feat: Make it possible to add a storage wrapper using public APIs

Before that every app is using an internal call to
Filesystem::addStorageWrapper. The new API enforce that this is called
at the right moment.

Signed-off-by: Carl Schwan <carlschwan@kde.org>

Author: CarlSchwan

lib/private/Files/SetupManager.php

@@ -319,6 +319,10 @@ private function oneTimeUserSetup(IUser $user) {
 		$event = new BeforeFileSystemSetupEvent($user);
 		$this->eventDispatcher->dispatchTyped($event);
 
+		foreach ($event->getStorageWrappers() as $name => $wrapper) {
+			Filesystem::addStorageWrapper($name, $wrapper['wrapper'], $wrapper['priority']);
+		}
+
 		Filesystem::logWarningWhenAddingStorageWrapper($prevLogging);
 
 		$userDir = '/' . $user->getUID() . '/files';

lib/public/Files/Events/BeforeFileSystemSetupEvent.php

@@ -10,19 +10,23 @@
 namespace OCP\Files\Events;
 
 use OCP\EventDispatcher\Event;
+use OCP\Files\Storage\IStorage;
 use OCP\IUser;
 
 /**
- * Event triggered before the file system is setup
+ * Event triggered before the file system is set up.
  *
  * @since 31.0.0
  */
 class BeforeFileSystemSetupEvent extends Event {
+	/** @var array<string, array{wrapper: callable(string $mountPoint, IStorage $storage): IStorage, priority: int}> $storageWrappers */
+	private array $storageWrappers = [];
+
 	/**
 	 * @since 31.0.0
 	 */
 	public function __construct(
-		private IUser $user,
+		private readonly IUser $user,
 	) {
 		parent::__construct();
 	}
@@ -33,4 +37,25 @@ public function __construct(
 	public function getUser(): IUser {
 		return $this->user;
 	}
+
+	/**
+	 * Add a storage wrapper to the file system. This allows apps to inject storage wrappers
+	 * for every mount.
+	 *
+	 * @param callable(string $mountPoint, IStorage $storage): IStorage $wrapper
+	 * @since 35.0.0
+	 */
+	public function addStorageWrapper(string $name, callable $wrapper, int $priority = 50): void {
+		$this->storageWrappers[$name] = ['wrapper' => $wrapper, 'priority' => $priority];
+	}
+
+	/**
+	 * Get the storage wrappers.
+	 *
+	 * @since 35.0.0
+	 * @return array<string, array{wrapper: callable(string $mountPoint, IStorage $storage): IStorage, priority: int}>
+	 */
+	public function getStorageWrappers(): array {
+		return $this->storageWrappers;
+	}
 }