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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 LT |
9 | struct cache_entry **active_cache = NULL; |
10 | unsigned int active_nr = 0, active_alloc = 0; | |
11 | ||
734aab75 LT |
12 | int cache_match_stat(struct cache_entry *ce, struct stat *st) |
13 | { | |
14 | unsigned int changed = 0; | |
15 | ||
ccc4feb5 | 16 | if (ce->ce_mtime.sec != htonl(st->st_mtime)) |
734aab75 | 17 | changed |= MTIME_CHANGED; |
ccc4feb5 LT |
18 | if (ce->ce_ctime.sec != htonl(st->st_ctime)) |
19 | changed |= CTIME_CHANGED; | |
20 | ||
bdd4da59 | 21 | #ifdef NSEC |
ccc4feb5 LT |
22 | /* |
23 | * nsec seems unreliable - not all filesystems support it, so | |
24 | * as long as it is in the inode cache you get right nsec | |
25 | * but after it gets flushed, you get zero nsec. | |
26 | */ | |
27 | if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec) | |
28 | changed |= MTIME_CHANGED; | |
29 | if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec) | |
734aab75 | 30 | changed |= CTIME_CHANGED; |
ccc4feb5 LT |
31 | #endif |
32 | ||
33 | if (ce->ce_uid != htonl(st->st_uid) || | |
34 | ce->ce_gid != htonl(st->st_gid)) | |
734aab75 | 35 | changed |= OWNER_CHANGED; |
e4479470 | 36 | /* We consider only the owner x bit to be relevant for "mode changes" */ |
e8871e88 | 37 | if (0100 & (ntohl(ce->ce_mode) ^ st->st_mode)) |
734aab75 | 38 | changed |= MODE_CHANGED; |
ccc4feb5 LT |
39 | if (ce->ce_dev != htonl(st->st_dev) || |
40 | ce->ce_ino != htonl(st->st_ino)) | |
734aab75 | 41 | changed |= INODE_CHANGED; |
ccc4feb5 | 42 | if (ce->ce_size != htonl(st->st_size)) |
734aab75 LT |
43 | changed |= DATA_CHANGED; |
44 | return changed; | |
45 | } | |
46 | ||
95fd5bf8 | 47 | int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2) |
eb38c22f | 48 | { |
95fd5bf8 LT |
49 | int len1 = flags1 & CE_NAMEMASK; |
50 | int len2 = flags2 & CE_NAMEMASK; | |
eb38c22f LT |
51 | int len = len1 < len2 ? len1 : len2; |
52 | int cmp; | |
53 | ||
54 | cmp = memcmp(name1, name2, len); | |
55 | if (cmp) | |
56 | return cmp; | |
57 | if (len1 < len2) | |
58 | return -1; | |
59 | if (len1 > len2) | |
60 | return 1; | |
95fd5bf8 LT |
61 | if (flags1 < flags2) |
62 | return -1; | |
63 | if (flags1 > flags2) | |
64 | return 1; | |
eb38c22f LT |
65 | return 0; |
66 | } | |
67 | ||
68 | int cache_name_pos(const char *name, int namelen) | |
69 | { | |
70 | int first, last; | |
71 | ||
72 | first = 0; | |
73 | last = active_nr; | |
74 | while (last > first) { | |
75 | int next = (last + first) >> 1; | |
76 | struct cache_entry *ce = active_cache[next]; | |
95fd5bf8 | 77 | int cmp = cache_name_compare(name, namelen, ce->name, htons(ce->ce_flags)); |
eb38c22f | 78 | if (!cmp) |
76e7f4ec | 79 | return next; |
eb38c22f LT |
80 | if (cmp < 0) { |
81 | last = next; | |
82 | continue; | |
83 | } | |
84 | first = next+1; | |
85 | } | |
76e7f4ec | 86 | return -first-1; |
eb38c22f LT |
87 | } |
88 | ||
7b937ca3 LT |
89 | /* Remove entry, return true if there are more entries to go.. */ |
90 | static int remove_entry_at(int pos) | |
91 | { | |
92 | active_nr--; | |
93 | if (pos >= active_nr) | |
94 | return 0; | |
95 | memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos) * sizeof(struct cache_entry *)); | |
96 | return 1; | |
97 | } | |
98 | ||
197ee8c9 LT |
99 | int remove_file_from_cache(char *path) |
100 | { | |
101 | int pos = cache_name_pos(path, strlen(path)); | |
c4e3cca1 JH |
102 | if (pos < 0) |
103 | pos = -pos-1; | |
104 | while (pos < active_nr && !strcmp(active_cache[pos]->name, path)) | |
7b937ca3 | 105 | remove_entry_at(pos); |
197ee8c9 LT |
106 | return 0; |
107 | } | |
108 | ||
7b937ca3 LT |
109 | static int same_name(struct cache_entry *a, struct cache_entry *b) |
110 | { | |
111 | int len = ce_namelen(a); | |
112 | return ce_namelen(b) == len && !memcmp(a->name, b->name, len); | |
113 | } | |
114 | ||
121481ab | 115 | int add_cache_entry(struct cache_entry *ce, int ok_to_add) |
197ee8c9 LT |
116 | { |
117 | int pos; | |
118 | ||
95fd5bf8 | 119 | pos = cache_name_pos(ce->name, htons(ce->ce_flags)); |
197ee8c9 LT |
120 | |
121 | /* existing match? Just replace it */ | |
76e7f4ec LT |
122 | if (pos >= 0) { |
123 | active_cache[pos] = ce; | |
197ee8c9 LT |
124 | return 0; |
125 | } | |
76e7f4ec | 126 | pos = -pos-1; |
197ee8c9 | 127 | |
7b937ca3 LT |
128 | /* |
129 | * Inserting a merged entry ("stage 0") into the index | |
130 | * will always replace all non-merged entries.. | |
131 | */ | |
132 | if (pos < active_nr && ce_stage(ce) == 0) { | |
133 | while (same_name(active_cache[pos], ce)) { | |
134 | ok_to_add = 1; | |
7b937ca3 LT |
135 | if (!remove_entry_at(pos)) |
136 | break; | |
137 | } | |
138 | } | |
139 | ||
121481ab LT |
140 | if (!ok_to_add) |
141 | return -1; | |
142 | ||
197ee8c9 LT |
143 | /* Make sure the array is big enough .. */ |
144 | if (active_nr == active_alloc) { | |
145 | active_alloc = alloc_nr(active_alloc); | |
146 | active_cache = realloc(active_cache, active_alloc * sizeof(struct cache_entry *)); | |
147 | } | |
148 | ||
149 | /* Add it in.. */ | |
150 | active_nr++; | |
151 | if (active_nr > pos) | |
152 | memmove(active_cache + pos + 1, active_cache + pos, (active_nr - pos - 1) * sizeof(ce)); | |
153 | active_cache[pos] = ce; | |
154 | return 0; | |
155 | } | |
156 | ||
e83c5163 LT |
157 | static int verify_hdr(struct cache_header *hdr, unsigned long size) |
158 | { | |
159 | SHA_CTX c; | |
160 | unsigned char sha1[20]; | |
161 | ||
ccc4feb5 | 162 | if (hdr->hdr_signature != htonl(CACHE_SIGNATURE)) |
e83c5163 | 163 | return error("bad signature"); |
ccc4feb5 | 164 | if (hdr->hdr_version != htonl(1)) |
e83c5163 LT |
165 | return error("bad version"); |
166 | SHA1_Init(&c); | |
167 | SHA1_Update(&c, hdr, offsetof(struct cache_header, sha1)); | |
168 | SHA1_Update(&c, hdr+1, size - sizeof(*hdr)); | |
169 | SHA1_Final(sha1, &c); | |
170 | if (memcmp(sha1, hdr->sha1, 20)) | |
171 | return error("bad header sha1"); | |
172 | return 0; | |
173 | } | |
174 | ||
175 | int read_cache(void) | |
176 | { | |
177 | int fd, i; | |
178 | struct stat st; | |
179 | unsigned long size, offset; | |
180 | void *map; | |
181 | struct cache_header *hdr; | |
182 | ||
183 | errno = EBUSY; | |
184 | if (active_cache) | |
185 | return error("more than one cachefile"); | |
186 | errno = ENOENT; | |
187 | sha1_file_directory = getenv(DB_ENVIRONMENT); | |
188 | if (!sha1_file_directory) | |
189 | sha1_file_directory = DEFAULT_DB_ENVIRONMENT; | |
190 | if (access(sha1_file_directory, X_OK) < 0) | |
191 | return error("no access to SHA1 file directory"); | |
4bb04f21 | 192 | fd = open(".git/index", O_RDONLY); |
e83c5163 LT |
193 | if (fd < 0) |
194 | return (errno == ENOENT) ? 0 : error("open failed"); | |
195 | ||
19b2860c | 196 | size = 0; // avoid gcc warning |
e83c5163 LT |
197 | map = (void *)-1; |
198 | if (!fstat(fd, &st)) { | |
e83c5163 LT |
199 | size = st.st_size; |
200 | errno = EINVAL; | |
59c1e249 | 201 | if (size >= sizeof(struct cache_header)) |
e83c5163 LT |
202 | map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0); |
203 | } | |
204 | close(fd); | |
205 | if (-1 == (int)(long)map) | |
206 | return error("mmap failed"); | |
207 | ||
208 | hdr = map; | |
209 | if (verify_hdr(hdr, size) < 0) | |
210 | goto unmap; | |
211 | ||
ccc4feb5 | 212 | active_nr = ntohl(hdr->hdr_entries); |
e83c5163 LT |
213 | active_alloc = alloc_nr(active_nr); |
214 | active_cache = calloc(active_alloc, sizeof(struct cache_entry *)); | |
215 | ||
216 | offset = sizeof(*hdr); | |
ccc4feb5 | 217 | for (i = 0; i < active_nr; i++) { |
e83c5163 LT |
218 | struct cache_entry *ce = map + offset; |
219 | offset = offset + ce_size(ce); | |
220 | active_cache[i] = ce; | |
221 | } | |
222 | return active_nr; | |
223 | ||
224 | unmap: | |
225 | munmap(map, size); | |
226 | errno = EINVAL; | |
227 | return error("verify header failed"); | |
228 | } | |
229 | ||
4990aadc LT |
230 | #define WRITE_BUFFER_SIZE 8192 |
231 | static char write_buffer[WRITE_BUFFER_SIZE]; | |
232 | static unsigned long write_buffer_len; | |
233 | ||
234 | static int ce_write(int fd, void *data, unsigned int len) | |
235 | { | |
236 | while (len) { | |
237 | unsigned int buffered = write_buffer_len; | |
238 | unsigned int partial = WRITE_BUFFER_SIZE - buffered; | |
239 | if (partial > len) | |
240 | partial = len; | |
241 | memcpy(write_buffer + buffered, data, partial); | |
242 | buffered += partial; | |
243 | if (buffered == WRITE_BUFFER_SIZE) { | |
244 | if (write(fd, write_buffer, WRITE_BUFFER_SIZE) != WRITE_BUFFER_SIZE) | |
245 | return -1; | |
246 | buffered = 0; | |
247 | } | |
248 | write_buffer_len = buffered; | |
249 | len -= partial; | |
250 | data += partial; | |
251 | } | |
252 | return 0; | |
253 | } | |
254 | ||
255 | static int ce_flush(int fd) | |
256 | { | |
257 | unsigned int left = write_buffer_len; | |
258 | if (left) { | |
259 | write_buffer_len = 0; | |
260 | if (write(fd, write_buffer, left) != left) | |
261 | return -1; | |
262 | } | |
263 | return 0; | |
264 | } | |
265 | ||
197ee8c9 LT |
266 | int write_cache(int newfd, struct cache_entry **cache, int entries) |
267 | { | |
268 | SHA_CTX c; | |
269 | struct cache_header hdr; | |
270 | int i; | |
271 | ||
ccc4feb5 LT |
272 | hdr.hdr_signature = htonl(CACHE_SIGNATURE); |
273 | hdr.hdr_version = htonl(1); | |
274 | hdr.hdr_entries = htonl(entries); | |
197ee8c9 LT |
275 | |
276 | SHA1_Init(&c); | |
277 | SHA1_Update(&c, &hdr, offsetof(struct cache_header, sha1)); | |
278 | for (i = 0; i < entries; i++) { | |
279 | struct cache_entry *ce = cache[i]; | |
280 | int size = ce_size(ce); | |
281 | SHA1_Update(&c, ce, size); | |
282 | } | |
283 | SHA1_Final(hdr.sha1, &c); | |
284 | ||
4990aadc | 285 | if (ce_write(newfd, &hdr, sizeof(hdr)) < 0) |
197ee8c9 LT |
286 | return -1; |
287 | ||
288 | for (i = 0; i < entries; i++) { | |
289 | struct cache_entry *ce = cache[i]; | |
4990aadc | 290 | if (ce_write(newfd, ce, ce_size(ce)) < 0) |
197ee8c9 LT |
291 | return -1; |
292 | } | |
4990aadc | 293 | return ce_flush(newfd); |
197ee8c9 | 294 | } |