+ if (write(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
+ write(lock->lock_fd, &term, 1) != 1
+ || close(lock->lock_fd) < 0) {
+ error("Couldn't write %s", lock->lk->filename);
+ unlock_ref(lock);
+ return -1;
+ }
+ if (log_ref_write(lock, sha1, logmsg) < 0) {
+ unlock_ref(lock);
+ return -1;
+ }
+ if (commit_lock_file(lock->lk)) {
+ error("Couldn't set %s", lock->ref_file);
+ unlock_ref(lock);
+ return -1;
+ }
+ lock->lock_fd = -1;
+ unlock_ref(lock);
+ return 0;
+}
+
+int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1)
+{
+ const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
+ char *tz_c;
+ int logfd, tz;
+ struct stat st;
+ unsigned long date;
+ unsigned char logged_sha1[20];
+
+ logfile = git_path("logs/%s", ref);
+ logfd = open(logfile, O_RDONLY, 0);
+ if (logfd < 0)
+ die("Unable to read log %s: %s", logfile, strerror(errno));
+ fstat(logfd, &st);
+ if (!st.st_size)
+ die("Log %s is empty.", logfile);
+ logdata = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, logfd, 0);
+ close(logfd);
+
+ lastrec = NULL;
+ rec = logend = logdata + st.st_size;
+ while (logdata < rec) {
+ if (logdata < rec && *(rec-1) == '\n')
+ rec--;
+ lastgt = NULL;
+ while (logdata < rec && *(rec-1) != '\n') {
+ rec--;
+ if (*rec == '>')
+ lastgt = rec;
+ }
+ if (!lastgt)
+ die("Log %s is corrupt.", logfile);
+ date = strtoul(lastgt + 1, &tz_c, 10);
+ if (date <= at_time) {
+ if (lastrec) {
+ if (get_sha1_hex(lastrec, logged_sha1))
+ die("Log %s is corrupt.", logfile);
+ if (get_sha1_hex(rec + 41, sha1))
+ die("Log %s is corrupt.", logfile);
+ if (memcmp(logged_sha1, sha1, 20)) {
+ tz = strtoul(tz_c, NULL, 10);
+ fprintf(stderr,
+ "warning: Log %s has gap after %s.\n",
+ logfile, show_rfc2822_date(date, tz));
+ }
+ } else if (date == at_time) {
+ if (get_sha1_hex(rec + 41, sha1))
+ die("Log %s is corrupt.", logfile);
+ } else {
+ if (get_sha1_hex(rec + 41, logged_sha1))
+ die("Log %s is corrupt.", logfile);
+ if (memcmp(logged_sha1, sha1, 20)) {
+ tz = strtoul(tz_c, NULL, 10);
+ fprintf(stderr,
+ "warning: Log %s unexpectedly ended on %s.\n",
+ logfile, show_rfc2822_date(date, tz));
+ }
+ }
+ munmap((void*)logdata, st.st_size);
+ return 0;
+ }
+ lastrec = rec;
+ }
+
+ rec = logdata;
+ while (rec < logend && *rec != '>' && *rec != '\n')
+ rec++;
+ if (rec == logend || *rec == '\n')
+ die("Log %s is corrupt.", logfile);
+ date = strtoul(rec + 1, &tz_c, 10);
+ tz = strtoul(tz_c, NULL, 10);
+ if (get_sha1_hex(logdata, sha1))
+ die("Log %s is corrupt.", logfile);
+ munmap((void*)logdata, st.st_size);
+ fprintf(stderr, "warning: Log %s only goes back to %s.\n",
+ logfile, show_rfc2822_date(date, tz));
+ return 0;