com.h3c.util.persistence.cassandra.index

Class StringShardStrategy

java.lang.Object

com.h3c.util.persistence.cassandra.index.StringShardStrategy

All Implemented Interfaces:

ShardStrategy<String,String>

public class StringShardStrategy
extends Object
implements ShardStrategy<String,String>

Shard strategy to distribute String type column names into several row keys based on the first char (lower-case converted) of the String value.

Examples:

Prefix	Column Name	Sharded Row Key
my_prefix	Hello World	my_prefix_h
my_prefix	hello world	my_prefix_h
Null	Hello World	h
Empty	Hello World	h

Constructor Summary

Constructors

Constructor and Description
StringShardStrategy() Creates a shard strategy.
StringShardStrategy(String rowKeyPrefix) Creates a shard strategy.

Method Summary

Methods

Modifier and Type	Method and Description
String	getRowKey(String 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

StringShardStrategy

public StringShardStrategy()

Creates a shard strategy.

StringShardStrategy

public StringShardStrategy(String rowKeyPrefix)

Creates a shard strategy.

Parameters:

rowKeyPrefix - row key prefix.

Method Detail

getRowKey

public String getRowKey(String 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,String>

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.