org.apache.hadoop.contrib.index.example
Class RoundRobinDistributionPolicy

java.lang.Object
  org.apache.hadoop.contrib.index.example.RoundRobinDistributionPolicy

All Implemented Interfaces:

IDistributionPolicy

public class RoundRobinDistributionPolicy
extends Object
implements IDistributionPolicy

Choose a shard for each insert in a round-robin fashion. Choose all the shards for each delete because we don't know where it is stored.

Constructor Summary

RoundRobinDistributionPolicy()

Method Summary

int	chooseShardForDelete(DocumentID key) Choose a shard or all shards to send a delete request.
int	chooseShardForInsert(DocumentID key) Choose a shard to send an insert request.
void	init(Shard[] shards) Initialization.

Methods inherited from class java.lang.Object

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

Constructor Detail

RoundRobinDistributionPolicy

public RoundRobinDistributionPolicy()

Method Detail

init

public void init(Shard[] shards)

Description copied from interface: IDistributionPolicy

Initialization. It must be called before any chooseShard() is called.

Specified by:

init in interface IDistributionPolicy

chooseShardForInsert

public int chooseShardForInsert(DocumentID key)

Description copied from interface: IDistributionPolicy

Choose a shard to send an insert request.

Specified by:

chooseShardForInsert in interface IDistributionPolicy

Returns:

the index of the chosen shard

chooseShardForDelete

public int chooseShardForDelete(DocumentID key)

Description copied from interface: IDistributionPolicy

Choose a shard or all shards to send a delete request. E.g. a round-robin distribution policy would send a delete request to all the shards. -1 represents all the shards.

Specified by:

chooseShardForDelete in interface IDistributionPolicy

Returns:

the index of the chosen shard, -1 if all the shards are chosen