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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
|
#include "refs.h"
#include "cache.h"
#include <errno.h>
static int read_ref(const char *path, unsigned char *sha1)
{
int ret = -1;
int fd = open(path, O_RDONLY);
if (fd >= 0) {
char buffer[60];
if (read(fd, buffer, sizeof(buffer)) >= 40)
ret = get_sha1_hex(buffer, sha1);
close(fd);
}
return ret;
}
static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1))
{
int retval = 0;
DIR *dir = opendir(base);
if (dir) {
struct dirent *de;
int baselen = strlen(base);
char *path = xmalloc(baselen + 257);
if (!strncmp(base, "./", 2)) {
base += 2;
baselen -= 2;
}
memcpy(path, base, baselen);
if (baselen && base[baselen-1] != '/')
path[baselen++] = '/';
while ((de = readdir(dir)) != NULL) {
unsigned char sha1[20];
struct stat st;
int namelen;
if (de->d_name[0] == '.')
continue;
namelen = strlen(de->d_name);
if (namelen > 255)
continue;
memcpy(path + baselen, de->d_name, namelen+1);
if (lstat(path, &st) < 0)
continue;
if (S_ISDIR(st.st_mode)) {
retval = do_for_each_ref(path, fn);
if (retval)
break;
continue;
}
if (read_ref(path, sha1) < 0)
continue;
if (!has_sha1_file(sha1))
continue;
retval = fn(path, sha1);
if (retval)
break;
}
free(path);
closedir(dir);
}
return retval;
}
int head_ref(int (*fn)(const char *path, const unsigned char *sha1))
{
unsigned char sha1[20];
const char *headpath = git_path("HEAD");
if (!read_ref(headpath, sha1))
return fn(headpath, sha1);
return 0;
}
int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1))
{
return do_for_each_ref(get_refs_directory(), fn);
}
static char *ref_file_name(const char *ref)
{
char *base = get_refs_directory();
int baselen = strlen(base);
int reflen = strlen(ref);
char *ret = xmalloc(baselen + 2 + reflen);
sprintf(ret, "%s/%s", base, ref);
return ret;
}
static char *ref_lock_file_name(const char *ref)
{
char *base = get_refs_directory();
int baselen = strlen(base);
int reflen = strlen(ref);
char *ret = xmalloc(baselen + 7 + reflen);
sprintf(ret, "%s/%s.lock", base, ref);
return ret;
}
static int read_ref_file(const char *filename, unsigned char *sha1) {
int fd = open(filename, O_RDONLY);
char hex[41];
if (fd < 0) {
return error("Couldn't open %s\n", filename);
}
if ((read(fd, hex, 41) < 41) ||
(hex[40] != '\n') ||
get_sha1_hex(hex, sha1)) {
error("Couldn't read a hash from %s\n", filename);
close(fd);
return -1;
}
close(fd);
return 0;
}
int get_ref_sha1(const char *ref, unsigned char *sha1)
{
char *filename;
int retval;
if (check_ref_format(ref))
return -1;
filename = ref_file_name(ref);
retval = read_ref_file(filename, sha1);
free(filename);
return retval;
}
static int lock_ref_file(const char *filename, const char *lock_filename,
const unsigned char *old_sha1)
{
int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
unsigned char current_sha1[20];
int retval;
if (fd < 0) {
return error("Couldn't open lock file for %s: %s",
filename, strerror(errno));
}
retval = read_ref_file(filename, current_sha1);
if (old_sha1) {
if (retval) {
close(fd);
unlink(lock_filename);
return error("Could not read the current value of %s",
filename);
}
if (memcmp(current_sha1, old_sha1, 20)) {
close(fd);
unlink(lock_filename);
error("The current value of %s is %s",
filename, sha1_to_hex(current_sha1));
return error("Expected %s",
sha1_to_hex(old_sha1));
}
} else {
if (!retval) {
close(fd);
unlink(lock_filename);
return error("Unexpectedly found a value of %s for %s",
sha1_to_hex(current_sha1), filename);
}
}
return fd;
}
int lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
{
char *filename;
char *lock_filename;
int retval;
if (check_ref_format(ref))
return -1;
filename = ref_file_name(ref);
lock_filename = ref_lock_file_name(ref);
retval = lock_ref_file(filename, lock_filename, old_sha1);
free(filename);
free(lock_filename);
return retval;
}
static int write_ref_file(const char *filename,
const char *lock_filename, int fd,
const unsigned char *sha1)
{
char *hex = sha1_to_hex(sha1);
char term = '\n';
if (write(fd, hex, 40) < 40 ||
write(fd, &term, 1) < 1) {
error("Couldn't write %s\n", filename);
close(fd);
return -1;
}
close(fd);
rename(lock_filename, filename);
return 0;
}
int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1)
{
char *filename;
char *lock_filename;
int retval;
if (fd < 0)
return -1;
if (check_ref_format(ref))
return -1;
filename = ref_file_name(ref);
lock_filename = ref_lock_file_name(ref);
retval = write_ref_file(filename, lock_filename, fd, sha1);
free(filename);
free(lock_filename);
return retval;
}
int check_ref_format(const char *ref)
{
char *middle;
if (ref[0] == '.' || ref[0] == '/')
return -1;
middle = strchr(ref, '/');
if (!middle || !middle[1])
return -1;
if (strchr(middle + 1, '/'))
return -1;
return 0;
}
int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1)
{
char *filename;
char *lock_filename;
int fd;
int retval;
if (check_ref_format(ref))
return -1;
filename = ref_file_name(ref);
lock_filename = ref_lock_file_name(ref);
fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
if (fd < 0) {
error("Writing %s", lock_filename);
perror("Open");
}
retval = write_ref_file(filename, lock_filename, fd, sha1);
free(filename);
free(lock_filename);
return retval;
}
|
