Fix performance issue because of memory constraint

Author: abluchet

src/EventListener/SerializeListener.php

@@ -60,7 +60,9 @@ public function onKernelView(GetResponseForControllerResultEvent $event)
 
         $context = $this->serializerContextBuilder->createFromRequest($request, true, $attributes);
         $resources = [];
-        $context['resources'] = &$resources;
+        $context['resources'] = function ($iri) use (&$resources) {
+            $resources[$iri] = $iri;
+        };
 
         $event->setControllerResult($this->serializer->serialize($controllerResult, $request->getRequestFormat(), $context));
 

src/Serializer/AbstractItemNormalizer.php

@@ -88,7 +88,7 @@ public function normalize($object, $format = null, array $context = [])
 
         if (isset($context['resources'])) {
             $resource = $context['iri'] ?? $this->iriConverter->getIriFromItem($object);
-            $context['resources'][$resource] = $resource;
+            $context['resources']($resource);
         }
 
         return parent::normalize($object, $format, $context);
@@ -439,7 +439,7 @@ private function normalizeRelation(PropertyMetadata $propertyMetadata, $relatedO
 
         $iri = $this->iriConverter->getIriFromItem($relatedObject);
         if (isset($context['resources'])) {
-            $context['resources'][$iri] = $iri;
+            $context['resources']($iri);
         }
 
         return $iri;

tests/EventListener/SerializeListenerTest.php

@@ -102,9 +102,13 @@ public function testDoNotSerializeWhenOperationNotSet()
 
     public function testSerializeCollectionOperation()
     {
-        $expectedContext = ['request_uri' => '', 'resource_class' => 'Foo', 'collection_operation_name' => 'get', 'resources' => []];
+        $expectedContext = ['request_uri' => '', 'resource_class' => 'Foo', 'collection_operation_name' => 'get'];
         $serializerProphecy = $this->prophesize(SerializerInterface::class);
-        $serializerProphecy->serialize(Argument::any(), 'xml', $expectedContext)->willReturn('bar')->shouldBeCalled();
+        $serializerProphecy->serialize(Argument::any(), 'xml', Argument::that(function ($context) use ($expectedContext) {
+            unset($context['resources']);
+
+            return $expectedContext === $context;
+        }))->willReturn('bar')->shouldBeCalled();
 
         $request = new Request([], [], ['_api_resource_class' => 'Foo', '_api_collection_operation_name' => 'get']);
         $request->setRequestFormat('xml');
@@ -123,9 +127,13 @@ public function testSerializeCollectionOperation()
 
     public function testSerializeItemOperation()
     {
-        $expectedContext = ['request_uri' => '', 'resource_class' => 'Foo', 'item_operation_name' => 'get', 'resources' => []];
+        $expectedContext = ['request_uri' => '', 'resource_class' => 'Foo', 'item_operation_name' => 'get'];
         $serializerProphecy = $this->prophesize(SerializerInterface::class);
-        $serializerProphecy->serialize(Argument::any(), 'xml', $expectedContext)->willReturn('bar')->shouldBeCalled();
+        $serializerProphecy->serialize(Argument::any(), 'xml', Argument::that(function ($context) use ($expectedContext) {
+            unset($context['resources']);
+
+            return $expectedContext === $context;
+        }))->willReturn('bar')->shouldBeCalled();
 
         $request = new Request([], [], ['_api_resource_class' => 'Foo', '_api_item_operation_name' => 'get']);
         $request->setRequestFormat('xml');

tests/Serializer/AbstractItemNormalizerTest.php

@@ -145,7 +145,7 @@ public function testNormalize()
             'name' => 'foo',
             'relatedDummy' => '/dummies/2',
             'relatedDummies' => ['/dummies/2'],
-        ], $normalizer->normalize($dummy, null, ['resources' => []]));
+        ], $normalizer->normalize($dummy, null, ['resources' => function () {}]));
     }
 
     public function testNormalizeReadableLinks()
@@ -211,7 +211,7 @@ public function testNormalizeReadableLinks()
         $this->assertEquals([
             'relatedDummy' => ['foo' => 'hello'],
             'relatedDummies' => [['foo' => 'hello']],
-        ], $normalizer->normalize($dummy, null, ['resources' => []]));
+        ], $normalizer->normalize($dummy, null, ['resources' => function () {}]));
     }
 
     public function testDenormalize()
@@ -642,6 +642,6 @@ public function testChildInheritedProperty()
         $this->assertEquals([
             'name' => 'foo',
             'nickname' => null,
-        ], $normalizer->normalize($dummy, null, ['resource_class' => DummyTableInheritance::class, 'resources' => []]));
+        ], $normalizer->normalize($dummy, null, ['resource_class' => DummyTableInheritance::class, 'resources' => function () {}]));
     }
 }

tests/Serializer/ItemNormalizerTest.php

@@ -95,7 +95,7 @@ public function testNormalize()
         );
         $normalizer->setSerializer($serializerProphecy->reveal());
 
-        $this->assertEquals(['name' => 'hello'], $normalizer->normalize($dummy, null, ['resources' => []]));
+        $this->assertEquals(['name' => 'hello'], $normalizer->normalize($dummy, null, ['resources' => function () {}]));
     }
 
     public function testDenormalize()