web/Zend/Service/WindowsAzure/Storage/Table.php
changeset 0 4eba9c11703f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/Zend/Service/WindowsAzure/Storage/Table.php	Mon Dec 13 18:29:26 2010 +0100
@@ -0,0 +1,866 @@
+<?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 Storage
+ * @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: Table.php 23170 2010-10-19 18:29:24Z mabe $
+ */
+
+/**
+ * @see Zend_Service_WindowsAzure_Credentials_CredentialsAbstract
+ */
+require_once 'Zend/Service/WindowsAzure/Credentials/CredentialsAbstract.php';
+
+/**
+ * @see Zend_Service_WindowsAzure_Credentials_SharedKey
+ */
+require_once 'Zend/Service/WindowsAzure/Credentials/SharedKey.php';
+
+/**
+ * @see Zend_Service_WindowsAzure_Credentials_SharedKeyLite
+ */
+require_once 'Zend/Service/WindowsAzure/Credentials/SharedKeyLite.php';
+
+/**
+ * @see Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract
+ */
+require_once 'Zend/Service/WindowsAzure/RetryPolicy/RetryPolicyAbstract.php';
+
+/**
+ * @see Zend_Http_Client
+ */
+require_once 'Zend/Http/Client.php';
+
+/**
+ * @see Zend_Http_Response
+ */
+require_once 'Zend/Http/Response.php';
+
+/**
+ * @see Zend_Service_WindowsAzure_Storage
+ */
+require_once 'Zend/Service/WindowsAzure/Storage.php';
+
+/**
+ * @see Zend_Service_WindowsAzure_Storage_BatchStorageAbstract
+ */
+require_once 'Zend/Service/WindowsAzure/Storage/BatchStorageAbstract.php';
+
+/**
+ * @see Zend_Service_WindowsAzure_Storage_TableInstance
+ */
+require_once 'Zend/Service/WindowsAzure/Storage/TableInstance.php';
+
+/**
+ * @see Zend_Service_WindowsAzure_Storage_TableEntity
+ */
+require_once 'Zend/Service/WindowsAzure/Storage/TableEntity.php';
+
+/**
+ * @see Zend_Service_WindowsAzure_Storage_DynamicTableEntity
+ */
+require_once 'Zend/Service/WindowsAzure/Storage/DynamicTableEntity.php';
+
+/**
+ * @see Zend_Service_WindowsAzure_Storage_TableEntityQuery
+ */
+require_once 'Zend/Service/WindowsAzure/Storage/TableEntityQuery.php';
+
+/**
+ * @see Zend_Service_WindowsAzure_Exception
+ */
+require_once 'Zend/Service/WindowsAzure/Exception.php';
+
+
+/**
+ * @category   Zend
+ * @package    Zend_Service_WindowsAzure
+ * @subpackage Storage
+ * @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_Storage_Table
+    extends Zend_Service_WindowsAzure_Storage_BatchStorageAbstract
+{
+	/**
+	 * Creates a new Zend_Service_WindowsAzure_Storage_Table instance
+	 *
+	 * @param string $host Storage host name
+	 * @param string $accountName Account name for Windows Azure
+	 * @param string $accountKey Account key for Windows Azure
+	 * @param boolean $usePathStyleUri Use path-style URI's
+	 * @param Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract $retryPolicy Retry policy to use when making requests
+	 */
+	public function __construct($host = Zend_Service_WindowsAzure_Storage::URL_DEV_TABLE, $accountName = Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::DEVSTORE_ACCOUNT, $accountKey = Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::DEVSTORE_KEY, $usePathStyleUri = false, Zend_Service_WindowsAzure_RetryPolicy_RetryPolicyAbstract $retryPolicy = null)
+	{
+		parent::__construct($host, $accountName, $accountKey, $usePathStyleUri, $retryPolicy);
+
+	    // Always use SharedKeyLite authentication
+	    $this->_credentials = new Zend_Service_WindowsAzure_Credentials_SharedKeyLite($accountName, $accountKey, $this->_usePathStyleUri);
+	    
+	    // API version
+		$this->_apiVersion = '2009-09-19';
+	}
+	
+	/**
+	 * Check if a table exists
+	 * 
+	 * @param string $tableName Table name
+	 * @return boolean
+	 */
+	public function tableExists($tableName = '')
+	{
+		if ($tableName === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Table name is not specified.');
+		}
+			
+		// List tables
+        $tables = $this->listTables(); // 2009-09-19 does not support $this->listTables($tableName); all of a sudden...
+        foreach ($tables as $table) {
+            if ($table->Name == $tableName) {
+                return true;
+            }
+        }
+        
+        return false;
+	}
+	
+	/**
+	 * List tables
+	 *
+	 * @param  string $nextTableName Next table name, used for listing tables when total amount of tables is > 1000.
+	 * @return array
+	 * @throws Zend_Service_WindowsAzure_Exception
+	 */
+	public function listTables($nextTableName = '')
+	{
+	    // Build query string
+		$queryString = array();
+	    if ($nextTableName != '') {
+	        $queryString[] = 'NextTableName=' . $nextTableName;
+	    }
+	    $queryString = self::createQueryStringFromArray($queryString);
+	    
+		// Perform request
+		$response = $this->_performRequest('Tables', $queryString, Zend_Http_Client::GET, null, true);
+		if ($response->isSuccessful()) {	    
+		    // Parse result
+		    $result = $this->_parseResponse($response);	
+		    
+		    if (!$result || !$result->entry) {
+		        return array();
+		    }
+	        
+		    $entries = null;
+		    if (count($result->entry) > 1) {
+		        $entries = $result->entry;
+		    } else {
+		        $entries = array($result->entry);
+		    }
+
+		    // Create return value
+		    $returnValue = array();		    
+		    foreach ($entries as $entry) {
+		        $tableName = $entry->xpath('.//m:properties/d:TableName');
+		        $tableName = (string)$tableName[0];
+		        
+		        $returnValue[] = new Zend_Service_WindowsAzure_Storage_TableInstance(
+		            (string)$entry->id,
+		            $tableName,
+		            (string)$entry->link['href'],
+		            (string)$entry->updated
+		        );
+		    }
+		    
+			// More tables?
+		    if ($response->getHeader('x-ms-continuation-NextTableName') !== null) {
+		        $returnValue = array_merge($returnValue, $this->listTables($response->getHeader('x-ms-continuation-NextTableName')));
+		    }
+
+		    return $returnValue;
+		} else {
+			throw new Zend_Service_WindowsAzure_Exception($this->_getErrorMessage($response, 'Resource could not be accessed.'));
+		}
+	}
+	
+	/**
+	 * Create table
+	 *
+	 * @param string $tableName Table name
+	 * @return Zend_Service_WindowsAzure_Storage_TableInstance
+	 * @throws Zend_Service_WindowsAzure_Exception
+	 */
+	public function createTable($tableName = '')
+	{
+		if ($tableName === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Table name is not specified.');
+		}
+			
+		// Generate request body
+		$requestBody = '<?xml version="1.0" encoding="utf-8" standalone="yes"?>
+                        <entry
+                        	xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices"
+                        	xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata"
+                        	xmlns="http://www.w3.org/2005/Atom">
+                          <title />
+                          <updated>{tpl:Updated}</updated>
+                          <author>
+                            <name />
+                          </author>
+                          <id />
+                          <content type="application/xml">
+                            <m:properties>
+                              <d:TableName>{tpl:TableName}</d:TableName>
+                            </m:properties>
+                          </content>
+                        </entry>';
+		
+        $requestBody = $this->_fillTemplate($requestBody, array(
+            'BaseUrl' => $this->getBaseUrl(),
+            'TableName' => htmlspecialchars($tableName),
+        	'Updated' => $this->isoDate(),
+            'AccountName' => $this->_accountName
+        ));
+        
+        // Add header information
+        $headers = array();
+        $headers['Content-Type'] = 'application/atom+xml';
+        $headers['DataServiceVersion'] = '1.0;NetFx';
+        $headers['MaxDataServiceVersion'] = '1.0;NetFx';        
+
+		// Perform request
+		$response = $this->_performRequest('Tables', '', Zend_Http_Client::POST, $headers, true, $requestBody);
+		if ($response->isSuccessful()) {
+		    // Parse response
+		    $entry = $this->_parseResponse($response);
+		    
+		    $tableName = $entry->xpath('.//m:properties/d:TableName');
+		    $tableName = (string)$tableName[0];
+		        
+		    return new Zend_Service_WindowsAzure_Storage_TableInstance(
+		        (string)$entry->id,
+		        $tableName,
+		        (string)$entry->link['href'],
+		        (string)$entry->updated
+		    );
+		} else {
+			throw new Zend_Service_WindowsAzure_Exception($this->_getErrorMessage($response, 'Resource could not be accessed.'));
+		}
+	}
+	
+	/**
+	 * Delete table
+	 *
+	 * @param string $tableName Table name
+	 * @throws Zend_Service_WindowsAzure_Exception
+	 */
+	public function deleteTable($tableName = '')
+	{
+		if ($tableName === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Table name is not specified.');
+		}
+
+        // Add header information
+        $headers = array();
+        $headers['Content-Type'] = 'application/atom+xml';
+
+		// Perform request
+		$response = $this->_performRequest('Tables(\'' . $tableName . '\')', '', Zend_Http_Client::DELETE, $headers, true, null);
+		if (!$response->isSuccessful()) {
+			throw new Zend_Service_WindowsAzure_Exception($this->_getErrorMessage($response, 'Resource could not be accessed.'));
+		}
+	}
+	
+	/**
+	 * Insert entity into table
+	 * 
+	 * @param string                              $tableName   Table name
+	 * @param Zend_Service_WindowsAzure_Storage_TableEntity $entity      Entity to insert
+	 * @return Zend_Service_WindowsAzure_Storage_TableEntity
+	 * @throws Zend_Service_WindowsAzure_Exception
+	 */
+	public function insertEntity($tableName = '', Zend_Service_WindowsAzure_Storage_TableEntity $entity = null)
+	{
+		if ($tableName === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Table name is not specified.');
+		}
+		if ($entity === null) {
+			throw new Zend_Service_WindowsAzure_Exception('Entity is not specified.');
+		}
+		                     
+		// Generate request body
+		$requestBody = '<?xml version="1.0" encoding="utf-8" standalone="yes"?>
+                        <entry xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" xmlns="http://www.w3.org/2005/Atom">
+                          <title />
+                          <updated>{tpl:Updated}</updated>
+                          <author>
+                            <name />
+                          </author>
+                          <id />
+                          <content type="application/xml">
+                            <m:properties>
+                              {tpl:Properties}
+                            </m:properties>
+                          </content>
+                        </entry>';
+		
+        $requestBody = $this->_fillTemplate($requestBody, array(
+        	'Updated'    => $this->isoDate(),
+            'Properties' => $this->_generateAzureRepresentation($entity)
+        ));
+
+        // Add header information
+        $headers = array();
+        $headers['Content-Type'] = 'application/atom+xml';
+
+		// Perform request
+	    $response = null;
+	    if ($this->isInBatch()) {
+		    $this->getCurrentBatch()->enlistOperation($tableName, '', Zend_Http_Client::POST, $headers, true, $requestBody);
+		    return null;
+		} else {
+		    $response = $this->_performRequest($tableName, '', Zend_Http_Client::POST, $headers, true, $requestBody);
+		}
+		if ($response->isSuccessful()) {
+		    // Parse result
+		    $result = $this->_parseResponse($response);
+		    
+		    $timestamp = $result->xpath('//m:properties/d:Timestamp');
+		    $timestamp = (string)$timestamp[0];
+
+		    $etag      = $result->attributes('http://schemas.microsoft.com/ado/2007/08/dataservices/metadata');
+		    $etag      = (string)$etag['etag'];
+		    
+		    // Update properties
+		    $entity->setTimestamp($timestamp);
+		    $entity->setEtag($etag);
+
+		    return $entity;
+		} else {
+			throw new Zend_Service_WindowsAzure_Exception($this->_getErrorMessage($response, 'Resource could not be accessed.'));
+		}
+	}
+	
+	/**
+	 * Delete entity from table
+	 * 
+	 * @param string                              $tableName   Table name
+	 * @param Zend_Service_WindowsAzure_Storage_TableEntity $entity      Entity to delete
+	 * @param boolean                             $verifyEtag  Verify etag of the entity (used for concurrency)
+	 * @throws Zend_Service_WindowsAzure_Exception
+	 */
+	public function deleteEntity($tableName = '', Zend_Service_WindowsAzure_Storage_TableEntity $entity = null, $verifyEtag = false)
+	{
+		if ($tableName === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Table name is not specified.');
+		}
+		if ($entity === null) {
+			throw new Zend_Service_WindowsAzure_Exception('Entity is not specified.');
+		}
+		                     
+        // Add header information
+        $headers = array();
+        if (!$this->isInBatch()) {
+        	// http://social.msdn.microsoft.com/Forums/en-US/windowsazure/thread/9e255447-4dc7-458a-99d3-bdc04bdc5474/
+            $headers['Content-Type']   = 'application/atom+xml';
+        }
+        $headers['Content-Length'] = 0;
+        if (!$verifyEtag) {
+            $headers['If-Match']       = '*';
+        } else {
+            $headers['If-Match']       = $entity->getEtag();
+        }
+
+		// Perform request
+	    $response = null;
+	    if ($this->isInBatch()) {
+		    $this->getCurrentBatch()->enlistOperation($tableName . '(PartitionKey=\'' . $entity->getPartitionKey() . '\', RowKey=\'' . $entity->getRowKey() . '\')', '', Zend_Http_Client::DELETE, $headers, true, null);
+		    return null;
+		} else {
+		    $response = $this->_performRequest($tableName . '(PartitionKey=\'' . $entity->getPartitionKey() . '\', RowKey=\'' . $entity->getRowKey() . '\')', '', Zend_Http_Client::DELETE, $headers, true, null);
+		}
+		if (!$response->isSuccessful()) {
+		    throw new Zend_Service_WindowsAzure_Exception($this->_getErrorMessage($response, 'Resource could not be accessed.'));
+		}
+	}
+	
+	/**
+	 * Retrieve entity from table, by id
+	 * 
+	 * @param string $tableName    Table name
+	 * @param string $partitionKey Partition key
+	 * @param string $rowKey       Row key
+	 * @param string $entityClass  Entity class name* 
+	 * @return Zend_Service_WindowsAzure_Storage_TableEntity
+	 * @throws Zend_Service_WindowsAzure_Exception
+	 */
+	public function retrieveEntityById($tableName = '', $partitionKey = '', $rowKey = '', $entityClass = 'Zend_Service_WindowsAzure_Storage_DynamicTableEntity')
+	{
+		if ($tableName === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Table name is not specified.');
+		}
+		if ($partitionKey === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Partition key is not specified.');
+		}
+		if ($rowKey === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Row key is not specified.');
+		}
+		if ($entityClass === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Entity class is not specified.');
+		}
+
+			
+		// Check for combined size of partition key and row key
+		// http://msdn.microsoft.com/en-us/library/dd179421.aspx
+		if (strlen($partitionKey . $rowKey) >= 256) {
+		    // Start a batch if possible
+		    if ($this->isInBatch()) {
+		        throw new Zend_Service_WindowsAzure_Exception('Entity cannot be retrieved. A transaction is required to retrieve the entity, but another transaction is already active.');
+		    }
+		        
+		    $this->startBatch();
+		}
+		
+		// Fetch entities from Azure
+        $result = $this->retrieveEntities(
+            $this->select()
+                 ->from($tableName)
+                 ->wherePartitionKey($partitionKey)
+                 ->whereRowKey($rowKey),
+            '',
+            $entityClass
+        );
+        
+        // Return
+        if (count($result) == 1) {
+            return $result[0];
+        }
+        
+        return null;
+	}
+	
+	/**
+	 * Create a new Zend_Service_WindowsAzure_Storage_TableEntityQuery
+	 * 
+	 * @return Zend_Service_WindowsAzure_Storage_TableEntityQuery
+	 */
+	public function select()
+	{
+	    return new Zend_Service_WindowsAzure_Storage_TableEntityQuery();
+	}
+	
+	/**
+	 * Retrieve entities from table
+	 * 
+	 * @param string $tableName|Zend_Service_WindowsAzure_Storage_TableEntityQuery    Table name -or- Zend_Service_WindowsAzure_Storage_TableEntityQuery instance
+	 * @param string $filter                                                Filter condition (not applied when $tableName is a Zend_Service_WindowsAzure_Storage_TableEntityQuery instance)
+	 * @param string $entityClass                                           Entity class name
+	 * @param string $nextPartitionKey                                      Next partition key, used for listing entities when total amount of entities is > 1000.
+	 * @param string $nextRowKey                                            Next row key, used for listing entities when total amount of entities is > 1000.
+	 * @return array Array of Zend_Service_WindowsAzure_Storage_TableEntity
+	 * @throws Zend_Service_WindowsAzure_Exception
+	 */
+	public function retrieveEntities($tableName = '', $filter = '', $entityClass = 'Zend_Service_WindowsAzure_Storage_DynamicTableEntity', $nextPartitionKey = null, $nextRowKey = null)
+	{
+		if ($tableName === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Table name is not specified.');
+		}
+		if ($entityClass === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Entity class is not specified.');
+		}
+
+		// Convenience...
+		if (class_exists($filter)) {
+		    $entityClass = $filter;
+		    $filter = '';
+		}
+			
+		// Query string
+		$queryString = '';
+
+		// Determine query
+		if (is_string($tableName)) {
+		    // Option 1: $tableName is a string
+		    
+		    // Append parentheses
+		    $tableName .= '()';
+		    
+    	    // Build query
+    	    $query = array();
+    	    
+    		// Filter?
+    		if ($filter !== '') {
+    		    $query[] = '$filter=' . Zend_Service_WindowsAzure_Storage_TableEntityQuery::encodeQuery($filter);
+    		}
+    		    
+    	    // Build queryString
+    	    if (count($query) > 0)  {
+    	        $queryString = '?' . implode('&', $query);
+    	    }
+		} else if (get_class($tableName) == 'Zend_Service_WindowsAzure_Storage_TableEntityQuery') {
+		    // Option 2: $tableName is a Zend_Service_WindowsAzure_Storage_TableEntityQuery instance
+
+		    // Build queryString
+		    $queryString = $tableName->assembleQueryString(true);
+
+		    // Change $tableName
+		    $tableName = $tableName->assembleFrom(true);
+		} else {
+		    throw new Zend_Service_WindowsAzure_Exception('Invalid argument: $tableName');
+		}
+		
+		// Add continuation querystring parameters?
+		if ($nextPartitionKey !== null && $nextRowKey !== null) {
+		    if ($queryString !== '') {
+		        $queryString .= '&';
+		    }
+		        
+		    $queryString .= '&NextPartitionKey=' . rawurlencode($nextPartitionKey) . '&NextRowKey=' . rawurlencode($nextRowKey);
+		}
+
+		// Perform request
+	    $response = null;
+	    if ($this->isInBatch() && $this->getCurrentBatch()->getOperationCount() == 0) {
+		    $this->getCurrentBatch()->enlistOperation($tableName, $queryString, Zend_Http_Client::GET, array(), true, null);
+		    $response = $this->getCurrentBatch()->commit();
+		    
+		    // Get inner response (multipart)
+		    $innerResponse = $response->getBody();
+		    $innerResponse = substr($innerResponse, strpos($innerResponse, 'HTTP/1.1 200 OK'));
+		    $innerResponse = substr($innerResponse, 0, strpos($innerResponse, '--batchresponse'));
+		    $response = Zend_Http_Response::fromString($innerResponse);
+		} else {
+		    $response = $this->_performRequest($tableName, $queryString, Zend_Http_Client::GET, array(), true, null);
+		}
+
+		if ($response->isSuccessful()) {
+		    // Parse result
+		    $result = $this->_parseResponse($response);
+		    if (!$result) {
+		        return array();
+		    }
+
+		    $entries = null;
+		    if ($result->entry) {
+    		    if (count($result->entry) > 1) {
+    		        $entries = $result->entry;
+    		    } else {
+    		        $entries = array($result->entry);
+    		    }
+		    } else {
+		        // This one is tricky... If we have properties defined, we have an entity.
+		        $properties = $result->xpath('//m:properties');
+		        if ($properties) {
+		            $entries = array($result);
+		        } else {
+		            return array();
+		        }
+		    }
+
+		    // Create return value
+		    $returnValue = array();		    
+		    foreach ($entries as $entry) {
+    		    // Parse properties
+    		    $properties = $entry->xpath('.//m:properties');
+    		    $properties = $properties[0]->children('http://schemas.microsoft.com/ado/2007/08/dataservices');
+    		    
+    		    // Create entity
+    		    $entity = new $entityClass('', '');
+    		    $entity->setAzureValues((array)$properties, true);
+    		    
+    		    // If we have a Zend_Service_WindowsAzure_Storage_DynamicTableEntity, make sure all property types are OK
+    		    if ($entity instanceof Zend_Service_WindowsAzure_Storage_DynamicTableEntity) {
+    		        foreach ($properties as $key => $value) {  
+    		            $attributes = $value->attributes('http://schemas.microsoft.com/ado/2007/08/dataservices/metadata');
+    		            $type = (string)$attributes['type'];
+    		            if ($type !== '') {
+    		                $entity->setAzurePropertyType($key, $type);
+    		            }
+    		        }
+    		    }
+    
+    		    // Update etag
+    		    $etag      = $entry->attributes('http://schemas.microsoft.com/ado/2007/08/dataservices/metadata');
+    		    $etag      = (string)$etag['etag'];
+    		    $entity->setEtag($etag);
+    		    
+    		    // Add to result
+    		    $returnValue[] = $entity;
+		    }
+
+			// More entities?
+		    if ($response->getHeader('x-ms-continuation-NextPartitionKey') !== null && $response->getHeader('x-ms-continuation-NextRowKey') !== null) {
+		        if (strpos($queryString, '$top') === false) {
+		            $returnValue = array_merge($returnValue, $this->retrieveEntities($tableName, $filter, $entityClass, $response->getHeader('x-ms-continuation-NextPartitionKey'), $response->getHeader('x-ms-continuation-NextRowKey')));
+		        }
+		    }
+		    
+		    // Return
+		    return $returnValue;
+		} else {
+		    throw new Zend_Service_WindowsAzure_Exception($this->_getErrorMessage($response, 'Resource could not be accessed.'));
+		}
+	}
+	
+	/**
+	 * Update entity by replacing it
+	 * 
+	 * @param string                              $tableName   Table name
+	 * @param Zend_Service_WindowsAzure_Storage_TableEntity $entity      Entity to update
+	 * @param boolean                             $verifyEtag  Verify etag of the entity (used for concurrency)
+	 * @throws Zend_Service_WindowsAzure_Exception
+	 */
+	public function updateEntity($tableName = '', Zend_Service_WindowsAzure_Storage_TableEntity $entity = null, $verifyEtag = false)
+	{
+	    return $this->_changeEntity(Zend_Http_Client::PUT, $tableName, $entity, $verifyEtag);
+	}
+	
+	/**
+	 * Update entity by adding or updating properties
+	 * 
+	 * @param string                              $tableName   Table name
+	 * @param Zend_Service_WindowsAzure_Storage_TableEntity $entity      Entity to update
+	 * @param boolean                             $verifyEtag  Verify etag of the entity (used for concurrency)
+	 * @param array                               $properties  Properties to merge. All properties will be used when omitted.
+	 * @throws Zend_Service_WindowsAzure_Exception
+	 */
+	public function mergeEntity($tableName = '', Zend_Service_WindowsAzure_Storage_TableEntity $entity = null, $verifyEtag = false, $properties = array())
+	{
+		$mergeEntity = null;
+		if (is_array($properties) && count($properties) > 0) {
+			// Build a new object
+			$mergeEntity = new Zend_Service_WindowsAzure_Storage_DynamicTableEntity($entity->getPartitionKey(), $entity->getRowKey());
+			
+			// Keep only values mentioned in $properties
+			$azureValues = $entity->getAzureValues();
+			foreach ($azureValues as $key => $value) {
+				if (in_array($value->Name, $properties)) {
+					$mergeEntity->setAzureProperty($value->Name, $value->Value, $value->Type);
+				}
+			}
+		} else {
+			$mergeEntity = $entity;
+		}
+
+        // Ensure entity timestamp matches updated timestamp 
+        $entity->setTimestamp($this->isoDate());
+		
+	    return $this->_changeEntity(Zend_Http_Client::MERGE, $tableName, $mergeEntity, $verifyEtag);
+	}
+	
+	/**
+	 * Get error message from Zend_Http_Response
+	 * 
+	 * @param Zend_Http_Response $response Repsonse
+	 * @param string $alternativeError Alternative error message
+	 * @return string
+	 */
+	protected function _getErrorMessage(Zend_Http_Response $response, $alternativeError = 'Unknown error.')
+	{
+		$response = $this->_parseResponse($response);
+		if ($response && $response->message) {
+		    return (string)$response->message;
+		} else {
+		    return $alternativeError;
+		}
+	}
+	
+	/**
+	 * Update entity / merge entity
+	 * 
+	 * @param string                              $httpVerb    HTTP verb to use (PUT = update, MERGE = merge)
+	 * @param string                              $tableName   Table name
+	 * @param Zend_Service_WindowsAzure_Storage_TableEntity $entity      Entity to update
+	 * @param boolean                             $verifyEtag  Verify etag of the entity (used for concurrency)
+	 * @throws Zend_Service_WindowsAzure_Exception
+	 */
+	protected function _changeEntity($httpVerb = Zend_Http_Client::PUT, $tableName = '', Zend_Service_WindowsAzure_Storage_TableEntity $entity = null, $verifyEtag = false)
+	{
+		if ($tableName === '') {
+			throw new Zend_Service_WindowsAzure_Exception('Table name is not specified.');
+		}
+		if ($entity === null) {
+			throw new Zend_Service_WindowsAzure_Exception('Entity is not specified.');
+		}
+		                     
+        // Add header information
+        $headers = array();
+        $headers['Content-Type']   = 'application/atom+xml';
+        $headers['Content-Length'] = 0;
+        if (!$verifyEtag) {
+            $headers['If-Match']       = '*';
+        } else {
+            $headers['If-Match']       = $entity->getEtag();
+        }
+
+	    // Generate request body
+		$requestBody = '<?xml version="1.0" encoding="utf-8" standalone="yes"?>
+                        <entry xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" xmlns="http://www.w3.org/2005/Atom">
+                          <title />
+                          <updated>{tpl:Updated}</updated>
+                          <author>
+                            <name />
+                          </author>
+                          <id />
+                          <content type="application/xml">
+                            <m:properties>
+                              {tpl:Properties}
+                            </m:properties>
+                          </content>
+                        </entry>';
+		
+        // Attempt to get timestamp from entity
+        $timestamp = $entity->getTimestamp();
+        if ($timestamp == Zend_Service_WindowsAzure_Storage_TableEntity::DEFAULT_TIMESTAMP) {
+            $timestamp = $this->isoDate();
+        }
+
+        $requestBody = $this->_fillTemplate($requestBody, array(
+        	'Updated'    => $timestamp,
+            'Properties' => $this->_generateAzureRepresentation($entity)
+        ));
+
+        // Add header information
+        $headers = array();
+        $headers['Content-Type'] = 'application/atom+xml';
+	    if (!$verifyEtag) {
+            $headers['If-Match']       = '*';
+        } else {
+            $headers['If-Match']       = $entity->getEtag();
+        }
+        
+		// Perform request
+		$response = null;
+	    if ($this->isInBatch()) {
+		    $this->getCurrentBatch()->enlistOperation($tableName . '(PartitionKey=\'' . $entity->getPartitionKey() . '\',RowKey=\'' . $entity->getRowKey() . '\')', '', $httpVerb, $headers, true, $requestBody);
+		    return null;
+		} else {
+		    $response = $this->_performRequest($tableName . '(PartitionKey=\'' . $entity->getPartitionKey() . '\',RowKey=\'' . $entity->getRowKey() . '\')', '', $httpVerb, $headers, true, $requestBody);
+		}
+		if ($response->isSuccessful()) {
+		    // Update properties
+			$entity->setEtag($response->getHeader('Etag'));
+			$entity->setTimestamp($response->getHeader('Last-modified'));
+
+		    return $entity;
+		} else {
+			throw new Zend_Service_WindowsAzure_Exception($this->_getErrorMessage($response, 'Resource could not be accessed.'));
+		}
+	}
+	
+	/**
+	 * Generate RFC 1123 compliant date string
+	 * 
+	 * @return string
+	 */
+	protected function _rfcDate()
+	{
+	    return gmdate('D, d M Y H:i:s', time()) . ' GMT'; // RFC 1123
+	}
+	
+	/**
+	 * Fill text template with variables from key/value array
+	 * 
+	 * @param string $templateText Template text
+	 * @param array $variables Array containing key/value pairs
+	 * @return string
+	 */
+	protected function _fillTemplate($templateText, $variables = array())
+	{
+	    foreach ($variables as $key => $value) {
+	        $templateText = str_replace('{tpl:' . $key . '}', $value, $templateText);
+	    }
+	    return $templateText;
+	}
+	
+	/**
+	 * Generate Azure representation from entity (creates atompub markup from properties)
+	 * 
+	 * @param Zend_Service_WindowsAzure_Storage_TableEntity $entity
+	 * @return string
+	 */
+	protected function _generateAzureRepresentation(Zend_Service_WindowsAzure_Storage_TableEntity $entity = null)
+	{
+		// Generate Azure representation from entity
+		$azureRepresentation = array();
+		$azureValues         = $entity->getAzureValues();
+		foreach ($azureValues as $azureValue) {
+		    $value = array();
+		    $value[] = '<d:' . $azureValue->Name;
+		    if ($azureValue->Type != '') {
+		        $value[] = ' m:type="' . $azureValue->Type . '"';
+		    }
+		    if ($azureValue->Value === null) {
+		        $value[] = ' m:null="true"'; 
+		    }
+		    $value[] = '>';
+		    
+		    if ($azureValue->Value !== null) {
+		        if (strtolower($azureValue->Type) == 'edm.boolean') {
+		            $value[] = ($azureValue->Value == true ? '1' : '0');
+		        } else {
+		            $value[] = htmlspecialchars($azureValue->Value);
+		        }
+		    }
+		    
+		    $value[] = '</d:' . $azureValue->Name . '>';
+		    $azureRepresentation[] = implode('', $value);
+		}
+
+		return implode('', $azureRepresentation);
+	}
+	
+		/**
+	 * Perform request using Zend_Http_Client channel
+	 *
+	 * @param string $path Path
+	 * @param string $queryString Query string
+	 * @param string $httpVerb HTTP verb the request will use
+	 * @param array $headers x-ms headers to add
+	 * @param boolean $forTableStorage Is the request for table storage?
+	 * @param mixed $rawData Optional RAW HTTP data to be sent over the wire
+	 * @param string $resourceType Resource type
+	 * @param string $requiredPermission Required permission
+	 * @return Zend_Http_Response
+	 */
+	protected function _performRequest(
+		$path = '/',
+		$queryString = '',
+		$httpVerb = Zend_Http_Client::GET,
+		$headers = array(),
+		$forTableStorage = false,
+		$rawData = null,
+		$resourceType = Zend_Service_WindowsAzure_Storage::RESOURCE_UNKNOWN,
+		$requiredPermission = Zend_Service_WindowsAzure_Credentials_CredentialsAbstract::PERMISSION_READ
+	) {
+		// Add headers
+		$headers['DataServiceVersion'] = '1.0;NetFx';
+		$headers['MaxDataServiceVersion'] = '1.0;NetFx';
+
+		// Perform request
+		return parent::_performRequest(
+			$path,
+			$queryString,
+			$httpVerb,
+			$headers,
+			$forTableStorage,
+			$rawData,
+			$resourceType,
+			$requiredPermission
+		);
+	}
+}