7 /* We allow "recursive" symbolic refs. Only within reason, though */
10 const char *resolve_ref(const char *path, unsigned char *sha1, int reading)
12 int depth = MAXDEPTH, len;
23 /* Special case: non-existing file.
24 * Not having the refs/heads/new-branch is OK
25 * if we are writing into it, so is .git/HEAD
26 * that points at refs/heads/master still to be
27 * born. It is NOT OK if we are resolving for
30 if (lstat(path, &st) < 0) {
31 if (reading || errno != ENOENT)
37 /* Follow "normalized" - ie "refs/.." symlinks by hand */
38 if (S_ISLNK(st.st_mode)) {
39 len = readlink(path, buffer, sizeof(buffer)-1);
40 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
41 path = git_path("%.*s", len, buffer);
47 * Anything else, just open it and try to use it as
50 fd = open(path, O_RDONLY);
53 len = read(fd, buffer, sizeof(buffer)-1);
57 * Is it a symbolic ref?
59 if (len < 4 || memcmp("ref:", buffer, 4))
63 while (len && isspace(*buf))
65 while (len && isspace(buf[len-1]))
67 path = git_path("%.*s", len, buf);
69 if (len < 40 || get_sha1_hex(buffer, sha1))
74 int read_ref(const char *filename, unsigned char *sha1)
76 if (resolve_ref(filename, sha1, 1))
81 static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1))
84 DIR *dir = opendir(git_path("%s", base));
88 int baselen = strlen(base);
89 char *path = xmalloc(baselen + 257);
91 if (!strncmp(base, "./", 2)) {
95 memcpy(path, base, baselen);
96 if (baselen && base[baselen-1] != '/')
97 path[baselen++] = '/';
99 while ((de = readdir(dir)) != NULL) {
100 unsigned char sha1[20];
104 if (de->d_name[0] == '.')
106 namelen = strlen(de->d_name);
109 memcpy(path + baselen, de->d_name, namelen+1);
110 if (stat(git_path("%s", path), &st) < 0)
112 if (S_ISDIR(st.st_mode)) {
113 retval = do_for_each_ref(path, fn);
118 if (read_ref(git_path("%s", path), sha1) < 0)
120 if (!has_sha1_file(sha1))
122 retval = fn(path, sha1);
132 int head_ref(int (*fn)(const char *path, const unsigned char *sha1))
134 unsigned char sha1[20];
135 if (!read_ref(git_path("HEAD"), sha1))
136 return fn("HEAD", sha1);
140 int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1))
142 return do_for_each_ref("refs", fn);
145 static char *ref_file_name(const char *ref)
147 char *base = get_refs_directory();
148 int baselen = strlen(base);
149 int reflen = strlen(ref);
150 char *ret = xmalloc(baselen + 2 + reflen);
151 sprintf(ret, "%s/%s", base, ref);
155 static char *ref_lock_file_name(const char *ref)
157 char *base = get_refs_directory();
158 int baselen = strlen(base);
159 int reflen = strlen(ref);
160 char *ret = xmalloc(baselen + 7 + reflen);
161 sprintf(ret, "%s/%s.lock", base, ref);
165 int get_ref_sha1(const char *ref, unsigned char *sha1)
167 const char *filename;
169 if (check_ref_format(ref))
171 filename = git_path("refs/%s", ref);
172 return read_ref(filename, sha1);
175 static int lock_ref_file(const char *filename, const char *lock_filename,
176 const unsigned char *old_sha1)
178 int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
179 unsigned char current_sha1[20];
182 return error("Couldn't open lock file for %s: %s",
183 filename, strerror(errno));
185 retval = read_ref(filename, current_sha1);
189 unlink(lock_filename);
190 return error("Could not read the current value of %s",
193 if (memcmp(current_sha1, old_sha1, 20)) {
195 unlink(lock_filename);
196 error("The current value of %s is %s",
197 filename, sha1_to_hex(current_sha1));
198 return error("Expected %s",
199 sha1_to_hex(old_sha1));
204 unlink(lock_filename);
205 return error("Unexpectedly found a value of %s for %s",
206 sha1_to_hex(current_sha1), filename);
212 int lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
217 if (check_ref_format(ref))
219 filename = ref_file_name(ref);
220 lock_filename = ref_lock_file_name(ref);
221 retval = lock_ref_file(filename, lock_filename, old_sha1);
227 static int write_ref_file(const char *filename,
228 const char *lock_filename, int fd,
229 const unsigned char *sha1)
231 char *hex = sha1_to_hex(sha1);
233 if (write(fd, hex, 40) < 40 ||
234 write(fd, &term, 1) < 1) {
235 error("Couldn't write %s\n", filename);
240 rename(lock_filename, filename);
244 int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1)
251 if (check_ref_format(ref))
253 filename = ref_file_name(ref);
254 lock_filename = ref_lock_file_name(ref);
255 retval = write_ref_file(filename, lock_filename, fd, sha1);
261 int check_ref_format(const char *ref)
264 if (ref[0] == '.' || ref[0] == '/')
266 middle = strchr(ref, '/');
267 if (!middle || !middle[1])
269 if (strchr(middle + 1, '/'))
274 int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1)
280 if (check_ref_format(ref))
282 filename = ref_file_name(ref);
283 lock_filename = ref_lock_file_name(ref);
284 fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
286 error("Writing %s", lock_filename);
289 retval = write_ref_file(filename, lock_filename, fd, sha1);