feature #42335 [Messenger] Add WorkerMetadata to Worker class. (okwinza)

lyrixx · lyrixx · commit 99ebc6930919 · 2021-09-22T16:55:57.000+02:00
This PR was merged into the 5.4 branch. Discussion ---------- [Messenger] Add `WorkerMetadata` to `Worker` class. | Q | A | ------------- | --- | Branch? | 5.4 | Bug fix? | no | New feature? | yes | Deprecations? | no | Tickets | Fixes #37736 | License | MIT | Doc PR | - At the moment, there is no clean way to access the values of `transportNames` or recently introduced `queueNames` that the worker was configured with, although such data might be quite useful for logging/monitoring or other tasks. This PR attempts to fix that by adding a new and extensible way to provide additional information about a particular `Worker` object. So far, the following PRs could benefit from this change: - #43133 - #42723 **Use case example:** ---- - As I developer - When a message was consumed from transport with name `async`. - And the worker state is `idle`. - Then I want to reset services. **Before this PR**, the only solution not relying on using Reflection API would look like this: ```php private $servicesResetter; private $receiversName; private $actualReceiverName = null; public function __construct(ServicesResetter $servicesResetter, array $receiversName) { $this->servicesResetter = $servicesResetter; $this->receiversName = $receiversName; } public function saveReceiverName(AbstractWorkerMessageEvent $event): void { $this->actualReceiverName = $event->getReceiverName(); } public function resetServices(WorkerRunningEvent $event): void { if (!$event->isWorkerIdle() && \in_array($this->actualReceiverName, $this->receiversName, true)) { $this->servicesResetter->reset(); } $this->actualReceiverName = null; } public static function getSubscribedEvents(): array { return [ WorkerMessageHandledEvent::class => ['saveReceiverName'], WorkerMessageFailedEvent::class => ['saveReceiverName'], WorkerRunningEvent::class => ['resetServices'], ]; } ``` **With this PR**, one could simply use this to retrieve the transport name. ```php $event->getWorker()->getWorkerMetadata()->getTransportName() === $this->transportName; ``` So the whole solution would look like this: ```php private $servicesResetter; private $receiversName; public function __construct(ServicesResetter $servicesResetter, array $receiversName) { $this->servicesResetter = $servicesResetter; $this->receiversName = $receiversName; } public function resetServices(WorkerRunningEvent $event): void { $actualTransportName = $event->getWorker()->getWorkerMetadata()->getTransportName(); if (!$event->isWorkerIdle() || !in_array($actualTransportName, $this->receiversName, true)) { return; } $this->servicesResetter->reset(); } public static function getSubscribedEvents(): array { return [ WorkerRunningEvent::class => ['resetServices'], ]; } ``` Commits ------- 583f85b [Messenger] Add WorkerMetadata to Worker class
diff --git a/src/Symfony/Component/Messenger/CHANGELOG.md b/src/Symfony/Component/Messenger/CHANGELOG.md
@@ -6,6 +6,8 @@ CHANGELOG
 
  * Add `StopWorkerExceptionInterface` and its implementation `StopWorkerException` to stop the worker.
  * Add support for resetting container services after each messenger message.
+ * Added `WorkerMetadata` class which allows you to access the configuration details of a worker, like `queueNames` and `transportNames` it consumes from.
+ * New method `getMetadata()` was added to `Worker` class which returns the `WorkerMetadata` object.
 
 5.3
 ---
diff --git a/src/Symfony/Component/Messenger/Tests/WorkerMetadataTest.php b/src/Symfony/Component/Messenger/Tests/WorkerMetadataTest.php
@@ -0,0 +1,57 @@
+<?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\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Messenger\WorkerMetadata;
+
+/**
+ * @author Oleg Krasavin <okwinza@gmail.com>
+ */
+class WorkerMetadataTest extends TestCase
+{
+    public function testItReturnsDefaultValuesIfNoneProvided()
+    {
+        $metadata = new WorkerMetadata([]);
+
+        $this->assertNull($metadata->getQueueNames());
+        $this->assertSame([], $metadata->getTransportNames());
+    }
+
+    public function testItReturnsProvidedMetadata()
+    {
+        $data = [
+            'queueNames' => ['c', 'b', 'a'],
+            'transportNames' => ['a', 'b', 'c'],
+        ];
+
+        $metadata = new WorkerMetadata($data);
+
+        $this->assertSame($data['queueNames'], $metadata->getQueueNames());
+        $this->assertSame($data['transportNames'], $metadata->getTransportNames());
+    }
+
+    public function testItSetsMetadataViaSetter()
+    {
+        $data = [
+            'queueNames' => ['c', 'b', 'a'],
+            'transportNames' => ['a', 'b', 'c'],
+        ];
+
+        $metadata = new WorkerMetadata([]);
+
+        $metadata->set($data);
+
+        $this->assertSame($data['queueNames'], $metadata->getQueueNames());
+        $this->assertSame($data['transportNames'], $metadata->getTransportNames());
+    }
+}
diff --git a/src/Symfony/Component/Messenger/Tests/WorkerTest.php b/src/Symfony/Component/Messenger/Tests/WorkerTest.php
@@ -167,6 +167,28 @@ public function testWorkerDispatchesEventsOnError()
         $worker->run();
     }
 
+    public function testWorkerContainsMetadata()
+    {
+        $envelope = new Envelope(new DummyMessage('Hello'));
+        $receiver = new DummyQueueReceiver([[$envelope]]);
+
+        $bus = $this->createMock(MessageBusInterface::class);
+        $bus->method('dispatch')->willReturn($envelope);
+
+        $dispatcher = new EventDispatcher();
+        $dispatcher->addListener(WorkerRunningEvent::class, function (WorkerRunningEvent $event) {
+            $event->getWorker()->stop();
+        });
+
+        $worker = new Worker(['dummyReceiver' => $receiver], $bus, $dispatcher);
+        $worker->run(['queues' => ['queue1', 'queue2']]);
+
+        $workerMetadata = $worker->getMetadata();
+
+        $this->assertSame(['queue1', 'queue2'], $workerMetadata->getQueueNames());
+        $this->assertSame(['dummyReceiver'], $workerMetadata->getTransportNames());
+    }
+
     public function testTimeoutIsConfigurable()
     {
         $apiMessage = new DummyMessage('API');
@@ -359,3 +381,11 @@ public function getAcknowledgedEnvelopes(): array
         return $this->acknowledgedEnvelopes;
     }
 }
+
+class DummyQueueReceiver extends DummyReceiver implements QueueReceiverInterface
+{
+    public function getFromQueues(array $queueNames): iterable
+    {
+        return $this->get();
+    }
+}
diff --git a/src/Symfony/Component/Messenger/Worker.php b/src/Symfony/Component/Messenger/Worker.php
@@ -42,6 +42,7 @@ class Worker
     private $eventDispatcher;
     private $logger;
     private $shouldStop = false;
+    private $metadata;
 
     /**
      * @param ReceiverInterface[] $receivers Where the key is the transport name
@@ -52,6 +53,9 @@ public function __construct(array $receivers, MessageBusInterface $bus, EventDis
         $this->bus = $bus;
         $this->logger = $logger;
         $this->eventDispatcher = class_exists(Event::class) ? LegacyEventDispatcherProxy::decorate($eventDispatcher) : $eventDispatcher;
+        $this->metadata = new WorkerMetadata([
+            'transportNames' => array_keys($receivers),
+        ]);
     }
 
     /**
@@ -63,12 +67,14 @@ public function __construct(array $receivers, MessageBusInterface $bus, EventDis
      */
     public function run(array $options = []): void
     {
-        $this->dispatchEvent(new WorkerStartedEvent($this));
-
         $options = array_merge([
             'sleep' => 1000000,
         ], $options);
-        $queueNames = $options['queues'] ?? false;
+        $queueNames = $options['queues'] ?? null;
+
+        $this->metadata->set(['queueNames' => $queueNames]);
+
+        $this->dispatchEvent(new WorkerStartedEvent($this));
 
         if ($queueNames) {
             // if queue names are specified, all receivers must implement the QueueReceiverInterface
@@ -173,6 +179,11 @@ public function stop(): void
         $this->shouldStop = true;
     }
 
+    public function getMetadata(): WorkerMetadata
+    {
+        return $this->metadata;
+    }
+
     private function dispatchEvent(object $event): void
     {
         if (null === $this->eventDispatcher) {
diff --git a/src/Symfony/Component/Messenger/WorkerMetadata.php b/src/Symfony/Component/Messenger/WorkerMetadata.php
@@ -0,0 +1,47 @@
+<?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;
+
+/**
+ * @author Oleg Krasavin <okwinza@gmail.com>
+ */
+final class WorkerMetadata
+{
+    private $metadata;
+
+    public function __construct(array $metadata)
+    {
+        $this->metadata = $metadata;
+    }
+
+    public function set(array $newMetadata): void
+    {
+        $this->metadata = array_merge($this->metadata, $newMetadata);
+    }
+
+    /**
+     * Returns the queue names the worker consumes from, if "--queues" option was used.
+     * Returns null otherwise.
+     */
+    public function getQueueNames(): ?array
+    {
+        return $this->metadata['queueNames'] ?? null;
+    }
+
+    /**
+     * Returns an array of unique identifiers for transport receivers the worker consumes from.
+     */
+    public function getTransportNames(): array
+    {
+        return $this->metadata['transportNames'] ?? [];
+    }
+}
