<?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>
// +----------------------------------------------------------------------

/**
 * Redis缓存驱动
 * 要求安装phpredis扩展：https://github.com/nicolasff/phpredis.
 *
 * @category   Extend
 *
 * @author    尘缘 <130775@qq.com>
 */
class CacheRedis extends Cache
{
    /**
     * 架构函数.
     *
     * @param array $options 缓存参数
     */
    public function __construct($options = array())
    {
        if (!extension_loaded('redis')) {
            throw_exception(L('_NOT_SUPPERT_').':redis');
        }
        if (empty($options)) {
            $options = array(
                'host'       => C('REDIS_HOST') ? C('REDIS_HOST') : '127.0.0.1',
                'port'       => C('REDIS_PORT') ? C('REDIS_PORT') : 6379,
                'timeout'    => C('DATA_CACHE_TIMEOUT') ? C('DATA_CACHE_TIMEOUT') : false,
                'persistent' => false,
            );
        }
        $this->options = $options;
        $this->options['expire'] = isset($options['expire']) ? $options['expire'] : C('DATA_CACHE_TIME');
        $this->options['prefix'] = isset($options['prefix']) ? $options['prefix'] : C('DATA_CACHE_PREFIX');
        $this->options['length'] = isset($options['length']) ? $options['length'] : 0;
        $func = $options['persistent'] ? 'pconnect' : 'connect';
        $this->handler = new Redis();
        $options['timeout'] === false ?
            $this->handler->$func($options['host'], $options['port']) :
            $this->handler->$func($options['host'], $options['port'], $options['timeout']);
    }

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

        return $this->handler->get($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 (is_int($expire)) {
            $result = $this->handler->setex($name, $expire, $value);
        } else {
            $result = $this->handler->set($name, $value);
        }
        if ($result && $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 $this->handler->delete($this->options['prefix'].$name);
    }

    /**
     * 清除缓存.
     *
     * @return boolen
     */
    public function clear()
    {
        return $this->handler->flushDB();
    }
}
