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

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

All Implemented Interfaces:

IDistributionPolicy

public class HashingDistributionPolicy
extends Object
implements IDistributionPolicy

Choose a shard for each insert or delete based on document id hashing. Do NOT use this distribution policy when the number of shards changes.

Constructor Summary

HashingDistributionPolicy()

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

HashingDistributionPolicy

public HashingDistributionPolicy()

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