chore(poc): decrease memory consumption at first call

Author: AntoineSmagghe

src/Application/Regulation/DatexGeneratorInterface.php

@@ -7,4 +7,6 @@
 interface DatexGeneratorInterface
 {
     public function generate(): void;
+
+    public function getCachedDatex(): string;
 }

src/Infrastructure/Adapter/DatexGenerator.php

@@ -28,24 +28,37 @@ public function generate(): void
             new GetRegulationOrdersToDatexFormatQuery(),
         );
 
-        $content = $this->twig->render('api/regulations.xml.twig', [
-            'publicationTime' => $this->dateUtils->getNow(),
-            'regulationOrders' => $regulationOrders,
-        ]);
-
         $dir = \dirname($this->datexFilePath);
 
         if (!is_dir($dir)) {
             mkdir($dir, 0o755, true);
         }
 
         $tmpFile = $this->datexFilePath . '.tmp';
-        file_put_contents($tmpFile, $content);
+        $handle = fopen($tmpFile, 'w');
+
+        ob_start(function (string $buffer) use ($handle): string {
+            fwrite($handle, $buffer);
+
+            return '';
+        }, 262144);
+
+        $this->twig->display('api/regulations.xml.twig', [
+            'publicationTime' => $this->dateUtils->getNow(),
+            'regulationOrders' => $regulationOrders,
+        ]);
+
+        ob_end_flush();
+        fclose($handle);
         rename($tmpFile, $this->datexFilePath);
     }
 
-    public function getDatexFilePath(): string
+    public function getCachedDatex(): string
     {
-        return $this->datexFilePath;
+        if (!file_exists($this->datexFilePath)) {
+            $this->generate();
+        }
+
+        return file_get_contents($this->datexFilePath);
     }
 }

src/Infrastructure/Controller/Api/Regulations/GetRegulationsController.php

@@ -6,8 +6,8 @@
 
 use App\Application\DateUtilsInterface;
 use App\Application\QueryBusInterface;
+use App\Application\Regulation\DatexGeneratorInterface;
 use App\Application\Regulation\Query\GetRegulationOrdersToDatexFormatQuery;
-use App\Infrastructure\Adapter\DatexGenerator;
 use OpenApi\Attributes as OA;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpFoundation\StreamedResponse;
@@ -20,7 +20,7 @@ public function __construct(
         private \Twig\Environment $twig,
         private DateUtilsInterface $dateUtils,
         private QueryBusInterface $queryBus,
-        private DatexGenerator $datexGenerator,
+        private DatexGeneratorInterface $datexGenerator,
     ) {
     }
 
@@ -40,15 +40,12 @@ public function __invoke(
         bool $includeExpired = false,
     ): Response {
         $isDefaultParams = $includePermanent && $includeTemporary && !$includeExpired;
-        $datexFilePath = $this->datexGenerator->getDatexFilePath();
 
         if ($isDefaultParams) {
-            if (!file_exists($datexFilePath)) {
-                $this->datexGenerator->generate();
-            }
+            $regulationOrders = $this->datexGenerator->getCachedDatex();
 
             return new Response(
-                file_get_contents($datexFilePath),
+                $regulationOrders,
                 Response::HTTP_OK,
                 ['Content-Type' => 'text/xml; charset=UTF-8'],
             );