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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.index.search;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.index.Term;
import org.apache.lucene.queries.BlendedTermQuery;
import org.apache.lucene.search.BoostQuery;
import org.apache.lucene.search.DisjunctionMaxQuery;
import org.apache.lucene.search.MatchNoDocsQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.util.BytesRef;
import org.elasticsearch.common.lucene.search.Queries;
import org.elasticsearch.index.mapper.MappedFieldType;
import org.elasticsearch.index.query.AbstractQueryBuilder;
import org.elasticsearch.index.query.MultiMatchQueryBuilder;
import org.elasticsearch.index.query.QueryShardContext;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import static org.elasticsearch.common.lucene.search.Queries.newLenientFieldQuery;
public class MultiMatchQuery extends MatchQuery {
private Float groupTieBreaker = null;
public MultiMatchQuery(QueryShardContext context) {
super(context);
}
public void setTieBreaker(float tieBreaker) {
this.groupTieBreaker = tieBreaker;
}
public Query parse(MultiMatchQueryBuilder.Type type, Map fieldNames,
Object value, String minimumShouldMatch) throws IOException {
boolean hasMappedField = fieldNames.keySet().stream()
.anyMatch(k -> context.fieldMapper(k) != null);
if (hasMappedField == false) {
// all query fields are unmapped
return Queries.newUnmappedFieldsQuery(fieldNames.keySet());
}
final float tieBreaker = groupTieBreaker == null ? type.tieBreaker() : groupTieBreaker;
final List queries;
switch (type) {
case PHRASE:
case PHRASE_PREFIX:
case BEST_FIELDS:
case MOST_FIELDS:
case BOOL_PREFIX:
queries = buildFieldQueries(type, fieldNames, value, minimumShouldMatch);
break;
case CROSS_FIELDS:
queries = buildCrossFieldQuery(type, fieldNames, value, minimumShouldMatch, tieBreaker);
break;
default:
throw new IllegalStateException("No such type: " + type);
}
return combineGrouped(queries, tieBreaker);
}
private Query combineGrouped(List groupQuery, float tieBreaker) {
if (groupQuery.isEmpty()) {
return zeroTermsQuery();
}
if (groupQuery.size() == 1) {
return groupQuery.get(0);
}
return new DisjunctionMaxQuery(groupQuery, tieBreaker);
}
private List buildFieldQueries(MultiMatchQueryBuilder.Type type, Map fieldNames,
Object value, String minimumShouldMatch) throws IOException {
List queries = new ArrayList<>();
for (String fieldName : fieldNames.keySet()) {
if (context.fieldMapper(fieldName) == null) {
// ignore unmapped fields
continue;
}
float boostValue = fieldNames.getOrDefault(fieldName, 1.0f);
Query query = parse(type.matchQueryType(), fieldName, value);
query = Queries.maybeApplyMinimumShouldMatch(query, minimumShouldMatch);
if (query != null
&& boostValue != AbstractQueryBuilder.DEFAULT_BOOST
&& query instanceof MatchNoDocsQuery == false) {
query = new BoostQuery(query, boostValue);
}
if (query != null) {
queries.add(query);
}
}
return queries;
}
private List buildCrossFieldQuery(MultiMatchQueryBuilder.Type type, Map fieldNames,
Object value, String minimumShouldMatch, float tieBreaker) throws IOException {
Map> groups = new HashMap<>();
List queries = new ArrayList<>();
for (Map.Entry entry : fieldNames.entrySet()) {
String name = entry.getKey();
MappedFieldType fieldType = context.fieldMapper(name);
if (fieldType != null) {
Analyzer actualAnalyzer = getAnalyzer(fieldType, type == MultiMatchQueryBuilder.Type.PHRASE);
if (!groups.containsKey(actualAnalyzer)) {
groups.put(actualAnalyzer, new ArrayList<>());
}
float boost = entry.getValue() == null ? 1.0f : entry.getValue();
groups.get(actualAnalyzer).add(new FieldAndBoost(fieldType, boost));
}
}
for (Map.Entry> group : groups.entrySet()) {
final MatchQueryBuilder builder;
if (group.getValue().size() == 1) {
builder = new MatchQueryBuilder(group.getKey(), group.getValue().get(0).fieldType,
enablePositionIncrements, autoGenerateSynonymsPhraseQuery);
} else {
builder = new BlendedQueryBuilder(group.getKey(), group.getValue(), tieBreaker,
enablePositionIncrements, autoGenerateSynonymsPhraseQuery);
}
/*
* We have to pick some field to pass through the superclass so
* we just pick the first field. It shouldn't matter because
* fields are already grouped by their analyzers/types.
*/
String representativeField = group.getValue().get(0).fieldType.name();
Query query = parseInternal(type.matchQueryType(), representativeField, builder, value);
query = Queries.maybeApplyMinimumShouldMatch(query, minimumShouldMatch);
if (query != null) {
if (group.getValue().size() == 1) {
// apply the field boost to groups that contain a single field
float boost = group.getValue().get(0).boost;
if (boost != AbstractQueryBuilder.DEFAULT_BOOST) {
query = new BoostQuery(query, boost);
}
}
queries.add(query);
}
}
return queries;
}
private class BlendedQueryBuilder extends MatchQueryBuilder {
private final List blendedFields;
private final float tieBreaker;
BlendedQueryBuilder(Analyzer analyzer, List blendedFields, float tieBreaker,
boolean enablePositionIncrements, boolean autoGenerateSynonymsPhraseQuery) {
super(analyzer, blendedFields.get(0).fieldType, enablePositionIncrements, autoGenerateSynonymsPhraseQuery);
this.blendedFields = blendedFields;
this.tieBreaker = tieBreaker;
}
@Override
protected Query newSynonymQuery(Term[] terms) {
BytesRef[] values = new BytesRef[terms.length];
for (int i = 0; i < terms.length; i++) {
values[i] = terms[i].bytes();
}
return blendTerms(context, values, commonTermsCutoff, tieBreaker, lenient, blendedFields);
}
@Override
protected Query newTermQuery(Term term) {
return blendTerm(context, term.bytes(), commonTermsCutoff, tieBreaker, lenient, blendedFields);
}
@Override
protected Query newPrefixQuery(Term term) {
List disjunctions = new ArrayList<>();
for (FieldAndBoost fieldType : blendedFields) {
Query query = fieldType.fieldType.prefixQuery(term.text(), null, context);
if (fieldType.boost != 1f) {
query = new BoostQuery(query, fieldType.boost);
}
disjunctions.add(query);
}
return new DisjunctionMaxQuery(disjunctions, tieBreaker);
}
@Override
protected Query analyzePhrase(String field, TokenStream stream, int slop) throws IOException {
List disjunctions = new ArrayList<>();
for (FieldAndBoost fieldType : blendedFields) {
Query query = fieldType.fieldType.phraseQuery(stream, slop, enablePositionIncrements);
if (fieldType.boost != 1f) {
query = new BoostQuery(query, fieldType.boost);
}
disjunctions.add(query);
}
return new DisjunctionMaxQuery(disjunctions, tieBreaker);
}
@Override
protected Query analyzeMultiPhrase(String field, TokenStream stream, int slop) throws IOException {
List disjunctions = new ArrayList<>();
for (FieldAndBoost fieldType : blendedFields) {
Query query = fieldType.fieldType.multiPhraseQuery(stream, slop, enablePositionIncrements);
if (fieldType.boost != 1f) {
query = new BoostQuery(query, fieldType.boost);
}
disjunctions.add(query);
}
return new DisjunctionMaxQuery(disjunctions, tieBreaker);
}
}
static Query blendTerm(QueryShardContext context, BytesRef value, Float commonTermsCutoff, float tieBreaker,
boolean lenient, List blendedFields) {
return blendTerms(context, new BytesRef[] {value}, commonTermsCutoff, tieBreaker, lenient, blendedFields);
}
static Query blendTerms(QueryShardContext context, BytesRef[] values, Float commonTermsCutoff, float tieBreaker,
boolean lenient, List blendedFields) {
List queries = new ArrayList<>();
Term[] terms = new Term[blendedFields.size() * values.length];
float[] blendedBoost = new float[blendedFields.size() * values.length];
int i = 0;
for (FieldAndBoost ft : blendedFields) {
for (BytesRef term : values) {
Query query;
try {
query = ft.fieldType.termQuery(term, context);
} catch (RuntimeException e) {
if (lenient) {
query = newLenientFieldQuery(ft.fieldType.name(), e);
} else {
throw e;
}
}
float boost = ft.boost;
while (query instanceof BoostQuery) {
BoostQuery bq = (BoostQuery) query;
query = bq.getQuery();
boost *= bq.getBoost();
}
if (query.getClass() == TermQuery.class) {
terms[i] = ((TermQuery) query).getTerm();
blendedBoost[i] = boost;
i++;
} else {
if (boost != 1f && query instanceof MatchNoDocsQuery == false) {
query = new BoostQuery(query, boost);
}
queries.add(query);
}
}
}
if (i > 0) {
terms = Arrays.copyOf(terms, i);
blendedBoost = Arrays.copyOf(blendedBoost, i);
if (commonTermsCutoff != null) {
queries.add(BlendedTermQuery.commonTermsBlendedQuery(terms, blendedBoost, commonTermsCutoff));
} else {
queries.add(BlendedTermQuery.dismaxBlendedQuery(terms, blendedBoost, tieBreaker));
}
}
if (queries.size() == 1) {
return queries.get(0);
} else {
// best effort: add clauses that are not term queries so that they have an opportunity to match
// however their score contribution will be different
// TODO: can we improve this?
return new DisjunctionMaxQuery(queries, tieBreaker);
}
}
static final class FieldAndBoost {
final MappedFieldType fieldType;
final float boost;
FieldAndBoost(MappedFieldType fieldType, float boost) {
this.fieldType = Objects.requireNonNull(fieldType);
this.boost = boost;
}
}
}