com.github.sparkfy.network.util.NettyUtils.java Source code

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Here is the source code for com.github.sparkfy.network.util.NettyUtils.java

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/*
 * 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 com.github.sparkfy.network.util;

import com.google.common.util.concurrent.ThreadFactoryBuilder;
import io.netty.buffer.PooledByteBufAllocator;
import io.netty.channel.Channel;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.ServerChannel;
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.util.internal.PlatformDependent;

import java.lang.reflect.Field;
import java.util.concurrent.ThreadFactory;

/**
 * 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 TransportFrameDecoder createFrameDecoder() {
        return new TransportFrameDecoder();
    }

    /** Returns the remote address on the channel or "&lt;unknown remote&gt;" if none exists. */
    public static String getRemoteAddress(Channel channel) {
        if (channel != null && channel.remoteAddress() != null) {
            return channel.remoteAddress().toString();
        }
        return "<unknown remote>";
    }

    /**
     * Create a pooled ByteBuf allocator but disables the thread-local cache. Thread-local caches
     * are disabled for TransportClients because the ByteBufs are allocated by the event loop thread,
     * but released by the executor thread rather than the event loop thread. Those thread-local
     * caches actually delay the recycling of buffers, leading to larger memory usage.
     */
    public static PooledByteBufAllocator createPooledByteBufAllocator(boolean allowDirectBufs, boolean allowCache,
            int numCores) {
        if (numCores == 0) {
            numCores = Runtime.getRuntime().availableProcessors();
        }
        return new PooledByteBufAllocator(allowDirectBufs && PlatformDependent.directBufferPreferred(),
                Math.min(getPrivateStaticField("DEFAULT_NUM_HEAP_ARENA"), numCores),
                Math.min(getPrivateStaticField("DEFAULT_NUM_DIRECT_ARENA"), allowDirectBufs ? numCores : 0),
                getPrivateStaticField("DEFAULT_PAGE_SIZE"), getPrivateStaticField("DEFAULT_MAX_ORDER"),
                allowCache ? getPrivateStaticField("DEFAULT_TINY_CACHE_SIZE") : 0,
                allowCache ? getPrivateStaticField("DEFAULT_SMALL_CACHE_SIZE") : 0,
                allowCache ? getPrivateStaticField("DEFAULT_NORMAL_CACHE_SIZE") : 0);
    }

    /** Used to get defaults from Netty's private static fields. */
    private static int getPrivateStaticField(String name) {
        try {
            Field f = PooledByteBufAllocator.DEFAULT.getClass().getDeclaredField(name);
            f.setAccessible(true);
            return f.getInt(null);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}