org.apache.flink.streaming.api.operators

Interface BoundedOneInput

All Known Implementing Classes:

AsyncWaitOperator, KeyedSortPartitionOperator, MapPartitionOperator, PartitionAggregateOperator, PartitionReduceOperator, SortPartitionOperator

@PublicEvolving
public interface BoundedOneInput

Interface for one-input operators that need to be notified about the logical/semantical end of input.

NOTE: Classes should not implement both BoundedOneInput and BoundedMultiInput at the same time!

See Also:

BoundedMultiInput, StreamOperator.finish()

Method Summary

Modifier and Type	Method and Description
void	endInput() It is notified that no more data will arrive from the input.

Method Detail

endInput

void endInput()
       throws Exception

It is notified that no more data will arrive from the input.

Stateful operators need to be aware that a restart with rescaling may occur after receiving this notification. A changed source split assignment may imply that the same subtask of this operator that received endInput, has its state after endInput snapshotted, and will receive new data after restart. Hence, the state should not contain any finalization that would make it impossible to process new data.

WARNING: It is not safe to use this method to commit any transactions or other side effects! You can use this method to flush any buffered data that can later on be committed e.g. in a CheckpointListener.notifyCheckpointComplete(long).

NOTE: Given it is semantically very similar to the StreamOperator.finish() method. It might be dropped in favour of the other method at some point in time.

Throws:

Exception