1 files changed, 56 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..e34310b4116
--- /dev/null
+++ b/lib/private/AppFramework/Middleware/NotModifiedMiddleware.php
@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2020, Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+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(\DateTime::RFC2822)) {
+			$response->setStatus(Http::STATUS_NOT_MODIFIED);
+			return $response;
+		}
+
+		return $response;
+	}
+}