Package pl.allegro.tech.hermes.consumers.consumer.offset

Class PendingOffsets

java.lang.Object

pl.allegro.tech.hermes.consumers.consumer.offset.PendingOffsets

public class PendingOffsets
extends Object

This class manages pending offsets for message consumption in a thread-safe manner. It ensures that the number of pending offsets does not exceed a specified maximum limit.

The slots map is effectively a bounded map, guarded by the maxPendingOffsetsSemaphore. This semaphore ensures that the number of entries in the slots map does not exceed maxPendingOffsets and prevents running out of memory. The semaphore is used to acquire permits before adding entries to the map and to release permits when entries are removed.

The inflightSemaphore is used to limit the number of messages that are currently being processed (inflight). It helps control the concurrency level of message processing.

Note: Methods that modify the state of the slots map, such as markAsProcessed and markAsInflight, must only be called after successfully acquiring a permit using the tryAcquireSlot method.

Constructor Summary

Constructors

Constructor	Description
PendingOffsets(pl.allegro.tech.hermes.api.SubscriptionName subscriptionName, pl.allegro.tech.hermes.common.metric.MetricsFacade metrics, int inflightQueueSize, int maxPendingOffsets)

Method Summary

Modifier and Type	Method	Description
Map<SubscriptionPartitionOffset,MessageState>	getOffsetsSnapshotAndReleaseProcessedSlots()
void	markAsInflight(SubscriptionPartitionOffset subscriptionPartitionOffset)
void	markAsProcessed(SubscriptionPartitionOffset subscriptionPartitionOffset)
void	releaseSlot()
void	setInflightSize(int inflightQueueSize)
boolean	tryAcquireSlot(Duration processingInterval)

Methods inherited from class java.lang.Object

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

Constructor Details

PendingOffsets

public PendingOffsets(pl.allegro.tech.hermes.api.SubscriptionName subscriptionName,
 pl.allegro.tech.hermes.common.metric.MetricsFacade metrics,
 int inflightQueueSize,
 int maxPendingOffsets)

Method Details

setInflightSize

public void setInflightSize(int inflightQueueSize)

markAsProcessed

public void markAsProcessed(SubscriptionPartitionOffset subscriptionPartitionOffset)

tryAcquireSlot

public boolean tryAcquireSlot(Duration processingInterval)
                       throws InterruptedException

Throws:

InterruptedException

markAsInflight

public void markAsInflight(SubscriptionPartitionOffset subscriptionPartitionOffset)

getOffsetsSnapshotAndReleaseProcessedSlots

public Map<SubscriptionPartitionOffset,MessageState> getOffsetsSnapshotAndReleaseProcessedSlots()

releaseSlot

public void releaseSlot()