8 unsigned char sha1[20];
12 static const char *parse_ref_line(char *line, unsigned char *sha1)
15 * 42: the answer to everything.
17 * In this case, it happens to be the answer to
18 * 40 (length of sha1 hex representation)
19 * +1 (space in between hex and name)
20 * +1 (newline at the end of the line)
22 int len = strlen(line) - 42;
26 if (get_sha1_hex(line, sha1) < 0)
28 if (!isspace(line[40]))
33 if (line[len] != '\n')
39 static struct ref_list *add_ref(const char *name, const unsigned char *sha1, struct ref_list *list)
42 struct ref_list **p = &list, *entry;
44 /* Find the place to insert the ref into.. */
45 while ((entry = *p) != NULL) {
46 int cmp = strcmp(entry->name, name);
50 /* Same as existing entry? */
56 /* Allocate it and add it in.. */
57 len = strlen(name) + 1;
58 entry = xmalloc(sizeof(struct ref_list) + len);
59 hashcpy(entry->sha1, sha1);
60 memcpy(entry->name, name, len);
66 static struct ref_list *get_packed_refs(void)
68 static int did_refs = 0;
69 static struct ref_list *refs = NULL;
72 FILE *f = fopen(git_path("packed-refs"), "r");
74 struct ref_list *list = NULL;
75 char refline[PATH_MAX];
76 while (fgets(refline, sizeof(refline), f)) {
77 unsigned char sha1[20];
78 const char *name = parse_ref_line(refline, sha1);
81 list = add_ref(name, sha1, list);
91 static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
93 DIR *dir = opendir(git_path("%s", base));
97 int baselen = strlen(base);
98 char *ref = xmalloc(baselen + 257);
100 memcpy(ref, base, baselen);
101 if (baselen && base[baselen-1] != '/')
102 ref[baselen++] = '/';
104 while ((de = readdir(dir)) != NULL) {
105 unsigned char sha1[20];
109 if (de->d_name[0] == '.')
111 namelen = strlen(de->d_name);
114 if (has_extension(de->d_name, ".lock"))
116 memcpy(ref + baselen, de->d_name, namelen+1);
117 if (stat(git_path("%s", ref), &st) < 0)
119 if (S_ISDIR(st.st_mode)) {
120 list = get_ref_dir(ref, list);
123 if (read_ref(ref, sha1) < 0) {
124 error("%s points nowhere!", ref);
127 list = add_ref(ref, sha1, list);
135 static struct ref_list *get_loose_refs(void)
137 static int did_refs = 0;
138 static struct ref_list *refs = NULL;
141 refs = get_ref_dir("refs", NULL);
147 /* We allow "recursive" symbolic refs. Only within reason, though */
150 const char *resolve_ref(const char *ref, unsigned char *sha1, int reading)
152 int depth = MAXDEPTH, len;
154 static char ref_buffer[256];
157 const char *path = git_path("%s", ref);
165 /* Special case: non-existing file.
166 * Not having the refs/heads/new-branch is OK
167 * if we are writing into it, so is .git/HEAD
168 * that points at refs/heads/master still to be
169 * born. It is NOT OK if we are resolving for
172 if (lstat(path, &st) < 0) {
173 struct ref_list *list = get_packed_refs();
175 if (!strcmp(ref, list->name)) {
176 hashcpy(sha1, list->sha1);
181 if (reading || errno != ENOENT)
187 /* Follow "normalized" - ie "refs/.." symlinks by hand */
188 if (S_ISLNK(st.st_mode)) {
189 len = readlink(path, buffer, sizeof(buffer)-1);
190 if (len >= 5 && !memcmp("refs/", buffer, 5)) {
192 strcpy(ref_buffer, buffer);
199 * Anything else, just open it and try to use it as
202 fd = open(path, O_RDONLY);
205 len = read(fd, buffer, sizeof(buffer)-1);
209 * Is it a symbolic ref?
211 if (len < 4 || memcmp("ref:", buffer, 4))
215 while (len && isspace(*buf))
217 while (len && isspace(buf[len-1]))
220 memcpy(ref_buffer, buf, len + 1);
223 if (len < 40 || get_sha1_hex(buffer, sha1))
228 int create_symref(const char *ref_target, const char *refs_heads_master)
230 const char *lockpath;
232 int fd, len, written;
233 const char *git_HEAD = git_path("%s", ref_target);
235 #ifndef NO_SYMLINK_HEAD
236 if (prefer_symlink_refs) {
238 if (!symlink(refs_heads_master, git_HEAD))
240 fprintf(stderr, "no symlink - falling back to symbolic ref\n");
244 len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
245 if (sizeof(ref) <= len) {
246 error("refname too long: %s", refs_heads_master);
249 lockpath = mkpath("%s.lock", git_HEAD);
250 fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
251 written = write(fd, ref, len);
253 if (written != len) {
255 error("Unable to write to %s", lockpath);
258 if (rename(lockpath, git_HEAD) < 0) {
260 error("Unable to create %s", git_HEAD);
263 if (adjust_shared_perm(git_HEAD)) {
265 error("Unable to fix permissions on %s", lockpath);
271 int read_ref(const char *ref, unsigned char *sha1)
273 if (resolve_ref(ref, sha1, 1))
278 static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1), int trim)
281 struct ref_list *packed = get_packed_refs();
282 struct ref_list *loose = get_loose_refs();
284 while (packed && loose) {
285 struct ref_list *entry;
286 int cmp = strcmp(packed->name, loose->name);
288 packed = packed->next;
296 packed = packed->next;
298 if (strncmp(base, entry->name, trim))
300 if (is_null_sha1(entry->sha1))
302 if (!has_sha1_file(entry->sha1)) {
303 error("%s does not point to a valid object!", entry->name);
306 retval = fn(entry->name + trim, entry->sha1);
311 packed = packed ? packed : loose;
313 if (!strncmp(base, packed->name, trim)) {
314 retval = fn(packed->name + trim, packed->sha1);
318 packed = packed->next;
323 int head_ref(int (*fn)(const char *path, const unsigned char *sha1))
325 unsigned char sha1[20];
326 if (!read_ref("HEAD", sha1))
327 return fn("HEAD", sha1);
331 int for_each_ref(int (*fn)(const char *path, const unsigned char *sha1))
333 return do_for_each_ref("refs/", fn, 0);
336 int for_each_tag_ref(int (*fn)(const char *path, const unsigned char *sha1))
338 return do_for_each_ref("refs/tags/", fn, 10);
341 int for_each_branch_ref(int (*fn)(const char *path, const unsigned char *sha1))
343 return do_for_each_ref("refs/heads/", fn, 11);
346 int for_each_remote_ref(int (*fn)(const char *path, const unsigned char *sha1))
348 return do_for_each_ref("refs/remotes/", fn, 13);
351 int get_ref_sha1(const char *ref, unsigned char *sha1)
353 if (check_ref_format(ref))
355 return read_ref(mkpath("refs/%s", ref), sha1);
359 * Make sure "ref" is something reasonable to have under ".git/refs/";
360 * We do not like it if:
362 * - any path component of it begins with ".", or
363 * - it has double dots "..", or
364 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
365 * - it ends with a "/".
368 static inline int bad_ref_char(int ch)
370 return (((unsigned) ch) <= ' ' ||
371 ch == '~' || ch == '^' || ch == ':' ||
372 /* 2.13 Pattern Matching Notation */
373 ch == '?' || ch == '*' || ch == '[');
376 int check_ref_format(const char *ref)
379 const char *cp = ref;
383 while ((ch = *cp++) == '/')
384 ; /* tolerate duplicated slashes */
386 return -1; /* should not end with slashes */
388 /* we are at the beginning of the path component */
389 if (ch == '.' || bad_ref_char(ch))
392 /* scan the rest of the path component */
393 while ((ch = *cp++) != 0) {
394 if (bad_ref_char(ch))
398 if (ch == '.' && *cp == '.')
404 return -1; /* at least of form "heads/blah" */
410 static struct ref_lock *verify_lock(struct ref_lock *lock,
411 const unsigned char *old_sha1, int mustexist)
413 if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist)) {
414 error("Can't verify ref %s", lock->ref_name);
418 if (hashcmp(lock->old_sha1, old_sha1)) {
419 error("Ref %s is at %s but expected %s", lock->ref_name,
420 sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
427 static struct ref_lock *lock_ref_sha1_basic(const char *ref,
429 const unsigned char *old_sha1, int mustexist)
432 const char *orig_ref = ref;
433 struct ref_lock *lock;
436 lock = xcalloc(1, sizeof(struct ref_lock));
439 ref = resolve_ref(ref, lock->old_sha1, mustexist);
441 int last_errno = errno;
442 error("unable to resolve reference %s: %s",
443 orig_ref, strerror(errno));
448 lock->lk = xcalloc(1, sizeof(struct lock_file));
450 lock->ref_name = xstrdup(ref);
451 lock->log_file = xstrdup(git_path("logs/%s", ref));
452 ref_file = git_path(ref);
453 lock->force_write = lstat(ref_file, &st) && errno == ENOENT;
455 if (safe_create_leading_directories(ref_file))
456 die("unable to create directory for %s", ref_file);
457 lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
459 return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
462 struct ref_lock *lock_ref_sha1(const char *ref,
463 const unsigned char *old_sha1, int mustexist)
465 if (check_ref_format(ref))
467 return lock_ref_sha1_basic(mkpath("refs/%s", ref),
468 5 + strlen(ref), old_sha1, mustexist);
471 struct ref_lock *lock_any_ref_for_update(const char *ref,
472 const unsigned char *old_sha1, int mustexist)
474 return lock_ref_sha1_basic(ref, strlen(ref), old_sha1, mustexist);
477 void unlock_ref(struct ref_lock *lock)
479 if (lock->lock_fd >= 0) {
480 close(lock->lock_fd);
481 /* Do not free lock->lk -- atexit() still looks at them */
483 rollback_lock_file(lock->lk);
485 free(lock->ref_name);
486 free(lock->log_file);
490 static int log_ref_write(struct ref_lock *lock,
491 const unsigned char *sha1, const char *msg)
493 int logfd, written, oflags = O_APPEND | O_WRONLY;
494 unsigned maxlen, len;
496 const char *committer;
498 if (log_all_ref_updates) {
499 if (safe_create_leading_directories(lock->log_file) < 0)
500 return error("unable to create directory for %s",
505 logfd = open(lock->log_file, oflags, 0666);
507 if (!log_all_ref_updates && errno == ENOENT)
509 return error("Unable to append to %s: %s",
510 lock->log_file, strerror(errno));
513 committer = git_committer_info(1);
515 maxlen = strlen(committer) + strlen(msg) + 2*40 + 5;
516 logrec = xmalloc(maxlen);
517 len = snprintf(logrec, maxlen, "%s %s %s\t%s\n",
518 sha1_to_hex(lock->old_sha1),
524 maxlen = strlen(committer) + 2*40 + 4;
525 logrec = xmalloc(maxlen);
526 len = snprintf(logrec, maxlen, "%s %s %s\n",
527 sha1_to_hex(lock->old_sha1),
531 written = len <= maxlen ? write(logfd, logrec, len) : -1;
535 return error("Unable to append to %s", lock->log_file);
539 int write_ref_sha1(struct ref_lock *lock,
540 const unsigned char *sha1, const char *logmsg)
542 static char term = '\n';
546 if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
550 if (write(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
551 write(lock->lock_fd, &term, 1) != 1
552 || close(lock->lock_fd) < 0) {
553 error("Couldn't write %s", lock->lk->filename);
557 if (log_ref_write(lock, sha1, logmsg) < 0) {
561 if (commit_lock_file(lock->lk)) {
562 error("Couldn't set %s", lock->ref_name);
571 int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1)
573 const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
578 unsigned char logged_sha1[20];
580 logfile = git_path("logs/%s", ref);
581 logfd = open(logfile, O_RDONLY, 0);
583 die("Unable to read log %s: %s", logfile, strerror(errno));
586 die("Log %s is empty.", logfile);
587 logdata = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, logfd, 0);
591 rec = logend = logdata + st.st_size;
592 while (logdata < rec) {
593 if (logdata < rec && *(rec-1) == '\n')
596 while (logdata < rec && *(rec-1) != '\n') {
602 die("Log %s is corrupt.", logfile);
603 date = strtoul(lastgt + 1, &tz_c, 10);
604 if (date <= at_time) {
606 if (get_sha1_hex(lastrec, logged_sha1))
607 die("Log %s is corrupt.", logfile);
608 if (get_sha1_hex(rec + 41, sha1))
609 die("Log %s is corrupt.", logfile);
610 if (hashcmp(logged_sha1, sha1)) {
611 tz = strtoul(tz_c, NULL, 10);
613 "warning: Log %s has gap after %s.\n",
614 logfile, show_rfc2822_date(date, tz));
617 else if (date == at_time) {
618 if (get_sha1_hex(rec + 41, sha1))
619 die("Log %s is corrupt.", logfile);
622 if (get_sha1_hex(rec + 41, logged_sha1))
623 die("Log %s is corrupt.", logfile);
624 if (hashcmp(logged_sha1, sha1)) {
625 tz = strtoul(tz_c, NULL, 10);
627 "warning: Log %s unexpectedly ended on %s.\n",
628 logfile, show_rfc2822_date(date, tz));
631 munmap((void*)logdata, st.st_size);
638 while (rec < logend && *rec != '>' && *rec != '\n')
640 if (rec == logend || *rec == '\n')
641 die("Log %s is corrupt.", logfile);
642 date = strtoul(rec + 1, &tz_c, 10);
643 tz = strtoul(tz_c, NULL, 10);
644 if (get_sha1_hex(logdata, sha1))
645 die("Log %s is corrupt.", logfile);
646 munmap((void*)logdata, st.st_size);
647 fprintf(stderr, "warning: Log %s only goes back to %s.\n",
648 logfile, show_rfc2822_date(date, tz));