Merge branch 'jc/help' into maint
[git/jnareb-git.git] / read-cache.c
blobfda78bc353afcfd4d01864f2a13158d9c9c55173
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 /* Mask for the name length in ce_flags in the on-disk index */
22 #define CE_NAMEMASK (0x0fff)
24 /* Index extensions.
26 * The first letter should be 'A'..'Z' for extensions that are not
27 * necessary for a correct operation (i.e. optimization data).
28 * When new extensions are added that _needs_ to be understood in
29 * order to correctly interpret the index file, pick character that
30 * is outside the range, to cause the reader to abort.
33 #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
34 #define CACHE_EXT_TREE 0x54524545 /* "TREE" */
35 #define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
37 struct index_state the_index;
39 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
41 istate->cache[nr] = ce;
42 add_name_hash(istate, ce);
45 static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
47 struct cache_entry *old = istate->cache[nr];
49 remove_name_hash(old);
50 set_index_entry(istate, nr, ce);
51 istate->cache_changed = 1;
54 void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name)
56 struct cache_entry *old = istate->cache[nr], *new;
57 int namelen = strlen(new_name);
59 new = xmalloc(cache_entry_size(namelen));
60 copy_cache_entry(new, old);
61 new->ce_flags &= ~CE_STATE_MASK;
62 new->ce_namelen = namelen;
63 memcpy(new->name, new_name, namelen + 1);
65 cache_tree_invalidate_path(istate->cache_tree, old->name);
66 remove_index_entry_at(istate, nr);
67 add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
71 * This only updates the "non-critical" parts of the directory
72 * cache, ie the parts that aren't tracked by GIT, and only used
73 * to validate the cache.
75 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
77 ce->ce_ctime.sec = (unsigned int)st->st_ctime;
78 ce->ce_mtime.sec = (unsigned int)st->st_mtime;
79 ce->ce_ctime.nsec = ST_CTIME_NSEC(*st);
80 ce->ce_mtime.nsec = ST_MTIME_NSEC(*st);
81 ce->ce_dev = st->st_dev;
82 ce->ce_ino = st->st_ino;
83 ce->ce_uid = st->st_uid;
84 ce->ce_gid = st->st_gid;
85 ce->ce_size = st->st_size;
87 if (assume_unchanged)
88 ce->ce_flags |= CE_VALID;
90 if (S_ISREG(st->st_mode))
91 ce_mark_uptodate(ce);
94 static int ce_compare_data(struct cache_entry *ce, struct stat *st)
96 int match = -1;
97 int fd = open(ce->name, O_RDONLY);
99 if (fd >= 0) {
100 unsigned char sha1[20];
101 if (!index_fd(sha1, fd, st, OBJ_BLOB, ce->name, 0))
102 match = hashcmp(sha1, ce->sha1);
103 /* index_fd() closed the file descriptor already */
105 return match;
108 static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
110 int match = -1;
111 void *buffer;
112 unsigned long size;
113 enum object_type type;
114 struct strbuf sb = STRBUF_INIT;
116 if (strbuf_readlink(&sb, ce->name, expected_size))
117 return -1;
119 buffer = read_sha1_file(ce->sha1, &type, &size);
120 if (buffer) {
121 if (size == sb.len)
122 match = memcmp(buffer, sb.buf, size);
123 free(buffer);
125 strbuf_release(&sb);
126 return match;
129 static int ce_compare_gitlink(struct cache_entry *ce)
131 unsigned char sha1[20];
134 * We don't actually require that the .git directory
135 * under GITLINK directory be a valid git directory. It
136 * might even be missing (in case nobody populated that
137 * sub-project).
139 * If so, we consider it always to match.
141 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
142 return 0;
143 return hashcmp(sha1, ce->sha1);
146 static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
148 switch (st->st_mode & S_IFMT) {
149 case S_IFREG:
150 if (ce_compare_data(ce, st))
151 return DATA_CHANGED;
152 break;
153 case S_IFLNK:
154 if (ce_compare_link(ce, xsize_t(st->st_size)))
155 return DATA_CHANGED;
156 break;
157 case S_IFDIR:
158 if (S_ISGITLINK(ce->ce_mode))
159 return ce_compare_gitlink(ce) ? DATA_CHANGED : 0;
160 default:
161 return TYPE_CHANGED;
163 return 0;
166 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
168 unsigned int changed = 0;
170 if (ce->ce_flags & CE_REMOVE)
171 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
173 switch (ce->ce_mode & S_IFMT) {
174 case S_IFREG:
175 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
176 /* We consider only the owner x bit to be relevant for
177 * "mode changes"
179 if (trust_executable_bit &&
180 (0100 & (ce->ce_mode ^ st->st_mode)))
181 changed |= MODE_CHANGED;
182 break;
183 case S_IFLNK:
184 if (!S_ISLNK(st->st_mode) &&
185 (has_symlinks || !S_ISREG(st->st_mode)))
186 changed |= TYPE_CHANGED;
187 break;
188 case S_IFGITLINK:
189 /* We ignore most of the st_xxx fields for gitlinks */
190 if (!S_ISDIR(st->st_mode))
191 changed |= TYPE_CHANGED;
192 else if (ce_compare_gitlink(ce))
193 changed |= DATA_CHANGED;
194 return changed;
195 default:
196 die("internal error: ce_mode is %o", ce->ce_mode);
198 if (ce->ce_mtime.sec != (unsigned int)st->st_mtime)
199 changed |= MTIME_CHANGED;
200 if (trust_ctime && ce->ce_ctime.sec != (unsigned int)st->st_ctime)
201 changed |= CTIME_CHANGED;
203 #ifdef USE_NSEC
204 if (ce->ce_mtime.nsec != ST_MTIME_NSEC(*st))
205 changed |= MTIME_CHANGED;
206 if (trust_ctime && ce->ce_ctime.nsec != ST_CTIME_NSEC(*st))
207 changed |= CTIME_CHANGED;
208 #endif
210 if (ce->ce_uid != (unsigned int) st->st_uid ||
211 ce->ce_gid != (unsigned int) st->st_gid)
212 changed |= OWNER_CHANGED;
213 if (ce->ce_ino != (unsigned int) st->st_ino)
214 changed |= INODE_CHANGED;
216 #ifdef USE_STDEV
218 * st_dev breaks on network filesystems where different
219 * clients will have different views of what "device"
220 * the filesystem is on
222 if (ce->ce_dev != (unsigned int) st->st_dev)
223 changed |= INODE_CHANGED;
224 #endif
226 if (ce->ce_size != (unsigned int) st->st_size)
227 changed |= DATA_CHANGED;
229 /* Racily smudged entry? */
230 if (!ce->ce_size) {
231 if (!is_empty_blob_sha1(ce->sha1))
232 changed |= DATA_CHANGED;
235 return changed;
238 static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
240 return (!S_ISGITLINK(ce->ce_mode) &&
241 istate->timestamp.sec &&
242 #ifdef USE_NSEC
243 /* nanosecond timestamped files can also be racy! */
244 (istate->timestamp.sec < ce->ce_mtime.sec ||
245 (istate->timestamp.sec == ce->ce_mtime.sec &&
246 istate->timestamp.nsec <= ce->ce_mtime.nsec))
247 #else
248 istate->timestamp.sec <= ce->ce_mtime.sec
249 #endif
253 int ie_match_stat(const struct index_state *istate,
254 struct cache_entry *ce, struct stat *st,
255 unsigned int options)
257 unsigned int changed;
258 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
259 int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
260 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
263 * If it's marked as always valid in the index, it's
264 * valid whatever the checked-out copy says.
266 * skip-worktree has the same effect with higher precedence
268 if (!ignore_skip_worktree && ce_skip_worktree(ce))
269 return 0;
270 if (!ignore_valid && (ce->ce_flags & CE_VALID))
271 return 0;
274 * Intent-to-add entries have not been added, so the index entry
275 * by definition never matches what is in the work tree until it
276 * actually gets added.
278 if (ce->ce_flags & CE_INTENT_TO_ADD)
279 return DATA_CHANGED | TYPE_CHANGED | MODE_CHANGED;
281 changed = ce_match_stat_basic(ce, st);
284 * Within 1 second of this sequence:
285 * echo xyzzy >file && git-update-index --add file
286 * running this command:
287 * echo frotz >file
288 * would give a falsely clean cache entry. The mtime and
289 * length match the cache, and other stat fields do not change.
291 * We could detect this at update-index time (the cache entry
292 * being registered/updated records the same time as "now")
293 * and delay the return from git-update-index, but that would
294 * effectively mean we can make at most one commit per second,
295 * which is not acceptable. Instead, we check cache entries
296 * whose mtime are the same as the index file timestamp more
297 * carefully than others.
299 if (!changed && is_racy_timestamp(istate, ce)) {
300 if (assume_racy_is_modified)
301 changed |= DATA_CHANGED;
302 else
303 changed |= ce_modified_check_fs(ce, st);
306 return changed;
309 int ie_modified(const struct index_state *istate,
310 struct cache_entry *ce, struct stat *st, unsigned int options)
312 int changed, changed_fs;
314 changed = ie_match_stat(istate, ce, st, options);
315 if (!changed)
316 return 0;
318 * If the mode or type has changed, there's no point in trying
319 * to refresh the entry - it's not going to match
321 if (changed & (MODE_CHANGED | TYPE_CHANGED))
322 return changed;
325 * Immediately after read-tree or update-index --cacheinfo,
326 * the length field is zero, as we have never even read the
327 * lstat(2) information once, and we cannot trust DATA_CHANGED
328 * returned by ie_match_stat() which in turn was returned by
329 * ce_match_stat_basic() to signal that the filesize of the
330 * blob changed. We have to actually go to the filesystem to
331 * see if the contents match, and if so, should answer "unchanged".
333 * The logic does not apply to gitlinks, as ce_match_stat_basic()
334 * already has checked the actual HEAD from the filesystem in the
335 * subproject. If ie_match_stat() already said it is different,
336 * then we know it is.
338 if ((changed & DATA_CHANGED) &&
339 (S_ISGITLINK(ce->ce_mode) || ce->ce_size != 0))
340 return changed;
342 changed_fs = ce_modified_check_fs(ce, st);
343 if (changed_fs)
344 return changed | changed_fs;
345 return 0;
348 int base_name_compare(const char *name1, int len1, int mode1,
349 const char *name2, int len2, int mode2)
351 unsigned char c1, c2;
352 int len = len1 < len2 ? len1 : len2;
353 int cmp;
355 cmp = memcmp(name1, name2, len);
356 if (cmp)
357 return cmp;
358 c1 = name1[len];
359 c2 = name2[len];
360 if (!c1 && S_ISDIR(mode1))
361 c1 = '/';
362 if (!c2 && S_ISDIR(mode2))
363 c2 = '/';
364 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
368 * df_name_compare() is identical to base_name_compare(), except it
369 * compares conflicting directory/file entries as equal. Note that
370 * while a directory name compares as equal to a regular file, they
371 * then individually compare _differently_ to a filename that has
372 * a dot after the basename (because '\0' < '.' < '/').
374 * This is used by routines that want to traverse the git namespace
375 * but then handle conflicting entries together when possible.
377 int df_name_compare(const char *name1, int len1, int mode1,
378 const char *name2, int len2, int mode2)
380 int len = len1 < len2 ? len1 : len2, cmp;
381 unsigned char c1, c2;
383 cmp = memcmp(name1, name2, len);
384 if (cmp)
385 return cmp;
386 /* Directories and files compare equal (same length, same name) */
387 if (len1 == len2)
388 return 0;
389 c1 = name1[len];
390 if (!c1 && S_ISDIR(mode1))
391 c1 = '/';
392 c2 = name2[len];
393 if (!c2 && S_ISDIR(mode2))
394 c2 = '/';
395 if (c1 == '/' && !c2)
396 return 0;
397 if (c2 == '/' && !c1)
398 return 0;
399 return c1 - c2;
402 int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2)
404 int len = len1 < len2 ? len1 : len2;
405 int cmp;
407 cmp = memcmp(name1, name2, len);
408 if (cmp)
409 return cmp;
410 if (len1 < len2)
411 return -1;
412 if (len1 > len2)
413 return 1;
415 if (stage1 < stage2)
416 return -1;
417 if (stage1 > stage2)
418 return 1;
419 return 0;
422 int cache_name_compare(const char *name1, int len1, const char *name2, int len2)
424 return cache_name_stage_compare(name1, len1, 0, name2, len2, 0);
427 static int index_name_stage_pos(const struct index_state *istate, const char *name, int namelen, int stage)
429 int first, last;
431 first = 0;
432 last = istate->cache_nr;
433 while (last > first) {
434 int next = (last + first) >> 1;
435 struct cache_entry *ce = istate->cache[next];
436 int cmp = cache_name_stage_compare(name, namelen, stage, ce->name, ce_namelen(ce), ce_stage(ce));
437 if (!cmp)
438 return next;
439 if (cmp < 0) {
440 last = next;
441 continue;
443 first = next+1;
445 return -first-1;
448 int index_name_pos(const struct index_state *istate, const char *name, int namelen)
450 return index_name_stage_pos(istate, name, namelen, 0);
453 /* Remove entry, return true if there are more entries to go.. */
454 int remove_index_entry_at(struct index_state *istate, int pos)
456 struct cache_entry *ce = istate->cache[pos];
458 record_resolve_undo(istate, ce);
459 remove_name_hash(ce);
460 istate->cache_changed = 1;
461 istate->cache_nr--;
462 if (pos >= istate->cache_nr)
463 return 0;
464 memmove(istate->cache + pos,
465 istate->cache + pos + 1,
466 (istate->cache_nr - pos) * sizeof(struct cache_entry *));
467 return 1;
471 * Remove all cache ententries marked for removal, that is where
472 * CE_REMOVE is set in ce_flags. This is much more effective than
473 * calling remove_index_entry_at() for each entry to be removed.
475 void remove_marked_cache_entries(struct index_state *istate)
477 struct cache_entry **ce_array = istate->cache;
478 unsigned int i, j;
480 for (i = j = 0; i < istate->cache_nr; i++) {
481 if (ce_array[i]->ce_flags & CE_REMOVE)
482 remove_name_hash(ce_array[i]);
483 else
484 ce_array[j++] = ce_array[i];
486 istate->cache_changed = 1;
487 istate->cache_nr = j;
490 int remove_file_from_index(struct index_state *istate, const char *path)
492 int pos = index_name_pos(istate, path, strlen(path));
493 if (pos < 0)
494 pos = -pos-1;
495 cache_tree_invalidate_path(istate->cache_tree, path);
496 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
497 remove_index_entry_at(istate, pos);
498 return 0;
501 static int compare_name(struct cache_entry *ce, const char *path, int namelen)
503 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
506 static int index_name_pos_also_unmerged(struct index_state *istate,
507 const char *path, int namelen)
509 int pos = index_name_pos(istate, path, namelen);
510 struct cache_entry *ce;
512 if (pos >= 0)
513 return pos;
515 /* maybe unmerged? */
516 pos = -1 - pos;
517 if (pos >= istate->cache_nr ||
518 compare_name((ce = istate->cache[pos]), path, namelen))
519 return -1;
521 /* order of preference: stage 2, 1, 3 */
522 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
523 ce_stage((ce = istate->cache[pos + 1])) == 2 &&
524 !compare_name(ce, path, namelen))
525 pos++;
526 return pos;
529 static int different_name(struct cache_entry *ce, struct cache_entry *alias)
531 int len = ce_namelen(ce);
532 return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
536 * If we add a filename that aliases in the cache, we will use the
537 * name that we already have - but we don't want to update the same
538 * alias twice, because that implies that there were actually two
539 * different files with aliasing names!
541 * So we use the CE_ADDED flag to verify that the alias was an old
542 * one before we accept it as
544 static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias)
546 int len;
547 struct cache_entry *new;
549 if (alias->ce_flags & CE_ADDED)
550 die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
552 /* Ok, create the new entry using the name of the existing alias */
553 len = ce_namelen(alias);
554 new = xcalloc(1, cache_entry_size(len));
555 memcpy(new->name, alias->name, len);
556 copy_cache_entry(new, ce);
557 free(ce);
558 return new;
561 static void record_intent_to_add(struct cache_entry *ce)
563 unsigned char sha1[20];
564 if (write_sha1_file("", 0, blob_type, sha1))
565 die("cannot create an empty blob in the object database");
566 hashcpy(ce->sha1, sha1);
569 int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
571 int size, namelen, was_same;
572 mode_t st_mode = st->st_mode;
573 struct cache_entry *ce, *alias;
574 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE|CE_MATCH_RACY_IS_DIRTY;
575 int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND);
576 int pretend = flags & ADD_CACHE_PRETEND;
577 int intent_only = flags & ADD_CACHE_INTENT;
578 int add_option = (ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE|
579 (intent_only ? ADD_CACHE_NEW_ONLY : 0));
581 if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode))
582 return error("%s: can only add regular files, symbolic links or git-directories", path);
584 namelen = strlen(path);
585 if (S_ISDIR(st_mode)) {
586 while (namelen && path[namelen-1] == '/')
587 namelen--;
589 size = cache_entry_size(namelen);
590 ce = xcalloc(1, size);
591 memcpy(ce->name, path, namelen);
592 ce->ce_namelen = namelen;
593 if (!intent_only)
594 fill_stat_cache_info(ce, st);
595 else
596 ce->ce_flags |= CE_INTENT_TO_ADD;
598 if (trust_executable_bit && has_symlinks)
599 ce->ce_mode = create_ce_mode(st_mode);
600 else {
601 /* If there is an existing entry, pick the mode bits and type
602 * from it, otherwise assume unexecutable regular file.
604 struct cache_entry *ent;
605 int pos = index_name_pos_also_unmerged(istate, path, namelen);
607 ent = (0 <= pos) ? istate->cache[pos] : NULL;
608 ce->ce_mode = ce_mode_from_stat(ent, st_mode);
611 /* When core.ignorecase=true, determine if a directory of the same name but differing
612 * case already exists within the Git repository. If it does, ensure the directory
613 * case of the file being added to the repository matches (is folded into) the existing
614 * entry's directory case.
616 if (ignore_case) {
617 const char *startPtr = ce->name;
618 const char *ptr = startPtr;
619 while (*ptr) {
620 while (*ptr && *ptr != '/')
621 ++ptr;
622 if (*ptr == '/') {
623 struct cache_entry *foundce;
624 ++ptr;
625 foundce = index_name_exists(&the_index, ce->name, ptr - ce->name, ignore_case);
626 if (foundce) {
627 memcpy((void *)startPtr, foundce->name + (startPtr - ce->name), ptr - startPtr);
628 startPtr = ptr;
634 alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case);
635 if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) {
636 /* Nothing changed, really */
637 free(ce);
638 if (!S_ISGITLINK(alias->ce_mode))
639 ce_mark_uptodate(alias);
640 alias->ce_flags |= CE_ADDED;
641 return 0;
643 if (!intent_only) {
644 if (index_path(ce->sha1, path, st, HASH_WRITE_OBJECT))
645 return error("unable to index file %s", path);
646 } else
647 record_intent_to_add(ce);
649 if (ignore_case && alias && different_name(ce, alias))
650 ce = create_alias_ce(ce, alias);
651 ce->ce_flags |= CE_ADDED;
653 /* It was suspected to be racily clean, but it turns out to be Ok */
654 was_same = (alias &&
655 !ce_stage(alias) &&
656 !hashcmp(alias->sha1, ce->sha1) &&
657 ce->ce_mode == alias->ce_mode);
659 if (pretend)
661 else if (add_index_entry(istate, ce, add_option))
662 return error("unable to add %s to index",path);
663 if (verbose && !was_same)
664 printf("add '%s'\n", path);
665 return 0;
668 int add_file_to_index(struct index_state *istate, const char *path, int flags)
670 struct stat st;
671 if (lstat(path, &st))
672 die_errno("unable to stat '%s'", path);
673 return add_to_index(istate, path, &st, flags);
676 struct cache_entry *make_cache_entry(unsigned int mode,
677 const unsigned char *sha1, const char *path, int stage,
678 int refresh)
680 int size, len;
681 struct cache_entry *ce;
683 if (!verify_path(path)) {
684 error("Invalid path '%s'", path);
685 return NULL;
688 len = strlen(path);
689 size = cache_entry_size(len);
690 ce = xcalloc(1, size);
692 hashcpy(ce->sha1, sha1);
693 memcpy(ce->name, path, len);
694 ce->ce_flags = create_ce_flags(stage);
695 ce->ce_namelen = len;
696 ce->ce_mode = create_ce_mode(mode);
698 if (refresh)
699 return refresh_cache_entry(ce, 0);
701 return ce;
704 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
706 int len = ce_namelen(a);
707 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
710 int ce_path_match(const struct cache_entry *ce, const struct pathspec *pathspec)
712 return match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL);
716 * We fundamentally don't like some paths: we don't want
717 * dot or dot-dot anywhere, and for obvious reasons don't
718 * want to recurse into ".git" either.
720 * Also, we don't want double slashes or slashes at the
721 * end that can make pathnames ambiguous.
723 static int verify_dotfile(const char *rest)
726 * The first character was '.', but that
727 * has already been discarded, we now test
728 * the rest.
731 /* "." is not allowed */
732 if (*rest == '\0' || is_dir_sep(*rest))
733 return 0;
735 switch (*rest) {
737 * ".git" followed by NUL or slash is bad. This
738 * shares the path end test with the ".." case.
740 case 'g':
741 if (rest[1] != 'i')
742 break;
743 if (rest[2] != 't')
744 break;
745 rest += 2;
746 /* fallthrough */
747 case '.':
748 if (rest[1] == '\0' || is_dir_sep(rest[1]))
749 return 0;
751 return 1;
754 int verify_path(const char *path)
756 char c;
758 if (has_dos_drive_prefix(path))
759 return 0;
761 goto inside;
762 for (;;) {
763 if (!c)
764 return 1;
765 if (is_dir_sep(c)) {
766 inside:
767 c = *path++;
768 if ((c == '.' && !verify_dotfile(path)) ||
769 is_dir_sep(c) || c == '\0')
770 return 0;
772 c = *path++;
777 * Do we have another file that has the beginning components being a
778 * proper superset of the name we're trying to add?
780 static int has_file_name(struct index_state *istate,
781 const struct cache_entry *ce, int pos, int ok_to_replace)
783 int retval = 0;
784 int len = ce_namelen(ce);
785 int stage = ce_stage(ce);
786 const char *name = ce->name;
788 while (pos < istate->cache_nr) {
789 struct cache_entry *p = istate->cache[pos++];
791 if (len >= ce_namelen(p))
792 break;
793 if (memcmp(name, p->name, len))
794 break;
795 if (ce_stage(p) != stage)
796 continue;
797 if (p->name[len] != '/')
798 continue;
799 if (p->ce_flags & CE_REMOVE)
800 continue;
801 retval = -1;
802 if (!ok_to_replace)
803 break;
804 remove_index_entry_at(istate, --pos);
806 return retval;
810 * Do we have another file with a pathname that is a proper
811 * subset of the name we're trying to add?
813 static int has_dir_name(struct index_state *istate,
814 const struct cache_entry *ce, int pos, int ok_to_replace)
816 int retval = 0;
817 int stage = ce_stage(ce);
818 const char *name = ce->name;
819 const char *slash = name + ce_namelen(ce);
821 for (;;) {
822 int len;
824 for (;;) {
825 if (*--slash == '/')
826 break;
827 if (slash <= ce->name)
828 return retval;
830 len = slash - name;
832 pos = index_name_stage_pos(istate, name, len, stage);
833 if (pos >= 0) {
835 * Found one, but not so fast. This could
836 * be a marker that says "I was here, but
837 * I am being removed". Such an entry is
838 * not a part of the resulting tree, and
839 * it is Ok to have a directory at the same
840 * path.
842 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
843 retval = -1;
844 if (!ok_to_replace)
845 break;
846 remove_index_entry_at(istate, pos);
847 continue;
850 else
851 pos = -pos-1;
854 * Trivial optimization: if we find an entry that
855 * already matches the sub-directory, then we know
856 * we're ok, and we can exit.
858 while (pos < istate->cache_nr) {
859 struct cache_entry *p = istate->cache[pos];
860 if ((ce_namelen(p) <= len) ||
861 (p->name[len] != '/') ||
862 memcmp(p->name, name, len))
863 break; /* not our subdirectory */
864 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
866 * p is at the same stage as our entry, and
867 * is a subdirectory of what we are looking
868 * at, so we cannot have conflicts at our
869 * level or anything shorter.
871 return retval;
872 pos++;
875 return retval;
878 /* We may be in a situation where we already have path/file and path
879 * is being added, or we already have path and path/file is being
880 * added. Either one would result in a nonsense tree that has path
881 * twice when git-write-tree tries to write it out. Prevent it.
883 * If ok-to-replace is specified, we remove the conflicting entries
884 * from the cache so the caller should recompute the insert position.
885 * When this happens, we return non-zero.
887 static int check_file_directory_conflict(struct index_state *istate,
888 const struct cache_entry *ce,
889 int pos, int ok_to_replace)
891 int retval;
894 * When ce is an "I am going away" entry, we allow it to be added
896 if (ce->ce_flags & CE_REMOVE)
897 return 0;
900 * We check if the path is a sub-path of a subsequent pathname
901 * first, since removing those will not change the position
902 * in the array.
904 retval = has_file_name(istate, ce, pos, ok_to_replace);
907 * Then check if the path might have a clashing sub-directory
908 * before it.
910 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
913 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
915 int pos;
916 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
917 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
918 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
919 int new_only = option & ADD_CACHE_NEW_ONLY;
921 cache_tree_invalidate_path(istate->cache_tree, ce->name);
922 pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
924 /* existing match? Just replace it. */
925 if (pos >= 0) {
926 if (!new_only)
927 replace_index_entry(istate, pos, ce);
928 return 0;
930 pos = -pos-1;
933 * Inserting a merged entry ("stage 0") into the index
934 * will always replace all non-merged entries..
936 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
937 while (ce_same_name(istate->cache[pos], ce)) {
938 ok_to_add = 1;
939 if (!remove_index_entry_at(istate, pos))
940 break;
944 if (!ok_to_add)
945 return -1;
946 if (!verify_path(ce->name))
947 return error("Invalid path '%s'", ce->name);
949 if (!skip_df_check &&
950 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
951 if (!ok_to_replace)
952 return error("'%s' appears as both a file and as a directory",
953 ce->name);
954 pos = index_name_stage_pos(istate, ce->name, ce_namelen(ce), ce_stage(ce));
955 pos = -pos-1;
957 return pos + 1;
960 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
962 int pos;
964 if (option & ADD_CACHE_JUST_APPEND)
965 pos = istate->cache_nr;
966 else {
967 int ret;
968 ret = add_index_entry_with_check(istate, ce, option);
969 if (ret <= 0)
970 return ret;
971 pos = ret - 1;
974 /* Make sure the array is big enough .. */
975 if (istate->cache_nr == istate->cache_alloc) {
976 istate->cache_alloc = alloc_nr(istate->cache_alloc);
977 istate->cache = xrealloc(istate->cache,
978 istate->cache_alloc * sizeof(struct cache_entry *));
981 /* Add it in.. */
982 istate->cache_nr++;
983 if (istate->cache_nr > pos + 1)
984 memmove(istate->cache + pos + 1,
985 istate->cache + pos,
986 (istate->cache_nr - pos - 1) * sizeof(ce));
987 set_index_entry(istate, pos, ce);
988 istate->cache_changed = 1;
989 return 0;
993 * "refresh" does not calculate a new sha1 file or bring the
994 * cache up-to-date for mode/content changes. But what it
995 * _does_ do is to "re-match" the stat information of a file
996 * with the cache, so that you can refresh the cache for a
997 * file that hasn't been changed but where the stat entry is
998 * out of date.
1000 * For example, you'd want to do this after doing a "git-read-tree",
1001 * to link up the stat cache details with the proper files.
1003 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
1004 struct cache_entry *ce,
1005 unsigned int options, int *err,
1006 int *changed_ret)
1008 struct stat st;
1009 struct cache_entry *updated;
1010 int changed, size;
1011 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
1012 int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
1014 if (ce_uptodate(ce))
1015 return ce;
1018 * CE_VALID or CE_SKIP_WORKTREE means the user promised us
1019 * that the change to the work tree does not matter and told
1020 * us not to worry.
1022 if (!ignore_skip_worktree && ce_skip_worktree(ce)) {
1023 ce_mark_uptodate(ce);
1024 return ce;
1026 if (!ignore_valid && (ce->ce_flags & CE_VALID)) {
1027 ce_mark_uptodate(ce);
1028 return ce;
1031 if (lstat(ce->name, &st) < 0) {
1032 if (err)
1033 *err = errno;
1034 return NULL;
1037 changed = ie_match_stat(istate, ce, &st, options);
1038 if (changed_ret)
1039 *changed_ret = changed;
1040 if (!changed) {
1042 * The path is unchanged. If we were told to ignore
1043 * valid bit, then we did the actual stat check and
1044 * found that the entry is unmodified. If the entry
1045 * is not marked VALID, this is the place to mark it
1046 * valid again, under "assume unchanged" mode.
1048 if (ignore_valid && assume_unchanged &&
1049 !(ce->ce_flags & CE_VALID))
1050 ; /* mark this one VALID again */
1051 else {
1053 * We do not mark the index itself "modified"
1054 * because CE_UPTODATE flag is in-core only;
1055 * we are not going to write this change out.
1057 if (!S_ISGITLINK(ce->ce_mode))
1058 ce_mark_uptodate(ce);
1059 return ce;
1063 if (ie_modified(istate, ce, &st, options)) {
1064 if (err)
1065 *err = EINVAL;
1066 return NULL;
1069 size = ce_size(ce);
1070 updated = xmalloc(size);
1071 memcpy(updated, ce, size);
1072 fill_stat_cache_info(updated, &st);
1074 * If ignore_valid is not set, we should leave CE_VALID bit
1075 * alone. Otherwise, paths marked with --no-assume-unchanged
1076 * (i.e. things to be edited) will reacquire CE_VALID bit
1077 * automatically, which is not really what we want.
1079 if (!ignore_valid && assume_unchanged &&
1080 !(ce->ce_flags & CE_VALID))
1081 updated->ce_flags &= ~CE_VALID;
1083 return updated;
1086 static void show_file(const char * fmt, const char * name, int in_porcelain,
1087 int * first, const char *header_msg)
1089 if (in_porcelain && *first && header_msg) {
1090 printf("%s\n", header_msg);
1091 *first = 0;
1093 printf(fmt, name);
1096 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec,
1097 char *seen, const char *header_msg)
1099 int i;
1100 int has_errors = 0;
1101 int really = (flags & REFRESH_REALLY) != 0;
1102 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
1103 int quiet = (flags & REFRESH_QUIET) != 0;
1104 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
1105 int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
1106 int first = 1;
1107 int in_porcelain = (flags & REFRESH_IN_PORCELAIN);
1108 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
1109 const char *modified_fmt;
1110 const char *deleted_fmt;
1111 const char *typechange_fmt;
1112 const char *added_fmt;
1113 const char *unmerged_fmt;
1115 modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
1116 deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n");
1117 typechange_fmt = (in_porcelain ? "T\t%s\n" : "%s needs update\n");
1118 added_fmt = (in_porcelain ? "A\t%s\n" : "%s needs update\n");
1119 unmerged_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n");
1120 for (i = 0; i < istate->cache_nr; i++) {
1121 struct cache_entry *ce, *new;
1122 int cache_errno = 0;
1123 int changed = 0;
1124 int filtered = 0;
1126 ce = istate->cache[i];
1127 if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
1128 continue;
1130 if (pathspec &&
1131 !match_pathspec(pathspec, ce->name, ce_namelen(ce), 0, seen))
1132 filtered = 1;
1134 if (ce_stage(ce)) {
1135 while ((i < istate->cache_nr) &&
1136 ! strcmp(istate->cache[i]->name, ce->name))
1137 i++;
1138 i--;
1139 if (allow_unmerged)
1140 continue;
1141 if (!filtered)
1142 show_file(unmerged_fmt, ce->name, in_porcelain,
1143 &first, header_msg);
1144 has_errors = 1;
1145 continue;
1148 if (filtered)
1149 continue;
1151 new = refresh_cache_ent(istate, ce, options, &cache_errno, &changed);
1152 if (new == ce)
1153 continue;
1154 if (!new) {
1155 const char *fmt;
1157 if (not_new && cache_errno == ENOENT)
1158 continue;
1159 if (really && cache_errno == EINVAL) {
1160 /* If we are doing --really-refresh that
1161 * means the index is not valid anymore.
1163 ce->ce_flags &= ~CE_VALID;
1164 istate->cache_changed = 1;
1166 if (quiet)
1167 continue;
1169 if (cache_errno == ENOENT)
1170 fmt = deleted_fmt;
1171 else if (ce->ce_flags & CE_INTENT_TO_ADD)
1172 fmt = added_fmt; /* must be before other checks */
1173 else if (changed & TYPE_CHANGED)
1174 fmt = typechange_fmt;
1175 else
1176 fmt = modified_fmt;
1177 show_file(fmt,
1178 ce->name, in_porcelain, &first, header_msg);
1179 has_errors = 1;
1180 continue;
1183 replace_index_entry(istate, i, new);
1185 return has_errors;
1188 static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
1190 return refresh_cache_ent(&the_index, ce, really, NULL, NULL);
1194 /*****************************************************************
1195 * Index File I/O
1196 *****************************************************************/
1198 #define INDEX_FORMAT_DEFAULT 3
1201 * dev/ino/uid/gid/size are also just tracked to the low 32 bits
1202 * Again - this is just a (very strong in practice) heuristic that
1203 * the inode hasn't changed.
1205 * We save the fields in big-endian order to allow using the
1206 * index file over NFS transparently.
1208 struct ondisk_cache_entry {
1209 struct cache_time ctime;
1210 struct cache_time mtime;
1211 unsigned int dev;
1212 unsigned int ino;
1213 unsigned int mode;
1214 unsigned int uid;
1215 unsigned int gid;
1216 unsigned int size;
1217 unsigned char sha1[20];
1218 unsigned short flags;
1219 char name[FLEX_ARRAY]; /* more */
1223 * This struct is used when CE_EXTENDED bit is 1
1224 * The struct must match ondisk_cache_entry exactly from
1225 * ctime till flags
1227 struct ondisk_cache_entry_extended {
1228 struct cache_time ctime;
1229 struct cache_time mtime;
1230 unsigned int dev;
1231 unsigned int ino;
1232 unsigned int mode;
1233 unsigned int uid;
1234 unsigned int gid;
1235 unsigned int size;
1236 unsigned char sha1[20];
1237 unsigned short flags;
1238 unsigned short flags2;
1239 char name[FLEX_ARRAY]; /* more */
1242 /* These are only used for v3 or lower */
1243 #define align_flex_name(STRUCT,len) ((offsetof(struct STRUCT,name) + (len) + 8) & ~7)
1244 #define ondisk_cache_entry_size(len) align_flex_name(ondisk_cache_entry,len)
1245 #define ondisk_cache_entry_extended_size(len) align_flex_name(ondisk_cache_entry_extended,len)
1246 #define ondisk_ce_size(ce) (((ce)->ce_flags & CE_EXTENDED) ? \
1247 ondisk_cache_entry_extended_size(ce_namelen(ce)) : \
1248 ondisk_cache_entry_size(ce_namelen(ce)))
1250 static int verify_hdr(struct cache_header *hdr, unsigned long size)
1252 git_SHA_CTX c;
1253 unsigned char sha1[20];
1254 int hdr_version;
1256 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
1257 return error("bad signature");
1258 hdr_version = ntohl(hdr->hdr_version);
1259 if (hdr_version < 2 || 4 < hdr_version)
1260 return error("bad index version %d", hdr_version);
1261 git_SHA1_Init(&c);
1262 git_SHA1_Update(&c, hdr, size - 20);
1263 git_SHA1_Final(sha1, &c);
1264 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1265 return error("bad index file sha1 signature");
1266 return 0;
1269 static int read_index_extension(struct index_state *istate,
1270 const char *ext, void *data, unsigned long sz)
1272 switch (CACHE_EXT(ext)) {
1273 case CACHE_EXT_TREE:
1274 istate->cache_tree = cache_tree_read(data, sz);
1275 break;
1276 case CACHE_EXT_RESOLVE_UNDO:
1277 istate->resolve_undo = resolve_undo_read(data, sz);
1278 break;
1279 default:
1280 if (*ext < 'A' || 'Z' < *ext)
1281 return error("index uses %.4s extension, which we do not understand",
1282 ext);
1283 fprintf(stderr, "ignoring %.4s extension\n", ext);
1284 break;
1286 return 0;
1289 int read_index(struct index_state *istate)
1291 return read_index_from(istate, get_index_file());
1294 #ifndef NEEDS_ALIGNED_ACCESS
1295 #define ntoh_s(var) ntohs(var)
1296 #define ntoh_l(var) ntohl(var)
1297 #else
1298 static inline uint16_t ntoh_s_force_align(void *p)
1300 uint16_t x;
1301 memcpy(&x, p, sizeof(x));
1302 return ntohs(x);
1304 static inline uint32_t ntoh_l_force_align(void *p)
1306 uint32_t x;
1307 memcpy(&x, p, sizeof(x));
1308 return ntohl(x);
1310 #define ntoh_s(var) ntoh_s_force_align(&(var))
1311 #define ntoh_l(var) ntoh_l_force_align(&(var))
1312 #endif
1314 static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk,
1315 unsigned int flags,
1316 const char *name,
1317 size_t len)
1319 struct cache_entry *ce = xmalloc(cache_entry_size(len));
1321 ce->ce_ctime.sec = ntoh_l(ondisk->ctime.sec);
1322 ce->ce_mtime.sec = ntoh_l(ondisk->mtime.sec);
1323 ce->ce_ctime.nsec = ntoh_l(ondisk->ctime.nsec);
1324 ce->ce_mtime.nsec = ntoh_l(ondisk->mtime.nsec);
1325 ce->ce_dev = ntoh_l(ondisk->dev);
1326 ce->ce_ino = ntoh_l(ondisk->ino);
1327 ce->ce_mode = ntoh_l(ondisk->mode);
1328 ce->ce_uid = ntoh_l(ondisk->uid);
1329 ce->ce_gid = ntoh_l(ondisk->gid);
1330 ce->ce_size = ntoh_l(ondisk->size);
1331 ce->ce_flags = flags & ~CE_NAMEMASK;
1332 ce->ce_namelen = len;
1333 hashcpy(ce->sha1, ondisk->sha1);
1334 memcpy(ce->name, name, len);
1335 ce->name[len] = '\0';
1336 return ce;
1340 * Adjacent cache entries tend to share the leading paths, so it makes
1341 * sense to only store the differences in later entries. In the v4
1342 * on-disk format of the index, each on-disk cache entry stores the
1343 * number of bytes to be stripped from the end of the previous name,
1344 * and the bytes to append to the result, to come up with its name.
1346 static unsigned long expand_name_field(struct strbuf *name, const char *cp_)
1348 const unsigned char *ep, *cp = (const unsigned char *)cp_;
1349 size_t len = decode_varint(&cp);
1351 if (name->len < len)
1352 die("malformed name field in the index");
1353 strbuf_remove(name, name->len - len, len);
1354 for (ep = cp; *ep; ep++)
1355 ; /* find the end */
1356 strbuf_add(name, cp, ep - cp);
1357 return (const char *)ep + 1 - cp_;
1360 static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk,
1361 unsigned long *ent_size,
1362 struct strbuf *previous_name)
1364 struct cache_entry *ce;
1365 size_t len;
1366 const char *name;
1367 unsigned int flags;
1369 /* On-disk flags are just 16 bits */
1370 flags = ntoh_s(ondisk->flags);
1371 len = flags & CE_NAMEMASK;
1373 if (flags & CE_EXTENDED) {
1374 struct ondisk_cache_entry_extended *ondisk2;
1375 int extended_flags;
1376 ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
1377 extended_flags = ntoh_s(ondisk2->flags2) << 16;
1378 /* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
1379 if (extended_flags & ~CE_EXTENDED_FLAGS)
1380 die("Unknown index entry format %08x", extended_flags);
1381 flags |= extended_flags;
1382 name = ondisk2->name;
1384 else
1385 name = ondisk->name;
1387 if (!previous_name) {
1388 /* v3 and earlier */
1389 if (len == CE_NAMEMASK)
1390 len = strlen(name);
1391 ce = cache_entry_from_ondisk(ondisk, flags, name, len);
1393 *ent_size = ondisk_ce_size(ce);
1394 } else {
1395 unsigned long consumed;
1396 consumed = expand_name_field(previous_name, name);
1397 ce = cache_entry_from_ondisk(ondisk, flags,
1398 previous_name->buf,
1399 previous_name->len);
1401 *ent_size = (name - ((char *)ondisk)) + consumed;
1403 return ce;
1406 /* remember to discard_cache() before reading a different cache! */
1407 int read_index_from(struct index_state *istate, const char *path)
1409 int fd, i;
1410 struct stat st;
1411 unsigned long src_offset;
1412 struct cache_header *hdr;
1413 void *mmap;
1414 size_t mmap_size;
1415 struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
1417 if (istate->initialized)
1418 return istate->cache_nr;
1420 istate->timestamp.sec = 0;
1421 istate->timestamp.nsec = 0;
1422 fd = open(path, O_RDONLY);
1423 if (fd < 0) {
1424 if (errno == ENOENT)
1425 return 0;
1426 die_errno("index file open failed");
1429 if (fstat(fd, &st))
1430 die_errno("cannot stat the open index");
1432 mmap_size = xsize_t(st.st_size);
1433 if (mmap_size < sizeof(struct cache_header) + 20)
1434 die("index file smaller than expected");
1436 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1437 if (mmap == MAP_FAILED)
1438 die_errno("unable to map index file");
1439 close(fd);
1441 hdr = mmap;
1442 if (verify_hdr(hdr, mmap_size) < 0)
1443 goto unmap;
1445 istate->version = ntohl(hdr->hdr_version);
1446 istate->cache_nr = ntohl(hdr->hdr_entries);
1447 istate->cache_alloc = alloc_nr(istate->cache_nr);
1448 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1449 istate->initialized = 1;
1451 if (istate->version == 4)
1452 previous_name = &previous_name_buf;
1453 else
1454 previous_name = NULL;
1456 src_offset = sizeof(*hdr);
1457 for (i = 0; i < istate->cache_nr; i++) {
1458 struct ondisk_cache_entry *disk_ce;
1459 struct cache_entry *ce;
1460 unsigned long consumed;
1462 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1463 ce = create_from_disk(disk_ce, &consumed, previous_name);
1464 set_index_entry(istate, i, ce);
1466 src_offset += consumed;
1468 strbuf_release(&previous_name_buf);
1469 istate->timestamp.sec = st.st_mtime;
1470 istate->timestamp.nsec = ST_MTIME_NSEC(st);
1472 while (src_offset <= mmap_size - 20 - 8) {
1473 /* After an array of active_nr index entries,
1474 * there can be arbitrary number of extended
1475 * sections, each of which is prefixed with
1476 * extension name (4-byte) and section length
1477 * in 4-byte network byte order.
1479 uint32_t extsize;
1480 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1481 extsize = ntohl(extsize);
1482 if (read_index_extension(istate,
1483 (const char *) mmap + src_offset,
1484 (char *) mmap + src_offset + 8,
1485 extsize) < 0)
1486 goto unmap;
1487 src_offset += 8;
1488 src_offset += extsize;
1490 munmap(mmap, mmap_size);
1491 return istate->cache_nr;
1493 unmap:
1494 munmap(mmap, mmap_size);
1495 die("index file corrupt");
1498 int is_index_unborn(struct index_state *istate)
1500 return (!istate->cache_nr && !istate->timestamp.sec);
1503 int discard_index(struct index_state *istate)
1505 int i;
1507 for (i = 0; i < istate->cache_nr; i++)
1508 free(istate->cache[i]);
1509 resolve_undo_clear_index(istate);
1510 istate->cache_nr = 0;
1511 istate->cache_changed = 0;
1512 istate->timestamp.sec = 0;
1513 istate->timestamp.nsec = 0;
1514 istate->name_hash_initialized = 0;
1515 free_hash(&istate->name_hash);
1516 cache_tree_free(&(istate->cache_tree));
1517 istate->initialized = 0;
1519 /* no need to throw away allocated active_cache */
1520 return 0;
1523 int unmerged_index(const struct index_state *istate)
1525 int i;
1526 for (i = 0; i < istate->cache_nr; i++) {
1527 if (ce_stage(istate->cache[i]))
1528 return 1;
1530 return 0;
1533 #define WRITE_BUFFER_SIZE 8192
1534 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1535 static unsigned long write_buffer_len;
1537 static int ce_write_flush(git_SHA_CTX *context, int fd)
1539 unsigned int buffered = write_buffer_len;
1540 if (buffered) {
1541 git_SHA1_Update(context, write_buffer, buffered);
1542 if (write_in_full(fd, write_buffer, buffered) != buffered)
1543 return -1;
1544 write_buffer_len = 0;
1546 return 0;
1549 static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
1551 while (len) {
1552 unsigned int buffered = write_buffer_len;
1553 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1554 if (partial > len)
1555 partial = len;
1556 memcpy(write_buffer + buffered, data, partial);
1557 buffered += partial;
1558 if (buffered == WRITE_BUFFER_SIZE) {
1559 write_buffer_len = buffered;
1560 if (ce_write_flush(context, fd))
1561 return -1;
1562 buffered = 0;
1564 write_buffer_len = buffered;
1565 len -= partial;
1566 data = (char *) data + partial;
1568 return 0;
1571 static int write_index_ext_header(git_SHA_CTX *context, int fd,
1572 unsigned int ext, unsigned int sz)
1574 ext = htonl(ext);
1575 sz = htonl(sz);
1576 return ((ce_write(context, fd, &ext, 4) < 0) ||
1577 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1580 static int ce_flush(git_SHA_CTX *context, int fd)
1582 unsigned int left = write_buffer_len;
1584 if (left) {
1585 write_buffer_len = 0;
1586 git_SHA1_Update(context, write_buffer, left);
1589 /* Flush first if not enough space for SHA1 signature */
1590 if (left + 20 > WRITE_BUFFER_SIZE) {
1591 if (write_in_full(fd, write_buffer, left) != left)
1592 return -1;
1593 left = 0;
1596 /* Append the SHA1 signature at the end */
1597 git_SHA1_Final(write_buffer + left, context);
1598 left += 20;
1599 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1602 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1605 * The only thing we care about in this function is to smudge the
1606 * falsely clean entry due to touch-update-touch race, so we leave
1607 * everything else as they are. We are called for entries whose
1608 * ce_mtime match the index file mtime.
1610 * Note that this actually does not do much for gitlinks, for
1611 * which ce_match_stat_basic() always goes to the actual
1612 * contents. The caller checks with is_racy_timestamp() which
1613 * always says "no" for gitlinks, so we are not called for them ;-)
1615 struct stat st;
1617 if (lstat(ce->name, &st) < 0)
1618 return;
1619 if (ce_match_stat_basic(ce, &st))
1620 return;
1621 if (ce_modified_check_fs(ce, &st)) {
1622 /* This is "racily clean"; smudge it. Note that this
1623 * is a tricky code. At first glance, it may appear
1624 * that it can break with this sequence:
1626 * $ echo xyzzy >frotz
1627 * $ git-update-index --add frotz
1628 * $ : >frotz
1629 * $ sleep 3
1630 * $ echo filfre >nitfol
1631 * $ git-update-index --add nitfol
1633 * but it does not. When the second update-index runs,
1634 * it notices that the entry "frotz" has the same timestamp
1635 * as index, and if we were to smudge it by resetting its
1636 * size to zero here, then the object name recorded
1637 * in index is the 6-byte file but the cached stat information
1638 * becomes zero --- which would then match what we would
1639 * obtain from the filesystem next time we stat("frotz").
1641 * However, the second update-index, before calling
1642 * this function, notices that the cached size is 6
1643 * bytes and what is on the filesystem is an empty
1644 * file, and never calls us, so the cached size information
1645 * for "frotz" stays 6 which does not match the filesystem.
1647 ce->ce_size = 0;
1651 /* Copy miscellaneous fields but not the name */
1652 static char *copy_cache_entry_to_ondisk(struct ondisk_cache_entry *ondisk,
1653 struct cache_entry *ce)
1655 short flags;
1657 ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
1658 ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
1659 ondisk->ctime.nsec = htonl(ce->ce_ctime.nsec);
1660 ondisk->mtime.nsec = htonl(ce->ce_mtime.nsec);
1661 ondisk->dev = htonl(ce->ce_dev);
1662 ondisk->ino = htonl(ce->ce_ino);
1663 ondisk->mode = htonl(ce->ce_mode);
1664 ondisk->uid = htonl(ce->ce_uid);
1665 ondisk->gid = htonl(ce->ce_gid);
1666 ondisk->size = htonl(ce->ce_size);
1667 hashcpy(ondisk->sha1, ce->sha1);
1669 flags = ce->ce_flags;
1670 flags |= (ce_namelen(ce) >= CE_NAMEMASK ? CE_NAMEMASK : ce_namelen(ce));
1671 ondisk->flags = htons(flags);
1672 if (ce->ce_flags & CE_EXTENDED) {
1673 struct ondisk_cache_entry_extended *ondisk2;
1674 ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
1675 ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
1676 return ondisk2->name;
1678 else {
1679 return ondisk->name;
1683 static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce,
1684 struct strbuf *previous_name)
1686 int size;
1687 struct ondisk_cache_entry *ondisk;
1688 char *name;
1689 int result;
1691 if (!previous_name) {
1692 size = ondisk_ce_size(ce);
1693 ondisk = xcalloc(1, size);
1694 name = copy_cache_entry_to_ondisk(ondisk, ce);
1695 memcpy(name, ce->name, ce_namelen(ce));
1696 } else {
1697 int common, to_remove, prefix_size;
1698 unsigned char to_remove_vi[16];
1699 for (common = 0;
1700 (ce->name[common] &&
1701 common < previous_name->len &&
1702 ce->name[common] == previous_name->buf[common]);
1703 common++)
1704 ; /* still matching */
1705 to_remove = previous_name->len - common;
1706 prefix_size = encode_varint(to_remove, to_remove_vi);
1708 if (ce->ce_flags & CE_EXTENDED)
1709 size = offsetof(struct ondisk_cache_entry_extended, name);
1710 else
1711 size = offsetof(struct ondisk_cache_entry, name);
1712 size += prefix_size + (ce_namelen(ce) - common + 1);
1714 ondisk = xcalloc(1, size);
1715 name = copy_cache_entry_to_ondisk(ondisk, ce);
1716 memcpy(name, to_remove_vi, prefix_size);
1717 memcpy(name + prefix_size, ce->name + common, ce_namelen(ce) - common);
1719 strbuf_splice(previous_name, common, to_remove,
1720 ce->name + common, ce_namelen(ce) - common);
1723 result = ce_write(c, fd, ondisk, size);
1724 free(ondisk);
1725 return result;
1728 static int has_racy_timestamp(struct index_state *istate)
1730 int entries = istate->cache_nr;
1731 int i;
1733 for (i = 0; i < entries; i++) {
1734 struct cache_entry *ce = istate->cache[i];
1735 if (is_racy_timestamp(istate, ce))
1736 return 1;
1738 return 0;
1742 * Opportunisticly update the index but do not complain if we can't
1744 void update_index_if_able(struct index_state *istate, struct lock_file *lockfile)
1746 if ((istate->cache_changed || has_racy_timestamp(istate)) &&
1747 !write_index(istate, lockfile->fd))
1748 commit_locked_index(lockfile);
1749 else
1750 rollback_lock_file(lockfile);
1753 int write_index(struct index_state *istate, int newfd)
1755 git_SHA_CTX c;
1756 struct cache_header hdr;
1757 int i, err, removed, extended, hdr_version;
1758 struct cache_entry **cache = istate->cache;
1759 int entries = istate->cache_nr;
1760 struct stat st;
1761 struct strbuf previous_name_buf = STRBUF_INIT, *previous_name;
1763 for (i = removed = extended = 0; i < entries; i++) {
1764 if (cache[i]->ce_flags & CE_REMOVE)
1765 removed++;
1767 /* reduce extended entries if possible */
1768 cache[i]->ce_flags &= ~CE_EXTENDED;
1769 if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) {
1770 extended++;
1771 cache[i]->ce_flags |= CE_EXTENDED;
1775 if (!istate->version)
1776 istate->version = INDEX_FORMAT_DEFAULT;
1778 /* demote version 3 to version 2 when the latter suffices */
1779 if (istate->version == 3 || istate->version == 2)
1780 istate->version = extended ? 3 : 2;
1782 hdr_version = istate->version;
1784 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1785 hdr.hdr_version = htonl(hdr_version);
1786 hdr.hdr_entries = htonl(entries - removed);
1788 git_SHA1_Init(&c);
1789 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1790 return -1;
1792 previous_name = (hdr_version == 4) ? &previous_name_buf : NULL;
1793 for (i = 0; i < entries; i++) {
1794 struct cache_entry *ce = cache[i];
1795 if (ce->ce_flags & CE_REMOVE)
1796 continue;
1797 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
1798 ce_smudge_racily_clean_entry(ce);
1799 if (is_null_sha1(ce->sha1))
1800 return error("cache entry has null sha1: %s", ce->name);
1801 if (ce_write_entry(&c, newfd, ce, previous_name) < 0)
1802 return -1;
1804 strbuf_release(&previous_name_buf);
1806 /* Write extension data here */
1807 if (istate->cache_tree) {
1808 struct strbuf sb = STRBUF_INIT;
1810 cache_tree_write(&sb, istate->cache_tree);
1811 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1812 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1813 strbuf_release(&sb);
1814 if (err)
1815 return -1;
1817 if (istate->resolve_undo) {
1818 struct strbuf sb = STRBUF_INIT;
1820 resolve_undo_write(&sb, istate->resolve_undo);
1821 err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,
1822 sb.len) < 0
1823 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1824 strbuf_release(&sb);
1825 if (err)
1826 return -1;
1829 if (ce_flush(&c, newfd) || fstat(newfd, &st))
1830 return -1;
1831 istate->timestamp.sec = (unsigned int)st.st_mtime;
1832 istate->timestamp.nsec = ST_MTIME_NSEC(st);
1833 return 0;
1837 * Read the index file that is potentially unmerged into given
1838 * index_state, dropping any unmerged entries. Returns true if
1839 * the index is unmerged. Callers who want to refuse to work
1840 * from an unmerged state can call this and check its return value,
1841 * instead of calling read_cache().
1843 int read_index_unmerged(struct index_state *istate)
1845 int i;
1846 int unmerged = 0;
1848 read_index(istate);
1849 for (i = 0; i < istate->cache_nr; i++) {
1850 struct cache_entry *ce = istate->cache[i];
1851 struct cache_entry *new_ce;
1852 int size, len;
1854 if (!ce_stage(ce))
1855 continue;
1856 unmerged = 1;
1857 len = ce_namelen(ce);
1858 size = cache_entry_size(len);
1859 new_ce = xcalloc(1, size);
1860 memcpy(new_ce->name, ce->name, len);
1861 new_ce->ce_flags = create_ce_flags(0) | CE_CONFLICTED;
1862 new_ce->ce_namelen = len;
1863 new_ce->ce_mode = ce->ce_mode;
1864 if (add_index_entry(istate, new_ce, 0))
1865 return error("%s: cannot drop to stage #0",
1866 ce->name);
1867 i = index_name_pos(istate, new_ce->name, len);
1869 return unmerged;
1873 * Returns 1 if the path is an "other" path with respect to
1874 * the index; that is, the path is not mentioned in the index at all,
1875 * either as a file, a directory with some files in the index,
1876 * or as an unmerged entry.
1878 * We helpfully remove a trailing "/" from directories so that
1879 * the output of read_directory can be used as-is.
1881 int index_name_is_other(const struct index_state *istate, const char *name,
1882 int namelen)
1884 int pos;
1885 if (namelen && name[namelen - 1] == '/')
1886 namelen--;
1887 pos = index_name_pos(istate, name, namelen);
1888 if (0 <= pos)
1889 return 0; /* exact match */
1890 pos = -pos - 1;
1891 if (pos < istate->cache_nr) {
1892 struct cache_entry *ce = istate->cache[pos];
1893 if (ce_namelen(ce) == namelen &&
1894 !memcmp(ce->name, name, namelen))
1895 return 0; /* Yup, this one exists unmerged */
1897 return 1;