Package org.axonframework.eventsourcing

Class CachingEventSourcingRepository<T>

java.lang.Object

org.axonframework.modelling.command.AbstractRepository<T,LockAwareAggregate<T,EventSourcedAggregate<T>>>

org.axonframework.modelling.command.LockingRepository<T,EventSourcedAggregate<T>>

org.axonframework.eventsourcing.EventSourcingRepository<T>

org.axonframework.eventsourcing.CachingEventSourcingRepository<T>

Type Parameters:

T - The type of aggregate this repository stores

All Implemented Interfaces:

ScopeAware, Repository<T>

public class CachingEventSourcingRepository<T>
extends EventSourcingRepository<T>

Implementation of the event sourcing repository that uses a cache to improve loading performance. The cache removes the need to read all events from disk, at the cost of memory usage.

Note that an entry of a cached aggregate is immediately invalidated when an error occurs while saving that aggregate. This is done to prevent the cache from returning aggregates that may not have fully persisted to disk.

Since:

0.3

Author:

Allard Buijze

Nested Class Summary

Nested classes/interfaces inherited from class org.axonframework.eventsourcing.EventSourcingRepository

EventSourcingRepository.Builder<T>

Field Summary

Fields inherited from class org.axonframework.modelling.command.AbstractRepository

spanFactory

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CachingEventSourcingRepository(EventSourcingRepository.Builder<T> builder)	Instantiate a CachingEventSourcingRepository based on the fields contained in the EventSourcingRepository.Builder.

Method Summary

Modifier and Type	Method	Description
protected void	doDeleteWithLock(EventSourcedAggregate<T> aggregate)	Perform the actual deleting of the aggregate.
protected EventSourcedAggregate<T>	doLoadWithLock(String aggregateIdentifier, Long expectedVersion)	Perform the actual loading of an aggregate.
protected void	doSaveWithLock(EventSourcedAggregate<T> aggregate)	Perform the actual saving of the aggregate.
protected void	validateOnLoad(Aggregate<T> aggregate, Long expectedVersion)	Checks the aggregate for concurrent changes.

Methods inherited from class org.axonframework.eventsourcing.EventSourcingRepository

builder, doCreateNewForLock, getAggregateFactory, readEvents, reportIllegalState

Methods inherited from class org.axonframework.modelling.command.LockingRepository

doCreateNew, doDelete, doLoad, doLoadOrCreate, doSave, prepareForCommit

Methods inherited from class org.axonframework.modelling.command.AbstractRepository

aggregateModel, canResolve, getAggregateType, load, load, loadOrCreate, managedAggregates, newInstance, newInstance, postDelete, postSave, send

Methods inherited from class java.lang.Object

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

Constructor Details

CachingEventSourcingRepository

protected CachingEventSourcingRepository(EventSourcingRepository.Builder<T> builder)

Instantiate a CachingEventSourcingRepository based on the fields contained in the EventSourcingRepository.Builder.

A goal of the provided Builder is to create an AggregateModel specifying generic T as the aggregate type to be stored. All aggregates in this repository must be instanceOf this aggregate type. To instantiate this AggregateModel, either an AggregateModel can be provided directly or an aggregateType of type Class can be used. The latter will internally resolve to an AggregateModel. Thus, either the AggregateModel or the aggregateType should be provided. An AxonConfigurationException is thrown if this criteria is not met. The same criteria holds for the AggregateFactory. Either the AggregateFactory can be set directly or it will be instantiated internally based on the aggregateType. Hence, one of both is a hard requirement, and will also result in an AxonConfigurationException if both are missing.

Additionally will assert that the LockFactory, EventStore, SnapshotTriggerDefinition and Cache are not null, resulting in an AxonConfigurationException if for any of these this is the case.

Parameters:

builder - the EventSourcingRepository.Builder used to instantiate a CachingEventSourcingRepository instance

Method Details

validateOnLoad

protected void validateOnLoad(Aggregate<T> aggregate,
 Long expectedVersion)

Description copied from class: AbstractRepository

Checks the aggregate for concurrent changes. Throws a ConflictingModificationException when conflicting changes have been detected.

This implementation throws a ConflictingAggregateVersionException if the expected version is not null and the version number of the aggregate does not match the expected version

Overrides:

validateOnLoad in class EventSourcingRepository<T>

Parameters:

aggregate - The loaded aggregate

expectedVersion - The expected version of the aggregate

doSaveWithLock

protected void doSaveWithLock(EventSourcedAggregate<T> aggregate)

Description copied from class: LockingRepository

Perform the actual saving of the aggregate. All necessary locks have been verified.

Overrides:

doSaveWithLock in class EventSourcingRepository<T>

Parameters:

aggregate - the aggregate to store

doDeleteWithLock

protected void doDeleteWithLock(EventSourcedAggregate<T> aggregate)

Description copied from class: LockingRepository

Perform the actual deleting of the aggregate. All necessary locks have been verified.

Overrides:

doDeleteWithLock in class EventSourcingRepository<T>

Parameters:

aggregate - the aggregate to delete

doLoadWithLock

protected EventSourcedAggregate<T> doLoadWithLock(String aggregateIdentifier,
 Long expectedVersion)

Perform the actual loading of an aggregate. The necessary locks have been obtained. If the aggregate is available in the cache, it is returned from there. Otherwise the underlying persistence logic is called to retrieve the aggregate.

Overrides:

doLoadWithLock in class EventSourcingRepository<T>

Parameters:

aggregateIdentifier - the identifier of the aggregate to load

expectedVersion - The expected version of the aggregate

Returns:

the fully initialized aggregate