php cache类代码(php数据缓存类)

/*
//php-kcache class v_0.1
//Author: kangzj
//Email : kangzj@mail.bnu.edu.cn
//Blog : http://kangzj.net.ru
//作者不保证本程序没有bug，对于使用本程序
//而引起的任何问题不担负任何责任。
*/
class php_kcache {
    //相对或者绝对目录，末尾不要加 '/'
    var $cache_dir = './cache';
    var $cache_extension = '.cache.php';

    function set_cache($name, $value){
        $pre = "< ?\n//Cache Created at: ".date('Y-m-d H:i:s')."\n";
        if(!is_array($value)){
            $value = $value;
            $str = "\$$name = '$value';";
        }else{
            $str = "\$$name = " . $this->arrayeval($value) . ';';
        }
        $end = "\n?>";
        echo $cache = $pre . $str . $end;
        $cache_file = $this->cache_dir . '/' . $name . $this->cache_extension;

        if($fp = @fopen($cache_file, 'wb')) {
            fwrite($fp, $cache);
            fclose($fp);
            return true;
        } else {
            echo $cache_file;
            exit('Can not write to cache files, please check cache directory ');
            return false;
        }
    }

    //将array变成字符串, 来自discuz!
    function arrayeval($array, $level = 0) {

        if(!is_array($array)) {
            return "'".$array."'";
        }

        $space = '';
        for($i = 0; $i < = $level; $i++) {
            $space .= "\t";
        }
        $evaluate = "Array\n$space(\n";
        $comma = $space;
        if(is_array($array)) {
            foreach($array as $key => $val) {
                $key = is_string($key) ? '\''.addcslashes($key, '\'\\').'\'' : $key;
                $val = !is_array($val) && (!preg_match("/^\-?[1-9]\d*$/", $val) || strlen($val) > 12) ? '\''.addcslashes($val, '\'\\').'\'' : $val;
                if(is_array($val)) {
                    $evaluate .= "$comma$key => ".arrayeval($val, $level + 1);
                } else {
                    $evaluate .= "$comma$key => $val";
                }
                $comma = ",\n$space";
            }
        }
        $evaluate .= "\n$space)";
        return $evaluate;
    }
}

include './php_kcache_class.php';
$pc = new php_kcache;
$a = array('a', 'b', 'c');
$pc->set_cache('a', addslashes($a));