org.apache.lucene.search.MatchAllDocsQuery.java Source code

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Here is the source code for org.apache.lucene.search.MatchAllDocsQuery.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;

import java.io.IOException;

import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.util.Bits;

/**
 * A query that matches all documents.
 */
public final class MatchAllDocsQuery extends Query {

    @Override
    public Weight createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost) {
        return new ConstantScoreWeight(this, boost) {
            @Override
            public String toString() {
                return "weight(" + MatchAllDocsQuery.this + ")";
            }

            @Override
            public Scorer scorer(LeafReaderContext context) throws IOException {
                return new ConstantScoreScorer(this, score(), scoreMode,
                        DocIdSetIterator.all(context.reader().maxDoc()));
            }

            @Override
            public boolean isCacheable(LeafReaderContext ctx) {
                return true;
            }

            @Override
            public BulkScorer bulkScorer(LeafReaderContext context) throws IOException {
                if (scoreMode == ScoreMode.TOP_SCORES) {
                    return super.bulkScorer(context);
                }
                final float score = score();
                final int maxDoc = context.reader().maxDoc();
                return new BulkScorer() {
                    @Override
                    public int score(LeafCollector collector, Bits acceptDocs, int min, int max)
                            throws IOException {
                        max = Math.min(max, maxDoc);
                        ScoreAndDoc scorer = new ScoreAndDoc();
                        scorer.score = score;
                        collector.setScorer(scorer);
                        for (int doc = min; doc < max; ++doc) {
                            scorer.doc = doc;
                            if (acceptDocs == null || acceptDocs.get(doc)) {
                                collector.collect(doc);
                            }
                        }
                        return max == maxDoc ? DocIdSetIterator.NO_MORE_DOCS : max;
                    }

                    @Override
                    public long cost() {
                        return maxDoc;
                    }
                };
            }
        };
    }

    @Override
    public String toString(String field) {
        return "*:*";
    }

    @Override
    public boolean equals(Object o) {
        return sameClassAs(o);
    }

    @Override
    public int hashCode() {
        return classHash();
    }

    @Override
    public void visit(QueryVisitor visitor) {
        visitor.visitLeaf(this);
    }
}