/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Apr 16, 2008
*/
package com.bigdata.rdf.model;
import java.io.IOException;
import com.bigdata.bop.IElement;
import com.bigdata.rdf.internal.IV;
import com.bigdata.rdf.internal.IVUtility;
/**
* Abstract base class for {@link BigdataValue} implementations.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public abstract class BigdataValueImpl implements BigdataValue {
/**
*
*/
private static final long serialVersionUID = 3114316856174115308L;
private volatile transient BigdataValueFactory valueFactory;
protected volatile IV iv;
@Override
public final BigdataValueFactory getValueFactory() {
return valueFactory;
}
// Note: unused.
// /**
// *
// * @param valueFactory
// *
// * @throws IllegalArgumentException
// * if the argument is <code>null</code>.
// * @throws IllegalStateException
// * if a different {@link BigdataValueFactoryImpl} has already been
// * set.
// */
// public final void setValueFactory(final BigdataValueFactory valueFactory) {
//
// if (valueFactory == null)
// throw new IllegalArgumentException();
//
// if (this.valueFactory != null && this.valueFactory != valueFactory)
// throw new IllegalStateException();
//
// this.valueFactory = valueFactory;
//
// }
/**
* @param valueFactory
* The value factory that created this object (optional).
* @param iv
* The internal value (optional).
*/
protected BigdataValueImpl(final BigdataValueFactory valueFactory,
final IV iv) {
// if (valueFactory == null)
// throw new IllegalArgumentException();
this.valueFactory = valueFactory;
this.iv = iv;
}
@Override
final public void clearInternalValue() {
iv = null;
}
final public boolean isRealIV() {
if (iv == null)
return false;
if (iv.isNullIV())
return false;
return true;
}
@Override
public IV getIV() {
return iv;
}
@Override
final public void setIV(final IV iv) {
if (iv == null) {
throw new IllegalArgumentException(
"Can not set IV to null: term=" + this);
}
if (this.iv != null && !IVUtility.equals(this.iv, iv)) {
throw new IllegalStateException("Already assigned: old="
+ this.iv + ", new=" + iv + ", this: " + this);
}
this.iv = iv;
}
/**
* Extends the serialization format to include the namespace of the lexicon
* so we can recover the {@link BigdataValueFactory} singleton reference for
* that namespace when the value is deserialized.
*/
private void writeObject(final java.io.ObjectOutputStream out) throws IOException {
out.defaultWriteObject();
out.writeUTF(((BigdataValueFactoryImpl) valueFactory).getNamespace());
}
/**
* Imposes the canonicalizing mapping on the non-Serializable
* BigdataValueFactory during object de-serialization.
*/
private void readObject(final java.io.ObjectInputStream in) throws IOException,
ClassNotFoundException {
in.defaultReadObject();
final String namespace = in.readUTF();
valueFactory = BigdataValueFactoryImpl.getInstance(namespace);
}
/**
* Implements {@link IElement}. BigdataValue acts as a lexicon element,
* with the term in the 0th index position and the IV in the 1st index
* position.
*/
@Override
public Object get(int index) {
if (index == 0) {
return this;
} else if (index == 1) {
return getIV();
} else {
throw new IllegalArgumentException();
}
}
}