/*
 * 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.
/** * 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.isExhaustive() == false) { 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); } }