<?php /* * This file is part of SwiftMailer. * (c) 2004-2009 Chris Corbyn * * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */ /** * Redundantly and rotationally uses several Transports when sending. * * @author Chris Corbyn */ class Swift_Transport_LoadBalancedTransport implements Swift_Transport { /** * Transports which are deemed useless. * * @var Swift_Transport[] */ private $_deadTransports = array(); /** * The Transports which are used in rotation. * * @var Swift_Transport[] */ protected $_transports = array(); /** * The Transport used in the last successful send operation. * * @var Swift_Transport */ protected $_lastUsedTransport = null; // needed as __construct is called from elsewhere explicitly public function __construct() { } /** * Set $transports to delegate to. * * @param Swift_Transport[] $transports */ public function setTransports(array $transports) { $this->_transports = $transports; $this->_deadTransports = array(); } /** * Get $transports to delegate to. * * @return Swift_Transport[] */ public function getTransports() { return array_merge($this->_transports, $this->_deadTransports); } /** * Get the Transport used in the last successful send operation. * * @return Swift_Transport */ public function getLastUsedTransport() { return $this->_lastUsedTransport; } /** * Test if this Transport mechanism has started. * * @return bool */ public function isStarted() { return count($this->_transports) > 0; } /** * Start this Transport mechanism. */ public function start() { $this->_transports = array_merge($this->_transports, $this->_deadTransports); } /** * Stop this Transport mechanism. */ public function stop() { foreach ($this->_transports as $transport) { $transport->stop(); } } /** * Send the given Message. * * Recipient/sender data will be retrieved from the Message API. * The return value is the number of recipients who were accepted for delivery. * * @param Swift_Mime_Message $message * @param string[] $failedRecipients An array of failures by-reference * * @return int */ public function send(Swift_Mime_Message $message, &$failedRecipients = null) { $maxTransports = count($this->_transports); $sent = 0; $this->_lastUsedTransport = null; for ($i = 0; $i < $maxTransports && $transport = $this->_getNextTransport(); ++$i) { try { if (!$transport->isStarted()) { $transport->start(); } if ($sent = $transport->send($message, $failedRecipients)) { $this->_lastUsedTransport = $transport; break; } } catch (Swift_TransportException $e) { $this->_killCurrentTransport(); } } if (count($this->_transports) == 0) { throw new Swift_TransportException( 'All Transports in LoadBalancedTransport failed, or no Transports available' ); } return $sent; } /** * Register a plugin. * * @param Swift_Events_EventListener $plugin */ public function registerPlugin(Swift_Events_EventListener $plugin) { foreach ($this->_transports as $transport) { $transport->registerPlugin($plugin); } } /** * Rotates the transport list around and returns the first instance. * * @return Swift_Transport */ protected function _getNextTransport() { if ($next = array_shift($this->_transports)) { $this->_transports[] = $next; } return $next; } /** * Tag the currently used (top of stack) transport as dead/useless. */ protected function _killCurrentTransport() { if ($transport = array_pop($this->_transports)) { try { $transport->stop(); } catch (Exception $e) { } $this->_deadTransports[] = $transport; } } }