1 files changed, 39 insertions, 0 deletions
diff --git a/lib/private/AppFramework/Middleware/NotModifiedMiddleware.php b/lib/private/AppFramework/Middleware/NotModifiedMiddleware.php
new file mode 100644
index 00000000000..08b30092155
--- /dev/null
+++ b/lib/private/AppFramework/Middleware/NotModifiedMiddleware.php
@@ -0,0 +1,39 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2020 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\AppFramework\Middleware;
+
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\Response;
+use OCP\AppFramework\Middleware;
+use OCP\IRequest;
+
+class NotModifiedMiddleware extends Middleware {
+	/** @var IRequest */
+	private $request;
+
+	public function __construct(IRequest $request) {
+		$this->request = $request;
+	}
+
+	public function afterController($controller, $methodName, Response $response) {
+		$etagHeader = $this->request->getHeader('IF_NONE_MATCH');
+		if ($etagHeader !== '' && $response->getETag() !== null && trim($etagHeader) === '"' . $response->getETag() . '"') {
+			$response->setStatus(Http::STATUS_NOT_MODIFIED);
+			return $response;
+		}
+
+		$modifiedSinceHeader = $this->request->getHeader('IF_MODIFIED_SINCE');
+		if ($modifiedSinceHeader !== '' && $response->getLastModified() !== null && trim($modifiedSinceHeader) === $response->getLastModified()->format(\DateTimeInterface::RFC7231)) {
+			$response->setStatus(Http::STATUS_NOT_MODIFIED);
+			return $response;
+		}
+
+		return $response;
+	}
+}