| /* |
| * 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 java.util.Objects; |
| |
| import org.apache.lucene.index.LeafReader; |
| import org.apache.lucene.index.NumericDocValues; |
| import org.apache.lucene.search.similarities.Similarity.SimScorer; |
| |
| /** |
| * {@link SimScorer} on a specific {@link LeafReader}. |
| */ |
| public final class LeafSimScorer { |
| |
| private final SimScorer scorer; |
| private final NumericDocValues norms; |
| |
| /** |
| * Sole constructor: Score documents of {@code reader} with {@code scorer}. |
| */ |
| public LeafSimScorer(SimScorer scorer, LeafReader reader, String field, boolean needsScores) throws IOException { |
| this.scorer = Objects.requireNonNull(scorer); |
| norms = needsScores ? reader.getNormValues(field) : null; |
| } |
| |
| /** Return the wrapped {@link SimScorer}. */ |
| public SimScorer getSimScorer() { |
| return scorer; |
| } |
| |
| private long getNormValue(int doc) throws IOException { |
| if (norms != null) { |
| boolean found = norms.advanceExact(doc); |
| assert found; |
| return norms.longValue(); |
| } else { |
| return 1L; // default norm |
| } |
| } |
| |
| /** Score the provided document assuming the given term document frequency. |
| * This method must be called on non-decreasing sequences of doc ids. |
| * @see SimScorer#score(float, long) */ |
| public float score(int doc, float freq) throws IOException { |
| return scorer.score(freq, getNormValue(doc)); |
| } |
| |
| /** Explain the score for the provided document assuming the given term document frequency. |
| * This method must be called on non-decreasing sequences of doc ids. |
| * @see SimScorer#explain(Explanation, long) */ |
| public Explanation explain(int doc, Explanation freqExpl) throws IOException { |
| return scorer.explain(freqExpl, getNormValue(doc)); |
| } |
| |
| } |