backtype.storm.grouping

Class CustomStreamGroupingDelegate

java.lang.Object

backtype.storm.grouping.CustomStreamGroupingDelegate

All Implemented Interfaces:

CustomStreamGrouping, java.io.Serializable

public class CustomStreamGroupingDelegate
extends java.lang.Object
implements CustomStreamGrouping

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
CustomStreamGroupingDelegate(CustomStreamGrouping delegate)

Method Summary

Modifier and Type	Method and Description
java.util.List<java.lang.Integer>	chooseTasks(java.util.List<java.lang.Object> values) This function implements a custom stream grouping.
void	prepare(TopologyContext context, java.lang.String component, java.lang.String streamId, java.util.List<java.lang.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 Detail

CustomStreamGroupingDelegate

public CustomStreamGroupingDelegate(CustomStreamGrouping delegate)

Method Detail

prepare

public void prepare(TopologyContext context,
                    java.lang.String component,
                    java.lang.String streamId,
                    java.util.List<java.lang.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 java.util.List<java.lang.Integer> chooseTasks(java.util.List<java.lang.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

Parameters:

values - the values to group on