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);
30 if (!strncmp(base, "./", 2)) {
34 memcpy(path, base, baselen);
35 if (baselen && base[baselen-1] != '/')
36 path[baselen++] = '/';
38 while ((de = readdir(dir)) != NULL) {
39 unsigned char sha1[20];
43 if (de->d_name[0] == '.')
45 namelen = strlen(de->d_name);
48 memcpy(path + baselen, de->d_name, namelen+1);
49 if (lstat(path, &st) < 0)
51 if (S_ISDIR(st.st_mode)) {
52 retval = do_for_each_ref(path, fn);
57 if (read_ref(path, sha1) < 0)
59 if (!has_sha1_file(sha1))
61 retval = fn(path, sha1);
71 int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1))
73 return do_for_each_ref(get_refs_directory(), fn);
76 static char *ref_file_name(const char *ref)
78 char *base = get_refs_directory();
79 int baselen = strlen(base);
80 int reflen = strlen(ref);
81 char *ret = xmalloc(baselen + 2 + reflen);
82 sprintf(ret, "%s/%s", base, ref);
86 static char *ref_lock_file_name(const char *ref)
88 char *base = get_refs_directory();
89 int baselen = strlen(base);
90 int reflen = strlen(ref);
91 char *ret = xmalloc(baselen + 7 + reflen);
92 sprintf(ret, "%s/%s.lock", base, ref);
96 static int read_ref_file(const char *filename, unsigned char *sha1) {
97 int fd = open(filename, O_RDONLY);
100 return error("Couldn't open %s\n", filename);
102 if ((read(fd, hex, 41) < 41) ||
104 get_sha1_hex(hex, sha1)) {
105 error("Couldn't read a hash from %s\n", filename);
113 int get_ref_sha1(const char *ref, unsigned char *sha1)
117 if (check_ref_format(ref))
119 filename = ref_file_name(ref);
120 retval = read_ref_file(filename, sha1);
125 static int lock_ref_file(const char *filename, const char *lock_filename,
126 const unsigned char *old_sha1)
128 int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
129 unsigned char current_sha1[20];
132 return error("Couldn't open lock file for %s: %s",
133 filename, strerror(errno));
135 retval = read_ref_file(filename, current_sha1);
139 unlink(lock_filename);
140 return error("Could not read the current value of %s",
143 if (memcmp(current_sha1, old_sha1, 20)) {
145 unlink(lock_filename);
146 error("The current value of %s is %s",
147 filename, sha1_to_hex(current_sha1));
148 return error("Expected %s",
149 sha1_to_hex(old_sha1));
154 unlink(lock_filename);
155 return error("Unexpectedly found a value of %s for %s",
156 sha1_to_hex(current_sha1), filename);
162 int lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
167 if (check_ref_format(ref))
169 filename = ref_file_name(ref);
170 lock_filename = ref_lock_file_name(ref);
171 retval = lock_ref_file(filename, lock_filename, old_sha1);
177 static int write_ref_file(const char *filename,
178 const char *lock_filename, int fd,
179 const unsigned char *sha1)
181 char *hex = sha1_to_hex(sha1);
183 if (write(fd, hex, 40) < 40 ||
184 write(fd, &term, 1) < 1) {
185 error("Couldn't write %s\n", filename);
190 rename(lock_filename, filename);
194 int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1)
201 if (check_ref_format(ref))
203 filename = ref_file_name(ref);
204 lock_filename = ref_lock_file_name(ref);
205 retval = write_ref_file(filename, lock_filename, fd, sha1);
211 int check_ref_format(const char *ref)
214 if (ref[0] == '.' || ref[0] == '/')
216 middle = strchr(ref, '/');
217 if (!middle || !middle[1])
219 if (strchr(middle + 1, '/'))
224 int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1)
230 if (check_ref_format(ref))
232 filename = ref_file_name(ref);
233 lock_filename = ref_lock_file_name(ref);
234 fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
236 error("Writing %s", lock_filename);
239 retval = write_ref_file(filename, lock_filename, fd, sha1);