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"
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 */
21 #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
22 #define CACHE_EXT_TREE 0x54524545 /* "TREE" */
24 struct index_state the_index;
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 }
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];
36 remove_name_hash(old);
37 set_index_entry(istate, nr, ce);
38 istate->cache_changed = 1;
39 }
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;
56 if (assume_unchanged)
57 ce->ce_flags |= CE_VALID;
59 if (S_ISREG(st->st_mode))
60 ce_mark_uptodate(ce);
61 }
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);
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 }
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;
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 }
104 static int ce_compare_gitlink(struct cache_entry *ce)
105 {
106 unsigned char sha1[20];
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 }
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 }
141 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
142 {
143 unsigned int changed = 0;
145 if (ce->ce_flags & CE_REMOVE)
146 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
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;
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;
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
193 if (ce->ce_size != (unsigned int) st->st_size)
194 changed |= DATA_CHANGED;
196 return changed;
197 }
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 }
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;
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;
221 changed = ce_match_stat_basic(ce, st);
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 }
246 return changed;
247 }
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;
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;
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;
271 changed_fs = ce_modified_check_fs(ce, st);
272 if (changed_fs)
273 return changed | changed_fs;
274 return 0;
275 }
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;
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 }
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;
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 }
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;
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;
346 /* Compare stages */
347 flags1 &= CE_STAGEMASK;
348 flags2 &= CE_STAGEMASK;
350 if (flags1 < flags2)
351 return -1;
352 if (flags1 > flags2)
353 return 1;
354 return 0;
355 }
357 int index_name_pos(const struct index_state *istate, const char *name, int namelen)
358 {
359 int first, last;
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 }
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];
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 }
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 }
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 }
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;
416 if (pos >= 0)
417 return pos;
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;
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 }
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 }
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;
453 if (alias->ce_flags & CE_ADDED)
454 die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
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 }
465 int add_file_to_index(struct index_state *istate, const char *path, int verbose)
466 {
467 int size, namelen;
468 struct stat st;
469 struct cache_entry *ce, *alias;
470 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY;
472 if (lstat(path, &st))
473 die("%s: unable to stat (%s)", path, strerror(errno));
475 if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode))
476 die("%s: can only add regular files, symbolic links or git-directories", path);
478 namelen = strlen(path);
479 if (S_ISDIR(st.st_mode)) {
480 while (namelen && path[namelen-1] == '/')
481 namelen--;
482 }
483 size = cache_entry_size(namelen);
484 ce = xcalloc(1, size);
485 memcpy(ce->name, path, namelen);
486 ce->ce_flags = namelen;
487 fill_stat_cache_info(ce, &st);
489 if (trust_executable_bit && has_symlinks)
490 ce->ce_mode = create_ce_mode(st.st_mode);
491 else {
492 /* If there is an existing entry, pick the mode bits and type
493 * from it, otherwise assume unexecutable regular file.
494 */
495 struct cache_entry *ent;
496 int pos = index_name_pos_also_unmerged(istate, path, namelen);
498 ent = (0 <= pos) ? istate->cache[pos] : NULL;
499 ce->ce_mode = ce_mode_from_stat(ent, st.st_mode);
500 }
502 alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case);
503 if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, &st, ce_option)) {
504 /* Nothing changed, really */
505 free(ce);
506 ce_mark_uptodate(alias);
507 alias->ce_flags |= CE_ADDED;
508 return 0;
509 }
510 if (index_path(ce->sha1, path, &st, 1))
511 die("unable to index file %s", path);
512 if (ignore_case && alias && different_name(ce, alias))
513 ce = create_alias_ce(ce, alias);
514 ce->ce_flags |= CE_ADDED;
515 if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
516 die("unable to add %s to index",path);
517 if (verbose)
518 printf("add '%s'\n", path);
519 return 0;
520 }
522 struct cache_entry *make_cache_entry(unsigned int mode,
523 const unsigned char *sha1, const char *path, int stage,
524 int refresh)
525 {
526 int size, len;
527 struct cache_entry *ce;
529 if (!verify_path(path))
530 return NULL;
532 len = strlen(path);
533 size = cache_entry_size(len);
534 ce = xcalloc(1, size);
536 hashcpy(ce->sha1, sha1);
537 memcpy(ce->name, path, len);
538 ce->ce_flags = create_ce_flags(len, stage);
539 ce->ce_mode = create_ce_mode(mode);
541 if (refresh)
542 return refresh_cache_entry(ce, 0);
544 return ce;
545 }
547 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
548 {
549 int len = ce_namelen(a);
550 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
551 }
553 int ce_path_match(const struct cache_entry *ce, const char **pathspec)
554 {
555 const char *match, *name;
556 int len;
558 if (!pathspec)
559 return 1;
561 len = ce_namelen(ce);
562 name = ce->name;
563 while ((match = *pathspec++) != NULL) {
564 int matchlen = strlen(match);
565 if (matchlen > len)
566 continue;
567 if (memcmp(name, match, matchlen))
568 continue;
569 if (matchlen && name[matchlen-1] == '/')
570 return 1;
571 if (name[matchlen] == '/' || !name[matchlen])
572 return 1;
573 if (!matchlen)
574 return 1;
575 }
576 return 0;
577 }
579 /*
580 * We fundamentally don't like some paths: we don't want
581 * dot or dot-dot anywhere, and for obvious reasons don't
582 * want to recurse into ".git" either.
583 *
584 * Also, we don't want double slashes or slashes at the
585 * end that can make pathnames ambiguous.
586 */
587 static int verify_dotfile(const char *rest)
588 {
589 /*
590 * The first character was '.', but that
591 * has already been discarded, we now test
592 * the rest.
593 */
594 switch (*rest) {
595 /* "." is not allowed */
596 case '\0': case '/':
597 return 0;
599 /*
600 * ".git" followed by NUL or slash is bad. This
601 * shares the path end test with the ".." case.
602 */
603 case 'g':
604 if (rest[1] != 'i')
605 break;
606 if (rest[2] != 't')
607 break;
608 rest += 2;
609 /* fallthrough */
610 case '.':
611 if (rest[1] == '\0' || rest[1] == '/')
612 return 0;
613 }
614 return 1;
615 }
617 int verify_path(const char *path)
618 {
619 char c;
621 goto inside;
622 for (;;) {
623 if (!c)
624 return 1;
625 if (c == '/') {
626 inside:
627 c = *path++;
628 switch (c) {
629 default:
630 continue;
631 case '/': case '\0':
632 break;
633 case '.':
634 if (verify_dotfile(path))
635 continue;
636 }
637 return 0;
638 }
639 c = *path++;
640 }
641 }
643 /*
644 * Do we have another file that has the beginning components being a
645 * proper superset of the name we're trying to add?
646 */
647 static int has_file_name(struct index_state *istate,
648 const struct cache_entry *ce, int pos, int ok_to_replace)
649 {
650 int retval = 0;
651 int len = ce_namelen(ce);
652 int stage = ce_stage(ce);
653 const char *name = ce->name;
655 while (pos < istate->cache_nr) {
656 struct cache_entry *p = istate->cache[pos++];
658 if (len >= ce_namelen(p))
659 break;
660 if (memcmp(name, p->name, len))
661 break;
662 if (ce_stage(p) != stage)
663 continue;
664 if (p->name[len] != '/')
665 continue;
666 if (p->ce_flags & CE_REMOVE)
667 continue;
668 retval = -1;
669 if (!ok_to_replace)
670 break;
671 remove_index_entry_at(istate, --pos);
672 }
673 return retval;
674 }
676 /*
677 * Do we have another file with a pathname that is a proper
678 * subset of the name we're trying to add?
679 */
680 static int has_dir_name(struct index_state *istate,
681 const struct cache_entry *ce, int pos, int ok_to_replace)
682 {
683 int retval = 0;
684 int stage = ce_stage(ce);
685 const char *name = ce->name;
686 const char *slash = name + ce_namelen(ce);
688 for (;;) {
689 int len;
691 for (;;) {
692 if (*--slash == '/')
693 break;
694 if (slash <= ce->name)
695 return retval;
696 }
697 len = slash - name;
699 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
700 if (pos >= 0) {
701 /*
702 * Found one, but not so fast. This could
703 * be a marker that says "I was here, but
704 * I am being removed". Such an entry is
705 * not a part of the resulting tree, and
706 * it is Ok to have a directory at the same
707 * path.
708 */
709 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
710 retval = -1;
711 if (!ok_to_replace)
712 break;
713 remove_index_entry_at(istate, pos);
714 continue;
715 }
716 }
717 else
718 pos = -pos-1;
720 /*
721 * Trivial optimization: if we find an entry that
722 * already matches the sub-directory, then we know
723 * we're ok, and we can exit.
724 */
725 while (pos < istate->cache_nr) {
726 struct cache_entry *p = istate->cache[pos];
727 if ((ce_namelen(p) <= len) ||
728 (p->name[len] != '/') ||
729 memcmp(p->name, name, len))
730 break; /* not our subdirectory */
731 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
732 /*
733 * p is at the same stage as our entry, and
734 * is a subdirectory of what we are looking
735 * at, so we cannot have conflicts at our
736 * level or anything shorter.
737 */
738 return retval;
739 pos++;
740 }
741 }
742 return retval;
743 }
745 /* We may be in a situation where we already have path/file and path
746 * is being added, or we already have path and path/file is being
747 * added. Either one would result in a nonsense tree that has path
748 * twice when git-write-tree tries to write it out. Prevent it.
749 *
750 * If ok-to-replace is specified, we remove the conflicting entries
751 * from the cache so the caller should recompute the insert position.
752 * When this happens, we return non-zero.
753 */
754 static int check_file_directory_conflict(struct index_state *istate,
755 const struct cache_entry *ce,
756 int pos, int ok_to_replace)
757 {
758 int retval;
760 /*
761 * When ce is an "I am going away" entry, we allow it to be added
762 */
763 if (ce->ce_flags & CE_REMOVE)
764 return 0;
766 /*
767 * We check if the path is a sub-path of a subsequent pathname
768 * first, since removing those will not change the position
769 * in the array.
770 */
771 retval = has_file_name(istate, ce, pos, ok_to_replace);
773 /*
774 * Then check if the path might have a clashing sub-directory
775 * before it.
776 */
777 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
778 }
780 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
781 {
782 int pos;
783 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
784 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
785 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
787 cache_tree_invalidate_path(istate->cache_tree, ce->name);
788 pos = index_name_pos(istate, ce->name, ce->ce_flags);
790 /* existing match? Just replace it. */
791 if (pos >= 0) {
792 replace_index_entry(istate, pos, ce);
793 return 0;
794 }
795 pos = -pos-1;
797 /*
798 * Inserting a merged entry ("stage 0") into the index
799 * will always replace all non-merged entries..
800 */
801 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
802 while (ce_same_name(istate->cache[pos], ce)) {
803 ok_to_add = 1;
804 if (!remove_index_entry_at(istate, pos))
805 break;
806 }
807 }
809 if (!ok_to_add)
810 return -1;
811 if (!verify_path(ce->name))
812 return -1;
814 if (!skip_df_check &&
815 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
816 if (!ok_to_replace)
817 return error("'%s' appears as both a file and as a directory",
818 ce->name);
819 pos = index_name_pos(istate, ce->name, ce->ce_flags);
820 pos = -pos-1;
821 }
822 return pos + 1;
823 }
825 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
826 {
827 int pos;
829 if (option & ADD_CACHE_JUST_APPEND)
830 pos = istate->cache_nr;
831 else {
832 int ret;
833 ret = add_index_entry_with_check(istate, ce, option);
834 if (ret <= 0)
835 return ret;
836 pos = ret - 1;
837 }
839 /* Make sure the array is big enough .. */
840 if (istate->cache_nr == istate->cache_alloc) {
841 istate->cache_alloc = alloc_nr(istate->cache_alloc);
842 istate->cache = xrealloc(istate->cache,
843 istate->cache_alloc * sizeof(struct cache_entry *));
844 }
846 /* Add it in.. */
847 istate->cache_nr++;
848 if (istate->cache_nr > pos + 1)
849 memmove(istate->cache + pos + 1,
850 istate->cache + pos,
851 (istate->cache_nr - pos - 1) * sizeof(ce));
852 set_index_entry(istate, pos, ce);
853 istate->cache_changed = 1;
854 return 0;
855 }
857 /*
858 * "refresh" does not calculate a new sha1 file or bring the
859 * cache up-to-date for mode/content changes. But what it
860 * _does_ do is to "re-match" the stat information of a file
861 * with the cache, so that you can refresh the cache for a
862 * file that hasn't been changed but where the stat entry is
863 * out of date.
864 *
865 * For example, you'd want to do this after doing a "git-read-tree",
866 * to link up the stat cache details with the proper files.
867 */
868 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
869 struct cache_entry *ce,
870 unsigned int options, int *err)
871 {
872 struct stat st;
873 struct cache_entry *updated;
874 int changed, size;
875 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
877 if (ce_uptodate(ce))
878 return ce;
880 if (lstat(ce->name, &st) < 0) {
881 if (err)
882 *err = errno;
883 return NULL;
884 }
886 changed = ie_match_stat(istate, ce, &st, options);
887 if (!changed) {
888 /*
889 * The path is unchanged. If we were told to ignore
890 * valid bit, then we did the actual stat check and
891 * found that the entry is unmodified. If the entry
892 * is not marked VALID, this is the place to mark it
893 * valid again, under "assume unchanged" mode.
894 */
895 if (ignore_valid && assume_unchanged &&
896 !(ce->ce_flags & CE_VALID))
897 ; /* mark this one VALID again */
898 else {
899 /*
900 * We do not mark the index itself "modified"
901 * because CE_UPTODATE flag is in-core only;
902 * we are not going to write this change out.
903 */
904 ce_mark_uptodate(ce);
905 return ce;
906 }
907 }
909 if (ie_modified(istate, ce, &st, options)) {
910 if (err)
911 *err = EINVAL;
912 return NULL;
913 }
915 size = ce_size(ce);
916 updated = xmalloc(size);
917 memcpy(updated, ce, size);
918 fill_stat_cache_info(updated, &st);
919 /*
920 * If ignore_valid is not set, we should leave CE_VALID bit
921 * alone. Otherwise, paths marked with --no-assume-unchanged
922 * (i.e. things to be edited) will reacquire CE_VALID bit
923 * automatically, which is not really what we want.
924 */
925 if (!ignore_valid && assume_unchanged &&
926 !(ce->ce_flags & CE_VALID))
927 updated->ce_flags &= ~CE_VALID;
929 return updated;
930 }
932 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
933 {
934 int i;
935 int has_errors = 0;
936 int really = (flags & REFRESH_REALLY) != 0;
937 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
938 int quiet = (flags & REFRESH_QUIET) != 0;
939 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
940 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
942 for (i = 0; i < istate->cache_nr; i++) {
943 struct cache_entry *ce, *new;
944 int cache_errno = 0;
946 ce = istate->cache[i];
947 if (ce_stage(ce)) {
948 while ((i < istate->cache_nr) &&
949 ! strcmp(istate->cache[i]->name, ce->name))
950 i++;
951 i--;
952 if (allow_unmerged)
953 continue;
954 printf("%s: needs merge\n", ce->name);
955 has_errors = 1;
956 continue;
957 }
959 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
960 continue;
962 new = refresh_cache_ent(istate, ce, options, &cache_errno);
963 if (new == ce)
964 continue;
965 if (!new) {
966 if (not_new && cache_errno == ENOENT)
967 continue;
968 if (really && cache_errno == EINVAL) {
969 /* If we are doing --really-refresh that
970 * means the index is not valid anymore.
971 */
972 ce->ce_flags &= ~CE_VALID;
973 istate->cache_changed = 1;
974 }
975 if (quiet)
976 continue;
977 printf("%s: needs update\n", ce->name);
978 has_errors = 1;
979 continue;
980 }
982 replace_index_entry(istate, i, new);
983 }
984 return has_errors;
985 }
987 struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
988 {
989 return refresh_cache_ent(&the_index, ce, really, NULL);
990 }
992 static int verify_hdr(struct cache_header *hdr, unsigned long size)
993 {
994 SHA_CTX c;
995 unsigned char sha1[20];
997 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
998 return error("bad signature");
999 if (hdr->hdr_version != htonl(2))
1000 return error("bad index version");
1001 SHA1_Init(&c);
1002 SHA1_Update(&c, hdr, size - 20);
1003 SHA1_Final(sha1, &c);
1004 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1005 return error("bad index file sha1 signature");
1006 return 0;
1007 }
1009 static int read_index_extension(struct index_state *istate,
1010 const char *ext, void *data, unsigned long sz)
1011 {
1012 switch (CACHE_EXT(ext)) {
1013 case CACHE_EXT_TREE:
1014 istate->cache_tree = cache_tree_read(data, sz);
1015 break;
1016 default:
1017 if (*ext < 'A' || 'Z' < *ext)
1018 return error("index uses %.4s extension, which we do not understand",
1019 ext);
1020 fprintf(stderr, "ignoring %.4s extension\n", ext);
1021 break;
1022 }
1023 return 0;
1024 }
1026 int read_index(struct index_state *istate)
1027 {
1028 return read_index_from(istate, get_index_file());
1029 }
1031 static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
1032 {
1033 size_t len;
1035 ce->ce_ctime = ntohl(ondisk->ctime.sec);
1036 ce->ce_mtime = ntohl(ondisk->mtime.sec);
1037 ce->ce_dev = ntohl(ondisk->dev);
1038 ce->ce_ino = ntohl(ondisk->ino);
1039 ce->ce_mode = ntohl(ondisk->mode);
1040 ce->ce_uid = ntohl(ondisk->uid);
1041 ce->ce_gid = ntohl(ondisk->gid);
1042 ce->ce_size = ntohl(ondisk->size);
1043 /* On-disk flags are just 16 bits */
1044 ce->ce_flags = ntohs(ondisk->flags);
1045 hashcpy(ce->sha1, ondisk->sha1);
1047 len = ce->ce_flags & CE_NAMEMASK;
1048 if (len == CE_NAMEMASK)
1049 len = strlen(ondisk->name);
1050 /*
1051 * NEEDSWORK: If the original index is crafted, this copy could
1052 * go unchecked.
1053 */
1054 memcpy(ce->name, ondisk->name, len + 1);
1055 }
1057 static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
1058 {
1059 long per_entry;
1061 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
1063 /*
1064 * Alignment can cause differences. This should be "alignof", but
1065 * since that's a gcc'ism, just use the size of a pointer.
1066 */
1067 per_entry += sizeof(void *);
1068 return ondisk_size + entries*per_entry;
1069 }
1071 /* remember to discard_cache() before reading a different cache! */
1072 int read_index_from(struct index_state *istate, const char *path)
1073 {
1074 int fd, i;
1075 struct stat st;
1076 unsigned long src_offset, dst_offset;
1077 struct cache_header *hdr;
1078 void *mmap;
1079 size_t mmap_size;
1081 errno = EBUSY;
1082 if (istate->alloc)
1083 return istate->cache_nr;
1085 errno = ENOENT;
1086 istate->timestamp = 0;
1087 fd = open(path, O_RDONLY);
1088 if (fd < 0) {
1089 if (errno == ENOENT)
1090 return 0;
1091 die("index file open failed (%s)", strerror(errno));
1092 }
1094 if (fstat(fd, &st))
1095 die("cannot stat the open index (%s)", strerror(errno));
1097 errno = EINVAL;
1098 mmap_size = xsize_t(st.st_size);
1099 if (mmap_size < sizeof(struct cache_header) + 20)
1100 die("index file smaller than expected");
1102 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1103 close(fd);
1104 if (mmap == MAP_FAILED)
1105 die("unable to map index file");
1107 hdr = mmap;
1108 if (verify_hdr(hdr, mmap_size) < 0)
1109 goto unmap;
1111 istate->cache_nr = ntohl(hdr->hdr_entries);
1112 istate->cache_alloc = alloc_nr(istate->cache_nr);
1113 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1115 /*
1116 * The disk format is actually larger than the in-memory format,
1117 * due to space for nsec etc, so even though the in-memory one
1118 * has room for a few more flags, we can allocate using the same
1119 * index size
1120 */
1121 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
1123 src_offset = sizeof(*hdr);
1124 dst_offset = 0;
1125 for (i = 0; i < istate->cache_nr; i++) {
1126 struct ondisk_cache_entry *disk_ce;
1127 struct cache_entry *ce;
1129 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1130 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
1131 convert_from_disk(disk_ce, ce);
1132 set_index_entry(istate, i, ce);
1134 src_offset += ondisk_ce_size(ce);
1135 dst_offset += ce_size(ce);
1136 }
1137 istate->timestamp = st.st_mtime;
1138 while (src_offset <= mmap_size - 20 - 8) {
1139 /* After an array of active_nr index entries,
1140 * there can be arbitrary number of extended
1141 * sections, each of which is prefixed with
1142 * extension name (4-byte) and section length
1143 * in 4-byte network byte order.
1144 */
1145 unsigned long extsize;
1146 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1147 extsize = ntohl(extsize);
1148 if (read_index_extension(istate,
1149 (const char *) mmap + src_offset,
1150 (char *) mmap + src_offset + 8,
1151 extsize) < 0)
1152 goto unmap;
1153 src_offset += 8;
1154 src_offset += extsize;
1155 }
1156 munmap(mmap, mmap_size);
1157 return istate->cache_nr;
1159 unmap:
1160 munmap(mmap, mmap_size);
1161 errno = EINVAL;
1162 die("index file corrupt");
1163 }
1165 int discard_index(struct index_state *istate)
1166 {
1167 istate->cache_nr = 0;
1168 istate->cache_changed = 0;
1169 istate->timestamp = 0;
1170 free_hash(&istate->name_hash);
1171 cache_tree_free(&(istate->cache_tree));
1172 free(istate->alloc);
1173 istate->alloc = NULL;
1175 /* no need to throw away allocated active_cache */
1176 return 0;
1177 }
1179 int unmerged_index(const struct index_state *istate)
1180 {
1181 int i;
1182 for (i = 0; i < istate->cache_nr; i++) {
1183 if (ce_stage(istate->cache[i]))
1184 return 1;
1185 }
1186 return 0;
1187 }
1189 #define WRITE_BUFFER_SIZE 8192
1190 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1191 static unsigned long write_buffer_len;
1193 static int ce_write_flush(SHA_CTX *context, int fd)
1194 {
1195 unsigned int buffered = write_buffer_len;
1196 if (buffered) {
1197 SHA1_Update(context, write_buffer, buffered);
1198 if (write_in_full(fd, write_buffer, buffered) != buffered)
1199 return -1;
1200 write_buffer_len = 0;
1201 }
1202 return 0;
1203 }
1205 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
1206 {
1207 while (len) {
1208 unsigned int buffered = write_buffer_len;
1209 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1210 if (partial > len)
1211 partial = len;
1212 memcpy(write_buffer + buffered, data, partial);
1213 buffered += partial;
1214 if (buffered == WRITE_BUFFER_SIZE) {
1215 write_buffer_len = buffered;
1216 if (ce_write_flush(context, fd))
1217 return -1;
1218 buffered = 0;
1219 }
1220 write_buffer_len = buffered;
1221 len -= partial;
1222 data = (char *) data + partial;
1223 }
1224 return 0;
1225 }
1227 static int write_index_ext_header(SHA_CTX *context, int fd,
1228 unsigned int ext, unsigned int sz)
1229 {
1230 ext = htonl(ext);
1231 sz = htonl(sz);
1232 return ((ce_write(context, fd, &ext, 4) < 0) ||
1233 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1234 }
1236 static int ce_flush(SHA_CTX *context, int fd)
1237 {
1238 unsigned int left = write_buffer_len;
1240 if (left) {
1241 write_buffer_len = 0;
1242 SHA1_Update(context, write_buffer, left);
1243 }
1245 /* Flush first if not enough space for SHA1 signature */
1246 if (left + 20 > WRITE_BUFFER_SIZE) {
1247 if (write_in_full(fd, write_buffer, left) != left)
1248 return -1;
1249 left = 0;
1250 }
1252 /* Append the SHA1 signature at the end */
1253 SHA1_Final(write_buffer + left, context);
1254 left += 20;
1255 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1256 }
1258 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1259 {
1260 /*
1261 * The only thing we care about in this function is to smudge the
1262 * falsely clean entry due to touch-update-touch race, so we leave
1263 * everything else as they are. We are called for entries whose
1264 * ce_mtime match the index file mtime.
1265 */
1266 struct stat st;
1268 if (lstat(ce->name, &st) < 0)
1269 return;
1270 if (ce_match_stat_basic(ce, &st))
1271 return;
1272 if (ce_modified_check_fs(ce, &st)) {
1273 /* This is "racily clean"; smudge it. Note that this
1274 * is a tricky code. At first glance, it may appear
1275 * that it can break with this sequence:
1276 *
1277 * $ echo xyzzy >frotz
1278 * $ git-update-index --add frotz
1279 * $ : >frotz
1280 * $ sleep 3
1281 * $ echo filfre >nitfol
1282 * $ git-update-index --add nitfol
1283 *
1284 * but it does not. When the second update-index runs,
1285 * it notices that the entry "frotz" has the same timestamp
1286 * as index, and if we were to smudge it by resetting its
1287 * size to zero here, then the object name recorded
1288 * in index is the 6-byte file but the cached stat information
1289 * becomes zero --- which would then match what we would
1290 * obtain from the filesystem next time we stat("frotz").
1291 *
1292 * However, the second update-index, before calling
1293 * this function, notices that the cached size is 6
1294 * bytes and what is on the filesystem is an empty
1295 * file, and never calls us, so the cached size information
1296 * for "frotz" stays 6 which does not match the filesystem.
1297 */
1298 ce->ce_size = 0;
1299 }
1300 }
1302 static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)
1303 {
1304 int size = ondisk_ce_size(ce);
1305 struct ondisk_cache_entry *ondisk = xcalloc(1, size);
1307 ondisk->ctime.sec = htonl(ce->ce_ctime);
1308 ondisk->ctime.nsec = 0;
1309 ondisk->mtime.sec = htonl(ce->ce_mtime);
1310 ondisk->mtime.nsec = 0;
1311 ondisk->dev = htonl(ce->ce_dev);
1312 ondisk->ino = htonl(ce->ce_ino);
1313 ondisk->mode = htonl(ce->ce_mode);
1314 ondisk->uid = htonl(ce->ce_uid);
1315 ondisk->gid = htonl(ce->ce_gid);
1316 ondisk->size = htonl(ce->ce_size);
1317 hashcpy(ondisk->sha1, ce->sha1);
1318 ondisk->flags = htons(ce->ce_flags);
1319 memcpy(ondisk->name, ce->name, ce_namelen(ce));
1321 return ce_write(c, fd, ondisk, size);
1322 }
1324 int write_index(const struct index_state *istate, int newfd)
1325 {
1326 SHA_CTX c;
1327 struct cache_header hdr;
1328 int i, err, removed;
1329 struct cache_entry **cache = istate->cache;
1330 int entries = istate->cache_nr;
1332 for (i = removed = 0; i < entries; i++)
1333 if (cache[i]->ce_flags & CE_REMOVE)
1334 removed++;
1336 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1337 hdr.hdr_version = htonl(2);
1338 hdr.hdr_entries = htonl(entries - removed);
1340 SHA1_Init(&c);
1341 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1342 return -1;
1344 for (i = 0; i < entries; i++) {
1345 struct cache_entry *ce = cache[i];
1346 if (ce->ce_flags & CE_REMOVE)
1347 continue;
1348 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
1349 ce_smudge_racily_clean_entry(ce);
1350 if (ce_write_entry(&c, newfd, ce) < 0)
1351 return -1;
1352 }
1354 /* Write extension data here */
1355 if (istate->cache_tree) {
1356 struct strbuf sb;
1358 strbuf_init(&sb, 0);
1359 cache_tree_write(&sb, istate->cache_tree);
1360 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1361 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1362 strbuf_release(&sb);
1363 if (err)
1364 return -1;
1365 }
1366 return ce_flush(&c, newfd);
1367 }