Module io.netty5.handler

Package io.netty5.handler.flow

Class FlowControlHandler

java.lang.Object

io.netty5.handler.flow.FlowControlHandler

All Implemented Interfaces:

ChannelHandler

public class FlowControlHandler
extends Object
implements ChannelHandler

The FlowControlHandler ensures that only one message per read() is sent downstream. Classes such as ByteToMessageDecoder or MessageToByteEncoder are free to emit as many events as they like for any given input. A channel's auto reading configuration doesn't usually apply in these scenarios. This is causing problems in downstream ChannelHandlers that would like to hold subsequent events while they're processing one event. It's a common problem with the HttpObjectDecoder that will very often fire an HttpRequest that is immediately followed by a LastHttpContent event.

{@code
 ChannelPipeline pipeline = ...;

 pipeline.addLast(new HttpServerCodec());
 pipeline.addLast(new FlowControlHandler());

 pipeline.addLast(new MyExampleHandler());

 class MyExampleHandler extends ChannelInboundHandlerAdapter {

Constructor Summary

Constructors

Constructor	Description
FlowControlHandler()
FlowControlHandler(boolean releaseMessages)

Method Summary

Modifier and Type	Method	Description
void	channelInactive(ChannelHandlerContext ctx)	The Channel of the ChannelHandlerContext was registered is now inactive and reached its end of lifetime.
void	channelRead(ChannelHandlerContext ctx, Object msg)	Invoked when the current Channel has read a message from the peer.
void	channelReadComplete(ChannelHandlerContext ctx)	Invoked when the last message read by the current read operation has been consumed by ChannelHandler.channelRead(ChannelHandlerContext, Object).
void	handlerRemoved(ChannelHandlerContext ctx)	Gets called after the ChannelHandler was removed from the actual context and it doesn't handle events anymore.
void	read(ChannelHandlerContext ctx)	Intercepts ChannelHandlerContext.read().

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.netty5.channel.ChannelHandler

bind, channelActive, channelExceptionCaught, channelInboundEvent, channelRegistered, channelShutdown, channelUnregistered, channelWritabilityChanged, close, connect, deregister, disconnect, flush, handlerAdded, isSharable, pendingOutboundBytes, register, sendOutboundEvent, shutdown, write

Constructor Detail

FlowControlHandler

public FlowControlHandler()

FlowControlHandler

public FlowControlHandler(boolean releaseMessages)

Method Detail

handlerRemoved

public void handlerRemoved(ChannelHandlerContext ctx)
                    throws Exception

Description copied from interface: ChannelHandler

Gets called after the ChannelHandler was removed from the actual context and it doesn't handle events anymore.

Specified by:

handlerRemoved in interface ChannelHandler

Throws:

Exception

channelInactive

public void channelInactive(ChannelHandlerContext ctx)
                     throws Exception

Description copied from interface: ChannelHandler

The Channel of the ChannelHandlerContext was registered is now inactive and reached its end of lifetime.

Specified by:

channelInactive in interface ChannelHandler

Throws:

Exception

read

public void read(ChannelHandlerContext ctx)

Description copied from interface: ChannelHandler

Intercepts ChannelHandlerContext.read().

Specified by:

read in interface ChannelHandler

channelRead

public void channelRead(ChannelHandlerContext ctx,
                        Object msg)
                 throws Exception

Description copied from interface: ChannelHandler

Invoked when the current Channel has read a message from the peer.

Specified by:

channelRead in interface ChannelHandler

Throws:

Exception

channelReadComplete

public void channelReadComplete(ChannelHandlerContext ctx)
                         throws Exception

Description copied from interface: ChannelHandler

Invoked when the last message read by the current read operation has been consumed by ChannelHandler.channelRead(ChannelHandlerContext, Object). If ChannelOption.AUTO_READ is off, no further attempt to read an inbound data from the current Channel will be made until ChannelHandlerContext.read() is called.

Specified by:

channelReadComplete in interface ChannelHandler

Throws:

Exception