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;
27 * This only updates the "non-critical" parts of the directory
28 * cache, ie the parts that aren't tracked by GIT, and only used
29 * to validate the cache.
31 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
33 ce->ce_ctime.sec = htonl(st->st_ctime);
34 ce->ce_mtime.sec = htonl(st->st_mtime);
36 ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
37 ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
39 ce->ce_dev = htonl(st->st_dev);
40 ce->ce_ino = htonl(st->st_ino);
41 ce->ce_uid = htonl(st->st_uid);
42 ce->ce_gid = htonl(st->st_gid);
43 ce->ce_size = htonl(st->st_size);
46 ce->ce_flags |= htons(CE_VALID);
49 static int ce_compare_data(struct cache_entry *ce, struct stat *st)
52 int fd = open(ce->name, O_RDONLY);
55 unsigned char sha1[20];
56 if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name))
57 match = hashcmp(sha1, ce->sha1);
58 /* index_fd() closed the file descriptor already */
63 static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
69 enum object_type type;
72 target = xmalloc(expected_size);
73 len = readlink(ce->name, target, expected_size);
74 if (len != expected_size) {
78 buffer = read_sha1_file(ce->sha1, &type, &size);
83 if (size == expected_size)
84 match = memcmp(buffer, target, size);
90 static int ce_compare_gitlink(struct cache_entry *ce)
92 unsigned char sha1[20];
95 * We don't actually require that the .git directory
96 * under GITLINK directory be a valid git directory. It
97 * might even be missing (in case nobody populated that
100 * If so, we consider it always to match.
102 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
104 return hashcmp(sha1, ce->sha1);
107 static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
109 switch (st->st_mode & S_IFMT) {
111 if (ce_compare_data(ce, st))
115 if (ce_compare_link(ce, xsize_t(st->st_size)))
119 if (S_ISGITLINK(ntohl(ce->ce_mode)))
127 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
129 unsigned int changed = 0;
131 switch (ntohl(ce->ce_mode) & S_IFMT) {
133 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
134 /* We consider only the owner x bit to be relevant for
137 if (trust_executable_bit &&
138 (0100 & (ntohl(ce->ce_mode) ^ st->st_mode)))
139 changed |= MODE_CHANGED;
142 if (!S_ISLNK(st->st_mode) &&
143 (has_symlinks || !S_ISREG(st->st_mode)))
144 changed |= TYPE_CHANGED;
147 if (!S_ISDIR(st->st_mode))
148 changed |= TYPE_CHANGED;
149 else if (ce_compare_gitlink(ce))
150 changed |= DATA_CHANGED;
152 case 0: /* Special case: unmerged file in index */
153 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
155 die("internal error: ce_mode is %o", ntohl(ce->ce_mode));
157 if (ce->ce_mtime.sec != htonl(st->st_mtime))
158 changed |= MTIME_CHANGED;
159 if (ce->ce_ctime.sec != htonl(st->st_ctime))
160 changed |= CTIME_CHANGED;
164 * nsec seems unreliable - not all filesystems support it, so
165 * as long as it is in the inode cache you get right nsec
166 * but after it gets flushed, you get zero nsec.
168 if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec))
169 changed |= MTIME_CHANGED;
170 if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec))
171 changed |= CTIME_CHANGED;
174 if (ce->ce_uid != htonl(st->st_uid) ||
175 ce->ce_gid != htonl(st->st_gid))
176 changed |= OWNER_CHANGED;
177 if (ce->ce_ino != htonl(st->st_ino))
178 changed |= INODE_CHANGED;
182 * st_dev breaks on network filesystems where different
183 * clients will have different views of what "device"
184 * the filesystem is on
186 if (ce->ce_dev != htonl(st->st_dev))
187 changed |= INODE_CHANGED;
190 if (ce->ce_size != htonl(st->st_size))
191 changed |= DATA_CHANGED;
196 int ie_match_stat(struct index_state *istate,
197 struct cache_entry *ce, struct stat *st,
198 unsigned int options)
200 unsigned int changed;
201 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
202 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
205 * If it's marked as always valid in the index, it's
206 * valid whatever the checked-out copy says.
208 if (!ignore_valid && (ce->ce_flags & htons(CE_VALID)))
211 changed = ce_match_stat_basic(ce, st);
214 * Within 1 second of this sequence:
215 * echo xyzzy >file && git-update-index --add file
216 * running this command:
218 * would give a falsely clean cache entry. The mtime and
219 * length match the cache, and other stat fields do not change.
221 * We could detect this at update-index time (the cache entry
222 * being registered/updated records the same time as "now")
223 * and delay the return from git-update-index, but that would
224 * effectively mean we can make at most one commit per second,
225 * which is not acceptable. Instead, we check cache entries
226 * whose mtime are the same as the index file timestamp more
227 * carefully than others.
231 istate->timestamp <= ntohl(ce->ce_mtime.sec)) {
232 if (assume_racy_is_modified)
233 changed |= DATA_CHANGED;
235 changed |= ce_modified_check_fs(ce, st);
241 int ie_modified(struct index_state *istate,
242 struct cache_entry *ce, struct stat *st, unsigned int options)
244 int changed, changed_fs;
246 changed = ie_match_stat(istate, ce, st, options);
250 * If the mode or type has changed, there's no point in trying
251 * to refresh the entry - it's not going to match
253 if (changed & (MODE_CHANGED | TYPE_CHANGED))
256 /* Immediately after read-tree or update-index --cacheinfo,
257 * the length field is zero. For other cases the ce_size
258 * should match the SHA1 recorded in the index entry.
260 if ((changed & DATA_CHANGED) && ce->ce_size != htonl(0))
263 changed_fs = ce_modified_check_fs(ce, st);
265 return changed | changed_fs;
269 int base_name_compare(const char *name1, int len1, int mode1,
270 const char *name2, int len2, int mode2)
272 unsigned char c1, c2;
273 int len = len1 < len2 ? len1 : len2;
276 cmp = memcmp(name1, name2, len);
281 if (!c1 && S_ISDIR(mode1))
283 if (!c2 && S_ISDIR(mode2))
285 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
288 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
290 int len1 = flags1 & CE_NAMEMASK;
291 int len2 = flags2 & CE_NAMEMASK;
292 int len = len1 < len2 ? len1 : len2;
295 cmp = memcmp(name1, name2, len);
304 flags1 &= CE_STAGEMASK;
305 flags2 &= CE_STAGEMASK;
314 int index_name_pos(struct index_state *istate, const char *name, int namelen)
319 last = istate->cache_nr;
320 while (last > first) {
321 int next = (last + first) >> 1;
322 struct cache_entry *ce = istate->cache[next];
323 int cmp = cache_name_compare(name, namelen, ce->name, ntohs(ce->ce_flags));
335 /* Remove entry, return true if there are more entries to go.. */
336 int remove_index_entry_at(struct index_state *istate, int pos)
338 istate->cache_changed = 1;
340 if (pos >= istate->cache_nr)
342 memmove(istate->cache + pos,
343 istate->cache + pos + 1,
344 (istate->cache_nr - pos) * sizeof(struct cache_entry *));
348 int remove_file_from_index(struct index_state *istate, const char *path)
350 int pos = index_name_pos(istate, path, strlen(path));
353 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
354 remove_index_entry_at(istate, pos);
358 static int compare_name(struct cache_entry *ce, const char *path, int namelen)
360 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
363 static int index_name_pos_also_unmerged(struct index_state *istate,
364 const char *path, int namelen)
366 int pos = index_name_pos(istate, path, namelen);
367 struct cache_entry *ce;
372 /* maybe unmerged? */
374 if (pos >= istate->cache_nr ||
375 compare_name((ce = istate->cache[pos]), path, namelen))
378 /* order of preference: stage 2, 1, 3 */
379 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
380 ce_stage((ce = istate->cache[pos + 1])) == 2 &&
381 !compare_name(ce, path, namelen))
386 int add_file_to_index(struct index_state *istate, const char *path, int verbose)
388 int size, namelen, pos;
390 struct cache_entry *ce;
391 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY;
393 if (lstat(path, &st))
394 die("%s: unable to stat (%s)", path, strerror(errno));
396 if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode))
397 die("%s: can only add regular files, symbolic links or git-directories", path);
399 namelen = strlen(path);
400 if (S_ISDIR(st.st_mode)) {
401 while (namelen && path[namelen-1] == '/')
404 size = cache_entry_size(namelen);
405 ce = xcalloc(1, size);
406 memcpy(ce->name, path, namelen);
407 ce->ce_flags = htons(namelen);
408 fill_stat_cache_info(ce, &st);
410 if (trust_executable_bit && has_symlinks)
411 ce->ce_mode = create_ce_mode(st.st_mode);
413 /* If there is an existing entry, pick the mode bits and type
414 * from it, otherwise assume unexecutable regular file.
416 struct cache_entry *ent;
417 int pos = index_name_pos_also_unmerged(istate, path, namelen);
419 ent = (0 <= pos) ? istate->cache[pos] : NULL;
420 ce->ce_mode = ce_mode_from_stat(ent, st.st_mode);
423 pos = index_name_pos(istate, ce->name, namelen);
425 !ce_stage(istate->cache[pos]) &&
426 !ie_match_stat(istate, istate->cache[pos], &st, ce_option)) {
427 /* Nothing changed, really */
432 if (index_path(ce->sha1, path, &st, 1))
433 die("unable to index file %s", path);
434 if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
435 die("unable to add %s to index",path);
437 printf("add '%s'\n", path);
438 cache_tree_invalidate_path(istate->cache_tree, path);
442 struct cache_entry *make_cache_entry(unsigned int mode,
443 const unsigned char *sha1, const char *path, int stage,
447 struct cache_entry *ce;
449 if (!verify_path(path))
453 size = cache_entry_size(len);
454 ce = xcalloc(1, size);
456 hashcpy(ce->sha1, sha1);
457 memcpy(ce->name, path, len);
458 ce->ce_flags = create_ce_flags(len, stage);
459 ce->ce_mode = create_ce_mode(mode);
462 return refresh_cache_entry(ce, 0);
467 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
469 int len = ce_namelen(a);
470 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
473 int ce_path_match(const struct cache_entry *ce, const char **pathspec)
475 const char *match, *name;
481 len = ce_namelen(ce);
483 while ((match = *pathspec++) != NULL) {
484 int matchlen = strlen(match);
487 if (memcmp(name, match, matchlen))
489 if (matchlen && name[matchlen-1] == '/')
491 if (name[matchlen] == '/' || !name[matchlen])
500 * We fundamentally don't like some paths: we don't want
501 * dot or dot-dot anywhere, and for obvious reasons don't
502 * want to recurse into ".git" either.
504 * Also, we don't want double slashes or slashes at the
505 * end that can make pathnames ambiguous.
507 static int verify_dotfile(const char *rest)
510 * The first character was '.', but that
511 * has already been discarded, we now test
515 /* "." is not allowed */
520 * ".git" followed by NUL or slash is bad. This
521 * shares the path end test with the ".." case.
531 if (rest[1] == '\0' || rest[1] == '/')
537 int verify_path(const char *path)
554 if (verify_dotfile(path))
564 * Do we have another file that has the beginning components being a
565 * proper superset of the name we're trying to add?
567 static int has_file_name(struct index_state *istate,
568 const struct cache_entry *ce, int pos, int ok_to_replace)
571 int len = ce_namelen(ce);
572 int stage = ce_stage(ce);
573 const char *name = ce->name;
575 while (pos < istate->cache_nr) {
576 struct cache_entry *p = istate->cache[pos++];
578 if (len >= ce_namelen(p))
580 if (memcmp(name, p->name, len))
582 if (ce_stage(p) != stage)
584 if (p->name[len] != '/')
586 if (!ce_stage(p) && !p->ce_mode)
591 remove_index_entry_at(istate, --pos);
597 * Do we have another file with a pathname that is a proper
598 * subset of the name we're trying to add?
600 static int has_dir_name(struct index_state *istate,
601 const struct cache_entry *ce, int pos, int ok_to_replace)
604 int stage = ce_stage(ce);
605 const char *name = ce->name;
606 const char *slash = name + ce_namelen(ce);
614 if (slash <= ce->name)
619 pos = index_name_pos(istate, name, ntohs(create_ce_flags(len, stage)));
622 * Found one, but not so fast. This could
623 * be a marker that says "I was here, but
624 * I am being removed". Such an entry is
625 * not a part of the resulting tree, and
626 * it is Ok to have a directory at the same
629 if (stage || istate->cache[pos]->ce_mode) {
633 remove_index_entry_at(istate, pos);
641 * Trivial optimization: if we find an entry that
642 * already matches the sub-directory, then we know
643 * we're ok, and we can exit.
645 while (pos < istate->cache_nr) {
646 struct cache_entry *p = istate->cache[pos];
647 if ((ce_namelen(p) <= len) ||
648 (p->name[len] != '/') ||
649 memcmp(p->name, name, len))
650 break; /* not our subdirectory */
651 if (ce_stage(p) == stage && (stage || p->ce_mode))
652 /* p is at the same stage as our entry, and
653 * is a subdirectory of what we are looking
654 * at, so we cannot have conflicts at our
655 * level or anything shorter.
664 /* We may be in a situation where we already have path/file and path
665 * is being added, or we already have path and path/file is being
666 * added. Either one would result in a nonsense tree that has path
667 * twice when git-write-tree tries to write it out. Prevent it.
669 * If ok-to-replace is specified, we remove the conflicting entries
670 * from the cache so the caller should recompute the insert position.
671 * When this happens, we return non-zero.
673 static int check_file_directory_conflict(struct index_state *istate,
674 const struct cache_entry *ce,
675 int pos, int ok_to_replace)
680 * When ce is an "I am going away" entry, we allow it to be added
682 if (!ce_stage(ce) && !ce->ce_mode)
686 * We check if the path is a sub-path of a subsequent pathname
687 * first, since removing those will not change the position
690 retval = has_file_name(istate, ce, pos, ok_to_replace);
693 * Then check if the path might have a clashing sub-directory
696 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
699 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
702 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
703 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
704 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
706 pos = index_name_pos(istate, ce->name, ntohs(ce->ce_flags));
708 /* existing match? Just replace it. */
710 istate->cache_changed = 1;
711 istate->cache[pos] = ce;
717 * Inserting a merged entry ("stage 0") into the index
718 * will always replace all non-merged entries..
720 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
721 while (ce_same_name(istate->cache[pos], ce)) {
723 if (!remove_index_entry_at(istate, pos))
730 if (!verify_path(ce->name))
733 if (!skip_df_check &&
734 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
736 return error("'%s' appears as both a file and as a directory",
738 pos = index_name_pos(istate, ce->name, ntohs(ce->ce_flags));
744 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
748 if (option & ADD_CACHE_JUST_APPEND)
749 pos = istate->cache_nr;
752 ret = add_index_entry_with_check(istate, ce, option);
758 /* Make sure the array is big enough .. */
759 if (istate->cache_nr == istate->cache_alloc) {
760 istate->cache_alloc = alloc_nr(istate->cache_alloc);
761 istate->cache = xrealloc(istate->cache,
762 istate->cache_alloc * sizeof(struct cache_entry *));
767 if (istate->cache_nr > pos + 1)
768 memmove(istate->cache + pos + 1,
770 (istate->cache_nr - pos - 1) * sizeof(ce));
771 istate->cache[pos] = ce;
772 istate->cache_changed = 1;
777 * "refresh" does not calculate a new sha1 file or bring the
778 * cache up-to-date for mode/content changes. But what it
779 * _does_ do is to "re-match" the stat information of a file
780 * with the cache, so that you can refresh the cache for a
781 * file that hasn't been changed but where the stat entry is
784 * For example, you'd want to do this after doing a "git-read-tree",
785 * to link up the stat cache details with the proper files.
787 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
788 struct cache_entry *ce,
789 unsigned int options, int *err)
792 struct cache_entry *updated;
794 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
796 if (lstat(ce->name, &st) < 0) {
802 changed = ie_match_stat(istate, ce, &st, options);
805 * The path is unchanged. If we were told to ignore
806 * valid bit, then we did the actual stat check and
807 * found that the entry is unmodified. If the entry
808 * is not marked VALID, this is the place to mark it
809 * valid again, under "assume unchanged" mode.
811 if (ignore_valid && assume_unchanged &&
812 !(ce->ce_flags & htons(CE_VALID)))
813 ; /* mark this one VALID again */
818 if (ie_modified(istate, ce, &st, options)) {
825 updated = xmalloc(size);
826 memcpy(updated, ce, size);
827 fill_stat_cache_info(updated, &st);
830 * If ignore_valid is not set, we should leave CE_VALID bit
831 * alone. Otherwise, paths marked with --no-assume-unchanged
832 * (i.e. things to be edited) will reacquire CE_VALID bit
833 * automatically, which is not really what we want.
835 if (!ignore_valid && assume_unchanged &&
836 !(ce->ce_flags & htons(CE_VALID)))
837 updated->ce_flags &= ~htons(CE_VALID);
842 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
846 int really = (flags & REFRESH_REALLY) != 0;
847 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
848 int quiet = (flags & REFRESH_QUIET) != 0;
849 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
850 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
852 for (i = 0; i < istate->cache_nr; i++) {
853 struct cache_entry *ce, *new;
856 ce = istate->cache[i];
858 while ((i < istate->cache_nr) &&
859 ! strcmp(istate->cache[i]->name, ce->name))
864 printf("%s: needs merge\n", ce->name);
869 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
872 new = refresh_cache_ent(istate, ce, options, &cache_errno);
876 if (not_new && cache_errno == ENOENT)
878 if (really && cache_errno == EINVAL) {
879 /* If we are doing --really-refresh that
880 * means the index is not valid anymore.
882 ce->ce_flags &= ~htons(CE_VALID);
883 istate->cache_changed = 1;
887 printf("%s: needs update\n", ce->name);
891 istate->cache_changed = 1;
892 /* You can NOT just free istate->cache[i] here, since it
893 * might not be necessarily malloc()ed but can also come
895 istate->cache[i] = new;
900 struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
902 return refresh_cache_ent(&the_index, ce, really, NULL);
905 static int verify_hdr(struct cache_header *hdr, unsigned long size)
908 unsigned char sha1[20];
910 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
911 return error("bad signature");
912 if (hdr->hdr_version != htonl(2))
913 return error("bad index version");
915 SHA1_Update(&c, hdr, size - 20);
916 SHA1_Final(sha1, &c);
917 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
918 return error("bad index file sha1 signature");
922 static int read_index_extension(struct index_state *istate,
923 const char *ext, void *data, unsigned long sz)
925 switch (CACHE_EXT(ext)) {
927 istate->cache_tree = cache_tree_read(data, sz);
930 if (*ext < 'A' || 'Z' < *ext)
931 return error("index uses %.4s extension, which we do not understand",
933 fprintf(stderr, "ignoring %.4s extension\n", ext);
939 int read_index(struct index_state *istate)
941 return read_index_from(istate, get_index_file());
944 /* remember to discard_cache() before reading a different cache! */
945 int read_index_from(struct index_state *istate, const char *path)
949 unsigned long offset;
950 struct cache_header *hdr;
954 return istate->cache_nr;
957 istate->timestamp = 0;
958 fd = open(path, O_RDONLY);
962 die("index file open failed (%s)", strerror(errno));
966 die("cannot stat the open index (%s)", strerror(errno));
969 istate->mmap_size = xsize_t(st.st_size);
970 if (istate->mmap_size < sizeof(struct cache_header) + 20)
971 die("index file smaller than expected");
973 istate->mmap = xmmap(NULL, istate->mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
977 if (verify_hdr(hdr, istate->mmap_size) < 0)
980 istate->cache_nr = ntohl(hdr->hdr_entries);
981 istate->cache_alloc = alloc_nr(istate->cache_nr);
982 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
984 offset = sizeof(*hdr);
985 for (i = 0; i < istate->cache_nr; i++) {
986 struct cache_entry *ce;
988 ce = (struct cache_entry *)((char *)(istate->mmap) + offset);
989 offset = offset + ce_size(ce);
990 istate->cache[i] = ce;
992 istate->timestamp = st.st_mtime;
993 while (offset <= istate->mmap_size - 20 - 8) {
994 /* After an array of active_nr index entries,
995 * there can be arbitrary number of extended
996 * sections, each of which is prefixed with
997 * extension name (4-byte) and section length
998 * in 4-byte network byte order.
1000 unsigned long extsize;
1001 memcpy(&extsize, (char *)(istate->mmap) + offset + 4, 4);
1002 extsize = ntohl(extsize);
1003 if (read_index_extension(istate,
1004 ((const char *) (istate->mmap)) + offset,
1005 (char *) (istate->mmap) + offset + 8,
1011 return istate->cache_nr;
1014 munmap(istate->mmap, istate->mmap_size);
1016 die("index file corrupt");
1019 int discard_index(struct index_state *istate)
1023 istate->cache_nr = 0;
1024 istate->cache_changed = 0;
1025 istate->timestamp = 0;
1026 cache_tree_free(&(istate->cache_tree));
1027 if (istate->mmap == NULL)
1029 ret = munmap(istate->mmap, istate->mmap_size);
1030 istate->mmap = NULL;
1031 istate->mmap_size = 0;
1033 /* no need to throw away allocated active_cache */
1037 #define WRITE_BUFFER_SIZE 8192
1038 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1039 static unsigned long write_buffer_len;
1041 static int ce_write_flush(SHA_CTX *context, int fd)
1043 unsigned int buffered = write_buffer_len;
1045 SHA1_Update(context, write_buffer, buffered);
1046 if (write_in_full(fd, write_buffer, buffered) != buffered)
1048 write_buffer_len = 0;
1053 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
1056 unsigned int buffered = write_buffer_len;
1057 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1060 memcpy(write_buffer + buffered, data, partial);
1061 buffered += partial;
1062 if (buffered == WRITE_BUFFER_SIZE) {
1063 write_buffer_len = buffered;
1064 if (ce_write_flush(context, fd))
1068 write_buffer_len = buffered;
1070 data = (char *) data + partial;
1075 static int write_index_ext_header(SHA_CTX *context, int fd,
1076 unsigned int ext, unsigned int sz)
1080 return ((ce_write(context, fd, &ext, 4) < 0) ||
1081 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1084 static int ce_flush(SHA_CTX *context, int fd)
1086 unsigned int left = write_buffer_len;
1089 write_buffer_len = 0;
1090 SHA1_Update(context, write_buffer, left);
1093 /* Flush first if not enough space for SHA1 signature */
1094 if (left + 20 > WRITE_BUFFER_SIZE) {
1095 if (write_in_full(fd, write_buffer, left) != left)
1100 /* Append the SHA1 signature at the end */
1101 SHA1_Final(write_buffer + left, context);
1103 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1106 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1109 * The only thing we care about in this function is to smudge the
1110 * falsely clean entry due to touch-update-touch race, so we leave
1111 * everything else as they are. We are called for entries whose
1112 * ce_mtime match the index file mtime.
1116 if (lstat(ce->name, &st) < 0)
1118 if (ce_match_stat_basic(ce, &st))
1120 if (ce_modified_check_fs(ce, &st)) {
1121 /* This is "racily clean"; smudge it. Note that this
1122 * is a tricky code. At first glance, it may appear
1123 * that it can break with this sequence:
1125 * $ echo xyzzy >frotz
1126 * $ git-update-index --add frotz
1129 * $ echo filfre >nitfol
1130 * $ git-update-index --add nitfol
1132 * but it does not. When the second update-index runs,
1133 * it notices that the entry "frotz" has the same timestamp
1134 * as index, and if we were to smudge it by resetting its
1135 * size to zero here, then the object name recorded
1136 * in index is the 6-byte file but the cached stat information
1137 * becomes zero --- which would then match what we would
1138 * obtain from the filesystem next time we stat("frotz").
1140 * However, the second update-index, before calling
1141 * this function, notices that the cached size is 6
1142 * bytes and what is on the filesystem is an empty
1143 * file, and never calls us, so the cached size information
1144 * for "frotz" stays 6 which does not match the filesystem.
1146 ce->ce_size = htonl(0);
1150 int write_index(struct index_state *istate, int newfd)
1153 struct cache_header hdr;
1155 struct cache_entry **cache = istate->cache;
1156 int entries = istate->cache_nr;
1158 for (i = removed = 0; i < entries; i++)
1159 if (!cache[i]->ce_mode)
1162 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1163 hdr.hdr_version = htonl(2);
1164 hdr.hdr_entries = htonl(entries - removed);
1167 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1170 for (i = 0; i < entries; i++) {
1171 struct cache_entry *ce = cache[i];
1174 if (istate->timestamp &&
1175 istate->timestamp <= ntohl(ce->ce_mtime.sec))
1176 ce_smudge_racily_clean_entry(ce);
1177 if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
1181 /* Write extension data here */
1182 if (istate->cache_tree) {
1184 void *data = cache_tree_write(istate->cache_tree, &sz);
1186 !write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sz) &&
1187 !ce_write(&c, newfd, data, sz))
1194 return ce_flush(&c, newfd);