/**
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
*/
package com.bigdata.rdf.lexicon;
import java.util.Map;
import org.openrdf.model.Value;
import com.bigdata.bop.BOp;
import com.bigdata.bop.IBindingSet;
import com.bigdata.bop.IVariable;
import com.bigdata.bop.IVariableOrConstant;
import com.bigdata.bop.NV;
import com.bigdata.bop.Var;
import com.bigdata.bop.ap.Predicate;
import com.bigdata.journal.ITx;
import com.bigdata.rdf.internal.IV;
import com.bigdata.rdf.model.BigdataValue;
/**
* A <code>
* lex(BigdataValue,IV)
* </code> predicate used for querying the {@link LexiconRelation}'s TERMS
* index.
*
* @author <a href="mailto:mrpersonick@users.sourceforge.net">Mike Personick</a>
* @version $Id$
*/
public class LexPredicate extends Predicate<BigdataValue> {
/**
*
*/
private static final long serialVersionUID = 6379772624297485704L;
/**
* Simplified forward lookup ctor. Use this ctor to lookup an {@link IV}
* from a {@link BigdataValue}.
*
* @param relationName
* the namespace of the lexicon relation
* @param timestamp
* The timestamp of the view to read on. This should be the same
* as the timestamp associated with the view of the triple store
* except for a full read/write transaction. Since all writes on
* the lexicon are unisolated, a full read/write transaction must
* use the {@link ITx#UNISOLATED} view of the lexicon in order to
* ensure that any writes it performs will be visible.
* @param var
* The variable on which the {@link IV} will be bound when we
* read on the access path.
* @param term
* the term to resolve using forward lookup (term2id)
*/
public static LexPredicate forwardInstance(//
final String relationName,//
final long timestamp,//
final IVariableOrConstant<BigdataValue> term,//
final IVariable<IV> var//
) {
return new LexPredicate(
new IVariableOrConstant[] {
term, // term
Var.var(), // iv
},
new NV(Annotations.RELATION_NAME, new String[] { relationName }),
new NV(Annotations.TIMESTAMP, timestamp) //
);
}
/**
* Simplified reverse lookup ctor. Use this ctor to lookup a
* {@link BigdataValue} from an {@link IV}.
*
* @param relationName
* the namespace of the lexicon relation
* @param timestamp
* The timestamp of the view to read on. This should be the same
* as the timestamp associated with the view of the triple store
* except for a full read/write transaction. Since all writes on
* the lexicon are unisolated, a full read/write transaction must
* use the {@link ITx#UNISOLATED} view of the lexicon in order to
* ensure that any writes it performs will be visible.
* @param var The
* variable on which the {@link Value} will be bound when we read
* on the access path.
* @param term
* the term to resolve using reverse lookup (id2term)
*/
public static LexPredicate reverseInstance(final String relationName,
final long timestamp,
final IVariable<BigdataValue> var,
final IVariableOrConstant<IV> term) {
return new LexPredicate(//
new IVariableOrConstant[] {//
var, // term
term, // iv
},
new NV(Annotations.RELATION_NAME, new String[] { relationName }),
new NV(Annotations.TIMESTAMP, timestamp) //
);
}
/**
* Variable argument version of the shallow copy constructor.
*/
public LexPredicate(final BOp[] args, final NV... anns) {
super(args, anns);
}
/**
* Required shallow copy constructor.
*/
public LexPredicate(final BOp[] args, final Map<String, Object> anns) {
super(args, anns);
}
/**
* Constructor required for {@link com.bigdata.bop.BOpUtility#deepCopy(FilterNode)}.
*/
public LexPredicate(final LexPredicate op) {
super(op);
}
@Override
public LexPredicate clone() {
// Fast path for clone().
return new LexPredicate(this);
}
/**
* Return the {@link BigdataValue} at index position
* {@value LexiconKeyOrder#SLOT_TERM}.
*/
@SuppressWarnings("unchecked")
final public IVariableOrConstant<BigdataValue> term() {
return (IVariableOrConstant<BigdataValue>) get(LexiconKeyOrder.SLOT_TERM);
}
/**
* Return the {@link IV} at index position {@value LexiconKeyOrder#SLOT_IV}.
*/
@SuppressWarnings("unchecked")
final public IVariableOrConstant<IV> iv() {
return (IVariableOrConstant<IV>) get(LexiconKeyOrder.SLOT_IV);
}
/**
* Strengthened return type.
* <p>
* {@inheritDoc}
*/
@Override
public LexPredicate asBound(final IBindingSet bindingSet) {
return (LexPredicate) new LexPredicate(argsCopy(), annotationsRef())
._asBound(bindingSet);
// return (LexPredicate) super.asBound(bindingSet);
}
}