<?php

// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2012 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------

/**
 * Apc缓存驱动.
 *
 * @category   Extend
 *
 * @author    liu21st <liu21st@gmail.com>
 */
class CacheApc extends Cache
{
    /**
     * 架构函数.
     *
     * @param array $options 缓存参数
     */
    public function __construct($options = array())
    {
        if (!function_exists('apc_cache_info')) {
            throw_exception(L('_NOT_SUPPERT_').':Apc');
        }
        $this->options['prefix'] = isset($options['prefix']) ? $options['prefix'] : C('DATA_CACHE_PREFIX');
        $this->options['length'] = isset($options['length']) ? $options['length'] : 0;
        $this->options['expire'] = isset($options['expire']) ? $options['expire'] : C('DATA_CACHE_TIME');
    }

     /**
      * 读取缓存.
      *
      * @param string $name 缓存变量名
      *
      * @return mixed
      */
     public function get($name)
     {
         N('cache_read', 1);

         return apc_fetch($this->options['prefix'].$name);
     }

     /**
      * 写入缓存.
      *
      * @param string $name 缓存变量名
      * @param mixed $value  存储数据
      * @param int $expire  有效时间（秒）
      *
      * @return boolen
      */
     public function set($name, $value, $expire = null)
     {
         N('cache_write', 1);
         if (is_null($expire)) {
             $expire = $this->options['expire'];
         }
         $name = $this->options['prefix'].$name;
         if ($result = apc_store($name, $value, $expire)) {
             if ($this->options['length'] > 0) {
                 // 记录缓存队列
                $this->queue($name);
             }
         }

         return $result;
     }

     /**
      * 删除缓存.
      *
      * @param string $name 缓存变量名
      *
      * @return boolen
      */
     public function rm($name)
     {
         return apc_delete($this->options['prefix'].$name);
     }

    /**
     * 清除缓存.
     *
     * @return boolen
     */
    public function clear()
    {
        return apc_clear_cache();
    }
}
