| 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 OR like queries, counterpart of <code>ConjunctionScorer</code>. |
| * This Scorer implements {@link Scorer#advance(int)} and uses advance() on the given Scorers. |
| */ |
| class DisjunctionSumScorer extends DisjunctionScorer { |
| |
| /** The number of subscorers that provide the current match. */ |
| protected int nrMatchers = -1; |
| |
| protected double score = Float.NaN; |
| private final float[] coord; |
| |
| /** Construct a <code>DisjunctionScorer</code>. |
| * @param weight The weight to be used. |
| * @param subScorers Array of at least two subscorers. |
| * @param coord Table of coordination factors |
| */ |
| DisjunctionSumScorer(Weight weight, Scorer[] subScorers, float[] coord) throws IOException { |
| super(weight, subScorers); |
| |
| if (numScorers <= 1) { |
| throw new IllegalArgumentException("There must be at least 2 subScorers"); |
| } |
| this.coord = coord; |
| } |
| |
| @Override |
| protected void afterNext() throws IOException { |
| final Scorer sub = subScorers[0]; |
| doc = sub.docID(); |
| if (doc != NO_MORE_DOCS) { |
| score = sub.score(); |
| nrMatchers = 1; |
| countMatches(1); |
| countMatches(2); |
| } |
| } |
| |
| // TODO: this currently scores, but so did the previous impl |
| // TODO: remove recursion. |
| // TODO: if we separate scoring, out of here, |
| // then change freq() to just always compute it from scratch |
| private void countMatches(int root) throws IOException { |
| if (root < numScorers && subScorers[root].docID() == doc) { |
| nrMatchers++; |
| score += subScorers[root].score(); |
| countMatches((root<<1)+1); |
| countMatches((root<<1)+2); |
| } |
| } |
| |
| /** Returns the score of the current document matching the query. |
| * Initially invalid, until {@link #nextDoc()} is called the first time. |
| */ |
| @Override |
| public float score() throws IOException { |
| return (float)score * coord[nrMatchers]; |
| } |
| |
| @Override |
| public int freq() throws IOException { |
| return nrMatchers; |
| } |
| } |