upload/receive-pack: allow hiding ref hierarchies
[git/git.git] / refs.c
1 #include "cache.h"
2 #include "refs.h"
3 #include "object.h"
4 #include "tag.h"
5 #include "dir.h"
6 #include "string-list.h"
7
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 */
19
20 /* Return true iff ch is not allowed in reference names. */
21 static 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 */
37 static 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)
55 return 0; /* Component has zero length. */
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
71 int check_refname_format(const char *refname, int flags)
72 {
73 int component_len, component_count = 0;
74
75 while (1) {
76 /* We are at the start of a path component. */
77 component_len = check_refname_component(refname, flags);
78 if (component_len <= 0) {
79 if ((flags & REFNAME_REFSPEC_PATTERN) &&
80 refname[0] == '*' &&
81 (refname[1] == '\0' || refname[1] == '/')) {
82 /* Accept one wildcard as a full refname component. */
83 flags &= ~REFNAME_REFSPEC_PATTERN;
84 component_len = 1;
85 } else {
86 return -1;
87 }
88 }
89 component_count++;
90 if (refname[component_len] == '\0')
91 break;
92 /* Skip to next component. */
93 refname += component_len + 1;
94 }
95
96 if (refname[component_len - 1] == '.')
97 return -1; /* Refname ends with '.'. */
98 if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
99 return -1; /* Refname has only one component. */
100 return 0;
101 }
102
103 struct ref_entry;
104
105 /*
106 * Information used (along with the information in ref_entry) to
107 * describe a single cached reference. This data structure only
108 * occurs embedded in a union in struct ref_entry, and only when
109 * (ref_entry->flag & REF_DIR) is zero.
110 */
111 struct ref_value {
112 unsigned char sha1[20];
113 unsigned char peeled[20];
114 };
115
116 struct ref_cache;
117
118 /*
119 * Information used (along with the information in ref_entry) to
120 * describe a level in the hierarchy of references. This data
121 * structure only occurs embedded in a union in struct ref_entry, and
122 * only when (ref_entry.flag & REF_DIR) is set. In that case,
123 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
124 * in the directory have already been read:
125 *
126 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
127 * or packed references, already read.
128 *
129 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
130 * references that hasn't been read yet (nor has any of its
131 * subdirectories).
132 *
133 * Entries within a directory are stored within a growable array of
134 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
135 * sorted are sorted by their component name in strcmp() order and the
136 * remaining entries are unsorted.
137 *
138 * Loose references are read lazily, one directory at a time. When a
139 * directory of loose references is read, then all of the references
140 * in that directory are stored, and REF_INCOMPLETE stubs are created
141 * for any subdirectories, but the subdirectories themselves are not
142 * read. The reading is triggered by get_ref_dir().
143 */
144 struct ref_dir {
145 int nr, alloc;
146
147 /*
148 * Entries with index 0 <= i < sorted are sorted by name. New
149 * entries are appended to the list unsorted, and are sorted
150 * only when required; thus we avoid the need to sort the list
151 * after the addition of every reference.
152 */
153 int sorted;
154
155 /* A pointer to the ref_cache that contains this ref_dir. */
156 struct ref_cache *ref_cache;
157
158 struct ref_entry **entries;
159 };
160
161 /* ISSYMREF=0x01, ISPACKED=0x02, and ISBROKEN=0x04 are public interfaces */
162 #define REF_KNOWS_PEELED 0x08
163
164 /* ref_entry represents a directory of references */
165 #define REF_DIR 0x10
166
167 /*
168 * Entry has not yet been read from disk (used only for REF_DIR
169 * entries representing loose references)
170 */
171 #define REF_INCOMPLETE 0x20
172
173 /*
174 * A ref_entry represents either a reference or a "subdirectory" of
175 * references.
176 *
177 * Each directory in the reference namespace is represented by a
178 * ref_entry with (flags & REF_DIR) set and containing a subdir member
179 * that holds the entries in that directory that have been read so
180 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
181 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
182 * used for loose reference directories.
183 *
184 * References are represented by a ref_entry with (flags & REF_DIR)
185 * unset and a value member that describes the reference's value. The
186 * flag member is at the ref_entry level, but it is also needed to
187 * interpret the contents of the value field (in other words, a
188 * ref_value object is not very much use without the enclosing
189 * ref_entry).
190 *
191 * Reference names cannot end with slash and directories' names are
192 * always stored with a trailing slash (except for the top-level
193 * directory, which is always denoted by ""). This has two nice
194 * consequences: (1) when the entries in each subdir are sorted
195 * lexicographically by name (as they usually are), the references in
196 * a whole tree can be generated in lexicographic order by traversing
197 * the tree in left-to-right, depth-first order; (2) the names of
198 * references and subdirectories cannot conflict, and therefore the
199 * presence of an empty subdirectory does not block the creation of a
200 * similarly-named reference. (The fact that reference names with the
201 * same leading components can conflict *with each other* is a
202 * separate issue that is regulated by is_refname_available().)
203 *
204 * Please note that the name field contains the fully-qualified
205 * reference (or subdirectory) name. Space could be saved by only
206 * storing the relative names. But that would require the full names
207 * to be generated on the fly when iterating in do_for_each_ref(), and
208 * would break callback functions, who have always been able to assume
209 * that the name strings that they are passed will not be freed during
210 * the iteration.
211 */
212 struct ref_entry {
213 unsigned char flag; /* ISSYMREF? ISPACKED? */
214 union {
215 struct ref_value value; /* if not (flags&REF_DIR) */
216 struct ref_dir subdir; /* if (flags&REF_DIR) */
217 } u;
218 /*
219 * The full name of the reference (e.g., "refs/heads/master")
220 * or the full name of the directory with a trailing slash
221 * (e.g., "refs/heads/"):
222 */
223 char name[FLEX_ARRAY];
224 };
225
226 static void read_loose_refs(const char *dirname, struct ref_dir *dir);
227
228 static struct ref_dir *get_ref_dir(struct ref_entry *entry)
229 {
230 struct ref_dir *dir;
231 assert(entry->flag & REF_DIR);
232 dir = &entry->u.subdir;
233 if (entry->flag & REF_INCOMPLETE) {
234 read_loose_refs(entry->name, dir);
235 entry->flag &= ~REF_INCOMPLETE;
236 }
237 return dir;
238 }
239
240 static struct ref_entry *create_ref_entry(const char *refname,
241 const unsigned char *sha1, int flag,
242 int check_name)
243 {
244 int len;
245 struct ref_entry *ref;
246
247 if (check_name &&
248 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
249 die("Reference has invalid format: '%s'", refname);
250 len = strlen(refname) + 1;
251 ref = xmalloc(sizeof(struct ref_entry) + len);
252 hashcpy(ref->u.value.sha1, sha1);
253 hashclr(ref->u.value.peeled);
254 memcpy(ref->name, refname, len);
255 ref->flag = flag;
256 return ref;
257 }
258
259 static void clear_ref_dir(struct ref_dir *dir);
260
261 static void free_ref_entry(struct ref_entry *entry)
262 {
263 if (entry->flag & REF_DIR) {
264 /*
265 * Do not use get_ref_dir() here, as that might
266 * trigger the reading of loose refs.
267 */
268 clear_ref_dir(&entry->u.subdir);
269 }
270 free(entry);
271 }
272
273 /*
274 * Add a ref_entry to the end of dir (unsorted). Entry is always
275 * stored directly in dir; no recursion into subdirectories is
276 * done.
277 */
278 static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
279 {
280 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
281 dir->entries[dir->nr++] = entry;
282 /* optimize for the case that entries are added in order */
283 if (dir->nr == 1 ||
284 (dir->nr == dir->sorted + 1 &&
285 strcmp(dir->entries[dir->nr - 2]->name,
286 dir->entries[dir->nr - 1]->name) < 0))
287 dir->sorted = dir->nr;
288 }
289
290 /*
291 * Clear and free all entries in dir, recursively.
292 */
293 static void clear_ref_dir(struct ref_dir *dir)
294 {
295 int i;
296 for (i = 0; i < dir->nr; i++)
297 free_ref_entry(dir->entries[i]);
298 free(dir->entries);
299 dir->sorted = dir->nr = dir->alloc = 0;
300 dir->entries = NULL;
301 }
302
303 /*
304 * Create a struct ref_entry object for the specified dirname.
305 * dirname is the name of the directory with a trailing slash (e.g.,
306 * "refs/heads/") or "" for the top-level directory.
307 */
308 static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
309 const char *dirname, size_t len,
310 int incomplete)
311 {
312 struct ref_entry *direntry;
313 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
314 memcpy(direntry->name, dirname, len);
315 direntry->name[len] = '\0';
316 direntry->u.subdir.ref_cache = ref_cache;
317 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
318 return direntry;
319 }
320
321 static int ref_entry_cmp(const void *a, const void *b)
322 {
323 struct ref_entry *one = *(struct ref_entry **)a;
324 struct ref_entry *two = *(struct ref_entry **)b;
325 return strcmp(one->name, two->name);
326 }
327
328 static void sort_ref_dir(struct ref_dir *dir);
329
330 struct string_slice {
331 size_t len;
332 const char *str;
333 };
334
335 static int ref_entry_cmp_sslice(const void *key_, const void *ent_)
336 {
337 struct string_slice *key = (struct string_slice *)key_;
338 struct ref_entry *ent = *(struct ref_entry **)ent_;
339 int entlen = strlen(ent->name);
340 int cmplen = key->len < entlen ? key->len : entlen;
341 int cmp = memcmp(key->str, ent->name, cmplen);
342 if (cmp)
343 return cmp;
344 return key->len - entlen;
345 }
346
347 /*
348 * Return the entry with the given refname from the ref_dir
349 * (non-recursively), sorting dir if necessary. Return NULL if no
350 * such entry is found. dir must already be complete.
351 */
352 static struct ref_entry *search_ref_dir(struct ref_dir *dir,
353 const char *refname, size_t len)
354 {
355 struct ref_entry **r;
356 struct string_slice key;
357
358 if (refname == NULL || !dir->nr)
359 return NULL;
360
361 sort_ref_dir(dir);
362 key.len = len;
363 key.str = refname;
364 r = bsearch(&key, dir->entries, dir->nr, sizeof(*dir->entries),
365 ref_entry_cmp_sslice);
366
367 if (r == NULL)
368 return NULL;
369
370 return *r;
371 }
372
373 /*
374 * Search for a directory entry directly within dir (without
375 * recursing). Sort dir if necessary. subdirname must be a directory
376 * name (i.e., end in '/'). If mkdir is set, then create the
377 * directory if it is missing; otherwise, return NULL if the desired
378 * directory cannot be found. dir must already be complete.
379 */
380 static struct ref_dir *search_for_subdir(struct ref_dir *dir,
381 const char *subdirname, size_t len,
382 int mkdir)
383 {
384 struct ref_entry *entry = search_ref_dir(dir, subdirname, len);
385 if (!entry) {
386 if (!mkdir)
387 return NULL;
388 /*
389 * Since dir is complete, the absence of a subdir
390 * means that the subdir really doesn't exist;
391 * therefore, create an empty record for it but mark
392 * the record complete.
393 */
394 entry = create_dir_entry(dir->ref_cache, subdirname, len, 0);
395 add_entry_to_dir(dir, entry);
396 }
397 return get_ref_dir(entry);
398 }
399
400 /*
401 * If refname is a reference name, find the ref_dir within the dir
402 * tree that should hold refname. If refname is a directory name
403 * (i.e., ends in '/'), then return that ref_dir itself. dir must
404 * represent the top-level directory and must already be complete.
405 * Sort ref_dirs and recurse into subdirectories as necessary. If
406 * mkdir is set, then create any missing directories; otherwise,
407 * return NULL if the desired directory cannot be found.
408 */
409 static struct ref_dir *find_containing_dir(struct ref_dir *dir,
410 const char *refname, int mkdir)
411 {
412 const char *slash;
413 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
414 size_t dirnamelen = slash - refname + 1;
415 struct ref_dir *subdir;
416 subdir = search_for_subdir(dir, refname, dirnamelen, mkdir);
417 if (!subdir) {
418 dir = NULL;
419 break;
420 }
421 dir = subdir;
422 }
423
424 return dir;
425 }
426
427 /*
428 * Find the value entry with the given name in dir, sorting ref_dirs
429 * and recursing into subdirectories as necessary. If the name is not
430 * found or it corresponds to a directory entry, return NULL.
431 */
432 static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
433 {
434 struct ref_entry *entry;
435 dir = find_containing_dir(dir, refname, 0);
436 if (!dir)
437 return NULL;
438 entry = search_ref_dir(dir, refname, strlen(refname));
439 return (entry && !(entry->flag & REF_DIR)) ? entry : NULL;
440 }
441
442 /*
443 * Add a ref_entry to the ref_dir (unsorted), recursing into
444 * subdirectories as necessary. dir must represent the top-level
445 * directory. Return 0 on success.
446 */
447 static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
448 {
449 dir = find_containing_dir(dir, ref->name, 1);
450 if (!dir)
451 return -1;
452 add_entry_to_dir(dir, ref);
453 return 0;
454 }
455
456 /*
457 * Emit a warning and return true iff ref1 and ref2 have the same name
458 * and the same sha1. Die if they have the same name but different
459 * sha1s.
460 */
461 static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
462 {
463 if (strcmp(ref1->name, ref2->name))
464 return 0;
465
466 /* Duplicate name; make sure that they don't conflict: */
467
468 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
469 /* This is impossible by construction */
470 die("Reference directory conflict: %s", ref1->name);
471
472 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
473 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
474
475 warning("Duplicated ref: %s", ref1->name);
476 return 1;
477 }
478
479 /*
480 * Sort the entries in dir non-recursively (if they are not already
481 * sorted) and remove any duplicate entries.
482 */
483 static void sort_ref_dir(struct ref_dir *dir)
484 {
485 int i, j;
486 struct ref_entry *last = NULL;
487
488 /*
489 * This check also prevents passing a zero-length array to qsort(),
490 * which is a problem on some platforms.
491 */
492 if (dir->sorted == dir->nr)
493 return;
494
495 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
496
497 /* Remove any duplicates: */
498 for (i = 0, j = 0; j < dir->nr; j++) {
499 struct ref_entry *entry = dir->entries[j];
500 if (last && is_dup_ref(last, entry))
501 free_ref_entry(entry);
502 else
503 last = dir->entries[i++] = entry;
504 }
505 dir->sorted = dir->nr = i;
506 }
507
508 #define DO_FOR_EACH_INCLUDE_BROKEN 01
509
510 static struct ref_entry *current_ref;
511
512 static int do_one_ref(const char *base, each_ref_fn fn, int trim,
513 int flags, void *cb_data, struct ref_entry *entry)
514 {
515 int retval;
516 if (prefixcmp(entry->name, base))
517 return 0;
518
519 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
520 if (entry->flag & REF_ISBROKEN)
521 return 0; /* ignore broken refs e.g. dangling symref */
522 if (!has_sha1_file(entry->u.value.sha1)) {
523 error("%s does not point to a valid object!", entry->name);
524 return 0;
525 }
526 }
527 current_ref = entry;
528 retval = fn(entry->name + trim, entry->u.value.sha1, entry->flag, cb_data);
529 current_ref = NULL;
530 return retval;
531 }
532
533 /*
534 * Call fn for each reference in dir that has index in the range
535 * offset <= index < dir->nr. Recurse into subdirectories that are in
536 * that index range, sorting them before iterating. This function
537 * does not sort dir itself; it should be sorted beforehand.
538 */
539 static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
540 const char *base,
541 each_ref_fn fn, int trim, int flags, void *cb_data)
542 {
543 int i;
544 assert(dir->sorted == dir->nr);
545 for (i = offset; i < dir->nr; i++) {
546 struct ref_entry *entry = dir->entries[i];
547 int retval;
548 if (entry->flag & REF_DIR) {
549 struct ref_dir *subdir = get_ref_dir(entry);
550 sort_ref_dir(subdir);
551 retval = do_for_each_ref_in_dir(subdir, 0,
552 base, fn, trim, flags, cb_data);
553 } else {
554 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
555 }
556 if (retval)
557 return retval;
558 }
559 return 0;
560 }
561
562 /*
563 * Call fn for each reference in the union of dir1 and dir2, in order
564 * by refname. Recurse into subdirectories. If a value entry appears
565 * in both dir1 and dir2, then only process the version that is in
566 * dir2. The input dirs must already be sorted, but subdirs will be
567 * sorted as needed.
568 */
569 static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
570 struct ref_dir *dir2,
571 const char *base, each_ref_fn fn, int trim,
572 int flags, void *cb_data)
573 {
574 int retval;
575 int i1 = 0, i2 = 0;
576
577 assert(dir1->sorted == dir1->nr);
578 assert(dir2->sorted == dir2->nr);
579 while (1) {
580 struct ref_entry *e1, *e2;
581 int cmp;
582 if (i1 == dir1->nr) {
583 return do_for_each_ref_in_dir(dir2, i2,
584 base, fn, trim, flags, cb_data);
585 }
586 if (i2 == dir2->nr) {
587 return do_for_each_ref_in_dir(dir1, i1,
588 base, fn, trim, flags, cb_data);
589 }
590 e1 = dir1->entries[i1];
591 e2 = dir2->entries[i2];
592 cmp = strcmp(e1->name, e2->name);
593 if (cmp == 0) {
594 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
595 /* Both are directories; descend them in parallel. */
596 struct ref_dir *subdir1 = get_ref_dir(e1);
597 struct ref_dir *subdir2 = get_ref_dir(e2);
598 sort_ref_dir(subdir1);
599 sort_ref_dir(subdir2);
600 retval = do_for_each_ref_in_dirs(
601 subdir1, subdir2,
602 base, fn, trim, flags, cb_data);
603 i1++;
604 i2++;
605 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
606 /* Both are references; ignore the one from dir1. */
607 retval = do_one_ref(base, fn, trim, flags, cb_data, e2);
608 i1++;
609 i2++;
610 } else {
611 die("conflict between reference and directory: %s",
612 e1->name);
613 }
614 } else {
615 struct ref_entry *e;
616 if (cmp < 0) {
617 e = e1;
618 i1++;
619 } else {
620 e = e2;
621 i2++;
622 }
623 if (e->flag & REF_DIR) {
624 struct ref_dir *subdir = get_ref_dir(e);
625 sort_ref_dir(subdir);
626 retval = do_for_each_ref_in_dir(
627 subdir, 0,
628 base, fn, trim, flags, cb_data);
629 } else {
630 retval = do_one_ref(base, fn, trim, flags, cb_data, e);
631 }
632 }
633 if (retval)
634 return retval;
635 }
636 if (i1 < dir1->nr)
637 return do_for_each_ref_in_dir(dir1, i1,
638 base, fn, trim, flags, cb_data);
639 if (i2 < dir2->nr)
640 return do_for_each_ref_in_dir(dir2, i2,
641 base, fn, trim, flags, cb_data);
642 return 0;
643 }
644
645 /*
646 * Return true iff refname1 and refname2 conflict with each other.
647 * Two reference names conflict if one of them exactly matches the
648 * leading components of the other; e.g., "foo/bar" conflicts with
649 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
650 * "foo/barbados".
651 */
652 static int names_conflict(const char *refname1, const char *refname2)
653 {
654 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
655 ;
656 return (*refname1 == '\0' && *refname2 == '/')
657 || (*refname1 == '/' && *refname2 == '\0');
658 }
659
660 struct name_conflict_cb {
661 const char *refname;
662 const char *oldrefname;
663 const char *conflicting_refname;
664 };
665
666 static int name_conflict_fn(const char *existingrefname, const unsigned char *sha1,
667 int flags, void *cb_data)
668 {
669 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
670 if (data->oldrefname && !strcmp(data->oldrefname, existingrefname))
671 return 0;
672 if (names_conflict(data->refname, existingrefname)) {
673 data->conflicting_refname = existingrefname;
674 return 1;
675 }
676 return 0;
677 }
678
679 /*
680 * Return true iff a reference named refname could be created without
681 * conflicting with the name of an existing reference in array. If
682 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
683 * (e.g., because oldrefname is scheduled for deletion in the same
684 * operation).
685 */
686 static int is_refname_available(const char *refname, const char *oldrefname,
687 struct ref_dir *dir)
688 {
689 struct name_conflict_cb data;
690 data.refname = refname;
691 data.oldrefname = oldrefname;
692 data.conflicting_refname = NULL;
693
694 sort_ref_dir(dir);
695 if (do_for_each_ref_in_dir(dir, 0, "", name_conflict_fn,
696 0, DO_FOR_EACH_INCLUDE_BROKEN,
697 &data)) {
698 error("'%s' exists; cannot create '%s'",
699 data.conflicting_refname, refname);
700 return 0;
701 }
702 return 1;
703 }
704
705 /*
706 * Future: need to be in "struct repository"
707 * when doing a full libification.
708 */
709 static struct ref_cache {
710 struct ref_cache *next;
711 struct ref_entry *loose;
712 struct ref_entry *packed;
713 /* The submodule name, or "" for the main repo. */
714 char name[FLEX_ARRAY];
715 } *ref_cache;
716
717 static void clear_packed_ref_cache(struct ref_cache *refs)
718 {
719 if (refs->packed) {
720 free_ref_entry(refs->packed);
721 refs->packed = NULL;
722 }
723 }
724
725 static void clear_loose_ref_cache(struct ref_cache *refs)
726 {
727 if (refs->loose) {
728 free_ref_entry(refs->loose);
729 refs->loose = NULL;
730 }
731 }
732
733 static struct ref_cache *create_ref_cache(const char *submodule)
734 {
735 int len;
736 struct ref_cache *refs;
737 if (!submodule)
738 submodule = "";
739 len = strlen(submodule) + 1;
740 refs = xcalloc(1, sizeof(struct ref_cache) + len);
741 memcpy(refs->name, submodule, len);
742 return refs;
743 }
744
745 /*
746 * Return a pointer to a ref_cache for the specified submodule. For
747 * the main repository, use submodule==NULL. The returned structure
748 * will be allocated and initialized but not necessarily populated; it
749 * should not be freed.
750 */
751 static struct ref_cache *get_ref_cache(const char *submodule)
752 {
753 struct ref_cache *refs = ref_cache;
754 if (!submodule)
755 submodule = "";
756 while (refs) {
757 if (!strcmp(submodule, refs->name))
758 return refs;
759 refs = refs->next;
760 }
761
762 refs = create_ref_cache(submodule);
763 refs->next = ref_cache;
764 ref_cache = refs;
765 return refs;
766 }
767
768 void invalidate_ref_cache(const char *submodule)
769 {
770 struct ref_cache *refs = get_ref_cache(submodule);
771 clear_packed_ref_cache(refs);
772 clear_loose_ref_cache(refs);
773 }
774
775 /*
776 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
777 * Return a pointer to the refname within the line (null-terminated),
778 * or NULL if there was a problem.
779 */
780 static const char *parse_ref_line(char *line, unsigned char *sha1)
781 {
782 /*
783 * 42: the answer to everything.
784 *
785 * In this case, it happens to be the answer to
786 * 40 (length of sha1 hex representation)
787 * +1 (space in between hex and name)
788 * +1 (newline at the end of the line)
789 */
790 int len = strlen(line) - 42;
791
792 if (len <= 0)
793 return NULL;
794 if (get_sha1_hex(line, sha1) < 0)
795 return NULL;
796 if (!isspace(line[40]))
797 return NULL;
798 line += 41;
799 if (isspace(*line))
800 return NULL;
801 if (line[len] != '\n')
802 return NULL;
803 line[len] = 0;
804
805 return line;
806 }
807
808 static void read_packed_refs(FILE *f, struct ref_dir *dir)
809 {
810 struct ref_entry *last = NULL;
811 char refline[PATH_MAX];
812 int flag = REF_ISPACKED;
813
814 while (fgets(refline, sizeof(refline), f)) {
815 unsigned char sha1[20];
816 const char *refname;
817 static const char header[] = "# pack-refs with:";
818
819 if (!strncmp(refline, header, sizeof(header)-1)) {
820 const char *traits = refline + sizeof(header) - 1;
821 if (strstr(traits, " peeled "))
822 flag |= REF_KNOWS_PEELED;
823 /* perhaps other traits later as well */
824 continue;
825 }
826
827 refname = parse_ref_line(refline, sha1);
828 if (refname) {
829 last = create_ref_entry(refname, sha1, flag, 1);
830 add_ref(dir, last);
831 continue;
832 }
833 if (last &&
834 refline[0] == '^' &&
835 strlen(refline) == 42 &&
836 refline[41] == '\n' &&
837 !get_sha1_hex(refline + 1, sha1))
838 hashcpy(last->u.value.peeled, sha1);
839 }
840 }
841
842 static struct ref_dir *get_packed_refs(struct ref_cache *refs)
843 {
844 if (!refs->packed) {
845 const char *packed_refs_file;
846 FILE *f;
847
848 refs->packed = create_dir_entry(refs, "", 0, 0);
849 if (*refs->name)
850 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
851 else
852 packed_refs_file = git_path("packed-refs");
853 f = fopen(packed_refs_file, "r");
854 if (f) {
855 read_packed_refs(f, get_ref_dir(refs->packed));
856 fclose(f);
857 }
858 }
859 return get_ref_dir(refs->packed);
860 }
861
862 void add_packed_ref(const char *refname, const unsigned char *sha1)
863 {
864 add_ref(get_packed_refs(get_ref_cache(NULL)),
865 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
866 }
867
868 /*
869 * Read the loose references from the namespace dirname into dir
870 * (without recursing). dirname must end with '/'. dir must be the
871 * directory entry corresponding to dirname.
872 */
873 static void read_loose_refs(const char *dirname, struct ref_dir *dir)
874 {
875 struct ref_cache *refs = dir->ref_cache;
876 DIR *d;
877 const char *path;
878 struct dirent *de;
879 int dirnamelen = strlen(dirname);
880 struct strbuf refname;
881
882 if (*refs->name)
883 path = git_path_submodule(refs->name, "%s", dirname);
884 else
885 path = git_path("%s", dirname);
886
887 d = opendir(path);
888 if (!d)
889 return;
890
891 strbuf_init(&refname, dirnamelen + 257);
892 strbuf_add(&refname, dirname, dirnamelen);
893
894 while ((de = readdir(d)) != NULL) {
895 unsigned char sha1[20];
896 struct stat st;
897 int flag;
898 const char *refdir;
899
900 if (de->d_name[0] == '.')
901 continue;
902 if (has_extension(de->d_name, ".lock"))
903 continue;
904 strbuf_addstr(&refname, de->d_name);
905 refdir = *refs->name
906 ? git_path_submodule(refs->name, "%s", refname.buf)
907 : git_path("%s", refname.buf);
908 if (stat(refdir, &st) < 0) {
909 ; /* silently ignore */
910 } else if (S_ISDIR(st.st_mode)) {
911 strbuf_addch(&refname, '/');
912 add_entry_to_dir(dir,
913 create_dir_entry(refs, refname.buf,
914 refname.len, 1));
915 } else {
916 if (*refs->name) {
917 hashclr(sha1);
918 flag = 0;
919 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
920 hashclr(sha1);
921 flag |= REF_ISBROKEN;
922 }
923 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
924 hashclr(sha1);
925 flag |= REF_ISBROKEN;
926 }
927 add_entry_to_dir(dir,
928 create_ref_entry(refname.buf, sha1, flag, 1));
929 }
930 strbuf_setlen(&refname, dirnamelen);
931 }
932 strbuf_release(&refname);
933 closedir(d);
934 }
935
936 static struct ref_dir *get_loose_refs(struct ref_cache *refs)
937 {
938 if (!refs->loose) {
939 /*
940 * Mark the top-level directory complete because we
941 * are about to read the only subdirectory that can
942 * hold references:
943 */
944 refs->loose = create_dir_entry(refs, "", 0, 0);
945 /*
946 * Create an incomplete entry for "refs/":
947 */
948 add_entry_to_dir(get_ref_dir(refs->loose),
949 create_dir_entry(refs, "refs/", 5, 1));
950 }
951 return get_ref_dir(refs->loose);
952 }
953
954 /* We allow "recursive" symbolic refs. Only within reason, though */
955 #define MAXDEPTH 5
956 #define MAXREFLEN (1024)
957
958 /*
959 * Called by resolve_gitlink_ref_recursive() after it failed to read
960 * from the loose refs in ref_cache refs. Find <refname> in the
961 * packed-refs file for the submodule.
962 */
963 static int resolve_gitlink_packed_ref(struct ref_cache *refs,
964 const char *refname, unsigned char *sha1)
965 {
966 struct ref_entry *ref;
967 struct ref_dir *dir = get_packed_refs(refs);
968
969 ref = find_ref(dir, refname);
970 if (ref == NULL)
971 return -1;
972
973 memcpy(sha1, ref->u.value.sha1, 20);
974 return 0;
975 }
976
977 static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
978 const char *refname, unsigned char *sha1,
979 int recursion)
980 {
981 int fd, len;
982 char buffer[128], *p;
983 char *path;
984
985 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
986 return -1;
987 path = *refs->name
988 ? git_path_submodule(refs->name, "%s", refname)
989 : git_path("%s", refname);
990 fd = open(path, O_RDONLY);
991 if (fd < 0)
992 return resolve_gitlink_packed_ref(refs, refname, sha1);
993
994 len = read(fd, buffer, sizeof(buffer)-1);
995 close(fd);
996 if (len < 0)
997 return -1;
998 while (len && isspace(buffer[len-1]))
999 len--;
1000 buffer[len] = 0;
1001
1002 /* Was it a detached head or an old-fashioned symlink? */
1003 if (!get_sha1_hex(buffer, sha1))
1004 return 0;
1005
1006 /* Symref? */
1007 if (strncmp(buffer, "ref:", 4))
1008 return -1;
1009 p = buffer + 4;
1010 while (isspace(*p))
1011 p++;
1012
1013 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
1014 }
1015
1016 int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
1017 {
1018 int len = strlen(path), retval;
1019 char *submodule;
1020 struct ref_cache *refs;
1021
1022 while (len && path[len-1] == '/')
1023 len--;
1024 if (!len)
1025 return -1;
1026 submodule = xstrndup(path, len);
1027 refs = get_ref_cache(submodule);
1028 free(submodule);
1029
1030 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1031 return retval;
1032 }
1033
1034 /*
1035 * Try to read ref from the packed references. On success, set sha1
1036 * and return 0; otherwise, return -1.
1037 */
1038 static int get_packed_ref(const char *refname, unsigned char *sha1)
1039 {
1040 struct ref_dir *packed = get_packed_refs(get_ref_cache(NULL));
1041 struct ref_entry *entry = find_ref(packed, refname);
1042 if (entry) {
1043 hashcpy(sha1, entry->u.value.sha1);
1044 return 0;
1045 }
1046 return -1;
1047 }
1048
1049 const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
1050 {
1051 int depth = MAXDEPTH;
1052 ssize_t len;
1053 char buffer[256];
1054 static char refname_buffer[256];
1055
1056 if (flag)
1057 *flag = 0;
1058
1059 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1060 return NULL;
1061
1062 for (;;) {
1063 char path[PATH_MAX];
1064 struct stat st;
1065 char *buf;
1066 int fd;
1067
1068 if (--depth < 0)
1069 return NULL;
1070
1071 git_snpath(path, sizeof(path), "%s", refname);
1072
1073 if (lstat(path, &st) < 0) {
1074 if (errno != ENOENT)
1075 return NULL;
1076 /*
1077 * The loose reference file does not exist;
1078 * check for a packed reference.
1079 */
1080 if (!get_packed_ref(refname, sha1)) {
1081 if (flag)
1082 *flag |= REF_ISPACKED;
1083 return refname;
1084 }
1085 /* The reference is not a packed reference, either. */
1086 if (reading) {
1087 return NULL;
1088 } else {
1089 hashclr(sha1);
1090 return refname;
1091 }
1092 }
1093
1094 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1095 if (S_ISLNK(st.st_mode)) {
1096 len = readlink(path, buffer, sizeof(buffer)-1);
1097 if (len < 0)
1098 return NULL;
1099 buffer[len] = 0;
1100 if (!prefixcmp(buffer, "refs/") &&
1101 !check_refname_format(buffer, 0)) {
1102 strcpy(refname_buffer, buffer);
1103 refname = refname_buffer;
1104 if (flag)
1105 *flag |= REF_ISSYMREF;
1106 continue;
1107 }
1108 }
1109
1110 /* Is it a directory? */
1111 if (S_ISDIR(st.st_mode)) {
1112 errno = EISDIR;
1113 return NULL;
1114 }
1115
1116 /*
1117 * Anything else, just open it and try to use it as
1118 * a ref
1119 */
1120 fd = open(path, O_RDONLY);
1121 if (fd < 0)
1122 return NULL;
1123 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1124 close(fd);
1125 if (len < 0)
1126 return NULL;
1127 while (len && isspace(buffer[len-1]))
1128 len--;
1129 buffer[len] = '\0';
1130
1131 /*
1132 * Is it a symbolic ref?
1133 */
1134 if (prefixcmp(buffer, "ref:"))
1135 break;
1136 if (flag)
1137 *flag |= REF_ISSYMREF;
1138 buf = buffer + 4;
1139 while (isspace(*buf))
1140 buf++;
1141 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1142 if (flag)
1143 *flag |= REF_ISBROKEN;
1144 return NULL;
1145 }
1146 refname = strcpy(refname_buffer, buf);
1147 }
1148 /* Please note that FETCH_HEAD has a second line containing other data. */
1149 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
1150 if (flag)
1151 *flag |= REF_ISBROKEN;
1152 return NULL;
1153 }
1154 return refname;
1155 }
1156
1157 char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1158 {
1159 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
1160 return ret ? xstrdup(ret) : NULL;
1161 }
1162
1163 /* The argument to filter_refs */
1164 struct ref_filter {
1165 const char *pattern;
1166 each_ref_fn *fn;
1167 void *cb_data;
1168 };
1169
1170 int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
1171 {
1172 if (resolve_ref_unsafe(refname, sha1, reading, flags))
1173 return 0;
1174 return -1;
1175 }
1176
1177 int read_ref(const char *refname, unsigned char *sha1)
1178 {
1179 return read_ref_full(refname, sha1, 1, NULL);
1180 }
1181
1182 int ref_exists(const char *refname)
1183 {
1184 unsigned char sha1[20];
1185 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
1186 }
1187
1188 static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1189 void *data)
1190 {
1191 struct ref_filter *filter = (struct ref_filter *)data;
1192 if (fnmatch(filter->pattern, refname, 0))
1193 return 0;
1194 return filter->fn(refname, sha1, flags, filter->cb_data);
1195 }
1196
1197 int peel_ref(const char *refname, unsigned char *sha1)
1198 {
1199 int flag;
1200 unsigned char base[20];
1201 struct object *o;
1202
1203 if (current_ref && (current_ref->name == refname
1204 || !strcmp(current_ref->name, refname))) {
1205 if (current_ref->flag & REF_KNOWS_PEELED) {
1206 if (is_null_sha1(current_ref->u.value.peeled))
1207 return -1;
1208 hashcpy(sha1, current_ref->u.value.peeled);
1209 return 0;
1210 }
1211 hashcpy(base, current_ref->u.value.sha1);
1212 goto fallback;
1213 }
1214
1215 if (read_ref_full(refname, base, 1, &flag))
1216 return -1;
1217
1218 if ((flag & REF_ISPACKED)) {
1219 struct ref_dir *dir = get_packed_refs(get_ref_cache(NULL));
1220 struct ref_entry *r = find_ref(dir, refname);
1221
1222 if (r != NULL && r->flag & REF_KNOWS_PEELED) {
1223 hashcpy(sha1, r->u.value.peeled);
1224 return 0;
1225 }
1226 }
1227
1228 fallback:
1229 o = lookup_unknown_object(base);
1230 if (o->type == OBJ_NONE) {
1231 int type = sha1_object_info(base, NULL);
1232 if (type < 0)
1233 return -1;
1234 o->type = type;
1235 }
1236
1237 if (o->type == OBJ_TAG) {
1238 o = deref_tag_noverify(o);
1239 if (o) {
1240 hashcpy(sha1, o->sha1);
1241 return 0;
1242 }
1243 }
1244 return -1;
1245 }
1246
1247 struct warn_if_dangling_data {
1248 FILE *fp;
1249 const char *refname;
1250 const char *msg_fmt;
1251 };
1252
1253 static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1254 int flags, void *cb_data)
1255 {
1256 struct warn_if_dangling_data *d = cb_data;
1257 const char *resolves_to;
1258 unsigned char junk[20];
1259
1260 if (!(flags & REF_ISSYMREF))
1261 return 0;
1262
1263 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1264 if (!resolves_to || strcmp(resolves_to, d->refname))
1265 return 0;
1266
1267 fprintf(d->fp, d->msg_fmt, refname);
1268 fputc('\n', d->fp);
1269 return 0;
1270 }
1271
1272 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1273 {
1274 struct warn_if_dangling_data data;
1275
1276 data.fp = fp;
1277 data.refname = refname;
1278 data.msg_fmt = msg_fmt;
1279 for_each_rawref(warn_if_dangling_symref, &data);
1280 }
1281
1282 static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
1283 int trim, int flags, void *cb_data)
1284 {
1285 struct ref_cache *refs = get_ref_cache(submodule);
1286 struct ref_dir *packed_dir = get_packed_refs(refs);
1287 struct ref_dir *loose_dir = get_loose_refs(refs);
1288 int retval = 0;
1289
1290 if (base && *base) {
1291 packed_dir = find_containing_dir(packed_dir, base, 0);
1292 loose_dir = find_containing_dir(loose_dir, base, 0);
1293 }
1294
1295 if (packed_dir && loose_dir) {
1296 sort_ref_dir(packed_dir);
1297 sort_ref_dir(loose_dir);
1298 retval = do_for_each_ref_in_dirs(
1299 packed_dir, loose_dir,
1300 base, fn, trim, flags, cb_data);
1301 } else if (packed_dir) {
1302 sort_ref_dir(packed_dir);
1303 retval = do_for_each_ref_in_dir(
1304 packed_dir, 0,
1305 base, fn, trim, flags, cb_data);
1306 } else if (loose_dir) {
1307 sort_ref_dir(loose_dir);
1308 retval = do_for_each_ref_in_dir(
1309 loose_dir, 0,
1310 base, fn, trim, flags, cb_data);
1311 }
1312
1313 return retval;
1314 }
1315
1316 static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1317 {
1318 unsigned char sha1[20];
1319 int flag;
1320
1321 if (submodule) {
1322 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1323 return fn("HEAD", sha1, 0, cb_data);
1324
1325 return 0;
1326 }
1327
1328 if (!read_ref_full("HEAD", sha1, 1, &flag))
1329 return fn("HEAD", sha1, flag, cb_data);
1330
1331 return 0;
1332 }
1333
1334 int head_ref(each_ref_fn fn, void *cb_data)
1335 {
1336 return do_head_ref(NULL, fn, cb_data);
1337 }
1338
1339 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1340 {
1341 return do_head_ref(submodule, fn, cb_data);
1342 }
1343
1344 int for_each_ref(each_ref_fn fn, void *cb_data)
1345 {
1346 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
1347 }
1348
1349 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1350 {
1351 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
1352 }
1353
1354 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1355 {
1356 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
1357 }
1358
1359 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1360 each_ref_fn fn, void *cb_data)
1361 {
1362 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
1363 }
1364
1365 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1366 {
1367 return for_each_ref_in("refs/tags/", fn, cb_data);
1368 }
1369
1370 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1371 {
1372 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1373 }
1374
1375 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1376 {
1377 return for_each_ref_in("refs/heads/", fn, cb_data);
1378 }
1379
1380 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1381 {
1382 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1383 }
1384
1385 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1386 {
1387 return for_each_ref_in("refs/remotes/", fn, cb_data);
1388 }
1389
1390 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1391 {
1392 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1393 }
1394
1395 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1396 {
1397 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
1398 }
1399
1400 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1401 {
1402 struct strbuf buf = STRBUF_INIT;
1403 int ret = 0;
1404 unsigned char sha1[20];
1405 int flag;
1406
1407 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
1408 if (!read_ref_full(buf.buf, sha1, 1, &flag))
1409 ret = fn(buf.buf, sha1, flag, cb_data);
1410 strbuf_release(&buf);
1411
1412 return ret;
1413 }
1414
1415 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1416 {
1417 struct strbuf buf = STRBUF_INIT;
1418 int ret;
1419 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1420 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1421 strbuf_release(&buf);
1422 return ret;
1423 }
1424
1425 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1426 const char *prefix, void *cb_data)
1427 {
1428 struct strbuf real_pattern = STRBUF_INIT;
1429 struct ref_filter filter;
1430 int ret;
1431
1432 if (!prefix && prefixcmp(pattern, "refs/"))
1433 strbuf_addstr(&real_pattern, "refs/");
1434 else if (prefix)
1435 strbuf_addstr(&real_pattern, prefix);
1436 strbuf_addstr(&real_pattern, pattern);
1437
1438 if (!has_glob_specials(pattern)) {
1439 /* Append implied '/' '*' if not present. */
1440 if (real_pattern.buf[real_pattern.len - 1] != '/')
1441 strbuf_addch(&real_pattern, '/');
1442 /* No need to check for '*', there is none. */
1443 strbuf_addch(&real_pattern, '*');
1444 }
1445
1446 filter.pattern = real_pattern.buf;
1447 filter.fn = fn;
1448 filter.cb_data = cb_data;
1449 ret = for_each_ref(filter_refs, &filter);
1450
1451 strbuf_release(&real_pattern);
1452 return ret;
1453 }
1454
1455 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1456 {
1457 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1458 }
1459
1460 int for_each_rawref(each_ref_fn fn, void *cb_data)
1461 {
1462 return do_for_each_ref(NULL, "", fn, 0,
1463 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1464 }
1465
1466 const char *prettify_refname(const char *name)
1467 {
1468 return name + (
1469 !prefixcmp(name, "refs/heads/") ? 11 :
1470 !prefixcmp(name, "refs/tags/") ? 10 :
1471 !prefixcmp(name, "refs/remotes/") ? 13 :
1472 0);
1473 }
1474
1475 const char *ref_rev_parse_rules[] = {
1476 "%.*s",
1477 "refs/%.*s",
1478 "refs/tags/%.*s",
1479 "refs/heads/%.*s",
1480 "refs/remotes/%.*s",
1481 "refs/remotes/%.*s/HEAD",
1482 NULL
1483 };
1484
1485 int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1486 {
1487 const char **p;
1488 const int abbrev_name_len = strlen(abbrev_name);
1489
1490 for (p = rules; *p; p++) {
1491 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1492 return 1;
1493 }
1494 }
1495
1496 return 0;
1497 }
1498
1499 static struct ref_lock *verify_lock(struct ref_lock *lock,
1500 const unsigned char *old_sha1, int mustexist)
1501 {
1502 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
1503 error("Can't verify ref %s", lock->ref_name);
1504 unlock_ref(lock);
1505 return NULL;
1506 }
1507 if (hashcmp(lock->old_sha1, old_sha1)) {
1508 error("Ref %s is at %s but expected %s", lock->ref_name,
1509 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1510 unlock_ref(lock);
1511 return NULL;
1512 }
1513 return lock;
1514 }
1515
1516 static int remove_empty_directories(const char *file)
1517 {
1518 /* we want to create a file but there is a directory there;
1519 * if that is an empty directory (or a directory that contains
1520 * only empty directories), remove them.
1521 */
1522 struct strbuf path;
1523 int result;
1524
1525 strbuf_init(&path, 20);
1526 strbuf_addstr(&path, file);
1527
1528 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
1529
1530 strbuf_release(&path);
1531
1532 return result;
1533 }
1534
1535 /*
1536 * *string and *len will only be substituted, and *string returned (for
1537 * later free()ing) if the string passed in is a magic short-hand form
1538 * to name a branch.
1539 */
1540 static char *substitute_branch_name(const char **string, int *len)
1541 {
1542 struct strbuf buf = STRBUF_INIT;
1543 int ret = interpret_branch_name(*string, &buf);
1544
1545 if (ret == *len) {
1546 size_t size;
1547 *string = strbuf_detach(&buf, &size);
1548 *len = size;
1549 return (char *)*string;
1550 }
1551
1552 return NULL;
1553 }
1554
1555 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1556 {
1557 char *last_branch = substitute_branch_name(&str, &len);
1558 const char **p, *r;
1559 int refs_found = 0;
1560
1561 *ref = NULL;
1562 for (p = ref_rev_parse_rules; *p; p++) {
1563 char fullref[PATH_MAX];
1564 unsigned char sha1_from_ref[20];
1565 unsigned char *this_result;
1566 int flag;
1567
1568 this_result = refs_found ? sha1_from_ref : sha1;
1569 mksnpath(fullref, sizeof(fullref), *p, len, str);
1570 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
1571 if (r) {
1572 if (!refs_found++)
1573 *ref = xstrdup(r);
1574 if (!warn_ambiguous_refs)
1575 break;
1576 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
1577 warning("ignoring dangling symref %s.", fullref);
1578 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1579 warning("ignoring broken ref %s.", fullref);
1580 }
1581 }
1582 free(last_branch);
1583 return refs_found;
1584 }
1585
1586 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1587 {
1588 char *last_branch = substitute_branch_name(&str, &len);
1589 const char **p;
1590 int logs_found = 0;
1591
1592 *log = NULL;
1593 for (p = ref_rev_parse_rules; *p; p++) {
1594 struct stat st;
1595 unsigned char hash[20];
1596 char path[PATH_MAX];
1597 const char *ref, *it;
1598
1599 mksnpath(path, sizeof(path), *p, len, str);
1600 ref = resolve_ref_unsafe(path, hash, 1, NULL);
1601 if (!ref)
1602 continue;
1603 if (!stat(git_path("logs/%s", path), &st) &&
1604 S_ISREG(st.st_mode))
1605 it = path;
1606 else if (strcmp(ref, path) &&
1607 !stat(git_path("logs/%s", ref), &st) &&
1608 S_ISREG(st.st_mode))
1609 it = ref;
1610 else
1611 continue;
1612 if (!logs_found++) {
1613 *log = xstrdup(it);
1614 hashcpy(sha1, hash);
1615 }
1616 if (!warn_ambiguous_refs)
1617 break;
1618 }
1619 free(last_branch);
1620 return logs_found;
1621 }
1622
1623 static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1624 const unsigned char *old_sha1,
1625 int flags, int *type_p)
1626 {
1627 char *ref_file;
1628 const char *orig_refname = refname;
1629 struct ref_lock *lock;
1630 int last_errno = 0;
1631 int type, lflags;
1632 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1633 int missing = 0;
1634
1635 lock = xcalloc(1, sizeof(struct ref_lock));
1636 lock->lock_fd = -1;
1637
1638 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
1639 if (!refname && errno == EISDIR) {
1640 /* we are trying to lock foo but we used to
1641 * have foo/bar which now does not exist;
1642 * it is normal for the empty directory 'foo'
1643 * to remain.
1644 */
1645 ref_file = git_path("%s", orig_refname);
1646 if (remove_empty_directories(ref_file)) {
1647 last_errno = errno;
1648 error("there are still refs under '%s'", orig_refname);
1649 goto error_return;
1650 }
1651 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
1652 }
1653 if (type_p)
1654 *type_p = type;
1655 if (!refname) {
1656 last_errno = errno;
1657 error("unable to resolve reference %s: %s",
1658 orig_refname, strerror(errno));
1659 goto error_return;
1660 }
1661 missing = is_null_sha1(lock->old_sha1);
1662 /* When the ref did not exist and we are creating it,
1663 * make sure there is no existing ref that is packed
1664 * whose name begins with our refname, nor a ref whose
1665 * name is a proper prefix of our refname.
1666 */
1667 if (missing &&
1668 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
1669 last_errno = ENOTDIR;
1670 goto error_return;
1671 }
1672
1673 lock->lk = xcalloc(1, sizeof(struct lock_file));
1674
1675 lflags = LOCK_DIE_ON_ERROR;
1676 if (flags & REF_NODEREF) {
1677 refname = orig_refname;
1678 lflags |= LOCK_NODEREF;
1679 }
1680 lock->ref_name = xstrdup(refname);
1681 lock->orig_ref_name = xstrdup(orig_refname);
1682 ref_file = git_path("%s", refname);
1683 if (missing)
1684 lock->force_write = 1;
1685 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1686 lock->force_write = 1;
1687
1688 if (safe_create_leading_directories(ref_file)) {
1689 last_errno = errno;
1690 error("unable to create directory for %s", ref_file);
1691 goto error_return;
1692 }
1693
1694 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
1695 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
1696
1697 error_return:
1698 unlock_ref(lock);
1699 errno = last_errno;
1700 return NULL;
1701 }
1702
1703 struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
1704 {
1705 char refpath[PATH_MAX];
1706 if (check_refname_format(refname, 0))
1707 return NULL;
1708 strcpy(refpath, mkpath("refs/%s", refname));
1709 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
1710 }
1711
1712 struct ref_lock *lock_any_ref_for_update(const char *refname,
1713 const unsigned char *old_sha1, int flags)
1714 {
1715 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1716 return NULL;
1717 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
1718 }
1719
1720 struct repack_without_ref_sb {
1721 const char *refname;
1722 int fd;
1723 };
1724
1725 static int repack_without_ref_fn(const char *refname, const unsigned char *sha1,
1726 int flags, void *cb_data)
1727 {
1728 struct repack_without_ref_sb *data = cb_data;
1729 char line[PATH_MAX + 100];
1730 int len;
1731
1732 if (!strcmp(data->refname, refname))
1733 return 0;
1734 len = snprintf(line, sizeof(line), "%s %s\n",
1735 sha1_to_hex(sha1), refname);
1736 /* this should not happen but just being defensive */
1737 if (len > sizeof(line))
1738 die("too long a refname '%s'", refname);
1739 write_or_die(data->fd, line, len);
1740 return 0;
1741 }
1742
1743 static struct lock_file packlock;
1744
1745 static int repack_without_ref(const char *refname)
1746 {
1747 struct repack_without_ref_sb data;
1748 struct ref_cache *refs = get_ref_cache(NULL);
1749 struct ref_dir *packed = get_packed_refs(refs);
1750 if (find_ref(packed, refname) == NULL)
1751 return 0;
1752 data.refname = refname;
1753 data.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1754 if (data.fd < 0) {
1755 unable_to_lock_error(git_path("packed-refs"), errno);
1756 return error("cannot delete '%s' from packed refs", refname);
1757 }
1758 clear_packed_ref_cache(refs);
1759 packed = get_packed_refs(refs);
1760 do_for_each_ref_in_dir(packed, 0, "", repack_without_ref_fn, 0, 0, &data);
1761 return commit_lock_file(&packlock);
1762 }
1763
1764 int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
1765 {
1766 struct ref_lock *lock;
1767 int err, i = 0, ret = 0, flag = 0;
1768
1769 lock = lock_ref_sha1_basic(refname, sha1, delopt, &flag);
1770 if (!lock)
1771 return 1;
1772 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
1773 /* loose */
1774 i = strlen(lock->lk->filename) - 5; /* .lock */
1775 lock->lk->filename[i] = 0;
1776 err = unlink_or_warn(lock->lk->filename);
1777 if (err && errno != ENOENT)
1778 ret = 1;
1779
1780 lock->lk->filename[i] = '.';
1781 }
1782 /* removing the loose one could have resurrected an earlier
1783 * packed one. Also, if it was not loose we need to repack
1784 * without it.
1785 */
1786 ret |= repack_without_ref(lock->ref_name);
1787
1788 unlink_or_warn(git_path("logs/%s", lock->ref_name));
1789 invalidate_ref_cache(NULL);
1790 unlock_ref(lock);
1791 return ret;
1792 }
1793
1794 /*
1795 * People using contrib's git-new-workdir have .git/logs/refs ->
1796 * /some/other/path/.git/logs/refs, and that may live on another device.
1797 *
1798 * IOW, to avoid cross device rename errors, the temporary renamed log must
1799 * live into logs/refs.
1800 */
1801 #define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1802
1803 int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
1804 {
1805 unsigned char sha1[20], orig_sha1[20];
1806 int flag = 0, logmoved = 0;
1807 struct ref_lock *lock;
1808 struct stat loginfo;
1809 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
1810 const char *symref = NULL;
1811 struct ref_cache *refs = get_ref_cache(NULL);
1812
1813 if (log && S_ISLNK(loginfo.st_mode))
1814 return error("reflog for %s is a symlink", oldrefname);
1815
1816 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
1817 if (flag & REF_ISSYMREF)
1818 return error("refname %s is a symbolic ref, renaming it is not supported",
1819 oldrefname);
1820 if (!symref)
1821 return error("refname %s not found", oldrefname);
1822
1823 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
1824 return 1;
1825
1826 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
1827 return 1;
1828
1829 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
1830 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
1831 oldrefname, strerror(errno));
1832
1833 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
1834 error("unable to delete old %s", oldrefname);
1835 goto rollback;
1836 }
1837
1838 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
1839 delete_ref(newrefname, sha1, REF_NODEREF)) {
1840 if (errno==EISDIR) {
1841 if (remove_empty_directories(git_path("%s", newrefname))) {
1842 error("Directory not empty: %s", newrefname);
1843 goto rollback;
1844 }
1845 } else {
1846 error("unable to delete existing %s", newrefname);
1847 goto rollback;
1848 }
1849 }
1850
1851 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
1852 error("unable to create directory for %s", newrefname);
1853 goto rollback;
1854 }
1855
1856 retry:
1857 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
1858 if (errno==EISDIR || errno==ENOTDIR) {
1859 /*
1860 * rename(a, b) when b is an existing
1861 * directory ought to result in ISDIR, but
1862 * Solaris 5.8 gives ENOTDIR. Sheesh.
1863 */
1864 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
1865 error("Directory not empty: logs/%s", newrefname);
1866 goto rollback;
1867 }
1868 goto retry;
1869 } else {
1870 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
1871 newrefname, strerror(errno));
1872 goto rollback;
1873 }
1874 }
1875 logmoved = log;
1876
1877 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
1878 if (!lock) {
1879 error("unable to lock %s for update", newrefname);
1880 goto rollback;
1881 }
1882 lock->force_write = 1;
1883 hashcpy(lock->old_sha1, orig_sha1);
1884 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1885 error("unable to write current sha1 into %s", newrefname);
1886 goto rollback;
1887 }
1888
1889 return 0;
1890
1891 rollback:
1892 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
1893 if (!lock) {
1894 error("unable to lock %s for rollback", oldrefname);
1895 goto rollbacklog;
1896 }
1897
1898 lock->force_write = 1;
1899 flag = log_all_ref_updates;
1900 log_all_ref_updates = 0;
1901 if (write_ref_sha1(lock, orig_sha1, NULL))
1902 error("unable to write current sha1 into %s", oldrefname);
1903 log_all_ref_updates = flag;
1904
1905 rollbacklog:
1906 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
1907 error("unable to restore logfile %s from %s: %s",
1908 oldrefname, newrefname, strerror(errno));
1909 if (!logmoved && log &&
1910 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
1911 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
1912 oldrefname, strerror(errno));
1913
1914 return 1;
1915 }
1916
1917 int close_ref(struct ref_lock *lock)
1918 {
1919 if (close_lock_file(lock->lk))
1920 return -1;
1921 lock->lock_fd = -1;
1922 return 0;
1923 }
1924
1925 int commit_ref(struct ref_lock *lock)
1926 {
1927 if (commit_lock_file(lock->lk))
1928 return -1;
1929 lock->lock_fd = -1;
1930 return 0;
1931 }
1932
1933 void unlock_ref(struct ref_lock *lock)
1934 {
1935 /* Do not free lock->lk -- atexit() still looks at them */
1936 if (lock->lk)
1937 rollback_lock_file(lock->lk);
1938 free(lock->ref_name);
1939 free(lock->orig_ref_name);
1940 free(lock);
1941 }
1942
1943 /*
1944 * copy the reflog message msg to buf, which has been allocated sufficiently
1945 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1946 * because reflog file is one line per entry.
1947 */
1948 static int copy_msg(char *buf, const char *msg)
1949 {
1950 char *cp = buf;
1951 char c;
1952 int wasspace = 1;
1953
1954 *cp++ = '\t';
1955 while ((c = *msg++)) {
1956 if (wasspace && isspace(c))
1957 continue;
1958 wasspace = isspace(c);
1959 if (wasspace)
1960 c = ' ';
1961 *cp++ = c;
1962 }
1963 while (buf < cp && isspace(cp[-1]))
1964 cp--;
1965 *cp++ = '\n';
1966 return cp - buf;
1967 }
1968
1969 int log_ref_setup(const char *refname, char *logfile, int bufsize)
1970 {
1971 int logfd, oflags = O_APPEND | O_WRONLY;
1972
1973 git_snpath(logfile, bufsize, "logs/%s", refname);
1974 if (log_all_ref_updates &&
1975 (!prefixcmp(refname, "refs/heads/") ||
1976 !prefixcmp(refname, "refs/remotes/") ||
1977 !prefixcmp(refname, "refs/notes/") ||
1978 !strcmp(refname, "HEAD"))) {
1979 if (safe_create_leading_directories(logfile) < 0)
1980 return error("unable to create directory for %s",
1981 logfile);
1982 oflags |= O_CREAT;
1983 }
1984
1985 logfd = open(logfile, oflags, 0666);
1986 if (logfd < 0) {
1987 if (!(oflags & O_CREAT) && errno == ENOENT)
1988 return 0;
1989
1990 if ((oflags & O_CREAT) && errno == EISDIR) {
1991 if (remove_empty_directories(logfile)) {
1992 return error("There are still logs under '%s'",
1993 logfile);
1994 }
1995 logfd = open(logfile, oflags, 0666);
1996 }
1997
1998 if (logfd < 0)
1999 return error("Unable to append to %s: %s",
2000 logfile, strerror(errno));
2001 }
2002
2003 adjust_shared_perm(logfile);
2004 close(logfd);
2005 return 0;
2006 }
2007
2008 static int log_ref_write(const char *refname, const unsigned char *old_sha1,
2009 const unsigned char *new_sha1, const char *msg)
2010 {
2011 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
2012 unsigned maxlen, len;
2013 int msglen;
2014 char log_file[PATH_MAX];
2015 char *logrec;
2016 const char *committer;
2017
2018 if (log_all_ref_updates < 0)
2019 log_all_ref_updates = !is_bare_repository();
2020
2021 result = log_ref_setup(refname, log_file, sizeof(log_file));
2022 if (result)
2023 return result;
2024
2025 logfd = open(log_file, oflags);
2026 if (logfd < 0)
2027 return 0;
2028 msglen = msg ? strlen(msg) : 0;
2029 committer = git_committer_info(0);
2030 maxlen = strlen(committer) + msglen + 100;
2031 logrec = xmalloc(maxlen);
2032 len = sprintf(logrec, "%s %s %s\n",
2033 sha1_to_hex(old_sha1),
2034 sha1_to_hex(new_sha1),
2035 committer);
2036 if (msglen)
2037 len += copy_msg(logrec + len - 1, msg) - 1;
2038 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
2039 free(logrec);
2040 if (close(logfd) != 0 || written != len)
2041 return error("Unable to append to %s", log_file);
2042 return 0;
2043 }
2044
2045 static int is_branch(const char *refname)
2046 {
2047 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2048 }
2049
2050 int write_ref_sha1(struct ref_lock *lock,
2051 const unsigned char *sha1, const char *logmsg)
2052 {
2053 static char term = '\n';
2054 struct object *o;
2055
2056 if (!lock)
2057 return -1;
2058 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
2059 unlock_ref(lock);
2060 return 0;
2061 }
2062 o = parse_object(sha1);
2063 if (!o) {
2064 error("Trying to write ref %s with nonexistent object %s",
2065 lock->ref_name, sha1_to_hex(sha1));
2066 unlock_ref(lock);
2067 return -1;
2068 }
2069 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2070 error("Trying to write non-commit object %s to branch %s",
2071 sha1_to_hex(sha1), lock->ref_name);
2072 unlock_ref(lock);
2073 return -1;
2074 }
2075 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2076 write_in_full(lock->lock_fd, &term, 1) != 1
2077 || close_ref(lock) < 0) {
2078 error("Couldn't write %s", lock->lk->filename);
2079 unlock_ref(lock);
2080 return -1;
2081 }
2082 clear_loose_ref_cache(get_ref_cache(NULL));
2083 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2084 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2085 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
2086 unlock_ref(lock);
2087 return -1;
2088 }
2089 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2090 /*
2091 * Special hack: If a branch is updated directly and HEAD
2092 * points to it (may happen on the remote side of a push
2093 * for example) then logically the HEAD reflog should be
2094 * updated too.
2095 * A generic solution implies reverse symref information,
2096 * but finding all symrefs pointing to the given branch
2097 * would be rather costly for this rare event (the direct
2098 * update of a branch) to be worth it. So let's cheat and
2099 * check with HEAD only which should cover 99% of all usage
2100 * scenarios (even 100% of the default ones).
2101 */
2102 unsigned char head_sha1[20];
2103 int head_flag;
2104 const char *head_ref;
2105 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
2106 if (head_ref && (head_flag & REF_ISSYMREF) &&
2107 !strcmp(head_ref, lock->ref_name))
2108 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2109 }
2110 if (commit_ref(lock)) {
2111 error("Couldn't set %s", lock->ref_name);
2112 unlock_ref(lock);
2113 return -1;
2114 }
2115 unlock_ref(lock);
2116 return 0;
2117 }
2118
2119 int create_symref(const char *ref_target, const char *refs_heads_master,
2120 const char *logmsg)
2121 {
2122 const char *lockpath;
2123 char ref[1000];
2124 int fd, len, written;
2125 char *git_HEAD = git_pathdup("%s", ref_target);
2126 unsigned char old_sha1[20], new_sha1[20];
2127
2128 if (logmsg && read_ref(ref_target, old_sha1))
2129 hashclr(old_sha1);
2130
2131 if (safe_create_leading_directories(git_HEAD) < 0)
2132 return error("unable to create directory for %s", git_HEAD);
2133
2134 #ifndef NO_SYMLINK_HEAD
2135 if (prefer_symlink_refs) {
2136 unlink(git_HEAD);
2137 if (!symlink(refs_heads_master, git_HEAD))
2138 goto done;
2139 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2140 }
2141 #endif
2142
2143 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2144 if (sizeof(ref) <= len) {
2145 error("refname too long: %s", refs_heads_master);
2146 goto error_free_return;
2147 }
2148 lockpath = mkpath("%s.lock", git_HEAD);
2149 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2150 if (fd < 0) {
2151 error("Unable to open %s for writing", lockpath);
2152 goto error_free_return;
2153 }
2154 written = write_in_full(fd, ref, len);
2155 if (close(fd) != 0 || written != len) {
2156 error("Unable to write to %s", lockpath);
2157 goto error_unlink_return;
2158 }
2159 if (rename(lockpath, git_HEAD) < 0) {
2160 error("Unable to create %s", git_HEAD);
2161 goto error_unlink_return;
2162 }
2163 if (adjust_shared_perm(git_HEAD)) {
2164 error("Unable to fix permissions on %s", lockpath);
2165 error_unlink_return:
2166 unlink_or_warn(lockpath);
2167 error_free_return:
2168 free(git_HEAD);
2169 return -1;
2170 }
2171
2172 #ifndef NO_SYMLINK_HEAD
2173 done:
2174 #endif
2175 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2176 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2177
2178 free(git_HEAD);
2179 return 0;
2180 }
2181
2182 static char *ref_msg(const char *line, const char *endp)
2183 {
2184 const char *ep;
2185 line += 82;
2186 ep = memchr(line, '\n', endp - line);
2187 if (!ep)
2188 ep = endp;
2189 return xmemdupz(line, ep - line);
2190 }
2191
2192 int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2193 unsigned char *sha1, char **msg,
2194 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
2195 {
2196 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
2197 char *tz_c;
2198 int logfd, tz, reccnt = 0;
2199 struct stat st;
2200 unsigned long date;
2201 unsigned char logged_sha1[20];
2202 void *log_mapped;
2203 size_t mapsz;
2204
2205 logfile = git_path("logs/%s", refname);
2206 logfd = open(logfile, O_RDONLY, 0);
2207 if (logfd < 0)
2208 die_errno("Unable to read log '%s'", logfile);
2209 fstat(logfd, &st);
2210 if (!st.st_size)
2211 die("Log %s is empty.", logfile);
2212 mapsz = xsize_t(st.st_size);
2213 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
2214 logdata = log_mapped;
2215 close(logfd);
2216
2217 lastrec = NULL;
2218 rec = logend = logdata + st.st_size;
2219 while (logdata < rec) {
2220 reccnt++;
2221 if (logdata < rec && *(rec-1) == '\n')
2222 rec--;
2223 lastgt = NULL;
2224 while (logdata < rec && *(rec-1) != '\n') {
2225 rec--;
2226 if (*rec == '>')
2227 lastgt = rec;
2228 }
2229 if (!lastgt)
2230 die("Log %s is corrupt.", logfile);
2231 date = strtoul(lastgt + 1, &tz_c, 10);
2232 if (date <= at_time || cnt == 0) {
2233 tz = strtoul(tz_c, NULL, 10);
2234 if (msg)
2235 *msg = ref_msg(rec, logend);
2236 if (cutoff_time)
2237 *cutoff_time = date;
2238 if (cutoff_tz)
2239 *cutoff_tz = tz;
2240 if (cutoff_cnt)
2241 *cutoff_cnt = reccnt - 1;
2242 if (lastrec) {
2243 if (get_sha1_hex(lastrec, logged_sha1))
2244 die("Log %s is corrupt.", logfile);
2245 if (get_sha1_hex(rec + 41, sha1))
2246 die("Log %s is corrupt.", logfile);
2247 if (hashcmp(logged_sha1, sha1)) {
2248 warning("Log %s has gap after %s.",
2249 logfile, show_date(date, tz, DATE_RFC2822));
2250 }
2251 }
2252 else if (date == at_time) {
2253 if (get_sha1_hex(rec + 41, sha1))
2254 die("Log %s is corrupt.", logfile);
2255 }
2256 else {
2257 if (get_sha1_hex(rec + 41, logged_sha1))
2258 die("Log %s is corrupt.", logfile);
2259 if (hashcmp(logged_sha1, sha1)) {
2260 warning("Log %s unexpectedly ended on %s.",
2261 logfile, show_date(date, tz, DATE_RFC2822));
2262 }
2263 }
2264 munmap(log_mapped, mapsz);
2265 return 0;
2266 }
2267 lastrec = rec;
2268 if (cnt > 0)
2269 cnt--;
2270 }
2271
2272 rec = logdata;
2273 while (rec < logend && *rec != '>' && *rec != '\n')
2274 rec++;
2275 if (rec == logend || *rec == '\n')
2276 die("Log %s is corrupt.", logfile);
2277 date = strtoul(rec + 1, &tz_c, 10);
2278 tz = strtoul(tz_c, NULL, 10);
2279 if (get_sha1_hex(logdata, sha1))
2280 die("Log %s is corrupt.", logfile);
2281 if (is_null_sha1(sha1)) {
2282 if (get_sha1_hex(logdata + 41, sha1))
2283 die("Log %s is corrupt.", logfile);
2284 }
2285 if (msg)
2286 *msg = ref_msg(logdata, logend);
2287 munmap(log_mapped, mapsz);
2288
2289 if (cutoff_time)
2290 *cutoff_time = date;
2291 if (cutoff_tz)
2292 *cutoff_tz = tz;
2293 if (cutoff_cnt)
2294 *cutoff_cnt = reccnt;
2295 return 1;
2296 }
2297
2298 int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
2299 {
2300 const char *logfile;
2301 FILE *logfp;
2302 struct strbuf sb = STRBUF_INIT;
2303 int ret = 0;
2304
2305 logfile = git_path("logs/%s", refname);
2306 logfp = fopen(logfile, "r");
2307 if (!logfp)
2308 return -1;
2309
2310 if (ofs) {
2311 struct stat statbuf;
2312 if (fstat(fileno(logfp), &statbuf) ||
2313 statbuf.st_size < ofs ||
2314 fseek(logfp, -ofs, SEEK_END) ||
2315 strbuf_getwholeline(&sb, logfp, '\n')) {
2316 fclose(logfp);
2317 strbuf_release(&sb);
2318 return -1;
2319 }
2320 }
2321
2322 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2323 unsigned char osha1[20], nsha1[20];
2324 char *email_end, *message;
2325 unsigned long timestamp;
2326 int tz;
2327
2328 /* old SP new SP name <email> SP time TAB msg LF */
2329 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
2330 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
2331 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
2332 !(email_end = strchr(sb.buf + 82, '>')) ||
2333 email_end[1] != ' ' ||
2334 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2335 !message || message[0] != ' ' ||
2336 (message[1] != '+' && message[1] != '-') ||
2337 !isdigit(message[2]) || !isdigit(message[3]) ||
2338 !isdigit(message[4]) || !isdigit(message[5]))
2339 continue; /* corrupt? */
2340 email_end[1] = '\0';
2341 tz = strtol(message + 1, NULL, 10);
2342 if (message[6] != '\t')
2343 message += 6;
2344 else
2345 message += 7;
2346 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
2347 cb_data);
2348 if (ret)
2349 break;
2350 }
2351 fclose(logfp);
2352 strbuf_release(&sb);
2353 return ret;
2354 }
2355
2356 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2357 {
2358 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
2359 }
2360
2361 /*
2362 * Call fn for each reflog in the namespace indicated by name. name
2363 * must be empty or end with '/'. Name will be used as a scratch
2364 * space, but its contents will be restored before return.
2365 */
2366 static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
2367 {
2368 DIR *d = opendir(git_path("logs/%s", name->buf));
2369 int retval = 0;
2370 struct dirent *de;
2371 int oldlen = name->len;
2372
2373 if (!d)
2374 return name->len ? errno : 0;
2375
2376 while ((de = readdir(d)) != NULL) {
2377 struct stat st;
2378
2379 if (de->d_name[0] == '.')
2380 continue;
2381 if (has_extension(de->d_name, ".lock"))
2382 continue;
2383 strbuf_addstr(name, de->d_name);
2384 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2385 ; /* silently ignore */
2386 } else {
2387 if (S_ISDIR(st.st_mode)) {
2388 strbuf_addch(name, '/');
2389 retval = do_for_each_reflog(name, fn, cb_data);
2390 } else {
2391 unsigned char sha1[20];
2392 if (read_ref_full(name->buf, sha1, 0, NULL))
2393 retval = error("bad ref for %s", name->buf);
2394 else
2395 retval = fn(name->buf, sha1, 0, cb_data);
2396 }
2397 if (retval)
2398 break;
2399 }
2400 strbuf_setlen(name, oldlen);
2401 }
2402 closedir(d);
2403 return retval;
2404 }
2405
2406 int for_each_reflog(each_ref_fn fn, void *cb_data)
2407 {
2408 int retval;
2409 struct strbuf name;
2410 strbuf_init(&name, PATH_MAX);
2411 retval = do_for_each_reflog(&name, fn, cb_data);
2412 strbuf_release(&name);
2413 return retval;
2414 }
2415
2416 int update_ref(const char *action, const char *refname,
2417 const unsigned char *sha1, const unsigned char *oldval,
2418 int flags, enum action_on_err onerr)
2419 {
2420 static struct ref_lock *lock;
2421 lock = lock_any_ref_for_update(refname, oldval, flags);
2422 if (!lock) {
2423 const char *str = "Cannot lock the ref '%s'.";
2424 switch (onerr) {
2425 case MSG_ON_ERR: error(str, refname); break;
2426 case DIE_ON_ERR: die(str, refname); break;
2427 case QUIET_ON_ERR: break;
2428 }
2429 return 1;
2430 }
2431 if (write_ref_sha1(lock, sha1, action) < 0) {
2432 const char *str = "Cannot update the ref '%s'.";
2433 switch (onerr) {
2434 case MSG_ON_ERR: error(str, refname); break;
2435 case DIE_ON_ERR: die(str, refname); break;
2436 case QUIET_ON_ERR: break;
2437 }
2438 return 1;
2439 }
2440 return 0;
2441 }
2442
2443 struct ref *find_ref_by_name(const struct ref *list, const char *name)
2444 {
2445 for ( ; list; list = list->next)
2446 if (!strcmp(list->name, name))
2447 return (struct ref *)list;
2448 return NULL;
2449 }
2450
2451 /*
2452 * generate a format suitable for scanf from a ref_rev_parse_rules
2453 * rule, that is replace the "%.*s" spec with a "%s" spec
2454 */
2455 static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2456 {
2457 char *spec;
2458
2459 spec = strstr(rule, "%.*s");
2460 if (!spec || strstr(spec + 4, "%.*s"))
2461 die("invalid rule in ref_rev_parse_rules: %s", rule);
2462
2463 /* copy all until spec */
2464 strncpy(scanf_fmt, rule, spec - rule);
2465 scanf_fmt[spec - rule] = '\0';
2466 /* copy new spec */
2467 strcat(scanf_fmt, "%s");
2468 /* copy remaining rule */
2469 strcat(scanf_fmt, spec + 4);
2470
2471 return;
2472 }
2473
2474 char *shorten_unambiguous_ref(const char *refname, int strict)
2475 {
2476 int i;
2477 static char **scanf_fmts;
2478 static int nr_rules;
2479 char *short_name;
2480
2481 /* pre generate scanf formats from ref_rev_parse_rules[] */
2482 if (!nr_rules) {
2483 size_t total_len = 0;
2484
2485 /* the rule list is NULL terminated, count them first */
2486 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2487 /* no +1 because strlen("%s") < strlen("%.*s") */
2488 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2489
2490 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2491
2492 total_len = 0;
2493 for (i = 0; i < nr_rules; i++) {
2494 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2495 + total_len;
2496 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2497 total_len += strlen(ref_rev_parse_rules[i]);
2498 }
2499 }
2500
2501 /* bail out if there are no rules */
2502 if (!nr_rules)
2503 return xstrdup(refname);
2504
2505 /* buffer for scanf result, at most refname must fit */
2506 short_name = xstrdup(refname);
2507
2508 /* skip first rule, it will always match */
2509 for (i = nr_rules - 1; i > 0 ; --i) {
2510 int j;
2511 int rules_to_fail = i;
2512 int short_name_len;
2513
2514 if (1 != sscanf(refname, scanf_fmts[i], short_name))
2515 continue;
2516
2517 short_name_len = strlen(short_name);
2518
2519 /*
2520 * in strict mode, all (except the matched one) rules
2521 * must fail to resolve to a valid non-ambiguous ref
2522 */
2523 if (strict)
2524 rules_to_fail = nr_rules;
2525
2526 /*
2527 * check if the short name resolves to a valid ref,
2528 * but use only rules prior to the matched one
2529 */
2530 for (j = 0; j < rules_to_fail; j++) {
2531 const char *rule = ref_rev_parse_rules[j];
2532 char refname[PATH_MAX];
2533
2534 /* skip matched rule */
2535 if (i == j)
2536 continue;
2537
2538 /*
2539 * the short name is ambiguous, if it resolves
2540 * (with this previous rule) to a valid ref
2541 * read_ref() returns 0 on success
2542 */
2543 mksnpath(refname, sizeof(refname),
2544 rule, short_name_len, short_name);
2545 if (ref_exists(refname))
2546 break;
2547 }
2548
2549 /*
2550 * short name is non-ambiguous if all previous rules
2551 * haven't resolved to a valid ref
2552 */
2553 if (j == rules_to_fail)
2554 return short_name;
2555 }
2556
2557 free(short_name);
2558 return xstrdup(refname);
2559 }
2560
2561 static struct string_list *hide_refs;
2562
2563 int parse_hide_refs_config(const char *var, const char *value, const char *section)
2564 {
2565 if (!strcmp("transfer.hiderefs", var) ||
2566 /* NEEDSWORK: use parse_config_key() once both are merged */
2567 (!prefixcmp(var, section) && var[strlen(section)] == '.' &&
2568 !strcmp(var + strlen(section), ".hiderefs"))) {
2569 char *ref;
2570 int len;
2571
2572 if (!value)
2573 return config_error_nonbool(var);
2574 ref = xstrdup(value);
2575 len = strlen(ref);
2576 while (len && ref[len - 1] == '/')
2577 ref[--len] = '\0';
2578 if (!hide_refs) {
2579 hide_refs = xcalloc(1, sizeof(*hide_refs));
2580 hide_refs->strdup_strings = 1;
2581 }
2582 string_list_append(hide_refs, ref);
2583 }
2584 return 0;
2585 }
2586
2587 int ref_is_hidden(const char *refname)
2588 {
2589 struct string_list_item *item;
2590
2591 if (!hide_refs)
2592 return 0;
2593 for_each_string_list_item(item, hide_refs) {
2594 int len;
2595 if (prefixcmp(refname, item->string))
2596 continue;
2597 len = strlen(item->string);
2598 if (!refname[len] || refname[len] == '/')
2599 return 1;
2600 }
2601 return 0;
2602 }