com.alipay.disruptor

类 MultiProducerSequencer

java.lang.Object

com.alipay.disruptor.AbstractSequencer

com.alipay.disruptor.MultiProducerSequencer

所有已实现的接口:

Cursored, Sequenced, Sequencer

public final class MultiProducerSequencer
extends AbstractSequencer

Coordinator for claiming sequences for access to a data structure while tracking dependent Sequences. Suitable for use for sequencing across multiple publisher threads.

*

Note on Cursored.getCursor(): With this sequencer the cursor value is updated after the call to Sequenced.next(), to determine the highest available sequence that can be read, then Sequencer.getHighestPublishedSequence(long, long) should be used.

字段概要

从类继承的字段 com.alipay.disruptor.AbstractSequencer

bufferSize, cursor, gatingSequences, waitStrategy

从接口继承的字段 com.alipay.disruptor.Sequencer

INITIAL_CURSOR_VALUE

构造器概要

构造器

构造器和说明
MultiProducerSequencer(int bufferSize, WaitStrategy waitStrategy) Construct a Sequencer with the selected wait strategy and buffer size.

方法概要

方法

限定符和类型	方法和说明
void	claim(long sequence) Claim a specific sequence.
long	getHighestPublishedSequence(long lowerBound, long availableSequence) Get the highest sequence number that can be safely read from the ring buffer.
boolean	hasAvailableCapacity(int requiredCapacity) Has the buffer got capacity to allocate another sequence.
boolean	isAvailable(long sequence) Confirms if a sequence is published and the event is available for use; non-blocking.
long	next() Claim the next event in sequence for publishing.
long	next(int n) Claim the next n events in sequence for publishing.
void	publish(long sequence) Publishes a sequence.
void	publish(long lo, long hi) Batch publish sequences.
long	remainingCapacity() Get the remaining capacity for this sequencer.
long	tryNext() Attempt to claim the next event in sequence for publishing.
long	tryNext(int n) Attempt to claim the next n events in sequence for publishing.

从类继承的方法 com.alipay.disruptor.AbstractSequencer

addGatingSequences, getBufferSize, getCursor, getMinimumSequence, newBarrier, newPoller, removeGatingSequence, toString

从类继承的方法 java.lang.Object

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

构造器详细资料

MultiProducerSequencer

public MultiProducerSequencer(int bufferSize,
                      WaitStrategy waitStrategy)

Construct a Sequencer with the selected wait strategy and buffer size.

参数:

bufferSize - the size of the buffer that this will sequence over.

waitStrategy - for those waiting on sequences.

方法详细资料

hasAvailableCapacity

public boolean hasAvailableCapacity(int requiredCapacity)

从接口复制的说明: Sequenced

Has the buffer got capacity to allocate another sequence. This is a concurrent method so the response should only be taken as an indication of available capacity.

参数:

requiredCapacity - in the buffer

返回:

true if the buffer has the capacity to allocate the next sequence otherwise false.

另请参阅:

Sequenced.hasAvailableCapacity(int)

claim

public void claim(long sequence)

从接口复制的说明: Sequencer

Claim a specific sequence. Only used if initialising the ring buffer to a specific value.

参数:

sequence - The sequence to initialise too.

另请参阅:

Sequencer.claim(long)

next

public long next()

从接口复制的说明: Sequenced

Claim the next event in sequence for publishing.

返回:

the claimed sequence value

另请参阅:

Sequenced.next()

next

public long next(int n)

从接口复制的说明: Sequenced

Claim the next n events in sequence for publishing. This is for batch event producing. Using batch producing requires a little care and some math.

 int n = 10;
 long hi = sequencer.next(n);
 long lo = hi - (n - 1);
 for (long sequence = lo; sequence <= hi; sequence++) {
     // Do work.
 }
 sequencer.publish(lo, hi);
 

参数:

n - the number of sequences to claim

返回:

the highest claimed sequence value

另请参阅:

Sequenced.next(int)

tryNext

public long tryNext()
             throws InsufficientCapacityException

从接口复制的说明: Sequenced

Attempt to claim the next event in sequence for publishing. Will return the number of the slot if there is at least requiredCapacity slots available.

返回:

the claimed sequence value

抛出:

InsufficientCapacityException - InsufficientCapacityException

另请参阅:

Sequenced.tryNext()

tryNext

public long tryNext(int n)
             throws InsufficientCapacityException

从接口复制的说明: Sequenced

Attempt to claim the next n events in sequence for publishing. Will return the highest numbered slot if there is at least requiredCapacity slots available. Have a look at Sequenced.next() for a description on how to use this method.

参数:

n - the number of sequences to claim

返回:

the claimed sequence value

抛出:

InsufficientCapacityException - InsufficientCapacityException

另请参阅:

Sequenced.tryNext(int)

remainingCapacity

public long remainingCapacity()

从接口复制的说明: Sequenced

Get the remaining capacity for this sequencer.

返回:

The number of slots remaining.

另请参阅:

Sequenced.remainingCapacity()

publish

public void publish(long sequence)

从接口复制的说明: Sequenced

Publishes a sequence. Call when the event has been filled.

参数:

sequence - sequence

另请参阅:

Sequenced.publish(long)

publish

public void publish(long lo,
           long hi)

从接口复制的说明: Sequenced

Batch publish sequences. Called when all of the events have been filled.

参数:

lo - first sequence number to publish

hi - last sequence number to publish

另请参阅:

Sequenced.publish(long, long)

isAvailable

public boolean isAvailable(long sequence)

从接口复制的说明: Sequencer

Confirms if a sequence is published and the event is available for use; non-blocking.

参数:

sequence - of the buffer to check

返回:

true if the sequence is available for use, false if not

另请参阅:

Sequencer.isAvailable(long)

getHighestPublishedSequence

public long getHighestPublishedSequence(long lowerBound,
                               long availableSequence)

从接口复制的说明: Sequencer

Get the highest sequence number that can be safely read from the ring buffer. Depending on the implementation of the Sequencer this call may need to scan a number of values in the Sequencer. The scan will range from nextSequence to availableSequence. If there are no available values >= nextSequence the return value will be nextSequence - 1. To work correctly a consumer should pass a value that it 1 higher than the last sequence that was successfully processed.

参数:

lowerBound - The sequence to start scanning from.

availableSequence - The sequence to scan to.

返回:

The highest value that can be safely read, will be at least nextSequence - 1.