[PATCH] Rename and extend read_tree_with_tree_or_commit_sha1
[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 */
f2a19340 6#include <signal.h>
e83c5163
LT
7#include "cache.h"
8
121481ab
LT
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 */
c6e007b0
JB
16static int allow_add = 0, allow_remove = 0, not_new = 0;
17
18/* Three functions to allow overloaded pointer return; see linux/err.h */
19static inline void *ERR_PTR(long error)
20{
21 return (void *) error;
22}
23
24static inline long PTR_ERR(const void *ptr)
25{
26 return (long) ptr;
27}
28
29static inline long IS_ERR(const void *ptr)
30{
31 return (unsigned long)ptr > (unsigned long)-1000L;
32}
121481ab 33
c747fc6f 34static int index_fd(unsigned char *sha1, int fd, struct stat *st)
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LT
35{
36 z_stream stream;
3607c27f 37 unsigned long size = st->st_size;
c747fc6f 38 int max_out_bytes = size + 200;
812666c8
CL
39 void *out = xmalloc(max_out_bytes);
40 void *metadata = xmalloc(200);
f18ca731 41 int metadata_size;
3607c27f 42 void *in;
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LT
43 SHA_CTX c;
44
3607c27f
LT
45 in = "";
46 if (size)
47 in = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
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LT
48 close(fd);
49 if (!out || (int)(long)in == -1)
50 return -1;
51
f18ca731
LT
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
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LT
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;
f18ca731 66 stream.avail_in = metadata_size;
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LT
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;
3607c27f 76 stream.avail_in = size;
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LT
77 while (deflate(&stream, Z_FINISH) == Z_OK)
78 /*nothing */;
79
80 deflateEnd(&stream);
81
c747fc6f 82 return write_sha1_buffer(sha1, out, stream.total_out);
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83}
84
711cf3a0
LT
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 */
90static void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
91{
ccc4feb5
LT
92 ce->ce_ctime.sec = htonl(st->st_ctime);
93 ce->ce_mtime.sec = htonl(st->st_mtime);
5ade8628 94#ifdef NSEC
ccc4feb5
LT
95 ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
96 ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
5ade8628 97#endif
ccc4feb5
LT
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);
711cf3a0
LT
103}
104
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LT
105static 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) {
121481ab
LT
114 if (errno == ENOENT) {
115 if (allow_remove)
116 return remove_file_from_cache(path);
117 }
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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);
812666c8 126 ce = xmalloc(size);
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LT
127 memset(ce, 0, size);
128 memcpy(ce->name, path, namelen);
711cf3a0 129 fill_stat_cache_info(ce, &st);
e4479470 130 ce->ce_mode = create_ce_mode(st.st_mode);
f5cabd13 131 ce->ce_flags = htons(namelen);
e83c5163 132
c747fc6f 133 if (index_fd(ce->sha1, fd, &st) < 0)
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134 return -1;
135
121481ab
LT
136 return add_cache_entry(ce, allow_add);
137}
138
711cf3a0
LT
139static 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
32d197f1 153static int compare_data(struct cache_entry *ce, unsigned long expected_size)
121481ab 154{
711cf3a0
LT
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) {
32d197f1 165 if (size == expected_size && !strcmp(type, "blob"))
711cf3a0
LT
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 */
185static 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)
c6e007b0 192 return ERR_PTR(-errno);
711cf3a0
LT
193
194 changed = cache_match_stat(ce, &st);
195 if (!changed)
196 return ce;
197
121481ab 198 /*
32d197f1 199 * If the mode has changed, there's no point in trying
711cf3a0 200 * to refresh the entry - it's not going to match
121481ab 201 */
32d197f1 202 if (changed & MODE_CHANGED)
c6e007b0 203 return ERR_PTR(-EINVAL);
711cf3a0 204
32d197f1 205 if (compare_data(ce, st.st_size))
c6e007b0 206 return ERR_PTR(-EINVAL);
711cf3a0
LT
207
208 size = ce_size(ce);
812666c8 209 updated = xmalloc(size);
711cf3a0
LT
210 memcpy(updated, ce, size);
211 fill_stat_cache_info(updated, &st);
212 return updated;
121481ab
LT
213}
214
215static void refresh_cache(void)
216{
217 int i;
218
711cf3a0 219 for (i = 0; i < active_nr; i++) {
1bc992ac
JH
220 struct cache_entry *ce, *new;
221 ce = active_cache[i];
222 if (ce_stage(ce)) {
223 printf("%s: needs merge\n", ce->name);
224 while ((i < active_nr) &&
225 ! strcmp(active_cache[i]->name, ce->name))
226 i++;
227 i--;
228 continue;
229 }
711cf3a0 230
1bc992ac 231 new = refresh_entry(ce);
c6e007b0
JB
232 if (IS_ERR(new)) {
233 if (!(not_new && PTR_ERR(new) == -ENOENT))
234 printf("%s: needs update\n", ce->name);
711cf3a0
LT
235 continue;
236 }
237 active_cache[i] = new;
238 }
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239}
240
e83c5163
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241/*
242 * We fundamentally don't like some paths: we don't want
243 * dot or dot-dot anywhere, and in fact, we don't even want
4bb04f21 244 * any other dot-files (.git or anything else). They
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LT
245 * are hidden, for chist sake.
246 *
247 * Also, we don't want double slashes or slashes at the
aebb2679 248 * end that can make pathnames ambiguous.
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249 */
250static int verify_path(char *path)
251{
252 char c;
253
254 goto inside;
255 for (;;) {
256 if (!c)
257 return 1;
258 if (c == '/') {
259inside:
260 c = *path++;
261 if (c != '/' && c != '.' && c != '\0')
262 continue;
263 return 0;
264 }
265 c = *path++;
266 }
267}
268
9945d980
LT
269static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
270{
271 int size, len;
272 unsigned int mode;
273 unsigned char sha1[20];
274 struct cache_entry *ce;
275
276 if (sscanf(arg1, "%o", &mode) != 1)
277 return -1;
9945d980
LT
278 if (get_sha1_hex(arg2, sha1))
279 return -1;
9945d980
LT
280 if (!verify_path(arg3))
281 return -1;
9945d980
LT
282
283 len = strlen(arg3);
284 size = cache_entry_size(len);
812666c8 285 ce = xmalloc(size);
9945d980
LT
286 memset(ce, 0, size);
287
288 memcpy(ce->sha1, sha1, 20);
289 memcpy(ce->name, arg3, len);
f5cabd13 290 ce->ce_flags = htons(len);
e4479470 291 ce->ce_mode = create_ce_mode(mode);
9945d980
LT
292 return add_cache_entry(ce, allow_add);
293}
294
bb233d69 295static const char *lockfile_name = NULL;
9614b8dc
LT
296
297static void remove_lock_file(void)
298{
bb233d69
LT
299 if (lockfile_name)
300 unlink(lockfile_name);
9614b8dc
LT
301}
302
f2a19340
LT
303static void remove_lock_file_on_signal(int signo)
304{
305 remove_lock_file();
306}
307
e83c5163
LT
308int main(int argc, char **argv)
309{
310 int i, newfd, entries;
121481ab 311 int allow_options = 1;
bb233d69
LT
312 static char lockfile[MAXPATHLEN+1];
313 const char *indexfile = get_index_file();
e83c5163 314
bb233d69
LT
315 snprintf(lockfile, sizeof(lockfile), "%s.lock", indexfile);
316
317 newfd = open(lockfile, O_RDWR | O_CREAT | O_EXCL, 0600);
9614b8dc 318 if (newfd < 0)
2de381f9 319 die("unable to create new cachefile");
9614b8dc 320
f2a19340 321 signal(SIGINT, remove_lock_file_on_signal);
9614b8dc 322 atexit(remove_lock_file);
bb233d69 323 lockfile_name = lockfile;
9614b8dc 324
e83c5163 325 entries = read_cache();
9614b8dc 326 if (entries < 0)
2de381f9 327 die("cache corrupted");
e83c5163 328
e83c5163
LT
329 for (i = 1 ; i < argc; i++) {
330 char *path = argv[i];
121481ab
LT
331
332 if (allow_options && *path == '-') {
333 if (!strcmp(path, "--")) {
334 allow_options = 0;
335 continue;
336 }
337 if (!strcmp(path, "--add")) {
338 allow_add = 1;
339 continue;
340 }
341 if (!strcmp(path, "--remove")) {
342 allow_remove = 1;
343 continue;
344 }
345 if (!strcmp(path, "--refresh")) {
346 refresh_cache();
347 continue;
348 }
9945d980
LT
349 if (!strcmp(path, "--cacheinfo")) {
350 if (i+3 >= argc || add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
351 die("update-cache: --cacheinfo <mode> <sha1> <path>");
352 i += 3;
353 continue;
354 }
c6e007b0
JB
355 if (!strcmp(path, "--ignore-missing")) {
356 not_new = 1;
357 continue;
358 }
2de381f9 359 die("unknown option %s", path);
121481ab 360 }
e83c5163
LT
361 if (!verify_path(path)) {
362 fprintf(stderr, "Ignoring path %s\n", argv[i]);
363 continue;
364 }
9614b8dc 365 if (add_file_to_cache(path))
2de381f9 366 die("Unable to add %s to database", path);
e83c5163 367 }
bb233d69 368 if (write_cache(newfd, active_cache, active_nr) || rename(lockfile, indexfile))
2de381f9 369 die("Unable to write new cachefile");
9614b8dc 370
bb233d69 371 lockfile_name = NULL;
19b2860c 372 return 0;
e83c5163 373}