6 static int read_ref(const char *path, unsigned char *sha1)
9 int fd = open(path, O_RDONLY);
13 if (read(fd, buffer, sizeof(buffer)) >= 40)
14 ret = get_sha1_hex(buffer, sha1);
20 static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1))
23 DIR *dir = opendir(base);
27 int baselen = strlen(base);
28 char *path = xmalloc(baselen + 257);
29 memcpy(path, base, baselen);
30 if (baselen && base[baselen-1] != '/')
31 path[baselen++] = '/';
33 while ((de = readdir(dir)) != NULL) {
34 unsigned char sha1[20];
38 if (de->d_name[0] == '.')
40 namelen = strlen(de->d_name);
43 memcpy(path + baselen, de->d_name, namelen+1);
44 if (lstat(path, &st) < 0)
46 if (S_ISDIR(st.st_mode)) {
47 retval = do_for_each_ref(path, fn);
52 if (read_ref(path, sha1) < 0)
54 if (!has_sha1_file(sha1))
56 retval = fn(path, sha1);
66 int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1))
68 return do_for_each_ref(get_refs_directory(), fn);
71 static char *ref_file_name(const char *ref)
73 char *base = get_refs_directory();
74 int baselen = strlen(base);
75 int reflen = strlen(ref);
76 char *ret = xmalloc(baselen + 2 + reflen);
77 sprintf(ret, "%s/%s", base, ref);
81 static char *ref_lock_file_name(const char *ref)
83 char *base = get_refs_directory();
84 int baselen = strlen(base);
85 int reflen = strlen(ref);
86 char *ret = xmalloc(baselen + 7 + reflen);
87 sprintf(ret, "%s/%s.lock", base, ref);
91 static int read_ref_file(const char *filename, unsigned char *sha1) {
92 int fd = open(filename, O_RDONLY);
95 return error("Couldn't open %s\n", filename);
97 if ((read(fd, hex, 41) < 41) ||
99 get_sha1_hex(hex, sha1)) {
100 error("Couldn't read a hash from %s\n", filename);
108 int get_ref_sha1(const char *ref, unsigned char *sha1)
112 if (check_ref_format(ref))
114 filename = ref_file_name(ref);
115 retval = read_ref_file(filename, sha1);
120 static int lock_ref_file(const char *filename, const char *lock_filename,
121 const unsigned char *old_sha1)
123 int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
124 unsigned char current_sha1[20];
127 return error("Couldn't open lock file for %s: %s",
128 filename, strerror(errno));
130 retval = read_ref_file(filename, current_sha1);
134 unlink(lock_filename);
135 return error("Could not read the current value of %s",
138 if (memcmp(current_sha1, old_sha1, 20)) {
140 unlink(lock_filename);
141 error("The current value of %s is %s",
142 filename, sha1_to_hex(current_sha1));
143 return error("Expected %s",
144 sha1_to_hex(old_sha1));
149 unlink(lock_filename);
150 return error("Unexpectedly found a value of %s for %s",
151 sha1_to_hex(current_sha1), filename);
157 int lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
162 if (check_ref_format(ref))
164 filename = ref_file_name(ref);
165 lock_filename = ref_lock_file_name(ref);
166 retval = lock_ref_file(filename, lock_filename, old_sha1);
172 static int write_ref_file(const char *filename,
173 const char *lock_filename, int fd,
174 const unsigned char *sha1)
176 char *hex = sha1_to_hex(sha1);
178 if (write(fd, hex, 40) < 40 ||
179 write(fd, &term, 1) < 1) {
180 error("Couldn't write %s\n", filename);
185 rename(lock_filename, filename);
189 int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1)
196 if (check_ref_format(ref))
198 filename = ref_file_name(ref);
199 lock_filename = ref_lock_file_name(ref);
200 retval = write_ref_file(filename, lock_filename, fd, sha1);
206 int check_ref_format(const char *ref)
209 if (ref[0] == '.' || ref[0] == '/')
211 middle = strchr(ref, '/');
212 if (!middle || !middle[1])
214 if (strchr(middle + 1, '/'))
219 int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1)
225 if (check_ref_format(ref))
227 filename = ref_file_name(ref);
228 lock_filename = ref_lock_file_name(ref);
229 fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
231 error("Writing %s", lock_filename);
234 retval = write_ref_file(filename, lock_filename, fd, sha1);