jtlsinputstream.java

jxta_src_2.41b jxta 2.41b 最新版源码 from www.jxta.org

            Iterator eachSACK = sackList.iterator();

            while (eachSACK.hasNext()) {
                int aSack = ((Integer) 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 (LOG.isEnabledFor(Level.DEBUG)) {
                LOG.debug("SENT ACK, seqn#" + seqnAck + " and " + sackList.size() + " SACKs ");
            }
        } catch (IOException e) {
            if (LOG.isEnabledFor(Level.INFO)) {
                LOG.info("sendACK caught IOException:", e);
            }
        }
    }

    /**
     *  queue messages by sequence number.
     */
    public void queueIncomingMessage(Message msg) {

        if (LOG.isEnabledFor(Level.DEBUG)) {
            LOG.debug("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 = (MessageElement) e.next();
            e.remove();

            int msgSeqn = 0;

            try {
                msgSeqn = Integer.parseInt(elt.getElementName());
            } catch (NumberFormatException n) {
                if (LOG.isEnabledFor(Level.WARN)) {
                    LOG.warn("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 (LOG.isEnabledFor(Level.DEBUG)) {
                    LOG.debug("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 = (IQElt) inputQueue.elementAt(j);
                    if (newElt.seqnum < iq.seqnum) {
                        insertIndex = j;
                        break;
                    } else if (newElt.seqnum == iq.seqnum) {
                            duplicate = true;
                            break;
                        }
                }

                if (duplicate) {
                    if (LOG.isEnabledFor(Level.DEBUG)) {
                        LOG.debug("RCVD OLD MESSAGE : Discard duplicate msg, seqn#" + newElt.seqnum);
                    }
                    newElt = null;
                    break;
                }

                inputQueue.add(insertIndex, newElt);

                if (LOG.isEnabledFor(Level.DEBUG)) {
                    LOG.debug("Enqueued msg with seqn#" + newElt.seqnum + " at index " + insertIndex);
                }

                inputQueue.notifyAll();
                newElt = null;
            }
        }
        if (LOG.isEnabledFor(Level.DEBUG)) {
            long waited = TimeUtils.toRelativeTimeMillis(TimeUtils.timeNow(), startEnqueue);

            LOG.debug("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 = (IQElt) 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 (LOG.isEnabledFor(Level.DEBUG)) {
                                LOG.info("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 (LOG.isEnabledFor(Level.INFO)) {
            long waited =
                TimeUtils.toRelativeTimeMillis(TimeUtils.timeNow(),
                                               startDequeue);

            LOG.info("DEQUEUED seqn#" + iQ.seqnum + " in " + waited +
                     " msec on input queue" );
            if (wct > 0) {
                LOG.debug("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 (LOG.isEnabledFor(Level.DEBUG)) {
                    LOG.debug("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 (LOG.isEnabledFor(Level.DEBUG)) {
                    LOG.debug("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 (LOG.isEnabledFor(Level.DEBUG)) {
                    LOG.debug("local_read: Requested " + length + ", Read " + copied + " bytes");
                }
            }

            return copied;
        }
    }
}