/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you under
* the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.elasticsearch.transport.netty4;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import org.elasticsearch.common.bytes.BytesReference;
import org.elasticsearch.transport.TcpHeader;
import org.elasticsearch.transport.TcpTransport;
import org.elasticsearch.transport.TransportServiceAdapter;
import org.elasticsearch.transport.Transports;
import java.net.InetSocketAddress;
/**
* A handler (must be the last one!) that does size based frame decoding and forwards the actual message
* to the relevant action.
*/
final class Netty4MessageChannelHandler extends ChannelDuplexHandler {
private final TransportServiceAdapter transportServiceAdapter;
private final Netty4Transport transport;
private final String profileName;
Netty4MessageChannelHandler(Netty4Transport transport, String profileName) {
this.transportServiceAdapter = transport.transportServiceAdapter();
this.transport = transport;
this.profileName = profileName;
}
@Override
public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
if (msg instanceof ByteBuf && transportServiceAdapter != null) {
// record the number of bytes send on the channel
promise.addListener(f -> transportServiceAdapter.addBytesSent(((ByteBuf) msg).readableBytes()));
}
ctx.write(msg, promise);
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
Transports.assertTransportThread();
if (!(msg instanceof ByteBuf)) {
ctx.fireChannelRead(msg);
return;
}
final ByteBuf buffer = (ByteBuf) msg;
final int remainingMessageSize = buffer.getInt(buffer.readerIndex() - TcpHeader.MESSAGE_LENGTH_SIZE);
final int expectedReaderIndex = buffer.readerIndex() + remainingMessageSize;
try {
InetSocketAddress remoteAddress = (InetSocketAddress) ctx.channel().remoteAddress();
// netty always copies a buffer, either in NioWorker in its read handler, where it copies to a fresh
// buffer, or in the cumulative buffer, which is cleaned each time so it could be bigger than the actual size
BytesReference reference = Netty4Utils.toBytesReference(buffer, remainingMessageSize);
transport.messageReceived(reference, ctx.channel(), profileName, remoteAddress, remainingMessageSize);
} finally {
// Set the expected position of the buffer, no matter what happened
buffer.readerIndex(expectedReaderIndex);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
Netty4Utils.maybeDie(cause);
transport.exceptionCaught(ctx, cause);
}
}