| package org.apache.lucene.search; |
| /** |
| * 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. |
| */ |
| |
| import java.io.IOException; |
| |
| /** A Scorer for queries with a required part and an optional part. |
| * Delays skipTo() on the optional part until a score() is needed. |
| * <br> |
| * This <code>Scorer</code> implements {@link Scorer#skipTo(int)}. |
| */ |
| class ReqOptSumScorer extends Scorer { |
| /** The scorers passed from the constructor. |
| * These are set to null as soon as their next() or skipTo() returns false. |
| */ |
| private Scorer reqScorer; |
| private Scorer optScorer; |
| |
| /** Construct a <code>ReqOptScorer</code>. |
| * @param reqScorer The required scorer. This must match. |
| * @param optScorer The optional scorer. This is used for scoring only. |
| */ |
| public ReqOptSumScorer( |
| Scorer reqScorer, |
| Scorer optScorer) |
| { |
| super(reqScorer.weight); |
| this.reqScorer = reqScorer; |
| this.optScorer = optScorer; |
| } |
| |
| @Override |
| public int nextDoc() throws IOException { |
| return reqScorer.nextDoc(); |
| } |
| |
| @Override |
| public int advance(int target) throws IOException { |
| return reqScorer.advance(target); |
| } |
| |
| @Override |
| public int docID() { |
| return reqScorer.docID(); |
| } |
| |
| /** Returns the score of the current document matching the query. |
| * Initially invalid, until {@link #nextDoc()} is called the first time. |
| * @return The score of the required scorer, eventually increased by the score |
| * of the optional scorer when it also matches the current document. |
| */ |
| @Override |
| public float score() throws IOException { |
| int curDoc = reqScorer.docID(); |
| float reqScore = reqScorer.score(); |
| if (optScorer == null) { |
| return reqScore; |
| } |
| |
| int optScorerDoc = optScorer.docID(); |
| if (optScorerDoc < curDoc && (optScorerDoc = optScorer.advance(curDoc)) == NO_MORE_DOCS) { |
| optScorer = null; |
| return reqScore; |
| } |
| |
| return optScorerDoc == curDoc ? reqScore + optScorer.score() : reqScore; |
| } |
| |
| } |
| |