com.lmax.disruptor

Class AbstractSequencer

java.lang.Object

com.lmax.disruptor.AbstractSequencer

All Implemented Interfaces:

Cursored, Sequencer

Direct Known Subclasses:

MultiProducerSequencer, SingleProducerSequencer

public abstract class AbstractSequencer
extends java.lang.Object
implements Sequencer

Base class for the various sequencer types (single/multi). Provides common functionality like the management of gating sequences (add/remove) and ownership of the current cursor.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	bufferSize
protected Sequence	cursor
protected Sequence[]	gatingSequences
protected WaitStrategy	waitStrategy

Fields inherited from interface com.lmax.disruptor.Sequencer

INITIAL_CURSOR_VALUE

Constructor Summary

Constructors

Constructor and Description
AbstractSequencer(int bufferSize, WaitStrategy waitStrategy) Create with the specified buffer size and wait strategy.

Method Summary

Methods

Modifier and Type	Method and Description
void	addGatingSequences(Sequence... gatingSequences) Add the specified gating sequences to this instance of the Disruptor.
int	getBufferSize() The capacity of the data structure to hold entries.
long	getCursor() Get the current cursor value.
long	getMinimumSequence() Get the minimum sequence value from all of the gating sequences added to this ringBuffer.
SequenceBarrier	newBarrier(Sequence... sequencesToTrack) Create a new SequenceBarrier to be used by an EventProcessor to track which messages are available to be read from the ring buffer given a list of sequences to track.
boolean	removeGatingSequence(Sequence sequence) Remove the specified sequence from this sequencer.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.lmax.disruptor.Sequencer

claim, getHighestPublishedSequence, hasAvailableCapacity, isAvailable, next, next, publish, publish, remainingCapacity, tryNext, tryNext

Field Detail

bufferSize

protected final int bufferSize

waitStrategy

protected final WaitStrategy waitStrategy

cursor

protected final Sequence cursor

gatingSequences

protected volatile Sequence[] gatingSequences

Constructor Detail

AbstractSequencer

public AbstractSequencer(int bufferSize,
                 WaitStrategy waitStrategy)

Create with the specified buffer size and wait strategy.

Parameters:

bufferSize - The total number of entries, must be a positive power of 2.

waitStrategy -

Method Detail

getCursor

public final long getCursor()

Description copied from interface: Cursored

Get the current cursor value.

Specified by:

getCursor in interface Cursored

Returns:

current cursor value

See Also:

Cursored.getCursor()

getBufferSize

public final int getBufferSize()

Description copied from interface: Sequencer

The capacity of the data structure to hold entries.

Specified by:

getBufferSize in interface Sequencer

Returns:

the size of the RingBuffer.

See Also:

Sequencer.getBufferSize()

addGatingSequences

public final void addGatingSequences(Sequence... gatingSequences)

Description copied from interface: Sequencer

Add the specified gating sequences to this instance of the Disruptor. They will safely and atomically added to the list of gating sequences.

Specified by:

addGatingSequences in interface Sequencer

Parameters:

gatingSequences - The sequences to add.

See Also:

Sequencer.addGatingSequences(Sequence...)

removeGatingSequence

public boolean removeGatingSequence(Sequence sequence)

Description copied from interface: Sequencer

Remove the specified sequence from this sequencer.

Specified by:

removeGatingSequence in interface Sequencer

Parameters:

sequence - to be removed.

Returns:

true if this sequence was found, false otherwise.

See Also:

Sequencer.removeGatingSequence(Sequence)

getMinimumSequence

public long getMinimumSequence()

Description copied from interface: Sequencer

Get the minimum sequence value from all of the gating sequences added to this ringBuffer.

Specified by:

getMinimumSequence in interface Sequencer

Returns:

The minimum gating sequence or the cursor sequence if no sequences have been added.

See Also:

Sequencer.getMinimumSequence()

newBarrier

public SequenceBarrier newBarrier(Sequence... sequencesToTrack)

Description copied from interface: Sequencer

Create a new SequenceBarrier to be used by an EventProcessor to track which messages are available to be read from the ring buffer given a list of sequences to track.

Specified by:

newBarrier in interface Sequencer

Returns:

A sequence barrier that will track the specified sequences.

See Also:

Sequencer.newBarrier(Sequence...)