【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);
}

}
?>