2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
8 int trust_executable_bit = 1;
9 struct cache_entry **active_cache = NULL;
10 unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;
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.
17 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
19 ce->ce_ctime.sec = htonl(st->st_ctime);
20 ce->ce_mtime.sec = htonl(st->st_mtime);
22 ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
23 ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
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);
32 int ce_match_stat(struct cache_entry *ce, struct stat *st)
34 unsigned int changed = 0;
36 switch (ntohl(ce->ce_mode) & S_IFMT) {
38 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
39 /* We consider only the owner x bit to be relevant for "mode changes" */
40 if (0100 & (ntohl(ce->ce_mode) ^ st->st_mode))
41 changed |= MODE_CHANGED;
44 changed |= !S_ISLNK(st->st_mode) ? TYPE_CHANGED : 0;
47 die("internal error: ce_mode is %o", ntohl(ce->ce_mode));
49 if (ce->ce_mtime.sec != htonl(st->st_mtime))
50 changed |= MTIME_CHANGED;
51 if (ce->ce_ctime.sec != htonl(st->st_ctime))
52 changed |= CTIME_CHANGED;
56 * nsec seems unreliable - not all filesystems support it, so
57 * as long as it is in the inode cache you get right nsec
58 * but after it gets flushed, you get zero nsec.
60 if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec))
61 changed |= MTIME_CHANGED;
62 if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec))
63 changed |= CTIME_CHANGED;
66 if (ce->ce_uid != htonl(st->st_uid) ||
67 ce->ce_gid != htonl(st->st_gid))
68 changed |= OWNER_CHANGED;
69 if (ce->ce_ino != htonl(st->st_ino))
70 changed |= INODE_CHANGED;
74 * st_dev breaks on network filesystems where different
75 * clients will have different views of what "device"
76 * the filesystem is on
78 if (ce->ce_dev != htonl(st->st_dev))
79 changed |= INODE_CHANGED;
82 if (ce->ce_size != htonl(st->st_size))
83 changed |= DATA_CHANGED;
87 static int ce_compare_data(struct cache_entry *ce, struct stat *st)
90 int fd = open(ce->name, O_RDONLY);
93 unsigned char sha1[20];
94 if (!index_fd(sha1, fd, st, 0, NULL))
95 match = memcmp(sha1, ce->sha1, 20);
101 static int ce_compare_link(struct cache_entry *ce, unsigned long expected_size)
110 target = xmalloc(expected_size);
111 len = readlink(ce->name, target, expected_size);
112 if (len != expected_size) {
116 buffer = read_sha1_file(ce->sha1, type, &size);
121 if (size == expected_size)
122 match = memcmp(buffer, target, size);
128 int ce_modified(struct cache_entry *ce, struct stat *st)
131 changed = ce_match_stat(ce, st);
136 * If the mode or type has changed, there's no point in trying
137 * to refresh the entry - it's not going to match
139 if (changed & (MODE_CHANGED | TYPE_CHANGED))
142 /* Immediately after read-tree or update-index --cacheinfo,
143 * the length field is zero. For other cases the ce_size
144 * should match the SHA1 recorded in the index entry.
146 if ((changed & DATA_CHANGED) && ce->ce_size != htonl(0))
149 switch (st->st_mode & S_IFMT) {
151 if (ce_compare_data(ce, st))
152 return changed | DATA_CHANGED;
155 if (ce_compare_link(ce, st->st_size))
156 return changed | DATA_CHANGED;
159 return changed | TYPE_CHANGED;
164 int base_name_compare(const char *name1, int len1, int mode1,
165 const char *name2, int len2, int mode2)
167 unsigned char c1, c2;
168 int len = len1 < len2 ? len1 : len2;
171 cmp = memcmp(name1, name2, len);
176 if (!c1 && S_ISDIR(mode1))
178 if (!c2 && S_ISDIR(mode2))
180 return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
183 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
185 int len1 = flags1 & CE_NAMEMASK;
186 int len2 = flags2 & CE_NAMEMASK;
187 int len = len1 < len2 ? len1 : len2;
190 cmp = memcmp(name1, name2, len);
204 int cache_name_pos(const char *name, int namelen)
210 while (last > first) {
211 int next = (last + first) >> 1;
212 struct cache_entry *ce = active_cache[next];
213 int cmp = cache_name_compare(name, namelen, ce->name, ntohs(ce->ce_flags));
225 /* Remove entry, return true if there are more entries to go.. */
226 int remove_cache_entry_at(int pos)
228 active_cache_changed = 1;
230 if (pos >= active_nr)
232 memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos) * sizeof(struct cache_entry *));
236 int remove_file_from_cache(const char *path)
238 int pos = cache_name_pos(path, strlen(path));
241 while (pos < active_nr && !strcmp(active_cache[pos]->name, path))
242 remove_cache_entry_at(pos);
246 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
248 int len = ce_namelen(a);
249 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
252 int ce_path_match(const struct cache_entry *ce, const char **pathspec)
254 const char *match, *name;
260 len = ce_namelen(ce);
262 while ((match = *pathspec++) != NULL) {
263 int matchlen = strlen(match);
266 if (memcmp(name, match, matchlen))
268 if (matchlen && name[matchlen-1] == '/')
270 if (name[matchlen] == '/' || !name[matchlen])
279 * Do we have another file that has the beginning components being a
280 * proper superset of the name we're trying to add?
282 static int has_file_name(const struct cache_entry *ce, int pos, int ok_to_replace)
285 int len = ce_namelen(ce);
286 int stage = ce_stage(ce);
287 const char *name = ce->name;
289 while (pos < active_nr) {
290 struct cache_entry *p = active_cache[pos++];
292 if (len >= ce_namelen(p))
294 if (memcmp(name, p->name, len))
296 if (ce_stage(p) != stage)
298 if (p->name[len] != '/')
303 remove_cache_entry_at(--pos);
309 * Do we have another file with a pathname that is a proper
310 * subset of the name we're trying to add?
312 static int has_dir_name(const struct cache_entry *ce, int pos, int ok_to_replace)
315 int stage = ce_stage(ce);
316 const char *name = ce->name;
317 const char *slash = name + ce_namelen(ce);
325 if (slash <= ce->name)
330 pos = cache_name_pos(name, ntohs(create_ce_flags(len, stage)));
335 remove_cache_entry_at(pos);
340 * Trivial optimization: if we find an entry that
341 * already matches the sub-directory, then we know
342 * we're ok, and we can exit.
345 while (pos < active_nr) {
346 struct cache_entry *p = active_cache[pos];
347 if ((ce_namelen(p) <= len) ||
348 (p->name[len] != '/') ||
349 memcmp(p->name, name, len))
350 break; /* not our subdirectory */
351 if (ce_stage(p) == stage)
352 /* p is at the same stage as our entry, and
353 * is a subdirectory of what we are looking
354 * at, so we cannot have conflicts at our
355 * level or anything shorter.
364 /* We may be in a situation where we already have path/file and path
365 * is being added, or we already have path and path/file is being
366 * added. Either one would result in a nonsense tree that has path
367 * twice when git-write-tree tries to write it out. Prevent it.
369 * If ok-to-replace is specified, we remove the conflicting entries
370 * from the cache so the caller should recompute the insert position.
371 * When this happens, we return non-zero.
373 static int check_file_directory_conflict(const struct cache_entry *ce, int pos, int ok_to_replace)
376 * We check if the path is a sub-path of a subsequent pathname
377 * first, since removing those will not change the position
380 int retval = has_file_name(ce, pos, ok_to_replace);
382 * Then check if the path might have a clashing sub-directory
385 return retval + has_dir_name(ce, pos, ok_to_replace);
388 int add_cache_entry(struct cache_entry *ce, int option)
391 int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
392 int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
393 int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
394 pos = cache_name_pos(ce->name, ntohs(ce->ce_flags));
396 /* existing match? Just replace it */
398 active_cache_changed = 1;
399 active_cache[pos] = ce;
405 * Inserting a merged entry ("stage 0") into the index
406 * will always replace all non-merged entries..
408 if (pos < active_nr && ce_stage(ce) == 0) {
409 while (ce_same_name(active_cache[pos], ce)) {
411 if (!remove_cache_entry_at(pos))
419 if (!skip_df_check && check_file_directory_conflict(ce, pos, ok_to_replace)) {
422 pos = cache_name_pos(ce->name, ntohs(ce->ce_flags));
426 /* Make sure the array is big enough .. */
427 if (active_nr == active_alloc) {
428 active_alloc = alloc_nr(active_alloc);
429 active_cache = xrealloc(active_cache, active_alloc * sizeof(struct cache_entry *));
435 memmove(active_cache + pos + 1, active_cache + pos, (active_nr - pos - 1) * sizeof(ce));
436 active_cache[pos] = ce;
437 active_cache_changed = 1;
441 static int verify_hdr(struct cache_header *hdr, unsigned long size)
444 unsigned char sha1[20];
446 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
447 return error("bad signature");
448 if (hdr->hdr_version != htonl(2))
449 return error("bad index version");
451 SHA1_Update(&c, hdr, size - 20);
452 SHA1_Final(sha1, &c);
453 if (memcmp(sha1, (void *)hdr + size - 20, 20))
454 return error("bad index file sha1 signature");
462 unsigned long size, offset;
464 struct cache_header *hdr;
471 fd = open(get_index_file(), O_RDONLY);
475 die("index file open failed (%s)", strerror(errno));
478 size = 0; // avoid gcc warning
480 if (!fstat(fd, &st)) {
483 if (size >= sizeof(struct cache_header) + 20)
484 map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
487 if (map == MAP_FAILED)
488 die("index file mmap failed (%s)", strerror(errno));
491 if (verify_hdr(hdr, size) < 0)
494 active_nr = ntohl(hdr->hdr_entries);
495 active_alloc = alloc_nr(active_nr);
496 active_cache = calloc(active_alloc, sizeof(struct cache_entry *));
498 offset = sizeof(*hdr);
499 for (i = 0; i < active_nr; i++) {
500 struct cache_entry *ce = map + offset;
501 offset = offset + ce_size(ce);
502 active_cache[i] = ce;
509 die("index file corrupt");
512 #define WRITE_BUFFER_SIZE 8192
513 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
514 static unsigned long write_buffer_len;
516 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
519 unsigned int buffered = write_buffer_len;
520 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
523 memcpy(write_buffer + buffered, data, partial);
525 if (buffered == WRITE_BUFFER_SIZE) {
526 SHA1_Update(context, write_buffer, WRITE_BUFFER_SIZE);
527 if (write(fd, write_buffer, WRITE_BUFFER_SIZE) != WRITE_BUFFER_SIZE)
531 write_buffer_len = buffered;
538 static int ce_flush(SHA_CTX *context, int fd)
540 unsigned int left = write_buffer_len;
543 write_buffer_len = 0;
544 SHA1_Update(context, write_buffer, left);
547 /* Flush first if not enough space for SHA1 signature */
548 if (left + 20 > WRITE_BUFFER_SIZE) {
549 if (write(fd, write_buffer, left) != left)
554 /* Append the SHA1 signature at the end */
555 SHA1_Final(write_buffer + left, context);
557 if (write(fd, write_buffer, left) != left)
562 int write_cache(int newfd, struct cache_entry **cache, int entries)
565 struct cache_header hdr;
568 for (i = removed = 0; i < entries; i++)
569 if (!cache[i]->ce_mode)
572 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
573 hdr.hdr_version = htonl(2);
574 hdr.hdr_entries = htonl(entries - removed);
577 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
580 for (i = 0; i < entries; i++) {
581 struct cache_entry *ce = cache[i];
584 if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
587 return ce_flush(&c, newfd);