Merge commit 'junio/next' into next
[git/platforms/storm.git] / read-cache.c
blob3ae67846795de39a93da44d88eb06f4916aa7479
1 /*
2 * GIT - The information manager from hell
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.
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.
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)
28 istate->cache[nr] = ce;
29 add_name_hash(istate, ce);
32 static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
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;
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.
46 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
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);
63 static int ce_compare_data(struct cache_entry *ce, struct stat *st)
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 */
74 return match;
77 static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
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;
92 buffer = read_sha1_file(ce->sha1, &type, &size);
93 if (!buffer) {
94 free(target);
95 return -1;
97 if (size == expected_size)
98 match = memcmp(buffer, target, size);
99 free(buffer);
100 free(target);
101 return match;
104 static int ce_compare_gitlink(struct cache_entry *ce)
106 unsigned char sha1[20];
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).
114 * If so, we consider it always to match.
116 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
117 return 0;
118 return hashcmp(sha1, ce->sha1);
121 static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
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;
138 return 0;
141 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
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"
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);
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
185 * st_dev breaks on network filesystems where different
186 * clients will have different views of what "device"
187 * the filesystem is on
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;
199 static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
201 return (!S_ISGITLINK(ce->ce_mode) &&
202 istate->timestamp &&
203 ((unsigned int)istate->timestamp) <= ce->ce_mtime);
206 int ie_match_stat(const struct index_state *istate,
207 struct cache_entry *ce, struct stat *st,
208 unsigned int options)
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;
215 * If it's marked as always valid in the index, it's
216 * valid whatever the checked-out copy says.
218 if (!ignore_valid && (ce->ce_flags & CE_VALID))
219 return 0;
221 changed = ce_match_stat_basic(ce, st);
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.
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.
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);
246 return changed;
249 int ie_modified(const struct index_state *istate,
250 struct cache_entry *ce, struct stat *st, unsigned int options)
252 int changed, changed_fs;
254 changed = ie_match_stat(istate, ce, st, options);
255 if (!changed)
256 return 0;
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
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.
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;
277 int base_name_compare(const char *name1, int len1, int mode1,
278 const char *name2, int len2, int mode2)
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;
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' < '.' < '/').
303 * This is used by routines that want to traverse the git namespace
304 * but then handle conflicting entries together when possible.
306 int df_name_compare(const char *name1, int len1, int mode1,
307 const char *name2, int len2, int mode2)
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;
331 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
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;
357 int index_name_pos(const struct index_state *istate, const char *name, int namelen)
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;
373 first = next+1;
375 return -first-1;
378 /* Remove entry, return true if there are more entries to go.. */
379 int remove_index_entry_at(struct index_state *istate, int pos)
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;
394 int remove_file_from_index(struct index_state *istate, const char *path)
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;
405 static int compare_name(struct cache_entry *ce, const char *path, int namelen)
407 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
410 static int index_name_pos_also_unmerged(struct index_state *istate,
411 const char *path, int namelen)
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;
433 static int different_name(struct cache_entry *ce, struct cache_entry *alias)
435 int len = ce_namelen(ce);
436 return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
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!
445 * So we use the CE_ADDED flag to verify that the alias was an old
446 * one before we accept it as
448 static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias)
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;
465 int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
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;
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);
477 namelen = strlen(path);
478 if (S_ISDIR(st_mode)) {
479 while (namelen && path[namelen-1] == '/')
480 namelen--;
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);
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.
494 struct cache_entry *ent;
495 int pos = index_name_pos_also_unmerged(istate, path, namelen);
497 ent = (0 <= pos) ? istate->cache[pos] : NULL;
498 ce->ce_mode = ce_mode_from_stat(ent, st_mode);
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;
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;
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);
521 if (pretend)
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;
530 int add_file_to_index(struct index_state *istate, const char *path, int flags)
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);
538 struct cache_entry *make_cache_entry(unsigned int mode,
539 const unsigned char *sha1, const char *path, int stage,
540 int refresh)
542 int size, len;
543 struct cache_entry *ce;
545 if (!verify_path(path))
546 return NULL;
548 len = strlen(path);
549 size = cache_entry_size(len);
550 ce = xcalloc(1, size);
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);
557 if (refresh)
558 return refresh_cache_entry(ce, 0);
560 return ce;
563 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
565 int len = ce_namelen(a);
566 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
569 int ce_path_match(const struct cache_entry *ce, const char **pathspec)
571 const char *match, *name;
572 int len;
574 if (!pathspec)
575 return 1;
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;
592 return 0;
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.
600 * Also, we don't want double slashes or slashes at the
601 * end that can make pathnames ambiguous.
603 static int verify_dotfile(const char *rest)
606 * The first character was '.', but that
607 * has already been discarded, we now test
608 * the rest.
610 switch (*rest) {
611 /* "." is not allowed */
612 case '\0': case '/':
613 return 0;
616 * ".git" followed by NUL or slash is bad. This
617 * shares the path end test with the ".." case.
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;
630 return 1;
633 int verify_path(const char *path)
635 char c;
637 #ifdef __MINGW32__
638 if (is_absolute_path(path))
639 return error("Cannot handle absolute path: %s", path);
640 #endif
642 goto inside;
643 for (;;) {
644 if (!c)
645 return 1;
646 if (c == '/') {
647 inside:
648 c = *path++;
649 switch (c) {
650 default:
651 continue;
652 case '/': case '\0':
653 break;
654 case '.':
655 if (verify_dotfile(path))
656 continue;
658 return 0;
660 c = *path++;
665 * Do we have another file that has the beginning components being a
666 * proper superset of the name we're trying to add?
668 static int has_file_name(struct index_state *istate,
669 const struct cache_entry *ce, int pos, int ok_to_replace)
671 int retval = 0;
672 int len = ce_namelen(ce);
673 int stage = ce_stage(ce);
674 const char *name = ce->name;
676 while (pos < istate->cache_nr) {
677 struct cache_entry *p = istate->cache[pos++];
679 if (len >= ce_namelen(p))
680 break;
681 if (memcmp(name, p->name, len))
682 break;
683 if (ce_stage(p) != stage)
684 continue;
685 if (p->name[len] != '/')
686 continue;
687 if (p->ce_flags & CE_REMOVE)
688 continue;
689 retval = -1;
690 if (!ok_to_replace)
691 break;
692 remove_index_entry_at(istate, --pos);
694 return retval;
698 * Do we have another file with a pathname that is a proper
699 * subset of the name we're trying to add?
701 static int has_dir_name(struct index_state *istate,
702 const struct cache_entry *ce, int pos, int ok_to_replace)
704 int retval = 0;
705 int stage = ce_stage(ce);
706 const char *name = ce->name;
707 const char *slash = name + ce_namelen(ce);
709 for (;;) {
710 int len;
712 for (;;) {
713 if (*--slash == '/')
714 break;
715 if (slash <= ce->name)
716 return retval;
718 len = slash - name;
720 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
721 if (pos >= 0) {
723 * Found one, but not so fast. This could
724 * be a marker that says "I was here, but
725 * I am being removed". Such an entry is
726 * not a part of the resulting tree, and
727 * it is Ok to have a directory at the same
728 * path.
730 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
731 retval = -1;
732 if (!ok_to_replace)
733 break;
734 remove_index_entry_at(istate, pos);
735 continue;
738 else
739 pos = -pos-1;
742 * Trivial optimization: if we find an entry that
743 * already matches the sub-directory, then we know
744 * we're ok, and we can exit.
746 while (pos < istate->cache_nr) {
747 struct cache_entry *p = istate->cache[pos];
748 if ((ce_namelen(p) <= len) ||
749 (p->name[len] != '/') ||
750 memcmp(p->name, name, len))
751 break; /* not our subdirectory */
752 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
754 * p is at the same stage as our entry, and
755 * is a subdirectory of what we are looking
756 * at, so we cannot have conflicts at our
757 * level or anything shorter.
759 return retval;
760 pos++;
763 return retval;
766 /* We may be in a situation where we already have path/file and path
767 * is being added, or we already have path and path/file is being
768 * added. Either one would result in a nonsense tree that has path
769 * twice when git-write-tree tries to write it out. Prevent it.
771 * If ok-to-replace is specified, we remove the conflicting entries
772 * from the cache so the caller should recompute the insert position.
773 * When this happens, we return non-zero.
775 static int check_file_directory_conflict(struct index_state *istate,
776 const struct cache_entry *ce,
777 int pos, int ok_to_replace)
779 int retval;
782 * When ce is an "I am going away" entry, we allow it to be added
784 if (ce->ce_flags & CE_REMOVE)
785 return 0;
788 * We check if the path is a sub-path of a subsequent pathname
789 * first, since removing those will not change the position
790 * in the array.
792 retval = has_file_name(istate, ce, pos, ok_to_replace);
795 * Then check if the path might have a clashing sub-directory
796 * before it.
798 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
801 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
803 int pos;
804 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
805 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
806 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
808 cache_tree_invalidate_path(istate->cache_tree, ce->name);
809 pos = index_name_pos(istate, ce->name, ce->ce_flags);
811 /* existing match? Just replace it. */
812 if (pos >= 0) {
813 replace_index_entry(istate, pos, ce);
814 return 0;
816 pos = -pos-1;
819 * Inserting a merged entry ("stage 0") into the index
820 * will always replace all non-merged entries..
822 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
823 while (ce_same_name(istate->cache[pos], ce)) {
824 ok_to_add = 1;
825 if (!remove_index_entry_at(istate, pos))
826 break;
830 if (!ok_to_add)
831 return -1;
832 if (!verify_path(ce->name))
833 return -1;
835 if (!skip_df_check &&
836 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
837 if (!ok_to_replace)
838 return error("'%s' appears as both a file and as a directory",
839 ce->name);
840 pos = index_name_pos(istate, ce->name, ce->ce_flags);
841 pos = -pos-1;
843 return pos + 1;
846 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
848 int pos;
850 if (option & ADD_CACHE_JUST_APPEND)
851 pos = istate->cache_nr;
852 else {
853 int ret;
854 ret = add_index_entry_with_check(istate, ce, option);
855 if (ret <= 0)
856 return ret;
857 pos = ret - 1;
860 /* Make sure the array is big enough .. */
861 if (istate->cache_nr == istate->cache_alloc) {
862 istate->cache_alloc = alloc_nr(istate->cache_alloc);
863 istate->cache = xrealloc(istate->cache,
864 istate->cache_alloc * sizeof(struct cache_entry *));
867 /* Add it in.. */
868 istate->cache_nr++;
869 if (istate->cache_nr > pos + 1)
870 memmove(istate->cache + pos + 1,
871 istate->cache + pos,
872 (istate->cache_nr - pos - 1) * sizeof(ce));
873 set_index_entry(istate, pos, ce);
874 istate->cache_changed = 1;
875 return 0;
879 * "refresh" does not calculate a new sha1 file or bring the
880 * cache up-to-date for mode/content changes. But what it
881 * _does_ do is to "re-match" the stat information of a file
882 * with the cache, so that you can refresh the cache for a
883 * file that hasn't been changed but where the stat entry is
884 * out of date.
886 * For example, you'd want to do this after doing a "git-read-tree",
887 * to link up the stat cache details with the proper files.
889 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
890 struct cache_entry *ce,
891 unsigned int options, int *err)
893 struct stat st;
894 struct cache_entry *updated;
895 int changed, size;
896 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
898 if (ce_uptodate(ce))
899 return ce;
901 if (lstat(ce->name, &st) < 0) {
902 if (err)
903 *err = errno;
904 return NULL;
907 changed = ie_match_stat(istate, ce, &st, options);
908 if (!changed) {
910 * The path is unchanged. If we were told to ignore
911 * valid bit, then we did the actual stat check and
912 * found that the entry is unmodified. If the entry
913 * is not marked VALID, this is the place to mark it
914 * valid again, under "assume unchanged" mode.
916 if (ignore_valid && assume_unchanged &&
917 !(ce->ce_flags & CE_VALID))
918 ; /* mark this one VALID again */
919 else {
921 * We do not mark the index itself "modified"
922 * because CE_UPTODATE flag is in-core only;
923 * we are not going to write this change out.
925 ce_mark_uptodate(ce);
926 return ce;
930 if (ie_modified(istate, ce, &st, options)) {
931 if (err)
932 *err = EINVAL;
933 return NULL;
936 size = ce_size(ce);
937 updated = xmalloc(size);
938 memcpy(updated, ce, size);
939 fill_stat_cache_info(updated, &st);
941 * If ignore_valid is not set, we should leave CE_VALID bit
942 * alone. Otherwise, paths marked with --no-assume-unchanged
943 * (i.e. things to be edited) will reacquire CE_VALID bit
944 * automatically, which is not really what we want.
946 if (!ignore_valid && assume_unchanged &&
947 !(ce->ce_flags & CE_VALID))
948 updated->ce_flags &= ~CE_VALID;
950 return updated;
953 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
955 int i;
956 int has_errors = 0;
957 int really = (flags & REFRESH_REALLY) != 0;
958 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
959 int quiet = (flags & REFRESH_QUIET) != 0;
960 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
961 int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
962 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
964 for (i = 0; i < istate->cache_nr; i++) {
965 struct cache_entry *ce, *new;
966 int cache_errno = 0;
968 ce = istate->cache[i];
969 if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
970 continue;
972 if (ce_stage(ce)) {
973 while ((i < istate->cache_nr) &&
974 ! strcmp(istate->cache[i]->name, ce->name))
975 i++;
976 i--;
977 if (allow_unmerged)
978 continue;
979 printf("%s: needs merge\n", ce->name);
980 has_errors = 1;
981 continue;
984 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
985 continue;
987 new = refresh_cache_ent(istate, ce, options, &cache_errno);
988 if (new == ce)
989 continue;
990 if (!new) {
991 if (not_new && cache_errno == ENOENT)
992 continue;
993 if (really && cache_errno == EINVAL) {
994 /* If we are doing --really-refresh that
995 * means the index is not valid anymore.
997 ce->ce_flags &= ~CE_VALID;
998 istate->cache_changed = 1;
1000 if (quiet)
1001 continue;
1002 printf("%s: needs update\n", ce->name);
1003 has_errors = 1;
1004 continue;
1007 replace_index_entry(istate, i, new);
1009 return has_errors;
1012 struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
1014 return refresh_cache_ent(&the_index, ce, really, NULL);
1017 static int verify_hdr(struct cache_header *hdr, unsigned long size)
1019 SHA_CTX c;
1020 unsigned char sha1[20];
1022 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
1023 return error("bad signature");
1024 if (hdr->hdr_version != htonl(2))
1025 return error("bad index version");
1026 SHA1_Init(&c);
1027 SHA1_Update(&c, hdr, size - 20);
1028 SHA1_Final(sha1, &c);
1029 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1030 return error("bad index file sha1 signature");
1031 return 0;
1034 static int read_index_extension(struct index_state *istate,
1035 const char *ext, void *data, unsigned long sz)
1037 switch (CACHE_EXT(ext)) {
1038 case CACHE_EXT_TREE:
1039 istate->cache_tree = cache_tree_read(data, sz);
1040 break;
1041 default:
1042 if (*ext < 'A' || 'Z' < *ext)
1043 return error("index uses %.4s extension, which we do not understand",
1044 ext);
1045 fprintf(stderr, "ignoring %.4s extension\n", ext);
1046 break;
1048 return 0;
1051 int read_index(struct index_state *istate)
1053 return read_index_from(istate, get_index_file());
1056 static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
1058 size_t len;
1060 ce->ce_ctime = ntohl(ondisk->ctime.sec);
1061 ce->ce_mtime = ntohl(ondisk->mtime.sec);
1062 ce->ce_dev = ntohl(ondisk->dev);
1063 ce->ce_ino = ntohl(ondisk->ino);
1064 ce->ce_mode = ntohl(ondisk->mode);
1065 ce->ce_uid = ntohl(ondisk->uid);
1066 ce->ce_gid = ntohl(ondisk->gid);
1067 ce->ce_size = ntohl(ondisk->size);
1068 /* On-disk flags are just 16 bits */
1069 ce->ce_flags = ntohs(ondisk->flags);
1070 hashcpy(ce->sha1, ondisk->sha1);
1072 len = ce->ce_flags & CE_NAMEMASK;
1073 if (len == CE_NAMEMASK)
1074 len = strlen(ondisk->name);
1076 * NEEDSWORK: If the original index is crafted, this copy could
1077 * go unchecked.
1079 memcpy(ce->name, ondisk->name, len + 1);
1082 static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
1084 long per_entry;
1086 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
1089 * Alignment can cause differences. This should be "alignof", but
1090 * since that's a gcc'ism, just use the size of a pointer.
1092 per_entry += sizeof(void *);
1093 return ondisk_size + entries*per_entry;
1096 /* remember to discard_cache() before reading a different cache! */
1097 int read_index_from(struct index_state *istate, const char *path)
1099 int fd, i;
1100 struct stat st;
1101 unsigned long src_offset, dst_offset;
1102 struct cache_header *hdr;
1103 void *mmap;
1104 size_t mmap_size;
1106 errno = EBUSY;
1107 if (istate->alloc)
1108 return istate->cache_nr;
1110 errno = ENOENT;
1111 istate->timestamp = 0;
1112 fd = open(path, O_RDONLY);
1113 if (fd < 0) {
1114 if (errno == ENOENT)
1115 return 0;
1116 die("index file open failed (%s)", strerror(errno));
1119 if (fstat(fd, &st))
1120 die("cannot stat the open index (%s)", strerror(errno));
1122 errno = EINVAL;
1123 mmap_size = xsize_t(st.st_size);
1124 if (mmap_size < sizeof(struct cache_header) + 20)
1125 die("index file smaller than expected");
1127 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1128 close(fd);
1129 if (mmap == MAP_FAILED)
1130 die("unable to map index file");
1132 hdr = mmap;
1133 if (verify_hdr(hdr, mmap_size) < 0)
1134 goto unmap;
1136 istate->cache_nr = ntohl(hdr->hdr_entries);
1137 istate->cache_alloc = alloc_nr(istate->cache_nr);
1138 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1141 * The disk format is actually larger than the in-memory format,
1142 * due to space for nsec etc, so even though the in-memory one
1143 * has room for a few more flags, we can allocate using the same
1144 * index size
1146 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
1148 src_offset = sizeof(*hdr);
1149 dst_offset = 0;
1150 for (i = 0; i < istate->cache_nr; i++) {
1151 struct ondisk_cache_entry *disk_ce;
1152 struct cache_entry *ce;
1154 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1155 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
1156 convert_from_disk(disk_ce, ce);
1157 set_index_entry(istate, i, ce);
1159 src_offset += ondisk_ce_size(ce);
1160 dst_offset += ce_size(ce);
1162 istate->timestamp = st.st_mtime;
1163 while (src_offset <= mmap_size - 20 - 8) {
1164 /* After an array of active_nr index entries,
1165 * there can be arbitrary number of extended
1166 * sections, each of which is prefixed with
1167 * extension name (4-byte) and section length
1168 * in 4-byte network byte order.
1170 unsigned long extsize;
1171 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1172 extsize = ntohl(extsize);
1173 if (read_index_extension(istate,
1174 (const char *) mmap + src_offset,
1175 (char *) mmap + src_offset + 8,
1176 extsize) < 0)
1177 goto unmap;
1178 src_offset += 8;
1179 src_offset += extsize;
1181 munmap(mmap, mmap_size);
1182 return istate->cache_nr;
1184 unmap:
1185 munmap(mmap, mmap_size);
1186 errno = EINVAL;
1187 die("index file corrupt");
1190 int discard_index(struct index_state *istate)
1192 istate->cache_nr = 0;
1193 istate->cache_changed = 0;
1194 istate->timestamp = 0;
1195 free_hash(&istate->name_hash);
1196 cache_tree_free(&(istate->cache_tree));
1197 free(istate->alloc);
1198 istate->alloc = NULL;
1200 /* no need to throw away allocated active_cache */
1201 return 0;
1204 int unmerged_index(const struct index_state *istate)
1206 int i;
1207 for (i = 0; i < istate->cache_nr; i++) {
1208 if (ce_stage(istate->cache[i]))
1209 return 1;
1211 return 0;
1214 #define WRITE_BUFFER_SIZE 8192
1215 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1216 static unsigned long write_buffer_len;
1218 static int ce_write_flush(SHA_CTX *context, int fd)
1220 unsigned int buffered = write_buffer_len;
1221 if (buffered) {
1222 SHA1_Update(context, write_buffer, buffered);
1223 if (write_in_full(fd, write_buffer, buffered) != buffered)
1224 return -1;
1225 write_buffer_len = 0;
1227 return 0;
1230 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
1232 while (len) {
1233 unsigned int buffered = write_buffer_len;
1234 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1235 if (partial > len)
1236 partial = len;
1237 memcpy(write_buffer + buffered, data, partial);
1238 buffered += partial;
1239 if (buffered == WRITE_BUFFER_SIZE) {
1240 write_buffer_len = buffered;
1241 if (ce_write_flush(context, fd))
1242 return -1;
1243 buffered = 0;
1245 write_buffer_len = buffered;
1246 len -= partial;
1247 data = (char *) data + partial;
1249 return 0;
1252 static int write_index_ext_header(SHA_CTX *context, int fd,
1253 unsigned int ext, unsigned int sz)
1255 ext = htonl(ext);
1256 sz = htonl(sz);
1257 return ((ce_write(context, fd, &ext, 4) < 0) ||
1258 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1261 static int ce_flush(SHA_CTX *context, int fd)
1263 unsigned int left = write_buffer_len;
1265 if (left) {
1266 write_buffer_len = 0;
1267 SHA1_Update(context, write_buffer, left);
1270 /* Flush first if not enough space for SHA1 signature */
1271 if (left + 20 > WRITE_BUFFER_SIZE) {
1272 if (write_in_full(fd, write_buffer, left) != left)
1273 return -1;
1274 left = 0;
1277 /* Append the SHA1 signature at the end */
1278 SHA1_Final(write_buffer + left, context);
1279 left += 20;
1280 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1283 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1286 * The only thing we care about in this function is to smudge the
1287 * falsely clean entry due to touch-update-touch race, so we leave
1288 * everything else as they are. We are called for entries whose
1289 * ce_mtime match the index file mtime.
1291 struct stat st;
1293 if (lstat(ce->name, &st) < 0)
1294 return;
1295 if (ce_match_stat_basic(ce, &st))
1296 return;
1297 if (ce_modified_check_fs(ce, &st)) {
1298 /* This is "racily clean"; smudge it. Note that this
1299 * is a tricky code. At first glance, it may appear
1300 * that it can break with this sequence:
1302 * $ echo xyzzy >frotz
1303 * $ git-update-index --add frotz
1304 * $ : >frotz
1305 * $ sleep 3
1306 * $ echo filfre >nitfol
1307 * $ git-update-index --add nitfol
1309 * but it does not. When the second update-index runs,
1310 * it notices that the entry "frotz" has the same timestamp
1311 * as index, and if we were to smudge it by resetting its
1312 * size to zero here, then the object name recorded
1313 * in index is the 6-byte file but the cached stat information
1314 * becomes zero --- which would then match what we would
1315 * obtain from the filesystem next time we stat("frotz").
1317 * However, the second update-index, before calling
1318 * this function, notices that the cached size is 6
1319 * bytes and what is on the filesystem is an empty
1320 * file, and never calls us, so the cached size information
1321 * for "frotz" stays 6 which does not match the filesystem.
1323 ce->ce_size = 0;
1327 static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)
1329 int size = ondisk_ce_size(ce);
1330 struct ondisk_cache_entry *ondisk = xcalloc(1, size);
1332 ondisk->ctime.sec = htonl(ce->ce_ctime);
1333 ondisk->ctime.nsec = 0;
1334 ondisk->mtime.sec = htonl(ce->ce_mtime);
1335 ondisk->mtime.nsec = 0;
1336 ondisk->dev = htonl(ce->ce_dev);
1337 ondisk->ino = htonl(ce->ce_ino);
1338 ondisk->mode = htonl(ce->ce_mode);
1339 ondisk->uid = htonl(ce->ce_uid);
1340 ondisk->gid = htonl(ce->ce_gid);
1341 ondisk->size = htonl(ce->ce_size);
1342 hashcpy(ondisk->sha1, ce->sha1);
1343 ondisk->flags = htons(ce->ce_flags);
1344 memcpy(ondisk->name, ce->name, ce_namelen(ce));
1346 return ce_write(c, fd, ondisk, size);
1349 int write_index(const struct index_state *istate, int newfd)
1351 SHA_CTX c;
1352 struct cache_header hdr;
1353 int i, err, removed;
1354 struct cache_entry **cache = istate->cache;
1355 int entries = istate->cache_nr;
1357 for (i = removed = 0; i < entries; i++)
1358 if (cache[i]->ce_flags & CE_REMOVE)
1359 removed++;
1361 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1362 hdr.hdr_version = htonl(2);
1363 hdr.hdr_entries = htonl(entries - removed);
1365 SHA1_Init(&c);
1366 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1367 return -1;
1369 for (i = 0; i < entries; i++) {
1370 struct cache_entry *ce = cache[i];
1371 if (ce->ce_flags & CE_REMOVE)
1372 continue;
1373 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
1374 ce_smudge_racily_clean_entry(ce);
1375 if (ce_write_entry(&c, newfd, ce) < 0)
1376 return -1;
1379 /* Write extension data here */
1380 if (istate->cache_tree) {
1381 struct strbuf sb;
1383 strbuf_init(&sb, 0);
1384 cache_tree_write(&sb, istate->cache_tree);
1385 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1386 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1387 strbuf_release(&sb);
1388 if (err)
1389 return -1;
1391 return ce_flush(&c, newfd);