Package org.axonframework.messaging.eventhandling.processing.streaming.segmenting

Class SequenceCachingEventHandlingComponent

java.lang.Object

org.axonframework.messaging.eventhandling.DelegatingEventHandlingComponent

org.axonframework.messaging.eventhandling.processing.streaming.segmenting.SequenceCachingEventHandlingComponent

All Implemented Interfaces:

DescribableComponent, MessageHandler, EventHandler, EventHandlingComponent

@Internal
public class SequenceCachingEventHandlingComponent
extends DelegatingEventHandlingComponent

Decorator for EventHandlingComponent. This implementation acts as a performance optimization layer by caching the results of sequence identifier calculations. Since sequence identifier computation can be expensive, this caching component reduces redundant calculations for events which sequence identifier has already been calculated within the same ProcessingContext.

The cache is stored as a resource in the ProcessingContext, ensuring that the cache is scoped to the current processing unit of work. This means the cache is automatically cleaned up when the processing context is completed.

Example usage within framework configuration:

 EventHandlingComponent component = // ... create base component
 EventHandlingComponent cachingComponent = new SequenceCachingEventHandlingComponent(component);
 

Since:

5.0.0

Author:

Mateusz Nowak

Field Summary

Fields inherited from class org.axonframework.messaging.eventhandling.DelegatingEventHandlingComponent

delegate

Constructor Summary

Constructors

Constructor	Description
SequenceCachingEventHandlingComponent(EventHandlingComponent delegate)	Constructs the component with given delegate to receive calls.

Method Summary

Modifier and Type	Method	Description
Object	sequenceIdentifierFor(EventMessage event, ProcessingContext context)	Returns the sequence identifier for the given event.

Methods inherited from class org.axonframework.messaging.eventhandling.DelegatingEventHandlingComponent

describeTo, handle, supportedEvents, supports

Methods inherited from class java.lang.Object

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

Constructor Details

SequenceCachingEventHandlingComponent

@Internal
public SequenceCachingEventHandlingComponent(@Nonnull
 EventHandlingComponent delegate)

Constructs the component with given delegate to receive calls.

Parameters:

delegate - The EventHandlingComponent instance to delegate calls to.

Method Details

sequenceIdentifierFor

@Nonnull
public Object sequenceIdentifierFor(@Nonnull
 EventMessage event,
 @Nonnull
 ProcessingContext context)

Description copied from interface: EventHandlingComponent

Returns the sequence identifier for the given event. When two events have the same sequence identifier (as defined by their equals method), they will be executed sequentially. Important: All EventHandlers for the same QualifiedName within a single EventHandlingComponent must return the same sequence identifier for a given event. Mixing different sequence identifiers within the scope of a single EventHandlingComponent is not supported and may lead to undefined behavior.

Specified by:

sequenceIdentifierFor in interface EventHandlingComponent

Overrides:

sequenceIdentifierFor in class DelegatingEventHandlingComponent

Parameters:

event - The event for which to get the sequencing identifier.

context - The processing context in which the event is being handled.

Returns:

A sequence identifier for the given event.