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

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

Class AggregateSnapshotDeletionStrategy.KeepHistoricSnapshots

java.lang.Object

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

All Implemented Interfaces:

AggregateSnapshotDeletionStrategy

Enclosing interface:

AggregateSnapshotDeletionStrategy

public static class AggregateSnapshotDeletionStrategy.KeepHistoricSnapshots
extends Object
implements AggregateSnapshotDeletionStrategy

Strategy that keeps all or a specific number of historic aggregate snapshots

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
KeepHistoricSnapshots()	Strategy that keeps all historic aggregate snapshots
KeepHistoricSnapshots(long numberOfHistoricSnapshotsToKeep)	Strategy that keeps a specific number historic aggregate snapshots

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
long	getNumberOfHistoricSnapshotsToKeep()
int	hashCode()
static AggregateSnapshotDeletionStrategy.KeepHistoricSnapshots	keepALimitedNumberOfHistoricSnapshots(long numberOfHistoricSnapshotsToKeep)	Strategy that keeps all historic aggregate snapshots
static AggregateSnapshotDeletionStrategy.KeepHistoricSnapshots	keepAllHistoricSnapshots()	Strategy that keeps all historic aggregate snapshots
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, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Details

KeepHistoricSnapshots

public KeepHistoricSnapshots()

Strategy that keeps all historic aggregate snapshots

KeepHistoricSnapshots

public KeepHistoricSnapshots(long numberOfHistoricSnapshotsToKeep)

Strategy that keeps a specific number historic aggregate snapshots

Parameters:

numberOfHistoricSnapshotsToKeep - the number of historic aggregate snapshots to keep (must be >= 0)

Method Details

keepALimitedNumberOfHistoricSnapshots

public static AggregateSnapshotDeletionStrategy.KeepHistoricSnapshots keepALimitedNumberOfHistoricSnapshots(long numberOfHistoricSnapshotsToKeep)

Strategy that keeps all historic aggregate snapshots

Parameters:

numberOfHistoricSnapshotsToKeep - the number of historic aggregate snapshots to keep

Returns:

Strategy that keeps all historic aggregate snapshots

keepAllHistoricSnapshots

public static AggregateSnapshotDeletionStrategy.KeepHistoricSnapshots keepAllHistoricSnapshots()

Strategy that keeps all historic aggregate snapshots

Returns:

Strategy that keeps all historic aggregate snapshots

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

getNumberOfHistoricSnapshotsToKeep

public long getNumberOfHistoricSnapshotsToKeep()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object