<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Service_WindowsAzure

 * @subpackage Session

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: SessionHandler.php 20785 2010-01-31 09:43:03Z mikaelkael $

 */

/** Zend_Service_WindowsAzure_Storage_Table */

require_once 'Zend/Service/WindowsAzure/Storage/Table.php';

/**

 * @see Zend_Service_WindowsAzure_Exception

 */

require_once 'Zend/Service/WindowsAzure/Exception.php';

/**

 * @category   Zend

 * @package    Zend_Service_WindowsAzure

 * @subpackage Session

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Service_WindowsAzure_SessionHandler

{

    /**

     * Table storage

     * 

     * @var Zend_Service_WindowsAzure_Storage_Table

     */

    protected $_tableStorage;

    /**

     * Session table name

     * 

     * @var string

     */

    protected $_sessionTable;

    /**

     * Session table partition

     * 

     * @var string

     */

    protected $_sessionTablePartition;

    /**

     * Creates a new Zend_Service_WindowsAzure_SessionHandler instance

     * 

     * @param Zend_Service_WindowsAzure_Storage_Table $tableStorage Table storage

     * @param string $sessionTable Session table name

     * @param string $sessionTablePartition Session table partition

     */

    public function __construct(Zend_Service_WindowsAzure_Storage_Table $tableStorage, $sessionTable = 'phpsessions', $sessionTablePartition = 'sessions')

	{

	    // Set properties

		$this->_tableStorage = $tableStorage;

		$this->_sessionTable = $sessionTable;

		$this->_sessionTablePartition = $sessionTablePartition;

	}

	/**

	 * Registers the current session handler as PHP's session handler

	 * 

	 * @return boolean

	 */

	public function register()

	{

        return session_set_save_handler(array($this, 'open'),

                                        array($this, 'close'),

                                        array($this, 'read'),

                                        array($this, 'write'),

                                        array($this, 'destroy'),

                                        array($this, 'gc')

        );

	}

    /**

     * Open the session store

     * 

     * @return bool

     */

    public function open()

    {

    	// Make sure table exists

    	$tableExists = $this->_tableStorage->tableExists($this->_sessionTable);

    	if (!$tableExists) {

		    $this->_tableStorage->createTable($this->_sessionTable);

		}

		// Ok!

		return true;

    }

    /**

     * Close the session store

     * 

     * @return bool

     */

    public function close()

    {

        return true;

    }

    /**

     * Read a specific session

     * 

     * @param int $id Session Id

     * @return string

     */

    public function read($id)

    {

        try

        {

            $sessionRecord = $this->_tableStorage->retrieveEntityById(

                $this->_sessionTable,

                $this->_sessionTablePartition,

                $id

            );

            return base64_decode($sessionRecord->serializedData);

        }

        catch (Zend_Service_WindowsAzure_Exception $ex)

        {

            return '';

        }

    }

    /**

     * Write a specific session

     * 

     * @param int $id Session Id

     * @param string $serializedData Serialized PHP object

     */

    public function write($id, $serializedData)

    {

        $sessionRecord = new Zend_Service_WindowsAzure_Storage_DynamicTableEntity($this->_sessionTablePartition, $id);

        $sessionRecord->sessionExpires = time();

        $sessionRecord->serializedData = base64_encode($serializedData);

        $sessionRecord->setAzurePropertyType('sessionExpires', 'Edm.Int32');

        try

        {

            $this->_tableStorage->updateEntity($this->_sessionTable, $sessionRecord);

        }

        catch (Zend_Service_WindowsAzure_Exception $unknownRecord)

        {

            $this->_tableStorage->insertEntity($this->_sessionTable, $sessionRecord);

        }

    }

    /**

     * Destroy a specific session

     * 

     * @param int $id Session Id

     * @return boolean

     */

    public function destroy($id)

    {

        try

        {

            $sessionRecord = $this->_tableStorage->retrieveEntityById(

                $this->_sessionTable,

                $this->_sessionTablePartition,

                $id

            );

            $this->_tableStorage->deleteEntity($this->_sessionTable, $sessionRecord);

            return true;

        }

        catch (Zend_Service_WindowsAzure_Exception $ex)

        {

            return false;

        }

    }

    /**

     * Garbage collector

     * 

     * @param int $lifeTime Session maximal lifetime

     * @see session.gc_divisor  100

     * @see session.gc_maxlifetime 1440

     * @see session.gc_probability 1

     * @usage Execution rate 1/100 (session.gc_probability/session.gc_divisor)

     * @return boolean

     */

    public function gc($lifeTime)

    {

        try

        {

            $result = $this->_tableStorage->retrieveEntities($this->_sessionTable, 'PartitionKey eq \'' . $this->_sessionTablePartition . '\' and sessionExpires lt ' . (time() - $lifeTime));

            foreach ($result as $sessionRecord)

            {

                $this->_tableStorage->deleteEntity($this->_sessionTable, $sessionRecord);

            }

            return true;

        }

        catch (Zend_Service_WindowsAzure_exception $ex)

        {

            return false;

        }

    }

}