求帮忙修改下PHP代码

014131

把缓存页面的代码去掉，但不影响正常调用现有的缓存数据   
应该把那部分删掉呢？
【其调用的是 ：cacheData/xxx/a864452.txt   txt里是html页面缓存的代码】

<?php

class dirCache {
private $_unitNum = 999;
private $_unitFloor = 3;
private $_pix = '_';
private $_now = 0;
public $baseDir = '';
public $dirMode = 0777;
public function __construct($baseDir = null) {
if ($baseDir) {
$this->baseDir = $baseDir;
}else {
$this->baseDir = dirname(__FILE__) .DIRECTORY_SEPARATOR .'cacheData';
}
if ($_SERVER['REQUEST_TIME']) {
$this->_now = $_SERVER['REQUEST_TIME'];
}else {
$this->_now = time();
}
}
public function isExists($id,$timeout = 0,$isCreate = false) {
$file = $this->hashId($id);
if (!is_file($file)) {
if (is_file($file .'.lock')) {
return 'LOCKED';
}
return false;
}
$timefun = $isCreate ?'filectime': 'filemtime';
if ($timeout &&$timefun($file) +$timeout <$this->_now) {
return false;
}
return true;
}
public function set($id,$data = null) {
return $this->_writeFile($this->hashId($id),$this->_encode($data));
}
public function get($id,$lockread = false) {
return $this->_decode($this->_readFile($this->hashId($id),$lockread));
}
public function del($id) {
return $this->_deleteFile($this->hashId($id));
}
public function hashId($id) {
if (!is_numeric($id)) {
$id = $this->enId($id);
$notNum = 'a';
}
$id = $tid = $id;
$hash = '';
$pow = 0;
for ($i = $this->_unitFloor;$i ;$i--) {
$pow = pow($this->_unitNum,$i);
$unit = floor($tid / $pow);
if ($unit >$this->_unitNum) {
$unit = $this->_unitNum;
}
$hash .= $this->_pix .$unit .DIRECTORY_SEPARATOR;
$tid = $tid -$unit * $pow;
}
unset($pow,$tid,$unit,$i);
return $this->baseDir .DIRECTORY_SEPARATOR .$hash .($notNum) .$id .'.txt';
}
public function enId($data) {
return sprintf('%011u',crc32($data));
}
private function _encode($data) {
$array = array('source'=>$data);
return '<?php die(\'Cache Page by dirCache.\') ?>'.serialize($array);
}
protected function _decode($data) {
$array = unserialize($data);
return $array['source'];
}
protected function _writeFile($file,$data) {
$dir = dirname($file);
if (!is_dir($dir)) {
mkdir($dir,$this->dirMode,true);
}
if (!is_file($file) &&is_file($file .'.lock'))
{
return false;
}
$mqr = get_magic_quotes_runtime();
set_magic_quotes_runtime(0);
$re = @ file_put_contents($file,$data,LOCK_EX);
set_magic_quotes_runtime($mqr);
return $re;
}
protected function _readFile($file,$lockread = false) {
if (!is_file($file))
{
if (!$lockread) {
return false;
}
$file .= '.lock';
if (!is_file($file)) {
return false;
}
}
return file_get_contents($file,null,null,39);
}
protected function _deleteFile($file) {
if (is_file($file))
{
return unlink($file);
}
return false;
}
public function lock($id) {
$file = $this->hashId($id);
if (!is_file($file) &&is_file($file .'.lock'))
{
return true;
}
return rename($file,$file .'.lock');
}
public function unlock($id) {
$file = $this->hashId($id);
if (is_file($file) &&!is_file($file .'.lock'))
{
return true;
}
return rename( $file .'.lock',$file);
}
}
?>