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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 #include "tree.h"
12 #include "commit.h"
13 #include "blob.h"
14 #include "resolve-undo.h"
16 static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
18 /* Index extensions.
19 *
20 * The first letter should be 'A'..'Z' for extensions that are not
21 * necessary for a correct operation (i.e. optimization data).
22 * When new extensions are added that _needs_ to be understood in
23 * order to correctly interpret the index file, pick character that
24 * is outside the range, to cause the reader to abort.
25 */
27 #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
28 #define CACHE_EXT_TREE 0x54524545 /* "TREE" */
29 #define CACHE_EXT_RESOLVE_UNDO 0x52455543 /* "REUC" */
31 struct index_state the_index;
33 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
34 {
35 istate->cache[nr] = ce;
36 add_name_hash(istate, ce);
37 }
39 static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
40 {
41 struct cache_entry *old = istate->cache[nr];
43 remove_name_hash(old);
44 set_index_entry(istate, nr, ce);
45 istate->cache_changed = 1;
46 }
48 void rename_index_entry_at(struct index_state *istate, int nr, const char *new_name)
49 {
50 struct cache_entry *old = istate->cache[nr], *new;
51 int namelen = strlen(new_name);
53 new = xmalloc(cache_entry_size(namelen));
54 copy_cache_entry(new, old);
55 new->ce_flags &= ~(CE_STATE_MASK | CE_NAMEMASK);
56 new->ce_flags |= (namelen >= CE_NAMEMASK ? CE_NAMEMASK : namelen);
57 memcpy(new->name, new_name, namelen + 1);
59 cache_tree_invalidate_path(istate->cache_tree, old->name);
60 remove_index_entry_at(istate, nr);
61 add_index_entry(istate, new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
62 }
64 /*
65 * This only updates the "non-critical" parts of the directory
66 * cache, ie the parts that aren't tracked by GIT, and only used
67 * to validate the cache.
68 */
69 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
70 {
71 ce->ce_ctime.sec = (unsigned int)st->st_ctime;
72 ce->ce_mtime.sec = (unsigned int)st->st_mtime;
73 ce->ce_ctime.nsec = ST_CTIME_NSEC(*st);
74 ce->ce_mtime.nsec = ST_MTIME_NSEC(*st);
75 ce->ce_dev = st->st_dev;
76 ce->ce_ino = st->st_ino;
77 ce->ce_uid = st->st_uid;
78 ce->ce_gid = st->st_gid;
79 ce->ce_size = st->st_size;
81 if (assume_unchanged)
82 ce->ce_flags |= CE_VALID;
84 if (S_ISREG(st->st_mode))
85 ce_mark_uptodate(ce);
86 }
88 static int ce_compare_data(struct cache_entry *ce, struct stat *st)
89 {
90 int match = -1;
91 int fd = open(ce->name, O_RDONLY);
93 if (fd >= 0) {
94 unsigned char sha1[20];
95 if (!index_fd(sha1, fd, st, OBJ_BLOB, ce->name, 0))
96 match = hashcmp(sha1, ce->sha1);
97 /* index_fd() closed the file descriptor already */
98 }
99 return match;
100 }
102 static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
103 {
104 int match = -1;
105 void *buffer;
106 unsigned long size;
107 enum object_type type;
108 struct strbuf sb = STRBUF_INIT;
110 if (strbuf_readlink(&sb, ce->name, expected_size))
111 return -1;
113 buffer = read_sha1_file(ce->sha1, &type, &size);
114 if (buffer) {
115 if (size == sb.len)
116 match = memcmp(buffer, sb.buf, size);
117 free(buffer);
118 }
119 strbuf_release(&sb);
120 return match;
121 }
123 static int ce_compare_gitlink(struct cache_entry *ce)
124 {
125 unsigned char sha1[20];
127 /*
128 * We don't actually require that the .git directory
129 * under GITLINK directory be a valid git directory. It
130 * might even be missing (in case nobody populated that
131 * sub-project).
132 *
133 * If so, we consider it always to match.
134 */
135 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
136 return 0;
137 return hashcmp(sha1, ce->sha1);
138 }
140 static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
141 {
142 switch (st->st_mode & S_IFMT) {
143 case S_IFREG:
144 if (ce_compare_data(ce, st))
145 return DATA_CHANGED;
146 break;
147 case S_IFLNK:
148 if (ce_compare_link(ce, xsize_t(st->st_size)))
149 return DATA_CHANGED;
150 break;
151 case S_IFDIR:
152 if (S_ISGITLINK(ce->ce_mode))
153 return ce_compare_gitlink(ce) ? DATA_CHANGED : 0;
154 default:
155 return TYPE_CHANGED;
156 }
157 return 0;
158 }
160 static int is_empty_blob_sha1(const unsigned char *sha1)
161 {
162 static const unsigned char empty_blob_sha1[20] = {
163 0xe6,0x9d,0xe2,0x9b,0xb2,0xd1,0xd6,0x43,0x4b,0x8b,
164 0x29,0xae,0x77,0x5a,0xd8,0xc2,0xe4,0x8c,0x53,0x91
165 };
167 return !hashcmp(sha1, empty_blob_sha1);
168 }
170 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
171 {
172 unsigned int changed = 0;
174 if (ce->ce_flags & CE_REMOVE)
175 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
177 switch (ce->ce_mode & S_IFMT) {
178 case S_IFREG:
179 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
180 /* We consider only the owner x bit to be relevant for
181 * "mode changes"
182 */
183 if (trust_executable_bit &&
184 (0100 & (ce->ce_mode ^ st->st_mode)))
185 changed |= MODE_CHANGED;
186 break;
187 case S_IFLNK:
188 if (!S_ISLNK(st->st_mode) &&
189 (has_symlinks || !S_ISREG(st->st_mode)))
190 changed |= TYPE_CHANGED;
191 break;
192 case S_IFGITLINK:
193 /* We ignore most of the st_xxx fields for gitlinks */
194 if (!S_ISDIR(st->st_mode))
195 changed |= TYPE_CHANGED;
196 else if (ce_compare_gitlink(ce))
197 changed |= DATA_CHANGED;
198 return changed;
199 default:
200 die("internal error: ce_mode is %o", ce->ce_mode);
201 }
202 if (ce->ce_mtime.sec != (unsigned int)st->st_mtime)
203 changed |= MTIME_CHANGED;
204 if (trust_ctime && ce->ce_ctime.sec != (unsigned int)st->st_ctime)
205 changed |= CTIME_CHANGED;
207 #ifdef USE_NSEC
208 if (ce->ce_mtime.nsec != ST_MTIME_NSEC(*st))
209 changed |= MTIME_CHANGED;
210 if (trust_ctime && ce->ce_ctime.nsec != ST_CTIME_NSEC(*st))
211 changed |= CTIME_CHANGED;
212 #endif
214 if (ce->ce_uid != (unsigned int) st->st_uid ||
215 ce->ce_gid != (unsigned int) st->st_gid)
216 changed |= OWNER_CHANGED;
217 if (ce->ce_ino != (unsigned int) st->st_ino)
218 changed |= INODE_CHANGED;
220 #ifdef USE_STDEV
221 /*
222 * st_dev breaks on network filesystems where different
223 * clients will have different views of what "device"
224 * the filesystem is on
225 */
226 if (ce->ce_dev != (unsigned int) st->st_dev)
227 changed |= INODE_CHANGED;
228 #endif
230 if (ce->ce_size != (unsigned int) st->st_size)
231 changed |= DATA_CHANGED;
233 /* Racily smudged entry? */
234 if (!ce->ce_size) {
235 if (!is_empty_blob_sha1(ce->sha1))
236 changed |= DATA_CHANGED;
237 }
239 return changed;
240 }
242 static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
243 {
244 return (!S_ISGITLINK(ce->ce_mode) &&
245 istate->timestamp.sec &&
246 #ifdef USE_NSEC
247 /* nanosecond timestamped files can also be racy! */
248 (istate->timestamp.sec < ce->ce_mtime.sec ||
249 (istate->timestamp.sec == ce->ce_mtime.sec &&
250 istate->timestamp.nsec <= ce->ce_mtime.nsec))
251 #else
252 istate->timestamp.sec <= ce->ce_mtime.sec
253 #endif
254 );
255 }
257 int ie_match_stat(const struct index_state *istate,
258 struct cache_entry *ce, struct stat *st,
259 unsigned int options)
260 {
261 unsigned int changed;
262 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
263 int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
264 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
266 /*
267 * If it's marked as always valid in the index, it's
268 * valid whatever the checked-out copy says.
269 *
270 * skip-worktree has the same effect with higher precedence
271 */
272 if (!ignore_skip_worktree && ce_skip_worktree(ce))
273 return 0;
274 if (!ignore_valid && (ce->ce_flags & CE_VALID))
275 return 0;
277 /*
278 * Intent-to-add entries have not been added, so the index entry
279 * by definition never matches what is in the work tree until it
280 * actually gets added.
281 */
282 if (ce->ce_flags & CE_INTENT_TO_ADD)
283 return DATA_CHANGED | TYPE_CHANGED | MODE_CHANGED;
285 changed = ce_match_stat_basic(ce, st);
287 /*
288 * Within 1 second of this sequence:
289 * echo xyzzy >file && git-update-index --add file
290 * running this command:
291 * echo frotz >file
292 * would give a falsely clean cache entry. The mtime and
293 * length match the cache, and other stat fields do not change.
294 *
295 * We could detect this at update-index time (the cache entry
296 * being registered/updated records the same time as "now")
297 * and delay the return from git-update-index, but that would
298 * effectively mean we can make at most one commit per second,
299 * which is not acceptable. Instead, we check cache entries
300 * whose mtime are the same as the index file timestamp more
301 * carefully than others.
302 */
303 if (!changed && is_racy_timestamp(istate, ce)) {
304 if (assume_racy_is_modified)
305 changed |= DATA_CHANGED;
306 else
307 changed |= ce_modified_check_fs(ce, st);
308 }
310 return changed;
311 }
313 int ie_modified(const struct index_state *istate,
314 struct cache_entry *ce, struct stat *st, unsigned int options)
315 {
316 int changed, changed_fs;
318 changed = ie_match_stat(istate, ce, st, options);
319 if (!changed)
320 return 0;
321 /*
322 * If the mode or type has changed, there's no point in trying
323 * to refresh the entry - it's not going to match
324 */
325 if (changed & (MODE_CHANGED | TYPE_CHANGED))
326 return changed;
328 /*
329 * Immediately after read-tree or update-index --cacheinfo,
330 * the length field is zero, as we have never even read the
331 * lstat(2) information once, and we cannot trust DATA_CHANGED
332 * returned by ie_match_stat() which in turn was returned by
333 * ce_match_stat_basic() to signal that the filesize of the
334 * blob changed. We have to actually go to the filesystem to
335 * see if the contents match, and if so, should answer "unchanged".
336 *
337 * The logic does not apply to gitlinks, as ce_match_stat_basic()
338 * already has checked the actual HEAD from the filesystem in the
339 * subproject. If ie_match_stat() already said it is different,
340 * then we know it is.
341 */
342 if ((changed & DATA_CHANGED) &&
343 (S_ISGITLINK(ce->ce_mode) || ce->ce_size != 0))
344 return changed;
346 changed_fs = ce_modified_check_fs(ce, st);
347 if (changed_fs)
348 return changed | changed_fs;
349 return 0;
350 }
352 int base_name_compare(const char *name1, int len1, int mode1,
353 const char *name2, int len2, int mode2)
354 {
355 unsigned char c1, c2;
356 int len = len1 < len2 ? len1 : len2;
357 int cmp;
359 cmp = memcmp(name1, name2, len);
360 if (cmp)
361 return cmp;
362 c1 = name1[len];
363 c2 = name2[len];
364 if (!c1 && S_ISDIR(mode1))
365 c1 = '/';
366 if (!c2 && S_ISDIR(mode2))
367 c2 = '/';
368 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
369 }
371 /*
372 * df_name_compare() is identical to base_name_compare(), except it
373 * compares conflicting directory/file entries as equal. Note that
374 * while a directory name compares as equal to a regular file, they
375 * then individually compare _differently_ to a filename that has
376 * a dot after the basename (because '\0' < '.' < '/').
377 *
378 * This is used by routines that want to traverse the git namespace
379 * but then handle conflicting entries together when possible.
380 */
381 int df_name_compare(const char *name1, int len1, int mode1,
382 const char *name2, int len2, int mode2)
383 {
384 int len = len1 < len2 ? len1 : len2, cmp;
385 unsigned char c1, c2;
387 cmp = memcmp(name1, name2, len);
388 if (cmp)
389 return cmp;
390 /* Directories and files compare equal (same length, same name) */
391 if (len1 == len2)
392 return 0;
393 c1 = name1[len];
394 if (!c1 && S_ISDIR(mode1))
395 c1 = '/';
396 c2 = name2[len];
397 if (!c2 && S_ISDIR(mode2))
398 c2 = '/';
399 if (c1 == '/' && !c2)
400 return 0;
401 if (c2 == '/' && !c1)
402 return 0;
403 return c1 - c2;
404 }
406 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
407 {
408 int len1 = flags1 & CE_NAMEMASK;
409 int len2 = flags2 & CE_NAMEMASK;
410 int len = len1 < len2 ? len1 : len2;
411 int cmp;
413 cmp = memcmp(name1, name2, len);
414 if (cmp)
415 return cmp;
416 if (len1 < len2)
417 return -1;
418 if (len1 > len2)
419 return 1;
421 /* Compare stages */
422 flags1 &= CE_STAGEMASK;
423 flags2 &= CE_STAGEMASK;
425 if (flags1 < flags2)
426 return -1;
427 if (flags1 > flags2)
428 return 1;
429 return 0;
430 }
432 int index_name_pos(const struct index_state *istate, const char *name, int namelen)
433 {
434 int first, last;
436 first = 0;
437 last = istate->cache_nr;
438 while (last > first) {
439 int next = (last + first) >> 1;
440 struct cache_entry *ce = istate->cache[next];
441 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags);
442 if (!cmp)
443 return next;
444 if (cmp < 0) {
445 last = next;
446 continue;
447 }
448 first = next+1;
449 }
450 return -first-1;
451 }
453 /* Remove entry, return true if there are more entries to go.. */
454 int remove_index_entry_at(struct index_state *istate, int pos)
455 {
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;
468 }
470 /*
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.
474 */
475 void remove_marked_cache_entries(struct index_state *istate)
476 {
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];
485 }
486 istate->cache_changed = 1;
487 istate->cache_nr = j;
488 }
490 int remove_file_from_index(struct index_state *istate, const char *path)
491 {
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;
499 }
501 static int compare_name(struct cache_entry *ce, const char *path, int namelen)
502 {
503 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
504 }
506 static int index_name_pos_also_unmerged(struct index_state *istate,
507 const char *path, int namelen)
508 {
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;
527 }
529 static int different_name(struct cache_entry *ce, struct cache_entry *alias)
530 {
531 int len = ce_namelen(ce);
532 return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
533 }
535 /*
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!
540 *
541 * So we use the CE_ADDED flag to verify that the alias was an old
542 * one before we accept it as
543 */
544 static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias)
545 {
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;
559 }
561 static void record_intent_to_add(struct cache_entry *ce)
562 {
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);
567 }
569 int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
570 {
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--;
588 }
589 size = cache_entry_size(namelen);
590 ce = xcalloc(1, size);
591 memcpy(ce->name, path, namelen);
592 ce->ce_flags = 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.
603 */
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);
609 }
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.
615 */
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;
629 }
630 }
631 }
632 }
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;
642 }
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)
660 ;
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;
666 }
668 int add_file_to_index(struct index_state *istate, const char *path, int flags)
669 {
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);
674 }
676 struct cache_entry *make_cache_entry(unsigned int mode,
677 const unsigned char *sha1, const char *path, int stage,
678 int refresh)
679 {
680 int size, len;
681 struct cache_entry *ce;
683 if (!verify_path(path)) {
684 error("Invalid path '%s'", path);
685 return NULL;
686 }
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(len, stage);
695 ce->ce_mode = create_ce_mode(mode);
697 if (refresh)
698 return refresh_cache_entry(ce, 0);
700 return ce;
701 }
703 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
704 {
705 int len = ce_namelen(a);
706 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
707 }
709 int ce_path_match(const struct cache_entry *ce, const struct pathspec *pathspec)
710 {
711 return match_pathspec_depth(pathspec, ce->name, ce_namelen(ce), 0, NULL);
712 }
714 /*
715 * We fundamentally don't like some paths: we don't want
716 * dot or dot-dot anywhere, and for obvious reasons don't
717 * want to recurse into ".git" either.
718 *
719 * Also, we don't want double slashes or slashes at the
720 * end that can make pathnames ambiguous.
721 */
722 static int verify_dotfile(const char *rest)
723 {
724 /*
725 * The first character was '.', but that
726 * has already been discarded, we now test
727 * the rest.
728 */
730 /* "." is not allowed */
731 if (*rest == '\0' || is_dir_sep(*rest))
732 return 0;
734 switch (*rest) {
735 /*
736 * ".git" followed by NUL or slash is bad. This
737 * shares the path end test with the ".." case.
738 */
739 case 'g':
740 if (rest[1] != 'i')
741 break;
742 if (rest[2] != 't')
743 break;
744 rest += 2;
745 /* fallthrough */
746 case '.':
747 if (rest[1] == '\0' || is_dir_sep(rest[1]))
748 return 0;
749 }
750 return 1;
751 }
753 int verify_path(const char *path)
754 {
755 char c;
757 if (has_dos_drive_prefix(path))
758 return 0;
760 goto inside;
761 for (;;) {
762 if (!c)
763 return 1;
764 if (is_dir_sep(c)) {
765 inside:
766 c = *path++;
767 if ((c == '.' && !verify_dotfile(path)) ||
768 is_dir_sep(c) || c == '\0')
769 return 0;
770 }
771 c = *path++;
772 }
773 }
775 /*
776 * Do we have another file that has the beginning components being a
777 * proper superset of the name we're trying to add?
778 */
779 static int has_file_name(struct index_state *istate,
780 const struct cache_entry *ce, int pos, int ok_to_replace)
781 {
782 int retval = 0;
783 int len = ce_namelen(ce);
784 int stage = ce_stage(ce);
785 const char *name = ce->name;
787 while (pos < istate->cache_nr) {
788 struct cache_entry *p = istate->cache[pos++];
790 if (len >= ce_namelen(p))
791 break;
792 if (memcmp(name, p->name, len))
793 break;
794 if (ce_stage(p) != stage)
795 continue;
796 if (p->name[len] != '/')
797 continue;
798 if (p->ce_flags & CE_REMOVE)
799 continue;
800 retval = -1;
801 if (!ok_to_replace)
802 break;
803 remove_index_entry_at(istate, --pos);
804 }
805 return retval;
806 }
808 /*
809 * Do we have another file with a pathname that is a proper
810 * subset of the name we're trying to add?
811 */
812 static int has_dir_name(struct index_state *istate,
813 const struct cache_entry *ce, int pos, int ok_to_replace)
814 {
815 int retval = 0;
816 int stage = ce_stage(ce);
817 const char *name = ce->name;
818 const char *slash = name + ce_namelen(ce);
820 for (;;) {
821 int len;
823 for (;;) {
824 if (*--slash == '/')
825 break;
826 if (slash <= ce->name)
827 return retval;
828 }
829 len = slash - name;
831 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
832 if (pos >= 0) {
833 /*
834 * Found one, but not so fast. This could
835 * be a marker that says "I was here, but
836 * I am being removed". Such an entry is
837 * not a part of the resulting tree, and
838 * it is Ok to have a directory at the same
839 * path.
840 */
841 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
842 retval = -1;
843 if (!ok_to_replace)
844 break;
845 remove_index_entry_at(istate, pos);
846 continue;
847 }
848 }
849 else
850 pos = -pos-1;
852 /*
853 * Trivial optimization: if we find an entry that
854 * already matches the sub-directory, then we know
855 * we're ok, and we can exit.
856 */
857 while (pos < istate->cache_nr) {
858 struct cache_entry *p = istate->cache[pos];
859 if ((ce_namelen(p) <= len) ||
860 (p->name[len] != '/') ||
861 memcmp(p->name, name, len))
862 break; /* not our subdirectory */
863 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
864 /*
865 * p is at the same stage as our entry, and
866 * is a subdirectory of what we are looking
867 * at, so we cannot have conflicts at our
868 * level or anything shorter.
869 */
870 return retval;
871 pos++;
872 }
873 }
874 return retval;
875 }
877 /* We may be in a situation where we already have path/file and path
878 * is being added, or we already have path and path/file is being
879 * added. Either one would result in a nonsense tree that has path
880 * twice when git-write-tree tries to write it out. Prevent it.
881 *
882 * If ok-to-replace is specified, we remove the conflicting entries
883 * from the cache so the caller should recompute the insert position.
884 * When this happens, we return non-zero.
885 */
886 static int check_file_directory_conflict(struct index_state *istate,
887 const struct cache_entry *ce,
888 int pos, int ok_to_replace)
889 {
890 int retval;
892 /*
893 * When ce is an "I am going away" entry, we allow it to be added
894 */
895 if (ce->ce_flags & CE_REMOVE)
896 return 0;
898 /*
899 * We check if the path is a sub-path of a subsequent pathname
900 * first, since removing those will not change the position
901 * in the array.
902 */
903 retval = has_file_name(istate, ce, pos, ok_to_replace);
905 /*
906 * Then check if the path might have a clashing sub-directory
907 * before it.
908 */
909 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
910 }
912 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
913 {
914 int pos;
915 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
916 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
917 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
918 int new_only = option & ADD_CACHE_NEW_ONLY;
920 cache_tree_invalidate_path(istate->cache_tree, ce->name);
921 pos = index_name_pos(istate, ce->name, ce->ce_flags);
923 /* existing match? Just replace it. */
924 if (pos >= 0) {
925 if (!new_only)
926 replace_index_entry(istate, pos, ce);
927 return 0;
928 }
929 pos = -pos-1;
931 /*
932 * Inserting a merged entry ("stage 0") into the index
933 * will always replace all non-merged entries..
934 */
935 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
936 while (ce_same_name(istate->cache[pos], ce)) {
937 ok_to_add = 1;
938 if (!remove_index_entry_at(istate, pos))
939 break;
940 }
941 }
943 if (!ok_to_add)
944 return -1;
945 if (!verify_path(ce->name))
946 return error("Invalid path '%s'", ce->name);
948 if (!skip_df_check &&
949 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
950 if (!ok_to_replace)
951 return error("'%s' appears as both a file and as a directory",
952 ce->name);
953 pos = index_name_pos(istate, ce->name, ce->ce_flags);
954 pos = -pos-1;
955 }
956 return pos + 1;
957 }
959 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
960 {
961 int pos;
963 if (option & ADD_CACHE_JUST_APPEND)
964 pos = istate->cache_nr;
965 else {
966 int ret;
967 ret = add_index_entry_with_check(istate, ce, option);
968 if (ret <= 0)
969 return ret;
970 pos = ret - 1;
971 }
973 /* Make sure the array is big enough .. */
974 if (istate->cache_nr == istate->cache_alloc) {
975 istate->cache_alloc = alloc_nr(istate->cache_alloc);
976 istate->cache = xrealloc(istate->cache,
977 istate->cache_alloc * sizeof(struct cache_entry *));
978 }
980 /* Add it in.. */
981 istate->cache_nr++;
982 if (istate->cache_nr > pos + 1)
983 memmove(istate->cache + pos + 1,
984 istate->cache + pos,
985 (istate->cache_nr - pos - 1) * sizeof(ce));
986 set_index_entry(istate, pos, ce);
987 istate->cache_changed = 1;
988 return 0;
989 }
991 /*
992 * "refresh" does not calculate a new sha1 file or bring the
993 * cache up-to-date for mode/content changes. But what it
994 * _does_ do is to "re-match" the stat information of a file
995 * with the cache, so that you can refresh the cache for a
996 * file that hasn't been changed but where the stat entry is
997 * out of date.
998 *
999 * For example, you'd want to do this after doing a "git-read-tree",
1000 * to link up the stat cache details with the proper files.
1001 */
1002 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
1003 struct cache_entry *ce,
1004 unsigned int options, int *err,
1005 int *changed_ret)
1006 {
1007 struct stat st;
1008 struct cache_entry *updated;
1009 int changed, size;
1010 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
1011 int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
1013 if (ce_uptodate(ce))
1014 return ce;
1016 /*
1017 * CE_VALID or CE_SKIP_WORKTREE means the user promised us
1018 * that the change to the work tree does not matter and told
1019 * us not to worry.
1020 */
1021 if (!ignore_skip_worktree && ce_skip_worktree(ce)) {
1022 ce_mark_uptodate(ce);
1023 return ce;
1024 }
1025 if (!ignore_valid && (ce->ce_flags & CE_VALID)) {
1026 ce_mark_uptodate(ce);
1027 return ce;
1028 }
1030 if (lstat(ce->name, &st) < 0) {
1031 if (err)
1032 *err = errno;
1033 return NULL;
1034 }
1036 changed = ie_match_stat(istate, ce, &st, options);
1037 if (changed_ret)
1038 *changed_ret = changed;
1039 if (!changed) {
1040 /*
1041 * The path is unchanged. If we were told to ignore
1042 * valid bit, then we did the actual stat check and
1043 * found that the entry is unmodified. If the entry
1044 * is not marked VALID, this is the place to mark it
1045 * valid again, under "assume unchanged" mode.
1046 */
1047 if (ignore_valid && assume_unchanged &&
1048 !(ce->ce_flags & CE_VALID))
1049 ; /* mark this one VALID again */
1050 else {
1051 /*
1052 * We do not mark the index itself "modified"
1053 * because CE_UPTODATE flag is in-core only;
1054 * we are not going to write this change out.
1055 */
1056 if (!S_ISGITLINK(ce->ce_mode))
1057 ce_mark_uptodate(ce);
1058 return ce;
1059 }
1060 }
1062 if (ie_modified(istate, ce, &st, options)) {
1063 if (err)
1064 *err = EINVAL;
1065 return NULL;
1066 }
1068 size = ce_size(ce);
1069 updated = xmalloc(size);
1070 memcpy(updated, ce, size);
1071 fill_stat_cache_info(updated, &st);
1072 /*
1073 * If ignore_valid is not set, we should leave CE_VALID bit
1074 * alone. Otherwise, paths marked with --no-assume-unchanged
1075 * (i.e. things to be edited) will reacquire CE_VALID bit
1076 * automatically, which is not really what we want.
1077 */
1078 if (!ignore_valid && assume_unchanged &&
1079 !(ce->ce_flags & CE_VALID))
1080 updated->ce_flags &= ~CE_VALID;
1082 return updated;
1083 }
1085 static void show_file(const char * fmt, const char * name, int in_porcelain,
1086 int * first, const char *header_msg)
1087 {
1088 if (in_porcelain && *first && header_msg) {
1089 printf("%s\n", header_msg);
1090 *first = 0;
1091 }
1092 printf(fmt, name);
1093 }
1095 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec,
1096 char *seen, const char *header_msg)
1097 {
1098 int i;
1099 int has_errors = 0;
1100 int really = (flags & REFRESH_REALLY) != 0;
1101 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
1102 int quiet = (flags & REFRESH_QUIET) != 0;
1103 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
1104 int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
1105 int first = 1;
1106 int in_porcelain = (flags & REFRESH_IN_PORCELAIN);
1107 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
1108 const char *modified_fmt;
1109 const char *deleted_fmt;
1110 const char *typechange_fmt;
1111 const char *added_fmt;
1112 const char *unmerged_fmt;
1114 modified_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
1115 deleted_fmt = (in_porcelain ? "D\t%s\n" : "%s: needs update\n");
1116 typechange_fmt = (in_porcelain ? "T\t%s\n" : "%s needs update\n");
1117 added_fmt = (in_porcelain ? "A\t%s\n" : "%s needs update\n");
1118 unmerged_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n");
1119 for (i = 0; i < istate->cache_nr; i++) {
1120 struct cache_entry *ce, *new;
1121 int cache_errno = 0;
1122 int changed = 0;
1123 int filtered = 0;
1125 ce = istate->cache[i];
1126 if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
1127 continue;
1129 if (pathspec &&
1130 !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
1131 filtered = 1;
1133 if (ce_stage(ce)) {
1134 while ((i < istate->cache_nr) &&
1135 ! strcmp(istate->cache[i]->name, ce->name))
1136 i++;
1137 i--;
1138 if (allow_unmerged)
1139 continue;
1140 if (!filtered)
1141 show_file(unmerged_fmt, ce->name, in_porcelain,
1142 &first, header_msg);
1143 has_errors = 1;
1144 continue;
1145 }
1147 if (filtered)
1148 continue;
1150 new = refresh_cache_ent(istate, ce, options, &cache_errno, &changed);
1151 if (new == ce)
1152 continue;
1153 if (!new) {
1154 const char *fmt;
1156 if (not_new && cache_errno == ENOENT)
1157 continue;
1158 if (really && cache_errno == EINVAL) {
1159 /* If we are doing --really-refresh that
1160 * means the index is not valid anymore.
1161 */
1162 ce->ce_flags &= ~CE_VALID;
1163 istate->cache_changed = 1;
1164 }
1165 if (quiet)
1166 continue;
1168 if (cache_errno == ENOENT)
1169 fmt = deleted_fmt;
1170 else if (ce->ce_flags & CE_INTENT_TO_ADD)
1171 fmt = added_fmt; /* must be before other checks */
1172 else if (changed & TYPE_CHANGED)
1173 fmt = typechange_fmt;
1174 else
1175 fmt = modified_fmt;
1176 show_file(fmt,
1177 ce->name, in_porcelain, &first, header_msg);
1178 has_errors = 1;
1179 continue;
1180 }
1182 replace_index_entry(istate, i, new);
1183 }
1184 return has_errors;
1185 }
1187 static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
1188 {
1189 return refresh_cache_ent(&the_index, ce, really, NULL, NULL);
1190 }
1192 static int verify_hdr(struct cache_header *hdr, unsigned long size)
1193 {
1194 git_SHA_CTX c;
1195 unsigned char sha1[20];
1197 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
1198 return error("bad signature");
1199 if (hdr->hdr_version != htonl(2) && hdr->hdr_version != htonl(3))
1200 return error("bad index version");
1201 git_SHA1_Init(&c);
1202 git_SHA1_Update(&c, hdr, size - 20);
1203 git_SHA1_Final(sha1, &c);
1204 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1205 return error("bad index file sha1 signature");
1206 return 0;
1207 }
1209 static int read_index_extension(struct index_state *istate,
1210 const char *ext, void *data, unsigned long sz)
1211 {
1212 switch (CACHE_EXT(ext)) {
1213 case CACHE_EXT_TREE:
1214 istate->cache_tree = cache_tree_read(data, sz);
1215 break;
1216 case CACHE_EXT_RESOLVE_UNDO:
1217 istate->resolve_undo = resolve_undo_read(data, sz);
1218 break;
1219 default:
1220 if (*ext < 'A' || 'Z' < *ext)
1221 return error("index uses %.4s extension, which we do not understand",
1222 ext);
1223 fprintf(stderr, "ignoring %.4s extension\n", ext);
1224 break;
1225 }
1226 return 0;
1227 }
1229 int read_index(struct index_state *istate)
1230 {
1231 return read_index_from(istate, get_index_file());
1232 }
1234 static struct cache_entry *create_from_disk(struct ondisk_cache_entry *ondisk)
1235 {
1236 struct cache_entry *ce;
1237 size_t len;
1238 const char *name;
1239 unsigned int flags;
1241 /* On-disk flags are just 16 bits */
1242 flags = ntohs(ondisk->flags);
1243 len = flags & CE_NAMEMASK;
1245 if (flags & CE_EXTENDED) {
1246 struct ondisk_cache_entry_extended *ondisk2;
1247 int extended_flags;
1248 ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
1249 extended_flags = ntohs(ondisk2->flags2) << 16;
1250 /* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
1251 if (extended_flags & ~CE_EXTENDED_FLAGS)
1252 die("Unknown index entry format %08x", extended_flags);
1253 flags |= extended_flags;
1254 name = ondisk2->name;
1255 }
1256 else
1257 name = ondisk->name;
1259 if (len == CE_NAMEMASK)
1260 len = strlen(name);
1262 ce = xmalloc(cache_entry_size(len));
1264 ce->ce_ctime.sec = ntohl(ondisk->ctime.sec);
1265 ce->ce_mtime.sec = ntohl(ondisk->mtime.sec);
1266 ce->ce_ctime.nsec = ntohl(ondisk->ctime.nsec);
1267 ce->ce_mtime.nsec = ntohl(ondisk->mtime.nsec);
1268 ce->ce_dev = ntohl(ondisk->dev);
1269 ce->ce_ino = ntohl(ondisk->ino);
1270 ce->ce_mode = ntohl(ondisk->mode);
1271 ce->ce_uid = ntohl(ondisk->uid);
1272 ce->ce_gid = ntohl(ondisk->gid);
1273 ce->ce_size = ntohl(ondisk->size);
1274 ce->ce_flags = flags;
1276 hashcpy(ce->sha1, ondisk->sha1);
1278 memcpy(ce->name, name, len);
1279 ce->name[len] = '\0';
1280 return ce;
1281 }
1283 /* remember to discard_cache() before reading a different cache! */
1284 int read_index_from(struct index_state *istate, const char *path)
1285 {
1286 int fd, i;
1287 struct stat st;
1288 unsigned long src_offset;
1289 struct cache_header *hdr;
1290 void *mmap;
1291 size_t mmap_size;
1293 errno = EBUSY;
1294 if (istate->initialized)
1295 return istate->cache_nr;
1297 errno = ENOENT;
1298 istate->timestamp.sec = 0;
1299 istate->timestamp.nsec = 0;
1300 fd = open(path, O_RDONLY);
1301 if (fd < 0) {
1302 if (errno == ENOENT)
1303 return 0;
1304 die_errno("index file open failed");
1305 }
1307 if (fstat(fd, &st))
1308 die_errno("cannot stat the open index");
1310 errno = EINVAL;
1311 mmap_size = xsize_t(st.st_size);
1312 if (mmap_size < sizeof(struct cache_header) + 20)
1313 die("index file smaller than expected");
1315 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1316 close(fd);
1317 if (mmap == MAP_FAILED)
1318 die_errno("unable to map index file");
1320 hdr = mmap;
1321 if (verify_hdr(hdr, mmap_size) < 0)
1322 goto unmap;
1324 istate->cache_nr = ntohl(hdr->hdr_entries);
1325 istate->cache_alloc = alloc_nr(istate->cache_nr);
1326 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1327 istate->initialized = 1;
1329 src_offset = sizeof(*hdr);
1330 for (i = 0; i < istate->cache_nr; i++) {
1331 struct ondisk_cache_entry *disk_ce;
1332 struct cache_entry *ce;
1334 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1335 ce = create_from_disk(disk_ce);
1336 set_index_entry(istate, i, ce);
1338 src_offset += ondisk_ce_size(ce);
1339 }
1340 istate->timestamp.sec = st.st_mtime;
1341 istate->timestamp.nsec = ST_MTIME_NSEC(st);
1343 while (src_offset <= mmap_size - 20 - 8) {
1344 /* After an array of active_nr index entries,
1345 * there can be arbitrary number of extended
1346 * sections, each of which is prefixed with
1347 * extension name (4-byte) and section length
1348 * in 4-byte network byte order.
1349 */
1350 uint32_t extsize;
1351 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1352 extsize = ntohl(extsize);
1353 if (read_index_extension(istate,
1354 (const char *) mmap + src_offset,
1355 (char *) mmap + src_offset + 8,
1356 extsize) < 0)
1357 goto unmap;
1358 src_offset += 8;
1359 src_offset += extsize;
1360 }
1361 munmap(mmap, mmap_size);
1362 return istate->cache_nr;
1364 unmap:
1365 munmap(mmap, mmap_size);
1366 errno = EINVAL;
1367 die("index file corrupt");
1368 }
1370 int is_index_unborn(struct index_state *istate)
1371 {
1372 return (!istate->cache_nr && !istate->timestamp.sec);
1373 }
1375 int discard_index(struct index_state *istate)
1376 {
1377 int i;
1379 for (i = 0; i < istate->cache_nr; i++)
1380 free(istate->cache[i]);
1381 resolve_undo_clear_index(istate);
1382 istate->cache_nr = 0;
1383 istate->cache_changed = 0;
1384 istate->timestamp.sec = 0;
1385 istate->timestamp.nsec = 0;
1386 istate->name_hash_initialized = 0;
1387 free_hash(&istate->name_hash);
1388 cache_tree_free(&(istate->cache_tree));
1389 istate->initialized = 0;
1391 /* no need to throw away allocated active_cache */
1392 return 0;
1393 }
1395 int unmerged_index(const struct index_state *istate)
1396 {
1397 int i;
1398 for (i = 0; i < istate->cache_nr; i++) {
1399 if (ce_stage(istate->cache[i]))
1400 return 1;
1401 }
1402 return 0;
1403 }
1405 #define WRITE_BUFFER_SIZE 8192
1406 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1407 static unsigned long write_buffer_len;
1409 static int ce_write_flush(git_SHA_CTX *context, int fd)
1410 {
1411 unsigned int buffered = write_buffer_len;
1412 if (buffered) {
1413 git_SHA1_Update(context, write_buffer, buffered);
1414 if (write_in_full(fd, write_buffer, buffered) != buffered)
1415 return -1;
1416 write_buffer_len = 0;
1417 }
1418 return 0;
1419 }
1421 static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
1422 {
1423 while (len) {
1424 unsigned int buffered = write_buffer_len;
1425 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1426 if (partial > len)
1427 partial = len;
1428 memcpy(write_buffer + buffered, data, partial);
1429 buffered += partial;
1430 if (buffered == WRITE_BUFFER_SIZE) {
1431 write_buffer_len = buffered;
1432 if (ce_write_flush(context, fd))
1433 return -1;
1434 buffered = 0;
1435 }
1436 write_buffer_len = buffered;
1437 len -= partial;
1438 data = (char *) data + partial;
1439 }
1440 return 0;
1441 }
1443 static int write_index_ext_header(git_SHA_CTX *context, int fd,
1444 unsigned int ext, unsigned int sz)
1445 {
1446 ext = htonl(ext);
1447 sz = htonl(sz);
1448 return ((ce_write(context, fd, &ext, 4) < 0) ||
1449 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1450 }
1452 static int ce_flush(git_SHA_CTX *context, int fd)
1453 {
1454 unsigned int left = write_buffer_len;
1456 if (left) {
1457 write_buffer_len = 0;
1458 git_SHA1_Update(context, write_buffer, left);
1459 }
1461 /* Flush first if not enough space for SHA1 signature */
1462 if (left + 20 > WRITE_BUFFER_SIZE) {
1463 if (write_in_full(fd, write_buffer, left) != left)
1464 return -1;
1465 left = 0;
1466 }
1468 /* Append the SHA1 signature at the end */
1469 git_SHA1_Final(write_buffer + left, context);
1470 left += 20;
1471 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1472 }
1474 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1475 {
1476 /*
1477 * The only thing we care about in this function is to smudge the
1478 * falsely clean entry due to touch-update-touch race, so we leave
1479 * everything else as they are. We are called for entries whose
1480 * ce_mtime match the index file mtime.
1481 *
1482 * Note that this actually does not do much for gitlinks, for
1483 * which ce_match_stat_basic() always goes to the actual
1484 * contents. The caller checks with is_racy_timestamp() which
1485 * always says "no" for gitlinks, so we are not called for them ;-)
1486 */
1487 struct stat st;
1489 if (lstat(ce->name, &st) < 0)
1490 return;
1491 if (ce_match_stat_basic(ce, &st))
1492 return;
1493 if (ce_modified_check_fs(ce, &st)) {
1494 /* This is "racily clean"; smudge it. Note that this
1495 * is a tricky code. At first glance, it may appear
1496 * that it can break with this sequence:
1497 *
1498 * $ echo xyzzy >frotz
1499 * $ git-update-index --add frotz
1500 * $ : >frotz
1501 * $ sleep 3
1502 * $ echo filfre >nitfol
1503 * $ git-update-index --add nitfol
1504 *
1505 * but it does not. When the second update-index runs,
1506 * it notices that the entry "frotz" has the same timestamp
1507 * as index, and if we were to smudge it by resetting its
1508 * size to zero here, then the object name recorded
1509 * in index is the 6-byte file but the cached stat information
1510 * becomes zero --- which would then match what we would
1511 * obtain from the filesystem next time we stat("frotz").
1512 *
1513 * However, the second update-index, before calling
1514 * this function, notices that the cached size is 6
1515 * bytes and what is on the filesystem is an empty
1516 * file, and never calls us, so the cached size information
1517 * for "frotz" stays 6 which does not match the filesystem.
1518 */
1519 ce->ce_size = 0;
1520 }
1521 }
1523 static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce)
1524 {
1525 int size = ondisk_ce_size(ce);
1526 struct ondisk_cache_entry *ondisk = xcalloc(1, size);
1527 char *name;
1528 int result;
1530 ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
1531 ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
1532 ondisk->ctime.nsec = htonl(ce->ce_ctime.nsec);
1533 ondisk->mtime.nsec = htonl(ce->ce_mtime.nsec);
1534 ondisk->dev = htonl(ce->ce_dev);
1535 ondisk->ino = htonl(ce->ce_ino);
1536 ondisk->mode = htonl(ce->ce_mode);
1537 ondisk->uid = htonl(ce->ce_uid);
1538 ondisk->gid = htonl(ce->ce_gid);
1539 ondisk->size = htonl(ce->ce_size);
1540 hashcpy(ondisk->sha1, ce->sha1);
1541 ondisk->flags = htons(ce->ce_flags);
1542 if (ce->ce_flags & CE_EXTENDED) {
1543 struct ondisk_cache_entry_extended *ondisk2;
1544 ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
1545 ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
1546 name = ondisk2->name;
1547 }
1548 else
1549 name = ondisk->name;
1550 memcpy(name, ce->name, ce_namelen(ce));
1552 result = ce_write(c, fd, ondisk, size);
1553 free(ondisk);
1554 return result;
1555 }
1557 static int has_racy_timestamp(struct index_state *istate)
1558 {
1559 int entries = istate->cache_nr;
1560 int i;
1562 for (i = 0; i < entries; i++) {
1563 struct cache_entry *ce = istate->cache[i];
1564 if (is_racy_timestamp(istate, ce))
1565 return 1;
1566 }
1567 return 0;
1568 }
1570 /*
1571 * Opportunisticly update the index but do not complain if we can't
1572 */
1573 void update_index_if_able(struct index_state *istate, struct lock_file *lockfile)
1574 {
1575 if ((istate->cache_changed || has_racy_timestamp(istate)) &&
1576 !write_index(istate, lockfile->fd))
1577 commit_locked_index(lockfile);
1578 else
1579 rollback_lock_file(lockfile);
1580 }
1582 int write_index(struct index_state *istate, int newfd)
1583 {
1584 git_SHA_CTX c;
1585 struct cache_header hdr;
1586 int i, err, removed, extended;
1587 struct cache_entry **cache = istate->cache;
1588 int entries = istate->cache_nr;
1589 struct stat st;
1591 for (i = removed = extended = 0; i < entries; i++) {
1592 if (cache[i]->ce_flags & CE_REMOVE)
1593 removed++;
1595 /* reduce extended entries if possible */
1596 cache[i]->ce_flags &= ~CE_EXTENDED;
1597 if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) {
1598 extended++;
1599 cache[i]->ce_flags |= CE_EXTENDED;
1600 }
1601 }
1603 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1604 /* for extended format, increase version so older git won't try to read it */
1605 hdr.hdr_version = htonl(extended ? 3 : 2);
1606 hdr.hdr_entries = htonl(entries - removed);
1608 git_SHA1_Init(&c);
1609 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1610 return -1;
1612 for (i = 0; i < entries; i++) {
1613 struct cache_entry *ce = cache[i];
1614 if (ce->ce_flags & CE_REMOVE)
1615 continue;
1616 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
1617 ce_smudge_racily_clean_entry(ce);
1618 if (ce_write_entry(&c, newfd, ce) < 0)
1619 return -1;
1620 }
1622 /* Write extension data here */
1623 if (istate->cache_tree) {
1624 struct strbuf sb = STRBUF_INIT;
1626 cache_tree_write(&sb, istate->cache_tree);
1627 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1628 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1629 strbuf_release(&sb);
1630 if (err)
1631 return -1;
1632 }
1633 if (istate->resolve_undo) {
1634 struct strbuf sb = STRBUF_INIT;
1636 resolve_undo_write(&sb, istate->resolve_undo);
1637 err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,
1638 sb.len) < 0
1639 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1640 strbuf_release(&sb);
1641 if (err)
1642 return -1;
1643 }
1645 if (ce_flush(&c, newfd) || fstat(newfd, &st))
1646 return -1;
1647 istate->timestamp.sec = (unsigned int)st.st_mtime;
1648 istate->timestamp.nsec = ST_MTIME_NSEC(st);
1649 return 0;
1650 }
1652 /*
1653 * Read the index file that is potentially unmerged into given
1654 * index_state, dropping any unmerged entries. Returns true if
1655 * the index is unmerged. Callers who want to refuse to work
1656 * from an unmerged state can call this and check its return value,
1657 * instead of calling read_cache().
1658 */
1659 int read_index_unmerged(struct index_state *istate)
1660 {
1661 int i;
1662 int unmerged = 0;
1664 read_index(istate);
1665 for (i = 0; i < istate->cache_nr; i++) {
1666 struct cache_entry *ce = istate->cache[i];
1667 struct cache_entry *new_ce;
1668 int size, len;
1670 if (!ce_stage(ce))
1671 continue;
1672 unmerged = 1;
1673 len = strlen(ce->name);
1674 size = cache_entry_size(len);
1675 new_ce = xcalloc(1, size);
1676 memcpy(new_ce->name, ce->name, len);
1677 new_ce->ce_flags = create_ce_flags(len, 0) | CE_CONFLICTED;
1678 new_ce->ce_mode = ce->ce_mode;
1679 if (add_index_entry(istate, new_ce, 0))
1680 return error("%s: cannot drop to stage #0",
1681 ce->name);
1682 i = index_name_pos(istate, new_ce->name, len);
1683 }
1684 return unmerged;
1685 }
1687 /*
1688 * Returns 1 if the path is an "other" path with respect to
1689 * the index; that is, the path is not mentioned in the index at all,
1690 * either as a file, a directory with some files in the index,
1691 * or as an unmerged entry.
1692 *
1693 * We helpfully remove a trailing "/" from directories so that
1694 * the output of read_directory can be used as-is.
1695 */
1696 int index_name_is_other(const struct index_state *istate, const char *name,
1697 int namelen)
1698 {
1699 int pos;
1700 if (namelen && name[namelen - 1] == '/')
1701 namelen--;
1702 pos = index_name_pos(istate, name, namelen);
1703 if (0 <= pos)
1704 return 0; /* exact match */
1705 pos = -pos - 1;
1706 if (pos < istate->cache_nr) {
1707 struct cache_entry *ce = istate->cache[pos];
1708 if (ce_namelen(ce) == namelen &&
1709 !memcmp(ce->name, name, namelen))
1710 return 0; /* Yup, this one exists unmerged */
1711 }
1712 return 1;
1713 }