org.apache.lucene.search.spans.SpanWithinQuery.java Source code

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Here is the source code for org.apache.lucene.search.spans.SpanWithinQuery.java

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/*
 * 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.search.spans;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Map;

import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TermStates;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.ScoreMode;

/** Keep matches that are contained within another Spans. */
public final class SpanWithinQuery extends SpanContainQuery {

    /** Construct a SpanWithinQuery matching spans from <code>little</code>
     * that are inside of <code>big</code>.
     * This query has the boost of <code>little</code>.
     * <code>big</code> and <code>little</code> must be in the same field.
     */
    public SpanWithinQuery(SpanQuery big, SpanQuery little) {
        super(big, little);
    }

    @Override
    public String toString(String field) {
        return toString(field, "SpanWithin");
    }

    @Override
    public SpanWeight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) throws IOException {
        SpanWeight bigWeight = big.createWeight(searcher, scoreMode, boost);
        SpanWeight littleWeight = little.createWeight(searcher, scoreMode, boost);
        return new SpanWithinWeight(searcher,
                scoreMode.needsScores() ? getTermStates(bigWeight, littleWeight) : null, bigWeight, littleWeight,
                boost);
    }

    public class SpanWithinWeight extends SpanContainWeight {

        public SpanWithinWeight(IndexSearcher searcher, Map<Term, TermStates> terms, SpanWeight bigWeight,
                SpanWeight littleWeight, float boost) throws IOException {
            super(searcher, terms, bigWeight, littleWeight, boost);
        }

        /**
         * Return spans from <code>little</code> that are contained in a spans from <code>big</code>.
         * The payload is from the spans of <code>little</code>.
         */
        @Override
        public Spans getSpans(final LeafReaderContext context, Postings requiredPostings) throws IOException {
            ArrayList<Spans> containerContained = prepareConjunction(context, requiredPostings);
            if (containerContained == null) {
                return null;
            }

            Spans big = containerContained.get(0);
            Spans little = containerContained.get(1);

            return new ContainSpans(big, little, little) {

                @Override
                boolean twoPhaseCurrentDocMatches() throws IOException {
                    oneExhaustedInCurrentDoc = false;
                    assert littleSpans.startPosition() == -1;
                    while (littleSpans.nextStartPosition() != NO_MORE_POSITIONS) {
                        while (bigSpans.endPosition() < littleSpans.endPosition()) {
                            if (bigSpans.nextStartPosition() == NO_MORE_POSITIONS) {
                                oneExhaustedInCurrentDoc = true;
                                return false;
                            }
                        }
                        if (bigSpans.startPosition() <= littleSpans.startPosition()) {
                            atFirstInCurrentDoc = true;
                            return true;
                        }
                    }
                    oneExhaustedInCurrentDoc = true;
                    return false;
                }

                @Override
                public int nextStartPosition() throws IOException {
                    if (atFirstInCurrentDoc) {
                        atFirstInCurrentDoc = false;
                        return littleSpans.startPosition();
                    }
                    while (littleSpans.nextStartPosition() != NO_MORE_POSITIONS) {
                        while (bigSpans.endPosition() < littleSpans.endPosition()) {
                            if (bigSpans.nextStartPosition() == NO_MORE_POSITIONS) {
                                oneExhaustedInCurrentDoc = true;
                                return NO_MORE_POSITIONS;
                            }
                        }
                        if (bigSpans.startPosition() <= littleSpans.startPosition()) {
                            return littleSpans.startPosition();
                        }
                    }
                    oneExhaustedInCurrentDoc = true;
                    return NO_MORE_POSITIONS;
                }
            };
        }

        @Override
        public boolean isCacheable(LeafReaderContext ctx) {
            return littleWeight.isCacheable(ctx) && bigWeight.isCacheable(ctx);
        }

    }

}