com.h3c.util.persistence.cassandra.index

Class HashShardStrategy<C>

java.lang.Object

com.h3c.util.persistence.cassandra.index.HashShardStrategy<C>

Type Parameters:

C - type of the column name or column key.

All Implemented Interfaces:

ShardStrategy<String,C>

public class HashShardStrategy<C>
extends Object
implements ShardStrategy<String,C>

Shard strategy to distribute column names into several row keys based on a hash function applied to the column value.

Constructor Summary

Constructors

Constructor and Description
HashShardStrategy(String rowKeyPrefix, int partition) Creates a shard strategy.

Method Summary

Methods

Modifier and Type	Method and Description
String	getRowKey(C columnName) Gets the row key to be used for the given column name.

Methods inherited from class java.lang.Object

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

Constructor Detail

HashShardStrategy

public HashShardStrategy(String rowKeyPrefix,
                 int partition)

Creates a shard strategy.

Parameters:

rowKeyPrefix - row key prefix.

partition - the number of rows we want to split the data across.

Method Detail

getRowKey

public String getRowKey(C columnName)

Description copied from interface: ShardStrategy

Gets the row key to be used for the given column name.

Specified by:

getRowKey in interface ShardStrategy<String,C>

Parameters:

columnName - column name to fins a sharded key for. This could be part of the column name if the shard strategy is applied to a single component of a composite column name.

Returns:

a sharded key for the given column name.