io.aeron.driver

Class LossDetector

java.lang.Object

io.aeron.driver.LossDetector

All Implemented Interfaces:

io.aeron.logbuffer.TermGapScanner.GapHandler

public class LossDetector
extends java.lang.Object
implements io.aeron.logbuffer.TermGapScanner.GapHandler

Detecting and handling of gaps in a stream

This detector only notifies a single NAK at a time.

Constructor Summary

Constructors

Constructor and Description
LossDetector(FeedbackDelayGenerator delayGenerator, NakMessageSender nakMessageSender) Create a loss handler for a channel.

Method Summary

Modifier and Type	Method and Description
void	onGap(int termId, org.agrona.concurrent.UnsafeBuffer buffer, int offset, int length)
void	onNak(long now, int termId, int termOffset) Called on reception of a NAK
int	rebuildOffset() Get the offset to which the term is rebuilt after a scan(UnsafeBuffer, long, long, long, int, int, int).
int	scan(org.agrona.concurrent.UnsafeBuffer termBuffer, long rebuildPosition, long hwmPosition, long now, int termLengthMask, int positionBitsToShift, int initialTermId) Scan for gaps and handle received data.

Methods inherited from class java.lang.Object

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

Constructor Detail

LossDetector

public LossDetector(FeedbackDelayGenerator delayGenerator,
                    NakMessageSender nakMessageSender)

Create a loss handler for a channel.

Parameters:

delayGenerator - to use for delay determination

nakMessageSender - to call when sending a NAK is indicated

Method Detail

rebuildOffset

public int rebuildOffset()

Get the offset to which the term is rebuilt after a scan(UnsafeBuffer, long, long, long, int, int, int).

Returns:

the offset to which the term is rebuilt after a scan(UnsafeBuffer, long, long, long, int, int, int).

scan

public int scan(org.agrona.concurrent.UnsafeBuffer termBuffer,
                long rebuildPosition,
                long hwmPosition,
                long now,
                int termLengthMask,
                int positionBitsToShift,
                int initialTermId)

Scan for gaps and handle received data.

The handler keeps track from scan to scan what is a gap and what must have been repaired.

Parameters:

termBuffer - to scan

rebuildPosition - to start scanning from

hwmPosition - to scan up to

now - time in nanoseconds

termLengthMask - used for offset calculation

positionBitsToShift - used for position calculation

initialTermId - used by the scanner

Returns:

the work count for this operation.

onNak

public void onNak(long now,
                  int termId,
                  int termOffset)

Called on reception of a NAK

Parameters:

now - time in nanoseconds

termId - in the NAK

termOffset - in the NAK

onGap

public void onGap(int termId,
                  org.agrona.concurrent.UnsafeBuffer buffer,
                  int offset,
                  int length)

Specified by:

onGap in interface io.aeron.logbuffer.TermGapScanner.GapHandler