/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hp.hpl.jena.sparql.pfunction.library;
import java.util.ArrayList ;
import java.util.Iterator ;
import java.util.List ;
import com.hp.hpl.jena.graph.Node ;
import com.hp.hpl.jena.graph.NodeFactory ;
import com.hp.hpl.jena.sparql.SystemARQ ;
import com.hp.hpl.jena.sparql.core.Var ;
import com.hp.hpl.jena.sparql.engine.ExecutionContext ;
import com.hp.hpl.jena.sparql.engine.QueryIterator ;
import com.hp.hpl.jena.sparql.engine.binding.Binding ;
import com.hp.hpl.jena.sparql.engine.binding.BindingFactory ;
import com.hp.hpl.jena.sparql.engine.binding.BindingMap ;
import com.hp.hpl.jena.sparql.engine.iterator.QueryIterPlainWrapper ;
import com.hp.hpl.jena.sparql.mgt.SystemInfo ;
import com.hp.hpl.jena.sparql.pfunction.PropFuncArg ;
import com.hp.hpl.jena.sparql.pfunction.PropFuncArgType ;
import com.hp.hpl.jena.sparql.pfunction.PropertyFunctionEval ;
/** Access the subsystem version registry and yield URI/version for each entry */
public class version extends PropertyFunctionEval
{
public version()
{ super(PropFuncArgType.PF_ARG_SINGLE, PropFuncArgType.PF_ARG_SINGLE) ; }
@Override
public QueryIterator execEvaluated(Binding binding, PropFuncArg subject, Node predicate, PropFuncArg object, ExecutionContext execCxt)
{
List<Binding> results = new ArrayList<>() ;
Node subj = subject.getArg() ;
Node obj = object.getArg() ;
Iterator<SystemInfo> iter = SystemARQ.registeredSubsystems() ;
for ( ; iter.hasNext() ; )
{
SystemInfo info = iter.next();
if ( ! isSameOrVar(subj, info.getIRI()) )
continue ;
Node version = NodeFactory.createLiteral(info.getVersion()) ;
if ( ! isSameOrVar(obj, version) )
continue ;
BindingMap b = BindingFactory.create(binding) ;
if ( subj.isVariable() )
b.add(Var.alloc(subj), info.getIRI()) ;
if ( subj.isVariable() )
b.add(Var.alloc(obj), version) ;
results.add(b) ;
}
return new QueryIterPlainWrapper(results.iterator(), execCxt) ;
}
private boolean isSameOrVar(Node var, Node value)
{
return var.isVariable() || var.equals(value) ;
}
}