Package org.elasticsearch.index.seqno

Class LocalCheckpointTracker

java.lang.Object

org.elasticsearch.index.seqno.LocalCheckpointTracker

public class LocalCheckpointTracker
extends java.lang.Object

This class generates sequences numbers and keeps track of the so-called "local checkpoint" which is the highest number for which all previous sequence numbers have been processed (inclusive).

Constructor Summary

Constructors

Constructor	Description
LocalCheckpointTracker(long maxSeqNo, long localCheckpoint)	Initialize the local checkpoint service.

Method Summary

Modifier and Type	Method	Description
long	generateSeqNo()	Issue the next sequence number.
long	getCheckpoint()	The current checkpoint which can be advanced by markSeqNoAsCompleted(long).
long	getMaxSeqNo()	The maximum sequence number issued so far.
SeqNoStats	getStats(long globalCheckpoint)	constructs a SeqNoStats object, using local state and the supplied global checkpoint This is needed to make sure the local checkpoint and max seq no are consistent
void	markSeqNoAsCompleted(long seqNo)	Marks the processing of the provided sequence number as completed as updates the checkpoint if possible.
void	resetCheckpoint(long checkpoint)	Resets the checkpoint to the specified value.
void	waitForOpsToComplete(long seqNo)	Waits for all operations up to the provided sequence number to complete.

Methods inherited from class java.lang.Object

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

Constructor Detail

LocalCheckpointTracker

public LocalCheckpointTracker(long maxSeqNo,
                              long localCheckpoint)

Initialize the local checkpoint service. The maxSeqNo should be set to the last sequence number assigned, or SequenceNumbers.NO_OPS_PERFORMED and localCheckpoint should be set to the last known local checkpoint, or SequenceNumbers.NO_OPS_PERFORMED.

Parameters:

maxSeqNo - the last sequence number assigned, or SequenceNumbers.NO_OPS_PERFORMED

localCheckpoint - the last known local checkpoint, or SequenceNumbers.NO_OPS_PERFORMED

Method Detail

generateSeqNo

public long generateSeqNo()

Issue the next sequence number.

Returns:

the next assigned sequence number

markSeqNoAsCompleted

public void markSeqNoAsCompleted(long seqNo)

Marks the processing of the provided sequence number as completed as updates the checkpoint if possible.

Parameters:

seqNo - the sequence number to mark as completed

resetCheckpoint

public void resetCheckpoint(long checkpoint)

Resets the checkpoint to the specified value.

Parameters:

checkpoint - the local checkpoint to reset this tracker to

getCheckpoint

public long getCheckpoint()

The current checkpoint which can be advanced by markSeqNoAsCompleted(long).

Returns:

the current checkpoint

getMaxSeqNo

public long getMaxSeqNo()

The maximum sequence number issued so far.

Returns:

the maximum sequence number

getStats

public SeqNoStats getStats(long globalCheckpoint)

constructs a SeqNoStats object, using local state and the supplied global checkpoint This is needed to make sure the local checkpoint and max seq no are consistent

waitForOpsToComplete

public void waitForOpsToComplete(long seqNo)
                          throws java.lang.InterruptedException

Waits for all operations up to the provided sequence number to complete.

Parameters:

seqNo - the sequence number that the checkpoint must advance to before this method returns

Throws:

java.lang.InterruptedException - if the thread was interrupted while blocking on the condition