Simplify show-diff cache entry name handling.
[git/git.git] / update-cache.c
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 */
6 #include "cache.h"
7
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 "update-cache *" and suddenly having all the object
13 * files be revision controlled.
14 */
15 static int allow_add = 0, allow_remove = 0;
16
17 static int index_fd(const char *path, int namelen, struct cache_entry *ce, int fd, struct stat *st)
18 {
19 z_stream stream;
20 unsigned long size = st->st_size;
21 int max_out_bytes = namelen + size + 200;
22 void *out = malloc(max_out_bytes);
23 void *metadata = malloc(namelen + 200);
24 void *in;
25 SHA_CTX c;
26
27 in = "";
28 if (size)
29 in = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
30 close(fd);
31 if (!out || (int)(long)in == -1)
32 return -1;
33
34 memset(&stream, 0, sizeof(stream));
35 deflateInit(&stream, Z_BEST_COMPRESSION);
36
37 /*
38 * ASCII size + nul byte
39 */
40 stream.next_in = metadata;
41 stream.avail_in = 1+sprintf(metadata, "blob %lu", size);
42 stream.next_out = out;
43 stream.avail_out = max_out_bytes;
44 while (deflate(&stream, 0) == Z_OK)
45 /* nothing */;
46
47 /*
48 * File content
49 */
50 stream.next_in = in;
51 stream.avail_in = size;
52 while (deflate(&stream, Z_FINISH) == Z_OK)
53 /*nothing */;
54
55 deflateEnd(&stream);
56
57 SHA1_Init(&c);
58 SHA1_Update(&c, out, stream.total_out);
59 SHA1_Final(ce->sha1, &c);
60
61 return write_sha1_buffer(ce->sha1, out, stream.total_out);
62 }
63
64 /*
65 * This only updates the "non-critical" parts of the directory
66 * cache, ie the parts that aren't tracked by GIT, and only used
67 * to validate the cache.
68 */
69 static void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
70 {
71 ce->ce_ctime.sec = htonl(st->st_ctime);
72 ce->ce_mtime.sec = htonl(st->st_mtime);
73 #ifdef NSEC
74 ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
75 ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
76 #endif
77 ce->ce_dev = htonl(st->st_dev);
78 ce->ce_ino = htonl(st->st_ino);
79 ce->ce_uid = htonl(st->st_uid);
80 ce->ce_gid = htonl(st->st_gid);
81 ce->ce_size = htonl(st->st_size);
82 }
83
84 static int add_file_to_cache(char *path)
85 {
86 int size, namelen;
87 struct cache_entry *ce;
88 struct stat st;
89 int fd;
90
91 fd = open(path, O_RDONLY);
92 if (fd < 0) {
93 if (errno == ENOENT) {
94 if (allow_remove)
95 return remove_file_from_cache(path);
96 }
97 return -1;
98 }
99 if (fstat(fd, &st) < 0) {
100 close(fd);
101 return -1;
102 }
103 namelen = strlen(path);
104 size = cache_entry_size(namelen);
105 ce = malloc(size);
106 memset(ce, 0, size);
107 memcpy(ce->name, path, namelen);
108 fill_stat_cache_info(ce, &st);
109 ce->ce_mode = htonl(st.st_mode);
110 ce->ce_namelen = htons(namelen);
111
112 if (index_fd(path, namelen, ce, fd, &st) < 0)
113 return -1;
114
115 return add_cache_entry(ce, allow_add);
116 }
117
118 static int match_data(int fd, void *buffer, unsigned long size)
119 {
120 while (size) {
121 char compare[1024];
122 int ret = read(fd, compare, sizeof(compare));
123
124 if (ret <= 0 || ret > size || memcmp(buffer, compare, ret))
125 return -1;
126 size -= ret;
127 buffer += ret;
128 }
129 return 0;
130 }
131
132 static int compare_data(struct cache_entry *ce, unsigned long expected_size)
133 {
134 int match = -1;
135 int fd = open(ce->name, O_RDONLY);
136
137 if (fd >= 0) {
138 void *buffer;
139 unsigned long size;
140 char type[10];
141
142 buffer = read_sha1_file(ce->sha1, type, &size);
143 if (buffer) {
144 if (size == expected_size && !strcmp(type, "blob"))
145 match = match_data(fd, buffer, size);
146 free(buffer);
147 }
148 close(fd);
149 }
150 return match;
151 }
152
153 /*
154 * "refresh" does not calculate a new sha1 file or bring the
155 * cache up-to-date for mode/content changes. But what it
156 * _does_ do is to "re-match" the stat information of a file
157 * with the cache, so that you can refresh the cache for a
158 * file that hasn't been changed but where the stat entry is
159 * out of date.
160 *
161 * For example, you'd want to do this after doing a "read-tree",
162 * to link up the stat cache details with the proper files.
163 */
164 static struct cache_entry *refresh_entry(struct cache_entry *ce)
165 {
166 struct stat st;
167 struct cache_entry *updated;
168 int changed, size;
169
170 if (stat(ce->name, &st) < 0)
171 return NULL;
172
173 changed = cache_match_stat(ce, &st);
174 if (!changed)
175 return ce;
176
177 /*
178 * If the mode has changed, there's no point in trying
179 * to refresh the entry - it's not going to match
180 */
181 if (changed & MODE_CHANGED)
182 return NULL;
183
184 if (compare_data(ce, st.st_size))
185 return NULL;
186
187 size = ce_size(ce);
188 updated = malloc(size);
189 memcpy(updated, ce, size);
190 fill_stat_cache_info(updated, &st);
191 return updated;
192 }
193
194 static void refresh_cache(void)
195 {
196 int i;
197
198 for (i = 0; i < active_nr; i++) {
199 struct cache_entry *ce = active_cache[i];
200 struct cache_entry *new = refresh_entry(ce);
201
202 if (!new) {
203 printf("%s: needs update\n", ce->name);
204 continue;
205 }
206 active_cache[i] = new;
207 }
208 }
209
210 /*
211 * We fundamentally don't like some paths: we don't want
212 * dot or dot-dot anywhere, and in fact, we don't even want
213 * any other dot-files (.git or anything else). They
214 * are hidden, for chist sake.
215 *
216 * Also, we don't want double slashes or slashes at the
217 * end that can make pathnames ambiguous.
218 */
219 static int verify_path(char *path)
220 {
221 char c;
222
223 goto inside;
224 for (;;) {
225 if (!c)
226 return 1;
227 if (c == '/') {
228 inside:
229 c = *path++;
230 if (c != '/' && c != '.' && c != '\0')
231 continue;
232 return 0;
233 }
234 c = *path++;
235 }
236 }
237
238 static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
239 {
240 int size, len;
241 unsigned int mode;
242 unsigned char sha1[20];
243 struct cache_entry *ce;
244
245 if (sscanf(arg1, "%o", &mode) != 1)
246 return -1;
247 printf("got mode %o\n", mode);
248 if (get_sha1_hex(arg2, sha1))
249 return -1;
250 printf("got sha1 %s\n", sha1_to_hex(sha1));
251 if (!verify_path(arg3))
252 return -1;
253 printf("got path %s\n", arg3);
254
255 len = strlen(arg3);
256 size = cache_entry_size(len);
257 ce = malloc(size);
258 memset(ce, 0, size);
259
260 memcpy(ce->sha1, sha1, 20);
261 memcpy(ce->name, arg3, len);
262 ce->ce_namelen = htons(len);
263 ce->ce_mode = htonl(mode);
264 return add_cache_entry(ce, allow_add);
265 }
266
267 static int remove_lock = 0;
268
269 static void remove_lock_file(void)
270 {
271 if (remove_lock)
272 unlink(".git/index.lock");
273 }
274
275 int main(int argc, char **argv)
276 {
277 int i, newfd, entries;
278 int allow_options = 1;
279
280 newfd = open(".git/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
281 if (newfd < 0)
282 die("unable to create new cachefile");
283
284 atexit(remove_lock_file);
285 remove_lock = 1;
286
287 entries = read_cache();
288 if (entries < 0)
289 die("cache corrupted");
290
291 for (i = 1 ; i < argc; i++) {
292 char *path = argv[i];
293
294 if (allow_options && *path == '-') {
295 if (!strcmp(path, "--")) {
296 allow_options = 0;
297 continue;
298 }
299 if (!strcmp(path, "--add")) {
300 allow_add = 1;
301 continue;
302 }
303 if (!strcmp(path, "--remove")) {
304 allow_remove = 1;
305 continue;
306 }
307 if (!strcmp(path, "--refresh")) {
308 refresh_cache();
309 continue;
310 }
311 if (!strcmp(path, "--cacheinfo")) {
312 if (i+3 >= argc || add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
313 die("update-cache: --cacheinfo <mode> <sha1> <path>");
314 i += 3;
315 continue;
316 }
317 die("unknown option %s", path);
318 }
319 if (!verify_path(path)) {
320 fprintf(stderr, "Ignoring path %s\n", argv[i]);
321 continue;
322 }
323 if (add_file_to_cache(path))
324 die("Unable to add %s to database", path);
325 }
326 if (write_cache(newfd, active_cache, active_nr) ||
327 rename(".git/index.lock", ".git/index"))
328 die("Unable to write new cachefile");
329
330 remove_lock = 0;
331 return 0;
332 }