Module dk.cloudcreate.essentials.components.eventsourced.aggregates

Package dk.cloudcreate.essentials.components.eventsourced.aggregates.snapshot

Class AggregateSnapshotDeletionStrategy.DeleteAllHistoricSnapshots

java.lang.Object

dk.cloudcreate.essentials.components.eventsourced.aggregates.snapshot.AggregateSnapshotDeletionStrategy.DeleteAllHistoricSnapshots

All Implemented Interfaces:

AggregateSnapshotDeletionStrategy

Enclosing interface:

AggregateSnapshotDeletionStrategy

public static class AggregateSnapshotDeletionStrategy.DeleteAllHistoricSnapshots
extends Object
implements AggregateSnapshotDeletionStrategy

Strategy that deletes any historic aggregate snapshots when a new snapshot is persisted

Nested Class Summary

Nested classes/interfaces inherited from interface dk.cloudcreate.essentials.components.eventsourced.aggregates.snapshot.AggregateSnapshotDeletionStrategy

AggregateSnapshotDeletionStrategy.DeleteAllHistoricSnapshots, AggregateSnapshotDeletionStrategy.KeepHistoricSnapshots

Constructor Summary

Constructors

Constructor	Description
DeleteAllHistoricSnapshots()

Method Summary

Modifier and Type	Method	Description
boolean	requiresExistingSnapshotDetailsToDetermineWhichAggregateSnapshotsToDelete()	Guard method that determines if Aggregate Snapshot statistics are required in order to determine which Snapshots to delete
<ID, AGGREGATE_IMPL_TYPE> Stream<AggregateSnapshot<ID,AGGREGATE_IMPL_TYPE>>	resolveSnapshotsToDelete(List<AggregateSnapshot<ID,AGGREGATE_IMPL_TYPE>> existingSnapshots)	Out of all the existing snapshots (loaded without the snapshot payload), return the AggregateSnapshot's that should be deleted This method is called just prior to adding a new AggregateSnapshot, so if the purpose it to keep 3 snapshots, and we already have 3 snapshots, then this method should return a Stream containing the oldest snapshot, which will then be deleted
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

DeleteAllHistoricSnapshots

public DeleteAllHistoricSnapshots()

Method Details

toString

public String toString()

Overrides:

toString in class Object

requiresExistingSnapshotDetailsToDetermineWhichAggregateSnapshotsToDelete

public boolean requiresExistingSnapshotDetailsToDetermineWhichAggregateSnapshotsToDelete()

Description copied from interface: AggregateSnapshotDeletionStrategy

Guard method that determines if Aggregate Snapshot statistics are required in order to determine which Snapshots to delete

Specified by:

requiresExistingSnapshotDetailsToDetermineWhichAggregateSnapshotsToDelete in interface AggregateSnapshotDeletionStrategy

Returns:

true if AggregateSnapshotRepository.aggregateUpdated(Object, AggregateEventStream) should fetch existing AggregateSnapshot's (without the payload) as input to AggregateSnapshotDeletionStrategy.resolveSnapshotsToDelete(List) or false if all existing snapshots can be deleted (solves AggregateSnapshotDeletionStrategy.DeleteAllHistoricSnapshots without incurring additional DB queries)

resolveSnapshotsToDelete

public <ID,
AGGREGATE_IMPL_TYPE>
Stream<AggregateSnapshot<ID,AGGREGATE_IMPL_TYPE>> resolveSnapshotsToDelete(List<AggregateSnapshot<ID,AGGREGATE_IMPL_TYPE>> existingSnapshots)

Description copied from interface: AggregateSnapshotDeletionStrategy

Out of all the existing snapshots (loaded without the snapshot payload), return the AggregateSnapshot's that should be deleted
This method is called just prior to adding a new AggregateSnapshot, so if the purpose it to keep 3 snapshots, and we already have 3 snapshots, then this method should return a Stream containing the oldest snapshot, which will then be deleted

Specified by:

resolveSnapshotsToDelete in interface AggregateSnapshotDeletionStrategy

Type Parameters:

ID - the id type for the aggregate

AGGREGATE_IMPL_TYPE - the aggregate type implementation type

Parameters:

existingSnapshots - all the existing snapshots pertaining to a given aggregate instance

Returns:

all the AggregateSnapshot's that should be deleted