@Override
public void init(final Channel channel) {
    final Http2FrameCodecBuilder multiplexCodecBuilder = forServer()
            // We do not want close to trigger graceful closure (go away), instead when user triggers a graceful
            // close, we do the appropriate go away handling.
            .decoupleCloseAndGoAway(true)
            // We don't want to rely upon Netty to manage the graceful close timeout, because we expect
            // the user to apply their own timeout at the call site.
            .gracefulShutdownTimeoutMillis(-1);

    final BiPredicate<CharSequence, CharSequence> headersSensitivityDetector =
            config.headersSensitivityDetector();
    multiplexCodecBuilder.headerSensitivityDetector(headersSensitivityDetector::test);

    final String frameLoggerName = config.frameLoggerName();
    if (frameLoggerName != null) {
        multiplexCodecBuilder.frameLogger(new Http2FrameLogger(TRACE, frameLoggerName));
    }

    // TODO(scott): more configuration. header validation, settings stream, etc...

    channel.pipeline().addLast(multiplexCodecBuilder.build(), new Http2MultiplexHandler(streamChannelInitializer));
}
 

@Override
public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
    LOGGER.info("{} : handlerAdded", connectionInfo);

    Http2Connection connection = new DefaultHttp2Connection(true);
    ChannelHandler http2ConnHandler = new HttpToHttp2ConnectionHandlerBuilder()
            .frameListener(new DelegatingDecompressorFrameListener(
                    connection,
                    new InboundHttp2ToHttpAdapterBuilder(connection)
                            .maxContentLength(master.config().getMaxContentLength())
                            .propagateSettings(true)
                            .build()))
            .connection(connection)
            .frameLogger(new Http2FrameLogger(LogLevel.DEBUG))
            .build();
    ctx.pipeline()
       .addBefore(ctx.name(), null, http2ConnHandler)
       .addBefore(ctx.name(), null, new Http2Handler());
}
 

@Override
public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
    LOGGER.info("{} : handlerAdded", connectionInfo);

    Http2Connection connection = new DefaultHttp2Connection(false);
    ChannelHandler http2ConnHandler = new HttpToHttp2ConnectionHandlerBuilder()
            .frameListener(new DelegatingDecompressorFrameListener(
                    connection,
                    new InboundHttp2ToHttpAdapterBuilder(connection)
                            .maxContentLength(master.config().getMaxContentLength())
                            .propagateSettings(true)
                            .build()))
            .frameLogger(new Http2FrameLogger(LogLevel.DEBUG))
            .connection(connection)
            .build();
    ctx.pipeline()
       .addBefore(ctx.name(), null, http2ConnHandler)
       .addBefore(ctx.name(), null, new Http2Handler());
}
 

static void configureHttp2Pipeline(ChannelPipeline p, HttpResponseDecoderSpec decoder, Http2Settings http2Settings,
		ConnectionObserver observer) {
	Http2FrameCodecBuilder http2FrameCodecBuilder =
			Http2FrameCodecBuilder.forClient()
			                      .validateHeaders(decoder.validateHeaders())
			                      .initialSettings(http2Settings);

	if (p.get(NettyPipeline.LoggingHandler) != null) {
		http2FrameCodecBuilder.frameLogger(new Http2FrameLogger(LogLevel.DEBUG,
				"reactor.netty.http.client.h2"));
	}

	p.addBefore(NettyPipeline.ReactiveBridge, NettyPipeline.HttpCodec, http2FrameCodecBuilder.build())
	 .addBefore(NettyPipeline.ReactiveBridge, NettyPipeline.H2MultiplexHandler, new Http2MultiplexHandler(new H2Codec()))
	 .addBefore(NettyPipeline.ReactiveBridge, NettyPipeline.HttpTrafficHandler, new HttpTrafficHandler(observer));
}
 

static void configureH2Pipeline(ChannelPipeline p,
		ServerCookieDecoder cookieDecoder,
		ServerCookieEncoder cookieEncoder,
		boolean forwarded,
		Http2Settings http2Settings,
		ConnectionObserver listener,
		ChannelOperations.OnSetup opsFactory,
		boolean validate) {
	p.remove(NettyPipeline.ReactiveBridge);

	Http2FrameCodecBuilder http2FrameCodecBuilder =
			Http2FrameCodecBuilder.forServer()
			                      .validateHeaders(validate)
			                      .initialSettings(http2Settings);

	if (p.get(NettyPipeline.LoggingHandler) != null) {
		http2FrameCodecBuilder.frameLogger(new Http2FrameLogger(LogLevel.DEBUG,
				"reactor.netty.http.server.h2"));
	}

	p.addLast(NettyPipeline.HttpCodec, http2FrameCodecBuilder.build())
	 .addLast(NettyPipeline.H2MultiplexHandler,
	          new Http2MultiplexHandler(new H2Codec(opsFactory, listener, forwarded, cookieEncoder, cookieDecoder)));
}
 

Http11OrH2CleartextCodec(
		ServerCookieDecoder cookieDecoder,
		ServerCookieEncoder cookieEncoder,
		boolean debug,
		boolean forwarded,
		Http2Settings http2Settings,
		ConnectionObserver listener,
		ChannelOperations.OnSetup opsFactory,
		boolean validate) {
	this.cookieDecoder = cookieDecoder;
	this.cookieEncoder = cookieEncoder;
	this.forwarded = forwarded;
	Http2FrameCodecBuilder http2FrameCodecBuilder =
			Http2FrameCodecBuilder.forServer()
			                      .validateHeaders(validate)
			                      .initialSettings(http2Settings);

	if (debug) {
		http2FrameCodecBuilder.frameLogger(new Http2FrameLogger(
				LogLevel.DEBUG,
				"reactor.netty.http.server.h2"));
	}
	this.http2FrameCodec = http2FrameCodecBuilder.build();
	this.listener = listener;
	this.opsFactory = opsFactory;
}
 

@Override
public void init(final Channel channel) {
    final Http2FrameCodecBuilder multiplexCodecBuilder = forClient()
            // We do not want close to trigger graceful closure (go away), instead when user triggers a graceful
            // close, we do the appropriate go away handling.
            .decoupleCloseAndGoAway(true)
            // The max concurrent streams is made available via a publisher and may be consumed asynchronously
            // (e.g. when offloading is enabled), so we manually control the SETTINGS ACK frames.
            .autoAckSettingsFrame(false)
            // We don't want to rely upon Netty to manage the graceful close timeout, because we expect
            // the user to apply their own timeout at the call site.
            .gracefulShutdownTimeoutMillis(-1);

    // Notify server that this client does not support server push and request it to be disabled.
    multiplexCodecBuilder.initialSettings().pushEnabled(false).maxConcurrentStreams(0L);

    final BiPredicate<CharSequence, CharSequence> headersSensitivityDetector =
            config.headersSensitivityDetector();
    multiplexCodecBuilder.headerSensitivityDetector(headersSensitivityDetector::test);

    final String frameLoggerName = config.frameLoggerName();
    if (frameLoggerName != null) {
        multiplexCodecBuilder.frameLogger(new Http2FrameLogger(TRACE, frameLoggerName));
    }

    // TODO(scott): more configuration. header validation, settings stream, etc...

    channel.pipeline().addLast(multiplexCodecBuilder.build(),
            new Http2MultiplexHandler(H2PushStreamHandler.INSTANCE));
}
 

public static EmbeddedChannel newHttp2Channel(ChannelHandler channelHandler) {
    Http2FrameCodec http2FrameCodec = Http2FrameCodecBuilder.forClient().initialSettings(
        Http2Settings.defaultSettings().initialWindowSize(INITIAL_WINDOW_SIZE))
                                                            .frameLogger(new Http2FrameLogger(LogLevel.DEBUG)).build();
    EmbeddedChannel channel = new EmbeddedChannel(http2FrameCodec,
                                                  new Http2MultiplexHandler(channelHandler));

    channel.attr(ChannelAttributeKey.HTTP2_CONNECTION).set(http2FrameCodec.connection());
    channel.attr(ChannelAttributeKey.HTTP2_INITIAL_WINDOW_SIZE).set(INITIAL_WINDOW_SIZE);
    channel.attr(ChannelAttributeKey.PROTOCOL_FUTURE).set(CompletableFuture.completedFuture(Protocol.HTTP2));
    return channel;
}
 

public static ApplicationProtocolNegotiationHandler getClientAPNHandler(int maxContentLength, Http2SettingsHandler settingsHandler, Http2ClientResponseHandler responseHandler) {
    final Http2FrameLogger logger = new Http2FrameLogger(INFO, Http2Util.class);
    final Http2Connection connection = new DefaultHttp2Connection(false);

    HttpToHttp2ConnectionHandler connectionHandler = new HttpToHttp2ConnectionHandlerBuilder()
        .frameListener(new DelegatingDecompressorFrameListener(connection, new InboundHttp2ToHttpAdapterBuilder(connection).maxContentLength(maxContentLength)
        .propagateSettings(true)
        .build()))
        .frameLogger(logger)
        .connection(connection)
        .build();

    ApplicationProtocolNegotiationHandler clientAPNHandler = new ApplicationProtocolNegotiationHandler(ApplicationProtocolNames.HTTP_2) {
        @Override
        protected void configurePipeline(ChannelHandlerContext ctx, String protocol) {
            if (ApplicationProtocolNames.HTTP_2.equals(protocol)) {
                ChannelPipeline p = ctx.pipeline();
                p.addLast(connectionHandler);
                p.addLast(settingsHandler, responseHandler);
                return;
            }
            ctx.close();
            throw new IllegalStateException("Protocol: " + protocol + " not supported");
        }
    };

    return clientAPNHandler;

}
 

@Override
public void channelCreated(Channel ch) throws Exception {
  ChannelPipeline pipeline = ch.pipeline();
  SslHandler sslHandler = new SslHandler(sslFactory.createSSLEngine(host, port, SSLFactory.Mode.CLIENT));
  pipeline.addLast(sslHandler);
  pipeline.addLast(Http2FrameCodecBuilder.forClient()
      .initialSettings(Http2Settings.defaultSettings()
          .maxFrameSize(http2ClientConfig.http2FrameMaxSize)
          .initialWindowSize(http2ClientConfig.http2InitialWindowSize))
      .frameLogger(new Http2FrameLogger(LogLevel.DEBUG, "client"))
      .build());
  pipeline.addLast(new Http2MultiplexHandler(new ChannelInboundHandlerAdapter()));
}
 

@Override
protected void initChannel(SocketChannel ch) throws Exception {
  // To honor http2 window size, WriteBufferWaterMark.high() should be greater or equal to http2 window size.
  // Also see: https://github.com/netty/netty/issues/10193
  // https://stackoverflow.com/questions/25281124/netty-4-high-and-low-write-watermarks
  ch.config()
      .setSendBufferSize(http2ClientConfig.nettySendBufferSize)
      .setReceiveBufferSize(http2ClientConfig.nettyReceiveBufferSize)
      .setWriteBufferWaterMark(new WriteBufferWaterMark(http2ClientConfig.http2InitialWindowSize,
          2 * http2ClientConfig.http2InitialWindowSize));
  // If channel handler implementations are not annotated with @Sharable, Netty creates a new instance of every class
  // in the pipeline for every connection.
  // i.e. if there are a 1000 active connections there will be a 1000 NettyMessageProcessor instances.
  ChannelPipeline pipeline = ch.pipeline();
  // connection stats handler to track connection related metrics
  pipeline.addLast("ConnectionStatsHandler", connectionStatsHandler);
  InetSocketAddress peerAddress = ch.remoteAddress();
  String peerHost = peerAddress.getHostName();
  int peerPort = peerAddress.getPort();
  SslHandler sslHandler = new SslHandler(sslFactory.createSSLEngine(peerHost, peerPort, SSLFactory.Mode.SERVER));
  pipeline.addLast("SslHandler", sslHandler);
  pipeline.addLast("SecurityChecker", serverSecurityHandler);
  pipeline.addLast("Http2FrameCodec", Http2FrameCodecBuilder.forServer()
      .initialSettings(Http2Settings.defaultSettings()
          .maxFrameSize(http2ClientConfig.http2FrameMaxSize)
          .initialWindowSize(http2ClientConfig.http2InitialWindowSize))
      .frameLogger(new Http2FrameLogger(LogLevel.DEBUG, "server"))
      .build());
  pipeline.addLast("Http2MultiplexHandler", new Http2MultiplexHandler(http2ServerStreamHandler));
  pipeline.addLast("CloseOnExceptionHandler", closeOnExceptionHandler);
}
 

static NettyServerHandler newHandler(
    ServerTransportListener transportListener,
    ChannelPromise channelUnused,
    List<ServerStreamTracer.Factory> streamTracerFactories,
    TransportTracer transportTracer,
    int maxStreams,
    int flowControlWindow,
    int maxHeaderListSize,
    int maxMessageSize,
    long keepAliveTimeInNanos,
    long keepAliveTimeoutInNanos,
    long maxConnectionIdleInNanos,
    long maxConnectionAgeInNanos,
    long maxConnectionAgeGraceInNanos,
    boolean permitKeepAliveWithoutCalls,
    long permitKeepAliveTimeInNanos) {
  Preconditions.checkArgument(maxHeaderListSize > 0, "maxHeaderListSize must be positive");
  Http2FrameLogger frameLogger = new Http2FrameLogger(LogLevel.DEBUG, NettyServerHandler.class);
  Http2HeadersDecoder headersDecoder = new GrpcHttp2ServerHeadersDecoder(maxHeaderListSize);
  Http2FrameReader frameReader = new Http2InboundFrameLogger(
      new DefaultHttp2FrameReader(headersDecoder), frameLogger);
  Http2FrameWriter frameWriter =
      new Http2OutboundFrameLogger(new DefaultHttp2FrameWriter(), frameLogger);
  return newHandler(
      channelUnused,
      frameReader,
      frameWriter,
      transportListener,
      streamTracerFactories,
      transportTracer,
      maxStreams,
      flowControlWindow,
      maxHeaderListSize,
      maxMessageSize,
      keepAliveTimeInNanos,
      keepAliveTimeoutInNanos,
      maxConnectionIdleInNanos,
      maxConnectionAgeInNanos,
      maxConnectionAgeGraceInNanos,
      permitKeepAliveWithoutCalls,
      permitKeepAliveTimeInNanos);
}
 

public Http2HandlerBuilder() {
  if (FRAME_LOGGER.isDebugEnabled()) {
    frameLogger(new Http2FrameLogger(LogLevel.DEBUG, FRAME_LOGGER_NAME));
  }
}
 

static void configureHttp11OrH2CleartextPipeline(
		ChannelPipeline p,
		boolean acceptGzip,
		HttpResponseDecoderSpec decoder,
		Http2Settings http2Settings,
		@Nullable Supplier<? extends ChannelMetricsRecorder> metricsRecorder,
		ConnectionObserver observer,
		ChannelOperations.OnSetup opsFactory,
		@Nullable Function<String, String> uriTagValue) {
	HttpClientCodec httpClientCodec =
			new HttpClientCodec(
					decoder.maxInitialLineLength(),
					decoder.maxHeaderSize(),
					decoder.maxChunkSize(),
					decoder.failOnMissingResponse,
					decoder.validateHeaders(),
					decoder.initialBufferSize(),
					decoder.parseHttpAfterConnectRequest);

	Http2FrameCodecBuilder http2FrameCodecBuilder =
			Http2FrameCodecBuilder.forClient()
					.validateHeaders(decoder.validateHeaders())
					.initialSettings(http2Settings);

	if (p.get(NettyPipeline.LoggingHandler) != null) {
		http2FrameCodecBuilder.frameLogger(new Http2FrameLogger(LogLevel.DEBUG,
				"reactor.netty.http.client.h2"));
	}

	Http2FrameCodec http2FrameCodec = http2FrameCodecBuilder.build();

	Http2ClientUpgradeCodec upgradeCodec = new Http2ClientUpgradeCodec(http2FrameCodec, new H2CleartextCodec(http2FrameCodec, opsFactory));

	HttpClientUpgradeHandler upgradeHandler = new HttpClientUpgradeHandler(httpClientCodec, upgradeCodec, decoder.h2cMaxContentLength());

	p.addBefore(NettyPipeline.ReactiveBridge, null, httpClientCodec)
	 .addBefore(NettyPipeline.ReactiveBridge, NettyPipeline.H2CUpgradeHandler, upgradeHandler)
	 .addBefore(NettyPipeline.ReactiveBridge, NettyPipeline.HttpTrafficHandler, new HttpTrafficHandler(observer));

	if (acceptGzip) {
		p.addAfter(NettyPipeline.HttpCodec, NettyPipeline.HttpDecompressor, new HttpContentDecompressor());
	}

	if (metricsRecorder != null) {
		ChannelMetricsRecorder channelMetricsRecorder = metricsRecorder.get();
		if (channelMetricsRecorder instanceof HttpClientMetricsRecorder) {
			p.addBefore(NettyPipeline.ReactiveBridge,
					NettyPipeline.HttpMetricsHandler,
					new HttpClientMetricsHandler((HttpClientMetricsRecorder) channelMetricsRecorder, uriTagValue));
		}
	}

}
 

static NettyServerHandler newHandler(
    ServerTransportListener transportListener,
    ChannelPromise channelUnused,
    List<? extends ServerStreamTracer.Factory> streamTracerFactories,
    TransportTracer transportTracer,
    int maxStreams,
    boolean autoFlowControl,
    int flowControlWindow,
    int maxHeaderListSize,
    int maxMessageSize,
    long keepAliveTimeInNanos,
    long keepAliveTimeoutInNanos,
    long maxConnectionIdleInNanos,
    long maxConnectionAgeInNanos,
    long maxConnectionAgeGraceInNanos,
    boolean permitKeepAliveWithoutCalls,
    long permitKeepAliveTimeInNanos) {
  Preconditions.checkArgument(maxHeaderListSize > 0, "maxHeaderListSize must be positive: %s",
      maxHeaderListSize);
  Http2FrameLogger frameLogger = new Http2FrameLogger(LogLevel.DEBUG, NettyServerHandler.class);
  Http2HeadersDecoder headersDecoder = new GrpcHttp2ServerHeadersDecoder(maxHeaderListSize);
  Http2FrameReader frameReader = new Http2InboundFrameLogger(
      new DefaultHttp2FrameReader(headersDecoder), frameLogger);
  Http2FrameWriter frameWriter =
      new Http2OutboundFrameLogger(new DefaultHttp2FrameWriter(), frameLogger);
  return newHandler(
      channelUnused,
      frameReader,
      frameWriter,
      transportListener,
      streamTracerFactories,
      transportTracer,
      maxStreams,
      autoFlowControl,
      flowControlWindow,
      maxHeaderListSize,
      maxMessageSize,
      keepAliveTimeInNanos,
      keepAliveTimeoutInNanos,
      maxConnectionIdleInNanos,
      maxConnectionAgeInNanos,
      maxConnectionAgeGraceInNanos,
      permitKeepAliveWithoutCalls,
      permitKeepAliveTimeInNanos);
}