org.apache.flink.api.common.state

Class FoldingStateDescriptor<T,ACC>

java.lang.Object

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

org.apache.flink.api.common.state.FoldingStateDescriptor<T,ACC>

Type Parameters:

T - Type of the values folded int othe state

ACC - Type of the value in the state

All Implemented Interfaces:

Serializable

@PublicEvolving
public class FoldingStateDescriptor<T,ACC>
extends StateDescriptor<FoldingState<T,ACC>,ACC>

StateDescriptor for FoldingState. This can be used to create partitioned folding state.

See Also:

Serialized Form

Field Summary

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

defaultValue, name, serializer

Constructor Summary

Constructors

Constructor and Description
FoldingStateDescriptor(String name, ACC initialValue, FoldFunction<T,ACC> foldFunction, Class<ACC> typeClass) Creates a new FoldingStateDescriptor with the given name, type, and initial value.
FoldingStateDescriptor(String name, ACC initialValue, FoldFunction<T,ACC> foldFunction, TypeInformation<ACC> typeInfo) Creates a new FoldingStateDescriptor with the given name and default value.
FoldingStateDescriptor(String name, ACC initialValue, FoldFunction<T,ACC> foldFunction, TypeSerializer<ACC> typeSerializer) Creates a new ValueStateDescriptor with the given name and default value.

Method Summary

Modifier and Type	Method and Description
FoldingState<T,ACC>	bind(StateBackend stateBackend) Creates a new State on the given StateBackend.
boolean	equals(Object o)
FoldFunction<T,ACC>	getFoldFunction() Returns the fold function to be used for the folding state.
int	hashCode()
String	toString()

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

getDefaultValue, getName, getSerializer, initializeSerializerUnlessSet, isSerializerInitialized

Methods inherited from class java.lang.Object

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

Constructor Detail

FoldingStateDescriptor

public FoldingStateDescriptor(String name,
                              ACC initialValue,
                              FoldFunction<T,ACC> foldFunction,
                              Class<ACC> typeClass)

Creates a new FoldingStateDescriptor with the given name, type, and initial value.

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

Parameters:

name - The (unique) name for the state.

initialValue - The initial value of the fold.

foldFunction - The FoldFunction used to aggregate the state.

typeClass - The type of the values in the state.

FoldingStateDescriptor

public FoldingStateDescriptor(String name,
                              ACC initialValue,
                              FoldFunction<T,ACC> foldFunction,
                              TypeInformation<ACC> typeInfo)

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

Parameters:

name - The (unique) name for the state.

initialValue - The initial value of the fold.

foldFunction - The FoldFunction used to aggregate the state.

typeInfo - The type of the values in the state.

FoldingStateDescriptor

public FoldingStateDescriptor(String name,
                              ACC initialValue,
                              FoldFunction<T,ACC> foldFunction,
                              TypeSerializer<ACC> typeSerializer)

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

Parameters:

name - The (unique) name for the state.

initialValue - The initial value of the fold.

foldFunction - The FoldFunction used to aggregate the state.

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

Method Detail

bind

public FoldingState<T,ACC> bind(StateBackend stateBackend)
                         throws Exception

Description copied from class: StateDescriptor

Creates a new State on the given StateBackend.

Specified by:

bind in class StateDescriptor<FoldingState<T,ACC>,ACC>

Parameters:

stateBackend - The StateBackend on which to create the State.

Throws:

Exception

getFoldFunction

public FoldFunction<T,ACC> getFoldFunction()

Returns the fold function to be used for the folding state.

equals

public boolean equals(Object o)

Specified by:

equals in class StateDescriptor<FoldingState<T,ACC>,ACC>

hashCode

public int hashCode()

Specified by:

hashCode in class StateDescriptor<FoldingState<T,ACC>,ACC>

toString

public String toString()

Overrides:

toString in class StateDescriptor<FoldingState<T,ACC>,ACC>