com.streamsets.pipeline.lib.network.BaseNettyServer.java Source code

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Here is the source code for com.streamsets.pipeline.lib.network.BaseNettyServer.java

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/*
 * Copyright 2017 StreamSets Inc.
 *
 * Licensed 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.streamsets.pipeline.lib.network;

import com.google.common.collect.ImmutableList;
import com.streamsets.pipeline.api.impl.Utils;
import io.netty.bootstrap.AbstractBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.util.ArrayList;
import java.util.List;

public abstract class BaseNettyServer {
    private static final Logger LOG = LoggerFactory.getLogger(BaseNettyServer.class);
    protected static final String NETTY_UNSAFE = "io.netty.noUnsafe";
    protected final boolean enableEpoll;
    protected final int numThreads;
    protected final List<InetSocketAddress> addresses;
    protected final List<ChannelFuture> channelFutures = new ArrayList<>();
    protected final List<EventLoopGroup> groups = new ArrayList<>();

    private static boolean directBuffersDisabled = false;
    private static boolean directBuffersEnabled = false;

    public BaseNettyServer(boolean enableEpoll, int numThreads, List<InetSocketAddress> addresses) {
        this.enableEpoll = enableEpoll;
        this.numThreads = numThreads;
        this.addresses = ImmutableList.copyOf(addresses);
    }

    public void listen() throws Exception {
        for (SocketAddress address : addresses) {
            AbstractBootstrap b = bootstrap(enableEpoll);
            LOG.info("Starting server on address {}", address);
            if (enableEpoll) {
                // for epoll, bind for each thread
                for (int i = 0; i < numThreads; i++) {
                    ChannelFuture channelFuture = b.bind(address).sync();
                    channelFutures.add(channelFuture);
                }
            } else {
                // for non-epoll (NIO threadpool), bind once
                ChannelFuture channelFuture = b.bind(address).sync();
                channelFutures.add(channelFuture);
            }
        }
    }

    protected abstract AbstractBootstrap bootstrap(boolean enableEpoll);

    public void destroy() {
        LOG.info("Destroying server on address(es) {}", addresses);
        for (ChannelFuture channelFuture : channelFutures) {
            if (channelFuture != null && channelFuture.isCancellable()) {
                channelFuture.cancel(true);
            }
        }
        try {
            for (EventLoopGroup group : groups) {
                if (group != null && !group.isShutdown() && !group.isShuttingDown()) {
                    try {
                        group.shutdownGracefully().get();
                    } catch (InterruptedException ex) {
                        LOG.error("InterruptedException thrown while shutting down: " + ex, ex);
                        Thread.currentThread().interrupt();
                    } catch (Exception ex) {
                        LOG.error("Unexpected error shutting down: " + ex, ex);
                    }
                }
            }
        } finally {
            channelFutures.clear();
        }
    }

    public void start() {
        Utils.checkNotNull(channelFutures, "Channel future cannot be null");
        Utils.checkState(!groups.isEmpty(), "Event group cannot be null");
        for (ChannelFuture channelFuture : channelFutures) {
            channelFuture.channel().closeFuture();
        }
    }

    protected static void disableDirectBuffers() {
        // required to fully disable direct buffers which
        // while faster to allocate when shared, come with
        // unpredictable limits
        if (directBuffersEnabled) {
            LOG.warn("Calling disableDirectBuffers, but Netty direct buffers were previously enabled");
        }
        LOG.info("Disabling Netty direct buffers");
        directBuffersDisabled = true;
        System.setProperty(NETTY_UNSAFE, "true");
    }

    protected static void enableDirectBuffers() {
        if (directBuffersDisabled) {
            LOG.warn("Calling enableDirectBuffers, but Netty direct buffers were previously disabled");
        }
        LOG.info("Enabling Netty direct buffers");
        directBuffersEnabled = true;
        System.setProperty(NETTY_UNSAFE, "false");
    }
}