IN- Type of the value that can be added to the state.
OUT- Type of the value that can be retrieved from the state.
@PublicEvolving public interface AppendingState<IN,OUT> extends State
The state is accessed and modified by user functions, and checkpointed consistently by the system as part of the distributed snapshots.
The state is only accessible by functions applied on a
KeyedStream. The key is
automatically supplied by the system, so the function always sees the value mapped to the
key of the current element. That way, the system can handle stream and state partitioning
|Modifier and Type||Method and Description|
Updates the operator state accessible by
Returns the current value for the state.
NOTE TO IMPLEMENTERS: if the state is empty, then this method
nullif the state is empty.
Exception- Thrown if the system cannot access the state.
get()by adding the given value to the list of values. The next time
get()is called (for the same state partition) the returned state will represent the updated list.
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