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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 | */ | |
2de381f9 | 6 | #include <stdarg.h> |
e83c5163 LT |
7 | #include "cache.h" |
8 | ||
e83c5163 | 9 | struct cache_entry **active_cache = NULL; |
ee267527 | 10 | unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0; |
e83c5163 | 11 | |
734aab75 LT |
12 | int cache_match_stat(struct cache_entry *ce, struct stat *st) |
13 | { | |
14 | unsigned int changed = 0; | |
15 | ||
8ae0a8c5 KS |
16 | switch (ntohl(ce->ce_mode) & S_IFMT) { |
17 | case S_IFREG: | |
18 | changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0; | |
ffbe1add KS |
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; | |
8ae0a8c5 KS |
22 | break; |
23 | case S_IFLNK: | |
24 | changed |= !S_ISLNK(st->st_mode) ? TYPE_CHANGED : 0; | |
25 | break; | |
26 | default: | |
27 | die("internal error: ce_mode is %o", ntohl(ce->ce_mode)); | |
28 | } | |
ccc4feb5 | 29 | if (ce->ce_mtime.sec != htonl(st->st_mtime)) |
734aab75 | 30 | changed |= MTIME_CHANGED; |
ccc4feb5 LT |
31 | if (ce->ce_ctime.sec != htonl(st->st_ctime)) |
32 | changed |= CTIME_CHANGED; | |
33 | ||
bdd4da59 | 34 | #ifdef NSEC |
ccc4feb5 LT |
35 | /* |
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. | |
39 | */ | |
94dfb7f2 | 40 | if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec)) |
ccc4feb5 | 41 | changed |= MTIME_CHANGED; |
94dfb7f2 | 42 | if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec)) |
734aab75 | 43 | changed |= CTIME_CHANGED; |
ccc4feb5 LT |
44 | #endif |
45 | ||
46 | if (ce->ce_uid != htonl(st->st_uid) || | |
47 | ce->ce_gid != htonl(st->st_gid)) | |
734aab75 | 48 | changed |= OWNER_CHANGED; |
ccc4feb5 LT |
49 | if (ce->ce_dev != htonl(st->st_dev) || |
50 | ce->ce_ino != htonl(st->st_ino)) | |
734aab75 | 51 | changed |= INODE_CHANGED; |
ccc4feb5 | 52 | if (ce->ce_size != htonl(st->st_size)) |
734aab75 LT |
53 | changed |= DATA_CHANGED; |
54 | return changed; | |
55 | } | |
56 | ||
95fd5bf8 | 57 | int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2) |
eb38c22f | 58 | { |
95fd5bf8 LT |
59 | int len1 = flags1 & CE_NAMEMASK; |
60 | int len2 = flags2 & CE_NAMEMASK; | |
eb38c22f LT |
61 | int len = len1 < len2 ? len1 : len2; |
62 | int cmp; | |
63 | ||
64 | cmp = memcmp(name1, name2, len); | |
65 | if (cmp) | |
66 | return cmp; | |
67 | if (len1 < len2) | |
68 | return -1; | |
69 | if (len1 > len2) | |
70 | return 1; | |
95fd5bf8 LT |
71 | if (flags1 < flags2) |
72 | return -1; | |
73 | if (flags1 > flags2) | |
74 | return 1; | |
eb38c22f LT |
75 | return 0; |
76 | } | |
77 | ||
78 | int cache_name_pos(const char *name, int namelen) | |
79 | { | |
80 | int first, last; | |
81 | ||
82 | first = 0; | |
83 | last = active_nr; | |
84 | while (last > first) { | |
85 | int next = (last + first) >> 1; | |
86 | struct cache_entry *ce = active_cache[next]; | |
95fd5bf8 | 87 | int cmp = cache_name_compare(name, namelen, ce->name, htons(ce->ce_flags)); |
eb38c22f | 88 | if (!cmp) |
76e7f4ec | 89 | return next; |
eb38c22f LT |
90 | if (cmp < 0) { |
91 | last = next; | |
92 | continue; | |
93 | } | |
94 | first = next+1; | |
95 | } | |
76e7f4ec | 96 | return -first-1; |
eb38c22f LT |
97 | } |
98 | ||
7b937ca3 | 99 | /* Remove entry, return true if there are more entries to go.. */ |
b5af9107 | 100 | int remove_entry_at(int pos) |
7b937ca3 | 101 | { |
ee267527 | 102 | active_cache_changed = 1; |
7b937ca3 LT |
103 | active_nr--; |
104 | if (pos >= active_nr) | |
105 | return 0; | |
106 | memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos) * sizeof(struct cache_entry *)); | |
107 | return 1; | |
108 | } | |
109 | ||
197ee8c9 LT |
110 | int remove_file_from_cache(char *path) |
111 | { | |
112 | int pos = cache_name_pos(path, strlen(path)); | |
c4e3cca1 JH |
113 | if (pos < 0) |
114 | pos = -pos-1; | |
115 | while (pos < active_nr && !strcmp(active_cache[pos]->name, path)) | |
7b937ca3 | 116 | remove_entry_at(pos); |
197ee8c9 LT |
117 | return 0; |
118 | } | |
119 | ||
b5af9107 | 120 | int same_name(struct cache_entry *a, struct cache_entry *b) |
7b937ca3 LT |
121 | { |
122 | int len = ce_namelen(a); | |
123 | return ce_namelen(b) == len && !memcmp(a->name, b->name, len); | |
124 | } | |
125 | ||
0f1e4f04 JH |
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. | |
130 | */ | |
131 | static int check_file_directory_conflict(const struct cache_entry *ce) | |
132 | { | |
133 | int pos; | |
134 | const char *path = ce->name; | |
135 | int namelen = strlen(path); | |
136 | int stage = ce_stage(ce); | |
137 | char *pathbuf = xmalloc(namelen + 1); | |
138 | char *cp; | |
139 | ||
140 | memcpy(pathbuf, path, namelen + 1); | |
141 | ||
142 | /* | |
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 | |
145 | * subpath. | |
146 | */ | |
147 | cp = pathbuf; | |
148 | while (1) { | |
149 | char *ep = strchr(cp, '/'); | |
150 | if (ep == 0) | |
151 | break; | |
152 | *ep = 0; /* first cut it at slash */ | |
153 | pos = cache_name_pos(pathbuf, | |
154 | htons(create_ce_flags(ep-cp, stage))); | |
155 | if (0 <= pos) { | |
156 | /* Our leading path component is registered as a file, | |
157 | * and we are trying to make it a directory. This is | |
158 | * bad. | |
159 | */ | |
160 | free(pathbuf); | |
161 | return -1; | |
162 | } | |
163 | *ep = '/'; /* then restore it and go downwards */ | |
164 | cp = ep + 1; | |
165 | } | |
166 | free(pathbuf); | |
167 | ||
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 | |
170 | * a directory there? | |
171 | */ | |
172 | pos = cache_name_pos(path, | |
173 | htons(create_ce_flags(namelen, stage))); | |
174 | ||
175 | /* (0 <= pos) cannot happen because add_cache_entry() | |
176 | * should have taken care of that case. | |
177 | */ | |
178 | pos = -pos-1; | |
179 | ||
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. | |
183 | * | |
184 | * E.g. when we are inserting path at stage 2, | |
185 | * | |
186 | * 1 path | |
187 | * pos-> 3 path | |
188 | * 2 path/file | |
189 | * 3 path/file | |
190 | * | |
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 | |
193 | * complain. | |
194 | */ | |
195 | ||
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] == '/') | |
201 | return -1; | |
202 | pos++; | |
203 | } | |
204 | ||
205 | return 0; | |
206 | } | |
207 | ||
121481ab | 208 | int add_cache_entry(struct cache_entry *ce, int ok_to_add) |
197ee8c9 LT |
209 | { |
210 | int pos; | |
211 | ||
95fd5bf8 | 212 | pos = cache_name_pos(ce->name, htons(ce->ce_flags)); |
197ee8c9 LT |
213 | |
214 | /* existing match? Just replace it */ | |
76e7f4ec | 215 | if (pos >= 0) { |
ee267527 | 216 | active_cache_changed = 1; |
76e7f4ec | 217 | active_cache[pos] = ce; |
197ee8c9 LT |
218 | return 0; |
219 | } | |
76e7f4ec | 220 | pos = -pos-1; |
197ee8c9 | 221 | |
7b937ca3 LT |
222 | /* |
223 | * Inserting a merged entry ("stage 0") into the index | |
224 | * will always replace all non-merged entries.. | |
225 | */ | |
226 | if (pos < active_nr && ce_stage(ce) == 0) { | |
227 | while (same_name(active_cache[pos], ce)) { | |
228 | ok_to_add = 1; | |
7b937ca3 LT |
229 | if (!remove_entry_at(pos)) |
230 | break; | |
231 | } | |
232 | } | |
233 | ||
121481ab LT |
234 | if (!ok_to_add) |
235 | return -1; | |
236 | ||
0f1e4f04 JH |
237 | if (check_file_directory_conflict(ce)) |
238 | return -1; | |
239 | ||
197ee8c9 LT |
240 | /* Make sure the array is big enough .. */ |
241 | if (active_nr == active_alloc) { | |
242 | active_alloc = alloc_nr(active_alloc); | |
812666c8 | 243 | active_cache = xrealloc(active_cache, active_alloc * sizeof(struct cache_entry *)); |
197ee8c9 LT |
244 | } |
245 | ||
246 | /* Add it in.. */ | |
247 | active_nr++; | |
248 | if (active_nr > pos) | |
249 | memmove(active_cache + pos + 1, active_cache + pos, (active_nr - pos - 1) * sizeof(ce)); | |
250 | active_cache[pos] = ce; | |
ee267527 | 251 | active_cache_changed = 1; |
197ee8c9 LT |
252 | return 0; |
253 | } | |
254 | ||
e83c5163 LT |
255 | static int verify_hdr(struct cache_header *hdr, unsigned long size) |
256 | { | |
257 | SHA_CTX c; | |
258 | unsigned char sha1[20]; | |
259 | ||
ccc4feb5 | 260 | if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) |
e83c5163 | 261 | return error("bad signature"); |
ca9be054 LT |
262 | if (hdr->hdr_version != htonl(2)) |
263 | return error("bad index version"); | |
e83c5163 | 264 | SHA1_Init(&c); |
ca9be054 | 265 | SHA1_Update(&c, hdr, size - 20); |
e83c5163 | 266 | SHA1_Final(sha1, &c); |
ca9be054 LT |
267 | if (memcmp(sha1, (void *)hdr + size - 20, 20)) |
268 | return error("bad index file sha1 signature"); | |
e83c5163 LT |
269 | return 0; |
270 | } | |
271 | ||
272 | int read_cache(void) | |
273 | { | |
274 | int fd, i; | |
275 | struct stat st; | |
276 | unsigned long size, offset; | |
277 | void *map; | |
278 | struct cache_header *hdr; | |
279 | ||
280 | errno = EBUSY; | |
281 | if (active_cache) | |
282 | return error("more than one cachefile"); | |
283 | errno = ENOENT; | |
bb233d69 | 284 | fd = open(get_index_file(), O_RDONLY); |
e83c5163 LT |
285 | if (fd < 0) |
286 | return (errno == ENOENT) ? 0 : error("open failed"); | |
287 | ||
19b2860c | 288 | size = 0; // avoid gcc warning |
e83c5163 LT |
289 | map = (void *)-1; |
290 | if (!fstat(fd, &st)) { | |
e83c5163 LT |
291 | size = st.st_size; |
292 | errno = EINVAL; | |
ca9be054 | 293 | if (size >= sizeof(struct cache_header) + 20) |
520fc241 | 294 | map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); |
e83c5163 LT |
295 | } |
296 | close(fd); | |
297 | if (-1 == (int)(long)map) | |
298 | return error("mmap failed"); | |
299 | ||
300 | hdr = map; | |
301 | if (verify_hdr(hdr, size) < 0) | |
302 | goto unmap; | |
303 | ||
ccc4feb5 | 304 | active_nr = ntohl(hdr->hdr_entries); |
e83c5163 LT |
305 | active_alloc = alloc_nr(active_nr); |
306 | active_cache = calloc(active_alloc, sizeof(struct cache_entry *)); | |
307 | ||
308 | offset = sizeof(*hdr); | |
ccc4feb5 | 309 | for (i = 0; i < active_nr; i++) { |
e83c5163 LT |
310 | struct cache_entry *ce = map + offset; |
311 | offset = offset + ce_size(ce); | |
312 | active_cache[i] = ce; | |
313 | } | |
314 | return active_nr; | |
315 | ||
316 | unmap: | |
317 | munmap(map, size); | |
318 | errno = EINVAL; | |
319 | return error("verify header failed"); | |
320 | } | |
321 | ||
4990aadc LT |
322 | #define WRITE_BUFFER_SIZE 8192 |
323 | static char write_buffer[WRITE_BUFFER_SIZE]; | |
324 | static unsigned long write_buffer_len; | |
325 | ||
ca9be054 | 326 | static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len) |
4990aadc LT |
327 | { |
328 | while (len) { | |
329 | unsigned int buffered = write_buffer_len; | |
330 | unsigned int partial = WRITE_BUFFER_SIZE - buffered; | |
331 | if (partial > len) | |
332 | partial = len; | |
333 | memcpy(write_buffer + buffered, data, partial); | |
334 | buffered += partial; | |
335 | if (buffered == WRITE_BUFFER_SIZE) { | |
ca9be054 | 336 | SHA1_Update(context, write_buffer, WRITE_BUFFER_SIZE); |
4990aadc LT |
337 | if (write(fd, write_buffer, WRITE_BUFFER_SIZE) != WRITE_BUFFER_SIZE) |
338 | return -1; | |
339 | buffered = 0; | |
340 | } | |
341 | write_buffer_len = buffered; | |
342 | len -= partial; | |
343 | data += partial; | |
344 | } | |
345 | return 0; | |
346 | } | |
347 | ||
ca9be054 | 348 | static int ce_flush(SHA_CTX *context, int fd) |
4990aadc LT |
349 | { |
350 | unsigned int left = write_buffer_len; | |
ca9be054 | 351 | |
4990aadc LT |
352 | if (left) { |
353 | write_buffer_len = 0; | |
ca9be054 | 354 | SHA1_Update(context, write_buffer, left); |
4990aadc | 355 | } |
ca9be054 LT |
356 | |
357 | /* Append the SHA1 signature at the end */ | |
358 | SHA1_Final(write_buffer + left, context); | |
359 | left += 20; | |
360 | if (write(fd, write_buffer, left) != left) | |
361 | return -1; | |
4990aadc LT |
362 | return 0; |
363 | } | |
364 | ||
197ee8c9 LT |
365 | int write_cache(int newfd, struct cache_entry **cache, int entries) |
366 | { | |
367 | SHA_CTX c; | |
368 | struct cache_header hdr; | |
369 | int i; | |
370 | ||
ccc4feb5 | 371 | hdr.hdr_signature = htonl(CACHE_SIGNATURE); |
ca9be054 | 372 | hdr.hdr_version = htonl(2); |
ccc4feb5 | 373 | hdr.hdr_entries = htonl(entries); |
197ee8c9 LT |
374 | |
375 | SHA1_Init(&c); | |
ca9be054 | 376 | if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0) |
197ee8c9 LT |
377 | return -1; |
378 | ||
379 | for (i = 0; i < entries; i++) { | |
380 | struct cache_entry *ce = cache[i]; | |
ca9be054 | 381 | if (ce_write(&c, newfd, ce, ce_size(ce)) < 0) |
197ee8c9 LT |
382 | return -1; |
383 | } | |
ca9be054 | 384 | return ce_flush(&c, newfd); |
197ee8c9 | 385 | } |