9. 問題の実装 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 <?php class BlackListDB { const DBPATH = "/tmp/db.gdbm"; public function isBlock($id) { $dbh = dba_open(self::DBPATH, "r", "gdbm"); if ($dbh === false) { return null; } $ret = dba_exists($id, $dbh); dba_close($dbh); return $ret; } } 10. 問題点 10 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 <?php class BlackListDB { const DBPATH = "/tmp/db.gdbm"; publ