Fix various compatibility issues with PHP 8

libs/swiftmailer/classes/Swift/Transport/LoadBalancedTransport.php

@@ -0,0 +1,183 @@
+<?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;
+        }
+    }
+}