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    }