org.apache.flink.runtime.state.memory

Class AbstractMemStateSnapshot<K,N,SV,S extends State,SD extends StateDescriptor<S,?>>

java.lang.Object

org.apache.flink.runtime.state.memory.AbstractMemStateSnapshot<K,N,SV,S,SD>

Type Parameters:

K - The type of the key in the snapshot state.

N - The type of the namespace in the snapshot state.

SV - The type of the value in the snapshot state.

All Implemented Interfaces:

Serializable, KvStateSnapshot<K,N,S,SD,MemoryStateBackend>

Direct Known Subclasses:

MemFoldingState.Snapshot, MemListState.Snapshot, MemReducingState.Snapshot, MemValueState.Snapshot

public abstract class AbstractMemStateSnapshot<K,N,SV,S extends State,SD extends StateDescriptor<S,?>>
extends Object
implements KvStateSnapshot<K,N,S,SD,MemoryStateBackend>

A snapshot of a MemValueState for a checkpoint. The data is stored in a heap byte array, in serialized form.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected TypeSerializer<K>	keySerializer Key Serializer
protected TypeSerializer<N>	namespaceSerializer Namespace Serializer
protected SD	stateDesc StateDescriptor, for sanity checks
protected TypeSerializer<SV>	stateSerializer Serializer for the state value

Constructor Summary

Constructors

Constructor and Description
AbstractMemStateSnapshot(TypeSerializer<K> keySerializer, TypeSerializer<N> namespaceSerializer, TypeSerializer<SV> stateSerializer, SD stateDesc, byte[] data) Creates a new heap memory state snapshot.

Method Summary

Modifier and Type	Method and Description
abstract KvState<K,N,S,SD,MemoryStateBackend>	createMemState(HashMap<N,Map<K,SV>> stateMap)
void	discardState() Discarding the heap state is a no-op.
long	getStateSize() Returns the size of the state in bytes.
KvState<K,N,S,SD,MemoryStateBackend>	restoreState(MemoryStateBackend stateBackend, TypeSerializer<K> keySerializer, ClassLoader classLoader, long recoveryTimestamp) Loads the key/value state back from this snapshot.

Methods inherited from class java.lang.Object

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

Field Detail

keySerializer

protected final TypeSerializer<K> keySerializer

Key Serializer

namespaceSerializer

protected final TypeSerializer<N> namespaceSerializer

Namespace Serializer

stateSerializer

protected final TypeSerializer<SV> stateSerializer

Serializer for the state value

stateDesc

protected final SD extends StateDescriptor<S,?> stateDesc

StateDescriptor, for sanity checks

Constructor Detail

AbstractMemStateSnapshot

public AbstractMemStateSnapshot(TypeSerializer<K> keySerializer,
                                TypeSerializer<N> namespaceSerializer,
                                TypeSerializer<SV> stateSerializer,
                                SD stateDesc,
                                byte[] data)

Creates a new heap memory state snapshot.

Parameters:

keySerializer - The serializer for the keys.

namespaceSerializer - The serializer for the namespace.

stateSerializer - The serializer for the elements in the state HashMap

stateDesc - The state identifier

data - The serialized data of the state key/value pairs

Method Detail

createMemState

public abstract KvState<K,N,S,SD,MemoryStateBackend> createMemState(HashMap<N,Map<K,SV>> stateMap)

restoreState

public KvState<K,N,S,SD,MemoryStateBackend> restoreState(MemoryStateBackend stateBackend,
                                                         TypeSerializer<K> keySerializer,
                                                         ClassLoader classLoader,
                                                         long recoveryTimestamp)
                                                  throws Exception

Description copied from interface: KvStateSnapshot

Loads the key/value state back from this snapshot.

Specified by:

restoreState in interface KvStateSnapshot<K,N,S extends State,SD extends StateDescriptor<S,?>,MemoryStateBackend>

Parameters:

stateBackend - The state backend that created this snapshot and can restore the key/value state from this snapshot.

keySerializer - The serializer for the keys.

classLoader - The class loader for user-defined types.

recoveryTimestamp - The timestamp of the checkpoint we are recovering from.

Returns:

An instance of the key/value state loaded from this snapshot.

Throws:

Exception - Exceptions can occur during the state loading and are forwarded.

discardState

public void discardState()

Discarding the heap state is a no-op.

Specified by:

discardState in interface KvStateSnapshot<K,N,S extends State,SD extends StateDescriptor<S,?>,MemoryStateBackend>

getStateSize

public long getStateSize()

Description copied from interface: KvStateSnapshot

Returns the size of the state in bytes.

If the the size is not known, return 0.

Specified by:

getStateSize in interface KvStateSnapshot<K,N,S extends State,SD extends StateDescriptor<S,?>,MemoryStateBackend>

Returns:

Size of the state in bytes.