org.apache.beam.sdk.state

Interface StateSpec<StateT extends State>

Type Parameters:

StateT - The type of state being described.

All Superinterfaces:

java.io.Serializable

@Experimental(value=STATE)
public interface StateSpec<StateT extends State>
extends java.io.Serializable

A specification of a persistent state cell. This includes information necessary to encode the value and details about the intended access pattern.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	StateSpec.Cases<ResultT> Cases for doing a "switch" on the type of StateSpec.

Method Summary

Modifier and Type	Method and Description
StateT	bind(java.lang.String id, StateBinder binder) For internal use only; no backwards-compatibility guarantees.
void	finishSpecifying() For internal use only; no backwards-compatibility guarantees.
<ResultT> ResultT	match(StateSpec.Cases<ResultT> cases) For internal use only; no backwards-compatibility guarantees.
void	offerCoders(Coder[] coders) For internal use only; no backwards-compatibility guarantees.

Method Detail

bind

@Internal
StateT bind(java.lang.String id,
                      StateBinder binder)

For internal use only; no backwards-compatibility guarantees.

Use the binder to create an instance of StateT appropriate for this address.

match

@Internal
<ResultT> ResultT match(StateSpec.Cases<ResultT> cases)

For internal use only; no backwards-compatibility guarantees.

Perform case analysis on this StateSpec using the provided StateSpec.Cases.

offerCoders

@Internal
void offerCoders(Coder[] coders)

For internal use only; no backwards-compatibility guarantees.

Given {code coders} are inferred from type arguments defined for this class. Coders which are already set should take precedence over offered coders.

Parameters:

coders - Array of coders indexed by the type arguments order. Entries might be null if the coder could not be inferred.

finishSpecifying

@Internal
void finishSpecifying()

For internal use only; no backwards-compatibility guarantees.

Validates that this StateSpec has been specified correctly and finalizes it. Automatically invoked when the pipeline is built.