Package org.apache.flink.runtime.state.v2

Class AbstractReducingState<K,N,V>

java.lang.Object

org.apache.flink.runtime.state.v2.AbstractKeyedState<K,N,V>

org.apache.flink.runtime.state.v2.AbstractReducingState<K,N,V>

Type Parameters:

K - The type of key the state is associated to.

V - The type of values kept internally in state.

All Implemented Interfaces:

AggregatingState<V,V>, AppendingState<V,V,V>, MergingState<V,V,V>, ReducingState<V>, State, InternalAggregatingState<K,N,V,V,V>, InternalAppendingState<K,N,V,V,V,V>, InternalKeyedState<K,N,V>, InternalMergingState<K,N,V,V,V,V>, InternalPartitionedState<N>, InternalReducingState<K,N,V>

Direct Known Subclasses:

ForStReducingState

public class AbstractReducingState<K,N,V>
extends AbstractKeyedState<K,N,V>
implements InternalReducingState<K,N,V>

A default implementation of ReducingState which delegates all async requests to StateRequestHandler.

Field Summary

Fields

Modifier and Type	Field	Description
protected ReduceFunction<V>	reduceFunction

Fields inherited from class org.apache.flink.runtime.state.v2.AbstractKeyedState

stateRequestHandler

Constructor Summary

Constructors

Constructor	Description
AbstractReducingState(StateRequestHandler stateRequestHandler, ReducingStateDescriptor<V> stateDescriptor)

Method Summary

Modifier and Type	Method	Description
void	add(V value)	Updates the operator state accessible by AppendingState.get() by adding the given value to the list of values.
StateFuture<Void>	asyncAdd(V value)	Updates the operator state accessible by AppendingState.asyncGet() by adding the given value to the list of values asynchronously.
StateFuture<V>	asyncGet()	Returns the current value for the state asynchronously.
StateFuture<V>	asyncGetInternal()	Get internally stored value.
StateFuture<Void>	asyncMergeNamespaces(N target, Collection<N> sources)	Merges the state of the current key for the given source namespaces into the state of the target namespace.
StateFuture<Void>	asyncUpdateInternal(V valueToStore)	Update internally stored value.
V	get()	Returns the current value for the state.
V	getInternal()	Get internally stored value.
void	mergeNamespaces(N target, Collection<N> sources)	Merges the state of the current key for the given source namespaces into the state of the target namespace.
void	updateInternal(V valueToStore)	Update internally stored value.

Methods inherited from class org.apache.flink.runtime.state.v2.AbstractKeyedState

asyncClear, clear, getStateDescriptor, getStateRequestHandler, getValueSerializer, handleRequest, handleRequestSync, setCurrentNamespace

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.flink.runtime.state.v2.internal.InternalPartitionedState

setCurrentNamespace

Methods inherited from interface org.apache.flink.api.common.state.v2.State

asyncClear, clear

Field Detail

reduceFunction

protected final ReduceFunction<V> reduceFunction

Constructor Detail

AbstractReducingState

public AbstractReducingState(StateRequestHandler stateRequestHandler,
                             ReducingStateDescriptor<V> stateDescriptor)

Method Detail

asyncGet

public StateFuture<V> asyncGet()

Description copied from interface: AppendingState

Returns the current value for the state asynchronously. When the state is not partitioned the returned value is the same for all inputs in a given operator instance. If state partitioning is applied, the value returned depends on the current operator input, as the operator maintains an independent state for each partition.

NOTE TO IMPLEMENTERS: if the state is empty, then this method should return null wrapped by a StateFuture.

Specified by:

asyncGet in interface AppendingState<K,N,V>

Returns:

The operator state value corresponding to the current input or null wrapped by a StateFuture if the state is empty.

asyncAdd

public StateFuture<Void> asyncAdd(V value)

Description copied from interface: AppendingState

Updates the operator state accessible by AppendingState.asyncGet() by adding the given value to the list of values asynchronously. The next time AppendingState.asyncGet() is called (for the same state partition) the returned state will represent the updated list.

null value is not allowed to be passed in.

Specified by:

asyncAdd in interface AppendingState<K,N,V>

Parameters:

value - The new value for the state.

get

public V get()

Description copied from interface: AppendingState

Returns the current value for the state. When the state is not partitioned the returned value is the same for all inputs in a given operator instance. If state partitioning is applied, the value returned depends on the current operator input, as the operator maintains an independent state for each partition.

NOTE TO IMPLEMENTERS: if the state is empty, then this method should return null.

Specified by:

get in interface AppendingState<K,N,V>

Returns:

The operator state value corresponding to the current input or null if the state is empty.

add

public void add(V value)

Description copied from interface: AppendingState

Updates the operator state accessible by AppendingState.get() by adding the given value to the list of values. The next time AppendingState.get() is called (for the same state partition) the returned state will represent the updated list.

If null is passed in, the behaviour is undefined (implementation related).

Specified by:

add in interface AppendingState<K,N,V>

Parameters:

value - The new value for the state.

asyncMergeNamespaces

public StateFuture<Void> asyncMergeNamespaces(N target,
                                              Collection<N> sources)

Description copied from interface: InternalMergingState

Merges the state of the current key for the given source namespaces into the state of the target namespace.

Specified by:

asyncMergeNamespaces in interface InternalMergingState<K,N,V,V,V,V>

Parameters:

target - The target namespace where the merged state should be stored.

sources - The source namespaces whose state should be merged.

mergeNamespaces

public void mergeNamespaces(N target,
                            Collection<N> sources)

Description copied from interface: InternalMergingState

Merges the state of the current key for the given source namespaces into the state of the target namespace.

Specified by:

mergeNamespaces in interface InternalMergingState<K,N,V,V,V,V>

Parameters:

target - The target namespace where the merged state should be stored.

sources - The source namespaces whose state should be merged.

asyncGetInternal

public StateFuture<V> asyncGetInternal()

Description copied from interface: InternalAppendingState

Get internally stored value.

Specified by:

asyncGetInternal in interface InternalAppendingState<K,N,V,V,V,V>

Returns:

internally stored value.

asyncUpdateInternal

public StateFuture<Void> asyncUpdateInternal(V valueToStore)

Description copied from interface: InternalAppendingState

Update internally stored value.

Specified by:

asyncUpdateInternal in interface InternalAppendingState<K,N,V,V,V,V>

Parameters:

valueToStore - new value to store.

getInternal

public V getInternal()

Description copied from interface: InternalAppendingState

Get internally stored value.

Specified by:

getInternal in interface InternalAppendingState<K,N,V,V,V,V>

Returns:

internally stored value.

updateInternal

public void updateInternal(V valueToStore)

Description copied from interface: InternalAppendingState

Update internally stored value.

Specified by:

updateInternal in interface InternalAppendingState<K,N,V,V,V,V>

Parameters:

valueToStore - new value to store.