Performance: Cache salesrule attributes to prevent unnecessary database queries

app/code/Magento/SalesRule/Model/Plugin/QuoteConfigProductAttributes.php

@@ -6,11 +6,23 @@
 
 namespace Magento\SalesRule\Model\Plugin;
 
+use Magento\Framework\App\CacheInterface;
+use Magento\Framework\Serialize\SerializerInterface;
 use Magento\Quote\Model\Quote\Config;
 use Magento\SalesRule\Model\ResourceModel\Rule as RuleResource;
 
 class QuoteConfigProductAttributes
 {
+    /**
+     * Cache key for active salesrule attributes
+     */
+    private const CACHE_KEY = 'salesrule_active_product_attributes';
+
+    /**
+     * Cache tag for salesrule attributes
+     */
+    private const CACHE_TAG = 'salesrule';
+
     /**
      * @var RuleResource
      */
@@ -21,17 +33,36 @@ class QuoteConfigProductAttributes
      */
     private $activeAttributeCodes;
 
+    /**
+     * @var CacheInterface
+     */
+    private $cache;
+
+    /**
+     * @var SerializerInterface
+     */
+    private $serializer;
+
     /**
      * @param RuleResource $ruleResource
+     * @param CacheInterface $cache
+     * @param SerializerInterface $serializer
      */
-    public function __construct(RuleResource $ruleResource)
-    {
+    public function __construct(
+        RuleResource $ruleResource,
+        CacheInterface $cache,
+        SerializerInterface $serializer
+    ) {
         $this->ruleResource = $ruleResource;
+        $this->cache = $cache;
+        $this->serializer = $serializer;
     }
 
     /**
      * Append sales rule product attribute keys to select by quote item collection
      *
+     * Uses cache to avoid database queries on every request.
+     *
      * @param Config $subject
      * @param array $attributeKeys
      *
@@ -41,7 +72,21 @@ public function __construct(RuleResource $ruleResource)
     public function afterGetProductAttributes(Config $subject, array $attributeKeys): array
     {
         if ($this->activeAttributeCodes === null) {
-            $this->activeAttributeCodes = array_column($this->ruleResource->getActiveAttributes(), 'attribute_code');
+            $cachedData = $this->cache->load(self::CACHE_KEY);
+
+            if ($cachedData !== false) {
+                $this->activeAttributeCodes = $this->serializer->unserialize($cachedData);
+            } else {
+                $this->activeAttributeCodes = array_column(
+                    $this->ruleResource->getActiveAttributes(),
+                    'attribute_code'
+                );
+                $this->cache->save(
+                    $this->serializer->serialize($this->activeAttributeCodes),
+                    self::CACHE_KEY,
+                    [self::CACHE_TAG]
+                );
+            }
         }
 
         return array_merge($attributeKeys, $this->activeAttributeCodes);

app/code/Magento/SalesRule/Observer/ClearProductAttributesCacheObserver.php

@@ -0,0 +1,47 @@
+<?php
+/**
+ * Copyright 2024 Adobe
+ * All Rights Reserved.
+ */
+
+namespace Magento\SalesRule\Observer;
+
+use Magento\Framework\App\CacheInterface;
+use Magento\Framework\Event\Observer;
+use Magento\Framework\Event\ObserverInterface;
+
+/**
+ * Clear cached salesrule product attributes when rules are saved
+ */
+class ClearProductAttributesCacheObserver implements ObserverInterface
+{
+    /**
+     * Cache key for active salesrule attributes
+     */
+    private const CACHE_KEY = 'salesrule_active_product_attributes';
+
+    /**
+     * @var CacheInterface
+     */
+    private $cache;
+
+    /**
+     * @param CacheInterface $cache
+     */
+    public function __construct(CacheInterface $cache)
+    {
+        $this->cache = $cache;
+    }
+
+    /**
+     * Clear salesrule product attributes cache
+     *
+     * @param Observer $observer
+     * @return void
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function execute(Observer $observer): void
+    {
+        $this->cache->remove(self::CACHE_KEY);
+    }
+}

app/code/Magento/SalesRule/Test/Unit/Model/Plugin/QuoteConfigProductAttributesTest.php

@@ -7,6 +7,8 @@
 
 namespace Magento\SalesRule\Test\Unit\Model\Plugin;
 
+use Magento\Framework\App\CacheInterface;
+use Magento\Framework\Serialize\SerializerInterface;
 use Magento\Framework\TestFramework\Unit\Helper\ObjectManager;
 use Magento\Quote\Model\Quote\Config;
 use Magento\SalesRule\Model\Plugin\QuoteConfigProductAttributes;
@@ -17,7 +19,7 @@
 class QuoteConfigProductAttributesTest extends TestCase
 {
     /**
-     * @var QuoteConfigProductAttributes|MockObject
+     * @var QuoteConfigProductAttributes
      */
     protected $plugin;
 
@@ -26,24 +28,67 @@ class QuoteConfigProductAttributesTest extends TestCase
      */
     protected $ruleResource;
 
+    /**
+     * @var CacheInterface|MockObject
+     */
+    protected $cache;
+
+    /**
+     * @var SerializerInterface|MockObject
+     */
+    protected $serializer;
+
     protected function setUp(): void
     {
         $objectManager = new ObjectManager($this);
         $this->ruleResource = $this->createMock(Rule::class);
+        $this->cache = $this->createMock(CacheInterface::class);
+        $this->serializer = $this->createMock(SerializerInterface::class);
 
         $this->plugin = $objectManager->getObject(
             QuoteConfigProductAttributes::class,
             [
-                'ruleResource' => $this->ruleResource
+                'ruleResource' => $this->ruleResource,
+                'cache' => $this->cache,
+                'serializer' => $this->serializer
             ]
         );
     }
 
-    public function testAfterGetProductAttributes()
+    public function testAfterGetProductAttributesWithCache()
+    {
+        $subject = $this->createMock(Config::class);
+        $attributeCode = 'code of the attribute';
+        $expected = [0 => $attributeCode];
+        $serializedData = '["' . $attributeCode . '"]';
+
+        $this->cache->expects($this->once())
+            ->method('load')
+            ->with('salesrule_active_product_attributes')
+            ->willReturn($serializedData);
+
+        $this->serializer->expects($this->once())
+            ->method('unserialize')
+            ->with($serializedData)
+            ->willReturn([$attributeCode]);
+
+        $this->ruleResource->expects($this->never())
+            ->method('getActiveAttributes');
+
+        $this->assertEquals($expected, $this->plugin->afterGetProductAttributes($subject, []));
+    }
+
+    public function testAfterGetProductAttributesWithoutCache()
     {
         $subject = $this->createMock(Config::class);
         $attributeCode = 'code of the attribute';
         $expected = [0 => $attributeCode];
+        $serializedData = '["' . $attributeCode . '"]';
+
+        $this->cache->expects($this->once())
+            ->method('load')
+            ->with('salesrule_active_product_attributes')
+            ->willReturn(false);
 
         $this->ruleResource->expects($this->once())
             ->method('getActiveAttributes')
@@ -53,6 +98,15 @@ public function testAfterGetProductAttributes()
                 ]
             );
 
+        $this->serializer->expects($this->once())
+            ->method('serialize')
+            ->with([$attributeCode])
+            ->willReturn($serializedData);
+
+        $this->cache->expects($this->once())
+            ->method('save')
+            ->with($serializedData, 'salesrule_active_product_attributes', ['salesrule']);
+
         $this->assertEquals($expected, $this->plugin->afterGetProductAttributes($subject, []));
     }
 }

app/code/Magento/SalesRule/Test/Unit/Observer/ClearProductAttributesCacheObserverTest.php

@@ -0,0 +1,44 @@
+<?php
+/**
+ * Copyright 2024 Adobe
+ * All Rights Reserved.
+ */
+declare(strict_types=1);
+
+namespace Magento\SalesRule\Test\Unit\Observer;
+
+use Magento\Framework\App\CacheInterface;
+use Magento\Framework\Event\Observer;
+use Magento\SalesRule\Observer\ClearProductAttributesCacheObserver;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+
+class ClearProductAttributesCacheObserverTest extends TestCase
+{
+    /**
+     * @var ClearProductAttributesCacheObserver
+     */
+    private $observer;
+
+    /**
+     * @var CacheInterface|MockObject
+     */
+    private $cache;
+
+    protected function setUp(): void
+    {
+        $this->cache = $this->createMock(CacheInterface::class);
+        $this->observer = new ClearProductAttributesCacheObserver($this->cache);
+    }
+
+    public function testExecuteClearsCache()
+    {
+        $event = $this->createMock(Observer::class);
+
+        $this->cache->expects($this->once())
+            ->method('remove')
+            ->with('salesrule_active_product_attributes');
+
+        $this->observer->execute($event);
+    }
+}

app/code/Magento/SalesRule/etc/events.xml

@@ -32,9 +32,11 @@
     </event>
     <event name="salesrule_rule_save_commit_after">
         <observer name="salesrule_quote_recollect_totals_on_disabled" instance="\Magento\SalesRule\Observer\RuleQuoteRecollectTotalsObserver" />
+        <observer name="clear_product_attributes_cache" instance="Magento\SalesRule\Observer\ClearProductAttributesCacheObserver" />
     </event>
     <event name="salesrule_rule_delete_commit_after">
         <observer name="salesrule_quote_recollect_totals_on_delete" instance="\Magento\SalesRule\Observer\RuleQuoteRecollectTotalsObserver" />
+        <observer name="clear_product_attributes_cache_on_delete" instance="Magento\SalesRule\Observer\ClearProductAttributesCacheObserver" />
     </event>
     <event name="sales_quote_collect_totals_before">
         <observer name="salesrule_sales_quote_collect_totals_before" instance="\Magento\SalesRule\Observer\QuoteResetAppliedRulesObserver" />