File Source for SessionHandler.php

<?php
/**
* Copyright (c) 2009 - 2011, RealDolmen
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of RealDolmen nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RealDolmen ''AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL RealDolmen BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @category Microsoft
* @package Microsoft_WindowsAzure
* @subpackage Session
* @copyright Copyright (c) 2009 - 2011, RealDolmen (http://www.realdolmen.com)
* @license http://phpazure.codeplex.com/license
* @version $Id: Storage.php 21617 2009-06-12 10:46:31Z unknown $
*/
/**
* @see Microsoft_AutoLoader
*/
require_once dirname(__FILE__) . '/../AutoLoader.php';
/**
* @category Microsoft
* @package Microsoft_WindowsAzure
* @subpackage Session
* @copyright Copyright (c) 2009 - 2011, RealDolmen (http://www.realdolmen.com)
* @license http://phpazure.codeplex.com/license
*/
class Microsoft_WindowsAzure_SessionHandler
{
/**
* Maximal property size in table storage.
*
* @var int
* @see http://msdn.microsoft.com/en-us/library/dd179338.aspx
*/
const MAX_TS_PROPERTY_SIZE = 65536;
/** Storage backend type */
const STORAGE_TYPE_TABLE = 'table';
const STORAGE_TYPE_BLOB = 'blob';
/**
* Storage back-end
*
* @var Microsoft_WindowsAzure_Storage_Table|Microsoft_WindowsAzure_Storage_Blob
*/
protected $_storage;
/**
* Storage backend type
*
* @var string
*/
protected $_storageType;
/**
* Session container name
*
* @var string
*/
protected $_sessionContainer;
/**
* Session container partition
*
* @var string
*/
protected $_sessionContainerPartition;
/**
* Creates a new Microsoft_WindowsAzure_SessionHandler instance
*
* @param Microsoft_WindowsAzure_Storage_Table|Microsoft_WindowsAzure_Storage_Blob$storage Storage back-end, can be table storage and blob storage
* @param string $sessionContainer Session container name
* @param string $sessionContainerPartition Session container partition
*/
public function __construct(Microsoft_WindowsAzure_Storage $storage, $sessionContainer = 'phpsessions', $sessionContainerPartition = 'sessions')
{
// Validate $storage
if (!($storage instanceof Microsoft_WindowsAzure_Storage_Table || $storage instanceof Microsoft_WindowsAzure_Storage_Blob)) {
throw new Microsoft_WindowsAzure_Exception('Invalid storage back-end given. Storage back-end should be of type Microsoft_WindowsAzure_Storage_Table or Microsoft_WindowsAzure_Storage_Blob.');
}
// Validate other parameters
if ($sessionContainer == '' || $sessionContainerPartition == '') {
throw new Microsoft_WindowsAzure_Exception('Session container and session partition should be specified.');
}
// Determine storage type
$storageType = self::STORAGE_TYPE_TABLE;
if ($storage instanceof Microsoft_WindowsAzure_Storage_Blob) {
$storageType = self::STORAGE_TYPE_BLOB;
}
// Set properties
$this->_storage = $storage;
$this->_storageType = $storageType;
$this->_sessionContainer = $sessionContainer;
$this->_sessionContainerPartition = $sessionContainerPartition;
}
/**
* Object destructor
*/
public function __destruct() {
session_write_close();
}
/**
* Registers the current session handler as PHP's session handler
*
* @return boolean
*/
public function register()
{
return session_set_save_handler(array($this, 'open'),
array($this, 'close'),
array($this, 'read'),
array($this, 'write'),
array($this, 'destroy'),
array($this, 'gc')
);
}
/**
* Open the session store
*
* @return bool
*/
public function open()
{
// Make sure storage container exists
if ($this->_storageType == self::STORAGE_TYPE_TABLE) {
$this->_storage->createTableIfNotExists($this->_sessionContainer);
} else if ($this->_storageType == self::STORAGE_TYPE_BLOB) {
$this->_storage->createContainerIfNotExists($this->_sessionContainer);
}
// 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)
{
// Read data
if ($this->_storageType == self::STORAGE_TYPE_TABLE) {
// In table storage
try
{
$sessionRecord = $this->_storage->retrieveEntityById(
$this->_sessionContainer,
$this->_sessionContainerPartition,
$id
);
return unserialize(base64_decode($sessionRecord->serializedData));
}
catch (Microsoft_WindowsAzure_Exception $ex)
{
return '';
}
} else if ($this->_storageType == self::STORAGE_TYPE_BLOB) {
// In blob storage
try
{
$data = $this->_storage->getBlobData(
$this->_sessionContainer,
$this->_sessionContainerPartition . '/' . $id
);
return unserialize(base64_decode($data));
}
catch (Microsoft_WindowsAzure_Exception $ex)
{
return false;
}
}
}
/**
* Write a specific session
*
* @param int $id Session Id
* @param string $serializedData Serialized PHP object
* @throws Exception
*/
public function write($id, $serializedData)
{
// Encode data
$serializedData = base64_encode(serialize($serializedData));
if (strlen($serializedData) >= self::MAX_TS_PROPERTY_SIZE && $this->_storageType == self::STORAGE_TYPE_TABLE) {
throw new Microsoft_WindowsAzure_Exception('Session data exceeds the maximum allowed size of ' . self::MAX_TS_PROPERTY_SIZE . ' bytes that can be stored using table storage. Consider switching to a blob storage back-end or try reducing session data size.');
}
// Store data
if ($this->_storageType == self::STORAGE_TYPE_TABLE) {
// In table storage
$sessionRecord = new Microsoft_WindowsAzure_Storage_DynamicTableEntity($this->_sessionContainerPartition, $id);
$sessionRecord->sessionExpires = time();
$sessionRecord->serializedData = $serializedData;
$sessionRecord->setAzurePropertyType('sessionExpires', 'Edm.Int32');
try
{
$this->_storage->updateEntity($this->_sessionContainer, $sessionRecord);
}
catch (Microsoft_WindowsAzure_Exception $unknownRecord)
{
$this->_storage->insertEntity($this->_sessionContainer, $sessionRecord);
}
} else if ($this->_storageType == self::STORAGE_TYPE_BLOB) {
// In blob storage
$this->_storage->putBlobData(
$this->_sessionContainer,
$this->_sessionContainerPartition . '/' . $id,
$serializedData,
array('sessionexpires' => time())
);
}
}
/**
* Destroy a specific session
*
* @param int $id Session Id
* @return boolean
*/
public function destroy($id)
{
// Destroy data
if ($this->_storageType == self::STORAGE_TYPE_TABLE) {
// In table storage
try
{
$sessionRecord = $this->_storage->retrieveEntityById(
$this->_sessionContainer,
$this->_sessionContainerPartition,
$id
);
$this->_storage->deleteEntity($this->_sessionContainer, $sessionRecord);
return true;
}
catch (Microsoft_WindowsAzure_Exception $ex)
{
return false;
}
} else if ($this->_storageType == self::STORAGE_TYPE_BLOB) {
// In blob storage
try
{
$this->_storage->deleteBlob(
$this->_sessionContainer,
$this->_sessionContainerPartition . '/' . $id
);
return true;
}
catch (Microsoft_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)
{
if ($this->_storageType == self::STORAGE_TYPE_TABLE) {
// In table storage
try
{
$result = $this->_storage->retrieveEntities($this->_sessionContainer, 'PartitionKey eq \'' . $this->_sessionContainerPartition . '\' and sessionExpires lt ' . (time() - $lifeTime));
foreach ($result as $sessionRecord)
{
$this->_storage->deleteEntity($this->_sessionContainer, $sessionRecord);
}
return true;
}
catch (Microsoft_WindowsAzure_exception $ex)
{
return false;
}
} else if ($this->_storageType == self::STORAGE_TYPE_BLOB) {
// In blob storage
try
{
$result = $this->_storage->listBlobs($this->_sessionContainer, $this->_sessionContainerPartition, '', null, null, 'metadata');
foreach ($result as $sessionRecord)
{
if ($sessionRecord->Metadata['sessionexpires'] < (time() - $lifeTime)) {
$this->_storage->deleteBlob($this->_sessionContainer, $sessionRecord->Name);
}
}
return true;
}
catch (Microsoft_WindowsAzure_exception $ex)
{
return false;
}
}
}
}

Source for file SessionHandler.php