private void forcefulClose(final ChannelHandlerContext ctx, final ForcefulCloseCommand msg,
    ChannelPromise promise) throws Exception {
  close(ctx, promise);
  connection().forEachActiveStream(new Http2StreamVisitor() {
    @Override
    public boolean visit(Http2Stream stream) throws Http2Exception {
      NettyServerStream.TransportState serverStream = serverStream(stream);
      if (serverStream != null) {
        serverStream.transportReportStatus(msg.getStatus());
        resetStream(ctx, stream.id(), Http2Error.CANCEL.code(), ctx.newPromise());
      }
      stream.close();
      return true;
    }
  });
}
 

private void forcefulClose(final ChannelHandlerContext ctx, final ForcefulCloseCommand msg,
    ChannelPromise promise) throws Exception {
  // close() already called by NettyClientTransport, so just need to clean up streams
  connection().forEachActiveStream(new Http2StreamVisitor() {
    @Override
    public boolean visit(Http2Stream stream) throws Http2Exception {
      NettyClientStream.TransportState clientStream = clientStream(stream);
      if (clientStream != null) {
        clientStream.transportReportStatus(msg.getStatus(), true, new Metadata());
        resetStream(ctx, stream.id(), Http2Error.CANCEL.code(), ctx.newPromise());
      }
      stream.close();
      return true;
    }
  });
  promise.setSuccess();
}
 

/**
 * Handler for a GOAWAY being received. Fails any streams created after the
 * last known stream.
 */
private void goingAway(Status status) {
  lifecycleManager.notifyShutdown(status);
  final Status goAwayStatus = lifecycleManager.getShutdownStatus();
  final int lastKnownStream = connection().local().lastStreamKnownByPeer();
  try {
    connection().forEachActiveStream(new Http2StreamVisitor() {
      @Override
      public boolean visit(Http2Stream stream) throws Http2Exception {
        if (stream.id() > lastKnownStream) {
          NettyClientStream.TransportState clientStream = clientStream(stream);
          if (clientStream != null) {
            clientStream.transportReportStatus(
                goAwayStatus, RpcProgress.REFUSED, false, new Metadata());
          }
          stream.close();
        }
        return true;
      }
    });
  } catch (Http2Exception e) {
    throw new RuntimeException(e);
  }
}
 

@Test
public void windowShouldNotExceedMaxWindowSize() throws Exception {
  manualSetUp();
  makeStream();
  AbstractNettyHandler handler = (AbstractNettyHandler) handler();
  handler.setAutoTuneFlowControl(true);
  Http2Stream connectionStream = connection().connectionStream();
  Http2LocalFlowController localFlowController = connection().local().flowController();
  int maxWindow = handler.flowControlPing().maxWindow();

  handler.flowControlPing().setDataSizeSincePing(maxWindow);
  long payload = handler.flowControlPing().payload();
  channelRead(pingFrame(true, payload));

  assertEquals(maxWindow, localFlowController.initialWindowSize(connectionStream));
}
 

@Override
public void write(Http2Stream stream, int numBytes) {
    if (numBytes > 0) {
        // Add the data to the refresher so that it can be given back to the
        // stream at the end of the iteration.
        DataRefresher refresher = dataRefresher(stream);
        refresher.add(numBytes);

        ++counters.numWrites;
        counters.totalBytes += numBytes;
        if (numBytes < counters.minWriteSize) {
            counters.minWriteSize = numBytes;
        }
        if (numBytes > counters.maxWriteSize) {
            counters.maxWriteSize = numBytes;
        }
    }

    delegate.write(stream, numBytes);
}
 

@Override
public int onDataRead(ChannelHandlerContext ctx, int streamId, ByteBuf data, int padding, boolean endOfStream) {
    int processed = data.readableBytes() + padding;

    Http2Stream http2Stream = connection().stream(streamId);
    ByteBuf msg = http2Stream.getProperty(messageKey);
    if (msg == null) {
        msg = ctx.alloc().buffer();
        http2Stream.setProperty(messageKey, msg);
    }
    final int dataReadableBytes = data.readableBytes();
    msg.writeBytes(data, data.readerIndex(), dataReadableBytes);

    if (endOfStream) {
        // read cached http2 header from stream
        Http2Headers headers = http2Stream.getProperty(headerKey);
        handleRequest(ctx, streamId, headers, msg);
    }
    return processed;
}
 

/**
 * By default, connection window size is a constant value:
 * connectionWindowSize = 65535 + (configureInitialWindowSize - 65535) * 2.
 * See https://github.com/netty/netty/blob/5c458c9a98d4d3d0345e58495e017175156d624f/codec-http2/src/main/java/io/netty
 * /handler/codec/http2/Http2FrameCodec.java#L255
 * We should expand connection window so that the window size proportional to the number of concurrent streams within the
 * connection.
 * Note that when {@code WINDOW_UPDATE} will be sent depends on the processedWindow in DefaultHttp2LocalFlowController.
 */
private void tryExpandConnectionWindow(Channel parentChannel) {
    doInEventLoop(parentChannel.eventLoop(), () -> {
        Http2Connection http2Connection = parentChannel.attr(HTTP2_CONNECTION).get();
        Integer initialWindowSize = parentChannel.attr(HTTP2_INITIAL_WINDOW_SIZE).get();

        Validate.notNull(http2Connection, "http2Connection should not be null on channel " + parentChannel);
        Validate.notNull(http2Connection, "initialWindowSize should not be null on channel " + parentChannel);

        Http2Stream connectionStream = http2Connection.connectionStream();
        log.debug(() -> "Expanding connection window size for " + parentChannel + " by " + initialWindowSize);
        try {
            Http2LocalFlowController localFlowController = http2Connection.local().flowController();
            localFlowController.incrementWindowSize(connectionStream, initialWindowSize);

        } catch (Http2Exception e) {
            log.warn(() -> "Failed to increment windowSize of connection " + parentChannel, e);
        }
    });
}
 

private void writeErrorResponse(ChannelHandlerContext ctx, int streamId, HttpResponseStatus status,
                                @Nullable ByteBuf content) throws Http2Exception {
    final ByteBuf data =
            content != null ? content
                            : Unpooled.wrappedBuffer(status.toString().getBytes(StandardCharsets.UTF_8));

    writer.writeHeaders(
            ctx, streamId,
            new DefaultHttp2Headers(false)
                    .status(status.codeAsText())
                    .set(HttpHeaderNames.CONTENT_TYPE, MediaType.PLAIN_TEXT_UTF_8.toString())
                    .setInt(HttpHeaderNames.CONTENT_LENGTH, data.readableBytes()),
            0, false, ctx.voidPromise());

    writer.writeData(ctx, streamId, data, 0, true, ctx.voidPromise());

    final Http2Stream stream = writer.connection().stream(streamId);
    if (stream != null && writer.flowController().hasFlowControlled(stream)) {
        // Ensure to flush the error response if it's flow-controlled so that it is sent
        // before an RST_STREAM frame.
        writer.flowController().writePendingBytes();
    }
}
 

/**
 * Returns {@code true} if the stream with the given {@code streamId} has been created and is writable.
 * Note that this method will return {@code false} for the stream which was not created yet.
 */
protected final boolean isStreamPresentAndWritable(int streamId) {
    final Http2Stream stream = encoder.connection().stream(streamId);
    if (stream == null) {
        return false;
    }

    switch (stream.state()) {
        case RESERVED_LOCAL:
        case OPEN:
        case HALF_CLOSED_REMOTE:
            return true;
        default:
            // The response has been sent already.
            return false;
    }
}
 

private void forcefulClose(final ChannelHandlerContext ctx, final ForcefulCloseCommand msg,
    ChannelPromise promise) throws Exception {
  super.close(ctx, promise);
  connection().forEachActiveStream(new Http2StreamVisitor() {
    @Override
    public boolean visit(Http2Stream stream) throws Http2Exception {
      NettyServerStream.TransportState serverStream = serverStream(stream);
      if (serverStream != null) {
        PerfMark.startTask("NettyServerHandler.forcefulClose", serverStream.tag());
        PerfMark.linkIn(msg.getLink());
        try {
          serverStream.transportReportStatus(msg.getStatus());
          resetStream(ctx, stream.id(), Http2Error.CANCEL.code(), ctx.newPromise());
        } finally {
          PerfMark.stopTask("NettyServerHandler.forcefulClose", serverStream.tag());
        }
      }
      stream.close();
      return true;
    }
  });
}
 

private void forcefulClose(final ChannelHandlerContext ctx, final ForcefulCloseCommand msg,
    ChannelPromise promise) throws Exception {
  // close() already called by NettyClientTransport, so just need to clean up streams
  connection().forEachActiveStream(new Http2StreamVisitor() {
    @Override
    public boolean visit(Http2Stream stream) throws Http2Exception {
      NettyClientStream.TransportState clientStream = clientStream(stream);
      Tag tag = clientStream != null ? clientStream.tag() : PerfMark.createTag();
      PerfMark.startTask("NettyClientHandler.forcefulClose", tag);
      PerfMark.linkIn(msg.getLink());
      try {
        if (clientStream != null) {
          clientStream.transportReportStatus(msg.getStatus(), true, new Metadata());
          resetStream(ctx, stream.id(), Http2Error.CANCEL.code(), ctx.newPromise());
        }
        stream.close();
        return true;
      } finally {
        PerfMark.stopTask("NettyClientHandler.forcefulClose", tag);
      }
    }
  });
  promise.setSuccess();
}
 

@Test
public void windowShouldNotExceedMaxWindowSize() throws Exception {
  manualSetUp();
  makeStream();
  AbstractNettyHandler handler = (AbstractNettyHandler) handler();
  handler.setAutoTuneFlowControl(true);
  Http2Stream connectionStream = connection().connectionStream();
  Http2LocalFlowController localFlowController = connection().local().flowController();
  int maxWindow = handler.flowControlPing().maxWindow();

  handler.flowControlPing().setDataSizeAndSincePing(maxWindow);
  long payload = handler.flowControlPing().payload();
  channelRead(pingFrame(true, payload));

  assertEquals(maxWindow, localFlowController.initialWindowSize(connectionStream));
}
 

/**
 * Sets the underlying Netty {@link Http2Stream} for this stream. This must be called in the
 * context of the transport thread.
 */
public void setHttp2Stream(Http2Stream http2Stream) {
  checkNotNull(http2Stream, "http2Stream");
  checkState(this.http2Stream == null, "Can only set http2Stream once");
  this.http2Stream = http2Stream;

  // Now that the stream has actually been initialized, call the listener's onReady callback if
  // appropriate.
  onStreamAllocated();
  getTransportTracer().reportLocalStreamStarted();
}
 

public TransportState(
    NettyServerHandler handler,
    EventLoop eventLoop,
    Http2Stream http2Stream,
    int maxMessageSize,
    StatsTraceContext statsTraceCtx,
    TransportTracer transportTracer) {
  super(maxMessageSize, statsTraceCtx, transportTracer);
  this.http2Stream = checkNotNull(http2Stream, "http2Stream");
  this.handler = checkNotNull(handler, "handler");
  this.eventLoop = eventLoop;
}
 

/**
 * Handler for the Channel shutting down.
 */
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
  try {
    if (keepAliveManager != null) {
      keepAliveManager.onTransportTermination();
    }
    if (maxConnectionIdleManager != null) {
      maxConnectionIdleManager.onTransportTermination();
    }
    if (maxConnectionAgeMonitor != null) {
      maxConnectionAgeMonitor.cancel(false);
    }
    final Status status =
        Status.UNAVAILABLE.withDescription("connection terminated for unknown reason");
    // Any streams that are still active must be closed
    connection().forEachActiveStream(new Http2StreamVisitor() {
      @Override
      public boolean visit(Http2Stream stream) throws Http2Exception {
        NettyServerStream.TransportState serverStream = serverStream(stream);
        if (serverStream != null) {
          serverStream.transportReportStatus(status);
        }
        return true;
      }
    });
  } finally {
    super.channelInactive(ctx);
  }
}
 

/**
 * Returns the given processed bytes back to inbound flow control.
 */
void returnProcessedBytes(Http2Stream http2Stream, int bytes) {
  try {
    decoder().flowController().consumeBytes(http2Stream, bytes);
  } catch (Http2Exception e) {
    throw new RuntimeException(e);
  }
}
 

private Http2Stream requireHttp2Stream(int streamId) {
  Http2Stream stream = connection().stream(streamId);
  if (stream == null) {
    // This should never happen.
    throw new AssertionError("Stream does not exist: " + streamId);
  }
  return stream;
}
 

/**
 * Returns the given processed bytes back to inbound flow control.
 */
void returnProcessedBytes(Http2Stream stream, int bytes) {
  try {
    decoder().flowController().consumeBytes(stream, bytes);
  } catch (Http2Exception e) {
    throw new RuntimeException(e);
  }
}
 

/**
 * Handler for the Channel shutting down.
 */
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
  try {
    logger.fine("Network channel is closed");
    Status status = Status.UNAVAILABLE.withDescription("Network closed for unknown reason");
    lifecycleManager.notifyShutdown(status);
    try {
      cancelPing(lifecycleManager.getShutdownThrowable());
      // Report status to the application layer for any open streams
      connection().forEachActiveStream(new Http2StreamVisitor() {
        @Override
        public boolean visit(Http2Stream stream) throws Http2Exception {
          NettyClientStream.TransportState clientStream = clientStream(stream);
          if (clientStream != null) {
            clientStream.transportReportStatus(
                lifecycleManager.getShutdownStatus(), false, new Metadata());
          }
          return true;
        }
      });
    } finally {
      lifecycleManager.notifyTerminated(status);
    }
  } finally {
    // Close any open streams
    super.channelInactive(ctx);
    if (keepAliveManager != null) {
      keepAliveManager.onTransportTermination();
    }
  }
}
 

private Http2Stream requireHttp2Stream(int streamId) {
  Http2Stream stream = connection().stream(streamId);
  if (stream == null) {
    // This should never happen.
    throw new AssertionError("Stream does not exist: " + streamId);
  }
  return stream;
}
 

/**
 * Sends initial connection window to the remote endpoint if necessary.
 */
private void sendInitialConnectionWindow() throws Http2Exception {
  if (ctx.channel().isActive() && initialConnectionWindow > 0) {
    Http2Stream connectionStream = connection().connectionStream();
    int currentSize = connection().local().flowController().windowSize(connectionStream);
    int delta = initialConnectionWindow - currentSize;
    decoder().flowController().incrementWindowSize(connectionStream, delta);
    initialConnectionWindow = -1;
    ctx.flush();
  }
}
 

@Test
public void connectionWindowShouldBeOverridden() throws Exception {
  flowControlWindow = 1048576; // 1MiB
  manualSetUp();

  Http2Stream connectionStream = connection().connectionStream();
  Http2LocalFlowController localFlowController = connection().local().flowController();
  int actualInitialWindowSize = localFlowController.initialWindowSize(connectionStream);
  int actualWindowSize = localFlowController.windowSize(connectionStream);
  assertEquals(flowControlWindow, actualWindowSize);
  assertEquals(flowControlWindow, actualInitialWindowSize);
}
 

@Test
public void connectionWindowShouldBeOverridden() throws Exception {
  flowControlWindow = 1048576; // 1MiB
  setUp();

  Http2Stream connectionStream = connection().connectionStream();
  Http2LocalFlowController localFlowController = connection().local().flowController();
  int actualInitialWindowSize = localFlowController.initialWindowSize(connectionStream);
  int actualWindowSize = localFlowController.windowSize(connectionStream);
  assertEquals(flowControlWindow, actualWindowSize);
  assertEquals(flowControlWindow, actualInitialWindowSize);
  assertEquals(1048576, actualWindowSize);
}
 

@Override
protected NettyClientHandler newHandler() throws Http2Exception {
  Http2Connection connection = new DefaultHttp2Connection(false);

  // Create and close a stream previous to the nextStreamId.
  Http2Stream stream = connection.local().createStream(streamId - 2, true);
  stream.close();

  final Ticker ticker = new Ticker() {
    @Override
    public long read() {
      return nanoTime;
    }
  };
  Supplier<Stopwatch> stopwatchSupplier = new Supplier<Stopwatch>() {
    @Override
    public Stopwatch get() {
      return Stopwatch.createUnstarted(ticker);
    }
  };
  return NettyClientHandler.newHandler(
      connection,
      frameReader(),
      frameWriter(),
      lifecycleManager,
      mockKeepAliveManager,
      flowControlWindow,
      maxHeaderListSize,
      stopwatchSupplier,
      tooManyPingsRunnable,
      transportTracer,
      Attributes.EMPTY,
      "someauthority");
}
 

@Test
public void windowUpdateMatchesTarget() throws Exception {
  manualSetUp();
  Http2Stream connectionStream = connection().connectionStream();
  Http2LocalFlowController localFlowController = connection().local().flowController();
  makeStream();
  AbstractNettyHandler handler = (AbstractNettyHandler) handler();
  handler.setAutoTuneFlowControl(true);

  ByteBuf data = ctx().alloc().buffer(1024);
  while (data.isWritable()) {
    data.writeLong(1111);
  }
  int length = data.readableBytes();
  ByteBuf frame = dataFrame(3, false, data.copy());
  channelRead(frame);
  int accumulator = length;
  // 40 is arbitrary, any number large enough to trigger a window update would work
  for (int i = 0; i < 40; i++) {
    channelRead(dataFrame(3, false, data.copy()));
    accumulator += length;
  }
  long pingData = handler.flowControlPing().payload();
  channelRead(pingFrame(true, pingData));

  assertEquals(accumulator, handler.flowControlPing().getDataSincePing());
  assertEquals(2 * accumulator, localFlowController.initialWindowSize(connectionStream));
}
 

@Override
public void addFlowControlled(Http2Stream stream, FlowControlled payload) {
    // Don't check size beforehand because Headers payload returns 0 all the time.
    do {
        payload.write(ctx, MAX_INITIAL_WINDOW_SIZE);
    } while (payload.size() > 0);
}
 

@Setup(Level.Trial)
public void setupTrial() throws Exception {
    connection = new DefaultHttp2Connection(false);
    dataRefresherKey = connection.newKey();

    // Create the flow controller
    switch (algorithm) {
        case WFQ:
            distributor = new WeightedFairQueueByteDistributor(connection, 0);
            break;
        case UNIFORM:
            distributor = new UniformStreamByteDistributor(connection);
            break;
    }
    controller = new DefaultHttp2RemoteFlowController(connection, new ByteCounter(distributor));
    connection.remote().flowController(controller);
    Http2ConnectionHandler handler = new Http2ConnectionHandlerBuilder()
        .encoderEnforceMaxConcurrentStreams(false).validateHeaders(false)
        .frameListener(new Http2FrameAdapter())
        .connection(connection)
        .build();
    ctx = new EmbeddedChannelWriteReleaseHandlerContext(PooledByteBufAllocator.DEFAULT, handler) {
        @Override
        protected void handleException(Throwable t) {
            handleUnexpectedException(t);
        }
    };
    handler.handlerAdded(ctx);
    handler.channelActive(ctx);

    // Create the streams, each initialized with MAX_INT bytes.
    for (int i = 0; i < numStreams; ++i) {
        Http2Stream stream = connection.local().createStream(toStreamId(i), false);
        addData(stream, Integer.MAX_VALUE);
        stream.setProperty(dataRefresherKey, new DataRefresher(stream));
    }
}
 

/** Removes all requests and handlers for a given stream. */
@Override
public void onStreamRemoved(Http2Stream stream) {
  int id = stream.id();
  requests.remove(id);
  handlers.remove(id);
}
 

@Override
public void onStreamClosed(Http2Stream stream) {
    goAwayHandler.onStreamClosed(channel(), stream);

    final HttpResponseWrapper res = getResponse(streamIdToId(stream.id()), true);
    if (res == null) {
        return;
    }

    if (!goAwayHandler.receivedGoAway()) {
        res.close(ClosedStreamException.get());
        return;
    }

    final int lastStreamId = conn.local().lastStreamKnownByPeer();
    if (stream.id() > lastStreamId) {
        res.close(UnprocessedRequestException.of(GoAwayReceivedException.get()));
    } else {
        res.close(ClosedStreamException.get());
    }

    // Send a GOAWAY frame if the connection has been scheduled for disconnection and
    // it did not receive or send a GOAWAY frame.
    if (needsToDisconnectNow() && !goAwayHandler.sentGoAway() && !goAwayHandler.receivedGoAway()) {
        channel().close();
    }
}
 

@Override
public void onStreamClosed(Http2Stream stream) {
    goAwayHandler.onStreamClosed(channel, stream);

    final DecodedHttpRequest req = requests.remove(stream.id());
    if (req != null) {
        // Ignored if the stream has already been closed.
        req.close(ClosedStreamException.get());
    }
}