16 files changed, 392 insertions, 18 deletions

diff --git a/lib/private/AppFramework/DependencyInjection/DIContainer.php b/lib/private/AppFramework/DependencyInjection/DIContainer.php
index f21b34a6b4a..32a85606abf 100644
--- a/lib/private/AppFramework/DependencyInjection/DIContainer.php
+++ b/lib/private/AppFramework/DependencyInjection/DIContainer.php
@@ -38,6 +38,7 @@ use OC\AppFramework\Http\Dispatcher;
 use OC\AppFramework\Http\Output;
 use OC\AppFramework\Middleware\MiddlewareDispatcher;
 use OC\AppFramework\Middleware\Security\CORSMiddleware;
+use OC\AppFramework\Middleware\OCSMiddleware;
 use OC\AppFramework\Middleware\Security\SecurityMiddleware;
 use OC\AppFramework\Middleware\SessionMiddleware;
 use OC\AppFramework\Utility\SimpleContainer;
@@ -373,6 +374,12 @@ class DIContainer extends SimpleContainer implements IAppContainer {
 			return new TwoFactorMiddleware($twoFactorManager, $userSession, $session, $urlGenerator, $reflector, $request);
 		});
 
+		$this->registerService('OCSMiddleware', function (SimpleContainer $c) {
+			return new OCSMiddleware(
+				$c['Request']
+			);
+		});
+
 		$middleWares = &$this->middleWares;
 		$this->registerService('MiddlewareDispatcher', function($c) use (&$middleWares) {
 			$dispatcher = new MiddlewareDispatcher();
@@ -385,6 +392,7 @@ class DIContainer extends SimpleContainer implements IAppContainer {
 			}
 
 			$dispatcher->registerMiddleware($c['SessionMiddleware']);
+			$dispatcher->registerMiddleware($c['OCSMiddleware']);
 			return $dispatcher;
 		});
 
diff --git a/lib/private/AppFramework/Middleware/OCSMiddleware.php b/lib/private/AppFramework/Middleware/OCSMiddleware.php
new file mode 100644
index 00000000000..2c7d1167e7c
--- /dev/null
+++ b/lib/private/AppFramework/Middleware/OCSMiddleware.php
@@ -0,0 +1,80 @@
+<?php
+/**
+ *
+ * @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 OC\AppFramework\Http;
+use OCP\AppFramework\Http\OCSResponse;
+use OCP\AppFramework\OCS\OCSException;
+use OCP\AppFramework\OCSController;
+use OCP\IRequest;
+use OCP\AppFramework\Middleware;
+
+class OCSMiddleware extends Middleware {
+
+	/** @var IRequest */
+	private $request;
+
+	/**
+	 * @param IRequest $request
+	 */
+	public function __construct(IRequest $request) {
+		$this->request = $request;
+	}
+
+	/**
+	 * @param \OCP\AppFramework\Controller $controller
+	 * @param string $methodName
+	 * @param \Exception $exception
+	 * @throws \Exception
+	 * @return OCSResponse
+	 */
+	public function afterException($controller, $methodName, \Exception $exception) {
+		if ($controller instanceof OCSController && $exception instanceof OCSException) {
+			$format = $this->getFormat($controller);
+
+			$code = $exception->getCode();
+			if ($code === 0) {
+				$code = Http::STATUS_INTERNAL_SERVER_ERROR;
+			}
+			return new OCSResponse($format, $code, $exception->getMessage());
+		}
+
+		throw $exception;
+	}
+
+	/**
+	 * @param \OCP\AppFramework\Controller $controller
+	 * @return string
+	 */
+	private function getFormat($controller) {
+		// get format from the url format or request format parameter
+		$format = $this->request->getParam('format');
+
+		// if none is given try the first Accept header
+		if($format === null) {
+			$headers = $this->request->getHeader('Accept');
+			$format = $controller->getResponderByHTTPHeader($headers);
+		}
+
+		return $format;
+	}
+}
diff --git a/lib/private/Files/Config/CachedMountInfo.php b/lib/private/Files/Config/CachedMountInfo.php
index ce75cb66896..b81cd11a1c1 100644
--- a/lib/private/Files/Config/CachedMountInfo.php
+++ b/lib/private/Files/Config/CachedMountInfo.php
@@ -48,18 +48,25 @@ class CachedMountInfo implements ICachedMountInfo {
 	protected $mountPoint;
 
 	/**
+	 * @var int|null
+	 */
+	protected $mountId;
+
+	/**
 	 * CachedMountInfo constructor.
 	 *
 	 * @param IUser $user
 	 * @param int $storageId
 	 * @param int $rootId
 	 * @param string $mountPoint
+	 * @param int|null $mountId
 	 */
-	public function __construct(IUser $user, $storageId, $rootId, $mountPoint) {
+	public function __construct(IUser $user, $storageId, $rootId, $mountPoint, $mountId = null) {
 		$this->user = $user;
 		$this->storageId = $storageId;
 		$this->rootId = $rootId;
 		$this->mountPoint = $mountPoint;
+		$this->mountId = $mountId;
 	}
 
 	/**
@@ -104,4 +111,14 @@ class CachedMountInfo implements ICachedMountInfo {
 	public function getMountPoint() {
 		return $this->mountPoint;
 	}
+
+	/**
+	 * Get the id of the configured mount
+	 *
+	 * @return int|null mount id or null if not applicable
+	 * @since 9.1.0
+	 */
+	public function getMountId() {
+		return $this->mountId;
+	}
 }
diff --git a/lib/private/Files/Config/LazyStorageMountInfo.php b/lib/private/Files/Config/LazyStorageMountInfo.php
index 5df04c4b78e..58f288135e6 100644
--- a/lib/private/Files/Config/LazyStorageMountInfo.php
+++ b/lib/private/Files/Config/LazyStorageMountInfo.php
@@ -75,4 +75,8 @@ class LazyStorageMountInfo extends CachedMountInfo {
 		}
 		return parent::getMountPoint();
 	}
+
+	public function getMountId() {
+		return $this->mount->getMountId();
+	}
 }
diff --git a/lib/private/Files/Config/UserMountCache.php b/lib/private/Files/Config/UserMountCache.php
index bc6ad1b34f0..d9b538a002a 100644
--- a/lib/private/Files/Config/UserMountCache.php
+++ b/lib/private/Files/Config/UserMountCache.php
@@ -112,13 +112,7 @@ class UserMountCache implements IUserMountCache {
 		/** @var ICachedMountInfo[] $removedMounts */
 		$removedMounts = array_udiff($cachedMounts, $newMounts, $mountDiff);
 
-		$changedMounts = array_uintersect($newMounts, $cachedMounts, function (ICachedMountInfo $mount1, ICachedMountInfo $mount2) {
-			// filter mounts with the same root id and different mountpoints
-			if ($mount1->getRootId() !== $mount2->getRootId()) {
-				return -1;
-			}
-			return ($mount1->getMountPoint() !== $mount2->getMountPoint()) ? 0 : 1;
-		});
+		$changedMounts = $this->findChangedMounts($newMounts, $cachedMounts);
 
 		foreach ($addedMounts as $mount) {
 			$this->addToCache($mount);
@@ -130,8 +124,28 @@ class UserMountCache implements IUserMountCache {
 			unset($this->mountsForUsers[$user->getUID()][$index]);
 		}
 		foreach ($changedMounts as $mount) {
-			$this->setMountPoint($mount);
+			$this->updateCachedMount($mount);
+		}
+	}
+
+	/**
+	 * @param ICachedMountInfo[] $newMounts
+	 * @param ICachedMountInfo[] $cachedMounts
+	 * @return ICachedMountInfo[]
+	 */
+	private function findChangedMounts(array $newMounts, array $cachedMounts) {
+		$changed = [];
+		foreach ($newMounts as $newMount) {
+			foreach ($cachedMounts as $cachedMount) {
+				if (
+					$newMount->getRootId() === $cachedMount->getRootId() &&
+					($newMount->getMountPoint() !== $cachedMount->getMountPoint() || $newMount->getMountId() !== $cachedMount->getMountId())
+				) {
+					$changed[] = $newMount;
+				}
+			}
 		}
+		return $changed;
 	}
 
 	private function addToCache(ICachedMountInfo $mount) {
@@ -140,18 +154,20 @@ class UserMountCache implements IUserMountCache {
 				'storage_id' => $mount->getStorageId(),
 				'root_id' => $mount->getRootId(),
 				'user_id' => $mount->getUser()->getUID(),
-				'mount_point' => $mount->getMountPoint()
+				'mount_point' => $mount->getMountPoint(),
+				'mount_id' => $mount->getMountId()
 			], ['root_id', 'user_id']);
 		} else {
 			$this->logger->error('Error getting storage info for mount at ' . $mount->getMountPoint());
 		}
 	}
 
-	private function setMountPoint(ICachedMountInfo $mount) {
+	private function updateCachedMount(ICachedMountInfo $mount) {
 		$builder = $this->connection->getQueryBuilder();
 
 		$query = $builder->update('mounts')
 			->set('mount_point', $builder->createNamedParameter($mount->getMountPoint()))
+			->set('mount_id', $builder->createNamedParameter($mount->getMountId(), IQueryBuilder::PARAM_INT))
 			->where($builder->expr()->eq('user_id', $builder->createNamedParameter($mount->getUser()->getUID())))
 			->andWhere($builder->expr()->eq('root_id', $builder->createNamedParameter($mount->getRootId(), IQueryBuilder::PARAM_INT)));
 
@@ -169,7 +185,7 @@ class UserMountCache implements IUserMountCache {
 
 	private function dbRowToMountInfo(array $row) {
 		$user = $this->userManager->get($row['user_id']);
-		return new CachedMountInfo($user, (int)$row['storage_id'], (int)$row['root_id'], $row['mount_point']);
+		return new CachedMountInfo($user, (int)$row['storage_id'], (int)$row['root_id'], $row['mount_point'], $row['mount_id']);
 	}
 
 	/**
@@ -179,7 +195,7 @@ class UserMountCache implements IUserMountCache {
 	public function getMountsForUser(IUser $user) {
 		if (!isset($this->mountsForUsers[$user->getUID()])) {
 			$builder = $this->connection->getQueryBuilder();
-			$query = $builder->select('storage_id', 'root_id', 'user_id', 'mount_point')
+			$query = $builder->select('storage_id', 'root_id', 'user_id', 'mount_point', 'mount_id')
 				->from('mounts')
 				->where($builder->expr()->eq('user_id', $builder->createPositionalParameter($user->getUID())));
 
@@ -196,7 +212,7 @@ class UserMountCache implements IUserMountCache {
 	 */
 	public function getMountsForStorageId($numericStorageId) {
 		$builder = $this->connection->getQueryBuilder();
-		$query = $builder->select('storage_id', 'root_id', 'user_id', 'mount_point')
+		$query = $builder->select('storage_id', 'root_id', 'user_id', 'mount_point', 'mount_id')
 			->from('mounts')
 			->where($builder->expr()->eq('storage_id', $builder->createPositionalParameter($numericStorageId, IQueryBuilder::PARAM_INT)));
 
@@ -211,7 +227,7 @@ class UserMountCache implements IUserMountCache {
 	 */
 	public function getMountsForRootId($rootFileId) {
 		$builder = $this->connection->getQueryBuilder();
-		$query = $builder->select('storage_id', 'root_id', 'user_id', 'mount_point')
+		$query = $builder->select('storage_id', 'root_id', 'user_id', 'mount_point', 'mount_id')
 			->from('mounts')
 			->where($builder->expr()->eq('root_id', $builder->createPositionalParameter($rootFileId, IQueryBuilder::PARAM_INT)));
 
diff --git a/lib/private/Files/Mount/MountPoint.php b/lib/private/Files/Mount/MountPoint.php
index e11da9e5c74..f76e8151059 100644
--- a/lib/private/Files/Mount/MountPoint.php
+++ b/lib/private/Files/Mount/MountPoint.php
@@ -68,14 +68,19 @@ class MountPoint implements IMountPoint {
 	 */
 	private $invalidStorage = false;
 
+	/** @var int|null  */
+	protected $mountId;
+
 	/**
 	 * @param string|\OC\Files\Storage\Storage $storage
 	 * @param string $mountpoint
 	 * @param array $arguments (optional) configuration for the storage backend
 	 * @param \OCP\Files\Storage\IStorageFactory $loader
 	 * @param array $mountOptions mount specific options
+	 * @param int|null $mountId
+	 * @throws \Exception
 	 */
-	public function __construct($storage, $mountpoint, $arguments = null, $loader = null, $mountOptions = null) {
+	public function __construct($storage, $mountpoint, $arguments = null, $loader = null, $mountOptions = null, $mountId = null) {
 		if (is_null($arguments)) {
 			$arguments = array();
 		}
@@ -102,6 +107,7 @@ class MountPoint implements IMountPoint {
 			$this->class = $storage;
 			$this->arguments = $arguments;
 		}
+		$this->mountId = $mountId;
 	}
 
 	/**
@@ -249,4 +255,8 @@ class MountPoint implements IMountPoint {
 	public function getStorageRootId() {
 		return (int)$this->getStorage()->getCache()->getId('');
 	}
+
+	public function getMountId() {
+		return $this->mountId;
+	}
 }
diff --git a/lib/private/legacy/app.php b/lib/private/legacy/app.php
index 87553cca805..37ceea35ac0 100644
--- a/lib/private/legacy/app.php
+++ b/lib/private/legacy/app.php
@@ -1091,6 +1091,7 @@ class OC_App {
 	 * @throws Exception if no app-name was specified
 	 */
 	public static function installApp($app) {
+		$appName = $app; // $app will be overwritten, preserve name for error logging
 		$l = \OC::$server->getL10N('core');
 		$config = \OC::$server->getConfig();
 		$ocsClient = new OCSClient(
@@ -1163,7 +1164,11 @@ class OC_App {
 			}
 			\OC_Hook::emit('OC_App', 'post_enable', array('app' => $app));
 		} else {
-			throw new \Exception($l->t("No app name specified"));
+			if(empty($appName) ) {
+				throw new \Exception($l->t("No app name specified"));
+			} else {
+				throw new \Exception($l->t("App '%s' could not be installed!", $appName));
+			}
 		}
 
 		return $app;
diff --git a/lib/private/legacy/files.php b/lib/private/legacy/files.php
index 8cf98322223..cb8dc35aa5c 100644
--- a/lib/private/legacy/files.php
+++ b/lib/private/legacy/files.php
@@ -192,7 +192,7 @@ class OC_Files {
 	 * @return array $rangeArray ('from'=>int,'to'=>int), ...
 	 */
 	private static function parseHttpRangeHeader($rangeHeaderPos, $fileSize) {
-		$rArray=split(',', $rangeHeaderPos);
+		$rArray=explode(',', $rangeHeaderPos);
 		$minOffset = 0;
 		$ind = 0;
 
diff --git a/lib/public/API.php b/lib/public/API.php
index 4d68bef6f29..d5c08f43347 100644
--- a/lib/public/API.php
+++ b/lib/public/API.php
@@ -35,6 +35,7 @@ namespace OCP;
 /**
  * This class provides functions to manage apps in ownCloud
  * @since 5.0.0
+ * @deprecated 9.1.0 Use the AppFramework
  */
 class API {
 
@@ -66,6 +67,7 @@ class API {
 	 * @param array $defaults
 	 * @param array $requirements
 	 * @since 5.0.0
+	 * @deprecated 9.1.0 Use the AppFramework
 	 */
 	public static function register($method, $url, $action, $app, $authLevel = self::USER_AUTH,
 		$defaults = array(), $requirements = array()){
diff --git a/lib/public/AppFramework/OCS/OCSBadRequestException.php b/lib/public/AppFramework/OCS/OCSBadRequestException.php
new file mode 100644
index 00000000000..0f4278fddc4
--- /dev/null
+++ b/lib/public/AppFramework/OCS/OCSBadRequestException.php
@@ -0,0 +1,45 @@
+<?php
+/**
+ *
+ * @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 OCP\AppFramework\OCS;
+
+use Exception;
+use OCP\AppFramework\Http;
+
+/**
+ * Class OCSBadRequestException
+ *
+ * @package OCP\AppFramework
+ * @since 9.1.0
+ */
+class OCSBadRequestException extends OCSException {
+	/**
+	 * OCSBadRequestException constructor.
+	 *
+	 * @param string $message
+	 * @param Exception|null $previous
+	 * @since 9.1.0
+	 */
+	public function __construct($message = '', Exception $previous = null) {
+		parent::__construct($message, Http::STATUS_BAD_REQUEST, $previous);
+	}
+
+}
diff --git a/lib/public/AppFramework/OCS/OCSException.php b/lib/public/AppFramework/OCS/OCSException.php
new file mode 100644
index 00000000000..f95b5a16844
--- /dev/null
+++ b/lib/public/AppFramework/OCS/OCSException.php
@@ -0,0 +1,32 @@
+<?php
+/**
+ *
+ * @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 OCP\AppFramework\OCS;
+
+use Exception;
+
+/**
+ * Class OCSException
+ *
+ * @package OCP\AppFramework
+ * @since 9.1.0
+ */
+class OCSException extends Exception {}
diff --git a/lib/public/AppFramework/OCS/OCSForbiddenException.php b/lib/public/AppFramework/OCS/OCSForbiddenException.php
new file mode 100644
index 00000000000..0c792722d9a
--- /dev/null
+++ b/lib/public/AppFramework/OCS/OCSForbiddenException.php
@@ -0,0 +1,44 @@
+<?php
+/**
+ *
+ * @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 OCP\AppFramework\OCS;
+
+use Exception;
+use OCP\AppFramework\Http;
+
+/**
+ * Class OCSForbiddenException
+ *
+ * @package OCP\AppFramework
+ * @since 9.1.0
+ */
+class OCSForbiddenException extends OCSException {
+	/**
+	 * OCSForbiddenException constructor.
+	 *
+	 * @param string $message
+	 * @param Exception|null $previous
+	 * @since 9.1.0
+	 */
+	public function __construct($message = '', Exception $previous = null) {
+		parent::__construct($message, Http::STATUS_FORBIDDEN, $previous);
+	}
+}
diff --git a/lib/public/AppFramework/OCS/OCSNotFoundException.php b/lib/public/AppFramework/OCS/OCSNotFoundException.php
new file mode 100644
index 00000000000..aaef36af1c7
--- /dev/null
+++ b/lib/public/AppFramework/OCS/OCSNotFoundException.php
@@ -0,0 +1,44 @@
+<?php
+/**
+ *
+ * @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 OCP\AppFramework\OCS;
+
+use Exception;
+use OCP\AppFramework\Http;
+
+/**
+ * Class OCSNotFoundException
+ *
+ * @package OCP\AppFramework
+ * @since 9.1.0
+ */
+class OCSNotFoundException extends OCSException {
+	/**
+	 * OCSNotFoundException constructor.
+	 *
+	 * @param string $message
+	 * @param Exception|null $previous
+	 * @since 9.1.0
+	 */
+	public function __construct($message = '', Exception $previous = null) {
+		parent::__construct($message, Http::STATUS_NOT_FOUND, $previous);
+	}
+}
diff --git a/lib/public/Files/Config/ICachedMountInfo.php b/lib/public/Files/Config/ICachedMountInfo.php
index e09c1a7f014..24c09654212 100644
--- a/lib/public/Files/Config/ICachedMountInfo.php
+++ b/lib/public/Files/Config/ICachedMountInfo.php
@@ -59,4 +59,12 @@ interface ICachedMountInfo {
 	 * @since 9.0.0
 	 */
 	public function getMountPoint();
+
+	/**
+	 * Get the id of the configured mount
+	 *
+	 * @return int|null mount id or null if not applicable
+	 * @since 9.1.0
+	 */
+	public function getMountId();
 }
diff --git a/lib/public/Files/Mount/IMountPoint.php b/lib/public/Files/Mount/IMountPoint.php
index bc7bf81709f..824b60a1024 100644
--- a/lib/public/Files/Mount/IMountPoint.php
+++ b/lib/public/Files/Mount/IMountPoint.php
@@ -102,4 +102,12 @@ interface IMountPoint {
 	 * @since 9.1.0
 	 */
 	public function getStorageRootId();
+
+	/**
+	 * Get the id of the configured mount
+	 *
+	 * @return int|null mount id or null if not applicable
+	 * @since 9.1.0
+	 */
+	public function getMountId();
 }
diff --git a/lib/public/Files/Storage/INotifyStorage.php b/lib/public/Files/Storage/INotifyStorage.php
new file mode 100644
index 00000000000..0ebfd689b87
--- /dev/null
+++ b/lib/public/Files/Storage/INotifyStorage.php
@@ -0,0 +1,51 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Robin Appelman <robin@icewind.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 OCP\Files\Storage;
+
+/**
+ * Storage backend that support active notifications
+ *
+ * @since 9.1.0
+ */
+interface INotifyStorage {
+	const NOTIFY_ADDED = 1;
+	const NOTIFY_REMOVED = 2;
+	const NOTIFY_MODIFIED = 3;
+	const NOTIFY_RENAMED = 4;
+
+	/**
+	 * Start listening for update notifications
+	 *
+	 * The provided callback will be called for every incoming notification with the following parameters
+	 *  - int $type the type of update, one of the INotifyStorage::NOTIFY_* constants
+	 *  - string $path the path of the update
+	 *  - string $renameTarget the target of the rename operation, only provided for rename updates
+	 *
+	 * Note that this call is blocking and will not exit on it's own, to stop listening for notifications return `false` from the callback
+	 *
+	 * @param string $path
+	 * @param callable $callback
+	 *
+	 * @since 9.1.0
+	 */
+	public function listen($path, callable $callback);
+}