[PATCH] Fix warning in convert-cache
[git/git.git] / update-cache.c
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 */
6 #include <signal.h>
7 #include "cache.h"
8
9 /*
10 * Default to not allowing changes to the list of files. The
11 * tool doesn't actually care, but this makes it harder to add
12 * files to the revision control by mistake by doing something
13 * like "update-cache *" and suddenly having all the object
14 * files be revision controlled.
15 */
16 static int allow_add = 0, allow_remove = 0, not_new = 0;
17
18 /* Three functions to allow overloaded pointer return; see linux/err.h */
19 static inline void *ERR_PTR(long error)
20 {
21 return (void *) error;
22 }
23
24 static inline long PTR_ERR(const void *ptr)
25 {
26 return (long) ptr;
27 }
28
29 static inline long IS_ERR(const void *ptr)
30 {
31 return (unsigned long)ptr > (unsigned long)-1000L;
32 }
33
34 static int index_fd(unsigned char *sha1, int fd, struct stat *st)
35 {
36 z_stream stream;
37 unsigned long size = st->st_size;
38 int max_out_bytes = size + 200;
39 void *out = xmalloc(max_out_bytes);
40 void *metadata = xmalloc(200);
41 int metadata_size;
42 void *in;
43 SHA_CTX c;
44
45 in = "";
46 if (size)
47 in = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
48 close(fd);
49 if (!out || (int)(long)in == -1)
50 return -1;
51
52 metadata_size = 1+sprintf(metadata, "blob %lu", size);
53
54 SHA1_Init(&c);
55 SHA1_Update(&c, metadata, metadata_size);
56 SHA1_Update(&c, in, size);
57 SHA1_Final(sha1, &c);
58
59 memset(&stream, 0, sizeof(stream));
60 deflateInit(&stream, Z_BEST_COMPRESSION);
61
62 /*
63 * ASCII size + nul byte
64 */
65 stream.next_in = metadata;
66 stream.avail_in = metadata_size;
67 stream.next_out = out;
68 stream.avail_out = max_out_bytes;
69 while (deflate(&stream, 0) == Z_OK)
70 /* nothing */;
71
72 /*
73 * File content
74 */
75 stream.next_in = in;
76 stream.avail_in = size;
77 while (deflate(&stream, Z_FINISH) == Z_OK)
78 /*nothing */;
79
80 deflateEnd(&stream);
81
82 return write_sha1_buffer(sha1, out, stream.total_out);
83 }
84
85 /*
86 * This only updates the "non-critical" parts of the directory
87 * cache, ie the parts that aren't tracked by GIT, and only used
88 * to validate the cache.
89 */
90 static void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
91 {
92 ce->ce_ctime.sec = htonl(st->st_ctime);
93 ce->ce_mtime.sec = htonl(st->st_mtime);
94 #ifdef NSEC
95 ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
96 ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
97 #endif
98 ce->ce_dev = htonl(st->st_dev);
99 ce->ce_ino = htonl(st->st_ino);
100 ce->ce_uid = htonl(st->st_uid);
101 ce->ce_gid = htonl(st->st_gid);
102 ce->ce_size = htonl(st->st_size);
103 }
104
105 static int add_file_to_cache(char *path)
106 {
107 int size, namelen;
108 struct cache_entry *ce;
109 struct stat st;
110 int fd;
111
112 fd = open(path, O_RDONLY);
113 if (fd < 0) {
114 if (errno == ENOENT || errno == ENOTDIR) {
115 if (allow_remove)
116 return remove_file_from_cache(path);
117 }
118 return -1;
119 }
120 if (fstat(fd, &st) < 0) {
121 close(fd);
122 return -1;
123 }
124 namelen = strlen(path);
125 size = cache_entry_size(namelen);
126 ce = xmalloc(size);
127 memset(ce, 0, size);
128 memcpy(ce->name, path, namelen);
129 fill_stat_cache_info(ce, &st);
130 ce->ce_mode = create_ce_mode(st.st_mode);
131 ce->ce_flags = htons(namelen);
132
133 if (index_fd(ce->sha1, fd, &st) < 0)
134 return -1;
135
136 return add_cache_entry(ce, allow_add);
137 }
138
139 static int match_data(int fd, void *buffer, unsigned long size)
140 {
141 while (size) {
142 char compare[1024];
143 int ret = read(fd, compare, sizeof(compare));
144
145 if (ret <= 0 || ret > size || memcmp(buffer, compare, ret))
146 return -1;
147 size -= ret;
148 buffer += ret;
149 }
150 return 0;
151 }
152
153 static int compare_data(struct cache_entry *ce, unsigned long expected_size)
154 {
155 int match = -1;
156 int fd = open(ce->name, O_RDONLY);
157
158 if (fd >= 0) {
159 void *buffer;
160 unsigned long size;
161 char type[10];
162
163 buffer = read_sha1_file(ce->sha1, type, &size);
164 if (buffer) {
165 if (size == expected_size && !strcmp(type, "blob"))
166 match = match_data(fd, buffer, size);
167 free(buffer);
168 }
169 close(fd);
170 }
171 return match;
172 }
173
174 /*
175 * "refresh" does not calculate a new sha1 file or bring the
176 * cache up-to-date for mode/content changes. But what it
177 * _does_ do is to "re-match" the stat information of a file
178 * with the cache, so that you can refresh the cache for a
179 * file that hasn't been changed but where the stat entry is
180 * out of date.
181 *
182 * For example, you'd want to do this after doing a "read-tree",
183 * to link up the stat cache details with the proper files.
184 */
185 static struct cache_entry *refresh_entry(struct cache_entry *ce)
186 {
187 struct stat st;
188 struct cache_entry *updated;
189 int changed, size;
190
191 if (stat(ce->name, &st) < 0)
192 return ERR_PTR(-errno);
193
194 changed = cache_match_stat(ce, &st);
195 if (!changed)
196 return ce;
197
198 /*
199 * If the mode has changed, there's no point in trying
200 * to refresh the entry - it's not going to match
201 */
202 if (changed & MODE_CHANGED)
203 return ERR_PTR(-EINVAL);
204
205 if (compare_data(ce, st.st_size))
206 return ERR_PTR(-EINVAL);
207
208 size = ce_size(ce);
209 updated = xmalloc(size);
210 memcpy(updated, ce, size);
211 fill_stat_cache_info(updated, &st);
212 return updated;
213 }
214
215 static int refresh_cache(void)
216 {
217 int i;
218 int has_errors = 0;
219
220 for (i = 0; i < active_nr; i++) {
221 struct cache_entry *ce, *new;
222 ce = active_cache[i];
223 if (ce_stage(ce)) {
224 printf("%s: needs merge\n", ce->name);
225 has_errors = 1;
226 while ((i < active_nr) &&
227 ! strcmp(active_cache[i]->name, ce->name))
228 i++;
229 i--;
230 continue;
231 }
232
233 new = refresh_entry(ce);
234 if (IS_ERR(new)) {
235 if (!(not_new && PTR_ERR(new) == -ENOENT)) {
236 printf("%s: needs update\n", ce->name);
237 has_errors = 1;
238 }
239 continue;
240 }
241 active_cache[i] = new;
242 }
243 return has_errors;
244 }
245
246 /*
247 * We fundamentally don't like some paths: we don't want
248 * dot or dot-dot anywhere, and in fact, we don't even want
249 * any other dot-files (.git or anything else). They
250 * are hidden, for chist sake.
251 *
252 * Also, we don't want double slashes or slashes at the
253 * end that can make pathnames ambiguous.
254 */
255 static int verify_path(char *path)
256 {
257 char c;
258
259 goto inside;
260 for (;;) {
261 if (!c)
262 return 1;
263 if (c == '/') {
264 inside:
265 c = *path++;
266 if (c != '/' && c != '.' && c != '\0')
267 continue;
268 return 0;
269 }
270 c = *path++;
271 }
272 }
273
274 static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
275 {
276 int size, len;
277 unsigned int mode;
278 unsigned char sha1[20];
279 struct cache_entry *ce;
280
281 if (sscanf(arg1, "%o", &mode) != 1)
282 return -1;
283 if (get_sha1_hex(arg2, sha1))
284 return -1;
285 if (!verify_path(arg3))
286 return -1;
287
288 len = strlen(arg3);
289 size = cache_entry_size(len);
290 ce = xmalloc(size);
291 memset(ce, 0, size);
292
293 memcpy(ce->sha1, sha1, 20);
294 memcpy(ce->name, arg3, len);
295 ce->ce_flags = htons(len);
296 ce->ce_mode = create_ce_mode(mode);
297 return add_cache_entry(ce, allow_add);
298 }
299
300 static const char *lockfile_name = NULL;
301
302 static void remove_lock_file(void)
303 {
304 if (lockfile_name)
305 unlink(lockfile_name);
306 }
307
308 static void remove_lock_file_on_signal(int signo)
309 {
310 remove_lock_file();
311 }
312
313 int main(int argc, char **argv)
314 {
315 int i, newfd, entries, has_errors = 0;
316 int allow_options = 1;
317 static char lockfile[MAXPATHLEN+1];
318 const char *indexfile = get_index_file();
319
320 snprintf(lockfile, sizeof(lockfile), "%s.lock", indexfile);
321
322 newfd = open(lockfile, O_RDWR | O_CREAT | O_EXCL, 0600);
323 if (newfd < 0)
324 die("unable to create new cachefile");
325
326 signal(SIGINT, remove_lock_file_on_signal);
327 atexit(remove_lock_file);
328 lockfile_name = lockfile;
329
330 entries = read_cache();
331 if (entries < 0)
332 die("cache corrupted");
333
334 for (i = 1 ; i < argc; i++) {
335 char *path = argv[i];
336
337 if (allow_options && *path == '-') {
338 if (!strcmp(path, "--")) {
339 allow_options = 0;
340 continue;
341 }
342 if (!strcmp(path, "--add")) {
343 allow_add = 1;
344 continue;
345 }
346 if (!strcmp(path, "--remove")) {
347 allow_remove = 1;
348 continue;
349 }
350 if (!strcmp(path, "--refresh")) {
351 has_errors |= refresh_cache();
352 continue;
353 }
354 if (!strcmp(path, "--cacheinfo")) {
355 if (i+3 >= argc || add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
356 die("update-cache: --cacheinfo <mode> <sha1> <path>");
357 i += 3;
358 continue;
359 }
360 if (!strcmp(path, "--ignore-missing")) {
361 not_new = 1;
362 continue;
363 }
364 die("unknown option %s", path);
365 }
366 if (!verify_path(path)) {
367 fprintf(stderr, "Ignoring path %s\n", argv[i]);
368 continue;
369 }
370 if (add_file_to_cache(path))
371 die("Unable to add %s to database", path);
372 }
373 if (write_cache(newfd, active_cache, active_nr) || rename(lockfile, indexfile))
374 die("Unable to write new cachefile");
375
376 lockfile_name = NULL;
377 return has_errors;
378 }