/branches/1.0RC4/src/LibWebta/library/NET/API/AWS/class.AmazonSQS.php

<?php



	class AmazonSQS

	{

		const API_VERSION 	= "2008-01-01";

		const HASH_ALGO 	= 'SHA1';

		const USER_AGENT 	= 'Libwebta AWS Client (http://webta.net)';

	    

		private $AWSAccessKeyId = NULL;

		private $AWSAccessKey = NULL;

		private $LastResponseHeaders = array();

		private static $Instance;

		

		public static function GetInstance($AWSAccessKeyId, $AWSAccessKey)

		{

			 self::$Instance = new AmazonSQS($AWSAccessKeyId, $AWSAccessKey);

			 return self::$Instance;

		}

		

		public function __construct($AWSAccessKeyId, $AWSAccessKey)

		{

			$this->AWSAccessKeyId = $AWSAccessKeyId;

			$this->AWSAccessKey = $AWSAccessKey;

			

			if (!function_exists("hash_hmac"))

                throw new Exception("hash_hmac() function not found. Please install HASH Pecl extension.", E_ERROR);

		}

		

		private function GetRESTSignature($params)

		{

			return base64_encode(@hash_hmac(AmazonCloudFront::HASH_ALGO, implode("\n", $params), $this->AWSAccessKey, 1));

		}

		

		/**

		 * Return GMT timestamp for Amazon AWS S3 Requests

		 *

		 * @return unknown

		 */

		private function GetTimestamp()

		{

		    date_default_timezone_set("GMT");

		    

		    return date("c", time()+3600);

		}

		

		private function Request($method, $uri, $args)

		{

			$HttpRequest = new HttpRequest();

			

			$HttpRequest->setOptions(array(    "redirect" => 10, 

			                                         "useragent" => "LibWebta AWS Client (http://webta.net)"

			                                    )

			                              );

						

			$timestamp = $this->GetTimestamp();

			$URL = "queue.amazonaws.com";

			

			$args['Version'] = self::API_VERSION;

			$args['SignatureVersion'] = 2;

			$args['SignatureMethod'] = "HmacSHA1";

			$args['Expires'] = $timestamp;

			$args['AWSAccessKeyId'] = $this->AWSAccessKeyId;



			ksort($args);

			

			foreach ($args as $k=>$v)

				$CanonicalizedQueryString .= "&{$k}=".urlencode($v);

			$CanonicalizedQueryString = trim($CanonicalizedQueryString, "&");

			

			

			$args['Signature'] = $this->GetRESTSignature(array($method, $URL, $uri, $CanonicalizedQueryString));

			

			$HttpRequest->setUrl("https://{$URL}{$uri}");

			

		    $HttpRequest->setMethod(constant("HTTP_METH_{$method}"));

		    

		    if ($args)

		    	$HttpRequest->addQueryData($args);



			try 

            {

                $HttpRequest->send();

                //$info = $HttpRequest->getResponseInfo();

                $data = $HttpRequest->getResponseData();

                

                $this->LastResponseHeaders = $data['headers'];

                

                $response = simplexml_load_string($data['body']);               

                if ($response->Error)

                	throw new Exception($response->Error->Message);

                else

                	return $response;

            }

            catch (Exception $e)

            {

            	if ($e->innerException)

            		$message = $e->innerException->getMessage();

            	else

            		$message = $e->getMessage();  

            	

            	throw new Exception($message);

            }

		}

		

		/**

		 * The SendMessage action delivers a message to the specified queue. The maximum allowed message size is 8 KB.

		 * @param $queue_name

		 * @param $message

		 * @return string $messageID

		 */

		public function SendMessage($queue_name, $message)

		{

			$response = $this->Request("GET", "/{$queue_name}", array("Action" => "SendMessage", "MessageBody" => base64_encode($message)));

			return $response->SendMessageResult->MessageId;

		}

		

		/**

		 * The DeleteMessage action deletes the specified message from the specified queue.

		 * @param $receipt_handle

		 * @return bool

		 */

		public function DeleteMessage($receipt_handle)

		{

			$response = $this->Request("GET", "/{$queue_name}", array("Action" => "DeleteMessage", "ReceiptHandle" => $receipt_handle));

			return true;

		}

		

		/**

		 * The CreateQueue action creates a new queue.

		 * @param $queue_name

		 * @param $visibility_timeout

		 * @return string $QueueUrl

		 */

		public function CreateQueue($queue_name, $visibility_timeout = 30)

		{

			$response = $this->Request("GET", "", array("Action" => "CreateQueue", "QueueName" => $queue_name, "DefaultVisibilityTimeout" => $visibility_timeout));

			return $response->CreateQueueResult->QueueUrl;

		}

		

		/**

		 * The ReceiveMessage action retrieves one or more messages from the specified queue. 

		 * @param $queue_name

		 * @param $max_number_of_messages

		 * @param $visibility_timeout

		 * @return array

		 */

		public function ReceiveMessage($queue_name, $max_number_of_messages = 1, $visibility_timeout = 30)

		{

			$response = $this->Request("GET", "/$queue_name", array("Action" => "ReceiveMessage", "MaxNumberOfMessages" => $max_number_of_messages, "DefaultVisibilityTimeout" => $visibility_timeout));

			

			if (!is_array($response->ReceiveMessageResult->Message))

				$retval = array($response->ReceiveMessageResult->Message);

			else

				$retval = $response->ReceiveMessageResult->Message;

				

			foreach ($retval as &$r)

			{

				$r = (array)$r;

				$r['Body'] = base64_decode($r['Body']);

			}

				

			return $retval;

		}

	}

?>