- <?php
- /*
-  * This file is part of the Symfony package.
-  *
-  * (c) Fabien Potencier <fabien@symfony.com>
-  *
-  * For the full copyright and license information, please view the LICENSE
-  * file that was distributed with this source code.
-  */
- namespace Symfony\Component\Messenger;
- use Symfony\Component\Messenger\Middleware\MiddlewareInterface;
- use Symfony\Component\Messenger\Middleware\StackMiddleware;
- /**
-  * @author Samuel Roze <samuel.roze@gmail.com>
-  * @author Matthias Noback <matthiasnoback@gmail.com>
-  * @author Nicolas Grekas <p@tchwork.com>
-  */
- class MessageBus implements MessageBusInterface
- {
-     private $middlewareAggregate;
-     /**
-      * @param iterable<mixed, MiddlewareInterface> $middlewareHandlers
-      */
-     public function __construct(iterable $middlewareHandlers = [])
-     {
-         if ($middlewareHandlers instanceof \IteratorAggregate) {
-             $this->middlewareAggregate = $middlewareHandlers;
-         } elseif (\is_array($middlewareHandlers)) {
-             $this->middlewareAggregate = new \ArrayObject($middlewareHandlers);
-         } else {
-             // $this->middlewareAggregate should be an instance of IteratorAggregate.
-             // When $middlewareHandlers is an Iterator, we wrap it to ensure it is lazy-loaded and can be rewound.
-             $this->middlewareAggregate = new class($middlewareHandlers) implements \IteratorAggregate {
-                 private $middlewareHandlers;
-                 private $cachedIterator;
-                 public function __construct(\Traversable $middlewareHandlers)
-                 {
-                     $this->middlewareHandlers = $middlewareHandlers;
-                 }
-                 public function getIterator(): \Traversable
-                 {
-                     if (null === $this->cachedIterator) {
-                         $this->cachedIterator = new \ArrayObject(iterator_to_array($this->middlewareHandlers, false));
-                     }
-                     return $this->cachedIterator;
-                 }
-             };
-         }
-     }
-     /**
-      * {@inheritdoc}
-      */
-     public function dispatch(object $message, array $stamps = []): Envelope
-     {
-         $envelope = Envelope::wrap($message, $stamps);
-         $middlewareIterator = $this->middlewareAggregate->getIterator();
-         while ($middlewareIterator instanceof \IteratorAggregate) {
-             $middlewareIterator = $middlewareIterator->getIterator();
-         }
-         $middlewareIterator->rewind();
-         if (!$middlewareIterator->valid()) {
-             return $envelope;
-         }
-         $stack = new StackMiddleware($middlewareIterator);
-         return $middlewareIterator->current()->handle($envelope, $stack);
-     }
- }
-