Merge branch 'jc/add-n-u'
[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 (!S_ISGITLINK(ce->ce_mode) &&
202 istate->timestamp &&
203 ((unsigned int)istate->timestamp) <= ce->ce_mtime);
204 }
205
206 int ie_match_stat(const struct index_state *istate,
207 struct cache_entry *ce, struct stat *st,
208 unsigned int options)
209 {
210 unsigned int changed;
211 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
212 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
213
214 /*
215 * If it's marked as always valid in the index, it's
216 * valid whatever the checked-out copy says.
217 */
218 if (!ignore_valid && (ce->ce_flags & CE_VALID))
219 return 0;
220
221 changed = ce_match_stat_basic(ce, st);
222
223 /*
224 * Within 1 second of this sequence:
225 * echo xyzzy >file && git-update-index --add file
226 * running this command:
227 * echo frotz >file
228 * would give a falsely clean cache entry. The mtime and
229 * length match the cache, and other stat fields do not change.
230 *
231 * We could detect this at update-index time (the cache entry
232 * being registered/updated records the same time as "now")
233 * and delay the return from git-update-index, but that would
234 * effectively mean we can make at most one commit per second,
235 * which is not acceptable. Instead, we check cache entries
236 * whose mtime are the same as the index file timestamp more
237 * carefully than others.
238 */
239 if (!changed && is_racy_timestamp(istate, ce)) {
240 if (assume_racy_is_modified)
241 changed |= DATA_CHANGED;
242 else
243 changed |= ce_modified_check_fs(ce, st);
244 }
245
246 return changed;
247 }
248
249 int ie_modified(const struct index_state *istate,
250 struct cache_entry *ce, struct stat *st, unsigned int options)
251 {
252 int changed, changed_fs;
253
254 changed = ie_match_stat(istate, ce, st, options);
255 if (!changed)
256 return 0;
257 /*
258 * If the mode or type has changed, there's no point in trying
259 * to refresh the entry - it's not going to match
260 */
261 if (changed & (MODE_CHANGED | TYPE_CHANGED))
262 return changed;
263
264 /* Immediately after read-tree or update-index --cacheinfo,
265 * the length field is zero. For other cases the ce_size
266 * should match the SHA1 recorded in the index entry.
267 */
268 if ((changed & DATA_CHANGED) && ce->ce_size != 0)
269 return changed;
270
271 changed_fs = ce_modified_check_fs(ce, st);
272 if (changed_fs)
273 return changed | changed_fs;
274 return 0;
275 }
276
277 int base_name_compare(const char *name1, int len1, int mode1,
278 const char *name2, int len2, int mode2)
279 {
280 unsigned char c1, c2;
281 int len = len1 < len2 ? len1 : len2;
282 int cmp;
283
284 cmp = memcmp(name1, name2, len);
285 if (cmp)
286 return cmp;
287 c1 = name1[len];
288 c2 = name2[len];
289 if (!c1 && S_ISDIR(mode1))
290 c1 = '/';
291 if (!c2 && S_ISDIR(mode2))
292 c2 = '/';
293 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
294 }
295
296 /*
297 * df_name_compare() is identical to base_name_compare(), except it
298 * compares conflicting directory/file entries as equal. Note that
299 * while a directory name compares as equal to a regular file, they
300 * then individually compare _differently_ to a filename that has
301 * a dot after the basename (because '\0' < '.' < '/').
302 *
303 * This is used by routines that want to traverse the git namespace
304 * but then handle conflicting entries together when possible.
305 */
306 int df_name_compare(const char *name1, int len1, int mode1,
307 const char *name2, int len2, int mode2)
308 {
309 int len = len1 < len2 ? len1 : len2, cmp;
310 unsigned char c1, c2;
311
312 cmp = memcmp(name1, name2, len);
313 if (cmp)
314 return cmp;
315 /* Directories and files compare equal (same length, same name) */
316 if (len1 == len2)
317 return 0;
318 c1 = name1[len];
319 if (!c1 && S_ISDIR(mode1))
320 c1 = '/';
321 c2 = name2[len];
322 if (!c2 && S_ISDIR(mode2))
323 c2 = '/';
324 if (c1 == '/' && !c2)
325 return 0;
326 if (c2 == '/' && !c1)
327 return 0;
328 return c1 - c2;
329 }
330
331 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
332 {
333 int len1 = flags1 & CE_NAMEMASK;
334 int len2 = flags2 & CE_NAMEMASK;
335 int len = len1 < len2 ? len1 : len2;
336 int cmp;
337
338 cmp = memcmp(name1, name2, len);
339 if (cmp)
340 return cmp;
341 if (len1 < len2)
342 return -1;
343 if (len1 > len2)
344 return 1;
345
346 /* Compare stages */
347 flags1 &= CE_STAGEMASK;
348 flags2 &= CE_STAGEMASK;
349
350 if (flags1 < flags2)
351 return -1;
352 if (flags1 > flags2)
353 return 1;
354 return 0;
355 }
356
357 int index_name_pos(const struct index_state *istate, const char *name, int namelen)
358 {
359 int first, last;
360
361 first = 0;
362 last = istate->cache_nr;
363 while (last > first) {
364 int next = (last + first) >> 1;
365 struct cache_entry *ce = istate->cache[next];
366 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags);
367 if (!cmp)
368 return next;
369 if (cmp < 0) {
370 last = next;
371 continue;
372 }
373 first = next+1;
374 }
375 return -first-1;
376 }
377
378 /* Remove entry, return true if there are more entries to go.. */
379 int remove_index_entry_at(struct index_state *istate, int pos)
380 {
381 struct cache_entry *ce = istate->cache[pos];
382
383 remove_name_hash(ce);
384 istate->cache_changed = 1;
385 istate->cache_nr--;
386 if (pos >= istate->cache_nr)
387 return 0;
388 memmove(istate->cache + pos,
389 istate->cache + pos + 1,
390 (istate->cache_nr - pos) * sizeof(struct cache_entry *));
391 return 1;
392 }
393
394 int remove_file_from_index(struct index_state *istate, const char *path)
395 {
396 int pos = index_name_pos(istate, path, strlen(path));
397 if (pos < 0)
398 pos = -pos-1;
399 cache_tree_invalidate_path(istate->cache_tree, path);
400 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
401 remove_index_entry_at(istate, pos);
402 return 0;
403 }
404
405 static int compare_name(struct cache_entry *ce, const char *path, int namelen)
406 {
407 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
408 }
409
410 static int index_name_pos_also_unmerged(struct index_state *istate,
411 const char *path, int namelen)
412 {
413 int pos = index_name_pos(istate, path, namelen);
414 struct cache_entry *ce;
415
416 if (pos >= 0)
417 return pos;
418
419 /* maybe unmerged? */
420 pos = -1 - pos;
421 if (pos >= istate->cache_nr ||
422 compare_name((ce = istate->cache[pos]), path, namelen))
423 return -1;
424
425 /* order of preference: stage 2, 1, 3 */
426 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
427 ce_stage((ce = istate->cache[pos + 1])) == 2 &&
428 !compare_name(ce, path, namelen))
429 pos++;
430 return pos;
431 }
432
433 static int different_name(struct cache_entry *ce, struct cache_entry *alias)
434 {
435 int len = ce_namelen(ce);
436 return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
437 }
438
439 /*
440 * If we add a filename that aliases in the cache, we will use the
441 * name that we already have - but we don't want to update the same
442 * alias twice, because that implies that there were actually two
443 * different files with aliasing names!
444 *
445 * So we use the CE_ADDED flag to verify that the alias was an old
446 * one before we accept it as
447 */
448 static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias)
449 {
450 int len;
451 struct cache_entry *new;
452
453 if (alias->ce_flags & CE_ADDED)
454 die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
455
456 /* Ok, create the new entry using the name of the existing alias */
457 len = ce_namelen(alias);
458 new = xcalloc(1, cache_entry_size(len));
459 memcpy(new->name, alias->name, len);
460 copy_cache_entry(new, ce);
461 free(ce);
462 return new;
463 }
464
465 int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
466 {
467 int size, namelen, was_same;
468 mode_t st_mode = st->st_mode;
469 struct cache_entry *ce, *alias;
470 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY;
471 int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND);
472 int pretend = flags & ADD_CACHE_PRETEND;
473
474 if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode))
475 return error("%s: can only add regular files, symbolic links or git-directories", path);
476
477 namelen = strlen(path);
478 if (S_ISDIR(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_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_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 return error("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
515 /* It was suspected to be recily clean, but it turns out to be Ok */
516 was_same = (alias &&
517 !ce_stage(alias) &&
518 !hashcmp(alias->sha1, ce->sha1) &&
519 ce->ce_mode == alias->ce_mode);
520
521 if (pretend)
522 ;
523 else if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
524 return error("unable to add %s to index",path);
525 if (verbose && !was_same)
526 printf("add '%s'\n", path);
527 return 0;
528 }
529
530 int add_file_to_index(struct index_state *istate, const char *path, int flags)
531 {
532 struct stat st;
533 if (lstat(path, &st))
534 die("%s: unable to stat (%s)", path, strerror(errno));
535 return add_to_index(istate, path, &st, flags);
536 }
537
538 struct cache_entry *make_cache_entry(unsigned int mode,
539 const unsigned char *sha1, const char *path, int stage,
540 int refresh)
541 {
542 int size, len;
543 struct cache_entry *ce;
544
545 if (!verify_path(path))
546 return NULL;
547
548 len = strlen(path);
549 size = cache_entry_size(len);
550 ce = xcalloc(1, size);
551
552 hashcpy(ce->sha1, sha1);
553 memcpy(ce->name, path, len);
554 ce->ce_flags = create_ce_flags(len, stage);
555 ce->ce_mode = create_ce_mode(mode);
556
557 if (refresh)
558 return refresh_cache_entry(ce, 0);
559
560 return ce;
561 }
562
563 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
564 {
565 int len = ce_namelen(a);
566 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
567 }
568
569 int ce_path_match(const struct cache_entry *ce, const char **pathspec)
570 {
571 const char *match, *name;
572 int len;
573
574 if (!pathspec)
575 return 1;
576
577 len = ce_namelen(ce);
578 name = ce->name;
579 while ((match = *pathspec++) != NULL) {
580 int matchlen = strlen(match);
581 if (matchlen > len)
582 continue;
583 if (memcmp(name, match, matchlen))
584 continue;
585 if (matchlen && name[matchlen-1] == '/')
586 return 1;
587 if (name[matchlen] == '/' || !name[matchlen])
588 return 1;
589 if (!matchlen)
590 return 1;
591 }
592 return 0;
593 }
594
595 /*
596 * We fundamentally don't like some paths: we don't want
597 * dot or dot-dot anywhere, and for obvious reasons don't
598 * want to recurse into ".git" either.
599 *
600 * Also, we don't want double slashes or slashes at the
601 * end that can make pathnames ambiguous.
602 */
603 static int verify_dotfile(const char *rest)
604 {
605 /*
606 * The first character was '.', but that
607 * has already been discarded, we now test
608 * the rest.
609 */
610 switch (*rest) {
611 /* "." is not allowed */
612 case '\0': case '/':
613 return 0;
614
615 /*
616 * ".git" followed by NUL or slash is bad. This
617 * shares the path end test with the ".." case.
618 */
619 case 'g':
620 if (rest[1] != 'i')
621 break;
622 if (rest[2] != 't')
623 break;
624 rest += 2;
625 /* fallthrough */
626 case '.':
627 if (rest[1] == '\0' || rest[1] == '/')
628 return 0;
629 }
630 return 1;
631 }
632
633 int verify_path(const char *path)
634 {
635 char c;
636
637 goto inside;
638 for (;;) {
639 if (!c)
640 return 1;
641 if (c == '/') {
642 inside:
643 c = *path++;
644 switch (c) {
645 default:
646 continue;
647 case '/': case '\0':
648 break;
649 case '.':
650 if (verify_dotfile(path))
651 continue;
652 }
653 return 0;
654 }
655 c = *path++;
656 }
657 }
658
659 /*
660 * Do we have another file that has the beginning components being a
661 * proper superset of the name we're trying to add?
662 */
663 static int has_file_name(struct index_state *istate,
664 const struct cache_entry *ce, int pos, int ok_to_replace)
665 {
666 int retval = 0;
667 int len = ce_namelen(ce);
668 int stage = ce_stage(ce);
669 const char *name = ce->name;
670
671 while (pos < istate->cache_nr) {
672 struct cache_entry *p = istate->cache[pos++];
673
674 if (len >= ce_namelen(p))
675 break;
676 if (memcmp(name, p->name, len))
677 break;
678 if (ce_stage(p) != stage)
679 continue;
680 if (p->name[len] != '/')
681 continue;
682 if (p->ce_flags & CE_REMOVE)
683 continue;
684 retval = -1;
685 if (!ok_to_replace)
686 break;
687 remove_index_entry_at(istate, --pos);
688 }
689 return retval;
690 }
691
692 /*
693 * Do we have another file with a pathname that is a proper
694 * subset of the name we're trying to add?
695 */
696 static int has_dir_name(struct index_state *istate,
697 const struct cache_entry *ce, int pos, int ok_to_replace)
698 {
699 int retval = 0;
700 int stage = ce_stage(ce);
701 const char *name = ce->name;
702 const char *slash = name + ce_namelen(ce);
703
704 for (;;) {
705 int len;
706
707 for (;;) {
708 if (*--slash == '/')
709 break;
710 if (slash <= ce->name)
711 return retval;
712 }
713 len = slash - name;
714
715 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
716 if (pos >= 0) {
717 /*
718 * Found one, but not so fast. This could
719 * be a marker that says "I was here, but
720 * I am being removed". Such an entry is
721 * not a part of the resulting tree, and
722 * it is Ok to have a directory at the same
723 * path.
724 */
725 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
726 retval = -1;
727 if (!ok_to_replace)
728 break;
729 remove_index_entry_at(istate, pos);
730 continue;
731 }
732 }
733 else
734 pos = -pos-1;
735
736 /*
737 * Trivial optimization: if we find an entry that
738 * already matches the sub-directory, then we know
739 * we're ok, and we can exit.
740 */
741 while (pos < istate->cache_nr) {
742 struct cache_entry *p = istate->cache[pos];
743 if ((ce_namelen(p) <= len) ||
744 (p->name[len] != '/') ||
745 memcmp(p->name, name, len))
746 break; /* not our subdirectory */
747 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
748 /*
749 * p is at the same stage as our entry, and
750 * is a subdirectory of what we are looking
751 * at, so we cannot have conflicts at our
752 * level or anything shorter.
753 */
754 return retval;
755 pos++;
756 }
757 }
758 return retval;
759 }
760
761 /* We may be in a situation where we already have path/file and path
762 * is being added, or we already have path and path/file is being
763 * added. Either one would result in a nonsense tree that has path
764 * twice when git-write-tree tries to write it out. Prevent it.
765 *
766 * If ok-to-replace is specified, we remove the conflicting entries
767 * from the cache so the caller should recompute the insert position.
768 * When this happens, we return non-zero.
769 */
770 static int check_file_directory_conflict(struct index_state *istate,
771 const struct cache_entry *ce,
772 int pos, int ok_to_replace)
773 {
774 int retval;
775
776 /*
777 * When ce is an "I am going away" entry, we allow it to be added
778 */
779 if (ce->ce_flags & CE_REMOVE)
780 return 0;
781
782 /*
783 * We check if the path is a sub-path of a subsequent pathname
784 * first, since removing those will not change the position
785 * in the array.
786 */
787 retval = has_file_name(istate, ce, pos, ok_to_replace);
788
789 /*
790 * Then check if the path might have a clashing sub-directory
791 * before it.
792 */
793 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
794 }
795
796 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
797 {
798 int pos;
799 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
800 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
801 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
802
803 cache_tree_invalidate_path(istate->cache_tree, ce->name);
804 pos = index_name_pos(istate, ce->name, ce->ce_flags);
805
806 /* existing match? Just replace it. */
807 if (pos >= 0) {
808 replace_index_entry(istate, pos, ce);
809 return 0;
810 }
811 pos = -pos-1;
812
813 /*
814 * Inserting a merged entry ("stage 0") into the index
815 * will always replace all non-merged entries..
816 */
817 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
818 while (ce_same_name(istate->cache[pos], ce)) {
819 ok_to_add = 1;
820 if (!remove_index_entry_at(istate, pos))
821 break;
822 }
823 }
824
825 if (!ok_to_add)
826 return -1;
827 if (!verify_path(ce->name))
828 return -1;
829
830 if (!skip_df_check &&
831 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
832 if (!ok_to_replace)
833 return error("'%s' appears as both a file and as a directory",
834 ce->name);
835 pos = index_name_pos(istate, ce->name, ce->ce_flags);
836 pos = -pos-1;
837 }
838 return pos + 1;
839 }
840
841 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
842 {
843 int pos;
844
845 if (option & ADD_CACHE_JUST_APPEND)
846 pos = istate->cache_nr;
847 else {
848 int ret;
849 ret = add_index_entry_with_check(istate, ce, option);
850 if (ret <= 0)
851 return ret;
852 pos = ret - 1;
853 }
854
855 /* Make sure the array is big enough .. */
856 if (istate->cache_nr == istate->cache_alloc) {
857 istate->cache_alloc = alloc_nr(istate->cache_alloc);
858 istate->cache = xrealloc(istate->cache,
859 istate->cache_alloc * sizeof(struct cache_entry *));
860 }
861
862 /* Add it in.. */
863 istate->cache_nr++;
864 if (istate->cache_nr > pos + 1)
865 memmove(istate->cache + pos + 1,
866 istate->cache + pos,
867 (istate->cache_nr - pos - 1) * sizeof(ce));
868 set_index_entry(istate, pos, ce);
869 istate->cache_changed = 1;
870 return 0;
871 }
872
873 /*
874 * "refresh" does not calculate a new sha1 file or bring the
875 * cache up-to-date for mode/content changes. But what it
876 * _does_ do is to "re-match" the stat information of a file
877 * with the cache, so that you can refresh the cache for a
878 * file that hasn't been changed but where the stat entry is
879 * out of date.
880 *
881 * For example, you'd want to do this after doing a "git-read-tree",
882 * to link up the stat cache details with the proper files.
883 */
884 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
885 struct cache_entry *ce,
886 unsigned int options, int *err)
887 {
888 struct stat st;
889 struct cache_entry *updated;
890 int changed, size;
891 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
892
893 if (ce_uptodate(ce))
894 return ce;
895
896 if (lstat(ce->name, &st) < 0) {
897 if (err)
898 *err = errno;
899 return NULL;
900 }
901
902 changed = ie_match_stat(istate, ce, &st, options);
903 if (!changed) {
904 /*
905 * The path is unchanged. If we were told to ignore
906 * valid bit, then we did the actual stat check and
907 * found that the entry is unmodified. If the entry
908 * is not marked VALID, this is the place to mark it
909 * valid again, under "assume unchanged" mode.
910 */
911 if (ignore_valid && assume_unchanged &&
912 !(ce->ce_flags & CE_VALID))
913 ; /* mark this one VALID again */
914 else {
915 /*
916 * We do not mark the index itself "modified"
917 * because CE_UPTODATE flag is in-core only;
918 * we are not going to write this change out.
919 */
920 ce_mark_uptodate(ce);
921 return ce;
922 }
923 }
924
925 if (ie_modified(istate, ce, &st, options)) {
926 if (err)
927 *err = EINVAL;
928 return NULL;
929 }
930
931 size = ce_size(ce);
932 updated = xmalloc(size);
933 memcpy(updated, ce, size);
934 fill_stat_cache_info(updated, &st);
935 /*
936 * If ignore_valid is not set, we should leave CE_VALID bit
937 * alone. Otherwise, paths marked with --no-assume-unchanged
938 * (i.e. things to be edited) will reacquire CE_VALID bit
939 * automatically, which is not really what we want.
940 */
941 if (!ignore_valid && assume_unchanged &&
942 !(ce->ce_flags & CE_VALID))
943 updated->ce_flags &= ~CE_VALID;
944
945 return updated;
946 }
947
948 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
949 {
950 int i;
951 int has_errors = 0;
952 int really = (flags & REFRESH_REALLY) != 0;
953 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
954 int quiet = (flags & REFRESH_QUIET) != 0;
955 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
956 int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
957 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
958
959 for (i = 0; i < istate->cache_nr; i++) {
960 struct cache_entry *ce, *new;
961 int cache_errno = 0;
962
963 ce = istate->cache[i];
964 if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
965 continue;
966
967 if (ce_stage(ce)) {
968 while ((i < istate->cache_nr) &&
969 ! strcmp(istate->cache[i]->name, ce->name))
970 i++;
971 i--;
972 if (allow_unmerged)
973 continue;
974 printf("%s: needs merge\n", ce->name);
975 has_errors = 1;
976 continue;
977 }
978
979 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
980 continue;
981
982 new = refresh_cache_ent(istate, ce, options, &cache_errno);
983 if (new == ce)
984 continue;
985 if (!new) {
986 if (not_new && cache_errno == ENOENT)
987 continue;
988 if (really && cache_errno == EINVAL) {
989 /* If we are doing --really-refresh that
990 * means the index is not valid anymore.
991 */
992 ce->ce_flags &= ~CE_VALID;
993 istate->cache_changed = 1;
994 }
995 if (quiet)
996 continue;
997 printf("%s: needs update\n", ce->name);
998 has_errors = 1;
999 continue;
1000 }
1001
1002 replace_index_entry(istate, i, new);
1003 }
1004 return has_errors;
1005 }
1006
1007 struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
1008 {
1009 return refresh_cache_ent(&the_index, ce, really, NULL);
1010 }
1011
1012 static int verify_hdr(struct cache_header *hdr, unsigned long size)
1013 {
1014 SHA_CTX c;
1015 unsigned char sha1[20];
1016
1017 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
1018 return error("bad signature");
1019 if (hdr->hdr_version != htonl(2))
1020 return error("bad index version");
1021 SHA1_Init(&c);
1022 SHA1_Update(&c, hdr, size - 20);
1023 SHA1_Final(sha1, &c);
1024 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1025 return error("bad index file sha1 signature");
1026 return 0;
1027 }
1028
1029 static int read_index_extension(struct index_state *istate,
1030 const char *ext, void *data, unsigned long sz)
1031 {
1032 switch (CACHE_EXT(ext)) {
1033 case CACHE_EXT_TREE:
1034 istate->cache_tree = cache_tree_read(data, sz);
1035 break;
1036 default:
1037 if (*ext < 'A' || 'Z' < *ext)
1038 return error("index uses %.4s extension, which we do not understand",
1039 ext);
1040 fprintf(stderr, "ignoring %.4s extension\n", ext);
1041 break;
1042 }
1043 return 0;
1044 }
1045
1046 int read_index(struct index_state *istate)
1047 {
1048 return read_index_from(istate, get_index_file());
1049 }
1050
1051 static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
1052 {
1053 size_t len;
1054
1055 ce->ce_ctime = ntohl(ondisk->ctime.sec);
1056 ce->ce_mtime = ntohl(ondisk->mtime.sec);
1057 ce->ce_dev = ntohl(ondisk->dev);
1058 ce->ce_ino = ntohl(ondisk->ino);
1059 ce->ce_mode = ntohl(ondisk->mode);
1060 ce->ce_uid = ntohl(ondisk->uid);
1061 ce->ce_gid = ntohl(ondisk->gid);
1062 ce->ce_size = ntohl(ondisk->size);
1063 /* On-disk flags are just 16 bits */
1064 ce->ce_flags = ntohs(ondisk->flags);
1065 hashcpy(ce->sha1, ondisk->sha1);
1066
1067 len = ce->ce_flags & CE_NAMEMASK;
1068 if (len == CE_NAMEMASK)
1069 len = strlen(ondisk->name);
1070 /*
1071 * NEEDSWORK: If the original index is crafted, this copy could
1072 * go unchecked.
1073 */
1074 memcpy(ce->name, ondisk->name, len + 1);
1075 }
1076
1077 static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
1078 {
1079 long per_entry;
1080
1081 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
1082
1083 /*
1084 * Alignment can cause differences. This should be "alignof", but
1085 * since that's a gcc'ism, just use the size of a pointer.
1086 */
1087 per_entry += sizeof(void *);
1088 return ondisk_size + entries*per_entry;
1089 }
1090
1091 /* remember to discard_cache() before reading a different cache! */
1092 int read_index_from(struct index_state *istate, const char *path)
1093 {
1094 int fd, i;
1095 struct stat st;
1096 unsigned long src_offset, dst_offset;
1097 struct cache_header *hdr;
1098 void *mmap;
1099 size_t mmap_size;
1100
1101 errno = EBUSY;
1102 if (istate->alloc)
1103 return istate->cache_nr;
1104
1105 errno = ENOENT;
1106 istate->timestamp = 0;
1107 fd = open(path, O_RDONLY);
1108 if (fd < 0) {
1109 if (errno == ENOENT)
1110 return 0;
1111 die("index file open failed (%s)", strerror(errno));
1112 }
1113
1114 if (fstat(fd, &st))
1115 die("cannot stat the open index (%s)", strerror(errno));
1116
1117 errno = EINVAL;
1118 mmap_size = xsize_t(st.st_size);
1119 if (mmap_size < sizeof(struct cache_header) + 20)
1120 die("index file smaller than expected");
1121
1122 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1123 close(fd);
1124 if (mmap == MAP_FAILED)
1125 die("unable to map index file");
1126
1127 hdr = mmap;
1128 if (verify_hdr(hdr, mmap_size) < 0)
1129 goto unmap;
1130
1131 istate->cache_nr = ntohl(hdr->hdr_entries);
1132 istate->cache_alloc = alloc_nr(istate->cache_nr);
1133 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1134
1135 /*
1136 * The disk format is actually larger than the in-memory format,
1137 * due to space for nsec etc, so even though the in-memory one
1138 * has room for a few more flags, we can allocate using the same
1139 * index size
1140 */
1141 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
1142
1143 src_offset = sizeof(*hdr);
1144 dst_offset = 0;
1145 for (i = 0; i < istate->cache_nr; i++) {
1146 struct ondisk_cache_entry *disk_ce;
1147 struct cache_entry *ce;
1148
1149 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1150 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
1151 convert_from_disk(disk_ce, ce);
1152 set_index_entry(istate, i, ce);
1153
1154 src_offset += ondisk_ce_size(ce);
1155 dst_offset += ce_size(ce);
1156 }
1157 istate->timestamp = st.st_mtime;
1158 while (src_offset <= mmap_size - 20 - 8) {
1159 /* After an array of active_nr index entries,
1160 * there can be arbitrary number of extended
1161 * sections, each of which is prefixed with
1162 * extension name (4-byte) and section length
1163 * in 4-byte network byte order.
1164 */
1165 unsigned long extsize;
1166 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1167 extsize = ntohl(extsize);
1168 if (read_index_extension(istate,
1169 (const char *) mmap + src_offset,
1170 (char *) mmap + src_offset + 8,
1171 extsize) < 0)
1172 goto unmap;
1173 src_offset += 8;
1174 src_offset += extsize;
1175 }
1176 munmap(mmap, mmap_size);
1177 return istate->cache_nr;
1178
1179 unmap:
1180 munmap(mmap, mmap_size);
1181 errno = EINVAL;
1182 die("index file corrupt");
1183 }
1184
1185 int discard_index(struct index_state *istate)
1186 {
1187 istate->cache_nr = 0;
1188 istate->cache_changed = 0;
1189 istate->timestamp = 0;
1190 free_hash(&istate->name_hash);
1191 cache_tree_free(&(istate->cache_tree));
1192 free(istate->alloc);
1193 istate->alloc = NULL;
1194
1195 /* no need to throw away allocated active_cache */
1196 return 0;
1197 }
1198
1199 int unmerged_index(const struct index_state *istate)
1200 {
1201 int i;
1202 for (i = 0; i < istate->cache_nr; i++) {
1203 if (ce_stage(istate->cache[i]))
1204 return 1;
1205 }
1206 return 0;
1207 }
1208
1209 #define WRITE_BUFFER_SIZE 8192
1210 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1211 static unsigned long write_buffer_len;
1212
1213 static int ce_write_flush(SHA_CTX *context, int fd)
1214 {
1215 unsigned int buffered = write_buffer_len;
1216 if (buffered) {
1217 SHA1_Update(context, write_buffer, buffered);
1218 if (write_in_full(fd, write_buffer, buffered) != buffered)
1219 return -1;
1220 write_buffer_len = 0;
1221 }
1222 return 0;
1223 }
1224
1225 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
1226 {
1227 while (len) {
1228 unsigned int buffered = write_buffer_len;
1229 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1230 if (partial > len)
1231 partial = len;
1232 memcpy(write_buffer + buffered, data, partial);
1233 buffered += partial;
1234 if (buffered == WRITE_BUFFER_SIZE) {
1235 write_buffer_len = buffered;
1236 if (ce_write_flush(context, fd))
1237 return -1;
1238 buffered = 0;
1239 }
1240 write_buffer_len = buffered;
1241 len -= partial;
1242 data = (char *) data + partial;
1243 }
1244 return 0;
1245 }
1246
1247 static int write_index_ext_header(SHA_CTX *context, int fd,
1248 unsigned int ext, unsigned int sz)
1249 {
1250 ext = htonl(ext);
1251 sz = htonl(sz);
1252 return ((ce_write(context, fd, &ext, 4) < 0) ||
1253 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1254 }
1255
1256 static int ce_flush(SHA_CTX *context, int fd)
1257 {
1258 unsigned int left = write_buffer_len;
1259
1260 if (left) {
1261 write_buffer_len = 0;
1262 SHA1_Update(context, write_buffer, left);
1263 }
1264
1265 /* Flush first if not enough space for SHA1 signature */
1266 if (left + 20 > WRITE_BUFFER_SIZE) {
1267 if (write_in_full(fd, write_buffer, left) != left)
1268 return -1;
1269 left = 0;
1270 }
1271
1272 /* Append the SHA1 signature at the end */
1273 SHA1_Final(write_buffer + left, context);
1274 left += 20;
1275 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1276 }
1277
1278 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1279 {
1280 /*
1281 * The only thing we care about in this function is to smudge the
1282 * falsely clean entry due to touch-update-touch race, so we leave
1283 * everything else as they are. We are called for entries whose
1284 * ce_mtime match the index file mtime.
1285 */
1286 struct stat st;
1287
1288 if (lstat(ce->name, &st) < 0)
1289 return;
1290 if (ce_match_stat_basic(ce, &st))
1291 return;
1292 if (ce_modified_check_fs(ce, &st)) {
1293 /* This is "racily clean"; smudge it. Note that this
1294 * is a tricky code. At first glance, it may appear
1295 * that it can break with this sequence:
1296 *
1297 * $ echo xyzzy >frotz
1298 * $ git-update-index --add frotz
1299 * $ : >frotz
1300 * $ sleep 3
1301 * $ echo filfre >nitfol
1302 * $ git-update-index --add nitfol
1303 *
1304 * but it does not. When the second update-index runs,
1305 * it notices that the entry "frotz" has the same timestamp
1306 * as index, and if we were to smudge it by resetting its
1307 * size to zero here, then the object name recorded
1308 * in index is the 6-byte file but the cached stat information
1309 * becomes zero --- which would then match what we would
1310 * obtain from the filesystem next time we stat("frotz").
1311 *
1312 * However, the second update-index, before calling
1313 * this function, notices that the cached size is 6
1314 * bytes and what is on the filesystem is an empty
1315 * file, and never calls us, so the cached size information
1316 * for "frotz" stays 6 which does not match the filesystem.
1317 */
1318 ce->ce_size = 0;
1319 }
1320 }
1321
1322 static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)
1323 {
1324 int size = ondisk_ce_size(ce);
1325 struct ondisk_cache_entry *ondisk = xcalloc(1, size);
1326
1327 ondisk->ctime.sec = htonl(ce->ce_ctime);
1328 ondisk->ctime.nsec = 0;
1329 ondisk->mtime.sec = htonl(ce->ce_mtime);
1330 ondisk->mtime.nsec = 0;
1331 ondisk->dev = htonl(ce->ce_dev);
1332 ondisk->ino = htonl(ce->ce_ino);
1333 ondisk->mode = htonl(ce->ce_mode);
1334 ondisk->uid = htonl(ce->ce_uid);
1335 ondisk->gid = htonl(ce->ce_gid);
1336 ondisk->size = htonl(ce->ce_size);
1337 hashcpy(ondisk->sha1, ce->sha1);
1338 ondisk->flags = htons(ce->ce_flags);
1339 memcpy(ondisk->name, ce->name, ce_namelen(ce));
1340
1341 return ce_write(c, fd, ondisk, size);
1342 }
1343
1344 int write_index(const struct index_state *istate, int newfd)
1345 {
1346 SHA_CTX c;
1347 struct cache_header hdr;
1348 int i, err, removed;
1349 struct cache_entry **cache = istate->cache;
1350 int entries = istate->cache_nr;
1351
1352 for (i = removed = 0; i < entries; i++)
1353 if (cache[i]->ce_flags & CE_REMOVE)
1354 removed++;
1355
1356 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1357 hdr.hdr_version = htonl(2);
1358 hdr.hdr_entries = htonl(entries - removed);
1359
1360 SHA1_Init(&c);
1361 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1362 return -1;
1363
1364 for (i = 0; i < entries; i++) {
1365 struct cache_entry *ce = cache[i];
1366 if (ce->ce_flags & CE_REMOVE)
1367 continue;
1368 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
1369 ce_smudge_racily_clean_entry(ce);
1370 if (ce_write_entry(&c, newfd, ce) < 0)
1371 return -1;
1372 }
1373
1374 /* Write extension data here */
1375 if (istate->cache_tree) {
1376 struct strbuf sb;
1377
1378 strbuf_init(&sb, 0);
1379 cache_tree_write(&sb, istate->cache_tree);
1380 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1381 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1382 strbuf_release(&sb);
1383 if (err)
1384 return -1;
1385 }
1386 return ce_flush(&c, newfd);
1387 }