jtlsinputstream.java

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

        try {
            dos.writeInt(seqnAck);
            
            Iterator<Integer> eachSACK = sackList.iterator();
            
            while (eachSACK.hasNext()) {
                int aSack = (eachSACK.next()).intValue();

                dos.writeInt(aSack);
            }
            dos.close();
            bos.close();
            
            Message ACKMsg = new Message();
            MessageElement elt = new ByteArrayMessageElement(JTlsDefs.ACKKEY, JTlsDefs.ACKS, bos.toByteArray(), null);
            
            ACKMsg.addMessageElement(JTlsDefs.TLSNameSpace, elt);
            
            conn.sendToRemoteTls(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_INFO && LOG.isLoggable(Level.INFO)) {
                LOG.log(Level.INFO, "sendACK caught IOException:", e);
            }
        }
    }
    
    /**
     *  queue messages by sequence number.
     */
    public void queueIncomingMessage(Message msg) {
        
        if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
            LOG.fine("Queue Incoming Message begins for " + msg);
        }
        
        long startEnqueue = TimeUtils.timeNow();
        
        Message.ElementIterator e = msg.getMessageElements(JTlsDefs.TLSNameSpace, JTlsDefs.BLOCKS);
        
        // OK look for jxta message
        while (!closed && !closing && e.hasNext()) {
            MessageElement elt = e.next();

            e.remove();
            
            int msgSeqn = 0;
            
            try {
                msgSeqn = Integer.parseInt(elt.getElementName());
            } catch (NumberFormatException n) {
                if (Logging.SHOW_WARNING && LOG.isLoggable(Level.WARNING)) {
                    LOG.warning("Discarding element (" + elt.getElementName() + ") Not one of ours.");
                }
                continue;
            }
            
            IQElt newElt = new IQElt();
            
            newElt.seqnum = msgSeqn;
            newElt.elt = elt;
            newElt.ackd = false;
            
            // OK we must inqueue:
            // Wait until someone dequeues if we are at the size limit
            // see if this is a duplicate
            if (newElt.seqnum <= sequenceNumber) {
                if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                    LOG.fine("RCVD OLD MESSAGE : Discard seqn#" + newElt.seqnum + " now at seqn#" + sequenceNumber);
                }
                break;
            }
            synchronized (inputQueue) {
                // dbl check with the lock held.
                if (closing || closed) {
                    return;
                }
                
                // Insert this message into the input queue.
                // 1. Do not add duplicate messages
                // 2. Store in increasing sequence nos.
                int insertIndex = inputQueue.size();
                boolean duplicate = false;
                
                for (int j = 0; j < inputQueue.size(); j++) {
                    IQElt iq = inputQueue.elementAt(j);

                    if (newElt.seqnum < iq.seqnum) {
                        insertIndex = j;
                        break;
                    } else if (newElt.seqnum == iq.seqnum) {
                        duplicate = true;
                        break;
                    }
                }
                
                if (duplicate) {
                    if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                        LOG.fine("RCVD OLD MESSAGE : Discard duplicate msg, seqn#" + newElt.seqnum);
                    }
                    newElt = null;
                    break;
                }
                
                inputQueue.add(insertIndex, newElt);
                
                if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                    LOG.fine("Enqueued msg with seqn#" + newElt.seqnum + " at index " + insertIndex);
                }
                
                inputQueue.notifyAll();
                newElt = null;
            }
        }
        if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
            long waited = TimeUtils.toRelativeTimeMillis(TimeUtils.timeNow(), startEnqueue);
            
            LOG.fine("Queue Incoming Message for " + msg + " completed in " + waited + " msec.");
        }
    }
    
    /**
     *  Dequeue the message with the desired sequence number waiting as needed
     *  until the message is available.
     *
     *  @param desiredSeqn the sequence number to be dequeued.
     *  @return the Message Element with the desired sequence number or null if
     *  the queue has been closed.
     **/
    private MessageElement dequeueMessage(int desiredSeqn) throws IOException {
        IQElt iQ = null;
        
        // Wait for incoming message here
        long startDequeue = TimeUtils.timeNow();
        long whenToTimeout = startDequeue + timeout;
        int wct = 0;
        
        long nextRetransRequest = TimeUtils.toAbsoluteTimeMillis(TimeUtils.ASECOND);
        
        synchronized (inputQueue) {
            while (!closed) {
                if (inputQueue.size() == 0) {
                    if (closing) {
                        return null;
                    }
                    try {
                        wct++;
                        inputQueue.wait(TimeUtils.ASECOND);
                        if (whenToTimeout < TimeUtils.timeNow()) {
                            throw new SocketTimeoutException("Read timeout reached");
                        }
                    } catch (InterruptedException e) {
                        Thread.interrupted(); // just continue
                    }
                    // we reset the retrans request timer since we don't want to
                    // immediately request retry after a long wait for out of
                    // order messages.
                    
                    nextRetransRequest = TimeUtils.toAbsoluteTimeMillis(TimeUtils.ASECOND);
                    continue;
                }
                
                iQ = inputQueue.elementAt(0); // FIFO
                
                if (iQ.seqnum < desiredSeqn) {
                    // Ooops a DUPE slipped in the head of the queue undetected
                    // (seqnum consistency issue).
                    // Just drop it.
                    inputQueue.remove(0);
                    // if such is the case then notify the other end so that
                    // the message does not remain in the retry queue eventually
                    // triggering a broken pipe exception
                    sendACK(iQ.seqnum);
                    continue;
                } else if (iQ.seqnum != desiredSeqn) {
                    if (TimeUtils.toRelativeTimeMillis(nextRetransRequest) < 0) {
                        if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                            LOG.fine("Trigger retransmission. Wanted seqn#" + desiredSeqn + " found seqn#" + iQ.seqnum);
                        }
                        sendACK(desiredSeqn - 1);
                        nextRetransRequest = TimeUtils.toAbsoluteTimeMillis(TimeUtils.ASECOND);
                    }
                    
                    try {
                        wct++;
                        inputQueue.wait(TimeUtils.ASECOND);
                        if (whenToTimeout < TimeUtils.timeNow()) {
                            throw new SocketTimeoutException("Read timeout reached");
                        }
                    } catch (InterruptedException e) {
                        throw new InterruptedIOException("IO interrupted ");
                    }
                    continue;
                }
                
                inputQueue.remove(0);
                break;
            }
        }
        
        nextRetransRequest = 0;
        sendACK(desiredSeqn);
        // if we are closed then we return null
        if (null == iQ) {
            return null;
        }
        
        if (Logging.SHOW_INFO && LOG.isLoggable(Level.INFO)) {
            long waited = TimeUtils.toRelativeTimeMillis(TimeUtils.timeNow(), startDequeue);
            
            LOG.info("DEQUEUED seqn#" + iQ.seqnum + " in " + waited + " msec on input queue");
            if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                if (wct > 0) {
                    LOG.fine("DEQUEUE waited " + wct + " times on input queue");
                }
            }
        }
        
        return iQ.elt;
    }
    
    /**
     *
     */
    private int local_read(byte[] a, int offset, int length) throws IOException {
        
        synchronized (jtrec) {
            if ((jtrec.size == 0) || (jtrec.nextByte == jtrec.size)) {
                
                // reset the record
                jtrec.resetRecord(); // GC as necessary(tlsRecord byte[])
                
                if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                    LOG.fine("local_read: getting next data block at seqn#" + (sequenceNumber + 1));
                }
                
                MessageElement elt = null;

                try {
                    elt = dequeueMessage(sequenceNumber + 1);
                } catch (SocketTimeoutException ste) {
                    // timed out with no data
                    // SSLSocket expects a 0 data in this case
                    return 0;
                }
                
                if (null == elt) {
                    return -1;
                }
                
                sequenceNumber += 1; // next msg sequence number
                
                // Get the length of the TLS Record
                jtrec.size = elt.getByteLength();
                jtrec.tlsRecord = elt.getStream();
                
                if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                    LOG.fine("local_read: new seqn#" + sequenceNumber + ", bytes = " + jtrec.size);
                }
            }
            
            // return the requested TLS Record data
            // These calls should NEVER ask for more data than is in the
            // received TLS Record.
            
            long left = jtrec.size - jtrec.nextByte;
            int copyLen = (int) Math.min(length, left);
            int copied = 0;
            
            do {
                int res = jtrec.tlsRecord.read(a, offset + copied, copyLen - copied);
                
                if (res < 0) {
                    break;
                }
                
                copied += res;
            } while (copied < copyLen);
            
            jtrec.nextByte += copied;
            
            if (DEBUGIO) {
                if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                    LOG.fine("local_read: Requested " + length + ", Read " + copied + " bytes");
                }
            }
            
            return copied;
        }
    }
}