Merge branch 'lt/case-insensitive'
[git/git.git] / read-cache.c
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 */
6 #define NO_THE_INDEX_COMPATIBILITY_MACROS
7 #include "cache.h"
8 #include "cache-tree.h"
9 #include "refs.h"
10 #include "dir.h"
11
12 /* Index extensions.
13 *
14 * The first letter should be 'A'..'Z' for extensions that are not
15 * necessary for a correct operation (i.e. optimization data).
16 * When new extensions are added that _needs_ to be understood in
17 * order to correctly interpret the index file, pick character that
18 * is outside the range, to cause the reader to abort.
19 */
20
21 #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
22 #define CACHE_EXT_TREE 0x54524545 /* "TREE" */
23
24 struct index_state the_index;
25
26 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
27 {
28 istate->cache[nr] = ce;
29 add_name_hash(istate, ce);
30 }
31
32 static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
33 {
34 struct cache_entry *old = istate->cache[nr];
35
36 remove_name_hash(old);
37 set_index_entry(istate, nr, ce);
38 istate->cache_changed = 1;
39 }
40
41 /*
42 * This only updates the "non-critical" parts of the directory
43 * cache, ie the parts that aren't tracked by GIT, and only used
44 * to validate the cache.
45 */
46 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
47 {
48 ce->ce_ctime = st->st_ctime;
49 ce->ce_mtime = st->st_mtime;
50 ce->ce_dev = st->st_dev;
51 ce->ce_ino = st->st_ino;
52 ce->ce_uid = st->st_uid;
53 ce->ce_gid = st->st_gid;
54 ce->ce_size = st->st_size;
55
56 if (assume_unchanged)
57 ce->ce_flags |= CE_VALID;
58
59 if (S_ISREG(st->st_mode))
60 ce_mark_uptodate(ce);
61 }
62
63 static int ce_compare_data(struct cache_entry *ce, struct stat *st)
64 {
65 int match = -1;
66 int fd = open(ce->name, O_RDONLY);
67
68 if (fd >= 0) {
69 unsigned char sha1[20];
70 if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name))
71 match = hashcmp(sha1, ce->sha1);
72 /* index_fd() closed the file descriptor already */
73 }
74 return match;
75 }
76
77 static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
78 {
79 int match = -1;
80 char *target;
81 void *buffer;
82 unsigned long size;
83 enum object_type type;
84 int len;
85
86 target = xmalloc(expected_size);
87 len = readlink(ce->name, target, expected_size);
88 if (len != expected_size) {
89 free(target);
90 return -1;
91 }
92 buffer = read_sha1_file(ce->sha1, &type, &size);
93 if (!buffer) {
94 free(target);
95 return -1;
96 }
97 if (size == expected_size)
98 match = memcmp(buffer, target, size);
99 free(buffer);
100 free(target);
101 return match;
102 }
103
104 static int ce_compare_gitlink(struct cache_entry *ce)
105 {
106 unsigned char sha1[20];
107
108 /*
109 * We don't actually require that the .git directory
110 * under GITLINK directory be a valid git directory. It
111 * might even be missing (in case nobody populated that
112 * sub-project).
113 *
114 * If so, we consider it always to match.
115 */
116 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
117 return 0;
118 return hashcmp(sha1, ce->sha1);
119 }
120
121 static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
122 {
123 switch (st->st_mode & S_IFMT) {
124 case S_IFREG:
125 if (ce_compare_data(ce, st))
126 return DATA_CHANGED;
127 break;
128 case S_IFLNK:
129 if (ce_compare_link(ce, xsize_t(st->st_size)))
130 return DATA_CHANGED;
131 break;
132 case S_IFDIR:
133 if (S_ISGITLINK(ce->ce_mode))
134 return 0;
135 default:
136 return TYPE_CHANGED;
137 }
138 return 0;
139 }
140
141 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
142 {
143 unsigned int changed = 0;
144
145 if (ce->ce_flags & CE_REMOVE)
146 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
147
148 switch (ce->ce_mode & S_IFMT) {
149 case S_IFREG:
150 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
151 /* We consider only the owner x bit to be relevant for
152 * "mode changes"
153 */
154 if (trust_executable_bit &&
155 (0100 & (ce->ce_mode ^ st->st_mode)))
156 changed |= MODE_CHANGED;
157 break;
158 case S_IFLNK:
159 if (!S_ISLNK(st->st_mode) &&
160 (has_symlinks || !S_ISREG(st->st_mode)))
161 changed |= TYPE_CHANGED;
162 break;
163 case S_IFGITLINK:
164 if (!S_ISDIR(st->st_mode))
165 changed |= TYPE_CHANGED;
166 else if (ce_compare_gitlink(ce))
167 changed |= DATA_CHANGED;
168 return changed;
169 default:
170 die("internal error: ce_mode is %o", ce->ce_mode);
171 }
172 if (ce->ce_mtime != (unsigned int) st->st_mtime)
173 changed |= MTIME_CHANGED;
174 if (ce->ce_ctime != (unsigned int) st->st_ctime)
175 changed |= CTIME_CHANGED;
176
177 if (ce->ce_uid != (unsigned int) st->st_uid ||
178 ce->ce_gid != (unsigned int) st->st_gid)
179 changed |= OWNER_CHANGED;
180 if (ce->ce_ino != (unsigned int) st->st_ino)
181 changed |= INODE_CHANGED;
182
183 #ifdef USE_STDEV
184 /*
185 * st_dev breaks on network filesystems where different
186 * clients will have different views of what "device"
187 * the filesystem is on
188 */
189 if (ce->ce_dev != (unsigned int) st->st_dev)
190 changed |= INODE_CHANGED;
191 #endif
192
193 if (ce->ce_size != (unsigned int) st->st_size)
194 changed |= DATA_CHANGED;
195
196 return changed;
197 }
198
199 static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
200 {
201 return (istate->timestamp &&
202 ((unsigned int)istate->timestamp) <= ce->ce_mtime);
203 }
204
205 int ie_match_stat(const struct index_state *istate,
206 struct cache_entry *ce, struct stat *st,
207 unsigned int options)
208 {
209 unsigned int changed;
210 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
211 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
212
213 /*
214 * If it's marked as always valid in the index, it's
215 * valid whatever the checked-out copy says.
216 */
217 if (!ignore_valid && (ce->ce_flags & CE_VALID))
218 return 0;
219
220 changed = ce_match_stat_basic(ce, st);
221
222 /*
223 * Within 1 second of this sequence:
224 * echo xyzzy >file && git-update-index --add file
225 * running this command:
226 * echo frotz >file
227 * would give a falsely clean cache entry. The mtime and
228 * length match the cache, and other stat fields do not change.
229 *
230 * We could detect this at update-index time (the cache entry
231 * being registered/updated records the same time as "now")
232 * and delay the return from git-update-index, but that would
233 * effectively mean we can make at most one commit per second,
234 * which is not acceptable. Instead, we check cache entries
235 * whose mtime are the same as the index file timestamp more
236 * carefully than others.
237 */
238 if (!changed && is_racy_timestamp(istate, ce)) {
239 if (assume_racy_is_modified)
240 changed |= DATA_CHANGED;
241 else
242 changed |= ce_modified_check_fs(ce, st);
243 }
244
245 return changed;
246 }
247
248 int ie_modified(const struct index_state *istate,
249 struct cache_entry *ce, struct stat *st, unsigned int options)
250 {
251 int changed, changed_fs;
252
253 changed = ie_match_stat(istate, ce, st, options);
254 if (!changed)
255 return 0;
256 /*
257 * If the mode or type has changed, there's no point in trying
258 * to refresh the entry - it's not going to match
259 */
260 if (changed & (MODE_CHANGED | TYPE_CHANGED))
261 return changed;
262
263 /* Immediately after read-tree or update-index --cacheinfo,
264 * the length field is zero. For other cases the ce_size
265 * should match the SHA1 recorded in the index entry.
266 */
267 if ((changed & DATA_CHANGED) && ce->ce_size != 0)
268 return changed;
269
270 changed_fs = ce_modified_check_fs(ce, st);
271 if (changed_fs)
272 return changed | changed_fs;
273 return 0;
274 }
275
276 int base_name_compare(const char *name1, int len1, int mode1,
277 const char *name2, int len2, int mode2)
278 {
279 unsigned char c1, c2;
280 int len = len1 < len2 ? len1 : len2;
281 int cmp;
282
283 cmp = memcmp(name1, name2, len);
284 if (cmp)
285 return cmp;
286 c1 = name1[len];
287 c2 = name2[len];
288 if (!c1 && S_ISDIR(mode1))
289 c1 = '/';
290 if (!c2 && S_ISDIR(mode2))
291 c2 = '/';
292 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
293 }
294
295 /*
296 * df_name_compare() is identical to base_name_compare(), except it
297 * compares conflicting directory/file entries as equal. Note that
298 * while a directory name compares as equal to a regular file, they
299 * then individually compare _differently_ to a filename that has
300 * a dot after the basename (because '\0' < '.' < '/').
301 *
302 * This is used by routines that want to traverse the git namespace
303 * but then handle conflicting entries together when possible.
304 */
305 int df_name_compare(const char *name1, int len1, int mode1,
306 const char *name2, int len2, int mode2)
307 {
308 int len = len1 < len2 ? len1 : len2, cmp;
309 unsigned char c1, c2;
310
311 cmp = memcmp(name1, name2, len);
312 if (cmp)
313 return cmp;
314 /* Directories and files compare equal (same length, same name) */
315 if (len1 == len2)
316 return 0;
317 c1 = name1[len];
318 if (!c1 && S_ISDIR(mode1))
319 c1 = '/';
320 c2 = name2[len];
321 if (!c2 && S_ISDIR(mode2))
322 c2 = '/';
323 if (c1 == '/' && !c2)
324 return 0;
325 if (c2 == '/' && !c1)
326 return 0;
327 return c1 - c2;
328 }
329
330 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
331 {
332 int len1 = flags1 & CE_NAMEMASK;
333 int len2 = flags2 & CE_NAMEMASK;
334 int len = len1 < len2 ? len1 : len2;
335 int cmp;
336
337 cmp = memcmp(name1, name2, len);
338 if (cmp)
339 return cmp;
340 if (len1 < len2)
341 return -1;
342 if (len1 > len2)
343 return 1;
344
345 /* Compare stages */
346 flags1 &= CE_STAGEMASK;
347 flags2 &= CE_STAGEMASK;
348
349 if (flags1 < flags2)
350 return -1;
351 if (flags1 > flags2)
352 return 1;
353 return 0;
354 }
355
356 int index_name_pos(const struct index_state *istate, const char *name, int namelen)
357 {
358 int first, last;
359
360 first = 0;
361 last = istate->cache_nr;
362 while (last > first) {
363 int next = (last + first) >> 1;
364 struct cache_entry *ce = istate->cache[next];
365 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags);
366 if (!cmp)
367 return next;
368 if (cmp < 0) {
369 last = next;
370 continue;
371 }
372 first = next+1;
373 }
374 return -first-1;
375 }
376
377 /* Remove entry, return true if there are more entries to go.. */
378 int remove_index_entry_at(struct index_state *istate, int pos)
379 {
380 struct cache_entry *ce = istate->cache[pos];
381
382 remove_name_hash(ce);
383 istate->cache_changed = 1;
384 istate->cache_nr--;
385 if (pos >= istate->cache_nr)
386 return 0;
387 memmove(istate->cache + pos,
388 istate->cache + pos + 1,
389 (istate->cache_nr - pos) * sizeof(struct cache_entry *));
390 return 1;
391 }
392
393 int remove_file_from_index(struct index_state *istate, const char *path)
394 {
395 int pos = index_name_pos(istate, path, strlen(path));
396 if (pos < 0)
397 pos = -pos-1;
398 cache_tree_invalidate_path(istate->cache_tree, path);
399 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
400 remove_index_entry_at(istate, pos);
401 return 0;
402 }
403
404 static int compare_name(struct cache_entry *ce, const char *path, int namelen)
405 {
406 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
407 }
408
409 static int index_name_pos_also_unmerged(struct index_state *istate,
410 const char *path, int namelen)
411 {
412 int pos = index_name_pos(istate, path, namelen);
413 struct cache_entry *ce;
414
415 if (pos >= 0)
416 return pos;
417
418 /* maybe unmerged? */
419 pos = -1 - pos;
420 if (pos >= istate->cache_nr ||
421 compare_name((ce = istate->cache[pos]), path, namelen))
422 return -1;
423
424 /* order of preference: stage 2, 1, 3 */
425 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
426 ce_stage((ce = istate->cache[pos + 1])) == 2 &&
427 !compare_name(ce, path, namelen))
428 pos++;
429 return pos;
430 }
431
432 static int different_name(struct cache_entry *ce, struct cache_entry *alias)
433 {
434 int len = ce_namelen(ce);
435 return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
436 }
437
438 /*
439 * If we add a filename that aliases in the cache, we will use the
440 * name that we already have - but we don't want to update the same
441 * alias twice, because that implies that there were actually two
442 * different files with aliasing names!
443 *
444 * So we use the CE_ADDED flag to verify that the alias was an old
445 * one before we accept it as
446 */
447 static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias)
448 {
449 int len;
450 struct cache_entry *new;
451
452 if (alias->ce_flags & CE_ADDED)
453 die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
454
455 /* Ok, create the new entry using the name of the existing alias */
456 len = ce_namelen(alias);
457 new = xcalloc(1, cache_entry_size(len));
458 memcpy(new->name, alias->name, len);
459 copy_cache_entry(new, ce);
460 free(ce);
461 return new;
462 }
463
464 int add_file_to_index(struct index_state *istate, const char *path, int verbose)
465 {
466 int size, namelen;
467 struct stat st;
468 struct cache_entry *ce, *alias;
469 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY;
470
471 if (lstat(path, &st))
472 die("%s: unable to stat (%s)", path, strerror(errno));
473
474 if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode))
475 die("%s: can only add regular files, symbolic links or git-directories", path);
476
477 namelen = strlen(path);
478 if (S_ISDIR(st.st_mode)) {
479 while (namelen && path[namelen-1] == '/')
480 namelen--;
481 }
482 size = cache_entry_size(namelen);
483 ce = xcalloc(1, size);
484 memcpy(ce->name, path, namelen);
485 ce->ce_flags = namelen;
486 fill_stat_cache_info(ce, &st);
487
488 if (trust_executable_bit && has_symlinks)
489 ce->ce_mode = create_ce_mode(st.st_mode);
490 else {
491 /* If there is an existing entry, pick the mode bits and type
492 * from it, otherwise assume unexecutable regular file.
493 */
494 struct cache_entry *ent;
495 int pos = index_name_pos_also_unmerged(istate, path, namelen);
496
497 ent = (0 <= pos) ? istate->cache[pos] : NULL;
498 ce->ce_mode = ce_mode_from_stat(ent, st.st_mode);
499 }
500
501 alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case);
502 if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, &st, ce_option)) {
503 /* Nothing changed, really */
504 free(ce);
505 ce_mark_uptodate(alias);
506 alias->ce_flags |= CE_ADDED;
507 return 0;
508 }
509 if (index_path(ce->sha1, path, &st, 1))
510 die("unable to index file %s", path);
511 if (ignore_case && alias && different_name(ce, alias))
512 ce = create_alias_ce(ce, alias);
513 ce->ce_flags |= CE_ADDED;
514 if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
515 die("unable to add %s to index",path);
516 if (verbose)
517 printf("add '%s'\n", path);
518 return 0;
519 }
520
521 struct cache_entry *make_cache_entry(unsigned int mode,
522 const unsigned char *sha1, const char *path, int stage,
523 int refresh)
524 {
525 int size, len;
526 struct cache_entry *ce;
527
528 if (!verify_path(path))
529 return NULL;
530
531 len = strlen(path);
532 size = cache_entry_size(len);
533 ce = xcalloc(1, size);
534
535 hashcpy(ce->sha1, sha1);
536 memcpy(ce->name, path, len);
537 ce->ce_flags = create_ce_flags(len, stage);
538 ce->ce_mode = create_ce_mode(mode);
539
540 if (refresh)
541 return refresh_cache_entry(ce, 0);
542
543 return ce;
544 }
545
546 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
547 {
548 int len = ce_namelen(a);
549 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
550 }
551
552 int ce_path_match(const struct cache_entry *ce, const char **pathspec)
553 {
554 const char *match, *name;
555 int len;
556
557 if (!pathspec)
558 return 1;
559
560 len = ce_namelen(ce);
561 name = ce->name;
562 while ((match = *pathspec++) != NULL) {
563 int matchlen = strlen(match);
564 if (matchlen > len)
565 continue;
566 if (memcmp(name, match, matchlen))
567 continue;
568 if (matchlen && name[matchlen-1] == '/')
569 return 1;
570 if (name[matchlen] == '/' || !name[matchlen])
571 return 1;
572 if (!matchlen)
573 return 1;
574 }
575 return 0;
576 }
577
578 /*
579 * We fundamentally don't like some paths: we don't want
580 * dot or dot-dot anywhere, and for obvious reasons don't
581 * want to recurse into ".git" either.
582 *
583 * Also, we don't want double slashes or slashes at the
584 * end that can make pathnames ambiguous.
585 */
586 static int verify_dotfile(const char *rest)
587 {
588 /*
589 * The first character was '.', but that
590 * has already been discarded, we now test
591 * the rest.
592 */
593 switch (*rest) {
594 /* "." is not allowed */
595 case '\0': case '/':
596 return 0;
597
598 /*
599 * ".git" followed by NUL or slash is bad. This
600 * shares the path end test with the ".." case.
601 */
602 case 'g':
603 if (rest[1] != 'i')
604 break;
605 if (rest[2] != 't')
606 break;
607 rest += 2;
608 /* fallthrough */
609 case '.':
610 if (rest[1] == '\0' || rest[1] == '/')
611 return 0;
612 }
613 return 1;
614 }
615
616 int verify_path(const char *path)
617 {
618 char c;
619
620 goto inside;
621 for (;;) {
622 if (!c)
623 return 1;
624 if (c == '/') {
625 inside:
626 c = *path++;
627 switch (c) {
628 default:
629 continue;
630 case '/': case '\0':
631 break;
632 case '.':
633 if (verify_dotfile(path))
634 continue;
635 }
636 return 0;
637 }
638 c = *path++;
639 }
640 }
641
642 /*
643 * Do we have another file that has the beginning components being a
644 * proper superset of the name we're trying to add?
645 */
646 static int has_file_name(struct index_state *istate,
647 const struct cache_entry *ce, int pos, int ok_to_replace)
648 {
649 int retval = 0;
650 int len = ce_namelen(ce);
651 int stage = ce_stage(ce);
652 const char *name = ce->name;
653
654 while (pos < istate->cache_nr) {
655 struct cache_entry *p = istate->cache[pos++];
656
657 if (len >= ce_namelen(p))
658 break;
659 if (memcmp(name, p->name, len))
660 break;
661 if (ce_stage(p) != stage)
662 continue;
663 if (p->name[len] != '/')
664 continue;
665 if (p->ce_flags & CE_REMOVE)
666 continue;
667 retval = -1;
668 if (!ok_to_replace)
669 break;
670 remove_index_entry_at(istate, --pos);
671 }
672 return retval;
673 }
674
675 /*
676 * Do we have another file with a pathname that is a proper
677 * subset of the name we're trying to add?
678 */
679 static int has_dir_name(struct index_state *istate,
680 const struct cache_entry *ce, int pos, int ok_to_replace)
681 {
682 int retval = 0;
683 int stage = ce_stage(ce);
684 const char *name = ce->name;
685 const char *slash = name + ce_namelen(ce);
686
687 for (;;) {
688 int len;
689
690 for (;;) {
691 if (*--slash == '/')
692 break;
693 if (slash <= ce->name)
694 return retval;
695 }
696 len = slash - name;
697
698 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
699 if (pos >= 0) {
700 /*
701 * Found one, but not so fast. This could
702 * be a marker that says "I was here, but
703 * I am being removed". Such an entry is
704 * not a part of the resulting tree, and
705 * it is Ok to have a directory at the same
706 * path.
707 */
708 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
709 retval = -1;
710 if (!ok_to_replace)
711 break;
712 remove_index_entry_at(istate, pos);
713 continue;
714 }
715 }
716 else
717 pos = -pos-1;
718
719 /*
720 * Trivial optimization: if we find an entry that
721 * already matches the sub-directory, then we know
722 * we're ok, and we can exit.
723 */
724 while (pos < istate->cache_nr) {
725 struct cache_entry *p = istate->cache[pos];
726 if ((ce_namelen(p) <= len) ||
727 (p->name[len] != '/') ||
728 memcmp(p->name, name, len))
729 break; /* not our subdirectory */
730 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
731 /*
732 * p is at the same stage as our entry, and
733 * is a subdirectory of what we are looking
734 * at, so we cannot have conflicts at our
735 * level or anything shorter.
736 */
737 return retval;
738 pos++;
739 }
740 }
741 return retval;
742 }
743
744 /* We may be in a situation where we already have path/file and path
745 * is being added, or we already have path and path/file is being
746 * added. Either one would result in a nonsense tree that has path
747 * twice when git-write-tree tries to write it out. Prevent it.
748 *
749 * If ok-to-replace is specified, we remove the conflicting entries
750 * from the cache so the caller should recompute the insert position.
751 * When this happens, we return non-zero.
752 */
753 static int check_file_directory_conflict(struct index_state *istate,
754 const struct cache_entry *ce,
755 int pos, int ok_to_replace)
756 {
757 int retval;
758
759 /*
760 * When ce is an "I am going away" entry, we allow it to be added
761 */
762 if (ce->ce_flags & CE_REMOVE)
763 return 0;
764
765 /*
766 * We check if the path is a sub-path of a subsequent pathname
767 * first, since removing those will not change the position
768 * in the array.
769 */
770 retval = has_file_name(istate, ce, pos, ok_to_replace);
771
772 /*
773 * Then check if the path might have a clashing sub-directory
774 * before it.
775 */
776 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
777 }
778
779 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
780 {
781 int pos;
782 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
783 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
784 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
785
786 cache_tree_invalidate_path(istate->cache_tree, ce->name);
787 pos = index_name_pos(istate, ce->name, ce->ce_flags);
788
789 /* existing match? Just replace it. */
790 if (pos >= 0) {
791 replace_index_entry(istate, pos, ce);
792 return 0;
793 }
794 pos = -pos-1;
795
796 /*
797 * Inserting a merged entry ("stage 0") into the index
798 * will always replace all non-merged entries..
799 */
800 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
801 while (ce_same_name(istate->cache[pos], ce)) {
802 ok_to_add = 1;
803 if (!remove_index_entry_at(istate, pos))
804 break;
805 }
806 }
807
808 if (!ok_to_add)
809 return -1;
810 if (!verify_path(ce->name))
811 return -1;
812
813 if (!skip_df_check &&
814 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
815 if (!ok_to_replace)
816 return error("'%s' appears as both a file and as a directory",
817 ce->name);
818 pos = index_name_pos(istate, ce->name, ce->ce_flags);
819 pos = -pos-1;
820 }
821 return pos + 1;
822 }
823
824 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
825 {
826 int pos;
827
828 if (option & ADD_CACHE_JUST_APPEND)
829 pos = istate->cache_nr;
830 else {
831 int ret;
832 ret = add_index_entry_with_check(istate, ce, option);
833 if (ret <= 0)
834 return ret;
835 pos = ret - 1;
836 }
837
838 /* Make sure the array is big enough .. */
839 if (istate->cache_nr == istate->cache_alloc) {
840 istate->cache_alloc = alloc_nr(istate->cache_alloc);
841 istate->cache = xrealloc(istate->cache,
842 istate->cache_alloc * sizeof(struct cache_entry *));
843 }
844
845 /* Add it in.. */
846 istate->cache_nr++;
847 if (istate->cache_nr > pos + 1)
848 memmove(istate->cache + pos + 1,
849 istate->cache + pos,
850 (istate->cache_nr - pos - 1) * sizeof(ce));
851 set_index_entry(istate, pos, ce);
852 istate->cache_changed = 1;
853 return 0;
854 }
855
856 /*
857 * "refresh" does not calculate a new sha1 file or bring the
858 * cache up-to-date for mode/content changes. But what it
859 * _does_ do is to "re-match" the stat information of a file
860 * with the cache, so that you can refresh the cache for a
861 * file that hasn't been changed but where the stat entry is
862 * out of date.
863 *
864 * For example, you'd want to do this after doing a "git-read-tree",
865 * to link up the stat cache details with the proper files.
866 */
867 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
868 struct cache_entry *ce,
869 unsigned int options, int *err)
870 {
871 struct stat st;
872 struct cache_entry *updated;
873 int changed, size;
874 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
875
876 if (ce_uptodate(ce))
877 return ce;
878
879 if (lstat(ce->name, &st) < 0) {
880 if (err)
881 *err = errno;
882 return NULL;
883 }
884
885 changed = ie_match_stat(istate, ce, &st, options);
886 if (!changed) {
887 /*
888 * The path is unchanged. If we were told to ignore
889 * valid bit, then we did the actual stat check and
890 * found that the entry is unmodified. If the entry
891 * is not marked VALID, this is the place to mark it
892 * valid again, under "assume unchanged" mode.
893 */
894 if (ignore_valid && assume_unchanged &&
895 !(ce->ce_flags & CE_VALID))
896 ; /* mark this one VALID again */
897 else {
898 /*
899 * We do not mark the index itself "modified"
900 * because CE_UPTODATE flag is in-core only;
901 * we are not going to write this change out.
902 */
903 ce_mark_uptodate(ce);
904 return ce;
905 }
906 }
907
908 if (ie_modified(istate, ce, &st, options)) {
909 if (err)
910 *err = EINVAL;
911 return NULL;
912 }
913
914 size = ce_size(ce);
915 updated = xmalloc(size);
916 memcpy(updated, ce, size);
917 fill_stat_cache_info(updated, &st);
918 /*
919 * If ignore_valid is not set, we should leave CE_VALID bit
920 * alone. Otherwise, paths marked with --no-assume-unchanged
921 * (i.e. things to be edited) will reacquire CE_VALID bit
922 * automatically, which is not really what we want.
923 */
924 if (!ignore_valid && assume_unchanged &&
925 !(ce->ce_flags & CE_VALID))
926 updated->ce_flags &= ~CE_VALID;
927
928 return updated;
929 }
930
931 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
932 {
933 int i;
934 int has_errors = 0;
935 int really = (flags & REFRESH_REALLY) != 0;
936 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
937 int quiet = (flags & REFRESH_QUIET) != 0;
938 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
939 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
940
941 for (i = 0; i < istate->cache_nr; i++) {
942 struct cache_entry *ce, *new;
943 int cache_errno = 0;
944
945 ce = istate->cache[i];
946 if (ce_stage(ce)) {
947 while ((i < istate->cache_nr) &&
948 ! strcmp(istate->cache[i]->name, ce->name))
949 i++;
950 i--;
951 if (allow_unmerged)
952 continue;
953 printf("%s: needs merge\n", ce->name);
954 has_errors = 1;
955 continue;
956 }
957
958 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
959 continue;
960
961 new = refresh_cache_ent(istate, ce, options, &cache_errno);
962 if (new == ce)
963 continue;
964 if (!new) {
965 if (not_new && cache_errno == ENOENT)
966 continue;
967 if (really && cache_errno == EINVAL) {
968 /* If we are doing --really-refresh that
969 * means the index is not valid anymore.
970 */
971 ce->ce_flags &= ~CE_VALID;
972 istate->cache_changed = 1;
973 }
974 if (quiet)
975 continue;
976 printf("%s: needs update\n", ce->name);
977 has_errors = 1;
978 continue;
979 }
980
981 replace_index_entry(istate, i, new);
982 }
983 return has_errors;
984 }
985
986 struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
987 {
988 return refresh_cache_ent(&the_index, ce, really, NULL);
989 }
990
991 static int verify_hdr(struct cache_header *hdr, unsigned long size)
992 {
993 SHA_CTX c;
994 unsigned char sha1[20];
995
996 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
997 return error("bad signature");
998 if (hdr->hdr_version != htonl(2))
999 return error("bad index version");
1000 SHA1_Init(&c);
1001 SHA1_Update(&c, hdr, size - 20);
1002 SHA1_Final(sha1, &c);
1003 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1004 return error("bad index file sha1 signature");
1005 return 0;
1006 }
1007
1008 static int read_index_extension(struct index_state *istate,
1009 const char *ext, void *data, unsigned long sz)
1010 {
1011 switch (CACHE_EXT(ext)) {
1012 case CACHE_EXT_TREE:
1013 istate->cache_tree = cache_tree_read(data, sz);
1014 break;
1015 default:
1016 if (*ext < 'A' || 'Z' < *ext)
1017 return error("index uses %.4s extension, which we do not understand",
1018 ext);
1019 fprintf(stderr, "ignoring %.4s extension\n", ext);
1020 break;
1021 }
1022 return 0;
1023 }
1024
1025 int read_index(struct index_state *istate)
1026 {
1027 return read_index_from(istate, get_index_file());
1028 }
1029
1030 static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
1031 {
1032 size_t len;
1033
1034 ce->ce_ctime = ntohl(ondisk->ctime.sec);
1035 ce->ce_mtime = ntohl(ondisk->mtime.sec);
1036 ce->ce_dev = ntohl(ondisk->dev);
1037 ce->ce_ino = ntohl(ondisk->ino);
1038 ce->ce_mode = ntohl(ondisk->mode);
1039 ce->ce_uid = ntohl(ondisk->uid);
1040 ce->ce_gid = ntohl(ondisk->gid);
1041 ce->ce_size = ntohl(ondisk->size);
1042 /* On-disk flags are just 16 bits */
1043 ce->ce_flags = ntohs(ondisk->flags);
1044 hashcpy(ce->sha1, ondisk->sha1);
1045
1046 len = ce->ce_flags & CE_NAMEMASK;
1047 if (len == CE_NAMEMASK)
1048 len = strlen(ondisk->name);
1049 /*
1050 * NEEDSWORK: If the original index is crafted, this copy could
1051 * go unchecked.
1052 */
1053 memcpy(ce->name, ondisk->name, len + 1);
1054 }
1055
1056 static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
1057 {
1058 long per_entry;
1059
1060 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
1061
1062 /*
1063 * Alignment can cause differences. This should be "alignof", but
1064 * since that's a gcc'ism, just use the size of a pointer.
1065 */
1066 per_entry += sizeof(void *);
1067 return ondisk_size + entries*per_entry;
1068 }
1069
1070 /* remember to discard_cache() before reading a different cache! */
1071 int read_index_from(struct index_state *istate, const char *path)
1072 {
1073 int fd, i;
1074 struct stat st;
1075 unsigned long src_offset, dst_offset;
1076 struct cache_header *hdr;
1077 void *mmap;
1078 size_t mmap_size;
1079
1080 errno = EBUSY;
1081 if (istate->alloc)
1082 return istate->cache_nr;
1083
1084 errno = ENOENT;
1085 istate->timestamp = 0;
1086 fd = open(path, O_RDONLY);
1087 if (fd < 0) {
1088 if (errno == ENOENT)
1089 return 0;
1090 die("index file open failed (%s)", strerror(errno));
1091 }
1092
1093 if (fstat(fd, &st))
1094 die("cannot stat the open index (%s)", strerror(errno));
1095
1096 errno = EINVAL;
1097 mmap_size = xsize_t(st.st_size);
1098 if (mmap_size < sizeof(struct cache_header) + 20)
1099 die("index file smaller than expected");
1100
1101 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1102 close(fd);
1103 if (mmap == MAP_FAILED)
1104 die("unable to map index file");
1105
1106 hdr = mmap;
1107 if (verify_hdr(hdr, mmap_size) < 0)
1108 goto unmap;
1109
1110 istate->cache_nr = ntohl(hdr->hdr_entries);
1111 istate->cache_alloc = alloc_nr(istate->cache_nr);
1112 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1113
1114 /*
1115 * The disk format is actually larger than the in-memory format,
1116 * due to space for nsec etc, so even though the in-memory one
1117 * has room for a few more flags, we can allocate using the same
1118 * index size
1119 */
1120 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
1121
1122 src_offset = sizeof(*hdr);
1123 dst_offset = 0;
1124 for (i = 0; i < istate->cache_nr; i++) {
1125 struct ondisk_cache_entry *disk_ce;
1126 struct cache_entry *ce;
1127
1128 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1129 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
1130 convert_from_disk(disk_ce, ce);
1131 set_index_entry(istate, i, ce);
1132
1133 src_offset += ondisk_ce_size(ce);
1134 dst_offset += ce_size(ce);
1135 }
1136 istate->timestamp = st.st_mtime;
1137 while (src_offset <= mmap_size - 20 - 8) {
1138 /* After an array of active_nr index entries,
1139 * there can be arbitrary number of extended
1140 * sections, each of which is prefixed with
1141 * extension name (4-byte) and section length
1142 * in 4-byte network byte order.
1143 */
1144 unsigned long extsize;
1145 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1146 extsize = ntohl(extsize);
1147 if (read_index_extension(istate,
1148 (const char *) mmap + src_offset,
1149 (char *) mmap + src_offset + 8,
1150 extsize) < 0)
1151 goto unmap;
1152 src_offset += 8;
1153 src_offset += extsize;
1154 }
1155 munmap(mmap, mmap_size);
1156 return istate->cache_nr;
1157
1158 unmap:
1159 munmap(mmap, mmap_size);
1160 errno = EINVAL;
1161 die("index file corrupt");
1162 }
1163
1164 int discard_index(struct index_state *istate)
1165 {
1166 istate->cache_nr = 0;
1167 istate->cache_changed = 0;
1168 istate->timestamp = 0;
1169 free_hash(&istate->name_hash);
1170 cache_tree_free(&(istate->cache_tree));
1171 free(istate->alloc);
1172 istate->alloc = NULL;
1173
1174 /* no need to throw away allocated active_cache */
1175 return 0;
1176 }
1177
1178 int unmerged_index(const struct index_state *istate)
1179 {
1180 int i;
1181 for (i = 0; i < istate->cache_nr; i++) {
1182 if (ce_stage(istate->cache[i]))
1183 return 1;
1184 }
1185 return 0;
1186 }
1187
1188 #define WRITE_BUFFER_SIZE 8192
1189 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1190 static unsigned long write_buffer_len;
1191
1192 static int ce_write_flush(SHA_CTX *context, int fd)
1193 {
1194 unsigned int buffered = write_buffer_len;
1195 if (buffered) {
1196 SHA1_Update(context, write_buffer, buffered);
1197 if (write_in_full(fd, write_buffer, buffered) != buffered)
1198 return -1;
1199 write_buffer_len = 0;
1200 }
1201 return 0;
1202 }
1203
1204 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
1205 {
1206 while (len) {
1207 unsigned int buffered = write_buffer_len;
1208 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1209 if (partial > len)
1210 partial = len;
1211 memcpy(write_buffer + buffered, data, partial);
1212 buffered += partial;
1213 if (buffered == WRITE_BUFFER_SIZE) {
1214 write_buffer_len = buffered;
1215 if (ce_write_flush(context, fd))
1216 return -1;
1217 buffered = 0;
1218 }
1219 write_buffer_len = buffered;
1220 len -= partial;
1221 data = (char *) data + partial;
1222 }
1223 return 0;
1224 }
1225
1226 static int write_index_ext_header(SHA_CTX *context, int fd,
1227 unsigned int ext, unsigned int sz)
1228 {
1229 ext = htonl(ext);
1230 sz = htonl(sz);
1231 return ((ce_write(context, fd, &ext, 4) < 0) ||
1232 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1233 }
1234
1235 static int ce_flush(SHA_CTX *context, int fd)
1236 {
1237 unsigned int left = write_buffer_len;
1238
1239 if (left) {
1240 write_buffer_len = 0;
1241 SHA1_Update(context, write_buffer, left);
1242 }
1243
1244 /* Flush first if not enough space for SHA1 signature */
1245 if (left + 20 > WRITE_BUFFER_SIZE) {
1246 if (write_in_full(fd, write_buffer, left) != left)
1247 return -1;
1248 left = 0;
1249 }
1250
1251 /* Append the SHA1 signature at the end */
1252 SHA1_Final(write_buffer + left, context);
1253 left += 20;
1254 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1255 }
1256
1257 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1258 {
1259 /*
1260 * The only thing we care about in this function is to smudge the
1261 * falsely clean entry due to touch-update-touch race, so we leave
1262 * everything else as they are. We are called for entries whose
1263 * ce_mtime match the index file mtime.
1264 */
1265 struct stat st;
1266
1267 if (lstat(ce->name, &st) < 0)
1268 return;
1269 if (ce_match_stat_basic(ce, &st))
1270 return;
1271 if (ce_modified_check_fs(ce, &st)) {
1272 /* This is "racily clean"; smudge it. Note that this
1273 * is a tricky code. At first glance, it may appear
1274 * that it can break with this sequence:
1275 *
1276 * $ echo xyzzy >frotz
1277 * $ git-update-index --add frotz
1278 * $ : >frotz
1279 * $ sleep 3
1280 * $ echo filfre >nitfol
1281 * $ git-update-index --add nitfol
1282 *
1283 * but it does not. When the second update-index runs,
1284 * it notices that the entry "frotz" has the same timestamp
1285 * as index, and if we were to smudge it by resetting its
1286 * size to zero here, then the object name recorded
1287 * in index is the 6-byte file but the cached stat information
1288 * becomes zero --- which would then match what we would
1289 * obtain from the filesystem next time we stat("frotz").
1290 *
1291 * However, the second update-index, before calling
1292 * this function, notices that the cached size is 6
1293 * bytes and what is on the filesystem is an empty
1294 * file, and never calls us, so the cached size information
1295 * for "frotz" stays 6 which does not match the filesystem.
1296 */
1297 ce->ce_size = 0;
1298 }
1299 }
1300
1301 static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)
1302 {
1303 int size = ondisk_ce_size(ce);
1304 struct ondisk_cache_entry *ondisk = xcalloc(1, size);
1305
1306 ondisk->ctime.sec = htonl(ce->ce_ctime);
1307 ondisk->ctime.nsec = 0;
1308 ondisk->mtime.sec = htonl(ce->ce_mtime);
1309 ondisk->mtime.nsec = 0;
1310 ondisk->dev = htonl(ce->ce_dev);
1311 ondisk->ino = htonl(ce->ce_ino);
1312 ondisk->mode = htonl(ce->ce_mode);
1313 ondisk->uid = htonl(ce->ce_uid);
1314 ondisk->gid = htonl(ce->ce_gid);
1315 ondisk->size = htonl(ce->ce_size);
1316 hashcpy(ondisk->sha1, ce->sha1);
1317 ondisk->flags = htons(ce->ce_flags);
1318 memcpy(ondisk->name, ce->name, ce_namelen(ce));
1319
1320 return ce_write(c, fd, ondisk, size);
1321 }
1322
1323 int write_index(const struct index_state *istate, int newfd)
1324 {
1325 SHA_CTX c;
1326 struct cache_header hdr;
1327 int i, err, removed;
1328 struct cache_entry **cache = istate->cache;
1329 int entries = istate->cache_nr;
1330
1331 for (i = removed = 0; i < entries; i++)
1332 if (cache[i]->ce_flags & CE_REMOVE)
1333 removed++;
1334
1335 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1336 hdr.hdr_version = htonl(2);
1337 hdr.hdr_entries = htonl(entries - removed);
1338
1339 SHA1_Init(&c);
1340 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1341 return -1;
1342
1343 for (i = 0; i < entries; i++) {
1344 struct cache_entry *ce = cache[i];
1345 if (ce->ce_flags & CE_REMOVE)
1346 continue;
1347 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
1348 ce_smudge_racily_clean_entry(ce);
1349 if (ce_write_entry(&c, newfd, ce) < 0)
1350 return -1;
1351 }
1352
1353 /* Write extension data here */
1354 if (istate->cache_tree) {
1355 struct strbuf sb;
1356
1357 strbuf_init(&sb, 0);
1358 cache_tree_write(&sb, istate->cache_tree);
1359 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1360 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1361 strbuf_release(&sb);
1362 if (err)
1363 return -1;
1364 }
1365 return ce_flush(&c, newfd);
1366 }