@PublicEvolving
public interface InputSelectable
StreamRecord
.
IMPORTANT: This interface is a loose contract. The runtime may read multiple records
continuously before calling nextSelection()
again to determine whether to change the
input to be read. That is, it is not guaranteed that nextSelection()
will be called
immediately after the operator has processed a record and the reading input will be changed
according to InputSelection
returned. This means that the operator may receive some data
that it does not currently want to process. Therefore, if an operator needs a strict convention,
it must cache the unexpected data itself and handle them correctly.
This interface also makes the following conventions: 1.The runtime must call nextSelection()
to determine the input to read the first record. 2.When the input being read
reaches the end, the runtime must call nextSelection()
to determine the next input to be
read.
Modifier and Type | Method and Description |
---|---|
InputSelection |
nextSelection()
Returns the next
InputSelection that wants to get the record. |
InputSelection nextSelection()
InputSelection
that wants to get the record. This method is
guaranteed to not be called concurrently with other methods of the operator.Copyright © 2014–2021 The Apache Software Foundation. All rights reserved.