Package io.awspring.cloud.sqs.listener

Class SemaphoreBackPressureHandler

java.lang.Object

io.awspring.cloud.sqs.listener.SemaphoreBackPressureHandler

All Implemented Interfaces:

BackPressureHandler, BatchAwareBackPressureHandler, IdentifiableContainerComponent

public class SemaphoreBackPressureHandler
extends Object
implements BatchAwareBackPressureHandler, IdentifiableContainerComponent

BackPressureHandler implementation that uses a Semaphore for handling backpressure.

Since:

3.0

Author:

Tomaz Fernandes

See Also:

• PollingMessageSource

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SemaphoreBackPressureHandler.Builder

Method Summary

Modifier and Type	Method	Description
static SemaphoreBackPressureHandler.Builder	builder()
boolean	drain(Duration timeout)	Attempts to acquire all permits up to the specified timeout.
int	getBatchSize()	Return the configured batch size for this handler.
String	getId()	Get the component id.
void	release(int amount)	Release the specified amount of permits.
void	releaseBatch()	Release a batch of permits.
int	request(int amount)	Request a number of permits.
int	requestBatch()	Request a batch of permits.
void	setId(String id)	Set the component id.

Methods inherited from class java.lang.Object

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

Method Details

builder

public static SemaphoreBackPressureHandler.Builder builder()

setId

public void setId(String id)

Description copied from interface: IdentifiableContainerComponent

Set the component id.

Specified by:

setId in interface IdentifiableContainerComponent

Parameters:

id - the id.

getId

public String getId()

Description copied from interface: IdentifiableContainerComponent

Get the component id.

Specified by:

getId in interface IdentifiableContainerComponent

Returns:

the id.

request

public int request(int amount)
            throws InterruptedException

Description copied from interface: BackPressureHandler

Request a number of permits. Each obtained permit allows the MessageSource to retrieve one message.

Specified by:

request in interface BackPressureHandler

Parameters:

amount - the amount of permits to request.

Returns:

the amount of permits obtained.

Throws:

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

requestBatch

public int requestBatch()
                 throws InterruptedException

Description copied from interface: BatchAwareBackPressureHandler

Request a batch of permits.

Specified by:

requestBatch in interface BatchAwareBackPressureHandler

Returns:

the number of permits acquired.

Throws:

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

releaseBatch

public void releaseBatch()

Description copied from interface: BatchAwareBackPressureHandler

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.

Specified by:

releaseBatch in interface BatchAwareBackPressureHandler

getBatchSize

public int getBatchSize()

Description copied from interface: BatchAwareBackPressureHandler

Return the configured batch size for this handler.

Specified by:

getBatchSize in interface BatchAwareBackPressureHandler

Returns:

the batch size.

release

public void release(int amount)

Description copied from interface: BackPressureHandler

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

Specified by:

release in interface BackPressureHandler

Parameters:

amount - the amount of permits to release.

drain

public boolean drain(Duration timeout)

Description copied from interface: BackPressureHandler

Attempts to acquire all permits up to the specified timeout. If successful, means all permits were returned and thus no activity is left in the MessageSource.

Specified by:

drain in interface BackPressureHandler

Parameters:

timeout - the maximum amount of time to wait for all permits to be released.

Returns:

whether all permits were acquired.