001/*
002 * CDDL HEADER START
003 *
004 * The contents of this file are subject to the terms of the
005 * Common Development and Distribution License, Version 1.0 only
006 * (the "License").  You may not use this file except in compliance
007 * with the License.
008 *
009 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
010 * or http://forgerock.org/license/CDDLv1.0.html.
011 * See the License for the specific language governing permissions
012 * and limitations under the License.
013 *
014 * When distributing Covered Code, include this CDDL HEADER in each
015 * file and include the License file at legal-notices/CDDLv1_0.txt.
016 * If applicable, add the following below this CDDL HEADER, with the
017 * fields enclosed by brackets "[]" replaced with your own identifying
018 * information:
019 *      Portions Copyright [yyyy] [name of copyright owner]
020 *
021 * CDDL HEADER END
022 *
023 *
024 *      Copyright 2006-2009 Sun Microsystems, Inc.
025 *      Portions Copyright 2012-2015 ForgeRock AS.
026 */
027
028package org.opends.server.extensions;
029
030
031
032import java.io.IOException;
033import java.nio.ByteBuffer;
034import java.nio.channels.ByteChannel;
035
036
037
038/**
039 * This class redirects read and write requests either to a child byte channel,
040 * or a byte channel to be redirected to.
041 */
042public class RedirectingByteChannel implements ByteChannel
043{
044  /**
045   * Create an instance of a redirecting byte channel using the specified byte
046   * channel as the child.
047   *
048   * @param bc
049   *          A byte channel to use as the child.
050   * @return A redirecting byte channel.
051   */
052  public static RedirectingByteChannel getRedirectingByteChannel(
053      final ByteChannel bc)
054  {
055    return new RedirectingByteChannel(bc);
056  }
057
058
059
060  private final ByteChannel child;
061  private volatile ByteChannel redirect;
062
063
064
065  private RedirectingByteChannel(final ByteChannel child)
066  {
067    this.child = child;
068  }
069
070
071
072  /** {@inheritDoc} */
073  public void close() throws IOException
074  {
075    final ByteChannel tmp = redirect;
076    if (tmp != null)
077    {
078      tmp.close();
079    }
080    else
081    {
082      child.close();
083    }
084  }
085
086
087
088  /**
089   * Disable redirection.
090   */
091  public final void disable()
092  {
093    redirect = null;
094  }
095
096
097
098  /** {@inheritDoc} */
099  public boolean isOpen()
100  {
101    final ByteChannel tmp = redirect;
102    if (tmp != null)
103    {
104      return tmp.isOpen();
105    }
106    else
107    {
108      return child.isOpen();
109    }
110  }
111
112
113
114  /** {@inheritDoc} */
115  public int read(final ByteBuffer buffer) throws IOException
116  {
117    final ByteChannel tmp = redirect;
118    if (tmp != null)
119    {
120      return tmp.read(buffer);
121    }
122    else
123    {
124      return child.read(buffer);
125    }
126  }
127
128
129
130  /**
131   * Redirects a byte channel to a byte channel associated with the specified
132   * provider.
133   *
134   * @param provider
135   *          The provider to redirect to.
136   */
137  public final void redirect(final ConnectionSecurityProvider provider)
138  {
139    redirect = provider.getChannel();
140  }
141
142
143
144  /** {@inheritDoc} */
145  public int write(final ByteBuffer buffer) throws IOException
146  {
147    final ByteChannel tmp = redirect;
148    if (tmp != null)
149    {
150      return tmp.write(buffer);
151    }
152    else
153    {
154      return child.write(buffer);
155    }
156  }
157}