<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2014 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
namespace Think\Cache\Driver;

use Think\Cache;

/**
 * Redis缓存驱动
 * 要求安装phpredis扩展：https://github.com/nicolasff/phpredis
 */
class Redis extends Cache
{
    /**
     * 架构函数
     * @param array $options 缓存参数
     * @access public
     */
    public function __construct($options = array())
    {
        if (!extension_loaded('redis')) {
            E(L('_NOT_SUPPORT_') . ':redis');
        }
        $options = array_merge(array(
            'host'       => C('REDIS_HOST') ?: '127.0.0.1',
            'port'       => C('REDIS_PORT') ?: 6379,
            'password'   => C('REDIS_PASSWORD') ?: '',
            'timeout'    => C('DATA_CACHE_TIMEOUT') ?: false,
            'persistent' => false,
        ), $options);

        $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;
        false === $options['timeout'] ?
        $this->handler->$func($options['host'], $options['port']) :
        $this->handler->$func($options['host'], $options['port'], $options['timeout']);
        if ('' != $options['password']) {
            $this->handler->auth($options['password']);
        }
    }

    /**
     * 读取缓存
     * @access public
     * @param string $name 缓存变量名
     * @return mixed
     */
    public function get($name)
    {
        N('cache_read', 1);
        $value    = $this->handler->get($this->options['prefix'] . $name);
        $jsonData = json_decode($value, true);
        return (null === $jsonData) ? $value : $jsonData; //检测是否为JSON数据 true 返回JSON解析数组, false返回源数据
    }

    /**
     * 写入缓存
     * @access public
     * @param string $name 缓存变量名
     * @param mixed $value  存储数据
     * @param integer $expire  有效时间（秒）
     * @return boolean
     */
    public function set($name, $value, $expire = null)
    {
        N('cache_write', 1);
        if (is_null($expire)) {
            $expire = $this->options['expire'];
        }
        $name = $this->options['prefix'] . $name;
        //对数组/对象数据进行缓存处理，保证数据完整性
        $value = (is_object($value) || is_array($value)) ? json_encode($value) : $value;
        if (is_int($expire) && $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
     * @access public
     * @param string $name 缓存变量名
     * @return boolean
     */
    public function rm($name)
    {
        return $this->handler->delete($this->options['prefix'] . $name);
    }

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

}
