001 /*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020 package org.crsh.vfs;
021
022 import org.crsh.vfs.spi.FSDriver;
023
024 import java.io.IOException;
025
026 class Mount<H> {
027
028 static <H> Mount<H> wrap(FSDriver<H> driver) {
029 return new Mount<H>(driver);
030 }
031
032 /** . */
033 final FSDriver<H> driver;
034
035 /**
036 * Create a new mount
037 *
038 * @param driver the driver
039 * @throws NullPointerException if the driver is null
040 */
041 Mount(FSDriver<H> driver) throws NullPointerException {
042 if (driver == null) {
043 throw new NullPointerException("No null driver accepted");
044 }
045 this.driver = driver;
046 }
047
048 Handle<H> getHandle(Path path) throws IOException {
049 H current = driver.root();
050 for (String name : path) {
051 H next = null;
052 for (H child : driver.children(current)) {
053 String childName = driver.name(child);
054 if (childName.equals(name)) {
055 next = child;
056 break;
057 }
058 }
059 if (next == null) {
060 return null;
061 } else {
062 current = next;
063 }
064 }
065 if (path.isDir() == driver.isDir(current)) {
066 return new Handle<H>(driver, current);
067 } else {
068 return null;
069 }
070 }
071 }