summaryrefslogtreecommitdiff
path: root/update-cache.c
blob: 942e309fe63f0eeffc0e24fa70027eaa39cc1a56 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Linus Torvalds, 2005
 */
#include "cache.h"
 
/*
 * Default to not allowing changes to the list of files. The
 * tool doesn't actually care, but this makes it harder to add
 * files to the revision control by mistake by doing something
 * like "update-cache *" and suddenly having all the object
 * files be revision controlled.
 */
static int allow_add = 0, allow_remove = 0;
 
static int index_fd(const char *path, int namelen, struct cache_entry *ce, int fd, struct stat *st)
{
	z_stream stream;
	int max_out_bytes = namelen + st->st_size + 200;
	void *out = malloc(max_out_bytes);
	void *metadata = malloc(namelen + 200);
	void *in = mmap(NULL, st->st_size, PROT_READ, MAP_PRIVATE, fd, 0);
	SHA_CTX c;
 
	close(fd);
	if (!out || (int)(long)in == -1)
		return -1;
 
	memset(&stream, 0, sizeof(stream));
	deflateInit(&stream, Z_BEST_COMPRESSION);
 
	/*
	 * ASCII size + nul byte
	 */	
	stream.next_in = metadata;
	stream.avail_in = 1+sprintf(metadata, "blob %lu", (unsigned long) st->st_size);
	stream.next_out = out;
	stream.avail_out = max_out_bytes;
	while (deflate(&stream, 0) == Z_OK)
		/* nothing */;
 
	/*
	 * File content
	 */
	stream.next_in = in;
	stream.avail_in = st->st_size;
	while (deflate(&stream, Z_FINISH) == Z_OK)
		/*nothing */;
 
	deflateEnd(&stream);
 
	SHA1_Init(&c);
	SHA1_Update(&c, out, stream.total_out);
	SHA1_Final(ce->sha1, &c);
 
	return write_sha1_buffer(ce->sha1, out, stream.total_out);
}
 
static int add_file_to_cache(char *path)
{
	int size, namelen;
	struct cache_entry *ce;
	struct stat st;
	int fd;
 
	fd = open(path, O_RDONLY);
	if (fd < 0) {
		if (errno == ENOENT) {
			if (allow_remove)
				return remove_file_from_cache(path);
		}
		return -1;
	}
	if (fstat(fd, &st) < 0) {
		close(fd);
		return -1;
	}
	namelen = strlen(path);
	size = cache_entry_size(namelen);
	ce = malloc(size);
	memset(ce, 0, size);
	memcpy(ce->name, path, namelen);
	ce->ctime.sec = st.st_ctime;
	ce->ctime.nsec = st.st_ctim.tv_nsec;
	ce->mtime.sec = st.st_mtime;
	ce->mtime.nsec = st.st_mtim.tv_nsec;
	ce->st_dev = st.st_dev;
	ce->st_ino = st.st_ino;
	ce->st_mode = st.st_mode;
	ce->st_uid = st.st_uid;
	ce->st_gid = st.st_gid;
	ce->st_size = st.st_size;
	ce->namelen = namelen;
 
	if (index_fd(path, namelen, ce, fd, &st) < 0)
		return -1;
 
	return add_cache_entry(ce, allow_add);
}
 
static void refresh_entry(struct cache_entry *ce)
{
	/*
	 * This is really not the right way to do it, but
	 * add_file_to_cache() does do the right thing.
	 *
	 * We should really just update the cache
	 * entry in-place, I think. With this approach we
	 * end up allocating a new one, searching for where
	 * to insert it etc etc crud.
	 */
	add_file_to_cache(ce->name);
}
 
static void refresh_cache(void)
{
	int i;
 
	for (i = 0; i < active_nr; i++)
		refresh_entry(active_cache[i]);
}
 
/*
 * We fundamentally don't like some paths: we don't want
 * dot or dot-dot anywhere, and in fact, we don't even want
 * any other dot-files (.dircache or anything else). They
 * are hidden, for chist sake.
 *
 * Also, we don't want double slashes or slashes at the
 * end that can make pathnames ambiguous. 
 */
static int verify_path(char *path)
{
	char c;
 
	goto inside;
	for (;;) {
		if (!c)
			return 1;
		if (c == '/') {
inside:
			c = *path++;
			if (c != '/' && c != '.' && c != '\0')
				continue;
			return 0;
		}
		c = *path++;
	}
}
 
int main(int argc, char **argv)
{
	int i, newfd, entries;
	int allow_options = 1;
 
	entries = read_cache();
	if (entries < 0) {
		perror("cache corrupted");
		return -1;
	}
 
	newfd = open(".dircache/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
	if (newfd < 0) {
		perror("unable to create new cachefile");
		return -1;
	}
	for (i = 1 ; i < argc; i++) {
		char *path = argv[i];
 
		if (allow_options && *path == '-') {
			if (!strcmp(path, "--")) {
				allow_options = 0;
				continue;
			}
			if (!strcmp(path, "--add")) {
				allow_add = 1;
				continue;
			}
			if (!strcmp(path, "--remove")) {
				allow_remove = 1;
				continue;
			}
			if (!strcmp(path, "--refresh")) {
				refresh_cache();
				continue;
			}
			usage("unknown option %s", path);
		}
		if (!verify_path(path)) {
			fprintf(stderr, "Ignoring path %s\n", argv[i]);
			continue;
		}
		if (add_file_to_cache(path)) {
			fprintf(stderr, "Unable to add %s to database\n", path);
			goto out;
		}
	}
	if (!write_cache(newfd, active_cache, active_nr) && !rename(".dircache/index.lock", ".dircache/index"))
		return 0;
out:
	unlink(".dircache/index.lock");
	return 0;
}