org.zalando.nakadiproducer.snapshots

Interface SnapshotEventProvider

public interface SnapshotEventProvider

The SnapshotEventProvider interface should be implemented by any Event Producer that wants to support snapshot events feature. The class must define a method getSnapshot.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	SnapshotEventProvider.Snapshot

Method Summary

Modifier and Type	Method and Description
List<SnapshotEventProvider.Snapshot>	getSnapshot(String eventType, Object withIdGreaterThan) Returns a batch of snapshots of given type (event type is an event channel topic name).
Set<String>	getSupportedEventTypes()

Method Detail

getSnapshot

List<SnapshotEventProvider.Snapshot> getSnapshot(String eventType,
                                                 Object withIdGreaterThan)

Returns a batch of snapshots of given type (event type is an event channel topic name). The implementation may return an arbitrary amount of results, but it must return at least one element if there are entities matching the parameters. The library will call your implementation like this: Request: getSnapshot(eventType, null) Response: 1,2,3 Request: getSnapshot(eventType, 3) Response: 4,5 Request: getSnapshot(eventType, 5) Response: emptyList It is your responsibility to make sure that the returned events are ordered by their id asc and that, given you return a list of events for entities with ids {id1, ..., idN}, there exists no entity with an id between id1 and idN, that is not part of the result.

Parameters:

eventType - event type to make a snapshot of

withIdGreaterThan - if not null, only events for entities with an id greater than the given one must be returned

Returns:

list of elements ordered by their id

Throws:

UnknownEventTypeException - if eventType is unknown

getSupportedEventTypes

Set<String> getSupportedEventTypes()