refs: extract function peel_object()
[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"
95fc7512 6
bc5fd6d3
MH
7/*
8 * Make sure "ref" is something reasonable to have under ".git/refs/";
9 * We do not like it if:
10 *
11 * - any path component of it begins with ".", or
12 * - it has double dots "..", or
13 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
14 * - it ends with a "/".
15 * - it ends with ".lock"
16 * - it contains a "\" (backslash)
17 */
f4204ab9 18
bc5fd6d3
MH
19/* Return true iff ch is not allowed in reference names. */
20static inline int bad_ref_char(int ch)
21{
22 if (((unsigned) ch) <= ' ' || ch == 0x7f ||
23 ch == '~' || ch == '^' || ch == ':' || ch == '\\')
24 return 1;
25 /* 2.13 Pattern Matching Notation */
26 if (ch == '*' || ch == '?' || ch == '[') /* Unsupported */
27 return 1;
28 return 0;
29}
30
31/*
32 * Try to read one refname component from the front of refname. Return
33 * the length of the component found, or -1 if the component is not
34 * legal.
35 */
36static int check_refname_component(const char *refname, int flags)
37{
38 const char *cp;
39 char last = '\0';
40
41 for (cp = refname; ; cp++) {
42 char ch = *cp;
43 if (ch == '\0' || ch == '/')
44 break;
45 if (bad_ref_char(ch))
46 return -1; /* Illegal character in refname. */
47 if (last == '.' && ch == '.')
48 return -1; /* Refname contains "..". */
49 if (last == '@' && ch == '{')
50 return -1; /* Refname contains "@{". */
51 last = ch;
52 }
53 if (cp == refname)
dac529e4 54 return 0; /* Component has zero length. */
bc5fd6d3
MH
55 if (refname[0] == '.') {
56 if (!(flags & REFNAME_DOT_COMPONENT))
57 return -1; /* Component starts with '.'. */
58 /*
59 * Even if leading dots are allowed, don't allow "."
60 * as a component (".." is prevented by a rule above).
61 */
62 if (refname[1] == '\0')
63 return -1; /* Component equals ".". */
64 }
65 if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
66 return -1; /* Refname ends with ".lock". */
67 return cp - refname;
68}
69
70int check_refname_format(const char *refname, int flags)
71{
72 int component_len, component_count = 0;
73
74 while (1) {
75 /* We are at the start of a path component. */
76 component_len = check_refname_component(refname, flags);
dac529e4 77 if (component_len <= 0) {
bc5fd6d3
MH
78 if ((flags & REFNAME_REFSPEC_PATTERN) &&
79 refname[0] == '*' &&
80 (refname[1] == '\0' || refname[1] == '/')) {
81 /* Accept one wildcard as a full refname component. */
82 flags &= ~REFNAME_REFSPEC_PATTERN;
83 component_len = 1;
84 } else {
85 return -1;
86 }
87 }
88 component_count++;
89 if (refname[component_len] == '\0')
90 break;
91 /* Skip to next component. */
92 refname += component_len + 1;
93 }
94
95 if (refname[component_len - 1] == '.')
96 return -1; /* Refname ends with '.'. */
97 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
98 return -1; /* Refname has only one component. */
99 return 0;
100}
101
102struct ref_entry;
e1e22e37 103
28e6a34e
MH
104/*
105 * Information used (along with the information in ref_entry) to
106 * describe a single cached reference. This data structure only
107 * occurs embedded in a union in struct ref_entry, and only when
108 * (ref_entry->flag & REF_DIR) is zero.
109 */
593f1bb8 110struct ref_value {
6c6f58df
MH
111 /*
112 * The name of the object to which this reference resolves
113 * (which may be a tag object). If REF_ISBROKEN, this is
114 * null. If REF_ISSYMREF, then this is the name of the object
115 * referred to by the last reference in the symlink chain.
116 */
593f1bb8 117 unsigned char sha1[20];
6c6f58df
MH
118
119 /*
120 * If REF_KNOWS_PEELED, then this field holds the peeled value
121 * of this reference, or null if the reference is known not to
122 * be peelable.
123 */
593f1bb8
MH
124 unsigned char peeled[20];
125};
126
f006c42a
MH
127struct ref_cache;
128
28e6a34e
MH
129/*
130 * Information used (along with the information in ref_entry) to
131 * describe a level in the hierarchy of references. This data
132 * structure only occurs embedded in a union in struct ref_entry, and
133 * only when (ref_entry.flag & REF_DIR) is set. In that case,
134 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
135 * in the directory have already been read:
136 *
137 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
138 * or packed references, already read.
139 *
140 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
141 * references that hasn't been read yet (nor has any of its
142 * subdirectories).
143 *
144 * Entries within a directory are stored within a growable array of
145 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
146 * sorted are sorted by their component name in strcmp() order and the
147 * remaining entries are unsorted.
148 *
149 * Loose references are read lazily, one directory at a time. When a
150 * directory of loose references is read, then all of the references
151 * in that directory are stored, and REF_INCOMPLETE stubs are created
152 * for any subdirectories, but the subdirectories themselves are not
153 * read. The reading is triggered by get_ref_dir().
154 */
d3177275 155struct ref_dir {
e9c4c111 156 int nr, alloc;
e6ed3ca6
MH
157
158 /*
159 * Entries with index 0 <= i < sorted are sorted by name. New
160 * entries are appended to the list unsorted, and are sorted
161 * only when required; thus we avoid the need to sort the list
162 * after the addition of every reference.
163 */
164 int sorted;
165
f006c42a
MH
166 /* A pointer to the ref_cache that contains this ref_dir. */
167 struct ref_cache *ref_cache;
168
d3177275 169 struct ref_entry **entries;
e9c4c111
JP
170};
171
89df9c84
MH
172/*
173 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01,
174 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see
175 * refs.h.
176 */
177
178/*
179 * The field ref_entry->u.value.peeled of this value entry contains
180 * the correct peeled value for the reference, which might be
181 * null_sha1 if the reference is not a tag or if it is broken.
182 */
432ad41e 183#define REF_KNOWS_PEELED 0x08
28e6a34e
MH
184
185/* ref_entry represents a directory of references */
432ad41e 186#define REF_DIR 0x10
cf0adba7 187
28e6a34e
MH
188/*
189 * Entry has not yet been read from disk (used only for REF_DIR
190 * entries representing loose references)
191 */
192#define REF_INCOMPLETE 0x20
193
432ad41e
MH
194/*
195 * A ref_entry represents either a reference or a "subdirectory" of
28e6a34e
MH
196 * references.
197 *
198 * Each directory in the reference namespace is represented by a
199 * ref_entry with (flags & REF_DIR) set and containing a subdir member
200 * that holds the entries in that directory that have been read so
201 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
202 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
203 * used for loose reference directories.
204 *
205 * References are represented by a ref_entry with (flags & REF_DIR)
206 * unset and a value member that describes the reference's value. The
207 * flag member is at the ref_entry level, but it is also needed to
208 * interpret the contents of the value field (in other words, a
209 * ref_value object is not very much use without the enclosing
210 * ref_entry).
432ad41e
MH
211 *
212 * Reference names cannot end with slash and directories' names are
213 * always stored with a trailing slash (except for the top-level
214 * directory, which is always denoted by ""). This has two nice
215 * consequences: (1) when the entries in each subdir are sorted
216 * lexicographically by name (as they usually are), the references in
217 * a whole tree can be generated in lexicographic order by traversing
218 * the tree in left-to-right, depth-first order; (2) the names of
219 * references and subdirectories cannot conflict, and therefore the
220 * presence of an empty subdirectory does not block the creation of a
221 * similarly-named reference. (The fact that reference names with the
222 * same leading components can conflict *with each other* is a
223 * separate issue that is regulated by is_refname_available().)
224 *
225 * Please note that the name field contains the fully-qualified
226 * reference (or subdirectory) name. Space could be saved by only
227 * storing the relative names. But that would require the full names
228 * to be generated on the fly when iterating in do_for_each_ref(), and
229 * would break callback functions, who have always been able to assume
230 * that the name strings that they are passed will not be freed during
231 * the iteration.
232 */
bc5fd6d3
MH
233struct ref_entry {
234 unsigned char flag; /* ISSYMREF? ISPACKED? */
593f1bb8 235 union {
432ad41e
MH
236 struct ref_value value; /* if not (flags&REF_DIR) */
237 struct ref_dir subdir; /* if (flags&REF_DIR) */
593f1bb8 238 } u;
432ad41e
MH
239 /*
240 * The full name of the reference (e.g., "refs/heads/master")
241 * or the full name of the directory with a trailing slash
242 * (e.g., "refs/heads/"):
243 */
bc5fd6d3
MH
244 char name[FLEX_ARRAY];
245};
e1e22e37 246
28e6a34e
MH
247static void read_loose_refs(const char *dirname, struct ref_dir *dir);
248
d7826d54
MH
249static struct ref_dir *get_ref_dir(struct ref_entry *entry)
250{
28e6a34e 251 struct ref_dir *dir;
d7826d54 252 assert(entry->flag & REF_DIR);
28e6a34e
MH
253 dir = &entry->u.subdir;
254 if (entry->flag & REF_INCOMPLETE) {
255 read_loose_refs(entry->name, dir);
256 entry->flag &= ~REF_INCOMPLETE;
257 }
258 return dir;
d7826d54
MH
259}
260
cddc4258
MH
261static struct ref_entry *create_ref_entry(const char *refname,
262 const unsigned char *sha1, int flag,
263 int check_name)
e1e22e37
LT
264{
265 int len;
cddc4258 266 struct ref_entry *ref;
e1e22e37 267
09116a1c 268 if (check_name &&
dfefa935
MH
269 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
270 die("Reference has invalid format: '%s'", refname);
cddc4258
MH
271 len = strlen(refname) + 1;
272 ref = xmalloc(sizeof(struct ref_entry) + len);
593f1bb8
MH
273 hashcpy(ref->u.value.sha1, sha1);
274 hashclr(ref->u.value.peeled);
cddc4258
MH
275 memcpy(ref->name, refname, len);
276 ref->flag = flag;
277 return ref;
278}
279
432ad41e
MH
280static void clear_ref_dir(struct ref_dir *dir);
281
732134ed
MH
282static void free_ref_entry(struct ref_entry *entry)
283{
27b5587c
MH
284 if (entry->flag & REF_DIR) {
285 /*
286 * Do not use get_ref_dir() here, as that might
287 * trigger the reading of loose refs.
288 */
289 clear_ref_dir(&entry->u.subdir);
290 }
732134ed
MH
291 free(entry);
292}
293
432ad41e
MH
294/*
295 * Add a ref_entry to the end of dir (unsorted). Entry is always
296 * stored directly in dir; no recursion into subdirectories is
297 * done.
298 */
299static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
cddc4258 300{
432ad41e
MH
301 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
302 dir->entries[dir->nr++] = entry;
654ad400
MH
303 /* optimize for the case that entries are added in order */
304 if (dir->nr == 1 ||
305 (dir->nr == dir->sorted + 1 &&
306 strcmp(dir->entries[dir->nr - 2]->name,
307 dir->entries[dir->nr - 1]->name) < 0))
308 dir->sorted = dir->nr;
c774aab9
JP
309}
310
432ad41e
MH
311/*
312 * Clear and free all entries in dir, recursively.
313 */
d3177275 314static void clear_ref_dir(struct ref_dir *dir)
bc5fd6d3
MH
315{
316 int i;
d3177275
MH
317 for (i = 0; i < dir->nr; i++)
318 free_ref_entry(dir->entries[i]);
319 free(dir->entries);
320 dir->sorted = dir->nr = dir->alloc = 0;
321 dir->entries = NULL;
bc5fd6d3
MH
322}
323
432ad41e
MH
324/*
325 * Create a struct ref_entry object for the specified dirname.
326 * dirname is the name of the directory with a trailing slash (e.g.,
327 * "refs/heads/") or "" for the top-level directory.
328 */
f006c42a 329static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
b9146f51
RS
330 const char *dirname, size_t len,
331 int incomplete)
432ad41e
MH
332{
333 struct ref_entry *direntry;
432ad41e 334 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
b9146f51
RS
335 memcpy(direntry->name, dirname, len);
336 direntry->name[len] = '\0';
f006c42a 337 direntry->u.subdir.ref_cache = ref_cache;
28e6a34e 338 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
432ad41e
MH
339 return direntry;
340}
341
e9c4c111 342static int ref_entry_cmp(const void *a, const void *b)
c774aab9 343{
e9c4c111
JP
344 struct ref_entry *one = *(struct ref_entry **)a;
345 struct ref_entry *two = *(struct ref_entry **)b;
346 return strcmp(one->name, two->name);
347}
c774aab9 348
d3177275 349static void sort_ref_dir(struct ref_dir *dir);
bc5fd6d3 350
e1980c9d
JH
351struct string_slice {
352 size_t len;
353 const char *str;
354};
355
356static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
357{
358 struct string_slice *key = (struct string_slice *)key_;
359 struct ref_entry *ent = *(struct ref_entry **)ent_;
360 int entlen = strlen(ent->name);
361 int cmplen = key->len < entlen ? key->len : entlen;
362 int cmp = memcmp(key->str, ent->name, cmplen);
363 if (cmp)
364 return cmp;
365 return key->len - entlen;
366}
367
432ad41e
MH
368/*
369 * Return the entry with the given refname from the ref_dir
370 * (non-recursively), sorting dir if necessary. Return NULL if no
28e6a34e 371 * such entry is found. dir must already be complete.
432ad41e 372 */
40ad937d
RS
373static struct ref_entry *search_ref_dir(struct ref_dir *dir,
374 const char *refname, size_t len)
bc5fd6d3 375{
e1980c9d
JH
376 struct ref_entry **r;
377 struct string_slice key;
bc5fd6d3 378
432ad41e 379 if (refname == NULL || !dir->nr)
bc5fd6d3
MH
380 return NULL;
381
d3177275 382 sort_ref_dir(dir);
e1980c9d
JH
383 key.len = len;
384 key.str = refname;
385 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
386 ref_entry_cmp_sslice);
bc5fd6d3
MH
387
388 if (r == NULL)
389 return NULL;
390
391 return *r;
392}
393
f348ac92
MH
394/*
395 * Search for a directory entry directly within dir (without
396 * recursing). Sort dir if necessary. subdirname must be a directory
397 * name (i.e., end in '/'). If mkdir is set, then create the
398 * directory if it is missing; otherwise, return NULL if the desired
28e6a34e 399 * directory cannot be found. dir must already be complete.
f348ac92 400 */
3f3aa1bc 401static struct ref_dir *search_for_subdir(struct ref_dir *dir,
dd02e728
RS
402 const char *subdirname, size_t len,
403 int mkdir)
f348ac92 404{
40ad937d 405 struct ref_entry *entry = search_ref_dir(dir, subdirname, len);
f348ac92
MH
406 if (!entry) {
407 if (!mkdir)
408 return NULL;
28e6a34e
MH
409 /*
410 * Since dir is complete, the absence of a subdir
411 * means that the subdir really doesn't exist;
412 * therefore, create an empty record for it but mark
413 * the record complete.
414 */
b9146f51 415 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
f348ac92
MH
416 add_entry_to_dir(dir, entry);
417 }
3f3aa1bc 418 return get_ref_dir(entry);
f348ac92
MH
419}
420
432ad41e
MH
421/*
422 * If refname is a reference name, find the ref_dir within the dir
423 * tree that should hold refname. If refname is a directory name
424 * (i.e., ends in '/'), then return that ref_dir itself. dir must
28e6a34e
MH
425 * represent the top-level directory and must already be complete.
426 * Sort ref_dirs and recurse into subdirectories as necessary. If
427 * mkdir is set, then create any missing directories; otherwise,
428 * return NULL if the desired directory cannot be found.
432ad41e
MH
429 */
430static struct ref_dir *find_containing_dir(struct ref_dir *dir,
431 const char *refname, int mkdir)
432{
5fa04418 433 const char *slash;
5fa04418 434 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
dd02e728 435 size_t dirnamelen = slash - refname + 1;
3f3aa1bc 436 struct ref_dir *subdir;
dd02e728 437 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
663c1295
JH
438 if (!subdir) {
439 dir = NULL;
f348ac92 440 break;
432ad41e 441 }
3f3aa1bc 442 dir = subdir;
432ad41e
MH
443 }
444
432ad41e
MH
445 return dir;
446}
447
448/*
449 * Find the value entry with the given name in dir, sorting ref_dirs
450 * and recursing into subdirectories as necessary. If the name is not
451 * found or it corresponds to a directory entry, return NULL.
452 */
453static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
454{
455 struct ref_entry *entry;
456 dir = find_containing_dir(dir, refname, 0);
457 if (!dir)
458 return NULL;
40ad937d 459 entry = search_ref_dir(dir, refname, strlen(refname));
432ad41e
MH
460 return (entry && !(entry->flag & REF_DIR)) ? entry : NULL;
461}
462
463/*
464 * Add a ref_entry to the ref_dir (unsorted), recursing into
465 * subdirectories as necessary. dir must represent the top-level
466 * directory. Return 0 on success.
467 */
468static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
469{
470 dir = find_containing_dir(dir, ref->name, 1);
471 if (!dir)
472 return -1;
473 add_entry_to_dir(dir, ref);
474 return 0;
475}
476
202a56a9
MH
477/*
478 * Emit a warning and return true iff ref1 and ref2 have the same name
479 * and the same sha1. Die if they have the same name but different
480 * sha1s.
481 */
482static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
483{
432ad41e 484 if (strcmp(ref1->name, ref2->name))
202a56a9 485 return 0;
432ad41e
MH
486
487 /* Duplicate name; make sure that they don't conflict: */
488
489 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
490 /* This is impossible by construction */
491 die("Reference directory conflict: %s", ref1->name);
492
493 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
494 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
495
496 warning("Duplicated ref: %s", ref1->name);
497 return 1;
202a56a9
MH
498}
499
e6ed3ca6 500/*
432ad41e
MH
501 * Sort the entries in dir non-recursively (if they are not already
502 * sorted) and remove any duplicate entries.
e6ed3ca6 503 */
d3177275 504static void sort_ref_dir(struct ref_dir *dir)
e9c4c111 505{
202a56a9 506 int i, j;
81a79d8e 507 struct ref_entry *last = NULL;
c774aab9 508
e6ed3ca6
MH
509 /*
510 * This check also prevents passing a zero-length array to qsort(),
511 * which is a problem on some platforms.
512 */
d3177275 513 if (dir->sorted == dir->nr)
e9c4c111 514 return;
c774aab9 515
d3177275 516 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
c774aab9 517
81a79d8e
MH
518 /* Remove any duplicates: */
519 for (i = 0, j = 0; j < dir->nr; j++) {
520 struct ref_entry *entry = dir->entries[j];
521 if (last && is_dup_ref(last, entry))
522 free_ref_entry(entry);
523 else
524 last = dir->entries[i++] = entry;
e9c4c111 525 }
81a79d8e 526 dir->sorted = dir->nr = i;
e9c4c111 527}
c774aab9 528
fcce1703
MH
529/* Include broken references in a do_for_each_ref*() iteration: */
530#define DO_FOR_EACH_INCLUDE_BROKEN 0x01
c774aab9 531
662428f4
MH
532/*
533 * Return true iff the reference described by entry can be resolved to
534 * an object in the database. Emit a warning if the referred-to
535 * object does not exist.
536 */
537static int ref_resolves_to_object(struct ref_entry *entry)
538{
539 if (entry->flag & REF_ISBROKEN)
540 return 0;
541 if (!has_sha1_file(entry->u.value.sha1)) {
542 error("%s does not point to a valid object!", entry->name);
543 return 0;
544 }
545 return 1;
546}
547
7d76fdc8
MH
548/*
549 * current_ref is a performance hack: when iterating over references
550 * using the for_each_ref*() functions, current_ref is set to the
551 * current reference's entry before calling the callback function. If
552 * the callback function calls peel_ref(), then peel_ref() first
553 * checks whether the reference to be peeled is the current reference
554 * (it usually is) and if so, returns that reference's peeled version
555 * if it is available. This avoids a refname lookup in a common case.
556 */
bc5fd6d3 557static struct ref_entry *current_ref;
c774aab9 558
fcce1703
MH
559/*
560 * Handle one reference in a do_for_each_ref*()-style iteration.
561 */
bc5fd6d3
MH
562static int do_one_ref(const char *base, each_ref_fn fn, int trim,
563 int flags, void *cb_data, struct ref_entry *entry)
564{
429213e4 565 int retval;
bc5fd6d3
MH
566 if (prefixcmp(entry->name, base))
567 return 0;
c774aab9 568
662428f4
MH
569 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN) &&
570 !ref_resolves_to_object(entry))
571 return 0;
572
bc5fd6d3 573 current_ref = entry;
593f1bb8 574 retval = fn(entry->name + trim, entry->u.value.sha1, entry->flag, cb_data);
429213e4
MH
575 current_ref = NULL;
576 return retval;
bc5fd6d3 577}
c774aab9 578
c36b5bc2 579/*
d3177275 580 * Call fn for each reference in dir that has index in the range
432ad41e
MH
581 * offset <= index < dir->nr. Recurse into subdirectories that are in
582 * that index range, sorting them before iterating. This function
583 * does not sort dir itself; it should be sorted beforehand.
c36b5bc2 584 */
d3177275
MH
585static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
586 const char *base,
587 each_ref_fn fn, int trim, int flags, void *cb_data)
c36b5bc2
MH
588{
589 int i;
d3177275
MH
590 assert(dir->sorted == dir->nr);
591 for (i = offset; i < dir->nr; i++) {
432ad41e
MH
592 struct ref_entry *entry = dir->entries[i];
593 int retval;
594 if (entry->flag & REF_DIR) {
d7826d54
MH
595 struct ref_dir *subdir = get_ref_dir(entry);
596 sort_ref_dir(subdir);
597 retval = do_for_each_ref_in_dir(subdir, 0,
432ad41e
MH
598 base, fn, trim, flags, cb_data);
599 } else {
600 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
601 }
c36b5bc2
MH
602 if (retval)
603 return retval;
604 }
605 return 0;
606}
607
b3fd060f 608/*
d3177275 609 * Call fn for each reference in the union of dir1 and dir2, in order
432ad41e
MH
610 * by refname. Recurse into subdirectories. If a value entry appears
611 * in both dir1 and dir2, then only process the version that is in
612 * dir2. The input dirs must already be sorted, but subdirs will be
613 * sorted as needed.
b3fd060f 614 */
d3177275
MH
615static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
616 struct ref_dir *dir2,
617 const char *base, each_ref_fn fn, int trim,
618 int flags, void *cb_data)
b3fd060f
MH
619{
620 int retval;
621 int i1 = 0, i2 = 0;
622
d3177275
MH
623 assert(dir1->sorted == dir1->nr);
624 assert(dir2->sorted == dir2->nr);
432ad41e
MH
625 while (1) {
626 struct ref_entry *e1, *e2;
627 int cmp;
628 if (i1 == dir1->nr) {
629 return do_for_each_ref_in_dir(dir2, i2,
630 base, fn, trim, flags, cb_data);
631 }
632 if (i2 == dir2->nr) {
633 return do_for_each_ref_in_dir(dir1, i1,
634 base, fn, trim, flags, cb_data);
635 }
636 e1 = dir1->entries[i1];
637 e2 = dir2->entries[i2];
638 cmp = strcmp(e1->name, e2->name);
639 if (cmp == 0) {
640 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
641 /* Both are directories; descend them in parallel. */
d7826d54
MH
642 struct ref_dir *subdir1 = get_ref_dir(e1);
643 struct ref_dir *subdir2 = get_ref_dir(e2);
644 sort_ref_dir(subdir1);
645 sort_ref_dir(subdir2);
432ad41e 646 retval = do_for_each_ref_in_dirs(
d7826d54 647 subdir1, subdir2,
432ad41e
MH
648 base, fn, trim, flags, cb_data);
649 i1++;
650 i2++;
651 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
652 /* Both are references; ignore the one from dir1. */
653 retval = do_one_ref(base, fn, trim, flags, cb_data, e2);
654 i1++;
655 i2++;
656 } else {
657 die("conflict between reference and directory: %s",
658 e1->name);
659 }
b3fd060f 660 } else {
432ad41e
MH
661 struct ref_entry *e;
662 if (cmp < 0) {
663 e = e1;
b3fd060f 664 i1++;
432ad41e
MH
665 } else {
666 e = e2;
667 i2++;
668 }
669 if (e->flag & REF_DIR) {
d7826d54
MH
670 struct ref_dir *subdir = get_ref_dir(e);
671 sort_ref_dir(subdir);
432ad41e 672 retval = do_for_each_ref_in_dir(
d7826d54 673 subdir, 0,
432ad41e
MH
674 base, fn, trim, flags, cb_data);
675 } else {
676 retval = do_one_ref(base, fn, trim, flags, cb_data, e);
b3fd060f
MH
677 }
678 }
679 if (retval)
680 return retval;
681 }
b3fd060f
MH
682}
683
d66da478
MH
684/*
685 * Return true iff refname1 and refname2 conflict with each other.
686 * Two reference names conflict if one of them exactly matches the
687 * leading components of the other; e.g., "foo/bar" conflicts with
688 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
689 * "foo/barbados".
690 */
691static int names_conflict(const char *refname1, const char *refname2)
692{
5a4d4947
MH
693 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
694 ;
695 return (*refname1 == '\0' && *refname2 == '/')
696 || (*refname1 == '/' && *refname2 == '\0');
697}
698
699struct name_conflict_cb {
700 const char *refname;
701 const char *oldrefname;
702 const char *conflicting_refname;
703};
704
705static int name_conflict_fn(const char *existingrefname, const unsigned char *sha1,
706 int flags, void *cb_data)
707{
708 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
709 if (data->oldrefname && !strcmp(data->oldrefname, existingrefname))
710 return 0;
711 if (names_conflict(data->refname, existingrefname)) {
712 data->conflicting_refname = existingrefname;
713 return 1;
d66da478 714 }
5a4d4947 715 return 0;
d66da478
MH
716}
717
bc5fd6d3
MH
718/*
719 * Return true iff a reference named refname could be created without
5a4d4947
MH
720 * conflicting with the name of an existing reference in array. If
721 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
722 * (e.g., because oldrefname is scheduled for deletion in the same
bc5fd6d3
MH
723 * operation).
724 */
725static int is_refname_available(const char *refname, const char *oldrefname,
d3177275 726 struct ref_dir *dir)
bc5fd6d3 727{
5a4d4947
MH
728 struct name_conflict_cb data;
729 data.refname = refname;
730 data.oldrefname = oldrefname;
731 data.conflicting_refname = NULL;
732
d3177275
MH
733 sort_ref_dir(dir);
734 if (do_for_each_ref_in_dir(dir, 0, "", name_conflict_fn,
735 0, DO_FOR_EACH_INCLUDE_BROKEN,
736 &data)) {
5a4d4947
MH
737 error("'%s' exists; cannot create '%s'",
738 data.conflicting_refname, refname);
739 return 0;
bc5fd6d3
MH
740 }
741 return 1;
e1e22e37
LT
742}
743
5e290ff7
JH
744/*
745 * Future: need to be in "struct repository"
746 * when doing a full libification.
747 */
79c7ca54
MH
748static struct ref_cache {
749 struct ref_cache *next;
d12229f5
MH
750 struct ref_entry *loose;
751 struct ref_entry *packed;
ce40979c
MH
752 /* The submodule name, or "" for the main repo. */
753 char name[FLEX_ARRAY];
79c7ca54 754} *ref_cache;
0e88c130 755
760c4512 756static void clear_packed_ref_cache(struct ref_cache *refs)
e1e22e37 757{
d12229f5
MH
758 if (refs->packed) {
759 free_ref_entry(refs->packed);
760 refs->packed = NULL;
761 }
5e290ff7 762}
e1e22e37 763
760c4512
MH
764static void clear_loose_ref_cache(struct ref_cache *refs)
765{
d12229f5
MH
766 if (refs->loose) {
767 free_ref_entry(refs->loose);
768 refs->loose = NULL;
769 }
760c4512
MH
770}
771
79c7ca54 772static struct ref_cache *create_ref_cache(const char *submodule)
e5dbf605 773{
ce40979c 774 int len;
79c7ca54 775 struct ref_cache *refs;
ce40979c
MH
776 if (!submodule)
777 submodule = "";
778 len = strlen(submodule) + 1;
79c7ca54 779 refs = xcalloc(1, sizeof(struct ref_cache) + len);
ce40979c 780 memcpy(refs->name, submodule, len);
e5dbf605
MH
781 return refs;
782}
783
4349a668 784/*
79c7ca54 785 * Return a pointer to a ref_cache for the specified submodule. For
4349a668
MH
786 * the main repository, use submodule==NULL. The returned structure
787 * will be allocated and initialized but not necessarily populated; it
788 * should not be freed.
789 */
79c7ca54 790static struct ref_cache *get_ref_cache(const char *submodule)
4349a668 791{
79c7ca54 792 struct ref_cache *refs = ref_cache;
0e88c130
MH
793 if (!submodule)
794 submodule = "";
795 while (refs) {
796 if (!strcmp(submodule, refs->name))
797 return refs;
798 refs = refs->next;
4349a668 799 }
0e88c130 800
79c7ca54
MH
801 refs = create_ref_cache(submodule);
802 refs->next = ref_cache;
803 ref_cache = refs;
0e88c130 804 return refs;
4349a668
MH
805}
806
8be8bde7 807void invalidate_ref_cache(const char *submodule)
f130b116 808{
c5f29abd
MH
809 struct ref_cache *refs = get_ref_cache(submodule);
810 clear_packed_ref_cache(refs);
811 clear_loose_ref_cache(refs);
5e290ff7 812}
e1e22e37 813
3feb4f0c
MH
814/* The length of a peeled reference line in packed-refs, including EOL: */
815#define PEELED_LINE_LENGTH 42
816
bc5fd6d3
MH
817/*
818 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
819 * Return a pointer to the refname within the line (null-terminated),
820 * or NULL if there was a problem.
821 */
822static const char *parse_ref_line(char *line, unsigned char *sha1)
823{
824 /*
825 * 42: the answer to everything.
826 *
827 * In this case, it happens to be the answer to
828 * 40 (length of sha1 hex representation)
829 * +1 (space in between hex and name)
830 * +1 (newline at the end of the line)
831 */
832 int len = strlen(line) - 42;
833
834 if (len <= 0)
835 return NULL;
836 if (get_sha1_hex(line, sha1) < 0)
837 return NULL;
838 if (!isspace(line[40]))
839 return NULL;
840 line += 41;
841 if (isspace(*line))
842 return NULL;
843 if (line[len] != '\n')
844 return NULL;
845 line[len] = 0;
846
847 return line;
848}
849
c29c46fa
MH
850/*
851 * Read f, which is a packed-refs file, into dir.
852 *
853 * A comment line of the form "# pack-refs with: " may contain zero or
854 * more traits. We interpret the traits as follows:
855 *
856 * No traits:
857 *
858 * Probably no references are peeled. But if the file contains a
859 * peeled value for a reference, we will use it.
860 *
861 * peeled:
862 *
863 * References under "refs/tags/", if they *can* be peeled, *are*
864 * peeled in this file. References outside of "refs/tags/" are
865 * probably not peeled even if they could have been, but if we find
866 * a peeled value for such a reference we will use it.
867 *
868 * fully-peeled:
869 *
870 * All references in the file that can be peeled are peeled.
871 * Inversely (and this is more important), any references in the
872 * file for which no peeled value is recorded is not peelable. This
873 * trait should typically be written alongside "peeled" for
874 * compatibility with older clients, but we do not require it
875 * (i.e., "peeled" is a no-op if "fully-peeled" is set).
876 */
d3177275 877static void read_packed_refs(FILE *f, struct ref_dir *dir)
f4204ab9 878{
e9c4c111 879 struct ref_entry *last = NULL;
f4204ab9 880 char refline[PATH_MAX];
c29c46fa 881 enum { PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;
f4204ab9
JH
882
883 while (fgets(refline, sizeof(refline), f)) {
884 unsigned char sha1[20];
dfefa935 885 const char *refname;
f4204ab9
JH
886 static const char header[] = "# pack-refs with:";
887
888 if (!strncmp(refline, header, sizeof(header)-1)) {
889 const char *traits = refline + sizeof(header) - 1;
c29c46fa
MH
890 if (strstr(traits, " fully-peeled "))
891 peeled = PEELED_FULLY;
892 else if (strstr(traits, " peeled "))
893 peeled = PEELED_TAGS;
f4204ab9
JH
894 /* perhaps other traits later as well */
895 continue;
896 }
897
dfefa935
MH
898 refname = parse_ref_line(refline, sha1);
899 if (refname) {
c29c46fa
MH
900 last = create_ref_entry(refname, sha1, REF_ISPACKED, 1);
901 if (peeled == PEELED_FULLY ||
902 (peeled == PEELED_TAGS && !prefixcmp(refname, "refs/tags/")))
903 last->flag |= REF_KNOWS_PEELED;
d3177275 904 add_ref(dir, last);
f4204ab9
JH
905 continue;
906 }
907 if (last &&
908 refline[0] == '^' &&
3feb4f0c
MH
909 strlen(refline) == PEELED_LINE_LENGTH &&
910 refline[PEELED_LINE_LENGTH - 1] == '\n' &&
c29c46fa 911 !get_sha1_hex(refline + 1, sha1)) {
593f1bb8 912 hashcpy(last->u.value.peeled, sha1);
c29c46fa
MH
913 /*
914 * Regardless of what the file header said,
915 * we definitely know the value of *this*
916 * reference:
917 */
918 last->flag |= REF_KNOWS_PEELED;
919 }
f4204ab9 920 }
f4204ab9
JH
921}
922
d3177275 923static struct ref_dir *get_packed_refs(struct ref_cache *refs)
5e290ff7 924{
d12229f5 925 if (!refs->packed) {
4349a668
MH
926 const char *packed_refs_file;
927 FILE *f;
0bad611b 928
b9146f51 929 refs->packed = create_dir_entry(refs, "", 0, 0);
316b097a
MH
930 if (*refs->name)
931 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
4349a668
MH
932 else
933 packed_refs_file = git_path("packed-refs");
934 f = fopen(packed_refs_file, "r");
e1e22e37 935 if (f) {
d7826d54 936 read_packed_refs(f, get_ref_dir(refs->packed));
e1e22e37 937 fclose(f);
e1e22e37 938 }
e1e22e37 939 }
d7826d54 940 return get_ref_dir(refs->packed);
e1e22e37
LT
941}
942
30249ee6
MH
943void add_packed_ref(const char *refname, const unsigned char *sha1)
944{
945 add_ref(get_packed_refs(get_ref_cache(NULL)),
946 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
947}
948
abc39098 949/*
28e6a34e
MH
950 * Read the loose references from the namespace dirname into dir
951 * (without recursing). dirname must end with '/'. dir must be the
952 * directory entry corresponding to dirname.
abc39098 953 */
423a1afc 954static void read_loose_refs(const char *dirname, struct ref_dir *dir)
e1e22e37 955{
423a1afc 956 struct ref_cache *refs = dir->ref_cache;
d3177275 957 DIR *d;
0bad611b 958 const char *path;
d5fdae67 959 struct dirent *de;
abc39098 960 int dirnamelen = strlen(dirname);
72b64b44 961 struct strbuf refname;
0bad611b 962
3b124823 963 if (*refs->name)
66a3d20b 964 path = git_path_submodule(refs->name, "%s", dirname);
0bad611b 965 else
66a3d20b 966 path = git_path("%s", dirname);
0bad611b 967
d3177275 968 d = opendir(path);
d5fdae67
MH
969 if (!d)
970 return;
971
66a3d20b
MH
972 strbuf_init(&refname, dirnamelen + 257);
973 strbuf_add(&refname, dirname, dirnamelen);
d5fdae67
MH
974
975 while ((de = readdir(d)) != NULL) {
976 unsigned char sha1[20];
977 struct stat st;
978 int flag;
d5fdae67
MH
979 const char *refdir;
980
981 if (de->d_name[0] == '.')
982 continue;
d5fdae67
MH
983 if (has_extension(de->d_name, ".lock"))
984 continue;
72b64b44 985 strbuf_addstr(&refname, de->d_name);
d5fdae67 986 refdir = *refs->name
72b64b44
MH
987 ? git_path_submodule(refs->name, "%s", refname.buf)
988 : git_path("%s", refname.buf);
989 if (stat(refdir, &st) < 0) {
990 ; /* silently ignore */
991 } else if (S_ISDIR(st.st_mode)) {
abc39098 992 strbuf_addch(&refname, '/');
28e6a34e 993 add_entry_to_dir(dir,
b9146f51
RS
994 create_dir_entry(refs, refname.buf,
995 refname.len, 1));
72b64b44 996 } else {
3b124823 997 if (*refs->name) {
f8948e2f 998 hashclr(sha1);
0bad611b 999 flag = 0;
72b64b44 1000 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
0bad611b 1001 hashclr(sha1);
98ac34b2 1002 flag |= REF_ISBROKEN;
0bad611b 1003 }
72b64b44 1004 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
09116a1c
JH
1005 hashclr(sha1);
1006 flag |= REF_ISBROKEN;
1007 }
9f2fb4a3
MH
1008 add_entry_to_dir(dir,
1009 create_ref_entry(refname.buf, sha1, flag, 1));
e1e22e37 1010 }
66a3d20b 1011 strbuf_setlen(&refname, dirnamelen);
e1e22e37 1012 }
72b64b44 1013 strbuf_release(&refname);
d5fdae67 1014 closedir(d);
e1e22e37
LT
1015}
1016
d3177275 1017static struct ref_dir *get_loose_refs(struct ref_cache *refs)
e1e22e37 1018{
d12229f5 1019 if (!refs->loose) {
28e6a34e
MH
1020 /*
1021 * Mark the top-level directory complete because we
1022 * are about to read the only subdirectory that can
1023 * hold references:
1024 */
b9146f51 1025 refs->loose = create_dir_entry(refs, "", 0, 0);
28e6a34e
MH
1026 /*
1027 * Create an incomplete entry for "refs/":
1028 */
1029 add_entry_to_dir(get_ref_dir(refs->loose),
b9146f51 1030 create_dir_entry(refs, "refs/", 5, 1));
e1e22e37 1031 }
d7826d54 1032 return get_ref_dir(refs->loose);
e1e22e37
LT
1033}
1034
ca8db142
LT
1035/* We allow "recursive" symbolic refs. Only within reason, though */
1036#define MAXDEPTH 5
0ebde32c
LT
1037#define MAXREFLEN (1024)
1038
e5fa45c1
JH
1039/*
1040 * Called by resolve_gitlink_ref_recursive() after it failed to read
b0626608
MH
1041 * from the loose refs in ref_cache refs. Find <refname> in the
1042 * packed-refs file for the submodule.
e5fa45c1 1043 */
b0626608 1044static int resolve_gitlink_packed_ref(struct ref_cache *refs,
85be1fe3 1045 const char *refname, unsigned char *sha1)
0ebde32c 1046{
2c5c66be 1047 struct ref_entry *ref;
d3177275 1048 struct ref_dir *dir = get_packed_refs(refs);
0ebde32c 1049
432ad41e 1050 ref = find_ref(dir, refname);
b0626608
MH
1051 if (ref == NULL)
1052 return -1;
1053
593f1bb8 1054 memcpy(sha1, ref->u.value.sha1, 20);
b0626608 1055 return 0;
0ebde32c
LT
1056}
1057
b0626608 1058static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
85be1fe3 1059 const char *refname, unsigned char *sha1,
dfefa935 1060 int recursion)
0ebde32c 1061{
064d51dc 1062 int fd, len;
0ebde32c 1063 char buffer[128], *p;
064d51dc 1064 char *path;
0ebde32c 1065
064d51dc 1066 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
0ebde32c 1067 return -1;
064d51dc
MH
1068 path = *refs->name
1069 ? git_path_submodule(refs->name, "%s", refname)
1070 : git_path("%s", refname);
1071 fd = open(path, O_RDONLY);
0ebde32c 1072 if (fd < 0)
b0626608 1073 return resolve_gitlink_packed_ref(refs, refname, sha1);
0ebde32c
LT
1074
1075 len = read(fd, buffer, sizeof(buffer)-1);
1076 close(fd);
1077 if (len < 0)
1078 return -1;
1079 while (len && isspace(buffer[len-1]))
1080 len--;
1081 buffer[len] = 0;
1082
1083 /* Was it a detached head or an old-fashioned symlink? */
85be1fe3 1084 if (!get_sha1_hex(buffer, sha1))
0ebde32c
LT
1085 return 0;
1086
1087 /* Symref? */
1088 if (strncmp(buffer, "ref:", 4))
1089 return -1;
1090 p = buffer + 4;
1091 while (isspace(*p))
1092 p++;
1093
064d51dc 1094 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
0ebde32c
LT
1095}
1096
85be1fe3 1097int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
0ebde32c
LT
1098{
1099 int len = strlen(path), retval;
064d51dc 1100 char *submodule;
b0626608 1101 struct ref_cache *refs;
0ebde32c
LT
1102
1103 while (len && path[len-1] == '/')
1104 len--;
1105 if (!len)
1106 return -1;
b0626608
MH
1107 submodule = xstrndup(path, len);
1108 refs = get_ref_cache(submodule);
1109 free(submodule);
1110
064d51dc 1111 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
0ebde32c
LT
1112 return retval;
1113}
ca8db142 1114
4886b89f 1115/*
63331581
MH
1116 * Return the ref_entry for the given refname from the packed
1117 * references. If it does not exist, return NULL.
4886b89f 1118 */
63331581 1119static struct ref_entry *get_packed_ref(const char *refname)
c224ca7f 1120{
63331581 1121 return find_ref(get_packed_refs(get_ref_cache(NULL)), refname);
c224ca7f
MH
1122}
1123
8d68493f 1124const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
8a65ff76 1125{
0104ca09
HO
1126 int depth = MAXDEPTH;
1127 ssize_t len;
a876ed83 1128 char buffer[256];
dfefa935 1129 static char refname_buffer[256];
ca8db142 1130
8da19775
JH
1131 if (flag)
1132 *flag = 0;
1133
dfefa935 1134 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
8384d788
MH
1135 return NULL;
1136
a876ed83 1137 for (;;) {
55956350 1138 char path[PATH_MAX];
a876ed83
JH
1139 struct stat st;
1140 char *buf;
1141 int fd;
8a65ff76 1142
a876ed83
JH
1143 if (--depth < 0)
1144 return NULL;
ca8db142 1145
dfefa935 1146 git_snpath(path, sizeof(path), "%s", refname);
c224ca7f 1147
a876ed83 1148 if (lstat(path, &st) < 0) {
63331581
MH
1149 struct ref_entry *entry;
1150
c224ca7f
MH
1151 if (errno != ENOENT)
1152 return NULL;
1153 /*
1154 * The loose reference file does not exist;
1155 * check for a packed reference.
1156 */
63331581
MH
1157 entry = get_packed_ref(refname);
1158 if (entry) {
1159 hashcpy(sha1, entry->u.value.sha1);
c224ca7f
MH
1160 if (flag)
1161 *flag |= REF_ISPACKED;
dfefa935 1162 return refname;
434cd0cd 1163 }
c224ca7f
MH
1164 /* The reference is not a packed reference, either. */
1165 if (reading) {
a876ed83 1166 return NULL;
c224ca7f
MH
1167 } else {
1168 hashclr(sha1);
dfefa935 1169 return refname;
c224ca7f 1170 }
a876ed83 1171 }
ca8db142 1172
a876ed83
JH
1173 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1174 if (S_ISLNK(st.st_mode)) {
1175 len = readlink(path, buffer, sizeof(buffer)-1);
7bb2bf8e
MH
1176 if (len < 0)
1177 return NULL;
b54cb795 1178 buffer[len] = 0;
1f58a038
MH
1179 if (!prefixcmp(buffer, "refs/") &&
1180 !check_refname_format(buffer, 0)) {
dfefa935
MH
1181 strcpy(refname_buffer, buffer);
1182 refname = refname_buffer;
8da19775
JH
1183 if (flag)
1184 *flag |= REF_ISSYMREF;
a876ed83
JH
1185 continue;
1186 }
ca8db142 1187 }
a876ed83 1188
7a21632f
DS
1189 /* Is it a directory? */
1190 if (S_ISDIR(st.st_mode)) {
1191 errno = EISDIR;
1192 return NULL;
1193 }
1194
a876ed83
JH
1195 /*
1196 * Anything else, just open it and try to use it as
1197 * a ref
1198 */
1199 fd = open(path, O_RDONLY);
1200 if (fd < 0)
1201 return NULL;
93d26e4c 1202 len = read_in_full(fd, buffer, sizeof(buffer)-1);
a876ed83 1203 close(fd);
28775050
MH
1204 if (len < 0)
1205 return NULL;
1206 while (len && isspace(buffer[len-1]))
1207 len--;
1208 buffer[len] = '\0';
a876ed83
JH
1209
1210 /*
1211 * Is it a symbolic ref?
1212 */
28775050 1213 if (prefixcmp(buffer, "ref:"))
a876ed83 1214 break;
55956350
JH
1215 if (flag)
1216 *flag |= REF_ISSYMREF;
a876ed83 1217 buf = buffer + 4;
28775050
MH
1218 while (isspace(*buf))
1219 buf++;
313fb010 1220 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
55956350
JH
1221 if (flag)
1222 *flag |= REF_ISBROKEN;
313fb010
MH
1223 return NULL;
1224 }
dfefa935 1225 refname = strcpy(refname_buffer, buf);
8a65ff76 1226 }
f989fea0
MH
1227 /* Please note that FETCH_HEAD has a second line containing other data. */
1228 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
55956350
JH
1229 if (flag)
1230 *flag |= REF_ISBROKEN;
a876ed83 1231 return NULL;
629cd3ac 1232 }
dfefa935 1233 return refname;
a876ed83
JH
1234}
1235
96ec7b1e
NTND
1236char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1237{
8cad4744 1238 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
96ec7b1e
NTND
1239 return ret ? xstrdup(ret) : NULL;
1240}
1241
d08bae7e
IL
1242/* The argument to filter_refs */
1243struct ref_filter {
1244 const char *pattern;
1245 each_ref_fn *fn;
1246 void *cb_data;
1247};
1248
dfefa935 1249int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
a876ed83 1250{
8d68493f 1251 if (resolve_ref_unsafe(refname, sha1, reading, flags))
a876ed83
JH
1252 return 0;
1253 return -1;
8a65ff76
LT
1254}
1255
dfefa935 1256int read_ref(const char *refname, unsigned char *sha1)
c6893323 1257{
dfefa935 1258 return read_ref_full(refname, sha1, 1, NULL);
c6893323
NTND
1259}
1260
bc5fd6d3 1261int ref_exists(const char *refname)
ef06b918 1262{
bc5fd6d3
MH
1263 unsigned char sha1[20];
1264 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
ef06b918
JH
1265}
1266
85be1fe3 1267static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
dfefa935 1268 void *data)
d08bae7e
IL
1269{
1270 struct ref_filter *filter = (struct ref_filter *)data;
dfefa935 1271 if (fnmatch(filter->pattern, refname, 0))
d08bae7e 1272 return 0;
85be1fe3 1273 return filter->fn(refname, sha1, flags, filter->cb_data);
d08bae7e
IL
1274}
1275
cb2ae1c4
MH
1276/*
1277 * Peel the named object; i.e., if the object is a tag, resolve the
1278 * tag recursively until a non-tag is found. Store the result to sha1
1279 * and return 0 iff successful. If the object is not a tag or is not
1280 * valid, return -1 and leave sha1 unchanged.
1281 */
1282static int peel_object(const unsigned char *name, unsigned char *sha1)
1283{
1284 struct object *o = lookup_unknown_object(name);
1285
1286 if (o->type == OBJ_NONE) {
1287 int type = sha1_object_info(name, NULL);
1288 if (type < 0)
1289 return -1;
1290 o->type = type;
1291 }
1292
1293 if (o->type != OBJ_TAG)
1294 return -1;
1295
1296 o = deref_tag_noverify(o);
1297 if (!o)
1298 return -1;
1299
1300 hashcpy(sha1, o->sha1);
1301 return 0;
1302}
1303
dfefa935 1304int peel_ref(const char *refname, unsigned char *sha1)
cf0adba7
JH
1305{
1306 int flag;
1307 unsigned char base[20];
cf0adba7 1308
dfefa935
MH
1309 if (current_ref && (current_ref->name == refname
1310 || !strcmp(current_ref->name, refname))) {
0ae91be0 1311 if (current_ref->flag & REF_KNOWS_PEELED) {
e6dbffa6
JK
1312 if (is_null_sha1(current_ref->u.value.peeled))
1313 return -1;
593f1bb8 1314 hashcpy(sha1, current_ref->u.value.peeled);
0ae91be0
SP
1315 return 0;
1316 }
cb2ae1c4 1317 return peel_object(current_ref->u.value.sha1, sha1);
0ae91be0
SP
1318 }
1319
dfefa935 1320 if (read_ref_full(refname, base, 1, &flag))
cf0adba7
JH
1321 return -1;
1322
1323 if ((flag & REF_ISPACKED)) {
f361baeb 1324 struct ref_entry *r = get_packed_ref(refname);
cf0adba7 1325
f361baeb 1326 if (r && (r->flag & REF_KNOWS_PEELED)) {
593f1bb8 1327 hashcpy(sha1, r->u.value.peeled);
e9c4c111 1328 return 0;
cf0adba7 1329 }
cf0adba7
JH
1330 }
1331
cb2ae1c4 1332 return peel_object(base, sha1);
cf0adba7
JH
1333}
1334
bc5fd6d3
MH
1335struct warn_if_dangling_data {
1336 FILE *fp;
1337 const char *refname;
1338 const char *msg_fmt;
1339};
1340
1341static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1342 int flags, void *cb_data)
1343{
1344 struct warn_if_dangling_data *d = cb_data;
1345 const char *resolves_to;
1346 unsigned char junk[20];
1347
1348 if (!(flags & REF_ISSYMREF))
1349 return 0;
1350
1351 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1352 if (!resolves_to || strcmp(resolves_to, d->refname))
1353 return 0;
1354
1355 fprintf(d->fp, d->msg_fmt, refname);
1be65eda 1356 fputc('\n', d->fp);
bc5fd6d3
MH
1357 return 0;
1358}
1359
1360void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1361{
1362 struct warn_if_dangling_data data;
1363
1364 data.fp = fp;
1365 data.refname = refname;
1366 data.msg_fmt = msg_fmt;
1367 for_each_rawref(warn_if_dangling_symref, &data);
1368}
1369
fcce1703
MH
1370/*
1371 * Call fn for each reference in the specified submodule for which the
1372 * refname begins with base. If trim is non-zero, then trim that many
1373 * characters off the beginning of each refname before passing the
1374 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include
1375 * broken references in the iteration. If fn ever returns a non-zero
1376 * value, stop the iteration and return that value; otherwise, return
1377 * 0.
1378 */
0bad611b
HV
1379static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
1380 int trim, int flags, void *cb_data)
8a65ff76 1381{
316b097a 1382 struct ref_cache *refs = get_ref_cache(submodule);
933ac036
MH
1383 struct ref_dir *packed_dir = get_packed_refs(refs);
1384 struct ref_dir *loose_dir = get_loose_refs(refs);
1385 int retval = 0;
1386
1387 if (base && *base) {
1388 packed_dir = find_containing_dir(packed_dir, base, 0);
1389 loose_dir = find_containing_dir(loose_dir, base, 0);
1390 }
1391
1392 if (packed_dir && loose_dir) {
1393 sort_ref_dir(packed_dir);
1394 sort_ref_dir(loose_dir);
1395 retval = do_for_each_ref_in_dirs(
1396 packed_dir, loose_dir,
1397 base, fn, trim, flags, cb_data);
1398 } else if (packed_dir) {
1399 sort_ref_dir(packed_dir);
1400 retval = do_for_each_ref_in_dir(
1401 packed_dir, 0,
1402 base, fn, trim, flags, cb_data);
1403 } else if (loose_dir) {
1404 sort_ref_dir(loose_dir);
1405 retval = do_for_each_ref_in_dir(
1406 loose_dir, 0,
1407 base, fn, trim, flags, cb_data);
1408 }
1409
1410 return retval;
8a65ff76
LT
1411}
1412
0bad611b 1413static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
723c31fe
LT
1414{
1415 unsigned char sha1[20];
8da19775
JH
1416 int flag;
1417
0bad611b
HV
1418 if (submodule) {
1419 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1420 return fn("HEAD", sha1, 0, cb_data);
1421
1422 return 0;
1423 }
1424
c6893323 1425 if (!read_ref_full("HEAD", sha1, 1, &flag))
8da19775 1426 return fn("HEAD", sha1, flag, cb_data);
0bad611b 1427
2f34ba32 1428 return 0;
723c31fe
LT
1429}
1430
0bad611b
HV
1431int head_ref(each_ref_fn fn, void *cb_data)
1432{
1433 return do_head_ref(NULL, fn, cb_data);
1434}
1435
9ef6aeb0
HV
1436int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1437{
1438 return do_head_ref(submodule, fn, cb_data);
1439}
1440
cb5d709f 1441int for_each_ref(each_ref_fn fn, void *cb_data)
8a65ff76 1442{
b3cfc406 1443 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
a62be77f
SE
1444}
1445
9ef6aeb0
HV
1446int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1447{
b3cfc406 1448 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
a62be77f
SE
1449}
1450
2a8177b6
CC
1451int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1452{
0bad611b 1453 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1454}
1455
9ef6aeb0
HV
1456int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1457 each_ref_fn fn, void *cb_data)
1458{
1459 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
2a8177b6
CC
1460}
1461
cb5d709f 1462int for_each_tag_ref(each_ref_fn fn, void *cb_data)
a62be77f 1463{
2a8177b6 1464 return for_each_ref_in("refs/tags/", fn, cb_data);
a62be77f
SE
1465}
1466
9ef6aeb0
HV
1467int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1468{
1469 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1470}
1471
cb5d709f 1472int for_each_branch_ref(each_ref_fn fn, void *cb_data)
a62be77f 1473{
2a8177b6 1474 return for_each_ref_in("refs/heads/", fn, cb_data);
a62be77f
SE
1475}
1476
9ef6aeb0
HV
1477int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1478{
1479 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1480}
1481
cb5d709f 1482int for_each_remote_ref(each_ref_fn fn, void *cb_data)
a62be77f 1483{
2a8177b6 1484 return for_each_ref_in("refs/remotes/", fn, cb_data);
f8948e2f
JH
1485}
1486
9ef6aeb0
HV
1487int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1488{
1489 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1490}
1491
29268700
CC
1492int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1493{
0bad611b 1494 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
29268700
CC
1495}
1496
a1bea2c1
JT
1497int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1498{
1499 struct strbuf buf = STRBUF_INIT;
1500 int ret = 0;
1501 unsigned char sha1[20];
1502 int flag;
1503
1504 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
c6893323 1505 if (!read_ref_full(buf.buf, sha1, 1, &flag))
a1bea2c1
JT
1506 ret = fn(buf.buf, sha1, flag, cb_data);
1507 strbuf_release(&buf);
1508
1509 return ret;
1510}
1511
1512int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1513{
1514 struct strbuf buf = STRBUF_INIT;
1515 int ret;
1516 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1517 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1518 strbuf_release(&buf);
1519 return ret;
1520}
1521
b09fe971
IL
1522int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1523 const char *prefix, void *cb_data)
d08bae7e
IL
1524{
1525 struct strbuf real_pattern = STRBUF_INIT;
1526 struct ref_filter filter;
d08bae7e
IL
1527 int ret;
1528
b09fe971 1529 if (!prefix && prefixcmp(pattern, "refs/"))
d08bae7e 1530 strbuf_addstr(&real_pattern, "refs/");
b09fe971
IL
1531 else if (prefix)
1532 strbuf_addstr(&real_pattern, prefix);
d08bae7e
IL
1533 strbuf_addstr(&real_pattern, pattern);
1534
894a9d33 1535 if (!has_glob_specials(pattern)) {
9517e6b8 1536 /* Append implied '/' '*' if not present. */
d08bae7e
IL
1537 if (real_pattern.buf[real_pattern.len - 1] != '/')
1538 strbuf_addch(&real_pattern, '/');
1539 /* No need to check for '*', there is none. */
1540 strbuf_addch(&real_pattern, '*');
1541 }
1542
1543 filter.pattern = real_pattern.buf;
1544 filter.fn = fn;
1545 filter.cb_data = cb_data;
1546 ret = for_each_ref(filter_refs, &filter);
1547
1548 strbuf_release(&real_pattern);
1549 return ret;
1550}
1551
b09fe971
IL
1552int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1553{
1554 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1555}
1556
f8948e2f
JH
1557int for_each_rawref(each_ref_fn fn, void *cb_data)
1558{
b3cfc406 1559 return do_for_each_ref(NULL, "", fn, 0,
f8948e2f 1560 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
8a65ff76
LT
1561}
1562
4577e483 1563const char *prettify_refname(const char *name)
a9c37a72 1564{
a9c37a72
DB
1565 return name + (
1566 !prefixcmp(name, "refs/heads/") ? 11 :
1567 !prefixcmp(name, "refs/tags/") ? 10 :
1568 !prefixcmp(name, "refs/remotes/") ? 13 :
1569 0);
1570}
1571
79803322
SP
1572const char *ref_rev_parse_rules[] = {
1573 "%.*s",
1574 "refs/%.*s",
1575 "refs/tags/%.*s",
1576 "refs/heads/%.*s",
1577 "refs/remotes/%.*s",
1578 "refs/remotes/%.*s/HEAD",
1579 NULL
1580};
1581
1582int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1583{
1584 const char **p;
1585 const int abbrev_name_len = strlen(abbrev_name);
1586
1587 for (p = rules; *p; p++) {
1588 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1589 return 1;
1590 }
1591 }
1592
1593 return 0;
1594}
1595
e5f38ec3 1596static struct ref_lock *verify_lock(struct ref_lock *lock,
4bd18c43
SP
1597 const unsigned char *old_sha1, int mustexist)
1598{
c6893323 1599 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
434cd0cd 1600 error("Can't verify ref %s", lock->ref_name);
4bd18c43
SP
1601 unlock_ref(lock);
1602 return NULL;
1603 }
a89fccd2 1604 if (hashcmp(lock->old_sha1, old_sha1)) {
434cd0cd 1605 error("Ref %s is at %s but expected %s", lock->ref_name,
4bd18c43
SP
1606 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1607 unlock_ref(lock);
1608 return NULL;
1609 }
1610 return lock;
1611}
1612
7155b727 1613static int remove_empty_directories(const char *file)
bc7127ef
JH
1614{
1615 /* we want to create a file but there is a directory there;
1616 * if that is an empty directory (or a directory that contains
1617 * only empty directories), remove them.
1618 */
7155b727
JS
1619 struct strbuf path;
1620 int result;
bc7127ef 1621
7155b727
JS
1622 strbuf_init(&path, 20);
1623 strbuf_addstr(&path, file);
1624
a0f4afbe 1625 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
7155b727
JS
1626
1627 strbuf_release(&path);
1628
1629 return result;
bc7127ef
JH
1630}
1631
ff74f7f1
JH
1632/*
1633 * *string and *len will only be substituted, and *string returned (for
1634 * later free()ing) if the string passed in is a magic short-hand form
1635 * to name a branch.
1636 */
1637static char *substitute_branch_name(const char **string, int *len)
1638{
1639 struct strbuf buf = STRBUF_INIT;
1640 int ret = interpret_branch_name(*string, &buf);
1641
1642 if (ret == *len) {
1643 size_t size;
1644 *string = strbuf_detach(&buf, &size);
1645 *len = size;
1646 return (char *)*string;
1647 }
1648
1649 return NULL;
1650}
1651
1652int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1653{
1654 char *last_branch = substitute_branch_name(&str, &len);
1655 const char **p, *r;
1656 int refs_found = 0;
1657
1658 *ref = NULL;
1659 for (p = ref_rev_parse_rules; *p; p++) {
1660 char fullref[PATH_MAX];
1661 unsigned char sha1_from_ref[20];
1662 unsigned char *this_result;
1663 int flag;
1664
1665 this_result = refs_found ? sha1_from_ref : sha1;
1666 mksnpath(fullref, sizeof(fullref), *p, len, str);
8cad4744 1667 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
ff74f7f1
JH
1668 if (r) {
1669 if (!refs_found++)
1670 *ref = xstrdup(r);
1671 if (!warn_ambiguous_refs)
1672 break;
55956350 1673 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
ff74f7f1 1674 warning("ignoring dangling symref %s.", fullref);
55956350
JH
1675 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1676 warning("ignoring broken ref %s.", fullref);
1677 }
ff74f7f1
JH
1678 }
1679 free(last_branch);
1680 return refs_found;
1681}
1682
1683int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1684{
1685 char *last_branch = substitute_branch_name(&str, &len);
1686 const char **p;
1687 int logs_found = 0;
1688
1689 *log = NULL;
1690 for (p = ref_rev_parse_rules; *p; p++) {
1691 struct stat st;
1692 unsigned char hash[20];
1693 char path[PATH_MAX];
1694 const char *ref, *it;
1695
1696 mksnpath(path, sizeof(path), *p, len, str);
8cad4744 1697 ref = resolve_ref_unsafe(path, hash, 1, NULL);
ff74f7f1
JH
1698 if (!ref)
1699 continue;
1700 if (!stat(git_path("logs/%s", path), &st) &&
1701 S_ISREG(st.st_mode))
1702 it = path;
1703 else if (strcmp(ref, path) &&
1704 !stat(git_path("logs/%s", ref), &st) &&
1705 S_ISREG(st.st_mode))
1706 it = ref;
1707 else
1708 continue;
1709 if (!logs_found++) {
1710 *log = xstrdup(it);
1711 hashcpy(sha1, hash);
1712 }
1713 if (!warn_ambiguous_refs)
1714 break;
1715 }
1716 free(last_branch);
1717 return logs_found;
1718}
1719
dfefa935
MH
1720static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1721 const unsigned char *old_sha1,
1722 int flags, int *type_p)
4bd18c43 1723{
434cd0cd 1724 char *ref_file;
dfefa935 1725 const char *orig_refname = refname;
4bd18c43 1726 struct ref_lock *lock;
5cc3cef9 1727 int last_errno = 0;
acd3b9ec 1728 int type, lflags;
4431fcc4 1729 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
5bdd8d4a 1730 int missing = 0;
4bd18c43
SP
1731
1732 lock = xcalloc(1, sizeof(struct ref_lock));
1733 lock->lock_fd = -1;
1734
8d68493f 1735 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
dfefa935 1736 if (!refname && errno == EISDIR) {
bc7127ef
JH
1737 /* we are trying to lock foo but we used to
1738 * have foo/bar which now does not exist;
1739 * it is normal for the empty directory 'foo'
1740 * to remain.
1741 */
dfefa935 1742 ref_file = git_path("%s", orig_refname);
5cc3cef9
JH
1743 if (remove_empty_directories(ref_file)) {
1744 last_errno = errno;
dfefa935 1745 error("there are still refs under '%s'", orig_refname);
5cc3cef9
JH
1746 goto error_return;
1747 }
8d68493f 1748 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
bc7127ef 1749 }
68db31cc
SV
1750 if (type_p)
1751 *type_p = type;
dfefa935 1752 if (!refname) {
5cc3cef9 1753 last_errno = errno;
818f477c 1754 error("unable to resolve reference %s: %s",
dfefa935 1755 orig_refname, strerror(errno));
5cc3cef9 1756 goto error_return;
4bd18c43 1757 }
5bdd8d4a 1758 missing = is_null_sha1(lock->old_sha1);
c976d415
LH
1759 /* When the ref did not exist and we are creating it,
1760 * make sure there is no existing ref that is packed
1761 * whose name begins with our refname, nor a ref whose
1762 * name is a proper prefix of our refname.
1763 */
5bdd8d4a 1764 if (missing &&
316b097a 1765 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
f475e08e 1766 last_errno = ENOTDIR;
c976d415 1767 goto error_return;
f475e08e 1768 }
22a3844e 1769
c33d5174 1770 lock->lk = xcalloc(1, sizeof(struct lock_file));
4bd18c43 1771
acd3b9ec
JH
1772 lflags = LOCK_DIE_ON_ERROR;
1773 if (flags & REF_NODEREF) {
dfefa935 1774 refname = orig_refname;
acd3b9ec
JH
1775 lflags |= LOCK_NODEREF;
1776 }
dfefa935
MH
1777 lock->ref_name = xstrdup(refname);
1778 lock->orig_ref_name = xstrdup(orig_refname);
1779 ref_file = git_path("%s", refname);
5bdd8d4a 1780 if (missing)
68db31cc
SV
1781 lock->force_write = 1;
1782 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1783 lock->force_write = 1;
4bd18c43 1784
5cc3cef9
JH
1785 if (safe_create_leading_directories(ref_file)) {
1786 last_errno = errno;
1787 error("unable to create directory for %s", ref_file);
1788 goto error_return;
1789 }
4bd18c43 1790
acd3b9ec 1791 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
4bd18c43 1792 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
5cc3cef9
JH
1793
1794 error_return:
1795 unlock_ref(lock);
1796 errno = last_errno;
1797 return NULL;
4bd18c43
SP
1798}
1799
dfefa935 1800struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
95fc7512 1801{
53cce84c 1802 char refpath[PATH_MAX];
dfefa935 1803 if (check_refname_format(refname, 0))
4bd18c43 1804 return NULL;
dfefa935 1805 strcpy(refpath, mkpath("refs/%s", refname));
68db31cc 1806 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
4bd18c43
SP
1807}
1808
dfefa935
MH
1809struct ref_lock *lock_any_ref_for_update(const char *refname,
1810 const unsigned char *old_sha1, int flags)
4bd18c43 1811{
dfefa935 1812 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
257f3020 1813 return NULL;
dfefa935 1814 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
c0277d15
JH
1815}
1816
d66da478
MH
1817struct repack_without_ref_sb {
1818 const char *refname;
1819 int fd;
1820};
1821
1822static int repack_without_ref_fn(const char *refname, const unsigned char *sha1,
1823 int flags, void *cb_data)
1824{
1825 struct repack_without_ref_sb *data = cb_data;
1826 char line[PATH_MAX + 100];
1827 int len;
1828
1829 if (!strcmp(data->refname, refname))
1830 return 0;
1831 len = snprintf(line, sizeof(line), "%s %s\n",
1832 sha1_to_hex(sha1), refname);
1833 /* this should not happen but just being defensive */
1834 if (len > sizeof(line))
1835 die("too long a refname '%s'", refname);
1836 write_or_die(data->fd, line, len);
1837 return 0;
1838}
1839
26a063a1
JH
1840static struct lock_file packlock;
1841
c0277d15
JH
1842static int repack_without_ref(const char *refname)
1843{
d66da478 1844 struct repack_without_ref_sb data;
b3f1280e 1845 struct ref_cache *refs = get_ref_cache(NULL);
7618fd80
MH
1846 struct ref_dir *packed;
1847
1848 if (!get_packed_ref(refname))
1849 return 0; /* refname does not exist in packed refs */
1850
d66da478
MH
1851 data.refname = refname;
1852 data.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1853 if (data.fd < 0) {
1b018fd9 1854 unable_to_lock_error(git_path("packed-refs"), errno);
c0277d15 1855 return error("cannot delete '%s' from packed refs", refname);
1b018fd9 1856 }
b3f1280e
JK
1857 clear_packed_ref_cache(refs);
1858 packed = get_packed_refs(refs);
d3177275 1859 do_for_each_ref_in_dir(packed, 0, "", repack_without_ref_fn, 0, 0, &data);
c0277d15
JH
1860 return commit_lock_file(&packlock);
1861}
1862
eca35a25 1863int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
c0277d15
JH
1864{
1865 struct ref_lock *lock;
eca35a25 1866 int err, i = 0, ret = 0, flag = 0;
c0277d15 1867
547d058f 1868 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
c0277d15
JH
1869 if (!lock)
1870 return 1;
045a476f 1871 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
c0277d15 1872 /* loose */
547d058f
RS
1873 i = strlen(lock->lk->filename) - 5; /* .lock */
1874 lock->lk->filename[i] = 0;
1875 err = unlink_or_warn(lock->lk->filename);
691f1a28 1876 if (err && errno != ENOENT)
c0277d15 1877 ret = 1;
691f1a28 1878
547d058f 1879 lock->lk->filename[i] = '.';
c0277d15
JH
1880 }
1881 /* removing the loose one could have resurrected an earlier
1882 * packed one. Also, if it was not loose we need to repack
1883 * without it.
1884 */
b274a714 1885 ret |= repack_without_ref(lock->ref_name);
c0277d15 1886
691f1a28 1887 unlink_or_warn(git_path("logs/%s", lock->ref_name));
3870a0d1 1888 invalidate_ref_cache(NULL);
c0277d15
JH
1889 unlock_ref(lock);
1890 return ret;
4bd18c43
SP
1891}
1892
765c2258
PH
1893/*
1894 * People using contrib's git-new-workdir have .git/logs/refs ->
1895 * /some/other/path/.git/logs/refs, and that may live on another device.
1896 *
1897 * IOW, to avoid cross device rename errors, the temporary renamed log must
1898 * live into logs/refs.
1899 */
1900#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1901
dfefa935 1902int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
c976d415 1903{
c976d415
LH
1904 unsigned char sha1[20], orig_sha1[20];
1905 int flag = 0, logmoved = 0;
1906 struct ref_lock *lock;
c976d415 1907 struct stat loginfo;
dfefa935 1908 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
eca35a25 1909 const char *symref = NULL;
316b097a 1910 struct ref_cache *refs = get_ref_cache(NULL);
c976d415 1911
450d4c0f 1912 if (log && S_ISLNK(loginfo.st_mode))
dfefa935 1913 return error("reflog for %s is a symlink", oldrefname);
c976d415 1914
8d68493f 1915 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
eca35a25 1916 if (flag & REF_ISSYMREF)
fa58186c 1917 return error("refname %s is a symbolic ref, renaming it is not supported",
dfefa935 1918 oldrefname);
eca35a25 1919 if (!symref)
dfefa935 1920 return error("refname %s not found", oldrefname);
c976d415 1921
316b097a 1922 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
c976d415
LH
1923 return 1;
1924
316b097a 1925 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
c976d415
LH
1926 return 1;
1927
dfefa935 1928 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
765c2258 1929 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
dfefa935 1930 oldrefname, strerror(errno));
c976d415 1931
dfefa935
MH
1932 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
1933 error("unable to delete old %s", oldrefname);
c976d415
LH
1934 goto rollback;
1935 }
1936
dfefa935
MH
1937 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
1938 delete_ref(newrefname, sha1, REF_NODEREF)) {
c976d415 1939 if (errno==EISDIR) {
dfefa935
MH
1940 if (remove_empty_directories(git_path("%s", newrefname))) {
1941 error("Directory not empty: %s", newrefname);
c976d415
LH
1942 goto rollback;
1943 }
1944 } else {
dfefa935 1945 error("unable to delete existing %s", newrefname);
c976d415
LH
1946 goto rollback;
1947 }
1948 }
1949
dfefa935
MH
1950 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
1951 error("unable to create directory for %s", newrefname);
c976d415
LH
1952 goto rollback;
1953 }
1954
1955 retry:
dfefa935 1956 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
d9e74d57
JR
1957 if (errno==EISDIR || errno==ENOTDIR) {
1958 /*
1959 * rename(a, b) when b is an existing
1960 * directory ought to result in ISDIR, but
1961 * Solaris 5.8 gives ENOTDIR. Sheesh.
1962 */
dfefa935
MH
1963 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
1964 error("Directory not empty: logs/%s", newrefname);
c976d415
LH
1965 goto rollback;
1966 }
1967 goto retry;
1968 } else {
765c2258 1969 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
dfefa935 1970 newrefname, strerror(errno));
c976d415
LH
1971 goto rollback;
1972 }
1973 }
1974 logmoved = log;
1975
dfefa935 1976 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
c976d415 1977 if (!lock) {
dfefa935 1978 error("unable to lock %s for update", newrefname);
c976d415
LH
1979 goto rollback;
1980 }
c976d415
LH
1981 lock->force_write = 1;
1982 hashcpy(lock->old_sha1, orig_sha1);
678d0f4c 1983 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
dfefa935 1984 error("unable to write current sha1 into %s", newrefname);
c976d415
LH
1985 goto rollback;
1986 }
1987
1988 return 0;
1989
1990 rollback:
dfefa935 1991 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
c976d415 1992 if (!lock) {
dfefa935 1993 error("unable to lock %s for rollback", oldrefname);
c976d415
LH
1994 goto rollbacklog;
1995 }
1996
1997 lock->force_write = 1;
1998 flag = log_all_ref_updates;
1999 log_all_ref_updates = 0;
2000 if (write_ref_sha1(lock, orig_sha1, NULL))
dfefa935 2001 error("unable to write current sha1 into %s", oldrefname);
c976d415
LH
2002 log_all_ref_updates = flag;
2003
2004 rollbacklog:
dfefa935 2005 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
c976d415 2006 error("unable to restore logfile %s from %s: %s",
dfefa935 2007 oldrefname, newrefname, strerror(errno));
c976d415 2008 if (!logmoved && log &&
dfefa935 2009 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
765c2258 2010 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
dfefa935 2011 oldrefname, strerror(errno));
c976d415
LH
2012
2013 return 1;
2014}
2015
435fc852 2016int close_ref(struct ref_lock *lock)
b531394d
BC
2017{
2018 if (close_lock_file(lock->lk))
2019 return -1;
2020 lock->lock_fd = -1;
2021 return 0;
2022}
2023
435fc852 2024int commit_ref(struct ref_lock *lock)
b531394d
BC
2025{
2026 if (commit_lock_file(lock->lk))
2027 return -1;
2028 lock->lock_fd = -1;
2029 return 0;
2030}
2031
e5f38ec3 2032void unlock_ref(struct ref_lock *lock)
4bd18c43 2033{
4ed7cd3a
BC
2034 /* Do not free lock->lk -- atexit() still looks at them */
2035 if (lock->lk)
2036 rollback_lock_file(lock->lk);
434cd0cd 2037 free(lock->ref_name);
1655707c 2038 free(lock->orig_ref_name);
4bd18c43
SP
2039 free(lock);
2040}
2041
0ec29a47
JH
2042/*
2043 * copy the reflog message msg to buf, which has been allocated sufficiently
2044 * large, while cleaning up the whitespaces. Especially, convert LF to space,
2045 * because reflog file is one line per entry.
2046 */
2047static int copy_msg(char *buf, const char *msg)
2048{
2049 char *cp = buf;
2050 char c;
2051 int wasspace = 1;
2052
2053 *cp++ = '\t';
2054 while ((c = *msg++)) {
2055 if (wasspace && isspace(c))
2056 continue;
2057 wasspace = isspace(c);
2058 if (wasspace)
2059 c = ' ';
2060 *cp++ = c;
2061 }
2062 while (buf < cp && isspace(cp[-1]))
2063 cp--;
2064 *cp++ = '\n';
2065 return cp - buf;
2066}
2067
dfefa935 2068int log_ref_setup(const char *refname, char *logfile, int bufsize)
6de08ae6 2069{
859c3017 2070 int logfd, oflags = O_APPEND | O_WRONLY;
9a13f0b7 2071
dfefa935 2072 git_snpath(logfile, bufsize, "logs/%s", refname);
4057deb5 2073 if (log_all_ref_updates &&
dfefa935
MH
2074 (!prefixcmp(refname, "refs/heads/") ||
2075 !prefixcmp(refname, "refs/remotes/") ||
2076 !prefixcmp(refname, "refs/notes/") ||
2077 !strcmp(refname, "HEAD"))) {
157aaea5 2078 if (safe_create_leading_directories(logfile) < 0)
6de08ae6 2079 return error("unable to create directory for %s",
157aaea5 2080 logfile);
6de08ae6
SP
2081 oflags |= O_CREAT;
2082 }
2083
157aaea5 2084 logfd = open(logfile, oflags, 0666);
6de08ae6 2085 if (logfd < 0) {
1974bf62 2086 if (!(oflags & O_CREAT) && errno == ENOENT)
6de08ae6 2087 return 0;
3b463c3f
JH
2088
2089 if ((oflags & O_CREAT) && errno == EISDIR) {
157aaea5 2090 if (remove_empty_directories(logfile)) {
3b463c3f 2091 return error("There are still logs under '%s'",
157aaea5 2092 logfile);
3b463c3f 2093 }
157aaea5 2094 logfd = open(logfile, oflags, 0666);
3b463c3f
JH
2095 }
2096
2097 if (logfd < 0)
2098 return error("Unable to append to %s: %s",
157aaea5 2099 logfile, strerror(errno));
6de08ae6
SP
2100 }
2101
157aaea5 2102 adjust_shared_perm(logfile);
859c3017
EM
2103 close(logfd);
2104 return 0;
2105}
443b92b6 2106
dfefa935 2107static int log_ref_write(const char *refname, const unsigned char *old_sha1,
859c3017
EM
2108 const unsigned char *new_sha1, const char *msg)
2109{
2110 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2111 unsigned maxlen, len;
2112 int msglen;
157aaea5 2113 char log_file[PATH_MAX];
859c3017
EM
2114 char *logrec;
2115 const char *committer;
2116
2117 if (log_all_ref_updates < 0)
2118 log_all_ref_updates = !is_bare_repository();
2119
dfefa935 2120 result = log_ref_setup(refname, log_file, sizeof(log_file));
859c3017
EM
2121 if (result)
2122 return result;
2123
2124 logfd = open(log_file, oflags);
2125 if (logfd < 0)
2126 return 0;
0ec29a47 2127 msglen = msg ? strlen(msg) : 0;
774751a8 2128 committer = git_committer_info(0);
8ac65937
JH
2129 maxlen = strlen(committer) + msglen + 100;
2130 logrec = xmalloc(maxlen);
2131 len = sprintf(logrec, "%s %s %s\n",
9a13f0b7
NP
2132 sha1_to_hex(old_sha1),
2133 sha1_to_hex(new_sha1),
8ac65937
JH
2134 committer);
2135 if (msglen)
0ec29a47 2136 len += copy_msg(logrec + len - 1, msg) - 1;
93822c22 2137 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
6de08ae6 2138 free(logrec);
91c8d590 2139 if (close(logfd) != 0 || written != len)
9a13f0b7 2140 return error("Unable to append to %s", log_file);
6de08ae6
SP
2141 return 0;
2142}
2143
c3b0dec5
LT
2144static int is_branch(const char *refname)
2145{
2146 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2147}
2148
4bd18c43
SP
2149int write_ref_sha1(struct ref_lock *lock,
2150 const unsigned char *sha1, const char *logmsg)
2151{
2152 static char term = '\n';
c3b0dec5 2153 struct object *o;
4bd18c43
SP
2154
2155 if (!lock)
95fc7512 2156 return -1;
a89fccd2 2157 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
4bd18c43
SP
2158 unlock_ref(lock);
2159 return 0;
95fc7512 2160 }
c3b0dec5
LT
2161 o = parse_object(sha1);
2162 if (!o) {
7be8b3ba 2163 error("Trying to write ref %s with nonexistent object %s",
c3b0dec5
LT
2164 lock->ref_name, sha1_to_hex(sha1));
2165 unlock_ref(lock);
2166 return -1;
2167 }
2168 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2169 error("Trying to write non-commit object %s to branch %s",
2170 sha1_to_hex(sha1), lock->ref_name);
2171 unlock_ref(lock);
2172 return -1;
2173 }
93822c22
AW
2174 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2175 write_in_full(lock->lock_fd, &term, 1) != 1
b531394d 2176 || close_ref(lock) < 0) {
c33d5174 2177 error("Couldn't write %s", lock->lk->filename);
4bd18c43
SP
2178 unlock_ref(lock);
2179 return -1;
2180 }
8bf90dc9 2181 clear_loose_ref_cache(get_ref_cache(NULL));
bd104db1
NP
2182 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2183 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2184 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
6de08ae6
SP
2185 unlock_ref(lock);
2186 return -1;
2187 }
605fac8b
NP
2188 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2189 /*
2190 * Special hack: If a branch is updated directly and HEAD
2191 * points to it (may happen on the remote side of a push
2192 * for example) then logically the HEAD reflog should be
2193 * updated too.
2194 * A generic solution implies reverse symref information,
2195 * but finding all symrefs pointing to the given branch
2196 * would be rather costly for this rare event (the direct
2197 * update of a branch) to be worth it. So let's cheat and
2198 * check with HEAD only which should cover 99% of all usage
2199 * scenarios (even 100% of the default ones).
2200 */
2201 unsigned char head_sha1[20];
2202 int head_flag;
2203 const char *head_ref;
8cad4744 2204 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
605fac8b
NP
2205 if (head_ref && (head_flag & REF_ISSYMREF) &&
2206 !strcmp(head_ref, lock->ref_name))
2207 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2208 }
b531394d 2209 if (commit_ref(lock)) {
434cd0cd 2210 error("Couldn't set %s", lock->ref_name);
4bd18c43
SP
2211 unlock_ref(lock);
2212 return -1;
2213 }
4bd18c43
SP
2214 unlock_ref(lock);
2215 return 0;
95fc7512 2216}
d556fae2 2217
8b5157e4
NP
2218int create_symref(const char *ref_target, const char *refs_heads_master,
2219 const char *logmsg)
41b625b0
NP
2220{
2221 const char *lockpath;
2222 char ref[1000];
2223 int fd, len, written;
a4f34cbb 2224 char *git_HEAD = git_pathdup("%s", ref_target);
8b5157e4
NP
2225 unsigned char old_sha1[20], new_sha1[20];
2226
2227 if (logmsg && read_ref(ref_target, old_sha1))
2228 hashclr(old_sha1);
41b625b0 2229
d48744d1
JH
2230 if (safe_create_leading_directories(git_HEAD) < 0)
2231 return error("unable to create directory for %s", git_HEAD);
2232
41b625b0
NP
2233#ifndef NO_SYMLINK_HEAD
2234 if (prefer_symlink_refs) {
2235 unlink(git_HEAD);
2236 if (!symlink(refs_heads_master, git_HEAD))
8b5157e4 2237 goto done;
41b625b0
NP
2238 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2239 }
2240#endif
2241
2242 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2243 if (sizeof(ref) <= len) {
2244 error("refname too long: %s", refs_heads_master);
47fc52e2 2245 goto error_free_return;
41b625b0
NP
2246 }
2247 lockpath = mkpath("%s.lock", git_HEAD);
2248 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2249 if (fd < 0) {
2250 error("Unable to open %s for writing", lockpath);
47fc52e2 2251 goto error_free_return;
41b625b0
NP
2252 }
2253 written = write_in_full(fd, ref, len);
91c8d590 2254 if (close(fd) != 0 || written != len) {
41b625b0 2255 error("Unable to write to %s", lockpath);
47fc52e2 2256 goto error_unlink_return;
41b625b0
NP
2257 }
2258 if (rename(lockpath, git_HEAD) < 0) {
41b625b0 2259 error("Unable to create %s", git_HEAD);
47fc52e2 2260 goto error_unlink_return;
41b625b0
NP
2261 }
2262 if (adjust_shared_perm(git_HEAD)) {
41b625b0 2263 error("Unable to fix permissions on %s", lockpath);
47fc52e2 2264 error_unlink_return:
691f1a28 2265 unlink_or_warn(lockpath);
47fc52e2
JH
2266 error_free_return:
2267 free(git_HEAD);
2268 return -1;
41b625b0 2269 }
8b5157e4 2270
ee96d11b 2271#ifndef NO_SYMLINK_HEAD
8b5157e4 2272 done:
ee96d11b 2273#endif
8b5157e4
NP
2274 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2275 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2276
47fc52e2 2277 free(git_HEAD);
41b625b0
NP
2278 return 0;
2279}
2280
16d7cc90
JH
2281static char *ref_msg(const char *line, const char *endp)
2282{
2283 const char *ep;
16d7cc90 2284 line += 82;
182af834
PH
2285 ep = memchr(line, '\n', endp - line);
2286 if (!ep)
2287 ep = endp;
2288 return xmemdupz(line, ep - line);
16d7cc90
JH
2289}
2290
dfefa935
MH
2291int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2292 unsigned char *sha1, char **msg,
2293 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
d556fae2 2294{
e5229042 2295 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
d556fae2 2296 char *tz_c;
e29cb53a 2297 int logfd, tz, reccnt = 0;
d556fae2
SP
2298 struct stat st;
2299 unsigned long date;
e5229042 2300 unsigned char logged_sha1[20];
cb48cb58 2301 void *log_mapped;
dc49cd76 2302 size_t mapsz;
d556fae2 2303
dfefa935 2304 logfile = git_path("logs/%s", refname);
d556fae2
SP
2305 logfd = open(logfile, O_RDONLY, 0);
2306 if (logfd < 0)
d824cbba 2307 die_errno("Unable to read log '%s'", logfile);
d556fae2
SP
2308 fstat(logfd, &st);
2309 if (!st.st_size)
2310 die("Log %s is empty.", logfile);
dc49cd76
SP
2311 mapsz = xsize_t(st.st_size);
2312 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
cb48cb58 2313 logdata = log_mapped;
d556fae2
SP
2314 close(logfd);
2315
e5229042 2316 lastrec = NULL;
d556fae2
SP
2317 rec = logend = logdata + st.st_size;
2318 while (logdata < rec) {
e29cb53a 2319 reccnt++;
d556fae2
SP
2320 if (logdata < rec && *(rec-1) == '\n')
2321 rec--;
e5229042
SP
2322 lastgt = NULL;
2323 while (logdata < rec && *(rec-1) != '\n') {
d556fae2 2324 rec--;
e5229042
SP
2325 if (*rec == '>')
2326 lastgt = rec;
2327 }
2328 if (!lastgt)
d556fae2 2329 die("Log %s is corrupt.", logfile);
e5229042 2330 date = strtoul(lastgt + 1, &tz_c, 10);
ab2a1a32 2331 if (date <= at_time || cnt == 0) {
76a44c5c 2332 tz = strtoul(tz_c, NULL, 10);
16d7cc90
JH
2333 if (msg)
2334 *msg = ref_msg(rec, logend);
2335 if (cutoff_time)
2336 *cutoff_time = date;
2337 if (cutoff_tz)
2338 *cutoff_tz = tz;
2339 if (cutoff_cnt)
76a44c5c 2340 *cutoff_cnt = reccnt - 1;
e5229042
SP
2341 if (lastrec) {
2342 if (get_sha1_hex(lastrec, logged_sha1))
2343 die("Log %s is corrupt.", logfile);
2344 if (get_sha1_hex(rec + 41, sha1))
2345 die("Log %s is corrupt.", logfile);
a89fccd2 2346 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2347 warning("Log %s has gap after %s.",
73013afd 2348 logfile, show_date(date, tz, DATE_RFC2822));
e5229042 2349 }
e5f38ec3
JH
2350 }
2351 else if (date == at_time) {
e5229042
SP
2352 if (get_sha1_hex(rec + 41, sha1))
2353 die("Log %s is corrupt.", logfile);
e5f38ec3
JH
2354 }
2355 else {
e5229042
SP
2356 if (get_sha1_hex(rec + 41, logged_sha1))
2357 die("Log %s is corrupt.", logfile);
a89fccd2 2358 if (hashcmp(logged_sha1, sha1)) {
edbc25c5 2359 warning("Log %s unexpectedly ended on %s.",
73013afd 2360 logfile, show_date(date, tz, DATE_RFC2822));
e5229042
SP
2361 }
2362 }
dc49cd76 2363 munmap(log_mapped, mapsz);
d556fae2
SP
2364 return 0;
2365 }
e5229042 2366 lastrec = rec;
ab2a1a32
JH
2367 if (cnt > 0)
2368 cnt--;
d556fae2
SP
2369 }
2370
e5229042
SP
2371 rec = logdata;
2372 while (rec < logend && *rec != '>' && *rec != '\n')
2373 rec++;
2374 if (rec == logend || *rec == '\n')
d556fae2 2375 die("Log %s is corrupt.", logfile);
e5229042 2376 date = strtoul(rec + 1, &tz_c, 10);
d556fae2
SP
2377 tz = strtoul(tz_c, NULL, 10);
2378 if (get_sha1_hex(logdata, sha1))
2379 die("Log %s is corrupt.", logfile);
d1a4489a
JK
2380 if (is_null_sha1(sha1)) {
2381 if (get_sha1_hex(logdata + 41, sha1))
2382 die("Log %s is corrupt.", logfile);
2383 }
16d7cc90
JH
2384 if (msg)
2385 *msg = ref_msg(logdata, logend);
dc49cd76 2386 munmap(log_mapped, mapsz);
16d7cc90
JH
2387
2388 if (cutoff_time)
2389 *cutoff_time = date;
2390 if (cutoff_tz)
2391 *cutoff_tz = tz;
2392 if (cutoff_cnt)
2393 *cutoff_cnt = reccnt;
2394 return 1;
d556fae2 2395}
2ff81662 2396
dfefa935 2397int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
2ff81662
JH
2398{
2399 const char *logfile;
2400 FILE *logfp;
8ca78803 2401 struct strbuf sb = STRBUF_INIT;
2266bf27 2402 int ret = 0;
2ff81662 2403
dfefa935 2404 logfile = git_path("logs/%s", refname);
2ff81662
JH
2405 logfp = fopen(logfile, "r");
2406 if (!logfp)
883d60fa 2407 return -1;
101d15e0
JH
2408
2409 if (ofs) {
2410 struct stat statbuf;
2411 if (fstat(fileno(logfp), &statbuf) ||
2412 statbuf.st_size < ofs ||
2413 fseek(logfp, -ofs, SEEK_END) ||
8ca78803 2414 strbuf_getwholeline(&sb, logfp, '\n')) {
9d33f7c2 2415 fclose(logfp);
8ca78803 2416 strbuf_release(&sb);
101d15e0 2417 return -1;
9d33f7c2 2418 }
101d15e0
JH
2419 }
2420
8ca78803 2421 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2ff81662 2422 unsigned char osha1[20], nsha1[20];
883d60fa
JS
2423 char *email_end, *message;
2424 unsigned long timestamp;
8ca78803 2425 int tz;
2ff81662
JH
2426
2427 /* old SP new SP name <email> SP time TAB msg LF */
8ca78803
RS
2428 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
2429 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
2430 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
2431 !(email_end = strchr(sb.buf + 82, '>')) ||
883d60fa
JS
2432 email_end[1] != ' ' ||
2433 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2434 !message || message[0] != ' ' ||
2435 (message[1] != '+' && message[1] != '-') ||
2436 !isdigit(message[2]) || !isdigit(message[3]) ||
b4dd4856 2437 !isdigit(message[4]) || !isdigit(message[5]))
2ff81662 2438 continue; /* corrupt? */
883d60fa
JS
2439 email_end[1] = '\0';
2440 tz = strtol(message + 1, NULL, 10);
b4dd4856
JS
2441 if (message[6] != '\t')
2442 message += 6;
2443 else
2444 message += 7;
8ca78803
RS
2445 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
2446 cb_data);
883d60fa 2447 if (ret)
2266bf27 2448 break;
2ff81662
JH
2449 }
2450 fclose(logfp);
8ca78803 2451 strbuf_release(&sb);
2266bf27 2452 return ret;
2ff81662 2453}
e29cb53a 2454
dfefa935 2455int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
101d15e0 2456{
dfefa935 2457 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
101d15e0
JH
2458}
2459
989c0e5d
MH
2460/*
2461 * Call fn for each reflog in the namespace indicated by name. name
2462 * must be empty or end with '/'. Name will be used as a scratch
2463 * space, but its contents will be restored before return.
2464 */
2465static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
eb8381c8 2466{
989c0e5d 2467 DIR *d = opendir(git_path("logs/%s", name->buf));
fcee5a14 2468 int retval = 0;
93c603fc 2469 struct dirent *de;
989c0e5d 2470 int oldlen = name->len;
eb8381c8 2471
93c603fc 2472 if (!d)
989c0e5d 2473 return name->len ? errno : 0;
eb8381c8 2474
93c603fc
MH
2475 while ((de = readdir(d)) != NULL) {
2476 struct stat st;
eb8381c8 2477
93c603fc
MH
2478 if (de->d_name[0] == '.')
2479 continue;
93c603fc
MH
2480 if (has_extension(de->d_name, ".lock"))
2481 continue;
989c0e5d
MH
2482 strbuf_addstr(name, de->d_name);
2483 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2484 ; /* silently ignore */
93c603fc 2485 } else {
eb8381c8 2486 if (S_ISDIR(st.st_mode)) {
989c0e5d
MH
2487 strbuf_addch(name, '/');
2488 retval = do_for_each_reflog(name, fn, cb_data);
eb8381c8
NP
2489 } else {
2490 unsigned char sha1[20];
989c0e5d
MH
2491 if (read_ref_full(name->buf, sha1, 0, NULL))
2492 retval = error("bad ref for %s", name->buf);
eb8381c8 2493 else
989c0e5d 2494 retval = fn(name->buf, sha1, 0, cb_data);
eb8381c8
NP
2495 }
2496 if (retval)
2497 break;
2498 }
989c0e5d 2499 strbuf_setlen(name, oldlen);
eb8381c8 2500 }
93c603fc 2501 closedir(d);
eb8381c8
NP
2502 return retval;
2503}
2504
2505int for_each_reflog(each_ref_fn fn, void *cb_data)
2506{
989c0e5d
MH
2507 int retval;
2508 struct strbuf name;
2509 strbuf_init(&name, PATH_MAX);
2510 retval = do_for_each_reflog(&name, fn, cb_data);
2511 strbuf_release(&name);
2512 return retval;
eb8381c8 2513}
3d9f037c
CR
2514
2515int update_ref(const char *action, const char *refname,
2516 const unsigned char *sha1, const unsigned char *oldval,
2517 int flags, enum action_on_err onerr)
2518{
2519 static struct ref_lock *lock;
2520 lock = lock_any_ref_for_update(refname, oldval, flags);
2521 if (!lock) {
2522 const char *str = "Cannot lock the ref '%s'.";
2523 switch (onerr) {
2524 case MSG_ON_ERR: error(str, refname); break;
2525 case DIE_ON_ERR: die(str, refname); break;
2526 case QUIET_ON_ERR: break;
2527 }
2528 return 1;
2529 }
2530 if (write_ref_sha1(lock, sha1, action) < 0) {
2531 const char *str = "Cannot update the ref '%s'.";
2532 switch (onerr) {
2533 case MSG_ON_ERR: error(str, refname); break;
2534 case DIE_ON_ERR: die(str, refname); break;
2535 case QUIET_ON_ERR: break;
2536 }
2537 return 1;
2538 }
2539 return 0;
2540}
cda69f48 2541
5483f799 2542struct ref *find_ref_by_name(const struct ref *list, const char *name)
cda69f48
JK
2543{
2544 for ( ; list; list = list->next)
2545 if (!strcmp(list->name, name))
5483f799 2546 return (struct ref *)list;
cda69f48
JK
2547 return NULL;
2548}
7c2b3029
JK
2549
2550/*
2551 * generate a format suitable for scanf from a ref_rev_parse_rules
2552 * rule, that is replace the "%.*s" spec with a "%s" spec
2553 */
2554static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2555{
2556 char *spec;
2557
2558 spec = strstr(rule, "%.*s");
2559 if (!spec || strstr(spec + 4, "%.*s"))
2560 die("invalid rule in ref_rev_parse_rules: %s", rule);
2561
2562 /* copy all until spec */
2563 strncpy(scanf_fmt, rule, spec - rule);
2564 scanf_fmt[spec - rule] = '\0';
2565 /* copy new spec */
2566 strcat(scanf_fmt, "%s");
2567 /* copy remaining rule */
2568 strcat(scanf_fmt, spec + 4);
2569
2570 return;
2571}
2572
dfefa935 2573char *shorten_unambiguous_ref(const char *refname, int strict)
7c2b3029
JK
2574{
2575 int i;
2576 static char **scanf_fmts;
2577 static int nr_rules;
2578 char *short_name;
2579
2580 /* pre generate scanf formats from ref_rev_parse_rules[] */
2581 if (!nr_rules) {
2582 size_t total_len = 0;
2583
2584 /* the rule list is NULL terminated, count them first */
2585 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2586 /* no +1 because strlen("%s") < strlen("%.*s") */
2587 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2588
2589 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2590
2591 total_len = 0;
2592 for (i = 0; i < nr_rules; i++) {
2593 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2594 + total_len;
2595 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2596 total_len += strlen(ref_rev_parse_rules[i]);
2597 }
2598 }
2599
2600 /* bail out if there are no rules */
2601 if (!nr_rules)
dfefa935 2602 return xstrdup(refname);
7c2b3029 2603
dfefa935
MH
2604 /* buffer for scanf result, at most refname must fit */
2605 short_name = xstrdup(refname);
7c2b3029
JK
2606
2607 /* skip first rule, it will always match */
2608 for (i = nr_rules - 1; i > 0 ; --i) {
2609 int j;
6e7b3309 2610 int rules_to_fail = i;
7c2b3029
JK
2611 int short_name_len;
2612
dfefa935 2613 if (1 != sscanf(refname, scanf_fmts[i], short_name))
7c2b3029
JK
2614 continue;
2615
2616 short_name_len = strlen(short_name);
2617
6e7b3309
BW
2618 /*
2619 * in strict mode, all (except the matched one) rules
2620 * must fail to resolve to a valid non-ambiguous ref
2621 */
2622 if (strict)
2623 rules_to_fail = nr_rules;
2624
7c2b3029
JK
2625 /*
2626 * check if the short name resolves to a valid ref,
2627 * but use only rules prior to the matched one
2628 */
6e7b3309 2629 for (j = 0; j < rules_to_fail; j++) {
7c2b3029 2630 const char *rule = ref_rev_parse_rules[j];
7c2b3029
JK
2631 char refname[PATH_MAX];
2632
6e7b3309
BW
2633 /* skip matched rule */
2634 if (i == j)
2635 continue;
2636
7c2b3029
JK
2637 /*
2638 * the short name is ambiguous, if it resolves
2639 * (with this previous rule) to a valid ref
2640 * read_ref() returns 0 on success
2641 */
2642 mksnpath(refname, sizeof(refname),
2643 rule, short_name_len, short_name);
c6893323 2644 if (ref_exists(refname))
7c2b3029
JK
2645 break;
2646 }
2647
2648 /*
2649 * short name is non-ambiguous if all previous rules
2650 * haven't resolved to a valid ref
2651 */
6e7b3309 2652 if (j == rules_to_fail)
7c2b3029
JK
2653 return short_name;
2654 }
2655
2656 free(short_name);
dfefa935 2657 return xstrdup(refname);
7c2b3029 2658}