add notify support to smb storage

apps/files_external/lib/Lib/Storage/SMB.php

@@ -34,15 +34,18 @@ use Icewind\SMB\Exception\ConnectException;
 use Icewind\SMB\Exception\Exception;
 use Icewind\SMB\Exception\ForbiddenException;
 use Icewind\SMB\Exception\NotFoundException;
+use Icewind\SMB\IShare;
 use Icewind\SMB\NativeServer;
 use Icewind\SMB\Server;
 use Icewind\Streams\CallbackWrapper;
 use Icewind\Streams\IteratorDirectory;
 use OC\Cache\CappedMemoryCache;
 use OC\Files\Filesystem;
+use OC\Files\Storage\Common;
+use OCP\Files\Storage\INotifyStorage;
 use OCP\Files\StorageNotAvailableException;
 
-class SMB extends \OC\Files\Storage\Common {
+class SMB extends Common implements INotifyStorage {
 	/**
 	 * @var \Icewind\SMB\Server
 	 */
@@ -103,6 +106,16 @@ class SMB extends \OC\Files\Storage\Common {
 		return Filesystem::normalizePath($this->root . '/' . $path, true, false, true);
 	}
 
+	protected function relativePath($fullPath) {
+		if ($fullPath === $this->root) {
+			return '';
+		} else if (substr($fullPath, 0, strlen($this->root)) === $this->root) {
+			return substr($fullPath, strlen($this->root));
+		} else {
+			return null;
+		}
+	}
+
 	/**
 	 * @param string $path
 	 * @return \Icewind\SMB\IFileInfo
@@ -413,4 +426,48 @@ class SMB extends \OC\Files\Storage\Common {
 			return false;
 		}
 	}
+
+	public function listen($path, callable $callback) {
+		$fullPath = $this->buildPath($path);
+		$oldRenamePath = null;
+		$this->share->notify($fullPath, function ($smbType, $fullPath) use (&$oldRenamePath, $callback) {
+			$path = $this->relativePath($fullPath);
+			if (is_null($path)) {
+				return true;
+			}
+			if ($smbType === IShare::NOTIFY_RENAMED_OLD) {
+				$oldRenamePath = $path;
+				return true;
+			}
+			$type = $this->mapNotifyType($smbType);
+			if (is_null($type)) {
+				return true;
+			}
+			if ($type === INotifyStorage::NOTIFY_RENAMED && !is_null($oldRenamePath)) {
+				$result = $callback($type, $path, $oldRenamePath);
+				$oldRenamePath = null;
+			} else {
+				$result = $callback($type, $path);
+			}
+			return $result;
+		});
+	}
+
+	private function mapNotifyType($smbType) {
+		switch ($smbType) {
+			case IShare::NOTIFY_ADDED:
+				return INotifyStorage::NOTIFY_ADDED;
+			case IShare::NOTIFY_REMOVED:
+				return INotifyStorage::NOTIFY_REMOVED;
+			case IShare::NOTIFY_MODIFIED:
+			case IShare::NOTIFY_ADDED_STREAM:
+			case IShare::NOTIFY_MODIFIED_STREAM:
+			case IShare::NOTIFY_REMOVED_STREAM:
+				return INotifyStorage::NOTIFY_MODIFIED;
+			case IShare::NOTIFY_RENAMED_NEW:
+				return INotifyStorage::NOTIFY_RENAMED;
+			default:
+				return null;
+		}
+	}
 }

lib/public/Files/Storage/INotifyStorage.php

@@ -0,0 +1,47 @@
+<?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
+ */
+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 $callback
+	 */
+	public function listen($path, callable $callback);
+}