doc: A few minor copy edits.
[git/jnareb-git.git] / read-cache.c
blobb645827c06a268ee4721fda5fc8cdcd84775c9ec
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"
11 #include "tree.h"
12 #include "commit.h"
13 #include "blob.h"
14 #include "resolve-undo.h"
15 #include "strbuf.h"
16 #include "varint.h"
18 static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
20 /* Index extensions.
22 * The first letter should be 'A'..'Z' for extensions that are not
23 * necessary for a correct operation (i.e. optimization data).
24 * When new extensions are added that _needs_ to be understood in
25 * order to correctly interpret the index file, pick character that
26 * is outside the range, to cause the reader to abort.
29 #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
30 #define CACHE_EXT_TREE 0x54524545 /* "TREE" */
31 #define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
33 struct index_state the_index;
35 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
37 istate->cache[nr] = ce;
38 add_name_hash(istate, ce);
41 static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
43 struct cache_entry *old = istate->cache[nr];
45 remove_name_hash(old);
46 set_index_entry(istate, nr, ce);
47 istate->cache_changed = 1;
50 void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name)
52 struct cache_entry *old = istate->cache[nr], *new;
53 int namelen = strlen(new_name);
55 new = xmalloc(cache_entry_size(namelen));
56 copy_cache_entry(new, old);
57 new->ce_flags &= ~(CE_STATE_MASK | CE_NAMEMASK);
58 new->ce_flags |= (namelen >= CE_NAMEMASK ? CE_NAMEMASK : namelen);
59 memcpy(new->name, new_name, namelen + 1);
61 cache_tree_invalidate_path(istate->cache_tree, old->name);
62 remove_index_entry_at(istate, nr);
63 add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
67 * This only updates the "non-critical" parts of the directory
68 * cache, ie the parts that aren't tracked by GIT, and only used
69 * to validate the cache.
71 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
73 ce->ce_ctime.sec = (unsigned int)st->st_ctime;
74 ce->ce_mtime.sec = (unsigned int)st->st_mtime;
75 ce->ce_ctime.nsec = ST_CTIME_NSEC(*st);
76 ce->ce_mtime.nsec = ST_MTIME_NSEC(*st);
77 ce->ce_dev = st->st_dev;
78 ce->ce_ino = st->st_ino;
79 ce->ce_uid = st->st_uid;
80 ce->ce_gid = st->st_gid;
81 ce->ce_size = st->st_size;
83 if (assume_unchanged)
84 ce->ce_flags |= CE_VALID;
86 if (S_ISREG(st->st_mode))
87 ce_mark_uptodate(ce);
90 static int ce_compare_data(struct cache_entry *ce, struct stat *st)
92 int match = -1;
93 int fd = open(ce->name, O_RDONLY);
95 if (fd >= 0) {
96 unsigned char sha1[20];
97 if (!index_fd(sha1, fd, st, OBJ_BLOB, ce->name, 0))
98 match = hashcmp(sha1, ce->sha1);
99 /* index_fd() closed the file descriptor already */
101 return match;
104 static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
106 int match = -1;
107 void *buffer;
108 unsigned long size;
109 enum object_type type;
110 struct strbuf sb = STRBUF_INIT;
112 if (strbuf_readlink(&sb, ce->name, expected_size))
113 return -1;
115 buffer = read_sha1_file(ce->sha1, &type, &size);
116 if (buffer) {
117 if (size == sb.len)
118 match = memcmp(buffer, sb.buf, size);
119 free(buffer);
121 strbuf_release(&sb);
122 return match;
125 static int ce_compare_gitlink(struct cache_entry *ce)
127 unsigned char sha1[20];
130 * We don't actually require that the .git directory
131 * under GITLINK directory be a valid git directory. It
132 * might even be missing (in case nobody populated that
133 * sub-project).
135 * If so, we consider it always to match.
137 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
138 return 0;
139 return hashcmp(sha1, ce->sha1);
142 static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
144 switch (st->st_mode & S_IFMT) {
145 case S_IFREG:
146 if (ce_compare_data(ce, st))
147 return DATA_CHANGED;
148 break;
149 case S_IFLNK:
150 if (ce_compare_link(ce, xsize_t(st->st_size)))
151 return DATA_CHANGED;
152 break;
153 case S_IFDIR:
154 if (S_ISGITLINK(ce->ce_mode))
155 return ce_compare_gitlink(ce) ? DATA_CHANGED : 0;
156 default:
157 return TYPE_CHANGED;
159 return 0;
162 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
164 unsigned int changed = 0;
166 if (ce->ce_flags & CE_REMOVE)
167 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
169 switch (ce->ce_mode & S_IFMT) {
170 case S_IFREG:
171 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
172 /* We consider only the owner x bit to be relevant for
173 * "mode changes"
175 if (trust_executable_bit &&
176 (0100 & (ce->ce_mode ^ st->st_mode)))
177 changed |= MODE_CHANGED;
178 break;
179 case S_IFLNK:
180 if (!S_ISLNK(st->st_mode) &&
181 (has_symlinks || !S_ISREG(st->st_mode)))
182 changed |= TYPE_CHANGED;
183 break;
184 case S_IFGITLINK:
185 /* We ignore most of the st_xxx fields for gitlinks */
186 if (!S_ISDIR(st->st_mode))
187 changed |= TYPE_CHANGED;
188 else if (ce_compare_gitlink(ce))
189 changed |= DATA_CHANGED;
190 return changed;
191 default:
192 die("internal error: ce_mode is %o", ce->ce_mode);
194 if (ce->ce_mtime.sec != (unsigned int)st->st_mtime)
195 changed |= MTIME_CHANGED;
196 if (trust_ctime && ce->ce_ctime.sec != (unsigned int)st->st_ctime)
197 changed |= CTIME_CHANGED;
199 #ifdef USE_NSEC
200 if (ce->ce_mtime.nsec != ST_MTIME_NSEC(*st))
201 changed |= MTIME_CHANGED;
202 if (trust_ctime && ce->ce_ctime.nsec != ST_CTIME_NSEC(*st))
203 changed |= CTIME_CHANGED;
204 #endif
206 if (ce->ce_uid != (unsigned int) st->st_uid ||
207 ce->ce_gid != (unsigned int) st->st_gid)
208 changed |= OWNER_CHANGED;
209 if (ce->ce_ino != (unsigned int) st->st_ino)
210 changed |= INODE_CHANGED;
212 #ifdef USE_STDEV
214 * st_dev breaks on network filesystems where different
215 * clients will have different views of what "device"
216 * the filesystem is on
218 if (ce->ce_dev != (unsigned int) st->st_dev)
219 changed |= INODE_CHANGED;
220 #endif
222 if (ce->ce_size != (unsigned int) st->st_size)
223 changed |= DATA_CHANGED;
225 /* Racily smudged entry? */
226 if (!ce->ce_size) {
227 if (!is_empty_blob_sha1(ce->sha1))
228 changed |= DATA_CHANGED;
231 return changed;
234 static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
236 return (!S_ISGITLINK(ce->ce_mode) &&
237 istate->timestamp.sec &&
238 #ifdef USE_NSEC
239 /* nanosecond timestamped files can also be racy! */
240 (istate->timestamp.sec < ce->ce_mtime.sec ||
241 (istate->timestamp.sec == ce->ce_mtime.sec &&
242 istate->timestamp.nsec <= ce->ce_mtime.nsec))
243 #else
244 istate->timestamp.sec <= ce->ce_mtime.sec
245 #endif
249 int ie_match_stat(const struct index_state *istate,
250 struct cache_entry *ce, struct stat *st,
251 unsigned int options)
253 unsigned int changed;
254 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
255 int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
256 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
259 * If it's marked as always valid in the index, it's
260 * valid whatever the checked-out copy says.
262 * skip-worktree has the same effect with higher precedence
264 if (!ignore_skip_worktree && ce_skip_worktree(ce))
265 return 0;
266 if (!ignore_valid && (ce->ce_flags & CE_VALID))
267 return 0;
270 * Intent-to-add entries have not been added, so the index entry
271 * by definition never matches what is in the work tree until it
272 * actually gets added.
274 if (ce->ce_flags & CE_INTENT_TO_ADD)
275 return DATA_CHANGED | TYPE_CHANGED | MODE_CHANGED;
277 changed = ce_match_stat_basic(ce, st);
280 * Within 1 second of this sequence:
281 * echo xyzzy >file && git-update-index --add file
282 * running this command:
283 * echo frotz >file
284 * would give a falsely clean cache entry. The mtime and
285 * length match the cache, and other stat fields do not change.
287 * We could detect this at update-index time (the cache entry
288 * being registered/updated records the same time as "now")
289 * and delay the return from git-update-index, but that would
290 * effectively mean we can make at most one commit per second,
291 * which is not acceptable. Instead, we check cache entries
292 * whose mtime are the same as the index file timestamp more
293 * carefully than others.
295 if (!changed && is_racy_timestamp(istate, ce)) {
296 if (assume_racy_is_modified)
297 changed |= DATA_CHANGED;
298 else
299 changed |= ce_modified_check_fs(ce, st);
302 return changed;
305 int ie_modified(const struct index_state *istate,
306 struct cache_entry *ce, struct stat *st, unsigned int options)
308 int changed, changed_fs;
310 changed = ie_match_stat(istate, ce, st, options);
311 if (!changed)
312 return 0;
314 * If the mode or type has changed, there's no point in trying
315 * to refresh the entry - it's not going to match
317 if (changed & (MODE_CHANGED | TYPE_CHANGED))
318 return changed;
321 * Immediately after read-tree or update-index --cacheinfo,
322 * the length field is zero, as we have never even read the
323 * lstat(2) information once, and we cannot trust DATA_CHANGED
324 * returned by ie_match_stat() which in turn was returned by
325 * ce_match_stat_basic() to signal that the filesize of the
326 * blob changed. We have to actually go to the filesystem to
327 * see if the contents match, and if so, should answer "unchanged".
329 * The logic does not apply to gitlinks, as ce_match_stat_basic()
330 * already has checked the actual HEAD from the filesystem in the
331 * subproject. If ie_match_stat() already said it is different,
332 * then we know it is.
334 if ((changed & DATA_CHANGED) &&
335 (S_ISGITLINK(ce->ce_mode) || ce->ce_size != 0))
336 return changed;
338 changed_fs = ce_modified_check_fs(ce, st);
339 if (changed_fs)
340 return changed | changed_fs;
341 return 0;
344 int base_name_compare(const char *name1, int len1, int mode1,
345 const char *name2, int len2, int mode2)
347 unsigned char c1, c2;
348 int len = len1 < len2 ? len1 : len2;
349 int cmp;
351 cmp = memcmp(name1, name2, len);
352 if (cmp)
353 return cmp;
354 c1 = name1[len];
355 c2 = name2[len];
356 if (!c1 && S_ISDIR(mode1))
357 c1 = '/';
358 if (!c2 && S_ISDIR(mode2))
359 c2 = '/';
360 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
364 * df_name_compare() is identical to base_name_compare(), except it
365 * compares conflicting directory/file entries as equal. Note that
366 * while a directory name compares as equal to a regular file, they
367 * then individually compare _differently_ to a filename that has
368 * a dot after the basename (because '\0' < '.' < '/').
370 * This is used by routines that want to traverse the git namespace
371 * but then handle conflicting entries together when possible.
373 int df_name_compare(const char *name1, int len1, int mode1,
374 const char *name2, int len2, int mode2)
376 int len = len1 < len2 ? len1 : len2, cmp;
377 unsigned char c1, c2;
379 cmp = memcmp(name1, name2, len);
380 if (cmp)
381 return cmp;
382 /* Directories and files compare equal (same length, same name) */
383 if (len1 == len2)
384 return 0;
385 c1 = name1[len];
386 if (!c1 && S_ISDIR(mode1))
387 c1 = '/';
388 c2 = name2[len];
389 if (!c2 && S_ISDIR(mode2))
390 c2 = '/';
391 if (c1 == '/' && !c2)
392 return 0;
393 if (c2 == '/' && !c1)
394 return 0;
395 return c1 - c2;
398 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
400 int len1, len2, len, cmp;
402 len1 = flags1 & CE_NAMEMASK;
403 if (CE_NAMEMASK <= len1)
404 len1 = strlen(name1 + CE_NAMEMASK) + CE_NAMEMASK;
405 len2 = flags2 & CE_NAMEMASK;
406 if (CE_NAMEMASK <= len2)
407 len2 = strlen(name2 + CE_NAMEMASK) + CE_NAMEMASK;
408 len = len1 < len2 ? len1 : len2;
410 cmp = memcmp(name1, name2, len);
411 if (cmp)
412 return cmp;
413 if (len1 < len2)
414 return -1;
415 if (len1 > len2)
416 return 1;
418 /* Compare stages */
419 flags1 &= CE_STAGEMASK;
420 flags2 &= CE_STAGEMASK;
422 if (flags1 < flags2)
423 return -1;
424 if (flags1 > flags2)
425 return 1;
426 return 0;
429 int index_name_pos(const struct index_state *istate, const char *name, int namelen)
431 int first, last;
433 first = 0;
434 last = istate->cache_nr;
435 while (last > first) {
436 int next = (last + first) >> 1;
437 struct cache_entry *ce = istate->cache[next];
438 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags);
439 if (!cmp)
440 return next;
441 if (cmp < 0) {
442 last = next;
443 continue;
445 first = next+1;
447 return -first-1;
450 /* Remove entry, return true if there are more entries to go.. */
451 int remove_index_entry_at(struct index_state *istate, int pos)
453 struct cache_entry *ce = istate->cache[pos];
455 record_resolve_undo(istate, ce);
456 remove_name_hash(ce);
457 istate->cache_changed = 1;
458 istate->cache_nr--;
459 if (pos >= istate->cache_nr)
460 return 0;
461 memmove(istate->cache + pos,
462 istate->cache + pos + 1,
463 (istate->cache_nr - pos) * sizeof(struct cache_entry *));
464 return 1;
468 * Remove all cache ententries marked for removal, that is where
469 * CE_REMOVE is set in ce_flags. This is much more effective than
470 * calling remove_index_entry_at() for each entry to be removed.
472 void remove_marked_cache_entries(struct index_state *istate)
474 struct cache_entry **ce_array = istate->cache;
475 unsigned int i, j;
477 for (i = j = 0; i < istate->cache_nr; i++) {
478 if (ce_array[i]->ce_flags & CE_REMOVE)
479 remove_name_hash(ce_array[i]);
480 else
481 ce_array[j++] = ce_array[i];
483 istate->cache_changed = 1;
484 istate->cache_nr = j;
487 int remove_file_from_index(struct index_state *istate, const char *path)
489 int pos = index_name_pos(istate, path, strlen(path));
490 if (pos < 0)
491 pos = -pos-1;
492 cache_tree_invalidate_path(istate->cache_tree, path);
493 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
494 remove_index_entry_at(istate, pos);
495 return 0;
498 static int compare_name(struct cache_entry *ce, const char *path, int namelen)
500 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
503 static int index_name_pos_also_unmerged(struct index_state *istate,
504 const char *path, int namelen)
506 int pos = index_name_pos(istate, path, namelen);
507 struct cache_entry *ce;
509 if (pos >= 0)
510 return pos;
512 /* maybe unmerged? */
513 pos = -1 - pos;
514 if (pos >= istate->cache_nr ||
515 compare_name((ce = istate->cache[pos]), path, namelen))
516 return -1;
518 /* order of preference: stage 2, 1, 3 */
519 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
520 ce_stage((ce = istate->cache[pos + 1])) == 2 &&
521 !compare_name(ce, path, namelen))
522 pos++;
523 return pos;
526 static int different_name(struct cache_entry *ce, struct cache_entry *alias)
528 int len = ce_namelen(ce);
529 return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
533 * If we add a filename that aliases in the cache, we will use the
534 * name that we already have - but we don't want to update the same
535 * alias twice, because that implies that there were actually two
536 * different files with aliasing names!
538 * So we use the CE_ADDED flag to verify that the alias was an old
539 * one before we accept it as
541 static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias)
543 int len;
544 struct cache_entry *new;
546 if (alias->ce_flags & CE_ADDED)
547 die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
549 /* Ok, create the new entry using the name of the existing alias */
550 len = ce_namelen(alias);
551 new = xcalloc(1, cache_entry_size(len));
552 memcpy(new->name, alias->name, len);
553 copy_cache_entry(new, ce);
554 free(ce);
555 return new;
558 static void record_intent_to_add(struct cache_entry *ce)
560 unsigned char sha1[20];
561 if (write_sha1_file("", 0, blob_type, sha1))
562 die("cannot create an empty blob in the object database");
563 hashcpy(ce->sha1, sha1);
566 int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
568 int size, namelen, was_same;
569 mode_t st_mode = st->st_mode;
570 struct cache_entry *ce, *alias;
571 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE|CE_MATCH_RACY_IS_DIRTY;
572 int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND);
573 int pretend = flags & ADD_CACHE_PRETEND;
574 int intent_only = flags & ADD_CACHE_INTENT;
575 int add_option = (ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE|
576 (intent_only ? ADD_CACHE_NEW_ONLY : 0));
578 if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode))
579 return error("%s: can only add regular files, symbolic links or git-directories", path);
581 namelen = strlen(path);
582 if (S_ISDIR(st_mode)) {
583 while (namelen && path[namelen-1] == '/')
584 namelen--;
586 size = cache_entry_size(namelen);
587 ce = xcalloc(1, size);
588 memcpy(ce->name, path, namelen);
589 ce->ce_flags = namelen;
590 if (!intent_only)
591 fill_stat_cache_info(ce, st);
592 else
593 ce->ce_flags |= CE_INTENT_TO_ADD;
595 if (trust_executable_bit && has_symlinks)
596 ce->ce_mode = create_ce_mode(st_mode);
597 else {
598 /* If there is an existing entry, pick the mode bits and type
599 * from it, otherwise assume unexecutable regular file.
601 struct cache_entry *ent;
602 int pos = index_name_pos_also_unmerged(istate, path, namelen);
604 ent = (0 <= pos) ? istate->cache[pos] : NULL;
605 ce->ce_mode = ce_mode_from_stat(ent, st_mode);
608 /* When core.ignorecase=true, determine if a directory of the same name but differing
609 * case already exists within the Git repository. If it does, ensure the directory
610 * case of the file being added to the repository matches (is folded into) the existing
611 * entry's directory case.
613 if (ignore_case) {
614 const char *startPtr = ce->name;
615 const char *ptr = startPtr;
616 while (*ptr) {
617 while (*ptr && *ptr != '/')
618 ++ptr;
619 if (*ptr == '/') {
620 struct cache_entry *foundce;
621 ++ptr;
622 foundce = index_name_exists(&the_index, ce->name, ptr - ce->name, ignore_case);
623 if (foundce) {
624 memcpy((void *)startPtr, foundce->name + (startPtr - ce->name), ptr - startPtr);
625 startPtr = ptr;
631 alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case);
632 if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) {
633 /* Nothing changed, really */
634 free(ce);
635 if (!S_ISGITLINK(alias->ce_mode))
636 ce_mark_uptodate(alias);
637 alias->ce_flags |= CE_ADDED;
638 return 0;
640 if (!intent_only) {
641 if (index_path(ce->sha1, path, st, HASH_WRITE_OBJECT))
642 return error("unable to index file %s", path);
643 } else
644 record_intent_to_add(ce);
646 if (ignore_case && alias && different_name(ce, alias))
647 ce = create_alias_ce(ce, alias);
648 ce->ce_flags |= CE_ADDED;
650 /* It was suspected to be racily clean, but it turns out to be Ok */
651 was_same = (alias &&
652 !ce_stage(alias) &&
653 !hashcmp(alias->sha1, ce->sha1) &&
654 ce->ce_mode == alias->ce_mode);
656 if (pretend)
658 else if (add_index_entry(istate, ce, add_option))
659 return error("unable to add %s to index",path);
660 if (verbose && !was_same)
661 printf("add '%s'\n", path);
662 return 0;
665 int add_file_to_index(struct index_state *istate, const char *path, int flags)
667 struct stat st;
668 if (lstat(path, &st))
669 die_errno("unable to stat '%s'", path);
670 return add_to_index(istate, path, &st, flags);
673 struct cache_entry *make_cache_entry(unsigned int mode,
674 const unsigned char *sha1, const char *path, int stage,
675 int refresh)
677 int size, len;
678 struct cache_entry *ce;
680 if (!verify_path(path)) {
681 error("Invalid path '%s'", path);
682 return NULL;
685 len = strlen(path);
686 size = cache_entry_size(len);
687 ce = xcalloc(1, size);
689 hashcpy(ce->sha1, sha1);
690 memcpy(ce->name, path, len);
691 ce->ce_flags = create_ce_flags(len, stage);
692 ce->ce_mode = create_ce_mode(mode);
694 if (refresh)
695 return refresh_cache_entry(ce, 0);
697 return ce;
700 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
702 int len = ce_namelen(a);
703 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
706 int ce_path_match(const struct cache_entry *ce, const struct pathspec *pathspec)
708 return match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL);
712 * We fundamentally don't like some paths: we don't want
713 * dot or dot-dot anywhere, and for obvious reasons don't
714 * want to recurse into ".git" either.
716 * Also, we don't want double slashes or slashes at the
717 * end that can make pathnames ambiguous.
719 static int verify_dotfile(const char *rest)
722 * The first character was '.', but that
723 * has already been discarded, we now test
724 * the rest.
727 /* "." is not allowed */
728 if (*rest == '\0' || is_dir_sep(*rest))
729 return 0;
731 switch (*rest) {
733 * ".git" followed by NUL or slash is bad. This
734 * shares the path end test with the ".." case.
736 case 'g':
737 if (rest[1] != 'i')
738 break;
739 if (rest[2] != 't')
740 break;
741 rest += 2;
742 /* fallthrough */
743 case '.':
744 if (rest[1] == '\0' || is_dir_sep(rest[1]))
745 return 0;
747 return 1;
750 int verify_path(const char *path)
752 char c;
754 if (has_dos_drive_prefix(path))
755 return 0;
757 goto inside;
758 for (;;) {
759 if (!c)
760 return 1;
761 if (is_dir_sep(c)) {
762 inside:
763 c = *path++;
764 if ((c == '.' && !verify_dotfile(path)) ||
765 is_dir_sep(c) || c == '\0')
766 return 0;
768 c = *path++;
773 * Do we have another file that has the beginning components being a
774 * proper superset of the name we're trying to add?
776 static int has_file_name(struct index_state *istate,
777 const struct cache_entry *ce, int pos, int ok_to_replace)
779 int retval = 0;
780 int len = ce_namelen(ce);
781 int stage = ce_stage(ce);
782 const char *name = ce->name;
784 while (pos < istate->cache_nr) {
785 struct cache_entry *p = istate->cache[pos++];
787 if (len >= ce_namelen(p))
788 break;
789 if (memcmp(name, p->name, len))
790 break;
791 if (ce_stage(p) != stage)
792 continue;
793 if (p->name[len] != '/')
794 continue;
795 if (p->ce_flags & CE_REMOVE)
796 continue;
797 retval = -1;
798 if (!ok_to_replace)
799 break;
800 remove_index_entry_at(istate, --pos);
802 return retval;
806 * Do we have another file with a pathname that is a proper
807 * subset of the name we're trying to add?
809 static int has_dir_name(struct index_state *istate,
810 const struct cache_entry *ce, int pos, int ok_to_replace)
812 int retval = 0;
813 int stage = ce_stage(ce);
814 const char *name = ce->name;
815 const char *slash = name + ce_namelen(ce);
817 for (;;) {
818 int len;
820 for (;;) {
821 if (*--slash == '/')
822 break;
823 if (slash <= ce->name)
824 return retval;
826 len = slash - name;
828 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
829 if (pos >= 0) {
831 * Found one, but not so fast. This could
832 * be a marker that says "I was here, but
833 * I am being removed". Such an entry is
834 * not a part of the resulting tree, and
835 * it is Ok to have a directory at the same
836 * path.
838 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
839 retval = -1;
840 if (!ok_to_replace)
841 break;
842 remove_index_entry_at(istate, pos);
843 continue;
846 else
847 pos = -pos-1;
850 * Trivial optimization: if we find an entry that
851 * already matches the sub-directory, then we know
852 * we're ok, and we can exit.
854 while (pos < istate->cache_nr) {
855 struct cache_entry *p = istate->cache[pos];
856 if ((ce_namelen(p) <= len) ||
857 (p->name[len] != '/') ||
858 memcmp(p->name, name, len))
859 break; /* not our subdirectory */
860 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
862 * p is at the same stage as our entry, and
863 * is a subdirectory of what we are looking
864 * at, so we cannot have conflicts at our
865 * level or anything shorter.
867 return retval;
868 pos++;
871 return retval;
874 /* We may be in a situation where we already have path/file and path
875 * is being added, or we already have path and path/file is being
876 * added. Either one would result in a nonsense tree that has path
877 * twice when git-write-tree tries to write it out. Prevent it.
879 * If ok-to-replace is specified, we remove the conflicting entries
880 * from the cache so the caller should recompute the insert position.
881 * When this happens, we return non-zero.
883 static int check_file_directory_conflict(struct index_state *istate,
884 const struct cache_entry *ce,
885 int pos, int ok_to_replace)
887 int retval;
890 * When ce is an "I am going away" entry, we allow it to be added
892 if (ce->ce_flags & CE_REMOVE)
893 return 0;
896 * We check if the path is a sub-path of a subsequent pathname
897 * first, since removing those will not change the position
898 * in the array.
900 retval = has_file_name(istate, ce, pos, ok_to_replace);
903 * Then check if the path might have a clashing sub-directory
904 * before it.
906 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
909 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
911 int pos;
912 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
913 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
914 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
915 int new_only = option & ADD_CACHE_NEW_ONLY;
917 cache_tree_invalidate_path(istate->cache_tree, ce->name);
918 pos = index_name_pos(istate, ce->name, ce->ce_flags);
920 /* existing match? Just replace it. */
921 if (pos >= 0) {
922 if (!new_only)
923 replace_index_entry(istate, pos, ce);
924 return 0;
926 pos = -pos-1;
929 * Inserting a merged entry ("stage 0") into the index
930 * will always replace all non-merged entries..
932 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
933 while (ce_same_name(istate->cache[pos], ce)) {
934 ok_to_add = 1;
935 if (!remove_index_entry_at(istate, pos))
936 break;
940 if (!ok_to_add)
941 return -1;
942 if (!verify_path(ce->name))
943 return error("Invalid path '%s'", ce->name);
945 if (!skip_df_check &&
946 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
947 if (!ok_to_replace)
948 return error("'%s' appears as both a file and as a directory",
949 ce->name);
950 pos = index_name_pos(istate, ce->name, ce->ce_flags);
951 pos = -pos-1;
953 return pos + 1;
956 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
958 int pos;
960 if (option & ADD_CACHE_JUST_APPEND)
961 pos = istate->cache_nr;
962 else {
963 int ret;
964 ret = add_index_entry_with_check(istate, ce, option);
965 if (ret <= 0)
966 return ret;
967 pos = ret - 1;
970 /* Make sure the array is big enough .. */
971 if (istate->cache_nr == istate->cache_alloc) {
972 istate->cache_alloc = alloc_nr(istate->cache_alloc);
973 istate->cache = xrealloc(istate->cache,
974 istate->cache_alloc * sizeof(struct cache_entry *));
977 /* Add it in.. */
978 istate->cache_nr++;
979 if (istate->cache_nr > pos + 1)
980 memmove(istate->cache + pos + 1,
981 istate->cache + pos,
982 (istate->cache_nr - pos - 1) * sizeof(ce));
983 set_index_entry(istate, pos, ce);
984 istate->cache_changed = 1;
985 return 0;
989 * "refresh" does not calculate a new sha1 file or bring the
990 * cache up-to-date for mode/content changes. But what it
991 * _does_ do is to "re-match" the stat information of a file
992 * with the cache, so that you can refresh the cache for a
993 * file that hasn't been changed but where the stat entry is
994 * out of date.
996 * For example, you'd want to do this after doing a "git-read-tree",
997 * to link up the stat cache details with the proper files.
999 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
1000 struct cache_entry *ce,
1001 unsigned int options, int *err,
1002 int *changed_ret)
1004 struct stat st;
1005 struct cache_entry *updated;
1006 int changed, size;
1007 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
1008 int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
1010 if (ce_uptodate(ce))
1011 return ce;
1014 * CE_VALID or CE_SKIP_WORKTREE means the user promised us
1015 * that the change to the work tree does not matter and told
1016 * us not to worry.
1018 if (!ignore_skip_worktree && ce_skip_worktree(ce)) {
1019 ce_mark_uptodate(ce);
1020 return ce;
1022 if (!ignore_valid && (ce->ce_flags & CE_VALID)) {
1023 ce_mark_uptodate(ce);
1024 return ce;
1027 if (lstat(ce->name, &st) < 0) {
1028 if (err)
1029 *err = errno;
1030 return NULL;
1033 changed = ie_match_stat(istate, ce, &st, options);
1034 if (changed_ret)
1035 *changed_ret = changed;
1036 if (!changed) {
1038 * The path is unchanged. If we were told to ignore
1039 * valid bit, then we did the actual stat check and
1040 * found that the entry is unmodified. If the entry
1041 * is not marked VALID, this is the place to mark it
1042 * valid again, under "assume unchanged" mode.
1044 if (ignore_valid && assume_unchanged &&
1045 !(ce->ce_flags & CE_VALID))
1046 ; /* mark this one VALID again */
1047 else {
1049 * We do not mark the index itself "modified"
1050 * because CE_UPTODATE flag is in-core only;
1051 * we are not going to write this change out.
1053 if (!S_ISGITLINK(ce->ce_mode))
1054 ce_mark_uptodate(ce);
1055 return ce;
1059 if (ie_modified(istate, ce, &st, options)) {
1060 if (err)
1061 *err = EINVAL;
1062 return NULL;
1065 size = ce_size(ce);
1066 updated = xmalloc(size);
1067 memcpy(updated, ce, size);
1068 fill_stat_cache_info(updated, &st);
1070 * If ignore_valid is not set, we should leave CE_VALID bit
1071 * alone. Otherwise, paths marked with --no-assume-unchanged
1072 * (i.e. things to be edited) will reacquire CE_VALID bit
1073 * automatically, which is not really what we want.
1075 if (!ignore_valid && assume_unchanged &&
1076 !(ce->ce_flags & CE_VALID))
1077 updated->ce_flags &= ~CE_VALID;
1079 return updated;
1082 static void show_file(const char * fmt, const char * name, int in_porcelain,
1083 int * first, const char *header_msg)
1085 if (in_porcelain && *first && header_msg) {
1086 printf("%s\n", header_msg);
1087 *first = 0;
1089 printf(fmt, name);
1092 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec,
1093 char *seen, const char *header_msg)
1095 int i;
1096 int has_errors = 0;
1097 int really = (flags & REFRESH_REALLY) != 0;
1098 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
1099 int quiet = (flags & REFRESH_QUIET) != 0;
1100 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
1101 int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
1102 int first = 1;
1103 int in_porcelain = (flags & REFRESH_IN_PORCELAIN);
1104 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
1105 const char *modified_fmt;
1106 const char *deleted_fmt;
1107 const char *typechange_fmt;
1108 const char *added_fmt;
1109 const char *unmerged_fmt;
1111 modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
1112 deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n");
1113 typechange_fmt = (in_porcelain ? "T\t%s\n" : "%s needs update\n");
1114 added_fmt = (in_porcelain ? "A\t%s\n" : "%s needs update\n");
1115 unmerged_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n");
1116 for (i = 0; i < istate->cache_nr; i++) {
1117 struct cache_entry *ce, *new;
1118 int cache_errno = 0;
1119 int changed = 0;
1120 int filtered = 0;
1122 ce = istate->cache[i];
1123 if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
1124 continue;
1126 if (pathspec &&
1127 !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
1128 filtered = 1;
1130 if (ce_stage(ce)) {
1131 while ((i < istate->cache_nr) &&
1132 ! strcmp(istate->cache[i]->name, ce->name))
1133 i++;
1134 i--;
1135 if (allow_unmerged)
1136 continue;
1137 if (!filtered)
1138 show_file(unmerged_fmt, ce->name, in_porcelain,
1139 &first, header_msg);
1140 has_errors = 1;
1141 continue;
1144 if (filtered)
1145 continue;
1147 new = refresh_cache_ent(istate, ce, options, &cache_errno, &changed);
1148 if (new == ce)
1149 continue;
1150 if (!new) {
1151 const char *fmt;
1153 if (not_new && cache_errno == ENOENT)
1154 continue;
1155 if (really && cache_errno == EINVAL) {
1156 /* If we are doing --really-refresh that
1157 * means the index is not valid anymore.
1159 ce->ce_flags &= ~CE_VALID;
1160 istate->cache_changed = 1;
1162 if (quiet)
1163 continue;
1165 if (cache_errno == ENOENT)
1166 fmt = deleted_fmt;
1167 else if (ce->ce_flags & CE_INTENT_TO_ADD)
1168 fmt = added_fmt; /* must be before other checks */
1169 else if (changed & TYPE_CHANGED)
1170 fmt = typechange_fmt;
1171 else
1172 fmt = modified_fmt;
1173 show_file(fmt,
1174 ce->name, in_porcelain, &first, header_msg);
1175 has_errors = 1;
1176 continue;
1179 replace_index_entry(istate, i, new);
1181 return has_errors;
1184 static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
1186 return refresh_cache_ent(&the_index, ce, really, NULL, NULL);
1190 /*****************************************************************
1191 * Index File I/O
1192 *****************************************************************/
1194 #define INDEX_FORMAT_DEFAULT 3
1197 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
1198 * Again - this is just a (very strong in practice) heuristic that
1199 * the inode hasn't changed.
1201 * We save the fields in big-endian order to allow using the
1202 * index file over NFS transparently.
1204 struct ondisk_cache_entry {
1205 struct cache_time ctime;
1206 struct cache_time mtime;
1207 unsigned int dev;
1208 unsigned int ino;
1209 unsigned int mode;
1210 unsigned int uid;
1211 unsigned int gid;
1212 unsigned int size;
1213 unsigned char sha1[20];
1214 unsigned short flags;
1215 char name[FLEX_ARRAY]; /* more */
1219 * This struct is used when CE_EXTENDED bit is 1
1220 * The struct must match ondisk_cache_entry exactly from
1221 * ctime till flags
1223 struct ondisk_cache_entry_extended {
1224 struct cache_time ctime;
1225 struct cache_time mtime;
1226 unsigned int dev;
1227 unsigned int ino;
1228 unsigned int mode;
1229 unsigned int uid;
1230 unsigned int gid;
1231 unsigned int size;
1232 unsigned char sha1[20];
1233 unsigned short flags;
1234 unsigned short flags2;
1235 char name[FLEX_ARRAY]; /* more */
1238 /* These are only used for v3 or lower */
1239 #define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,name) + (len) + 8) & ~7)
1240 #define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len)
1241 #define ondisk_cache_entry_extended_size(len) align_flex_name(ondisk_cache_entry_extended,len)
1242 #define ondisk_ce_size(ce) (((ce)->ce_flags & CE_EXTENDED) ? \
1243 ondisk_cache_entry_extended_size(ce_namelen(ce)) : \
1244 ondisk_cache_entry_size(ce_namelen(ce)))
1246 static int verify_hdr(struct cache_header *hdr, unsigned long size)
1248 git_SHA_CTX c;
1249 unsigned char sha1[20];
1250 int hdr_version;
1252 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
1253 return error("bad signature");
1254 hdr_version = ntohl(hdr->hdr_version);
1255 if (hdr_version < 2 || 4 < hdr_version)
1256 return error("bad index version %d", hdr_version);
1257 git_SHA1_Init(&c);
1258 git_SHA1_Update(&c, hdr, size - 20);
1259 git_SHA1_Final(sha1, &c);
1260 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1261 return error("bad index file sha1 signature");
1262 return 0;
1265 static int read_index_extension(struct index_state *istate,
1266 const char *ext, void *data, unsigned long sz)
1268 switch (CACHE_EXT(ext)) {
1269 case CACHE_EXT_TREE:
1270 istate->cache_tree = cache_tree_read(data, sz);
1271 break;
1272 case CACHE_EXT_RESOLVE_UNDO:
1273 istate->resolve_undo = resolve_undo_read(data, sz);
1274 break;
1275 default:
1276 if (*ext < 'A' || 'Z' < *ext)
1277 return error("index uses %.4s extension, which we do not understand",
1278 ext);
1279 fprintf(stderr, "ignoring %.4s extension\n", ext);
1280 break;
1282 return 0;
1285 int read_index(struct index_state *istate)
1287 return read_index_from(istate, get_index_file());
1290 #ifndef NEEDS_ALIGNED_ACCESS
1291 #define ntoh_s(var) ntohs(var)
1292 #define ntoh_l(var) ntohl(var)
1293 #else
1294 static inline uint16_t ntoh_s_force_align(void *p)
1296 uint16_t x;
1297 memcpy(&x, p, sizeof(x));
1298 return ntohs(x);
1300 static inline uint32_t ntoh_l_force_align(void *p)
1302 uint32_t x;
1303 memcpy(&x, p, sizeof(x));
1304 return ntohl(x);
1306 #define ntoh_s(var) ntoh_s_force_align(&(var))
1307 #define ntoh_l(var) ntoh_l_force_align(&(var))
1308 #endif
1310 static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk,
1311 unsigned int flags,
1312 const char *name,
1313 size_t len)
1315 struct cache_entry *ce = xmalloc(cache_entry_size(len));
1317 ce->ce_ctime.sec = ntoh_l(ondisk->ctime.sec);
1318 ce->ce_mtime.sec = ntoh_l(ondisk->mtime.sec);
1319 ce->ce_ctime.nsec = ntoh_l(ondisk->ctime.nsec);
1320 ce->ce_mtime.nsec = ntoh_l(ondisk->mtime.nsec);
1321 ce->ce_dev = ntoh_l(ondisk->dev);
1322 ce->ce_ino = ntoh_l(ondisk->ino);
1323 ce->ce_mode = ntoh_l(ondisk->mode);
1324 ce->ce_uid = ntoh_l(ondisk->uid);
1325 ce->ce_gid = ntoh_l(ondisk->gid);
1326 ce->ce_size = ntoh_l(ondisk->size);
1327 ce->ce_flags = flags;
1328 hashcpy(ce->sha1, ondisk->sha1);
1329 memcpy(ce->name, name, len);
1330 ce->name[len] = '\0';
1331 return ce;
1335 * Adjacent cache entries tend to share the leading paths, so it makes
1336 * sense to only store the differences in later entries. In the v4
1337 * on-disk format of the index, each on-disk cache entry stores the
1338 * number of bytes to be stripped from the end of the previous name,
1339 * and the bytes to append to the result, to come up with its name.
1341 static unsigned long expand_name_field(struct strbuf *name, const char *cp_)
1343 const unsigned char *ep, *cp = (const unsigned char *)cp_;
1344 size_t len = decode_varint(&cp);
1346 if (name->len < len)
1347 die("malformed name field in the index");
1348 strbuf_remove(name, name->len - len, len);
1349 for (ep = cp; *ep; ep++)
1350 ; /* find the end */
1351 strbuf_add(name, cp, ep - cp);
1352 return (const char *)ep + 1 - cp_;
1355 static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk,
1356 unsigned long *ent_size,
1357 struct strbuf *previous_name)
1359 struct cache_entry *ce;
1360 size_t len;
1361 const char *name;
1362 unsigned int flags;
1364 /* On-disk flags are just 16 bits */
1365 flags = ntoh_s(ondisk->flags);
1366 len = flags & CE_NAMEMASK;
1368 if (flags & CE_EXTENDED) {
1369 struct ondisk_cache_entry_extended *ondisk2;
1370 int extended_flags;
1371 ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
1372 extended_flags = ntoh_s(ondisk2->flags2) << 16;
1373 /* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
1374 if (extended_flags & ~CE_EXTENDED_FLAGS)
1375 die("Unknown index entry format %08x", extended_flags);
1376 flags |= extended_flags;
1377 name = ondisk2->name;
1379 else
1380 name = ondisk->name;
1382 if (!previous_name) {
1383 /* v3 and earlier */
1384 if (len == CE_NAMEMASK)
1385 len = strlen(name);
1386 ce = cache_entry_from_ondisk(ondisk, flags, name, len);
1388 *ent_size = ondisk_ce_size(ce);
1389 } else {
1390 unsigned long consumed;
1391 consumed = expand_name_field(previous_name, name);
1392 ce = cache_entry_from_ondisk(ondisk, flags,
1393 previous_name->buf,
1394 previous_name->len);
1396 *ent_size = (name - ((char *)ondisk)) + consumed;
1398 return ce;
1401 /* remember to discard_cache() before reading a different cache! */
1402 int read_index_from(struct index_state *istate, const char *path)
1404 int fd, i;
1405 struct stat st;
1406 unsigned long src_offset;
1407 struct cache_header *hdr;
1408 void *mmap;
1409 size_t mmap_size;
1410 struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
1412 errno = EBUSY;
1413 if (istate->initialized)
1414 return istate->cache_nr;
1416 errno = ENOENT;
1417 istate->timestamp.sec = 0;
1418 istate->timestamp.nsec = 0;
1419 fd = open(path, O_RDONLY);
1420 if (fd < 0) {
1421 if (errno == ENOENT)
1422 return 0;
1423 die_errno("index file open failed");
1426 if (fstat(fd, &st))
1427 die_errno("cannot stat the open index");
1429 errno = EINVAL;
1430 mmap_size = xsize_t(st.st_size);
1431 if (mmap_size < sizeof(struct cache_header) + 20)
1432 die("index file smaller than expected");
1434 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1435 close(fd);
1436 if (mmap == MAP_FAILED)
1437 die_errno("unable to map index file");
1439 hdr = mmap;
1440 if (verify_hdr(hdr, mmap_size) < 0)
1441 goto unmap;
1443 istate->version = ntohl(hdr->hdr_version);
1444 istate->cache_nr = ntohl(hdr->hdr_entries);
1445 istate->cache_alloc = alloc_nr(istate->cache_nr);
1446 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1447 istate->initialized = 1;
1449 if (istate->version == 4)
1450 previous_name = &previous_name_buf;
1451 else
1452 previous_name = NULL;
1454 src_offset = sizeof(*hdr);
1455 for (i = 0; i < istate->cache_nr; i++) {
1456 struct ondisk_cache_entry *disk_ce;
1457 struct cache_entry *ce;
1458 unsigned long consumed;
1460 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1461 ce = create_from_disk(disk_ce, &consumed, previous_name);
1462 set_index_entry(istate, i, ce);
1464 src_offset += consumed;
1466 strbuf_release(&previous_name_buf);
1467 istate->timestamp.sec = st.st_mtime;
1468 istate->timestamp.nsec = ST_MTIME_NSEC(st);
1470 while (src_offset <= mmap_size - 20 - 8) {
1471 /* After an array of active_nr index entries,
1472 * there can be arbitrary number of extended
1473 * sections, each of which is prefixed with
1474 * extension name (4-byte) and section length
1475 * in 4-byte network byte order.
1477 uint32_t extsize;
1478 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1479 extsize = ntohl(extsize);
1480 if (read_index_extension(istate,
1481 (const char *) mmap + src_offset,
1482 (char *) mmap + src_offset + 8,
1483 extsize) < 0)
1484 goto unmap;
1485 src_offset += 8;
1486 src_offset += extsize;
1488 munmap(mmap, mmap_size);
1489 return istate->cache_nr;
1491 unmap:
1492 munmap(mmap, mmap_size);
1493 errno = EINVAL;
1494 die("index file corrupt");
1497 int is_index_unborn(struct index_state *istate)
1499 return (!istate->cache_nr && !istate->timestamp.sec);
1502 int discard_index(struct index_state *istate)
1504 int i;
1506 for (i = 0; i < istate->cache_nr; i++)
1507 free(istate->cache[i]);
1508 resolve_undo_clear_index(istate);
1509 istate->cache_nr = 0;
1510 istate->cache_changed = 0;
1511 istate->timestamp.sec = 0;
1512 istate->timestamp.nsec = 0;
1513 istate->name_hash_initialized = 0;
1514 free_hash(&istate->name_hash);
1515 cache_tree_free(&(istate->cache_tree));
1516 istate->initialized = 0;
1518 /* no need to throw away allocated active_cache */
1519 return 0;
1522 int unmerged_index(const struct index_state *istate)
1524 int i;
1525 for (i = 0; i < istate->cache_nr; i++) {
1526 if (ce_stage(istate->cache[i]))
1527 return 1;
1529 return 0;
1532 #define WRITE_BUFFER_SIZE 8192
1533 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1534 static unsigned long write_buffer_len;
1536 static int ce_write_flush(git_SHA_CTX *context, int fd)
1538 unsigned int buffered = write_buffer_len;
1539 if (buffered) {
1540 git_SHA1_Update(context, write_buffer, buffered);
1541 if (write_in_full(fd, write_buffer, buffered) != buffered)
1542 return -1;
1543 write_buffer_len = 0;
1545 return 0;
1548 static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
1550 while (len) {
1551 unsigned int buffered = write_buffer_len;
1552 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1553 if (partial > len)
1554 partial = len;
1555 memcpy(write_buffer + buffered, data, partial);
1556 buffered += partial;
1557 if (buffered == WRITE_BUFFER_SIZE) {
1558 write_buffer_len = buffered;
1559 if (ce_write_flush(context, fd))
1560 return -1;
1561 buffered = 0;
1563 write_buffer_len = buffered;
1564 len -= partial;
1565 data = (char *) data + partial;
1567 return 0;
1570 static int write_index_ext_header(git_SHA_CTX *context, int fd,
1571 unsigned int ext, unsigned int sz)
1573 ext = htonl(ext);
1574 sz = htonl(sz);
1575 return ((ce_write(context, fd, &ext, 4) < 0) ||
1576 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1579 static int ce_flush(git_SHA_CTX *context, int fd)
1581 unsigned int left = write_buffer_len;
1583 if (left) {
1584 write_buffer_len = 0;
1585 git_SHA1_Update(context, write_buffer, left);
1588 /* Flush first if not enough space for SHA1 signature */
1589 if (left + 20 > WRITE_BUFFER_SIZE) {
1590 if (write_in_full(fd, write_buffer, left) != left)
1591 return -1;
1592 left = 0;
1595 /* Append the SHA1 signature at the end */
1596 git_SHA1_Final(write_buffer + left, context);
1597 left += 20;
1598 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1601 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1604 * The only thing we care about in this function is to smudge the
1605 * falsely clean entry due to touch-update-touch race, so we leave
1606 * everything else as they are. We are called for entries whose
1607 * ce_mtime match the index file mtime.
1609 * Note that this actually does not do much for gitlinks, for
1610 * which ce_match_stat_basic() always goes to the actual
1611 * contents. The caller checks with is_racy_timestamp() which
1612 * always says "no" for gitlinks, so we are not called for them ;-)
1614 struct stat st;
1616 if (lstat(ce->name, &st) < 0)
1617 return;
1618 if (ce_match_stat_basic(ce, &st))
1619 return;
1620 if (ce_modified_check_fs(ce, &st)) {
1621 /* This is "racily clean"; smudge it. Note that this
1622 * is a tricky code. At first glance, it may appear
1623 * that it can break with this sequence:
1625 * $ echo xyzzy >frotz
1626 * $ git-update-index --add frotz
1627 * $ : >frotz
1628 * $ sleep 3
1629 * $ echo filfre >nitfol
1630 * $ git-update-index --add nitfol
1632 * but it does not. When the second update-index runs,
1633 * it notices that the entry "frotz" has the same timestamp
1634 * as index, and if we were to smudge it by resetting its
1635 * size to zero here, then the object name recorded
1636 * in index is the 6-byte file but the cached stat information
1637 * becomes zero --- which would then match what we would
1638 * obtain from the filesystem next time we stat("frotz").
1640 * However, the second update-index, before calling
1641 * this function, notices that the cached size is 6
1642 * bytes and what is on the filesystem is an empty
1643 * file, and never calls us, so the cached size information
1644 * for "frotz" stays 6 which does not match the filesystem.
1646 ce->ce_size = 0;
1650 /* Copy miscellaneous fields but not the name */
1651 static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
1652 struct cache_entry *ce)
1654 ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
1655 ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
1656 ondisk->ctime.nsec = htonl(ce->ce_ctime.nsec);
1657 ondisk->mtime.nsec = htonl(ce->ce_mtime.nsec);
1658 ondisk->dev = htonl(ce->ce_dev);
1659 ondisk->ino = htonl(ce->ce_ino);
1660 ondisk->mode = htonl(ce->ce_mode);
1661 ondisk->uid = htonl(ce->ce_uid);
1662 ondisk->gid = htonl(ce->ce_gid);
1663 ondisk->size = htonl(ce->ce_size);
1664 hashcpy(ondisk->sha1, ce->sha1);
1665 ondisk->flags = htons(ce->ce_flags);
1666 if (ce->ce_flags & CE_EXTENDED) {
1667 struct ondisk_cache_entry_extended *ondisk2;
1668 ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
1669 ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
1670 return ondisk2->name;
1672 else {
1673 return ondisk->name;
1677 static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
1678 struct strbuf *previous_name)
1680 int size;
1681 struct ondisk_cache_entry *ondisk;
1682 char *name;
1683 int result;
1685 if (!previous_name) {
1686 size = ondisk_ce_size(ce);
1687 ondisk = xcalloc(1, size);
1688 name = copy_cache_entry_to_ondisk(ondisk, ce);
1689 memcpy(name, ce->name, ce_namelen(ce));
1690 } else {
1691 int common, to_remove, prefix_size;
1692 unsigned char to_remove_vi[16];
1693 for (common = 0;
1694 (ce->name[common] &&
1695 common < previous_name->len &&
1696 ce->name[common] == previous_name->buf[common]);
1697 common++)
1698 ; /* still matching */
1699 to_remove = previous_name->len - common;
1700 prefix_size = encode_varint(to_remove, to_remove_vi);
1702 if (ce->ce_flags & CE_EXTENDED)
1703 size = offsetof(struct ondisk_cache_entry_extended, name);
1704 else
1705 size = offsetof(struct ondisk_cache_entry, name);
1706 size += prefix_size + (ce_namelen(ce) - common + 1);
1708 ondisk = xcalloc(1, size);
1709 name = copy_cache_entry_to_ondisk(ondisk, ce);
1710 memcpy(name, to_remove_vi, prefix_size);
1711 memcpy(name + prefix_size, ce->name + common, ce_namelen(ce) - common);
1713 strbuf_splice(previous_name, common, to_remove,
1714 ce->name + common, ce_namelen(ce) - common);
1717 result = ce_write(c, fd, ondisk, size);
1718 free(ondisk);
1719 return result;
1722 static int has_racy_timestamp(struct index_state *istate)
1724 int entries = istate->cache_nr;
1725 int i;
1727 for (i = 0; i < entries; i++) {
1728 struct cache_entry *ce = istate->cache[i];
1729 if (is_racy_timestamp(istate, ce))
1730 return 1;
1732 return 0;
1736 * Opportunisticly update the index but do not complain if we can't
1738 void update_index_if_able(struct index_state *istate, struct lock_file *lockfile)
1740 if ((istate->cache_changed || has_racy_timestamp(istate)) &&
1741 !write_index(istate, lockfile->fd))
1742 commit_locked_index(lockfile);
1743 else
1744 rollback_lock_file(lockfile);
1747 int write_index(struct index_state *istate, int newfd)
1749 git_SHA_CTX c;
1750 struct cache_header hdr;
1751 int i, err, removed, extended, hdr_version;
1752 struct cache_entry **cache = istate->cache;
1753 int entries = istate->cache_nr;
1754 struct stat st;
1755 struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
1757 for (i = removed = extended = 0; i < entries; i++) {
1758 if (cache[i]->ce_flags & CE_REMOVE)
1759 removed++;
1761 /* reduce extended entries if possible */
1762 cache[i]->ce_flags &= ~CE_EXTENDED;
1763 if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) {
1764 extended++;
1765 cache[i]->ce_flags |= CE_EXTENDED;
1769 if (!istate->version)
1770 istate->version = INDEX_FORMAT_DEFAULT;
1772 /* demote version 3 to version 2 when the latter suffices */
1773 if (istate->version == 3 || istate->version == 2)
1774 istate->version = extended ? 3 : 2;
1776 hdr_version = istate->version;
1778 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1779 hdr.hdr_version = htonl(hdr_version);
1780 hdr.hdr_entries = htonl(entries - removed);
1782 git_SHA1_Init(&c);
1783 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1784 return -1;
1786 previous_name = (hdr_version == 4) ? &previous_name_buf : NULL;
1787 for (i = 0; i < entries; i++) {
1788 struct cache_entry *ce = cache[i];
1789 if (ce->ce_flags & CE_REMOVE)
1790 continue;
1791 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
1792 ce_smudge_racily_clean_entry(ce);
1793 if (ce_write_entry(&c, newfd, ce, previous_name) < 0)
1794 return -1;
1796 strbuf_release(&previous_name_buf);
1798 /* Write extension data here */
1799 if (istate->cache_tree) {
1800 struct strbuf sb = STRBUF_INIT;
1802 cache_tree_write(&sb, istate->cache_tree);
1803 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1804 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1805 strbuf_release(&sb);
1806 if (err)
1807 return -1;
1809 if (istate->resolve_undo) {
1810 struct strbuf sb = STRBUF_INIT;
1812 resolve_undo_write(&sb, istate->resolve_undo);
1813 err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,
1814 sb.len) < 0
1815 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1816 strbuf_release(&sb);
1817 if (err)
1818 return -1;
1821 if (ce_flush(&c, newfd) || fstat(newfd, &st))
1822 return -1;
1823 istate->timestamp.sec = (unsigned int)st.st_mtime;
1824 istate->timestamp.nsec = ST_MTIME_NSEC(st);
1825 return 0;
1829 * Read the index file that is potentially unmerged into given
1830 * index_state, dropping any unmerged entries. Returns true if
1831 * the index is unmerged. Callers who want to refuse to work
1832 * from an unmerged state can call this and check its return value,
1833 * instead of calling read_cache().
1835 int read_index_unmerged(struct index_state *istate)
1837 int i;
1838 int unmerged = 0;
1840 read_index(istate);
1841 for (i = 0; i < istate->cache_nr; i++) {
1842 struct cache_entry *ce = istate->cache[i];
1843 struct cache_entry *new_ce;
1844 int size, len;
1846 if (!ce_stage(ce))
1847 continue;
1848 unmerged = 1;
1849 len = strlen(ce->name);
1850 size = cache_entry_size(len);
1851 new_ce = xcalloc(1, size);
1852 memcpy(new_ce->name, ce->name, len);
1853 new_ce->ce_flags = create_ce_flags(len, 0) | CE_CONFLICTED;
1854 new_ce->ce_mode = ce->ce_mode;
1855 if (add_index_entry(istate, new_ce, 0))
1856 return error("%s: cannot drop to stage #0",
1857 ce->name);
1858 i = index_name_pos(istate, new_ce->name, len);
1860 return unmerged;
1864 * Returns 1 if the path is an "other" path with respect to
1865 * the index; that is, the path is not mentioned in the index at all,
1866 * either as a file, a directory with some files in the index,
1867 * or as an unmerged entry.
1869 * We helpfully remove a trailing "/" from directories so that
1870 * the output of read_directory can be used as-is.
1872 int index_name_is_other(const struct index_state *istate, const char *name,
1873 int namelen)
1875 int pos;
1876 if (namelen && name[namelen - 1] == '/')
1877 namelen--;
1878 pos = index_name_pos(istate, name, namelen);
1879 if (0 <= pos)
1880 return 0; /* exact match */
1881 pos = -pos - 1;
1882 if (pos < istate->cache_nr) {
1883 struct cache_entry *ce = istate->cache[pos];
1884 if (ce_namelen(ce) == namelen &&
1885 !memcmp(ce->name, name, namelen))
1886 return 0; /* Yup, this one exists unmerged */
1888 return 1;