2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
9 struct cache_entry **active_cache = NULL;
10 unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;
12 int cache_match_stat(struct cache_entry *ce, struct stat *st)
14 unsigned int changed = 0;
16 switch (ntohl(ce->ce_mode) & S_IFMT) {
18 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
19 /* We consider only the owner x bit to be relevant for "mode changes" */
20 if (0100 & (ntohl(ce->ce_mode) ^ st->st_mode))
21 changed |= MODE_CHANGED;
24 changed |= !S_ISLNK(st->st_mode) ? TYPE_CHANGED : 0;
27 die("internal error: ce_mode is %o", ntohl(ce->ce_mode));
29 if (ce->ce_mtime.sec != htonl(st->st_mtime))
30 changed |= MTIME_CHANGED;
31 if (ce->ce_ctime.sec != htonl(st->st_ctime))
32 changed |= CTIME_CHANGED;
36 * nsec seems unreliable - not all filesystems support it, so
37 * as long as it is in the inode cache you get right nsec
38 * but after it gets flushed, you get zero nsec.
40 if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec))
41 changed |= MTIME_CHANGED;
42 if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec))
43 changed |= CTIME_CHANGED;
46 if (ce->ce_uid != htonl(st->st_uid) ||
47 ce->ce_gid != htonl(st->st_gid))
48 changed |= OWNER_CHANGED;
49 if (ce->ce_dev != htonl(st->st_dev) ||
50 ce->ce_ino != htonl(st->st_ino))
51 changed |= INODE_CHANGED;
52 if (ce->ce_size != htonl(st->st_size))
53 changed |= DATA_CHANGED;
57 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
59 int len1 = flags1 & CE_NAMEMASK;
60 int len2 = flags2 & CE_NAMEMASK;
61 int len = len1 < len2 ? len1 : len2;
64 cmp = memcmp(name1, name2, len);
78 int cache_name_pos(const char *name, int namelen)
84 while (last > first) {
85 int next = (last + first) >> 1;
86 struct cache_entry *ce = active_cache[next];
87 int cmp = cache_name_compare(name, namelen, ce->name, htons(ce->ce_flags));
99 /* Remove entry, return true if there are more entries to go.. */
100 int remove_entry_at(int pos)
102 active_cache_changed = 1;
104 if (pos >= active_nr)
106 memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos) * sizeof(struct cache_entry *));
110 int remove_file_from_cache(char *path)
112 int pos = cache_name_pos(path, strlen(path));
115 while (pos < active_nr && !strcmp(active_cache[pos]->name, path))
116 remove_entry_at(pos);
120 int same_name(struct cache_entry *a, struct cache_entry *b)
122 int len = ce_namelen(a);
123 return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
126 /* We may be in a situation where we already have path/file and path
127 * is being added, or we already have path and path/file is being
128 * added. Either one would result in a nonsense tree that has path
129 * twice when git-write-tree tries to write it out. Prevent it.
131 static int check_file_directory_conflict(const struct cache_entry *ce)
134 const char *path = ce->name;
135 int namelen = strlen(path);
136 int stage = ce_stage(ce);
137 char *pathbuf = xmalloc(namelen + 1);
140 memcpy(pathbuf, path, namelen + 1);
143 * We are inserting path/file. Do they have path registered at
144 * the same stage? We need to do this for all the levels of our
149 char *ep = strchr(cp, '/');
152 *ep = 0; /* first cut it at slash */
153 pos = cache_name_pos(pathbuf,
154 htons(create_ce_flags(ep-cp, stage)));
156 /* Our leading path component is registered as a file,
157 * and we are trying to make it a directory. This is
163 *ep = '/'; /* then restore it and go downwards */
168 /* Do we have an entry in the cache that makes our path a prefix
169 * of it? That is, are we creating a file where they already expect
172 pos = cache_name_pos(path,
173 htons(create_ce_flags(namelen, stage)));
175 /* (0 <= pos) cannot happen because add_cache_entry()
176 * should have taken care of that case.
180 /* pos would point at an existing entry that would come immediately
181 * after our path. It could be the same as our path in higher stage,
182 * or different path but in a lower stage.
184 * E.g. when we are inserting path at stage 2,
191 * We need to examine pos, ignore it because it is at different
192 * stage, examine next to find the path/file at stage 2, and
196 while (pos < active_nr) {
197 struct cache_entry *other = active_cache[pos];
198 if (strncmp(other->name, path, namelen))
199 break; /* it is not our "subdirectory" anymore */
200 if ((ce_stage(other) == stage) && other->name[namelen] == '/')
208 int add_cache_entry(struct cache_entry *ce, int ok_to_add)
212 pos = cache_name_pos(ce->name, htons(ce->ce_flags));
214 /* existing match? Just replace it */
216 active_cache_changed = 1;
217 active_cache[pos] = ce;
223 * Inserting a merged entry ("stage 0") into the index
224 * will always replace all non-merged entries..
226 if (pos < active_nr && ce_stage(ce) == 0) {
227 while (same_name(active_cache[pos], ce)) {
229 if (!remove_entry_at(pos))
237 if (check_file_directory_conflict(ce))
240 /* Make sure the array is big enough .. */
241 if (active_nr == active_alloc) {
242 active_alloc = alloc_nr(active_alloc);
243 active_cache = xrealloc(active_cache, active_alloc * sizeof(struct cache_entry *));
249 memmove(active_cache + pos + 1, active_cache + pos, (active_nr - pos - 1) * sizeof(ce));
250 active_cache[pos] = ce;
251 active_cache_changed = 1;
255 static int verify_hdr(struct cache_header *hdr, unsigned long size)
258 unsigned char sha1[20];
260 if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
261 return error("bad signature");
262 if (hdr->hdr_version != htonl(2))
263 return error("bad index version");
265 SHA1_Update(&c, hdr, size - 20);
266 SHA1_Final(sha1, &c);
267 if (memcmp(sha1, (void *)hdr + size - 20, 20))
268 return error("bad index file sha1 signature");
276 unsigned long size, offset;
278 struct cache_header *hdr;
282 return error("more than one cachefile");
284 fd = open(get_index_file(), O_RDONLY);
286 return (errno == ENOENT) ? 0 : error("open failed");
288 size = 0; // avoid gcc warning
290 if (!fstat(fd, &st)) {
293 if (size >= sizeof(struct cache_header) + 20)
294 map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
297 if (-1 == (int)(long)map)
298 return error("mmap failed");
301 if (verify_hdr(hdr, size) < 0)
304 active_nr = ntohl(hdr->hdr_entries);
305 active_alloc = alloc_nr(active_nr);
306 active_cache = calloc(active_alloc, sizeof(struct cache_entry *));
308 offset = sizeof(*hdr);
309 for (i = 0; i < active_nr; i++) {
310 struct cache_entry *ce = map + offset;
311 offset = offset + ce_size(ce);
312 active_cache[i] = ce;
319 return error("verify header failed");
322 #define WRITE_BUFFER_SIZE 8192
323 static char write_buffer[WRITE_BUFFER_SIZE];
324 static unsigned long write_buffer_len;
326 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
329 unsigned int buffered = write_buffer_len;
330 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
333 memcpy(write_buffer + buffered, data, partial);
335 if (buffered == WRITE_BUFFER_SIZE) {
336 SHA1_Update(context, write_buffer, WRITE_BUFFER_SIZE);
337 if (write(fd, write_buffer, WRITE_BUFFER_SIZE) != WRITE_BUFFER_SIZE)
341 write_buffer_len = buffered;
348 static int ce_flush(SHA_CTX *context, int fd)
350 unsigned int left = write_buffer_len;
353 write_buffer_len = 0;
354 SHA1_Update(context, write_buffer, left);
357 /* Append the SHA1 signature at the end */
358 SHA1_Final(write_buffer + left, context);
360 if (write(fd, write_buffer, left) != left)
365 int write_cache(int newfd, struct cache_entry **cache, int entries)
368 struct cache_header hdr;
371 hdr.hdr_signature = htonl(CACHE_SIGNATURE);
372 hdr.hdr_version = htonl(2);
373 hdr.hdr_entries = htonl(entries);
376 if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
379 for (i = 0; i < entries; i++) {
380 struct cache_entry *ce = cache[i];
381 if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
384 return ce_flush(&c, newfd);