org.hypergraphdb.indexing

Class DirectValueIndexer<AtomType>

java.lang.Object

org.hypergraphdb.indexing.HGKeyIndexer<AtomType>

org.hypergraphdb.indexing.DirectValueIndexer<AtomType>

Type Parameters:

AtomType -

All Implemented Interfaces:

HGIndexer<AtomType,HGPersistentHandle>

public class DirectValueIndexer<AtomType>
extends HGKeyIndexer<AtomType>

Index atoms directly by their values serialized as byte[]. The type of the atoms indexed is assumed to be an instance of HGPrimitiveType so that a ByteArrayConverter and a Comparator are made available.

Author:

borislav

Constructor Summary

Constructors

Constructor and Description
DirectValueIndexer()
DirectValueIndexer(HGHandle type)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object x) Declared to enforce implementation.
Comparator<byte[]>	getComparator(HyperGraph graph) Return a comparator used to compare key values return by this indexer.
ByteArrayConverter<AtomType>	getConverter(HyperGraph graph) Return a ByteArrayConverter capable of translating keys returned by this indexer to/from a byte[].
AtomType	getKey(HyperGraph graph, Object atom) Returns an index key for the given atom.
int	hashCode() Declared to enforce implementation.

Methods inherited from class org.hypergraphdb.indexing.HGKeyIndexer

getName, getType, index, setName, setType, unindex

Methods inherited from class java.lang.Object

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

Constructor Detail

DirectValueIndexer

public DirectValueIndexer()

DirectValueIndexer

public DirectValueIndexer(HGHandle type)

Method Detail

getConverter

public ByteArrayConverter<AtomType> getConverter(HyperGraph graph)

Description copied from interface: HGIndexer

Return a ByteArrayConverter capable of translating keys returned by this indexer to/from a byte[].

Parameters:

graph - The current HyperGraph instance.

Returns:

The ByteArrayConverter for type of index keys return by this indexer or null if keys are of type byte[].

getComparator

public Comparator<byte[]> getComparator(HyperGraph graph)

Description copied from interface: HGIndexer

Return a comparator used to compare key values return by this indexer. Note that the comparator's compare method will be invoked with byte[] parameters. It is the comparator's responsibility to convert them to the appropriate run-time type for performing the comparison if need be.

The method may return null if a default byte-by-byte comparator is to be used.

Parameters:

graph - The current HyperGraph instance.

Returns:

A comparator used to compare key values return by this indexer or null to use a default byte-by-byte comparison of keys.

getKey

public AtomType getKey(HyperGraph graph,
              Object atom)

Description copied from class: HGKeyIndexer

Returns an index key for the given atom.

Specified by:

getKey in class HGKeyIndexer<AtomType>

Parameters:

graph - The current HyperGraph instance.

atom - The atom being indexed.

Returns:

The index key. If the return value is not a byte[], a non-null ByteArrayConverter must be provided by the getConverter method.

hashCode

public int hashCode()

Description copied from interface: HGIndexer

Declared to enforce implementation.

Specified by:

hashCode in interface HGIndexer<AtomType,HGPersistentHandle>

Overrides:

hashCode in class Object

equals

public boolean equals(Object x)

Description copied from interface: HGIndexer

Declared to enforce implementation.

Specified by:

equals in interface HGIndexer<AtomType,HGPersistentHandle>

Overrides:

equals in class Object