Merge pull request #28 from CandoImage/feat/optimize-cache-handling-to-reduce-impact-on-response-times

feat: Optimize cache handling to reduce impact on response times

Author: das-peter

src/EventListener/CacheListener.php

@@ -23,6 +23,7 @@
 use Pimcore\Model\Document\Link;
 use Pimcore\Model\Document\PageSnippet;
 use Pimcore\Model\Element\AbstractElement;
+use Symfony\Component\EventDispatcher\GenericEvent;
 
 class CacheListener
 {
@@ -58,18 +59,13 @@ public static function addCachingItem(
             self::$cachingItems = new \SplObjectStorage();
         }
 
-        // Load object to get cache tags.
-        $object = Concrete::getById($objectId);
-        if ($object) {
-            self::$cachingItems[$operation] = self::$cachingItems[$operation] ?? [];
-            $cacheTags = ['datahub-cache'] + (self::getObjectCacheTags($object) ?? []);
-            self::$cachingItems[$operation] += [$cid => [
-                'path' => $path,
-                'tags' => $cacheTags,
-                'indexKey' => $indexKey,
-                'lifetime' => $lifetime,
-            ]];
-        }
+        self::$cachingItems[$operation] = self::$cachingItems[$operation] ?? [];
+        self::$cachingItems[$operation] += [$cid => [
+            'objectId' => $objectId,
+            'path' => $path,
+            'indexKey' => $indexKey,
+            'lifetime' => $lifetime,
+        ]];
     }
 
     public static function clearCachingItems(OperationParams $operation = null): void
@@ -100,35 +96,72 @@ public static function arrayGetNestedValue(array &$array, array $parents, &$key_
         return $ref;
     }
 
+    /**
+     * Add the cache item meta-data before saving the cache items.
+     *
+     * Uses shutdown because at this point the response should be already
+     * delivered and any further processing shouldn't affect reponse times.
+     *
+     * @param \Symfony\Component\EventDispatcher\GenericEvent $event
+     *
+     * @return void
+     */
+    public function onPimcoreShutdown(GenericEvent $event): void
+    {
+        foreach (self::$cachingItems ?? [] as $operation) {
+            // Find items declared for caching in result set and store them in cache.
+            foreach (self::$cachingItems[$operation] as $cid => $item) {
+                // Extract the related cache tags.
+                $cacheTags = [];
+                $object = Concrete::getById($item['objectId']);
+                if (!empty($object)) {
+                    $cacheTags = ['datahub-cache'] + (self::getObjectCacheTags($object) ?? []);
+                }
+                // Not sure why force is necessary.
+                Cache::save(
+                    $item['data'],
+                    $cid,
+                    $cacheTags,
+                    $item['lifetime'] ?? null,
+                    0,
+                    true
+                );
+            }
+        }
+    }
+
+    /**
+     * Adds the actual data to the for caching prepared cache items.
+     *
+     * Do NOT save yet - wait for that till shutdown to ensure response is
+     * out before triggering any further processing.
+     *
+     *
+     * @param \Pimcore\Bundle\DataHubBundle\Event\GraphQL\Model\CacheItemEvent $event
+     *
+     * @return void
+     */
     public function onCacheItemEvent(CacheItemEvent $event): void
     {
         $operation = $event->getOperation();
-
         if (isset(self::$cachingItems[$operation])) {
             $result = $event->getResult();
             $data = $result->data;
-
             // Find items declared for caching in result set and store them in cache.
-            foreach (self::$cachingItems[$operation] as $cid => $item) {
+            $cachedItems = self::$cachingItems[$operation];
+            foreach ($cachedItems as $cid => $item) {
                 // replace the "delta" placeholder with the effective index to extract data
                 $path = $item['path'];
                 if ($index = array_search('delta', $path, true)) {
                     $path[$index] = $item['indexKey'];
                 }
                 // Extract the cacheable portion from the result.
                 $value = self::arrayGetNestedValue($data, $path);
-                $cacheTags = $item['tags'] ?? [];
-                Cache::save(
-                    $value,
-                    $cid,
-                    $cacheTags,
-                    $item['lifetime'] ?? null,
-                    0,
-                    true
-                );
+                $item['data'] = $value;
+                $cachedItems[$cid] = $item;
+                self::$cachingItems->offsetSet($operation, $cachedItems);
             }
         }
-        self::clearCachingItems($operation);
     }
 
     /**

src/Resources/config/eventlistener.yml

@@ -12,6 +12,7 @@ services:
     Pimcore\Bundle\DataHubBundle\EventListener\CacheListener:
         tags:
             - { name: kernel.event_listener, event: pimcore.datahub.graphql.cache.item, method: onCacheItemEvent }
+            - { name: kernel.event_listener, event: pimcore.system.shutdown, method: onPimcoreShutdown }
 
     Pimcore\Bundle\DataHubBundle\EventListener\AdminListener:
         bind: