2 * Copyright (c) 2020 PANTHEON.tech, s.r.o. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.mdsal.replicate.netty;
10 import io.netty.channel.ChannelHandlerContext;
11 import io.netty.handler.timeout.IdleStateEvent;
12 import org.slf4j.Logger;
13 import org.slf4j.LoggerFactory;
15 final class SourceKeepaliveHandler extends AbstractKeepaliveHandler {
16 private static final Logger LOG = LoggerFactory.getLogger(SourceKeepaliveHandler.class);
18 private final int maxMissedKeepalives;
20 private int pingsSinceLastContact;
22 SourceKeepaliveHandler(final int maxMissedKeepalives) {
23 this.maxMissedKeepalives = maxMissedKeepalives;
27 * Intercept messages from the Sink. Reset the pingsSinceLastContact counter and forward the message.
30 public void channelRead(final ChannelHandlerContext ctx, final Object msg) {
31 pingsSinceLastContact = 0;
32 ctx.fireChannelRead(msg);
36 * If the IdleStateEvent was fired, it means the Source has not written anything to the Sink for the duration
37 * specified by the keepalive-interval. PING will be sent and pingsSinceLastContact incremented.
38 * If pingsSinceLastContact reaches max-missed-keepalives a KeepaliveException will be raised and channel closed.
41 public void userEventTriggered(final ChannelHandlerContext ctx, final Object evt) {
42 if (evt instanceof IdleStateEvent) {
43 LOG.trace("IdleStateEvent received. Sending PING to sink");
44 if (pingsSinceLastContact > maxMissedKeepalives) {
45 ctx.fireExceptionCaught(new KeepaliveException(maxMissedKeepalives));
47 ctx.channel().writeAndFlush(Constants.PING);
49 ctx.fireUserEventTriggered(evt);