/**
* 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 org.apache.jena.sparql.engine.index;
import java.util.HashSet;
import java.util.Set;
import org.apache.jena.graph.Node ;
import org.apache.jena.sparql.core.Var ;
import org.apache.jena.sparql.engine.QueryIterator ;
import org.apache.jena.sparql.engine.binding.Binding ;
/**
* An {@link IndexTable} implementation optimized for the case where there is
* only a single common variable
*
*/
public class SetIndexTable implements IndexTable {
private Var var;
private Set<Node> values = new HashSet<>();
/**
* Creates a new index table
*
* @param commonVars
* Common Variables
* @param data
* Data
*/
public SetIndexTable(Set<Var> commonVars, QueryIterator data) {
if (commonVars.size() != 1)
throw new IllegalArgumentException("Common Variables must be of size 1");
this.var = commonVars.iterator().next();
while (data.hasNext()) {
Binding binding = data.next();
Node value = binding.get(this.var);
if (value == null)
continue;
this.values.add(value);
}
}
@Override
public boolean containsCompatibleWithSharedDomain(Binding binding) {
Node value = binding.get(this.var);
if (value == null)
return true;
return this.values.contains(value);
}
}