Class SpscOffHeapFixedSizeRingBuffer

java.lang.Object

org.jctools.channels.proxy.ProxyChannelRingBuffer

org.jctools.channels.OffHeapFixedMessageSizeRingBuffer

org.jctools.channels.spsc.SpscOffHeapFixedSizeRingBuffer

Direct Known Subclasses:

SpscChannelConsumer, SpscChannelProducer

public class SpscOffHeapFixedSizeRingBuffer
extends OffHeapFixedMessageSizeRingBuffer

Channel protocol: - Fixed message size - 'null' indicator in message preceding byte (potentially use same for type mapping in future) - Use FF algorithm relying on indicator to support in place detection of next element existence

Field Summary

Fields

Modifier and Type	Field	Description
static final long	EOF
private final int	lookAheadStep
private static final Integer	MAX_LOOK_AHEAD_STEP
private final long	producerLookAheadCacheAddress

Fields inherited from class OffHeapFixedMessageSizeRingBuffer

bufferAddress, consumerIndexAddress, HEADER_SIZE, mask, MESSAGE_INDICATOR_SIZE, messageSize, producerIndexAddress, READ_ACQUIRE_INDICATOR, READ_RELEASE_INDICATOR, referenceMessageSize, references, WRITE_ACQUIRE_INDICATOR, WRITE_RELEASE_INDICATOR

Constructor Summary

Constructors

Modifier	Constructor	Description
	SpscOffHeapFixedSizeRingBuffer(int capacity, int messageSize, int referenceMessageSize)
protected	SpscOffHeapFixedSizeRingBuffer(ByteBuffer buff, int capacity, boolean isProducer, boolean isConsumer, boolean initialize, int messageSize, Object[] references, int referenceMessageSize)	This is to be used for an IPC queue with the direct buffer used being a memory mapped file.

Method Summary

Modifier and Type	Method	Description
static int	getLookaheadStep(int capacity)
private long	lpLookAheadCache()
protected final long	readAcquire()	Acquire an offset to read from
protected final void	readRelease(long offset)	Release the offset from reading
private void	spLookAheadCache(long value)
protected final long	writeAcquire()	Acquire an offset to write to.
protected final void	writeRelease(long offset)
protected final void	writeRelease(long offset, int type)	Ordered store of the callTypeId for the message at offset

Methods inherited from class OffHeapFixedMessageSizeRingBuffer

arrayIndexForCursor, arrayIndexForCursor, capacity, consumerReferenceArrayIndex, createReferenceArray, getRequiredArraySize, getRequiredBufferSize, isEmpty, isReadReleased, lpConsumerIndex, lpProducerIndex, lvConsumerIndex, lvProducerIndex, offsetForIndex, offsetForIndex, producerReferenceArrayIndex, readAcquireState, readReference, readReleaseState, relativeIndexForOffset, relativeIndexForOffset, size, soConsumerIndex, soProducerIndex, writeAcquireState, writeReference, writeReleaseState

Methods inherited from class Object

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

Field Details

MAX_LOOK_AHEAD_STEP

private static final Integer MAX_LOOK_AHEAD_STEP

EOF

public static final long EOF

See Also:

• Constant Field Values

lookAheadStep

private final int lookAheadStep

producerLookAheadCacheAddress

private final long producerLookAheadCacheAddress

Constructor Details

SpscOffHeapFixedSizeRingBuffer

public SpscOffHeapFixedSizeRingBuffer(int capacity,
 int messageSize,
 int referenceMessageSize)

SpscOffHeapFixedSizeRingBuffer

protected SpscOffHeapFixedSizeRingBuffer(ByteBuffer buff,
 int capacity,
 boolean isProducer,
 boolean isConsumer,
 boolean initialize,
 int messageSize,
 Object[] references,
 int referenceMessageSize)

This is to be used for an IPC queue with the direct buffer used being a memory mapped file.

Parameters:

buff -

capacity - in messages, actual capacity will be

messageSize -

Method Details

getLookaheadStep

public static int getLookaheadStep(int capacity)

writeAcquire

protected final long writeAcquire()

Description copied from class: ProxyChannelRingBuffer

Acquire an offset to write to. If there's no space available a wait strategy may be used.

Specified by:

writeAcquire in class OffHeapFixedMessageSizeRingBuffer

Returns:

a base address for a message acquired to be written, or EOF if none is available

writeRelease

protected final void writeRelease(long offset)

Specified by:

writeRelease in class OffHeapFixedMessageSizeRingBuffer

Parameters:

offset - the base address of a message that we are done writing and can be read now

writeRelease

protected final void writeRelease(long offset,
 int type)

Description copied from class: ProxyChannelRingBuffer

Ordered store of the callTypeId for the message at offset

Specified by:

writeRelease in class ProxyChannelRingBuffer

Parameters:

offset - the offset that was released for writing

type - A unique ID for the call

readAcquire

protected final long readAcquire()

Description copied from class: ProxyChannelRingBuffer

Acquire an offset to read from

Specified by:

readAcquire in class OffHeapFixedMessageSizeRingBuffer

Returns:

a base address for a message acquired to be read, or EOF if none is available

readRelease

protected final void readRelease(long offset)

Description copied from class: ProxyChannelRingBuffer

Release the offset from reading

Specified by:

readRelease in class OffHeapFixedMessageSizeRingBuffer

Parameters:

offset - the base address of a message that we are done reading and can be overwritten now

lpLookAheadCache

private long lpLookAheadCache()

spLookAheadCache

private void spLookAheadCache(long value)