Update README to reflect the hierarchical tree objects,
[git/git.git] / update-cache.c
CommitLineData
8bc9a0c7
LT
1/*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 */
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6#include "cache.h"
7
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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 */
15static int allow_add = 0, allow_remove = 0;
16
c747fc6f 17static int index_fd(unsigned char *sha1, int fd, struct stat *st)
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18{
19 z_stream stream;
3607c27f 20 unsigned long size = st->st_size;
c747fc6f 21 int max_out_bytes = size + 200;
e83c5163 22 void *out = malloc(max_out_bytes);
c747fc6f 23 void *metadata = malloc(200);
3607c27f 24 void *in;
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25 SHA_CTX c;
26
3607c27f
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27 in = "";
28 if (size)
29 in = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
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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;
3607c27f 41 stream.avail_in = 1+sprintf(metadata, "blob %lu", size);
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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;
3607c27f 51 stream.avail_in = size;
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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);
c747fc6f 59 SHA1_Final(sha1, &c);
e83c5163 60
c747fc6f 61 return write_sha1_buffer(sha1, out, stream.total_out);
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62}
63
711cf3a0
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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 */
69static void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
70{
ccc4feb5
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71 ce->ce_ctime.sec = htonl(st->st_ctime);
72 ce->ce_mtime.sec = htonl(st->st_mtime);
5ade8628 73#ifdef NSEC
ccc4feb5
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74 ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
75 ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
5ade8628 76#endif
ccc4feb5
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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);
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82}
83
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84static 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) {
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93 if (errno == ENOENT) {
94 if (allow_remove)
95 return remove_file_from_cache(path);
96 }
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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);
711cf3a0 108 fill_stat_cache_info(ce, &st);
e4479470 109 ce->ce_mode = create_ce_mode(st.st_mode);
f5cabd13 110 ce->ce_flags = htons(namelen);
e83c5163 111
c747fc6f 112 if (index_fd(ce->sha1, fd, &st) < 0)
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113 return -1;
114
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115 return add_cache_entry(ce, allow_add);
116}
117
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118static 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
32d197f1 132static int compare_data(struct cache_entry *ce, unsigned long expected_size)
121481ab 133{
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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) {
32d197f1 144 if (size == expected_size && !strcmp(type, "blob"))
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LT
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 */
164static 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
121481ab 177 /*
32d197f1 178 * If the mode has changed, there's no point in trying
711cf3a0 179 * to refresh the entry - it's not going to match
121481ab 180 */
32d197f1 181 if (changed & MODE_CHANGED)
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182 return NULL;
183
32d197f1 184 if (compare_data(ce, st.st_size))
711cf3a0
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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;
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192}
193
194static void refresh_cache(void)
195{
196 int i;
197
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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 }
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208}
209
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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
4bb04f21 213 * any other dot-files (.git or anything else). They
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214 * are hidden, for chist sake.
215 *
216 * Also, we don't want double slashes or slashes at the
aebb2679 217 * end that can make pathnames ambiguous.
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218 */
219static int verify_path(char *path)
220{
221 char c;
222
223 goto inside;
224 for (;;) {
225 if (!c)
226 return 1;
227 if (c == '/') {
228inside:
229 c = *path++;
230 if (c != '/' && c != '.' && c != '\0')
231 continue;
232 return 0;
233 }
234 c = *path++;
235 }
236}
237
9945d980
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238static 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;
9945d980
LT
247 if (get_sha1_hex(arg2, sha1))
248 return -1;
9945d980
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249 if (!verify_path(arg3))
250 return -1;
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251
252 len = strlen(arg3);
253 size = cache_entry_size(len);
254 ce = malloc(size);
255 memset(ce, 0, size);
256
257 memcpy(ce->sha1, sha1, 20);
258 memcpy(ce->name, arg3, len);
f5cabd13 259 ce->ce_flags = htons(len);
e4479470 260 ce->ce_mode = create_ce_mode(mode);
9945d980
LT
261 return add_cache_entry(ce, allow_add);
262}
263
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264static int remove_lock = 0;
265
266static void remove_lock_file(void)
267{
268 if (remove_lock)
4bb04f21 269 unlink(".git/index.lock");
9614b8dc
LT
270}
271
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272int main(int argc, char **argv)
273{
274 int i, newfd, entries;
121481ab 275 int allow_options = 1;
e83c5163 276
4bb04f21 277 newfd = open(".git/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
9614b8dc 278 if (newfd < 0)
2de381f9 279 die("unable to create new cachefile");
9614b8dc
LT
280
281 atexit(remove_lock_file);
282 remove_lock = 1;
283
e83c5163 284 entries = read_cache();
9614b8dc 285 if (entries < 0)
2de381f9 286 die("cache corrupted");
e83c5163 287
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288 for (i = 1 ; i < argc; i++) {
289 char *path = argv[i];
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290
291 if (allow_options && *path == '-') {
292 if (!strcmp(path, "--")) {
293 allow_options = 0;
294 continue;
295 }
296 if (!strcmp(path, "--add")) {
297 allow_add = 1;
298 continue;
299 }
300 if (!strcmp(path, "--remove")) {
301 allow_remove = 1;
302 continue;
303 }
304 if (!strcmp(path, "--refresh")) {
305 refresh_cache();
306 continue;
307 }
9945d980
LT
308 if (!strcmp(path, "--cacheinfo")) {
309 if (i+3 >= argc || add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
310 die("update-cache: --cacheinfo <mode> <sha1> <path>");
311 i += 3;
312 continue;
313 }
2de381f9 314 die("unknown option %s", path);
121481ab 315 }
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LT
316 if (!verify_path(path)) {
317 fprintf(stderr, "Ignoring path %s\n", argv[i]);
318 continue;
319 }
9614b8dc 320 if (add_file_to_cache(path))
2de381f9 321 die("Unable to add %s to database", path);
e83c5163 322 }
9614b8dc 323 if (write_cache(newfd, active_cache, active_nr) ||
4bb04f21 324 rename(".git/index.lock", ".git/index"))
2de381f9 325 die("Unable to write new cachefile");
9614b8dc
LT
326
327 remove_lock = 0;
19b2860c 328 return 0;
e83c5163 329}