org.hypergraphdb.indexing

Class ByTargetIndexer

java.lang.Object

org.hypergraphdb.indexing.HGKeyIndexer<HGPersistentHandle>

org.hypergraphdb.indexing.ByTargetIndexer

All Implemented Interfaces:

HGIndexer<HGPersistentHandle,HGPersistentHandle>

public class ByTargetIndexer
extends HGKeyIndexer<HGPersistentHandle>

Represents an index by a specific target position in ordered links.

Author:

Borislav Iordanov

Constructor Summary

Constructors

Constructor and Description
ByTargetIndexer()
ByTargetIndexer(HGHandle type, int target)
ByTargetIndexer(String name, HGHandle type, int target)

Method Summary

Methods

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

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

ByTargetIndexer

public ByTargetIndexer()

ByTargetIndexer

public ByTargetIndexer(HGHandle type,
               int target)

ByTargetIndexer

public ByTargetIndexer(String name,
               HGHandle type,
               int target)

Method Detail

getTarget

public int getTarget()

setTarget

public void setTarget(int target)

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.

getConverter

public ByteArrayConverter<HGPersistentHandle> 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[].

getKey

public HGPersistentHandle getKey(HyperGraph graph,
                        Object atom)

Description copied from class: HGKeyIndexer

Returns an index key for the given atom.

Specified by:

getKey in class HGKeyIndexer<HGPersistentHandle>

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.

equals

public boolean equals(Object other)

Description copied from interface: HGIndexer

Declared to enforce implementation.

Specified by:

equals in interface HGIndexer<HGPersistentHandle,HGPersistentHandle>

Overrides:

equals in class Object

hashCode

public int hashCode()

Description copied from interface: HGIndexer

Declared to enforce implementation.

Specified by:

hashCode in interface HGIndexer<HGPersistentHandle,HGPersistentHandle>

Overrides:

hashCode in class Object