Package org.apache.storm.trident.partition

Class IndexHashGrouping

java.lang.Object

org.apache.storm.trident.partition.IndexHashGrouping

All Implemented Interfaces:

Serializable, CustomStreamGrouping

public class IndexHashGrouping
extends Object
implements CustomStreamGrouping

See Also:

• Serialized Form

Constructor Summary

Constructors

Constructor	Description
IndexHashGrouping(int index)

Method Summary

Modifier and Type	Method	Description
List<Integer>	chooseTasks(int fromTask, List<Object> values)	This function implements a custom stream grouping.
static int	objectToIndex(Object val, int numPartitions)
void	prepare(WorkerTopologyContext context, GlobalStreamId stream, List<Integer> targetTasks)	Tells the stream grouping at runtime the tasks in the target bolt.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

IndexHashGrouping

public IndexHashGrouping(int index)

Method Details

objectToIndex

public static int objectToIndex(Object val,
 int numPartitions)

prepare

public void prepare(WorkerTopologyContext context,
 GlobalStreamId stream,
 List<Integer> targetTasks)

Description copied from interface: CustomStreamGrouping

Tells the stream grouping at runtime the tasks in the target bolt. This information should be used in chooseTasks to determine the target tasks.

It also tells the grouping the metadata on the stream this grouping will be used on.

Specified by:

prepare in interface CustomStreamGrouping

chooseTasks

public List<Integer> chooseTasks(int fromTask,
 List<Object> values)

Description copied from interface: CustomStreamGrouping

This function implements a custom stream grouping. It takes in as input the number of tasks in the target bolt in prepare and returns the tasks to send the tuples to.

Specified by:

chooseTasks in interface CustomStreamGrouping

values - the values to group on