KeyedStateHandle (Flink : 2.0-SNAPSHOT API)

All Superinterfaces:

CompositeStateHandle, Serializable, StateObject

All Known Subinterfaces:

ChangelogStateBackendHandle, ChangelogStateHandle, CheckpointBoundKeyedStateHandle, IncrementalKeyedStateHandle, SavepointKeyedStateHandle

All Known Implementing Classes:

AbstractIncrementalStateHandle, ChangelogStateBackendHandle.ChangelogStateBackendHandleImpl, ChangelogStateBackendLocalHandle, ChangelogStateHandleStreamImpl, 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.

Nested Class Summary
- Nested classes/interfaces inherited from interface org.apache.flink.runtime.state.StateObject
  StateObject.StateObjectLocation, StateObject.StateObjectSizeStatsCollector

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	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
collectSizeStats, 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.