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;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.FloatDocValuesField;
import org.apache.lucene.index.AtomicReaderContext;
import org.apache.lucene.index.FieldInvertState;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.RandomIndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.similarities.PerFieldSimilarityWrapper;
import org.apache.lucene.search.similarities.Similarity;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.LuceneTestCase.SuppressCodecs;
import org.apache.lucene.util.LuceneTestCase;
/**
* Tests the use of indexdocvalues in scoring.
*
* In the example, a docvalues field is used as a per-document boost (separate from the norm)
* @lucene.experimental
*/
@SuppressCodecs("Lucene3x")
public class TestDocValuesScoring extends LuceneTestCase {
private static final float SCORE_EPSILON = 0.001f; /* for comparing floats */
public void testSimple() throws Exception {
Directory dir = newDirectory();
RandomIndexWriter iw = new RandomIndexWriter(random(), dir);
Document doc = new Document();
Field field = newTextField("foo", "", Field.Store.NO);
doc.add(field);
Field dvField = new FloatDocValuesField("foo_boost", 0.0F);
doc.add(dvField);
Field field2 = newTextField("bar", "", Field.Store.NO);
doc.add(field2);
field.setStringValue("quick brown fox");
field2.setStringValue("quick brown fox");
dvField.setFloatValue(2f); // boost x2
iw.addDocument(doc);
field.setStringValue("jumps over lazy brown dog");
field2.setStringValue("jumps over lazy brown dog");
dvField.setFloatValue(4f); // boost x4
iw.addDocument(doc);
IndexReader ir = iw.getReader();
iw.close();
// no boosting
IndexSearcher searcher1 = newSearcher(ir, false);
final Similarity base = searcher1.getSimilarity();
// boosting
IndexSearcher searcher2 = newSearcher(ir, false);
searcher2.setSimilarity(new PerFieldSimilarityWrapper() {
final Similarity fooSim = new BoostingSimilarity(base, "foo_boost");
@Override
public Similarity get(String field) {
return "foo".equals(field) ? fooSim : base;
}
@Override
public float coord(int overlap, int maxOverlap) {
return base.coord(overlap, maxOverlap);
}
@Override
public float queryNorm(float sumOfSquaredWeights) {
return base.queryNorm(sumOfSquaredWeights);
}
});
// in this case, we searched on field "foo". first document should have 2x the score.
TermQuery tq = new TermQuery(new Term("foo", "quick"));
QueryUtils.check(random(), tq, searcher1);
QueryUtils.check(random(), tq, searcher2);
TopDocs noboost = searcher1.search(tq, 10);
TopDocs boost = searcher2.search(tq, 10);
assertEquals(1, noboost.totalHits);
assertEquals(1, boost.totalHits);
//System.out.println(searcher2.explain(tq, boost.scoreDocs[0].doc));
assertEquals(boost.scoreDocs[0].score, noboost.scoreDocs[0].score*2f, SCORE_EPSILON);
// this query matches only the second document, which should have 4x the score.
tq = new TermQuery(new Term("foo", "jumps"));
QueryUtils.check(random(), tq, searcher1);
QueryUtils.check(random(), tq, searcher2);
noboost = searcher1.search(tq, 10);
boost = searcher2.search(tq, 10);
assertEquals(1, noboost.totalHits);
assertEquals(1, boost.totalHits);
assertEquals(boost.scoreDocs[0].score, noboost.scoreDocs[0].score*4f, SCORE_EPSILON);
// search on on field bar just for kicks, nothing should happen, since we setup
// our sim provider to only use foo_boost for field foo.
tq = new TermQuery(new Term("bar", "quick"));
QueryUtils.check(random(), tq, searcher1);
QueryUtils.check(random(), tq, searcher2);
noboost = searcher1.search(tq, 10);
boost = searcher2.search(tq, 10);
assertEquals(1, noboost.totalHits);
assertEquals(1, boost.totalHits);
assertEquals(boost.scoreDocs[0].score, noboost.scoreDocs[0].score, SCORE_EPSILON);
ir.close();
dir.close();
}
/**
* Similarity that wraps another similarity and boosts the final score
* according to whats in a docvalues field.
*
* @lucene.experimental
*/
static class BoostingSimilarity extends Similarity {
private final Similarity sim;
private final String boostField;
public BoostingSimilarity(Similarity sim, String boostField) {
this.sim = sim;
this.boostField = boostField;
}
@Override
public long computeNorm(FieldInvertState state) {
return sim.computeNorm(state);
}
@Override
public SimWeight computeWeight(float queryBoost, CollectionStatistics collectionStats, TermStatistics... termStats) {
return sim.computeWeight(queryBoost, collectionStats, termStats);
}
@Override
public SimScorer simScorer(SimWeight stats, AtomicReaderContext context) throws IOException {
final SimScorer sub = sim.simScorer(stats, context);
final FieldCache.Floats values = FieldCache.DEFAULT.getFloats(context.reader(), boostField, false);
return new SimScorer() {
@Override
public float score(int doc, float freq) {
return values.get(doc) * sub.score(doc, freq);
}
@Override
public float computeSlopFactor(int distance) {
return sub.computeSlopFactor(distance);
}
@Override
public float computePayloadFactor(int doc, int start, int end, BytesRef payload) {
return sub.computePayloadFactor(doc, start, end, payload);
}
@Override
public Explanation explain(int doc, Explanation freq) {
Explanation boostExplanation = new Explanation(values.get(doc), "indexDocValue(" + boostField + ")");
Explanation simExplanation = sub.explain(doc, freq);
Explanation expl = new Explanation(boostExplanation.getValue() * simExplanation.getValue(), "product of:");
expl.addDetail(boostExplanation);
expl.addDetail(simExplanation);
return expl;
}
};
}
}
}