/*
* Copyright (c) [2016] [ <ether.camp> ]
* This file is part of the ethereumJ library.
*
* The ethereumJ library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* The ethereumJ library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with the ethereumJ library. If not, see <http://www.gnu.org/licenses/>.
*/
package org.ethereum.net;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import org.ethereum.listener.EthereumListener;
import org.ethereum.net.eth.message.EthMessage;
import org.ethereum.net.message.Message;
import org.ethereum.net.message.ReasonCode;
import org.ethereum.net.p2p.DisconnectMessage;
import org.ethereum.net.p2p.PingMessage;
import org.ethereum.net.p2p.PongMessage;
import org.ethereum.net.server.Channel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;
import java.util.Queue;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;
import static org.ethereum.net.message.StaticMessages.DISCONNECT_MESSAGE;
/**
* This class contains the logic for sending messages in a queue
*
* Messages open by send and answered by receive of appropriate message
* PING by PONG
* GET_PEERS by PEERS
* GET_TRANSACTIONS by TRANSACTIONS
* GET_BLOCK_HASHES by BLOCK_HASHES
* GET_BLOCKS by BLOCKS
*
* The following messages will not be answered:
* PONG, PEERS, HELLO, STATUS, TRANSACTIONS, BLOCKS
*
* @author Roman Mandeleil
*/
@Component
@Scope("prototype")
public class MessageQueue {
private static final Logger logger = LoggerFactory.getLogger("net");
private static final ScheduledExecutorService timer = Executors.newScheduledThreadPool(4, new ThreadFactory() {
private AtomicInteger cnt = new AtomicInteger(0);
public Thread newThread(Runnable r) {
return new Thread(r, "MessageQueueTimer-" + cnt.getAndIncrement());
}
});
private Queue<MessageRoundtrip> requestQueue = new ConcurrentLinkedQueue<>();
private Queue<MessageRoundtrip> respondQueue = new ConcurrentLinkedQueue<>();
private ChannelHandlerContext ctx = null;
@Autowired
EthereumListener ethereumListener;
boolean hasPing = false;
private ScheduledFuture<?> timerTask;
private Channel channel;
public MessageQueue() {
}
public void activate(ChannelHandlerContext ctx) {
this.ctx = ctx;
timerTask = timer.scheduleAtFixedRate(new Runnable() {
public void run() {
try {
nudgeQueue();
} catch (Throwable t) {
logger.error("Unhandled exception", t);
}
}
}, 10, 10, TimeUnit.MILLISECONDS);
}
public void setChannel(Channel channel) {
this.channel = channel;
}
public void sendMessage(Message msg) {
if (msg instanceof PingMessage) {
if (hasPing) return;
hasPing = true;
}
if (msg.getAnswerMessage() != null)
requestQueue.add(new MessageRoundtrip(msg));
else
respondQueue.add(new MessageRoundtrip(msg));
}
public void disconnect() {
disconnect(DISCONNECT_MESSAGE);
}
public void disconnect(ReasonCode reason) {
disconnect(new DisconnectMessage(reason));
}
private void disconnect(DisconnectMessage msg) {
ctx.writeAndFlush(msg);
ctx.close();
}
public void receivedMessage(Message msg) throws InterruptedException {
ethereumListener.trace("[Recv: " + msg + "]");
if (requestQueue.peek() != null) {
MessageRoundtrip messageRoundtrip = requestQueue.peek();
Message waitingMessage = messageRoundtrip.getMsg();
if (waitingMessage instanceof PingMessage) hasPing = false;
if (waitingMessage.getAnswerMessage() != null
&& msg.getClass() == waitingMessage.getAnswerMessage()) {
messageRoundtrip.answer();
if (waitingMessage instanceof EthMessage)
channel.getPeerStats().pong(messageRoundtrip.lastTimestamp);
logger.trace("Message round trip covered: [{}] ",
messageRoundtrip.getMsg().getClass());
}
}
}
private void removeAnsweredMessage(MessageRoundtrip messageRoundtrip) {
if (messageRoundtrip != null && messageRoundtrip.isAnswered())
requestQueue.remove();
}
private void nudgeQueue() {
// remove last answered message on the queue
removeAnsweredMessage(requestQueue.peek());
// Now send the next message
sendToWire(respondQueue.poll());
sendToWire(requestQueue.peek());
}
private void sendToWire(MessageRoundtrip messageRoundtrip) {
if (messageRoundtrip != null && messageRoundtrip.getRetryTimes() == 0) {
// TODO: retry logic || messageRoundtrip.hasToRetry()){
Message msg = messageRoundtrip.getMsg();
ethereumListener.onSendMessage(channel, msg);
ctx.writeAndFlush(msg).addListener(ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE);
if (msg.getAnswerMessage() != null) {
messageRoundtrip.incRetryTimes();
messageRoundtrip.saveTime();
}
}
}
public void close() {
if (timerTask != null) {
timerTask.cancel(false);
}
}
}