org.apache.samza.container.grouper.stream

Interface SystemStreamPartitionMapper

public interface SystemStreamPartitionMapper

Input streams of a samza job can be either expanded or contracted by the user. This abstraction determines the previous SystemStreamPartition for a SystemStreamPartition of a input stream after the stream expansion or contraction.

Method Summary

Modifier and Type	Method and Description
SystemStreamPartition	getPreviousSSP(SystemStreamPartition currentSystemStreamPartition, int previousPartitionCount, int currentPartitionCount) Determines the previous SystemStreamPartition for a SystemStreamPartition of a input stream after the stream expansion or contraction.

Method Detail

getPreviousSSP

SystemStreamPartition getPreviousSSP(SystemStreamPartition currentSystemStreamPartition,
                                     int previousPartitionCount,
                                     int currentPartitionCount)

Determines the previous SystemStreamPartition for a SystemStreamPartition of a input stream after the stream expansion or contraction.

Parameters:

currentSystemStreamPartition - denotes the current partition after the stream partition count change.

previousPartitionCount - the partition count of the stream before the stream partition count change.

currentPartitionCount - the partition count of the stream after the stream partition count change.

Returns:

the mapped SystemStreamPartition.