Package org.apache.flink.api.common.state.v2

Class StateDescriptor<T>

java.lang.Object

org.apache.flink.api.common.state.v2.StateDescriptor<T>

Type Parameters:

T - The type of the value of the state object described by this state descriptor.

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

AggregatingStateDescriptor, ListStateDescriptor, MapStateDescriptor, ReducingStateDescriptor, ValueStateDescriptor

@Experimental
public abstract class StateDescriptor<T>
extends Object
implements Serializable

Base class for state descriptors. A StateDescriptor is used for creating partitioned State in stateful operations internally.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	StateDescriptor.Type	An enumeration of the types of supported states.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	StateDescriptor(String name, Class<T> type)	Create a new StateDescriptor with the given name and the given type information.
protected	StateDescriptor(String stateId, TypeInformation<T> typeInfo)	Create a new StateDescriptor with the given stateId and the given type information.
protected	StateDescriptor(String stateId, TypeSerializer<T> serializer)	Create a new StateDescriptor with the given stateId and the given type serializer.

Method Summary

Modifier and Type	Method	Description
void	enableTimeToLive(StateTtlConfig ttlConfig)	Configures optional activation of state time-to-live (TTL).
boolean	equals(Object o)
TypeSerializer<T>	getSerializer()
String	getStateId()
StateTtlConfig	getTtlConfig()
abstract StateDescriptor.Type	getType()	Return the specific Type of described state.
TypeInformation<T>	getTypeInformation()
int	hashCode()
void	initializeSerializerUnlessSet(ExecutionConfig executionConfig)	Initializes the serializer, unless it has been initialized before.
void	initializeSerializerUnlessSet(SerializerFactory serializerFactory)
boolean	isSerializerInitialized()	Checks whether the serializer has been initialized.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

StateDescriptor

protected StateDescriptor(@Nonnull
                          String stateId,
                          @Nonnull
                          TypeInformation<T> typeInfo)

Create a new StateDescriptor with the given stateId and the given type information.

Parameters:

stateId - The stateId of the StateDescriptor.

typeInfo - The type information for the values in the state.

StateDescriptor

protected StateDescriptor(@Nonnull
                          String stateId,
                          TypeSerializer<T> serializer)

Create a new StateDescriptor with the given stateId and the given type serializer.

Parameters:

stateId - The stateId of the StateDescriptor.

serializer - The type serializer for the values in the state.

StateDescriptor

protected StateDescriptor(String name,
                          Class<T> type)

Create a new StateDescriptor with the given name and the given type information.

If this constructor fails (because it is not possible to describe the type via a class), consider using the StateDescriptor(String, TypeInformation) constructor.

Parameters:

name - The name of the StateDescriptor.

type - The class of the type of values in the state.

Method Detail

enableTimeToLive

public void enableTimeToLive(StateTtlConfig ttlConfig)

Configures optional activation of state time-to-live (TTL).

State user value will expire, become unavailable and be cleaned up in storage depending on configured StateTtlConfig.

Parameters:

ttlConfig - configuration of state TTL

getTtlConfig

@Nonnull
public StateTtlConfig getTtlConfig()

getStateId

@Nonnull
public String getStateId()

getSerializer

@Nonnull
public TypeSerializer<T> getSerializer()

getTypeInformation

@Internal
@Nullable
public TypeInformation<T> getTypeInformation()

isSerializerInitialized

public boolean isSerializerInitialized()

Checks whether the serializer has been initialized. Serializer initialization is lazy, to allow parametrization of serializers with an ExecutionConfig via initializeSerializerUnlessSet(ExecutionConfig).

Returns:

True if the serializers have been initialized, false otherwise.

initializeSerializerUnlessSet

public void initializeSerializerUnlessSet(ExecutionConfig executionConfig)

Initializes the serializer, unless it has been initialized before.

Parameters:

executionConfig - The execution config to use when creating the serializer.

initializeSerializerUnlessSet

@Internal
public void initializeSerializerUnlessSet(SerializerFactory serializerFactory)

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

getType

@Internal
public abstract StateDescriptor.Type getType()

Return the specific Type of described state.