org.apache.flink.runtime.state

Class AsynchronousKvStateSnapshot<K,N,S extends org.apache.flink.api.common.state.State,SD extends org.apache.flink.api.common.state.StateDescriptor<S,?>,Backend extends AbstractStateBackend>

java.lang.Object

org.apache.flink.runtime.state.AsynchronousKvStateSnapshot<K,N,S,SD,Backend>

Type Parameters:

K - The type of the key

N - The type of the namespace

S - The type of the State

SD - The type of the StateDescriptor

Backend - The type of the backend that can restore the state from this snapshot.

All Implemented Interfaces:

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

public abstract class AsynchronousKvStateSnapshot<K,N,S extends org.apache.flink.api.common.state.State,SD extends org.apache.flink.api.common.state.StateDescriptor<S,?>,Backend extends AbstractStateBackend>
extends Object
implements KvStateSnapshot<K,N,S,SD,Backend>

KvStateSnapshot that asynchronously materializes the state that it represents. Instead of representing a materialized handle to state this would normally hold the (immutable) state internally and materializes it when materialize() is called.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AsynchronousKvStateSnapshot()

Method Summary

Modifier and Type	Method and Description
void	discardState() Discards the state snapshot, removing any resources occupied by it.
long	getStateSize() Returns the size of the state in bytes.
abstract KvStateSnapshot<K,N,S,SD,Backend>	materialize() Materializes the state held by this AsynchronousKvStateSnapshot.
KvState<K,N,S,SD,Backend>	restoreState(Backend stateBackend, org.apache.flink.api.common.typeutils.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

Constructor Detail

AsynchronousKvStateSnapshot

public AsynchronousKvStateSnapshot()

Method Detail

materialize

public abstract KvStateSnapshot<K,N,S,SD,Backend> materialize()
                                                       throws Exception

Materializes the state held by this AsynchronousKvStateSnapshot.

Throws:

Exception

restoreState

public final KvState<K,N,S,SD,Backend> restoreState(Backend stateBackend,
                                                    org.apache.flink.api.common.typeutils.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 org.apache.flink.api.common.state.State,SD extends org.apache.flink.api.common.state.StateDescriptor<S,?>,Backend extends AbstractStateBackend>

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()
                  throws Exception

Description copied from interface: KvStateSnapshot

Discards the state snapshot, removing any resources occupied by it.

Specified by:

discardState in interface KvStateSnapshot<K,N,S extends org.apache.flink.api.common.state.State,SD extends org.apache.flink.api.common.state.StateDescriptor<S,?>,Backend extends AbstractStateBackend>

Throws:

Exception - Exceptions occurring during the state disposal should be forwarded.

getStateSize

public long getStateSize()
                  throws Exception

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 org.apache.flink.api.common.state.State,SD extends org.apache.flink.api.common.state.StateDescriptor<S,?>,Backend extends AbstractStateBackend>

Returns:

Size of the state in bytes.

Throws:

Exception - If the operation fails during size retrieval.