feature #29006 [Messenger] make TraceableMiddleware decorate a StackInterface instead of each middleware to free the callstack from noisy frames (nicolas-grekas)

This PR was merged into the 4.2-dev branch.

Discussion
----------

[Messenger] make TraceableMiddleware decorate a StackInterface instead of each middleware to free the callstack from noisy frames

| Q             | A
| ------------- | ---
| Branch?       | 4.2
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | yes
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Right now, `TraceableMiddleware` works as a middleware decorator for the "handle" method. It means that *each middleware* frame in the call stack is wrapped between two noisy extra frames.
This is something we can remove by decorating the StackInterface instead: let's just stop/start events when the next middleware is fetched.
Thanks to this, only one frame *per bus* is added to measure middleware timings.

Commits
-------

73c8c23c79 [Messenger] make TraceableMiddleware decorate a StackInterface instead of each middleware to free the callstack from noisy frames

Author: nicolas-grekas

DependencyInjection/FrameworkExtension.php

@@ -1542,11 +1542,15 @@ private function registerMessengerConfiguration(array $config, ContainerBuilder
             }
 
             foreach ($middleware as $middlewareItem) {
-                if (!$validationConfig['enabled'] && 'messenger.middleware.validation' === $middlewareItem['id']) {
+                if (!$validationConfig['enabled'] && \in_array($middlewareItem['id'], array('validation', 'messenger.middleware.validation'), true)) {
                     throw new LogicException('The Validation middleware is only available when the Validator component is installed and enabled. Try running "composer require symfony/validator".');
                 }
             }
 
+            if ($container->getParameter('kernel.debug') && class_exists(Stopwatch::class)) {
+                array_unshift($middleware, array('id' => 'traceable', 'arguments' => array($busId)));
+            }
+
             $container->setParameter($busId.'.middleware', $middleware);
             $container->register($busId, MessageBus::class)->addArgument(array())->addTag('messenger.bus');
 

Resources/config/messenger.xml

@@ -33,11 +33,14 @@
             <argument type="service" id="validator" />
         </service>
 
+        <service id="messenger.middleware.traceable" class="Symfony\Component\Messenger\Middleware\TraceableMiddleware" abstract="true">
+            <argument type="service" id="debug.stopwatch" />
+        </service>
+
         <!-- Logging -->
         <service id="messenger.middleware.logging" class="Symfony\Component\Messenger\Middleware\LoggingMiddleware" abstract="true">
-            <argument type="service" id="logger" />
-
             <tag name="monolog.logger" channel="messenger" />
+            <argument type="service" id="logger" />
         </service>
 
         <!-- Discovery -->
@@ -56,10 +59,9 @@
         </service>
 
         <service id="messenger.transport.amqp.factory" class="Symfony\Component\Messenger\Transport\AmqpExt\AmqpTransportFactory">
+            <tag name="messenger.transport_factory" />
             <argument type="service" id="messenger.transport.serializer" />
             <argument>%kernel.debug%</argument>
-
-            <tag name="messenger.transport_factory" />
         </service>
     </services>
 </container>