sail/src/main/java/org/apache/rya/rdftriplestore/utils/DefaultStatistics.java

package org.apache.rya.rdftriplestore.utils;

/*
 * 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.
 */

import org.eclipse.rdf4j.query.algebra.StatementPattern;
import org.eclipse.rdf4j.query.algebra.evaluation.impl.EvaluationStatistics;

/**
 * Class DefaultStatistics
 * Date: Apr 12, 2011
 * Time: 1:31:05 PM
 */
public class DefaultStatistics extends EvaluationStatistics {

    public DefaultStatistics() {
    }

    @Override
    protected CardinalityCalculator createCardinalityCalculator() {
        return new DefaultCardinalityCalculator();
    }

    public class DefaultCardinalityCalculator extends CardinalityCalculator {

        double count = 0.0;

        @Override
        protected double getCardinality(StatementPattern sp) {
            //based on how many (subj, pred, obj) are set
//            int numSet = 3;
//            if (sp.getSubjectVar().hasValue()) numSet--;
//            if (sp.getPredicateVar().hasValue()) numSet--;
//            if (sp.getObjectVar().hasValue()) numSet--;
//            return numSet;
            return count++;
        }
    }

}