Add new test to ensure git-merge handles pull.twohead and pull.octopus
[git/git.git] / read-cache.c
CommitLineData
8bc9a0c7
LT
1/*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 */
4aab5b46 6#define NO_THE_INDEX_COMPATIBILITY_MACROS
e83c5163 7#include "cache.h"
bad68ec9 8#include "cache-tree.h"
f35a6d3b 9#include "refs.h"
d616813d 10#include "dir.h"
bad68ec9
JH
11
12/* Index extensions.
13 *
14 * The first letter should be 'A'..'Z' for extensions that are not
15 * necessary for a correct operation (i.e. optimization data).
16 * When new extensions are added that _needs_ to be understood in
17 * order to correctly interpret the index file, pick character that
18 * is outside the range, to cause the reader to abort.
19 */
20
21#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
22#define CACHE_EXT_TREE 0x54524545 /* "TREE" */
e83c5163 23
228e94f9 24struct index_state the_index;
8fd2cb40 25
9cb76b8c
JH
26static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
27{
28 istate->cache[nr] = ce;
96872bc2 29 add_name_hash(istate, ce);
9cb76b8c
JH
30}
31
cf558704
LT
32static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
33{
34 struct cache_entry *old = istate->cache[nr];
35
96872bc2 36 remove_name_hash(old);
a22c6371 37 set_index_entry(istate, nr, ce);
cf558704
LT
38 istate->cache_changed = 1;
39}
40
415e96c8
JH
41/*
42 * This only updates the "non-critical" parts of the directory
43 * cache, ie the parts that aren't tracked by GIT, and only used
44 * to validate the cache.
45 */
46void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
47{
7a51ed66
LT
48 ce->ce_ctime = st->st_ctime;
49 ce->ce_mtime = st->st_mtime;
50 ce->ce_dev = st->st_dev;
51 ce->ce_ino = st->st_ino;
52 ce->ce_uid = st->st_uid;
53 ce->ce_gid = st->st_gid;
54 ce->ce_size = st->st_size;
5f73076c
JH
55
56 if (assume_unchanged)
7a51ed66 57 ce->ce_flags |= CE_VALID;
eadb5831
JH
58
59 if (S_ISREG(st->st_mode))
60 ce_mark_uptodate(ce);
415e96c8
JH
61}
62
29e4d363
JH
63static int ce_compare_data(struct cache_entry *ce, struct stat *st)
64{
65 int match = -1;
66 int fd = open(ce->name, O_RDONLY);
67
68 if (fd >= 0) {
69 unsigned char sha1[20];
53bca91a 70 if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name))
a89fccd2 71 match = hashcmp(sha1, ce->sha1);
7f8508e8 72 /* index_fd() closed the file descriptor already */
29e4d363
JH
73 }
74 return match;
75}
76
dc49cd76 77static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
29e4d363
JH
78{
79 int match = -1;
80 char *target;
81 void *buffer;
82 unsigned long size;
21666f1a 83 enum object_type type;
29e4d363
JH
84 int len;
85
86 target = xmalloc(expected_size);
87 len = readlink(ce->name, target, expected_size);
88 if (len != expected_size) {
89 free(target);
90 return -1;
91 }
21666f1a 92 buffer = read_sha1_file(ce->sha1, &type, &size);
29e4d363
JH
93 if (!buffer) {
94 free(target);
95 return -1;
96 }
97 if (size == expected_size)
98 match = memcmp(buffer, target, size);
99 free(buffer);
100 free(target);
101 return match;
102}
103
f35a6d3b
LT
104static int ce_compare_gitlink(struct cache_entry *ce)
105{
106 unsigned char sha1[20];
107
108 /*
109 * We don't actually require that the .git directory
302b9282 110 * under GITLINK directory be a valid git directory. It
f35a6d3b
LT
111 * might even be missing (in case nobody populated that
112 * sub-project).
113 *
114 * If so, we consider it always to match.
115 */
116 if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
117 return 0;
118 return hashcmp(sha1, ce->sha1);
119}
120
29e4d363
JH
121static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
122{
123 switch (st->st_mode & S_IFMT) {
124 case S_IFREG:
125 if (ce_compare_data(ce, st))
126 return DATA_CHANGED;
127 break;
128 case S_IFLNK:
dc49cd76 129 if (ce_compare_link(ce, xsize_t(st->st_size)))
29e4d363
JH
130 return DATA_CHANGED;
131 break;
a8ee75bc 132 case S_IFDIR:
7a51ed66 133 if (S_ISGITLINK(ce->ce_mode))
a8ee75bc 134 return 0;
29e4d363
JH
135 default:
136 return TYPE_CHANGED;
137 }
138 return 0;
139}
140
f49c2c22
LT
141static int is_empty_blob_sha1(const unsigned char *sha1)
142{
143 static const unsigned char empty_blob_sha1[20] = {
144 0xe6,0x9d,0xe2,0x9b,0xb2,0xd1,0xd6,0x43,0x4b,0x8b,
145 0x29,0xae,0x77,0x5a,0xd8,0xc2,0xe4,0x8c,0x53,0x91
146 };
147
148 return !hashcmp(sha1, empty_blob_sha1);
149}
150
407c8eb0 151static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
734aab75
LT
152{
153 unsigned int changed = 0;
154
7a51ed66
LT
155 if (ce->ce_flags & CE_REMOVE)
156 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
157
158 switch (ce->ce_mode & S_IFMT) {
8ae0a8c5
KS
159 case S_IFREG:
160 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
3e09cdfd
JH
161 /* We consider only the owner x bit to be relevant for
162 * "mode changes"
163 */
164 if (trust_executable_bit &&
7a51ed66 165 (0100 & (ce->ce_mode ^ st->st_mode)))
ffbe1add 166 changed |= MODE_CHANGED;
8ae0a8c5
KS
167 break;
168 case S_IFLNK:
78a8d641
JS
169 if (!S_ISLNK(st->st_mode) &&
170 (has_symlinks || !S_ISREG(st->st_mode)))
171 changed |= TYPE_CHANGED;
8ae0a8c5 172 break;
302b9282 173 case S_IFGITLINK:
f35a6d3b
LT
174 if (!S_ISDIR(st->st_mode))
175 changed |= TYPE_CHANGED;
176 else if (ce_compare_gitlink(ce))
177 changed |= DATA_CHANGED;
a8ee75bc 178 return changed;
8ae0a8c5 179 default:
7a51ed66 180 die("internal error: ce_mode is %o", ce->ce_mode);
8ae0a8c5 181 }
7a51ed66 182 if (ce->ce_mtime != (unsigned int) st->st_mtime)
ccc4feb5 183 changed |= MTIME_CHANGED;
7a51ed66 184 if (ce->ce_ctime != (unsigned int) st->st_ctime)
734aab75 185 changed |= CTIME_CHANGED;
ccc4feb5 186
7a51ed66
LT
187 if (ce->ce_uid != (unsigned int) st->st_uid ||
188 ce->ce_gid != (unsigned int) st->st_gid)
734aab75 189 changed |= OWNER_CHANGED;
7a51ed66 190 if (ce->ce_ino != (unsigned int) st->st_ino)
734aab75 191 changed |= INODE_CHANGED;
2cb45e95
LT
192
193#ifdef USE_STDEV
194 /*
195 * st_dev breaks on network filesystems where different
196 * clients will have different views of what "device"
197 * the filesystem is on
198 */
7a51ed66 199 if (ce->ce_dev != (unsigned int) st->st_dev)
2cb45e95
LT
200 changed |= INODE_CHANGED;
201#endif
202
7a51ed66 203 if (ce->ce_size != (unsigned int) st->st_size)
734aab75 204 changed |= DATA_CHANGED;
b0391890 205
f49c2c22
LT
206 /* Racily smudged entry? */
207 if (!ce->ce_size) {
208 if (!is_empty_blob_sha1(ce->sha1))
209 changed |= DATA_CHANGED;
210 }
211
407c8eb0
JH
212 return changed;
213}
214
d1f128b0 215static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
6d91da6d 216{
050288d5
JH
217 return (!S_ISGITLINK(ce->ce_mode) &&
218 istate->timestamp &&
6d91da6d
JH
219 ((unsigned int)istate->timestamp) <= ce->ce_mtime);
220}
221
d1f128b0 222int ie_match_stat(const struct index_state *istate,
4bd5b7da
JH
223 struct cache_entry *ce, struct stat *st,
224 unsigned int options)
407c8eb0 225{
5f73076c 226 unsigned int changed;
4bd5b7da
JH
227 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
228 int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
5f73076c
JH
229
230 /*
231 * If it's marked as always valid in the index, it's
232 * valid whatever the checked-out copy says.
233 */
7a51ed66 234 if (!ignore_valid && (ce->ce_flags & CE_VALID))
5f73076c
JH
235 return 0;
236
237 changed = ce_match_stat_basic(ce, st);
407c8eb0 238
29e4d363
JH
239 /*
240 * Within 1 second of this sequence:
241 * echo xyzzy >file && git-update-index --add file
242 * running this command:
243 * echo frotz >file
244 * would give a falsely clean cache entry. The mtime and
245 * length match the cache, and other stat fields do not change.
246 *
247 * We could detect this at update-index time (the cache entry
248 * being registered/updated records the same time as "now")
249 * and delay the return from git-update-index, but that would
250 * effectively mean we can make at most one commit per second,
251 * which is not acceptable. Instead, we check cache entries
252 * whose mtime are the same as the index file timestamp more
5f73076c 253 * carefully than others.
29e4d363 254 */
6d91da6d 255 if (!changed && is_racy_timestamp(istate, ce)) {
42f77406
JH
256 if (assume_racy_is_modified)
257 changed |= DATA_CHANGED;
258 else
259 changed |= ce_modified_check_fs(ce, st);
260 }
b0391890 261
29e4d363 262 return changed;
b0391890
JH
263}
264
d1f128b0 265int ie_modified(const struct index_state *istate,
4bd5b7da 266 struct cache_entry *ce, struct stat *st, unsigned int options)
b0391890 267{
29e4d363 268 int changed, changed_fs;
4bd5b7da
JH
269
270 changed = ie_match_stat(istate, ce, st, options);
b0391890
JH
271 if (!changed)
272 return 0;
b0391890
JH
273 /*
274 * If the mode or type has changed, there's no point in trying
275 * to refresh the entry - it's not going to match
276 */
277 if (changed & (MODE_CHANGED | TYPE_CHANGED))
278 return changed;
279
280 /* Immediately after read-tree or update-index --cacheinfo,
281 * the length field is zero. For other cases the ce_size
282 * should match the SHA1 recorded in the index entry.
283 */
7a51ed66 284 if ((changed & DATA_CHANGED) && ce->ce_size != 0)
b0391890
JH
285 return changed;
286
29e4d363
JH
287 changed_fs = ce_modified_check_fs(ce, st);
288 if (changed_fs)
289 return changed | changed_fs;
b0391890
JH
290 return 0;
291}
292
958ba6c9
LT
293int base_name_compare(const char *name1, int len1, int mode1,
294 const char *name2, int len2, int mode2)
295{
296 unsigned char c1, c2;
297 int len = len1 < len2 ? len1 : len2;
298 int cmp;
299
300 cmp = memcmp(name1, name2, len);
301 if (cmp)
302 return cmp;
303 c1 = name1[len];
304 c2 = name2[len];
1833a925 305 if (!c1 && S_ISDIR(mode1))
958ba6c9 306 c1 = '/';
1833a925 307 if (!c2 && S_ISDIR(mode2))
958ba6c9
LT
308 c2 = '/';
309 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
310}
311
0ab9e1e8
LT
312/*
313 * df_name_compare() is identical to base_name_compare(), except it
314 * compares conflicting directory/file entries as equal. Note that
315 * while a directory name compares as equal to a regular file, they
316 * then individually compare _differently_ to a filename that has
317 * a dot after the basename (because '\0' < '.' < '/').
318 *
319 * This is used by routines that want to traverse the git namespace
320 * but then handle conflicting entries together when possible.
321 */
322int df_name_compare(const char *name1, int len1, int mode1,
323 const char *name2, int len2, int mode2)
324{
325 int len = len1 < len2 ? len1 : len2, cmp;
326 unsigned char c1, c2;
327
328 cmp = memcmp(name1, name2, len);
329 if (cmp)
330 return cmp;
331 /* Directories and files compare equal (same length, same name) */
332 if (len1 == len2)
333 return 0;
334 c1 = name1[len];
335 if (!c1 && S_ISDIR(mode1))
336 c1 = '/';
337 c2 = name2[len];
338 if (!c2 && S_ISDIR(mode2))
339 c2 = '/';
340 if (c1 == '/' && !c2)
341 return 0;
342 if (c2 == '/' && !c1)
343 return 0;
344 return c1 - c2;
345}
346
95fd5bf8 347int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
eb38c22f 348{
95fd5bf8
LT
349 int len1 = flags1 & CE_NAMEMASK;
350 int len2 = flags2 & CE_NAMEMASK;
eb38c22f
LT
351 int len = len1 < len2 ? len1 : len2;
352 int cmp;
353
354 cmp = memcmp(name1, name2, len);
355 if (cmp)
356 return cmp;
357 if (len1 < len2)
358 return -1;
359 if (len1 > len2)
360 return 1;
5f73076c 361
7b80be15
JH
362 /* Compare stages */
363 flags1 &= CE_STAGEMASK;
364 flags2 &= CE_STAGEMASK;
5f73076c 365
95fd5bf8
LT
366 if (flags1 < flags2)
367 return -1;
368 if (flags1 > flags2)
369 return 1;
eb38c22f
LT
370 return 0;
371}
372
d1f128b0 373int index_name_pos(const struct index_state *istate, const char *name, int namelen)
eb38c22f
LT
374{
375 int first, last;
376
377 first = 0;
4aab5b46 378 last = istate->cache_nr;
eb38c22f
LT
379 while (last > first) {
380 int next = (last + first) >> 1;
4aab5b46 381 struct cache_entry *ce = istate->cache[next];
7a51ed66 382 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags);
eb38c22f 383 if (!cmp)
76e7f4ec 384 return next;
eb38c22f
LT
385 if (cmp < 0) {
386 last = next;
387 continue;
388 }
389 first = next+1;
390 }
76e7f4ec 391 return -first-1;
eb38c22f
LT
392}
393
7b937ca3 394/* Remove entry, return true if there are more entries to go.. */
4aab5b46 395int remove_index_entry_at(struct index_state *istate, int pos)
7b937ca3 396{
cf558704
LT
397 struct cache_entry *ce = istate->cache[pos];
398
96872bc2 399 remove_name_hash(ce);
4aab5b46
JH
400 istate->cache_changed = 1;
401 istate->cache_nr--;
402 if (pos >= istate->cache_nr)
7b937ca3 403 return 0;
4aab5b46
JH
404 memmove(istate->cache + pos,
405 istate->cache + pos + 1,
406 (istate->cache_nr - pos) * sizeof(struct cache_entry *));
7b937ca3
LT
407 return 1;
408}
409
4aab5b46 410int remove_file_from_index(struct index_state *istate, const char *path)
197ee8c9 411{
4aab5b46 412 int pos = index_name_pos(istate, path, strlen(path));
c4e3cca1
JH
413 if (pos < 0)
414 pos = -pos-1;
09d5dc32 415 cache_tree_invalidate_path(istate->cache_tree, path);
4aab5b46
JH
416 while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
417 remove_index_entry_at(istate, pos);
197ee8c9
LT
418 return 0;
419}
420
20314271
JS
421static int compare_name(struct cache_entry *ce, const char *path, int namelen)
422{
423 return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
424}
425
426static int index_name_pos_also_unmerged(struct index_state *istate,
427 const char *path, int namelen)
428{
429 int pos = index_name_pos(istate, path, namelen);
430 struct cache_entry *ce;
431
432 if (pos >= 0)
433 return pos;
434
435 /* maybe unmerged? */
436 pos = -1 - pos;
437 if (pos >= istate->cache_nr ||
438 compare_name((ce = istate->cache[pos]), path, namelen))
439 return -1;
440
441 /* order of preference: stage 2, 1, 3 */
442 if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
443 ce_stage((ce = istate->cache[pos + 1])) == 2 &&
444 !compare_name(ce, path, namelen))
445 pos++;
446 return pos;
447}
448
1102952b
LT
449static int different_name(struct cache_entry *ce, struct cache_entry *alias)
450{
451 int len = ce_namelen(ce);
452 return ce_namelen(alias) != len || memcmp(ce->name, alias->name, len);
453}
454
455/*
456 * If we add a filename that aliases in the cache, we will use the
457 * name that we already have - but we don't want to update the same
458 * alias twice, because that implies that there were actually two
459 * different files with aliasing names!
460 *
461 * So we use the CE_ADDED flag to verify that the alias was an old
462 * one before we accept it as
463 */
464static struct cache_entry *create_alias_ce(struct cache_entry *ce, struct cache_entry *alias)
465{
466 int len;
467 struct cache_entry *new;
468
469 if (alias->ce_flags & CE_ADDED)
470 die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name);
471
472 /* Ok, create the new entry using the name of the existing alias */
473 len = ce_namelen(alias);
474 new = xcalloc(1, cache_entry_size(len));
475 memcpy(new->name, alias->name, len);
476 copy_cache_entry(new, ce);
477 free(ce);
478 return new;
479}
480
38ed1d89 481int add_to_index(struct index_state *istate, const char *path, struct stat *st, int flags)
11be42a4 482{
38ed1d89 483 int size, namelen, was_same;
d177cab0 484 mode_t st_mode = st->st_mode;
6835550d 485 struct cache_entry *ce, *alias;
fb63d7f8 486 unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY;
38ed1d89
JH
487 int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND);
488 int pretend = flags & ADD_CACHE_PRETEND;
11be42a4 489
d177cab0 490 if (!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode))
960b8ad1 491 return error("%s: can only add regular files, symbolic links or git-directories", path);
11be42a4
JS
492
493 namelen = strlen(path);
d177cab0 494 if (S_ISDIR(st_mode)) {
09595258
LT
495 while (namelen && path[namelen-1] == '/')
496 namelen--;
497 }
11be42a4
JS
498 size = cache_entry_size(namelen);
499 ce = xcalloc(1, size);
500 memcpy(ce->name, path, namelen);
7a51ed66 501 ce->ce_flags = namelen;
d177cab0 502 fill_stat_cache_info(ce, st);
11be42a4 503
78a8d641 504 if (trust_executable_bit && has_symlinks)
d177cab0 505 ce->ce_mode = create_ce_mode(st_mode);
185c975f 506 else {
78a8d641
JS
507 /* If there is an existing entry, pick the mode bits and type
508 * from it, otherwise assume unexecutable regular file.
11be42a4 509 */
185c975f 510 struct cache_entry *ent;
20314271 511 int pos = index_name_pos_also_unmerged(istate, path, namelen);
185c975f 512
4aab5b46 513 ent = (0 <= pos) ? istate->cache[pos] : NULL;
d177cab0 514 ce->ce_mode = ce_mode_from_stat(ent, st_mode);
11be42a4
JS
515 }
516
6835550d 517 alias = index_name_exists(istate, ce->name, ce_namelen(ce), ignore_case);
d177cab0 518 if (alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) {
0781b8a9
JH
519 /* Nothing changed, really */
520 free(ce);
6835550d 521 ce_mark_uptodate(alias);
1102952b 522 alias->ce_flags |= CE_ADDED;
0781b8a9
JH
523 return 0;
524 }
d177cab0 525 if (index_path(ce->sha1, path, st, 1))
960b8ad1 526 return error("unable to index file %s", path);
1102952b
LT
527 if (ignore_case && alias && different_name(ce, alias))
528 ce = create_alias_ce(ce, alias);
529 ce->ce_flags |= CE_ADDED;
38ed1d89
JH
530
531 /* It was suspected to be recily clean, but it turns out to be Ok */
532 was_same = (alias &&
533 !ce_stage(alias) &&
534 !hashcmp(alias->sha1, ce->sha1) &&
535 ce->ce_mode == alias->ce_mode);
536
537 if (pretend)
538 ;
539 else if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
960b8ad1 540 return error("unable to add %s to index",path);
38ed1d89 541 if (verbose && !was_same)
11be42a4 542 printf("add '%s'\n", path);
11be42a4
JS
543 return 0;
544}
545
38ed1d89 546int add_file_to_index(struct index_state *istate, const char *path, int flags)
d177cab0
LT
547{
548 struct stat st;
549 if (lstat(path, &st))
550 die("%s: unable to stat (%s)", path, strerror(errno));
38ed1d89 551 return add_to_index(istate, path, &st, flags);
d177cab0
LT
552}
553
6640f881
CR
554struct cache_entry *make_cache_entry(unsigned int mode,
555 const unsigned char *sha1, const char *path, int stage,
556 int refresh)
557{
558 int size, len;
559 struct cache_entry *ce;
560
561 if (!verify_path(path))
562 return NULL;
563
564 len = strlen(path);
565 size = cache_entry_size(len);
566 ce = xcalloc(1, size);
567
568 hashcpy(ce->sha1, sha1);
569 memcpy(ce->name, path, len);
570 ce->ce_flags = create_ce_flags(len, stage);
571 ce->ce_mode = create_ce_mode(mode);
572
573 if (refresh)
574 return refresh_cache_entry(ce, 0);
575
576 return ce;
577}
578
dbbce55b 579int ce_same_name(struct cache_entry *a, struct cache_entry *b)
7b937ca3
LT
580{
581 int len = ce_namelen(a);
582 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
583}
584
c0fd1f51
LT
585int ce_path_match(const struct cache_entry *ce, const char **pathspec)
586{
587 const char *match, *name;
588 int len;
589
590 if (!pathspec)
591 return 1;
592
593 len = ce_namelen(ce);
594 name = ce->name;
595 while ((match = *pathspec++) != NULL) {
596 int matchlen = strlen(match);
597 if (matchlen > len)
598 continue;
599 if (memcmp(name, match, matchlen))
600 continue;
601 if (matchlen && name[matchlen-1] == '/')
602 return 1;
603 if (name[matchlen] == '/' || !name[matchlen])
604 return 1;
f332726e
LT
605 if (!matchlen)
606 return 1;
c0fd1f51
LT
607 }
608 return 0;
609}
610
8dcf39c4
LT
611/*
612 * We fundamentally don't like some paths: we don't want
613 * dot or dot-dot anywhere, and for obvious reasons don't
614 * want to recurse into ".git" either.
615 *
616 * Also, we don't want double slashes or slashes at the
617 * end that can make pathnames ambiguous.
618 */
619static int verify_dotfile(const char *rest)
620{
621 /*
622 * The first character was '.', but that
623 * has already been discarded, we now test
624 * the rest.
625 */
626 switch (*rest) {
627 /* "." is not allowed */
628 case '\0': case '/':
629 return 0;
630
631 /*
632 * ".git" followed by NUL or slash is bad. This
633 * shares the path end test with the ".." case.
634 */
635 case 'g':
636 if (rest[1] != 'i')
637 break;
638 if (rest[2] != 't')
639 break;
640 rest += 2;
641 /* fallthrough */
642 case '.':
643 if (rest[1] == '\0' || rest[1] == '/')
644 return 0;
645 }
646 return 1;
647}
648
649int verify_path(const char *path)
650{
651 char c;
652
653 goto inside;
654 for (;;) {
655 if (!c)
656 return 1;
657 if (c == '/') {
658inside:
659 c = *path++;
660 switch (c) {
661 default:
662 continue;
663 case '/': case '\0':
664 break;
665 case '.':
666 if (verify_dotfile(path))
667 continue;
668 }
669 return 0;
670 }
671 c = *path++;
672 }
673}
674
12676608
LT
675/*
676 * Do we have another file that has the beginning components being a
677 * proper superset of the name we're trying to add?
0f1e4f04 678 */
4aab5b46
JH
679static int has_file_name(struct index_state *istate,
680 const struct cache_entry *ce, int pos, int ok_to_replace)
0f1e4f04 681{
12676608
LT
682 int retval = 0;
683 int len = ce_namelen(ce);
b155725d 684 int stage = ce_stage(ce);
12676608 685 const char *name = ce->name;
0f1e4f04 686
4aab5b46
JH
687 while (pos < istate->cache_nr) {
688 struct cache_entry *p = istate->cache[pos++];
0f1e4f04 689
12676608 690 if (len >= ce_namelen(p))
0f1e4f04 691 break;
12676608
LT
692 if (memcmp(name, p->name, len))
693 break;
b155725d
JH
694 if (ce_stage(p) != stage)
695 continue;
12676608
LT
696 if (p->name[len] != '/')
697 continue;
7a51ed66 698 if (p->ce_flags & CE_REMOVE)
21cd8d00 699 continue;
12676608
LT
700 retval = -1;
701 if (!ok_to_replace)
702 break;
4aab5b46 703 remove_index_entry_at(istate, --pos);
0f1e4f04 704 }
12676608
LT
705 return retval;
706}
0f1e4f04 707
12676608
LT
708/*
709 * Do we have another file with a pathname that is a proper
710 * subset of the name we're trying to add?
711 */
4aab5b46
JH
712static int has_dir_name(struct index_state *istate,
713 const struct cache_entry *ce, int pos, int ok_to_replace)
12676608
LT
714{
715 int retval = 0;
b155725d 716 int stage = ce_stage(ce);
12676608
LT
717 const char *name = ce->name;
718 const char *slash = name + ce_namelen(ce);
0f1e4f04 719
12676608
LT
720 for (;;) {
721 int len;
0f1e4f04 722
12676608
LT
723 for (;;) {
724 if (*--slash == '/')
725 break;
726 if (slash <= ce->name)
727 return retval;
728 }
729 len = slash - name;
0f1e4f04 730
7a51ed66 731 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
12676608 732 if (pos >= 0) {
21cd8d00
JH
733 /*
734 * Found one, but not so fast. This could
735 * be a marker that says "I was here, but
736 * I am being removed". Such an entry is
737 * not a part of the resulting tree, and
738 * it is Ok to have a directory at the same
739 * path.
740 */
077c48df 741 if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
21cd8d00
JH
742 retval = -1;
743 if (!ok_to_replace)
744 break;
4aab5b46 745 remove_index_entry_at(istate, pos);
21cd8d00
JH
746 continue;
747 }
12676608 748 }
21cd8d00
JH
749 else
750 pos = -pos-1;
12676608
LT
751
752 /*
753 * Trivial optimization: if we find an entry that
754 * already matches the sub-directory, then we know
b155725d 755 * we're ok, and we can exit.
12676608 756 */
4aab5b46
JH
757 while (pos < istate->cache_nr) {
758 struct cache_entry *p = istate->cache[pos];
b155725d
JH
759 if ((ce_namelen(p) <= len) ||
760 (p->name[len] != '/') ||
761 memcmp(p->name, name, len))
762 break; /* not our subdirectory */
077c48df
JH
763 if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
764 /*
765 * p is at the same stage as our entry, and
b155725d
JH
766 * is a subdirectory of what we are looking
767 * at, so we cannot have conflicts at our
768 * level or anything shorter.
769 */
770 return retval;
771 pos++;
192268c1 772 }
0f1e4f04 773 }
12676608
LT
774 return retval;
775}
776
777/* We may be in a situation where we already have path/file and path
778 * is being added, or we already have path and path/file is being
779 * added. Either one would result in a nonsense tree that has path
780 * twice when git-write-tree tries to write it out. Prevent it.
a6080a0a 781 *
12676608
LT
782 * If ok-to-replace is specified, we remove the conflicting entries
783 * from the cache so the caller should recompute the insert position.
784 * When this happens, we return non-zero.
785 */
4aab5b46
JH
786static int check_file_directory_conflict(struct index_state *istate,
787 const struct cache_entry *ce,
788 int pos, int ok_to_replace)
12676608 789{
21cd8d00
JH
790 int retval;
791
792 /*
793 * When ce is an "I am going away" entry, we allow it to be added
794 */
7a51ed66 795 if (ce->ce_flags & CE_REMOVE)
21cd8d00
JH
796 return 0;
797
12676608
LT
798 /*
799 * We check if the path is a sub-path of a subsequent pathname
800 * first, since removing those will not change the position
21cd8d00 801 * in the array.
12676608 802 */
4aab5b46 803 retval = has_file_name(istate, ce, pos, ok_to_replace);
21cd8d00 804
12676608
LT
805 /*
806 * Then check if the path might have a clashing sub-directory
807 * before it.
808 */
4aab5b46 809 return retval + has_dir_name(istate, ce, pos, ok_to_replace);
0f1e4f04
JH
810}
811
af3785dc 812static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
197ee8c9
LT
813{
814 int pos;
192268c1
JH
815 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
816 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
b155725d 817 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
5f73076c 818
09d5dc32 819 cache_tree_invalidate_path(istate->cache_tree, ce->name);
7a51ed66 820 pos = index_name_pos(istate, ce->name, ce->ce_flags);
197ee8c9 821
3e09cdfd 822 /* existing match? Just replace it. */
76e7f4ec 823 if (pos >= 0) {
cf558704 824 replace_index_entry(istate, pos, ce);
197ee8c9
LT
825 return 0;
826 }
76e7f4ec 827 pos = -pos-1;
197ee8c9 828
7b937ca3
LT
829 /*
830 * Inserting a merged entry ("stage 0") into the index
831 * will always replace all non-merged entries..
832 */
4aab5b46
JH
833 if (pos < istate->cache_nr && ce_stage(ce) == 0) {
834 while (ce_same_name(istate->cache[pos], ce)) {
7b937ca3 835 ok_to_add = 1;
4aab5b46 836 if (!remove_index_entry_at(istate, pos))
7b937ca3
LT
837 break;
838 }
839 }
840
121481ab
LT
841 if (!ok_to_add)
842 return -1;
8dcf39c4
LT
843 if (!verify_path(ce->name))
844 return -1;
121481ab 845
3e09cdfd 846 if (!skip_df_check &&
4aab5b46 847 check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
192268c1 848 if (!ok_to_replace)
4aab5b46
JH
849 return error("'%s' appears as both a file and as a directory",
850 ce->name);
7a51ed66 851 pos = index_name_pos(istate, ce->name, ce->ce_flags);
192268c1
JH
852 pos = -pos-1;
853 }
af3785dc
JH
854 return pos + 1;
855}
856
857int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
858{
859 int pos;
860
861 if (option & ADD_CACHE_JUST_APPEND)
862 pos = istate->cache_nr;
863 else {
864 int ret;
865 ret = add_index_entry_with_check(istate, ce, option);
866 if (ret <= 0)
867 return ret;
868 pos = ret - 1;
869 }
0f1e4f04 870
197ee8c9 871 /* Make sure the array is big enough .. */
4aab5b46
JH
872 if (istate->cache_nr == istate->cache_alloc) {
873 istate->cache_alloc = alloc_nr(istate->cache_alloc);
874 istate->cache = xrealloc(istate->cache,
875 istate->cache_alloc * sizeof(struct cache_entry *));
197ee8c9
LT
876 }
877
878 /* Add it in.. */
4aab5b46 879 istate->cache_nr++;
af3785dc 880 if (istate->cache_nr > pos + 1)
4aab5b46
JH
881 memmove(istate->cache + pos + 1,
882 istate->cache + pos,
883 (istate->cache_nr - pos - 1) * sizeof(ce));
cf558704 884 set_index_entry(istate, pos, ce);
4aab5b46 885 istate->cache_changed = 1;
197ee8c9
LT
886 return 0;
887}
888
405e5b2f
LT
889/*
890 * "refresh" does not calculate a new sha1 file or bring the
891 * cache up-to-date for mode/content changes. But what it
892 * _does_ do is to "re-match" the stat information of a file
893 * with the cache, so that you can refresh the cache for a
894 * file that hasn't been changed but where the stat entry is
895 * out of date.
896 *
897 * For example, you'd want to do this after doing a "git-read-tree",
898 * to link up the stat cache details with the proper files.
899 */
4aab5b46 900static struct cache_entry *refresh_cache_ent(struct index_state *istate,
4bd5b7da
JH
901 struct cache_entry *ce,
902 unsigned int options, int *err)
405e5b2f
LT
903{
904 struct stat st;
905 struct cache_entry *updated;
906 int changed, size;
4bd5b7da 907 int ignore_valid = options & CE_MATCH_IGNORE_VALID;
405e5b2f 908
eadb5831
JH
909 if (ce_uptodate(ce))
910 return ce;
911
aa9349d4
MSO
912 /*
913 * CE_VALID means the user promised us that the change to
914 * the work tree does not matter and told us not to worry.
915 */
916 if (!ignore_valid && (ce->ce_flags & CE_VALID)) {
917 ce_mark_uptodate(ce);
918 return ce;
919 }
920
8fd2cb40 921 if (lstat(ce->name, &st) < 0) {
ec0cc704
JH
922 if (err)
923 *err = errno;
8fd2cb40
JS
924 return NULL;
925 }
405e5b2f 926
4bd5b7da 927 changed = ie_match_stat(istate, ce, &st, options);
405e5b2f 928 if (!changed) {
4bd5b7da
JH
929 /*
930 * The path is unchanged. If we were told to ignore
931 * valid bit, then we did the actual stat check and
932 * found that the entry is unmodified. If the entry
933 * is not marked VALID, this is the place to mark it
934 * valid again, under "assume unchanged" mode.
935 */
936 if (ignore_valid && assume_unchanged &&
7a51ed66 937 !(ce->ce_flags & CE_VALID))
405e5b2f 938 ; /* mark this one VALID again */
eadb5831
JH
939 else {
940 /*
941 * We do not mark the index itself "modified"
942 * because CE_UPTODATE flag is in-core only;
943 * we are not going to write this change out.
944 */
945 ce_mark_uptodate(ce);
8fd2cb40 946 return ce;
eadb5831 947 }
405e5b2f
LT
948 }
949
4bd5b7da 950 if (ie_modified(istate, ce, &st, options)) {
ec0cc704
JH
951 if (err)
952 *err = EINVAL;
8fd2cb40
JS
953 return NULL;
954 }
405e5b2f
LT
955
956 size = ce_size(ce);
957 updated = xmalloc(size);
958 memcpy(updated, ce, size);
959 fill_stat_cache_info(updated, &st);
4bd5b7da
JH
960 /*
961 * If ignore_valid is not set, we should leave CE_VALID bit
962 * alone. Otherwise, paths marked with --no-assume-unchanged
963 * (i.e. things to be edited) will reacquire CE_VALID bit
964 * automatically, which is not really what we want.
405e5b2f 965 */
4bd5b7da 966 if (!ignore_valid && assume_unchanged &&
7a51ed66
LT
967 !(ce->ce_flags & CE_VALID))
968 updated->ce_flags &= ~CE_VALID;
405e5b2f
LT
969
970 return updated;
971}
972
d616813d 973int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
405e5b2f
LT
974{
975 int i;
976 int has_errors = 0;
977 int really = (flags & REFRESH_REALLY) != 0;
978 int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
979 int quiet = (flags & REFRESH_QUIET) != 0;
980 int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
5fdeacb0 981 int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) != 0;
4bd5b7da 982 unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
405e5b2f 983
4aab5b46 984 for (i = 0; i < istate->cache_nr; i++) {
405e5b2f 985 struct cache_entry *ce, *new;
ec0cc704
JH
986 int cache_errno = 0;
987
4aab5b46 988 ce = istate->cache[i];
5fdeacb0
JS
989 if (ignore_submodules && S_ISGITLINK(ce->ce_mode))
990 continue;
991
405e5b2f 992 if (ce_stage(ce)) {
4aab5b46
JH
993 while ((i < istate->cache_nr) &&
994 ! strcmp(istate->cache[i]->name, ce->name))
405e5b2f
LT
995 i++;
996 i--;
997 if (allow_unmerged)
998 continue;
999 printf("%s: needs merge\n", ce->name);
1000 has_errors = 1;
1001 continue;
1002 }
1003
d616813d
AJ
1004 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
1005 continue;
1006
4bd5b7da 1007 new = refresh_cache_ent(istate, ce, options, &cache_errno);
8fd2cb40 1008 if (new == ce)
405e5b2f 1009 continue;
8fd2cb40
JS
1010 if (!new) {
1011 if (not_new && cache_errno == ENOENT)
405e5b2f 1012 continue;
8fd2cb40 1013 if (really && cache_errno == EINVAL) {
405e5b2f
LT
1014 /* If we are doing --really-refresh that
1015 * means the index is not valid anymore.
1016 */
7a51ed66 1017 ce->ce_flags &= ~CE_VALID;
4aab5b46 1018 istate->cache_changed = 1;
405e5b2f
LT
1019 }
1020 if (quiet)
1021 continue;
1022 printf("%s: needs update\n", ce->name);
1023 has_errors = 1;
1024 continue;
1025 }
cf558704
LT
1026
1027 replace_index_entry(istate, i, new);
405e5b2f
LT
1028 }
1029 return has_errors;
1030}
1031
ec0cc704
JH
1032struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
1033{
4aab5b46 1034 return refresh_cache_ent(&the_index, ce, really, NULL);
ec0cc704
JH
1035}
1036
bad68ec9 1037static int verify_hdr(struct cache_header *hdr, unsigned long size)
e83c5163
LT
1038{
1039 SHA_CTX c;
bad68ec9 1040 unsigned char sha1[20];
e83c5163 1041
ccc4feb5 1042 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
e83c5163 1043 return error("bad signature");
ca9be054
LT
1044 if (hdr->hdr_version != htonl(2))
1045 return error("bad index version");
e83c5163 1046 SHA1_Init(&c);
ca9be054 1047 SHA1_Update(&c, hdr, size - 20);
e83c5163 1048 SHA1_Final(sha1, &c);
a89fccd2 1049 if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
ca9be054 1050 return error("bad index file sha1 signature");
e83c5163
LT
1051 return 0;
1052}
1053
4aab5b46
JH
1054static int read_index_extension(struct index_state *istate,
1055 const char *ext, void *data, unsigned long sz)
bad68ec9
JH
1056{
1057 switch (CACHE_EXT(ext)) {
1058 case CACHE_EXT_TREE:
4aab5b46 1059 istate->cache_tree = cache_tree_read(data, sz);
bad68ec9
JH
1060 break;
1061 default:
1062 if (*ext < 'A' || 'Z' < *ext)
1063 return error("index uses %.4s extension, which we do not understand",
1064 ext);
1065 fprintf(stderr, "ignoring %.4s extension\n", ext);
1066 break;
1067 }
1068 return 0;
1069}
1070
4aab5b46 1071int read_index(struct index_state *istate)
8fd2cb40 1072{
4aab5b46 1073 return read_index_from(istate, get_index_file());
8fd2cb40
JS
1074}
1075
7a51ed66
LT
1076static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
1077{
7fec10b7
JH
1078 size_t len;
1079
7a51ed66
LT
1080 ce->ce_ctime = ntohl(ondisk->ctime.sec);
1081 ce->ce_mtime = ntohl(ondisk->mtime.sec);
1082 ce->ce_dev = ntohl(ondisk->dev);
1083 ce->ce_ino = ntohl(ondisk->ino);
1084 ce->ce_mode = ntohl(ondisk->mode);
1085 ce->ce_uid = ntohl(ondisk->uid);
1086 ce->ce_gid = ntohl(ondisk->gid);
1087 ce->ce_size = ntohl(ondisk->size);
1088 /* On-disk flags are just 16 bits */
1089 ce->ce_flags = ntohs(ondisk->flags);
1090 hashcpy(ce->sha1, ondisk->sha1);
7fec10b7
JH
1091
1092 len = ce->ce_flags & CE_NAMEMASK;
1093 if (len == CE_NAMEMASK)
1094 len = strlen(ondisk->name);
1095 /*
1096 * NEEDSWORK: If the original index is crafted, this copy could
1097 * go unchecked.
1098 */
1099 memcpy(ce->name, ondisk->name, len + 1);
7a51ed66
LT
1100}
1101
cf558704
LT
1102static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
1103{
1104 long per_entry;
1105
1106 per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
1107
1108 /*
1109 * Alignment can cause differences. This should be "alignof", but
1110 * since that's a gcc'ism, just use the size of a pointer.
1111 */
1112 per_entry += sizeof(void *);
1113 return ondisk_size + entries*per_entry;
1114}
1115
8fd2cb40 1116/* remember to discard_cache() before reading a different cache! */
4aab5b46 1117int read_index_from(struct index_state *istate, const char *path)
e83c5163
LT
1118{
1119 int fd, i;
1120 struct stat st;
7a51ed66 1121 unsigned long src_offset, dst_offset;
e83c5163 1122 struct cache_header *hdr;
7a51ed66
LT
1123 void *mmap;
1124 size_t mmap_size;
e83c5163
LT
1125
1126 errno = EBUSY;
7a51ed66 1127 if (istate->alloc)
4aab5b46 1128 return istate->cache_nr;
5d1a5c02 1129
e83c5163 1130 errno = ENOENT;
4aab5b46 1131 istate->timestamp = 0;
8fd2cb40 1132 fd = open(path, O_RDONLY);
5d1a5c02
LT
1133 if (fd < 0) {
1134 if (errno == ENOENT)
1135 return 0;
1136 die("index file open failed (%s)", strerror(errno));
1137 }
e83c5163 1138
3511a377 1139 if (fstat(fd, &st))
5fe5c830 1140 die("cannot stat the open index (%s)", strerror(errno));
3511a377
LFC
1141
1142 errno = EINVAL;
7a51ed66
LT
1143 mmap_size = xsize_t(st.st_size);
1144 if (mmap_size < sizeof(struct cache_header) + 20)
3511a377
LFC
1145 die("index file smaller than expected");
1146
7a51ed66 1147 mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
e83c5163 1148 close(fd);
7a51ed66
LT
1149 if (mmap == MAP_FAILED)
1150 die("unable to map index file");
e83c5163 1151
7a51ed66
LT
1152 hdr = mmap;
1153 if (verify_hdr(hdr, mmap_size) < 0)
e83c5163
LT
1154 goto unmap;
1155
4aab5b46
JH
1156 istate->cache_nr = ntohl(hdr->hdr_entries);
1157 istate->cache_alloc = alloc_nr(istate->cache_nr);
1158 istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
e83c5163 1159
7a51ed66
LT
1160 /*
1161 * The disk format is actually larger than the in-memory format,
1162 * due to space for nsec etc, so even though the in-memory one
1163 * has room for a few more flags, we can allocate using the same
1164 * index size
1165 */
cf558704 1166 istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
7a51ed66
LT
1167
1168 src_offset = sizeof(*hdr);
1169 dst_offset = 0;
4aab5b46 1170 for (i = 0; i < istate->cache_nr; i++) {
7a51ed66 1171 struct ondisk_cache_entry *disk_ce;
4aab5b46
JH
1172 struct cache_entry *ce;
1173
7a51ed66
LT
1174 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1175 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
1176 convert_from_disk(disk_ce, ce);
cf558704 1177 set_index_entry(istate, i, ce);
7a51ed66
LT
1178
1179 src_offset += ondisk_ce_size(ce);
1180 dst_offset += ce_size(ce);
e83c5163 1181 }
4aab5b46 1182 istate->timestamp = st.st_mtime;
7a51ed66 1183 while (src_offset <= mmap_size - 20 - 8) {
bad68ec9
JH
1184 /* After an array of active_nr index entries,
1185 * there can be arbitrary number of extended
1186 * sections, each of which is prefixed with
1187 * extension name (4-byte) and section length
1188 * in 4-byte network byte order.
1189 */
1190 unsigned long extsize;
7a51ed66 1191 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
bad68ec9 1192 extsize = ntohl(extsize);
4aab5b46 1193 if (read_index_extension(istate,
7a51ed66
LT
1194 (const char *) mmap + src_offset,
1195 (char *) mmap + src_offset + 8,
1d7f171c 1196 extsize) < 0)
bad68ec9 1197 goto unmap;
7a51ed66
LT
1198 src_offset += 8;
1199 src_offset += extsize;
bad68ec9 1200 }
7a51ed66 1201 munmap(mmap, mmap_size);
4aab5b46 1202 return istate->cache_nr;
e83c5163
LT
1203
1204unmap:
7a51ed66 1205 munmap(mmap, mmap_size);
e83c5163 1206 errno = EINVAL;
5d1a5c02 1207 die("index file corrupt");
e83c5163
LT
1208}
1209
4aab5b46 1210int discard_index(struct index_state *istate)
6d297f81 1211{
4aab5b46
JH
1212 istate->cache_nr = 0;
1213 istate->cache_changed = 0;
1214 istate->timestamp = 0;
cf558704 1215 free_hash(&istate->name_hash);
4aab5b46 1216 cache_tree_free(&(istate->cache_tree));
7a51ed66
LT
1217 free(istate->alloc);
1218 istate->alloc = NULL;
6d297f81
JS
1219
1220 /* no need to throw away allocated active_cache */
7a51ed66 1221 return 0;
6d297f81
JS
1222}
1223
d1f128b0 1224int unmerged_index(const struct index_state *istate)
94a5728c
DB
1225{
1226 int i;
1227 for (i = 0; i < istate->cache_nr; i++) {
1228 if (ce_stage(istate->cache[i]))
1229 return 1;
1230 }
1231 return 0;
1232}
1233
4990aadc 1234#define WRITE_BUFFER_SIZE 8192
bf0f910d 1235static unsigned char write_buffer[WRITE_BUFFER_SIZE];
4990aadc
LT
1236static unsigned long write_buffer_len;
1237
6015c28b
JH
1238static int ce_write_flush(SHA_CTX *context, int fd)
1239{
1240 unsigned int buffered = write_buffer_len;
1241 if (buffered) {
1242 SHA1_Update(context, write_buffer, buffered);
93822c22 1243 if (write_in_full(fd, write_buffer, buffered) != buffered)
6015c28b
JH
1244 return -1;
1245 write_buffer_len = 0;
1246 }
1247 return 0;
1248}
1249
ca9be054 1250static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
4990aadc
LT
1251{
1252 while (len) {
1253 unsigned int buffered = write_buffer_len;
1254 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1255 if (partial > len)
1256 partial = len;
1257 memcpy(write_buffer + buffered, data, partial);
1258 buffered += partial;
1259 if (buffered == WRITE_BUFFER_SIZE) {
6015c28b
JH
1260 write_buffer_len = buffered;
1261 if (ce_write_flush(context, fd))
4990aadc
LT
1262 return -1;
1263 buffered = 0;
1264 }
1265 write_buffer_len = buffered;
1266 len -= partial;
1d7f171c 1267 data = (char *) data + partial;
a6080a0a
JH
1268 }
1269 return 0;
4990aadc
LT
1270}
1271
bad68ec9 1272static int write_index_ext_header(SHA_CTX *context, int fd,
ac58c7b1 1273 unsigned int ext, unsigned int sz)
bad68ec9
JH
1274{
1275 ext = htonl(ext);
1276 sz = htonl(sz);
968a1d65
DR
1277 return ((ce_write(context, fd, &ext, 4) < 0) ||
1278 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
bad68ec9
JH
1279}
1280
1281static int ce_flush(SHA_CTX *context, int fd)
4990aadc
LT
1282{
1283 unsigned int left = write_buffer_len;
ca9be054 1284
4990aadc
LT
1285 if (left) {
1286 write_buffer_len = 0;
ca9be054 1287 SHA1_Update(context, write_buffer, left);
4990aadc 1288 }
ca9be054 1289
2c865d9a
QH
1290 /* Flush first if not enough space for SHA1 signature */
1291 if (left + 20 > WRITE_BUFFER_SIZE) {
93822c22 1292 if (write_in_full(fd, write_buffer, left) != left)
2c865d9a
QH
1293 return -1;
1294 left = 0;
1295 }
1296
ca9be054 1297 /* Append the SHA1 signature at the end */
bad68ec9 1298 SHA1_Final(write_buffer + left, context);
ca9be054 1299 left += 20;
93822c22 1300 return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
4990aadc
LT
1301}
1302
407c8eb0
JH
1303static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1304{
1305 /*
1306 * The only thing we care about in this function is to smudge the
1307 * falsely clean entry due to touch-update-touch race, so we leave
1308 * everything else as they are. We are called for entries whose
1309 * ce_mtime match the index file mtime.
1310 */
1311 struct stat st;
1312
1313 if (lstat(ce->name, &st) < 0)
1314 return;
1315 if (ce_match_stat_basic(ce, &st))
1316 return;
1317 if (ce_modified_check_fs(ce, &st)) {
4b3511b0
JH
1318 /* This is "racily clean"; smudge it. Note that this
1319 * is a tricky code. At first glance, it may appear
1320 * that it can break with this sequence:
1321 *
1322 * $ echo xyzzy >frotz
1323 * $ git-update-index --add frotz
1324 * $ : >frotz
1325 * $ sleep 3
1326 * $ echo filfre >nitfol
1327 * $ git-update-index --add nitfol
1328 *
b7e58b17 1329 * but it does not. When the second update-index runs,
4b3511b0
JH
1330 * it notices that the entry "frotz" has the same timestamp
1331 * as index, and if we were to smudge it by resetting its
1332 * size to zero here, then the object name recorded
1333 * in index is the 6-byte file but the cached stat information
1334 * becomes zero --- which would then match what we would
a6080a0a 1335 * obtain from the filesystem next time we stat("frotz").
4b3511b0
JH
1336 *
1337 * However, the second update-index, before calling
1338 * this function, notices that the cached size is 6
1339 * bytes and what is on the filesystem is an empty
1340 * file, and never calls us, so the cached size information
1341 * for "frotz" stays 6 which does not match the filesystem.
1342 */
7a51ed66 1343 ce->ce_size = 0;
407c8eb0
JH
1344 }
1345}
1346
7a51ed66
LT
1347static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)
1348{
1349 int size = ondisk_ce_size(ce);
1350 struct ondisk_cache_entry *ondisk = xcalloc(1, size);
1351
1352 ondisk->ctime.sec = htonl(ce->ce_ctime);
1353 ondisk->ctime.nsec = 0;
1354 ondisk->mtime.sec = htonl(ce->ce_mtime);
1355 ondisk->mtime.nsec = 0;
1356 ondisk->dev = htonl(ce->ce_dev);
1357 ondisk->ino = htonl(ce->ce_ino);
1358 ondisk->mode = htonl(ce->ce_mode);
1359 ondisk->uid = htonl(ce->ce_uid);
1360 ondisk->gid = htonl(ce->ce_gid);
1361 ondisk->size = htonl(ce->ce_size);
1362 hashcpy(ondisk->sha1, ce->sha1);
1363 ondisk->flags = htons(ce->ce_flags);
1364 memcpy(ondisk->name, ce->name, ce_namelen(ce));
1365
1366 return ce_write(c, fd, ondisk, size);
1367}
1368
d1f128b0 1369int write_index(const struct index_state *istate, int newfd)
197ee8c9
LT
1370{
1371 SHA_CTX c;
1372 struct cache_header hdr;
1dffb8fa 1373 int i, err, removed;
4aab5b46
JH
1374 struct cache_entry **cache = istate->cache;
1375 int entries = istate->cache_nr;
025a0709
JH
1376
1377 for (i = removed = 0; i < entries; i++)
7a51ed66 1378 if (cache[i]->ce_flags & CE_REMOVE)
025a0709 1379 removed++;
197ee8c9 1380
ccc4feb5 1381 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
ca9be054 1382 hdr.hdr_version = htonl(2);
025a0709 1383 hdr.hdr_entries = htonl(entries - removed);
197ee8c9
LT
1384
1385 SHA1_Init(&c);
ca9be054 1386 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
197ee8c9
LT
1387 return -1;
1388
1389 for (i = 0; i < entries; i++) {
1390 struct cache_entry *ce = cache[i];
7a51ed66 1391 if (ce->ce_flags & CE_REMOVE)
aa16021e 1392 continue;
e06c43c7 1393 if (!ce_uptodate(ce) && is_racy_timestamp(istate, ce))
407c8eb0 1394 ce_smudge_racily_clean_entry(ce);
7a51ed66 1395 if (ce_write_entry(&c, newfd, ce) < 0)
197ee8c9
LT
1396 return -1;
1397 }
1af1c2b6 1398
bad68ec9 1399 /* Write extension data here */
4aab5b46 1400 if (istate->cache_tree) {
1dffb8fa
PH
1401 struct strbuf sb;
1402
1403 strbuf_init(&sb, 0);
1404 cache_tree_write(&sb, istate->cache_tree);
1405 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1406 || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1407 strbuf_release(&sb);
1408 if (err)
bad68ec9 1409 return -1;
bad68ec9
JH
1410 }
1411 return ce_flush(&c, newfd);
197ee8c9 1412}