Makefile: update the default build options for AIX
[git/git.git] / read-cache.c
1 /*
2 * GIT - The information manager from hell
3 *
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
12 /* Index extensions.
13 *
14 * The first letter should be 'A'..'Z' for extensions that are not
15 * necessary for a correct operation (i.e. optimization data).
16 * When new extensions are added that _needs_ to be understood in
17 * order to correctly interpret the index file, pick character that
18 * is outside the range, to cause the reader to abort.
19 */
20
21 #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
22 #define CACHE_EXT_TREE 0x54524545 /* "TREE" */
23
24 struct index_state the_index;
25
26 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
27 {
28 istate->cache[nr] = ce;
29 add_name_hash(istate, ce);
30 }
31
32 static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
33 {
34 struct cache_entry *old = istate->cache[nr];
35
36 remove_name_hash(old);
37 set_index_entry(istate, nr, ce);
38 istate->cache_changed = 1;
39 }
40
41 /*
42 * This only updates the "non-critical" parts of the directory
43 * cache, ie the parts that aren't tracked by GIT, and only used
44 * to validate the cache.
45 */
46 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
47 {
48 ce->ce_ctime = st->st_ctime;
49 ce->ce_mtime = st->st_mtime;
50 ce->ce_dev = st->st_dev;
51 ce->ce_ino = st->st_ino;
52 ce->ce_uid = st->st_uid;
53 ce->ce_gid = st->st_gid;
54 ce->ce_size = st->st_size;
55
56 if (assume_unchanged)
57 ce->ce_flags |= CE_VALID;
58
59 if (S_ISREG(st->st_mode))
60 ce_mark_uptodate(ce);
61 }
62
63 static int ce_compare_data(struct cache_entry *ce, struct stat *st)
64 {
65 int match = -1;
66 int fd = open(ce->name, O_RDONLY);
67
68 if (fd >= 0) {
69 unsigned char sha1[20];
70 if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name))
71 match = hashcmp(sha1, ce->sha1);
72 /* index_fd() closed the file descriptor already */
73 }
74 return match;
75 }
76
77 static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
78 {
79 int match = -1;
80 char *target;
81 void *buffer;
82 unsigned long size;
83 enum object_type type;
84 int len;
85
86 target = xmalloc(expected_size);
87 len = readlink(ce->name, target, expected_size);
88 if (len != expected_size) {
89 free(target);
90 return -1;
91 }
92 buffer = read_sha1_file(ce->sha1, &type, &size);
93 if (!buffer) {
94 free(target);
95 return -1;
96 }
97 if (size == expected_size)
98 match = memcmp(buffer, target, size);
99 free(buffer);
100 free(target);
101 return match;
102 }
103
104 static int ce_compare_gitlink(struct cache_entry *ce)
105 {
106 unsigned char sha1[20];
107
108 /*
109 * We don't actually require that the .git directory
110 * under GITLINK directory be a valid git directory. It
111 * might even be missing (in case nobody populated that
112 * sub-project).
113 *
114 * If so, we consider it always to match.
115 */
116 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
117 return 0;
118 return hashcmp(sha1, ce->sha1);
119 }
120
121 static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
122 {
123 switch (st->st_mode & S_IFMT) {
124 case S_IFREG:
125 if (ce_compare_data(ce, st))
126 return DATA_CHANGED;
127 break;
128 case S_IFLNK:
129 if (ce_compare_link(ce, xsize_t(st->st_size)))
130 return DATA_CHANGED;
131 break;
132 case S_IFDIR:
133 if (S_ISGITLINK(ce->ce_mode))
134 return 0;
135 default:
136 return TYPE_CHANGED;
137 }
138 return 0;
139 }
140
141 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
142 {
143 unsigned int changed = 0;
144
145 if (ce->ce_flags & CE_REMOVE)
146 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
147
148 switch (ce->ce_mode & S_IFMT) {
149 case S_IFREG:
150 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
151 /* We consider only the owner x bit to be relevant for
152 * "mode changes"
153 */
154 if (trust_executable_bit &&
155 (0100 & (ce->ce_mode ^ st->st_mode)))
156 changed |= MODE_CHANGED;
157 break;
158 case S_IFLNK:
159 if (!S_ISLNK(st->st_mode) &&
160 (has_symlinks || !S_ISREG(st->st_mode)))
161 changed |= TYPE_CHANGED;
162 break;
163 case S_IFGITLINK:
164 if (!S_ISDIR(st->st_mode))
165 changed |= TYPE_CHANGED;
166 else if (ce_compare_gitlink(ce))
167 changed |= DATA_CHANGED;
168 return changed;
169 default:
170 die("internal error: ce_mode is %o", ce->ce_mode);
171 }
172 if (ce->ce_mtime != (unsigned int) st->st_mtime)
173 changed |= MTIME_CHANGED;
174 if (ce->ce_ctime != (unsigned int) st->st_ctime)
175 changed |= CTIME_CHANGED;
176
177 if (ce->ce_uid != (unsigned int) st->st_uid ||
178 ce->ce_gid != (unsigned int) st->st_gid)
179 changed |= OWNER_CHANGED;
180 if (ce->ce_ino != (unsigned int) st->st_ino)
181 changed |= INODE_CHANGED;
182
183 #ifdef USE_STDEV
184 /*
185 * st_dev breaks on network filesystems where different
186 * clients will have different views of what "device"
187 * the filesystem is on
188 */
189 if (ce->ce_dev != (unsigned int) st->st_dev)
190 changed |= INODE_CHANGED;
191 #endif
192
193 if (ce->ce_size != (unsigned int) st->st_size)
194 changed |= DATA_CHANGED;
195
196 return changed;
197 }
198
199 static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
200 {
201 return (!S_ISGITLINK(ce->ce_mode) &&
202 istate->timestamp &&
203 ((unsigned int)istate->timestamp) <= ce->ce_mtime);
204 }
205
206 int ie_match_stat(const struct index_state *istate,
207 struct cache_entry *ce, struct stat *st,
208 unsigned int options)
209 {
210 unsigned int changed;
211 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
212 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
213
214 /*
215 * If it's marked as always valid in the index, it's
216 * valid whatever the checked-out copy says.
217 */
218 if (!ignore_valid && (ce->ce_flags & CE_VALID))
219 return 0;
220
221 changed = ce_match_stat_basic(ce, st);
222
223 /*
224 * Within 1 second of this sequence:
225 * echo xyzzy >file && git-update-index --add file
226 * running this command:
227 * echo frotz >file
228 * would give a falsely clean cache entry. The mtime and
229 * length match the cache, and other stat fields do not change.
230 *
231 * We could detect this at update-index time (the cache entry
232 * being registered/updated records the same time as "now")
233 * and delay the return from git-update-index, but that would
234 * effectively mean we can make at most one commit per second,
235 * which is not acceptable. Instead, we check cache entries
236 * whose mtime are the same as the index file timestamp more
237 * carefully than others.
238 */
239 if (!changed && is_racy_timestamp(istate, ce)) {
240 if (assume_racy_is_modified)
241 changed |= DATA_CHANGED;
242 else
243 changed |= ce_modified_check_fs(ce, st);
244 }
245
246 return changed;
247 }
248
249 int ie_modified(const struct index_state *istate,
250 struct cache_entry *ce, struct stat *st, unsigned int options)
251 {
252 int changed, changed_fs;
253
254 changed = ie_match_stat(istate, ce, st, options);
255 if (!changed)
256 return 0;
257 /*
258 * If the mode or type has changed, there's no point in trying
259 * to refresh the entry - it's not going to match
260 */
261 if (changed & (MODE_CHANGED | TYPE_CHANGED))
262 return changed;
263
264 /* Immediately after read-tree or update-index --cacheinfo,
265 * the length field is zero. For other cases the ce_size
266 * should match the SHA1 recorded in the index entry.
267 */
268 if ((changed & DATA_CHANGED) && ce->ce_size != 0)
269 return changed;
270
271 changed_fs = ce_modified_check_fs(ce, st);
272 if (changed_fs)
273 return changed | changed_fs;
274 return 0;
275 }
276
277 int base_name_compare(const char *name1, int len1, int mode1,
278 const char *name2, int len2, int mode2)
279 {
280 unsigned char c1, c2;
281 int len = len1 < len2 ? len1 : len2;
282 int cmp;
283
284 cmp = memcmp(name1, name2, len);
285 if (cmp)
286 return cmp;
287 c1 = name1[len];
288 c2 = name2[len];
289 if (!c1 && S_ISDIR(mode1))
290 c1 = '/';
291 if (!c2 && S_ISDIR(mode2))
292 c2 = '/';
293 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
294 }
295
296 /*
297 * df_name_compare() is identical to base_name_compare(), except it
298 * compares conflicting directory/file entries as equal. Note that
299 * while a directory name compares as equal to a regular file, they
300 * then individually compare _differently_ to a filename that has
301 * a dot after the basename (because '\0' < '.' < '/').
302 *
303 * This is used by routines that want to traverse the git namespace
304 * but then handle conflicting entries together when possible.
305 */
306 int df_name_compare(const char *name1, int len1, int mode1,
307 const char *name2, int len2, int mode2)
308 {
309 int len = len1 < len2 ? len1 : len2, cmp;
310 unsigned char c1, c2;
311
312 cmp = memcmp(name1, name2, len);
313 if (cmp)
314 return cmp;
315 /* Directories and files compare equal (same length, same name) */
316 if (len1 == len2)
317 return 0;
318 c1 = name1[len];
319 if (!c1 && S_ISDIR(mode1))
320 c1 = '/';
321 c2 = name2[len];
322 if (!c2 && S_ISDIR(mode2))
323 c2 = '/';
324 if (c1 == '/' && !c2)
325 return 0;
326 if (c2 == '/' && !c1)
327 return 0;
328 return c1 - c2;
329 }
330
331 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
332 {
333 int len1 = flags1 & CE_NAMEMASK;
334 int len2 = flags2 & CE_NAMEMASK;
335 int len = len1 < len2 ? len1 : len2;
336 int cmp;
337
338 cmp = memcmp(name1, name2, len);
339 if (cmp)
340 return cmp;
341 if (len1 < len2)
342 return -1;
343 if (len1 > len2)
344 return 1;
345
346 /* Compare stages */
347 flags1 &= CE_STAGEMASK;
348 flags2 &= CE_STAGEMASK;
349
350 if (flags1 < flags2)
351 return -1;
352 if (flags1 > flags2)
353 return 1;
354 return 0;
355 }
356
357 int index_name_pos(const struct index_state *istate, const char *name, int namelen)
358 {
359 int first, last;
360
361 first = 0;
362 last = istate->cache_nr;
363 while (last > first) {
364 int next = (last + first) >> 1;
365 struct cache_entry *ce = istate->cache[next];
366 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags);
367 if (!cmp)
368 return next;
369 if (cmp < 0) {
370 last = next;
371 continue;
372 }
373 first = next+1;
374 }
375 return -first-1;
376 }
377
378 /* Remove entry, return true if there are more entries to go.. */
379 int remove_index_entry_at(struct index_state *istate, int pos)
380 {
381 struct cache_entry *ce = istate->cache[pos];
382
383 remove_name_hash(ce);
384 istate->cache_changed = 1;
385 istate->cache_nr--;
386 if (pos >= istate->cache_nr)
387 return 0;
388 memmove(istate->cache + pos,
389 istate->cache + pos + 1,
390 (istate->cache_nr - pos) * sizeof(struct cache_entry *));
391 return 1;
392 }
393
394 int remove_file_from_index(struct index_state *istate, const char *path)
395 {
396 int pos = index_name_pos(istate, path, strlen(path));
397 if (pos < 0)
398 pos = -pos-1;
399 cache_tree_invalidate_path(istate->cache_tree, path);
400 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
401 remove_index_entry_at(istate, pos);
402 return 0;
403 }
404
405 static int compare_name(struct cache_entry *ce, const char *path, int namelen)
406 {
407 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
408 }
409
410 static int index_name_pos_also_unmerged(struct index_state *istate,
411 const char *path, int namelen)
412 {
413 int pos = index_name_pos(istate, path, namelen);
414 struct cache_entry *ce;
415
416 if (pos >= 0)
417 return pos;
418
419 /* maybe unmerged? */
420 pos = -1 - pos;
421 if (pos >= istate->cache_nr ||
422 compare_name((ce = istate->cache[pos]), path, namelen))
423 return -1;
424
425 /* order of preference: stage 2, 1, 3 */
426 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
427 ce_stage((ce = istate->cache[pos + 1])) == 2 &&
428 !compare_name(ce, path, namelen))
429 pos++;
430 return pos;
431 }
432
433 static int different_name(struct cache_entry *ce, struct cache_entry *alias)
434 {
435 int len = ce_namelen(ce);
436 return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
437 }
438
439 /*
440 * If we add a filename that aliases in the cache, we will use the
441 * name that we already have - but we don't want to update the same
442 * alias twice, because that implies that there were actually two
443 * different files with aliasing names!
444 *
445 * So we use the CE_ADDED flag to verify that the alias was an old
446 * one before we accept it as
447 */
448 static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias)
449 {
450 int len;
451 struct cache_entry *new;
452
453 if (alias->ce_flags & CE_ADDED)
454 die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
455
456 /* Ok, create the new entry using the name of the existing alias */
457 len = ce_namelen(alias);
458 new = xcalloc(1, cache_entry_size(len));
459 memcpy(new->name, alias->name, len);
460 copy_cache_entry(new, ce);
461 free(ce);
462 return new;
463 }
464
465 int add_to_index(struct index_state *istate, const char *path, struct stat *st, int verbose)
466 {
467 int size, namelen;
468 mode_t st_mode = st->st_mode;
469 struct cache_entry *ce, *alias;
470 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY;
471
472 if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode))
473 die("%s: can only add regular files, symbolic links or git-directories", path);
474
475 namelen = strlen(path);
476 if (S_ISDIR(st_mode)) {
477 while (namelen && path[namelen-1] == '/')
478 namelen--;
479 }
480 size = cache_entry_size(namelen);
481 ce = xcalloc(1, size);
482 memcpy(ce->name, path, namelen);
483 ce->ce_flags = namelen;
484 fill_stat_cache_info(ce, st);
485
486 if (trust_executable_bit && has_symlinks)
487 ce->ce_mode = create_ce_mode(st_mode);
488 else {
489 /* If there is an existing entry, pick the mode bits and type
490 * from it, otherwise assume unexecutable regular file.
491 */
492 struct cache_entry *ent;
493 int pos = index_name_pos_also_unmerged(istate, path, namelen);
494
495 ent = (0 <= pos) ? istate->cache[pos] : NULL;
496 ce->ce_mode = ce_mode_from_stat(ent, st_mode);
497 }
498
499 alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case);
500 if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) {
501 /* Nothing changed, really */
502 free(ce);
503 ce_mark_uptodate(alias);
504 alias->ce_flags |= CE_ADDED;
505 return 0;
506 }
507 if (index_path(ce->sha1, path, st, 1))
508 die("unable to index file %s", path);
509 if (ignore_case && alias && different_name(ce, alias))
510 ce = create_alias_ce(ce, alias);
511 ce->ce_flags |= CE_ADDED;
512 if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
513 die("unable to add %s to index",path);
514 if (verbose)
515 printf("add '%s'\n", path);
516 return 0;
517 }
518
519 int add_file_to_index(struct index_state *istate, const char *path, int verbose)
520 {
521 struct stat st;
522 if (lstat(path, &st))
523 die("%s: unable to stat (%s)", path, strerror(errno));
524 return add_to_index(istate, path, &st, verbose);
525 }
526
527 struct cache_entry *make_cache_entry(unsigned int mode,
528 const unsigned char *sha1, const char *path, int stage,
529 int refresh)
530 {
531 int size, len;
532 struct cache_entry *ce;
533
534 if (!verify_path(path))
535 return NULL;
536
537 len = strlen(path);
538 size = cache_entry_size(len);
539 ce = xcalloc(1, size);
540
541 hashcpy(ce->sha1, sha1);
542 memcpy(ce->name, path, len);
543 ce->ce_flags = create_ce_flags(len, stage);
544 ce->ce_mode = create_ce_mode(mode);
545
546 if (refresh)
547 return refresh_cache_entry(ce, 0);
548
549 return ce;
550 }
551
552 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
553 {
554 int len = ce_namelen(a);
555 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
556 }
557
558 int ce_path_match(const struct cache_entry *ce, const char **pathspec)
559 {
560 const char *match, *name;
561 int len;
562
563 if (!pathspec)
564 return 1;
565
566 len = ce_namelen(ce);
567 name = ce->name;
568 while ((match = *pathspec++) != NULL) {
569 int matchlen = strlen(match);
570 if (matchlen > len)
571 continue;
572 if (memcmp(name, match, matchlen))
573 continue;
574 if (matchlen && name[matchlen-1] == '/')
575 return 1;
576 if (name[matchlen] == '/' || !name[matchlen])
577 return 1;
578 if (!matchlen)
579 return 1;
580 }
581 return 0;
582 }
583
584 /*
585 * We fundamentally don't like some paths: we don't want
586 * dot or dot-dot anywhere, and for obvious reasons don't
587 * want to recurse into ".git" either.
588 *
589 * Also, we don't want double slashes or slashes at the
590 * end that can make pathnames ambiguous.
591 */
592 static int verify_dotfile(const char *rest)
593 {
594 /*
595 * The first character was '.', but that
596 * has already been discarded, we now test
597 * the rest.
598 */
599 switch (*rest) {
600 /* "." is not allowed */
601 case '\0': case '/':
602 return 0;
603
604 /*
605 * ".git" followed by NUL or slash is bad. This
606 * shares the path end test with the ".." case.
607 */
608 case 'g':
609 if (rest[1] != 'i')
610 break;
611 if (rest[2] != 't')
612 break;
613 rest += 2;
614 /* fallthrough */
615 case '.':
616 if (rest[1] == '\0' || rest[1] == '/')
617 return 0;
618 }
619 return 1;
620 }
621
622 int verify_path(const char *path)
623 {
624 char c;
625
626 goto inside;
627 for (;;) {
628 if (!c)
629 return 1;
630 if (c == '/') {
631 inside:
632 c = *path++;
633 switch (c) {
634 default:
635 continue;
636 case '/': case '\0':
637 break;
638 case '.':
639 if (verify_dotfile(path))
640 continue;
641 }
642 return 0;
643 }
644 c = *path++;
645 }
646 }
647
648 /*
649 * Do we have another file that has the beginning components being a
650 * proper superset of the name we're trying to add?
651 */
652 static int has_file_name(struct index_state *istate,
653 const struct cache_entry *ce, int pos, int ok_to_replace)
654 {
655 int retval = 0;
656 int len = ce_namelen(ce);
657 int stage = ce_stage(ce);
658 const char *name = ce->name;
659
660 while (pos < istate->cache_nr) {
661 struct cache_entry *p = istate->cache[pos++];
662
663 if (len >= ce_namelen(p))
664 break;
665 if (memcmp(name, p->name, len))
666 break;
667 if (ce_stage(p) != stage)
668 continue;
669 if (p->name[len] != '/')
670 continue;
671 if (p->ce_flags & CE_REMOVE)
672 continue;
673 retval = -1;
674 if (!ok_to_replace)
675 break;
676 remove_index_entry_at(istate, --pos);
677 }
678 return retval;
679 }
680
681 /*
682 * Do we have another file with a pathname that is a proper
683 * subset of the name we're trying to add?
684 */
685 static int has_dir_name(struct index_state *istate,
686 const struct cache_entry *ce, int pos, int ok_to_replace)
687 {
688 int retval = 0;
689 int stage = ce_stage(ce);
690 const char *name = ce->name;
691 const char *slash = name + ce_namelen(ce);
692
693 for (;;) {
694 int len;
695
696 for (;;) {
697 if (*--slash == '/')
698 break;
699 if (slash <= ce->name)
700 return retval;
701 }
702 len = slash - name;
703
704 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
705 if (pos >= 0) {
706 /*
707 * Found one, but not so fast. This could
708 * be a marker that says "I was here, but
709 * I am being removed". Such an entry is
710 * not a part of the resulting tree, and
711 * it is Ok to have a directory at the same
712 * path.
713 */
714 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
715 retval = -1;
716 if (!ok_to_replace)
717 break;
718 remove_index_entry_at(istate, pos);
719 continue;
720 }
721 }
722 else
723 pos = -pos-1;
724
725 /*
726 * Trivial optimization: if we find an entry that
727 * already matches the sub-directory, then we know
728 * we're ok, and we can exit.
729 */
730 while (pos < istate->cache_nr) {
731 struct cache_entry *p = istate->cache[pos];
732 if ((ce_namelen(p) <= len) ||
733 (p->name[len] != '/') ||
734 memcmp(p->name, name, len))
735 break; /* not our subdirectory */
736 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
737 /*
738 * p is at the same stage as our entry, and
739 * is a subdirectory of what we are looking
740 * at, so we cannot have conflicts at our
741 * level or anything shorter.
742 */
743 return retval;
744 pos++;
745 }
746 }
747 return retval;
748 }
749
750 /* We may be in a situation where we already have path/file and path
751 * is being added, or we already have path and path/file is being
752 * added. Either one would result in a nonsense tree that has path
753 * twice when git-write-tree tries to write it out. Prevent it.
754 *
755 * If ok-to-replace is specified, we remove the conflicting entries
756 * from the cache so the caller should recompute the insert position.
757 * When this happens, we return non-zero.
758 */
759 static int check_file_directory_conflict(struct index_state *istate,
760 const struct cache_entry *ce,
761 int pos, int ok_to_replace)
762 {
763 int retval;
764
765 /*
766 * When ce is an "I am going away" entry, we allow it to be added
767 */
768 if (ce->ce_flags & CE_REMOVE)
769 return 0;
770
771 /*
772 * We check if the path is a sub-path of a subsequent pathname
773 * first, since removing those will not change the position
774 * in the array.
775 */
776 retval = has_file_name(istate, ce, pos, ok_to_replace);
777
778 /*
779 * Then check if the path might have a clashing sub-directory
780 * before it.
781 */
782 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
783 }
784
785 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
786 {
787 int pos;
788 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
789 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
790 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
791
792 cache_tree_invalidate_path(istate->cache_tree, ce->name);
793 pos = index_name_pos(istate, ce->name, ce->ce_flags);
794
795 /* existing match? Just replace it. */
796 if (pos >= 0) {
797 replace_index_entry(istate, pos, ce);
798 return 0;
799 }
800 pos = -pos-1;
801
802 /*
803 * Inserting a merged entry ("stage 0") into the index
804 * will always replace all non-merged entries..
805 */
806 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
807 while (ce_same_name(istate->cache[pos], ce)) {
808 ok_to_add = 1;
809 if (!remove_index_entry_at(istate, pos))
810 break;
811 }
812 }
813
814 if (!ok_to_add)
815 return -1;
816 if (!verify_path(ce->name))
817 return -1;
818
819 if (!skip_df_check &&
820 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
821 if (!ok_to_replace)
822 return error("'%s' appears as both a file and as a directory",
823 ce->name);
824 pos = index_name_pos(istate, ce->name, ce->ce_flags);
825 pos = -pos-1;
826 }
827 return pos + 1;
828 }
829
830 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
831 {
832 int pos;
833
834 if (option & ADD_CACHE_JUST_APPEND)
835 pos = istate->cache_nr;
836 else {
837 int ret;
838 ret = add_index_entry_with_check(istate, ce, option);
839 if (ret <= 0)
840 return ret;
841 pos = ret - 1;
842 }
843
844 /* Make sure the array is big enough .. */
845 if (istate->cache_nr == istate->cache_alloc) {
846 istate->cache_alloc = alloc_nr(istate->cache_alloc);
847 istate->cache = xrealloc(istate->cache,
848 istate->cache_alloc * sizeof(struct cache_entry *));
849 }
850
851 /* Add it in.. */
852 istate->cache_nr++;
853 if (istate->cache_nr > pos + 1)
854 memmove(istate->cache + pos + 1,
855 istate->cache + pos,
856 (istate->cache_nr - pos - 1) * sizeof(ce));
857 set_index_entry(istate, pos, ce);
858 istate->cache_changed = 1;
859 return 0;
860 }
861
862 /*
863 * "refresh" does not calculate a new sha1 file or bring the
864 * cache up-to-date for mode/content changes. But what it
865 * _does_ do is to "re-match" the stat information of a file
866 * with the cache, so that you can refresh the cache for a
867 * file that hasn't been changed but where the stat entry is
868 * out of date.
869 *
870 * For example, you'd want to do this after doing a "git-read-tree",
871 * to link up the stat cache details with the proper files.
872 */
873 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
874 struct cache_entry *ce,
875 unsigned int options, int *err)
876 {
877 struct stat st;
878 struct cache_entry *updated;
879 int changed, size;
880 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
881
882 if (ce_uptodate(ce))
883 return ce;
884
885 if (lstat(ce->name, &st) < 0) {
886 if (err)
887 *err = errno;
888 return NULL;
889 }
890
891 changed = ie_match_stat(istate, ce, &st, options);
892 if (!changed) {
893 /*
894 * The path is unchanged. If we were told to ignore
895 * valid bit, then we did the actual stat check and
896 * found that the entry is unmodified. If the entry
897 * is not marked VALID, this is the place to mark it
898 * valid again, under "assume unchanged" mode.
899 */
900 if (ignore_valid && assume_unchanged &&
901 !(ce->ce_flags & CE_VALID))
902 ; /* mark this one VALID again */
903 else {
904 /*
905 * We do not mark the index itself "modified"
906 * because CE_UPTODATE flag is in-core only;
907 * we are not going to write this change out.
908 */
909 ce_mark_uptodate(ce);
910 return ce;
911 }
912 }
913
914 if (ie_modified(istate, ce, &st, options)) {
915 if (err)
916 *err = EINVAL;
917 return NULL;
918 }
919
920 size = ce_size(ce);
921 updated = xmalloc(size);
922 memcpy(updated, ce, size);
923 fill_stat_cache_info(updated, &st);
924 /*
925 * If ignore_valid is not set, we should leave CE_VALID bit
926 * alone. Otherwise, paths marked with --no-assume-unchanged
927 * (i.e. things to be edited) will reacquire CE_VALID bit
928 * automatically, which is not really what we want.
929 */
930 if (!ignore_valid && assume_unchanged &&
931 !(ce->ce_flags & CE_VALID))
932 updated->ce_flags &= ~CE_VALID;
933
934 return updated;
935 }
936
937 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
938 {
939 int i;
940 int has_errors = 0;
941 int really = (flags & REFRESH_REALLY) != 0;
942 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
943 int quiet = (flags & REFRESH_QUIET) != 0;
944 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
945 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
946
947 for (i = 0; i < istate->cache_nr; i++) {
948 struct cache_entry *ce, *new;
949 int cache_errno = 0;
950
951 ce = istate->cache[i];
952 if (ce_stage(ce)) {
953 while ((i < istate->cache_nr) &&
954 ! strcmp(istate->cache[i]->name, ce->name))
955 i++;
956 i--;
957 if (allow_unmerged)
958 continue;
959 printf("%s: needs merge\n", ce->name);
960 has_errors = 1;
961 continue;
962 }
963
964 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
965 continue;
966
967 new = refresh_cache_ent(istate, ce, options, &cache_errno);
968 if (new == ce)
969 continue;
970 if (!new) {
971 if (not_new && cache_errno == ENOENT)
972 continue;
973 if (really && cache_errno == EINVAL) {
974 /* If we are doing --really-refresh that
975 * means the index is not valid anymore.
976 */
977 ce->ce_flags &= ~CE_VALID;
978 istate->cache_changed = 1;
979 }
980 if (quiet)
981 continue;
982 printf("%s: needs update\n", ce->name);
983 has_errors = 1;
984 continue;
985 }
986
987 replace_index_entry(istate, i, new);
988 }
989 return has_errors;
990 }
991
992 struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
993 {
994 return refresh_cache_ent(&the_index, ce, really, NULL);
995 }
996
997 static int verify_hdr(struct cache_header *hdr, unsigned long size)
998 {
999 SHA_CTX c;
1000 unsigned char sha1[20];
1001
1002 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
1003 return error("bad signature");
1004 if (hdr->hdr_version != htonl(2))
1005 return error("bad index version");
1006 SHA1_Init(&c);
1007 SHA1_Update(&c, hdr, size - 20);
1008 SHA1_Final(sha1, &c);
1009 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1010 return error("bad index file sha1 signature");
1011 return 0;
1012 }
1013
1014 static int read_index_extension(struct index_state *istate,
1015 const char *ext, void *data, unsigned long sz)
1016 {
1017 switch (CACHE_EXT(ext)) {
1018 case CACHE_EXT_TREE:
1019 istate->cache_tree = cache_tree_read(data, sz);
1020 break;
1021 default:
1022 if (*ext < 'A' || 'Z' < *ext)
1023 return error("index uses %.4s extension, which we do not understand",
1024 ext);
1025 fprintf(stderr, "ignoring %.4s extension\n", ext);
1026 break;
1027 }
1028 return 0;
1029 }
1030
1031 int read_index(struct index_state *istate)
1032 {
1033 return read_index_from(istate, get_index_file());
1034 }
1035
1036 static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
1037 {
1038 size_t len;
1039
1040 ce->ce_ctime = ntohl(ondisk->ctime.sec);
1041 ce->ce_mtime = ntohl(ondisk->mtime.sec);
1042 ce->ce_dev = ntohl(ondisk->dev);
1043 ce->ce_ino = ntohl(ondisk->ino);
1044 ce->ce_mode = ntohl(ondisk->mode);
1045 ce->ce_uid = ntohl(ondisk->uid);
1046 ce->ce_gid = ntohl(ondisk->gid);
1047 ce->ce_size = ntohl(ondisk->size);
1048 /* On-disk flags are just 16 bits */
1049 ce->ce_flags = ntohs(ondisk->flags);
1050 hashcpy(ce->sha1, ondisk->sha1);
1051
1052 len = ce->ce_flags & CE_NAMEMASK;
1053 if (len == CE_NAMEMASK)
1054 len = strlen(ondisk->name);
1055 /*
1056 * NEEDSWORK: If the original index is crafted, this copy could
1057 * go unchecked.
1058 */
1059 memcpy(ce->name, ondisk->name, len + 1);
1060 }
1061
1062 static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
1063 {
1064 long per_entry;
1065
1066 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
1067
1068 /*
1069 * Alignment can cause differences. This should be "alignof", but
1070 * since that's a gcc'ism, just use the size of a pointer.
1071 */
1072 per_entry += sizeof(void *);
1073 return ondisk_size + entries*per_entry;
1074 }
1075
1076 /* remember to discard_cache() before reading a different cache! */
1077 int read_index_from(struct index_state *istate, const char *path)
1078 {
1079 int fd, i;
1080 struct stat st;
1081 unsigned long src_offset, dst_offset;
1082 struct cache_header *hdr;
1083 void *mmap;
1084 size_t mmap_size;
1085
1086 errno = EBUSY;
1087 if (istate->alloc)
1088 return istate->cache_nr;
1089
1090 errno = ENOENT;
1091 istate->timestamp = 0;
1092 fd = open(path, O_RDONLY);
1093 if (fd < 0) {
1094 if (errno == ENOENT)
1095 return 0;
1096 die("index file open failed (%s)", strerror(errno));
1097 }
1098
1099 if (fstat(fd, &st))
1100 die("cannot stat the open index (%s)", strerror(errno));
1101
1102 errno = EINVAL;
1103 mmap_size = xsize_t(st.st_size);
1104 if (mmap_size < sizeof(struct cache_header) + 20)
1105 die("index file smaller than expected");
1106
1107 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1108 close(fd);
1109 if (mmap == MAP_FAILED)
1110 die("unable to map index file");
1111
1112 hdr = mmap;
1113 if (verify_hdr(hdr, mmap_size) < 0)
1114 goto unmap;
1115
1116 istate->cache_nr = ntohl(hdr->hdr_entries);
1117 istate->cache_alloc = alloc_nr(istate->cache_nr);
1118 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1119
1120 /*
1121 * The disk format is actually larger than the in-memory format,
1122 * due to space for nsec etc, so even though the in-memory one
1123 * has room for a few more flags, we can allocate using the same
1124 * index size
1125 */
1126 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
1127
1128 src_offset = sizeof(*hdr);
1129 dst_offset = 0;
1130 for (i = 0; i < istate->cache_nr; i++) {
1131 struct ondisk_cache_entry *disk_ce;
1132 struct cache_entry *ce;
1133
1134 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1135 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
1136 convert_from_disk(disk_ce, ce);
1137 set_index_entry(istate, i, ce);
1138
1139 src_offset += ondisk_ce_size(ce);
1140 dst_offset += ce_size(ce);
1141 }
1142 istate->timestamp = st.st_mtime;
1143 while (src_offset <= mmap_size - 20 - 8) {
1144 /* After an array of active_nr index entries,
1145 * there can be arbitrary number of extended
1146 * sections, each of which is prefixed with
1147 * extension name (4-byte) and section length
1148 * in 4-byte network byte order.
1149 */
1150 unsigned long extsize;
1151 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1152 extsize = ntohl(extsize);
1153 if (read_index_extension(istate,
1154 (const char *) mmap + src_offset,
1155 (char *) mmap + src_offset + 8,
1156 extsize) < 0)
1157 goto unmap;
1158 src_offset += 8;
1159 src_offset += extsize;
1160 }
1161 munmap(mmap, mmap_size);
1162 return istate->cache_nr;
1163
1164 unmap:
1165 munmap(mmap, mmap_size);
1166 errno = EINVAL;
1167 die("index file corrupt");
1168 }
1169
1170 int discard_index(struct index_state *istate)
1171 {
1172 istate->cache_nr = 0;
1173 istate->cache_changed = 0;
1174 istate->timestamp = 0;
1175 free_hash(&istate->name_hash);
1176 cache_tree_free(&(istate->cache_tree));
1177 free(istate->alloc);
1178 istate->alloc = NULL;
1179
1180 /* no need to throw away allocated active_cache */
1181 return 0;
1182 }
1183
1184 int unmerged_index(const struct index_state *istate)
1185 {
1186 int i;
1187 for (i = 0; i < istate->cache_nr; i++) {
1188 if (ce_stage(istate->cache[i]))
1189 return 1;
1190 }
1191 return 0;
1192 }
1193
1194 #define WRITE_BUFFER_SIZE 8192
1195 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1196 static unsigned long write_buffer_len;
1197
1198 static int ce_write_flush(SHA_CTX *context, int fd)
1199 {
1200 unsigned int buffered = write_buffer_len;
1201 if (buffered) {
1202 SHA1_Update(context, write_buffer, buffered);
1203 if (write_in_full(fd, write_buffer, buffered) != buffered)
1204 return -1;
1205 write_buffer_len = 0;
1206 }
1207 return 0;
1208 }
1209
1210 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
1211 {
1212 while (len) {
1213 unsigned int buffered = write_buffer_len;
1214 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1215 if (partial > len)
1216 partial = len;
1217 memcpy(write_buffer + buffered, data, partial);
1218 buffered += partial;
1219 if (buffered == WRITE_BUFFER_SIZE) {
1220 write_buffer_len = buffered;
1221 if (ce_write_flush(context, fd))
1222 return -1;
1223 buffered = 0;
1224 }
1225 write_buffer_len = buffered;
1226 len -= partial;
1227 data = (char *) data + partial;
1228 }
1229 return 0;
1230 }
1231
1232 static int write_index_ext_header(SHA_CTX *context, int fd,
1233 unsigned int ext, unsigned int sz)
1234 {
1235 ext = htonl(ext);
1236 sz = htonl(sz);
1237 return ((ce_write(context, fd, &ext, 4) < 0) ||
1238 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1239 }
1240
1241 static int ce_flush(SHA_CTX *context, int fd)
1242 {
1243 unsigned int left = write_buffer_len;
1244
1245 if (left) {
1246 write_buffer_len = 0;
1247 SHA1_Update(context, write_buffer, left);
1248 }
1249
1250 /* Flush first if not enough space for SHA1 signature */
1251 if (left + 20 > WRITE_BUFFER_SIZE) {
1252 if (write_in_full(fd, write_buffer, left) != left)
1253 return -1;
1254 left = 0;
1255 }
1256
1257 /* Append the SHA1 signature at the end */
1258 SHA1_Final(write_buffer + left, context);
1259 left += 20;
1260 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1261 }
1262
1263 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1264 {
1265 /*
1266 * The only thing we care about in this function is to smudge the
1267 * falsely clean entry due to touch-update-touch race, so we leave
1268 * everything else as they are. We are called for entries whose
1269 * ce_mtime match the index file mtime.
1270 */
1271 struct stat st;
1272
1273 if (lstat(ce->name, &st) < 0)
1274 return;
1275 if (ce_match_stat_basic(ce, &st))
1276 return;
1277 if (ce_modified_check_fs(ce, &st)) {
1278 /* This is "racily clean"; smudge it. Note that this
1279 * is a tricky code. At first glance, it may appear
1280 * that it can break with this sequence:
1281 *
1282 * $ echo xyzzy >frotz
1283 * $ git-update-index --add frotz
1284 * $ : >frotz
1285 * $ sleep 3
1286 * $ echo filfre >nitfol
1287 * $ git-update-index --add nitfol
1288 *
1289 * but it does not. When the second update-index runs,
1290 * it notices that the entry "frotz" has the same timestamp
1291 * as index, and if we were to smudge it by resetting its
1292 * size to zero here, then the object name recorded
1293 * in index is the 6-byte file but the cached stat information
1294 * becomes zero --- which would then match what we would
1295 * obtain from the filesystem next time we stat("frotz").
1296 *
1297 * However, the second update-index, before calling
1298 * this function, notices that the cached size is 6
1299 * bytes and what is on the filesystem is an empty
1300 * file, and never calls us, so the cached size information
1301 * for "frotz" stays 6 which does not match the filesystem.
1302 */
1303 ce->ce_size = 0;
1304 }
1305 }
1306
1307 static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)
1308 {
1309 int size = ondisk_ce_size(ce);
1310 struct ondisk_cache_entry *ondisk = xcalloc(1, size);
1311
1312 ondisk->ctime.sec = htonl(ce->ce_ctime);
1313 ondisk->ctime.nsec = 0;
1314 ondisk->mtime.sec = htonl(ce->ce_mtime);
1315 ondisk->mtime.nsec = 0;
1316 ondisk->dev = htonl(ce->ce_dev);
1317 ondisk->ino = htonl(ce->ce_ino);
1318 ondisk->mode = htonl(ce->ce_mode);
1319 ondisk->uid = htonl(ce->ce_uid);
1320 ondisk->gid = htonl(ce->ce_gid);
1321 ondisk->size = htonl(ce->ce_size);
1322 hashcpy(ondisk->sha1, ce->sha1);
1323 ondisk->flags = htons(ce->ce_flags);
1324 memcpy(ondisk->name, ce->name, ce_namelen(ce));
1325
1326 return ce_write(c, fd, ondisk, size);
1327 }
1328
1329 int write_index(const struct index_state *istate, int newfd)
1330 {
1331 SHA_CTX c;
1332 struct cache_header hdr;
1333 int i, err, removed;
1334 struct cache_entry **cache = istate->cache;
1335 int entries = istate->cache_nr;
1336
1337 for (i = removed = 0; i < entries; i++)
1338 if (cache[i]->ce_flags & CE_REMOVE)
1339 removed++;
1340
1341 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1342 hdr.hdr_version = htonl(2);
1343 hdr.hdr_entries = htonl(entries - removed);
1344
1345 SHA1_Init(&c);
1346 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1347 return -1;
1348
1349 for (i = 0; i < entries; i++) {
1350 struct cache_entry *ce = cache[i];
1351 if (ce->ce_flags & CE_REMOVE)
1352 continue;
1353 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
1354 ce_smudge_racily_clean_entry(ce);
1355 if (ce_write_entry(&c, newfd, ce) < 0)
1356 return -1;
1357 }
1358
1359 /* Write extension data here */
1360 if (istate->cache_tree) {
1361 struct strbuf sb;
1362
1363 strbuf_init(&sb, 0);
1364 cache_tree_write(&sb, istate->cache_tree);
1365 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1366 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1367 strbuf_release(&sb);
1368 if (err)
1369 return -1;
1370 }
1371 return ce_flush(&c, newfd);
1372 }