PHP缓存, SimpleCache 类

一个简单的不能再简单的页面缓存，效果还是比较明显的

<?php
/* 页面缓存机制
* 摘要：页面缓存机制
* 类名：SimpleCache
* 文件名称：SimpleCache_class.php
* 版本：0.0.2
* 创建时间：2004.7.24 03:38
* 修改时间：2004.11.28 23:28
* 作者：shadow_wwp@yahoo.com
* 版权：COPYRIGHT(C) 2004-2005 流影工作室
*/

/* 使用方法
    require_once("SimpleCache.php");
    $effect_param = array(
        "a","b","c","d","e"
    );
    
    $effect_flag_param = array(
        "a", "b", "c"
    );
    $cache = new SimpleCache();
    $cache->start(5,$effect_param,$effect_flag_param);
    //-- ---//
    echo "HHHH";
    
    //-- --//
    
    $cache->end();
*/

define("CACHE_NO_CREATE", "NO" );
define("CACHE_CREATE","YES" );
define("CACHE_CREATE_FAULT","ERR" );

//缓存类路径
define("ROOT","/data1" );
define("CACHE",ROOT."/cache" );

class SimpleCache
{
    var $filename;   //要保存的文件名称
    var $flag ;
    var $effect_time ;
    var $cache_error ;
    
     //以下是 0.0.2 版更新
    var $effect_param = Array(); //有效参数
    var $effect_flag_param = Array(); //标记型参数
    var $cache_path;      //要保存文件的目录名称

    //启用缓存
    //$flag CACHE_CREATE  ob_start 启动
    //$flag CACHE_NO_CREATE 不需要创建缓存 读取缓存
    //$flag CACHE_CREATE_FAULT 创建缓存失败
    //0.0.2 版更新
    function start($effect, $effect_param, $effect_flag_param )
    {
        $this->effect_time = $effect ;
        if(!is_array($effect_param ))
        {
            $this->flag  = CACHE_CREATE_FAULT ;
            $this->cache_error .= "/n"."/$effect_param 不是数组" ;
        }
        else
        {
            $this->effect_param = $effect_param ;
        }
        
        if(!is_array($this->effect_flag_param ))
        {
            $this->flag  = CACHE_CREATE_FAULT ;
            $this->cache_error .= "/n"."effect_flag_param 不是数组" ;
        }
        else
        {
            $this->effect_flag_param = $effect_flag_param ;
        }
        
        $this->is_expire ();
        
        if ($this->flag == CACHE_NO_CREATE)    //读取信号 看是否应该创建
         {
            $this->cache_read ();
        }

        if ($this->flag == CACHE_CREATE )
        {
            if (!ob_start ())
            {
                $this->flag  = CACHE_CREATE_FAULT ;
                $this->cache_error .= "/n"."ob_start()失败！/n" ;
            }
            
            
        }

         //debug echo "/n<!-- 创建信号为：".$this->flag."-->/n";
     }


     //启用缓存结束
    function end ()
    {
        
        if ($this->flag == CACHE_CREATE )
        {
             //创建文件
            if(!$this->create_cache ())
            {
                $this->flag = CACHE_CREATE_FAULT ;
                $this->cache_error .= "/n"."创建缓存失败/n" ;
                exit(0 );
            }

             //标记下次不用创建
            $this->flag = CACHE_NO_CREATE ;
        

        }
    }


     //判断缓存文件是否过期
    //0.0.2 版本优化
    function is_expire ()
    {
        if (!$this->get_filename ())
        {
            $this->cache_error .= "/n"."不能生成文件名称!" ;
            $this->flag = CACHE_CREATE_FAULT ;
            return 0 ;
        }
        
        
        $now = time ();
        
        if (!file_exists($this->filename ))
        {
            $this->flag = CACHE_CREATE ;
            return 0 ;
        }

        $createtime = filemtime($this->filename );
        $time_field = $now - $createtime ;
         //debug echo "/n<!-- 时间差为".$time_field."-->/n";

        if ($time_field > $this->effect_time )
        {
            $this->flag = CACHE_CREATE ;
            return 0 ;
        }
        
        $this->flag = CACHE_NO_CREATE ;
    }

     //取得文件名称
    //命名规则是： 参数_参数值_创建的文件名称
    //0.0.2 版本优化
    function get_filename ()
    {
        if (!$this->get_dir ())
        {
            $this->cache_error .= "/n"."不能获得目录" ;
            return false ;
        }
        foreach ($this->effect_param as $key )
        {
            $this->filename = $this->filename."_".$key."_".$_REQUEST[$key ];
        }

        $this->filename = md5($this->filename). "_" .basename($_SERVER["PHP_SELF" ]);
        $this->filename = $this->cache_path ."/". $this->filename ;
        
        return true ;
    }
    
    
     //取得目录名称 如果目录不存在则创建    
    //0.0.2版增加
    function get_dir ()
    {
        $this->cache_path = CACHE ;
        
        foreach ($this->effect_flag_param as $key )
        {
            $this->cache_path = $this->cache_path."/".md5($_REQUEST[$key ]);
    
            if(!$this->check_dir ())
            {
                return false ;
            }
        }
        
        return true ;
    }
    
     //检测目录名称 如果目录不存在则创建
    //0.0.2版增加
    function check_dir ()
    {

        if(!is_dir($this->cache_path ))
        {
            if(!mkdir($this->cache_path ))
            {
                $this->cache_error .= "/n"."不能创建缓存目录！" ;
                    return false ;
            }
        }
    
        return true ;
    }
    
    
    
     //从缓存中取数据
    function cache_read ()
    {
        include($this->filename );
        die();
    }

     //生成缓存页面
    function create_cache ()
    {
        $this->info ();
        
         //将本页内容写入文件
        if(!($fp = fopen($this->filename, "w" )))
        {    
            return false ;
        }

        if (!$fp )
        {
            echo $this->filename ;
        }
    
        
        flock($fp, 2 );
        if (!fputs($fp, ob_get_contents ()))
        {
            return false ;
        }
        flock($fp, 3 );
        fclose($fp );
         //写入完成
        ob_end_flush ();
     //    ob_end_clean();
        return true ;
    }

     //打印调试信息
    function info ()
    {
         #echo "/n<!--/n";
        echo "创建时间：".time()."/n" ;
        echo "文件名称：".$this->filename."/n" ;
        echo "有效期限：". $this->effect_time."/n" ;
        echo "缓存目录：".$this->cache_path ."/n" ;
        echo "创建的缓存名称：".basename($_SERVER["PHP_SELF"])."/n" ;
        echo "---------------------------------------------/n" ;
        echo $this->cache_error."/n" ;
        echo "---------------------------------------------/n" ;
         #echo "-->/n";
     }

}
?>