org.apache.cassandra.dht
Interface IPartitioner<T extends Token>

All Known Implementing Classes:

CollatingOrderPreservingPartitioner, OrderPreservingPartitioner, RandomPartitioner

public interface IPartitioner<T extends Token>

Method Summary

DecoratedKey<T>	convertFromDiskFormat(java.lang.String key) Convert the on disk representation to a DecoratedKey object
java.lang.String	convertToDiskFormat(DecoratedKey<T> key) Convert the DecoratedKey to the on disk format used for this partitioner.
DecoratedKey<T>	decorateKey(java.lang.String key) Transform key to object representation of the on-disk format.
T	getMinimumToken()
T	getRandomToken()
T	getToken(java.lang.String key)
Token.TokenFactory	getTokenFactory()
T	midpoint(T left, T right) Calculate a Token representing the approximate "middle" of the given range.
boolean	preservesOrder()

Method Detail

convertFromDiskFormat

DecoratedKey<T> convertFromDiskFormat(java.lang.String key)

Convert the on disk representation to a DecoratedKey object

Parameters:

key - On disk representation

Returns:

DecoratedKey object

convertToDiskFormat

java.lang.String convertToDiskFormat(DecoratedKey<T> key)

Convert the DecoratedKey to the on disk format used for this partitioner.

Parameters:

key - The DecoratedKey in question

Returns:

decorateKey

DecoratedKey<T> decorateKey(java.lang.String key)

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

Parameters:

key - the raw, client-facing key

Returns:

decorated version of key

midpoint

T midpoint(T left,
           T right)

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

Returns:

The approximate midpoint between left and right.

getMinimumToken

T getMinimumToken()

Returns:

The minimum possible Token in the range that is being partitioned.

getToken

T getToken(java.lang.String key)

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.)

getRandomToken

T getRandomToken()

Returns:

a randomly generated token

getTokenFactory

Token.TokenFactory getTokenFactory()

preservesOrder

boolean preservesOrder()

Returns:

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