refs: wrap the packed refs cache in a level of indirection
[git/git.git] / refs.c
CommitLineData
95fc7512 1#include "cache.h"
85023577 2#include "refs.h"
cf0adba7
JH
3#include "object.h"
4#include "tag.h"
7155b727 5#include "dir.h"
daebaa78 6#include "string-list.h"
95fc7512 7
bc5fd6d3
MH
8/*
9 * Make sure "ref" is something reasonable to have under ".git/refs/";
10 * We do not like it if:
11 *
12 * - any path component of it begins with ".", or
13 * - it has double dots "..", or
14 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
15 * - it ends with a "/".
16 * - it ends with ".lock"
17 * - it contains a "\" (backslash)
18 */
f4204ab9 19
bc5fd6d3
MH
20/* Return true iff ch is not allowed in reference names. */
21static inline int bad_ref_char(int ch)
22{
23 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
24 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
25 return 1;
26 /* 2.13 Pattern Matching Notation */
27 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
28 return 1;
29 return 0;
30}
31
32/*
33 * Try to read one refname component from the front of refname. Return
34 * the length of the component found, or -1 if the component is not
35 * legal.
36 */
37static int check_refname_component(const char *refname, int flags)
38{
39 const char *cp;
40 char last = '\0';
41
42 for (cp = refname; ; cp++) {
43 char ch = *cp;
44 if (ch == '\0' || ch == '/')
45 break;
46 if (bad_ref_char(ch))
47 return -1; /* Illegal character in refname. */
48 if (last == '.' && ch == '.')
49 return -1; /* Refname contains "..". */
50 if (last == '@' && ch == '{')
51 return -1; /* Refname contains "@{". */
52 last = ch;
53 }
54 if (cp == refname)
dac529e4 55 return 0; /* Component has zero length. */
bc5fd6d3
MH
56 if (refname[0] == '.') {
57 if (!(flags & REFNAME_DOT_COMPONENT))
58 return -1; /* Component starts with '.'. */
59 /*
60 * Even if leading dots are allowed, don't allow "."
61 * as a component (".." is prevented by a rule above).
62 */
63 if (refname[1] == '\0')
64 return -1; /* Component equals ".". */
65 }
66 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
67 return -1; /* Refname ends with ".lock". */
68 return cp - refname;
69}
70
71int check_refname_format(const char *refname, int flags)
72{
73 int component_len, component_count = 0;
74
cdfd9483
FC
75 if (!strcmp(refname, "@"))
76 /* Refname is a single character '@'. */
77 return -1;
78
bc5fd6d3
MH
79 while (1) {
80 /* We are at the start of a path component. */
81 component_len = check_refname_component(refname, flags);
dac529e4 82 if (component_len <= 0) {
bc5fd6d3
MH
83 if ((flags & REFNAME_REFSPEC_PATTERN) &&
84 refname[0] == '*' &&
85 (refname[1] == '\0' || refname[1] == '/')) {
86 /* Accept one wildcard as a full refname component. */
87 flags &= ~REFNAME_REFSPEC_PATTERN;
88 component_len = 1;
89 } else {
90 return -1;
91 }
92 }
93 component_count++;
94 if (refname[component_len] == '\0')
95 break;
96 /* Skip to next component. */
97 refname += component_len + 1;
98 }
99
100 if (refname[component_len - 1] == '.')
101 return -1; /* Refname ends with '.'. */
102 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
103 return -1; /* Refname has only one component. */
104 return 0;
105}
106
107struct ref_entry;
e1e22e37 108
28e6a34e
MH
109/*
110 * Information used (along with the information in ref_entry) to
111 * describe a single cached reference. This data structure only
112 * occurs embedded in a union in struct ref_entry, and only when
113 * (ref_entry->flag & REF_DIR) is zero.
114 */
593f1bb8 115struct ref_value {
6c6f58df
MH
116 /*
117 * The name of the object to which this reference resolves
118 * (which may be a tag object). If REF_ISBROKEN, this is
119 * null. If REF_ISSYMREF, then this is the name of the object
120 * referred to by the last reference in the symlink chain.
121 */
593f1bb8 122 unsigned char sha1[20];
6c6f58df
MH
123
124 /*
125 * If REF_KNOWS_PEELED, then this field holds the peeled value
126 * of this reference, or null if the reference is known not to
2312a793
MH
127 * be peelable. See the documentation for peel_ref() for an
128 * exact definition of "peelable".
6c6f58df 129 */
593f1bb8
MH
130 unsigned char peeled[20];
131};
132
f006c42a
MH
133struct ref_cache;
134
28e6a34e
MH
135/*
136 * Information used (along with the information in ref_entry) to
137 * describe a level in the hierarchy of references. This data
138 * structure only occurs embedded in a union in struct ref_entry, and
139 * only when (ref_entry.flag & REF_DIR) is set. In that case,
140 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
141 * in the directory have already been read:
142 *
143 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
144 * or packed references, already read.
145 *
146 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
147 * references that hasn't been read yet (nor has any of its
148 * subdirectories).
149 *
150 * Entries within a directory are stored within a growable array of
151 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
152 * sorted are sorted by their component name in strcmp() order and the
153 * remaining entries are unsorted.
154 *
155 * Loose references are read lazily, one directory at a time. When a
156 * directory of loose references is read, then all of the references
157 * in that directory are stored, and REF_INCOMPLETE stubs are created
158 * for any subdirectories, but the subdirectories themselves are not
159 * read. The reading is triggered by get_ref_dir().
160 */
d3177275 161struct ref_dir {
e9c4c111 162 int nr, alloc;
e6ed3ca6
MH
163
164 /*
165 * Entries with index 0 <= i < sorted are sorted by name. New
166 * entries are appended to the list unsorted, and are sorted
167 * only when required; thus we avoid the need to sort the list
168 * after the addition of every reference.
169 */
170 int sorted;
171
f006c42a
MH
172 /* A pointer to the ref_cache that contains this ref_dir. */
173 struct ref_cache *ref_cache;
174
d3177275 175 struct ref_entry **entries;
e9c4c111
JP
176};
177
89df9c84
MH
178/*
179 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
180 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
181 * refs.h.
182 */
183
184/*
185 * The field ref_entry->u.value.peeled of this value entry contains
186 * the correct peeled value for the reference, which might be
187 * null_sha1 if the reference is not a tag or if it is broken.
188 */
432ad41e 189#define REF_KNOWS_PEELED 0x08
28e6a34e
MH
190
191/* ref_entry represents a directory of references */
432ad41e 192#define REF_DIR 0x10
cf0adba7 193
28e6a34e
MH
194/*
195 * Entry has not yet been read from disk (used only for REF_DIR
196 * entries representing loose references)
197 */
198#define REF_INCOMPLETE 0x20
199
432ad41e
MH
200/*
201 * A ref_entry represents either a reference or a "subdirectory" of
28e6a34e
MH
202 * references.
203 *
204 * Each directory in the reference namespace is represented by a
205 * ref_entry with (flags & REF_DIR) set and containing a subdir member
206 * that holds the entries in that directory that have been read so
207 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
208 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
209 * used for loose reference directories.
210 *
211 * References are represented by a ref_entry with (flags & REF_DIR)
212 * unset and a value member that describes the reference's value. The
213 * flag member is at the ref_entry level, but it is also needed to
214 * interpret the contents of the value field (in other words, a
215 * ref_value object is not very much use without the enclosing
216 * ref_entry).
432ad41e
MH
217 *
218 * Reference names cannot end with slash and directories' names are
219 * always stored with a trailing slash (except for the top-level
220 * directory, which is always denoted by ""). This has two nice
221 * consequences: (1) when the entries in each subdir are sorted
222 * lexicographically by name (as they usually are), the references in
223 * a whole tree can be generated in lexicographic order by traversing
224 * the tree in left-to-right, depth-first order; (2) the names of
225 * references and subdirectories cannot conflict, and therefore the
226 * presence of an empty subdirectory does not block the creation of a
227 * similarly-named reference. (The fact that reference names with the
228 * same leading components can conflict *with each other* is a
229 * separate issue that is regulated by is_refname_available().)
230 *
231 * Please note that the name field contains the fully-qualified
232 * reference (or subdirectory) name. Space could be saved by only
233 * storing the relative names. But that would require the full names
234 * to be generated on the fly when iterating in do_for_each_ref(), and
235 * would break callback functions, who have always been able to assume
236 * that the name strings that they are passed will not be freed during
237 * the iteration.
238 */
bc5fd6d3
MH
239struct ref_entry {
240 unsigned char flag; /* ISSYMREF? ISPACKED? */
593f1bb8 241 union {
432ad41e
MH
242 struct ref_value value; /* if not (flags&REF_DIR) */
243 struct ref_dir subdir; /* if (flags&REF_DIR) */
593f1bb8 244 } u;
432ad41e
MH
245 /*
246 * The full name of the reference (e.g., "refs/heads/master")
247 * or the full name of the directory with a trailing slash
248 * (e.g., "refs/heads/"):
249 */
bc5fd6d3
MH
250 char name[FLEX_ARRAY];
251};
e1e22e37 252
28e6a34e
MH
253static void read_loose_refs(const char *dirname, struct ref_dir *dir);
254
d7826d54
MH
255static struct ref_dir *get_ref_dir(struct ref_entry *entry)
256{
28e6a34e 257 struct ref_dir *dir;
d7826d54 258 assert(entry->flag & REF_DIR);
28e6a34e
MH
259 dir = &entry->u.subdir;
260 if (entry->flag & REF_INCOMPLETE) {
261 read_loose_refs(entry->name, dir);
262 entry->flag &= ~REF_INCOMPLETE;
263 }
264 return dir;
d7826d54
MH
265}
266
cddc4258
MH
267static struct ref_entry *create_ref_entry(const char *refname,
268 const unsigned char *sha1, int flag,
269 int check_name)
e1e22e37
LT
270{
271 int len;
cddc4258 272 struct ref_entry *ref;
e1e22e37 273
09116a1c 274 if (check_name &&
dfefa935
MH
275 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
276 die("Reference has invalid format: '%s'", refname);
cddc4258
MH
277 len = strlen(refname) + 1;
278 ref = xmalloc(sizeof(struct ref_entry) + len);
593f1bb8
MH
279 hashcpy(ref->u.value.sha1, sha1);
280 hashclr(ref->u.value.peeled);
cddc4258
MH
281 memcpy(ref->name, refname, len);
282 ref->flag = flag;
283 return ref;
284}
285
432ad41e
MH
286static void clear_ref_dir(struct ref_dir *dir);
287
732134ed
MH
288static void free_ref_entry(struct ref_entry *entry)
289{
27b5587c
MH
290 if (entry->flag & REF_DIR) {
291 /*
292 * Do not use get_ref_dir() here, as that might
293 * trigger the reading of loose refs.
294 */
295 clear_ref_dir(&entry->u.subdir);
296 }
732134ed
MH
297 free(entry);
298}
299
432ad41e
MH
300/*
301 * Add a ref_entry to the end of dir (unsorted). Entry is always
302 * stored directly in dir; no recursion into subdirectories is
303 * done.
304 */
305static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
cddc4258 306{
432ad41e
MH
307 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
308 dir->entries[dir->nr++] = entry;
654ad400
MH
309 /* optimize for the case that entries are added in order */
310 if (dir->nr == 1 ||
311 (dir->nr == dir->sorted + 1 &&
312 strcmp(dir->entries[dir->nr - 2]->name,
313 dir->entries[dir->nr - 1]->name) < 0))
314 dir->sorted = dir->nr;
c774aab9
JP
315}
316
432ad41e
MH
317/*
318 * Clear and free all entries in dir, recursively.
319 */
d3177275 320static void clear_ref_dir(struct ref_dir *dir)
bc5fd6d3
MH
321{
322 int i;
d3177275
MH
323 for (i = 0; i < dir->nr; i++)
324 free_ref_entry(dir->entries[i]);
325 free(dir->entries);
326 dir->sorted = dir->nr = dir->alloc = 0;
327 dir->entries = NULL;
bc5fd6d3
MH
328}
329
432ad41e
MH
330/*
331 * Create a struct ref_entry object for the specified dirname.
332 * dirname is the name of the directory with a trailing slash (e.g.,
333 * "refs/heads/") or "" for the top-level directory.
334 */
f006c42a 335static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
b9146f51
RS
336 const char *dirname, size_t len,
337 int incomplete)
432ad41e
MH
338{
339 struct ref_entry *direntry;
432ad41e 340 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
b9146f51
RS
341 memcpy(direntry->name, dirname, len);
342 direntry->name[len] = '\0';
f006c42a 343 direntry->u.subdir.ref_cache = ref_cache;
28e6a34e 344 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
432ad41e
MH
345 return direntry;
346}
347
e9c4c111 348static int ref_entry_cmp(const void *a, const void *b)
c774aab9 349{
e9c4c111
JP
350 struct ref_entry *one = *(struct ref_entry **)a;
351 struct ref_entry *two = *(struct ref_entry **)b;
352 return strcmp(one->name, two->name);
353}
c774aab9 354
d3177275 355static void sort_ref_dir(struct ref_dir *dir);
bc5fd6d3 356
e1980c9d
JH
357struct string_slice {
358 size_t len;
359 const char *str;
360};
361
362static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
363{
c971ddfd
RS
364 const struct string_slice *key = key_;
365 const struct ref_entry *ent = *(const struct ref_entry * const *)ent_;
366 int cmp = strncmp(key->str, ent->name, key->len);
e1980c9d
JH
367 if (cmp)
368 return cmp;
c971ddfd 369 return '\0' - (unsigned char)ent->name[key->len];
e1980c9d
JH
370}
371
432ad41e 372/*
9fc0a648
MH
373 * Return the index of the entry with the given refname from the
374 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if
375 * no such entry is found. dir must already be complete.
432ad41e 376 */
9fc0a648 377static int search_ref_dir(struct ref_dir *dir, const char *refname, size_t len)
bc5fd6d3 378{
e1980c9d
JH
379 struct ref_entry **r;
380 struct string_slice key;
bc5fd6d3 381
432ad41e 382 if (refname == NULL || !dir->nr)
9fc0a648 383 return -1;
bc5fd6d3 384
d3177275 385 sort_ref_dir(dir);
e1980c9d
JH
386 key.len = len;
387 key.str = refname;
388 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
389 ref_entry_cmp_sslice);
bc5fd6d3
MH
390
391 if (r == NULL)
9fc0a648 392 return -1;
bc5fd6d3 393
9fc0a648 394 return r - dir->entries;
bc5fd6d3
MH
395}
396
f348ac92
MH
397/*
398 * Search for a directory entry directly within dir (without
399 * recursing). Sort dir if necessary. subdirname must be a directory
400 * name (i.e., end in '/'). If mkdir is set, then create the
401 * directory if it is missing; otherwise, return NULL if the desired
28e6a34e 402 * directory cannot be found. dir must already be complete.
f348ac92 403 */
3f3aa1bc 404static struct ref_dir *search_for_subdir(struct ref_dir *dir,
dd02e728
RS
405 const char *subdirname, size_t len,
406 int mkdir)
f348ac92 407{
9fc0a648
MH
408 int entry_index = search_ref_dir(dir, subdirname, len);
409 struct ref_entry *entry;
410 if (entry_index == -1) {
f348ac92
MH
411 if (!mkdir)
412 return NULL;
28e6a34e
MH
413 /*
414 * Since dir is complete, the absence of a subdir
415 * means that the subdir really doesn't exist;
416 * therefore, create an empty record for it but mark
417 * the record complete.
418 */
b9146f51 419 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
f348ac92 420 add_entry_to_dir(dir, entry);
9fc0a648
MH
421 } else {
422 entry = dir->entries[entry_index];
f348ac92 423 }
3f3aa1bc 424 return get_ref_dir(entry);
f348ac92
MH
425}
426
432ad41e
MH
427/*
428 * If refname is a reference name, find the ref_dir within the dir
429 * tree that should hold refname. If refname is a directory name
430 * (i.e., ends in '/'), then return that ref_dir itself. dir must
28e6a34e
MH
431 * represent the top-level directory and must already be complete.
432 * Sort ref_dirs and recurse into subdirectories as necessary. If
433 * mkdir is set, then create any missing directories; otherwise,
434 * return NULL if the desired directory cannot be found.
432ad41e
MH
435 */
436static struct ref_dir *find_containing_dir(struct ref_dir *dir,
437 const char *refname, int mkdir)
438{
5fa04418 439 const char *slash;
5fa04418 440 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
dd02e728 441 size_t dirnamelen = slash - refname + 1;
3f3aa1bc 442 struct ref_dir *subdir;
dd02e728 443 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
663c1295
JH
444 if (!subdir) {
445 dir = NULL;
f348ac92 446 break;
432ad41e 447 }
3f3aa1bc 448 dir = subdir;
432ad41e
MH
449 }
450
432ad41e
MH
451 return dir;
452}
453
454/*
455 * Find the value entry with the given name in dir, sorting ref_dirs
456 * and recursing into subdirectories as necessary. If the name is not
457 * found or it corresponds to a directory entry, return NULL.
458 */
459static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
460{
9fc0a648 461 int entry_index;
432ad41e
MH
462 struct ref_entry *entry;
463 dir = find_containing_dir(dir, refname, 0);
464 if (!dir)
465 return NULL;
9fc0a648
MH
466 entry_index = search_ref_dir(dir, refname, strlen(refname));
467 if (entry_index == -1)
468 return NULL;
469 entry = dir->entries[entry_index];
470 return (entry->flag & REF_DIR) ? NULL : entry;
432ad41e
MH
471}
472
506a760d
MH
473/*
474 * Remove the entry with the given name from dir, recursing into
475 * subdirectories as necessary. If refname is the name of a directory
476 * (i.e., ends with '/'), then remove the directory and its contents.
477 * If the removal was successful, return the number of entries
478 * remaining in the directory entry that contained the deleted entry.
479 * If the name was not found, return -1. Please note that this
480 * function only deletes the entry from the cache; it does not delete
481 * it from the filesystem or ensure that other cache entries (which
482 * might be symbolic references to the removed entry) are updated.
483 * Nor does it remove any containing dir entries that might be made
484 * empty by the removal. dir must represent the top-level directory
485 * and must already be complete.
486 */
487static int remove_entry(struct ref_dir *dir, const char *refname)
488{
489 int refname_len = strlen(refname);
490 int entry_index;
491 struct ref_entry *entry;
492 int is_dir = refname[refname_len - 1] == '/';
493 if (is_dir) {
494 /*
495 * refname represents a reference directory. Remove
496 * the trailing slash; otherwise we will get the
497 * directory *representing* refname rather than the
498 * one *containing* it.
499 */
500 char *dirname = xmemdupz(refname, refname_len - 1);
501 dir = find_containing_dir(dir, dirname, 0);
502 free(dirname);
503 } else {
504 dir = find_containing_dir(dir, refname, 0);
505 }
506 if (!dir)
507 return -1;
508 entry_index = search_ref_dir(dir, refname, refname_len);
509 if (entry_index == -1)
510 return -1;
511 entry = dir->entries[entry_index];
512
513 memmove(&dir->entries[entry_index],
514 &dir->entries[entry_index + 1],
515 (dir->nr - entry_index - 1) * sizeof(*dir->entries)
516 );
517 dir->nr--;
518 if (dir->sorted > entry_index)
519 dir->sorted--;
520 free_ref_entry(entry);
521 return dir->nr;
432ad41e
MH
522}
523
524/*
525 * Add a ref_entry to the ref_dir (unsorted), recursing into
526 * subdirectories as necessary. dir must represent the top-level
527 * directory. Return 0 on success.
528 */
529static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
530{
531 dir = find_containing_dir(dir, ref->name, 1);
532 if (!dir)
533 return -1;
534 add_entry_to_dir(dir, ref);
535 return 0;
536}
537
202a56a9
MH
538/*
539 * Emit a warning and return true iff ref1 and ref2 have the same name
540 * and the same sha1. Die if they have the same name but different
541 * sha1s.
542 */
543static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
544{
432ad41e 545 if (strcmp(ref1->name, ref2->name))
202a56a9 546 return 0;
432ad41e
MH
547
548 /* Duplicate name; make sure that they don't conflict: */
549
550 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
551 /* This is impossible by construction */
552 die("Reference directory conflict: %s", ref1->name);
553
554 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
555 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
556
557 warning("Duplicated ref: %s", ref1->name);
558 return 1;
202a56a9
MH
559}
560
e6ed3ca6 561/*
432ad41e
MH
562 * Sort the entries in dir non-recursively (if they are not already
563 * sorted) and remove any duplicate entries.
e6ed3ca6 564 */
d3177275 565static void sort_ref_dir(struct ref_dir *dir)
e9c4c111 566{
202a56a9 567 int i, j;
81a79d8e 568 struct ref_entry *last = NULL;
c774aab9 569
e6ed3ca6
MH
570 /*
571 * This check also prevents passing a zero-length array to qsort(),
572 * which is a problem on some platforms.
573 */
d3177275 574 if (dir->sorted == dir->nr)
e9c4c111 575 return;
c774aab9 576
d3177275 577 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
c774aab9 578
81a79d8e
MH
579 /* Remove any duplicates: */
580 for (i = 0, j = 0; j < dir->nr; j++) {
581 struct ref_entry *entry = dir->entries[j];
582 if (last && is_dup_ref(last, entry))
583 free_ref_entry(entry);
584 else
585 last = dir->entries[i++] = entry;
e9c4c111 586 }
81a79d8e 587 dir->sorted = dir->nr = i;
e9c4c111 588}
c774aab9 589
fcce1703
MH
590/* Include broken references in a do_for_each_ref*() iteration: */
591#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
c774aab9 592
662428f4
MH
593/*
594 * Return true iff the reference described by entry can be resolved to
595 * an object in the database. Emit a warning if the referred-to
596 * object does not exist.
597 */
598static int ref_resolves_to_object(struct ref_entry *entry)
599{
600 if (entry->flag & REF_ISBROKEN)
601 return 0;
602 if (!has_sha1_file(entry->u.value.sha1)) {
603 error("%s does not point to a valid object!", entry->name);
604 return 0;
605 }
606 return 1;
607}
c774aab9 608
7d76fdc8
MH
609/*
610 * current_ref is a performance hack: when iterating over references
611 * using the for_each_ref*() functions, current_ref is set to the
612 * current reference's entry before calling the callback function. If
613 * the callback function calls peel_ref(), then peel_ref() first
614 * checks whether the reference to be peeled is the current reference
615 * (it usually is) and if so, returns that reference's peeled version
616 * if it is available. This avoids a refname lookup in a common case.
617 */
bc5fd6d3 618static struct ref_entry *current_ref;
c774aab9 619
624cac35
MH
620typedef int each_ref_entry_fn(struct ref_entry *entry, void *cb_data);
621
622struct ref_entry_cb {
623 const char *base;
624 int trim;
625 int flags;
626 each_ref_fn *fn;
627 void *cb_data;
628};
629
fcce1703 630/*
624cac35
MH
631 * Handle one reference in a do_for_each_ref*()-style iteration,
632 * calling an each_ref_fn for each entry.
fcce1703 633 */
624cac35 634static int do_one_ref(struct ref_entry *entry, void *cb_data)
bc5fd6d3 635{
624cac35 636 struct ref_entry_cb *data = cb_data;
429213e4 637 int retval;
624cac35 638 if (prefixcmp(entry->name, data->base))
bc5fd6d3 639 return 0;
c774aab9 640
624cac35 641 if (!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
662428f4 642 !ref_resolves_to_object(entry))
bc5fd6d3 643 return 0;
c774aab9 644
bc5fd6d3 645 current_ref = entry;
624cac35
MH
646 retval = data->fn(entry->name + data->trim, entry->u.value.sha1,
647 entry->flag, data->cb_data);
429213e4
MH
648 current_ref = NULL;
649 return retval;
bc5fd6d3 650}
c774aab9 651
c36b5bc2 652/*
d3177275 653 * Call fn for each reference in dir that has index in the range
432ad41e
MH
654 * offset <= index < dir->nr. Recurse into subdirectories that are in
655 * that index range, sorting them before iterating. This function
624cac35
MH
656 * does not sort dir itself; it should be sorted beforehand. fn is
657 * called for all references, including broken ones.
c36b5bc2 658 */
624cac35
MH
659static int do_for_each_entry_in_dir(struct ref_dir *dir, int offset,
660 each_ref_entry_fn fn, void *cb_data)
c36b5bc2
MH
661{
662 int i;
d3177275
MH
663 assert(dir->sorted == dir->nr);
664 for (i = offset; i < dir->nr; i++) {
432ad41e
MH
665 struct ref_entry *entry = dir->entries[i];
666 int retval;
667 if (entry->flag & REF_DIR) {
d7826d54
MH
668 struct ref_dir *subdir = get_ref_dir(entry);
669 sort_ref_dir(subdir);
624cac35 670 retval = do_for_each_entry_in_dir(subdir, 0, fn, cb_data);
432ad41e 671 } else {
624cac35 672 retval = fn(entry, cb_data);
432ad41e 673 }
c36b5bc2
MH
674 if (retval)
675 return retval;
676 }
677 return 0;
678}
679
b3fd060f 680/*
d3177275 681 * Call fn for each reference in the union of dir1 and dir2, in order
432ad41e
MH
682 * by refname. Recurse into subdirectories. If a value entry appears
683 * in both dir1 and dir2, then only process the version that is in
684 * dir2. The input dirs must already be sorted, but subdirs will be
624cac35
MH
685 * sorted as needed. fn is called for all references, including
686 * broken ones.
b3fd060f 687 */
624cac35
MH
688static int do_for_each_entry_in_dirs(struct ref_dir *dir1,
689 struct ref_dir *dir2,
690 each_ref_entry_fn fn, void *cb_data)
b3fd060f
MH
691{
692 int retval;
693 int i1 = 0, i2 = 0;
694
d3177275
MH
695 assert(dir1->sorted == dir1->nr);
696 assert(dir2->sorted == dir2->nr);
432ad41e
MH
697 while (1) {
698 struct ref_entry *e1, *e2;
699 int cmp;
700 if (i1 == dir1->nr) {
624cac35 701 return do_for_each_entry_in_dir(dir2, i2, fn, cb_data);
432ad41e
MH
702 }
703 if (i2 == dir2->nr) {
624cac35 704 return do_for_each_entry_in_dir(dir1, i1, fn, cb_data);
432ad41e
MH
705 }
706 e1 = dir1->entries[i1];
707 e2 = dir2->entries[i2];
708 cmp = strcmp(e1->name, e2->name);
709 if (cmp == 0) {
710 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
711 /* Both are directories; descend them in parallel. */
d7826d54
MH
712 struct ref_dir *subdir1 = get_ref_dir(e1);
713 struct ref_dir *subdir2 = get_ref_dir(e2);
714 sort_ref_dir(subdir1);
715 sort_ref_dir(subdir2);
624cac35
MH
716 retval = do_for_each_entry_in_dirs(
717 subdir1, subdir2, fn, cb_data);
432ad41e
MH
718 i1++;
719 i2++;
720 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
721 /* Both are references; ignore the one from dir1. */
624cac35 722 retval = fn(e2, cb_data);
432ad41e
MH
723 i1++;
724 i2++;
725 } else {
726 die("conflict between reference and directory: %s",
727 e1->name);
728 }
b3fd060f 729 } else {
432ad41e
MH
730 struct ref_entry *e;
731 if (cmp < 0) {
732 e = e1;
b3fd060f 733 i1++;
432ad41e
MH
734 } else {
735 e = e2;
736 i2++;
737 }
738 if (e->flag & REF_DIR) {
d7826d54
MH
739 struct ref_dir *subdir = get_ref_dir(e);
740 sort_ref_dir(subdir);
624cac35
MH
741 retval = do_for_each_entry_in_dir(
742 subdir, 0, fn, cb_data);
432ad41e 743 } else {
624cac35 744 retval = fn(e, cb_data);
b3fd060f
MH
745 }
746 }
747 if (retval)
748 return retval;
749 }
b3fd060f
MH
750}
751
d66da478
MH
752/*
753 * Return true iff refname1 and refname2 conflict with each other.
754 * Two reference names conflict if one of them exactly matches the
755 * leading components of the other; e.g., "foo/bar" conflicts with
756 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
757 * "foo/barbados".
758 */
759static int names_conflict(const char *refname1, const char *refname2)
760{
5a4d4947
MH
761 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
762 ;
763 return (*refname1 == '\0' && *refname2 == '/')
764 || (*refname1 == '/' && *refname2 == '\0');
765}
766
767struct name_conflict_cb {
768 const char *refname;
769 const char *oldrefname;
770 const char *conflicting_refname;
771};
772
624cac35 773static int name_conflict_fn(struct ref_entry *entry, void *cb_data)
5a4d4947
MH
774{
775 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
624cac35 776 if (data->oldrefname && !strcmp(data->oldrefname, entry->name))
5a4d4947 777 return 0;
624cac35
MH
778 if (names_conflict(data->refname, entry->name)) {
779 data->conflicting_refname = entry->name;
5a4d4947 780 return 1;
d66da478 781 }
5a4d4947 782 return 0;
d66da478
MH
783}
784
bc5fd6d3
MH
785/*
786 * Return true iff a reference named refname could be created without
624cac35 787 * conflicting with the name of an existing reference in dir. If
5a4d4947
MH
788 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
789 * (e.g., because oldrefname is scheduled for deletion in the same
bc5fd6d3
MH
790 * operation).
791 */
792static int is_refname_available(const char *refname, const char *oldrefname,
d3177275 793 struct ref_dir *dir)
bc5fd6d3 794{
5a4d4947
MH
795 struct name_conflict_cb data;
796 data.refname = refname;
797 data.oldrefname = oldrefname;
798 data.conflicting_refname = NULL;
799
d3177275 800 sort_ref_dir(dir);
624cac35 801 if (do_for_each_entry_in_dir(dir, 0, name_conflict_fn, &data)) {
5a4d4947
MH
802 error("'%s' exists; cannot create '%s'",
803 data.conflicting_refname, refname);
804 return 0;
bc5fd6d3
MH
805 }
806 return 1;
e1e22e37
LT
807}
808
2fff7812
MH
809struct packed_ref_cache {
810 struct ref_entry *root;
811};
812
5e290ff7
JH
813/*
814 * Future: need to be in "struct repository"
815 * when doing a full libification.
816 */
79c7ca54
MH
817static struct ref_cache {
818 struct ref_cache *next;
d12229f5 819 struct ref_entry *loose;
2fff7812 820 struct packed_ref_cache *packed;
9da31cb0
MH
821 /*
822 * The submodule name, or "" for the main repo. We allocate
823 * length 1 rather than FLEX_ARRAY so that the main ref_cache
824 * is initialized correctly.
825 */
826 char name[1];
827} ref_cache, *submodule_ref_caches;
0e88c130 828
760c4512 829static void clear_packed_ref_cache(struct ref_cache *refs)
e1e22e37 830{
d12229f5 831 if (refs->packed) {
2fff7812
MH
832 free_ref_entry(refs->packed->root);
833 free(refs->packed);
d12229f5
MH
834 refs->packed = NULL;
835 }
5e290ff7 836}
e1e22e37 837
760c4512
MH
838static void clear_loose_ref_cache(struct ref_cache *refs)
839{
d12229f5
MH
840 if (refs->loose) {
841 free_ref_entry(refs->loose);
842 refs->loose = NULL;
843 }
760c4512
MH
844}
845
79c7ca54 846static struct ref_cache *create_ref_cache(const char *submodule)
e5dbf605 847{
ce40979c 848 int len;
79c7ca54 849 struct ref_cache *refs;
ce40979c
MH
850 if (!submodule)
851 submodule = "";
852 len = strlen(submodule) + 1;
79c7ca54 853 refs = xcalloc(1, sizeof(struct ref_cache) + len);
ce40979c 854 memcpy(refs->name, submodule, len);
e5dbf605
MH
855 return refs;
856}
857
4349a668 858/*
79c7ca54 859 * Return a pointer to a ref_cache for the specified submodule. For
4349a668
MH
860 * the main repository, use submodule==NULL. The returned structure
861 * will be allocated and initialized but not necessarily populated; it
862 * should not be freed.
863 */
79c7ca54 864static struct ref_cache *get_ref_cache(const char *submodule)
4349a668 865{
9da31cb0
MH
866 struct ref_cache *refs;
867
868 if (!submodule || !*submodule)
869 return &ref_cache;
870
871 for (refs = submodule_ref_caches; refs; refs = refs->next)
0e88c130
MH
872 if (!strcmp(submodule, refs->name))
873 return refs;
0e88c130 874
79c7ca54 875 refs = create_ref_cache(submodule);
9da31cb0
MH
876 refs->next = submodule_ref_caches;
877 submodule_ref_caches = refs;
0e88c130 878 return refs;
4349a668
MH
879}
880
8be8bde7 881void invalidate_ref_cache(const char *submodule)
f130b116 882{
c5f29abd
MH
883 struct ref_cache *refs = get_ref_cache(submodule);
884 clear_packed_ref_cache(refs);
885 clear_loose_ref_cache(refs);
5e290ff7 886}
e1e22e37 887
3feb4f0c
MH
888/* The length of a peeled reference line in packed-refs, including EOL: */
889#define PEELED_LINE_LENGTH 42
890
694b7a19
MH
891/*
892 * The packed-refs header line that we write out. Perhaps other
893 * traits will be added later. The trailing space is required.
894 */
895static const char PACKED_REFS_HEADER[] =
896 "# pack-refs with: peeled fully-peeled \n";
897
bc5fd6d3
MH
898/*
899 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
900 * Return a pointer to the refname within the line (null-terminated),
901 * or NULL if there was a problem.
902 */
903static const char *parse_ref_line(char *line, unsigned char *sha1)
904{
905 /*
906 * 42: the answer to everything.
907 *
908 * In this case, it happens to be the answer to
909 * 40 (length of sha1 hex representation)
910 * +1 (space in between hex and name)
911 * +1 (newline at the end of the line)
912 */
913 int len = strlen(line) - 42;
914
915 if (len <= 0)
916 return NULL;
917 if (get_sha1_hex(line, sha1) < 0)
918 return NULL;
919 if (!isspace(line[40]))
920 return NULL;
921 line += 41;
922 if (isspace(*line))
923 return NULL;
924 if (line[len] != '\n')
925 return NULL;
926 line[len] = 0;
927
928 return line;
929}
930
c29c46fa
MH
931/*
932 * Read f, which is a packed-refs file, into dir.
933 *
934 * A comment line of the form "# pack-refs with: " may contain zero or
935 * more traits. We interpret the traits as follows:
936 *
937 * No traits:
938 *
939 * Probably no references are peeled. But if the file contains a
940 * peeled value for a reference, we will use it.
941 *
942 * peeled:
943 *
944 * References under "refs/tags/", if they *can* be peeled, *are*
945 * peeled in this file. References outside of "refs/tags/" are
946 * probably not peeled even if they could have been, but if we find
947 * a peeled value for such a reference we will use it.
948 *
949 * fully-peeled:
950 *
951 * All references in the file that can be peeled are peeled.
952 * Inversely (and this is more important), any references in the
953 * file for which no peeled value is recorded is not peelable. This
954 * trait should typically be written alongside "peeled" for
955 * compatibility with older clients, but we do not require it
956 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
957 */
d3177275 958static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 959{
e9c4c111 960 struct ref_entry *last = NULL;
f4204ab9 961 char refline[PATH_MAX];
c29c46fa 962 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
963
964 while (fgets(refline, sizeof(refline), f)) {
965 unsigned char sha1[20];
dfefa935 966 const char *refname;
f4204ab9
JH
967 static const char header[] = "# pack-refs with:";
968
969 if (!strncmp(refline, header, sizeof(header)-1)) {
970 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
971 if (strstr(traits, " fully-peeled "))
972 peeled = PEELED_FULLY;
973 else if (strstr(traits, " peeled "))
974 peeled = PEELED_TAGS;
f4204ab9
JH
975 /* perhaps other traits later as well */
976 continue;
977 }
978
dfefa935
MH
979 refname = parse_ref_line(refline, sha1);
980 if (refname) {
c29c46fa
MH
981 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
982 if (peeled == PEELED_FULLY ||
983 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
984 last->flag |= REF_KNOWS_PEELED;
d3177275 985 add_ref(dir, last);
f4204ab9
JH
986 continue;
987 }
988 if (last &&
989 refline[0] == '^' &&
3feb4f0c
MH
990 strlen(refline) == PEELED_LINE_LENGTH &&
991 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 992 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 993 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
994 /*
995 * Regardless of what the file header said,
996 * we definitely know the value of *this*
997 * reference:
998 */
999 last->flag |= REF_KNOWS_PEELED;
1000 }
f4204ab9 1001 }
f4204ab9
JH
1002}
1003
2fff7812
MH
1004/*
1005 * Get the packed_ref_cache for the specified ref_cache, creating it
1006 * if necessary.
1007 */
1008static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)
5e290ff7 1009{
d12229f5 1010 if (!refs->packed) {
4349a668
MH
1011 const char *packed_refs_file;
1012 FILE *f;
0bad611b 1013
2fff7812
MH
1014 refs->packed = xcalloc(1, sizeof(*refs->packed));
1015 refs->packed->root = create_dir_entry(refs, "", 0, 0);
316b097a
MH
1016 if (*refs->name)
1017 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
4349a668
MH
1018 else
1019 packed_refs_file = git_path("packed-refs");
1020 f = fopen(packed_refs_file, "r");
e1e22e37 1021 if (f) {
2fff7812 1022 read_packed_refs(f, get_ref_dir(refs->packed->root));
e1e22e37 1023 fclose(f);
e1e22e37 1024 }
e1e22e37 1025 }
2fff7812
MH
1026 return refs->packed;
1027}
1028
1029static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)
1030{
1031 return get_ref_dir(packed_ref_cache->root);
1032}
1033
1034static struct ref_dir *get_packed_refs(struct ref_cache *refs)
1035{
1036 return get_packed_ref_dir(get_packed_ref_cache(refs));
e1e22e37
LT
1037}
1038
30249ee6
MH
1039void add_packed_ref(const char *refname, const unsigned char *sha1)
1040{
9da31cb0
MH
1041 add_ref(get_packed_refs(&ref_cache),
1042 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
30249ee6
MH
1043}
1044
abc39098 1045/*
28e6a34e
MH
1046 * Read the loose references from the namespace dirname into dir
1047 * (without recursing). dirname must end with '/'. dir must be the
1048 * directory entry corresponding to dirname.
abc39098 1049 */
423a1afc 1050static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 1051{
423a1afc 1052 struct ref_cache *refs = dir->ref_cache;
d3177275 1053 DIR *d;
0bad611b 1054 const char *path;
d5fdae67 1055 struct dirent *de;
abc39098 1056 int dirnamelen = strlen(dirname);
72b64b44 1057 struct strbuf refname;
0bad611b 1058
3b124823 1059 if (*refs->name)
66a3d20b 1060 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 1061 else
66a3d20b 1062 path = git_path("%s", dirname);
0bad611b 1063
d3177275 1064 d = opendir(path);
d5fdae67
MH
1065 if (!d)
1066 return;
1067
66a3d20b
MH
1068 strbuf_init(&refname, dirnamelen + 257);
1069 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
1070
1071 while ((de = readdir(d)) != NULL) {
1072 unsigned char sha1[20];
1073 struct stat st;
1074 int flag;
d5fdae67
MH
1075 const char *refdir;
1076
1077 if (de->d_name[0] == '.')
1078 continue;
d5fdae67
MH
1079 if (has_extension(de->d_name, ".lock"))
1080 continue;
72b64b44 1081 strbuf_addstr(&refname, de->d_name);
d5fdae67 1082 refdir = *refs->name
72b64b44
MH
1083 ? git_path_submodule(refs->name, "%s", refname.buf)
1084 : git_path("%s", refname.buf);
1085 if (stat(refdir, &st) < 0) {
1086 ; /* silently ignore */
1087 } else if (S_ISDIR(st.st_mode)) {
abc39098 1088 strbuf_addch(&refname, '/');
28e6a34e 1089 add_entry_to_dir(dir,
b9146f51
RS
1090 create_dir_entry(refs, refname.buf,
1091 refname.len, 1));
72b64b44 1092 } else {
3b124823 1093 if (*refs->name) {
f8948e2f 1094 hashclr(sha1);
0bad611b 1095 flag = 0;
72b64b44 1096 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1097 hashclr(sha1);
98ac34b2 1098 flag |= REF_ISBROKEN;
0bad611b 1099 }
72b64b44 1100 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1101 hashclr(sha1);
1102 flag |= REF_ISBROKEN;
1103 }
9f2fb4a3
MH
1104 add_entry_to_dir(dir,
1105 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1106 }
66a3d20b 1107 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1108 }
72b64b44 1109 strbuf_release(&refname);
d5fdae67 1110 closedir(d);
e1e22e37
LT
1111}
1112
d3177275 1113static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1114{
d12229f5 1115 if (!refs->loose) {
28e6a34e
MH
1116 /*
1117 * Mark the top-level directory complete because we
1118 * are about to read the only subdirectory that can
1119 * hold references:
1120 */
b9146f51 1121 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1122 /*
1123 * Create an incomplete entry for "refs/":
1124 */
1125 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1126 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1127 }
d7826d54 1128 return get_ref_dir(refs->loose);
e1e22e37
LT
1129}
1130
ca8db142
LT
1131/* We allow "recursive" symbolic refs. Only within reason, though */
1132#define MAXDEPTH 5
0ebde32c
LT
1133#define MAXREFLEN (1024)
1134
e5fa45c1
JH
1135/*
1136 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1137 * from the loose refs in ref_cache refs. Find <refname> in the
1138 * packed-refs file for the submodule.
e5fa45c1 1139 */
b0626608 1140static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1141 const char *refname, unsigned char *sha1)
0ebde32c 1142{
2c5c66be 1143 struct ref_entry *ref;
d3177275 1144 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1145
432ad41e 1146 ref = find_ref(dir, refname);
b0626608
MH
1147 if (ref == NULL)
1148 return -1;
1149
593f1bb8 1150 memcpy(sha1, ref->u.value.sha1, 20);
b0626608 1151 return 0;
0ebde32c
LT
1152}
1153
b0626608 1154static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1155 const char *refname, unsigned char *sha1,
dfefa935 1156 int recursion)
0ebde32c 1157{
064d51dc 1158 int fd, len;
0ebde32c 1159 char buffer[128], *p;
064d51dc 1160 char *path;
0ebde32c 1161
064d51dc 1162 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1163 return -1;
064d51dc
MH
1164 path = *refs->name
1165 ? git_path_submodule(refs->name, "%s", refname)
1166 : git_path("%s", refname);
1167 fd = open(path, O_RDONLY);
0ebde32c 1168 if (fd < 0)
b0626608 1169 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1170
1171 len = read(fd, buffer, sizeof(buffer)-1);
1172 close(fd);
1173 if (len < 0)
1174 return -1;
1175 while (len && isspace(buffer[len-1]))
1176 len--;
1177 buffer[len] = 0;
1178
1179 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1180 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1181 return 0;
1182
1183 /* Symref? */
1184 if (strncmp(buffer, "ref:", 4))
1185 return -1;
1186 p = buffer + 4;
1187 while (isspace(*p))
1188 p++;
1189
064d51dc 1190 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1191}
1192
85be1fe3 1193int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1194{
1195 int len = strlen(path), retval;
064d51dc 1196 char *submodule;
b0626608 1197 struct ref_cache *refs;
0ebde32c
LT
1198
1199 while (len && path[len-1] == '/')
1200 len--;
1201 if (!len)
1202 return -1;
b0626608
MH
1203 submodule = xstrndup(path, len);
1204 refs = get_ref_cache(submodule);
1205 free(submodule);
1206
064d51dc 1207 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1208 return retval;
1209}
ca8db142 1210
4886b89f 1211/*
63331581
MH
1212 * Return the ref_entry for the given refname from the packed
1213 * references. If it does not exist, return NULL.
4886b89f 1214 */
63331581 1215static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1216{
9da31cb0 1217 return find_ref(get_packed_refs(&ref_cache), refname);
c224ca7f
MH
1218}
1219
8d68493f 1220const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1221{
0104ca09
HO
1222 int depth = MAXDEPTH;
1223 ssize_t len;
a876ed83 1224 char buffer[256];
dfefa935 1225 static char refname_buffer[256];
ca8db142 1226
8da19775
JH
1227 if (flag)
1228 *flag = 0;
1229
dfefa935 1230 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
8384d788
MH
1231 return NULL;
1232
a876ed83 1233 for (;;) {
55956350 1234 char path[PATH_MAX];
a876ed83
JH
1235 struct stat st;
1236 char *buf;
1237 int fd;
8a65ff76 1238
a876ed83
JH
1239 if (--depth < 0)
1240 return NULL;
ca8db142 1241
dfefa935 1242 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1243
a876ed83 1244 if (lstat(path, &st) < 0) {
63331581
MH
1245 struct ref_entry *entry;
1246
c224ca7f
MH
1247 if (errno != ENOENT)
1248 return NULL;
1249 /*
1250 * The loose reference file does not exist;
1251 * check for a packed reference.
1252 */
63331581
MH
1253 entry = get_packed_ref(refname);
1254 if (entry) {
1255 hashcpy(sha1, entry->u.value.sha1);
c224ca7f
MH
1256 if (flag)
1257 *flag |= REF_ISPACKED;
dfefa935 1258 return refname;
434cd0cd 1259 }
c224ca7f
MH
1260 /* The reference is not a packed reference, either. */
1261 if (reading) {
a876ed83 1262 return NULL;
c224ca7f
MH
1263 } else {
1264 hashclr(sha1);
dfefa935 1265 return refname;
c224ca7f 1266 }
a876ed83 1267 }
ca8db142 1268
a876ed83
JH
1269 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1270 if (S_ISLNK(st.st_mode)) {
1271 len = readlink(path, buffer, sizeof(buffer)-1);
7bb2bf8e
MH
1272 if (len < 0)
1273 return NULL;
b54cb795 1274 buffer[len] = 0;
1f58a038
MH
1275 if (!prefixcmp(buffer, "refs/") &&
1276 !check_refname_format(buffer, 0)) {
dfefa935
MH
1277 strcpy(refname_buffer, buffer);
1278 refname = refname_buffer;
8da19775
JH
1279 if (flag)
1280 *flag |= REF_ISSYMREF;
a876ed83
JH
1281 continue;
1282 }
ca8db142 1283 }
a876ed83 1284
7a21632f
DS
1285 /* Is it a directory? */
1286 if (S_ISDIR(st.st_mode)) {
1287 errno = EISDIR;
1288 return NULL;
1289 }
1290
a876ed83
JH
1291 /*
1292 * Anything else, just open it and try to use it as
1293 * a ref
1294 */
1295 fd = open(path, O_RDONLY);
1296 if (fd < 0)
1297 return NULL;
93d26e4c 1298 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83 1299 close(fd);
28775050
MH
1300 if (len < 0)
1301 return NULL;
1302 while (len && isspace(buffer[len-1]))
1303 len--;
1304 buffer[len] = '\0';
a876ed83
JH
1305
1306 /*
1307 * Is it a symbolic ref?
1308 */
28775050 1309 if (prefixcmp(buffer, "ref:"))
a876ed83 1310 break;
55956350
JH
1311 if (flag)
1312 *flag |= REF_ISSYMREF;
a876ed83 1313 buf = buffer + 4;
28775050
MH
1314 while (isspace(*buf))
1315 buf++;
313fb010 1316 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1317 if (flag)
1318 *flag |= REF_ISBROKEN;
313fb010
MH
1319 return NULL;
1320 }
dfefa935 1321 refname = strcpy(refname_buffer, buf);
8a65ff76 1322 }
f989fea0
MH
1323 /* Please note that FETCH_HEAD has a second line containing other data. */
1324 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
55956350
JH
1325 if (flag)
1326 *flag |= REF_ISBROKEN;
a876ed83 1327 return NULL;
629cd3ac 1328 }
dfefa935 1329 return refname;
a876ed83
JH
1330}
1331
96ec7b1e
NTND
1332char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1333{
8cad4744 1334 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1335 return ret ? xstrdup(ret) : NULL;
1336}
1337
d08bae7e
IL
1338/* The argument to filter_refs */
1339struct ref_filter {
1340 const char *pattern;
1341 each_ref_fn *fn;
1342 void *cb_data;
1343};
1344
dfefa935 1345int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1346{
8d68493f 1347 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1348 return 0;
1349 return -1;
8a65ff76
LT
1350}
1351
dfefa935 1352int read_ref(const char *refname, unsigned char *sha1)
c6893323 1353{
dfefa935 1354 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1355}
1356
bc5fd6d3 1357int ref_exists(const char *refname)
ef06b918 1358{
bc5fd6d3
MH
1359 unsigned char sha1[20];
1360 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1361}
1362
85be1fe3 1363static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1364 void *data)
d08bae7e
IL
1365{
1366 struct ref_filter *filter = (struct ref_filter *)data;
dfefa935 1367 if (fnmatch(filter->pattern, refname, 0))
d08bae7e 1368 return 0;
85be1fe3 1369 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1370}
1371
68cf8703
MH
1372enum peel_status {
1373 /* object was peeled successfully: */
1374 PEEL_PEELED = 0,
1375
1376 /*
1377 * object cannot be peeled because the named object (or an
1378 * object referred to by a tag in the peel chain), does not
1379 * exist.
1380 */
1381 PEEL_INVALID = -1,
1382
1383 /* object cannot be peeled because it is not a tag: */
9a489f3c
MH
1384 PEEL_NON_TAG = -2,
1385
1386 /* ref_entry contains no peeled value because it is a symref: */
1387 PEEL_IS_SYMREF = -3,
1388
1389 /*
1390 * ref_entry cannot be peeled because it is broken (i.e., the
1391 * symbolic reference cannot even be resolved to an object
1392 * name):
1393 */
1394 PEEL_BROKEN = -4
68cf8703
MH
1395};
1396
cb2ae1c4
MH
1397/*
1398 * Peel the named object; i.e., if the object is a tag, resolve the
68cf8703
MH
1399 * tag recursively until a non-tag is found. If successful, store the
1400 * result to sha1 and return PEEL_PEELED. If the object is not a tag
1401 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,
1402 * and leave sha1 unchanged.
cb2ae1c4 1403 */
68cf8703 1404static enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
cb2ae1c4
MH
1405{
1406 struct object *o = lookup_unknown_object(name);
1407
1408 if (o->type == OBJ_NONE) {
1409 int type = sha1_object_info(name, NULL);
1410 if (type < 0)
68cf8703 1411 return PEEL_INVALID;
cb2ae1c4
MH
1412 o->type = type;
1413 }
1414
1415 if (o->type != OBJ_TAG)
68cf8703 1416 return PEEL_NON_TAG;
cb2ae1c4
MH
1417
1418 o = deref_tag_noverify(o);
1419 if (!o)
68cf8703 1420 return PEEL_INVALID;
cb2ae1c4
MH
1421
1422 hashcpy(sha1, o->sha1);
68cf8703 1423 return PEEL_PEELED;
cb2ae1c4
MH
1424}
1425
9a489f3c 1426/*
f85354b5
MH
1427 * Peel the entry (if possible) and return its new peel_status. If
1428 * repeel is true, re-peel the entry even if there is an old peeled
1429 * value that is already stored in it.
694b7a19
MH
1430 *
1431 * It is OK to call this function with a packed reference entry that
1432 * might be stale and might even refer to an object that has since
1433 * been garbage-collected. In such a case, if the entry has
1434 * REF_KNOWS_PEELED then leave the status unchanged and return
1435 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.
9a489f3c 1436 */
f85354b5 1437static enum peel_status peel_entry(struct ref_entry *entry, int repeel)
9a489f3c
MH
1438{
1439 enum peel_status status;
1440
f85354b5
MH
1441 if (entry->flag & REF_KNOWS_PEELED) {
1442 if (repeel) {
1443 entry->flag &= ~REF_KNOWS_PEELED;
1444 hashclr(entry->u.value.peeled);
1445 } else {
1446 return is_null_sha1(entry->u.value.peeled) ?
1447 PEEL_NON_TAG : PEEL_PEELED;
1448 }
1449 }
9a489f3c
MH
1450 if (entry->flag & REF_ISBROKEN)
1451 return PEEL_BROKEN;
1452 if (entry->flag & REF_ISSYMREF)
1453 return PEEL_IS_SYMREF;
1454
1455 status = peel_object(entry->u.value.sha1, entry->u.value.peeled);
1456 if (status == PEEL_PEELED || status == PEEL_NON_TAG)
1457 entry->flag |= REF_KNOWS_PEELED;
1458 return status;
1459}
1460
dfefa935 1461int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1462{
1463 int flag;
1464 unsigned char base[20];
cf0adba7 1465
dfefa935 1466 if (current_ref && (current_ref->name == refname
9a489f3c 1467 || !strcmp(current_ref->name, refname))) {
f85354b5 1468 if (peel_entry(current_ref, 0))
9a489f3c
MH
1469 return -1;
1470 hashcpy(sha1, current_ref->u.value.peeled);
1471 return 0;
0ae91be0
SP
1472 }
1473
dfefa935 1474 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1475 return -1;
1476
9a489f3c
MH
1477 /*
1478 * If the reference is packed, read its ref_entry from the
1479 * cache in the hope that we already know its peeled value.
1480 * We only try this optimization on packed references because
1481 * (a) forcing the filling of the loose reference cache could
1482 * be expensive and (b) loose references anyway usually do not
1483 * have REF_KNOWS_PEELED.
1484 */
1485 if (flag & REF_ISPACKED) {
f361baeb 1486 struct ref_entry *r = get_packed_ref(refname);
9a489f3c 1487 if (r) {
f85354b5 1488 if (peel_entry(r, 0))
9a489f3c 1489 return -1;
593f1bb8 1490 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1491 return 0;
cf0adba7 1492 }
cf0adba7
JH
1493 }
1494
cb2ae1c4 1495 return peel_object(base, sha1);
cf0adba7
JH
1496}
1497
bc5fd6d3
MH
1498struct warn_if_dangling_data {
1499 FILE *fp;
1500 const char *refname;
1501 const char *msg_fmt;
1502};
1503
1504static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1505 int flags, void *cb_data)
1506{
1507 struct warn_if_dangling_data *d = cb_data;
1508 const char *resolves_to;
1509 unsigned char junk[20];
1510
1511 if (!(flags & REF_ISSYMREF))
1512 return 0;
1513
1514 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1515 if (!resolves_to || strcmp(resolves_to, d->refname))
1516 return 0;
1517
1518 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1519 fputc('\n', d->fp);
bc5fd6d3
MH
1520 return 0;
1521}
1522
1523void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1524{
1525 struct warn_if_dangling_data data;
1526
1527 data.fp = fp;
1528 data.refname = refname;
1529 data.msg_fmt = msg_fmt;
1530 for_each_rawref(warn_if_dangling_symref, &data);
1531}
1532
fcce1703 1533/*
65cf102b 1534 * Call fn for each reference in the specified ref_cache, omitting
624cac35
MH
1535 * references not in the containing_dir of base. fn is called for all
1536 * references, including broken ones. If fn ever returns a non-zero
fcce1703
MH
1537 * value, stop the iteration and return that value; otherwise, return
1538 * 0.
1539 */
65cf102b 1540static int do_for_each_entry(struct ref_cache *refs, const char *base,
624cac35 1541 each_ref_entry_fn fn, void *cb_data)
8a65ff76 1542{
933ac036
MH
1543 struct ref_dir *packed_dir = get_packed_refs(refs);
1544 struct ref_dir *loose_dir = get_loose_refs(refs);
1545 int retval = 0;
1546
1547 if (base && *base) {
1548 packed_dir = find_containing_dir(packed_dir, base, 0);
1549 loose_dir = find_containing_dir(loose_dir, base, 0);
1550 }
1551
1552 if (packed_dir && loose_dir) {
1553 sort_ref_dir(packed_dir);
1554 sort_ref_dir(loose_dir);
624cac35
MH
1555 retval = do_for_each_entry_in_dirs(
1556 packed_dir, loose_dir, fn, cb_data);
933ac036
MH
1557 } else if (packed_dir) {
1558 sort_ref_dir(packed_dir);
624cac35
MH
1559 retval = do_for_each_entry_in_dir(
1560 packed_dir, 0, fn, cb_data);
933ac036
MH
1561 } else if (loose_dir) {
1562 sort_ref_dir(loose_dir);
624cac35
MH
1563 retval = do_for_each_entry_in_dir(
1564 loose_dir, 0, fn, cb_data);
933ac036
MH
1565 }
1566
1567 return retval;
8a65ff76
LT
1568}
1569
624cac35 1570/*
65cf102b 1571 * Call fn for each reference in the specified ref_cache for which the
624cac35
MH
1572 * refname begins with base. If trim is non-zero, then trim that many
1573 * characters off the beginning of each refname before passing the
1574 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1575 * broken references in the iteration. If fn ever returns a non-zero
1576 * value, stop the iteration and return that value; otherwise, return
1577 * 0.
1578 */
65cf102b
MH
1579static int do_for_each_ref(struct ref_cache *refs, const char *base,
1580 each_ref_fn fn, int trim, int flags, void *cb_data)
624cac35
MH
1581{
1582 struct ref_entry_cb data;
1583 data.base = base;
1584 data.trim = trim;
1585 data.flags = flags;
1586 data.fn = fn;
1587 data.cb_data = cb_data;
1588
65cf102b 1589 return do_for_each_entry(refs, base, do_one_ref, &data);
624cac35
MH
1590}
1591
0bad611b 1592static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1593{
1594 unsigned char sha1[20];
8da19775
JH
1595 int flag;
1596
0bad611b
HV
1597 if (submodule) {
1598 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1599 return fn("HEAD", sha1, 0, cb_data);
1600
1601 return 0;
1602 }
1603
c6893323 1604 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1605 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1606
2f34ba32 1607 return 0;
723c31fe
LT
1608}
1609
0bad611b
HV
1610int head_ref(each_ref_fn fn, void *cb_data)
1611{
1612 return do_head_ref(NULL, fn, cb_data);
1613}
1614
9ef6aeb0
HV
1615int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1616{
1617 return do_head_ref(submodule, fn, cb_data);
1618}
1619
cb5d709f 1620int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1621{
9da31cb0 1622 return do_for_each_ref(&ref_cache, "", fn, 0, 0, cb_data);
a62be77f
SE
1623}
1624
9ef6aeb0
HV
1625int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1626{
65cf102b 1627 return do_for_each_ref(get_ref_cache(submodule), "", fn, 0, 0, cb_data);
a62be77f
SE
1628}
1629
2a8177b6
CC
1630int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1631{
9da31cb0 1632 return do_for_each_ref(&ref_cache, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1633}
1634
9ef6aeb0
HV
1635int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1636 each_ref_fn fn, void *cb_data)
1637{
65cf102b 1638 return do_for_each_ref(get_ref_cache(submodule), prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1639}
1640
cb5d709f 1641int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1642{
2a8177b6 1643 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1644}
1645
9ef6aeb0
HV
1646int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1647{
1648 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1649}
1650
cb5d709f 1651int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1652{
2a8177b6 1653 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1654}
1655
9ef6aeb0
HV
1656int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1657{
1658 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1659}
1660
cb5d709f 1661int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1662{
2a8177b6 1663 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1664}
1665
9ef6aeb0
HV
1666int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1667{
1668 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1669}
1670
29268700
CC
1671int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1672{
9da31cb0 1673 return do_for_each_ref(&ref_cache, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1674}
1675
a1bea2c1
JT
1676int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1677{
1678 struct strbuf buf = STRBUF_INIT;
1679 int ret = 0;
1680 unsigned char sha1[20];
1681 int flag;
1682
1683 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1684 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1685 ret = fn(buf.buf, sha1, flag, cb_data);
1686 strbuf_release(&buf);
1687
1688 return ret;
1689}
1690
1691int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1692{
1693 struct strbuf buf = STRBUF_INIT;
1694 int ret;
1695 strbuf_addf(&buf, "%srefs/", get_git_namespace());
9da31cb0 1696 ret = do_for_each_ref(&ref_cache, buf.buf, fn, 0, 0, cb_data);
a1bea2c1
JT
1697 strbuf_release(&buf);
1698 return ret;
1699}
1700
b09fe971
IL
1701int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1702 const char *prefix, void *cb_data)
d08bae7e
IL
1703{
1704 struct strbuf real_pattern = STRBUF_INIT;
1705 struct ref_filter filter;
d08bae7e
IL
1706 int ret;
1707
b09fe971 1708 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 1709 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1710 else if (prefix)
1711 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1712 strbuf_addstr(&real_pattern, pattern);
1713
894a9d33 1714 if (!has_glob_specials(pattern)) {
9517e6b8 1715 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1716 if (real_pattern.buf[real_pattern.len - 1] != '/')
1717 strbuf_addch(&real_pattern, '/');
1718 /* No need to check for '*', there is none. */
1719 strbuf_addch(&real_pattern, '*');
1720 }
1721
1722 filter.pattern = real_pattern.buf;
1723 filter.fn = fn;
1724 filter.cb_data = cb_data;
1725 ret = for_each_ref(filter_refs, &filter);
1726
1727 strbuf_release(&real_pattern);
1728 return ret;
1729}
1730
b09fe971
IL
1731int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1732{
1733 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1734}
1735
f8948e2f
JH
1736int for_each_rawref(each_ref_fn fn, void *cb_data)
1737{
9da31cb0 1738 return do_for_each_ref(&ref_cache, "", fn, 0,
f8948e2f 1739 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1740}
1741
4577e483 1742const char *prettify_refname(const char *name)
a9c37a72 1743{
a9c37a72
DB
1744 return name + (
1745 !prefixcmp(name, "refs/heads/") ? 11 :
1746 !prefixcmp(name, "refs/tags/") ? 10 :
1747 !prefixcmp(name, "refs/remotes/") ? 13 :
1748 0);
1749}
1750
79803322
SP
1751const char *ref_rev_parse_rules[] = {
1752 "%.*s",
1753 "refs/%.*s",
1754 "refs/tags/%.*s",
1755 "refs/heads/%.*s",
1756 "refs/remotes/%.*s",
1757 "refs/remotes/%.*s/HEAD",
1758 NULL
1759};
1760
1761int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1762{
1763 const char **p;
1764 const int abbrev_name_len = strlen(abbrev_name);
1765
1766 for (p = rules; *p; p++) {
1767 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1768 return 1;
1769 }
1770 }
1771
1772 return 0;
1773}
1774
e5f38ec3 1775static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1776 const unsigned char *old_sha1, int mustexist)
1777{
c6893323 1778 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1779 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1780 unlock_ref(lock);
1781 return NULL;
1782 }
a89fccd2 1783 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1784 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1785 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1786 unlock_ref(lock);
1787 return NULL;
1788 }
1789 return lock;
1790}
1791
7155b727 1792static int remove_empty_directories(const char *file)
bc7127ef
JH
1793{
1794 /* we want to create a file but there is a directory there;
1795 * if that is an empty directory (or a directory that contains
1796 * only empty directories), remove them.
1797 */
7155b727
JS
1798 struct strbuf path;
1799 int result;
bc7127ef 1800
7155b727
JS
1801 strbuf_init(&path, 20);
1802 strbuf_addstr(&path, file);
1803
a0f4afbe 1804 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1805
1806 strbuf_release(&path);
1807
1808 return result;
bc7127ef
JH
1809}
1810
ff74f7f1
JH
1811/*
1812 * *string and *len will only be substituted, and *string returned (for
1813 * later free()ing) if the string passed in is a magic short-hand form
1814 * to name a branch.
1815 */
1816static char *substitute_branch_name(const char **string, int *len)
1817{
1818 struct strbuf buf = STRBUF_INIT;
1819 int ret = interpret_branch_name(*string, &buf);
1820
1821 if (ret == *len) {
1822 size_t size;
1823 *string = strbuf_detach(&buf, &size);
1824 *len = size;
1825 return (char *)*string;
1826 }
1827
1828 return NULL;
1829}
1830
1831int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1832{
1833 char *last_branch = substitute_branch_name(&str, &len);
1834 const char **p, *r;
1835 int refs_found = 0;
1836
1837 *ref = NULL;
1838 for (p = ref_rev_parse_rules; *p; p++) {
1839 char fullref[PATH_MAX];
1840 unsigned char sha1_from_ref[20];
1841 unsigned char *this_result;
1842 int flag;
1843
1844 this_result = refs_found ? sha1_from_ref : sha1;
1845 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1846 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1847 if (r) {
1848 if (!refs_found++)
1849 *ref = xstrdup(r);
1850 if (!warn_ambiguous_refs)
1851 break;
55956350 1852 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1853 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1854 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1855 warning("ignoring broken ref %s.", fullref);
1856 }
ff74f7f1
JH
1857 }
1858 free(last_branch);
1859 return refs_found;
1860}
1861
1862int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1863{
1864 char *last_branch = substitute_branch_name(&str, &len);
1865 const char **p;
1866 int logs_found = 0;
1867
1868 *log = NULL;
1869 for (p = ref_rev_parse_rules; *p; p++) {
1870 struct stat st;
1871 unsigned char hash[20];
1872 char path[PATH_MAX];
1873 const char *ref, *it;
1874
1875 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 1876 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
1877 if (!ref)
1878 continue;
1879 if (!stat(git_path("logs/%s", path), &st) &&
1880 S_ISREG(st.st_mode))
1881 it = path;
1882 else if (strcmp(ref, path) &&
1883 !stat(git_path("logs/%s", ref), &st) &&
1884 S_ISREG(st.st_mode))
1885 it = ref;
1886 else
1887 continue;
1888 if (!logs_found++) {
1889 *log = xstrdup(it);
1890 hashcpy(sha1, hash);
1891 }
1892 if (!warn_ambiguous_refs)
1893 break;
1894 }
1895 free(last_branch);
1896 return logs_found;
1897}
1898
dfefa935
MH
1899static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1900 const unsigned char *old_sha1,
1901 int flags, int *type_p)
4bd18c43 1902{
434cd0cd 1903 char *ref_file;
dfefa935 1904 const char *orig_refname = refname;
4bd18c43 1905 struct ref_lock *lock;
5cc3cef9 1906 int last_errno = 0;
acd3b9ec 1907 int type, lflags;
4431fcc4 1908 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1909 int missing = 0;
4bd18c43
SP
1910
1911 lock = xcalloc(1, sizeof(struct ref_lock));
1912 lock->lock_fd = -1;
1913
8d68493f 1914 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 1915 if (!refname && errno == EISDIR) {
bc7127ef
JH
1916 /* we are trying to lock foo but we used to
1917 * have foo/bar which now does not exist;
1918 * it is normal for the empty directory 'foo'
1919 * to remain.
1920 */
dfefa935 1921 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
1922 if (remove_empty_directories(ref_file)) {
1923 last_errno = errno;
dfefa935 1924 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
1925 goto error_return;
1926 }
8d68493f 1927 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 1928 }
68db31cc
SV
1929 if (type_p)
1930 *type_p = type;
dfefa935 1931 if (!refname) {
5cc3cef9 1932 last_errno = errno;
818f477c 1933 error("unable to resolve reference %s: %s",
dfefa935 1934 orig_refname, strerror(errno));
5cc3cef9 1935 goto error_return;
4bd18c43 1936 }
5bdd8d4a 1937 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1938 /* When the ref did not exist and we are creating it,
1939 * make sure there is no existing ref that is packed
1940 * whose name begins with our refname, nor a ref whose
1941 * name is a proper prefix of our refname.
1942 */
5bdd8d4a 1943 if (missing &&
9da31cb0 1944 !is_refname_available(refname, NULL, get_packed_refs(&ref_cache))) {
f475e08e 1945 last_errno = ENOTDIR;
c976d415 1946 goto error_return;
f475e08e 1947 }
22a3844e 1948
c33d5174 1949 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1950
acd3b9ec
JH
1951 lflags = LOCK_DIE_ON_ERROR;
1952 if (flags & REF_NODEREF) {
dfefa935 1953 refname = orig_refname;
acd3b9ec
JH
1954 lflags |= LOCK_NODEREF;
1955 }
dfefa935
MH
1956 lock->ref_name = xstrdup(refname);
1957 lock->orig_ref_name = xstrdup(orig_refname);
1958 ref_file = git_path("%s", refname);
5bdd8d4a 1959 if (missing)
68db31cc
SV
1960 lock->force_write = 1;
1961 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1962 lock->force_write = 1;
4bd18c43 1963
5cc3cef9
JH
1964 if (safe_create_leading_directories(ref_file)) {
1965 last_errno = errno;
1966 error("unable to create directory for %s", ref_file);
1967 goto error_return;
1968 }
4bd18c43 1969
acd3b9ec 1970 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1971 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1972
1973 error_return:
1974 unlock_ref(lock);
1975 errno = last_errno;
1976 return NULL;
4bd18c43
SP
1977}
1978
dfefa935 1979struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 1980{
53cce84c 1981 char refpath[PATH_MAX];
dfefa935 1982 if (check_refname_format(refname, 0))
4bd18c43 1983 return NULL;
dfefa935 1984 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 1985 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1986}
1987
dfefa935
MH
1988struct ref_lock *lock_any_ref_for_update(const char *refname,
1989 const unsigned char *old_sha1, int flags)
4bd18c43 1990{
dfefa935 1991 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 1992 return NULL;
dfefa935 1993 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
c0277d15
JH
1994}
1995
fec3137f
MH
1996/*
1997 * Write an entry to the packed-refs file for the specified refname.
1998 * If peeled is non-NULL, write it as the entry's peeled value.
1999 */
2000static void write_packed_entry(int fd, char *refname, unsigned char *sha1,
2001 unsigned char *peeled)
d66da478 2002{
d66da478
MH
2003 char line[PATH_MAX + 100];
2004 int len;
2005
d66da478
MH
2006 len = snprintf(line, sizeof(line), "%s %s\n",
2007 sha1_to_hex(sha1), refname);
2008 /* this should not happen but just being defensive */
2009 if (len > sizeof(line))
2010 die("too long a refname '%s'", refname);
fec3137f
MH
2011 write_or_die(fd, line, len);
2012
2013 if (peeled) {
2014 if (snprintf(line, sizeof(line), "^%s\n",
2015 sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)
2016 die("internal error");
2017 write_or_die(fd, line, PEELED_LINE_LENGTH);
2018 }
2019}
2020
7b40d396
MH
2021/*
2022 * An each_ref_entry_fn that writes the entry to a packed-refs file.
2023 */
2024static int write_packed_entry_fn(struct ref_entry *entry, void *cb_data)
2025{
2026 int *fd = cb_data;
2027 enum peel_status peel_status = peel_entry(entry, 0);
2028
2029 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
2030 error("internal error: %s is not a valid packed reference!",
2031 entry->name);
2032 write_packed_entry(*fd, entry->name, entry->u.value.sha1,
2033 peel_status == PEEL_PEELED ?
2034 entry->u.value.peeled : NULL);
2035 return 0;
2036}
2037
32d462ce
MH
2038struct ref_to_prune {
2039 struct ref_to_prune *next;
2040 unsigned char sha1[20];
2041 char name[FLEX_ARRAY];
2042};
2043
2044struct pack_refs_cb_data {
2045 unsigned int flags;
267f9a8c 2046 struct ref_dir *packed_refs;
32d462ce 2047 struct ref_to_prune *ref_to_prune;
32d462ce
MH
2048};
2049
267f9a8c
MH
2050/*
2051 * An each_ref_entry_fn that is run over loose references only. If
2052 * the loose reference can be packed, add an entry in the packed ref
2053 * cache. If the reference should be pruned, also add it to
2054 * ref_to_prune in the pack_refs_cb_data.
2055 */
2056static int pack_if_possible_fn(struct ref_entry *entry, void *cb_data)
32d462ce
MH
2057{
2058 struct pack_refs_cb_data *cb = cb_data;
f85354b5 2059 enum peel_status peel_status;
267f9a8c 2060 struct ref_entry *packed_entry;
b2a8226d 2061 int is_tag_ref = !prefixcmp(entry->name, "refs/tags/");
32d462ce 2062
267f9a8c
MH
2063 /* ALWAYS pack tags */
2064 if (!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)
32d462ce
MH
2065 return 0;
2066
b2a8226d
MH
2067 /* Do not pack symbolic or broken refs: */
2068 if ((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))
2069 return 0;
2070
267f9a8c 2071 /* Add a packed ref cache entry equivalent to the loose entry. */
f85354b5 2072 peel_status = peel_entry(entry, 1);
0f29920f 2073 if (peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)
f85354b5
MH
2074 die("internal error peeling reference %s (%s)",
2075 entry->name, sha1_to_hex(entry->u.value.sha1));
267f9a8c
MH
2076 packed_entry = find_ref(cb->packed_refs, entry->name);
2077 if (packed_entry) {
2078 /* Overwrite existing packed entry with info from loose entry */
2079 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;
2080 hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);
2081 } else {
2082 packed_entry = create_ref_entry(entry->name, entry->u.value.sha1,
2083 REF_ISPACKED | REF_KNOWS_PEELED, 0);
2084 add_ref(cb->packed_refs, packed_entry);
2085 }
2086 hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);
32d462ce 2087
267f9a8c
MH
2088 /* Schedule the loose reference for pruning if requested. */
2089 if ((cb->flags & PACK_REFS_PRUNE)) {
12e77559 2090 int namelen = strlen(entry->name) + 1;
32d462ce 2091 struct ref_to_prune *n = xcalloc(1, sizeof(*n) + namelen);
12e77559
MH
2092 hashcpy(n->sha1, entry->u.value.sha1);
2093 strcpy(n->name, entry->name);
32d462ce
MH
2094 n->next = cb->ref_to_prune;
2095 cb->ref_to_prune = n;
2096 }
d66da478
MH
2097 return 0;
2098}
2099
32d462ce
MH
2100/*
2101 * Remove empty parents, but spare refs/ and immediate subdirs.
2102 * Note: munges *name.
2103 */
2104static void try_remove_empty_parents(char *name)
2105{
2106 char *p, *q;
2107 int i;
2108 p = name;
2109 for (i = 0; i < 2; i++) { /* refs/{heads,tags,...}/ */
2110 while (*p && *p != '/')
2111 p++;
2112 /* tolerate duplicate slashes; see check_refname_format() */
2113 while (*p == '/')
2114 p++;
2115 }
2116 for (q = p; *q; q++)
2117 ;
2118 while (1) {
2119 while (q > p && *q != '/')
2120 q--;
2121 while (q > p && *(q-1) == '/')
2122 q--;
2123 if (q == p)
2124 break;
2125 *q = '\0';
2126 if (rmdir(git_path("%s", name)))
2127 break;
2128 }
2129}
2130
2131/* make sure nobody touched the ref, and unlink */
2132static void prune_ref(struct ref_to_prune *r)
2133{
2134 struct ref_lock *lock = lock_ref_sha1(r->name + 5, r->sha1);
2135
2136 if (lock) {
2137 unlink_or_warn(git_path("%s", r->name));
2138 unlock_ref(lock);
2139 try_remove_empty_parents(r->name);
2140 }
2141}
2142
2143static void prune_refs(struct ref_to_prune *r)
2144{
2145 while (r) {
2146 prune_ref(r);
2147 r = r->next;
2148 }
2149}
2150
26a063a1
JH
2151static struct lock_file packlock;
2152
32d462ce
MH
2153int pack_refs(unsigned int flags)
2154{
32d462ce 2155 struct pack_refs_cb_data cbdata;
267f9a8c 2156 int fd;
32d462ce
MH
2157
2158 memset(&cbdata, 0, sizeof(cbdata));
2159 cbdata.flags = flags;
2160
267f9a8c
MH
2161 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"),
2162 LOCK_DIE_ON_ERROR);
2163 cbdata.packed_refs = get_packed_refs(&ref_cache);
2164
2165 do_for_each_entry_in_dir(get_loose_refs(&ref_cache), 0,
2166 pack_if_possible_fn, &cbdata);
32d462ce 2167
267f9a8c
MH
2168 write_or_die(fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
2169 do_for_each_entry_in_dir(cbdata.packed_refs, 0, write_packed_entry_fn, &fd);
32d462ce 2170
d9470330 2171 if (commit_lock_file(&packlock) < 0)
32d462ce
MH
2172 die_errno("unable to overwrite old ref-pack file");
2173 prune_refs(cbdata.ref_to_prune);
2174 return 0;
2175}
2176
7b40d396
MH
2177/*
2178 * If entry is no longer needed in packed-refs, add it to the string
2179 * list pointed to by cb_data. Reasons for deleting entries:
2180 *
2181 * - Entry is broken.
2182 * - Entry is overridden by a loose ref.
2183 * - Entry does not point at a valid object.
2184 *
2185 * In the first and third cases, also emit an error message because these
2186 * are indications of repository corruption.
2187 */
2188static int curate_packed_ref_fn(struct ref_entry *entry, void *cb_data)
c0277d15 2189{
7b40d396 2190 struct string_list *refs_to_delete = cb_data;
fec3137f 2191
ab292bc4
MH
2192 if (entry->flag & REF_ISBROKEN) {
2193 /* This shouldn't happen to packed refs. */
2194 error("%s is broken!", entry->name);
7b40d396 2195 string_list_append(refs_to_delete, entry->name);
c0277d15 2196 return 0;
ab292bc4
MH
2197 }
2198 if (!has_sha1_file(entry->u.value.sha1)) {
2199 unsigned char sha1[20];
2200 int flags;
2201
2202 if (read_ref_full(entry->name, sha1, 0, &flags))
2203 /* We should at least have found the packed ref. */
2204 die("Internal error");
7b40d396 2205 if ((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {
ab292bc4
MH
2206 /*
2207 * This packed reference is overridden by a
2208 * loose reference, so it is OK that its value
2209 * is no longer valid; for example, it might
2210 * refer to an object that has been garbage
2211 * collected. For this purpose we don't even
2212 * care whether the loose reference itself is
2213 * invalid, broken, symbolic, etc. Silently
7b40d396 2214 * remove the packed reference.
ab292bc4 2215 */
7b40d396 2216 string_list_append(refs_to_delete, entry->name);
ab292bc4 2217 return 0;
7b40d396 2218 }
ab292bc4
MH
2219 /*
2220 * There is no overriding loose reference, so the fact
2221 * that this reference doesn't refer to a valid object
2222 * indicates some kind of repository corruption.
2223 * Report the problem, then omit the reference from
2224 * the output.
2225 */
2226 error("%s does not point to a valid object!", entry->name);
7b40d396 2227 string_list_append(refs_to_delete, entry->name);
ab292bc4
MH
2228 return 0;
2229 }
2230
d66da478
MH
2231 return 0;
2232}
2233
c0277d15
JH
2234static int repack_without_ref(const char *refname)
2235{
506a760d 2236 int fd;
7618fd80 2237 struct ref_dir *packed;
7b40d396
MH
2238 struct string_list refs_to_delete = STRING_LIST_INIT_DUP;
2239 struct string_list_item *ref_to_delete;
7618fd80
MH
2240
2241 if (!get_packed_ref(refname))
2242 return 0; /* refname does not exist in packed refs */
2243
506a760d
MH
2244 fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
2245 if (fd < 0) {
1b018fd9 2246 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 2247 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 2248 }
9da31cb0
MH
2249 clear_packed_ref_cache(&ref_cache);
2250 packed = get_packed_refs(&ref_cache);
7b40d396
MH
2251
2252 /* Remove refname from the cache: */
506a760d
MH
2253 if (remove_entry(packed, refname) == -1) {
2254 /*
2255 * The packed entry disappeared while we were
2256 * acquiring the lock.
2257 */
2258 rollback_lock_file(&packlock);
2259 return 0;
2260 }
7b40d396
MH
2261
2262 /* Remove any other accumulated cruft: */
2263 do_for_each_entry_in_dir(packed, 0, curate_packed_ref_fn, &refs_to_delete);
2264 for_each_string_list_item(ref_to_delete, &refs_to_delete) {
2265 if (remove_entry(packed, ref_to_delete->string) == -1)
2266 die("internal error");
2267 }
2268
2269 /* Write what remains: */
694b7a19 2270 write_or_die(fd, PACKED_REFS_HEADER, strlen(PACKED_REFS_HEADER));
7b40d396 2271 do_for_each_entry_in_dir(packed, 0, write_packed_entry_fn, &fd);
c0277d15
JH
2272 return commit_lock_file(&packlock);
2273}
2274
eca35a25 2275int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
2276{
2277 struct ref_lock *lock;
eca35a25 2278 int err, i = 0, ret = 0, flag = 0;
c0277d15 2279
547d058f 2280 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
2281 if (!lock)
2282 return 1;
045a476f 2283 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 2284 /* loose */
547d058f
RS
2285 i = strlen(lock->lk->filename) - 5; /* .lock */
2286 lock->lk->filename[i] = 0;
2287 err = unlink_or_warn(lock->lk->filename);
691f1a28 2288 if (err && errno != ENOENT)
c0277d15 2289 ret = 1;
691f1a28 2290
547d058f 2291 lock->lk->filename[i] = '.';
c0277d15
JH
2292 }
2293 /* removing the loose one could have resurrected an earlier
2294 * packed one. Also, if it was not loose we need to repack
2295 * without it.
2296 */
b274a714 2297 ret |= repack_without_ref(lock->ref_name);
c0277d15 2298
691f1a28 2299 unlink_or_warn(git_path("logs/%s", lock->ref_name));
9da31cb0 2300 clear_loose_ref_cache(&ref_cache);
c0277d15
JH
2301 unlock_ref(lock);
2302 return ret;
4bd18c43
SP
2303}
2304
765c2258
PH
2305/*
2306 * People using contrib's git-new-workdir have .git/logs/refs ->
2307 * /some/other/path/.git/logs/refs, and that may live on another device.
2308 *
2309 * IOW, to avoid cross device rename errors, the temporary renamed log must
2310 * live into logs/refs.
2311 */
2312#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
2313
dfefa935 2314int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 2315{
c976d415
LH
2316 unsigned char sha1[20], orig_sha1[20];
2317 int flag = 0, logmoved = 0;
2318 struct ref_lock *lock;
c976d415 2319 struct stat loginfo;
dfefa935 2320 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 2321 const char *symref = NULL;
c976d415 2322
450d4c0f 2323 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 2324 return error("reflog for %s is a symlink", oldrefname);
c976d415 2325
8d68493f 2326 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 2327 if (flag & REF_ISSYMREF)
fa58186c 2328 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 2329 oldrefname);
eca35a25 2330 if (!symref)
dfefa935 2331 return error("refname %s not found", oldrefname);
c976d415 2332
9da31cb0 2333 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(&ref_cache)))
c976d415
LH
2334 return 1;
2335
9da31cb0 2336 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(&ref_cache)))
c976d415
LH
2337 return 1;
2338
dfefa935 2339 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 2340 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 2341 oldrefname, strerror(errno));
c976d415 2342
dfefa935
MH
2343 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
2344 error("unable to delete old %s", oldrefname);
c976d415
LH
2345 goto rollback;
2346 }
2347
dfefa935
MH
2348 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
2349 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 2350 if (errno==EISDIR) {
dfefa935
MH
2351 if (remove_empty_directories(git_path("%s", newrefname))) {
2352 error("Directory not empty: %s", newrefname);
c976d415
LH
2353 goto rollback;
2354 }
2355 } else {
dfefa935 2356 error("unable to delete existing %s", newrefname);
c976d415
LH
2357 goto rollback;
2358 }
2359 }
2360
dfefa935
MH
2361 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
2362 error("unable to create directory for %s", newrefname);
c976d415
LH
2363 goto rollback;
2364 }
2365
2366 retry:
dfefa935 2367 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
d9e74d57
JR
2368 if (errno==EISDIR || errno==ENOTDIR) {
2369 /*
2370 * rename(a, b) when b is an existing
2371 * directory ought to result in ISDIR, but
2372 * Solaris 5.8 gives ENOTDIR. Sheesh.
2373 */
dfefa935
MH
2374 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
2375 error("Directory not empty: logs/%s", newrefname);
c976d415
LH
2376 goto rollback;
2377 }
2378 goto retry;
2379 } else {
765c2258 2380 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
dfefa935 2381 newrefname, strerror(errno));
c976d415
LH
2382 goto rollback;
2383 }
2384 }
2385 logmoved = log;
2386
dfefa935 2387 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 2388 if (!lock) {
dfefa935 2389 error("unable to lock %s for update", newrefname);
c976d415
LH
2390 goto rollback;
2391 }
c976d415
LH
2392 lock->force_write = 1;
2393 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 2394 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 2395 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
2396 goto rollback;
2397 }
2398
2399 return 0;
2400
2401 rollback:
dfefa935 2402 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 2403 if (!lock) {
dfefa935 2404 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
2405 goto rollbacklog;
2406 }
2407
2408 lock->force_write = 1;
2409 flag = log_all_ref_updates;
2410 log_all_ref_updates = 0;
2411 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2412 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2413 log_all_ref_updates = flag;
2414
2415 rollbacklog:
dfefa935 2416 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2417 error("unable to restore logfile %s from %s: %s",
dfefa935 2418 oldrefname, newrefname, strerror(errno));
c976d415 2419 if (!logmoved && log &&
dfefa935 2420 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2421 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2422 oldrefname, strerror(errno));
c976d415
LH
2423
2424 return 1;
2425}
2426
435fc852 2427int close_ref(struct ref_lock *lock)
b531394d
BC
2428{
2429 if (close_lock_file(lock->lk))
2430 return -1;
2431 lock->lock_fd = -1;
2432 return 0;
2433}
2434
435fc852 2435int commit_ref(struct ref_lock *lock)
b531394d
BC
2436{
2437 if (commit_lock_file(lock->lk))
2438 return -1;
2439 lock->lock_fd = -1;
2440 return 0;
2441}
2442
e5f38ec3 2443void unlock_ref(struct ref_lock *lock)
4bd18c43 2444{
4ed7cd3a
BC
2445 /* Do not free lock->lk -- atexit() still looks at them */
2446 if (lock->lk)
2447 rollback_lock_file(lock->lk);
434cd0cd 2448 free(lock->ref_name);
1655707c 2449 free(lock->orig_ref_name);
4bd18c43
SP
2450 free(lock);
2451}
2452
0ec29a47
JH
2453/*
2454 * copy the reflog message msg to buf, which has been allocated sufficiently
2455 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2456 * because reflog file is one line per entry.
2457 */
2458static int copy_msg(char *buf, const char *msg)
2459{
2460 char *cp = buf;
2461 char c;
2462 int wasspace = 1;
2463
2464 *cp++ = '\t';
2465 while ((c = *msg++)) {
2466 if (wasspace && isspace(c))
2467 continue;
2468 wasspace = isspace(c);
2469 if (wasspace)
2470 c = ' ';
2471 *cp++ = c;
2472 }
2473 while (buf < cp && isspace(cp[-1]))
2474 cp--;
2475 *cp++ = '\n';
2476 return cp - buf;
2477}
2478
dfefa935 2479int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2480{
859c3017 2481 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2482
dfefa935 2483 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2484 if (log_all_ref_updates &&
dfefa935
MH
2485 (!prefixcmp(refname, "refs/heads/") ||
2486 !prefixcmp(refname, "refs/remotes/") ||
2487 !prefixcmp(refname, "refs/notes/") ||
2488 !strcmp(refname, "HEAD"))) {
157aaea5 2489 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2490 return error("unable to create directory for %s",
157aaea5 2491 logfile);
6de08ae6
SP
2492 oflags |= O_CREAT;
2493 }
2494
157aaea5 2495 logfd = open(logfile, oflags, 0666);
6de08ae6 2496 if (logfd < 0) {
1974bf62 2497 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2498 return 0;
3b463c3f
JH
2499
2500 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2501 if (remove_empty_directories(logfile)) {
3b463c3f 2502 return error("There are still logs under '%s'",
157aaea5 2503 logfile);
3b463c3f 2504 }
157aaea5 2505 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2506 }
2507
2508 if (logfd < 0)
2509 return error("Unable to append to %s: %s",
157aaea5 2510 logfile, strerror(errno));
6de08ae6
SP
2511 }
2512
157aaea5 2513 adjust_shared_perm(logfile);
859c3017
EM
2514 close(logfd);
2515 return 0;
2516}
443b92b6 2517
dfefa935 2518static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2519 const unsigned char *new_sha1, const char *msg)
2520{
2521 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2522 unsigned maxlen, len;
2523 int msglen;
157aaea5 2524 char log_file[PATH_MAX];
859c3017
EM
2525 char *logrec;
2526 const char *committer;
2527
2528 if (log_all_ref_updates < 0)
2529 log_all_ref_updates = !is_bare_repository();
2530
dfefa935 2531 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2532 if (result)
2533 return result;
2534
2535 logfd = open(log_file, oflags);
2536 if (logfd < 0)
2537 return 0;
0ec29a47 2538 msglen = msg ? strlen(msg) : 0;
774751a8 2539 committer = git_committer_info(0);
8ac65937
JH
2540 maxlen = strlen(committer) + msglen + 100;
2541 logrec = xmalloc(maxlen);
2542 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2543 sha1_to_hex(old_sha1),
2544 sha1_to_hex(new_sha1),
8ac65937
JH
2545 committer);
2546 if (msglen)
0ec29a47 2547 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2548 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2549 free(logrec);
91c8d590 2550 if (close(logfd) != 0 || written != len)
9a13f0b7 2551 return error("Unable to append to %s", log_file);
6de08ae6
SP
2552 return 0;
2553}
2554
c3b0dec5
LT
2555static int is_branch(const char *refname)
2556{
2557 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2558}
2559
4bd18c43
SP
2560int write_ref_sha1(struct ref_lock *lock,
2561 const unsigned char *sha1, const char *logmsg)
2562{
2563 static char term = '\n';
c3b0dec5 2564 struct object *o;
4bd18c43
SP
2565
2566 if (!lock)
95fc7512 2567 return -1;
a89fccd2 2568 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2569 unlock_ref(lock);
2570 return 0;
95fc7512 2571 }
c3b0dec5
LT
2572 o = parse_object(sha1);
2573 if (!o) {
7be8b3ba 2574 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2575 lock->ref_name, sha1_to_hex(sha1));
2576 unlock_ref(lock);
2577 return -1;
2578 }
2579 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2580 error("Trying to write non-commit object %s to branch %s",
2581 sha1_to_hex(sha1), lock->ref_name);
2582 unlock_ref(lock);
2583 return -1;
2584 }
93822c22
AW
2585 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2586 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2587 || close_ref(lock) < 0) {
c33d5174 2588 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2589 unlock_ref(lock);
2590 return -1;
2591 }
9da31cb0 2592 clear_loose_ref_cache(&ref_cache);
bd104db1
NP
2593 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2594 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2595 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2596 unlock_ref(lock);
2597 return -1;
2598 }
605fac8b
NP
2599 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2600 /*
2601 * Special hack: If a branch is updated directly and HEAD
2602 * points to it (may happen on the remote side of a push
2603 * for example) then logically the HEAD reflog should be
2604 * updated too.
2605 * A generic solution implies reverse symref information,
2606 * but finding all symrefs pointing to the given branch
2607 * would be rather costly for this rare event (the direct
2608 * update of a branch) to be worth it. So let's cheat and
2609 * check with HEAD only which should cover 99% of all usage
2610 * scenarios (even 100% of the default ones).
2611 */
2612 unsigned char head_sha1[20];
2613 int head_flag;
2614 const char *head_ref;
8cad4744 2615 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2616 if (head_ref && (head_flag & REF_ISSYMREF) &&
2617 !strcmp(head_ref, lock->ref_name))
2618 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2619 }
b531394d 2620 if (commit_ref(lock)) {
434cd0cd 2621 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2622 unlock_ref(lock);
2623 return -1;
2624 }
4bd18c43
SP
2625 unlock_ref(lock);
2626 return 0;
95fc7512 2627}
d556fae2 2628
8b5157e4
NP
2629int create_symref(const char *ref_target, const char *refs_heads_master,
2630 const char *logmsg)
41b625b0
NP
2631{
2632 const char *lockpath;
2633 char ref[1000];
2634 int fd, len, written;
a4f34cbb 2635 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2636 unsigned char old_sha1[20], new_sha1[20];
2637
2638 if (logmsg && read_ref(ref_target, old_sha1))
2639 hashclr(old_sha1);
41b625b0 2640
d48744d1
JH
2641 if (safe_create_leading_directories(git_HEAD) < 0)
2642 return error("unable to create directory for %s", git_HEAD);
2643
41b625b0
NP
2644#ifndef NO_SYMLINK_HEAD
2645 if (prefer_symlink_refs) {
2646 unlink(git_HEAD);
2647 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2648 goto done;
41b625b0
NP
2649 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2650 }
2651#endif
2652
2653 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2654 if (sizeof(ref) <= len) {
2655 error("refname too long: %s", refs_heads_master);
47fc52e2 2656 goto error_free_return;
41b625b0
NP
2657 }
2658 lockpath = mkpath("%s.lock", git_HEAD);
2659 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2660 if (fd < 0) {
2661 error("Unable to open %s for writing", lockpath);
47fc52e2 2662 goto error_free_return;
41b625b0
NP
2663 }
2664 written = write_in_full(fd, ref, len);
91c8d590 2665 if (close(fd) != 0 || written != len) {
41b625b0 2666 error("Unable to write to %s", lockpath);
47fc52e2 2667 goto error_unlink_return;
41b625b0
NP
2668 }
2669 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2670 error("Unable to create %s", git_HEAD);
47fc52e2 2671 goto error_unlink_return;
41b625b0
NP
2672 }
2673 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2674 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2675 error_unlink_return:
691f1a28 2676 unlink_or_warn(lockpath);
47fc52e2
JH
2677 error_free_return:
2678 free(git_HEAD);
2679 return -1;
41b625b0 2680 }
8b5157e4 2681
ee96d11b 2682#ifndef NO_SYMLINK_HEAD
8b5157e4 2683 done:
ee96d11b 2684#endif
8b5157e4
NP
2685 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2686 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2687
47fc52e2 2688 free(git_HEAD);
41b625b0
NP
2689 return 0;
2690}
2691
16d7cc90
JH
2692static char *ref_msg(const char *line, const char *endp)
2693{
2694 const char *ep;
16d7cc90 2695 line += 82;
182af834
PH
2696 ep = memchr(line, '\n', endp - line);
2697 if (!ep)
2698 ep = endp;
2699 return xmemdupz(line, ep - line);
16d7cc90
JH
2700}
2701
dfefa935
MH
2702int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2703 unsigned char *sha1, char **msg,
2704 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2705{
e5229042 2706 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2707 char *tz_c;
e29cb53a 2708 int logfd, tz, reccnt = 0;
d556fae2
SP
2709 struct stat st;
2710 unsigned long date;
e5229042 2711 unsigned char logged_sha1[20];
cb48cb58 2712 void *log_mapped;
dc49cd76 2713 size_t mapsz;
d556fae2 2714
dfefa935 2715 logfile = git_path("logs/%s", refname);
d556fae2
SP
2716 logfd = open(logfile, O_RDONLY, 0);
2717 if (logfd < 0)
d824cbba 2718 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2719 fstat(logfd, &st);
2720 if (!st.st_size)
2721 die("Log %s is empty.", logfile);
dc49cd76
SP
2722 mapsz = xsize_t(st.st_size);
2723 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2724 logdata = log_mapped;
d556fae2
SP
2725 close(logfd);
2726
e5229042 2727 lastrec = NULL;
d556fae2
SP
2728 rec = logend = logdata + st.st_size;
2729 while (logdata < rec) {
e29cb53a 2730 reccnt++;
d556fae2
SP
2731 if (logdata < rec && *(rec-1) == '\n')
2732 rec--;
e5229042
SP
2733 lastgt = NULL;
2734 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2735 rec--;
e5229042
SP
2736 if (*rec == '>')
2737 lastgt = rec;
2738 }
2739 if (!lastgt)
d556fae2 2740 die("Log %s is corrupt.", logfile);
e5229042 2741 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2742 if (date <= at_time || cnt == 0) {
76a44c5c 2743 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2744 if (msg)
2745 *msg = ref_msg(rec, logend);
2746 if (cutoff_time)
2747 *cutoff_time = date;
2748 if (cutoff_tz)
2749 *cutoff_tz = tz;
2750 if (cutoff_cnt)
76a44c5c 2751 *cutoff_cnt = reccnt - 1;
e5229042
SP
2752 if (lastrec) {
2753 if (get_sha1_hex(lastrec, logged_sha1))
2754 die("Log %s is corrupt.", logfile);
2755 if (get_sha1_hex(rec + 41, sha1))
2756 die("Log %s is corrupt.", logfile);
a89fccd2 2757 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2758 warning("Log %s has gap after %s.",
73013afd 2759 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 2760 }
e5f38ec3
JH
2761 }
2762 else if (date == at_time) {
e5229042
SP
2763 if (get_sha1_hex(rec + 41, sha1))
2764 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
2765 }
2766 else {
e5229042
SP
2767 if (get_sha1_hex(rec + 41, logged_sha1))
2768 die("Log %s is corrupt.", logfile);
a89fccd2 2769 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2770 warning("Log %s unexpectedly ended on %s.",
73013afd 2771 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
2772 }
2773 }
dc49cd76 2774 munmap(log_mapped, mapsz);
d556fae2
SP
2775 return 0;
2776 }
e5229042 2777 lastrec = rec;
ab2a1a32
JH
2778 if (cnt > 0)
2779 cnt--;
d556fae2
SP
2780 }
2781
e5229042
SP
2782 rec = logdata;
2783 while (rec < logend && *rec != '>' && *rec != '\n')
2784 rec++;
2785 if (rec == logend || *rec == '\n')
d556fae2 2786 die("Log %s is corrupt.", logfile);
e5229042 2787 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
2788 tz = strtoul(tz_c, NULL, 10);
2789 if (get_sha1_hex(logdata, sha1))
2790 die("Log %s is corrupt.", logfile);
d1a4489a
JK
2791 if (is_null_sha1(sha1)) {
2792 if (get_sha1_hex(logdata + 41, sha1))
2793 die("Log %s is corrupt.", logfile);
2794 }
16d7cc90
JH
2795 if (msg)
2796 *msg = ref_msg(logdata, logend);
dc49cd76 2797 munmap(log_mapped, mapsz);
16d7cc90
JH
2798
2799 if (cutoff_time)
2800 *cutoff_time = date;
2801 if (cutoff_tz)
2802 *cutoff_tz = tz;
2803 if (cutoff_cnt)
2804 *cutoff_cnt = reccnt;
2805 return 1;
d556fae2 2806}
2ff81662 2807
9a7a183b
JH
2808static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *cb_data)
2809{
2810 unsigned char osha1[20], nsha1[20];
2811 char *email_end, *message;
2812 unsigned long timestamp;
2813 int tz;
2814
2815 /* old SP new SP name <email> SP time TAB msg LF */
2816 if (sb->len < 83 || sb->buf[sb->len - 1] != '\n' ||
2817 get_sha1_hex(sb->buf, osha1) || sb->buf[40] != ' ' ||
2818 get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
2819 !(email_end = strchr(sb->buf + 82, '>')) ||
2820 email_end[1] != ' ' ||
2821 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2822 !message || message[0] != ' ' ||
2823 (message[1] != '+' && message[1] != '-') ||
2824 !isdigit(message[2]) || !isdigit(message[3]) ||
2825 !isdigit(message[4]) || !isdigit(message[5]))
2826 return 0; /* corrupt? */
2827 email_end[1] = '\0';
2828 tz = strtol(message + 1, NULL, 10);
2829 if (message[6] != '\t')
2830 message += 6;
2831 else
2832 message += 7;
2833 return fn(osha1, nsha1, sb->buf + 82, timestamp, tz, message, cb_data);
2834}
2835
98f85ff4
JH
2836static char *find_beginning_of_line(char *bob, char *scan)
2837{
2838 while (bob < scan && *(--scan) != '\n')
2839 ; /* keep scanning backwards */
2840 /*
2841 * Return either beginning of the buffer, or LF at the end of
2842 * the previous line.
2843 */
2844 return scan;
2845}
2846
2847int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2ff81662 2848{
8ca78803 2849 struct strbuf sb = STRBUF_INIT;
98f85ff4
JH
2850 FILE *logfp;
2851 long pos;
2852 int ret = 0, at_tail = 1;
2ff81662 2853
7ae07c1b 2854 logfp = fopen(git_path("logs/%s", refname), "r");
2ff81662 2855 if (!logfp)
883d60fa 2856 return -1;
101d15e0 2857
98f85ff4
JH
2858 /* Jump to the end */
2859 if (fseek(logfp, 0, SEEK_END) < 0)
2860 return error("cannot seek back reflog for %s: %s",
2861 refname, strerror(errno));
2862 pos = ftell(logfp);
2863 while (!ret && 0 < pos) {
2864 int cnt;
2865 size_t nread;
2866 char buf[BUFSIZ];
2867 char *endp, *scanp;
2868
2869 /* Fill next block from the end */
2870 cnt = (sizeof(buf) < pos) ? sizeof(buf) : pos;
2871 if (fseek(logfp, pos - cnt, SEEK_SET))
2872 return error("cannot seek back reflog for %s: %s",
2873 refname, strerror(errno));
2874 nread = fread(buf, cnt, 1, logfp);
e4ca819a 2875 if (nread != 1)
98f85ff4
JH
2876 return error("cannot read %d bytes from reflog for %s: %s",
2877 cnt, refname, strerror(errno));
2878 pos -= cnt;
2879
2880 scanp = endp = buf + cnt;
2881 if (at_tail && scanp[-1] == '\n')
2882 /* Looking at the final LF at the end of the file */
2883 scanp--;
2884 at_tail = 0;
2885
2886 while (buf < scanp) {
2887 /*
2888 * terminating LF of the previous line, or the beginning
2889 * of the buffer.
2890 */
2891 char *bp;
2892
2893 bp = find_beginning_of_line(buf, scanp);
2894
2895 if (*bp != '\n') {
2896 strbuf_splice(&sb, 0, 0, buf, endp - buf);
2897 if (pos)
2898 break; /* need to fill another block */
2899 scanp = buf - 1; /* leave loop */
2900 } else {
2901 /*
2902 * (bp + 1) thru endp is the beginning of the
2903 * current line we have in sb
2904 */
2905 strbuf_splice(&sb, 0, 0, bp + 1, endp - (bp + 1));
2906 scanp = bp;
2907 endp = bp + 1;
2908 }
2909 ret = show_one_reflog_ent(&sb, fn, cb_data);
2910 strbuf_reset(&sb);
2911 if (ret)
2912 break;
9d33f7c2 2913 }
101d15e0 2914
2ff81662 2915 }
98f85ff4 2916 if (!ret && sb.len)
9a7a183b 2917 ret = show_one_reflog_ent(&sb, fn, cb_data);
98f85ff4 2918
2ff81662 2919 fclose(logfp);
8ca78803 2920 strbuf_release(&sb);
2266bf27 2921 return ret;
2ff81662 2922}
e29cb53a 2923
dfefa935 2924int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 2925{
98f85ff4
JH
2926 FILE *logfp;
2927 struct strbuf sb = STRBUF_INIT;
2928 int ret = 0;
2929
2930 logfp = fopen(git_path("logs/%s", refname), "r");
2931 if (!logfp)
2932 return -1;
101d15e0 2933
98f85ff4
JH
2934 while (!ret && !strbuf_getwholeline(&sb, logfp, '\n'))
2935 ret = show_one_reflog_ent(&sb, fn, cb_data);
2936 fclose(logfp);
2937 strbuf_release(&sb);
2938 return ret;
2939}
989c0e5d
MH
2940/*
2941 * Call fn for each reflog in the namespace indicated by name. name
2942 * must be empty or end with '/'. Name will be used as a scratch
2943 * space, but its contents will be restored before return.
2944 */
2945static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 2946{
989c0e5d 2947 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 2948 int retval = 0;
93c603fc 2949 struct dirent *de;
989c0e5d 2950 int oldlen = name->len;
eb8381c8 2951
93c603fc 2952 if (!d)
989c0e5d 2953 return name->len ? errno : 0;
eb8381c8 2954
93c603fc
MH
2955 while ((de = readdir(d)) != NULL) {
2956 struct stat st;
eb8381c8 2957
93c603fc
MH
2958 if (de->d_name[0] == '.')
2959 continue;
93c603fc
MH
2960 if (has_extension(de->d_name, ".lock"))
2961 continue;
989c0e5d
MH
2962 strbuf_addstr(name, de->d_name);
2963 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2964 ; /* silently ignore */
93c603fc 2965 } else {
eb8381c8 2966 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
2967 strbuf_addch(name, '/');
2968 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
2969 } else {
2970 unsigned char sha1[20];
989c0e5d
MH
2971 if (read_ref_full(name->buf, sha1, 0, NULL))
2972 retval = error("bad ref for %s", name->buf);
eb8381c8 2973 else
989c0e5d 2974 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
2975 }
2976 if (retval)
2977 break;
2978 }
989c0e5d 2979 strbuf_setlen(name, oldlen);
eb8381c8 2980 }
93c603fc 2981 closedir(d);
eb8381c8
NP
2982 return retval;
2983}
2984
2985int for_each_reflog(each_ref_fn fn, void *cb_data)
2986{
989c0e5d
MH
2987 int retval;
2988 struct strbuf name;
2989 strbuf_init(&name, PATH_MAX);
2990 retval = do_for_each_reflog(&name, fn, cb_data);
2991 strbuf_release(&name);
2992 return retval;
eb8381c8 2993}
3d9f037c
CR
2994
2995int update_ref(const char *action, const char *refname,
2996 const unsigned char *sha1, const unsigned char *oldval,
2997 int flags, enum action_on_err onerr)
2998{
2999 static struct ref_lock *lock;
3000 lock = lock_any_ref_for_update(refname, oldval, flags);
3001 if (!lock) {
3002 const char *str = "Cannot lock the ref '%s'.";
3003 switch (onerr) {
3004 case MSG_ON_ERR: error(str, refname); break;
3005 case DIE_ON_ERR: die(str, refname); break;
3006 case QUIET_ON_ERR: break;
3007 }
3008 return 1;
3009 }
3010 if (write_ref_sha1(lock, sha1, action) < 0) {
3011 const char *str = "Cannot update the ref '%s'.";
3012 switch (onerr) {
3013 case MSG_ON_ERR: error(str, refname); break;
3014 case DIE_ON_ERR: die(str, refname); break;
3015 case QUIET_ON_ERR: break;
3016 }
3017 return 1;
3018 }
3019 return 0;
3020}
cda69f48 3021
5483f799 3022struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
3023{
3024 for ( ; list; list = list->next)
3025 if (!strcmp(list->name, name))
5483f799 3026 return (struct ref *)list;
cda69f48
JK
3027 return NULL;
3028}
7c2b3029
JK
3029
3030/*
3031 * generate a format suitable for scanf from a ref_rev_parse_rules
3032 * rule, that is replace the "%.*s" spec with a "%s" spec
3033 */
3034static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
3035{
3036 char *spec;
3037
3038 spec = strstr(rule, "%.*s");
3039 if (!spec || strstr(spec + 4, "%.*s"))
3040 die("invalid rule in ref_rev_parse_rules: %s", rule);
3041
3042 /* copy all until spec */
3043 strncpy(scanf_fmt, rule, spec - rule);
3044 scanf_fmt[spec - rule] = '\0';
3045 /* copy new spec */
3046 strcat(scanf_fmt, "%s");
3047 /* copy remaining rule */
3048 strcat(scanf_fmt, spec + 4);
3049
3050 return;
3051}
3052
dfefa935 3053char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
3054{
3055 int i;
3056 static char **scanf_fmts;
3057 static int nr_rules;
3058 char *short_name;
3059
3060 /* pre generate scanf formats from ref_rev_parse_rules[] */
3061 if (!nr_rules) {
3062 size_t total_len = 0;
3063
3064 /* the rule list is NULL terminated, count them first */
3065 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
3066 /* no +1 because strlen("%s") < strlen("%.*s") */
3067 total_len += strlen(ref_rev_parse_rules[nr_rules]);
3068
3069 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
3070
3071 total_len = 0;
3072 for (i = 0; i < nr_rules; i++) {
3073 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
3074 + total_len;
3075 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
3076 total_len += strlen(ref_rev_parse_rules[i]);
3077 }
3078 }
3079
3080 /* bail out if there are no rules */
3081 if (!nr_rules)
dfefa935 3082 return xstrdup(refname);
7c2b3029 3083
dfefa935
MH
3084 /* buffer for scanf result, at most refname must fit */
3085 short_name = xstrdup(refname);
7c2b3029
JK
3086
3087 /* skip first rule, it will always match */
3088 for (i = nr_rules - 1; i > 0 ; --i) {
3089 int j;
6e7b3309 3090 int rules_to_fail = i;
7c2b3029
JK
3091 int short_name_len;
3092
dfefa935 3093 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
3094 continue;
3095
3096 short_name_len = strlen(short_name);
3097
6e7b3309
BW
3098 /*
3099 * in strict mode, all (except the matched one) rules
3100 * must fail to resolve to a valid non-ambiguous ref
3101 */
3102 if (strict)
3103 rules_to_fail = nr_rules;
3104
7c2b3029
JK
3105 /*
3106 * check if the short name resolves to a valid ref,
3107 * but use only rules prior to the matched one
3108 */
6e7b3309 3109 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 3110 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
3111 char refname[PATH_MAX];
3112
6e7b3309
BW
3113 /* skip matched rule */
3114 if (i == j)
3115 continue;
3116
7c2b3029
JK
3117 /*
3118 * the short name is ambiguous, if it resolves
3119 * (with this previous rule) to a valid ref
3120 * read_ref() returns 0 on success
3121 */
3122 mksnpath(refname, sizeof(refname),
3123 rule, short_name_len, short_name);
c6893323 3124 if (ref_exists(refname))
7c2b3029
JK
3125 break;
3126 }
3127
3128 /*
3129 * short name is non-ambiguous if all previous rules
3130 * haven't resolved to a valid ref
3131 */
6e7b3309 3132 if (j == rules_to_fail)
7c2b3029
JK
3133 return short_name;
3134 }
3135
3136 free(short_name);
dfefa935 3137 return xstrdup(refname);
7c2b3029 3138}
daebaa78
JH
3139
3140static struct string_list *hide_refs;
3141
3142int parse_hide_refs_config(const char *var, const char *value, const char *section)
3143{
3144 if (!strcmp("transfer.hiderefs", var) ||
3145 /* NEEDSWORK: use parse_config_key() once both are merged */
3146 (!prefixcmp(var, section) && var[strlen(section)] == '.' &&
3147 !strcmp(var + strlen(section), ".hiderefs"))) {
3148 char *ref;
3149 int len;
3150
3151 if (!value)
3152 return config_error_nonbool(var);
3153 ref = xstrdup(value);
3154 len = strlen(ref);
3155 while (len && ref[len - 1] == '/')
3156 ref[--len] = '\0';
3157 if (!hide_refs) {
3158 hide_refs = xcalloc(1, sizeof(*hide_refs));
3159 hide_refs->strdup_strings = 1;
3160 }
3161 string_list_append(hide_refs, ref);
3162 }
3163 return 0;
3164}
3165
3166int ref_is_hidden(const char *refname)
3167{
3168 struct string_list_item *item;
3169
3170 if (!hide_refs)
3171 return 0;
3172 for_each_string_list_item(item, hide_refs) {
3173 int len;
3174 if (prefixcmp(refname, item->string))
3175 continue;
3176 len = strlen(item->string);
3177 if (!refname[len] || refname[len] == '/')
3178 return 1;
3179 }
3180 return 0;
3181}