Interface IStatefulOperator

Stateful operators shold consider implementing this interface so they can participate in state persistence (checkpointing) and recovery.

Checkpoint sequence:

SaveState
OnStateSaved

Recovery sequence:

SetContext
LoadState
Start

Inherited Members

IOperator.Subscribe()

IOperator.SetContext(IOperatorContext)

IOperator.Start()

IOperator.Inputs

IVersioned.Name

IVersioned.Version

Namespace: Reaqtive

Assembly: Reaqtive.Interfaces.dll

Syntax

public interface IStatefulOperator : IOperator, IDisposable, IVersioned

Properties

StateChanged

True if the state has changes since the last time it was saved and false otherwise. This flag can be used to avoid saving the state of the operator unnecessary. Operators might choose not to implement this and always return true.

Declaration

bool StateChanged { get; }

Property Value

Type	Description
System.Boolean

Methods

LoadState(IOperatorStateReader, Version)

Called to load the operator's state from a previously persisted snapshot.

Declaration

void LoadState(IOperatorStateReader reader, Version version)

Parameters

Type	Name	Description
IOperatorStateReader	reader	Reader to read operator state from.
System.Version	version	Version of the state being loaded.

OnStateSaved()

Called after a checkpoint (persisting the states of multiple operators) has completed and before any new incoming events are received. Operators can update/trim their state in this method.

Declaration

void OnStateSaved()

SaveState(IOperatorStateWriter, Version)

Called to persist a snapshot of the operator's state.

Declaration

void SaveState(IOperatorStateWriter writer, Version version)

Parameters

Type	Name	Description
IOperatorStateWriter	writer	Writer to write operator state to.
System.Version	version	Version of the state being saved.