/**
* 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.Set;
import org.apache.jena.sparql.core.Var ;
import org.apache.jena.sparql.engine.QueryIterator ;
import org.apache.jena.sparql.engine.index.HashIndexTable.MissingBindingException ;
import org.apache.jena.sparql.engine.iterator.QueryIterMinus ;
/**
* Creates {@link IndexTable}s for use by
* {@link QueryIterMinus}.
*/
public class IndexFactory {
// Contribution from P Gearon (@quoll)
public static IndexTable createIndex(Set<Var> commonVars, QueryIterator data) {
try {
if (commonVars.size() == 1) {
return new SetIndexTable(commonVars, data);
} else {
return new HashIndexTable(commonVars, data);
}
} catch (MissingBindingException e) {
return new LinearIndex(commonVars, data, e.getData(), e.getMap());
}
}
}