io.aeron.driver

Class UnicastFlowControl

java.lang.Object

io.aeron.driver.UnicastFlowControl

All Implemented Interfaces:

FlowControl, AutoCloseable

public class UnicastFlowControl
extends Object
implements FlowControl

Default unicast sender flow control strategy.

Max of right edges. No tracking of receivers.

Field Summary

Fields

Modifier and Type	Field and Description
static UnicastFlowControl	INSTANCE Singleton instance which can be used to avoid allocation.

Constructor Summary

Constructors

Constructor and Description
UnicastFlowControl()

Method Summary

Modifier and Type	Method and Description
void	close()
boolean	hasRequiredReceivers() Has the flow control strategy its required group of receivers to be considered connected? The result of this feeds into the determination of if a publication is connected.
void	initialize(MediaDriver.Context context, CountersManager countersManager, UdpChannel udpChannel, int streamId, int sessionId, long registrationId, int initialTermId, int termBufferLength) Initialize the flow control strategy for a stream.
int	maxRetransmissionLength(long resendPosition, int resendLength, int termBufferLength, int mtuLength) The maximum window length allowed to retransmit per NAK.
long	onIdle(long timeNs, long senderLimit, long senderPosition, boolean isEos) Perform any maintenance needed by the flow control strategy and return current sender limit position.
long	onSetup(SetupFlyweight flyweight, long senderLimit, long senderPosition, int positionBitsToShift, long timeNs) Update the sender flow control strategy based on an elicited setup message being sent out.
long	onStatusMessage(StatusMessageFlyweight flyweight, InetSocketAddress receiverAddress, long senderLimit, int initialTermId, int positionBitsToShift, long timeNs) Update the sender flow control strategy based on a status message from the receiver.
void	onTriggerSendSetup(StatusMessageFlyweight flyweight, InetSocketAddress receiverAddress, long timeNs) Update the sender flow control strategy based on a Status Message received triggering a setup to be sent.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final UnicastFlowControl INSTANCE

Singleton instance which can be used to avoid allocation.

Constructor Detail

UnicastFlowControl

public UnicastFlowControl()

Method Detail

onStatusMessage

public long onStatusMessage(StatusMessageFlyweight flyweight,
                            InetSocketAddress receiverAddress,
                            long senderLimit,
                            int initialTermId,
                            int positionBitsToShift,
                            long timeNs)

Update the sender flow control strategy based on a status message from the receiver.

Specified by:

onStatusMessage in interface FlowControl

Parameters:

flyweight - over the status message received.

receiverAddress - of the receiver.

senderLimit - the current sender position limit.

initialTermId - for the term buffers.

positionBitsToShift - in use for the length of each term buffer.

timeNs - current time (in nanoseconds).

Returns:

the new position limit to be employed by the sender.

onTriggerSendSetup

public void onTriggerSendSetup(StatusMessageFlyweight flyweight,
                               InetSocketAddress receiverAddress,
                               long timeNs)

Update the sender flow control strategy based on a Status Message received triggering a setup to be sent.

Specified by:

onTriggerSendSetup in interface FlowControl

Parameters:

flyweight - over the Status Message received

receiverAddress - of the receiver.

timeNs - current time (in nanoseconds).

onSetup

public long onSetup(SetupFlyweight flyweight,
                    long senderLimit,
                    long senderPosition,
                    int positionBitsToShift,
                    long timeNs)

Update the sender flow control strategy based on an elicited setup message being sent out.

Specified by:

onSetup in interface FlowControl

Parameters:

flyweight - over the setup to be sent.

senderLimit - for the current sender position.

senderPosition - which has been sent.

positionBitsToShift - in use for the length of each term buffer.

timeNs - current time in nanoseconds.

Returns:

the new position limit to be employed by the sender.

initialize

public void initialize(MediaDriver.Context context,
                       CountersManager countersManager,
                       UdpChannel udpChannel,
                       int streamId,
                       int sessionId,
                       long registrationId,
                       int initialTermId,
                       int termBufferLength)

Initialize the flow control strategy for a stream.

Specified by:

initialize in interface FlowControl

Parameters:

context - to allow access to media driver configuration

countersManager - to use for any counters in use by the strategy

udpChannel - for the stream.

streamId - for the stream.

sessionId - for the stream.

registrationId - for the stream.

initialTermId - at which the stream started.

termBufferLength - to use as the length of each term buffer.

close

public void close()

Specified by:

close in interface FlowControl

Specified by:

close in interface AutoCloseable

onIdle

public long onIdle(long timeNs,
                   long senderLimit,
                   long senderPosition,
                   boolean isEos)

Perform any maintenance needed by the flow control strategy and return current sender limit position.

Specified by:

onIdle in interface FlowControl

Parameters:

timeNs - current time in nanoseconds.

senderLimit - for the current sender position.

senderPosition - which has been sent.

isEos - is this end-of-stream for the sender.

Returns:

the position limit to be employed by the sender.

hasRequiredReceivers

public boolean hasRequiredReceivers()

Has the flow control strategy its required group of receivers to be considered connected? The result of this feeds into the determination of if a publication is connected.

Specified by:

hasRequiredReceivers in interface FlowControl

Returns:

true if the required group of receivers is connected, otherwise false.

maxRetransmissionLength

public int maxRetransmissionLength(long resendPosition,
                                   int resendLength,
                                   int termBufferLength,
                                   int mtuLength)

The maximum window length allowed to retransmit per NAK.

Specified by:

maxRetransmissionLength in interface FlowControl

Parameters:

resendPosition - of the NAK.

resendLength - of the NAK.

termBufferLength - of the publication.

mtuLength - of the publication.

Returns:

the maximum window length allowed to retransmit per NAK.