org.apache.flink.runtime.state

Interface KeyedStateHandle

All Superinterfaces:

CompositeStateHandle, Serializable, StateObject

All Known Subinterfaces:

ChangelogStateBackendHandle, ChangelogStateHandle, CheckpointBoundKeyedStateHandle, IncrementalKeyedStateHandle, SavepointKeyedStateHandle

All Known Implementing Classes:

ChangelogStateBackendHandle.ChangelogStateBackendHandleImpl, ChangelogStateBackendLocalHandle, ChangelogStateHandleStreamImpl, DirectoryKeyedStateHandle, IncrementalLocalKeyedStateHandle, IncrementalRemoteKeyedStateHandle, InMemoryChangelogStateHandle, KeyGroupsSavepointStateHandle, KeyGroupsStateHandle

public interface KeyedStateHandle
extends CompositeStateHandle

Base for the handles of the checkpointed states in keyed streams. When recovering from failures, the handle will be passed to all tasks whose key group ranges overlap with it.

Method Summary

Modifier and Type	Method and Description
KeyedStateHandle	getIntersection(KeyGroupRange keyGroupRange) Returns a state over a range that is the intersection between this handle's key-group range and the provided key-group range.
KeyGroupRange	getKeyGroupRange() Returns the range of the key groups contained in the state.
StateHandleID	getStateHandleId() Returns a unique state handle id to distinguish with other keyed state handles.

Methods inherited from interface org.apache.flink.runtime.state.CompositeStateHandle

getCheckpointedSize, registerSharedStates

Methods inherited from interface org.apache.flink.runtime.state.StateObject

discardState, getStateSize

Method Detail

getKeyGroupRange

KeyGroupRange getKeyGroupRange()

Returns the range of the key groups contained in the state.

getIntersection

@Nullable
KeyedStateHandle getIntersection(KeyGroupRange keyGroupRange)

Returns a state over a range that is the intersection between this handle's key-group range and the provided key-group range.

Parameters:

keyGroupRange - The key group range to intersect with, will return null if the intersection of this handle's key-group and the provided key-group is empty.

getStateHandleId

StateHandleID getStateHandleId()

Returns a unique state handle id to distinguish with other keyed state handles.

If this state handle would be used as materialized part of ChangelogStateBackendHandle, it should persist this state handle id when serializing of checkpoint and deserialize it back to ensure the state handle id is constant.

Returns:

A unique state handle id.