/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.apache.spark.network.util;
import java.util.concurrent.ThreadFactory;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import io.netty.channel.Channel;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.ServerChannel;
import io.netty.channel.epoll.Epoll;
import io.netty.channel.epoll.EpollEventLoopGroup;
import io.netty.channel.epoll.EpollServerSocketChannel;
import io.netty.channel.epoll.EpollSocketChannel;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.ByteToMessageDecoder;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
/**
* Utilities for creating various Netty constructs based on whether we're using EPOLL or NIO.
*/
public class NettyUtils {
/** Creates a new ThreadFactory which prefixes each thread with the given name. */
public static ThreadFactory createThreadFactory(String threadPoolPrefix) {
return new ThreadFactoryBuilder()
.setDaemon(true)
.setNameFormat(threadPoolPrefix + "-%d")
.build();
}
/** Creates a Netty EventLoopGroup based on the IOMode. */
public static EventLoopGroup createEventLoop(IOMode mode, int numThreads, String threadPrefix) {
ThreadFactory threadFactory = createThreadFactory(threadPrefix);
switch (mode) {
case NIO:
return new NioEventLoopGroup(numThreads, threadFactory);
case EPOLL:
return new EpollEventLoopGroup(numThreads, threadFactory);
default:
throw new IllegalArgumentException("Unknown io mode: " + mode);
}
}
/** Returns the correct (client) SocketChannel class based on IOMode. */
public static Class<? extends Channel> getClientChannelClass(IOMode mode) {
switch (mode) {
case NIO:
return NioSocketChannel.class;
case EPOLL:
return EpollSocketChannel.class;
default:
throw new IllegalArgumentException("Unknown io mode: " + mode);
}
}
/** Returns the correct ServerSocketChannel class based on IOMode. */
public static Class<? extends ServerChannel> getServerChannelClass(IOMode mode) {
switch (mode) {
case NIO:
return NioServerSocketChannel.class;
case EPOLL:
return EpollServerSocketChannel.class;
default:
throw new IllegalArgumentException("Unknown io mode: " + mode);
}
}
/**
* Creates a LengthFieldBasedFrameDecoder where the first 8 bytes are the length of the frame.
* This is used before all decoders.
*/
public static ByteToMessageDecoder createFrameDecoder() {
// maxFrameLength = 2G
// lengthFieldOffset = 0
// lengthFieldLength = 8
// lengthAdjustment = -8, i.e. exclude the 8 byte length itself
// initialBytesToStrip = 8, i.e. strip out the length field itself
return new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 8, -8, 8);
}
/** Returns the remote address on the channel or "<remote address>" if none exists. */
public static String getRemoteAddress(Channel channel) {
if (channel != null && channel.remoteAddress() != null) {
return channel.remoteAddress().toString();
}
return "<unknown remote>";
}
}