2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
6 #define NO_THE_INDEX_COMPATIBILITY_MACROS
8 #include "cache-tree.h"
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 unsigned int hash_name(const char *name, int namelen)
28 unsigned int hash = 0x123;
31 unsigned char c = *name++;
37 static void hash_index_entry(struct index_state *istate, struct cache_entry *ce)
42 if (ce->ce_flags & CE_HASHED)
44 ce->ce_flags |= CE_HASHED;
46 hash = hash_name(ce->name, ce_namelen(ce));
47 pos = insert_hash(hash, ce, &istate->name_hash);
54 static void lazy_init_name_hash(struct index_state *istate)
58 if (istate->name_hash_initialized)
60 for (nr = 0; nr < istate->cache_nr; nr++)
61 hash_index_entry(istate, istate->cache[nr]);
62 istate->name_hash_initialized = 1;
65 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
67 ce->ce_flags &= ~CE_UNHASHED;
68 istate->cache[nr] = ce;
69 if (istate->name_hash_initialized)
70 hash_index_entry(istate, ce);
74 * We don't actually *remove* it, we can just mark it invalid so that
75 * we won't find it in lookups.
77 * Not only would we have to search the lists (simple enough), but
78 * we'd also have to rehash other hash buckets in case this makes the
79 * hash bucket empty (common). So it's much better to just mark
82 static void remove_hash_entry(struct index_state *istate, struct cache_entry *ce)
84 ce->ce_flags |= CE_UNHASHED;
87 static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
89 struct cache_entry *old = istate->cache[nr];
91 remove_hash_entry(istate, old);
92 set_index_entry(istate, nr, ce);
93 istate->cache_changed = 1;
96 int index_name_exists(struct index_state *istate, const char *name, int namelen)
98 unsigned int hash = hash_name(name, namelen);
99 struct cache_entry *ce;
101 lazy_init_name_hash(istate);
102 ce = lookup_hash(hash, &istate->name_hash);
105 if (!(ce->ce_flags & CE_UNHASHED)) {
106 if (!cache_name_compare(name, namelen, ce->name, ce->ce_flags))
115 * This only updates the "non-critical" parts of the directory
116 * cache, ie the parts that aren't tracked by GIT, and only used
117 * to validate the cache.
119 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
121 ce->ce_ctime = st->st_ctime;
122 ce->ce_mtime = st->st_mtime;
123 ce->ce_dev = st->st_dev;
124 ce->ce_ino = st->st_ino;
125 ce->ce_uid = st->st_uid;
126 ce->ce_gid = st->st_gid;
127 ce->ce_size = st->st_size;
129 if (assume_unchanged)
130 ce->ce_flags |= CE_VALID;
132 if (S_ISREG(st->st_mode))
133 ce_mark_uptodate(ce);
136 static int ce_compare_data(struct cache_entry *ce, struct stat *st)
139 int fd = open(ce->name, O_RDONLY);
142 unsigned char sha1[20];
143 if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name))
144 match = hashcmp(sha1, ce->sha1);
145 /* index_fd() closed the file descriptor already */
150 static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
156 enum object_type type;
159 target = xmalloc(expected_size);
160 len = readlink(ce->name, target, expected_size);
161 if (len != expected_size) {
165 buffer = read_sha1_file(ce->sha1, &type, &size);
170 if (size == expected_size)
171 match = memcmp(buffer, target, size);
177 static int ce_compare_gitlink(struct cache_entry *ce)
179 unsigned char sha1[20];
182 * We don't actually require that the .git directory
183 * under GITLINK directory be a valid git directory. It
184 * might even be missing (in case nobody populated that
187 * If so, we consider it always to match.
189 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
191 return hashcmp(sha1, ce->sha1);
194 static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
196 switch (st->st_mode & S_IFMT) {
198 if (ce_compare_data(ce, st))
202 if (ce_compare_link(ce, xsize_t(st->st_size)))
206 if (S_ISGITLINK(ce->ce_mode))
214 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
216 unsigned int changed = 0;
218 if (ce->ce_flags & CE_REMOVE)
219 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
221 switch (ce->ce_mode & S_IFMT) {
223 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
224 /* We consider only the owner x bit to be relevant for
227 if (trust_executable_bit &&
228 (0100 & (ce->ce_mode ^ st->st_mode)))
229 changed |= MODE_CHANGED;
232 if (!S_ISLNK(st->st_mode) &&
233 (has_symlinks || !S_ISREG(st->st_mode)))
234 changed |= TYPE_CHANGED;
237 if (!S_ISDIR(st->st_mode))
238 changed |= TYPE_CHANGED;
239 else if (ce_compare_gitlink(ce))
240 changed |= DATA_CHANGED;
243 die("internal error: ce_mode is %o", ce->ce_mode);
245 if (ce->ce_mtime != (unsigned int) st->st_mtime)
246 changed |= MTIME_CHANGED;
247 if (ce->ce_ctime != (unsigned int) st->st_ctime)
248 changed |= CTIME_CHANGED;
250 if (ce->ce_uid != (unsigned int) st->st_uid ||
251 ce->ce_gid != (unsigned int) st->st_gid)
252 changed |= OWNER_CHANGED;
253 if (ce->ce_ino != (unsigned int) st->st_ino)
254 changed |= INODE_CHANGED;
258 * st_dev breaks on network filesystems where different
259 * clients will have different views of what "device"
260 * the filesystem is on
262 if (ce->ce_dev != (unsigned int) st->st_dev)
263 changed |= INODE_CHANGED;
266 if (ce->ce_size != (unsigned int) st->st_size)
267 changed |= DATA_CHANGED;
272 static int is_racy_timestamp(struct index_state *istate, struct cache_entry *ce)
274 return (istate->timestamp &&
275 ((unsigned int)istate->timestamp) <= ce->ce_mtime);
278 int ie_match_stat(struct index_state *istate,
279 struct cache_entry *ce, struct stat *st,
280 unsigned int options)
282 unsigned int changed;
283 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
284 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
287 * If it's marked as always valid in the index, it's
288 * valid whatever the checked-out copy says.
290 if (!ignore_valid && (ce->ce_flags & CE_VALID))
293 changed = ce_match_stat_basic(ce, st);
296 * Within 1 second of this sequence:
297 * echo xyzzy >file && git-update-index --add file
298 * running this command:
300 * would give a falsely clean cache entry. The mtime and
301 * length match the cache, and other stat fields do not change.
303 * We could detect this at update-index time (the cache entry
304 * being registered/updated records the same time as "now")
305 * and delay the return from git-update-index, but that would
306 * effectively mean we can make at most one commit per second,
307 * which is not acceptable. Instead, we check cache entries
308 * whose mtime are the same as the index file timestamp more
309 * carefully than others.
311 if (!changed && is_racy_timestamp(istate, ce)) {
312 if (assume_racy_is_modified)
313 changed |= DATA_CHANGED;
315 changed |= ce_modified_check_fs(ce, st);
321 int ie_modified(struct index_state *istate,
322 struct cache_entry *ce, struct stat *st, unsigned int options)
324 int changed, changed_fs;
326 changed = ie_match_stat(istate, ce, st, options);
330 * If the mode or type has changed, there's no point in trying
331 * to refresh the entry - it's not going to match
333 if (changed & (MODE_CHANGED | TYPE_CHANGED))
336 /* Immediately after read-tree or update-index --cacheinfo,
337 * the length field is zero. For other cases the ce_size
338 * should match the SHA1 recorded in the index entry.
340 if ((changed & DATA_CHANGED) && ce->ce_size != 0)
343 changed_fs = ce_modified_check_fs(ce, st);
345 return changed | changed_fs;
349 int base_name_compare(const char *name1, int len1, int mode1,
350 const char *name2, int len2, int mode2)
352 unsigned char c1, c2;
353 int len = len1 < len2 ? len1 : len2;
356 cmp = memcmp(name1, name2, len);
361 if (!c1 && S_ISDIR(mode1))
363 if (!c2 && S_ISDIR(mode2))
365 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
368 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
370 int len1 = flags1 & CE_NAMEMASK;
371 int len2 = flags2 & CE_NAMEMASK;
372 int len = len1 < len2 ? len1 : len2;
375 cmp = memcmp(name1, name2, len);
384 flags1 &= CE_STAGEMASK;
385 flags2 &= CE_STAGEMASK;
394 int index_name_pos(struct index_state *istate, const char *name, int namelen)
399 last = istate->cache_nr;
400 while (last > first) {
401 int next = (last + first) >> 1;
402 struct cache_entry *ce = istate->cache[next];
403 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags);
415 /* Remove entry, return true if there are more entries to go.. */
416 int remove_index_entry_at(struct index_state *istate, int pos)
418 struct cache_entry *ce = istate->cache[pos];
420 remove_hash_entry(istate, ce);
421 istate->cache_changed = 1;
423 if (pos >= istate->cache_nr)
425 memmove(istate->cache + pos,
426 istate->cache + pos + 1,
427 (istate->cache_nr - pos) * sizeof(struct cache_entry *));
431 int remove_file_from_index(struct index_state *istate, const char *path)
433 int pos = index_name_pos(istate, path, strlen(path));
436 cache_tree_invalidate_path(istate->cache_tree, path);
437 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
438 remove_index_entry_at(istate, pos);
442 static int compare_name(struct cache_entry *ce, const char *path, int namelen)
444 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
447 static int index_name_pos_also_unmerged(struct index_state *istate,
448 const char *path, int namelen)
450 int pos = index_name_pos(istate, path, namelen);
451 struct cache_entry *ce;
456 /* maybe unmerged? */
458 if (pos >= istate->cache_nr ||
459 compare_name((ce = istate->cache[pos]), path, namelen))
462 /* order of preference: stage 2, 1, 3 */
463 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
464 ce_stage((ce = istate->cache[pos + 1])) == 2 &&
465 !compare_name(ce, path, namelen))
470 int add_file_to_index(struct index_state *istate, const char *path, int verbose)
472 int size, namelen, pos;
474 struct cache_entry *ce;
475 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY;
477 if (lstat(path, &st))
478 die("%s: unable to stat (%s)", path, strerror(errno));
480 if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode))
481 die("%s: can only add regular files, symbolic links or git-directories", path);
483 namelen = strlen(path);
484 if (S_ISDIR(st.st_mode)) {
485 while (namelen && path[namelen-1] == '/')
488 size = cache_entry_size(namelen);
489 ce = xcalloc(1, size);
490 memcpy(ce->name, path, namelen);
491 ce->ce_flags = namelen;
492 fill_stat_cache_info(ce, &st);
494 if (trust_executable_bit && has_symlinks)
495 ce->ce_mode = create_ce_mode(st.st_mode);
497 /* If there is an existing entry, pick the mode bits and type
498 * from it, otherwise assume unexecutable regular file.
500 struct cache_entry *ent;
501 int pos = index_name_pos_also_unmerged(istate, path, namelen);
503 ent = (0 <= pos) ? istate->cache[pos] : NULL;
504 ce->ce_mode = ce_mode_from_stat(ent, st.st_mode);
507 pos = index_name_pos(istate, ce->name, namelen);
509 !ce_stage(istate->cache[pos]) &&
510 !ie_match_stat(istate, istate->cache[pos], &st, ce_option)) {
511 /* Nothing changed, really */
513 ce_mark_uptodate(istate->cache[pos]);
517 if (index_path(ce->sha1, path, &st, 1))
518 die("unable to index file %s", path);
519 if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
520 die("unable to add %s to index",path);
522 printf("add '%s'\n", path);
526 struct cache_entry *make_cache_entry(unsigned int mode,
527 const unsigned char *sha1, const char *path, int stage,
531 struct cache_entry *ce;
533 if (!verify_path(path))
537 size = cache_entry_size(len);
538 ce = xcalloc(1, size);
540 hashcpy(ce->sha1, sha1);
541 memcpy(ce->name, path, len);
542 ce->ce_flags = create_ce_flags(len, stage);
543 ce->ce_mode = create_ce_mode(mode);
546 return refresh_cache_entry(ce, 0);
551 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
553 int len = ce_namelen(a);
554 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
557 int ce_path_match(const struct cache_entry *ce, const char **pathspec)
559 const char *match, *name;
565 len = ce_namelen(ce);
567 while ((match = *pathspec++) != NULL) {
568 int matchlen = strlen(match);
571 if (memcmp(name, match, matchlen))
573 if (matchlen && name[matchlen-1] == '/')
575 if (name[matchlen] == '/' || !name[matchlen])
584 * We fundamentally don't like some paths: we don't want
585 * dot or dot-dot anywhere, and for obvious reasons don't
586 * want to recurse into ".git" either.
588 * Also, we don't want double slashes or slashes at the
589 * end that can make pathnames ambiguous.
591 static int verify_dotfile(const char *rest)
594 * The first character was '.', but that
595 * has already been discarded, we now test
599 /* "." is not allowed */
604 * ".git" followed by NUL or slash is bad. This
605 * shares the path end test with the ".." case.
615 if (rest[1] == '\0' || rest[1] == '/')
621 int verify_path(const char *path)
638 if (verify_dotfile(path))
648 * Do we have another file that has the beginning components being a
649 * proper superset of the name we're trying to add?
651 static int has_file_name(struct index_state *istate,
652 const struct cache_entry *ce, int pos, int ok_to_replace)
655 int len = ce_namelen(ce);
656 int stage = ce_stage(ce);
657 const char *name = ce->name;
659 while (pos < istate->cache_nr) {
660 struct cache_entry *p = istate->cache[pos++];
662 if (len >= ce_namelen(p))
664 if (memcmp(name, p->name, len))
666 if (ce_stage(p) != stage)
668 if (p->name[len] != '/')
670 if (p->ce_flags & CE_REMOVE)
675 remove_index_entry_at(istate, --pos);
681 * Do we have another file with a pathname that is a proper
682 * subset of the name we're trying to add?
684 static int has_dir_name(struct index_state *istate,
685 const struct cache_entry *ce, int pos, int ok_to_replace)
688 int stage = ce_stage(ce);
689 const char *name = ce->name;
690 const char *slash = name + ce_namelen(ce);
698 if (slash <= ce->name)
703 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
706 * Found one, but not so fast. This could
707 * be a marker that says "I was here, but
708 * I am being removed". Such an entry is
709 * not a part of the resulting tree, and
710 * it is Ok to have a directory at the same
713 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
717 remove_index_entry_at(istate, pos);
725 * Trivial optimization: if we find an entry that
726 * already matches the sub-directory, then we know
727 * we're ok, and we can exit.
729 while (pos < istate->cache_nr) {
730 struct cache_entry *p = istate->cache[pos];
731 if ((ce_namelen(p) <= len) ||
732 (p->name[len] != '/') ||
733 memcmp(p->name, name, len))
734 break; /* not our subdirectory */
735 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
737 * p is at the same stage as our entry, and
738 * is a subdirectory of what we are looking
739 * at, so we cannot have conflicts at our
740 * level or anything shorter.
749 /* We may be in a situation where we already have path/file and path
750 * is being added, or we already have path and path/file is being
751 * added. Either one would result in a nonsense tree that has path
752 * twice when git-write-tree tries to write it out. Prevent it.
754 * If ok-to-replace is specified, we remove the conflicting entries
755 * from the cache so the caller should recompute the insert position.
756 * When this happens, we return non-zero.
758 static int check_file_directory_conflict(struct index_state *istate,
759 const struct cache_entry *ce,
760 int pos, int ok_to_replace)
765 * When ce is an "I am going away" entry, we allow it to be added
767 if (ce->ce_flags & CE_REMOVE)
771 * We check if the path is a sub-path of a subsequent pathname
772 * first, since removing those will not change the position
775 retval = has_file_name(istate, ce, pos, ok_to_replace);
778 * Then check if the path might have a clashing sub-directory
781 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
784 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
787 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
788 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
789 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
791 cache_tree_invalidate_path(istate->cache_tree, ce->name);
792 pos = index_name_pos(istate, ce->name, ce->ce_flags);
794 /* existing match? Just replace it. */
796 replace_index_entry(istate, pos, ce);
802 * Inserting a merged entry ("stage 0") into the index
803 * will always replace all non-merged entries..
805 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
806 while (ce_same_name(istate->cache[pos], ce)) {
808 if (!remove_index_entry_at(istate, pos))
815 if (!verify_path(ce->name))
818 if (!skip_df_check &&
819 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
821 return error("'%s' appears as both a file and as a directory",
823 pos = index_name_pos(istate, ce->name, ce->ce_flags);
829 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
833 if (option & ADD_CACHE_JUST_APPEND)
834 pos = istate->cache_nr;
837 ret = add_index_entry_with_check(istate, ce, option);
843 /* Make sure the array is big enough .. */
844 if (istate->cache_nr == istate->cache_alloc) {
845 istate->cache_alloc = alloc_nr(istate->cache_alloc);
846 istate->cache = xrealloc(istate->cache,
847 istate->cache_alloc * sizeof(struct cache_entry *));
852 if (istate->cache_nr > pos + 1)
853 memmove(istate->cache + pos + 1,
855 (istate->cache_nr - pos - 1) * sizeof(ce));
856 set_index_entry(istate, pos, ce);
857 istate->cache_changed = 1;
862 * "refresh" does not calculate a new sha1 file or bring the
863 * cache up-to-date for mode/content changes. But what it
864 * _does_ do is to "re-match" the stat information of a file
865 * with the cache, so that you can refresh the cache for a
866 * file that hasn't been changed but where the stat entry is
869 * For example, you'd want to do this after doing a "git-read-tree",
870 * to link up the stat cache details with the proper files.
872 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
873 struct cache_entry *ce,
874 unsigned int options, int *err)
877 struct cache_entry *updated;
879 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
884 if (lstat(ce->name, &st) < 0) {
890 changed = ie_match_stat(istate, ce, &st, options);
893 * The path is unchanged. If we were told to ignore
894 * valid bit, then we did the actual stat check and
895 * found that the entry is unmodified. If the entry
896 * is not marked VALID, this is the place to mark it
897 * valid again, under "assume unchanged" mode.
899 if (ignore_valid && assume_unchanged &&
900 !(ce->ce_flags & CE_VALID))
901 ; /* mark this one VALID again */
904 * We do not mark the index itself "modified"
905 * because CE_UPTODATE flag is in-core only;
906 * we are not going to write this change out.
908 ce_mark_uptodate(ce);
913 if (ie_modified(istate, ce, &st, options)) {
920 updated = xmalloc(size);
921 memcpy(updated, ce, size);
922 fill_stat_cache_info(updated, &st);
924 * If ignore_valid is not set, we should leave CE_VALID bit
925 * alone. Otherwise, paths marked with --no-assume-unchanged
926 * (i.e. things to be edited) will reacquire CE_VALID bit
927 * automatically, which is not really what we want.
929 if (!ignore_valid && assume_unchanged &&
930 !(ce->ce_flags & CE_VALID))
931 updated->ce_flags &= ~CE_VALID;
936 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
940 int really = (flags & REFRESH_REALLY) != 0;
941 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
942 int quiet = (flags & REFRESH_QUIET) != 0;
943 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
944 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
946 for (i = 0; i < istate->cache_nr; i++) {
947 struct cache_entry *ce, *new;
950 ce = istate->cache[i];
952 while ((i < istate->cache_nr) &&
953 ! strcmp(istate->cache[i]->name, ce->name))
958 printf("%s: needs merge\n", ce->name);
963 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
966 new = refresh_cache_ent(istate, ce, options, &cache_errno);
970 if (not_new && cache_errno == ENOENT)
972 if (really && cache_errno == EINVAL) {
973 /* If we are doing --really-refresh that
974 * means the index is not valid anymore.
976 ce->ce_flags &= ~CE_VALID;
977 istate->cache_changed = 1;
981 printf("%s: needs update\n", ce->name);
986 replace_index_entry(istate, i, new);
991 struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
993 return refresh_cache_ent(&the_index, ce, really, NULL);
996 static int verify_hdr(struct cache_header *hdr, unsigned long size)
999 unsigned char sha1[20];
1001 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
1002 return error("bad signature");
1003 if (hdr->hdr_version != htonl(2))
1004 return error("bad index version");
1006 SHA1_Update(&c, hdr, size - 20);
1007 SHA1_Final(sha1, &c);
1008 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1009 return error("bad index file sha1 signature");
1013 static int read_index_extension(struct index_state *istate,
1014 const char *ext, void *data, unsigned long sz)
1016 switch (CACHE_EXT(ext)) {
1017 case CACHE_EXT_TREE:
1018 istate->cache_tree = cache_tree_read(data, sz);
1021 if (*ext < 'A' || 'Z' < *ext)
1022 return error("index uses %.4s extension, which we do not understand",
1024 fprintf(stderr, "ignoring %.4s extension\n", ext);
1030 int read_index(struct index_state *istate)
1032 return read_index_from(istate, get_index_file());
1035 static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
1039 ce->ce_ctime = ntohl(ondisk->ctime.sec);
1040 ce->ce_mtime = ntohl(ondisk->mtime.sec);
1041 ce->ce_dev = ntohl(ondisk->dev);
1042 ce->ce_ino = ntohl(ondisk->ino);
1043 ce->ce_mode = ntohl(ondisk->mode);
1044 ce->ce_uid = ntohl(ondisk->uid);
1045 ce->ce_gid = ntohl(ondisk->gid);
1046 ce->ce_size = ntohl(ondisk->size);
1047 /* On-disk flags are just 16 bits */
1048 ce->ce_flags = ntohs(ondisk->flags);
1049 hashcpy(ce->sha1, ondisk->sha1);
1051 len = ce->ce_flags & CE_NAMEMASK;
1052 if (len == CE_NAMEMASK)
1053 len = strlen(ondisk->name);
1055 * NEEDSWORK: If the original index is crafted, this copy could
1058 memcpy(ce->name, ondisk->name, len + 1);
1061 static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
1065 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
1068 * Alignment can cause differences. This should be "alignof", but
1069 * since that's a gcc'ism, just use the size of a pointer.
1071 per_entry += sizeof(void *);
1072 return ondisk_size + entries*per_entry;
1075 /* remember to discard_cache() before reading a different cache! */
1076 int read_index_from(struct index_state *istate, const char *path)
1080 unsigned long src_offset, dst_offset;
1081 struct cache_header *hdr;
1087 return istate->cache_nr;
1090 istate->timestamp = 0;
1091 fd = open(path, O_RDONLY);
1093 if (errno == ENOENT)
1095 die("index file open failed (%s)", strerror(errno));
1099 die("cannot stat the open index (%s)", strerror(errno));
1102 mmap_size = xsize_t(st.st_size);
1103 if (mmap_size < sizeof(struct cache_header) + 20)
1104 die("index file smaller than expected");
1106 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1108 if (mmap == MAP_FAILED)
1109 die("unable to map index file");
1112 if (verify_hdr(hdr, mmap_size) < 0)
1115 istate->cache_nr = ntohl(hdr->hdr_entries);
1116 istate->cache_alloc = alloc_nr(istate->cache_nr);
1117 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1120 * The disk format is actually larger than the in-memory format,
1121 * due to space for nsec etc, so even though the in-memory one
1122 * has room for a few more flags, we can allocate using the same
1125 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
1127 src_offset = sizeof(*hdr);
1129 for (i = 0; i < istate->cache_nr; i++) {
1130 struct ondisk_cache_entry *disk_ce;
1131 struct cache_entry *ce;
1133 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1134 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
1135 convert_from_disk(disk_ce, ce);
1136 set_index_entry(istate, i, ce);
1138 src_offset += ondisk_ce_size(ce);
1139 dst_offset += ce_size(ce);
1141 istate->timestamp = st.st_mtime;
1142 while (src_offset <= mmap_size - 20 - 8) {
1143 /* After an array of active_nr index entries,
1144 * there can be arbitrary number of extended
1145 * sections, each of which is prefixed with
1146 * extension name (4-byte) and section length
1147 * in 4-byte network byte order.
1149 unsigned long extsize;
1150 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1151 extsize = ntohl(extsize);
1152 if (read_index_extension(istate,
1153 (const char *) mmap + src_offset,
1154 (char *) mmap + src_offset + 8,
1158 src_offset += extsize;
1160 munmap(mmap, mmap_size);
1161 return istate->cache_nr;
1164 munmap(mmap, mmap_size);
1166 die("index file corrupt");
1169 int discard_index(struct index_state *istate)
1171 istate->cache_nr = 0;
1172 istate->cache_changed = 0;
1173 istate->timestamp = 0;
1174 free_hash(&istate->name_hash);
1175 cache_tree_free(&(istate->cache_tree));
1176 free(istate->alloc);
1177 istate->alloc = NULL;
1179 /* no need to throw away allocated active_cache */
1183 #define WRITE_BUFFER_SIZE 8192
1184 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1185 static unsigned long write_buffer_len;
1187 static int ce_write_flush(SHA_CTX *context, int fd)
1189 unsigned int buffered = write_buffer_len;
1191 SHA1_Update(context, write_buffer, buffered);
1192 if (write_in_full(fd, write_buffer, buffered) != buffered)
1194 write_buffer_len = 0;
1199 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
1202 unsigned int buffered = write_buffer_len;
1203 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1206 memcpy(write_buffer + buffered, data, partial);
1207 buffered += partial;
1208 if (buffered == WRITE_BUFFER_SIZE) {
1209 write_buffer_len = buffered;
1210 if (ce_write_flush(context, fd))
1214 write_buffer_len = buffered;
1216 data = (char *) data + partial;
1221 static int write_index_ext_header(SHA_CTX *context, int fd,
1222 unsigned int ext, unsigned int sz)
1226 return ((ce_write(context, fd, &ext, 4) < 0) ||
1227 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1230 static int ce_flush(SHA_CTX *context, int fd)
1232 unsigned int left = write_buffer_len;
1235 write_buffer_len = 0;
1236 SHA1_Update(context, write_buffer, left);
1239 /* Flush first if not enough space for SHA1 signature */
1240 if (left + 20 > WRITE_BUFFER_SIZE) {
1241 if (write_in_full(fd, write_buffer, left) != left)
1246 /* Append the SHA1 signature at the end */
1247 SHA1_Final(write_buffer + left, context);
1249 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1252 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1255 * The only thing we care about in this function is to smudge the
1256 * falsely clean entry due to touch-update-touch race, so we leave
1257 * everything else as they are. We are called for entries whose
1258 * ce_mtime match the index file mtime.
1262 if (lstat(ce->name, &st) < 0)
1264 if (ce_match_stat_basic(ce, &st))
1266 if (ce_modified_check_fs(ce, &st)) {
1267 /* This is "racily clean"; smudge it. Note that this
1268 * is a tricky code. At first glance, it may appear
1269 * that it can break with this sequence:
1271 * $ echo xyzzy >frotz
1272 * $ git-update-index --add frotz
1275 * $ echo filfre >nitfol
1276 * $ git-update-index --add nitfol
1278 * but it does not. When the second update-index runs,
1279 * it notices that the entry "frotz" has the same timestamp
1280 * as index, and if we were to smudge it by resetting its
1281 * size to zero here, then the object name recorded
1282 * in index is the 6-byte file but the cached stat information
1283 * becomes zero --- which would then match what we would
1284 * obtain from the filesystem next time we stat("frotz").
1286 * However, the second update-index, before calling
1287 * this function, notices that the cached size is 6
1288 * bytes and what is on the filesystem is an empty
1289 * file, and never calls us, so the cached size information
1290 * for "frotz" stays 6 which does not match the filesystem.
1296 static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)
1298 int size = ondisk_ce_size(ce);
1299 struct ondisk_cache_entry *ondisk = xcalloc(1, size);
1301 ondisk->ctime.sec = htonl(ce->ce_ctime);
1302 ondisk->ctime.nsec = 0;
1303 ondisk->mtime.sec = htonl(ce->ce_mtime);
1304 ondisk->mtime.nsec = 0;
1305 ondisk->dev = htonl(ce->ce_dev);
1306 ondisk->ino = htonl(ce->ce_ino);
1307 ondisk->mode = htonl(ce->ce_mode);
1308 ondisk->uid = htonl(ce->ce_uid);
1309 ondisk->gid = htonl(ce->ce_gid);
1310 ondisk->size = htonl(ce->ce_size);
1311 hashcpy(ondisk->sha1, ce->sha1);
1312 ondisk->flags = htons(ce->ce_flags);
1313 memcpy(ondisk->name, ce->name, ce_namelen(ce));
1315 return ce_write(c, fd, ondisk, size);
1318 int write_index(struct index_state *istate, int newfd)
1321 struct cache_header hdr;
1322 int i, err, removed;
1323 struct cache_entry **cache = istate->cache;
1324 int entries = istate->cache_nr;
1326 for (i = removed = 0; i < entries; i++)
1327 if (cache[i]->ce_flags & CE_REMOVE)
1330 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1331 hdr.hdr_version = htonl(2);
1332 hdr.hdr_entries = htonl(entries - removed);
1335 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1338 for (i = 0; i < entries; i++) {
1339 struct cache_entry *ce = cache[i];
1340 if (ce->ce_flags & CE_REMOVE)
1342 if (is_racy_timestamp(istate, ce))
1343 ce_smudge_racily_clean_entry(ce);
1344 if (ce_write_entry(&c, newfd, ce) < 0)
1348 /* Write extension data here */
1349 if (istate->cache_tree) {
1352 strbuf_init(&sb, 0);
1353 cache_tree_write(&sb, istate->cache_tree);
1354 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1355 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1356 strbuf_release(&sb);
1360 return ce_flush(&c, newfd);