Fix diff-tree recursion.
[git/git.git] / read-cache.c
CommitLineData
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
8const char *sha1_file_directory = NULL;
9struct cache_entry **active_cache = NULL;
10unsigned int active_nr = 0, active_alloc = 0;
11
121481ab 12void usage(const char *err, ...)
e83c5163 13{
121481ab
LT
14 va_list args;
15
16 va_start(args, err);
17 vfprintf(stderr, err, args);
18 va_end(args);
e83c5163
LT
19 exit(1);
20}
21
22static unsigned hexval(char c)
23{
24 if (c >= '0' && c <= '9')
25 return c - '0';
26 if (c >= 'a' && c <= 'f')
27 return c - 'a' + 10;
28 if (c >= 'A' && c <= 'F')
29 return c - 'A' + 10;
30 return ~0;
31}
32
197ee8c9 33int get_sha1_hex(const char *hex, unsigned char *sha1)
e83c5163
LT
34{
35 int i;
36 for (i = 0; i < 20; i++) {
37 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
38 if (val & ~0xff)
39 return -1;
40 *sha1++ = val;
41 hex += 2;
42 }
43 return 0;
44}
45
197ee8c9 46char * sha1_to_hex(const unsigned char *sha1)
e83c5163
LT
47{
48 static char buffer[50];
49 static const char hex[] = "0123456789abcdef";
50 char *buf = buffer;
51 int i;
52
53 for (i = 0; i < 20; i++) {
54 unsigned int val = *sha1++;
55 *buf++ = hex[val >> 4];
56 *buf++ = hex[val & 0xf];
57 }
58 return buffer;
59}
60
61/*
62 * NOTE! This returns a statically allocated buffer, so you have to be
63 * careful about using it. Do a "strdup()" if you need to save the
64 * filename.
65 */
73134b6d 66char *sha1_file_name(const unsigned char *sha1)
e83c5163
LT
67{
68 int i;
69 static char *name, *base;
70
71 if (!base) {
72 char *sha1_file_directory = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
73 int len = strlen(sha1_file_directory);
74 base = malloc(len + 60);
75 memcpy(base, sha1_file_directory, len);
76 memset(base+len, 0, 60);
77 base[len] = '/';
78 base[len+3] = '/';
79 name = base + len + 1;
80 }
81 for (i = 0; i < 20; i++) {
82 static char hex[] = "0123456789abcdef";
83 unsigned int val = sha1[i];
84 char *pos = name + i*2 + (i > 0);
85 *pos++ = hex[val >> 4];
86 *pos = hex[val & 0xf];
87 }
88 return base;
89}
90
2ade9340
LT
91int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size)
92{
93 unsigned char real_sha1[20];
94 SHA_CTX c;
95
96 SHA1_Init(&c);
97 SHA1_Update(&c, map, size);
98 SHA1_Final(real_sha1, &c);
99 return memcmp(sha1, real_sha1, 20) ? -1 : 0;
100}
101
73134b6d 102void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
e83c5163 103{
e83c5163 104 char *filename = sha1_file_name(sha1);
24778e33
LT
105 int fd = open(filename, O_RDONLY);
106 struct stat st;
107 void *map;
e83c5163 108
e83c5163
LT
109 if (fd < 0) {
110 perror(filename);
111 return NULL;
112 }
113 if (fstat(fd, &st) < 0) {
24778e33 114 close(fd);
e83c5163
LT
115 return NULL;
116 }
117 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
118 close(fd);
119 if (-1 == (int)(long)map)
120 return NULL;
24778e33
LT
121 *size = st.st_size;
122 return map;
123}
124
125void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
126{
127 int ret, bytes;
128 z_stream stream;
129 char buffer[8192];
130 char *buf;
e83c5163
LT
131
132 /* Get the data stream */
133 memset(&stream, 0, sizeof(stream));
134 stream.next_in = map;
24778e33 135 stream.avail_in = mapsize;
e83c5163
LT
136 stream.next_out = buffer;
137 stream.avail_out = sizeof(buffer);
138
139 inflateInit(&stream);
140 ret = inflate(&stream, 0);
141 if (sscanf(buffer, "%10s %lu", type, size) != 2)
142 return NULL;
24778e33 143
e83c5163
LT
144 bytes = strlen(buffer) + 1;
145 buf = malloc(*size);
146 if (!buf)
147 return NULL;
148
149 memcpy(buf, buffer + bytes, stream.total_out - bytes);
150 bytes = stream.total_out - bytes;
151 if (bytes < *size && ret == Z_OK) {
152 stream.next_out = buf + bytes;
153 stream.avail_out = *size - bytes;
154 while (inflate(&stream, Z_FINISH) == Z_OK)
155 /* nothing */;
156 }
157 inflateEnd(&stream);
158 return buf;
159}
160
73134b6d 161void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
24778e33
LT
162{
163 unsigned long mapsize;
164 void *map, *buf;
165
166 map = map_sha1_file(sha1, &mapsize);
167 if (map) {
168 buf = unpack_sha1_file(map, mapsize, type, size);
169 munmap(map, mapsize);
170 return buf;
171 }
172 return NULL;
173}
174
d6d3f9d0 175int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1)
e83c5163
LT
176{
177 int size;
178 char *compressed;
179 z_stream stream;
180 unsigned char sha1[20];
181 SHA_CTX c;
182
183 /* Set it up */
184 memset(&stream, 0, sizeof(stream));
185 deflateInit(&stream, Z_BEST_COMPRESSION);
186 size = deflateBound(&stream, len);
187 compressed = malloc(size);
188
189 /* Compress it */
190 stream.next_in = buf;
191 stream.avail_in = len;
192 stream.next_out = compressed;
193 stream.avail_out = size;
194 while (deflate(&stream, Z_FINISH) == Z_OK)
195 /* nothing */;
196 deflateEnd(&stream);
197 size = stream.total_out;
198
199 /* Sha1.. */
200 SHA1_Init(&c);
201 SHA1_Update(&c, compressed, size);
202 SHA1_Final(sha1, &c);
203
204 if (write_sha1_buffer(sha1, compressed, size) < 0)
205 return -1;
d6d3f9d0
LT
206 if (returnsha1)
207 memcpy(returnsha1, sha1, 20);
e83c5163
LT
208 return 0;
209}
210
73134b6d 211int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size)
e83c5163
LT
212{
213 char *filename = sha1_file_name(sha1);
19b2860c 214 int fd;
e83c5163
LT
215
216 fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
217 if (fd < 0)
218 return (errno == EEXIST) ? 0 : -1;
219 write(fd, buf, size);
220 close(fd);
221 return 0;
222}
223
224static int error(const char * string)
225{
226 fprintf(stderr, "error: %s\n", string);
227 return -1;
228}
229
734aab75
LT
230int cache_match_stat(struct cache_entry *ce, struct stat *st)
231{
232 unsigned int changed = 0;
233
234 if (ce->mtime.sec != (unsigned int)st->st_mtim.tv_sec ||
235 ce->mtime.nsec != (unsigned int)st->st_mtim.tv_nsec)
236 changed |= MTIME_CHANGED;
237 if (ce->ctime.sec != (unsigned int)st->st_ctim.tv_sec ||
238 ce->ctime.nsec != (unsigned int)st->st_ctim.tv_nsec)
239 changed |= CTIME_CHANGED;
240 if (ce->st_uid != (unsigned int)st->st_uid ||
241 ce->st_gid != (unsigned int)st->st_gid)
242 changed |= OWNER_CHANGED;
243 if (ce->st_mode != (unsigned int)st->st_mode)
244 changed |= MODE_CHANGED;
245 if (ce->st_dev != (unsigned int)st->st_dev ||
246 ce->st_ino != (unsigned int)st->st_ino)
247 changed |= INODE_CHANGED;
248 if (ce->st_size != (unsigned int)st->st_size)
249 changed |= DATA_CHANGED;
250 return changed;
251}
252
79517a06 253int cache_name_compare(const char *name1, int len1, const char *name2, int len2)
eb38c22f
LT
254{
255 int len = len1 < len2 ? len1 : len2;
256 int cmp;
257
258 cmp = memcmp(name1, name2, len);
259 if (cmp)
260 return cmp;
261 if (len1 < len2)
262 return -1;
263 if (len1 > len2)
264 return 1;
265 return 0;
266}
267
268int cache_name_pos(const char *name, int namelen)
269{
270 int first, last;
271
272 first = 0;
273 last = active_nr;
274 while (last > first) {
275 int next = (last + first) >> 1;
276 struct cache_entry *ce = active_cache[next];
277 int cmp = cache_name_compare(name, namelen, ce->name, ce->namelen);
278 if (!cmp)
279 return -next-1;
280 if (cmp < 0) {
281 last = next;
282 continue;
283 }
284 first = next+1;
285 }
286 return first;
287}
288
197ee8c9
LT
289int remove_file_from_cache(char *path)
290{
291 int pos = cache_name_pos(path, strlen(path));
292 if (pos < 0) {
293 pos = -pos-1;
294 active_nr--;
295 if (pos < active_nr)
296 memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos - 1) * sizeof(struct cache_entry *));
297 }
298 return 0;
299}
300
121481ab 301int add_cache_entry(struct cache_entry *ce, int ok_to_add)
197ee8c9
LT
302{
303 int pos;
304
305 pos = cache_name_pos(ce->name, ce->namelen);
306
307 /* existing match? Just replace it */
308 if (pos < 0) {
309 active_cache[-pos-1] = ce;
310 return 0;
311 }
312
121481ab
LT
313 if (!ok_to_add)
314 return -1;
315
197ee8c9
LT
316 /* Make sure the array is big enough .. */
317 if (active_nr == active_alloc) {
318 active_alloc = alloc_nr(active_alloc);
319 active_cache = realloc(active_cache, active_alloc * sizeof(struct cache_entry *));
320 }
321
322 /* Add it in.. */
323 active_nr++;
324 if (active_nr > pos)
325 memmove(active_cache + pos + 1, active_cache + pos, (active_nr - pos - 1) * sizeof(ce));
326 active_cache[pos] = ce;
327 return 0;
328}
329
e83c5163
LT
330static int verify_hdr(struct cache_header *hdr, unsigned long size)
331{
332 SHA_CTX c;
333 unsigned char sha1[20];
334
335 if (hdr->signature != CACHE_SIGNATURE)
336 return error("bad signature");
337 if (hdr->version != 1)
338 return error("bad version");
339 SHA1_Init(&c);
340 SHA1_Update(&c, hdr, offsetof(struct cache_header, sha1));
341 SHA1_Update(&c, hdr+1, size - sizeof(*hdr));
342 SHA1_Final(sha1, &c);
343 if (memcmp(sha1, hdr->sha1, 20))
344 return error("bad header sha1");
345 return 0;
346}
347
348int read_cache(void)
349{
350 int fd, i;
351 struct stat st;
352 unsigned long size, offset;
353 void *map;
354 struct cache_header *hdr;
355
356 errno = EBUSY;
357 if (active_cache)
358 return error("more than one cachefile");
359 errno = ENOENT;
360 sha1_file_directory = getenv(DB_ENVIRONMENT);
361 if (!sha1_file_directory)
362 sha1_file_directory = DEFAULT_DB_ENVIRONMENT;
363 if (access(sha1_file_directory, X_OK) < 0)
364 return error("no access to SHA1 file directory");
365 fd = open(".dircache/index", O_RDONLY);
366 if (fd < 0)
367 return (errno == ENOENT) ? 0 : error("open failed");
368
19b2860c 369 size = 0; // avoid gcc warning
e83c5163
LT
370 map = (void *)-1;
371 if (!fstat(fd, &st)) {
e83c5163
LT
372 size = st.st_size;
373 errno = EINVAL;
59c1e249 374 if (size >= sizeof(struct cache_header))
e83c5163
LT
375 map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
376 }
377 close(fd);
378 if (-1 == (int)(long)map)
379 return error("mmap failed");
380
381 hdr = map;
382 if (verify_hdr(hdr, size) < 0)
383 goto unmap;
384
385 active_nr = hdr->entries;
386 active_alloc = alloc_nr(active_nr);
387 active_cache = calloc(active_alloc, sizeof(struct cache_entry *));
388
389 offset = sizeof(*hdr);
390 for (i = 0; i < hdr->entries; i++) {
391 struct cache_entry *ce = map + offset;
392 offset = offset + ce_size(ce);
393 active_cache[i] = ce;
394 }
395 return active_nr;
396
397unmap:
398 munmap(map, size);
399 errno = EINVAL;
400 return error("verify header failed");
401}
402
197ee8c9
LT
403int write_cache(int newfd, struct cache_entry **cache, int entries)
404{
405 SHA_CTX c;
406 struct cache_header hdr;
407 int i;
408
409 hdr.signature = CACHE_SIGNATURE;
410 hdr.version = 1;
411 hdr.entries = entries;
412
413 SHA1_Init(&c);
414 SHA1_Update(&c, &hdr, offsetof(struct cache_header, sha1));
415 for (i = 0; i < entries; i++) {
416 struct cache_entry *ce = cache[i];
417 int size = ce_size(ce);
418 SHA1_Update(&c, ce, size);
419 }
420 SHA1_Final(hdr.sha1, &c);
421
422 if (write(newfd, &hdr, sizeof(hdr)) != sizeof(hdr))
423 return -1;
424
425 for (i = 0; i < entries; i++) {
426 struct cache_entry *ce = cache[i];
427 int size = ce_size(ce);
428 if (write(newfd, ce, size) != size)
429 return -1;
430 }
431 return 0;
432}