org.hypergraphdb.type.javaprimitive

Class EnumTypeConstructor

java.lang.Object

org.hypergraphdb.type.HGAtomTypeBase

org.hypergraphdb.type.javaprimitive.EnumTypeConstructor

All Implemented Interfaces:

HGGraphHolder, HGAtomType

public class EnumTypeConstructor
extends HGAtomTypeBase

Manages instances of EnumType. Each EnumType manages a concrete Java Enum.

To allow for cross-platform interoperability of enums, the list of symbolic constants is also recorded along with the fully-qualified Java class name of the enum. The Java HyperGraph implementation will only use the latter, though.

Author:

Borislav Iordanov

Field Summary

Fields inherited from class org.hypergraphdb.type.HGAtomTypeBase

graph

Constructor Summary

Constructors

Constructor and Description
EnumTypeConstructor()

Method Summary

Methods

Modifier and Type	Method and Description
Object	make(HGPersistentHandle handle, LazyRef<HGHandle[]> targetSet, IncidenceSetRef incidenceSet) Construct a new run-time instance of a hypergraph atom.
void	release(HGPersistentHandle handle) Release a hypergraph value instance from the persistent store.
HGPersistentHandle	store(Object instance) Store a run-time instance of a hypergraph atom into the hypergraph HGStore as a new atom.

Methods inherited from class org.hypergraphdb.type.HGAtomTypeBase

getHyperGraph, setHyperGraph, subsumes

Methods inherited from class java.lang.Object

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

Constructor Detail

EnumTypeConstructor

public EnumTypeConstructor()

Method Detail

make

public Object make(HGPersistentHandle handle,
          LazyRef<HGHandle[]> targetSet,
          IncidenceSetRef incidenceSet)

Description copied from interface: HGAtomType

Construct a new run-time instance of a hypergraph atom. A plain node must be constructed whenever the targetSet parameter is null or of length 0. Otherwise, a HGLink instance must be constructed.

It is not required that all atom types be able to construct both plain (node) atoms and HGLinks. It is up to an HGAtomType implementation to support either or both. When a HGLink counterpart is not available for a particular run-time type, an implementation may choose to create an instance of the default link value holder implementation HGValuedLink, provided by HyperGraph.

Parameters:

handle - The HGPersistentHandle of the atom value.

targetSet - When the atom is a link, this parameter holds the target set of the link. When the atom is a node, the parameter is an array of 0 length.

incidenceSet - A lazy reference to the set of links pointing to this atom. This is null if we are constructing an internal/nested value of some complex type.

Returns:

The run-time atom instance. The return value should never be null. In case the handle points to an invalid instance (inexisting or with a erronous layout), the method should throw a HGException.

store

public HGPersistentHandle store(Object instance)

Description copied from interface: HGAtomType

Store a run-time instance of a hypergraph atom into the hypergraph HGStore as a new atom.

Parameters:

instance - The atom instance.

Returns:

The persistent handle of the stored value.

release

public void release(HGPersistentHandle handle)

Description copied from interface: HGAtomType

Release a hypergraph value instance from the persistent store.

This method should be called when a HGPersistentHandle returned from the store is no longer in use.

Parameters:

handle - The persistent handle of the value to release.