Package io.awspring.cloud.sqs.listener.backpressure

Interface BatchAwareBackPressureHandler

All Superinterfaces:

BackPressureHandler

All Known Implementing Classes:

CompositeBackPressureHandler, ConcurrencyLimiterBlockingBackPressureHandler, FullBatchBackPressureHandler, SemaphoreBackPressureHandler

public interface BatchAwareBackPressureHandler
extends BackPressureHandler

BackPressureHandler specialization that allows requesting batches.

Since:

3.0

Author:

Tomaz Fernandes, Loïc Rouchon

Nested Class Summary

Nested classes/interfaces inherited from interface io.awspring.cloud.sqs.listener.backpressure.BackPressureHandler

BackPressureHandler.ReleaseReason

Method Summary

Modifier and Type	Method	Description
default int	getBatchSize()	Deprecated. This method is deprecated and will not be used by the Spring Cloud AWS SQS listener anymore.
default void	release(int amount, BackPressureHandler.ReleaseReason reason)	Releases the specified amount of permits for processed messages.
default void	releaseBatch()	Deprecated. This method is deprecated and will not be called by the Spring Cloud AWS SQS listener anymore.
int	requestBatch()	Request a batch of permits.

Methods inherited from interface io.awspring.cloud.sqs.listener.backpressure.BackPressureHandler

drain, release, request

Method Details

requestBatch

int requestBatch()
          throws InterruptedException

Request a batch of permits.

Returns:

the number of permits acquired.

Throws:

InterruptedException - if the Thread is interrupted while waiting for permits.

releaseBatch

@Deprecated
default void releaseBatch()

Deprecated.

This method is deprecated and will not be called by the Spring Cloud AWS SQS listener anymore. Implement BackPressureHandler.release(int, ReleaseReason) instead.

Release a batch of permits. This has the semantics of letting the BackPressureHandler know that all permits from a batch are being released, in opposition to BackPressureHandler.release(int) in which any number of permits can be specified.

release

default void release(int amount,
 BackPressureHandler.ReleaseReason reason)

Description copied from interface: BackPressureHandler

Releases the specified amount of permits for processed messages. Each message that has been processed should release one permit, whether processing was successful or not.

This method can be called in the following use cases:

• BackPressureHandler.ReleaseReason.LIMITED: all/some permits were not used because another BackPressureHandler has a lower permits limit and the difference in permits needs to be returned.
• BackPressureHandler.ReleaseReason.NONE_FETCHED: none of the permits were actually used because no messages were retrieved from SQS. Permits need to be returned.
• BackPressureHandler.ReleaseReason.PARTIAL_FETCH: some of the permits were used (some messages were retrieved from SQS). The unused ones need to be returned. The amount to be returned might be 0, in which case it means all the permits will be used as the same number of messages were fetched from SQS.
• BackPressureHandler.ReleaseReason.PROCESSED: a message processing finished, successfully or not.

Specified by:

release in interface BackPressureHandler

Parameters:

amount - the amount of permits to release.

reason - the reason why the permits were released.

getBatchSize

@Deprecated
default int getBatchSize()

Deprecated.

This method is deprecated and will not be used by the Spring Cloud AWS SQS listener anymore.

Return the configured batch size for this handler.

Returns:

the batch size.