com.google.appengine.tools.mapreduce.impl

Class HashingSharder

java.lang.Object

com.google.appengine.tools.mapreduce.impl.HashingSharder

All Implemented Interfaces:

Sharder, Serializable

public class HashingSharder
extends Object
implements Sharder

Splits input by hashing the key.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
HashingSharder(int numShards)

Method Summary

Methods

Modifier and Type	Method and Description
int	getNumShards()
int	getShardForKey(ByteBuffer key)

Methods inherited from class java.lang.Object

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

Constructor Detail

HashingSharder

public HashingSharder(int numShards)

Method Detail

getNumShards

public int getNumShards()

Specified by:

getNumShards in interface Sharder

Returns:

the number of shards that are items may be assigned to.

getShardForKey

public int getShardForKey(ByteBuffer key)

Specified by:

getShardForKey in interface Sharder

Parameters:

key - The serialized key. (The ByteBuffer should be unmodified by the implementation)

Returns:

a number between 0 and numShards-1 inclusive