Added ShareHelper

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

lib/private/Share20/ShareHelper.php

@@ -0,0 +1,64 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016, 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\Share20;
+
+use OCP\Files\IRootFolder;
+use OCP\Files\Node;
+use OCP\Files\NotFoundException;
+
+class ShareHelper {
+	/** @var IRootFolder */
+	private $rootFolder;
+
+	public function __construct(IRootFolder $rootFolder) {
+		$this->rootFolder = $rootFolder;
+	}
+
+	/**
+	 * If a user has access to a file
+	 *
+	 * @param Node $node
+	 * @param array $users Array of userIds
+	 * @return array Mapping $uid to an array of nodes
+	 */
+	public function getPathsForAccessList(Node $node, $users) {
+		$result = [];
+
+		foreach ($users as $user) {
+			try {
+				$userFolder = $this->rootFolder->getUserFolder($user);
+			} catch (NotFoundException $e) {
+				continue;
+			}
+
+			$nodes = $userFolder->getById($node->getId());
+			if ($nodes === []) {
+				continue;
+			}
+
+			$result[$user] = $nodes;
+		}
+
+		return $result;
+	}
+}