1#include "cache.h"
2#include "refs.h"
3#include "object.h"
4#include "tag.h"
5#include "dir.h"
6
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 */
18
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)
54 return 0; /* Component has zero length. */
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);
77 if (component_len <= 0) {
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;
103
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 */
110struct ref_value {
111 unsigned char sha1[20];
112 unsigned char peeled[20];
113};
114
115struct ref_cache;
116
117/*
118 * Information used (along with the information in ref_entry) to
119 * describe a level in the hierarchy of references. This data
120 * structure only occurs embedded in a union in struct ref_entry, and
121 * only when (ref_entry.flag & REF_DIR) is set. In that case,
122 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references
123 * in the directory have already been read:
124 *
125 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose
126 * or packed references, already read.
127 *
128 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose
129 * references that hasn't been read yet (nor has any of its
130 * subdirectories).
131 *
132 * Entries within a directory are stored within a growable array of
133 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i <
134 * sorted are sorted by their component name in strcmp() order and the
135 * remaining entries are unsorted.
136 *
137 * Loose references are read lazily, one directory at a time. When a
138 * directory of loose references is read, then all of the references
139 * in that directory are stored, and REF_INCOMPLETE stubs are created
140 * for any subdirectories, but the subdirectories themselves are not
141 * read. The reading is triggered by get_ref_dir().
142 */
143struct ref_dir {
144 int nr, alloc;
145
146 /*
147 * Entries with index 0 <= i < sorted are sorted by name. New
148 * entries are appended to the list unsorted, and are sorted
149 * only when required; thus we avoid the need to sort the list
150 * after the addition of every reference.
151 */
152 int sorted;
153
154 /* A pointer to the ref_cache that contains this ref_dir. */
155 struct ref_cache *ref_cache;
156
157 struct ref_entry **entries;
158};
159
160/* ISSYMREF=0x01, ISPACKED=0x02, and ISBROKEN=0x04 are public interfaces */
161#define REF_KNOWS_PEELED 0x08
162
163/* ref_entry represents a directory of references */
164#define REF_DIR 0x10
165
166/*
167 * Entry has not yet been read from disk (used only for REF_DIR
168 * entries representing loose references)
169 */
170#define REF_INCOMPLETE 0x20
171
172/*
173 * A ref_entry represents either a reference or a "subdirectory" of
174 * references.
175 *
176 * Each directory in the reference namespace is represented by a
177 * ref_entry with (flags & REF_DIR) set and containing a subdir member
178 * that holds the entries in that directory that have been read so
179 * far. If (flags & REF_INCOMPLETE) is set, then the directory and
180 * its subdirectories haven't been read yet. REF_INCOMPLETE is only
181 * used for loose reference directories.
182 *
183 * References are represented by a ref_entry with (flags & REF_DIR)
184 * unset and a value member that describes the reference's value. The
185 * flag member is at the ref_entry level, but it is also needed to
186 * interpret the contents of the value field (in other words, a
187 * ref_value object is not very much use without the enclosing
188 * ref_entry).
189 *
190 * Reference names cannot end with slash and directories' names are
191 * always stored with a trailing slash (except for the top-level
192 * directory, which is always denoted by ""). This has two nice
193 * consequences: (1) when the entries in each subdir are sorted
194 * lexicographically by name (as they usually are), the references in
195 * a whole tree can be generated in lexicographic order by traversing
196 * the tree in left-to-right, depth-first order; (2) the names of
197 * references and subdirectories cannot conflict, and therefore the
198 * presence of an empty subdirectory does not block the creation of a
199 * similarly-named reference. (The fact that reference names with the
200 * same leading components can conflict *with each other* is a
201 * separate issue that is regulated by is_refname_available().)
202 *
203 * Please note that the name field contains the fully-qualified
204 * reference (or subdirectory) name. Space could be saved by only
205 * storing the relative names. But that would require the full names
206 * to be generated on the fly when iterating in do_for_each_ref(), and
207 * would break callback functions, who have always been able to assume
208 * that the name strings that they are passed will not be freed during
209 * the iteration.
210 */
211struct ref_entry {
212 unsigned char flag; /* ISSYMREF? ISPACKED? */
213 union {
214 struct ref_value value; /* if not (flags&REF_DIR) */
215 struct ref_dir subdir; /* if (flags&REF_DIR) */
216 } u;
217 /*
218 * The full name of the reference (e.g., "refs/heads/master")
219 * or the full name of the directory with a trailing slash
220 * (e.g., "refs/heads/"):
221 */
222 char name[FLEX_ARRAY];
223};
224
225static void read_loose_refs(const char *dirname, struct ref_dir *dir);
226
227static struct ref_dir *get_ref_dir(struct ref_entry *entry)
228{
229 struct ref_dir *dir;
230 assert(entry->flag & REF_DIR);
231 dir = &entry->u.subdir;
232 if (entry->flag & REF_INCOMPLETE) {
233 read_loose_refs(entry->name, dir);
234 entry->flag &= ~REF_INCOMPLETE;
235 }
236 return dir;
237}
238
239static struct ref_entry *create_ref_entry(const char *refname,
240 const unsigned char *sha1, int flag,
241 int check_name)
242{
243 int len;
244 struct ref_entry *ref;
245
246 if (check_name &&
247 check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT))
248 die("Reference has invalid format: '%s'", refname);
249 len = strlen(refname) + 1;
250 ref = xmalloc(sizeof(struct ref_entry) + len);
251 hashcpy(ref->u.value.sha1, sha1);
252 hashclr(ref->u.value.peeled);
253 memcpy(ref->name, refname, len);
254 ref->flag = flag;
255 return ref;
256}
257
258static void clear_ref_dir(struct ref_dir *dir);
259
260static void free_ref_entry(struct ref_entry *entry)
261{
262 if (entry->flag & REF_DIR)
263 clear_ref_dir(get_ref_dir(entry));
264 free(entry);
265}
266
267/*
268 * Add a ref_entry to the end of dir (unsorted). Entry is always
269 * stored directly in dir; no recursion into subdirectories is
270 * done.
271 */
272static void add_entry_to_dir(struct ref_dir *dir, struct ref_entry *entry)
273{
274 ALLOC_GROW(dir->entries, dir->nr + 1, dir->alloc);
275 dir->entries[dir->nr++] = entry;
276}
277
278/*
279 * Clear and free all entries in dir, recursively.
280 */
281static void clear_ref_dir(struct ref_dir *dir)
282{
283 int i;
284 for (i = 0; i < dir->nr; i++)
285 free_ref_entry(dir->entries[i]);
286 free(dir->entries);
287 dir->sorted = dir->nr = dir->alloc = 0;
288 dir->entries = NULL;
289}
290
291/*
292 * Create a struct ref_entry object for the specified dirname.
293 * dirname is the name of the directory with a trailing slash (e.g.,
294 * "refs/heads/") or "" for the top-level directory.
295 */
296static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache,
297 const char *dirname, int incomplete)
298{
299 struct ref_entry *direntry;
300 int len = strlen(dirname);
301 direntry = xcalloc(1, sizeof(struct ref_entry) + len + 1);
302 memcpy(direntry->name, dirname, len + 1);
303 direntry->u.subdir.ref_cache = ref_cache;
304 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE : 0);
305 return direntry;
306}
307
308static int ref_entry_cmp(const void *a, const void *b)
309{
310 struct ref_entry *one = *(struct ref_entry **)a;
311 struct ref_entry *two = *(struct ref_entry **)b;
312 return strcmp(one->name, two->name);
313}
314
315static void sort_ref_dir(struct ref_dir *dir);
316
317/*
318 * Return the entry with the given refname from the ref_dir
319 * (non-recursively), sorting dir if necessary. Return NULL if no
320 * such entry is found. dir must already be complete.
321 */
322static struct ref_entry *search_ref_dir(struct ref_dir *dir, const char *refname)
323{
324 struct ref_entry *e, **r;
325 int len;
326
327 if (refname == NULL || !dir->nr)
328 return NULL;
329
330 sort_ref_dir(dir);
331
332 len = strlen(refname) + 1;
333 e = xmalloc(sizeof(struct ref_entry) + len);
334 memcpy(e->name, refname, len);
335
336 r = bsearch(&e, dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
337
338 free(e);
339
340 if (r == NULL)
341 return NULL;
342
343 return *r;
344}
345
346/*
347 * Search for a directory entry directly within dir (without
348 * recursing). Sort dir if necessary. subdirname must be a directory
349 * name (i.e., end in '/'). If mkdir is set, then create the
350 * directory if it is missing; otherwise, return NULL if the desired
351 * directory cannot be found. dir must already be complete.
352 */
353static struct ref_dir *search_for_subdir(struct ref_dir *dir,
354 const char *subdirname, int mkdir)
355{
356 struct ref_entry *entry = search_ref_dir(dir, subdirname);
357 if (!entry) {
358 if (!mkdir)
359 return NULL;
360 /*
361 * Since dir is complete, the absence of a subdir
362 * means that the subdir really doesn't exist;
363 * therefore, create an empty record for it but mark
364 * the record complete.
365 */
366 entry = create_dir_entry(dir->ref_cache, subdirname, 0);
367 add_entry_to_dir(dir, entry);
368 }
369 return get_ref_dir(entry);
370}
371
372/*
373 * If refname is a reference name, find the ref_dir within the dir
374 * tree that should hold refname. If refname is a directory name
375 * (i.e., ends in '/'), then return that ref_dir itself. dir must
376 * represent the top-level directory and must already be complete.
377 * Sort ref_dirs and recurse into subdirectories as necessary. If
378 * mkdir is set, then create any missing directories; otherwise,
379 * return NULL if the desired directory cannot be found.
380 */
381static struct ref_dir *find_containing_dir(struct ref_dir *dir,
382 const char *refname, int mkdir)
383{
384 struct strbuf dirname;
385 const char *slash;
386 strbuf_init(&dirname, PATH_MAX);
387 for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
388 struct ref_dir *subdir;
389 strbuf_add(&dirname,
390 refname + dirname.len,
391 (slash + 1) - (refname + dirname.len));
392 subdir = search_for_subdir(dir, dirname.buf, mkdir);
393 if (!subdir) {
394 dir = NULL;
395 break;
396 }
397 dir = subdir;
398 }
399
400 strbuf_release(&dirname);
401 return dir;
402}
403
404/*
405 * Find the value entry with the given name in dir, sorting ref_dirs
406 * and recursing into subdirectories as necessary. If the name is not
407 * found or it corresponds to a directory entry, return NULL.
408 */
409static struct ref_entry *find_ref(struct ref_dir *dir, const char *refname)
410{
411 struct ref_entry *entry;
412 dir = find_containing_dir(dir, refname, 0);
413 if (!dir)
414 return NULL;
415 entry = search_ref_dir(dir, refname);
416 return (entry && !(entry->flag & REF_DIR)) ? entry : NULL;
417}
418
419/*
420 * Add a ref_entry to the ref_dir (unsorted), recursing into
421 * subdirectories as necessary. dir must represent the top-level
422 * directory. Return 0 on success.
423 */
424static int add_ref(struct ref_dir *dir, struct ref_entry *ref)
425{
426 dir = find_containing_dir(dir, ref->name, 1);
427 if (!dir)
428 return -1;
429 add_entry_to_dir(dir, ref);
430 return 0;
431}
432
433/*
434 * Emit a warning and return true iff ref1 and ref2 have the same name
435 * and the same sha1. Die if they have the same name but different
436 * sha1s.
437 */
438static int is_dup_ref(const struct ref_entry *ref1, const struct ref_entry *ref2)
439{
440 if (strcmp(ref1->name, ref2->name))
441 return 0;
442
443 /* Duplicate name; make sure that they don't conflict: */
444
445 if ((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR))
446 /* This is impossible by construction */
447 die("Reference directory conflict: %s", ref1->name);
448
449 if (hashcmp(ref1->u.value.sha1, ref2->u.value.sha1))
450 die("Duplicated ref, and SHA1s don't match: %s", ref1->name);
451
452 warning("Duplicated ref: %s", ref1->name);
453 return 1;
454}
455
456/*
457 * Sort the entries in dir non-recursively (if they are not already
458 * sorted) and remove any duplicate entries.
459 */
460static void sort_ref_dir(struct ref_dir *dir)
461{
462 int i, j;
463 struct ref_entry *last = NULL;
464
465 /*
466 * This check also prevents passing a zero-length array to qsort(),
467 * which is a problem on some platforms.
468 */
469 if (dir->sorted == dir->nr)
470 return;
471
472 qsort(dir->entries, dir->nr, sizeof(*dir->entries), ref_entry_cmp);
473
474 /* Remove any duplicates: */
475 for (i = 0, j = 0; j < dir->nr; j++) {
476 struct ref_entry *entry = dir->entries[j];
477 if (last && is_dup_ref(last, entry))
478 free_ref_entry(entry);
479 else
480 last = dir->entries[i++] = entry;
481 }
482 dir->sorted = dir->nr = i;
483}
484
485#define DO_FOR_EACH_INCLUDE_BROKEN 01
486
487static struct ref_entry *current_ref;
488
489static int do_one_ref(const char *base, each_ref_fn fn, int trim,
490 int flags, void *cb_data, struct ref_entry *entry)
491{
492 int retval;
493 if (prefixcmp(entry->name, base))
494 return 0;
495
496 if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
497 if (entry->flag & REF_ISBROKEN)
498 return 0; /* ignore broken refs e.g. dangling symref */
499 if (!has_sha1_file(entry->u.value.sha1)) {
500 error("%s does not point to a valid object!", entry->name);
501 return 0;
502 }
503 }
504 current_ref = entry;
505 retval = fn(entry->name + trim, entry->u.value.sha1, entry->flag, cb_data);
506 current_ref = NULL;
507 return retval;
508}
509
510/*
511 * Call fn for each reference in dir that has index in the range
512 * offset <= index < dir->nr. Recurse into subdirectories that are in
513 * that index range, sorting them before iterating. This function
514 * does not sort dir itself; it should be sorted beforehand.
515 */
516static int do_for_each_ref_in_dir(struct ref_dir *dir, int offset,
517 const char *base,
518 each_ref_fn fn, int trim, int flags, void *cb_data)
519{
520 int i;
521 assert(dir->sorted == dir->nr);
522 for (i = offset; i < dir->nr; i++) {
523 struct ref_entry *entry = dir->entries[i];
524 int retval;
525 if (entry->flag & REF_DIR) {
526 struct ref_dir *subdir = get_ref_dir(entry);
527 sort_ref_dir(subdir);
528 retval = do_for_each_ref_in_dir(subdir, 0,
529 base, fn, trim, flags, cb_data);
530 } else {
531 retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
532 }
533 if (retval)
534 return retval;
535 }
536 return 0;
537}
538
539/*
540 * Call fn for each reference in the union of dir1 and dir2, in order
541 * by refname. Recurse into subdirectories. If a value entry appears
542 * in both dir1 and dir2, then only process the version that is in
543 * dir2. The input dirs must already be sorted, but subdirs will be
544 * sorted as needed.
545 */
546static int do_for_each_ref_in_dirs(struct ref_dir *dir1,
547 struct ref_dir *dir2,
548 const char *base, each_ref_fn fn, int trim,
549 int flags, void *cb_data)
550{
551 int retval;
552 int i1 = 0, i2 = 0;
553
554 assert(dir1->sorted == dir1->nr);
555 assert(dir2->sorted == dir2->nr);
556 while (1) {
557 struct ref_entry *e1, *e2;
558 int cmp;
559 if (i1 == dir1->nr) {
560 return do_for_each_ref_in_dir(dir2, i2,
561 base, fn, trim, flags, cb_data);
562 }
563 if (i2 == dir2->nr) {
564 return do_for_each_ref_in_dir(dir1, i1,
565 base, fn, trim, flags, cb_data);
566 }
567 e1 = dir1->entries[i1];
568 e2 = dir2->entries[i2];
569 cmp = strcmp(e1->name, e2->name);
570 if (cmp == 0) {
571 if ((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) {
572 /* Both are directories; descend them in parallel. */
573 struct ref_dir *subdir1 = get_ref_dir(e1);
574 struct ref_dir *subdir2 = get_ref_dir(e2);
575 sort_ref_dir(subdir1);
576 sort_ref_dir(subdir2);
577 retval = do_for_each_ref_in_dirs(
578 subdir1, subdir2,
579 base, fn, trim, flags, cb_data);
580 i1++;
581 i2++;
582 } else if (!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) {
583 /* Both are references; ignore the one from dir1. */
584 retval = do_one_ref(base, fn, trim, flags, cb_data, e2);
585 i1++;
586 i2++;
587 } else {
588 die("conflict between reference and directory: %s",
589 e1->name);
590 }
591 } else {
592 struct ref_entry *e;
593 if (cmp < 0) {
594 e = e1;
595 i1++;
596 } else {
597 e = e2;
598 i2++;
599 }
600 if (e->flag & REF_DIR) {
601 struct ref_dir *subdir = get_ref_dir(e);
602 sort_ref_dir(subdir);
603 retval = do_for_each_ref_in_dir(
604 subdir, 0,
605 base, fn, trim, flags, cb_data);
606 } else {
607 retval = do_one_ref(base, fn, trim, flags, cb_data, e);
608 }
609 }
610 if (retval)
611 return retval;
612 }
613 if (i1 < dir1->nr)
614 return do_for_each_ref_in_dir(dir1, i1,
615 base, fn, trim, flags, cb_data);
616 if (i2 < dir2->nr)
617 return do_for_each_ref_in_dir(dir2, i2,
618 base, fn, trim, flags, cb_data);
619 return 0;
620}
621
622/*
623 * Return true iff refname1 and refname2 conflict with each other.
624 * Two reference names conflict if one of them exactly matches the
625 * leading components of the other; e.g., "foo/bar" conflicts with
626 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or
627 * "foo/barbados".
628 */
629static int names_conflict(const char *refname1, const char *refname2)
630{
631 for (; *refname1 && *refname1 == *refname2; refname1++, refname2++)
632 ;
633 return (*refname1 == '\0' && *refname2 == '/')
634 || (*refname1 == '/' && *refname2 == '\0');
635}
636
637struct name_conflict_cb {
638 const char *refname;
639 const char *oldrefname;
640 const char *conflicting_refname;
641};
642
643static int name_conflict_fn(const char *existingrefname, const unsigned char *sha1,
644 int flags, void *cb_data)
645{
646 struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;
647 if (data->oldrefname && !strcmp(data->oldrefname, existingrefname))
648 return 0;
649 if (names_conflict(data->refname, existingrefname)) {
650 data->conflicting_refname = existingrefname;
651 return 1;
652 }
653 return 0;
654}
655
656/*
657 * Return true iff a reference named refname could be created without
658 * conflicting with the name of an existing reference in array. If
659 * oldrefname is non-NULL, ignore potential conflicts with oldrefname
660 * (e.g., because oldrefname is scheduled for deletion in the same
661 * operation).
662 */
663static int is_refname_available(const char *refname, const char *oldrefname,
664 struct ref_dir *dir)
665{
666 struct name_conflict_cb data;
667 data.refname = refname;
668 data.oldrefname = oldrefname;
669 data.conflicting_refname = NULL;
670
671 sort_ref_dir(dir);
672 if (do_for_each_ref_in_dir(dir, 0, "", name_conflict_fn,
673 0, DO_FOR_EACH_INCLUDE_BROKEN,
674 &data)) {
675 error("'%s' exists; cannot create '%s'",
676 data.conflicting_refname, refname);
677 return 0;
678 }
679 return 1;
680}
681
682/*
683 * Future: need to be in "struct repository"
684 * when doing a full libification.
685 */
686static struct ref_cache {
687 struct ref_cache *next;
688 struct ref_entry *loose;
689 struct ref_entry *packed;
690 /* The submodule name, or "" for the main repo. */
691 char name[FLEX_ARRAY];
692} *ref_cache;
693
694static void clear_packed_ref_cache(struct ref_cache *refs)
695{
696 if (refs->packed) {
697 free_ref_entry(refs->packed);
698 refs->packed = NULL;
699 }
700}
701
702static void clear_loose_ref_cache(struct ref_cache *refs)
703{
704 if (refs->loose) {
705 free_ref_entry(refs->loose);
706 refs->loose = NULL;
707 }
708}
709
710static struct ref_cache *create_ref_cache(const char *submodule)
711{
712 int len;
713 struct ref_cache *refs;
714 if (!submodule)
715 submodule = "";
716 len = strlen(submodule) + 1;
717 refs = xcalloc(1, sizeof(struct ref_cache) + len);
718 memcpy(refs->name, submodule, len);
719 return refs;
720}
721
722/*
723 * Return a pointer to a ref_cache for the specified submodule. For
724 * the main repository, use submodule==NULL. The returned structure
725 * will be allocated and initialized but not necessarily populated; it
726 * should not be freed.
727 */
728static struct ref_cache *get_ref_cache(const char *submodule)
729{
730 struct ref_cache *refs = ref_cache;
731 if (!submodule)
732 submodule = "";
733 while (refs) {
734 if (!strcmp(submodule, refs->name))
735 return refs;
736 refs = refs->next;
737 }
738
739 refs = create_ref_cache(submodule);
740 refs->next = ref_cache;
741 ref_cache = refs;
742 return refs;
743}
744
745void invalidate_ref_cache(const char *submodule)
746{
747 struct ref_cache *refs = get_ref_cache(submodule);
748 clear_packed_ref_cache(refs);
749 clear_loose_ref_cache(refs);
750}
751
752/*
753 * Parse one line from a packed-refs file. Write the SHA1 to sha1.
754 * Return a pointer to the refname within the line (null-terminated),
755 * or NULL if there was a problem.
756 */
757static const char *parse_ref_line(char *line, unsigned char *sha1)
758{
759 /*
760 * 42: the answer to everything.
761 *
762 * In this case, it happens to be the answer to
763 * 40 (length of sha1 hex representation)
764 * +1 (space in between hex and name)
765 * +1 (newline at the end of the line)
766 */
767 int len = strlen(line) - 42;
768
769 if (len <= 0)
770 return NULL;
771 if (get_sha1_hex(line, sha1) < 0)
772 return NULL;
773 if (!isspace(line[40]))
774 return NULL;
775 line += 41;
776 if (isspace(*line))
777 return NULL;
778 if (line[len] != '\n')
779 return NULL;
780 line[len] = 0;
781
782 return line;
783}
784
785static void read_packed_refs(FILE *f, struct ref_dir *dir)
786{
787 struct ref_entry *last = NULL;
788 char refline[PATH_MAX];
789 int flag = REF_ISPACKED;
790
791 while (fgets(refline, sizeof(refline), f)) {
792 unsigned char sha1[20];
793 const char *refname;
794 static const char header[] = "# pack-refs with:";
795
796 if (!strncmp(refline, header, sizeof(header)-1)) {
797 const char *traits = refline + sizeof(header) - 1;
798 if (strstr(traits, " peeled "))
799 flag |= REF_KNOWS_PEELED;
800 /* perhaps other traits later as well */
801 continue;
802 }
803
804 refname = parse_ref_line(refline, sha1);
805 if (refname) {
806 last = create_ref_entry(refname, sha1, flag, 1);
807 add_ref(dir, last);
808 continue;
809 }
810 if (last &&
811 refline[0] == '^' &&
812 strlen(refline) == 42 &&
813 refline[41] == '\n' &&
814 !get_sha1_hex(refline + 1, sha1))
815 hashcpy(last->u.value.peeled, sha1);
816 }
817}
818
819static struct ref_dir *get_packed_refs(struct ref_cache *refs)
820{
821 if (!refs->packed) {
822 const char *packed_refs_file;
823 FILE *f;
824
825 refs->packed = create_dir_entry(refs, "", 0);
826 if (*refs->name)
827 packed_refs_file = git_path_submodule(refs->name, "packed-refs");
828 else
829 packed_refs_file = git_path("packed-refs");
830 f = fopen(packed_refs_file, "r");
831 if (f) {
832 read_packed_refs(f, get_ref_dir(refs->packed));
833 fclose(f);
834 }
835 }
836 return get_ref_dir(refs->packed);
837}
838
839void add_packed_ref(const char *refname, const unsigned char *sha1)
840{
841 add_ref(get_packed_refs(get_ref_cache(NULL)),
842 create_ref_entry(refname, sha1, REF_ISPACKED, 1));
843}
844
845/*
846 * Read the loose references from the namespace dirname into dir
847 * (without recursing). dirname must end with '/'. dir must be the
848 * directory entry corresponding to dirname.
849 */
850static void read_loose_refs(const char *dirname, struct ref_dir *dir)
851{
852 struct ref_cache *refs = dir->ref_cache;
853 DIR *d;
854 const char *path;
855 struct dirent *de;
856 int dirnamelen = strlen(dirname);
857 struct strbuf refname;
858
859 if (*refs->name)
860 path = git_path_submodule(refs->name, "%s", dirname);
861 else
862 path = git_path("%s", dirname);
863
864 d = opendir(path);
865 if (!d)
866 return;
867
868 strbuf_init(&refname, dirnamelen + 257);
869 strbuf_add(&refname, dirname, dirnamelen);
870
871 while ((de = readdir(d)) != NULL) {
872 unsigned char sha1[20];
873 struct stat st;
874 int flag;
875 const char *refdir;
876
877 if (de->d_name[0] == '.')
878 continue;
879 if (has_extension(de->d_name, ".lock"))
880 continue;
881 strbuf_addstr(&refname, de->d_name);
882 refdir = *refs->name
883 ? git_path_submodule(refs->name, "%s", refname.buf)
884 : git_path("%s", refname.buf);
885 if (stat(refdir, &st) < 0) {
886 ; /* silently ignore */
887 } else if (S_ISDIR(st.st_mode)) {
888 strbuf_addch(&refname, '/');
889 add_entry_to_dir(dir,
890 create_dir_entry(refs, refname.buf, 1));
891 } else {
892 if (*refs->name) {
893 hashclr(sha1);
894 flag = 0;
895 if (resolve_gitlink_ref(refs->name, refname.buf, sha1) < 0) {
896 hashclr(sha1);
897 flag |= REF_ISBROKEN;
898 }
899 } else if (read_ref_full(refname.buf, sha1, 1, &flag)) {
900 hashclr(sha1);
901 flag |= REF_ISBROKEN;
902 }
903 add_entry_to_dir(dir,
904 create_ref_entry(refname.buf, sha1, flag, 1));
905 }
906 strbuf_setlen(&refname, dirnamelen);
907 }
908 strbuf_release(&refname);
909 closedir(d);
910}
911
912static struct ref_dir *get_loose_refs(struct ref_cache *refs)
913{
914 if (!refs->loose) {
915 /*
916 * Mark the top-level directory complete because we
917 * are about to read the only subdirectory that can
918 * hold references:
919 */
920 refs->loose = create_dir_entry(refs, "", 0);
921 /*
922 * Create an incomplete entry for "refs/":
923 */
924 add_entry_to_dir(get_ref_dir(refs->loose),
925 create_dir_entry(refs, "refs/", 1));
926 }
927 return get_ref_dir(refs->loose);
928}
929
930/* We allow "recursive" symbolic refs. Only within reason, though */
931#define MAXDEPTH 5
932#define MAXREFLEN (1024)
933
934/*
935 * Called by resolve_gitlink_ref_recursive() after it failed to read
936 * from the loose refs in ref_cache refs. Find <refname> in the
937 * packed-refs file for the submodule.
938 */
939static int resolve_gitlink_packed_ref(struct ref_cache *refs,
940 const char *refname, unsigned char *sha1)
941{
942 struct ref_entry *ref;
943 struct ref_dir *dir = get_packed_refs(refs);
944
945 ref = find_ref(dir, refname);
946 if (ref == NULL)
947 return -1;
948
949 memcpy(sha1, ref->u.value.sha1, 20);
950 return 0;
951}
952
953static int resolve_gitlink_ref_recursive(struct ref_cache *refs,
954 const char *refname, unsigned char *sha1,
955 int recursion)
956{
957 int fd, len;
958 char buffer[128], *p;
959 char *path;
960
961 if (recursion > MAXDEPTH || strlen(refname) > MAXREFLEN)
962 return -1;
963 path = *refs->name
964 ? git_path_submodule(refs->name, "%s", refname)
965 : git_path("%s", refname);
966 fd = open(path, O_RDONLY);
967 if (fd < 0)
968 return resolve_gitlink_packed_ref(refs, refname, sha1);
969
970 len = read(fd, buffer, sizeof(buffer)-1);
971 close(fd);
972 if (len < 0)
973 return -1;
974 while (len && isspace(buffer[len-1]))
975 len--;
976 buffer[len] = 0;
977
978 /* Was it a detached head or an old-fashioned symlink? */
979 if (!get_sha1_hex(buffer, sha1))
980 return 0;
981
982 /* Symref? */
983 if (strncmp(buffer, "ref:", 4))
984 return -1;
985 p = buffer + 4;
986 while (isspace(*p))
987 p++;
988
989 return resolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);
990}
991
992int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *sha1)
993{
994 int len = strlen(path), retval;
995 char *submodule;
996 struct ref_cache *refs;
997
998 while (len && path[len-1] == '/')
999 len--;
1000 if (!len)
1001 return -1;
1002 submodule = xstrndup(path, len);
1003 refs = get_ref_cache(submodule);
1004 free(submodule);
1005
1006 retval = resolve_gitlink_ref_recursive(refs, refname, sha1, 0);
1007 return retval;
1008}
1009
1010/*
1011 * Try to read ref from the packed references. On success, set sha1
1012 * and return 0; otherwise, return -1.
1013 */
1014static int get_packed_ref(const char *refname, unsigned char *sha1)
1015{
1016 struct ref_dir *packed = get_packed_refs(get_ref_cache(NULL));
1017 struct ref_entry *entry = find_ref(packed, refname);
1018 if (entry) {
1019 hashcpy(sha1, entry->u.value.sha1);
1020 return 0;
1021 }
1022 return -1;
1023}
1024
1025const char *resolve_ref_unsafe(const char *refname, unsigned char *sha1, int reading, int *flag)
1026{
1027 int depth = MAXDEPTH;
1028 ssize_t len;
1029 char buffer[256];
1030 static char refname_buffer[256];
1031
1032 if (flag)
1033 *flag = 0;
1034
1035 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1036 return NULL;
1037
1038 for (;;) {
1039 char path[PATH_MAX];
1040 struct stat st;
1041 char *buf;
1042 int fd;
1043
1044 if (--depth < 0)
1045 return NULL;
1046
1047 git_snpath(path, sizeof(path), "%s", refname);
1048
1049 if (lstat(path, &st) < 0) {
1050 if (errno != ENOENT)
1051 return NULL;
1052 /*
1053 * The loose reference file does not exist;
1054 * check for a packed reference.
1055 */
1056 if (!get_packed_ref(refname, sha1)) {
1057 if (flag)
1058 *flag |= REF_ISPACKED;
1059 return refname;
1060 }
1061 /* The reference is not a packed reference, either. */
1062 if (reading) {
1063 return NULL;
1064 } else {
1065 hashclr(sha1);
1066 return refname;
1067 }
1068 }
1069
1070 /* Follow "normalized" - ie "refs/.." symlinks by hand */
1071 if (S_ISLNK(st.st_mode)) {
1072 len = readlink(path, buffer, sizeof(buffer)-1);
1073 if (len < 0)
1074 return NULL;
1075 buffer[len] = 0;
1076 if (!prefixcmp(buffer, "refs/") &&
1077 !check_refname_format(buffer, 0)) {
1078 strcpy(refname_buffer, buffer);
1079 refname = refname_buffer;
1080 if (flag)
1081 *flag |= REF_ISSYMREF;
1082 continue;
1083 }
1084 }
1085
1086 /* Is it a directory? */
1087 if (S_ISDIR(st.st_mode)) {
1088 errno = EISDIR;
1089 return NULL;
1090 }
1091
1092 /*
1093 * Anything else, just open it and try to use it as
1094 * a ref
1095 */
1096 fd = open(path, O_RDONLY);
1097 if (fd < 0)
1098 return NULL;
1099 len = read_in_full(fd, buffer, sizeof(buffer)-1);
1100 close(fd);
1101 if (len < 0)
1102 return NULL;
1103 while (len && isspace(buffer[len-1]))
1104 len--;
1105 buffer[len] = '\0';
1106
1107 /*
1108 * Is it a symbolic ref?
1109 */
1110 if (prefixcmp(buffer, "ref:"))
1111 break;
1112 if (flag)
1113 *flag |= REF_ISSYMREF;
1114 buf = buffer + 4;
1115 while (isspace(*buf))
1116 buf++;
1117 if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
1118 if (flag)
1119 *flag |= REF_ISBROKEN;
1120 return NULL;
1121 }
1122 refname = strcpy(refname_buffer, buf);
1123 }
1124 /* Please note that FETCH_HEAD has a second line containing other data. */
1125 if (get_sha1_hex(buffer, sha1) || (buffer[40] != '\0' && !isspace(buffer[40]))) {
1126 if (flag)
1127 *flag |= REF_ISBROKEN;
1128 return NULL;
1129 }
1130 return refname;
1131}
1132
1133char *resolve_refdup(const char *ref, unsigned char *sha1, int reading, int *flag)
1134{
1135 const char *ret = resolve_ref_unsafe(ref, sha1, reading, flag);
1136 return ret ? xstrdup(ret) : NULL;
1137}
1138
1139/* The argument to filter_refs */
1140struct ref_filter {
1141 const char *pattern;
1142 each_ref_fn *fn;
1143 void *cb_data;
1144};
1145
1146int read_ref_full(const char *refname, unsigned char *sha1, int reading, int *flags)
1147{
1148 if (resolve_ref_unsafe(refname, sha1, reading, flags))
1149 return 0;
1150 return -1;
1151}
1152
1153int read_ref(const char *refname, unsigned char *sha1)
1154{
1155 return read_ref_full(refname, sha1, 1, NULL);
1156}
1157
1158int ref_exists(const char *refname)
1159{
1160 unsigned char sha1[20];
1161 return !!resolve_ref_unsafe(refname, sha1, 1, NULL);
1162}
1163
1164static int filter_refs(const char *refname, const unsigned char *sha1, int flags,
1165 void *data)
1166{
1167 struct ref_filter *filter = (struct ref_filter *)data;
1168 if (fnmatch(filter->pattern, refname, 0))
1169 return 0;
1170 return filter->fn(refname, sha1, flags, filter->cb_data);
1171}
1172
1173int peel_ref(const char *refname, unsigned char *sha1)
1174{
1175 int flag;
1176 unsigned char base[20];
1177 struct object *o;
1178
1179 if (current_ref && (current_ref->name == refname
1180 || !strcmp(current_ref->name, refname))) {
1181 if (current_ref->flag & REF_KNOWS_PEELED) {
1182 hashcpy(sha1, current_ref->u.value.peeled);
1183 return 0;
1184 }
1185 hashcpy(base, current_ref->u.value.sha1);
1186 goto fallback;
1187 }
1188
1189 if (read_ref_full(refname, base, 1, &flag))
1190 return -1;
1191
1192 if ((flag & REF_ISPACKED)) {
1193 struct ref_dir *dir = get_packed_refs(get_ref_cache(NULL));
1194 struct ref_entry *r = find_ref(dir, refname);
1195
1196 if (r != NULL && r->flag & REF_KNOWS_PEELED) {
1197 hashcpy(sha1, r->u.value.peeled);
1198 return 0;
1199 }
1200 }
1201
1202fallback:
1203 o = parse_object(base);
1204 if (o && o->type == OBJ_TAG) {
1205 o = deref_tag(o, refname, 0);
1206 if (o) {
1207 hashcpy(sha1, o->sha1);
1208 return 0;
1209 }
1210 }
1211 return -1;
1212}
1213
1214struct warn_if_dangling_data {
1215 FILE *fp;
1216 const char *refname;
1217 const char *msg_fmt;
1218};
1219
1220static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
1221 int flags, void *cb_data)
1222{
1223 struct warn_if_dangling_data *d = cb_data;
1224 const char *resolves_to;
1225 unsigned char junk[20];
1226
1227 if (!(flags & REF_ISSYMREF))
1228 return 0;
1229
1230 resolves_to = resolve_ref_unsafe(refname, junk, 0, NULL);
1231 if (!resolves_to || strcmp(resolves_to, d->refname))
1232 return 0;
1233
1234 fprintf(d->fp, d->msg_fmt, refname);
1235 return 0;
1236}
1237
1238void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
1239{
1240 struct warn_if_dangling_data data;
1241
1242 data.fp = fp;
1243 data.refname = refname;
1244 data.msg_fmt = msg_fmt;
1245 for_each_rawref(warn_if_dangling_symref, &data);
1246}
1247
1248static int do_for_each_ref(const char *submodule, const char *base, each_ref_fn fn,
1249 int trim, int flags, void *cb_data)
1250{
1251 struct ref_cache *refs = get_ref_cache(submodule);
1252 struct ref_dir *packed_dir = get_packed_refs(refs);
1253 struct ref_dir *loose_dir = get_loose_refs(refs);
1254 int retval = 0;
1255
1256 if (base && *base) {
1257 packed_dir = find_containing_dir(packed_dir, base, 0);
1258 loose_dir = find_containing_dir(loose_dir, base, 0);
1259 }
1260
1261 if (packed_dir && loose_dir) {
1262 sort_ref_dir(packed_dir);
1263 sort_ref_dir(loose_dir);
1264 retval = do_for_each_ref_in_dirs(
1265 packed_dir, loose_dir,
1266 base, fn, trim, flags, cb_data);
1267 } else if (packed_dir) {
1268 sort_ref_dir(packed_dir);
1269 retval = do_for_each_ref_in_dir(
1270 packed_dir, 0,
1271 base, fn, trim, flags, cb_data);
1272 } else if (loose_dir) {
1273 sort_ref_dir(loose_dir);
1274 retval = do_for_each_ref_in_dir(
1275 loose_dir, 0,
1276 base, fn, trim, flags, cb_data);
1277 }
1278
1279 return retval;
1280}
1281
1282static int do_head_ref(const char *submodule, each_ref_fn fn, void *cb_data)
1283{
1284 unsigned char sha1[20];
1285 int flag;
1286
1287 if (submodule) {
1288 if (resolve_gitlink_ref(submodule, "HEAD", sha1) == 0)
1289 return fn("HEAD", sha1, 0, cb_data);
1290
1291 return 0;
1292 }
1293
1294 if (!read_ref_full("HEAD", sha1, 1, &flag))
1295 return fn("HEAD", sha1, flag, cb_data);
1296
1297 return 0;
1298}
1299
1300int head_ref(each_ref_fn fn, void *cb_data)
1301{
1302 return do_head_ref(NULL, fn, cb_data);
1303}
1304
1305int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1306{
1307 return do_head_ref(submodule, fn, cb_data);
1308}
1309
1310int for_each_ref(each_ref_fn fn, void *cb_data)
1311{
1312 return do_for_each_ref(NULL, "", fn, 0, 0, cb_data);
1313}
1314
1315int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1316{
1317 return do_for_each_ref(submodule, "", fn, 0, 0, cb_data);
1318}
1319
1320int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1321{
1322 return do_for_each_ref(NULL, prefix, fn, strlen(prefix), 0, cb_data);
1323}
1324
1325int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1326 each_ref_fn fn, void *cb_data)
1327{
1328 return do_for_each_ref(submodule, prefix, fn, strlen(prefix), 0, cb_data);
1329}
1330
1331int for_each_tag_ref(each_ref_fn fn, void *cb_data)
1332{
1333 return for_each_ref_in("refs/tags/", fn, cb_data);
1334}
1335
1336int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1337{
1338 return for_each_ref_in_submodule(submodule, "refs/tags/", fn, cb_data);
1339}
1340
1341int for_each_branch_ref(each_ref_fn fn, void *cb_data)
1342{
1343 return for_each_ref_in("refs/heads/", fn, cb_data);
1344}
1345
1346int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1347{
1348 return for_each_ref_in_submodule(submodule, "refs/heads/", fn, cb_data);
1349}
1350
1351int for_each_remote_ref(each_ref_fn fn, void *cb_data)
1352{
1353 return for_each_ref_in("refs/remotes/", fn, cb_data);
1354}
1355
1356int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1357{
1358 return for_each_ref_in_submodule(submodule, "refs/remotes/", fn, cb_data);
1359}
1360
1361int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1362{
1363 return do_for_each_ref(NULL, "refs/replace/", fn, 13, 0, cb_data);
1364}
1365
1366int head_ref_namespaced(each_ref_fn fn, void *cb_data)
1367{
1368 struct strbuf buf = STRBUF_INIT;
1369 int ret = 0;
1370 unsigned char sha1[20];
1371 int flag;
1372
1373 strbuf_addf(&buf, "%sHEAD", get_git_namespace());
1374 if (!read_ref_full(buf.buf, sha1, 1, &flag))
1375 ret = fn(buf.buf, sha1, flag, cb_data);
1376 strbuf_release(&buf);
1377
1378 return ret;
1379}
1380
1381int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1382{
1383 struct strbuf buf = STRBUF_INIT;
1384 int ret;
1385 strbuf_addf(&buf, "%srefs/", get_git_namespace());
1386 ret = do_for_each_ref(NULL, buf.buf, fn, 0, 0, cb_data);
1387 strbuf_release(&buf);
1388 return ret;
1389}
1390
1391int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
1392 const char *prefix, void *cb_data)
1393{
1394 struct strbuf real_pattern = STRBUF_INIT;
1395 struct ref_filter filter;
1396 int ret;
1397
1398 if (!prefix && prefixcmp(pattern, "refs/"))
1399 strbuf_addstr(&real_pattern, "refs/");
1400 else if (prefix)
1401 strbuf_addstr(&real_pattern, prefix);
1402 strbuf_addstr(&real_pattern, pattern);
1403
1404 if (!has_glob_specials(pattern)) {
1405 /* Append implied '/' '*' if not present. */
1406 if (real_pattern.buf[real_pattern.len - 1] != '/')
1407 strbuf_addch(&real_pattern, '/');
1408 /* No need to check for '*', there is none. */
1409 strbuf_addch(&real_pattern, '*');
1410 }
1411
1412 filter.pattern = real_pattern.buf;
1413 filter.fn = fn;
1414 filter.cb_data = cb_data;
1415 ret = for_each_ref(filter_refs, &filter);
1416
1417 strbuf_release(&real_pattern);
1418 return ret;
1419}
1420
1421int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
1422{
1423 return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
1424}
1425
1426int for_each_rawref(each_ref_fn fn, void *cb_data)
1427{
1428 return do_for_each_ref(NULL, "", fn, 0,
1429 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1430}
1431
1432const char *prettify_refname(const char *name)
1433{
1434 return name + (
1435 !prefixcmp(name, "refs/heads/") ? 11 :
1436 !prefixcmp(name, "refs/tags/") ? 10 :
1437 !prefixcmp(name, "refs/remotes/") ? 13 :
1438 0);
1439}
1440
1441const char *ref_rev_parse_rules[] = {
1442 "%.*s",
1443 "refs/%.*s",
1444 "refs/tags/%.*s",
1445 "refs/heads/%.*s",
1446 "refs/remotes/%.*s",
1447 "refs/remotes/%.*s/HEAD",
1448 NULL
1449};
1450
1451int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
1452{
1453 const char **p;
1454 const int abbrev_name_len = strlen(abbrev_name);
1455
1456 for (p = rules; *p; p++) {
1457 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
1458 return 1;
1459 }
1460 }
1461
1462 return 0;
1463}
1464
1465static struct ref_lock *verify_lock(struct ref_lock *lock,
1466 const unsigned char *old_sha1, int mustexist)
1467{
1468 if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
1469 error("Can't verify ref %s", lock->ref_name);
1470 unlock_ref(lock);
1471 return NULL;
1472 }
1473 if (hashcmp(lock->old_sha1, old_sha1)) {
1474 error("Ref %s is at %s but expected %s", lock->ref_name,
1475 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
1476 unlock_ref(lock);
1477 return NULL;
1478 }
1479 return lock;
1480}
1481
1482static int remove_empty_directories(const char *file)
1483{
1484 /* we want to create a file but there is a directory there;
1485 * if that is an empty directory (or a directory that contains
1486 * only empty directories), remove them.
1487 */
1488 struct strbuf path;
1489 int result;
1490
1491 strbuf_init(&path, 20);
1492 strbuf_addstr(&path, file);
1493
1494 result = remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);
1495
1496 strbuf_release(&path);
1497
1498 return result;
1499}
1500
1501/*
1502 * *string and *len will only be substituted, and *string returned (for
1503 * later free()ing) if the string passed in is a magic short-hand form
1504 * to name a branch.
1505 */
1506static char *substitute_branch_name(const char **string, int *len)
1507{
1508 struct strbuf buf = STRBUF_INIT;
1509 int ret = interpret_branch_name(*string, &buf);
1510
1511 if (ret == *len) {
1512 size_t size;
1513 *string = strbuf_detach(&buf, &size);
1514 *len = size;
1515 return (char *)*string;
1516 }
1517
1518 return NULL;
1519}
1520
1521int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
1522{
1523 char *last_branch = substitute_branch_name(&str, &len);
1524 const char **p, *r;
1525 int refs_found = 0;
1526
1527 *ref = NULL;
1528 for (p = ref_rev_parse_rules; *p; p++) {
1529 char fullref[PATH_MAX];
1530 unsigned char sha1_from_ref[20];
1531 unsigned char *this_result;
1532 int flag;
1533
1534 this_result = refs_found ? sha1_from_ref : sha1;
1535 mksnpath(fullref, sizeof(fullref), *p, len, str);
1536 r = resolve_ref_unsafe(fullref, this_result, 1, &flag);
1537 if (r) {
1538 if (!refs_found++)
1539 *ref = xstrdup(r);
1540 if (!warn_ambiguous_refs)
1541 break;
1542 } else if ((flag & REF_ISSYMREF) && strcmp(fullref, "HEAD")) {
1543 warning("ignoring dangling symref %s.", fullref);
1544 } else if ((flag & REF_ISBROKEN) && strchr(fullref, '/')) {
1545 warning("ignoring broken ref %s.", fullref);
1546 }
1547 }
1548 free(last_branch);
1549 return refs_found;
1550}
1551
1552int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
1553{
1554 char *last_branch = substitute_branch_name(&str, &len);
1555 const char **p;
1556 int logs_found = 0;
1557
1558 *log = NULL;
1559 for (p = ref_rev_parse_rules; *p; p++) {
1560 struct stat st;
1561 unsigned char hash[20];
1562 char path[PATH_MAX];
1563 const char *ref, *it;
1564
1565 mksnpath(path, sizeof(path), *p, len, str);
1566 ref = resolve_ref_unsafe(path, hash, 1, NULL);
1567 if (!ref)
1568 continue;
1569 if (!stat(git_path("logs/%s", path), &st) &&
1570 S_ISREG(st.st_mode))
1571 it = path;
1572 else if (strcmp(ref, path) &&
1573 !stat(git_path("logs/%s", ref), &st) &&
1574 S_ISREG(st.st_mode))
1575 it = ref;
1576 else
1577 continue;
1578 if (!logs_found++) {
1579 *log = xstrdup(it);
1580 hashcpy(sha1, hash);
1581 }
1582 if (!warn_ambiguous_refs)
1583 break;
1584 }
1585 free(last_branch);
1586 return logs_found;
1587}
1588
1589static struct ref_lock *lock_ref_sha1_basic(const char *refname,
1590 const unsigned char *old_sha1,
1591 int flags, int *type_p)
1592{
1593 char *ref_file;
1594 const char *orig_refname = refname;
1595 struct ref_lock *lock;
1596 int last_errno = 0;
1597 int type, lflags;
1598 int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
1599 int missing = 0;
1600
1601 lock = xcalloc(1, sizeof(struct ref_lock));
1602 lock->lock_fd = -1;
1603
1604 refname = resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);
1605 if (!refname && errno == EISDIR) {
1606 /* we are trying to lock foo but we used to
1607 * have foo/bar which now does not exist;
1608 * it is normal for the empty directory 'foo'
1609 * to remain.
1610 */
1611 ref_file = git_path("%s", orig_refname);
1612 if (remove_empty_directories(ref_file)) {
1613 last_errno = errno;
1614 error("there are still refs under '%s'", orig_refname);
1615 goto error_return;
1616 }
1617 refname = resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);
1618 }
1619 if (type_p)
1620 *type_p = type;
1621 if (!refname) {
1622 last_errno = errno;
1623 error("unable to resolve reference %s: %s",
1624 orig_refname, strerror(errno));
1625 goto error_return;
1626 }
1627 missing = is_null_sha1(lock->old_sha1);
1628 /* When the ref did not exist and we are creating it,
1629 * make sure there is no existing ref that is packed
1630 * whose name begins with our refname, nor a ref whose
1631 * name is a proper prefix of our refname.
1632 */
1633 if (missing &&
1634 !is_refname_available(refname, NULL, get_packed_refs(get_ref_cache(NULL)))) {
1635 last_errno = ENOTDIR;
1636 goto error_return;
1637 }
1638
1639 lock->lk = xcalloc(1, sizeof(struct lock_file));
1640
1641 lflags = LOCK_DIE_ON_ERROR;
1642 if (flags & REF_NODEREF) {
1643 refname = orig_refname;
1644 lflags |= LOCK_NODEREF;
1645 }
1646 lock->ref_name = xstrdup(refname);
1647 lock->orig_ref_name = xstrdup(orig_refname);
1648 ref_file = git_path("%s", refname);
1649 if (missing)
1650 lock->force_write = 1;
1651 if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
1652 lock->force_write = 1;
1653
1654 if (safe_create_leading_directories(ref_file)) {
1655 last_errno = errno;
1656 error("unable to create directory for %s", ref_file);
1657 goto error_return;
1658 }
1659
1660 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
1661 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
1662
1663 error_return:
1664 unlock_ref(lock);
1665 errno = last_errno;
1666 return NULL;
1667}
1668
1669struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1)
1670{
1671 char refpath[PATH_MAX];
1672 if (check_refname_format(refname, 0))
1673 return NULL;
1674 strcpy(refpath, mkpath("refs/%s", refname));
1675 return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
1676}
1677
1678struct ref_lock *lock_any_ref_for_update(const char *refname,
1679 const unsigned char *old_sha1, int flags)
1680{
1681 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))
1682 return NULL;
1683 return lock_ref_sha1_basic(refname, old_sha1, flags, NULL);
1684}
1685
1686struct repack_without_ref_sb {
1687 const char *refname;
1688 int fd;
1689};
1690
1691static int repack_without_ref_fn(const char *refname, const unsigned char *sha1,
1692 int flags, void *cb_data)
1693{
1694 struct repack_without_ref_sb *data = cb_data;
1695 char line[PATH_MAX + 100];
1696 int len;
1697
1698 if (!strcmp(data->refname, refname))
1699 return 0;
1700 len = snprintf(line, sizeof(line), "%s %s\n",
1701 sha1_to_hex(sha1), refname);
1702 /* this should not happen but just being defensive */
1703 if (len > sizeof(line))
1704 die("too long a refname '%s'", refname);
1705 write_or_die(data->fd, line, len);
1706 return 0;
1707}
1708
1709static struct lock_file packlock;
1710
1711static int repack_without_ref(const char *refname)
1712{
1713 struct repack_without_ref_sb data;
1714 struct ref_dir *packed = get_packed_refs(get_ref_cache(NULL));
1715 if (find_ref(packed, refname) == NULL)
1716 return 0;
1717 data.refname = refname;
1718 data.fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
1719 if (data.fd < 0) {
1720 unable_to_lock_error(git_path("packed-refs"), errno);
1721 return error("cannot delete '%s' from packed refs", refname);
1722 }
1723 do_for_each_ref_in_dir(packed, 0, "", repack_without_ref_fn, 0, 0, &data);
1724 return commit_lock_file(&packlock);
1725}
1726
1727int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
1728{
1729 struct ref_lock *lock;
1730 int err, i = 0, ret = 0, flag = 0;
1731
1732 lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
1733 if (!lock)
1734 return 1;
1735 if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
1736 /* loose */
1737 const char *path;
1738
1739 if (!(delopt & REF_NODEREF)) {
1740 i = strlen(lock->lk->filename) - 5; /* .lock */
1741 lock->lk->filename[i] = 0;
1742 path = lock->lk->filename;
1743 } else {
1744 path = git_path("%s", refname);
1745 }
1746 err = unlink_or_warn(path);
1747 if (err && errno != ENOENT)
1748 ret = 1;
1749
1750 if (!(delopt & REF_NODEREF))
1751 lock->lk->filename[i] = '.';
1752 }
1753 /* removing the loose one could have resurrected an earlier
1754 * packed one. Also, if it was not loose we need to repack
1755 * without it.
1756 */
1757 ret |= repack_without_ref(refname);
1758
1759 unlink_or_warn(git_path("logs/%s", lock->ref_name));
1760 invalidate_ref_cache(NULL);
1761 unlock_ref(lock);
1762 return ret;
1763}
1764
1765/*
1766 * People using contrib's git-new-workdir have .git/logs/refs ->
1767 * /some/other/path/.git/logs/refs, and that may live on another device.
1768 *
1769 * IOW, to avoid cross device rename errors, the temporary renamed log must
1770 * live into logs/refs.
1771 */
1772#define TMP_RENAMED_LOG "logs/refs/.tmp-renamed-log"
1773
1774int rename_ref(const char *oldrefname, const char *newrefname, const char *logmsg)
1775{
1776 unsigned char sha1[20], orig_sha1[20];
1777 int flag = 0, logmoved = 0;
1778 struct ref_lock *lock;
1779 struct stat loginfo;
1780 int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);
1781 const char *symref = NULL;
1782 struct ref_cache *refs = get_ref_cache(NULL);
1783
1784 if (log && S_ISLNK(loginfo.st_mode))
1785 return error("reflog for %s is a symlink", oldrefname);
1786
1787 symref = resolve_ref_unsafe(oldrefname, orig_sha1, 1, &flag);
1788 if (flag & REF_ISSYMREF)
1789 return error("refname %s is a symbolic ref, renaming it is not supported",
1790 oldrefname);
1791 if (!symref)
1792 return error("refname %s not found", oldrefname);
1793
1794 if (!is_refname_available(newrefname, oldrefname, get_packed_refs(refs)))
1795 return 1;
1796
1797 if (!is_refname_available(newrefname, oldrefname, get_loose_refs(refs)))
1798 return 1;
1799
1800 if (log && rename(git_path("logs/%s", oldrefname), git_path(TMP_RENAMED_LOG)))
1801 return error("unable to move logfile logs/%s to "TMP_RENAMED_LOG": %s",
1802 oldrefname, strerror(errno));
1803
1804 if (delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {
1805 error("unable to delete old %s", oldrefname);
1806 goto rollback;
1807 }
1808
1809 if (!read_ref_full(newrefname, sha1, 1, &flag) &&
1810 delete_ref(newrefname, sha1, REF_NODEREF)) {
1811 if (errno==EISDIR) {
1812 if (remove_empty_directories(git_path("%s", newrefname))) {
1813 error("Directory not empty: %s", newrefname);
1814 goto rollback;
1815 }
1816 } else {
1817 error("unable to delete existing %s", newrefname);
1818 goto rollback;
1819 }
1820 }
1821
1822 if (log && safe_create_leading_directories(git_path("logs/%s", newrefname))) {
1823 error("unable to create directory for %s", newrefname);
1824 goto rollback;
1825 }
1826
1827 retry:
1828 if (log && rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", newrefname))) {
1829 if (errno==EISDIR || errno==ENOTDIR) {
1830 /*
1831 * rename(a, b) when b is an existing
1832 * directory ought to result in ISDIR, but
1833 * Solaris 5.8 gives ENOTDIR. Sheesh.
1834 */
1835 if (remove_empty_directories(git_path("logs/%s", newrefname))) {
1836 error("Directory not empty: logs/%s", newrefname);
1837 goto rollback;
1838 }
1839 goto retry;
1840 } else {
1841 error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s: %s",
1842 newrefname, strerror(errno));
1843 goto rollback;
1844 }
1845 }
1846 logmoved = log;
1847
1848 lock = lock_ref_sha1_basic(newrefname, NULL, 0, NULL);
1849 if (!lock) {
1850 error("unable to lock %s for update", newrefname);
1851 goto rollback;
1852 }
1853 lock->force_write = 1;
1854 hashcpy(lock->old_sha1, orig_sha1);
1855 if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1856 error("unable to write current sha1 into %s", newrefname);
1857 goto rollback;
1858 }
1859
1860 return 0;
1861
1862 rollback:
1863 lock = lock_ref_sha1_basic(oldrefname, NULL, 0, NULL);
1864 if (!lock) {
1865 error("unable to lock %s for rollback", oldrefname);
1866 goto rollbacklog;
1867 }
1868
1869 lock->force_write = 1;
1870 flag = log_all_ref_updates;
1871 log_all_ref_updates = 0;
1872 if (write_ref_sha1(lock, orig_sha1, NULL))
1873 error("unable to write current sha1 into %s", oldrefname);
1874 log_all_ref_updates = flag;
1875
1876 rollbacklog:
1877 if (logmoved && rename(git_path("logs/%s", newrefname), git_path("logs/%s", oldrefname)))
1878 error("unable to restore logfile %s from %s: %s",
1879 oldrefname, newrefname, strerror(errno));
1880 if (!logmoved && log &&
1881 rename(git_path(TMP_RENAMED_LOG), git_path("logs/%s", oldrefname)))
1882 error("unable to restore logfile %s from "TMP_RENAMED_LOG": %s",
1883 oldrefname, strerror(errno));
1884
1885 return 1;
1886}
1887
1888int close_ref(struct ref_lock *lock)
1889{
1890 if (close_lock_file(lock->lk))
1891 return -1;
1892 lock->lock_fd = -1;
1893 return 0;
1894}
1895
1896int commit_ref(struct ref_lock *lock)
1897{
1898 if (commit_lock_file(lock->lk))
1899 return -1;
1900 lock->lock_fd = -1;
1901 return 0;
1902}
1903
1904void unlock_ref(struct ref_lock *lock)
1905{
1906 /* Do not free lock->lk -- atexit() still looks at them */
1907 if (lock->lk)
1908 rollback_lock_file(lock->lk);
1909 free(lock->ref_name);
1910 free(lock->orig_ref_name);
1911 free(lock);
1912}
1913
1914/*
1915 * copy the reflog message msg to buf, which has been allocated sufficiently
1916 * large, while cleaning up the whitespaces. Especially, convert LF to space,
1917 * because reflog file is one line per entry.
1918 */
1919static int copy_msg(char *buf, const char *msg)
1920{
1921 char *cp = buf;
1922 char c;
1923 int wasspace = 1;
1924
1925 *cp++ = '\t';
1926 while ((c = *msg++)) {
1927 if (wasspace && isspace(c))
1928 continue;
1929 wasspace = isspace(c);
1930 if (wasspace)
1931 c = ' ';
1932 *cp++ = c;
1933 }
1934 while (buf < cp && isspace(cp[-1]))
1935 cp--;
1936 *cp++ = '\n';
1937 return cp - buf;
1938}
1939
1940int log_ref_setup(const char *refname, char *logfile, int bufsize)
1941{
1942 int logfd, oflags = O_APPEND | O_WRONLY;
1943
1944 git_snpath(logfile, bufsize, "logs/%s", refname);
1945 if (log_all_ref_updates &&
1946 (!prefixcmp(refname, "refs/heads/") ||
1947 !prefixcmp(refname, "refs/remotes/") ||
1948 !prefixcmp(refname, "refs/notes/") ||
1949 !strcmp(refname, "HEAD"))) {
1950 if (safe_create_leading_directories(logfile) < 0)
1951 return error("unable to create directory for %s",
1952 logfile);
1953 oflags |= O_CREAT;
1954 }
1955
1956 logfd = open(logfile, oflags, 0666);
1957 if (logfd < 0) {
1958 if (!(oflags & O_CREAT) && errno == ENOENT)
1959 return 0;
1960
1961 if ((oflags & O_CREAT) && errno == EISDIR) {
1962 if (remove_empty_directories(logfile)) {
1963 return error("There are still logs under '%s'",
1964 logfile);
1965 }
1966 logfd = open(logfile, oflags, 0666);
1967 }
1968
1969 if (logfd < 0)
1970 return error("Unable to append to %s: %s",
1971 logfile, strerror(errno));
1972 }
1973
1974 adjust_shared_perm(logfile);
1975 close(logfd);
1976 return 0;
1977}
1978
1979static int log_ref_write(const char *refname, const unsigned char *old_sha1,
1980 const unsigned char *new_sha1, const char *msg)
1981{
1982 int logfd, result, written, oflags = O_APPEND | O_WRONLY;
1983 unsigned maxlen, len;
1984 int msglen;
1985 char log_file[PATH_MAX];
1986 char *logrec;
1987 const char *committer;
1988
1989 if (log_all_ref_updates < 0)
1990 log_all_ref_updates = !is_bare_repository();
1991
1992 result = log_ref_setup(refname, log_file, sizeof(log_file));
1993 if (result)
1994 return result;
1995
1996 logfd = open(log_file, oflags);
1997 if (logfd < 0)
1998 return 0;
1999 msglen = msg ? strlen(msg) : 0;
2000 committer = git_committer_info(0);
2001 maxlen = strlen(committer) + msglen + 100;
2002 logrec = xmalloc(maxlen);
2003 len = sprintf(logrec, "%s %s %s\n",
2004 sha1_to_hex(old_sha1),
2005 sha1_to_hex(new_sha1),
2006 committer);
2007 if (msglen)
2008 len += copy_msg(logrec + len - 1, msg) - 1;
2009 written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
2010 free(logrec);
2011 if (close(logfd) != 0 || written != len)
2012 return error("Unable to append to %s", log_file);
2013 return 0;
2014}
2015
2016static int is_branch(const char *refname)
2017{
2018 return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
2019}
2020
2021int write_ref_sha1(struct ref_lock *lock,
2022 const unsigned char *sha1, const char *logmsg)
2023{
2024 static char term = '\n';
2025 struct object *o;
2026
2027 if (!lock)
2028 return -1;
2029 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
2030 unlock_ref(lock);
2031 return 0;
2032 }
2033 o = parse_object(sha1);
2034 if (!o) {
2035 error("Trying to write ref %s with nonexistent object %s",
2036 lock->ref_name, sha1_to_hex(sha1));
2037 unlock_ref(lock);
2038 return -1;
2039 }
2040 if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
2041 error("Trying to write non-commit object %s to branch %s",
2042 sha1_to_hex(sha1), lock->ref_name);
2043 unlock_ref(lock);
2044 return -1;
2045 }
2046 if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
2047 write_in_full(lock->lock_fd, &term, 1) != 1
2048 || close_ref(lock) < 0) {
2049 error("Couldn't write %s", lock->lk->filename);
2050 unlock_ref(lock);
2051 return -1;
2052 }
2053 clear_loose_ref_cache(get_ref_cache(NULL));
2054 if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
2055 (strcmp(lock->ref_name, lock->orig_ref_name) &&
2056 log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
2057 unlock_ref(lock);
2058 return -1;
2059 }
2060 if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
2061 /*
2062 * Special hack: If a branch is updated directly and HEAD
2063 * points to it (may happen on the remote side of a push
2064 * for example) then logically the HEAD reflog should be
2065 * updated too.
2066 * A generic solution implies reverse symref information,
2067 * but finding all symrefs pointing to the given branch
2068 * would be rather costly for this rare event (the direct
2069 * update of a branch) to be worth it. So let's cheat and
2070 * check with HEAD only which should cover 99% of all usage
2071 * scenarios (even 100% of the default ones).
2072 */
2073 unsigned char head_sha1[20];
2074 int head_flag;
2075 const char *head_ref;
2076 head_ref = resolve_ref_unsafe("HEAD", head_sha1, 1, &head_flag);
2077 if (head_ref && (head_flag & REF_ISSYMREF) &&
2078 !strcmp(head_ref, lock->ref_name))
2079 log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
2080 }
2081 if (commit_ref(lock)) {
2082 error("Couldn't set %s", lock->ref_name);
2083 unlock_ref(lock);
2084 return -1;
2085 }
2086 unlock_ref(lock);
2087 return 0;
2088}
2089
2090int create_symref(const char *ref_target, const char *refs_heads_master,
2091 const char *logmsg)
2092{
2093 const char *lockpath;
2094 char ref[1000];
2095 int fd, len, written;
2096 char *git_HEAD = git_pathdup("%s", ref_target);
2097 unsigned char old_sha1[20], new_sha1[20];
2098
2099 if (logmsg && read_ref(ref_target, old_sha1))
2100 hashclr(old_sha1);
2101
2102 if (safe_create_leading_directories(git_HEAD) < 0)
2103 return error("unable to create directory for %s", git_HEAD);
2104
2105#ifndef NO_SYMLINK_HEAD
2106 if (prefer_symlink_refs) {
2107 unlink(git_HEAD);
2108 if (!symlink(refs_heads_master, git_HEAD))
2109 goto done;
2110 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
2111 }
2112#endif
2113
2114 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
2115 if (sizeof(ref) <= len) {
2116 error("refname too long: %s", refs_heads_master);
2117 goto error_free_return;
2118 }
2119 lockpath = mkpath("%s.lock", git_HEAD);
2120 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
2121 if (fd < 0) {
2122 error("Unable to open %s for writing", lockpath);
2123 goto error_free_return;
2124 }
2125 written = write_in_full(fd, ref, len);
2126 if (close(fd) != 0 || written != len) {
2127 error("Unable to write to %s", lockpath);
2128 goto error_unlink_return;
2129 }
2130 if (rename(lockpath, git_HEAD) < 0) {
2131 error("Unable to create %s", git_HEAD);
2132 goto error_unlink_return;
2133 }
2134 if (adjust_shared_perm(git_HEAD)) {
2135 error("Unable to fix permissions on %s", lockpath);
2136 error_unlink_return:
2137 unlink_or_warn(lockpath);
2138 error_free_return:
2139 free(git_HEAD);
2140 return -1;
2141 }
2142
2143#ifndef NO_SYMLINK_HEAD
2144 done:
2145#endif
2146 if (logmsg && !read_ref(refs_heads_master, new_sha1))
2147 log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
2148
2149 free(git_HEAD);
2150 return 0;
2151}
2152
2153static char *ref_msg(const char *line, const char *endp)
2154{
2155 const char *ep;
2156 line += 82;
2157 ep = memchr(line, '\n', endp - line);
2158 if (!ep)
2159 ep = endp;
2160 return xmemdupz(line, ep - line);
2161}
2162
2163int read_ref_at(const char *refname, unsigned long at_time, int cnt,
2164 unsigned char *sha1, char **msg,
2165 unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
2166{
2167 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
2168 char *tz_c;
2169 int logfd, tz, reccnt = 0;
2170 struct stat st;
2171 unsigned long date;
2172 unsigned char logged_sha1[20];
2173 void *log_mapped;
2174 size_t mapsz;
2175
2176 logfile = git_path("logs/%s", refname);
2177 logfd = open(logfile, O_RDONLY, 0);
2178 if (logfd < 0)
2179 die_errno("Unable to read log '%s'", logfile);
2180 fstat(logfd, &st);
2181 if (!st.st_size)
2182 die("Log %s is empty.", logfile);
2183 mapsz = xsize_t(st.st_size);
2184 log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
2185 logdata = log_mapped;
2186 close(logfd);
2187
2188 lastrec = NULL;
2189 rec = logend = logdata + st.st_size;
2190 while (logdata < rec) {
2191 reccnt++;
2192 if (logdata < rec && *(rec-1) == '\n')
2193 rec--;
2194 lastgt = NULL;
2195 while (logdata < rec && *(rec-1) != '\n') {
2196 rec--;
2197 if (*rec == '>')
2198 lastgt = rec;
2199 }
2200 if (!lastgt)
2201 die("Log %s is corrupt.", logfile);
2202 date = strtoul(lastgt + 1, &tz_c, 10);
2203 if (date <= at_time || cnt == 0) {
2204 tz = strtoul(tz_c, NULL, 10);
2205 if (msg)
2206 *msg = ref_msg(rec, logend);
2207 if (cutoff_time)
2208 *cutoff_time = date;
2209 if (cutoff_tz)
2210 *cutoff_tz = tz;
2211 if (cutoff_cnt)
2212 *cutoff_cnt = reccnt - 1;
2213 if (lastrec) {
2214 if (get_sha1_hex(lastrec, logged_sha1))
2215 die("Log %s is corrupt.", logfile);
2216 if (get_sha1_hex(rec + 41, sha1))
2217 die("Log %s is corrupt.", logfile);
2218 if (hashcmp(logged_sha1, sha1)) {
2219 warning("Log %s has gap after %s.",
2220 logfile, show_date(date, tz, DATE_RFC2822));
2221 }
2222 }
2223 else if (date == at_time) {
2224 if (get_sha1_hex(rec + 41, sha1))
2225 die("Log %s is corrupt.", logfile);
2226 }
2227 else {
2228 if (get_sha1_hex(rec + 41, logged_sha1))
2229 die("Log %s is corrupt.", logfile);
2230 if (hashcmp(logged_sha1, sha1)) {
2231 warning("Log %s unexpectedly ended on %s.",
2232 logfile, show_date(date, tz, DATE_RFC2822));
2233 }
2234 }
2235 munmap(log_mapped, mapsz);
2236 return 0;
2237 }
2238 lastrec = rec;
2239 if (cnt > 0)
2240 cnt--;
2241 }
2242
2243 rec = logdata;
2244 while (rec < logend && *rec != '>' && *rec != '\n')
2245 rec++;
2246 if (rec == logend || *rec == '\n')
2247 die("Log %s is corrupt.", logfile);
2248 date = strtoul(rec + 1, &tz_c, 10);
2249 tz = strtoul(tz_c, NULL, 10);
2250 if (get_sha1_hex(logdata, sha1))
2251 die("Log %s is corrupt.", logfile);
2252 if (is_null_sha1(sha1)) {
2253 if (get_sha1_hex(logdata + 41, sha1))
2254 die("Log %s is corrupt.", logfile);
2255 }
2256 if (msg)
2257 *msg = ref_msg(logdata, logend);
2258 munmap(log_mapped, mapsz);
2259
2260 if (cutoff_time)
2261 *cutoff_time = date;
2262 if (cutoff_tz)
2263 *cutoff_tz = tz;
2264 if (cutoff_cnt)
2265 *cutoff_cnt = reccnt;
2266 return 1;
2267}
2268
2269int for_each_recent_reflog_ent(const char *refname, each_reflog_ent_fn fn, long ofs, void *cb_data)
2270{
2271 const char *logfile;
2272 FILE *logfp;
2273 struct strbuf sb = STRBUF_INIT;
2274 int ret = 0;
2275
2276 logfile = git_path("logs/%s", refname);
2277 logfp = fopen(logfile, "r");
2278 if (!logfp)
2279 return -1;
2280
2281 if (ofs) {
2282 struct stat statbuf;
2283 if (fstat(fileno(logfp), &statbuf) ||
2284 statbuf.st_size < ofs ||
2285 fseek(logfp, -ofs, SEEK_END) ||
2286 strbuf_getwholeline(&sb, logfp, '\n')) {
2287 fclose(logfp);
2288 strbuf_release(&sb);
2289 return -1;
2290 }
2291 }
2292
2293 while (!strbuf_getwholeline(&sb, logfp, '\n')) {
2294 unsigned char osha1[20], nsha1[20];
2295 char *email_end, *message;
2296 unsigned long timestamp;
2297 int tz;
2298
2299 /* old SP new SP name <email> SP time TAB msg LF */
2300 if (sb.len < 83 || sb.buf[sb.len - 1] != '\n' ||
2301 get_sha1_hex(sb.buf, osha1) || sb.buf[40] != ' ' ||
2302 get_sha1_hex(sb.buf + 41, nsha1) || sb.buf[81] != ' ' ||
2303 !(email_end = strchr(sb.buf + 82, '>')) ||
2304 email_end[1] != ' ' ||
2305 !(timestamp = strtoul(email_end + 2, &message, 10)) ||
2306 !message || message[0] != ' ' ||
2307 (message[1] != '+' && message[1] != '-') ||
2308 !isdigit(message[2]) || !isdigit(message[3]) ||
2309 !isdigit(message[4]) || !isdigit(message[5]))
2310 continue; /* corrupt? */
2311 email_end[1] = '\0';
2312 tz = strtol(message + 1, NULL, 10);
2313 if (message[6] != '\t')
2314 message += 6;
2315 else
2316 message += 7;
2317 ret = fn(osha1, nsha1, sb.buf + 82, timestamp, tz, message,
2318 cb_data);
2319 if (ret)
2320 break;
2321 }
2322 fclose(logfp);
2323 strbuf_release(&sb);
2324 return ret;
2325}
2326
2327int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn, void *cb_data)
2328{
2329 return for_each_recent_reflog_ent(refname, fn, 0, cb_data);
2330}
2331
2332/*
2333 * Call fn for each reflog in the namespace indicated by name. name
2334 * must be empty or end with '/'. Name will be used as a scratch
2335 * space, but its contents will be restored before return.
2336 */
2337static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data)
2338{
2339 DIR *d = opendir(git_path("logs/%s", name->buf));
2340 int retval = 0;
2341 struct dirent *de;
2342 int oldlen = name->len;
2343
2344 if (!d)
2345 return name->len ? errno : 0;
2346
2347 while ((de = readdir(d)) != NULL) {
2348 struct stat st;
2349
2350 if (de->d_name[0] == '.')
2351 continue;
2352 if (has_extension(de->d_name, ".lock"))
2353 continue;
2354 strbuf_addstr(name, de->d_name);
2355 if (stat(git_path("logs/%s", name->buf), &st) < 0) {
2356 ; /* silently ignore */
2357 } else {
2358 if (S_ISDIR(st.st_mode)) {
2359 strbuf_addch(name, '/');
2360 retval = do_for_each_reflog(name, fn, cb_data);
2361 } else {
2362 unsigned char sha1[20];
2363 if (read_ref_full(name->buf, sha1, 0, NULL))
2364 retval = error("bad ref for %s", name->buf);
2365 else
2366 retval = fn(name->buf, sha1, 0, cb_data);
2367 }
2368 if (retval)
2369 break;
2370 }
2371 strbuf_setlen(name, oldlen);
2372 }
2373 closedir(d);
2374 return retval;
2375}
2376
2377int for_each_reflog(each_ref_fn fn, void *cb_data)
2378{
2379 int retval;
2380 struct strbuf name;
2381 strbuf_init(&name, PATH_MAX);
2382 retval = do_for_each_reflog(&name, fn, cb_data);
2383 strbuf_release(&name);
2384 return retval;
2385}
2386
2387int update_ref(const char *action, const char *refname,
2388 const unsigned char *sha1, const unsigned char *oldval,
2389 int flags, enum action_on_err onerr)
2390{
2391 static struct ref_lock *lock;
2392 lock = lock_any_ref_for_update(refname, oldval, flags);
2393 if (!lock) {
2394 const char *str = "Cannot lock the ref '%s'.";
2395 switch (onerr) {
2396 case MSG_ON_ERR: error(str, refname); break;
2397 case DIE_ON_ERR: die(str, refname); break;
2398 case QUIET_ON_ERR: break;
2399 }
2400 return 1;
2401 }
2402 if (write_ref_sha1(lock, sha1, action) < 0) {
2403 const char *str = "Cannot update the ref '%s'.";
2404 switch (onerr) {
2405 case MSG_ON_ERR: error(str, refname); break;
2406 case DIE_ON_ERR: die(str, refname); break;
2407 case QUIET_ON_ERR: break;
2408 }
2409 return 1;
2410 }
2411 return 0;
2412}
2413
2414struct ref *find_ref_by_name(const struct ref *list, const char *name)
2415{
2416 for ( ; list; list = list->next)
2417 if (!strcmp(list->name, name))
2418 return (struct ref *)list;
2419 return NULL;
2420}
2421
2422/*
2423 * generate a format suitable for scanf from a ref_rev_parse_rules
2424 * rule, that is replace the "%.*s" spec with a "%s" spec
2425 */
2426static void gen_scanf_fmt(char *scanf_fmt, const char *rule)
2427{
2428 char *spec;
2429
2430 spec = strstr(rule, "%.*s");
2431 if (!spec || strstr(spec + 4, "%.*s"))
2432 die("invalid rule in ref_rev_parse_rules: %s", rule);
2433
2434 /* copy all until spec */
2435 strncpy(scanf_fmt, rule, spec - rule);
2436 scanf_fmt[spec - rule] = '\0';
2437 /* copy new spec */
2438 strcat(scanf_fmt, "%s");
2439 /* copy remaining rule */
2440 strcat(scanf_fmt, spec + 4);
2441
2442 return;
2443}
2444
2445char *shorten_unambiguous_ref(const char *refname, int strict)
2446{
2447 int i;
2448 static char **scanf_fmts;
2449 static int nr_rules;
2450 char *short_name;
2451
2452 /* pre generate scanf formats from ref_rev_parse_rules[] */
2453 if (!nr_rules) {
2454 size_t total_len = 0;
2455
2456 /* the rule list is NULL terminated, count them first */
2457 for (; ref_rev_parse_rules[nr_rules]; nr_rules++)
2458 /* no +1 because strlen("%s") < strlen("%.*s") */
2459 total_len += strlen(ref_rev_parse_rules[nr_rules]);
2460
2461 scanf_fmts = xmalloc(nr_rules * sizeof(char *) + total_len);
2462
2463 total_len = 0;
2464 for (i = 0; i < nr_rules; i++) {
2465 scanf_fmts[i] = (char *)&scanf_fmts[nr_rules]
2466 + total_len;
2467 gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);
2468 total_len += strlen(ref_rev_parse_rules[i]);
2469 }
2470 }
2471
2472 /* bail out if there are no rules */
2473 if (!nr_rules)
2474 return xstrdup(refname);
2475
2476 /* buffer for scanf result, at most refname must fit */
2477 short_name = xstrdup(refname);
2478
2479 /* skip first rule, it will always match */
2480 for (i = nr_rules - 1; i > 0 ; --i) {
2481 int j;
2482 int rules_to_fail = i;
2483 int short_name_len;
2484
2485 if (1 != sscanf(refname, scanf_fmts[i], short_name))
2486 continue;
2487
2488 short_name_len = strlen(short_name);
2489
2490 /*
2491 * in strict mode, all (except the matched one) rules
2492 * must fail to resolve to a valid non-ambiguous ref
2493 */
2494 if (strict)
2495 rules_to_fail = nr_rules;
2496
2497 /*
2498 * check if the short name resolves to a valid ref,
2499 * but use only rules prior to the matched one
2500 */
2501 for (j = 0; j < rules_to_fail; j++) {
2502 const char *rule = ref_rev_parse_rules[j];
2503 char refname[PATH_MAX];
2504
2505 /* skip matched rule */
2506 if (i == j)
2507 continue;
2508
2509 /*
2510 * the short name is ambiguous, if it resolves
2511 * (with this previous rule) to a valid ref
2512 * read_ref() returns 0 on success
2513 */
2514 mksnpath(refname, sizeof(refname),
2515 rule, short_name_len, short_name);
2516 if (ref_exists(refname))
2517 break;
2518 }
2519
2520 /*
2521 * short name is non-ambiguous if all previous rules
2522 * haven't resolved to a valid ref
2523 */
2524 if (j == rules_to_fail)
2525 return short_name;
2526 }
2527
2528 free(short_name);
2529 return xstrdup(refname);
2530}