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* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.common.lucene.all;
import org.apache.lucene.analysis.payloads.PayloadHelper;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.PostingsEnum;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TermContext;
import org.apache.lucene.index.TermState;
import org.apache.lucene.index.Terms;
import org.apache.lucene.index.TermsEnum;
import org.apache.lucene.search.CollectionStatistics;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.MatchNoDocsQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TermStatistics;
import org.apache.lucene.search.Weight;
import org.apache.lucene.search.similarities.Similarity;
import org.apache.lucene.search.similarities.Similarity.SimScorer;
import org.apache.lucene.search.similarities.Similarity.SimWeight;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.ToStringUtils;
import java.io.IOException;
import java.util.Set;
/**
* A term query that takes all payload boost values into account.
*
* It is like PayloadTermQuery with AveragePayloadFunction, except
* unlike PayloadTermQuery, it doesn't plug into the similarity to
* determine how the payload should be factored in, it just parses
* the float and multiplies the average with the regular score.
*/
public final class AllTermQuery extends Query {
private final Term term;
public AllTermQuery(Term term) {
this.term = term;
}
public Term getTerm() {
return term;
}
@Override
public Query rewrite(IndexReader reader) throws IOException {
if (getBoost() != 1f) {
return super.rewrite(reader);
}
boolean fieldExists = false;
boolean hasPayloads = false;
for (LeafReaderContext context : reader.leaves()) {
final Terms terms = context.reader().terms(term.field());
if (terms != null) {
fieldExists = true;
if (terms.hasPayloads()) {
hasPayloads = true;
break;
}
}
}
if (fieldExists == false) {
Query rewritten = new MatchNoDocsQuery();
rewritten.setBoost(getBoost());
return rewritten;
}
if (hasPayloads == false) {
TermQuery rewritten = new TermQuery(term);
rewritten.setBoost(getBoost());
return rewritten;
}
return this;
}
@Override
public Weight createWeight(IndexSearcher searcher, boolean needsScores) throws IOException {
if (needsScores == false) {
return new TermQuery(term).createWeight(searcher, needsScores);
}
final TermContext termStates = TermContext.build(searcher.getTopReaderContext(), term);
final CollectionStatistics collectionStats = searcher.collectionStatistics(term.field());
final TermStatistics termStats = searcher.termStatistics(term, termStates);
final Similarity similarity = searcher.getSimilarity(needsScores);
final SimWeight stats = similarity.computeWeight(collectionStats, termStats);
return new Weight(this) {
@Override
public final float getValueForNormalization() throws IOException {
return stats.getValueForNormalization();
}
@Override
public final void normalize(float norm, float topLevelBoost) {
stats.normalize(norm, topLevelBoost);
}
@Override
public void extractTerms(Set terms) {
terms.add(term);
}
@Override
public Explanation explain(LeafReaderContext context, int doc) throws IOException {
AllTermScorer scorer = scorer(context);
if (scorer != null) {
int newDoc = scorer.iterator().advance(doc);
if (newDoc == doc) {
float score = scorer.score();
float freq = scorer.freq();
SimScorer docScorer = similarity.simScorer(stats, context);
Explanation freqExplanation = Explanation.match(freq, "termFreq=" + freq);
Explanation termScoreExplanation = docScorer.explain(doc, freqExplanation);
Explanation payloadBoostExplanation = Explanation.match(scorer.payloadBoost(), "payloadBoost=" + scorer.payloadBoost());
return Explanation.match(
score,
"weight(" + getQuery() + " in " + doc + ") ["
+ similarity.getClass().getSimpleName() + "], product of:",
termScoreExplanation, payloadBoostExplanation);
}
}
return Explanation.noMatch("no matching term");
}
@Override
public AllTermScorer scorer(LeafReaderContext context) throws IOException {
final Terms terms = context.reader().terms(term.field());
if (terms == null) {
return null;
}
final TermsEnum termsEnum = terms.iterator();
if (termsEnum == null) {
return null;
}
final TermState state = termStates.get(context.ord);
if (state == null) {
// Term does not exist in this segment
return null;
}
termsEnum.seekExact(term.bytes(), state);
PostingsEnum docs = termsEnum.postings(null, PostingsEnum.PAYLOADS);
assert docs != null;
return new AllTermScorer(this, docs, similarity.simScorer(stats, context));
}
};
}
private static class AllTermScorer extends Scorer {
final PostingsEnum postings;
final Similarity.SimScorer docScorer;
int doc = -1;
float payloadBoost;
AllTermScorer(Weight weight, PostingsEnum postings, Similarity.SimScorer docScorer) {
super(weight);
this.postings = postings;
this.docScorer = docScorer;
}
float payloadBoost() throws IOException {
if (doc != docID()) {
final int freq = postings.freq();
payloadBoost = 0;
for (int i = 0; i < freq; ++i) {
postings.nextPosition();
final BytesRef payload = postings.getPayload();
float boost;
if (payload == null) {
boost = 1;
} else {
assert payload.length == 4;
boost = PayloadHelper.decodeFloat(payload.bytes, payload.offset);
}
payloadBoost += boost;
}
payloadBoost /= freq;
doc = docID();
}
return payloadBoost;
}
@Override
public float score() throws IOException {
return payloadBoost() * docScorer.score(postings.docID(), postings.freq());
}
@Override
public int freq() throws IOException {
return postings.freq();
}
@Override
public int docID() {
return postings.docID();
}
@Override
public DocIdSetIterator iterator() {
return postings;
}
}
@Override
public String toString(String field) {
return new TermQuery(term).toString(field) + ToStringUtils.boost(getBoost());
}
@Override
public boolean equals(Object obj) {
if (super.equals(obj) == false) {
return false;
}
AllTermQuery that = (AllTermQuery) obj;
return term.equals(that.term);
}
@Override
public int hashCode() {
return 31 * super.hashCode() + term.hashCode();
}
}