }
ca8db142 1374
a876ed83
JH
1375 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1376 if (S_ISLNK(st.st_mode)) {
1377 len = readlink(path, buffer, sizeof(buffer)-1);
fcb7c762
MH
1378 if (len < 0) {
1379 if (errno == ENOENT || errno == EINVAL)
1380 /* inconsistent with lstat; retry */
1381 goto stat_ref;
1382 else
1383 return NULL;
1384 }
b54cb795 1385 buffer[len] = 0;
1f58a038
MH
1386 if (!prefixcmp(buffer, "refs/") &&
1387 !check_refname_format(buffer, 0)) {
dfefa935
MH
1388 strcpy(refname_buffer, buffer);
1389 refname = refname_buffer;
8da19775
JH
1390 if (flag)
1391 *flag |= REF_ISSYMREF;
a876ed83
JH
1392 continue;
1393 }
ca8db142 1394 }
a876ed83 1395
7a21632f
DS
1396 /* Is it a directory? */
1397 if (S_ISDIR(st.st_mode)) {
1398 errno = EISDIR;
1399 return NULL;
1400 }
1401
a876ed83
JH
1402 /*
1403 * Anything else, just open it and try to use it as
1404 * a ref
1405 */
1406 fd = open(path, O_RDONLY);
fcb7c762
MH
1407 if (fd < 0) {
1408 if (errno == ENOENT)
1409 /* inconsistent with lstat; retry */
1410 goto stat_ref;
1411 else
1412 return NULL;
1413 }
93d26e4c 1414 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83 1415 close(fd);
28775050
MH
1416 if (len < 0)
1417 return NULL;
1418 while (len && isspace(buffer[len-1]))
1419 len--;
1420 buffer[len] = '\0';
a876ed83
JH
1421
1422 /*
1423 * Is it a symbolic ref?
1424 */
2884c06a
MH
1425 if (prefixcmp(buffer, "ref:")) {
1426 /*
1427 * Please note that FETCH_HEAD has a second
1428 * line containing other data.
1429 */
1430 if (get_sha1_hex(buffer, sha1) ||
1431 (buffer[40] != '\0' && !isspace(buffer[40]))) {
1432 if (flag)
1433 *flag |= REF_ISBROKEN;
1434 return NULL;
1435 }
1436 return refname;
1437 }
55956350
JH
1438 if (flag)
1439 *flag |= REF_ISSYMREF;
a876ed83 1440 buf = buffer + 4;
28775050
MH
1441 while (isspace(*buf))
1442 buf++;
313fb010 1443 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1444 if (flag)
1445 *flag |= REF_ISBROKEN;
313fb010
MH
1446 return NULL;
1447 }
dfefa935 1448 refname = strcpy(refname_buffer, buf);
8a65ff76 1449 }
a876ed83
JH
1450}
1451
96ec7b1e
NTND
1452char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1453{
8cad4744 1454 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1455 return ret ? xstrdup(ret) : NULL;
1456}
1457
d08bae7e
IL
1458/* The argument to filter_refs */
1459struct ref_filter {
1460 const char *pattern;
1461 each_ref_fn *fn;
1462 void *cb_data;
1463};
1464
dfefa935 1465int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1466{
8d68493f 1467 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1468 return 0;
1469 return -1;
8a65ff76
LT
1470}
1471
dfefa935 1472int read_ref(const char *refname, unsigned char *sha1)
c6893323 1473{
dfefa935 1474 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1475}
1476
bc5fd6d3 1477int ref_exists(const char *refname)
ef06b918 1478{
bc5fd6d3
MH
1479 unsigned char sha1[20];
1480 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1481}
1482
85be1fe3 1483static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1484 void *data)
d08bae7e
IL
1485{
1486 struct ref_filter *filter = (struct ref_filter *)data;
dfefa935 1487 if (fnmatch(filter->pattern, refname, 0))
d08bae7e 1488 return 0;
85be1fe3 1489 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1490}
1491
68cf8703
MH
1492enum peel_status {
1493 /* object was peeled successfully: */
1494 PEEL_PEELED = 0,
1495
1496 /*
1497 * object cannot be peeled because the named object (or an
1498 * object referred to by a tag in the peel chain), does not
1499 * exist.
1500 */
1501 PEEL_INVALID = -1,
1502
1503 /* object cannot be peeled because it is not a tag: */
9a489f3c
MH
1504 PEEL_NON_TAG = -2,
1505
1506 /* ref_entry contains no peeled value because it is a symref: */
1507 PEEL_IS_SYMREF = -3,
1508
1509 /*
1510 * ref_entry cannot be peeled because it is broken (i.e., the
1511 * symbolic reference cannot even be resolved to an object
1512 * name):
1513 */
1514 PEEL_BROKEN = -4
68cf8703
MH
1515};
1516
cb2ae1c4
MH
1517/*
1518 * Peel the named object; i.e., if the object is a tag, resolve the
68cf8703
MH
1519 * tag recursively until a non-tag is found. If successful, store the
1520 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1521 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1522 * and leave sha1 unchanged.
cb2ae1c4 1523 */
68cf8703 1524static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
cb2ae1c4
MH
1525{
1526 struct object *o = lookup_unknown_object(name);
1527
1528 if (o->type == OBJ_NONE) {
1529 int type = sha1_object_info(name, NULL);
1530 if (type < 0)
68cf8703 1531 return PEEL_INVALID;
cb2ae1c4
MH
1532 o->type = type;
1533 }
1534
1535 if (o->type != OBJ_TAG)
68cf8703 1536 return PEEL_NON_TAG;
cb2ae1c4
MH
1537
1538 o = deref_tag_noverify(o);
1539 if (!o)
68cf8703 1540 return PEEL_INVALID;
cb2ae1c4
MH
1541
1542 hashcpy(sha1, o->sha1);
68cf8703 1543 return PEEL_PEELED;
cb2ae1c4
MH
1544}
1545
9a489f3c 1546/*
f85354b5
MH
1547 * Peel the entry (if possible) and return its new peel_status. If
1548 * repeel is true, re-peel the entry even if there is an old peeled
1549 * value that is already stored in it.
694b7a19
MH
1550 *
1551 * It is OK to call this function with a packed reference entry that
1552 * might be stale and might even refer to an object that has since
1553 * been garbage-collected. In such a case, if the entry has
1554 * REF_KNOWS_PEELED then leave the status unchanged and return
1555 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
9a489f3c 1556 */
f85354b5 1557static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
9a489f3c
MH
1558{
1559 enum peel_status status;
1560
f85354b5
MH
1561 if (entry->flag & REF_KNOWS_PEELED) {
1562 if (repeel) {
1563 entry->flag &= ~REF_KNOWS_PEELED;
1564 hashclr(entry->u.value.peeled);
1565 } else {
1566 return is_null_sha1(entry->u.value.peeled) ?
1567 PEEL_NON_TAG : PEEL_PEELED;
1568 }
1569 }
9a489f3c
MH
1570 if (entry->flag & REF_ISBROKEN)
1571 return PEEL_BROKEN;
1572 if (entry->flag & REF_ISSYMREF)
1573 return PEEL_IS_SYMREF;
1574
1575 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1576 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1577 entry->flag |= REF_KNOWS_PEELED;
1578 return status;
1579}
1580
dfefa935 1581int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1582{
1583 int flag;
1584 unsigned char base[20];
cf0adba7 1585
dfefa935 1586 if (current_ref && (current_ref->name == refname
9a489f3c 1587 || !strcmp(current_ref->name, refname))) {
f85354b5 1588 if (peel_entry(current_ref, 0))
9a489f3c
MH
1589 return -1;
1590 hashcpy(sha1, current_ref->u.value.peeled);
1591 return 0;
0ae91be0
SP
1592 }
1593
dfefa935 1594 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1595 return -1;
1596
9a489f3c
MH
1597 /*
1598 * If the reference is packed, read its ref_entry from the
1599 * cache in the hope that we already know its peeled value.
1600 * We only try this optimization on packed references because
1601 * (a) forcing the filling of the loose reference cache could
1602 * be expensive and (b) loose references anyway usually do not
1603 * have REF_KNOWS_PEELED.
1604 */
1605 if (flag & REF_ISPACKED) {
f361baeb 1606 struct ref_entry *r = get_packed_ref(refname);
9a489f3c 1607 if (r) {
f85354b5 1608 if (peel_entry(r, 0))
9a489f3c 1609 return -1;
593f1bb8 1610 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1611 return 0;
cf0adba7 1612 }
cf0adba7
JH
1613 }
1614
cb2ae1c4 1615 return peel_object(base, sha1);
cf0adba7
JH
1616}
1617
bc5fd6d3
MH
1618struct warn_if_dangling_data {
1619 FILE *fp;
1620 const char *refname;
1621 const char *msg_fmt;
1622};
1623
1624static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1625 int flags, void *cb_data)
1626{
1627 struct warn_if_dangling_data *d = cb_data;
1628 const char *resolves_to;
1629 unsigned char junk[20];
1630
1631 if (!(flags & REF_ISSYMREF))
1632 return 0;
1633
1634 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1635 if (!resolves_to || strcmp(resolves_to, d->refname))
1636 return 0;
1637
1638 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1639 fputc('\n', d->fp);
bc5fd6d3
MH
1640 return 0;
1641}
1642
1643void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1644{
1645 struct warn_if_dangling_data data;
1646
1647 data.fp = fp;
1648 data.refname = refname;
1649 data.msg_fmt = msg_fmt;
1650 for_each_rawref(warn_if_dangling_symref, &data);
1651}
1652
fcce1703 1653/*
65cf102b 1654 * Call fn for each reference in the specified ref_cache, omitting
624cac35
MH
1655 * references not in the containing_dir of base. fn is called for all
1656 * references, including broken ones. If fn ever returns a non-zero
fcce1703
MH
1657 * value, stop the iteration and return that value; otherwise, return
1658 * 0.
1659 */
65cf102b 1660static int do_for_each_entry(struct ref_cache *refs, const char *base,
624cac35 1661 each_ref_entry_fn fn, void *cb_data)
8a65ff76 1662{
98eeb09e
JK
1663 struct packed_ref_cache *packed_ref_cache;
1664 struct ref_dir *loose_dir;
1665 struct ref_dir *packed_dir;
933ac036
MH
1666 int retval = 0;
1667
98eeb09e
JK
1668 /*
1669 * We must make sure that all loose refs are read before accessing the
1670 * packed-refs file; this avoids a race condition in which loose refs
1671 * are migrated to the packed-refs file by a simultaneous process, but
1672 * our in-memory view is from before the migration. get_packed_ref_cache()
1673 * takes care of making sure our view is up to date with what is on
1674 * disk.
1675 */
1676 loose_dir = get_loose_refs(refs);
933ac036 1677 if (base && *base) {
933ac036
MH
1678 loose_dir = find_containing_dir(loose_dir, base, 0);
1679 }
98eeb09e
JK
1680 if (loose_dir)
1681 prime_ref_dir(loose_dir);
1682
1683 packed_ref_cache = get_packed_ref_cache(refs);
8baf2bb9 1684 acquire_packed_ref_cache(packed_ref_cache);
98eeb09e 1685 packed_dir = get_packed_ref_dir(packed_ref_cache);
933ac036
MH
1686 if (base && *base) {
1687 packed_dir = find_containing_dir(packed_dir, base, 0);
933ac036
MH
1688 }
1689
1690 if (packed_dir && loose_dir) {
1691 sort_ref_dir(packed_dir);
1692 sort_ref_dir(loose_dir);
624cac35
MH
1693 retval = do_for_each_entry_in_dirs(
1694 packed_dir, loose_dir, fn, cb_data);
933ac036
MH
1695 } else if (packed_dir) {
1696 sort_ref_dir(packed_dir);
624cac35
MH
1697 retval = do_for_each_entry_in_dir(
1698 packed_dir, 0, fn, cb_data);
933ac036
MH
1699 } else if (loose_dir) {
1700 sort_ref_dir(loose_dir);
624cac35
MH
1701 retval = do_for_each_entry_in_dir(
1702 loose_dir, 0, fn, cb_data);
933ac036
MH
1703 }
1704
8baf2bb9 1705 release_packed_ref_cache(packed_ref_cache);
933ac036 1706 return retval;
8a65ff76
LT
1707}
1708
624cac35 1709/*
65cf102b 1710 * Call fn for each reference in the specified ref_cache for which the
624cac35
MH
1711 * refname begins with base. If trim is non-zero, then trim that many
1712 * characters off the beginning of each refname before passing the
1713 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1714 * broken references in the iteration. If fn ever returns a non-zero
1715 * value, stop the iteration and return that value; otherwise, return
1716 * 0.
1717 */
65cf102b
MH
1718static int do_for_each_ref(struct ref_cache *refs, const char *base,
1719 each_ref_fn fn, int trim, int flags, void *cb_data)
624cac35
MH
1720{
1721 struct ref_entry_cb data;
1722 data.base = base;
1723 data.trim = trim;
1724 data.flags = flags;
1725 data.fn = fn;
1726 data.cb_data = cb_data;
1727
65cf102b 1728 return do_for_each_entry(refs, base, do_one_ref, &data);
624cac35
MH
1729}
1730
0bad611b 1731static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1732{
1733 unsigned char sha1[20];
8da19775
JH
1734 int flag;
1735
0bad611b
HV
1736 if (submodule) {
1737 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1738 return fn("HEAD", sha1, 0, cb_data);
1739
1740 return 0;
1741 }
1742
c6893323 1743 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1744 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1745
2f34ba32 1746 return 0;
723c31fe
LT
1747}
1748
0bad611b
HV
1749int head_ref(each_ref_fn fn, void *cb_data)
1750{
1751 return do_head_ref(NULL, fn, cb_data);
1752}
1753
9ef6aeb0
HV
1754int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1755{
1756 return do_head_ref(submodule, fn, cb_data);
1757}
1758
cb5d709f 1759int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1760{
9da31cb0 1761 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
a62be77f
SE
1762}
1763
9ef6aeb0
HV
1764int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1765{
65cf102b 1766 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
a62be77f
SE
1767}
1768
2a8177b6
CC
1769int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1770{
9da31cb0 1771 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1772}
1773
9ef6aeb0
HV
1774int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1775 each_ref_fn fn, void *cb_data)
1776{
65cf102b 1777 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1778}
1779
cb5d709f 1780int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1781{
2a8177b6 1782 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1783}
1784
9ef6aeb0
HV
1785int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1786{
1787 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1788}
1789
cb5d709f 1790int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1791{
2a8177b6 1792 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1793}
1794
9ef6aeb0
HV
1795int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1796{
1797 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1798}
1799
cb5d709f 1800int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1801{
2a8177b6 1802 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1803}
1804
9ef6aeb0
HV
1805int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1806{
1807 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1808}
1809
29268700
CC
1810int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1811{
9da31cb0 1812 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1813}
1814
a1bea2c1
JT
1815int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1816{
1817 struct strbuf buf = STRBUF_INIT;
1818 int ret = 0;
1819 unsigned char sha1[20];
1820 int flag;
1821
1822 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1823 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1824 ret = fn(buf.buf, sha1, flag, cb_data);
1825 strbuf_release(&buf);
1826
1827 return ret;
1828}
1829
1830int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1831{
1832 struct strbuf buf = STRBUF_INIT;
1833 int ret;
1834 strbuf_addf(&buf, "%srefs/", get_git_namespace());
9da31cb0 1835 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
a1bea2c1
JT
1836 strbuf_release(&buf);
1837 return ret;
1838}
1839
b09fe971
IL
1840int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1841 const char *prefix, void *cb_data)
d08bae7e
IL
1842{
1843 struct strbuf real_pattern = STRBUF_INIT;
1844 struct ref_filter filter;
d08bae7e
IL
1845 int ret;
1846
b09fe971 1847 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 1848 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1849 else if (prefix)
1850 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1851 strbuf_addstr(&real_pattern, pattern);
1852
894a9d33 1853 if (!has_glob_specials(pattern)) {
9517e6b8 1854 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1855 if (real_pattern.buf[real_pattern.len - 1] != '/')
1856 strbuf_addch(&real_pattern, '/');
1857 /* No need to check for '*', there is none. */
1858 strbuf_addch(&real_pattern, '*');
1859 }
1860
1861 filter.pattern = real_pattern.buf;
1862 filter.fn = fn;
1863 filter.cb_data = cb_data;
1864 ret = for_each_ref(filter_refs, &filter);
1865
1866 strbuf_release(&real_pattern);
1867 return ret;
1868}
1869
b09fe971
IL
1870int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1871{
1872 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1873}
1874
f8948e2f
JH
1875int for_each_rawref(each_ref_fn fn, void *cb_data)
1876{
9da31cb0 1877 return do_for_each_ref(&ref_cache, "", fn, 0,
f8948e2f 1878 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1879}
1880
4577e483 1881const char *prettify_refname(const char *name)
a9c37a72 1882{
a9c37a72
DB
1883 return name + (
1884 !prefixcmp(name, "refs/heads/") ? 11 :
1885 !prefixcmp(name, "refs/tags/") ? 10 :
1886 !prefixcmp(name, "refs/remotes/") ? 13 :
1887 0);
1888}
1889
79803322
SP
1890const char *ref_rev_parse_rules[] = {
1891 "%.*s",
1892 "refs/%.*s",
1893 "refs/tags/%.*s",
1894 "refs/heads/%.*s",
1895 "refs/remotes/%.*s",
1896 "refs/remotes/%.*s/HEAD",
1897 NULL
1898};
1899
1900int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1901{
1902 const char **p;
1903 const int abbrev_name_len = strlen(abbrev_name);
1904
1905 for (p = rules; *p; p++) {
1906 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1907 return 1;
1908 }
1909 }
1910
1911 return 0;
1912}
1913
e5f38ec3 1914static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1915 const unsigned char *old_sha1, int mustexist)
1916{
c6893323 1917 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1918 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1919 unlock_ref(lock);
1920 return NULL;
1921 }
a89fccd2 1922 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1923 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1924 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1925 unlock_ref(lock);
1926 return NULL;
1927 }
1928 return lock;
1929}
1930
7155b727 1931static int remove_empty_directories(const char *file)
bc7127ef
JH
1932{
1933 /* we want to create a file but there is a directory there;
1934 * if that is an empty directory (or a directory that contains
1935 * only empty directories), remove them.
1936 */
7155b727
JS
1937 struct strbuf path;
1938 int result;
bc7127ef 1939
7155b727
JS
1940 strbuf_init(&path, 20);
1941 strbuf_addstr(&path, file);
1942
a0f4afbe 1943 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1944
1945 strbuf_release(&path);
1946
1947 return result;
bc7127ef
JH
1948}
1949
ff74f7f1
JH
1950/*
1951 * *string and *len will only be substituted, and *string returned (for
1952 * later free()ing) if the string passed in is a magic short-hand form
1953 * to name a branch.
1954 */
1955static char *substitute_branch_name(const char **string, int *len)
1956{
1957 struct strbuf buf = STRBUF_INIT;
cf99a761 1958 int ret = interpret_branch_name(*string, *len, &buf);
ff74f7f1
JH
1959
1960 if (ret == *len) {
1961 size_t size;
1962 *string = strbuf_detach(&buf, &size);
1963 *len = size;
1964 return (char *)*string;
1965 }
1966
1967 return NULL;
1968}
1969
1970int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1971{
1972 char *last_branch = substitute_branch_name(&str, &len);
1973 const char **p, *r;
1974 int refs_found = 0;
1975
1976 *ref = NULL;
1977 for (p = ref_rev_parse_rules; *p; p++) {
1978 char fullref[PATH_MAX];
1979 unsigned char sha1_from_ref[20];
1980 unsigned char *this_result;
1981 int flag;
1982
1983 this_result = refs_found ? sha1_from_ref : sha1;
1984 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1985 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1986 if (r) {
1987 if (!refs_found++)
1988 *ref = xstrdup(r);
1989 if (!warn_ambiguous_refs)
1990 break;
55956350 1991 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1992 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1993 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1994 warning("ignoring broken ref %s.", fullref);
1995 }
ff74f7f1
JH
1996 }
1997 free(last_branch);
1998 return refs_found;
1999}
2000
2001int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
2002{
2003 char *last_branch = substitute_branch_name(&str, &len);
2004 const char **p;
2005 int logs_found = 0;
2006
2007 *log = NULL;
2008 for (p = ref_rev_parse_rules; *p; p++) {
2009 struct stat st;
2010 unsigned char hash[20];
2011 char path[PATH_MAX];
2012 const char *ref, *it;
2013
2014 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 2015 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
2016 if (!ref)
2017 continue;
2018 if (!stat(git_path("logs/%s", path), &st) &&
2019 S_ISREG(st.st_mode))
2020 it = path;
2021 else if (strcmp(ref, path) &&
2022 !stat(git_path("logs/%s", ref), &st) &&
2023 S_ISREG(st.st_mode))
2024 it = ref;
2025 else
2026 continue;
2027 if (!logs_found++) {
2028 *log = xstrdup(it);
2029 hashcpy(sha1, hash);
2030 }
2031 if (!warn_ambiguous_refs)
2032 break;
2033 }
2034 free(last_branch);
2035 return logs_found;
2036}
2037
dfefa935
MH
2038static struct ref_lock *lock_ref_sha1_basic(const char *refname,
2039 const unsigned char *old_sha1,
2040 int flags, int *type_p)
4bd18c43 2041{
434cd0cd 2042 char *ref_file;
dfefa935 2043 const char *orig_refname = refname;
4bd18c43 2044 struct ref_lock *lock;
5cc3cef9 2045 int last_errno = 0;
acd3b9ec 2046 int type, lflags;
4431fcc4 2047 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 2048 int missing = 0;
4bd18c43
SP
2049
2050 lock = xcalloc(1, sizeof(struct ref_lock));
2051 lock->lock_fd = -1;
2052
8d68493f 2053 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 2054 if (!refname && errno == EISDIR) {
bc7127ef
JH
2055 /* we are trying to lock foo but we used to
2056 * have foo/bar which now does not exist;
2057 * it is normal for the empty directory 'foo'
2058 * to remain.
2059 */
dfefa935 2060 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
2061 if (remove_empty_directories(ref_file)) {
2062 last_errno = errno;
dfefa935 2063 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
2064 goto error_return;
2065 }
8d68493f 2066 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 2067 }
68db31cc
SV
2068 if (type_p)
2069 *type_p = type;
dfefa935 2070 if (!refname) {
5cc3cef9 2071 last_errno = errno;
818f477c 2072 error("unable to resolve reference %s: %s",
dfefa935 2073 orig_refname, strerror(errno));
5cc3cef9 2074 goto error_return;
4bd18c43 2075 }
5bdd8d4a 2076 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
2077 /* When the ref did not exist and we are creating it,
2078 * make sure there is no existing ref that is packed
2079 * whose name begins with our refname, nor a ref whose
2080 * name is a proper prefix of our refname.
2081 */
5bdd8d4a 2082 if (missing &&
9da31cb0 2083 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
f475e08e 2084 last_errno = ENOTDIR;
c976d415 2085 goto error_return;
f475e08e 2086 }
22a3844e 2087
c33d5174 2088 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 2089
acd3b9ec
JH
2090 lflags = LOCK_DIE_ON_ERROR;
2091 if (flags & REF_NODEREF) {
dfefa935 2092 refname = orig_refname;
acd3b9ec
JH
2093 lflags |= LOCK_NODEREF;
2094 }
dfefa935
MH
2095 lock->ref_name = xstrdup(refname);
2096 lock->orig_ref_name = xstrdup(orig_refname);
2097 ref_file = git_path("%s", refname);
5bdd8d4a 2098 if (missing)
68db31cc
SV
2099 lock->force_write = 1;
2100 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
2101 lock->force_write = 1;
4bd18c43 2102
5cc3cef9
JH
2103 if (safe_create_leading_directories(ref_file)) {
2104 last_errno = errno;
2105 error("unable to create directory for %s", ref_file);
2106 goto error_return;
2107 }
4bd18c43 2108
acd3b9ec 2109 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 2110 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
2111
2112 error_return:
2113 unlock_ref(lock);
2114 errno = last_errno;
2115 return NULL;
4bd18c43
SP
2116}
2117
dfefa935 2118struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 2119{
53cce84c 2120 char refpath[PATH_MAX];
dfefa935 2121 if (check_refname_format(refname, 0))
4bd18c43 2122 return NULL;
dfefa935 2123 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 2124 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
2125}
2126
dfefa935
MH
2127struct ref_lock *lock_any_ref_for_update(const char *refname,
2128 const unsigned char *old_sha1, int flags)
4bd18c43 2129{
dfefa935 2130 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 2131 return NULL;
dfefa935 2132 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
c0277d15
JH
2133}
2134
fec3137f
MH
2135/*
2136 * Write an entry to the packed-refs file for the specified refname.
2137 * If peeled is non-NULL, write it as the entry's peeled value.
2138 */
2139static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2140 unsigned char *peeled)
d66da478 2141{
d66da478
MH
2142 char line[PATH_MAX + 100];
2143 int len;
2144
d66da478
MH
2145 len = snprintf(line, sizeof(line), "%s %s\n",
2146 sha1_to_hex(sha1), refname);
2147 /* this should not happen but just being defensive */
2148 if (len > sizeof(line))
2149 die("too long a refname '%s'", refname);
fec3137f
MH
2150 write_or_die(fd, line, len);
2151
2152 if (peeled) {
2153 if (snprintf(line, sizeof(line), "^%s\n",
2154 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2155 die("internal error");
2156 write_or_die(fd, line, PEELED_LINE_LENGTH);
2157 }
2158}
2159
7b40d396
MH
2160/*
2161 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2162 */
2163static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2164{
2165 int *fd = cb_data;
2166 enum peel_status peel_status = peel_entry(entry, 0);
2167
2168 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2169 error("internal error: %s is not a valid packed reference!",
2170 entry->name);
2171 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2172 peel_status == PEEL_PEELED ?
2173 entry->u.value.peeled : NULL);
2174 return 0;
2175}
2176
9f69d297
MH
2177int lock_packed_refs(int flags)
2178{
2179 struct packed_ref_cache *packed_ref_cache;
2180
9f69d297
MH
2181 if (hold_lock_file_for_update(&packlock, git_path("packed-refs"), flags) < 0)
2182 return -1;
5d478f5c
MH
2183 /*
2184 * Get the current packed-refs while holding the lock. If the
2185 * packed-refs file has been modified since we last read it,
2186 * this will automatically invalidate the cache and re-read
2187 * the packed-refs file.
2188 */
9f69d297
MH
2189 packed_ref_cache = get_packed_ref_cache(&ref_cache);
2190 packed_ref_cache->lock = &packlock;
4f6b83e3
MH
2191 /* Increment the reference count to prevent it from being freed: */
2192 acquire_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2193 return 0;
2194}
2195
2196int commit_packed_refs(void)
2197{
2198 struct packed_ref_cache *packed_ref_cache =
2199 get_packed_ref_cache(&ref_cache);
2200 int error = 0;
2201
2202 if (!packed_ref_cache->lock)
2203 die("internal error: packed-refs not locked");
2204 write_or_die(packed_ref_cache->lock->fd,
2205 PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2206
2207 do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),
2208 0, write_packed_entry_fn,
2209 &packed_ref_cache->lock->fd);
2210 if (commit_lock_file(packed_ref_cache->lock))
2211 error = -1;
2212 packed_ref_cache->lock = NULL;
4f6b83e3 2213 release_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2214 return error;
2215}
2216
2217void rollback_packed_refs(void)
2218{
2219 struct packed_ref_cache *packed_ref_cache =
2220 get_packed_ref_cache(&ref_cache);
2221
2222 if (!packed_ref_cache->lock)
2223 die("internal error: packed-refs not locked");
2224 rollback_lock_file(packed_ref_cache->lock);
2225 packed_ref_cache->lock = NULL;
4f6b83e3 2226 release_packed_ref_cache(packed_ref_cache);
9f69d297
MH
2227 clear_packed_ref_cache(&ref_cache);
2228}
2229
32d462ce
MH
2230struct ref_to_prune {
2231 struct ref_to_prune *next;
2232 unsigned char sha1[20];
2233 char name[FLEX_ARRAY];
2234};
2235
2236struct pack_refs_cb_data {
2237 unsigned int flags;
267f9a8c 2238 struct ref_dir *packed_refs;
32d462ce 2239 struct ref_to_prune *ref_to_prune;
32d462ce
MH
2240};
2241
267f9a8c
MH
2242/*
2243 * An each_ref_entry_fn that is run over loose references only. If
2244 * the loose reference can be packed, add an entry in the packed ref
2245 * cache. If the reference should be pruned, also add it to
2246 * ref_to_prune in the pack_refs_cb_data.
2247 */
2248static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
32d462ce
MH
2249{
2250 struct pack_refs_cb_data *cb = cb_data;
f85354b5 2251 enum peel_status peel_status;
267f9a8c 2252 struct ref_entry *packed_entry;
b2a8226d 2253 int is_tag_ref = !prefixcmp(entry->name, "refs/tags/");
32d462ce 2254
267f9a8c
MH
2255 /* ALWAYS pack tags */
2256 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
32d462ce
MH
2257 return 0;
2258
b2a8226d
MH
2259 /* Do not pack symbolic or broken refs: */
2260 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2261 return 0;
2262
267f9a8c 2263 /* Add a packed ref cache entry equivalent to the loose entry. */
f85354b5 2264 peel_status = peel_entry(entry, 1);
0f29920f 2265 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
f85354b5
MH
2266 die("internal error peeling reference %s (%s)",
2267 entry->name, sha1_to_hex(entry->u.value.sha1));
267f9a8c
MH
2268 packed_entry = find_ref(cb->packed_refs, entry->name);
2269 if (packed_entry) {
2270 /* Overwrite existing packed entry with info from loose entry */
2271 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2272 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2273 } else {
2274 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2275 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2276 add_ref(cb->packed_refs, packed_entry);
2277 }
2278 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
32d462ce 2279
267f9a8c
MH
2280 /* Schedule the loose reference for pruning if requested. */
2281 if ((cb->flags & PACK_REFS_PRUNE)) {
12e77559 2282 int namelen = strlen(entry->name) + 1;
32d462ce 2283 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
12e77559
MH
2284 hashcpy(n->sha1, entry->u.value.sha1);
2285 strcpy(n->name, entry->name);
32d462ce
MH
2286 n->next = cb->ref_to_prune;
2287 cb->ref_to_prune = n;
2288 }
d66da478
MH
2289 return 0;
2290}
2291
32d462ce
MH
2292/*
2293 * Remove empty parents, but spare refs/ and immediate subdirs.
2294 * Note: munges *name.
2295 */
2296static void try_remove_empty_parents(char *name)
2297{
2298 char *p, *q;
2299 int i;
2300 p = name;
2301 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2302 while (*p && *p != '/')
2303 p++;
2304 /* tolerate duplicate slashes; see check_refname_format() */
2305 while (*p == '/')
2306 p++;
2307 }
2308 for (q = p; *q; q++)
2309 ;
2310 while (1) {
2311 while (q > p && *q != '/')
2312 q--;
2313 while (q > p && *(q-1) == '/')
2314 q--;
2315 if (q == p)
2316 break;
2317 *q = '\0';
2318 if (rmdir(git_path("%s", name)))
2319 break;
2320 }
2321}
2322
2323/* make sure nobody touched the ref, and unlink */
2324static void prune_ref(struct ref_to_prune *r)
2325{
2326 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2327
2328 if (lock) {
2329 unlink_or_warn(git_path("%s", r->name));
2330 unlock_ref(lock);
2331 try_remove_empty_parents(r->name);
2332 }
2333}
2334
2335static void prune_refs(struct ref_to_prune *r)
2336{
2337 while (r) {
2338 prune_ref(r);
2339 r = r->next;
2340 }
2341}
2342
32d462ce
MH
2343int pack_refs(unsigned int flags)
2344{
32d462ce
MH
2345 struct pack_refs_cb_data cbdata;
2346
2347 memset(&cbdata, 0, sizeof(cbdata));
2348 cbdata.flags = flags;
2349
9f69d297 2350 lock_packed_refs(LOCK_DIE_ON_ERROR);
267f9a8c 2351 cbdata.packed_refs = get_packed_refs(&ref_cache);
32d462ce 2352
267f9a8c
MH
2353 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2354 pack_if_possible_fn, &cbdata);
32d462ce 2355
9f69d297 2356 if (commit_packed_refs())
32d462ce 2357 die_errno("unable to overwrite old ref-pack file");
9f69d297 2358
32d462ce
MH
2359 prune_refs(cbdata.ref_to_prune);
2360 return 0;
2361}
2362
7b40d396
MH
2363/*
2364 * If entry is no longer needed in packed-refs, add it to the string
2365 * list pointed to by cb_data. Reasons for deleting entries:
2366 *
2367 * - Entry is broken.
2368 * - Entry is overridden by a loose ref.
2369 * - Entry does not point at a valid object.
2370 *
2371 * In the first and third cases, also emit an error message because these
2372 * are indications of repository corruption.
2373 */
2374static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
c0277d15 2375{
7b40d396 2376 struct string_list *refs_to_delete = cb_data;
fec3137f 2377
ab292bc4
MH
2378 if (entry->flag & REF_ISBROKEN) {
2379 /* This shouldn't happen to packed refs. */
2380 error("%s is broken!", entry->name);
7b40d396 2381 string_list_append(refs_to_delete, entry->name);
c0277d15 2382 return 0;
ab292bc4
MH
2383 }
2384 if (!has_sha1_file(entry->u.value.sha1)) {
2385 unsigned char sha1[20];
2386 int flags;
2387
2388 if (read_ref_full(entry->name, sha1, 0, &flags))
2389 /* We should at least have found the packed ref. */
2390 die("Internal error");
7b40d396 2391 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
ab292bc4
MH
2392 /*
2393 * This packed reference is overridden by a
2394 * loose reference, so it is OK that its value
2395 * is no longer valid; for example, it might
2396 * refer to an object that has been garbage
2397 * collected. For this purpose we don't even
2398 * care whether the loose reference itself is
2399 * invalid, broken, symbolic, etc. Silently
7b40d396 2400 * remove the packed reference.
ab292bc4 2401 */
7b40d396 2402 string_list_append(refs_to_delete, entry->name);
ab292bc4 2403 return 0;
7b40d396 2404 }
ab292bc4
MH
2405 /*
2406 * There is no overriding loose reference, so the fact
2407 * that this reference doesn't refer to a valid object
2408 * indicates some kind of repository corruption.
2409 * Report the problem, then omit the reference from
2410 * the output.
2411 */
2412 error("%s does not point to a valid object!", entry->name);
7b40d396 2413 string_list_append(refs_to_delete, entry->name);
ab292bc4
MH
2414 return 0;
2415 }
2416
d66da478
MH
2417 return 0;
2418}
2419
c0277d15
JH
2420static int repack_without_ref(const char *refname)
2421{
7618fd80 2422 struct ref_dir *packed;
7b40d396
MH
2423 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2424 struct string_list_item *ref_to_delete;
7618fd80
MH
2425
2426 if (!get_packed_ref(refname))
2427 return 0; /* refname does not exist in packed refs */
2428
9f69d297 2429 if (lock_packed_refs(0)) {
1b018fd9 2430 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 2431 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 2432 }
9da31cb0 2433 packed = get_packed_refs(&ref_cache);
7b40d396
MH
2434
2435 /* Remove refname from the cache: */
506a760d
MH
2436 if (remove_entry(packed, refname) == -1) {
2437 /*
2438 * The packed entry disappeared while we were
2439 * acquiring the lock.
2440 */
9f69d297 2441 rollback_packed_refs();
506a760d
MH
2442 return 0;
2443 }
7b40d396
MH
2444
2445 /* Remove any other accumulated cruft: */
2446 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2447 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2448 if (remove_entry(packed, ref_to_delete->string) == -1)
2449 die("internal error");
2450 }
2451
2452 /* Write what remains: */
9f69d297 2453 return commit_packed_refs();
c0277d15
JH
2454}
2455
eca35a25 2456int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
2457{
2458 struct ref_lock *lock;
eca35a25 2459 int err, i = 0, ret = 0, flag = 0;
c0277d15 2460
547d058f 2461 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
2462 if (!lock)
2463 return 1;
045a476f 2464 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 2465 /* loose */
547d058f
RS
2466 i = strlen(lock->lk->filename) - 5; /* .lock */
2467 lock->lk->filename[i] = 0;
2468 err = unlink_or_warn(lock->lk->filename);
691f1a28 2469 if (err && errno != ENOENT)
c0277d15 2470 ret = 1;
691f1a28 2471
547d058f 2472 lock->lk->filename[i] = '.';
c0277d15
JH
2473 }
2474 /* removing the loose one could have resurrected an earlier
2475 * packed one. Also, if it was not loose we need to repack
2476 * without it.
2477 */
b274a714 2478 ret |= repack_without_ref(lock->ref_name);
c0277d15 2479
691f1a28 2480 unlink_or_warn(git_path("logs/%s", lock->ref_name));
9da31cb0 2481 clear_loose_ref_cache(&ref_cache);
c0277d15
JH
2482 unlock_ref(lock);
2483 return ret;
4bd18c43
SP
2484}
2485
765c2258
PH
2486/*
2487 * People using contrib's git-new-workdir have .git/logs/refs ->
2488 * /some/other/path/.git/logs/refs, and that may live on another device.
2489 *
2490 * IOW, to avoid cross device rename errors, the temporary renamed log must
2491 * live into logs/refs.
2492 */
2493#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2494
dfefa935 2495int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 2496{
c976d415
LH
2497 unsigned char sha1[20], orig_sha1[20];
2498 int flag = 0, logmoved = 0;
2499 struct ref_lock *lock;
c976d415 2500 struct stat loginfo;
dfefa935 2501 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 2502 const char *symref = NULL;
c976d415 2503
450d4c0f 2504 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 2505 return error("reflog for %s is a symlink", oldrefname);
c976d415 2506
8d68493f 2507 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 2508 if (flag & REF_ISSYMREF)
fa58186c 2509 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 2510 oldrefname);
eca35a25 2511 if (!symref)
dfefa935 2512 return error("refname %s not found", oldrefname);
c976d415 2513
9da31cb0 2514 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
c976d415
LH
2515 return 1;
2516
9da31cb0 2517 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
c976d415
LH
2518 return 1;
2519
dfefa935 2520 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 2521 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 2522 oldrefname, strerror(errno));
c976d415 2523
dfefa935
MH
2524 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2525 error("unable to delete old %s", oldrefname);
c976d415
LH
2526 goto rollback;
2527 }
2528
dfefa935
MH
2529 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2530 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 2531 if (errno==EISDIR) {
dfefa935
MH
2532 if (remove_empty_directories(git_path("%s", newrefname))) {
2533 error("Directory not empty: %s", newrefname);
c976d415
LH
2534 goto rollback;
2535 }
2536 } else {
dfefa935 2537 error("unable to delete existing %s", newrefname);
c976d415
LH
2538 goto rollback;
2539 }
2540 }
2541
dfefa935
MH
2542 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2543 error("unable to create directory for %s", newrefname);
c976d415
LH
2544 goto rollback;
2545 }
2546
2547 retry:
dfefa935 2548 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
d9e74d57
JR
2549 if (errno==EISDIR || errno==ENOTDIR) {
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 */
dfefa935
MH
2555 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2556 error("Directory not empty: logs/%s", newrefname);
c976d415
LH
2557 goto rollback;
2558 }
2559 goto retry;
2560 } else {
765c2258 2561 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
dfefa935 2562 newrefname, strerror(errno));
c976d415
LH
2563 goto rollback;
2564 }
2565 }
2566 logmoved = log;
2567
dfefa935 2568 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2569 if (!lock) {
dfefa935 2570 error("unable to lock %s for update", newrefname);
c976d415
LH
2571 goto rollback;
2572 }
c976d415
LH
2573 lock->force_write = 1;
2574 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2575 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2576 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2577 goto rollback;
2578 }
2579
2580 return 0;
2581
2582 rollback:
dfefa935 2583 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2584 if (!lock) {
dfefa935 2585 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2586 goto rollbacklog;
2587 }
2588
2589 lock->force_write = 1;
2590 flag = log_all_ref_updates;
2591 log_all_ref_updates = 0;
2592 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2593 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2594 log_all_ref_updates = flag;
2595
2596 rollbacklog:
dfefa935 2597 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2598 error("unable to restore logfile %s from %s: %s",
dfefa935 2599 oldrefname, newrefname, strerror(errno));
c976d415 2600 if (!logmoved && log &&
dfefa935 2601 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2602 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2603 oldrefname, strerror(errno));
c976d415
LH
2604
2605 return 1;
2606}
2607
435fc852 2608int close_ref(struct ref_lock *lock)
b531394d
BC
2609{
2610 if (close_lock_file(lock->lk))
2611 return -1;
2612 lock->lock_fd = -1;
2613 return 0;
2614}
2615
435fc852 2616int commit_ref(struct ref_lock *lock)
b531394d
BC
2617{
2618 if (commit_lock_file(lock->lk))
2619 return -1;
2620 lock->lock_fd = -1;
2621 return 0;
2622}
2623
e5f38ec3 2624void unlock_ref(struct ref_lock *lock)
4bd18c43 2625{
4ed7cd3a
BC
2626 /* Do not free lock->lk -- atexit() still looks at them */
2627 if (lock->lk)
2628 rollback_lock_file(lock->lk);
434cd0cd 2629 free(lock->ref_name);
1655707c 2630 free(lock->orig_ref_name);
4bd18c43
SP
2631 free(lock);
2632}
2633
0ec29a47
JH
2634/*
2635 * copy the reflog message msg to buf, which has been allocated sufficiently
2636 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2637 * because reflog file is one line per entry.
2638 */
2639static int copy_msg(char *buf, const char *msg)
2640{
2641 char *cp = buf;
2642 char c;
2643 int wasspace = 1;
2644
2645 *cp++ = '\t';
2646 while ((c = *msg++)) {
2647 if (wasspace && isspace(c))
2648 continue;
2649 wasspace = isspace(c);
2650 if (wasspace)
2651 c = ' ';
2652 *cp++ = c;
2653 }
2654 while (buf < cp && isspace(cp[-1]))
2655 cp--;
2656 *cp++ = '\n';
2657 return cp - buf;
2658}
2659
dfefa935 2660int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2661{
859c3017 2662 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2663
dfefa935 2664 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2665 if (log_all_ref_updates &&
dfefa935
MH
2666 (!prefixcmp(refname, "refs/heads/") ||
2667 !prefixcmp(refname, "refs/remotes/") ||
2668 !prefixcmp(refname, "refs/notes/") ||
2669 !strcmp(refname, "HEAD"))) {
157aaea5 2670 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2671 return error("unable to create directory for %s",
157aaea5 2672 logfile);
6de08ae6
SP
2673 oflags |= O_CREAT;
2674 }
2675
157aaea5 2676 logfd = open(logfile, oflags, 0666);
6de08ae6 2677 if (logfd < 0) {
1974bf62 2678 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2679 return 0;
3b463c3f
JH
2680
2681 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2682 if (remove_empty_directories(logfile)) {
3b463c3f 2683 return error("There are still logs under '%s'",
157aaea5 2684 logfile);
3b463c3f 2685 }
157aaea5 2686 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2687 }
2688
2689 if (logfd < 0)
2690 return error("Unable to append to %s: %s",
157aaea5 2691 logfile, strerror(errno));
6de08ae6
SP
2692 }
2693
157aaea5 2694 adjust_shared_perm(logfile);
859c3017
EM
2695 close(logfd);
2696 return 0;
2697}
443b92b6 2698
dfefa935 2699static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2700 const unsigned char *new_sha1, const char *msg)
2701{
2702 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2703 unsigned maxlen, len;
2704 int msglen;
157aaea5 2705 char log_file[PATH_MAX];
859c3017
EM
2706 char *logrec;
2707 const char *committer;
2708
2709 if (log_all_ref_updates < 0)
2710 log_all_ref_updates = !is_bare_repository();
2711
dfefa935 2712 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2713 if (result)
2714 return result;
2715
2716 logfd = open(log_file, oflags);
2717 if (logfd < 0)
2718 return 0;
0ec29a47 2719 msglen = msg ? strlen(msg) : 0;
774751a8 2720 committer = git_committer_info(0);
8ac65937
JH
2721 maxlen = strlen(committer) + msglen + 100;
2722 logrec = xmalloc(maxlen);
2723 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2724 sha1_to_hex(old_sha1),
2725 sha1_to_hex(new_sha1),
8ac65937
JH
2726 committer);
2727 if (msglen)
0ec29a47 2728 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2729 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2730 free(logrec);
91c8d590 2731 if (close(logfd) != 0 || written != len)
9a13f0b7 2732 return error("Unable to append to %s", log_file);
6de08ae6
SP
2733 return 0;
2734}
2735
c3b0dec5
LT
2736static int is_branch(const char *refname)
2737{
2738 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2739}
2740
4bd18c43
SP
2741int write_ref_sha1(struct ref_lock *lock,
2742 const unsigned char *sha1, const char *logmsg)
2743{
2744 static char term = '\n';
c3b0dec5 2745 struct object *o;
4bd18c43
SP
2746
2747 if (!lock)
95fc7512 2748 return -1;
a89fccd2 2749 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2750 unlock_ref(lock);
2751 return 0;
95fc7512 2752 }
c3b0dec5
LT
2753 o = parse_object(sha1);
2754 if (!o) {
7be8b3ba 2755 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2756 lock->ref_name, sha1_to_hex(sha1));
2757 unlock_ref(lock);
2758 return -1;
2759 }
2760 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2761 error("Trying to write non-commit object %s to branch %s",
2762 sha1_to_hex(sha1), lock->ref_name);
2763 unlock_ref(lock);
2764 return -1;
2765 }
93822c22
AW
2766 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2767 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2768 || close_ref(lock) < 0) {
c33d5174 2769 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2770 unlock_ref(lock);
2771 return -1;
2772 }
9da31cb0 2773 clear_loose_ref_cache(&ref_cache);
bd104db1
NP
2774 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2775 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2776 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2777 unlock_ref(lock);
2778 return -1;
2779 }
605fac8b
NP
2780 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2781 /*
2782 * Special hack: If a branch is updated directly and HEAD
2783 * points to it (may happen on the remote side of a push
2784 * for example) then logically the HEAD reflog should be
2785 * updated too.
2786 * A generic solution implies reverse symref information,
2787 * but finding all symrefs pointing to the given branch
2788 * would be rather costly for this rare event (the direct
2789 * update of a branch) to be worth it. So let's cheat and
2790 * check with HEAD only which should cover 99% of all usage
2791 * scenarios (even 100% of the default ones).
2792 */
2793 unsigned char head_sha1[20];
2794 int head_flag;
2795 const char *head_ref;
8cad4744 2796 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2797 if (head_ref && (head_flag & REF_ISSYMREF) &&
2798 !strcmp(head_ref, lock->ref_name))
2799 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2800 }
b531394d 2801 if (commit_ref(lock)) {
434cd0cd 2802 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2803 unlock_ref(lock);
2804 return -1;
2805 }
4bd18c43
SP
2806 unlock_ref(lock);
2807 return 0;
95fc7512 2808}
d556fae2 2809
8b5157e4
NP
2810int create_symref(const char *ref_target, const char *refs_heads_master,
2811 const char *logmsg)
41b625b0
NP
2812{
2813 const char *lockpath;
2814 char ref[1000];
2815 int fd, len, written;
a4f34cbb 2816 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2817 unsigned char old_sha1[20], new_sha1[20];
2818
2819 if (logmsg && read_ref(ref_target, old_sha1))
2820 hashclr(old_sha1);
41b625b0 2821
d48744d1
JH
2822 if (safe_create_leading_directories(git_HEAD) < 0)
2823 return error("unable to create directory for %s", git_HEAD);
2824
41b625b0
NP
2825#ifndef NO_SYMLINK_HEAD
2826 if (prefer_symlink_refs) {
2827 unlink(git_HEAD);
2828 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2829 goto done;
41b625b0
NP
2830 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2831 }
2832#endif
2833
2834 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2835 if (sizeof(ref) <= len) {
2836 error("refname too long: %s", refs_heads_master);
47fc52e2 2837 goto error_free_return;
41b625b0
NP
2838 }
2839 lockpath = mkpath("%s.lock", git_HEAD);
2840 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2841 if (fd < 0) {
2842 error("Unable to open %s for writing", lockpath);
47fc52e2 2843 goto error_free_return;
41b625b0
NP
2844 }
2845 written = write_in_full(fd, ref, len);
91c8d590 2846 if (close(fd) != 0 || written != len) {
41b625b0 2847 error("Unable to write to %s", lockpath);
47fc52e2 2848 goto error_unlink_return;
41b625b0
NP
2849 }
2850 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2851 error("Unable to create %s", git_HEAD);
47fc52e2 2852 goto error_unlink_return;
41b625b0
NP
2853 }
2854 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2855 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2856 error_unlink_return:
691f1a28 2857 unlink_or_warn(lockpath);
47fc52e2
JH
2858 error_free_return:
2859 free(git_HEAD);
2860 return -1;
41b625b0 2861 }
8b5157e4 2862
ee96d11b 2863#ifndef NO_SYMLINK_HEAD
8b5157e4 2864 done:
ee96d11b 2865#endif
8b5157e4
NP
2866 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2867 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2868
47fc52e2 2869 free(git_HEAD);
41b625b0
NP
2870 return 0;
2871}
2872
16d7cc90
JH
2873static char *ref_msg(const char *line, const char *endp)
2874{
2875 const char *ep;
16d7cc90 2876 line += 82;
182af834
PH
2877 ep = memchr(line, '\n', endp - line);
2878 if (!ep)
2879 ep = endp;
2880 return xmemdupz(line, ep - line);
16d7cc90
JH
2881}
2882
dfefa935
MH
2883int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2884 unsigned char *sha1, char **msg,
2885 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2886{
e5229042 2887 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2888 char *tz_c;
e29cb53a 2889 int logfd, tz, reccnt = 0;
d556fae2
SP
2890 struct stat st;
2891 unsigned long date;
e5229042 2892 unsigned char logged_sha1[20];
cb48cb58 2893 void *log_mapped;
dc49cd76 2894 size_t mapsz;
d556fae2 2895
dfefa935 2896 logfile = git_path("logs/%s", refname);
d556fae2
SP
2897 logfd = open(logfile, O_RDONLY, 0);
2898 if (logfd < 0)
d824cbba 2899 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2900 fstat(logfd, &st);
2901 if (!st.st_size)
2902 die("Log %s is empty.", logfile);
dc49cd76
SP
2903 mapsz = xsize_t(st.st_size);
2904 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2905 logdata = log_mapped;
d556fae2
SP
2906 close(logfd);
2907
e5229042 2908 lastrec = NULL;
d556fae2
SP
2909 rec = logend = logdata + st.st_size;
2910 while (logdata < rec) {
e29cb53a 2911 reccnt++;
d556fae2
SP
2912 if (logdata < rec && *(rec-1) == '\n')
2913 rec--;
e5229042
SP
2914 lastgt = NULL;
2915 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2916 rec--;
e5229042
SP
2917 if (*rec == '>')
2918 lastgt = rec;
2919 }
2920 if (!lastgt)
d556fae2 2921 die("Log %s is corrupt.", logfile);
e5229042 2922 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2923 if (date <= at_time || cnt == 0) {
76a44c5c 2924 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2925 if (msg)
2926 *msg = ref_msg(rec, logend);
2927 if (cutoff_time)
2928 *cutoff_time = date;
2929 if (cutoff_tz)
2930 *cutoff_tz = tz;
2931 if (cutoff_cnt)
76a44c5c 2932 *cutoff_cnt = reccnt - 1;
e5229042
SP
2933 if (lastrec) {
2934 if (get_sha1_hex(lastrec, logged_sha1))
2935 die("Log %s is corrupt.", logfile);
2936 if (get_sha1_hex(rec + 41, sha1))
2937 die("Log %s is corrupt.", logfile);
a89fccd2 2938 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2939 warning("Log %s has gap after %s.",
73013afd 2940 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 2941 }
e5f38ec3
JH
2942 }
2943 else if (date == at_time) {
e5229042
SP
2944 if (get_sha1_hex(rec + 41, sha1))
2945 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
2946 }
2947 else {
e5229042
SP
2948 if (get_sha1_hex(rec + 41, logged_sha1))
2949 die("Log %s is corrupt.", logfile);
a89fccd2 2950 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2951 warning("Log %s unexpectedly ended on %s.",
73013afd 2952 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
2953 }
2954 }
dc49cd76 2955 munmap(log_mapped, mapsz);
d556fae2
SP
2956 return 0;
2957 }
e5229042 2958 lastrec = rec;
ab2a1a32
JH
2959 if (cnt > 0)
2960 cnt--;
d556fae2
SP
2961 }
2962
e5229042
SP
2963 rec = logdata;
2964 while (rec < logend && *rec != '>' && *rec != '\n')
2965 rec++;
2966 if (rec == logend || *rec == '\n')
d556fae2 2967 die("Log %s is corrupt.", logfile);
e5229042 2968 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
2969 tz = strtoul(tz_c, NULL, 10);
2970 if (get_sha1_hex(logdata, sha1))
2971 die("Log %s is corrupt.", logfile);
d1a4489a
JK
2972 if (is_null_sha1(sha1)) {
2973 if (get_sha1_hex(logdata + 41, sha1))
2974 die("Log %s is corrupt.", logfile);
2975 }
16d7cc90
JH
2976 if (msg)
2977 *msg = ref_msg(logdata, logend);
dc49cd76 2978 munmap(log_mapped, mapsz);
16d7cc90
JH
2979
2980 if (cutoff_time)
2981 *cutoff_time = date;
2982 if (cutoff_tz)
2983 *cutoff_tz = tz;
2984 if (cutoff_cnt)
2985 *cutoff_cnt = reccnt;
2986 return 1;
d556fae2 2987}
2ff81662 2988
9a7a183b
JH
2989static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
2990{
2991 unsigned char osha1[20], nsha1[20];
2992 char *email_end, *message;
2993 unsigned long timestamp;
2994 int tz;
2995
2996 /* old SP new SP name <email> SP time TAB msg LF */
2997 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
2998 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
2999 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
3000 !(email_end = strchr(sb->buf + 82, '>')) ||
3001 email_end[1] != ' ' ||
3002 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
3003 !message || message[0] != ' ' ||
3004 (message[1] != '+' && message[1] != '-') ||
3005 !isdigit(message[2]) || !isdigit(message[3]) ||
3006 !isdigit(message[4]) || !isdigit(message[5]))
3007 return 0; /* corrupt? */
3008 email_end[1] = '\0';
3009 tz = strtol(message + 1, NULL, 10);
3010 if (message[6] != '\t')
3011 message += 6;
3012 else
3013 message += 7;
3014 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
3015}
3016
98f85ff4
JH
3017static char *find_beginning_of_line(char *bob, char *scan)
3018{
3019 while (bob < scan && *(--scan) != '\n')
3020 ; /* keep scanning backwards */
3021 /*
3022 * Return either beginning of the buffer, or LF at the end of
3023 * the previous line.
3024 */
3025 return scan;
3026}
3027
3028int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2ff81662 3029{
8ca78803 3030 struct strbuf sb = STRBUF_INIT;
98f85ff4
JH
3031 FILE *logfp;
3032 long pos;
3033 int ret = 0, at_tail = 1;
2ff81662 3034
7ae07c1b 3035 logfp = fopen(git_path("logs/%s", refname), "r");
2ff81662 3036 if (!logfp)
883d60fa 3037 return -1;
101d15e0 3038
98f85ff4
JH
3039 /* Jump to the end */
3040 if (fseek(logfp, 0, SEEK_END) < 0)
3041 return error("cannot seek back reflog for %s: %s",
3042 refname, strerror(errno));
3043 pos = ftell(logfp);
3044 while (!ret && 0 < pos) {
3045 int cnt;
3046 size_t nread;
3047 char buf[BUFSIZ];
3048 char *endp, *scanp;
3049
3050 /* Fill next block from the end */
3051 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
3052 if (fseek(logfp, pos - cnt, SEEK_SET))
3053 return error("cannot seek back reflog for %s: %s",
3054 refname, strerror(errno));
3055 nread = fread(buf, cnt, 1, logfp);
e4ca819a 3056 if (nread != 1)
98f85ff4
JH
3057 return error("cannot read %d bytes from reflog for %s: %s",
3058 cnt, refname, strerror(errno));
3059 pos -= cnt;
3060
3061 scanp = endp = buf + cnt;
3062 if (at_tail && scanp[-1] == '\n')
3063 /* Looking at the final LF at the end of the file */
3064 scanp--;
3065 at_tail = 0;
3066
3067 while (buf < scanp) {
3068 /*
3069 * terminating LF of the previous line, or the beginning
3070 * of the buffer.
3071 */
3072 char *bp;
3073
3074 bp = find_beginning_of_line(buf, scanp);
3075
3076 if (*bp != '\n') {
3077 strbuf_splice(&sb, 0, 0, buf, endp - buf);
3078 if (pos)
3079 break; /* need to fill another block */
3080 scanp = buf - 1; /* leave loop */
3081 } else {
3082 /*
3083 * (bp + 1) thru endp is the beginning of the
3084 * current line we have in sb
3085 */
3086 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
3087 scanp = bp;
3088 endp = bp + 1;
3089 }
3090 ret = show_one_reflog_ent(&sb, fn, cb_data);
3091 strbuf_reset(&sb);
3092 if (ret)
3093 break;
9d33f7c2 3094 }
101d15e0 3095
2ff81662 3096 }
98f85ff4 3097 if (!ret && sb.len)
9a7a183b 3098 ret = show_one_reflog_ent(&sb, fn, cb_data);
98f85ff4 3099
2ff81662 3100 fclose(logfp);
8ca78803 3101 strbuf_release(&sb);
2266bf27 3102 return ret;
2ff81662 3103}
e29cb53a 3104
dfefa935 3105int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 3106{
98f85ff4
JH
3107 FILE *logfp;
3108 struct strbuf sb = STRBUF_INIT;
3109 int ret = 0;
3110
3111 logfp = fopen(git_path("logs/%s", refname), "r");
3112 if (!logfp)
3113 return -1;
101d15e0 3114
98f85ff4
JH
3115 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
3116 ret = show_one_reflog_ent(&sb, fn, cb_data);
3117 fclose(logfp);
3118 strbuf_release(&sb);
3119 return ret;
3120}
989c0e5d
MH
3121/*
3122 * Call fn for each reflog in the namespace indicated by name. name
3123 * must be empty or end with '/'. Name will be used as a scratch
3124 * space, but its contents will be restored before return.
3125 */
3126static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 3127{
989c0e5d 3128 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 3129 int retval = 0;
93c603fc 3130 struct dirent *de;
989c0e5d 3131 int oldlen = name->len;
eb8381c8 3132
93c603fc 3133 if (!d)
989c0e5d 3134 return name->len ? errno : 0;
eb8381c8 3135
93c603fc
MH
3136 while ((de = readdir(d)) != NULL) {
3137 struct stat st;
eb8381c8 3138
93c603fc
MH
3139 if (de->d_name[0] == '.')
3140 continue;
93c603fc
MH
3141 if (has_extension(de->d_name, ".lock"))
3142 continue;
989c0e5d
MH
3143 strbuf_addstr(name, de->d_name);
3144 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
3145 ; /* silently ignore */
93c603fc 3146 } else {
eb8381c8 3147 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
3148 strbuf_addch(name, '/');
3149 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
3150 } else {
3151 unsigned char sha1[20];
989c0e5d
MH
3152 if (read_ref_full(name->buf, sha1, 0, NULL))
3153 retval = error("bad ref for %s", name->buf);
eb8381c8 3154 else
989c0e5d 3155 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
3156 }
3157 if (retval)
3158 break;
3159 }
989c0e5d 3160 strbuf_setlen(name, oldlen);
eb8381c8 3161 }
93c603fc 3162 closedir(d);
eb8381c8
NP
3163 return retval;
3164}
3165
3166int for_each_reflog(each_ref_fn fn, void *cb_data)
3167{
989c0e5d
MH
3168 int retval;
3169 struct strbuf name;
3170 strbuf_init(&name, PATH_MAX);
3171 retval = do_for_each_reflog(&name, fn, cb_data);
3172 strbuf_release(&name);
3173 return retval;
eb8381c8 3174}
3d9f037c
CR
3175
3176int update_ref(const char *action, const char *refname,
3177 const unsigned char *sha1, const unsigned char *oldval,
3178 int flags, enum action_on_err onerr)
3179{
3180 static struct ref_lock *lock;
3181 lock = lock_any_ref_for_update(refname, oldval, flags);
3182 if (!lock) {
3183 const char *str = "Cannot lock the ref '%s'.";
3184 switch (onerr) {
3185 case MSG_ON_ERR: error(str, refname); break;
3186 case DIE_ON_ERR: die(str, refname); break;
3187 case QUIET_ON_ERR: break;
3188 }
3189 return 1;
3190 }
3191 if (write_ref_sha1(lock, sha1, action) < 0) {
3192 const char *str = "Cannot update the ref '%s'.";
3193 switch (onerr) {
3194 case MSG_ON_ERR: error(str, refname); break;
3195 case DIE_ON_ERR: die(str, refname); break;
3196 case QUIET_ON_ERR: break;
3197 }
3198 return 1;
3199 }
3200 return 0;
3201}
cda69f48 3202
5483f799 3203struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
3204{
3205 for ( ; list; list = list->next)
3206 if (!strcmp(list->name, name))
5483f799 3207 return (struct ref *)list;
cda69f48
JK
3208 return NULL;
3209}
7c2b3029
JK
3210
3211/*
3212 * generate a format suitable for scanf from a ref_rev_parse_rules
3213 * rule, that is replace the "%.*s" spec with a "%s" spec
3214 */
3215static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
3216{
3217 char *spec;
3218
3219 spec = strstr(rule, "%.*s");
3220 if (!spec || strstr(spec + 4, "%.*s"))
3221 die("invalid rule in ref_rev_parse_rules: %s", rule);
3222
3223 /* copy all until spec */
3224 strncpy(scanf_fmt, rule, spec - rule);
3225 scanf_fmt[spec - rule] = '\0';
3226 /* copy new spec */
3227 strcat(scanf_fmt, "%s");
3228 /* copy remaining rule */
3229 strcat(scanf_fmt, spec + 4);
3230
3231 return;
3232}
3233
dfefa935 3234char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
3235{
3236 int i;
3237 static char **scanf_fmts;
3238 static int nr_rules;
3239 char *short_name;
3240
3241 /* pre generate scanf formats from ref_rev_parse_rules[] */
3242 if (!nr_rules) {
3243 size_t total_len = 0;
3244
3245 /* the rule list is NULL terminated, count them first */
3246 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
3247 /* no +1 because strlen("%s") < strlen("%.*s") */
3248 total_len += strlen(ref_rev_parse_rules[nr_rules]);
3249
3250 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3251
3252 total_len = 0;
3253 for (i = 0; i < nr_rules; i++) {
3254 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
3255 + total_len;
3256 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
3257 total_len += strlen(ref_rev_parse_rules[i]);
3258 }
3259 }
3260
3261 /* bail out if there are no rules */
3262 if (!nr_rules)
dfefa935 3263 return xstrdup(refname);
7c2b3029 3264
dfefa935
MH
3265 /* buffer for scanf result, at most refname must fit */
3266 short_name = xstrdup(refname);
7c2b3029
JK
3267
3268 /* skip first rule, it will always match */
3269 for (i = nr_rules - 1; i > 0 ; --i) {
3270 int j;
6e7b3309 3271 int rules_to_fail = i;
7c2b3029
JK
3272 int short_name_len;
3273
dfefa935 3274 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
3275 continue;
3276
3277 short_name_len = strlen(short_name);
3278
6e7b3309
BW
3279 /*
3280 * in strict mode, all (except the matched one) rules
3281 * must fail to resolve to a valid non-ambiguous ref
3282 */
3283 if (strict)
3284 rules_to_fail = nr_rules;
3285
7c2b3029
JK
3286 /*
3287 * check if the short name resolves to a valid ref,
3288 * but use only rules prior to the matched one
3289 */
6e7b3309 3290 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 3291 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
3292 char refname[PATH_MAX];
3293
6e7b3309
BW
3294 /* skip matched rule */
3295 if (i == j)
3296 continue;
3297
7c2b3029
JK
3298 /*
3299 * the short name is ambiguous, if it resolves
3300 * (with this previous rule) to a valid ref
3301 * read_ref() returns 0 on success
3302 */
3303 mksnpath(refname, sizeof(refname),
3304 rule, short_name_len, short_name);
c6893323 3305 if (ref_exists(refname))
7c2b3029
JK
3306 break;
3307 }
3308
3309 /*
3310 * short name is non-ambiguous if all previous rules
3311 * haven't resolved to a valid ref
3312 */
6e7b3309 3313 if (j == rules_to_fail)
7c2b3029
JK
3314 return short_name;
3315 }
3316
3317 free(short_name);
dfefa935 3318 return xstrdup(refname);
7c2b3029 3319}
daebaa78
JH
3320
3321static struct string_list *hide_refs;
3322
3323int parse_hide_refs_config(const char *var, const char *value, const char *section)
3324{
3325 if (!strcmp("transfer.hiderefs", var) ||
3326 /* NEEDSWORK: use parse_config_key() once both are merged */
3327 (!prefixcmp(var, section) && var[strlen(section)] == '.' &&
3328 !strcmp(var + strlen(section), ".hiderefs"))) {
3329 char *ref;
3330 int len;
3331
3332 if (!value)
3333 return config_error_nonbool(var);
3334 ref = xstrdup(value);
3335 len = strlen(ref);
3336 while (len && ref[len - 1] == '/')
3337 ref[--len] = '\0';
3338 if (!hide_refs) {
3339 hide_refs = xcalloc(1, sizeof(*hide_refs));
3340 hide_refs->strdup_strings = 1;
3341 }
3342 string_list_append(hide_refs, ref);
3343 }
3344 return 0;
3345}
3346
3347int ref_is_hidden(const char *refname)
3348{
3349 struct string_list_item *item;
3350
3351 if (!hide_refs)
3352 return 0;
3353 for_each_string_list_item(item, hide_refs) {
3354 int len;
3355 if (prefixcmp(refname, item->string))
3356 continue;
3357 len = strlen(item->string);
3358 if (!refname[len] || refname[len] == '/')
3359 return 1;
3360 }
3361 return 0;
3362}