Package io.netty.handler.codec.http2

Class DefaultHttp2RemoteFlowController

java.lang.Object

io.netty.handler.codec.http2.DefaultHttp2RemoteFlowController

All Implemented Interfaces:

Http2FlowController, Http2RemoteFlowController

public class DefaultHttp2RemoteFlowController
extends java.lang.Object
implements Http2RemoteFlowController

Basic implementation of Http2RemoteFlowController.

This class is NOT thread safe. The assumption is all methods must be invoked from a single thread. Typically this thread is the event loop thread for the ChannelHandlerContext managed by this class.

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.handler.codec.http2.Http2RemoteFlowController

Http2RemoteFlowController.FlowControlled, Http2RemoteFlowController.Listener

Constructor Summary

Constructors

Constructor	Description
DefaultHttp2RemoteFlowController(Http2Connection connection)
DefaultHttp2RemoteFlowController(Http2Connection connection, Http2RemoteFlowController.Listener listener)
DefaultHttp2RemoteFlowController(Http2Connection connection, StreamByteDistributor streamByteDistributor)
DefaultHttp2RemoteFlowController(Http2Connection connection, StreamByteDistributor streamByteDistributor, Http2RemoteFlowController.Listener listener)

Method Summary

Modifier and Type	Method	Description
void	addFlowControlled(Http2Stream stream, Http2RemoteFlowController.FlowControlled frame)	Queues a payload for transmission to the remote endpoint.
ChannelHandlerContext	channelHandlerContext()	Get the ChannelHandlerContext for which to apply flow control on.
void	channelHandlerContext(ChannelHandlerContext ctx)	Set the ChannelHandlerContext for which to apply flow control on.
void	channelWritabilityChanged()	Notification that the writability of Http2RemoteFlowController.channelHandlerContext() has changed.
boolean	hasFlowControlled(Http2Stream stream)	Determine if stream has any Http2RemoteFlowController.FlowControlled frames currently queued.
void	incrementWindowSize(Http2Stream stream, int delta)	Increments the size of the stream's flow control window by the given delta.
int	initialWindowSize()	Gets the connection-wide initial flow control window size that is used as the basis for new stream flow control windows.
void	initialWindowSize(int newWindowSize)	Sets the connection-wide initial flow control window and updates all stream windows (but not the connection stream window) by the delta.
boolean	isWritable(Http2Stream stream)	Determine if the stream has bytes remaining for use in the flow control window.
void	listener(Http2RemoteFlowController.Listener listener)	Set the active listener on the flow-controller.
void	updateDependencyTree(int childStreamId, int parentStreamId, short weight, boolean exclusive)	Explicitly update the dependency tree.
int	windowSize(Http2Stream stream)	Get the portion of the flow control window for the given stream that is currently available for sending/receiving frames which are subject to flow control.
void	writePendingBytes()	Write all data pending in the flow controller up to the flow-control limits.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultHttp2RemoteFlowController

public DefaultHttp2RemoteFlowController(Http2Connection connection)

DefaultHttp2RemoteFlowController

public DefaultHttp2RemoteFlowController(Http2Connection connection,
                                        StreamByteDistributor streamByteDistributor)

DefaultHttp2RemoteFlowController

public DefaultHttp2RemoteFlowController(Http2Connection connection,
                                        Http2RemoteFlowController.Listener listener)

DefaultHttp2RemoteFlowController

public DefaultHttp2RemoteFlowController(Http2Connection connection,
                                        StreamByteDistributor streamByteDistributor,
                                        Http2RemoteFlowController.Listener listener)

Method Detail

channelHandlerContext

public void channelHandlerContext(ChannelHandlerContext ctx)
                           throws Http2Exception

Set the ChannelHandlerContext for which to apply flow control on.

This must be called to properly initialize the Http2FlowController. Not calling this is considered a programming error.

Any queued Http2RemoteFlowController.FlowControlled objects will be sent.

Specified by:

channelHandlerContext in interface Http2FlowController

Parameters:

ctx - The ChannelHandlerContext for which to apply flow control on.

Throws:

Http2Exception - if any protocol-related error occurred.

channelHandlerContext

public ChannelHandlerContext channelHandlerContext()

Description copied from interface: Http2RemoteFlowController

Get the ChannelHandlerContext for which to apply flow control on.

This is intended for us by Http2RemoteFlowController.FlowControlled implementations only. Use with caution.

Specified by:

channelHandlerContext in interface Http2RemoteFlowController

Returns:

The ChannelHandlerContext for which to apply flow control on.

initialWindowSize

public void initialWindowSize(int newWindowSize)
                       throws Http2Exception

Description copied from interface: Http2FlowController

Sets the connection-wide initial flow control window and updates all stream windows (but not the connection stream window) by the delta.

Represents the value for SETTINGS_INITIAL_WINDOW_SIZE. This method should only be called by Netty (not users) as a result of a receiving a SETTINGS frame.

Specified by:

initialWindowSize in interface Http2FlowController

Parameters:

newWindowSize - the new initial window size.

Throws:

Http2Exception - thrown if any protocol-related error occurred.

initialWindowSize

public int initialWindowSize()

Description copied from interface: Http2FlowController

Gets the connection-wide initial flow control window size that is used as the basis for new stream flow control windows.

Represents the value for SETTINGS_INITIAL_WINDOW_SIZE. The initial value returned by this method must be Http2CodecUtil.DEFAULT_WINDOW_SIZE.

Specified by:

initialWindowSize in interface Http2FlowController

windowSize

public int windowSize(Http2Stream stream)

Description copied from interface: Http2FlowController

Get the portion of the flow control window for the given stream that is currently available for sending/receiving frames which are subject to flow control. This quantity is measured in number of bytes.

Specified by:

windowSize in interface Http2FlowController

isWritable

public boolean isWritable(Http2Stream stream)

Description copied from interface: Http2RemoteFlowController

Determine if the stream has bytes remaining for use in the flow control window.

Note that this method respects channel writability. The channel must be writable for this method to return true.

Specified by:

isWritable in interface Http2RemoteFlowController

Parameters:

stream - The stream to test.

Returns:

true if the stream has bytes remaining for use in the flow control window and the channel is writable, false otherwise.

channelWritabilityChanged

public void channelWritabilityChanged()
                               throws Http2Exception

Description copied from interface: Http2RemoteFlowController

Notification that the writability of Http2RemoteFlowController.channelHandlerContext() has changed.

Specified by:

channelWritabilityChanged in interface Http2RemoteFlowController

Throws:

Http2Exception - If any writes occur as a result of this call and encounter errors.

updateDependencyTree

public void updateDependencyTree(int childStreamId,
                                 int parentStreamId,
                                 short weight,
                                 boolean exclusive)

Description copied from interface: Http2RemoteFlowController

Explicitly update the dependency tree. This method is called independently of stream state changes.

Specified by:

updateDependencyTree in interface Http2RemoteFlowController

Parameters:

childStreamId - The stream identifier associated with the child stream.

parentStreamId - The stream identifier associated with the parent stream. May be 0, to make childStreamId and immediate child of the connection.

weight - The weight which is used relative to other child streams for parentStreamId. This value must be between 1 and 256 (inclusive).

exclusive - If childStreamId should be the exclusive dependency of parentStreamId.

listener

public void listener(Http2RemoteFlowController.Listener listener)

Description copied from interface: Http2RemoteFlowController

Set the active listener on the flow-controller.

Specified by:

listener in interface Http2RemoteFlowController

Parameters:

listener - to notify when the a write occurs, can be null.

incrementWindowSize

public void incrementWindowSize(Http2Stream stream,
                                int delta)
                         throws Http2Exception

Description copied from interface: Http2FlowController

Increments the size of the stream's flow control window by the given delta.

In the case of a Http2RemoteFlowController this is called upon receipt of a WINDOW_UPDATE frame from the remote endpoint to mirror the changes to the window size.

For a Http2LocalFlowController this can be called to request the expansion of the window size published by this endpoint. It is up to the implementation, however, as to when a WINDOW_UPDATE is actually sent.

Specified by:

incrementWindowSize in interface Http2FlowController

Parameters:

stream - The subject stream. Use Http2Connection.connectionStream() for requesting the size of the connection window.

delta - the change in size of the flow control window.

Throws:

Http2Exception - thrown if a protocol-related error occurred.

addFlowControlled

public void addFlowControlled(Http2Stream stream,
                              Http2RemoteFlowController.FlowControlled frame)

Description copied from interface: Http2RemoteFlowController

Queues a payload for transmission to the remote endpoint. There is no guarantee as to when the data will be written or how it will be assigned to frames. before sending.

Writes do not actually occur until Http2RemoteFlowController.writePendingBytes() is called.

Specified by:

addFlowControlled in interface Http2RemoteFlowController

Parameters:

stream - the subject stream. Must not be the connection stream object.

frame - payload to write subject to flow-control accounting and ordering rules.

hasFlowControlled

public boolean hasFlowControlled(Http2Stream stream)

Description copied from interface: Http2RemoteFlowController

Determine if stream has any Http2RemoteFlowController.FlowControlled frames currently queued.

Specified by:

hasFlowControlled in interface Http2RemoteFlowController

Parameters:

stream - the stream to check if it has flow controlled frames.

Returns:

true if stream has any Http2RemoteFlowController.FlowControlled frames currently queued.

writePendingBytes

public void writePendingBytes()
                       throws Http2Exception

Description copied from interface: Http2RemoteFlowController

Write all data pending in the flow controller up to the flow-control limits.

Specified by:

writePendingBytes in interface Http2RemoteFlowController

Throws:

Http2Exception - throws if a protocol-related error occurred.