B2B-2677: [MediaGallery]Implement data caching for GraphQL results on resolver level

- Ensure orphaned cache ids are removed from cache tag files

Author: danmooney2

app/code/Magento/CatalogGraphQl/Model/Resolver/Cache/Product/MediaGallery/TagsStrategy.php

@@ -0,0 +1,45 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\CatalogGraphQl\Model\Resolver\Cache\Product\MediaGallery;
+
+use Magento\Catalog\Model\Product;
+use Magento\CatalogGraphQl\Model\Resolver\Product\MediaGallery\ChangeDetector;
+use Magento\Framework\App\Cache\Tag\StrategyInterface;
+
+class TagsStrategy implements StrategyInterface
+{
+    /**
+     * @var ChangeDetector
+     */
+    private $mediaGalleryChangeDetector;
+
+    /**
+     * @param ChangeDetector $mediaGalleryChangeDetector
+     */
+    public function __construct(ChangeDetector $mediaGalleryChangeDetector)
+    {
+        $this->mediaGalleryChangeDetector = $mediaGalleryChangeDetector;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getTags($object)
+    {
+        if ($object instanceof Product &&
+            !$object->isObjectNew() &&
+            $this->mediaGalleryChangeDetector->isChanged($object)
+        ) {
+            return [
+                sprintf('%s_%s', ResolverCacheIdentity::CACHE_TAG, $object->getSku())
+            ];
+        }
+
+        return [];
+    }
+}

app/code/Magento/CatalogGraphQl/Plugin/Product/UpdateIdentities.php renamed to app/code/Magento/CatalogGraphQl/Model/Resolver/Product/MediaGallery/ChangeDetector.php

@@ -5,17 +5,12 @@
  */
 declare(strict_types=1);
 
-namespace Magento\CatalogGraphQl\Plugin\Product;
+namespace Magento\CatalogGraphQl\Model\Resolver\Product\MediaGallery;
 
 use Magento\Catalog\Model\Product;
-use Magento\CatalogGraphQl\Model\Resolver\Cache\Product\MediaGallery\ResolverCacheIdentity;
 use Magento\Framework\Serialize\SerializerInterface;
 
-/**
- * This is a plugin to \Magento\Catalog\Model\Product.
- * It is used to add media gallery identities to product identities for invalidation purposes.
- */
-class UpdateIdentities
+class ChangeDetector
 {
     /**
      * @var SerializerInterface
@@ -31,29 +26,18 @@ public function __construct(
         $this->serializer = $serializer;
     }
 
-    /**
-     * Flag product media gallery as changed after adding or updating image, or on product removal
-     *
-     * @param Product $subject
-     * @param array $result
-     * @return array
-     */
-    public function afterGetIdentities(Product $subject, array $result): array
-    {
-        if (!$subject->isObjectNew() && ($subject->isDeleted() || $this->isMediaGalleryChanged($subject))) {
-            $result[] = sprintf('%s_%s', ResolverCacheIdentity::CACHE_TAG, $subject->getSku());
-        }
-        return $result;
-    }
-
     /**
      * Check if the media gallery of the given product is changed
      *
      * @param Product $product
      * @return bool
      */
-    private function isMediaGalleryChanged(Product $product): bool
+    public function isChanged(Product $product): bool
     {
+        if ($product->isDeleted()) {
+            return true;
+        }
+
         if (!$product->hasDataChanges()) {
             return false;
         }

app/code/Magento/CatalogGraphQl/etc/di.xml

@@ -125,7 +125,13 @@
             </argument>
         </arguments>
     </type>
-    <type name="Magento\Catalog\Model\Product">
-        <plugin name="add_media_gallery_identities" type="Magento\CatalogGraphQl\Plugin\Product\UpdateIdentities"/>
+    <type name="Magento\GraphQlResolverCache\App\Cache\Tag\Strategy\Locator">
+        <arguments>
+            <argument name="customStrategies" xsi:type="array">
+                <item name="Magento\Catalog\Api\Data\ProductInterface" xsi:type="object">
+                    Magento\CatalogGraphQl\Model\Resolver\Cache\Product\MediaGallery\TagsStrategy
+                </item>
+            </argument>
+        </arguments>
     </type>
 </config>

app/code/Magento/GraphQlResolverCache/App/Cache/Tag/Strategy/Locator.php

@@ -0,0 +1,56 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\GraphQlResolverCache\App\Cache\Tag\Strategy;
+
+use Magento\Framework\App\Cache\Tag\StrategyInterface;
+
+/**
+ * Locate GraphQL resolver cache tag strategy using configuration
+ */
+class Locator
+{
+    /**
+     * Strategies map
+     *
+     * @var array
+     */
+    private $customStrategies = [];
+
+    /**
+     * @param array $customStrategies
+     */
+    public function __construct(
+        array $customStrategies = []
+    ) {
+        $this->customStrategies = $customStrategies;
+    }
+
+    /**
+     * Return GraphQL Resolver Cache tag strategy for specified object
+     *
+     * @param object $object
+     * @throws \InvalidArgumentException
+     * @return StrategyInterface|null
+     */
+    public function getStrategy($object): ?StrategyInterface
+    {
+        if (!is_object($object)) {
+            throw new \InvalidArgumentException('Provided argument is not an object');
+        }
+
+        $classHierarchy = array_merge(
+            [get_class($object) => get_class($object)],
+            class_parents($object),
+            class_implements($object)
+        );
+
+        $result = array_intersect(array_keys($this->customStrategies), $classHierarchy);
+
+        return $this->customStrategies[array_shift($result)] ?? null;
+    }
+}

app/code/Magento/GraphQlResolverCache/Model/Resolver/Result/TagResolver.php

@@ -8,10 +8,16 @@
 namespace Magento\GraphQlResolverCache\Model\Resolver\Result;
 
 use Magento\Framework\App\Cache\Tag\Resolver;
-use Magento\Framework\App\Cache\Tag\Strategy\Factory as StrategyFactory;
+use Magento\Framework\App\Cache\Tag\Strategy\Factory as OtherCachesStrategyFactory;
+use Magento\GraphQlResolverCache\App\Cache\Tag\Strategy\Locator as ResolverCacheStrategyLocator;
 
 class TagResolver extends Resolver
 {
+    /**
+     * @var ResolverCacheStrategyLocator
+     */
+    private $resolverCacheTagStrategyLocator;
+
     /**
      * @var array
      */
@@ -20,16 +26,19 @@ class TagResolver extends Resolver
     /**
      * GraphQL Resolver cache-specific tag resolver for the purpose of invalidation
      *
-     * @param StrategyFactory $factory
+     * @param ResolverCacheStrategyLocator $resolverCacheStrategyLocator
+     * @param OtherCachesStrategyFactory $otherCachesStrategyFactory
      * @param array $invalidatableObjectTypes
      */
     public function __construct(
-        StrategyFactory $factory,
+        ResolverCacheStrategyLocator $resolverCacheStrategyLocator,
+        OtherCachesStrategyFactory $otherCachesStrategyFactory,
         array $invalidatableObjectTypes = []
     ) {
+        $this->resolverCacheTagStrategyLocator = $resolverCacheStrategyLocator;
         $this->invalidatableObjectTypes = $invalidatableObjectTypes;
 
-        parent::__construct($factory);
+        parent::__construct($otherCachesStrategyFactory);
     }
 
     /**
@@ -51,6 +60,12 @@ public function getTags($object)
             return [];
         }
 
+        $resolverCacheTagStrategy = $this->resolverCacheTagStrategyLocator->getStrategy($object);
+
+        if ($resolverCacheTagStrategy) {
+            return $resolverCacheTagStrategy->getTags($object);
+        }
+
         return parent::getTags($object);
     }
 }