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Commit | Line | Data |
---|---|---|
8bc9a0c7 LT |
1 | /* |
2 | * GIT - The information manager from hell | |
3 | * | |
4 | * Copyright (C) Linus Torvalds, 2005 | |
5 | */ | |
e83c5163 LT |
6 | #include "cache.h" |
7 | ||
e83c5163 | 8 | struct cache_entry **active_cache = NULL; |
29e4d363 | 9 | static time_t index_file_timestamp; |
ee267527 | 10 | unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0; |
e83c5163 | 11 | |
415e96c8 JH |
12 | /* |
13 | * This only updates the "non-critical" parts of the directory | |
14 | * cache, ie the parts that aren't tracked by GIT, and only used | |
15 | * to validate the cache. | |
16 | */ | |
17 | void fill_stat_cache_info(struct cache_entry *ce, struct stat *st) | |
18 | { | |
19 | ce->ce_ctime.sec = htonl(st->st_ctime); | |
20 | ce->ce_mtime.sec = htonl(st->st_mtime); | |
2cb45e95 | 21 | #ifdef USE_NSEC |
415e96c8 JH |
22 | ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec); |
23 | ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec); | |
24 | #endif | |
25 | ce->ce_dev = htonl(st->st_dev); | |
26 | ce->ce_ino = htonl(st->st_ino); | |
27 | ce->ce_uid = htonl(st->st_uid); | |
28 | ce->ce_gid = htonl(st->st_gid); | |
29 | ce->ce_size = htonl(st->st_size); | |
5f73076c JH |
30 | |
31 | if (assume_unchanged) | |
32 | ce->ce_flags |= htons(CE_VALID); | |
415e96c8 JH |
33 | } |
34 | ||
29e4d363 JH |
35 | static int ce_compare_data(struct cache_entry *ce, struct stat *st) |
36 | { | |
37 | int match = -1; | |
38 | int fd = open(ce->name, O_RDONLY); | |
39 | ||
40 | if (fd >= 0) { | |
41 | unsigned char sha1[20]; | |
42 | if (!index_fd(sha1, fd, st, 0, NULL)) | |
43 | match = memcmp(sha1, ce->sha1, 20); | |
44 | close(fd); | |
45 | } | |
46 | return match; | |
47 | } | |
48 | ||
49 | static int ce_compare_link(struct cache_entry *ce, unsigned long expected_size) | |
50 | { | |
51 | int match = -1; | |
52 | char *target; | |
53 | void *buffer; | |
54 | unsigned long size; | |
55 | char type[10]; | |
56 | int len; | |
57 | ||
58 | target = xmalloc(expected_size); | |
59 | len = readlink(ce->name, target, expected_size); | |
60 | if (len != expected_size) { | |
61 | free(target); | |
62 | return -1; | |
63 | } | |
64 | buffer = read_sha1_file(ce->sha1, type, &size); | |
65 | if (!buffer) { | |
66 | free(target); | |
67 | return -1; | |
68 | } | |
69 | if (size == expected_size) | |
70 | match = memcmp(buffer, target, size); | |
71 | free(buffer); | |
72 | free(target); | |
73 | return match; | |
74 | } | |
75 | ||
76 | static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st) | |
77 | { | |
78 | switch (st->st_mode & S_IFMT) { | |
79 | case S_IFREG: | |
80 | if (ce_compare_data(ce, st)) | |
81 | return DATA_CHANGED; | |
82 | break; | |
83 | case S_IFLNK: | |
84 | if (ce_compare_link(ce, st->st_size)) | |
85 | return DATA_CHANGED; | |
86 | break; | |
87 | default: | |
88 | return TYPE_CHANGED; | |
89 | } | |
90 | return 0; | |
91 | } | |
92 | ||
407c8eb0 | 93 | static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st) |
734aab75 LT |
94 | { |
95 | unsigned int changed = 0; | |
96 | ||
8ae0a8c5 KS |
97 | switch (ntohl(ce->ce_mode) & S_IFMT) { |
98 | case S_IFREG: | |
99 | changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; | |
3e09cdfd JH |
100 | /* We consider only the owner x bit to be relevant for |
101 | * "mode changes" | |
102 | */ | |
103 | if (trust_executable_bit && | |
104 | (0100 & (ntohl(ce->ce_mode) ^ st->st_mode))) | |
ffbe1add | 105 | changed |= MODE_CHANGED; |
8ae0a8c5 KS |
106 | break; |
107 | case S_IFLNK: | |
108 | changed |= !S_ISLNK(st->st_mode) ? TYPE_CHANGED : 0; | |
109 | break; | |
110 | default: | |
111 | die("internal error: ce_mode is %o", ntohl(ce->ce_mode)); | |
112 | } | |
ccc4feb5 | 113 | if (ce->ce_mtime.sec != htonl(st->st_mtime)) |
734aab75 | 114 | changed |= MTIME_CHANGED; |
ccc4feb5 LT |
115 | if (ce->ce_ctime.sec != htonl(st->st_ctime)) |
116 | changed |= CTIME_CHANGED; | |
117 | ||
2cb45e95 | 118 | #ifdef USE_NSEC |
ccc4feb5 LT |
119 | /* |
120 | * nsec seems unreliable - not all filesystems support it, so | |
121 | * as long as it is in the inode cache you get right nsec | |
122 | * but after it gets flushed, you get zero nsec. | |
123 | */ | |
94dfb7f2 | 124 | if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec)) |
ccc4feb5 | 125 | changed |= MTIME_CHANGED; |
94dfb7f2 | 126 | if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec)) |
734aab75 | 127 | changed |= CTIME_CHANGED; |
ccc4feb5 LT |
128 | #endif |
129 | ||
130 | if (ce->ce_uid != htonl(st->st_uid) || | |
131 | ce->ce_gid != htonl(st->st_gid)) | |
734aab75 | 132 | changed |= OWNER_CHANGED; |
2cb45e95 | 133 | if (ce->ce_ino != htonl(st->st_ino)) |
734aab75 | 134 | changed |= INODE_CHANGED; |
2cb45e95 LT |
135 | |
136 | #ifdef USE_STDEV | |
137 | /* | |
138 | * st_dev breaks on network filesystems where different | |
139 | * clients will have different views of what "device" | |
140 | * the filesystem is on | |
141 | */ | |
142 | if (ce->ce_dev != htonl(st->st_dev)) | |
143 | changed |= INODE_CHANGED; | |
144 | #endif | |
145 | ||
ccc4feb5 | 146 | if (ce->ce_size != htonl(st->st_size)) |
734aab75 | 147 | changed |= DATA_CHANGED; |
b0391890 | 148 | |
407c8eb0 JH |
149 | return changed; |
150 | } | |
151 | ||
5f73076c | 152 | int ce_match_stat(struct cache_entry *ce, struct stat *st, int ignore_valid) |
407c8eb0 | 153 | { |
5f73076c JH |
154 | unsigned int changed; |
155 | ||
156 | /* | |
157 | * If it's marked as always valid in the index, it's | |
158 | * valid whatever the checked-out copy says. | |
159 | */ | |
160 | if (!ignore_valid && (ce->ce_flags & htons(CE_VALID))) | |
161 | return 0; | |
162 | ||
163 | changed = ce_match_stat_basic(ce, st); | |
407c8eb0 | 164 | |
29e4d363 JH |
165 | /* |
166 | * Within 1 second of this sequence: | |
167 | * echo xyzzy >file && git-update-index --add file | |
168 | * running this command: | |
169 | * echo frotz >file | |
170 | * would give a falsely clean cache entry. The mtime and | |
171 | * length match the cache, and other stat fields do not change. | |
172 | * | |
173 | * We could detect this at update-index time (the cache entry | |
174 | * being registered/updated records the same time as "now") | |
175 | * and delay the return from git-update-index, but that would | |
176 | * effectively mean we can make at most one commit per second, | |
177 | * which is not acceptable. Instead, we check cache entries | |
178 | * whose mtime are the same as the index file timestamp more | |
5f73076c | 179 | * carefully than others. |
29e4d363 JH |
180 | */ |
181 | if (!changed && | |
182 | index_file_timestamp && | |
183 | index_file_timestamp <= ntohl(ce->ce_mtime.sec)) | |
184 | changed |= ce_modified_check_fs(ce, st); | |
b0391890 | 185 | |
29e4d363 | 186 | return changed; |
b0391890 JH |
187 | } |
188 | ||
5f73076c | 189 | int ce_modified(struct cache_entry *ce, struct stat *st, int really) |
b0391890 | 190 | { |
29e4d363 | 191 | int changed, changed_fs; |
5f73076c | 192 | changed = ce_match_stat(ce, st, really); |
b0391890 JH |
193 | if (!changed) |
194 | return 0; | |
b0391890 JH |
195 | /* |
196 | * If the mode or type has changed, there's no point in trying | |
197 | * to refresh the entry - it's not going to match | |
198 | */ | |
199 | if (changed & (MODE_CHANGED | TYPE_CHANGED)) | |
200 | return changed; | |
201 | ||
202 | /* Immediately after read-tree or update-index --cacheinfo, | |
203 | * the length field is zero. For other cases the ce_size | |
204 | * should match the SHA1 recorded in the index entry. | |
205 | */ | |
206 | if ((changed & DATA_CHANGED) && ce->ce_size != htonl(0)) | |
207 | return changed; | |
208 | ||
29e4d363 JH |
209 | changed_fs = ce_modified_check_fs(ce, st); |
210 | if (changed_fs) | |
211 | return changed | changed_fs; | |
b0391890 JH |
212 | return 0; |
213 | } | |
214 | ||
958ba6c9 LT |
215 | int base_name_compare(const char *name1, int len1, int mode1, |
216 | const char *name2, int len2, int mode2) | |
217 | { | |
218 | unsigned char c1, c2; | |
219 | int len = len1 < len2 ? len1 : len2; | |
220 | int cmp; | |
221 | ||
222 | cmp = memcmp(name1, name2, len); | |
223 | if (cmp) | |
224 | return cmp; | |
225 | c1 = name1[len]; | |
226 | c2 = name2[len]; | |
227 | if (!c1 && S_ISDIR(mode1)) | |
228 | c1 = '/'; | |
229 | if (!c2 && S_ISDIR(mode2)) | |
230 | c2 = '/'; | |
231 | return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0; | |
232 | } | |
233 | ||
95fd5bf8 | 234 | int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2) |
eb38c22f | 235 | { |
95fd5bf8 LT |
236 | int len1 = flags1 & CE_NAMEMASK; |
237 | int len2 = flags2 & CE_NAMEMASK; | |
eb38c22f LT |
238 | int len = len1 < len2 ? len1 : len2; |
239 | int cmp; | |
240 | ||
241 | cmp = memcmp(name1, name2, len); | |
242 | if (cmp) | |
243 | return cmp; | |
244 | if (len1 < len2) | |
245 | return -1; | |
246 | if (len1 > len2) | |
247 | return 1; | |
5f73076c | 248 | |
7b80be15 JH |
249 | /* Compare stages */ |
250 | flags1 &= CE_STAGEMASK; | |
251 | flags2 &= CE_STAGEMASK; | |
5f73076c | 252 | |
95fd5bf8 LT |
253 | if (flags1 < flags2) |
254 | return -1; | |
255 | if (flags1 > flags2) | |
256 | return 1; | |
eb38c22f LT |
257 | return 0; |
258 | } | |
259 | ||
260 | int cache_name_pos(const char *name, int namelen) | |
261 | { | |
262 | int first, last; | |
263 | ||
264 | first = 0; | |
265 | last = active_nr; | |
266 | while (last > first) { | |
267 | int next = (last + first) >> 1; | |
268 | struct cache_entry *ce = active_cache[next]; | |
972d1bb0 | 269 | int cmp = cache_name_compare(name, namelen, ce->name, ntohs(ce->ce_flags)); |
eb38c22f | 270 | if (!cmp) |
76e7f4ec | 271 | return next; |
eb38c22f LT |
272 | if (cmp < 0) { |
273 | last = next; | |
274 | continue; | |
275 | } | |
276 | first = next+1; | |
277 | } | |
76e7f4ec | 278 | return -first-1; |
eb38c22f LT |
279 | } |
280 | ||
7b937ca3 | 281 | /* Remove entry, return true if there are more entries to go.. */ |
dbbce55b | 282 | int remove_cache_entry_at(int pos) |
7b937ca3 | 283 | { |
ee267527 | 284 | active_cache_changed = 1; |
7b937ca3 LT |
285 | active_nr--; |
286 | if (pos >= active_nr) | |
287 | return 0; | |
288 | memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos) * sizeof(struct cache_entry *)); | |
289 | return 1; | |
290 | } | |
291 | ||
6b5ee137 | 292 | int remove_file_from_cache(const char *path) |
197ee8c9 LT |
293 | { |
294 | int pos = cache_name_pos(path, strlen(path)); | |
c4e3cca1 JH |
295 | if (pos < 0) |
296 | pos = -pos-1; | |
297 | while (pos < active_nr && !strcmp(active_cache[pos]->name, path)) | |
dbbce55b | 298 | remove_cache_entry_at(pos); |
197ee8c9 LT |
299 | return 0; |
300 | } | |
301 | ||
dbbce55b | 302 | int ce_same_name(struct cache_entry *a, struct cache_entry *b) |
7b937ca3 LT |
303 | { |
304 | int len = ce_namelen(a); | |
305 | return ce_namelen(b) == len && !memcmp(a->name, b->name, len); | |
306 | } | |
307 | ||
c0fd1f51 LT |
308 | int ce_path_match(const struct cache_entry *ce, const char **pathspec) |
309 | { | |
310 | const char *match, *name; | |
311 | int len; | |
312 | ||
313 | if (!pathspec) | |
314 | return 1; | |
315 | ||
316 | len = ce_namelen(ce); | |
317 | name = ce->name; | |
318 | while ((match = *pathspec++) != NULL) { | |
319 | int matchlen = strlen(match); | |
320 | if (matchlen > len) | |
321 | continue; | |
322 | if (memcmp(name, match, matchlen)) | |
323 | continue; | |
324 | if (matchlen && name[matchlen-1] == '/') | |
325 | return 1; | |
326 | if (name[matchlen] == '/' || !name[matchlen]) | |
327 | return 1; | |
f332726e LT |
328 | if (!matchlen) |
329 | return 1; | |
c0fd1f51 LT |
330 | } |
331 | return 0; | |
332 | } | |
333 | ||
12676608 LT |
334 | /* |
335 | * Do we have another file that has the beginning components being a | |
336 | * proper superset of the name we're trying to add? | |
0f1e4f04 | 337 | */ |
12676608 | 338 | static int has_file_name(const struct cache_entry *ce, int pos, int ok_to_replace) |
0f1e4f04 | 339 | { |
12676608 LT |
340 | int retval = 0; |
341 | int len = ce_namelen(ce); | |
b155725d | 342 | int stage = ce_stage(ce); |
12676608 | 343 | const char *name = ce->name; |
0f1e4f04 | 344 | |
12676608 LT |
345 | while (pos < active_nr) { |
346 | struct cache_entry *p = active_cache[pos++]; | |
0f1e4f04 | 347 | |
12676608 | 348 | if (len >= ce_namelen(p)) |
0f1e4f04 | 349 | break; |
12676608 LT |
350 | if (memcmp(name, p->name, len)) |
351 | break; | |
b155725d JH |
352 | if (ce_stage(p) != stage) |
353 | continue; | |
12676608 LT |
354 | if (p->name[len] != '/') |
355 | continue; | |
12676608 LT |
356 | retval = -1; |
357 | if (!ok_to_replace) | |
358 | break; | |
359 | remove_cache_entry_at(--pos); | |
0f1e4f04 | 360 | } |
12676608 LT |
361 | return retval; |
362 | } | |
0f1e4f04 | 363 | |
12676608 LT |
364 | /* |
365 | * Do we have another file with a pathname that is a proper | |
366 | * subset of the name we're trying to add? | |
367 | */ | |
368 | static int has_dir_name(const struct cache_entry *ce, int pos, int ok_to_replace) | |
369 | { | |
370 | int retval = 0; | |
b155725d | 371 | int stage = ce_stage(ce); |
12676608 LT |
372 | const char *name = ce->name; |
373 | const char *slash = name + ce_namelen(ce); | |
0f1e4f04 | 374 | |
12676608 LT |
375 | for (;;) { |
376 | int len; | |
0f1e4f04 | 377 | |
12676608 LT |
378 | for (;;) { |
379 | if (*--slash == '/') | |
380 | break; | |
381 | if (slash <= ce->name) | |
382 | return retval; | |
383 | } | |
384 | len = slash - name; | |
0f1e4f04 | 385 | |
b155725d | 386 | pos = cache_name_pos(name, ntohs(create_ce_flags(len, stage))); |
12676608 LT |
387 | if (pos >= 0) { |
388 | retval = -1; | |
389 | if (ok_to_replace) | |
390 | break; | |
dbbce55b | 391 | remove_cache_entry_at(pos); |
12676608 LT |
392 | continue; |
393 | } | |
394 | ||
395 | /* | |
396 | * Trivial optimization: if we find an entry that | |
397 | * already matches the sub-directory, then we know | |
b155725d | 398 | * we're ok, and we can exit. |
12676608 LT |
399 | */ |
400 | pos = -pos-1; | |
b155725d | 401 | while (pos < active_nr) { |
12676608 | 402 | struct cache_entry *p = active_cache[pos]; |
b155725d JH |
403 | if ((ce_namelen(p) <= len) || |
404 | (p->name[len] != '/') || | |
405 | memcmp(p->name, name, len)) | |
406 | break; /* not our subdirectory */ | |
407 | if (ce_stage(p) == stage) | |
408 | /* p is at the same stage as our entry, and | |
409 | * is a subdirectory of what we are looking | |
410 | * at, so we cannot have conflicts at our | |
411 | * level or anything shorter. | |
412 | */ | |
413 | return retval; | |
414 | pos++; | |
192268c1 | 415 | } |
0f1e4f04 | 416 | } |
12676608 LT |
417 | return retval; |
418 | } | |
419 | ||
420 | /* We may be in a situation where we already have path/file and path | |
421 | * is being added, or we already have path and path/file is being | |
422 | * added. Either one would result in a nonsense tree that has path | |
423 | * twice when git-write-tree tries to write it out. Prevent it. | |
424 | * | |
425 | * If ok-to-replace is specified, we remove the conflicting entries | |
426 | * from the cache so the caller should recompute the insert position. | |
427 | * When this happens, we return non-zero. | |
428 | */ | |
429 | static int check_file_directory_conflict(const struct cache_entry *ce, int pos, int ok_to_replace) | |
430 | { | |
431 | /* | |
432 | * We check if the path is a sub-path of a subsequent pathname | |
433 | * first, since removing those will not change the position | |
434 | * in the array | |
435 | */ | |
436 | int retval = has_file_name(ce, pos, ok_to_replace); | |
437 | /* | |
438 | * Then check if the path might have a clashing sub-directory | |
439 | * before it. | |
440 | */ | |
441 | return retval + has_dir_name(ce, pos, ok_to_replace); | |
0f1e4f04 JH |
442 | } |
443 | ||
192268c1 | 444 | int add_cache_entry(struct cache_entry *ce, int option) |
197ee8c9 LT |
445 | { |
446 | int pos; | |
192268c1 JH |
447 | int ok_to_add = option & ADD_CACHE_OK_TO_ADD; |
448 | int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE; | |
b155725d | 449 | int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK; |
5f73076c | 450 | |
972d1bb0 | 451 | pos = cache_name_pos(ce->name, ntohs(ce->ce_flags)); |
197ee8c9 | 452 | |
3e09cdfd | 453 | /* existing match? Just replace it. */ |
76e7f4ec | 454 | if (pos >= 0) { |
ee267527 | 455 | active_cache_changed = 1; |
76e7f4ec | 456 | active_cache[pos] = ce; |
197ee8c9 LT |
457 | return 0; |
458 | } | |
76e7f4ec | 459 | pos = -pos-1; |
197ee8c9 | 460 | |
7b937ca3 LT |
461 | /* |
462 | * Inserting a merged entry ("stage 0") into the index | |
463 | * will always replace all non-merged entries.. | |
464 | */ | |
465 | if (pos < active_nr && ce_stage(ce) == 0) { | |
dbbce55b | 466 | while (ce_same_name(active_cache[pos], ce)) { |
7b937ca3 | 467 | ok_to_add = 1; |
dbbce55b | 468 | if (!remove_cache_entry_at(pos)) |
7b937ca3 LT |
469 | break; |
470 | } | |
471 | } | |
472 | ||
121481ab LT |
473 | if (!ok_to_add) |
474 | return -1; | |
475 | ||
3e09cdfd JH |
476 | if (!skip_df_check && |
477 | check_file_directory_conflict(ce, pos, ok_to_replace)) { | |
192268c1 JH |
478 | if (!ok_to_replace) |
479 | return -1; | |
972d1bb0 | 480 | pos = cache_name_pos(ce->name, ntohs(ce->ce_flags)); |
192268c1 JH |
481 | pos = -pos-1; |
482 | } | |
0f1e4f04 | 483 | |
197ee8c9 LT |
484 | /* Make sure the array is big enough .. */ |
485 | if (active_nr == active_alloc) { | |
486 | active_alloc = alloc_nr(active_alloc); | |
812666c8 | 487 | active_cache = xrealloc(active_cache, active_alloc * sizeof(struct cache_entry *)); |
197ee8c9 LT |
488 | } |
489 | ||
490 | /* Add it in.. */ | |
491 | active_nr++; | |
492 | if (active_nr > pos) | |
493 | memmove(active_cache + pos + 1, active_cache + pos, (active_nr - pos - 1) * sizeof(ce)); | |
494 | active_cache[pos] = ce; | |
ee267527 | 495 | active_cache_changed = 1; |
197ee8c9 LT |
496 | return 0; |
497 | } | |
498 | ||
e83c5163 LT |
499 | static int verify_hdr(struct cache_header *hdr, unsigned long size) |
500 | { | |
501 | SHA_CTX c; | |
502 | unsigned char sha1[20]; | |
503 | ||
ccc4feb5 | 504 | if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) |
e83c5163 | 505 | return error("bad signature"); |
ca9be054 LT |
506 | if (hdr->hdr_version != htonl(2)) |
507 | return error("bad index version"); | |
e83c5163 | 508 | SHA1_Init(&c); |
ca9be054 | 509 | SHA1_Update(&c, hdr, size - 20); |
e83c5163 | 510 | SHA1_Final(sha1, &c); |
ca9be054 LT |
511 | if (memcmp(sha1, (void *)hdr + size - 20, 20)) |
512 | return error("bad index file sha1 signature"); | |
e83c5163 LT |
513 | return 0; |
514 | } | |
515 | ||
516 | int read_cache(void) | |
517 | { | |
518 | int fd, i; | |
519 | struct stat st; | |
520 | unsigned long size, offset; | |
521 | void *map; | |
522 | struct cache_header *hdr; | |
523 | ||
524 | errno = EBUSY; | |
525 | if (active_cache) | |
5d1a5c02 LT |
526 | return active_nr; |
527 | ||
e83c5163 | 528 | errno = ENOENT; |
29e4d363 | 529 | index_file_timestamp = 0; |
bb233d69 | 530 | fd = open(get_index_file(), O_RDONLY); |
5d1a5c02 LT |
531 | if (fd < 0) { |
532 | if (errno == ENOENT) | |
533 | return 0; | |
534 | die("index file open failed (%s)", strerror(errno)); | |
535 | } | |
e83c5163 | 536 | |
19b2860c | 537 | size = 0; // avoid gcc warning |
e35f9824 | 538 | map = MAP_FAILED; |
e83c5163 | 539 | if (!fstat(fd, &st)) { |
e83c5163 LT |
540 | size = st.st_size; |
541 | errno = EINVAL; | |
ca9be054 | 542 | if (size >= sizeof(struct cache_header) + 20) |
520fc241 | 543 | map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); |
e83c5163 LT |
544 | } |
545 | close(fd); | |
e35f9824 | 546 | if (map == MAP_FAILED) |
5d1a5c02 | 547 | die("index file mmap failed (%s)", strerror(errno)); |
e83c5163 LT |
548 | |
549 | hdr = map; | |
550 | if (verify_hdr(hdr, size) < 0) | |
551 | goto unmap; | |
552 | ||
ccc4feb5 | 553 | active_nr = ntohl(hdr->hdr_entries); |
e83c5163 LT |
554 | active_alloc = alloc_nr(active_nr); |
555 | active_cache = calloc(active_alloc, sizeof(struct cache_entry *)); | |
556 | ||
557 | offset = sizeof(*hdr); | |
ccc4feb5 | 558 | for (i = 0; i < active_nr; i++) { |
e83c5163 LT |
559 | struct cache_entry *ce = map + offset; |
560 | offset = offset + ce_size(ce); | |
561 | active_cache[i] = ce; | |
562 | } | |
29e4d363 | 563 | index_file_timestamp = st.st_mtime; |
e83c5163 LT |
564 | return active_nr; |
565 | ||
566 | unmap: | |
567 | munmap(map, size); | |
568 | errno = EINVAL; | |
5d1a5c02 | 569 | die("index file corrupt"); |
e83c5163 LT |
570 | } |
571 | ||
4990aadc | 572 | #define WRITE_BUFFER_SIZE 8192 |
bf0f910d | 573 | static unsigned char write_buffer[WRITE_BUFFER_SIZE]; |
4990aadc LT |
574 | static unsigned long write_buffer_len; |
575 | ||
ca9be054 | 576 | static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len) |
4990aadc LT |
577 | { |
578 | while (len) { | |
579 | unsigned int buffered = write_buffer_len; | |
580 | unsigned int partial = WRITE_BUFFER_SIZE - buffered; | |
581 | if (partial > len) | |
582 | partial = len; | |
583 | memcpy(write_buffer + buffered, data, partial); | |
584 | buffered += partial; | |
585 | if (buffered == WRITE_BUFFER_SIZE) { | |
ca9be054 | 586 | SHA1_Update(context, write_buffer, WRITE_BUFFER_SIZE); |
4990aadc LT |
587 | if (write(fd, write_buffer, WRITE_BUFFER_SIZE) != WRITE_BUFFER_SIZE) |
588 | return -1; | |
589 | buffered = 0; | |
590 | } | |
591 | write_buffer_len = buffered; | |
592 | len -= partial; | |
593 | data += partial; | |
594 | } | |
595 | return 0; | |
596 | } | |
597 | ||
ca9be054 | 598 | static int ce_flush(SHA_CTX *context, int fd) |
4990aadc LT |
599 | { |
600 | unsigned int left = write_buffer_len; | |
ca9be054 | 601 | |
4990aadc LT |
602 | if (left) { |
603 | write_buffer_len = 0; | |
ca9be054 | 604 | SHA1_Update(context, write_buffer, left); |
4990aadc | 605 | } |
ca9be054 | 606 | |
2c865d9a QH |
607 | /* Flush first if not enough space for SHA1 signature */ |
608 | if (left + 20 > WRITE_BUFFER_SIZE) { | |
609 | if (write(fd, write_buffer, left) != left) | |
610 | return -1; | |
611 | left = 0; | |
612 | } | |
613 | ||
ca9be054 LT |
614 | /* Append the SHA1 signature at the end */ |
615 | SHA1_Final(write_buffer + left, context); | |
616 | left += 20; | |
617 | if (write(fd, write_buffer, left) != left) | |
618 | return -1; | |
4990aadc LT |
619 | return 0; |
620 | } | |
621 | ||
407c8eb0 JH |
622 | static void ce_smudge_racily_clean_entry(struct cache_entry *ce) |
623 | { | |
624 | /* | |
625 | * The only thing we care about in this function is to smudge the | |
626 | * falsely clean entry due to touch-update-touch race, so we leave | |
627 | * everything else as they are. We are called for entries whose | |
628 | * ce_mtime match the index file mtime. | |
629 | */ | |
630 | struct stat st; | |
631 | ||
632 | if (lstat(ce->name, &st) < 0) | |
633 | return; | |
634 | if (ce_match_stat_basic(ce, &st)) | |
635 | return; | |
636 | if (ce_modified_check_fs(ce, &st)) { | |
4b3511b0 JH |
637 | /* This is "racily clean"; smudge it. Note that this |
638 | * is a tricky code. At first glance, it may appear | |
639 | * that it can break with this sequence: | |
640 | * | |
641 | * $ echo xyzzy >frotz | |
642 | * $ git-update-index --add frotz | |
643 | * $ : >frotz | |
644 | * $ sleep 3 | |
645 | * $ echo filfre >nitfol | |
646 | * $ git-update-index --add nitfol | |
647 | * | |
648 | * but it does not. Whe the second update-index runs, | |
649 | * it notices that the entry "frotz" has the same timestamp | |
650 | * as index, and if we were to smudge it by resetting its | |
651 | * size to zero here, then the object name recorded | |
652 | * in index is the 6-byte file but the cached stat information | |
653 | * becomes zero --- which would then match what we would | |
654 | * obtain from the filesystem next time we stat("frotz"). | |
655 | * | |
656 | * However, the second update-index, before calling | |
657 | * this function, notices that the cached size is 6 | |
658 | * bytes and what is on the filesystem is an empty | |
659 | * file, and never calls us, so the cached size information | |
660 | * for "frotz" stays 6 which does not match the filesystem. | |
661 | */ | |
407c8eb0 JH |
662 | ce->ce_size = htonl(0); |
663 | } | |
664 | } | |
665 | ||
197ee8c9 LT |
666 | int write_cache(int newfd, struct cache_entry **cache, int entries) |
667 | { | |
668 | SHA_CTX c; | |
669 | struct cache_header hdr; | |
025a0709 JH |
670 | int i, removed; |
671 | ||
672 | for (i = removed = 0; i < entries; i++) | |
673 | if (!cache[i]->ce_mode) | |
674 | removed++; | |
197ee8c9 | 675 | |
ccc4feb5 | 676 | hdr.hdr_signature = htonl(CACHE_SIGNATURE); |
ca9be054 | 677 | hdr.hdr_version = htonl(2); |
025a0709 | 678 | hdr.hdr_entries = htonl(entries - removed); |
197ee8c9 LT |
679 | |
680 | SHA1_Init(&c); | |
ca9be054 | 681 | if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0) |
197ee8c9 LT |
682 | return -1; |
683 | ||
684 | for (i = 0; i < entries; i++) { | |
685 | struct cache_entry *ce = cache[i]; | |
aa16021e LT |
686 | if (!ce->ce_mode) |
687 | continue; | |
407c8eb0 JH |
688 | if (index_file_timestamp && |
689 | index_file_timestamp <= ntohl(ce->ce_mtime.sec)) | |
690 | ce_smudge_racily_clean_entry(ce); | |
ca9be054 | 691 | if (ce_write(&c, newfd, ce, ce_size(ce)) < 0) |
197ee8c9 LT |
692 | return -1; |
693 | } | |
ca9be054 | 694 | return ce_flush(&c, newfd); |
197ee8c9 | 695 | } |