framework/library/think/session/driver/Memcache.php

<?php
namespace think\session\driver;

use think\session\Driver;
use think\Config;

class Memcache extends Driver
{
    protected $handler      = null;
    protected $config       = [
        'host'          => '127.0.0.1', // 主机
        'port'          => 1121,        // 端口
        'expire'        => 3600,        // 有效期
        'timeout'       => 1,           // 超时时间
        'persistent'    => 0,           // 是否长连接
        'session_name'  => '',          // memcache key前缀
    ];

    /**
     * 打开Session 
     * @access public 
     * @param string $savePath 
     * @param mixed $sessName  
     */
    public function open($savePath, $sessName) {
        // 检测php环境
        if (!extension_loaded('memcache')) {
            throw new Exception('_NOT_SUPPERT_:memcache');
        }
        $this->handler  = new \Memcache;
        // 支持集群
        $hosts          = explode(',', $this->config['host']);
        $ports          = explode(',', $this->config['port']);
        // 建立连接
        foreach ((array) $hosts as $i => $host) {
            $port       = isset($ports[$i]) ? $ports[$i] : $ports[0];
            false === $config['timeout'] ?
            $this->handler->addServer($host, $port, $this->config['persistent'], 1) :
            $this->handler->addServer($host, $port, $this->config['persistent'], 1, $this->config['timeout']);
        }
        return true;
    }

    /**
     * 关闭Session 
     * @access public 
     */
    public function close() {
        $this->gc(ini_get('session.gc_maxlifetime'));
        $this->handler->close();
        $this->handler  = null;
        return true;
    }

    /**
     * 读取Session 
     * @access public 
     * @param string $sessID 
     */
    public function read($sessID) {
        return $this->handler->get($this->config['session_name'].$sessID);
    }

    /**
     * 写入Session 
     * @access public 
     * @param string $sessID 
     * @param String $sessData  
     */
    public function write($sessID, $sessData) {
        return $this->handler->set($this->config['session_name'].$sessID, $sessData, 0, $this->config['expire']);
    }

    /**
     * 删除Session 
     * @access public 
     * @param string $sessID 
     */
    public function destroy($sessID) {
        return $this->handler->delete($this->config['session_name'].$sessID);
    }

    /**
     * Session 垃圾回收
     * @access public 
     * @param string $sessMaxLifeTime 
     */
    public function gc($sessMaxLifeTime) {
        return true;
    }
}