Discuz!X中SESSION机制实例详解

$mod = !in_array($discuz->var['mod'],$modarray) ? 'logging' : $discuz->var['mod']; //mod的值即是接下来加载的php页面
define('CURMODULE',$mod);
$modcachelist = array('register' => array('modreasons','stamptypeid','fields_required','fields_optional','ipctrl'));
$cachelist = array();
if(isset($modcachelist[CURMODULE])) {
 $cachelist = $modcachelist[CURMODULE];
}
$discuz->cachelist = $cachelist;
$discuz->init();
runhooks();
require DISCUZ_ROOT.'./source/module/member/member_'.$mod.'.php'; //完成程序的包含操作

$ctl_obj = new logging_ctl(); 
$method = 'on_'.$_G['gp_action']; // $_G['gp_action'] 等于action的值即 login 
$ctl_obj->$method(); //$ctl_obj->on_login(); 

if(!submitcheck('loginsubmit',1,$seccodecheck)) {
//判断语句是当游客浏览时,submitcheck 函数的返回值是假,取反,为真.
//当用户登录时,程序走的是else部分,在里面可看到下面五句代码：
} else { 
 $_G['uid'] = $_G['member']['uid'] = 0; 
 $_G['username'] = $_G['member']['username'] = $_G['member']['password'] = ''; //变量赋值 
 $result = userlogin($_G['gp_username'],$_G['gp_password'],$_G['gp_questionid'],$_G['gp_answer'],$_G['setting']['autoidselect'] ? 'auto' : $_G['gp_loginfield']); //从数据库查询用户数据,并返回相应的信息 
 if($result['status'] > 0) { //状态值大于 0,说明有此用户,可以登录 
  setloginstatus($result['member'],$_G['gp_cookietime'] ? 2592000 : 0); //设置登录状态,即是写 COOKIE 操作,COOKIE 中的数据即是 SESSION 中相应的数据,但此函数并不负责写 SESSION 的操作 

function setloginstatus($member,$cookietime) { 
 global $_G; 
 $_G['uid'] = $member['uid']; 
 $_G['username'] = $member['username']; 
 $_G['adminid'] = $member['adminid']; 
 $_G['groupid'] = $member['groupid']; 
 $_G['formhash'] = formhash(); 
 $_G['session']['invisible'] = getuserprofile('invisible'); 
 $_G['member'] = $member; 
 $_G['core']->session->isnew = 1; 
 dsetcookie('auth',authcode("{$member['password']}t{$member['uid']}",'ENCODE'),$cookietime,true); //authcode加密 
 dsetcookie('loginuser'); 
 dsetcookie('activationauth'); 
 dsetcookie('pmnum'); 
}

function _init_session() { 
 $this->session = new discuz_session(); //创建 SESSION 类 
 if($this->init_session) { 
  //从 COOKIE 中读取数据 
  $this->session->init($this->var['cookie']['sid'],$this->var['clientip'],$this->var['uid']); 
  $this->var['sid'] = $this->session->sid; 
  $this->var['session'] = $this->session->var; 
  //判断 SID 是否相等,不等,说明是多个用户在同一主机上登录网站,需要重新写 COOKIE 
  if($this->var['sid'] != $this->var['cookie']['sid']) { 
   dsetcookie('sid',$this->var['sid'],86400); 
  } 
  if($this->session->isnew) { 
   if(ipbanned($this->var['clientip'])) { 
    $this->session->set('groupid',6); 
   } 
  } 
  if($this->session->get('groupid') == 6) { 
   $this->var['member']['groupid'] = 6; 
   sysmessage('user_banned'); 
  } 
  //UID 不为空,且需要更新 SESSION 或是 SESSION 超时,更改用户状态,需要用户重新登录 
  if($this->var['uid'] && ($this->session->isnew || ($this->session->get('lastactivity') + 600) < TIMESTAMP)) { 
   $this->session->set('lastactivity',TIMESTAMP); 
   $update = array('lastip' => $this->var['clientip'],'lastactivity' => TIMESTAMP); 
   if($this->session->isnew) { 
    $update['lastvisit'] = TIMESTAMP; 
   } 
   DB::update('common_member_status',$update,"uid='".$this->var['uid']."'"); 
  } 
 } 
}

//此函数负责产生新的 SESSION,但并不负责写入数据库 
function create($ip,$uid) { 
//创建SESSION,执行插入数据,由随机函数产生一个六位随机数即是session的唯一值时间为当前时间,sid为cookie中的sid 
  $this->isnew = true; 
  $this->var = $this->newguest; 
  $this->set('sid',random(6)); 
  $this->set('uid',$uid); 
  $this->set('ip',$ip); 
  $this->set('lastactivity',time()); 
  $this->sid = $this->var['sid']; 
  return $this->var; 
} 
//此函数负责更新 SESSION 
function update() { 
  if($this->sid !== null) { 
   $data = daddslashes($this->var); 
   if($this->isnew) { 
    $this->delete(); 
    DB::insert('common_session',$data,false,true); 
   } else { 
    DB::update('common_session',"sid='$data[sid]'"); 
   } 
   dsetcookie('sid',$this->sid,86400); 
  } 
} 

function updatesession($force = false) { 
 global $_G; 
 static $updated = false; 
 if(!$updated) { 
  $discuz = & discuz_core::instance(); 
  foreach($discuz->session->var as $k => $v) { 
   if(isset($_G['member'][$k]) && $k != 'lastactivity') { 
    $discuz->session->set($k,$_G['member'][$k]); 
   } 
  } 
  foreach($_G['action'] as $k => $v) { 
   $discuz->session->set($k,$v); 
  } 
  $discuz->session->update(); 
  $updated = true; 
 } 
 return $updated; 
}