Split "git-pull-script" into two parts
[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 /*
35 * This only updates the "non-critical" parts of the directory
36 * cache, ie the parts that aren't tracked by GIT, and only used
37 * to validate the cache.
38 */
39 static void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
40 {
41 ce->ce_ctime.sec = htonl(st->st_ctime);
42 ce->ce_mtime.sec = htonl(st->st_mtime);
43 #ifdef NSEC
44 ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
45 ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
46 #endif
47 ce->ce_dev = htonl(st->st_dev);
48 ce->ce_ino = htonl(st->st_ino);
49 ce->ce_uid = htonl(st->st_uid);
50 ce->ce_gid = htonl(st->st_gid);
51 ce->ce_size = htonl(st->st_size);
52 }
53
54 static int add_file_to_cache(char *path)
55 {
56 int size, namelen;
57 struct cache_entry *ce;
58 struct stat st;
59 int fd;
60 unsigned int len;
61 char target[1024];
62
63 if (lstat(path, &st) < 0) {
64 if (errno == ENOENT || errno == ENOTDIR) {
65 if (allow_remove)
66 return remove_file_from_cache(path);
67 }
68 return -1;
69 }
70 namelen = strlen(path);
71 size = cache_entry_size(namelen);
72 ce = xmalloc(size);
73 memset(ce, 0, size);
74 memcpy(ce->name, path, namelen);
75 fill_stat_cache_info(ce, &st);
76 ce->ce_mode = create_ce_mode(st.st_mode);
77 ce->ce_flags = htons(namelen);
78 switch (st.st_mode & S_IFMT) {
79 case S_IFREG:
80 fd = open(path, O_RDONLY);
81 if (fd < 0)
82 return -1;
83 if (index_fd(ce->sha1, fd, &st) < 0)
84 return -1;
85 break;
86 case S_IFLNK:
87 len = readlink(path, target, sizeof(target));
88 if (len == -1 || len+1 > sizeof(target))
89 return -1;
90 if (write_sha1_file(target, len, "blob", ce->sha1))
91 return -1;
92 break;
93 default:
94 return -1;
95 }
96 return add_cache_entry(ce, allow_add);
97 }
98
99 static int match_data(int fd, void *buffer, unsigned long size)
100 {
101 while (size) {
102 char compare[1024];
103 int ret = read(fd, compare, sizeof(compare));
104
105 if (ret <= 0 || ret > size || memcmp(buffer, compare, ret))
106 return -1;
107 size -= ret;
108 buffer += ret;
109 }
110 return 0;
111 }
112
113 static int compare_data(struct cache_entry *ce, unsigned long expected_size)
114 {
115 int match = -1;
116 int fd = open(ce->name, O_RDONLY);
117
118 if (fd >= 0) {
119 void *buffer;
120 unsigned long size;
121 char type[10];
122
123 buffer = read_sha1_file(ce->sha1, type, &size);
124 if (buffer) {
125 if (size == expected_size && !strcmp(type, "blob"))
126 match = match_data(fd, buffer, size);
127 free(buffer);
128 }
129 close(fd);
130 }
131 return match;
132 }
133
134 /*
135 * "refresh" does not calculate a new sha1 file or bring the
136 * cache up-to-date for mode/content changes. But what it
137 * _does_ do is to "re-match" the stat information of a file
138 * with the cache, so that you can refresh the cache for a
139 * file that hasn't been changed but where the stat entry is
140 * out of date.
141 *
142 * For example, you'd want to do this after doing a "read-tree",
143 * to link up the stat cache details with the proper files.
144 */
145 static struct cache_entry *refresh_entry(struct cache_entry *ce)
146 {
147 struct stat st;
148 struct cache_entry *updated;
149 int changed, size;
150
151 if (lstat(ce->name, &st) < 0)
152 return ERR_PTR(-errno);
153
154 changed = cache_match_stat(ce, &st);
155 if (!changed)
156 return ce;
157
158 /*
159 * If the mode or type has changed, there's no point in trying
160 * to refresh the entry - it's not going to match
161 */
162 if (changed & (MODE_CHANGED | TYPE_CHANGED))
163 return ERR_PTR(-EINVAL);
164
165 if (compare_data(ce, st.st_size))
166 return ERR_PTR(-EINVAL);
167
168 size = ce_size(ce);
169 updated = xmalloc(size);
170 memcpy(updated, ce, size);
171 fill_stat_cache_info(updated, &st);
172 return updated;
173 }
174
175 static int refresh_cache(void)
176 {
177 int i;
178 int has_errors = 0;
179
180 for (i = 0; i < active_nr; i++) {
181 struct cache_entry *ce, *new;
182 ce = active_cache[i];
183 if (ce_stage(ce)) {
184 printf("%s: needs merge\n", ce->name);
185 has_errors = 1;
186 while ((i < active_nr) &&
187 ! strcmp(active_cache[i]->name, ce->name))
188 i++;
189 i--;
190 continue;
191 }
192
193 new = refresh_entry(ce);
194 if (IS_ERR(new)) {
195 if (!(not_new && PTR_ERR(new) == -ENOENT)) {
196 printf("%s: needs update\n", ce->name);
197 has_errors = 1;
198 }
199 continue;
200 }
201 active_cache[i] = new;
202 }
203 return has_errors;
204 }
205
206 /*
207 * We fundamentally don't like some paths: we don't want
208 * dot or dot-dot anywhere, and in fact, we don't even want
209 * any other dot-files (.git or anything else). They
210 * are hidden, for chist sake.
211 *
212 * Also, we don't want double slashes or slashes at the
213 * end that can make pathnames ambiguous.
214 */
215 static int verify_path(char *path)
216 {
217 char c;
218
219 goto inside;
220 for (;;) {
221 if (!c)
222 return 1;
223 if (c == '/') {
224 inside:
225 c = *path++;
226 if (c != '/' && c != '.' && c != '\0')
227 continue;
228 return 0;
229 }
230 c = *path++;
231 }
232 }
233
234 static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
235 {
236 int size, len;
237 unsigned int mode;
238 unsigned char sha1[20];
239 struct cache_entry *ce;
240
241 if (sscanf(arg1, "%o", &mode) != 1)
242 return -1;
243 if (get_sha1_hex(arg2, sha1))
244 return -1;
245 if (!verify_path(arg3))
246 return -1;
247
248 len = strlen(arg3);
249 size = cache_entry_size(len);
250 ce = xmalloc(size);
251 memset(ce, 0, size);
252
253 memcpy(ce->sha1, sha1, 20);
254 memcpy(ce->name, arg3, len);
255 ce->ce_flags = htons(len);
256 ce->ce_mode = create_ce_mode(mode);
257 return add_cache_entry(ce, allow_add);
258 }
259
260 static const char *lockfile_name = NULL;
261
262 static void remove_lock_file(void)
263 {
264 if (lockfile_name)
265 unlink(lockfile_name);
266 }
267
268 static void remove_lock_file_on_signal(int signo)
269 {
270 remove_lock_file();
271 }
272
273 int main(int argc, char **argv)
274 {
275 int i, newfd, entries, has_errors = 0;
276 int allow_options = 1;
277 static char lockfile[MAXPATHLEN+1];
278 const char *indexfile = get_index_file();
279
280 snprintf(lockfile, sizeof(lockfile), "%s.lock", indexfile);
281
282 newfd = open(lockfile, O_RDWR | O_CREAT | O_EXCL, 0600);
283 if (newfd < 0)
284 die("unable to create new cachefile");
285
286 signal(SIGINT, remove_lock_file_on_signal);
287 atexit(remove_lock_file);
288 lockfile_name = lockfile;
289
290 entries = read_cache();
291 if (entries < 0)
292 die("cache corrupted");
293
294 for (i = 1 ; i < argc; i++) {
295 char *path = argv[i];
296
297 if (allow_options && *path == '-') {
298 if (!strcmp(path, "--")) {
299 allow_options = 0;
300 continue;
301 }
302 if (!strcmp(path, "--add")) {
303 allow_add = 1;
304 continue;
305 }
306 if (!strcmp(path, "--remove")) {
307 allow_remove = 1;
308 continue;
309 }
310 if (!strcmp(path, "--refresh")) {
311 has_errors |= refresh_cache();
312 continue;
313 }
314 if (!strcmp(path, "--cacheinfo")) {
315 if (i+3 >= argc || add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
316 die("update-cache: --cacheinfo <mode> <sha1> <path>");
317 i += 3;
318 continue;
319 }
320 if (!strcmp(path, "--force-remove")) {
321 if (argc <= i + 1)
322 die("update-cache: --force-remove <path>");
323 if (remove_file_from_cache(argv[i+1]))
324 die("update-cache: --force-remove cannot remove %s", argv[i+1]);
325 i++;
326 continue;
327 }
328
329 if (!strcmp(path, "--ignore-missing")) {
330 not_new = 1;
331 continue;
332 }
333 die("unknown option %s", path);
334 }
335 if (!verify_path(path)) {
336 fprintf(stderr, "Ignoring path %s\n", argv[i]);
337 continue;
338 }
339 if (add_file_to_cache(path))
340 die("Unable to add %s to database", path);
341 }
342 if (write_cache(newfd, active_cache, active_nr) || rename(lockfile, indexfile))
343 die("Unable to write new cachefile");
344
345 lockfile_name = NULL;
346 return has_errors;
347 }