AC-13719: Cache Keys associated with FPC on Magento 2.4.7 multi-store implementations

Plugin for IdentifierForSave class which adds the MAGE_RUN_TYPE and MAGE_RUN_CODE prefix to the cache key.

Author: sumesh-GL

app/code/Magento/PageCache/Model/App/CacheIdentifierForSavePlugin.php

@@ -0,0 +1,79 @@
+<?php
+/**
+ * Copyright 2025 Adobe
+ * All rights reserved.
+ */
+declare(strict_types=1);
+
+namespace Magento\PageCache\Model\App;
+
+use Magento\Store\Model\StoreManager;
+
+/**
+ * Class CacheIdentifierForSavePlugin
+ *
+ * Should add design exceptions to identifier for built-in cache when saving
+ */
+class CacheIdentifierForSavePlugin
+{
+    /**
+     * @var \Magento\Framework\View\DesignExceptions
+     */
+    private $designExceptions;
+
+    /**
+     * @var \Magento\Framework\App\RequestInterface
+     */
+    private $request;
+
+    /**
+     * @var \Magento\PageCache\Model\Config
+     */
+    private $config;
+
+    /**
+     * @param \Magento\Framework\View\DesignExceptions $designExceptions
+     * @param \Magento\Framework\App\RequestInterface $request
+     * @param \Magento\PageCache\Model\Config $config
+     */
+    public function __construct(
+        \Magento\Framework\View\DesignExceptions $designExceptions,
+        \Magento\Framework\App\RequestInterface $request,
+        \Magento\PageCache\Model\Config $config
+    ) {
+        $this->designExceptions = $designExceptions;
+        $this->request = $request;
+        $this->config = $config;
+    }
+
+    /**
+     * Adds a theme key to identifier for a built-in cache if user-agent theme rule is actual
+     *
+     * @param \Magento\PageCache\Model\App\Request\Http\IdentifierForSave $identifier
+     * @param string $result
+     * @return string
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function afterGetValue(\Magento\PageCache\Model\App\Request\Http\IdentifierForSave $identifier, $result)
+    {
+        if ($this->config->getType() === \Magento\PageCache\Model\Config::BUILT_IN && $this->config->isEnabled()) {
+            $identifierPrefix = '';
+
+            $ruleDesignException = $this->designExceptions->getThemeByRequest($this->request);
+            if ($ruleDesignException !== false) {
+                $identifierPrefix .= 'DESIGN' . '=' . $ruleDesignException . '|';
+            }
+
+            if ($runType = $this->request->getServerValue(StoreManager::PARAM_RUN_TYPE)) {
+                $identifierPrefix .= StoreManager::PARAM_RUN_TYPE . '=' .  $runType . '|';
+            }
+
+            if ($runCode = $this->request->getServerValue(StoreManager::PARAM_RUN_CODE)) {
+                $identifierPrefix .= StoreManager::PARAM_RUN_CODE . '=' . $runCode . '|';
+            }
+
+            return $identifierPrefix . $result;
+        }
+        return $result;
+    }
+}

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

@@ -9,6 +9,9 @@
     <type name="Magento\Framework\App\PageCache\Identifier">
         <plugin name="core-app-area-design-exception-plugin" type="Magento\PageCache\Model\App\CacheIdentifierPlugin" sortOrder="10"/>
     </type>
+    <type name="Magento\PageCache\Model\App\Request\Http\IdentifierForSave">
+        <plugin name="core-app-area-design-exception-plugin-for-save" type="Magento\PageCache\Model\App\CacheIdentifierForSavePlugin" sortOrder="10"/>
+    </type>
     <type name="Magento\Framework\App\PageCache\Cache">
         <plugin name="fpc-type-plugin" type="Magento\PageCache\Model\App\PageCachePlugin"/>
     </type>

dev/tests/integration/testsuite/Magento/PageCache/Model/App/CacheIdentifierPluginTest.php

@@ -11,6 +11,7 @@
 use Magento\Framework\App\PageCache\Identifier;
 use Magento\Framework\App\Request\Http;
 use Magento\Framework\ObjectManagerInterface;
+use Magento\PageCache\Model\App\Request\Http\IdentifierForSave;
 use Magento\PageCache\Model\Cache\Type;
 use Magento\Store\Model\StoreManager;
 use Magento\Store\Test\Fixture\Group as StoreGroupFixture;
@@ -44,6 +45,11 @@ class CacheIdentifierPluginTest extends TestCase
      */
     private $identifier;
 
+    /**
+     * @var IdentifierForSave
+     */
+    private $identifierForSave;
+
     /**
      * @var DataFixtureStorage
      */
@@ -64,6 +70,7 @@ protected function setUp(): void
         $this->objectManager = Bootstrap::getObjectManager();
         $this->request = $this->objectManager->get(Http::class);
         $this->identifier = $this->objectManager->get(Identifier::class);
+        $this->identifierForSave = $this->objectManager->get(IdentifierForSave::class);
         $this->fixtures = $this->objectManager->get(DataFixtureStorageManager::class)->getStorage();
         $this->cacheState = $this->objectManager->get(StateInterface::class);
 
@@ -106,5 +113,10 @@ public function testAfterGetValueWithRunTypeAndCode()
         $this->assertNotEmpty($result);
         $this->assertStringContainsString('MAGE_RUN_TYPE=store', $result);
         $this->assertStringContainsString('MAGE_RUN_CODE=' . $storeCode, $result);
+
+        $resultForSave = $this->identifierForSave->getValue();
+        $this->assertNotEmpty($resultForSave);
+        $this->assertStringContainsString('MAGE_RUN_TYPE=store', $resultForSave);
+        $this->assertStringContainsString('MAGE_RUN_CODE=' . $storeCode, $resultForSave);
     }
 }