<?php

/**

 * memcache 操作实现

 * @author timeless

 */

class Memcache_manage {

    //CI原始的信息

    private $_ci;

    private $_memcache_prefix;

    private $host;

    private $port;

    private $expire;

    private $weight;

    /**

     * 读取配置文件信息然后更新

     * @access public

     */

    public function memcache($flag = 'default') {

        //要你自定义的类库中访问CodeIgniter的原始资源,你必须使用 get_instance() 函数.这个函数返回一个CodeIgniter super object.

        $this->_ci = &get_instance();

        //记载memcache 缓存配置　　　　 //memcached 中的数据　　　　 

/* memcahed.php 文件中的配置信息  CI框架中

$config = array(

    //现在是单独的memcache 服务器  以后可以添加多个  只需要 mem 对象添加 addserver

    'default' => array(

        'hostname' => '127.0.0.1',

        'port' => '11211',

        'weight' => '1',

        //100分钟

        'expire' => '6000',

        'memcache_prefix'=>'',

    ),

);

　　　　 */

        $this->_ci->config->load('memcached', FALSE, TRUE);

        //获取配置文件

        $default_conf = $this->_ci->config->item('default');

        $this->host = $default_conf['hostname'];

        $this->port = $default_conf['port'];

        $this->expire = $default_conf['expire'];

        $this->weight = $default_conf['weight'];

        $this->_memcache_prefix = $default_conf['memcache_prefix'];

        $this->connected_server = array();

        $this->_connect();

    }

    /**

     * 连接memcache 数据库

     * @access private

     */

    private function _connect() {

        if (function_exists('memcache_connect')) {

            $this->cache = new Memcache;

            $this->_connect_memcached();

        }

    }

    /**

     * 添加memcache 服务器

     * @access private

     */

    private function _connect_memcached() {

        $error_display = ini_get('display_errors');

        $error_reporting = ini_get('error_reporting');

        if ($this->cache->addServer($this->host, $this->port, TRUE, $this->weight)) {

            $this->connected_server[] = $this->host;

        }

        ini_set('error_reporting', $error_reporting);

    }

    public function get($key) {

        if (empty($this->connected_server)) {

            return false;

        }

        return $this->cache->get($this->key_name($key));

    }

    public function set($key, $data) {

        if (empty($this->connected_server)) {

            return false;

        }

        return $this->cache->set($this->key_name($key), $data, 0, $this->expire);

    }

    public function set_expire($key, $data, $expire) {

        if (empty($this->connected_server)) {

            return false;

        }

        return $this->cache->set($this->key_name($key), $data, 0, $expire);

    }

    public function replace($key, $data) {

        if (empty($this->connected_server)) {

            return false;

        }

        return $this->cache->replace($this->key_name($key), $data, 0, $this->expire);

    }

    public function delete($key, $when = 0) {

        if (empty($this->connected_server)) {

            return false;

        }

        return $this->cache->delete($this->key_name($key), $when);

    }

    public function flush() {

        return $this->cache->flush();

    }

    /**

     * @Name: 生成md5加密后的唯一键值

     * @param:$key key

     * @return : md5 string

     * */

    private function key_name($key) {

        return md5(strtolower($this->_memcache_prefix . $key));

    }

}