以文件形式缓存php变量的方法

本文实例讲述了以文件形式缓存php变量的方法。分享给大家供大家参考。具体实现方法如下：

    <?php
    /*
    $cache_set = array(
    //缓存路径 , 最后要加"/"
    'cacheRoot'=>'./cache/',
    //缓存时间
    'cacheTime'=>20,
    //cache type
    'cacheType'=>1,
    //扩展名
    'cacheExe'=>'.php'
    );
    $cache = new Cache($cache_set);
    $a=array('1','2');
    $a="aaa";
    $b='';
    if($cache->cache_is("d")){
     $c=$cache->cache_read("d");
     echo "c";
     print_r($c);
    }else {
    $b=$cache->cache_data('d',$a);
    }
    print_r($b);
    //$cache->clear("a");
    //echo $cache->cache_read("./cache/d.php");
    //echo $d;
    */
    /**
     * 数据缓存类 v1.0
     * @author shooke
     * 2009-11-13 16:02:26
     * 用于缓存数据,如变量,但不能缓存页面
     */
    class Cache{
     //配置
     public $config = array(
     //缓存路径
     'cacheRoot'=>'./cache/',
     //缓存时间
     'cacheTime'=>1,
     //cache 类型 1串化数据 2变量
     'cacheType'=>2,
     //扩展名
     'cacheExe'=>'.php'
     //转换中间变量
     );
     public $return_name=array();
     function __construct($cache_set = array())
     {
      if(!empty($cache_set)) $this->config=array_merge($this->config,$cache_set);
      $this->config['ClassName'] = __CLASS__;
     }
     public function clear($filename=''){
      if (file_exists($this->cache_file($filename))) {
       @unlink($this->cache_file($filename));
      }elseif (empty($filename)){
       $this->clear_dir($this->config['cacheRoot']);
      }else{
       $this->clear_dir($this->config['cacheRoot'].$filename);
       echo $this->config['cacheRoot'].$filename;
      }
     }
     //循环删除路径
     private function clear_dir($dir,$to = false)
     {
      if ($list = glob($dir.'/*'))
      {
       foreach ($list as $file)
       {
        is_dir($file) ? $this->clear_dir($file) : unlink($file);
       }
      }
      if ($to === false) rmdir($dir);
     }
     //写入缓存
     private function cache_write($filename, $writetext, $openmod='w'){
      if (!file_exists($filename)) {
       @$this->makeDir( dirname($filename ));
      }
      if(@$fp = fopen($filename, $openmod)) {
       flock($fp, 2);
       fwrite($fp, $writetext);
       fclose($fp);
       return true;
      } else {
       echo "File: $filename write error.";
       return false;
      }
     }
     //缓存有效期 有效返回 true
     public function cache_is($fileName){
      $fileName=$this->cache_file($fileName);
      if( file_exists( $fileName ) ) {
       //如果缓存时间为负数则永不过期
       if ($this->config['cacheTime'] < 0) {
        return true;
       }
       //如果缓存时间为0则一直过期
       if ($this->config['cacheTime'] == 0) {
        return false;
       }
       //获取缓存文件的建立时间
       $ctime = intval(filemtime( $fileName ));
       //比较是否大于缓存时间,是则过期 否则不过期
       if (time() - $ctime > $this->config['cacheTime']) {
        return false;
       }else {
        return true;
       }
       //文件不存在视为过期失效
      }else {
       return false;
      }
     }
     public function cache_data($name,$data){
      $varname=$name;
      $name = $this->cache_file($name);
      //config['cacheTime']==0也就是不启用缓存是直接返回数据
      if ($this->config['cacheTime'] <> 0) {
       if($this->config['cacheType']==1){
        $write_data = "<?php exit;?>".serialize($data);
        //return $data;
       }else {
        $write_data = "<?php\\r\\n\\$var= ";
        $write_data .= var_export($data,true);
        $write_data .=";\\r\\n?>";
       }
       $this->cache_write($name,$write_data);
      }
      return $data;
     }
     //缓存文件名
     private function cache_file($filename){
      return $this->config['cacheRoot'].$filename.$this->config['cacheExe'];
     }
     //读取文件
     public function cache_read($file){
      $file=$this->cache_file($file);
      if (!file_exists($file)) {
       return '';
      }
      if($this->config['cacheType']==1){
       if (function_exists('file_get_contents')){
        $cache_Content= file_get_contents($file);
       }else{
        $fopen = fopen($file,'r');
        $cache_Content = '';
        do {
         $data = fread($fopen,filesize($file));
         if (strlen($data)===0) break;
         $cache_Content .= $data;
        }while(1);
        fclose($fopen);
       }
       $cache_Content = substr($cache_Content,13);/* 去除<?php exit;?> */
       $cache_Content = unserialize($cache_Content);
       return $cache_Content;
      }else{
       include_once($file);
       return $var;
      }
     }
     //循环创建目录
     private function makeDir( $dir, $mode = 0777 ) {
      if( ! $dir ) return 0;
      $dir = str_replace( "\\\\", "/", $dir );
      $mdir = "";
      foreach( explode( "/", $dir ) as $val ) {
       $mdir .= $val."/";
       if( $val == ".." || $val == "." || trim( $val ) == "" ) continue;
       if( ! file_exists( $mdir ) ) {
        if(!@mkdir( $mdir, $mode )){
         return false;
        }
       }
      }
      return true;
     }
    }
    ?>

希望本文所述对大家的php程序设计有所帮助。