Package org.apache.pekko.persistence.query.typed.scaladsl

Interface DurableStateStoreBySliceQuery<A>

All Superinterfaces:

DurableStateStore<A>

All Known Implementing Classes:

PersistenceTestKitDurableStateStore

public interface DurableStateStoreBySliceQuery<A>
extends DurableStateStore<A>

Query API for reading durable state objects.

For Java API see DurableStateStoreBySliceQuery.

API May Change

Method Summary

Modifier and Type	Method	Description
Source<DurableStateChange<A>,NotUsed>	changesBySlices(java.lang.String entityType, int minSlice, int maxSlice, Offset offset)	Get a source of the most recent changes made to objects of the given slice range since the passed in offset.
Source<DurableStateChange<A>,NotUsed>	currentChangesBySlices(java.lang.String entityType, int minSlice, int maxSlice, Offset offset)	Get a source of the most recent changes made to objects with the given slice range since the passed in offset.
int	sliceForPersistenceId(java.lang.String persistenceId)
scala.collection.immutable.Seq<scala.collection.immutable.Range>	sliceRanges(int numberOfRanges)

Methods inherited from interface org.apache.pekko.persistence.state.scaladsl.DurableStateStore

getObject

Method Detail

changesBySlices

Source<DurableStateChange<A>,NotUsed> changesBySlices(java.lang.String entityType,
                                                            int minSlice,
                                                            int maxSlice,
                                                            Offset offset)

Get a source of the most recent changes made to objects of the given slice range since the passed in offset.

A slice is deterministically defined based on the persistence id. The purpose is to evenly distribute all persistence ids over the slices.

The returned source will never terminate, it effectively watches for changes to the objects and emits changes as they happen.

Not all changes that occur are guaranteed to be emitted, this call only guarantees that eventually, the most recent change for each object since the offset will be emitted. In particular, multiple updates to a given object in quick succession are likely to be skipped, with only the last update resulting in a change from this source.

The pekko.persistence.query.DurableStateChange elements can be pekko.persistence.query.UpdatedDurableState or pekko.persistence.query.DeletedDurableState.

currentChangesBySlices

Source<DurableStateChange<A>,NotUsed> currentChangesBySlices(java.lang.String entityType,
                                                                   int minSlice,
                                                                   int maxSlice,
                                                                   Offset offset)

Get a source of the most recent changes made to objects with the given slice range since the passed in offset.

A slice is deterministically defined based on the persistence id. The purpose is to evenly distribute all persistence ids over the slices.

Note that this only returns the most recent change to each object, if an object has been updated multiple times since the offset, only the most recent of those changes will be part of the stream.

This will return changes that occurred up to when the Source returned by this call is materialized. Changes to objects made since materialization are not guaranteed to be included in the results.

The pekko.persistence.query.DurableStateChange elements can be pekko.persistence.query.UpdatedDurableState or pekko.persistence.query.DeletedDurableState.

sliceForPersistenceId

int sliceForPersistenceId(java.lang.String persistenceId)

sliceRanges

scala.collection.immutable.Seq<scala.collection.immutable.Range> sliceRanges(int numberOfRanges)