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
020package org.crsh.vfs;
021
022import org.crsh.vfs.spi.FSDriver;
023
024import java.io.IOException;
025
026class 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}