org.apache.cassandra.dht
Class OrderPreservingPartitioner
java.lang.Object
org.apache.cassandra.dht.OrderPreservingPartitioner
- All Implemented Interfaces:
- IPartitioner<StringToken>
public class OrderPreservingPartitioner
- extends java.lang.Object
- implements IPartitioner<StringToken>
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
MINIMUM
public static final StringToken MINIMUM
CHAR_MASK
public static final java.math.BigInteger CHAR_MASK
OrderPreservingPartitioner
public OrderPreservingPartitioner()
decorateKey
public DecoratedKey<StringToken> decorateKey(java.lang.String key)
- Description copied from interface:
IPartitioner
- Transform key to object representation of the on-disk format.
- Specified by:
decorateKey
in interface IPartitioner<StringToken>
- Parameters:
key
- the raw, client-facing key
- Returns:
- decorated version of key
convertFromDiskFormat
public DecoratedKey<StringToken> convertFromDiskFormat(java.lang.String key)
- Description copied from interface:
IPartitioner
- Convert the on disk representation to a DecoratedKey object
- Specified by:
convertFromDiskFormat
in interface IPartitioner<StringToken>
- Parameters:
key
- On disk representation
- Returns:
- DecoratedKey object
convertToDiskFormat
public java.lang.String convertToDiskFormat(DecoratedKey<StringToken> key)
- Description copied from interface:
IPartitioner
- Convert the DecoratedKey to the on disk format used for
this partitioner.
- Specified by:
convertToDiskFormat
in interface IPartitioner<StringToken>
- Parameters:
key
- The DecoratedKey in question
- Returns:
midpoint
public StringToken midpoint(StringToken ltoken,
StringToken rtoken)
- Description copied from interface:
IPartitioner
- Calculate a Token representing the approximate "middle" of the given
range.
- Specified by:
midpoint
in interface IPartitioner<StringToken>
- Returns:
- The approximate midpoint between left and right.
getMinimumToken
public StringToken getMinimumToken()
- Specified by:
getMinimumToken
in interface IPartitioner<StringToken>
- Returns:
- The minimum possible Token in the range that is being partitioned.
getRandomToken
public StringToken getRandomToken()
- Specified by:
getRandomToken
in interface IPartitioner<StringToken>
- Returns:
- a randomly generated token
getTokenFactory
public Token.TokenFactory<java.lang.String> getTokenFactory()
- Specified by:
getTokenFactory
in interface IPartitioner<StringToken>
preservesOrder
public boolean preservesOrder()
- Specified by:
preservesOrder
in interface IPartitioner<StringToken>
- Returns:
- True if the implementing class preserves key order in the Tokens
it generates.
getToken
public StringToken getToken(java.lang.String key)
- Specified by:
getToken
in interface IPartitioner<StringToken>
- 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.)
Copyright © 2010 The Apache Software Foundation