用于以文件形式缓存php变量

<?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;
    }
 
}
?>