ChannelManager.java

/*
 * Copyright (c) 2014 AsyncHttpClient Project. All rights reserved.
 *
 * This program is licensed to you under the Apache License Version 2.0,
 * and you may not use this file except in compliance with the Apache License Version 2.0.
 * You may obtain a copy of the Apache License Version 2.0 at
 *     http://www.apache.org/licenses/LICENSE-2.0.
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the Apache License Version 2.0 is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Apache License Version 2.0 for the specific language governing permissions and limitations there under.
 */
package org.asynchttpclient.netty.channel;

import static org.asynchttpclient.handler.AsyncHandlerExtensionsUtils.toAsyncHandlerExtensions;

import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFactory;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.oio.OioEventLoopGroup;
import io.netty.handler.codec.http.HttpClientCodec;
import io.netty.handler.codec.http.HttpContentDecompressor;
import io.netty.handler.codec.http.websocketx.WebSocket08FrameDecoder;
import io.netty.handler.codec.http.websocketx.WebSocket08FrameEncoder;
import io.netty.handler.codec.http.websocketx.WebSocketFrameAggregator;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.ssl.SslHandler;
import io.netty.handler.stream.ChunkedWriteHandler;
import io.netty.util.Timer;
import io.netty.util.concurrent.DefaultThreadFactory;
import io.netty.util.concurrent.GlobalEventExecutor;

import java.net.InetSocketAddress;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.function.Function;
import java.util.stream.Collectors;

import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLException;

import org.asynchttpclient.AsyncHandler;
import org.asynchttpclient.AsyncHttpClientConfig;
import org.asynchttpclient.ClientStats;
import org.asynchttpclient.HostStats;
import org.asynchttpclient.SslEngineFactory;
import org.asynchttpclient.channel.ChannelPool;
import org.asynchttpclient.channel.ChannelPoolPartitioning;
import org.asynchttpclient.channel.NoopChannelPool;
import org.asynchttpclient.handler.AsyncHandlerExtensions;
import org.asynchttpclient.netty.NettyResponseFuture;
import org.asynchttpclient.netty.OnLastHttpContentCallback;
import org.asynchttpclient.netty.handler.AsyncHttpClientHandler;
import org.asynchttpclient.netty.handler.HttpHandler;
import org.asynchttpclient.netty.handler.WebSocketHandler;
import org.asynchttpclient.netty.request.NettyRequestSender;
import org.asynchttpclient.netty.ssl.DefaultSslEngineFactory;
import org.asynchttpclient.proxy.ProxyServer;
import org.asynchttpclient.uri.Uri;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ChannelManager {

    private static final Logger LOGGER = LoggerFactory.getLogger(ChannelManager.class);
    public static final String PINNED_ENTRY = "entry";
    public static final String HTTP_CLIENT_CODEC = "http";
    public static final String SSL_HANDLER = "ssl";
    public static final String DEFLATER_HANDLER = "deflater";
    public static final String INFLATER_HANDLER = "inflater";
    public static final String CHUNKED_WRITER_HANDLER = "chunked-writer";
    public static final String WS_DECODER_HANDLER = "ws-decoder";
    public static final String WS_FRAME_AGGREGATOR = "ws-aggregator";
    public static final String WS_ENCODER_HANDLER = "ws-encoder";
    public static final String AHC_HTTP_HANDLER = "ahc-http";
    public static final String AHC_WS_HANDLER = "ahc-ws";
    public static final String LOGGING_HANDLER = "logging";

    private final AsyncHttpClientConfig config;
    private final SslEngineFactory sslEngineFactory;
    private final EventLoopGroup eventLoopGroup;
    private final boolean allowReleaseEventLoopGroup;
    private final Bootstrap httpBootstrap;
    private final Bootstrap wsBootstrap;
    private final long handshakeTimeout;

    private final ChannelPool channelPool;
    private final ChannelGroup openChannels;

    private final CountDownLatch closeLatch;

    private AsyncHttpClientHandler wsHandler;

    public ChannelManager(final AsyncHttpClientConfig config, Timer nettyTimer) {

        this.config = config;
        
        closeLatch = new CountDownLatch(2);

        this.sslEngineFactory = config.getSslEngineFactory() != null ? config.getSslEngineFactory() : new DefaultSslEngineFactory();
        try {
            this.sslEngineFactory.init(config);
        } catch (SSLException e) {
            throw new RuntimeException("Could not initialize sslEngineFactory", e);
        }

        ChannelPool channelPool = config.getChannelPool();
        if (channelPool == null) {
            if (config.isKeepAlive()) {
                channelPool = new DefaultChannelPool(config, nettyTimer);
            } else {
                channelPool = NoopChannelPool.INSTANCE;
            }
        }
        this.channelPool = channelPool;

        openChannels = new DefaultChannelGroup("asyncHttpClient", GlobalEventExecutor.INSTANCE);

        handshakeTimeout = config.getHandshakeTimeout();

        // check if external EventLoopGroup is defined
        ThreadFactory threadFactory = config.getThreadFactory() != null ? config.getThreadFactory() : new DefaultThreadFactory(config.getThreadPoolName());
        allowReleaseEventLoopGroup = config.getEventLoopGroup() == null;
        ChannelFactory<? extends Channel> channelFactory;
        if (allowReleaseEventLoopGroup) {
            if (config.isUseNativeTransport()) {
                eventLoopGroup = newEpollEventLoopGroup(config.getIoThreadsCount(), threadFactory);
                channelFactory = getEpollSocketChannelFactory();

            } else {
                eventLoopGroup = new NioEventLoopGroup(config.getIoThreadsCount(), threadFactory);
                channelFactory = NioSocketChannelFactory.INSTANCE;
            }

        } else {
            eventLoopGroup = config.getEventLoopGroup();
            if (eventLoopGroup instanceof OioEventLoopGroup)
                throw new IllegalArgumentException("Oio is not supported");

            if (eventLoopGroup instanceof NioEventLoopGroup) {
                channelFactory = NioSocketChannelFactory.INSTANCE;
            } else {
                channelFactory = getEpollSocketChannelFactory();
            }
        }

        httpBootstrap = newBootstrap(channelFactory, eventLoopGroup, config);
        wsBootstrap = newBootstrap(channelFactory, eventLoopGroup, config);

        // for reactive streams
        httpBootstrap.option(ChannelOption.AUTO_READ, false);
    }

    private Bootstrap newBootstrap(ChannelFactory<? extends Channel> channelFactory, EventLoopGroup eventLoopGroup, AsyncHttpClientConfig config) {
        @SuppressWarnings("deprecation")
        Bootstrap bootstrap = new Bootstrap().channelFactory(channelFactory).group(eventLoopGroup)//
                .option(ChannelOption.ALLOCATOR, config.getAllocator() != null ? config.getAllocator() : ByteBufAllocator.DEFAULT)//
                .option(ChannelOption.TCP_NODELAY, config.isTcpNoDelay())//
                .option(ChannelOption.SO_REUSEADDR, config.isSoReuseAddress())//
                .option(ChannelOption.AUTO_CLOSE, false);

        if (config.getConnectTimeout() > 0) {
            bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, config.getConnectTimeout());
        }

        if (config.getSoLinger() >= 0) {
            bootstrap.option(ChannelOption.SO_LINGER, config.getSoLinger());
        }

        if (config.getSoSndBuf() >= 0) {
            bootstrap.option(ChannelOption.SO_SNDBUF, config.getSoSndBuf());
        }

        if (config.getSoRcvBuf() >= 0) {
            bootstrap.option(ChannelOption.SO_RCVBUF, config.getSoRcvBuf());
        }

        for (Entry<ChannelOption<Object>, Object> entry : config.getChannelOptions().entrySet()) {
            bootstrap.option(entry.getKey(), entry.getValue());
        }

        return bootstrap;
    }

    private EventLoopGroup newEpollEventLoopGroup(int ioThreadsCount, ThreadFactory threadFactory) {
        try {
            Class<?> epollEventLoopGroupClass = Class.forName("io.netty.channel.epoll.EpollEventLoopGroup");
            return (EventLoopGroup) epollEventLoopGroupClass.getConstructor(int.class, ThreadFactory.class).newInstance(ioThreadsCount, threadFactory);
        } catch (Exception e) {
            throw new IllegalArgumentException(e);
        }
    }

    @SuppressWarnings("unchecked")
    private ChannelFactory<? extends Channel> getEpollSocketChannelFactory() {
        try {
            return (ChannelFactory<? extends Channel>) Class.forName("org.asynchttpclient.netty.channel.EpollSocketChannelFactory").newInstance();
        } catch (Exception e) {
            throw new IllegalArgumentException(e);
        }
    }

    public void configureBootstraps(NettyRequestSender requestSender) {

        final AsyncHttpClientHandler httpHandler = new HttpHandler(config, this, requestSender);
        wsHandler = new WebSocketHandler(config, this, requestSender);

        final NoopHandler pinnedEntry = new NoopHandler();

        final LoggingHandler loggingHandler = new LoggingHandler(LogLevel.TRACE);

        httpBootstrap.handler(new ChannelInitializer<Channel>() {
            @Override
            protected void initChannel(Channel ch) throws Exception {
                ChannelPipeline pipeline = ch.pipeline()//
                        .addLast(PINNED_ENTRY, pinnedEntry)//
                        .addLast(HTTP_CLIENT_CODEC, newHttpClientCodec())//
                        .addLast(INFLATER_HANDLER, newHttpContentDecompressor())//
                        .addLast(CHUNKED_WRITER_HANDLER, new ChunkedWriteHandler())//
                        .addLast(AHC_HTTP_HANDLER, httpHandler);

                if (LOGGER.isTraceEnabled()) {
                    pipeline.addAfter(PINNED_ENTRY, LOGGING_HANDLER, loggingHandler);
                }

                if (config.getHttpAdditionalChannelInitializer() != null)
                    config.getHttpAdditionalChannelInitializer().initChannel(ch);
            }
        });

        wsBootstrap.handler(new ChannelInitializer<Channel>() {
            @Override
            protected void initChannel(Channel ch) throws Exception {
                ChannelPipeline pipeline = ch.pipeline()//
                        .addLast(PINNED_ENTRY, pinnedEntry)//
                        .addLast(HTTP_CLIENT_CODEC, newHttpClientCodec())//
                        .addLast(AHC_WS_HANDLER, wsHandler);

                if (LOGGER.isDebugEnabled()) {
                    pipeline.addAfter(PINNED_ENTRY, LOGGING_HANDLER, loggingHandler);
                }

                if (config.getWsAdditionalChannelInitializer() != null)
                    config.getWsAdditionalChannelInitializer().initChannel(ch);
            }
        });
    }

    private HttpContentDecompressor newHttpContentDecompressor() {
        if (config.isKeepEncodingHeader())
            return new HttpContentDecompressor() {
                @Override
                protected String getTargetContentEncoding(String contentEncoding) throws Exception {
                    return contentEncoding;
                }
            };
        else
            return new HttpContentDecompressor();
    }

    public final void tryToOfferChannelToPool(Channel channel, AsyncHandler<?> asyncHandler, boolean keepAlive, Object partitionKey) {
        if (channel.isActive() && keepAlive) {
            LOGGER.debug("Adding key: {} for channel {}", partitionKey, channel);
            Channels.setDiscard(channel);

            final AsyncHandlerExtensions asyncHandlerExtensions = toAsyncHandlerExtensions(asyncHandler);
            if (asyncHandlerExtensions != null) {
                try {
                    asyncHandlerExtensions.onConnectionOffer(channel);
                } catch (Exception e) {
                    LOGGER.error("onConnectionOffer crashed", e);
                }
            }

            if (!channelPool.offer(channel, partitionKey)) {
                // rejected by pool
                closeChannel(channel);
            }
        } else {
            // not offered
            closeChannel(channel);
        }
    }

    public Channel poll(Uri uri, String virtualHost, ProxyServer proxy, ChannelPoolPartitioning connectionPoolPartitioning) {
        Object partitionKey = connectionPoolPartitioning.getPartitionKey(uri, virtualHost, proxy);
        return channelPool.poll(partitionKey);
    }

    public boolean removeAll(Channel connection) {
        return channelPool.removeAll(connection);
    }

    private void doClose() {
        openChannels.close().addListener(future -> closeLatch.countDown());
        channelPool.destroy();
        
        //see https://github.com/netty/netty/issues/2084#issuecomment-44822314
        try {
            GlobalEventExecutor.INSTANCE.awaitInactivity(config.getShutdownTimeout(), TimeUnit.MILLISECONDS);
        } catch(InterruptedException t) {
            // Ignore
        } finally {
            closeLatch.countDown();
        }
    }

    public void close() {
        if (allowReleaseEventLoopGroup) {
            eventLoopGroup.shutdownGracefully(config.getShutdownQuietPeriod(), config.getShutdownTimeout(), TimeUnit.MILLISECONDS)//
                    .addListener(future -> doClose());
        } else
            doClose();

        try {
            closeLatch.await(config.getShutdownTimeout(), TimeUnit.MILLISECONDS);
        } catch (InterruptedException e) {
           // Ignore
        }
    }

    public void closeChannel(Channel channel) {
        LOGGER.debug("Closing Channel {} ", channel);
        Channels.setDiscard(channel);
        removeAll(channel);
        Channels.silentlyCloseChannel(channel);
    }

    public void registerOpenChannel(Channel channel, Object partitionKey) {
        openChannels.add(channel);
    }

    private HttpClientCodec newHttpClientCodec() {
        return new HttpClientCodec(//
                config.getHttpClientCodecMaxInitialLineLength(),//
                config.getHttpClientCodecMaxHeaderSize(),//
                config.getHttpClientCodecMaxChunkSize(),//
                false,//
                config.isValidateResponseHeaders(),//
                config.getHttpClientCodecInitialBufferSize());
    }

    private SslHandler createSslHandler(String peerHost, int peerPort) {
        SSLEngine sslEngine = sslEngineFactory.newSslEngine(config, peerHost, peerPort);
        SslHandler sslHandler = new SslHandler(sslEngine);
        if (handshakeTimeout > 0)
            sslHandler.setHandshakeTimeoutMillis(handshakeTimeout);
        return sslHandler;
    }

    public static boolean isSslHandlerConfigured(ChannelPipeline pipeline) {
        return pipeline.get(SSL_HANDLER) != null;
    }

    public void upgradeProtocol(ChannelPipeline pipeline, Uri requestUri) throws SSLException {
        if (pipeline.get(HTTP_CLIENT_CODEC) != null)
            pipeline.remove(HTTP_CLIENT_CODEC);

        if (requestUri.isSecured())
            if (isSslHandlerConfigured(pipeline)) {
                pipeline.addAfter(SSL_HANDLER, HTTP_CLIENT_CODEC, newHttpClientCodec());
            } else {
                pipeline.addAfter(PINNED_ENTRY, HTTP_CLIENT_CODEC, newHttpClientCodec());
                pipeline.addAfter(PINNED_ENTRY, SSL_HANDLER, createSslHandler(requestUri.getHost(), requestUri.getExplicitPort()));
            }

        else
            pipeline.addAfter(PINNED_ENTRY, HTTP_CLIENT_CODEC, newHttpClientCodec());

        if (requestUri.isWebSocket()) {
            pipeline.addAfter(AHC_HTTP_HANDLER, AHC_WS_HANDLER, wsHandler);
            pipeline.remove(AHC_HTTP_HANDLER);
        }
    }

    public SslHandler addSslHandler(ChannelPipeline pipeline, Uri uri, String virtualHost) {
        String peerHost;
        int peerPort;

        if (virtualHost != null) {
            int i = virtualHost.indexOf(':');
            if (i == -1) {
                peerHost = virtualHost;
                peerPort = uri.getSchemeDefaultPort();
            } else {
                peerHost = virtualHost.substring(0, i);
                peerPort = Integer.valueOf(virtualHost.substring(i + 1));
            }

        } else {
            peerHost = uri.getHost();
            peerPort = uri.getExplicitPort();
        }

        SslHandler sslHandler = createSslHandler(peerHost, peerPort);
        pipeline.addFirst(ChannelManager.SSL_HANDLER, sslHandler);
        return sslHandler;
    }

    public Bootstrap getBootstrap(Uri uri, ProxyServer proxy) {
        return uri.isWebSocket() && proxy == null ? wsBootstrap : httpBootstrap;
    }

    public void upgradePipelineForWebSockets(ChannelPipeline pipeline) {
        pipeline.addAfter(HTTP_CLIENT_CODEC, WS_ENCODER_HANDLER, new WebSocket08FrameEncoder(true));
        pipeline.addBefore(AHC_WS_HANDLER, WS_DECODER_HANDLER, new WebSocket08FrameDecoder(false, false, config.getWebSocketMaxFrameSize()));
        if (config.isAggregateWebSocketFrameFragments()) {
            pipeline.addAfter(WS_DECODER_HANDLER, WS_FRAME_AGGREGATOR, new WebSocketFrameAggregator(config.getWebSocketMaxBufferSize()));
        }
        pipeline.remove(HTTP_CLIENT_CODEC);
    }

    public final OnLastHttpContentCallback newDrainCallback(final NettyResponseFuture<?> future, final Channel channel, final boolean keepAlive, final Object partitionKey) {

        return new OnLastHttpContentCallback(future) {
            public void call() {
                tryToOfferChannelToPool(channel, future.getAsyncHandler(), keepAlive, partitionKey);
            }
        };
    }

    public void drainChannelAndOffer(Channel channel, NettyResponseFuture<?> future) {
        drainChannelAndOffer(channel, future, future.isKeepAlive(), future.getPartitionKey());
    }

    public void drainChannelAndOffer(Channel channel, NettyResponseFuture<?> future, boolean keepAlive, Object partitionKey) {
        Channels.setAttribute(channel, newDrainCallback(future, channel, keepAlive, partitionKey));
    }

    public ChannelPool getChannelPool() {
        return channelPool;
    }

    public EventLoopGroup getEventLoopGroup() {
        return eventLoopGroup;
    }

    public ClientStats getClientStats() {
        Map<String, Long> totalConnectionsPerHost = openChannels.stream().map(Channel::remoteAddress).filter(a -> a.getClass() == InetSocketAddress.class)
                .map(a -> (InetSocketAddress) a).map(InetSocketAddress::getHostName).collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
        Map<String, Long> idleConnectionsPerHost = channelPool.getIdleChannelCountPerHost();
        Map<String, HostStats> statsPerHost = totalConnectionsPerHost.entrySet().stream().collect(Collectors.toMap(Entry::getKey, entry -> {
            final long totalConnectionCount = entry.getValue();
            final long idleConnectionCount = idleConnectionsPerHost.getOrDefault(entry.getKey(), 0L);
            final long activeConnectionCount = totalConnectionCount - idleConnectionCount;
            return new HostStats(activeConnectionCount, idleConnectionCount);
        }));
        return new ClientStats(statsPerHost);
    }

    public boolean isOpen() {
        return channelPool.isOpen();
    }
}