org.apache.cassandra.dht

Class ByteOrderedPartitioner

java.lang.Object

org.apache.cassandra.dht.ByteOrderedPartitioner

All Implemented Interfaces:

IPartitioner

public class ByteOrderedPartitioner
extends java.lang.Object
implements IPartitioner

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ByteOrderedPartitioner.BytesToken

Field Summary

Fields

Modifier and Type	Field and Description
static java.math.BigInteger	BYTE_MASK
static ByteOrderedPartitioner	instance
static ByteOrderedPartitioner.BytesToken	MINIMUM

Constructor Summary

Constructors

Constructor and Description
ByteOrderedPartitioner()

Method Summary

Modifier and Type	Method and Description
DecoratedKey	decorateKey(java.nio.ByteBuffer key) Transform key to object representation of the on-disk format.
java.util.Map<Token,java.lang.Float>	describeOwnership(java.util.List<Token> sortedTokens) Calculate the deltas between tokens in the ring in order to compare relative sizes.
ByteOrderedPartitioner.BytesToken	getMinimumToken()
ByteOrderedPartitioner.BytesToken	getRandomToken()
ByteOrderedPartitioner.BytesToken	getRandomToken(java.util.Random random)
ByteOrderedPartitioner.BytesToken	getToken(java.nio.ByteBuffer key)
Token.TokenFactory	getTokenFactory()
AbstractType<?>	getTokenValidator()
ByteOrderedPartitioner.BytesToken	midpoint(Token lt, Token rt) Calculate a Token representing the approximate "middle" of the given range.
AbstractType<?>	partitionOrdering() Abstract type that orders the same way as DecoratedKeys provided by this partitioner.
boolean	preservesOrder()
Token	split(Token left, Token right, double ratioToLeft) Calculate a Token which take approximate 0 <= ratioToLeft <= 1 ownership of the given range.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cassandra.dht.IPartitioner

getMaximumToken, splitter

Field Detail

MINIMUM

public static final ByteOrderedPartitioner.BytesToken MINIMUM

BYTE_MASK

public static final java.math.BigInteger BYTE_MASK

instance

public static final ByteOrderedPartitioner instance

Constructor Detail

ByteOrderedPartitioner

public ByteOrderedPartitioner()

Method Detail

getToken

public ByteOrderedPartitioner.BytesToken getToken(java.nio.ByteBuffer key)

Specified by:

getToken in interface IPartitioner

Returns:

a Token that can be used to route a given key (This is NOT a method to create a Token from its string representation; for that, use TokenFactory.fromString.)

decorateKey

public DecoratedKey decorateKey(java.nio.ByteBuffer key)

Description copied from interface: IPartitioner

Transform key to object representation of the on-disk format.

Specified by:

decorateKey in interface IPartitioner

Parameters:

key - the raw, client-facing key

Returns:

decorated version of key

midpoint

public ByteOrderedPartitioner.BytesToken midpoint(Token lt,
                                                  Token rt)

Description copied from interface: IPartitioner

Calculate a Token representing the approximate "middle" of the given range.

Specified by:

midpoint in interface IPartitioner

Returns:

The approximate midpoint between left and right.

split

public Token split(Token left,
                   Token right,
                   double ratioToLeft)

Description copied from interface: IPartitioner

Calculate a Token which take approximate 0 <= ratioToLeft <= 1 ownership of the given range.

Specified by:

split in interface IPartitioner

getMinimumToken

public ByteOrderedPartitioner.BytesToken getMinimumToken()

Specified by:

getMinimumToken in interface IPartitioner

Returns:

A Token smaller than all others in the range that is being partitioned. Not legal to assign to a node or key. (But legal to use in range scans.)

getRandomToken

public ByteOrderedPartitioner.BytesToken getRandomToken()

Specified by:

getRandomToken in interface IPartitioner

Returns:

a randomly generated token

getRandomToken

public ByteOrderedPartitioner.BytesToken getRandomToken(java.util.Random random)

Specified by:

getRandomToken in interface IPartitioner

Parameters:

random - instance of Random to use when generating the token

Returns:

a randomly generated token

getTokenFactory

public Token.TokenFactory getTokenFactory()

Specified by:

getTokenFactory in interface IPartitioner

preservesOrder

public boolean preservesOrder()

Specified by:

preservesOrder in interface IPartitioner

Returns:

True if the implementing class preserves key order in the Tokens it generates.

describeOwnership

public java.util.Map<Token,java.lang.Float> describeOwnership(java.util.List<Token> sortedTokens)

Description copied from interface: IPartitioner

Calculate the deltas between tokens in the ring in order to compare relative sizes.

Specified by:

describeOwnership in interface IPartitioner

Parameters:

sortedTokens - a sorted List of Tokens

Returns:

the mapping from 'token' to 'percentage of the ring owned by that token'.

getTokenValidator

public AbstractType<?> getTokenValidator()

Specified by:

getTokenValidator in interface IPartitioner

partitionOrdering

public AbstractType<?> partitionOrdering()

Description copied from interface: IPartitioner

Abstract type that orders the same way as DecoratedKeys provided by this partitioner. Used by secondary indices.

Specified by:

partitionOrdering in interface IPartitioner