[DI] Add "container.hot_path" tag to flag the hot path and inline related services

Author: nicolas-grekas

DependencyInjection/Compiler/UnusedTagsPass.php

@@ -24,6 +24,7 @@ class UnusedTagsPass implements CompilerPassInterface
     private $whitelist = array(
         'cache.pool.clearer',
         'console.command',
+        'container.hot_path',
         'container.service_locator',
         'container.service_subscriber',
         'controller.service_arguments',

FrameworkBundle.php

@@ -43,6 +43,7 @@
 use Symfony\Component\Form\DependencyInjection\FormPass;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\Bundle\Bundle;
+use Symfony\Component\HttpKernel\KernelEvents;
 use Symfony\Component\Config\Resource\ClassExistenceResource;
 use Symfony\Component\Translation\DependencyInjection\TranslationDumperPass;
 use Symfony\Component\Translation\DependencyInjection\TranslationExtractorPass;
@@ -83,14 +84,22 @@ public function build(ContainerBuilder $container)
     {
         parent::build($container);
 
+        $hotPathEvents = array(
+            KernelEvents::REQUEST,
+            KernelEvents::CONTROLLER,
+            KernelEvents::CONTROLLER_ARGUMENTS,
+            KernelEvents::RESPONSE,
+            KernelEvents::FINISH_REQUEST,
+        );
+
         $container->addCompilerPass(new LoggerPass(), PassConfig::TYPE_BEFORE_OPTIMIZATION, -32);
         $container->addCompilerPass(new RegisterControllerArgumentLocatorsPass());
         $container->addCompilerPass(new RemoveEmptyControllerArgumentLocatorsPass(), PassConfig::TYPE_BEFORE_REMOVING);
         $container->addCompilerPass(new RoutingResolverPass());
         $container->addCompilerPass(new ProfilerPass());
         // must be registered before removing private services as some might be listeners/subscribers
         // but as late as possible to get resolved parameters
-        $container->addCompilerPass(new RegisterListenersPass(), PassConfig::TYPE_BEFORE_REMOVING);
+        $container->addCompilerPass((new RegisterListenersPass())->setHotPathEvents($hotPathEvents), PassConfig::TYPE_BEFORE_REMOVING);
         $container->addCompilerPass(new TemplatingPass());
         $this->addCompilerPassIfExists($container, AddConstraintValidatorsPass::class, PassConfig::TYPE_BEFORE_REMOVING);
         $container->addCompilerPass(new AddAnnotationsCachedReaderPass(), PassConfig::TYPE_BEFORE_REMOVING);

Resources/config/services.xml

@@ -9,6 +9,7 @@
 
         <service id="event_dispatcher" class="Symfony\Component\EventDispatcher\ContainerAwareEventDispatcher" public="true">
             <argument type="service" id="service_container" />
+            <tag name="container.hot_path" />
         </service>
         <service id="Symfony\Component\EventDispatcher\EventDispatcherInterface" alias="event_dispatcher" />
 
@@ -17,6 +18,7 @@
             <argument type="service" id="controller_resolver" />
             <argument type="service" id="request_stack" />
             <argument type="service" id="argument_resolver" />
+            <tag name="container.hot_path" />
         </service>
         <service id="Symfony\Component\HttpKernel\HttpKernelInterface" alias="http_kernel" />
 

composer.json

@@ -22,7 +22,7 @@
         "symfony/class-loader": "~3.2",
         "symfony/dependency-injection": "~3.4|~4.0",
         "symfony/config": "~3.4|~4.0",
-        "symfony/event-dispatcher": "^3.3.1|~4.0",
+        "symfony/event-dispatcher": "^3.4-beta4|~4.0-beta4",
         "symfony/http-foundation": "^3.3.11|~4.0",
         "symfony/http-kernel": "~3.4|~4.0",
         "symfony/polyfill-mbstring": "~1.0",