reliableinputstream.java

JXTA&#8482 is a set of open, generalized peer-to-peer (P2P) protocols that allow any networked devi

/*
 * Copyright (c) 2003-2007 Sun Microsystems, Inc.  All rights reserved.
 *  
 *  The Sun Project JXTA(TM) Software License
 *  
 *  Redistribution and use in source and binary forms, with or without 
 *  modification, are permitted provided that the following conditions are met:
 *  
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
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 *     this list of conditions and the following disclaimer in the documentation 
 *     and/or other materials provided with the distribution.
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 *  3. The end-user documentation included with the redistribution, if any, must 
 *     include the following acknowledgment: "This product includes software 
 *     developed by Sun Microsystems, Inc. for JXTA(TM) technology." 
 *     Alternately, this acknowledgment may appear in the software itself, if 
 *     and wherever such third-party acknowledgments normally appear.
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 *  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must 
 *     not be used to endorse or promote products derived from this software 
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 *     Project JXTA at http://www.jxta.org.
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 *  States and other countries.
 *  
 *  Please see the license information page at :
 *  <http://www.jxta.org/project/www/license.html> for instructions on use of 
 *  the license in source files.
 *  
 *  ====================================================================
 *  
 *  This software consists of voluntary contributions made by many individuals 
 *  on behalf of Project JXTA. For more information on Project JXTA, please see 
 *  http://www.jxta.org.
 *  
 *  This license is based on the BSD license adopted by the Apache Foundation. 
 */

package net.jxta.impl.util.pipe.reliable;


import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.net.SocketTimeoutException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

import net.jxta.endpoint.ByteArrayMessageElement;
import net.jxta.endpoint.Message;
import net.jxta.endpoint.MessageElement;
import net.jxta.endpoint.WireFormatMessageFactory;
import net.jxta.impl.util.TimeUtils;

import java.util.logging.Level;
import net.jxta.logging.Logging;
import java.util.logging.Logger;


/**
 *  Acts as a reliable input stream. Accepts data which
 *  arrives in messages and orders it.
 */
public class ReliableInputStream extends InputStream implements Incoming {
    
    /**
     *  Logger
     */
    private static final Logger LOG = Logger.getLogger(ReliableInputStream.class.getName());
    
    /**
     *  Connection we are working for.
     */
    private Outgoing outgoing;
    
    private volatile boolean closed = false;
    private boolean closing = false;
    
    private MsgListener listener = null;
    
    /**
     *  The amount of time that read() operation will block. > 0
     */
    private long timeout;
    
    /**
     *  The current sequence number we are reading bytes from.
     */
    private volatile int sequenceNumber = 0;
    
    /**
     *  Queue of incoming messages.
     */
    private final List<IQElt> inputQueue = new ArrayList<IQElt>();
    
    /**
     *  The I/O record for the message we are currently using for stream data.
     */
    private final Record record;
    
    /**
     * Input record Object
     */
    private static class Record {
        public InputStream inputStream;
        // next inbuff byte
        public long nextByte;
        // size of Record
        public long size;
        
        public Record() {
            inputStream = null; // allocated by caller
            nextByte = 0; // We read here (set by caller)
            size = 0; // Record size(set by caller)
        }
        
        /** reset the record element
         *
         */
        public void resetRecord() {
            if (null != inputStream) {
                try {
                    inputStream.close();
                } catch (IOException ignored) {}
            }
            inputStream = null;
            size = nextByte = 0;
        }
    }
    

    /**
     *  An input queue element which breaks out a received message in 
     *  enqueueMessage().
     */
    private static class IQElt implements Comparable {
        final int seqnum;
        final MessageElement elt;
        boolean ackd = false;
        
        IQElt(int sequence, MessageElement element) {
            seqnum = sequence;
            elt = element;
        }
        
        /**
         * {@inheritDoc}
         */
        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj instanceof IQElt) {
                IQElt targ = (IQElt) obj;

                return (this.seqnum == targ.seqnum);
            }
            return false;
        }
        
        public int compareTo(IQElt el) {
            return this.seqnum < el.seqnum ? -1 : this.seqnum == el.seqnum ? 0 : 1;
        }
        
        /**
         * {@inheritDoc}
         */
        public int compareTo(Object o) {
            return compareTo((IQElt) o);
        }
    }
    
    public ReliableInputStream(Outgoing outgoing, int timeout) {
        this(outgoing, timeout, null);
    }
    
    public ReliableInputStream(Outgoing outgoing, int timeout, MsgListener listener) {
        this.outgoing = outgoing;
        setTimeout(timeout);
        
        record = new Record();
        this.listener = listener;
        // 1 <= seq# <= maxint, monotonically increasing
        // Incremented before compare.
        sequenceNumber = 0;
        if (Logging.SHOW_INFO && LOG.isLoggable(Level.INFO)) {
            if (listener != null) {
                LOG.info("Listener based ReliableInputStream created");
            }
        }
    }
    
    /**
     * {@inheritDoc}
     *
     * <p/>This is an explicit close operation. All subsequent {@code read()}
     * operations will fail.
     */
    @Override
    public void close() throws IOException {
        super.close();
        synchronized (inputQueue) {
            closed = true;
            inputQueue.clear();
            inputQueue.notifyAll();
        }
    }
    
    /**
     * Returns true if closed
     *
     * @return true if closed
     */
    public boolean isInputShutdown() {
        return closed;
    }
    
    /**
     * Prepare this input stream to being closed. It will still deliver the
     * packets that have been received, but nothing more. This is meant to be
     * called in response to the other side having initiated closure. We assume
     * that when the other side does it it means that it is satisfied with what
     * we have acknowledged so far.
     */
    public void softClose() {
        synchronized (inputQueue) {
            closing = true;
            inputQueue.notifyAll();
        }
    }
    
    /**
     *  Sets the Timeout attribute. A timeout of 0 blocks forever
     *
     * @param  timeout The new soTimeout value
     */
    public void setTimeout(int timeout) {
        if (timeout < 0) {
            throw new IllegalArgumentException("Timeout must be >=0");
        }
        
        this.timeout = (0 == timeout) ? Long.MAX_VALUE : timeout;
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public int read() throws IOException {
        if (closed) {
            return -1;
        }
        
        byte[] a = new byte[1];
        
        while (true) {
            int len = local_read(a, 0, 1);
            
            if (len < 0) {
                break;
            }
            if (len > 0) {
                if (Logging.SHOW_FINER && LOG.isLoggable(Level.FINER)) {
                    LOG.finer("Read() : " + (a[0] & 255));
                }
                
                return a[0] & 0xFF; // The byte
            }
        }
        
        // If we've reached EOF, there's nothing to do but close().
        
        close();
        return -1;
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public int read(byte[] a, int offset, int length) throws IOException {
        if (closed) {
            return -1;
        }
        
        if (0 == length) {
            return 0;
        }
        
        int i = local_read(a, offset, length);
        
        if (Logging.SHOW_FINER && LOG.isLoggable(Level.FINER)) {
            LOG.finer("Read(byte[], int, " + length + "), bytes read = " + i);
        }
        
        // If we've reached EOF; there's nothing to do but close().
        if (i == -1) {
            close();
        }
        return i;
    }
    
    /**
     *  Send a sequential ACK and selective ACKs for all of
     *  the queued messages.
     *
     *  @param seqnAck the sequence number being sequential ACKed
     */
    private void sendACK(int seqnAck) {
        // No need to sync on inputQueue, acking as many as we can is want we want
        List<Integer> selectedAckList = new ArrayList<Integer>();
        List<IQElt> queue;
        
        synchronized (inputQueue) {
            queue = new ArrayList<IQElt>(inputQueue);
        }
        
        Iterator<IQElt> eachInQueue = queue.iterator();

        while (eachInQueue.hasNext() && (selectedAckList.size() < Defs.MAXQUEUESIZE)) {
            IQElt anIQElt = eachInQueue.next();

            if (anIQElt.seqnum > seqnAck) {
                if (!anIQElt.ackd) {
                    selectedAckList.add(anIQElt.seqnum);
                    anIQElt.ackd = true;
                }
            }
        }
        
        // PERMIT DUPLICATE ACKS. Just a list and one small message.
        sendACK(seqnAck, selectedAckList);
    }
    
    /**
     *  Build an ACK message. The message provides a sequential ACK count and
     *  an optional list of selective ACKs.
     *
     *  @param seqnAck the sequence number being sequential ACKed
     *  @param sackList a list of selective ACKs. Must be sorted in increasing
     *  order.
     */
    private void sendACK(int seqnAck, List<Integer> sackList) {
        ByteArrayOutputStream bos = new ByteArrayOutputStream((1 + sackList.size()) * 4);
        DataOutputStream dos = new DataOutputStream(bos);
        
        try {
            dos.writeInt(seqnAck);
            for (Integer aSackList : sackList) {
                dos.writeInt(aSackList);
            }
            dos.close();
            bos.close();
            
            Message ACKMsg = new Message();
            MessageElement elt = new ByteArrayMessageElement(Defs.ACK_ELEMENT_NAME, Defs.MIME_TYPE_ACK, bos.toByteArray(), null);
            
            ACKMsg.addMessageElement(Defs.NAMESPACE, elt);
            
            outgoing.send(ACKMsg);
            
            if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                LOG.fine("SENT ACK, seqn#" + seqnAck + " and " + sackList.size() + " SACKs ");
            }
        } catch (IOException e) {
            if (Logging.SHOW_WARNING && LOG.isLoggable(Level.WARNING)) {