【discuzX2】/source/class/class_core.php文件中session会话类discuz_session分析

<?php
//session类,session机制,discuz中session信息存储在数据库中，而不是存储在硬盘上
class discuz_session {

    var $sid = null;
    var $var;
    var $isnew = false;
        //初始化session数组
    var $newguest = array('sid' => 0, 'ip1' => 0, 'ip2' => 0, 'ip3' => 0, 'ip4' => 0,
    'uid' => 0, 'username' => '', 'groupid' => 7, 'invisible' => 0, 'action' => 0,
    'lastactivity' => 0, 'fid' => 0, 'tid' => 0, 'lastolupdate' => 0);

    var $old =  array('sid' =>  '', 'ip' =>  '', 'uid' =>  0);

    function discuz_session($sid = '', $ip = '', $uid = 0) {
        $this->old = array('sid' =>  $sid, 'ip' =>  $ip, 'uid' =>  $uid);
        $this->var = $this->newguest;
        if(!empty($ip)) {
            $this->init($sid, $ip, $uid);
        }
    }

        //设置
    function set($key, $value) {
        if(isset($this->newguest[$key])) {
            $this->var[$key] = $value;
        } elseif ($key == 'ip') {
            $ips = explode('.', $value);
            $this->set('ip1', $ips[0]);
            $this->set('ip2', $ips[1]);
            $this->set('ip3', $ips[2]);
            $this->set('ip4', $ips[3]);
        }
    }

        //获取
    function get($key) {
        if(isset($this->newguest[$key])) {
            return $this->var[$key];
        } elseif ($key == 'ip') {
            return $this->get('ip1').'.'.$this->get('ip2').'.'.$this->get('ip3').'.'.$this->get('ip4');
        }
    }

        //初始化
    function init($sid, $ip, $uid) {
        $this->old = array('sid' =>  $sid, 'ip' =>  $ip, 'uid' =>  $uid);
        $session = array();
        if($sid) {
            $session = DB::fetch_first("SELECT * FROM ".DB::table('common_session').
                " WHERE sid='$sid' AND CONCAT_WS('.', ip1,ip2,ip3,ip4)='$ip'");
        }

        if(empty($session) || $session['uid'] != $uid) {
            $session = $this->create($ip, $uid);
        }

        $this->var = $session;
        $this->sid = $session['sid'];
    }

        //创建
    function create($ip, $uid) {

        $this->isnew = true;
        $this->var = $this->newguest;
        $this->set('sid', random(6));
        $this->set('uid', $uid);
        $this->set('ip', $ip);
        $uid && $this->set('invisible', getuserprofile('invisible'));
        $this->set('lastactivity', time());
        $this->sid = $this->var['sid'];

        return $this->var;
    }

        //删除
    function delete() {

        global $_G;
        $onlinehold = $_G['setting']['onlinehold'];
        $guestspan = 60;

        $onlinehold = time() - $onlinehold;
        $guestspan = time() - $guestspan;

        $condition = " sid='{$this->sid}' ";
        $condition .= " OR lastactivity<$onlinehold ";
        $condition .= " OR (uid='0' AND ip1='{$this->var['ip1']}' AND ip2='{$this->var['ip2']}' AND ip3='{$this->var['ip3']}' AND ip4='{$this->var['ip4']}' AND lastactivity>$guestspan) ";
        $condition .= $this->var['uid'] ? " OR (uid='{$this->var['uid']}') " : '';
        DB::delete('common_session', $condition);
    }

        //更新数据
    function update() {
        global $_G;
        if($this->sid !== null) {

            $data = daddslashes($this->var);
            if($this->isnew) {
                $this->delete();
                DB::insert('common_session', $data, false, false, true);
            } else {
                DB::update('common_session', $data, "sid='$data[sid]'");
            }
            $_G['session'] = $data;
            dsetcookie('sid', $this->sid, 86400);
        }
    }

        /**
     * 取在线用户数量
     *
     * @param int $type 0=全部 1=会员 2=游客
     * @return int
     */
    function onlinecount($type = 0) {
        $condition = $type == 1 ? ' WHERE uid>0 ' : ($type == 2 ? ' WHERE invisible=1 ' : '');
        return DB::result_first("SELECT count(*) FROM ".DB::table('common_session').$condition);
    }

}
?>