php 文件缓存类

//文件缓存类
 
class FileCache {
 private $cacheTime = 3600;        //默认缓存时间   秒
    private $cacheDir = './filecache';    //缓存绝对路径   
    private $md5 = true;              //是否对键进行加密   
    private $suffix = ".php";         //设置文件后缀       
  
    public function __construct($config){   
        if( is_array( $config ) ){   
            foreach( $config as $key=>$val ){  
                $this->$key = $val;   
            }  
        }  
    }        
  
    //设置缓存   
    public function set($key,$val,$leftTime=null){  
        $key = $this->md5 ? md5($key) : $key;  
        $leftTime = $leftTime ? $leftTime : $this->cacheTime;   
        !file_exists($this->cacheDir) && mkdir($this->cacheDir,0777);   
        $file = $this->cacheDir.'/'.$key.$this->suffix;   
        $val = serialize($val);   
        @file_put_contents($file,$val) or $this->error(__line__,"文件写入失败");   
        @chmod($file,0777)  or $this->error(__line__,"设定文件权限失败");  
        @touch($file,time()+$leftTime) or $this->error(__line__,"更改文件时间失败");   
    }   
  
    //得到缓存   
    public function get($key){   
        $this->clear();   
        if( $this->_isset($key) ){   
            $key_md5 = $this->md5 ? md5($key) : $key;  
            $file = $this->cacheDir.'/'.$key_md5.$this->suffix;   
            $val = file_get_contents($file);   
            return unserialize($val);   
        }   
        return null;   
    }        
  
    //判断文件是否有效   
    public function _isset($key){   
        $key = $this->md5 ? md5($key) : $key;   
        $file = $this->cacheDir.'/'.$key.$this->suffix;   
        if( file_exists($file) ){   
            if( @filemtime($file) >= time() ){   
                return true;   
            }else{   
                @unlink($file);   
                return false;   
            }   
        }   
        return false;  
    }        
  
    //删除文件   
    public function _unset($key){   
        if( $this->_isset($key) ){   
            $key_md5 = $this->md5 ? md5($key) : $key;  
            $file = $this->cacheDir.'/'.$key_md5.$this->suffix;  
            return @unlink($file);   
        }   
        return false;   
    }     
  
    //清除过期缓存文件   
    public function clear(){   
        $files = scandir($this->cacheDir);  
        foreach ($files as $val){   
            if (@filemtime($this->cacheDir."/".$val) < time()){   
                @unlink($this->cacheDir."/".$val);   
            }  
        }   
    }       
  
    //清除所有缓存文件   
    public function clear_all(){  
        $files = scandir($this->cacheDir);  
        foreach ($files as $val){   
            @unlink($this->cacheDir."/".$val);   
        }  
    }        
  
    private function error($line,$msg){  
        die("出错文件：".__file__."/n出错行：$line/n错误信息：$msg");   
    }   

调用方法：
　　　　

 　　　　　　　　　　//cacheTime 缓存时间 1个小时
                    $cacheFile = new FileCache(array('cacheTime'=>3600,'suffix'=>'.php'));   
                    $cache_1 =$cacheFile->get('key1');
                    $cache_2 =$cacheFile->get('key2');
                    if( $cache_1 ){
                        $resArr_result = $cache_1;
                    }else{
                        //读数据库$resArr_result = array(***);
                         //设置缓存
                         $cacheFile->set('key1',$resArr_result);   
                    }