org.apache.lucene.queryparser.surround.query.BasicQueryFactory.java Source code

Introduction

Here is the source code for org.apache.lucene.queryparser.surround.query.BasicQueryFactory.java

Source

/*
 * 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.lucene.queryparser.surround.query;
/* Create basic queries to be used during rewrite.
 * The basic queries are TermQuery and SpanTermQuery.
 * An exception can be thrown when too many of these are used.
 * SpanTermQuery and TermQuery use IndexReader.termEnum(Term), which causes the buffer usage.
 *
 * Use this class to limit the buffer usage for reading terms from an index.
 * Default is 1024, the same as the max. number of subqueries for a BooleanQuery.
 */

import org.apache.lucene.index.Term;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.spans.SpanTermQuery;

/** Factory for creating basic term queries */
public class BasicQueryFactory {
    public BasicQueryFactory(int maxBasicQueries) {
        this.maxBasicQueries = maxBasicQueries;
        this.queriesMade = 0;
    }

    public BasicQueryFactory() {
        this(1024);
    }

    private int maxBasicQueries;
    private int queriesMade;

    public int getNrQueriesMade() {
        return queriesMade;
    }

    public int getMaxBasicQueries() {
        return maxBasicQueries;
    }

    @Override
    public String toString() {
        return getClass().getName() + "(maxBasicQueries: " + maxBasicQueries + ", queriesMade: " + queriesMade
                + ")";
    }

    private boolean atMax() {
        return queriesMade >= maxBasicQueries;
    }

    protected synchronized void checkMax() throws TooManyBasicQueries {
        if (atMax())
            throw new TooManyBasicQueries(getMaxBasicQueries());
        queriesMade++;
    }

    public TermQuery newTermQuery(Term term) throws TooManyBasicQueries {
        checkMax();
        return new TermQuery(term);
    }

    public SpanTermQuery newSpanTermQuery(Term term) throws TooManyBasicQueries {
        checkMax();
        return new SpanTermQuery(term);
    }

    @Override
    public int hashCode() {
        return getClass().hashCode() ^ (atMax() ? 7 : 31 * 32);
    }

    /** Two BasicQueryFactory's are equal when they generate
     *  the same types of basic queries, or both cannot generate queries anymore.
     */
    @Override
    public boolean equals(Object obj) {
        if (!(obj instanceof BasicQueryFactory))
            return false;
        BasicQueryFactory other = (BasicQueryFactory) obj;
        return atMax() == other.atMax();
    }
}