org.apache.flink.runtime.state.filesystem

Class FsReducingState<K,N,V>

java.lang.Object

org.apache.flink.runtime.state.AbstractHeapState<K,N,SV,S,SD,FsStateBackend>

org.apache.flink.runtime.state.filesystem.AbstractFsState<K,N,V,ReducingState<V>,ReducingStateDescriptor<V>>

org.apache.flink.runtime.state.filesystem.FsReducingState<K,N,V>

Type Parameters:

K - The type of the key.

N - The type of the namespace.

V - The type of the value.

All Implemented Interfaces:

MergingState<V,V>, ReducingState<V>, State, KvState<K,N,ReducingState<V>,ReducingStateDescriptor<V>,FsStateBackend>

public class FsReducingState<K,N,V>
extends AbstractFsState<K,N,V,ReducingState<V>,ReducingStateDescriptor<V>>
implements ReducingState<V>

Heap-backed partitioned ReducingState that is snapshotted into files.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FsReducingState.Snapshot<K,N,V>

Field Summary

Fields inherited from class org.apache.flink.runtime.state.AbstractHeapState

currentKey, currentNamespace, currentNSState, keySerializer, namespaceSerializer, state, stateDesc, stateSerializer

Constructor Summary

Constructors

Constructor and Description
FsReducingState(FsStateBackend backend, TypeSerializer<K> keySerializer, TypeSerializer<N> namespaceSerializer, ReducingStateDescriptor<V> stateDesc) Creates a new and empty partitioned state.
FsReducingState(FsStateBackend backend, TypeSerializer<K> keySerializer, TypeSerializer<N> namespaceSerializer, ReducingStateDescriptor<V> stateDesc, HashMap<N,Map<K,V>> state) Creates a new key/value state with the given state contents.

Method Summary

Modifier and Type	Method and Description
void	add(V value) Updates the operator state accessible by MergingState.get() by adding the given value to the list of values.
KvStateSnapshot<K,N,ReducingState<V>,ReducingStateDescriptor<V>,FsStateBackend>	createHeapSnapshot(Path filePath)
V	get() Returns the current value for the state.

Methods inherited from class org.apache.flink.runtime.state.filesystem.AbstractFsState

snapshot

Methods inherited from class org.apache.flink.runtime.state.AbstractHeapState

clear, dispose, getKeySerializer, getNamespaceSerializer, setCurrentKey, setCurrentNamespace, size

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.api.common.state.State

clear

Constructor Detail

FsReducingState

public FsReducingState(FsStateBackend backend,
                       TypeSerializer<K> keySerializer,
                       TypeSerializer<N> namespaceSerializer,
                       ReducingStateDescriptor<V> stateDesc)

Creates a new and empty partitioned state.

Parameters:

backend - The file system state backend backing snapshots of this state

keySerializer - The serializer for the key.

namespaceSerializer - The serializer for the namespace.

stateDesc - The state identifier for the state. This contains name and can create a default state value.

FsReducingState

public FsReducingState(FsStateBackend backend,
                       TypeSerializer<K> keySerializer,
                       TypeSerializer<N> namespaceSerializer,
                       ReducingStateDescriptor<V> stateDesc,
                       HashMap<N,Map<K,V>> state)

Creates a new key/value state with the given state contents. This method is used to re-create key/value state with existing data, for example from a snapshot.

Parameters:

backend - The file system state backend backing snapshots of this state

keySerializer - The serializer for the key.

namespaceSerializer - The serializer for the namespace.

stateDesc - The state identifier for the state. This contains name and can create a default state value.

state - The map of key/value pairs to initialize the state with.

Method Detail

get

public V get()

Description copied from interface: MergingState

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.

Specified by:

get in interface MergingState<V,V>

Returns:

The operator state value corresponding to the current input.

add

public void add(V value)
         throws IOException

Description copied from interface: MergingState

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

Specified by:

add in interface MergingState<V,V>

Parameters:

value - The new value for the state.

Throws:

IOException - Thrown if the system cannot access the state.

createHeapSnapshot

public KvStateSnapshot<K,N,ReducingState<V>,ReducingStateDescriptor<V>,FsStateBackend> createHeapSnapshot(Path filePath)

Specified by:

createHeapSnapshot in class AbstractFsState<K,N,V,ReducingState<V>,ReducingStateDescriptor<V>>