/**
 * @說明: 檔案快取輸出
 * @引數: $cachefile => cache檔案(絕對路徑)
 * @引數: $pertime => 快取輸出的間隔時間
 * @引數: $sql => sql語句
 * @引數: $templatefile => 模板檔名稱(絕對路徑)
**/
function __cache($cachefile,$pertime,$sql,$templatefile) {
 global $db;
 if(time() - @filemtime($cachefile) >= $pertime) {
  $query = $db->query($sql);
  while($r=$db->fetch($query)) {
   $cachelist[] = $r;
  } 
  include $templatefile.'.php';
  $cacheserialize = serialize($cachelist);
  file_put_contents($cachefile,$cacheserialize);
 }else{
  $cachelist = unserialize(file_get_contents($cachefile));
  include $templatefile.'.php';
 }
}