symfony · makasim · Jul 24, 2017
diff --git a/src/Symfony/Component/EventDispatcher/Async/AsyncEventDispatcher.php b/src/Symfony/Component/EventDispatcher/Async/AsyncEventDispatcher.php
@@ -0,0 +1,57 @@
+<?php
+
+namespace Symfony\Component\EventDispatcher\Async;
+
+use Symfony\Component\EventDispatcher\Event;
+use Symfony\Component\EventDispatcher\EventDispatcher;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+
+class AsyncEventDispatcher extends EventDispatcher
+{
+    /**
+     * @var EventDispatcherInterface
+     */
+    private $trueEventDispatcher;
+
+    /**
+     * @var AsyncListener
+     */
+    private $asyncListener;
+
+    /**
+     * @param EventDispatcherInterface $trueEventDispatcher
+     * @param AsyncListener            $asyncListener
+     */
+    public function __construct(EventDispatcherInterface $trueEventDispatcher, AsyncListener $asyncListener)
+    {
+        $this->trueEventDispatcher = $trueEventDispatcher;
+        $this->asyncListener = $asyncListener;
+    }
+
+    /**
+     * This method dispatches only those listeners that were marked as async.
+     *
+     * @param string     $eventName
+     * @param Event|null $event
+     */
+    public function dispatchAsyncListenersOnly($eventName, Event $event = null)
+    {
+        try {
+            $this->asyncListener->syncMode($eventName);
+
+            parent::dispatch($eventName, $event);
+        } finally {
+            $this->asyncListener->resetSyncMode();
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function dispatch($eventName, Event $event = null)
+    {
+        parent::dispatch($eventName, $event);
+
+        $this->trueEventDispatcher->dispatch($eventName, $event);
+    }
+}
diff --git a/src/Symfony/Component/EventDispatcher/Async/AsyncListener.php b/src/Symfony/Component/EventDispatcher/Async/AsyncListener.php
@@ -0,0 +1,87 @@
+<?php
+
+namespace Symfony\Component\EventDispatcher\Async;
+
+use Interop\Queue\PsrContext;
+use Interop\Queue\PsrQueue;
+use Symfony\Component\EventDispatcher\Event;
+
+class AsyncListener
+{
+    /**
+     * @var PsrContext
+     */
+    private $context;
+
+    /**
+     * @var Registry
+     */
+    private $registry;
+
+    /**
+     * @var PsrQueue
+     */
+    private $eventQueue;
+
+    /**
+     * @var bool
+     */
+    private $syncMode;
+
+    /**
+     * @param PsrContext      $context
+     * @param Registry        $registry
+     * @param PsrQueue|string $eventQueue
+     */
+    public function __construct(PsrContext $context, Registry $registry, $eventQueue)
+    {
+        $this->context = $context;
+        $this->registry = $registry;
+        $this->eventQueue = $eventQueue instanceof PsrQueue ? $eventQueue : $context->createQueue($eventQueue);
+    }
+
+    public function __invoke(Event $event, $eventName)
+    {
+        $this->onEvent($event, $eventName);
+    }
+
+    public function resetSyncMode()
+    {
+        $this->syncMode = [];
+    }
+
+    /**
+     * @param string $eventName
+     */
+    public function syncMode($eventName)
+    {
+        $this->syncMode[$eventName] = true;
+    }
+
+    /**
+     * @param string $eventName
+     *
+     * @return bool
+     */
+    public function isSyncMode($eventName)
+    {
+        return isset($this->syncMode[$eventName]);
+    }
+
+    /**
+     * @param Event  $event
+     * @param string $eventName
+     */
+    public function onEvent(Event $event, $eventName)
+    {
+        if (false == isset($this->syncMode[$eventName])) {
+            $transformerName = $this->registry->getTransformerNameForEvent($eventName);
+
+            $message = $this->registry->getTransformer($transformerName)->toMessage($eventName, $event);
+            $message->setProperty('event_name', $eventName);
+            $message->setProperty('transformer_name', $transformerName);
+
+            $this->context->createProducer()->send($this->eventQueue, $message);
+        }
+    }
+}
diff --git a/src/Symfony/Component/EventDispatcher/Async/AsyncProcessor.php b/src/Symfony/Component/EventDispatcher/Async/AsyncProcessor.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace Symfony\Component\EventDispatcher\Async;
+
+use Interop\Queue\PsrContext;
+use Interop\Queue\PsrMessage;
+use Interop\Queue\PsrProcessor;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+
+class AsyncProcessor implements PsrProcessor
+{
+    /**
+     * @var Registry
+     */
+    private $registry;
+
+    /**
+     * @var AsyncEventDispatcher
+     */
+    private $dispatcher;
+
+    /**
+     * @param Registry             $registry
+     * @param AsyncEventDispatcher $dispatcher
+     */
+    public function __construct(Registry $registry, AsyncEventDispatcher $dispatcher)
+    {
+        $this->registry = $registry;
+        $this->dispatcher = $dispatcher;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function process(PsrMessage $message, PsrContext $context)
+    {
+        if (false == $eventName = $message->getProperty('event_name')) {
+            return self::REJECT;
+        }
+        if (false == $transformerName = $message->getProperty('transformer_name')) {
+            return self::REJECT;
+        }
+
+        $event = $this->registry->getTransformer($transformerName)->toEvent($eventName, $message);
+
+        $this->dispatcher->dispatchAsyncListenersOnly($eventName, $event);
+
+        return self::ACK;
+    }
+}
diff --git a/src/Symfony/Component/EventDispatcher/Async/ContainerAwareRegistry.php b/src/Symfony/Component/EventDispatcher/Async/ContainerAwareRegistry.php
@@ -0,0 +1,82 @@
+<?php
+
+namespace Symfony\Component\EventDispatcher\Async;
+
+use Symfony\Component\DependencyInjection\ContainerAwareInterface;
+use Symfony\Component\DependencyInjection\ContainerAwareTrait;
+
+class ContainerAwareRegistry implements Registry, ContainerAwareInterface
+{
+    use ContainerAwareTrait;
+
+    /**
+     * @var string[]
+     */
+    private $eventsMap;
+
+    /**
+     * @var string[]
+     */
+    private $transformersMap;
+
+    /**
+     * @param string[] $eventsMap       [eventName => transformerName]
+     * @param string[] $transformersMap [transformerName => transformerServiceId]
+     */
+    public function __construct(array $eventsMap, array $transformersMap)
+    {
+        $this->eventsMap = $eventsMap;
+        $this->transformersMap = $transformersMap;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getTransformerNameForEvent($eventName)
+    {
+        $transformerName = null;
+        if (array_key_exists($eventName, $this->eventsMap)) {
+            $transformerName = $this->eventsMap[$eventName];
+        } else {
+            foreach ($this->eventsMap as $eventNamePattern => $name) {
+                if ('/' != $eventNamePattern[0]) {
+                    continue;
+                }
+
+                if (preg_match($eventNamePattern, $eventName)) {
+                    $transformerName = $name;
+
+                    break;
+                }
+            }
+        }
+
+        if (empty($transformerName)) {
+            throw new \LogicException(sprintf('There is no transformer registered for the given event %s', $eventName));
+        }
+
+        return $transformerName;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getTransformer($name)
+    {
+        if (false == array_key_exists($name, $this->transformersMap)) {
+            throw new \LogicException(sprintf('There is no transformer named %s', $name));
+        }
+
+        $transformer = $this->container->get($this->transformersMap[$name]);
+
+        if (false == $transformer instanceof  EventTransformer) {
+            throw new \LogicException(sprintf(
+                'The container must return instance of %s but got %s',
+                EventTransformer::class,
+                is_object($transformer) ? get_class($transformer) : gettype($transformer)
+            ));
+        }
+
+        return $transformer;
+    }
+}
diff --git a/src/Symfony/Component/EventDispatcher/Async/EventTransformer.php b/src/Symfony/Component/EventDispatcher/Async/EventTransformer.php
@@ -0,0 +1,29 @@
+<?php
+
+namespace Symfony\Component\EventDispatcher\Async;
+
+use Interop\Queue\PsrMessage;
+use Symfony\Component\EventDispatcher\Event;
+
+interface EventTransformer
+{
+    /**
+     * @param string     $eventName
+     * @param Event|null $event
+     *
+     * @return PsrMessage
+     */
+    public function toMessage($eventName, Event $event);
+
+    /**
+     * If you able to transform message back to event return it.
+     * If you failed to transform for some reason you can return a string status (@see PsrProcess constants) or an object that implements __toString method.
+     * The object must have a __toString method is supposed to be used as PsrProcessor::process return value.
+     *
+     * @param string     $eventName
+     * @param PsrMessage $message
+     *
+     * @return Event|string|object
+     */
+    public function toEvent($eventName, PsrMessage $message);
+}
diff --git a/src/Symfony/Component/EventDispatcher/Async/PhpSerializerEventTransformer.php b/src/Symfony/Component/EventDispatcher/Async/PhpSerializerEventTransformer.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace Symfony\Component\EventDispatcher\Async;
+
+use Interop\Queue\PsrContext;
+use Interop\Queue\PsrMessage;
+use Symfony\Component\EventDispatcher\Event;
+
+class PhpSerializerEventTransformer implements EventTransformer
+{
+    /**
+     * @var PsrContext
+     */
+    private $context;
+
+    /**
+     * @param PsrContext $context
+     */
+    public function __construct(PsrContext $context)
+    {
+        $this->context = $context;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toMessage($eventName, Event $event = null)
+    {
+        return $this->context->createMessage(serialize($event));
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toEvent($eventName, PsrMessage $message)
+    {
+        return unserialize($message->getBody());
+    }
+}
diff --git a/src/Symfony/Component/EventDispatcher/Async/Registry.php b/src/Symfony/Component/EventDispatcher/Async/Registry.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace Symfony\Component\EventDispatcher\Async;
+
+interface Registry
+{
+    /**
+     * @param string $eventName
+     *
+     * @return string
+     */
+    public function getTransformerNameForEvent($eventName);
+
+    /**
+     * @param string $name
+     *
+     * @return EventTransformer
+     */
+    public function getTransformer($name);
+}