1 files changed, 73 insertions, 0 deletions
diff --git a/lib/private/Files/Storage/StorageFactory.php b/lib/private/Files/Storage/StorageFactory.php
new file mode 100644
index 00000000000..603df7fe007
--- /dev/null
+++ b/lib/private/Files/Storage/StorageFactory.php
@@ -0,0 +1,73 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OC\Files\Storage;
+
+use OCP\Files\Mount\IMountPoint;
+use OCP\Files\Storage\IConstructableStorage;
+use OCP\Files\Storage\IStorage;
+use OCP\Files\Storage\IStorageFactory;
+use Psr\Log\LoggerInterface;
+
+class StorageFactory implements IStorageFactory {
+	/**
+	 * @var array[] [$name=>['priority'=>$priority, 'wrapper'=>$callable] $storageWrappers
+	 */
+	private $storageWrappers = [];
+
+	public function addStorageWrapper(string $wrapperName, callable $callback, int $priority = 50, array $existingMounts = []): bool {
+		if (isset($this->storageWrappers[$wrapperName])) {
+			return false;
+		}
+
+		// apply to existing mounts before registering it to prevent applying it double in MountPoint::createStorage
+		foreach ($existingMounts as $mount) {
+			$mount->wrapStorage($callback);
+		}
+
+		$this->storageWrappers[$wrapperName] = ['wrapper' => $callback, 'priority' => $priority];
+		return true;
+	}
+
+	/**
+	 * Remove a storage wrapper by name.
+	 * Note: internal method only to be used for cleanup
+	 *
+	 * @internal
+	 */
+	public function removeStorageWrapper(string $wrapperName): void {
+		unset($this->storageWrappers[$wrapperName]);
+	}
+
+	/**
+	 * Create an instance of a storage and apply the registered storage wrappers
+	 */
+	public function getInstance(IMountPoint $mountPoint, string $class, array $arguments): IStorage {
+		if (!is_a($class, IConstructableStorage::class, true)) {
+			\OCP\Server::get(LoggerInterface::class)->warning('Building a storage not implementing IConstructableStorage is deprecated since 31.0.0', ['class' => $class]);
+		}
+		return $this->wrap($mountPoint, new $class($arguments));
+	}
+
+	public function wrap(IMountPoint $mountPoint, IStorage $storage): IStorage {
+		$wrappers = array_values($this->storageWrappers);
+		usort($wrappers, function ($a, $b) {
+			return $b['priority'] - $a['priority'];
+		});
+		/** @var callable[] $wrappers */
+		$wrappers = array_map(function ($wrapper) {
+			return $wrapper['wrapper'];
+		}, $wrappers);
+		foreach ($wrappers as $wrapper) {
+			$storage = $wrapper($mountPoint->getMountPoint(), $storage, $mountPoint);
+			if (!($storage instanceof IStorage)) {
+				throw new \Exception('Invalid result from storage wrapper');
+			}
+		}
+		return $storage;
+	}
+}