之前寫過兩篇文章《自定義SESSION（二）——數(shù)據(jù)庫保存》和《我為什么不使用session》 但后來發(fā)現(xiàn)都有問題。前者處理在實際中幾乎沒什么用處，而且session回收還得自己另外處理。后者頻繁的操作數(shù)據(jù)庫，打來了很大的性能問題。

這兩天仔細(xì)考慮下，大致給出一個方案，但還沒有具體詳細(xì)的測試。 1、session處理和統(tǒng)計結(jié)合起來。同時游客也都有記錄。 2、完全使用數(shù)據(jù)庫和cookie來模擬session的功能。 3、用戶的對session的操作都盡量保證在一條sql語句完成。不用到session的時候，絕對不多一條查詢。 4、為了效率起見，session的回收沒有集成進(jìn)來，但提供了接口，可以調(diào)用實現(xiàn)。

暫時給出代碼，不具體解釋。sql

CREATE TABLE `*****_session` (`sid` char(32) NOT NULL,`uid` int(10) NOT NULL,`username` char(32) NOT NULL,`usertype` tinyint(1) NOT NULL,`activetime` int(10) NOT NULL,`expiry` int(10) NOT NULL,`ip` char(15) NOT NULL,`url` char(80) NOT NULL,`value` char(255) NOT NULL,PRIMARY KEY; (`sid`)) ENGINE=MEMORY DEFAULT CHARSET=utf8;

php代碼

<?class session{ private $_sessionPrex= '';//session的前綴 private $_time = '';//當(dāng)前時間 private $_model = null;//數(shù)據(jù)庫操作模型 private $_expiry = 1200;//session有效時間 private $_domain = '';//session的作用域 protected $isNew = 0;//判定操作動作 0 更新 1 增加 protected $session = array();//對應(yīng)的一條session記錄 public function __construct($options){ $this->_setOptions($options); if(empty($this->_time))$this->_time = time(); $this->session['activetime'] = $this->_time; } public function start(){ $this->_getSid(); } public function set($key,$value){ if(in_array($key,array('uid','username','usertype','url','expiry'))){ if($key == 'expiry'){ $this->_setCookie($this->_sessionPrex.'_sid',$this->session['sid'],$value); $this->_setCookie($this->_sessionPrex.'_uid',$this->session['uid'],$value); } $this->session[$key] = $value; }else{ $other = $this->session['value']; $other[$key] = $value; $this->session['value'] = $other; } } public function get($key){ if(in_array($key,array('uid','username','usertype','url','expiry'))){ return $this->session[$key]; }else{ if(isset($this->session['value'][$key])){ return $this->session['value'][$key]; } return null; } } public function gc($file,$time = 1200){ $lasttime = file_get_contents($file); if($lasttime + $time<$this->_time){ file_put_contents($file,$this->_time); return $this->_model->delete('activetime+expiry<'.$this->_time); } } public function destroy(){ $this->session['uid'] = 0; $this->session['username'] = ''; $this->session['usertype'] = -1; $this->session['expiry'] = $this->_expiry; $this->session['value'] = array(); $this->_setCookie($this->_sessionPrex.'_sid',$this->session['sid'],$this->_expiry); $this->_setCookie($this->_sessionPrex.'_uid',$this->session['uid'],$this->_expiry); } public function __destruct(){ $this->_save(); } private function _save(){ $dbSession = $this->session; $dbSession['value'] = serialize($dbSession['value']); if(strlen($dbSession['value'])>255)$this->_error('session->value is too long!'); if($this->isNew == 1){ //增加 $this->_model->insert($dbSession); }else{ //更新 $sid = $dbSession['sid']; $this->_model->update(array_slice($dbSession,1),'sid=''.$sid.'''); } } private function _getSession($sid){ $dbSession = $this->_model->detail('sid = ''.$sid.'''); if(!$dbSession)return false; $dbSession['value'] = unserialize($dbSession['value']); $this->session = array_merge($dbSession,$this->session) return true; } private function _getSid(){ $sid = strip_tags($_COOKIE[$this->_sessionPrex.'_sid']); if(strlen($sid)==32){ if($this->_getSession($sid)){ return true; } }else{ $sid = md5(time().mt_rand(1000,10000)); $this->_setCookie($this->_sessionPrex.'_sid',$sid); } $this->_setCookie($this->_sessionPrex.'_uid',0); $this->session = array( 'uid' => 0, 'username' => '', 'usertype' => -1, 'activetime' => $this->_time, 'ip' => $this->_getip(), 'url' => strip_tags($_SERVER['REQUEST_URI']), 'expiry' =>$this->_expiry, 'value' => array() ); $this->isNew = 1; $this->session['sid'] = $sid; } private function _setCookie($name,$value,$expiry=0){ if(empty($expiry))$expiry = $this->_expiry; if(empty($this->_domain)){ setcookie($name,$value,$this->_time + $expiry,'/'); }else{ setcookie($name,$value,$this->_time + $expiry,'/',$this->_domain); } } private function _getip(){ return getip(); } private function _setOptions($options){ foreach ($options as $key=>$value){ if(in_array($key,array('sessionPrex','time','model','expiry','domain'))){ $key = '_'.$key; $this->$key = $value; } } } private function _error($msg){ throw new Phpbean_Exception($msg); }}?>

(注意，該代碼不能直接使用，本文主要是提供一種思路)