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

Class ReducingStateDescriptor<T>

java.lang.Object

org.apache.flink.api.common.state.StateDescriptor<ReducingState<T>,T>

org.apache.flink.api.common.state.ReducingStateDescriptor<T>

Type Parameters:

T - The type of the values that can be added to the list state.

All Implemented Interfaces:

Serializable

@PublicEvolving
public class ReducingStateDescriptor<T>
extends StateDescriptor<ReducingState<T>,T>

StateDescriptor for ReducingState. This can be used to create partitioned reducing state using RuntimeContext.getReducingState(ReducingStateDescriptor).

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.flink.api.common.state.StateDescriptor

StateDescriptor.Type

Field Summary

Fields inherited from class org.apache.flink.api.common.state.StateDescriptor

defaultValue, name

Constructor Summary

Constructors

Constructor	Description
ReducingStateDescriptor(String name, ReduceFunction<T> reduceFunction, Class<T> typeClass)	Creates a new ReducingStateDescriptor with the given name, type, and default value.
ReducingStateDescriptor(String name, ReduceFunction<T> reduceFunction, TypeInformation<T> typeInfo)	Creates a new ReducingStateDescriptor with the given name and default value.
ReducingStateDescriptor(String name, ReduceFunction<T> reduceFunction, TypeSerializer<T> typeSerializer)	Creates a new ValueStateDescriptor with the given name and default value.

Method Summary

Modifier and Type	Method	Description
ReduceFunction<T>	getReduceFunction()	Returns the reduce function to be used for the reducing state.
StateDescriptor.Type	getType()

Methods inherited from class org.apache.flink.api.common.state.StateDescriptor

enableTimeToLive, equals, getDefaultValue, getName, getQueryableStateName, getSerializer, getTtlConfig, hashCode, initializeSerializerUnlessSet, isQueryable, isSerializerInitialized, setQueryable, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ReducingStateDescriptor

public ReducingStateDescriptor(String name,
                               ReduceFunction<T> reduceFunction,
                               Class<T> typeClass)

Creates a new ReducingStateDescriptor with the given name, type, and default value.

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

Parameters:

name - The (unique) name for the state.

reduceFunction - The ReduceFunction used to aggregate the state.

typeClass - The type of the values in the state.

ReducingStateDescriptor

public ReducingStateDescriptor(String name,
                               ReduceFunction<T> reduceFunction,
                               TypeInformation<T> typeInfo)

Creates a new ReducingStateDescriptor with the given name and default value.

Parameters:

name - The (unique) name for the state.

reduceFunction - The ReduceFunction used to aggregate the state.

typeInfo - The type of the values in the state.

ReducingStateDescriptor

public ReducingStateDescriptor(String name,
                               ReduceFunction<T> reduceFunction,
                               TypeSerializer<T> typeSerializer)

Creates a new ValueStateDescriptor with the given name and default value.

Parameters:

name - The (unique) name for the state.

reduceFunction - The ReduceFunction used to aggregate the state.

typeSerializer - The type serializer of the values in the state.

Method Detail

getReduceFunction

public ReduceFunction<T> getReduceFunction()

Returns the reduce function to be used for the reducing state.

getType

public StateDescriptor.Type getType()

Specified by:

getType in class StateDescriptor<ReducingState<T>,T>