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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 LT |
6 | #include "cache.h" |
7 | ||
8 | const char *sha1_file_directory = NULL; | |
9 | struct cache_entry **active_cache = NULL; | |
10 | unsigned int active_nr = 0, active_alloc = 0; | |
11 | ||
12 | void usage(const char *err) | |
13 | { | |
14 | fprintf(stderr, "read-tree: %s\n", err); | |
15 | exit(1); | |
16 | } | |
17 | ||
18 | static unsigned hexval(char c) | |
19 | { | |
20 | if (c >= '0' && c <= '9') | |
21 | return c - '0'; | |
22 | if (c >= 'a' && c <= 'f') | |
23 | return c - 'a' + 10; | |
24 | if (c >= 'A' && c <= 'F') | |
25 | return c - 'A' + 10; | |
26 | return ~0; | |
27 | } | |
28 | ||
29 | int get_sha1_hex(char *hex, unsigned char *sha1) | |
30 | { | |
31 | int i; | |
32 | for (i = 0; i < 20; i++) { | |
33 | unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]); | |
34 | if (val & ~0xff) | |
35 | return -1; | |
36 | *sha1++ = val; | |
37 | hex += 2; | |
38 | } | |
39 | return 0; | |
40 | } | |
41 | ||
42 | char * sha1_to_hex(unsigned char *sha1) | |
43 | { | |
44 | static char buffer[50]; | |
45 | static const char hex[] = "0123456789abcdef"; | |
46 | char *buf = buffer; | |
47 | int i; | |
48 | ||
49 | for (i = 0; i < 20; i++) { | |
50 | unsigned int val = *sha1++; | |
51 | *buf++ = hex[val >> 4]; | |
52 | *buf++ = hex[val & 0xf]; | |
53 | } | |
54 | return buffer; | |
55 | } | |
56 | ||
57 | /* | |
58 | * NOTE! This returns a statically allocated buffer, so you have to be | |
59 | * careful about using it. Do a "strdup()" if you need to save the | |
60 | * filename. | |
61 | */ | |
62 | char *sha1_file_name(unsigned char *sha1) | |
63 | { | |
64 | int i; | |
65 | static char *name, *base; | |
66 | ||
67 | if (!base) { | |
68 | char *sha1_file_directory = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT; | |
69 | int len = strlen(sha1_file_directory); | |
70 | base = malloc(len + 60); | |
71 | memcpy(base, sha1_file_directory, len); | |
72 | memset(base+len, 0, 60); | |
73 | base[len] = '/'; | |
74 | base[len+3] = '/'; | |
75 | name = base + len + 1; | |
76 | } | |
77 | for (i = 0; i < 20; i++) { | |
78 | static char hex[] = "0123456789abcdef"; | |
79 | unsigned int val = sha1[i]; | |
80 | char *pos = name + i*2 + (i > 0); | |
81 | *pos++ = hex[val >> 4]; | |
82 | *pos = hex[val & 0xf]; | |
83 | } | |
84 | return base; | |
85 | } | |
86 | ||
2ade9340 LT |
87 | int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size) |
88 | { | |
89 | unsigned char real_sha1[20]; | |
90 | SHA_CTX c; | |
91 | ||
92 | SHA1_Init(&c); | |
93 | SHA1_Update(&c, map, size); | |
94 | SHA1_Final(real_sha1, &c); | |
95 | return memcmp(sha1, real_sha1, 20) ? -1 : 0; | |
96 | } | |
97 | ||
24778e33 | 98 | void *map_sha1_file(unsigned char *sha1, unsigned long *size) |
e83c5163 | 99 | { |
e83c5163 | 100 | char *filename = sha1_file_name(sha1); |
24778e33 LT |
101 | int fd = open(filename, O_RDONLY); |
102 | struct stat st; | |
103 | void *map; | |
e83c5163 | 104 | |
e83c5163 LT |
105 | if (fd < 0) { |
106 | perror(filename); | |
107 | return NULL; | |
108 | } | |
109 | if (fstat(fd, &st) < 0) { | |
24778e33 | 110 | close(fd); |
e83c5163 LT |
111 | return NULL; |
112 | } | |
113 | map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); | |
114 | close(fd); | |
115 | if (-1 == (int)(long)map) | |
116 | return NULL; | |
24778e33 LT |
117 | *size = st.st_size; |
118 | return map; | |
119 | } | |
120 | ||
121 | void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size) | |
122 | { | |
123 | int ret, bytes; | |
124 | z_stream stream; | |
125 | char buffer[8192]; | |
126 | char *buf; | |
e83c5163 LT |
127 | |
128 | /* Get the data stream */ | |
129 | memset(&stream, 0, sizeof(stream)); | |
130 | stream.next_in = map; | |
24778e33 | 131 | stream.avail_in = mapsize; |
e83c5163 LT |
132 | stream.next_out = buffer; |
133 | stream.avail_out = sizeof(buffer); | |
134 | ||
135 | inflateInit(&stream); | |
136 | ret = inflate(&stream, 0); | |
137 | if (sscanf(buffer, "%10s %lu", type, size) != 2) | |
138 | return NULL; | |
24778e33 | 139 | |
e83c5163 LT |
140 | bytes = strlen(buffer) + 1; |
141 | buf = malloc(*size); | |
142 | if (!buf) | |
143 | return NULL; | |
144 | ||
145 | memcpy(buf, buffer + bytes, stream.total_out - bytes); | |
146 | bytes = stream.total_out - bytes; | |
147 | if (bytes < *size && ret == Z_OK) { | |
148 | stream.next_out = buf + bytes; | |
149 | stream.avail_out = *size - bytes; | |
150 | while (inflate(&stream, Z_FINISH) == Z_OK) | |
151 | /* nothing */; | |
152 | } | |
153 | inflateEnd(&stream); | |
154 | return buf; | |
155 | } | |
156 | ||
24778e33 LT |
157 | void * read_sha1_file(unsigned char *sha1, char *type, unsigned long *size) |
158 | { | |
159 | unsigned long mapsize; | |
160 | void *map, *buf; | |
161 | ||
162 | map = map_sha1_file(sha1, &mapsize); | |
163 | if (map) { | |
164 | buf = unpack_sha1_file(map, mapsize, type, size); | |
165 | munmap(map, mapsize); | |
166 | return buf; | |
167 | } | |
168 | return NULL; | |
169 | } | |
170 | ||
e83c5163 LT |
171 | int write_sha1_file(char *buf, unsigned len) |
172 | { | |
173 | int size; | |
174 | char *compressed; | |
175 | z_stream stream; | |
176 | unsigned char sha1[20]; | |
177 | SHA_CTX c; | |
178 | ||
179 | /* Set it up */ | |
180 | memset(&stream, 0, sizeof(stream)); | |
181 | deflateInit(&stream, Z_BEST_COMPRESSION); | |
182 | size = deflateBound(&stream, len); | |
183 | compressed = malloc(size); | |
184 | ||
185 | /* Compress it */ | |
186 | stream.next_in = buf; | |
187 | stream.avail_in = len; | |
188 | stream.next_out = compressed; | |
189 | stream.avail_out = size; | |
190 | while (deflate(&stream, Z_FINISH) == Z_OK) | |
191 | /* nothing */; | |
192 | deflateEnd(&stream); | |
193 | size = stream.total_out; | |
194 | ||
195 | /* Sha1.. */ | |
196 | SHA1_Init(&c); | |
197 | SHA1_Update(&c, compressed, size); | |
198 | SHA1_Final(sha1, &c); | |
199 | ||
200 | if (write_sha1_buffer(sha1, compressed, size) < 0) | |
201 | return -1; | |
202 | printf("%s\n", sha1_to_hex(sha1)); | |
203 | return 0; | |
204 | } | |
205 | ||
206 | int write_sha1_buffer(unsigned char *sha1, void *buf, unsigned int size) | |
207 | { | |
208 | char *filename = sha1_file_name(sha1); | |
19b2860c | 209 | int fd; |
e83c5163 LT |
210 | |
211 | fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666); | |
212 | if (fd < 0) | |
213 | return (errno == EEXIST) ? 0 : -1; | |
214 | write(fd, buf, size); | |
215 | close(fd); | |
216 | return 0; | |
217 | } | |
218 | ||
219 | static int error(const char * string) | |
220 | { | |
221 | fprintf(stderr, "error: %s\n", string); | |
222 | return -1; | |
223 | } | |
224 | ||
225 | static int verify_hdr(struct cache_header *hdr, unsigned long size) | |
226 | { | |
227 | SHA_CTX c; | |
228 | unsigned char sha1[20]; | |
229 | ||
230 | if (hdr->signature != CACHE_SIGNATURE) | |
231 | return error("bad signature"); | |
232 | if (hdr->version != 1) | |
233 | return error("bad version"); | |
234 | SHA1_Init(&c); | |
235 | SHA1_Update(&c, hdr, offsetof(struct cache_header, sha1)); | |
236 | SHA1_Update(&c, hdr+1, size - sizeof(*hdr)); | |
237 | SHA1_Final(sha1, &c); | |
238 | if (memcmp(sha1, hdr->sha1, 20)) | |
239 | return error("bad header sha1"); | |
240 | return 0; | |
241 | } | |
242 | ||
243 | int read_cache(void) | |
244 | { | |
245 | int fd, i; | |
246 | struct stat st; | |
247 | unsigned long size, offset; | |
248 | void *map; | |
249 | struct cache_header *hdr; | |
250 | ||
251 | errno = EBUSY; | |
252 | if (active_cache) | |
253 | return error("more than one cachefile"); | |
254 | errno = ENOENT; | |
255 | sha1_file_directory = getenv(DB_ENVIRONMENT); | |
256 | if (!sha1_file_directory) | |
257 | sha1_file_directory = DEFAULT_DB_ENVIRONMENT; | |
258 | if (access(sha1_file_directory, X_OK) < 0) | |
259 | return error("no access to SHA1 file directory"); | |
260 | fd = open(".dircache/index", O_RDONLY); | |
261 | if (fd < 0) | |
262 | return (errno == ENOENT) ? 0 : error("open failed"); | |
263 | ||
19b2860c | 264 | size = 0; // avoid gcc warning |
e83c5163 LT |
265 | map = (void *)-1; |
266 | if (!fstat(fd, &st)) { | |
e83c5163 LT |
267 | size = st.st_size; |
268 | errno = EINVAL; | |
59c1e249 | 269 | if (size >= sizeof(struct cache_header)) |
e83c5163 LT |
270 | map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0); |
271 | } | |
272 | close(fd); | |
273 | if (-1 == (int)(long)map) | |
274 | return error("mmap failed"); | |
275 | ||
276 | hdr = map; | |
277 | if (verify_hdr(hdr, size) < 0) | |
278 | goto unmap; | |
279 | ||
280 | active_nr = hdr->entries; | |
281 | active_alloc = alloc_nr(active_nr); | |
282 | active_cache = calloc(active_alloc, sizeof(struct cache_entry *)); | |
283 | ||
284 | offset = sizeof(*hdr); | |
285 | for (i = 0; i < hdr->entries; i++) { | |
286 | struct cache_entry *ce = map + offset; | |
287 | offset = offset + ce_size(ce); | |
288 | active_cache[i] = ce; | |
289 | } | |
290 | return active_nr; | |
291 | ||
292 | unmap: | |
293 | munmap(map, size); | |
294 | errno = EINVAL; | |
295 | return error("verify header failed"); | |
296 | } | |
297 |