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Commit | Line | Data |
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95fc7512 DB |
1 | #include "refs.h" |
2 | #include "cache.h" | |
3 | ||
4 | #include <errno.h> | |
ca8db142 | 5 | #include <ctype.h> |
95fc7512 | 6 | |
ca8db142 LT |
7 | /* We allow "recursive" symbolic refs. Only within reason, though */ |
8 | #define MAXDEPTH 5 | |
9 | ||
10 | int read_ref(const char *filename, unsigned char *sha1) | |
8a65ff76 | 11 | { |
ca8db142 LT |
12 | int depth = 0; |
13 | int ret = -1, fd; | |
14 | ||
15 | while ((fd = open(filename, O_RDONLY)) >= 0) { | |
16 | char buffer[256]; | |
17 | int len = read(fd, buffer, sizeof(buffer)-1); | |
8a65ff76 | 18 | |
8a65ff76 | 19 | close(fd); |
ca8db142 LT |
20 | if (len < 0) |
21 | break; | |
22 | ||
23 | buffer[len] = 0; | |
24 | while (len && isspace(buffer[len-1])) | |
25 | buffer[--len] = 0; | |
26 | ||
27 | if (!strncmp(buffer, "ref:", 4)) { | |
28 | char *buf; | |
29 | if (depth > MAXDEPTH) | |
30 | break; | |
31 | depth++; | |
32 | buf = buffer + 4; | |
33 | len -= 4; | |
34 | while (len && isspace(*buf)) | |
35 | buf++, len--; | |
36 | filename = git_path("%.*s", len, buf); | |
37 | continue; | |
38 | } | |
39 | if (len >= 40) | |
40 | ret = get_sha1_hex(buffer, sha1); | |
41 | break; | |
8a65ff76 LT |
42 | } |
43 | return ret; | |
44 | } | |
45 | ||
944d8589 | 46 | static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1)) |
8a65ff76 LT |
47 | { |
48 | int retval = 0; | |
4ec99bf0 | 49 | DIR *dir = opendir(git_path("%s", base)); |
8a65ff76 LT |
50 | |
51 | if (dir) { | |
52 | struct dirent *de; | |
53 | int baselen = strlen(base); | |
54 | char *path = xmalloc(baselen + 257); | |
6cada6a9 LT |
55 | |
56 | if (!strncmp(base, "./", 2)) { | |
57 | base += 2; | |
58 | baselen -= 2; | |
59 | } | |
8a65ff76 | 60 | memcpy(path, base, baselen); |
944d8589 LT |
61 | if (baselen && base[baselen-1] != '/') |
62 | path[baselen++] = '/'; | |
8a65ff76 LT |
63 | |
64 | while ((de = readdir(dir)) != NULL) { | |
65 | unsigned char sha1[20]; | |
66 | struct stat st; | |
67 | int namelen; | |
68 | ||
69 | if (de->d_name[0] == '.') | |
70 | continue; | |
71 | namelen = strlen(de->d_name); | |
72 | if (namelen > 255) | |
73 | continue; | |
74 | memcpy(path + baselen, de->d_name, namelen+1); | |
a7e66ae3 | 75 | if (stat(git_path("%s", path), &st) < 0) |
8a65ff76 LT |
76 | continue; |
77 | if (S_ISDIR(st.st_mode)) { | |
8a65ff76 LT |
78 | retval = do_for_each_ref(path, fn); |
79 | if (retval) | |
80 | break; | |
81 | continue; | |
82 | } | |
ca8db142 | 83 | if (read_ref(git_path("%s", path), sha1) < 0) |
8a65ff76 LT |
84 | continue; |
85 | if (!has_sha1_file(sha1)) | |
86 | continue; | |
87 | retval = fn(path, sha1); | |
88 | if (retval) | |
89 | break; | |
90 | } | |
91 | free(path); | |
92 | closedir(dir); | |
93 | } | |
94 | return retval; | |
95 | } | |
96 | ||
723c31fe LT |
97 | int head_ref(int (*fn)(const char *path, const unsigned char *sha1)) |
98 | { | |
99 | unsigned char sha1[20]; | |
ca8db142 | 100 | if (!read_ref(git_path("HEAD"), sha1)) |
99a0a6e0 | 101 | return fn("HEAD", sha1); |
2f34ba32 | 102 | return 0; |
723c31fe LT |
103 | } |
104 | ||
944d8589 | 105 | int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1)) |
8a65ff76 | 106 | { |
99a0a6e0 | 107 | return do_for_each_ref("refs", fn); |
8a65ff76 LT |
108 | } |
109 | ||
95fc7512 DB |
110 | static char *ref_file_name(const char *ref) |
111 | { | |
112 | char *base = get_refs_directory(); | |
113 | int baselen = strlen(base); | |
114 | int reflen = strlen(ref); | |
115 | char *ret = xmalloc(baselen + 2 + reflen); | |
116 | sprintf(ret, "%s/%s", base, ref); | |
117 | return ret; | |
118 | } | |
119 | ||
120 | static char *ref_lock_file_name(const char *ref) | |
121 | { | |
122 | char *base = get_refs_directory(); | |
123 | int baselen = strlen(base); | |
124 | int reflen = strlen(ref); | |
125 | char *ret = xmalloc(baselen + 7 + reflen); | |
126 | sprintf(ret, "%s/%s.lock", base, ref); | |
127 | return ret; | |
128 | } | |
129 | ||
95fc7512 DB |
130 | int get_ref_sha1(const char *ref, unsigned char *sha1) |
131 | { | |
ca8db142 LT |
132 | const char *filename; |
133 | ||
95fc7512 DB |
134 | if (check_ref_format(ref)) |
135 | return -1; | |
ca8db142 LT |
136 | filename = git_path("refs/%s", ref); |
137 | return read_ref(filename, sha1); | |
95fc7512 DB |
138 | } |
139 | ||
140 | static int lock_ref_file(const char *filename, const char *lock_filename, | |
141 | const unsigned char *old_sha1) | |
142 | { | |
143 | int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666); | |
144 | unsigned char current_sha1[20]; | |
145 | int retval; | |
146 | if (fd < 0) { | |
147 | return error("Couldn't open lock file for %s: %s", | |
148 | filename, strerror(errno)); | |
149 | } | |
ca8db142 | 150 | retval = read_ref(filename, current_sha1); |
95fc7512 DB |
151 | if (old_sha1) { |
152 | if (retval) { | |
153 | close(fd); | |
154 | unlink(lock_filename); | |
155 | return error("Could not read the current value of %s", | |
156 | filename); | |
157 | } | |
158 | if (memcmp(current_sha1, old_sha1, 20)) { | |
159 | close(fd); | |
160 | unlink(lock_filename); | |
161 | error("The current value of %s is %s", | |
162 | filename, sha1_to_hex(current_sha1)); | |
163 | return error("Expected %s", | |
164 | sha1_to_hex(old_sha1)); | |
165 | } | |
166 | } else { | |
167 | if (!retval) { | |
168 | close(fd); | |
169 | unlink(lock_filename); | |
170 | return error("Unexpectedly found a value of %s for %s", | |
171 | sha1_to_hex(current_sha1), filename); | |
172 | } | |
173 | } | |
174 | return fd; | |
175 | } | |
176 | ||
177 | int lock_ref_sha1(const char *ref, const unsigned char *old_sha1) | |
178 | { | |
179 | char *filename; | |
180 | char *lock_filename; | |
181 | int retval; | |
182 | if (check_ref_format(ref)) | |
183 | return -1; | |
184 | filename = ref_file_name(ref); | |
185 | lock_filename = ref_lock_file_name(ref); | |
186 | retval = lock_ref_file(filename, lock_filename, old_sha1); | |
187 | free(filename); | |
188 | free(lock_filename); | |
189 | return retval; | |
190 | } | |
191 | ||
192 | static int write_ref_file(const char *filename, | |
193 | const char *lock_filename, int fd, | |
194 | const unsigned char *sha1) | |
195 | { | |
196 | char *hex = sha1_to_hex(sha1); | |
197 | char term = '\n'; | |
198 | if (write(fd, hex, 40) < 40 || | |
199 | write(fd, &term, 1) < 1) { | |
200 | error("Couldn't write %s\n", filename); | |
201 | close(fd); | |
202 | return -1; | |
203 | } | |
204 | close(fd); | |
205 | rename(lock_filename, filename); | |
206 | return 0; | |
207 | } | |
208 | ||
209 | int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1) | |
210 | { | |
211 | char *filename; | |
212 | char *lock_filename; | |
213 | int retval; | |
214 | if (fd < 0) | |
215 | return -1; | |
216 | if (check_ref_format(ref)) | |
217 | return -1; | |
218 | filename = ref_file_name(ref); | |
219 | lock_filename = ref_lock_file_name(ref); | |
220 | retval = write_ref_file(filename, lock_filename, fd, sha1); | |
221 | free(filename); | |
222 | free(lock_filename); | |
223 | return retval; | |
224 | } | |
225 | ||
226 | int check_ref_format(const char *ref) | |
227 | { | |
228 | char *middle; | |
229 | if (ref[0] == '.' || ref[0] == '/') | |
230 | return -1; | |
231 | middle = strchr(ref, '/'); | |
232 | if (!middle || !middle[1]) | |
233 | return -1; | |
234 | if (strchr(middle + 1, '/')) | |
235 | return -1; | |
236 | return 0; | |
237 | } | |
238 | ||
239 | int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1) | |
240 | { | |
241 | char *filename; | |
242 | char *lock_filename; | |
243 | int fd; | |
244 | int retval; | |
245 | if (check_ref_format(ref)) | |
246 | return -1; | |
247 | filename = ref_file_name(ref); | |
248 | lock_filename = ref_lock_file_name(ref); | |
249 | fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666); | |
250 | if (fd < 0) { | |
251 | error("Writing %s", lock_filename); | |
252 | perror("Open"); | |
253 | } | |
254 | retval = write_ref_file(filename, lock_filename, fd, sha1); | |
255 | free(filename); | |
256 | free(lock_filename); | |
257 | return retval; | |
258 | } |