org.axonframework.eventstore.jpa

Interface EventEntryStore<T>

Type Parameters:

T - The data type used to store payloads

All Known Implementing Classes:

DefaultEventEntryStore

public interface EventEntryStore<T>

Interface describing the mechanism that stores Events into the backing data store.

Since:

1.2

Author:

Allard Buijze

Method Summary

Methods

Modifier and Type	Method and Description
Iterator<? extends SerializedDomainEventData<T>>	fetchAggregateStream(String aggregateType, Object identifier, long firstSequenceNumber, int batchSize, javax.persistence.EntityManager entityManager) Creates an iterator that iterates through the events for an aggregate of given type and given identifier starting at given firstSequenceNumber.
Iterator<? extends SerializedDomainEventData<T>>	fetchFiltered(String whereClause, Map<String,Object> parameters, int batchSize, javax.persistence.EntityManager entityManager) Creates an iterator that iterates through the Events that conform to the given JPA whereClause.
Class<T>	getDataType() Returns the type used to store serialized payloads.
SerializedDomainEventData<T>	loadLastSnapshotEvent(String aggregateType, Object identifier, javax.persistence.EntityManager entityManager) Load the last known snapshot event for aggregate of given type with given identifier using given entityManager.
void	persistEvent(String aggregateType, DomainEventMessage event, SerializedObject<T> serializedPayload, SerializedObject<T> serializedMetaData, javax.persistence.EntityManager entityManager) Persists the given event which has been serialized into serializedEvent in the backing data store using given entityManager.
void	persistSnapshot(String aggregateType, DomainEventMessage snapshotEvent, SerializedObject<T> serializedPayload, SerializedObject<T> serializedMetaData, javax.persistence.EntityManager entityManager) Persists the given event which has been serialized into serializedEvent in the backing data store using given entityManager.
void	pruneSnapshots(String type, DomainEventMessage mostRecentSnapshotEvent, int maxSnapshotsArchived, javax.persistence.EntityManager entityManager) Removes old snapshots from the storage for an aggregate of given type that generated the given mostRecentSnapshotEvent.

Method Detail

persistEvent

void persistEvent(String aggregateType,
                DomainEventMessage event,
                SerializedObject<T> serializedPayload,
                SerializedObject<T> serializedMetaData,
                javax.persistence.EntityManager entityManager)

Persists the given event which has been serialized into serializedEvent in the backing data store using given entityManager.

These events should be returned by the fetchAggregateStream(...) methods.

Parameters:

aggregateType - The type identifier of the aggregate that generated the event

event - The actual event instance. May be used to extract relevant meta data

serializedPayload - The serialized payload of the event

serializedMetaData - The serialized MetaData of the event

entityManager - The entity manager providing access to the data store

loadLastSnapshotEvent

SerializedDomainEventData<T> loadLastSnapshotEvent(String aggregateType,
                                                 Object identifier,
                                                 javax.persistence.EntityManager entityManager)

Load the last known snapshot event for aggregate of given type with given identifier using given entityManager.

Parameters:

aggregateType - The type identifier of the aggregate that generated the event

identifier - The identifier of the aggregate to load the snapshot for

entityManager - The entity manager providing access to the data store

Returns:

the serialized representation of the last known snapshot event

fetchAggregateStream

Iterator<? extends SerializedDomainEventData<T>> fetchAggregateStream(String aggregateType,
                                                                    Object identifier,
                                                                    long firstSequenceNumber,
                                                                    int batchSize,
                                                                    javax.persistence.EntityManager entityManager)

Creates an iterator that iterates through the events for an aggregate of given type and given identifier starting at given firstSequenceNumber. When using batched fetching, the given batchSize should be used. The given entityManager provides access to the backing data store.

Note that the result is expected to be ordered by sequence number, with the lowest number first.

Parameters:

aggregateType - The type identifier of the aggregate that generated the event

identifier - The identifier of the aggregate to load the snapshot for

firstSequenceNumber - The sequence number of the first event to include in the batch

batchSize - The number of entries to include in the batch (if available)

entityManager - The entity manager providing access to the data store

Returns:

a List of serialized representations of Events included in this batch

fetchFiltered

Iterator<? extends SerializedDomainEventData<T>> fetchFiltered(String whereClause,
                                                             Map<String,Object> parameters,
                                                             int batchSize,
                                                             javax.persistence.EntityManager entityManager)

Creates an iterator that iterates through the Events that conform to the given JPA whereClause. When the implementation uses batched fetching, it should use given batchSize. The given parameters provide the values for the placeholders used in the where clause.

The "WHERE" keyword must not be included in the whereClause. If the clause is null or an empty String, no filters are applied, and an iterator is returned that scans all events in the event store.

The iterator should return events in the order they were added to the event store. In either case, it must ensure that events originating from the same aggregate are always returned with the lowest sequence number first.

Parameters:

whereClause - The JPA clause to be included after the WHERE keyword

parameters - A map containing all the parameter values for parameter keys included in the where clause

batchSize - The total number of events to return in this batch

entityManager - The entity manager providing access to the data store

Returns:

a List of serialized representations of Events included in this batch

pruneSnapshots

void pruneSnapshots(String type,
                  DomainEventMessage mostRecentSnapshotEvent,
                  int maxSnapshotsArchived,
                  javax.persistence.EntityManager entityManager)

Removes old snapshots from the storage for an aggregate of given type that generated the given mostRecentSnapshotEvent. A number of maxSnapshotsArchived is expected to remain in the archive after pruning, unless that number of snapshots has not been created yet. The given entityManager provides access to the data store.

Parameters:

type - the type of the aggregate for which to prune snapshots

mostRecentSnapshotEvent - the last appended snapshot event

maxSnapshotsArchived - the number of snapshots that may remain archived

entityManager - the entityManager providing access to the data store

persistSnapshot

void persistSnapshot(String aggregateType,
                   DomainEventMessage snapshotEvent,
                   SerializedObject<T> serializedPayload,
                   SerializedObject<T> serializedMetaData,
                   javax.persistence.EntityManager entityManager)

Persists the given event which has been serialized into serializedEvent in the backing data store using given entityManager.

These snapshot events should be returned by the loadLastSnapshotEvent(...) methods.

Parameters:

aggregateType - The type identifier of the aggregate that generated the event

snapshotEvent - The actual snapshot event instance. May be used to extract relevant meta data

serializedPayload - The serialized payload of the event

serializedMetaData - The serialized MetaData of the event

entityManager - The entity manager providing access to the data store

getDataType

Class<T> getDataType()

Returns the type used to store serialized payloads. This data type is an indication to the Event Store implementation to which type events must be serialized.

Returns:

the type used to store serialized payloads