[PATCH] tutorial: mention "git clone" records .git/branches/origin
[alt-git.git] / update-cache.c
blob1fcc59a9c005e154c09731f25b7a99389dca2733
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
5 */
6 #include "cache.h"
8 /*
9 * Default to not allowing changes to the list of files. The
10 * tool doesn't actually care, but this makes it harder to add
11 * files to the revision control by mistake by doing something
12 * like "git-update-cache *" and suddenly having all the object
13 * files be revision controlled.
15 static int allow_add = 0, allow_remove = 0, allow_replace = 0, not_new = 0, quiet = 0, info_only = 0;
16 static int force_remove;
18 /* Three functions to allow overloaded pointer return; see linux/err.h */
19 static inline void *ERR_PTR(long error)
21 return (void *) error;
24 static inline long PTR_ERR(const void *ptr)
26 return (long) ptr;
29 static inline long IS_ERR(const void *ptr)
31 return (unsigned long)ptr > (unsigned long)-1000L;
34 static int add_file_to_cache(char *path)
36 int size, namelen, option, status;
37 struct cache_entry *ce;
38 struct stat st;
39 int fd;
40 char *target;
42 status = lstat(path, &st);
43 if (status < 0 || S_ISDIR(st.st_mode)) {
44 /* When we used to have "path" and now we want to add
45 * "path/file", we need a way to remove "path" before
46 * being able to add "path/file". However,
47 * "git-update-cache --remove path" would not work.
48 * --force-remove can be used but this is more user
49 * friendly, especially since we can do the opposite
50 * case just fine without --force-remove.
52 if (status == 0 || (errno == ENOENT || errno == ENOTDIR)) {
53 if (allow_remove)
54 return remove_file_from_cache(path);
56 return error("open(\"%s\"): %s", path, strerror(errno));
58 namelen = strlen(path);
59 size = cache_entry_size(namelen);
60 ce = xmalloc(size);
61 memset(ce, 0, size);
62 memcpy(ce->name, path, namelen);
63 fill_stat_cache_info(ce, &st);
64 ce->ce_mode = create_ce_mode(st.st_mode);
65 ce->ce_flags = htons(namelen);
66 switch (st.st_mode & S_IFMT) {
67 case S_IFREG:
68 fd = open(path, O_RDONLY);
69 if (fd < 0)
70 return -1;
71 if (index_fd(ce->sha1, fd, &st, !info_only, NULL) < 0)
72 return -1;
73 break;
74 case S_IFLNK:
75 target = xmalloc(st.st_size+1);
76 if (readlink(path, target, st.st_size+1) != st.st_size) {
77 free(target);
78 return -1;
80 if (info_only) {
81 unsigned char hdr[50];
82 int hdrlen;
83 write_sha1_file_prepare(target, st.st_size, "blob",
84 ce->sha1, hdr, &hdrlen);
85 } else if (write_sha1_file(target, st.st_size, "blob", ce->sha1))
86 return -1;
87 free(target);
88 break;
89 default:
90 return -1;
92 option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
93 option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
94 return add_cache_entry(ce, option);
97 static int compare_data(struct cache_entry *ce, struct stat *st)
99 int match = -1;
100 int fd = open(ce->name, O_RDONLY);
102 if (fd >= 0) {
103 unsigned char sha1[20];
104 if (!index_fd(sha1, fd, st, 0, NULL))
105 match = memcmp(sha1, ce->sha1, 20);
106 close(fd);
108 return match;
111 static int compare_link(struct cache_entry *ce, unsigned long expected_size)
113 int match = -1;
114 char *target;
115 void *buffer;
116 unsigned long size;
117 char type[10];
118 int len;
120 target = xmalloc(expected_size);
121 len = readlink(ce->name, target, expected_size);
122 if (len != expected_size) {
123 free(target);
124 return -1;
126 buffer = read_sha1_file(ce->sha1, type, &size);
127 if (!buffer) {
128 free(target);
129 return -1;
131 if (size == expected_size)
132 match = memcmp(buffer, target, size);
133 free(buffer);
134 free(target);
135 return match;
139 * "refresh" does not calculate a new sha1 file or bring the
140 * cache up-to-date for mode/content changes. But what it
141 * _does_ do is to "re-match" the stat information of a file
142 * with the cache, so that you can refresh the cache for a
143 * file that hasn't been changed but where the stat entry is
144 * out of date.
146 * For example, you'd want to do this after doing a "git-read-tree",
147 * to link up the stat cache details with the proper files.
149 static struct cache_entry *refresh_entry(struct cache_entry *ce)
151 struct stat st;
152 struct cache_entry *updated;
153 int changed, size;
155 if (lstat(ce->name, &st) < 0)
156 return ERR_PTR(-errno);
158 changed = ce_match_stat(ce, &st);
159 if (!changed)
160 return ce;
163 * If the mode or type has changed, there's no point in trying
164 * to refresh the entry - it's not going to match
166 if (changed & (MODE_CHANGED | TYPE_CHANGED))
167 return ERR_PTR(-EINVAL);
169 switch (st.st_mode & S_IFMT) {
170 case S_IFREG:
171 if (compare_data(ce, &st))
172 return ERR_PTR(-EINVAL);
173 break;
174 case S_IFLNK:
175 if (compare_link(ce, st.st_size))
176 return ERR_PTR(-EINVAL);
177 break;
178 default:
179 return ERR_PTR(-EINVAL);
182 size = ce_size(ce);
183 updated = xmalloc(size);
184 memcpy(updated, ce, size);
185 fill_stat_cache_info(updated, &st);
186 return updated;
189 static int refresh_cache(void)
191 int i;
192 int has_errors = 0;
194 for (i = 0; i < active_nr; i++) {
195 struct cache_entry *ce, *new;
196 ce = active_cache[i];
197 if (ce_stage(ce)) {
198 printf("%s: needs merge\n", ce->name);
199 has_errors = 1;
200 while ((i < active_nr) &&
201 ! strcmp(active_cache[i]->name, ce->name))
202 i++;
203 i--;
204 continue;
207 new = refresh_entry(ce);
208 if (IS_ERR(new)) {
209 if (not_new && PTR_ERR(new) == -ENOENT)
210 continue;
211 if (quiet)
212 continue;
213 printf("%s: needs update\n", ce->name);
214 has_errors = 1;
215 continue;
217 active_cache_changed = 1;
218 /* You can NOT just free active_cache[i] here, since it
219 * might not be necessarily malloc()ed but can also come
220 * from mmap(). */
221 active_cache[i] = new;
223 return has_errors;
227 * We fundamentally don't like some paths: we don't want
228 * dot or dot-dot anywhere, and for obvious reasons don't
229 * want to recurse into ".git" either.
231 * Also, we don't want double slashes or slashes at the
232 * end that can make pathnames ambiguous.
234 static int verify_dotfile(const char *rest)
237 * The first character was '.', but that
238 * has already been discarded, we now test
239 * the rest.
241 switch (*rest) {
242 /* "." is not allowed */
243 case '\0': case '/':
244 return 0;
247 * ".git" followed by NUL or slash is bad. This
248 * shares the path end test with the ".." case.
250 case 'g':
251 if (rest[1] != 'i')
252 break;
253 if (rest[2] != 't')
254 break;
255 rest += 2;
256 /* fallthrough */
257 case '.':
258 if (rest[1] == '\0' || rest[1] == '/')
259 return 0;
261 return 1;
264 static int verify_path(char *path)
266 char c;
268 goto inside;
269 for (;;) {
270 if (!c)
271 return 1;
272 if (c == '/') {
273 inside:
274 c = *path++;
275 switch (c) {
276 default:
277 continue;
278 case '/': case '\0':
279 break;
280 case '.':
281 if (verify_dotfile(path))
282 continue;
284 return 0;
286 c = *path++;
290 static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
292 int size, len, option;
293 unsigned int mode;
294 unsigned char sha1[20];
295 struct cache_entry *ce;
297 if (sscanf(arg1, "%o", &mode) != 1)
298 return -1;
299 if (get_sha1_hex(arg2, sha1))
300 return -1;
301 if (!verify_path(arg3))
302 return -1;
304 len = strlen(arg3);
305 size = cache_entry_size(len);
306 ce = xmalloc(size);
307 memset(ce, 0, size);
309 memcpy(ce->sha1, sha1, 20);
310 memcpy(ce->name, arg3, len);
311 ce->ce_flags = htons(len);
312 ce->ce_mode = create_ce_mode(mode);
313 option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
314 option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
315 return add_cache_entry(ce, option);
318 static struct cache_file cache_file;
320 int main(int argc, char **argv)
322 int i, newfd, entries, has_errors = 0;
323 int allow_options = 1;
325 newfd = hold_index_file_for_update(&cache_file, get_index_file());
326 if (newfd < 0)
327 die("unable to create new cachefile");
329 entries = read_cache();
330 if (entries < 0)
331 die("cache corrupted");
333 for (i = 1 ; i < argc; i++) {
334 char *path = argv[i];
336 if (allow_options && *path == '-') {
337 if (!strcmp(path, "--")) {
338 allow_options = 0;
339 continue;
341 if (!strcmp(path, "-q")) {
342 quiet = 1;
343 continue;
345 if (!strcmp(path, "--add")) {
346 allow_add = 1;
347 continue;
349 if (!strcmp(path, "--replace")) {
350 allow_replace = 1;
351 continue;
353 if (!strcmp(path, "--remove")) {
354 allow_remove = 1;
355 continue;
357 if (!strcmp(path, "--refresh")) {
358 has_errors |= refresh_cache();
359 continue;
361 if (!strcmp(path, "--cacheinfo")) {
362 if (i+3 >= argc)
363 die("git-update-cache: --cacheinfo <mode> <sha1> <path>");
364 if (add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
365 die("git-update-cache: --cacheinfo cannot add %s", argv[i+3]);
366 i += 3;
367 continue;
369 if (!strcmp(path, "--info-only")) {
370 info_only = 1;
371 continue;
373 if (!strcmp(path, "--force-remove")) {
374 force_remove = 1;
375 continue;
378 if (!strcmp(path, "--ignore-missing")) {
379 not_new = 1;
380 continue;
382 die("unknown option %s", path);
384 if (!verify_path(path)) {
385 fprintf(stderr, "Ignoring path %s\n", argv[i]);
386 continue;
388 if (force_remove) {
389 if (remove_file_from_cache(path))
390 die("git-update-cache: --force-remove cannot remove %s", path);
391 continue;
393 if (add_file_to_cache(path))
394 die("Unable to add %s to database", path);
396 if (write_cache(newfd, active_cache, active_nr) ||
397 commit_index_file(&cache_file))
398 die("Unable to write new cachefile");
400 return has_errors ? 1 : 0;