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Commit | Line | Data |
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8bc9a0c7 LT |
1 | /* |
2 | * GIT - The information manager from hell | |
3 | * | |
4 | * Copyright (C) Linus Torvalds, 2005 | |
5 | */ | |
e83c5163 | 6 | #include "cache.h" |
bad68ec9 JH |
7 | #include "cache-tree.h" |
8 | ||
9 | /* Index extensions. | |
10 | * | |
11 | * The first letter should be 'A'..'Z' for extensions that are not | |
12 | * necessary for a correct operation (i.e. optimization data). | |
13 | * When new extensions are added that _needs_ to be understood in | |
14 | * order to correctly interpret the index file, pick character that | |
15 | * is outside the range, to cause the reader to abort. | |
16 | */ | |
17 | ||
18 | #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) ) | |
19 | #define CACHE_EXT_TREE 0x54524545 /* "TREE" */ | |
e83c5163 | 20 | |
e83c5163 | 21 | struct cache_entry **active_cache = NULL; |
29e4d363 | 22 | static time_t index_file_timestamp; |
ee267527 | 23 | unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0; |
e83c5163 | 24 | |
bad68ec9 JH |
25 | struct cache_tree *active_cache_tree = NULL; |
26 | ||
415e96c8 JH |
27 | /* |
28 | * This only updates the "non-critical" parts of the directory | |
29 | * cache, ie the parts that aren't tracked by GIT, and only used | |
30 | * to validate the cache. | |
31 | */ | |
32 | void fill_stat_cache_info(struct cache_entry *ce, struct stat *st) | |
33 | { | |
34 | ce->ce_ctime.sec = htonl(st->st_ctime); | |
35 | ce->ce_mtime.sec = htonl(st->st_mtime); | |
2cb45e95 | 36 | #ifdef USE_NSEC |
415e96c8 JH |
37 | ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec); |
38 | ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec); | |
39 | #endif | |
40 | ce->ce_dev = htonl(st->st_dev); | |
41 | ce->ce_ino = htonl(st->st_ino); | |
42 | ce->ce_uid = htonl(st->st_uid); | |
43 | ce->ce_gid = htonl(st->st_gid); | |
44 | ce->ce_size = htonl(st->st_size); | |
5f73076c JH |
45 | |
46 | if (assume_unchanged) | |
47 | ce->ce_flags |= htons(CE_VALID); | |
415e96c8 JH |
48 | } |
49 | ||
29e4d363 JH |
50 | static int ce_compare_data(struct cache_entry *ce, struct stat *st) |
51 | { | |
52 | int match = -1; | |
53 | int fd = open(ce->name, O_RDONLY); | |
54 | ||
55 | if (fd >= 0) { | |
56 | unsigned char sha1[20]; | |
57 | if (!index_fd(sha1, fd, st, 0, NULL)) | |
58 | match = memcmp(sha1, ce->sha1, 20); | |
59 | close(fd); | |
60 | } | |
61 | return match; | |
62 | } | |
63 | ||
64 | static int ce_compare_link(struct cache_entry *ce, unsigned long expected_size) | |
65 | { | |
66 | int match = -1; | |
67 | char *target; | |
68 | void *buffer; | |
69 | unsigned long size; | |
70 | char type[10]; | |
71 | int len; | |
72 | ||
73 | target = xmalloc(expected_size); | |
74 | len = readlink(ce->name, target, expected_size); | |
75 | if (len != expected_size) { | |
76 | free(target); | |
77 | return -1; | |
78 | } | |
79 | buffer = read_sha1_file(ce->sha1, type, &size); | |
80 | if (!buffer) { | |
81 | free(target); | |
82 | return -1; | |
83 | } | |
84 | if (size == expected_size) | |
85 | match = memcmp(buffer, target, size); | |
86 | free(buffer); | |
87 | free(target); | |
88 | return match; | |
89 | } | |
90 | ||
91 | static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st) | |
92 | { | |
93 | switch (st->st_mode & S_IFMT) { | |
94 | case S_IFREG: | |
95 | if (ce_compare_data(ce, st)) | |
96 | return DATA_CHANGED; | |
97 | break; | |
98 | case S_IFLNK: | |
99 | if (ce_compare_link(ce, st->st_size)) | |
100 | return DATA_CHANGED; | |
101 | break; | |
102 | default: | |
103 | return TYPE_CHANGED; | |
104 | } | |
105 | return 0; | |
106 | } | |
107 | ||
407c8eb0 | 108 | static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st) |
734aab75 LT |
109 | { |
110 | unsigned int changed = 0; | |
111 | ||
8ae0a8c5 KS |
112 | switch (ntohl(ce->ce_mode) & S_IFMT) { |
113 | case S_IFREG: | |
114 | changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; | |
3e09cdfd JH |
115 | /* We consider only the owner x bit to be relevant for |
116 | * "mode changes" | |
117 | */ | |
118 | if (trust_executable_bit && | |
119 | (0100 & (ntohl(ce->ce_mode) ^ st->st_mode))) | |
ffbe1add | 120 | changed |= MODE_CHANGED; |
8ae0a8c5 KS |
121 | break; |
122 | case S_IFLNK: | |
123 | changed |= !S_ISLNK(st->st_mode) ? TYPE_CHANGED : 0; | |
124 | break; | |
125 | default: | |
126 | die("internal error: ce_mode is %o", ntohl(ce->ce_mode)); | |
127 | } | |
ccc4feb5 | 128 | if (ce->ce_mtime.sec != htonl(st->st_mtime)) |
734aab75 | 129 | changed |= MTIME_CHANGED; |
ccc4feb5 LT |
130 | if (ce->ce_ctime.sec != htonl(st->st_ctime)) |
131 | changed |= CTIME_CHANGED; | |
132 | ||
2cb45e95 | 133 | #ifdef USE_NSEC |
ccc4feb5 LT |
134 | /* |
135 | * nsec seems unreliable - not all filesystems support it, so | |
136 | * as long as it is in the inode cache you get right nsec | |
137 | * but after it gets flushed, you get zero nsec. | |
138 | */ | |
94dfb7f2 | 139 | if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec)) |
ccc4feb5 | 140 | changed |= MTIME_CHANGED; |
94dfb7f2 | 141 | if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec)) |
734aab75 | 142 | changed |= CTIME_CHANGED; |
ccc4feb5 LT |
143 | #endif |
144 | ||
145 | if (ce->ce_uid != htonl(st->st_uid) || | |
146 | ce->ce_gid != htonl(st->st_gid)) | |
734aab75 | 147 | changed |= OWNER_CHANGED; |
2cb45e95 | 148 | if (ce->ce_ino != htonl(st->st_ino)) |
734aab75 | 149 | changed |= INODE_CHANGED; |
2cb45e95 LT |
150 | |
151 | #ifdef USE_STDEV | |
152 | /* | |
153 | * st_dev breaks on network filesystems where different | |
154 | * clients will have different views of what "device" | |
155 | * the filesystem is on | |
156 | */ | |
157 | if (ce->ce_dev != htonl(st->st_dev)) | |
158 | changed |= INODE_CHANGED; | |
159 | #endif | |
160 | ||
ccc4feb5 | 161 | if (ce->ce_size != htonl(st->st_size)) |
734aab75 | 162 | changed |= DATA_CHANGED; |
b0391890 | 163 | |
407c8eb0 JH |
164 | return changed; |
165 | } | |
166 | ||
5f73076c | 167 | int ce_match_stat(struct cache_entry *ce, struct stat *st, int ignore_valid) |
407c8eb0 | 168 | { |
5f73076c JH |
169 | unsigned int changed; |
170 | ||
171 | /* | |
172 | * If it's marked as always valid in the index, it's | |
173 | * valid whatever the checked-out copy says. | |
174 | */ | |
175 | if (!ignore_valid && (ce->ce_flags & htons(CE_VALID))) | |
176 | return 0; | |
177 | ||
178 | changed = ce_match_stat_basic(ce, st); | |
407c8eb0 | 179 | |
29e4d363 JH |
180 | /* |
181 | * Within 1 second of this sequence: | |
182 | * echo xyzzy >file && git-update-index --add file | |
183 | * running this command: | |
184 | * echo frotz >file | |
185 | * would give a falsely clean cache entry. The mtime and | |
186 | * length match the cache, and other stat fields do not change. | |
187 | * | |
188 | * We could detect this at update-index time (the cache entry | |
189 | * being registered/updated records the same time as "now") | |
190 | * and delay the return from git-update-index, but that would | |
191 | * effectively mean we can make at most one commit per second, | |
192 | * which is not acceptable. Instead, we check cache entries | |
193 | * whose mtime are the same as the index file timestamp more | |
5f73076c | 194 | * carefully than others. |
29e4d363 JH |
195 | */ |
196 | if (!changed && | |
197 | index_file_timestamp && | |
198 | index_file_timestamp <= ntohl(ce->ce_mtime.sec)) | |
199 | changed |= ce_modified_check_fs(ce, st); | |
b0391890 | 200 | |
29e4d363 | 201 | return changed; |
b0391890 JH |
202 | } |
203 | ||
5f73076c | 204 | int ce_modified(struct cache_entry *ce, struct stat *st, int really) |
b0391890 | 205 | { |
29e4d363 | 206 | int changed, changed_fs; |
5f73076c | 207 | changed = ce_match_stat(ce, st, really); |
b0391890 JH |
208 | if (!changed) |
209 | return 0; | |
b0391890 JH |
210 | /* |
211 | * If the mode or type has changed, there's no point in trying | |
212 | * to refresh the entry - it's not going to match | |
213 | */ | |
214 | if (changed & (MODE_CHANGED | TYPE_CHANGED)) | |
215 | return changed; | |
216 | ||
217 | /* Immediately after read-tree or update-index --cacheinfo, | |
218 | * the length field is zero. For other cases the ce_size | |
219 | * should match the SHA1 recorded in the index entry. | |
220 | */ | |
221 | if ((changed & DATA_CHANGED) && ce->ce_size != htonl(0)) | |
222 | return changed; | |
223 | ||
29e4d363 JH |
224 | changed_fs = ce_modified_check_fs(ce, st); |
225 | if (changed_fs) | |
226 | return changed | changed_fs; | |
b0391890 JH |
227 | return 0; |
228 | } | |
229 | ||
958ba6c9 LT |
230 | int base_name_compare(const char *name1, int len1, int mode1, |
231 | const char *name2, int len2, int mode2) | |
232 | { | |
233 | unsigned char c1, c2; | |
234 | int len = len1 < len2 ? len1 : len2; | |
235 | int cmp; | |
236 | ||
237 | cmp = memcmp(name1, name2, len); | |
238 | if (cmp) | |
239 | return cmp; | |
240 | c1 = name1[len]; | |
241 | c2 = name2[len]; | |
242 | if (!c1 && S_ISDIR(mode1)) | |
243 | c1 = '/'; | |
244 | if (!c2 && S_ISDIR(mode2)) | |
245 | c2 = '/'; | |
246 | return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0; | |
247 | } | |
248 | ||
95fd5bf8 | 249 | int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2) |
eb38c22f | 250 | { |
95fd5bf8 LT |
251 | int len1 = flags1 & CE_NAMEMASK; |
252 | int len2 = flags2 & CE_NAMEMASK; | |
eb38c22f LT |
253 | int len = len1 < len2 ? len1 : len2; |
254 | int cmp; | |
255 | ||
256 | cmp = memcmp(name1, name2, len); | |
257 | if (cmp) | |
258 | return cmp; | |
259 | if (len1 < len2) | |
260 | return -1; | |
261 | if (len1 > len2) | |
262 | return 1; | |
5f73076c | 263 | |
7b80be15 JH |
264 | /* Compare stages */ |
265 | flags1 &= CE_STAGEMASK; | |
266 | flags2 &= CE_STAGEMASK; | |
5f73076c | 267 | |
95fd5bf8 LT |
268 | if (flags1 < flags2) |
269 | return -1; | |
270 | if (flags1 > flags2) | |
271 | return 1; | |
eb38c22f LT |
272 | return 0; |
273 | } | |
274 | ||
275 | int cache_name_pos(const char *name, int namelen) | |
276 | { | |
277 | int first, last; | |
278 | ||
279 | first = 0; | |
280 | last = active_nr; | |
281 | while (last > first) { | |
282 | int next = (last + first) >> 1; | |
283 | struct cache_entry *ce = active_cache[next]; | |
972d1bb0 | 284 | int cmp = cache_name_compare(name, namelen, ce->name, ntohs(ce->ce_flags)); |
eb38c22f | 285 | if (!cmp) |
76e7f4ec | 286 | return next; |
eb38c22f LT |
287 | if (cmp < 0) { |
288 | last = next; | |
289 | continue; | |
290 | } | |
291 | first = next+1; | |
292 | } | |
76e7f4ec | 293 | return -first-1; |
eb38c22f LT |
294 | } |
295 | ||
7b937ca3 | 296 | /* Remove entry, return true if there are more entries to go.. */ |
dbbce55b | 297 | int remove_cache_entry_at(int pos) |
7b937ca3 | 298 | { |
ee267527 | 299 | active_cache_changed = 1; |
7b937ca3 LT |
300 | active_nr--; |
301 | if (pos >= active_nr) | |
302 | return 0; | |
303 | memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos) * sizeof(struct cache_entry *)); | |
304 | return 1; | |
305 | } | |
306 | ||
6b5ee137 | 307 | int remove_file_from_cache(const char *path) |
197ee8c9 LT |
308 | { |
309 | int pos = cache_name_pos(path, strlen(path)); | |
c4e3cca1 JH |
310 | if (pos < 0) |
311 | pos = -pos-1; | |
312 | while (pos < active_nr && !strcmp(active_cache[pos]->name, path)) | |
dbbce55b | 313 | remove_cache_entry_at(pos); |
197ee8c9 LT |
314 | return 0; |
315 | } | |
316 | ||
dbbce55b | 317 | int ce_same_name(struct cache_entry *a, struct cache_entry *b) |
7b937ca3 LT |
318 | { |
319 | int len = ce_namelen(a); | |
320 | return ce_namelen(b) == len && !memcmp(a->name, b->name, len); | |
321 | } | |
322 | ||
c0fd1f51 LT |
323 | int ce_path_match(const struct cache_entry *ce, const char **pathspec) |
324 | { | |
325 | const char *match, *name; | |
326 | int len; | |
327 | ||
328 | if (!pathspec) | |
329 | return 1; | |
330 | ||
331 | len = ce_namelen(ce); | |
332 | name = ce->name; | |
333 | while ((match = *pathspec++) != NULL) { | |
334 | int matchlen = strlen(match); | |
335 | if (matchlen > len) | |
336 | continue; | |
337 | if (memcmp(name, match, matchlen)) | |
338 | continue; | |
339 | if (matchlen && name[matchlen-1] == '/') | |
340 | return 1; | |
341 | if (name[matchlen] == '/' || !name[matchlen]) | |
342 | return 1; | |
f332726e LT |
343 | if (!matchlen) |
344 | return 1; | |
c0fd1f51 LT |
345 | } |
346 | return 0; | |
347 | } | |
348 | ||
8dcf39c4 LT |
349 | /* |
350 | * We fundamentally don't like some paths: we don't want | |
351 | * dot or dot-dot anywhere, and for obvious reasons don't | |
352 | * want to recurse into ".git" either. | |
353 | * | |
354 | * Also, we don't want double slashes or slashes at the | |
355 | * end that can make pathnames ambiguous. | |
356 | */ | |
357 | static int verify_dotfile(const char *rest) | |
358 | { | |
359 | /* | |
360 | * The first character was '.', but that | |
361 | * has already been discarded, we now test | |
362 | * the rest. | |
363 | */ | |
364 | switch (*rest) { | |
365 | /* "." is not allowed */ | |
366 | case '\0': case '/': | |
367 | return 0; | |
368 | ||
369 | /* | |
370 | * ".git" followed by NUL or slash is bad. This | |
371 | * shares the path end test with the ".." case. | |
372 | */ | |
373 | case 'g': | |
374 | if (rest[1] != 'i') | |
375 | break; | |
376 | if (rest[2] != 't') | |
377 | break; | |
378 | rest += 2; | |
379 | /* fallthrough */ | |
380 | case '.': | |
381 | if (rest[1] == '\0' || rest[1] == '/') | |
382 | return 0; | |
383 | } | |
384 | return 1; | |
385 | } | |
386 | ||
387 | int verify_path(const char *path) | |
388 | { | |
389 | char c; | |
390 | ||
391 | goto inside; | |
392 | for (;;) { | |
393 | if (!c) | |
394 | return 1; | |
395 | if (c == '/') { | |
396 | inside: | |
397 | c = *path++; | |
398 | switch (c) { | |
399 | default: | |
400 | continue; | |
401 | case '/': case '\0': | |
402 | break; | |
403 | case '.': | |
404 | if (verify_dotfile(path)) | |
405 | continue; | |
406 | } | |
407 | return 0; | |
408 | } | |
409 | c = *path++; | |
410 | } | |
411 | } | |
412 | ||
12676608 LT |
413 | /* |
414 | * Do we have another file that has the beginning components being a | |
415 | * proper superset of the name we're trying to add? | |
0f1e4f04 | 416 | */ |
12676608 | 417 | static int has_file_name(const struct cache_entry *ce, int pos, int ok_to_replace) |
0f1e4f04 | 418 | { |
12676608 LT |
419 | int retval = 0; |
420 | int len = ce_namelen(ce); | |
b155725d | 421 | int stage = ce_stage(ce); |
12676608 | 422 | const char *name = ce->name; |
0f1e4f04 | 423 | |
12676608 LT |
424 | while (pos < active_nr) { |
425 | struct cache_entry *p = active_cache[pos++]; | |
0f1e4f04 | 426 | |
12676608 | 427 | if (len >= ce_namelen(p)) |
0f1e4f04 | 428 | break; |
12676608 LT |
429 | if (memcmp(name, p->name, len)) |
430 | break; | |
b155725d JH |
431 | if (ce_stage(p) != stage) |
432 | continue; | |
12676608 LT |
433 | if (p->name[len] != '/') |
434 | continue; | |
12676608 LT |
435 | retval = -1; |
436 | if (!ok_to_replace) | |
437 | break; | |
438 | remove_cache_entry_at(--pos); | |
0f1e4f04 | 439 | } |
12676608 LT |
440 | return retval; |
441 | } | |
0f1e4f04 | 442 | |
12676608 LT |
443 | /* |
444 | * Do we have another file with a pathname that is a proper | |
445 | * subset of the name we're trying to add? | |
446 | */ | |
447 | static int has_dir_name(const struct cache_entry *ce, int pos, int ok_to_replace) | |
448 | { | |
449 | int retval = 0; | |
b155725d | 450 | int stage = ce_stage(ce); |
12676608 LT |
451 | const char *name = ce->name; |
452 | const char *slash = name + ce_namelen(ce); | |
0f1e4f04 | 453 | |
12676608 LT |
454 | for (;;) { |
455 | int len; | |
0f1e4f04 | 456 | |
12676608 LT |
457 | for (;;) { |
458 | if (*--slash == '/') | |
459 | break; | |
460 | if (slash <= ce->name) | |
461 | return retval; | |
462 | } | |
463 | len = slash - name; | |
0f1e4f04 | 464 | |
b155725d | 465 | pos = cache_name_pos(name, ntohs(create_ce_flags(len, stage))); |
12676608 LT |
466 | if (pos >= 0) { |
467 | retval = -1; | |
468 | if (ok_to_replace) | |
469 | break; | |
dbbce55b | 470 | remove_cache_entry_at(pos); |
12676608 LT |
471 | continue; |
472 | } | |
473 | ||
474 | /* | |
475 | * Trivial optimization: if we find an entry that | |
476 | * already matches the sub-directory, then we know | |
b155725d | 477 | * we're ok, and we can exit. |
12676608 LT |
478 | */ |
479 | pos = -pos-1; | |
b155725d | 480 | while (pos < active_nr) { |
12676608 | 481 | struct cache_entry *p = active_cache[pos]; |
b155725d JH |
482 | if ((ce_namelen(p) <= len) || |
483 | (p->name[len] != '/') || | |
484 | memcmp(p->name, name, len)) | |
485 | break; /* not our subdirectory */ | |
486 | if (ce_stage(p) == stage) | |
487 | /* p is at the same stage as our entry, and | |
488 | * is a subdirectory of what we are looking | |
489 | * at, so we cannot have conflicts at our | |
490 | * level or anything shorter. | |
491 | */ | |
492 | return retval; | |
493 | pos++; | |
192268c1 | 494 | } |
0f1e4f04 | 495 | } |
12676608 LT |
496 | return retval; |
497 | } | |
498 | ||
499 | /* We may be in a situation where we already have path/file and path | |
500 | * is being added, or we already have path and path/file is being | |
501 | * added. Either one would result in a nonsense tree that has path | |
502 | * twice when git-write-tree tries to write it out. Prevent it. | |
503 | * | |
504 | * If ok-to-replace is specified, we remove the conflicting entries | |
505 | * from the cache so the caller should recompute the insert position. | |
506 | * When this happens, we return non-zero. | |
507 | */ | |
508 | static int check_file_directory_conflict(const struct cache_entry *ce, int pos, int ok_to_replace) | |
509 | { | |
510 | /* | |
511 | * We check if the path is a sub-path of a subsequent pathname | |
512 | * first, since removing those will not change the position | |
513 | * in the array | |
514 | */ | |
515 | int retval = has_file_name(ce, pos, ok_to_replace); | |
516 | /* | |
517 | * Then check if the path might have a clashing sub-directory | |
518 | * before it. | |
519 | */ | |
520 | return retval + has_dir_name(ce, pos, ok_to_replace); | |
0f1e4f04 JH |
521 | } |
522 | ||
192268c1 | 523 | int add_cache_entry(struct cache_entry *ce, int option) |
197ee8c9 LT |
524 | { |
525 | int pos; | |
192268c1 JH |
526 | int ok_to_add = option & ADD_CACHE_OK_TO_ADD; |
527 | int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE; | |
b155725d | 528 | int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK; |
5f73076c | 529 | |
972d1bb0 | 530 | pos = cache_name_pos(ce->name, ntohs(ce->ce_flags)); |
197ee8c9 | 531 | |
3e09cdfd | 532 | /* existing match? Just replace it. */ |
76e7f4ec | 533 | if (pos >= 0) { |
ee267527 | 534 | active_cache_changed = 1; |
76e7f4ec | 535 | active_cache[pos] = ce; |
197ee8c9 LT |
536 | return 0; |
537 | } | |
76e7f4ec | 538 | pos = -pos-1; |
197ee8c9 | 539 | |
7b937ca3 LT |
540 | /* |
541 | * Inserting a merged entry ("stage 0") into the index | |
542 | * will always replace all non-merged entries.. | |
543 | */ | |
544 | if (pos < active_nr && ce_stage(ce) == 0) { | |
dbbce55b | 545 | while (ce_same_name(active_cache[pos], ce)) { |
7b937ca3 | 546 | ok_to_add = 1; |
dbbce55b | 547 | if (!remove_cache_entry_at(pos)) |
7b937ca3 LT |
548 | break; |
549 | } | |
550 | } | |
551 | ||
121481ab LT |
552 | if (!ok_to_add) |
553 | return -1; | |
8dcf39c4 LT |
554 | if (!verify_path(ce->name)) |
555 | return -1; | |
121481ab | 556 | |
3e09cdfd JH |
557 | if (!skip_df_check && |
558 | check_file_directory_conflict(ce, pos, ok_to_replace)) { | |
192268c1 JH |
559 | if (!ok_to_replace) |
560 | return -1; | |
972d1bb0 | 561 | pos = cache_name_pos(ce->name, ntohs(ce->ce_flags)); |
192268c1 JH |
562 | pos = -pos-1; |
563 | } | |
0f1e4f04 | 564 | |
197ee8c9 LT |
565 | /* Make sure the array is big enough .. */ |
566 | if (active_nr == active_alloc) { | |
567 | active_alloc = alloc_nr(active_alloc); | |
812666c8 | 568 | active_cache = xrealloc(active_cache, active_alloc * sizeof(struct cache_entry *)); |
197ee8c9 LT |
569 | } |
570 | ||
571 | /* Add it in.. */ | |
572 | active_nr++; | |
573 | if (active_nr > pos) | |
574 | memmove(active_cache + pos + 1, active_cache + pos, (active_nr - pos - 1) * sizeof(ce)); | |
575 | active_cache[pos] = ce; | |
ee267527 | 576 | active_cache_changed = 1; |
197ee8c9 LT |
577 | return 0; |
578 | } | |
579 | ||
405e5b2f LT |
580 | /* Three functions to allow overloaded pointer return; see linux/err.h */ |
581 | static inline void *ERR_PTR(long error) | |
582 | { | |
583 | return (void *) error; | |
584 | } | |
585 | ||
586 | static inline long PTR_ERR(const void *ptr) | |
587 | { | |
588 | return (long) ptr; | |
589 | } | |
590 | ||
591 | static inline long IS_ERR(const void *ptr) | |
592 | { | |
593 | return (unsigned long)ptr > (unsigned long)-1000L; | |
594 | } | |
595 | ||
596 | /* | |
597 | * "refresh" does not calculate a new sha1 file or bring the | |
598 | * cache up-to-date for mode/content changes. But what it | |
599 | * _does_ do is to "re-match" the stat information of a file | |
600 | * with the cache, so that you can refresh the cache for a | |
601 | * file that hasn't been changed but where the stat entry is | |
602 | * out of date. | |
603 | * | |
604 | * For example, you'd want to do this after doing a "git-read-tree", | |
605 | * to link up the stat cache details with the proper files. | |
606 | */ | |
607 | static struct cache_entry *refresh_entry(struct cache_entry *ce, int really) | |
608 | { | |
609 | struct stat st; | |
610 | struct cache_entry *updated; | |
611 | int changed, size; | |
612 | ||
613 | if (lstat(ce->name, &st) < 0) | |
614 | return ERR_PTR(-errno); | |
615 | ||
616 | changed = ce_match_stat(ce, &st, really); | |
617 | if (!changed) { | |
618 | if (really && assume_unchanged && | |
619 | !(ce->ce_flags & htons(CE_VALID))) | |
620 | ; /* mark this one VALID again */ | |
621 | else | |
622 | return NULL; | |
623 | } | |
624 | ||
625 | if (ce_modified(ce, &st, really)) | |
626 | return ERR_PTR(-EINVAL); | |
627 | ||
628 | size = ce_size(ce); | |
629 | updated = xmalloc(size); | |
630 | memcpy(updated, ce, size); | |
631 | fill_stat_cache_info(updated, &st); | |
632 | ||
633 | /* In this case, if really is not set, we should leave | |
634 | * CE_VALID bit alone. Otherwise, paths marked with | |
635 | * --no-assume-unchanged (i.e. things to be edited) will | |
636 | * reacquire CE_VALID bit automatically, which is not | |
637 | * really what we want. | |
638 | */ | |
639 | if (!really && assume_unchanged && !(ce->ce_flags & htons(CE_VALID))) | |
640 | updated->ce_flags &= ~htons(CE_VALID); | |
641 | ||
642 | return updated; | |
643 | } | |
644 | ||
645 | int refresh_cache(unsigned int flags) | |
646 | { | |
647 | int i; | |
648 | int has_errors = 0; | |
649 | int really = (flags & REFRESH_REALLY) != 0; | |
650 | int allow_unmerged = (flags & REFRESH_UNMERGED) != 0; | |
651 | int quiet = (flags & REFRESH_QUIET) != 0; | |
652 | int not_new = (flags & REFRESH_IGNORE_MISSING) != 0; | |
653 | ||
654 | for (i = 0; i < active_nr; i++) { | |
655 | struct cache_entry *ce, *new; | |
656 | ce = active_cache[i]; | |
657 | if (ce_stage(ce)) { | |
658 | while ((i < active_nr) && | |
659 | ! strcmp(active_cache[i]->name, ce->name)) | |
660 | i++; | |
661 | i--; | |
662 | if (allow_unmerged) | |
663 | continue; | |
664 | printf("%s: needs merge\n", ce->name); | |
665 | has_errors = 1; | |
666 | continue; | |
667 | } | |
668 | ||
669 | new = refresh_entry(ce, really); | |
670 | if (!new) | |
671 | continue; | |
672 | if (IS_ERR(new)) { | |
673 | if (not_new && PTR_ERR(new) == -ENOENT) | |
674 | continue; | |
675 | if (really && PTR_ERR(new) == -EINVAL) { | |
676 | /* If we are doing --really-refresh that | |
677 | * means the index is not valid anymore. | |
678 | */ | |
679 | ce->ce_flags &= ~htons(CE_VALID); | |
680 | active_cache_changed = 1; | |
681 | } | |
682 | if (quiet) | |
683 | continue; | |
684 | printf("%s: needs update\n", ce->name); | |
685 | has_errors = 1; | |
686 | continue; | |
687 | } | |
688 | active_cache_changed = 1; | |
689 | /* You can NOT just free active_cache[i] here, since it | |
690 | * might not be necessarily malloc()ed but can also come | |
691 | * from mmap(). */ | |
692 | active_cache[i] = new; | |
693 | } | |
694 | return has_errors; | |
695 | } | |
696 | ||
bad68ec9 | 697 | static int verify_hdr(struct cache_header *hdr, unsigned long size) |
e83c5163 LT |
698 | { |
699 | SHA_CTX c; | |
bad68ec9 | 700 | unsigned char sha1[20]; |
e83c5163 | 701 | |
ccc4feb5 | 702 | if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) |
e83c5163 | 703 | return error("bad signature"); |
ca9be054 LT |
704 | if (hdr->hdr_version != htonl(2)) |
705 | return error("bad index version"); | |
e83c5163 | 706 | SHA1_Init(&c); |
ca9be054 | 707 | SHA1_Update(&c, hdr, size - 20); |
e83c5163 | 708 | SHA1_Final(sha1, &c); |
ca9be054 LT |
709 | if (memcmp(sha1, (void *)hdr + size - 20, 20)) |
710 | return error("bad index file sha1 signature"); | |
e83c5163 LT |
711 | return 0; |
712 | } | |
713 | ||
bad68ec9 JH |
714 | static int read_index_extension(const char *ext, void *data, unsigned long sz) |
715 | { | |
716 | switch (CACHE_EXT(ext)) { | |
717 | case CACHE_EXT_TREE: | |
718 | active_cache_tree = cache_tree_read(data, sz); | |
719 | break; | |
720 | default: | |
721 | if (*ext < 'A' || 'Z' < *ext) | |
722 | return error("index uses %.4s extension, which we do not understand", | |
723 | ext); | |
724 | fprintf(stderr, "ignoring %.4s extension\n", ext); | |
725 | break; | |
726 | } | |
727 | return 0; | |
728 | } | |
729 | ||
730 | int read_cache(void) | |
e83c5163 LT |
731 | { |
732 | int fd, i; | |
733 | struct stat st; | |
734 | unsigned long size, offset; | |
735 | void *map; | |
736 | struct cache_header *hdr; | |
737 | ||
738 | errno = EBUSY; | |
739 | if (active_cache) | |
5d1a5c02 LT |
740 | return active_nr; |
741 | ||
e83c5163 | 742 | errno = ENOENT; |
29e4d363 | 743 | index_file_timestamp = 0; |
bb233d69 | 744 | fd = open(get_index_file(), O_RDONLY); |
5d1a5c02 LT |
745 | if (fd < 0) { |
746 | if (errno == ENOENT) | |
747 | return 0; | |
748 | die("index file open failed (%s)", strerror(errno)); | |
749 | } | |
e83c5163 | 750 | |
19b2860c | 751 | size = 0; // avoid gcc warning |
e35f9824 | 752 | map = MAP_FAILED; |
e83c5163 | 753 | if (!fstat(fd, &st)) { |
e83c5163 LT |
754 | size = st.st_size; |
755 | errno = EINVAL; | |
ca9be054 | 756 | if (size >= sizeof(struct cache_header) + 20) |
520fc241 | 757 | map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); |
e83c5163 LT |
758 | } |
759 | close(fd); | |
e35f9824 | 760 | if (map == MAP_FAILED) |
5d1a5c02 | 761 | die("index file mmap failed (%s)", strerror(errno)); |
e83c5163 LT |
762 | |
763 | hdr = map; | |
bad68ec9 | 764 | if (verify_hdr(hdr, size) < 0) |
e83c5163 LT |
765 | goto unmap; |
766 | ||
ccc4feb5 | 767 | active_nr = ntohl(hdr->hdr_entries); |
e83c5163 | 768 | active_alloc = alloc_nr(active_nr); |
28cc4ab4 | 769 | active_cache = xcalloc(active_alloc, sizeof(struct cache_entry *)); |
e83c5163 LT |
770 | |
771 | offset = sizeof(*hdr); | |
ccc4feb5 | 772 | for (i = 0; i < active_nr; i++) { |
e83c5163 LT |
773 | struct cache_entry *ce = map + offset; |
774 | offset = offset + ce_size(ce); | |
775 | active_cache[i] = ce; | |
776 | } | |
29e4d363 | 777 | index_file_timestamp = st.st_mtime; |
bad68ec9 JH |
778 | while (offset <= size - 20 - 8) { |
779 | /* After an array of active_nr index entries, | |
780 | * there can be arbitrary number of extended | |
781 | * sections, each of which is prefixed with | |
782 | * extension name (4-byte) and section length | |
783 | * in 4-byte network byte order. | |
784 | */ | |
785 | unsigned long extsize; | |
786 | memcpy(&extsize, map + offset + 4, 4); | |
787 | extsize = ntohl(extsize); | |
788 | if (read_index_extension(map + offset, | |
789 | map + offset + 8, extsize) < 0) | |
790 | goto unmap; | |
791 | offset += 8; | |
792 | offset += extsize; | |
793 | } | |
e83c5163 LT |
794 | return active_nr; |
795 | ||
796 | unmap: | |
797 | munmap(map, size); | |
798 | errno = EINVAL; | |
5d1a5c02 | 799 | die("index file corrupt"); |
e83c5163 LT |
800 | } |
801 | ||
4990aadc | 802 | #define WRITE_BUFFER_SIZE 8192 |
bf0f910d | 803 | static unsigned char write_buffer[WRITE_BUFFER_SIZE]; |
4990aadc LT |
804 | static unsigned long write_buffer_len; |
805 | ||
ca9be054 | 806 | static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len) |
4990aadc LT |
807 | { |
808 | while (len) { | |
809 | unsigned int buffered = write_buffer_len; | |
810 | unsigned int partial = WRITE_BUFFER_SIZE - buffered; | |
811 | if (partial > len) | |
812 | partial = len; | |
813 | memcpy(write_buffer + buffered, data, partial); | |
814 | buffered += partial; | |
815 | if (buffered == WRITE_BUFFER_SIZE) { | |
ca9be054 | 816 | SHA1_Update(context, write_buffer, WRITE_BUFFER_SIZE); |
4990aadc LT |
817 | if (write(fd, write_buffer, WRITE_BUFFER_SIZE) != WRITE_BUFFER_SIZE) |
818 | return -1; | |
819 | buffered = 0; | |
820 | } | |
821 | write_buffer_len = buffered; | |
822 | len -= partial; | |
823 | data += partial; | |
824 | } | |
825 | return 0; | |
826 | } | |
827 | ||
bad68ec9 | 828 | static int write_index_ext_header(SHA_CTX *context, int fd, |
ac58c7b1 | 829 | unsigned int ext, unsigned int sz) |
bad68ec9 JH |
830 | { |
831 | ext = htonl(ext); | |
832 | sz = htonl(sz); | |
833 | if ((ce_write(context, fd, &ext, 4) < 0) || | |
834 | (ce_write(context, fd, &sz, 4) < 0)) | |
835 | return -1; | |
836 | return 0; | |
837 | } | |
838 | ||
839 | static int ce_flush(SHA_CTX *context, int fd) | |
4990aadc LT |
840 | { |
841 | unsigned int left = write_buffer_len; | |
ca9be054 | 842 | |
4990aadc LT |
843 | if (left) { |
844 | write_buffer_len = 0; | |
ca9be054 | 845 | SHA1_Update(context, write_buffer, left); |
4990aadc | 846 | } |
ca9be054 | 847 | |
2c865d9a QH |
848 | /* Flush first if not enough space for SHA1 signature */ |
849 | if (left + 20 > WRITE_BUFFER_SIZE) { | |
850 | if (write(fd, write_buffer, left) != left) | |
851 | return -1; | |
852 | left = 0; | |
853 | } | |
854 | ||
ca9be054 | 855 | /* Append the SHA1 signature at the end */ |
bad68ec9 | 856 | SHA1_Final(write_buffer + left, context); |
ca9be054 LT |
857 | left += 20; |
858 | if (write(fd, write_buffer, left) != left) | |
859 | return -1; | |
4990aadc LT |
860 | return 0; |
861 | } | |
862 | ||
407c8eb0 JH |
863 | static void ce_smudge_racily_clean_entry(struct cache_entry *ce) |
864 | { | |
865 | /* | |
866 | * The only thing we care about in this function is to smudge the | |
867 | * falsely clean entry due to touch-update-touch race, so we leave | |
868 | * everything else as they are. We are called for entries whose | |
869 | * ce_mtime match the index file mtime. | |
870 | */ | |
871 | struct stat st; | |
872 | ||
873 | if (lstat(ce->name, &st) < 0) | |
874 | return; | |
875 | if (ce_match_stat_basic(ce, &st)) | |
876 | return; | |
877 | if (ce_modified_check_fs(ce, &st)) { | |
4b3511b0 JH |
878 | /* This is "racily clean"; smudge it. Note that this |
879 | * is a tricky code. At first glance, it may appear | |
880 | * that it can break with this sequence: | |
881 | * | |
882 | * $ echo xyzzy >frotz | |
883 | * $ git-update-index --add frotz | |
884 | * $ : >frotz | |
885 | * $ sleep 3 | |
886 | * $ echo filfre >nitfol | |
887 | * $ git-update-index --add nitfol | |
888 | * | |
889 | * but it does not. Whe the second update-index runs, | |
890 | * it notices that the entry "frotz" has the same timestamp | |
891 | * as index, and if we were to smudge it by resetting its | |
892 | * size to zero here, then the object name recorded | |
893 | * in index is the 6-byte file but the cached stat information | |
894 | * becomes zero --- which would then match what we would | |
895 | * obtain from the filesystem next time we stat("frotz"). | |
896 | * | |
897 | * However, the second update-index, before calling | |
898 | * this function, notices that the cached size is 6 | |
899 | * bytes and what is on the filesystem is an empty | |
900 | * file, and never calls us, so the cached size information | |
901 | * for "frotz" stays 6 which does not match the filesystem. | |
902 | */ | |
407c8eb0 JH |
903 | ce->ce_size = htonl(0); |
904 | } | |
905 | } | |
906 | ||
bad68ec9 | 907 | int write_cache(int newfd, struct cache_entry **cache, int entries) |
197ee8c9 LT |
908 | { |
909 | SHA_CTX c; | |
910 | struct cache_header hdr; | |
025a0709 JH |
911 | int i, removed; |
912 | ||
913 | for (i = removed = 0; i < entries; i++) | |
914 | if (!cache[i]->ce_mode) | |
915 | removed++; | |
197ee8c9 | 916 | |
ccc4feb5 | 917 | hdr.hdr_signature = htonl(CACHE_SIGNATURE); |
ca9be054 | 918 | hdr.hdr_version = htonl(2); |
025a0709 | 919 | hdr.hdr_entries = htonl(entries - removed); |
197ee8c9 LT |
920 | |
921 | SHA1_Init(&c); | |
ca9be054 | 922 | if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0) |
197ee8c9 LT |
923 | return -1; |
924 | ||
925 | for (i = 0; i < entries; i++) { | |
926 | struct cache_entry *ce = cache[i]; | |
aa16021e LT |
927 | if (!ce->ce_mode) |
928 | continue; | |
407c8eb0 JH |
929 | if (index_file_timestamp && |
930 | index_file_timestamp <= ntohl(ce->ce_mtime.sec)) | |
931 | ce_smudge_racily_clean_entry(ce); | |
ca9be054 | 932 | if (ce_write(&c, newfd, ce, ce_size(ce)) < 0) |
197ee8c9 LT |
933 | return -1; |
934 | } | |
1af1c2b6 | 935 | |
bad68ec9 JH |
936 | /* Write extension data here */ |
937 | if (active_cache_tree) { | |
938 | unsigned long sz; | |
939 | void *data = cache_tree_write(active_cache_tree, &sz); | |
940 | if (data && | |
941 | !write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sz) && | |
942 | !ce_write(&c, newfd, data, sz)) | |
943 | ; | |
944 | else { | |
945 | free(data); | |
946 | return -1; | |
947 | } | |
948 | } | |
949 | return ce_flush(&c, newfd); | |
197ee8c9 | 950 | } |