org.apache.flink.api.common.state

Class AggregatingStateDescriptor<IN,ACC,OUT>

java.lang.Object

org.apache.flink.api.common.state.StateDescriptor<AggregatingState<IN,OUT>,ACC>

org.apache.flink.api.common.state.AggregatingStateDescriptor<IN,ACC,OUT>

Type Parameters:

IN - The type of the values that are added to the state.

ACC - The type of the accumulator (intermediate aggregation state).

OUT - The type of the values that are returned from the state.

All Implemented Interfaces:

Serializable

@PublicEvolving
public class AggregatingStateDescriptor<IN,ACC,OUT>
extends StateDescriptor<AggregatingState<IN,OUT>,ACC>

A StateDescriptor for AggregatingState.

The type internally stored in the state is the type of the Accumulator of the AggregateFunction.

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, serializer

Constructor Summary

Constructors

Constructor and Description
AggregatingStateDescriptor(String name, AggregateFunction<IN,ACC,OUT> aggFunction, Class<ACC> stateType) Creates a new state descriptor with the given name, function, and type.
AggregatingStateDescriptor(String name, AggregateFunction<IN,ACC,OUT> aggFunction, TypeInformation<ACC> stateType) Creates a new ReducingStateDescriptor with the given name and default value.
AggregatingStateDescriptor(String name, AggregateFunction<IN,ACC,OUT> aggFunction, TypeSerializer<ACC> typeSerializer) Creates a new ValueStateDescriptor with the given name and default value.

Method Summary

Methods

Modifier and Type	Method and Description
AggregatingState<IN,OUT>	bind(StateBinder stateBinder) Creates a new State on the given StateBinder.
boolean	equals(Object o)
AggregateFunction<IN,ACC,OUT>	getAggregateFunction() Returns the aggregate function to be used for the state.
StateDescriptor.Type	getType()
int	hashCode()
String	toString()

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

getDefaultValue, getName, getQueryableStateName, getSerializer, initializeSerializerUnlessSet, isQueryable, isSerializerInitialized, setQueryable

Methods inherited from class java.lang.Object

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

Constructor Detail

AggregatingStateDescriptor

public AggregatingStateDescriptor(String name,
                          AggregateFunction<IN,ACC,OUT> aggFunction,
                          Class<ACC> stateType)

Creates a new state descriptor with the given name, function, and type.

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

Parameters:

name - The (unique) name for the state.

aggFunction - The AggregateFunction used to aggregate the state.

stateType - The type of the accumulator. The accumulator is stored in the state.

AggregatingStateDescriptor

public AggregatingStateDescriptor(String name,
                          AggregateFunction<IN,ACC,OUT> aggFunction,
                          TypeInformation<ACC> stateType)

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

Parameters:

name - The (unique) name for the state.

aggFunction - The AggregateFunction used to aggregate the state.

stateType - The type of the accumulator. The accumulator is stored in the state.

AggregatingStateDescriptor

public AggregatingStateDescriptor(String name,
                          AggregateFunction<IN,ACC,OUT> aggFunction,
                          TypeSerializer<ACC> typeSerializer)

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

Parameters:

name - The (unique) name for the state.

aggFunction - The AggregateFunction used to aggregate the state.

typeSerializer - The serializer for the accumulator. The accumulator is stored in the state.

Method Detail

bind

public AggregatingState<IN,OUT> bind(StateBinder stateBinder)
                              throws Exception

Description copied from class: StateDescriptor

Creates a new State on the given StateBinder.

Specified by:

bind in class StateDescriptor<AggregatingState<IN,OUT>,ACC>

Parameters:

stateBinder - The StateBackend on which to create the State.

Throws:

Exception

getAggregateFunction

public AggregateFunction<IN,ACC,OUT> getAggregateFunction()

Returns the aggregate function to be used for the state.

getType

public StateDescriptor.Type getType()

Specified by:

getType in class StateDescriptor<AggregatingState<IN,OUT>,ACC>

equals

public boolean equals(Object o)

Specified by:

equals in class StateDescriptor<AggregatingState<IN,OUT>,ACC>

hashCode

public int hashCode()

Specified by:

hashCode in class StateDescriptor<AggregatingState<IN,OUT>,ACC>

toString

public String toString()

Overrides:

toString in class StateDescriptor<AggregatingState<IN,OUT>,ACC>