| /* |
| * 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.search.similarities.Similarity; |
| import org.apache.lucene.search.similarities.Similarity.SimScorer; |
| |
| abstract class PhraseWeight extends Weight { |
| |
| final ScoreMode scoreMode; |
| final Similarity.SimScorer stats; |
| final Similarity similarity; |
| final String field; |
| |
| protected PhraseWeight(Query query, String field, IndexSearcher searcher, ScoreMode scoreMode) throws IOException { |
| super(query); |
| this.scoreMode = scoreMode; |
| this.field = field; |
| this.similarity = searcher.getSimilarity(); |
| SimScorer stats = getStats(searcher); |
| if (stats == null) { // Means no terms or scores are not needed |
| stats = new SimScorer() { |
| @Override |
| public float score(float freq, long norm) { |
| return 1; |
| } |
| }; |
| } |
| this.stats = stats; |
| } |
| |
| protected abstract Similarity.SimScorer getStats(IndexSearcher searcher) throws IOException; |
| |
| protected abstract PhraseMatcher getPhraseMatcher(LeafReaderContext context, SimScorer scorer, boolean exposeOffsets) throws IOException; |
| |
| @Override |
| public Scorer scorer(LeafReaderContext context) throws IOException { |
| PhraseMatcher matcher = getPhraseMatcher(context, stats, false); |
| if (matcher == null) |
| return null; |
| LeafSimScorer simScorer = new LeafSimScorer(stats, context.reader(), field, scoreMode.needsScores()); |
| return new PhraseScorer(this, matcher, scoreMode, simScorer); |
| } |
| |
| @Override |
| public Explanation explain(LeafReaderContext context, int doc) throws IOException { |
| PhraseMatcher matcher = getPhraseMatcher(context, stats, false); |
| if (matcher == null || matcher.approximation().advance(doc) != doc) { |
| return Explanation.noMatch("no matching terms"); |
| } |
| matcher.reset(); |
| if (matcher.nextMatch() == false) { |
| return Explanation.noMatch("no matching phrase"); |
| } |
| float freq = matcher.sloppyWeight(); |
| while (matcher.nextMatch()) { |
| freq += matcher.sloppyWeight(); |
| } |
| LeafSimScorer docScorer = new LeafSimScorer(stats, context.reader(), field, scoreMode.needsScores()); |
| Explanation freqExplanation = Explanation.match(freq, "phraseFreq=" + freq); |
| Explanation scoreExplanation = docScorer.explain(doc, freqExplanation); |
| return Explanation.match( |
| scoreExplanation.getValue(), |
| "weight("+getQuery()+" in "+doc+") [" + similarity.getClass().getSimpleName() + "], result of:", |
| scoreExplanation); |
| } |
| |
| @Override |
| public Matches matches(LeafReaderContext context, int doc) throws IOException { |
| return MatchesUtils.forField(field, () -> { |
| PhraseMatcher matcher = getPhraseMatcher(context, stats, true); |
| if (matcher == null || matcher.approximation().advance(doc) != doc) { |
| return null; |
| } |
| matcher.reset(); |
| if (matcher.nextMatch() == false) { |
| return null; |
| } |
| return new MatchesIterator() { |
| boolean started = false; |
| @Override |
| public boolean next() throws IOException { |
| if (started == false) { |
| return started = true; |
| } |
| return matcher.nextMatch(); |
| } |
| |
| @Override |
| public int startPosition() { |
| return matcher.startPosition(); |
| } |
| |
| @Override |
| public int endPosition() { |
| return matcher.endPosition(); |
| } |
| |
| @Override |
| public int startOffset() throws IOException { |
| return matcher.startOffset(); |
| } |
| |
| @Override |
| public int endOffset() throws IOException { |
| return matcher.endOffset(); |
| } |
| |
| @Override |
| public MatchesIterator getSubMatches() throws IOException { |
| return null; // phrases are treated as leaves |
| } |
| |
| @Override |
| public Query getQuery() { |
| return PhraseWeight.this.getQuery(); |
| } |
| }; |
| }); |
| } |
| |
| @Override |
| public boolean isCacheable(LeafReaderContext ctx) { |
| return true; |
| } |
| } |