php缓存数组到文件

 

static function getIDs($kemuid) {  $cachefile="cache/" . $kemuid . ".cache";  $datas=array();  if (!file_exists($cachefile)||time() > (filemtime($cachefile) + 14400))  //缓存不存在或超过4小时  {   global $data;   //读取 id 集   $query="SELECT sid FROM shiti WHERE skemu = " . intval($kemuid);   $res = $data->query($query);   while($r = $data->fetchArray($res))   {    $datas[]=$r['sid'];   }   //写入缓存   file_put_contents($cachefile,serialize($datas));   /*      $fp= fopen($cachefile, "w");      fwrite($fp, serialize($datas));      fclose($fp);   */  }  else  {   //读出缓存   $fp = fopen($cachefile,'r');//读   $datas = unserialize(fread($fp,filesize($cachefile)));//反序列化，并赋值  }  return $datas; }