MAGETWO-59053: [Github] Merge CSS Files causes entire site to load Extremely Slow #4321

lib/internal/Magento/Framework/View/Asset/MergeStrategy/Checksum.php

@@ -6,6 +6,8 @@
 namespace Magento\Framework\View\Asset\MergeStrategy;
 
 use Magento\Framework\App\Filesystem\DirectoryList;
+use Magento\Framework\App\ObjectManager;
+use Magento\Framework\View\Asset\Source;
 
 /**
  * Skip merging if all of the files that need to be merged were not modified
@@ -25,6 +27,11 @@ class Checksum implements \Magento\Framework\View\Asset\MergeStrategyInterface
      */
     protected $filesystem;
 
+    /**
+     * @var Source
+     */
+    private $assetSource;
+
     /**
      * @param \Magento\Framework\View\Asset\MergeStrategyInterface $strategy
      * @param \Magento\Framework\Filesystem $filesystem
@@ -37,17 +44,31 @@ class Checksum implements \Magento\Framework\View\Asset\MergeStrategyInterface
         $this->filesystem = $filesystem;
     }
 
+    /**
+     * @deprecated
+     * @return Source
+     */
+    private function getAssetSource()
+    {
+        if (!$this->assetSource) {
+            $this->assetSource = ObjectManager::getInstance()->get(Source::class);
+        }
+        return $this->assetSource;
+    }
+
     /**
      * {@inheritdoc}
      */
     public function merge(array $assetsToMerge, \Magento\Framework\View\Asset\LocalInterface $resultAsset)
     {
-        $sourceDir = $this->filesystem->getDirectoryRead(DirectoryList::ROOT);
+        $rootDir = $this->filesystem->getDirectoryRead(DirectoryList::ROOT);
         $mTime = null;
         /** @var \Magento\Framework\View\Asset\MergeableInterface $asset */
         foreach ($assetsToMerge as $asset) {
-            $mTime .= $sourceDir->stat($sourceDir->getRelativePath($asset->getSourceFile()))['mtime'];
+            $sourceFile = $this->getAssetSource()->findSource($asset);
+            $mTime .= $rootDir->stat($rootDir->getRelativePath($sourceFile))['mtime'];
         }
+
         if (null === $mTime) {
             return; // nothing to merge
         }

lib/internal/Magento/Framework/View/Test/Unit/Asset/MergeStrategy/ChecksumTest.php

@@ -8,6 +8,7 @@ namespace Magento\Framework\View\Test\Unit\Asset\MergeStrategy;
 use \Magento\Framework\View\Asset\MergeStrategy\Checksum;
 
 use Magento\Framework\App\Filesystem\DirectoryList;
+use Magento\Framework\View\Asset\Source;
 
 class ChecksumTest extends \PHPUnit_Framework_TestCase
 {
@@ -31,6 +32,11 @@ class ChecksumTest extends \PHPUnit_Framework_TestCase
      */
     private $resultAsset;
 
+    /**
+     * @var Source|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $assetSource;
+
     /**
      * @var \Magento\Framework\View\Asset\MergeStrategy\Checksum
      */
@@ -53,6 +59,15 @@ class ChecksumTest extends \PHPUnit_Framework_TestCase
             ->with(DirectoryList::STATIC_VIEW)
             ->will($this->returnValue($this->targetDir));
         $this->checksum = new Checksum($this->mergerMock, $filesystem);
+        $this->assetSource = $this->getMockBuilder(Source::class)
+            ->disableOriginalConstructor()
+            ->getMock();
+
+        $reflection = new \ReflectionClass(Checksum::class);
+        $reflectionProperty = $reflection->getProperty('assetSource');
+        $reflectionProperty->setAccessible(true);
+        $reflectionProperty->setValue($this->checksum, $this->assetSource);
+
         $this->resultAsset = $this->getMock(\Magento\Framework\View\Asset\File::class, [], [], '', false);
     }
 
@@ -114,9 +129,13 @@ class ChecksumTest extends \PHPUnit_Framework_TestCase
     private function getAssetsToMerge()
     {
         $one = $this->getMock(\Magento\Framework\View\Asset\File::class, [], [], '', false);
-        $one->expects($this->once())->method('getSourceFile')->will($this->returnValue('/dir/file/one.txt'));
         $two = $this->getMock(\Magento\Framework\View\Asset\File::class, [], [], '', false);
-        $two->expects($this->once())->method('getSourceFile')->will($this->returnValue('/dir/file/two.txt'));
+
+        $this->assetSource->expects($this->exactly(2))
+            ->method('findSource')
+            ->withConsecutive([$one], [$two])
+            ->willReturnOnConsecutiveCalls('/dir/file/one.txt', '/dir/file/two.txt');
+
         $this->sourceDir->expects($this->exactly(2))
             ->method('getRelativePath')
             ->will($this->onConsecutiveCalls('file/one.txt', 'file/two.txt'));