io.netty.handler.flush

Class FlushConsolidationHandler

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.ChannelDuplexHandler

io.netty.handler.flush.FlushConsolidationHandler

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundHandler, io.netty.channel.ChannelOutboundHandler

public class FlushConsolidationHandler
extends io.netty.channel.ChannelDuplexHandler

ChannelDuplexHandler which consolidate Channel.flush() / ChannelHandlerContext.flush() operations (which also includes Channel.writeAndFlush(Object) / Channel.writeAndFlush(Object, ChannelPromise) and ChannelHandlerContext.writeAndFlush(Object) / ChannelHandlerContext.writeAndFlush(Object, ChannelPromise)).

Flush operations are general speaking expensive as these may trigger a syscall on the transport level. Thus it is in most cases (where write latency can be traded with throughput) a good idea to try to minimize flush operations as much as possible.

When flush(ChannelHandlerContext) is called it will only pass it on to the next ChannelOutboundHandler in the ChannelPipeline if no read loop is currently ongoing as it will pick up any pending flushes when channelReadComplete(ChannelHandlerContext) is trigged. If explicitFlushAfterFlushes is reached the flush will also be forwarded as well.

If the Channel becomes non-writable it will also try to execute any pending flush operations.

The FlushConsolidationHandler should be put as first ChannelHandler in the ChannelPipeline to have the best effect.

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

io.netty.channel.ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor and Description
FlushConsolidationHandler() Create new instance which explicit flush after 256 pending flush operations latest.
FlushConsolidationHandler(int explicitFlushAfterFlushes) Create new instance.

Method Summary

Methods

Modifier and Type	Method and Description
void	channelRead(io.netty.channel.ChannelHandlerContext ctx, Object msg)
void	channelReadComplete(io.netty.channel.ChannelHandlerContext ctx)
void	channelWritabilityChanged(io.netty.channel.ChannelHandlerContext ctx)
void	close(io.netty.channel.ChannelHandlerContext ctx, io.netty.channel.ChannelPromise promise)
void	disconnect(io.netty.channel.ChannelHandlerContext ctx, io.netty.channel.ChannelPromise promise)
void	exceptionCaught(io.netty.channel.ChannelHandlerContext ctx, Throwable cause)
void	flush(io.netty.channel.ChannelHandlerContext ctx)
void	handlerRemoved(io.netty.channel.ChannelHandlerContext ctx)

Methods inherited from class io.netty.channel.ChannelDuplexHandler

bind, connect, deregister, read, write

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelInactive, channelRegistered, channelUnregistered, userEventTriggered

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

handlerAdded, isSharable

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty.channel.ChannelHandler

handlerAdded

Constructor Detail

FlushConsolidationHandler

public FlushConsolidationHandler()

Create new instance which explicit flush after 256 pending flush operations latest.

FlushConsolidationHandler

public FlushConsolidationHandler(int explicitFlushAfterFlushes)

Create new instance.

Parameters:

explicitFlushAfterFlushes - the number of flushes after which an explicit flush will be done.

Method Detail

flush

public void flush(io.netty.channel.ChannelHandlerContext ctx)
           throws Exception

Specified by:

flush in interface io.netty.channel.ChannelOutboundHandler

Overrides:

flush in class io.netty.channel.ChannelDuplexHandler

Throws:

Exception

channelReadComplete

public void channelReadComplete(io.netty.channel.ChannelHandlerContext ctx)
                         throws Exception

Specified by:

channelReadComplete in interface io.netty.channel.ChannelInboundHandler

Overrides:

channelReadComplete in class io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

channelRead

public void channelRead(io.netty.channel.ChannelHandlerContext ctx,
               Object msg)
                 throws Exception

Specified by:

channelRead in interface io.netty.channel.ChannelInboundHandler

Overrides:

channelRead in class io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

exceptionCaught

public void exceptionCaught(io.netty.channel.ChannelHandlerContext ctx,
                   Throwable cause)
                     throws Exception

Specified by:

exceptionCaught in interface io.netty.channel.ChannelHandler

Specified by:

exceptionCaught in interface io.netty.channel.ChannelInboundHandler

Overrides:

exceptionCaught in class io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

disconnect

public void disconnect(io.netty.channel.ChannelHandlerContext ctx,
              io.netty.channel.ChannelPromise promise)
                throws Exception

Specified by:

disconnect in interface io.netty.channel.ChannelOutboundHandler

Overrides:

disconnect in class io.netty.channel.ChannelDuplexHandler

Throws:

Exception

close

public void close(io.netty.channel.ChannelHandlerContext ctx,
         io.netty.channel.ChannelPromise promise)
           throws Exception

Specified by:

close in interface io.netty.channel.ChannelOutboundHandler

Overrides:

close in class io.netty.channel.ChannelDuplexHandler

Throws:

Exception

channelWritabilityChanged

public void channelWritabilityChanged(io.netty.channel.ChannelHandlerContext ctx)
                               throws Exception

Specified by:

channelWritabilityChanged in interface io.netty.channel.ChannelInboundHandler

Overrides:

channelWritabilityChanged in class io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

handlerRemoved

public void handlerRemoved(io.netty.channel.ChannelHandlerContext ctx)
                    throws Exception

Specified by:

handlerRemoved in interface io.netty.channel.ChannelHandler

Overrides:

handlerRemoved in class io.netty.channel.ChannelHandlerAdapter

Throws:

Exception