Package org.playframework.netty

Class HandlerSubscriber<T>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.ChannelDuplexHandler

org.playframework.netty.HandlerSubscriber<T>

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundHandler, io.netty.channel.ChannelOutboundHandler, org.reactivestreams.Subscriber<T>

public class HandlerSubscriber<T>
extends io.netty.channel.ChannelDuplexHandler
implements org.reactivestreams.Subscriber<T>

Subscriber that publishes received messages to the handler pipeline.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static enum	HandlerSubscriber.State

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

io.netty.channel.ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field	Description
private io.netty.channel.ChannelHandlerContext	ctx
(package private) static final long	DEFAULT_HIGH_WATERMARK
(package private) static final long	DEFAULT_LOW_WATERMARK
private final long	demandHighWatermark
private final long	demandLowWatermark
private final io.netty.util.concurrent.EventExecutor	executor
private final AtomicBoolean	hasSubscription
private io.netty.channel.ChannelFuture	lastWriteFuture
private long	outstandingDemand
private HandlerSubscriber.State	state
private org.reactivestreams.Subscription	subscription

Constructor Summary

Constructors

Constructor	Description
HandlerSubscriber(io.netty.util.concurrent.EventExecutor executor)	Create a new handler subscriber with the default low and high watermarks.
HandlerSubscriber(io.netty.util.concurrent.EventExecutor executor, long demandLowWatermark, long demandHighWatermark)	Create a new handler subscriber.

Method Summary

Modifier and Type	Method	Description
private void	cancel()
void	channelActive(io.netty.channel.ChannelHandlerContext ctx)
void	channelInactive(io.netty.channel.ChannelHandlerContext ctx)
void	channelRegistered(io.netty.channel.ChannelHandlerContext ctx)
void	channelWritabilityChanged(io.netty.channel.ChannelHandlerContext ctx)
protected void	complete()	Override for custom completion handling.
private void	doClose()
protected void	error(Throwable error)	Override for custom error handling.
void	exceptionCaught(io.netty.channel.ChannelHandlerContext ctx, Throwable cause)
void	handlerAdded(io.netty.channel.ChannelHandlerContext ctx)
void	handlerRemoved(io.netty.channel.ChannelHandlerContext ctx)
private void	maybeRequestMore()
private void	maybeStart()
void	onComplete()
void	onError(Throwable error)
void	onNext(T t)
void	onSubscribe(org.reactivestreams.Subscription subscription)
private void	provideSubscription()
private void	verifyRegisteredWithRightExecutor(io.netty.channel.ChannelHandlerContext ctx)

Methods inherited from class io.netty.channel.ChannelDuplexHandler

bind, close, connect, deregister, disconnect, flush, read, write

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelRead, channelReadComplete, channelUnregistered, userEventTriggered

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, isSharable

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_LOW_WATERMARK

static final long DEFAULT_LOW_WATERMARK

See Also:

• Constant Field Values

DEFAULT_HIGH_WATERMARK

static final long DEFAULT_HIGH_WATERMARK

See Also:

• Constant Field Values

executor

private final io.netty.util.concurrent.EventExecutor executor

demandLowWatermark

private final long demandLowWatermark

demandHighWatermark

private final long demandHighWatermark

hasSubscription

private final AtomicBoolean hasSubscription

subscription

private volatile org.reactivestreams.Subscription subscription

ctx

private volatile io.netty.channel.ChannelHandlerContext ctx

state

private HandlerSubscriber.State state

outstandingDemand

private long outstandingDemand

lastWriteFuture

private io.netty.channel.ChannelFuture lastWriteFuture

Constructor Details

HandlerSubscriber

public HandlerSubscriber(io.netty.util.concurrent.EventExecutor executor,
 long demandLowWatermark,
 long demandHighWatermark)

Create a new handler subscriber. The supplied executor must be the same event loop as the event loop that this handler is eventually registered with, if not, an exception will be thrown when the handler is registered.

Parameters:

executor - The executor to execute asynchronous events from the publisher on.

demandLowWatermark - The low watermark for demand. When demand drops below this, more will be requested.

demandHighWatermark - The high watermark for demand. This is the maximum that will be requested.

HandlerSubscriber

public HandlerSubscriber(io.netty.util.concurrent.EventExecutor executor)

Create a new handler subscriber with the default low and high watermarks. The supplied executor must be the same event loop as the event loop that this handler is eventually registered with, if not, an exception will be thrown when the handler is registered.

Parameters:

executor - The executor to execute asynchronous events from the publisher on.

See Also:

• HandlerSubscriber(EventExecutor, long, long)

Method Details

error

protected void error(Throwable error)

Override for custom error handling. By default, it closes the channel.

Parameters:

error - The error to handle.

complete

protected void complete()

Override for custom completion handling. By default, it closes the channel.

handlerAdded

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

Specified by:

handlerAdded in interface io.netty.channel.ChannelHandler

Overrides:

handlerAdded in class io.netty.channel.ChannelHandlerAdapter

Throws:

Exception

channelRegistered

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

Specified by:

channelRegistered in interface io.netty.channel.ChannelInboundHandler

Overrides:

channelRegistered in class io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

verifyRegisteredWithRightExecutor

private void verifyRegisteredWithRightExecutor(io.netty.channel.ChannelHandlerContext ctx)

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

channelActive

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

Specified by:

channelActive in interface io.netty.channel.ChannelInboundHandler

Overrides:

channelActive in class io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

channelInactive

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

Specified by:

channelInactive in interface io.netty.channel.ChannelInboundHandler

Overrides:

channelInactive 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

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

cancel

private void cancel()

onSubscribe

public void onSubscribe(org.reactivestreams.Subscription subscription)

Specified by:

onSubscribe in interface org.reactivestreams.Subscriber<T>

provideSubscription

private void provideSubscription()

maybeStart

private void maybeStart()

onNext

public void onNext(T t)

Specified by:

onNext in interface org.reactivestreams.Subscriber<T>

onError

public void onError(Throwable error)

Specified by:

onError in interface org.reactivestreams.Subscriber<T>

onComplete

public void onComplete()

Specified by:

onComplete in interface org.reactivestreams.Subscriber<T>

doClose

private void doClose()

maybeRequestMore

private void maybeRequestMore()