mongodb_session_handler.php

<?php /*mongodb custom php session handler
copyright 2010 ryan day 
lgpl
*/

$mongo = new Mongo();
//MongoSession::setConfig('collection','session_test');
$mongo_session = new MongoSession($mongo);



echo $mongo_session->_id."<br/>";
echo $mongo_session->sid."<br/>";


if(!isset($_SESSION['inc'])) $_SESSION['inc'] = 0;

$_SESSION['inc']++;

echo "<pre>";
echo var_export($_SESSION,true);
echo "</pre>";

class mongoSession {
	public static $config = array(
		'db'=>'mongo_session',
		'collection'=>'session',
		'expire'=>86400,//day
		'expire_remember'=>2592000//month
	); 

	public static function setConfig($kv_or_k,$v = null){
		if(!is_array($kv_or_k)){
			$kv_or_k = array($kv_or_k=>$v);
		}

		self::$config = array_merge(self::$config,$kv_or_k);
	}

	private $collection;
	private $row;

	public $_id;
	public $sid;

	public function __construct($mongo){
		$db = $mongo->selectDB('session_test');
		$this->collection = new MongoCollection($db,'session');

		$this->row = $this->getRow();

		$_SESSION = $this->getData();

		$this->_id = $this->row['_id'];
		$this->sid = $this->row['sid'];
	}

	public function __destruct(){
		$fields = array("update" => time());
		if(count($_SESSION) || (count($row['data']) && !count($_SESSION)) ){
			$fields["data"] = $_SESSION;
		}
		$new_data = array('$set' => $fields);
		$this->collection->update(array('_id'=>$this->_id),$new_data);
	}

	private function getRow(){
		extract($this->cookieVals());

		$row = false;
		if($_id){
			$row = $this->collection->findOne(array('_id'=>new MongoId($_id)));

			//ensure sid match to pk
			if($row['sid'] != $sid){
				$row = false;
			}
		}

		if(!$row){
			$row = array('sid'=>$sid,'update'=>time(),'created'=>time()); 
			$this->collection->insert($row);
			$_id = $row['_id'];
		}

		$this->setCookies($sid,$_id);

		return $row;
	}

	public function getData(){
		return isset($this->row['data'])?$this->row['data']:array();
	}

	private function gc(){
		/*
		session gc... 
			capped collection wont work because changing object size and if you ever had over the capped max active/remembered sessions
				capped collection could work if you just stored a refrence to a session_data mongo id and you padded the value with 0's or something so the object would not change size

				because this is just as much a lookup table as a write table the index on _id would be useful but with no gc needed you would not need an index on time 
				if you wanted to flag session as deactivated you could use the last update

			load balanced delete
				every few requests hit mongo with a delete for expired records
				needs index on time
		*/
	}

	public function setCookies($sid,$_id){
		setcookie("sid", $sid, time()+self::$config['expire']);
		setcookie("_id", $_id, time()+self::$config['expire']);
		$_COOKIE['sid'] = $sid;
		$_COOKIE['_id'] = $_id.'';//ensure toString is called on MongoId
	} 

	public function cookieVals(){
		$sid = isset($_COOKIE['sid'])?$_COOKIE['sid']:$this->generate_sid();
		$_id = isset($_COOKIE['_id'])?$_COOKIE['_id']:false;
		//$remember = 
		return array('sid'=>$sid,'_id'=>$_id);
	}

	public function generate_sid(){
		return microtime(true);
	}
}
?>