io.netty.handler.flush

类 FlushConsolidationHandler

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.ChannelDuplexHandler

io.netty.handler.flush.FlushConsolidationHandler

所有已实现的接口:

ChannelHandler, ChannelInboundHandler, ChannelOutboundHandler

public class FlushConsolidationHandler
extends ChannelDuplexHandler

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

Flush operations are generally 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.

If a read loop is currently ongoing, flush(ChannelHandlerContext) will not be passed on to the next ChannelOutboundHandler in the ChannelPipeline, as it will pick up any pending flushes when channelReadComplete(ChannelHandlerContext) is triggered. If no read loop is ongoing, the behavior depends on the consolidateWhenNoReadInProgress constructor argument:

• if false, flushes are passed on to the next handler directly;
• if true, the invocation of the next handler is submitted as a separate task on the event loop. Under high throughput, this gives the opportunity to process other flushes before the task gets executed, thus batching multiple flushes into one.

If explicitFlushAfterFlushes is reached the flush will be forwarded as well (whether while in a read loop, or while batching outside of a read loop).

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.

嵌套类概要

从接口继承的嵌套类/接口 io.netty.channel.ChannelHandler

ChannelHandler.Sharable

字段概要

字段

限定符和类型	字段和说明
static int	DEFAULT_EXPLICIT_FLUSH_AFTER_FLUSHES The default number of flushes after which a flush will be forwarded to downstream handlers (whether while in a read loop, or while batching outside of a read loop).

构造器概要

构造器

构造器和说明
FlushConsolidationHandler() Create new instance which explicit flush after 256 pending flush operations at the latest.
FlushConsolidationHandler(int explicitFlushAfterFlushes) Create new instance which doesn't consolidate flushes when no read is in progress.
FlushConsolidationHandler(int explicitFlushAfterFlushes, boolean consolidateWhenNoReadInProgress) Create new instance.

方法概要

限定符和类型	方法和说明
void	channelRead(ChannelHandlerContext ctx, java.lang.Object msg) Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelReadComplete(ChannelHandlerContext ctx) Calls ChannelHandlerContext.fireChannelReadComplete() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	channelWritabilityChanged(ChannelHandlerContext ctx) Calls ChannelHandlerContext.fireChannelWritabilityChanged() to forward to the next ChannelInboundHandler in the ChannelPipeline.
void	close(ChannelHandlerContext ctx, ChannelPromise promise) Calls ChannelOutboundInvoker.close(ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.
void	disconnect(ChannelHandlerContext ctx, ChannelPromise promise) Calls ChannelOutboundInvoker.disconnect(ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.
void	exceptionCaught(ChannelHandlerContext ctx, java.lang.Throwable cause) Calls ChannelHandlerContext.fireExceptionCaught(Throwable) to forward to the next ChannelHandler in the ChannelPipeline.
void	flush(ChannelHandlerContext ctx) Calls ChannelHandlerContext.flush() to forward to the next ChannelOutboundHandler in the ChannelPipeline.
void	handlerAdded(ChannelHandlerContext ctx) Do nothing by default, sub-classes may override this method.
void	handlerRemoved(ChannelHandlerContext ctx) Do nothing by default, sub-classes may override this method.

从类继承的方法 io.netty.channel.ChannelDuplexHandler

bind, connect, deregister, read, write

从类继承的方法 io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelInactive, channelRegistered, channelUnregistered, userEventTriggered

从类继承的方法 io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, isSharable

从类继承的方法 java.lang.Object

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

字段详细资料

DEFAULT_EXPLICIT_FLUSH_AFTER_FLUSHES

public static final int DEFAULT_EXPLICIT_FLUSH_AFTER_FLUSHES

The default number of flushes after which a flush will be forwarded to downstream handlers (whether while in a read loop, or while batching outside of a read loop).

另请参阅:

常量字段值

构造器详细资料

FlushConsolidationHandler

public FlushConsolidationHandler()

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

FlushConsolidationHandler

public FlushConsolidationHandler(int explicitFlushAfterFlushes)

Create new instance which doesn't consolidate flushes when no read is in progress.

参数:

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

FlushConsolidationHandler

public FlushConsolidationHandler(int explicitFlushAfterFlushes,
                                 boolean consolidateWhenNoReadInProgress)

Create new instance.

参数:

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

consolidateWhenNoReadInProgress - whether to consolidate flushes even when no read loop is currently ongoing.

方法详细资料

handlerAdded

public void handlerAdded(ChannelHandlerContext ctx)
                  throws java.lang.Exception

从类复制的说明: ChannelHandlerAdapter

Do nothing by default, sub-classes may override this method.

指定者:

handlerAdded 在接口中 ChannelHandler

覆盖:

handlerAdded 在类中 ChannelHandlerAdapter

抛出:

java.lang.Exception

flush

public void flush(ChannelHandlerContext ctx)
           throws java.lang.Exception

从类复制的说明: ChannelDuplexHandler

Calls ChannelHandlerContext.flush() to forward to the next ChannelOutboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

指定者:

flush 在接口中 ChannelOutboundHandler

覆盖:

flush 在类中 ChannelDuplexHandler

参数:

ctx - the ChannelHandlerContext for which the flush operation is made

抛出:

java.lang.Exception - thrown if an error occurs

channelReadComplete

public void channelReadComplete(ChannelHandlerContext ctx)
                         throws java.lang.Exception

从类复制的说明: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireChannelReadComplete() to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

指定者:

channelReadComplete 在接口中 ChannelInboundHandler

覆盖:

channelReadComplete 在类中 ChannelInboundHandlerAdapter

抛出:

java.lang.Exception

channelRead

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

从类复制的说明: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

指定者:

channelRead 在接口中 ChannelInboundHandler

覆盖:

channelRead 在类中 ChannelInboundHandlerAdapter

抛出:

java.lang.Exception

exceptionCaught

public void exceptionCaught(ChannelHandlerContext ctx,
                            java.lang.Throwable cause)
                     throws java.lang.Exception

从类复制的说明: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireExceptionCaught(Throwable) to forward to the next ChannelHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

指定者:

exceptionCaught 在接口中 ChannelHandler

指定者:

exceptionCaught 在接口中 ChannelInboundHandler

覆盖:

exceptionCaught 在类中 ChannelInboundHandlerAdapter

抛出:

java.lang.Exception

disconnect

public void disconnect(ChannelHandlerContext ctx,
                       ChannelPromise promise)
                throws java.lang.Exception

从类复制的说明: ChannelDuplexHandler

Calls ChannelOutboundInvoker.disconnect(ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

指定者:

disconnect 在接口中 ChannelOutboundHandler

覆盖:

disconnect 在类中 ChannelDuplexHandler

参数:

ctx - the ChannelHandlerContext for which the disconnect operation is made

promise - the ChannelPromise to notify once the operation completes

抛出:

java.lang.Exception - thrown if an error occurs

close

public void close(ChannelHandlerContext ctx,
                  ChannelPromise promise)
           throws java.lang.Exception

从类复制的说明: ChannelDuplexHandler

Calls ChannelOutboundInvoker.close(ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

指定者:

close 在接口中 ChannelOutboundHandler

覆盖:

close 在类中 ChannelDuplexHandler

参数:

ctx - the ChannelHandlerContext for which the close operation is made

promise - the ChannelPromise to notify once the operation completes

抛出:

java.lang.Exception - thrown if an error occurs

channelWritabilityChanged

public void channelWritabilityChanged(ChannelHandlerContext ctx)
                               throws java.lang.Exception

从类复制的说明: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireChannelWritabilityChanged() to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

指定者:

channelWritabilityChanged 在接口中 ChannelInboundHandler

覆盖:

channelWritabilityChanged 在类中 ChannelInboundHandlerAdapter

抛出:

java.lang.Exception

handlerRemoved

public void handlerRemoved(ChannelHandlerContext ctx)
                    throws java.lang.Exception

从类复制的说明: ChannelHandlerAdapter

Do nothing by default, sub-classes may override this method.

指定者:

handlerRemoved 在接口中 ChannelHandler

覆盖:

handlerRemoved 在类中 ChannelHandlerAdapter

抛出:

java.lang.Exception