]> git.ipfire.org Git - thirdparty/git.git/blob - read-cache.c
Merge branch 'jc/log-quiet-fix'
[thirdparty/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 #include "tree.h"
12 #include "commit.h"
13 #include "blob.h"
14 #include "resolve-undo.h"
15
16 static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really);
17
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 */
26
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" */
30
31 struct index_state the_index;
32
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 }
38
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];
42
43 remove_name_hash(old);
44 set_index_entry(istate, nr, ce);
45 istate->cache_changed = 1;
46 }
47
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);
52
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);
58
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 }
63
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;
80
81 if (assume_unchanged)
82 ce->ce_flags |= CE_VALID;
83
84 if (S_ISREG(st->st_mode))
85 ce_mark_uptodate(ce);
86 }
87
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);
92
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 }
101
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;
109
110 if (strbuf_readlink(&sb, ce->name, expected_size))
111 return -1;
112
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 }
122
123 static int ce_compare_gitlink(struct cache_entry *ce)
124 {
125 unsigned char sha1[20];
126
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 }
139
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 }
159
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 };
166
167 return !hashcmp(sha1, empty_blob_sha1);
168 }
169
170 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
171 {
172 unsigned int changed = 0;
173
174 if (ce->ce_flags & CE_REMOVE)
175 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
176
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;
206
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
213
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;
219
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
229
230 if (ce->ce_size != (unsigned int) st->st_size)
231 changed |= DATA_CHANGED;
232
233 /* Racily smudged entry? */
234 if (!ce->ce_size) {
235 if (!is_empty_blob_sha1(ce->sha1))
236 changed |= DATA_CHANGED;
237 }
238
239 return changed;
240 }
241
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 }
256
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;
265
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;
276
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;
284
285 changed = ce_match_stat_basic(ce, st);
286
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 }
309
310 return changed;
311 }
312
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;
317
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;
327
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;
345
346 changed_fs = ce_modified_check_fs(ce, st);
347 if (changed_fs)
348 return changed | changed_fs;
349 return 0;
350 }
351
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;
358
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 }
370
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;
386
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 }
405
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;
412
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;
420
421 /* Compare stages */
422 flags1 &= CE_STAGEMASK;
423 flags2 &= CE_STAGEMASK;
424
425 if (flags1 < flags2)
426 return -1;
427 if (flags1 > flags2)
428 return 1;
429 return 0;
430 }
431
432 int index_name_pos(const struct index_state *istate, const char *name, int namelen)
433 {
434 int first, last;
435
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 }
452
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];
457
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 }
469
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;
479
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 }
489
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 }
500
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 }
505
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;
511
512 if (pos >= 0)
513 return pos;
514
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;
520
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 }
528
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 }
534
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;
548
549 if (alias->ce_flags & CE_ADDED)
550 die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
551
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 }
560
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 }
568
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));
580
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);
583
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;
597
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);
606
607 ent = (0 <= pos) ? istate->cache[pos] : NULL;
608 ce->ce_mode = ce_mode_from_stat(ent, st_mode);
609 }
610
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 }
633
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);
648
649 if (ignore_case && alias && different_name(ce, alias))
650 ce = create_alias_ce(ce, alias);
651 ce->ce_flags |= CE_ADDED;
652
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);
658
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 }
667
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 }
675
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;
682
683 if (!verify_path(path)) {
684 error("Invalid path '%s'", path);
685 return NULL;
686 }
687
688 len = strlen(path);
689 size = cache_entry_size(len);
690 ce = xcalloc(1, size);
691
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);
696
697 if (refresh)
698 return refresh_cache_entry(ce, 0);
699
700 return ce;
701 }
702
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 }
708
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 }
713
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 */
729 switch (*rest) {
730 /* "." is not allowed */
731 case '\0': case '/':
732 return 0;
733
734 /*
735 * ".git" followed by NUL or slash is bad. This
736 * shares the path end test with the ".." case.
737 */
738 case 'g':
739 if (rest[1] != 'i')
740 break;
741 if (rest[2] != 't')
742 break;
743 rest += 2;
744 /* fallthrough */
745 case '.':
746 if (rest[1] == '\0' || rest[1] == '/')
747 return 0;
748 }
749 return 1;
750 }
751
752 int verify_path(const char *path)
753 {
754 char c;
755
756 goto inside;
757 for (;;) {
758 if (!c)
759 return 1;
760 if (c == '/') {
761 inside:
762 c = *path++;
763 switch (c) {
764 default:
765 continue;
766 case '/': case '\0':
767 break;
768 case '.':
769 if (verify_dotfile(path))
770 continue;
771 }
772 return 0;
773 }
774 c = *path++;
775 }
776 }
777
778 /*
779 * Do we have another file that has the beginning components being a
780 * proper superset of the name we're trying to add?
781 */
782 static int has_file_name(struct index_state *istate,
783 const struct cache_entry *ce, int pos, int ok_to_replace)
784 {
785 int retval = 0;
786 int len = ce_namelen(ce);
787 int stage = ce_stage(ce);
788 const char *name = ce->name;
789
790 while (pos < istate->cache_nr) {
791 struct cache_entry *p = istate->cache[pos++];
792
793 if (len >= ce_namelen(p))
794 break;
795 if (memcmp(name, p->name, len))
796 break;
797 if (ce_stage(p) != stage)
798 continue;
799 if (p->name[len] != '/')
800 continue;
801 if (p->ce_flags & CE_REMOVE)
802 continue;
803 retval = -1;
804 if (!ok_to_replace)
805 break;
806 remove_index_entry_at(istate, --pos);
807 }
808 return retval;
809 }
810
811 /*
812 * Do we have another file with a pathname that is a proper
813 * subset of the name we're trying to add?
814 */
815 static int has_dir_name(struct index_state *istate,
816 const struct cache_entry *ce, int pos, int ok_to_replace)
817 {
818 int retval = 0;
819 int stage = ce_stage(ce);
820 const char *name = ce->name;
821 const char *slash = name + ce_namelen(ce);
822
823 for (;;) {
824 int len;
825
826 for (;;) {
827 if (*--slash == '/')
828 break;
829 if (slash <= ce->name)
830 return retval;
831 }
832 len = slash - name;
833
834 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
835 if (pos >= 0) {
836 /*
837 * Found one, but not so fast. This could
838 * be a marker that says "I was here, but
839 * I am being removed". Such an entry is
840 * not a part of the resulting tree, and
841 * it is Ok to have a directory at the same
842 * path.
843 */
844 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
845 retval = -1;
846 if (!ok_to_replace)
847 break;
848 remove_index_entry_at(istate, pos);
849 continue;
850 }
851 }
852 else
853 pos = -pos-1;
854
855 /*
856 * Trivial optimization: if we find an entry that
857 * already matches the sub-directory, then we know
858 * we're ok, and we can exit.
859 */
860 while (pos < istate->cache_nr) {
861 struct cache_entry *p = istate->cache[pos];
862 if ((ce_namelen(p) <= len) ||
863 (p->name[len] != '/') ||
864 memcmp(p->name, name, len))
865 break; /* not our subdirectory */
866 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
867 /*
868 * p is at the same stage as our entry, and
869 * is a subdirectory of what we are looking
870 * at, so we cannot have conflicts at our
871 * level or anything shorter.
872 */
873 return retval;
874 pos++;
875 }
876 }
877 return retval;
878 }
879
880 /* We may be in a situation where we already have path/file and path
881 * is being added, or we already have path and path/file is being
882 * added. Either one would result in a nonsense tree that has path
883 * twice when git-write-tree tries to write it out. Prevent it.
884 *
885 * If ok-to-replace is specified, we remove the conflicting entries
886 * from the cache so the caller should recompute the insert position.
887 * When this happens, we return non-zero.
888 */
889 static int check_file_directory_conflict(struct index_state *istate,
890 const struct cache_entry *ce,
891 int pos, int ok_to_replace)
892 {
893 int retval;
894
895 /*
896 * When ce is an "I am going away" entry, we allow it to be added
897 */
898 if (ce->ce_flags & CE_REMOVE)
899 return 0;
900
901 /*
902 * We check if the path is a sub-path of a subsequent pathname
903 * first, since removing those will not change the position
904 * in the array.
905 */
906 retval = has_file_name(istate, ce, pos, ok_to_replace);
907
908 /*
909 * Then check if the path might have a clashing sub-directory
910 * before it.
911 */
912 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
913 }
914
915 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
916 {
917 int pos;
918 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
919 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
920 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
921 int new_only = option & ADD_CACHE_NEW_ONLY;
922
923 cache_tree_invalidate_path(istate->cache_tree, ce->name);
924 pos = index_name_pos(istate, ce->name, ce->ce_flags);
925
926 /* existing match? Just replace it. */
927 if (pos >= 0) {
928 if (!new_only)
929 replace_index_entry(istate, pos, ce);
930 return 0;
931 }
932 pos = -pos-1;
933
934 /*
935 * Inserting a merged entry ("stage 0") into the index
936 * will always replace all non-merged entries..
937 */
938 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
939 while (ce_same_name(istate->cache[pos], ce)) {
940 ok_to_add = 1;
941 if (!remove_index_entry_at(istate, pos))
942 break;
943 }
944 }
945
946 if (!ok_to_add)
947 return -1;
948 if (!verify_path(ce->name))
949 return error("Invalid path '%s'", ce->name);
950
951 if (!skip_df_check &&
952 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
953 if (!ok_to_replace)
954 return error("'%s' appears as both a file and as a directory",
955 ce->name);
956 pos = index_name_pos(istate, ce->name, ce->ce_flags);
957 pos = -pos-1;
958 }
959 return pos + 1;
960 }
961
962 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
963 {
964 int pos;
965
966 if (option & ADD_CACHE_JUST_APPEND)
967 pos = istate->cache_nr;
968 else {
969 int ret;
970 ret = add_index_entry_with_check(istate, ce, option);
971 if (ret <= 0)
972 return ret;
973 pos = ret - 1;
974 }
975
976 /* Make sure the array is big enough .. */
977 if (istate->cache_nr == istate->cache_alloc) {
978 istate->cache_alloc = alloc_nr(istate->cache_alloc);
979 istate->cache = xrealloc(istate->cache,
980 istate->cache_alloc * sizeof(struct cache_entry *));
981 }
982
983 /* Add it in.. */
984 istate->cache_nr++;
985 if (istate->cache_nr > pos + 1)
986 memmove(istate->cache + pos + 1,
987 istate->cache + pos,
988 (istate->cache_nr - pos - 1) * sizeof(ce));
989 set_index_entry(istate, pos, ce);
990 istate->cache_changed = 1;
991 return 0;
992 }
993
994 /*
995 * "refresh" does not calculate a new sha1 file or bring the
996 * cache up-to-date for mode/content changes. But what it
997 * _does_ do is to "re-match" the stat information of a file
998 * with the cache, so that you can refresh the cache for a
999 * file that hasn't been changed but where the stat entry is
1000 * out of date.
1001 *
1002 * For example, you'd want to do this after doing a "git-read-tree",
1003 * to link up the stat cache details with the proper files.
1004 */
1005 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
1006 struct cache_entry *ce,
1007 unsigned int options, int *err)
1008 {
1009 struct stat st;
1010 struct cache_entry *updated;
1011 int changed, size;
1012 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
1013 int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;
1014
1015 if (ce_uptodate(ce))
1016 return ce;
1017
1018 /*
1019 * CE_VALID or CE_SKIP_WORKTREE means the user promised us
1020 * that the change to the work tree does not matter and told
1021 * us not to worry.
1022 */
1023 if (!ignore_skip_worktree && ce_skip_worktree(ce)) {
1024 ce_mark_uptodate(ce);
1025 return ce;
1026 }
1027 if (!ignore_valid && (ce->ce_flags & CE_VALID)) {
1028 ce_mark_uptodate(ce);
1029 return ce;
1030 }
1031
1032 if (lstat(ce->name, &st) < 0) {
1033 if (err)
1034 *err = errno;
1035 return NULL;
1036 }
1037
1038 changed = ie_match_stat(istate, ce, &st, options);
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 }
1061
1062 if (ie_modified(istate, ce, &st, options)) {
1063 if (err)
1064 *err = EINVAL;
1065 return NULL;
1066 }
1067
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;
1081
1082 return updated;
1083 }
1084
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 }
1094
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 *needs_update_fmt;
1109 const char *needs_merge_fmt;
1110
1111 needs_update_fmt = (in_porcelain ? "M\t%s\n" : "%s: needs update\n");
1112 needs_merge_fmt = (in_porcelain ? "U\t%s\n" : "%s: needs merge\n");
1113 for (i = 0; i < istate->cache_nr; i++) {
1114 struct cache_entry *ce, *new;
1115 int cache_errno = 0;
1116
1117 ce = istate->cache[i];
1118 if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
1119 continue;
1120
1121 if (ce_stage(ce)) {
1122 while ((i < istate->cache_nr) &&
1123 ! strcmp(istate->cache[i]->name, ce->name))
1124 i++;
1125 i--;
1126 if (allow_unmerged)
1127 continue;
1128 show_file(needs_merge_fmt, ce->name, in_porcelain, &first, header_msg);
1129 has_errors = 1;
1130 continue;
1131 }
1132
1133 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
1134 continue;
1135
1136 new = refresh_cache_ent(istate, ce, options, &cache_errno);
1137 if (new == ce)
1138 continue;
1139 if (!new) {
1140 if (not_new && cache_errno == ENOENT)
1141 continue;
1142 if (really && cache_errno == EINVAL) {
1143 /* If we are doing --really-refresh that
1144 * means the index is not valid anymore.
1145 */
1146 ce->ce_flags &= ~CE_VALID;
1147 istate->cache_changed = 1;
1148 }
1149 if (quiet)
1150 continue;
1151 show_file(needs_update_fmt, ce->name, in_porcelain, &first, header_msg);
1152 has_errors = 1;
1153 continue;
1154 }
1155
1156 replace_index_entry(istate, i, new);
1157 }
1158 return has_errors;
1159 }
1160
1161 static struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
1162 {
1163 return refresh_cache_ent(&the_index, ce, really, NULL);
1164 }
1165
1166 static int verify_hdr(struct cache_header *hdr, unsigned long size)
1167 {
1168 git_SHA_CTX c;
1169 unsigned char sha1[20];
1170
1171 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
1172 return error("bad signature");
1173 if (hdr->hdr_version != htonl(2) && hdr->hdr_version != htonl(3))
1174 return error("bad index version");
1175 git_SHA1_Init(&c);
1176 git_SHA1_Update(&c, hdr, size - 20);
1177 git_SHA1_Final(sha1, &c);
1178 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1179 return error("bad index file sha1 signature");
1180 return 0;
1181 }
1182
1183 static int read_index_extension(struct index_state *istate,
1184 const char *ext, void *data, unsigned long sz)
1185 {
1186 switch (CACHE_EXT(ext)) {
1187 case CACHE_EXT_TREE:
1188 istate->cache_tree = cache_tree_read(data, sz);
1189 break;
1190 case CACHE_EXT_RESOLVE_UNDO:
1191 istate->resolve_undo = resolve_undo_read(data, sz);
1192 break;
1193 default:
1194 if (*ext < 'A' || 'Z' < *ext)
1195 return error("index uses %.4s extension, which we do not understand",
1196 ext);
1197 fprintf(stderr, "ignoring %.4s extension\n", ext);
1198 break;
1199 }
1200 return 0;
1201 }
1202
1203 int read_index(struct index_state *istate)
1204 {
1205 return read_index_from(istate, get_index_file());
1206 }
1207
1208 static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
1209 {
1210 size_t len;
1211 const char *name;
1212
1213 ce->ce_ctime.sec = ntohl(ondisk->ctime.sec);
1214 ce->ce_mtime.sec = ntohl(ondisk->mtime.sec);
1215 ce->ce_ctime.nsec = ntohl(ondisk->ctime.nsec);
1216 ce->ce_mtime.nsec = ntohl(ondisk->mtime.nsec);
1217 ce->ce_dev = ntohl(ondisk->dev);
1218 ce->ce_ino = ntohl(ondisk->ino);
1219 ce->ce_mode = ntohl(ondisk->mode);
1220 ce->ce_uid = ntohl(ondisk->uid);
1221 ce->ce_gid = ntohl(ondisk->gid);
1222 ce->ce_size = ntohl(ondisk->size);
1223 /* On-disk flags are just 16 bits */
1224 ce->ce_flags = ntohs(ondisk->flags);
1225
1226 hashcpy(ce->sha1, ondisk->sha1);
1227
1228 len = ce->ce_flags & CE_NAMEMASK;
1229
1230 if (ce->ce_flags & CE_EXTENDED) {
1231 struct ondisk_cache_entry_extended *ondisk2;
1232 int extended_flags;
1233 ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
1234 extended_flags = ntohs(ondisk2->flags2) << 16;
1235 /* We do not yet understand any bit out of CE_EXTENDED_FLAGS */
1236 if (extended_flags & ~CE_EXTENDED_FLAGS)
1237 die("Unknown index entry format %08x", extended_flags);
1238 ce->ce_flags |= extended_flags;
1239 name = ondisk2->name;
1240 }
1241 else
1242 name = ondisk->name;
1243
1244 if (len == CE_NAMEMASK)
1245 len = strlen(name);
1246 /*
1247 * NEEDSWORK: If the original index is crafted, this copy could
1248 * go unchecked.
1249 */
1250 memcpy(ce->name, name, len + 1);
1251 }
1252
1253 static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
1254 {
1255 long per_entry;
1256
1257 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
1258
1259 /*
1260 * Alignment can cause differences. This should be "alignof", but
1261 * since that's a gcc'ism, just use the size of a pointer.
1262 */
1263 per_entry += sizeof(void *);
1264 return ondisk_size + entries*per_entry;
1265 }
1266
1267 /* remember to discard_cache() before reading a different cache! */
1268 int read_index_from(struct index_state *istate, const char *path)
1269 {
1270 int fd, i;
1271 struct stat st;
1272 unsigned long src_offset, dst_offset;
1273 struct cache_header *hdr;
1274 void *mmap;
1275 size_t mmap_size;
1276
1277 errno = EBUSY;
1278 if (istate->initialized)
1279 return istate->cache_nr;
1280
1281 errno = ENOENT;
1282 istate->timestamp.sec = 0;
1283 istate->timestamp.nsec = 0;
1284 fd = open(path, O_RDONLY);
1285 if (fd < 0) {
1286 if (errno == ENOENT)
1287 return 0;
1288 die_errno("index file open failed");
1289 }
1290
1291 if (fstat(fd, &st))
1292 die_errno("cannot stat the open index");
1293
1294 errno = EINVAL;
1295 mmap_size = xsize_t(st.st_size);
1296 if (mmap_size < sizeof(struct cache_header) + 20)
1297 die("index file smaller than expected");
1298
1299 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1300 close(fd);
1301 if (mmap == MAP_FAILED)
1302 die_errno("unable to map index file");
1303
1304 hdr = mmap;
1305 if (verify_hdr(hdr, mmap_size) < 0)
1306 goto unmap;
1307
1308 istate->cache_nr = ntohl(hdr->hdr_entries);
1309 istate->cache_alloc = alloc_nr(istate->cache_nr);
1310 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1311
1312 /*
1313 * The disk format is actually larger than the in-memory format,
1314 * due to space for nsec etc, so even though the in-memory one
1315 * has room for a few more flags, we can allocate using the same
1316 * index size
1317 */
1318 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
1319 istate->initialized = 1;
1320
1321 src_offset = sizeof(*hdr);
1322 dst_offset = 0;
1323 for (i = 0; i < istate->cache_nr; i++) {
1324 struct ondisk_cache_entry *disk_ce;
1325 struct cache_entry *ce;
1326
1327 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1328 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
1329 convert_from_disk(disk_ce, ce);
1330 set_index_entry(istate, i, ce);
1331
1332 src_offset += ondisk_ce_size(ce);
1333 dst_offset += ce_size(ce);
1334 }
1335 istate->timestamp.sec = st.st_mtime;
1336 istate->timestamp.nsec = ST_MTIME_NSEC(st);
1337
1338 while (src_offset <= mmap_size - 20 - 8) {
1339 /* After an array of active_nr index entries,
1340 * there can be arbitrary number of extended
1341 * sections, each of which is prefixed with
1342 * extension name (4-byte) and section length
1343 * in 4-byte network byte order.
1344 */
1345 uint32_t extsize;
1346 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1347 extsize = ntohl(extsize);
1348 if (read_index_extension(istate,
1349 (const char *) mmap + src_offset,
1350 (char *) mmap + src_offset + 8,
1351 extsize) < 0)
1352 goto unmap;
1353 src_offset += 8;
1354 src_offset += extsize;
1355 }
1356 munmap(mmap, mmap_size);
1357 return istate->cache_nr;
1358
1359 unmap:
1360 munmap(mmap, mmap_size);
1361 errno = EINVAL;
1362 die("index file corrupt");
1363 }
1364
1365 int is_index_unborn(struct index_state *istate)
1366 {
1367 return (!istate->cache_nr && !istate->alloc && !istate->timestamp.sec);
1368 }
1369
1370 int discard_index(struct index_state *istate)
1371 {
1372 resolve_undo_clear_index(istate);
1373 istate->cache_nr = 0;
1374 istate->cache_changed = 0;
1375 istate->timestamp.sec = 0;
1376 istate->timestamp.nsec = 0;
1377 istate->name_hash_initialized = 0;
1378 free_hash(&istate->name_hash);
1379 cache_tree_free(&(istate->cache_tree));
1380 free(istate->alloc);
1381 istate->alloc = NULL;
1382 istate->initialized = 0;
1383
1384 /* no need to throw away allocated active_cache */
1385 return 0;
1386 }
1387
1388 int unmerged_index(const struct index_state *istate)
1389 {
1390 int i;
1391 for (i = 0; i < istate->cache_nr; i++) {
1392 if (ce_stage(istate->cache[i]))
1393 return 1;
1394 }
1395 return 0;
1396 }
1397
1398 #define WRITE_BUFFER_SIZE 8192
1399 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1400 static unsigned long write_buffer_len;
1401
1402 static int ce_write_flush(git_SHA_CTX *context, int fd)
1403 {
1404 unsigned int buffered = write_buffer_len;
1405 if (buffered) {
1406 git_SHA1_Update(context, write_buffer, buffered);
1407 if (write_in_full(fd, write_buffer, buffered) != buffered)
1408 return -1;
1409 write_buffer_len = 0;
1410 }
1411 return 0;
1412 }
1413
1414 static int ce_write(git_SHA_CTX *context, int fd, void *data, unsigned int len)
1415 {
1416 while (len) {
1417 unsigned int buffered = write_buffer_len;
1418 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1419 if (partial > len)
1420 partial = len;
1421 memcpy(write_buffer + buffered, data, partial);
1422 buffered += partial;
1423 if (buffered == WRITE_BUFFER_SIZE) {
1424 write_buffer_len = buffered;
1425 if (ce_write_flush(context, fd))
1426 return -1;
1427 buffered = 0;
1428 }
1429 write_buffer_len = buffered;
1430 len -= partial;
1431 data = (char *) data + partial;
1432 }
1433 return 0;
1434 }
1435
1436 static int write_index_ext_header(git_SHA_CTX *context, int fd,
1437 unsigned int ext, unsigned int sz)
1438 {
1439 ext = htonl(ext);
1440 sz = htonl(sz);
1441 return ((ce_write(context, fd, &ext, 4) < 0) ||
1442 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1443 }
1444
1445 static int ce_flush(git_SHA_CTX *context, int fd)
1446 {
1447 unsigned int left = write_buffer_len;
1448
1449 if (left) {
1450 write_buffer_len = 0;
1451 git_SHA1_Update(context, write_buffer, left);
1452 }
1453
1454 /* Flush first if not enough space for SHA1 signature */
1455 if (left + 20 > WRITE_BUFFER_SIZE) {
1456 if (write_in_full(fd, write_buffer, left) != left)
1457 return -1;
1458 left = 0;
1459 }
1460
1461 /* Append the SHA1 signature at the end */
1462 git_SHA1_Final(write_buffer + left, context);
1463 left += 20;
1464 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1465 }
1466
1467 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1468 {
1469 /*
1470 * The only thing we care about in this function is to smudge the
1471 * falsely clean entry due to touch-update-touch race, so we leave
1472 * everything else as they are. We are called for entries whose
1473 * ce_mtime match the index file mtime.
1474 *
1475 * Note that this actually does not do much for gitlinks, for
1476 * which ce_match_stat_basic() always goes to the actual
1477 * contents. The caller checks with is_racy_timestamp() which
1478 * always says "no" for gitlinks, so we are not called for them ;-)
1479 */
1480 struct stat st;
1481
1482 if (lstat(ce->name, &st) < 0)
1483 return;
1484 if (ce_match_stat_basic(ce, &st))
1485 return;
1486 if (ce_modified_check_fs(ce, &st)) {
1487 /* This is "racily clean"; smudge it. Note that this
1488 * is a tricky code. At first glance, it may appear
1489 * that it can break with this sequence:
1490 *
1491 * $ echo xyzzy >frotz
1492 * $ git-update-index --add frotz
1493 * $ : >frotz
1494 * $ sleep 3
1495 * $ echo filfre >nitfol
1496 * $ git-update-index --add nitfol
1497 *
1498 * but it does not. When the second update-index runs,
1499 * it notices that the entry "frotz" has the same timestamp
1500 * as index, and if we were to smudge it by resetting its
1501 * size to zero here, then the object name recorded
1502 * in index is the 6-byte file but the cached stat information
1503 * becomes zero --- which would then match what we would
1504 * obtain from the filesystem next time we stat("frotz").
1505 *
1506 * However, the second update-index, before calling
1507 * this function, notices that the cached size is 6
1508 * bytes and what is on the filesystem is an empty
1509 * file, and never calls us, so the cached size information
1510 * for "frotz" stays 6 which does not match the filesystem.
1511 */
1512 ce->ce_size = 0;
1513 }
1514 }
1515
1516 static int ce_write_entry(git_SHA_CTX *c, int fd, struct cache_entry *ce)
1517 {
1518 int size = ondisk_ce_size(ce);
1519 struct ondisk_cache_entry *ondisk = xcalloc(1, size);
1520 char *name;
1521 int result;
1522
1523 ondisk->ctime.sec = htonl(ce->ce_ctime.sec);
1524 ondisk->mtime.sec = htonl(ce->ce_mtime.sec);
1525 ondisk->ctime.nsec = htonl(ce->ce_ctime.nsec);
1526 ondisk->mtime.nsec = htonl(ce->ce_mtime.nsec);
1527 ondisk->dev = htonl(ce->ce_dev);
1528 ondisk->ino = htonl(ce->ce_ino);
1529 ondisk->mode = htonl(ce->ce_mode);
1530 ondisk->uid = htonl(ce->ce_uid);
1531 ondisk->gid = htonl(ce->ce_gid);
1532 ondisk->size = htonl(ce->ce_size);
1533 hashcpy(ondisk->sha1, ce->sha1);
1534 ondisk->flags = htons(ce->ce_flags);
1535 if (ce->ce_flags & CE_EXTENDED) {
1536 struct ondisk_cache_entry_extended *ondisk2;
1537 ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;
1538 ondisk2->flags2 = htons((ce->ce_flags & CE_EXTENDED_FLAGS) >> 16);
1539 name = ondisk2->name;
1540 }
1541 else
1542 name = ondisk->name;
1543 memcpy(name, ce->name, ce_namelen(ce));
1544
1545 result = ce_write(c, fd, ondisk, size);
1546 free(ondisk);
1547 return result;
1548 }
1549
1550 static int has_racy_timestamp(struct index_state *istate)
1551 {
1552 int entries = istate->cache_nr;
1553 int i;
1554
1555 for (i = 0; i < entries; i++) {
1556 struct cache_entry *ce = istate->cache[i];
1557 if (is_racy_timestamp(istate, ce))
1558 return 1;
1559 }
1560 return 0;
1561 }
1562
1563 /*
1564 * Opportunisticly update the index but do not complain if we can't
1565 */
1566 void update_index_if_able(struct index_state *istate, struct lock_file *lockfile)
1567 {
1568 if ((istate->cache_changed || has_racy_timestamp(istate)) &&
1569 !write_index(istate, lockfile->fd))
1570 commit_locked_index(lockfile);
1571 else
1572 rollback_lock_file(lockfile);
1573 }
1574
1575 int write_index(struct index_state *istate, int newfd)
1576 {
1577 git_SHA_CTX c;
1578 struct cache_header hdr;
1579 int i, err, removed, extended;
1580 struct cache_entry **cache = istate->cache;
1581 int entries = istate->cache_nr;
1582 struct stat st;
1583
1584 for (i = removed = extended = 0; i < entries; i++) {
1585 if (cache[i]->ce_flags & CE_REMOVE)
1586 removed++;
1587
1588 /* reduce extended entries if possible */
1589 cache[i]->ce_flags &= ~CE_EXTENDED;
1590 if (cache[i]->ce_flags & CE_EXTENDED_FLAGS) {
1591 extended++;
1592 cache[i]->ce_flags |= CE_EXTENDED;
1593 }
1594 }
1595
1596 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1597 /* for extended format, increase version so older git won't try to read it */
1598 hdr.hdr_version = htonl(extended ? 3 : 2);
1599 hdr.hdr_entries = htonl(entries - removed);
1600
1601 git_SHA1_Init(&c);
1602 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1603 return -1;
1604
1605 for (i = 0; i < entries; i++) {
1606 struct cache_entry *ce = cache[i];
1607 if (ce->ce_flags & CE_REMOVE)
1608 continue;
1609 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
1610 ce_smudge_racily_clean_entry(ce);
1611 if (ce_write_entry(&c, newfd, ce) < 0)
1612 return -1;
1613 }
1614
1615 /* Write extension data here */
1616 if (istate->cache_tree) {
1617 struct strbuf sb = STRBUF_INIT;
1618
1619 cache_tree_write(&sb, istate->cache_tree);
1620 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1621 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1622 strbuf_release(&sb);
1623 if (err)
1624 return -1;
1625 }
1626 if (istate->resolve_undo) {
1627 struct strbuf sb = STRBUF_INIT;
1628
1629 resolve_undo_write(&sb, istate->resolve_undo);
1630 err = write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,
1631 sb.len) < 0
1632 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1633 strbuf_release(&sb);
1634 if (err)
1635 return -1;
1636 }
1637
1638 if (ce_flush(&c, newfd) || fstat(newfd, &st))
1639 return -1;
1640 istate->timestamp.sec = (unsigned int)st.st_mtime;
1641 istate->timestamp.nsec = ST_MTIME_NSEC(st);
1642 return 0;
1643 }
1644
1645 /*
1646 * Read the index file that is potentially unmerged into given
1647 * index_state, dropping any unmerged entries. Returns true if
1648 * the index is unmerged. Callers who want to refuse to work
1649 * from an unmerged state can call this and check its return value,
1650 * instead of calling read_cache().
1651 */
1652 int read_index_unmerged(struct index_state *istate)
1653 {
1654 int i;
1655 int unmerged = 0;
1656
1657 read_index(istate);
1658 for (i = 0; i < istate->cache_nr; i++) {
1659 struct cache_entry *ce = istate->cache[i];
1660 struct cache_entry *new_ce;
1661 int size, len;
1662
1663 if (!ce_stage(ce))
1664 continue;
1665 unmerged = 1;
1666 len = strlen(ce->name);
1667 size = cache_entry_size(len);
1668 new_ce = xcalloc(1, size);
1669 memcpy(new_ce->name, ce->name, len);
1670 new_ce->ce_flags = create_ce_flags(len, 0) | CE_CONFLICTED;
1671 new_ce->ce_mode = ce->ce_mode;
1672 if (add_index_entry(istate, new_ce, 0))
1673 return error("%s: cannot drop to stage #0",
1674 ce->name);
1675 i = index_name_pos(istate, new_ce->name, len);
1676 }
1677 return unmerged;
1678 }
1679
1680 /*
1681 * Returns 1 if the path is an "other" path with respect to
1682 * the index; that is, the path is not mentioned in the index at all,
1683 * either as a file, a directory with some files in the index,
1684 * or as an unmerged entry.
1685 *
1686 * We helpfully remove a trailing "/" from directories so that
1687 * the output of read_directory can be used as-is.
1688 */
1689 int index_name_is_other(const struct index_state *istate, const char *name,
1690 int namelen)
1691 {
1692 int pos;
1693 if (namelen && name[namelen - 1] == '/')
1694 namelen--;
1695 pos = index_name_pos(istate, name, namelen);
1696 if (0 <= pos)
1697 return 0; /* exact match */
1698 pos = -pos - 1;
1699 if (pos < istate->cache_nr) {
1700 struct cache_entry *ce = istate->cache[pos];
1701 if (ce_namelen(ce) == namelen &&
1702 !memcmp(ce->name, name, namelen))
1703 return 0; /* Yup, this one exists unmerged */
1704 }
1705 return 1;
1706 }