001/*
002 * The contents of this file are subject to the terms of the Common Development and
003 * Distribution License (the License). You may not use this file except in compliance with the
004 * License.
005 *
006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
007 * specific language governing permission and limitations under the License.
008 *
009 * When distributing Covered Software, include this CDDL Header Notice in each file and include
010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
011 * Header, with the fields enclosed by brackets [] replaced by your own identifying
012 * information: "Portions Copyright [year] [name of copyright owner]".
013 *
014 * Copyright 2010–2011 ApexIdentity Inc.
015 * Portions Copyright 2011-2016 ForgeRock AS.
016 */
017
018package org.forgerock.http.io;
019
020import java.io.IOException;
021import java.io.InputStream;
022
023/**
024 * An input stream that can branch into separate input streams to perform
025 * divergent reads.
026 */
027public abstract class BranchingInputStream extends InputStream {
028
029    /**
030     * Creates a new branch at this stream's current position.
031     * The returned stream will have this stream as its parent.
032     *
033     * @return a new branching stream, in the same position as this branch.
034     * @throws IOException
035     *             if an I/O exception occurs.
036     */
037    public abstract BranchingInputStream branch() throws IOException;
038
039    /**
040     * Creates a twin of this stream at this stream's current position.
041     * The returned stream will have the same parent as this stream.
042     *
043     * @return a new twin stream, in the same position as this branch.
044     * @throws IOException
045     *             if an I/O exception occurs.
046     */
047    public abstract BranchingInputStream copy() throws IOException;
048
049    /**
050     * Closes this branching stream and all of the branches created from it.
051     *
052     * @throws IOException
053     *             if an I/O exception occurs.
054     */
055    public abstract void close() throws IOException;
056
057    /**
058     * Returns the parent branching input stream from which this branch was
059     * created, or {@code null} if this is the trunk.
060     *
061     * @return the parent branching input stream from which this branch was
062     *         created, or {@code null} if this is the trunk.
063     */
064    public abstract BranchingInputStream parent();
065}