org.apache.flink.runtime.state.filesystem

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

java.lang.Object

org.apache.flink.runtime.state.filesystem.AbstractFileStateHandle

org.apache.flink.runtime.state.filesystem.AbstractFsStateSnapshot<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 state value.

All Implemented Interfaces:

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

Direct Known Subclasses:

FsFoldingState.Snapshot, FsListState.Snapshot, FsReducingState.Snapshot, FsValueState.Snapshot

public abstract class AbstractFsStateSnapshot<K,N,SV,S extends State,SD extends StateDescriptor<S,?>>
extends AbstractFileStateHandle
implements KvStateSnapshot<K,N,S,SD,FsStateBackend>

A snapshot of a heap key/value state stored in a file.

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
AbstractFsStateSnapshot(TypeSerializer<K> keySerializer, TypeSerializer<N> namespaceSerializer, TypeSerializer<SV> stateSerializer, SD stateDesc, Path filePath) Creates a new state snapshot with data in the file system.

Method Summary

Modifier and Type	Method and Description
abstract KvState<K,N,S,SD,FsStateBackend>	createFsState(FsStateBackend backend, HashMap<N,Map<K,SV>> stateMap)
long	getStateSize() Returns the file size in bytes.
KvState<K,N,S,SD,FsStateBackend>	restoreState(FsStateBackend stateBackend, TypeSerializer<K> keySerializer, ClassLoader classLoader, long recoveryTimestamp) Loads the key/value state back from this snapshot.

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

discardState, getFilePath, getFileSize, getFileSystem

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.KvStateSnapshot

discardState

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

AbstractFsStateSnapshot

public AbstractFsStateSnapshot(TypeSerializer<K> keySerializer,
                               TypeSerializer<N> namespaceSerializer,
                               TypeSerializer<SV> stateSerializer,
                               SD stateDesc,
                               Path filePath)

Creates a new state snapshot with data in the file system.

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

filePath - The path where the snapshot data is stored.

Method Detail

createFsState

public abstract KvState<K,N,S,SD,FsStateBackend> createFsState(FsStateBackend backend,
                                                               HashMap<N,Map<K,SV>> stateMap)

restoreState

public KvState<K,N,S,SD,FsStateBackend> restoreState(FsStateBackend 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,?>,FsStateBackend>

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.

getStateSize

public long getStateSize()
                  throws IOException

Returns the file size in bytes.

Specified by:

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

Returns:

The file size in bytes.

Throws:

IOException - Thrown if the file system cannot be accessed.