6 /* We allow "recursive" symbolic refs. Only within reason, though */
9 const char *resolve_ref(const char *path, unsigned char *sha1, int reading)
11 int depth = MAXDEPTH, len;
22 /* Special case: non-existing file.
23 * Not having the refs/heads/new-branch is OK
24 * if we are writing into it, so is .git/HEAD
25 * that points at refs/heads/master still to be
26 * born. It is NOT OK if we are resolving for
29 if (lstat(path, &st) < 0) {
30 if (reading || errno != ENOENT)
36 /* Follow "normalized" - ie "refs/.." symlinks by hand */
37 if (S_ISLNK(st.st_mode)) {
38 len = readlink(path, buffer, sizeof(buffer)-1);
39 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
40 path = git_path("%.*s", len, buffer);
46 * Anything else, just open it and try to use it as
49 fd = open(path, O_RDONLY);
52 len = read(fd, buffer, sizeof(buffer)-1);
56 * Is it a symbolic ref?
58 if (len < 4 || memcmp("ref:", buffer, 4))
62 while (len && isspace(*buf))
64 while (len && isspace(buf[len-1]))
66 path = git_path("%.*s", len, buf);
68 if (len < 40 || get_sha1_hex(buffer, sha1))
73 int create_symref(const char *git_HEAD, const char *refs_heads_master)
79 #ifdef USE_SYMLINK_HEAD
80 if (!only_use_symrefs) {
82 if (!symlink(refs_heads_master, git_HEAD))
84 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
88 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
89 if (sizeof(ref) <= len) {
90 error("refname too long: %s", refs_heads_master);
93 lockpath = mkpath("%s.lock", git_HEAD);
94 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
95 written = write(fd, ref, len);
99 error("Unable to write to %s", lockpath);
102 if (rename(lockpath, git_HEAD) < 0) {
104 error("Unable to create %s", git_HEAD);
110 int read_ref(const char *filename, unsigned char *sha1)
112 if (resolve_ref(filename, sha1, 1))
117 static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1))
120 DIR *dir = opendir(git_path("%s", base));
124 int baselen = strlen(base);
125 char *path = xmalloc(baselen + 257);
127 if (!strncmp(base, "./", 2)) {
131 memcpy(path, base, baselen);
132 if (baselen && base[baselen-1] != '/')
133 path[baselen++] = '/';
135 while ((de = readdir(dir)) != NULL) {
136 unsigned char sha1[20];
140 if (de->d_name[0] == '.')
142 namelen = strlen(de->d_name);
145 memcpy(path + baselen, de->d_name, namelen+1);
146 if (stat(git_path("%s", path), &st) < 0)
148 if (S_ISDIR(st.st_mode)) {
149 retval = do_for_each_ref(path, fn);
154 if (read_ref(git_path("%s", path), sha1) < 0)
156 if (!has_sha1_file(sha1))
158 retval = fn(path, sha1);
168 int head_ref(int (*fn)(const char *path, const unsigned char *sha1))
170 unsigned char sha1[20];
171 if (!read_ref(git_path("HEAD"), sha1))
172 return fn("HEAD", sha1);
176 int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1))
178 return do_for_each_ref("refs", fn);
181 static char *ref_file_name(const char *ref)
183 char *base = get_refs_directory();
184 int baselen = strlen(base);
185 int reflen = strlen(ref);
186 char *ret = xmalloc(baselen + 2 + reflen);
187 sprintf(ret, "%s/%s", base, ref);
191 static char *ref_lock_file_name(const char *ref)
193 char *base = get_refs_directory();
194 int baselen = strlen(base);
195 int reflen = strlen(ref);
196 char *ret = xmalloc(baselen + 7 + reflen);
197 sprintf(ret, "%s/%s.lock", base, ref);
201 int get_ref_sha1(const char *ref, unsigned char *sha1)
203 const char *filename;
205 if (check_ref_format(ref))
207 filename = git_path("refs/%s", ref);
208 return read_ref(filename, sha1);
211 static int lock_ref_file(const char *filename, const char *lock_filename,
212 const unsigned char *old_sha1)
214 int fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
215 unsigned char current_sha1[20];
218 return error("Couldn't open lock file for %s: %s",
219 filename, strerror(errno));
221 retval = read_ref(filename, current_sha1);
225 unlink(lock_filename);
226 return error("Could not read the current value of %s",
229 if (memcmp(current_sha1, old_sha1, 20)) {
231 unlink(lock_filename);
232 error("The current value of %s is %s",
233 filename, sha1_to_hex(current_sha1));
234 return error("Expected %s",
235 sha1_to_hex(old_sha1));
240 unlink(lock_filename);
241 return error("Unexpectedly found a value of %s for %s",
242 sha1_to_hex(current_sha1), filename);
248 int lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
253 if (check_ref_format(ref))
255 filename = ref_file_name(ref);
256 lock_filename = ref_lock_file_name(ref);
257 retval = lock_ref_file(filename, lock_filename, old_sha1);
263 static int write_ref_file(const char *filename,
264 const char *lock_filename, int fd,
265 const unsigned char *sha1)
267 char *hex = sha1_to_hex(sha1);
269 if (write(fd, hex, 40) < 40 ||
270 write(fd, &term, 1) < 1) {
271 error("Couldn't write %s\n", filename);
276 rename(lock_filename, filename);
280 int write_ref_sha1(const char *ref, int fd, const unsigned char *sha1)
287 if (check_ref_format(ref))
289 filename = ref_file_name(ref);
290 lock_filename = ref_lock_file_name(ref);
291 if (safe_create_leading_directories(filename))
292 die("unable to create leading directory for %s", filename);
293 retval = write_ref_file(filename, lock_filename, fd, sha1);
300 * Make sure "ref" is something reasonable to have under ".git/refs/";
301 * We do not like it if:
303 * - any path component of it begins with ".", or
304 * - it has double dots "..", or
305 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
306 * - it ends with a "/".
309 static inline int bad_ref_char(int ch)
311 return (((unsigned) ch) <= ' ' ||
312 ch == '~' || ch == '^' || ch == ':' ||
313 /* 2.13 Pattern Matching Notation */
314 ch == '?' || ch == '*' || ch == '[');
317 int check_ref_format(const char *ref)
320 const char *cp = ref;
324 while ((ch = *cp++) == '/')
325 ; /* tolerate duplicated slashes */
327 return -1; /* should not end with slashes */
329 /* we are at the beginning of the path component */
330 if (ch == '.' || bad_ref_char(ch))
333 /* scan the rest of the path component */
334 while ((ch = *cp++) != 0) {
335 if (bad_ref_char(ch))
339 if (ch == '.' && *cp == '.')
345 return -1; /* at least of form "heads/blah" */
351 int write_ref_sha1_unlocked(const char *ref, const unsigned char *sha1)
357 if (check_ref_format(ref))
359 filename = ref_file_name(ref);
360 lock_filename = ref_lock_file_name(ref);
361 if (safe_create_leading_directories(filename))
362 die("unable to create leading directory for %s", filename);
363 fd = open(lock_filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
365 error("Writing %s", lock_filename);
368 retval = write_ref_file(filename, lock_filename, fd, sha1);