I have written two articles before, "Customizing SESSION (2) - Database Saving" and "Why I Don't Use Session"
But later it was discovered that there were problems. The former processing is almost useless in practice, and session recycling has to be handled separately. The latter frequently operates the database, causing big performance problems.
After careful consideration in the past two days, a rough plan was given, but there was no specific and detailed test.
1. Combine session processing and statistics. Visitors are also recorded.
2. Completely use database and cookies to simulate session functions.
3. The user's operations on the session should be completed in one SQL statement as much as possible. When the session is not needed, there is absolutely no more than one query.
4. For the sake of efficiency, session recycling is not integrated, but an interface is provided and can be called to implement it.
The code is given temporarily without detailed explanation.
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 code
<?
class session{
private $_sessionPrex= '';//session prefix
private $_time = '';//current time
private $_model = null; //Database operation model
private $_expiry = 1200;//session validity time
private $_domain = '';//session scope
protected $isNew = 0;//determine operation action 0 update 1 increase
protected $session = array();//corresponding session record
public function __construct($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){
//Increase
$this->_model->insert($dbSession);
}else{
//renew
$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);
}
}
?>
(Note that this code cannot be used directly, this article mainly provides an idea)