| /* |
| * 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.Impacts; |
| import org.apache.lucene.index.ImpactsEnum; |
| import org.apache.lucene.index.ImpactsSource; |
| import org.apache.lucene.search.similarities.Similarity.SimScorer; |
| |
| /** |
| * {@link DocIdSetIterator} that skips non-competitive docs thanks to the |
| * indexed impacts. Call {@link #setMinCompetitiveScore(float)} in order to |
| * give this iterator the ability to skip low-scoring documents. |
| * @lucene.internal |
| */ |
| public final class ImpactsDISI extends DocIdSetIterator { |
| |
| private final DocIdSetIterator in; |
| private final ImpactsSource impactsSource; |
| private final MaxScoreCache maxScoreCache; |
| private final float globalMaxScore; |
| private float minCompetitiveScore = 0; |
| private int upTo = DocIdSetIterator.NO_MORE_DOCS; |
| private float maxScore = Float.MAX_VALUE; |
| |
| /** |
| * Sole constructor. |
| * @param in wrapped iterator |
| * @param impactsSource source of impacts |
| * @param scorer scorer |
| */ |
| public ImpactsDISI(DocIdSetIterator in, ImpactsSource impactsSource, SimScorer scorer) { |
| this.in = in; |
| this.impactsSource = impactsSource; |
| this.maxScoreCache = new MaxScoreCache(impactsSource, scorer); |
| this.globalMaxScore = scorer.score(Float.MAX_VALUE, 1L); |
| } |
| |
| /** |
| * Set the minimum competitive score. |
| * @see Scorer#setMinCompetitiveScore(float) |
| */ |
| public void setMinCompetitiveScore(float minCompetitiveScore) { |
| assert minCompetitiveScore >= this.minCompetitiveScore; |
| if (minCompetitiveScore > this.minCompetitiveScore) { |
| this.minCompetitiveScore = minCompetitiveScore; |
| // force upTo and maxScore to be recomputed so that we will skip documents |
| // if the current block of documents is not competitive - only if the min |
| // competitive score actually increased |
| upTo = -1; |
| } |
| } |
| |
| /** |
| * Implement the contract of {@link Scorer#advanceShallow(int)} based on the |
| * wrapped {@link ImpactsEnum}. |
| * @see Scorer#advanceShallow(int) |
| */ |
| public int advanceShallow(int target) throws IOException { |
| impactsSource.advanceShallow(target); |
| Impacts impacts = impactsSource.getImpacts(); |
| return impacts.getDocIdUpTo(0); |
| } |
| |
| /** |
| * Implement the contract of {@link Scorer#getMaxScore(int)} based on the |
| * wrapped {@link ImpactsEnum} and {@link Scorer}. |
| * @see Scorer#getMaxScore(int) |
| */ |
| public float getMaxScore(int upTo) throws IOException { |
| final int level = maxScoreCache.getLevel(upTo); |
| if (level == -1) { |
| return globalMaxScore; |
| } else { |
| return maxScoreCache.getMaxScoreForLevel(level); |
| } |
| } |
| |
| private int advanceTarget(int target) throws IOException { |
| if (target <= upTo) { |
| // we are still in the current block, which is considered competitive |
| // according to impacts, no skipping |
| return target; |
| } |
| |
| upTo = advanceShallow(target); |
| maxScore = maxScoreCache.getMaxScoreForLevel(0); |
| |
| while (true) { |
| assert upTo >= target; |
| |
| if (maxScore >= minCompetitiveScore) { |
| return target; |
| } |
| |
| if (upTo == NO_MORE_DOCS) { |
| return NO_MORE_DOCS; |
| } |
| |
| final int skipUpTo = maxScoreCache.getSkipUpTo(minCompetitiveScore); |
| if (skipUpTo == -1) { // no further skipping |
| target = upTo + 1; |
| } else if (skipUpTo == NO_MORE_DOCS) { |
| return NO_MORE_DOCS; |
| } else { |
| target = skipUpTo + 1; |
| } |
| upTo = advanceShallow(target); |
| maxScore = maxScoreCache.getMaxScoreForLevel(0); |
| } |
| } |
| |
| @Override |
| public int advance(int target) throws IOException { |
| return in.advance(advanceTarget(target)); |
| } |
| |
| @Override |
| public int nextDoc() throws IOException { |
| return advance(in.docID() + 1); |
| } |
| |
| @Override |
| public int docID() { |
| return in.docID(); |
| } |
| |
| @Override |
| public long cost() { |
| return in.cost(); |
| } |
| |
| } |