minor symfony#52156 [AssetMapper] Optimize memory usage (load only "compilable" assets) (smnandre)

This PR was squashed before being merged into the 6.4 branch.

Discussion
----------

[AssetMapper] Optimize memory usage (load only "compilable" assets)

| Q             | A
| ------------- | ---
| Branch?       | 6.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| License       | MIT

A bit late for 6.4... but this PR will have a sensible impact on performances.

Currently if the assets directory contains 500 images, they are all loaded in memory during the compile command.
Their contents are also serialized/unserialized and stored in cache.

This PR allow to load/store in memory/cache only the assets supported by the compilers (JS/CSS files today)

Commits
-------

9f63c81 [AssetMapper] Optimize memory usage (load only "compilable" assets)

Author: fabpot

src/Symfony/Component/AssetMapper/AssetMapperCompiler.php

@@ -42,4 +42,15 @@ public function compile(string $content, MappedAsset $asset): string
 
         return $content;
     }
+
+    public function supports(MappedAsset $asset): bool
+    {
+        foreach ($this->assetCompilers as $compiler) {
+            if ($compiler->supports($asset)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
 }

src/Symfony/Component/AssetMapper/AssetMapperDevServerSubscriber.php

@@ -13,6 +13,7 @@
 
 use Psr\Cache\CacheItemPoolInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpFoundation\BinaryFileResponse;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Event\RequestEvent;
 use Symfony\Component\HttpKernel\Event\ResponseEvent;
@@ -131,17 +132,20 @@ public function onKernelRequest(RequestEvent $event): void
 
         $this->profiler?->disable();
 
-        $mediaType = $this->getMediaType($asset->publicPath);
-        $response = (new Response(
-            $asset->content,
-            headers: $mediaType ? ['Content-Type' => $mediaType] : [],
-        ))
+        if (null !== $asset->content) {
+            $response = new Response($asset->content);
+        } else {
+            $response = new BinaryFileResponse($asset->sourcePath, autoLastModified: false);
+        }
+        $response
             ->setPublic()
-            ->setMaxAge(604800)
+            ->setMaxAge(604800) // 1 week
             ->setImmutable()
             ->setEtag($asset->digest)
         ;
-
+        if ($mediaType = $this->getMediaType($asset->publicPath)) {
+            $response->headers->set('Content-Type', $mediaType);
+        }
         $response->headers->set('X-Assets-Dev', true);
 
         $event->setResponse($response);

src/Symfony/Component/AssetMapper/Command/AssetMapperCompileCommand.php

@@ -139,12 +139,13 @@ private function createManifestAndWriteFiles(SymfonyStyle $io, string $publicDir
         foreach ($allAssets as $asset) {
             // $asset->getPublicPath() will start with a "/"
             $targetPath = $publicDir.$asset->publicPath;
-
-            if (!is_dir($dir = \dirname($targetPath))) {
-                $this->filesystem->mkdir($dir);
+            if (null !== $asset->content) {
+                // The original content has been modified by the AssetMapperCompiler
+                $this->filesystem->dumpFile($targetPath, $asset->content);
+            } else {
+                $this->filesystem->copy($asset->sourcePath, $targetPath, true);
             }
 
-            $this->filesystem->dumpFile($targetPath, $asset->content);
             $manifest[$asset->logicalPath] = $asset->publicPath;
         }
         ksort($manifest);

src/Symfony/Component/AssetMapper/Factory/MappedAssetFactory.php

@@ -37,13 +37,12 @@ public function __construct(
 
     public function createMappedAsset(string $logicalPath, string $sourcePath): ?MappedAsset
     {
-        if (\in_array($logicalPath, $this->assetsBeingCreated, true)) {
+        if (isset($this->assetsBeingCreated[$logicalPath])) {
             throw new CircularAssetsException(sprintf('Circular reference detected while creating asset for "%s": "%s".', $logicalPath, implode(' -> ', $this->assetsBeingCreated).' -> '.$logicalPath));
         }
+        $this->assetsBeingCreated[$logicalPath] = $logicalPath;
 
         if (!isset($this->assetsCache[$logicalPath])) {
-            $this->assetsBeingCreated[] = $logicalPath;
-
             $isVendor = $this->isVendor($sourcePath);
             $asset = new MappedAsset($logicalPath, $sourcePath, $this->assetsPathResolver->resolvePublicPath($logicalPath), isVendor: $isVendor);
 
@@ -54,7 +53,7 @@ public function createMappedAsset(string $logicalPath, string $sourcePath): ?Map
                 $asset->sourcePath,
                 $asset->publicPathWithoutDigest,
                 $this->getPublicPath($asset),
-                $this->calculateContent($asset),
+                $this->compileContent($asset),
                 $digest,
                 $isPredigested,
                 $isVendor,
@@ -64,10 +63,10 @@ public function createMappedAsset(string $logicalPath, string $sourcePath): ?Map
             );
 
             $this->assetsCache[$logicalPath] = $asset;
-
-            array_pop($this->assetsBeingCreated);
         }
 
+        unset($this->assetsBeingCreated[$logicalPath]);
+
         return $this->assetsCache[$logicalPath];
     }
 
@@ -83,28 +82,35 @@ private function getDigest(MappedAsset $asset): array
             return [$matches[1], true];
         }
 
+        // Use the compiled content if any
+        if (null !== $content = $this->compileContent($asset)) {
+            return [hash('xxh128', $content), false];
+        }
+
         return [
-            hash('xxh128', $this->calculateContent($asset)),
+            hash_file('xxh128', $asset->sourcePath),
             false,
         ];
     }
 
-    private function calculateContent(MappedAsset $asset): string
+    private function compileContent(MappedAsset $asset): ?string
     {
-        if (isset($this->fileContentsCache[$asset->logicalPath])) {
+        if (\array_key_exists($asset->logicalPath, $this->fileContentsCache)) {
             return $this->fileContentsCache[$asset->logicalPath];
         }
 
         if (!is_file($asset->sourcePath)) {
             throw new RuntimeException(sprintf('Asset source path "%s" could not be found.', $asset->sourcePath));
         }
 
+        if (!$this->compiler->supports($asset)) {
+            return $this->fileContentsCache[$asset->logicalPath] = null;
+        }
+
         $content = file_get_contents($asset->sourcePath);
         $content = $this->compiler->compile($content, $asset);
 
-        $this->fileContentsCache[$asset->logicalPath] = $content;
-
-        return $content;
+        return $this->fileContentsCache[$asset->logicalPath] = $content;
     }
 
     private function getPublicPath(MappedAsset $asset): ?string

src/Symfony/Component/AssetMapper/MappedAsset.php

@@ -24,7 +24,12 @@ final class MappedAsset
     public readonly string $publicPath;
     public readonly string $publicPathWithoutDigest;
     public readonly string $publicExtension;
-    public readonly string $content;
+
+    /**
+     * The final content of this asset, if different from the source.
+     */
+    public readonly ?string $content;
+
     public readonly string $digest;
     public readonly bool $isPredigested;
     public readonly bool $isVendor;
@@ -73,9 +78,7 @@ public function __construct(
             $this->publicPathWithoutDigest = $publicPathWithoutDigest;
             $this->publicExtension = pathinfo($publicPathWithoutDigest, \PATHINFO_EXTENSION);
         }
-        if (null !== $content) {
-            $this->content = $content;
-        }
+        $this->content = $content;
         if (null !== $digest) {
             $this->digest = $digest;
         }