org.elasticsearch.search.collapse.CollapseBuilder Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
Elasticsearch subproject :server
/*
* 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.search.collapse;
import org.apache.lucene.index.IndexOptions;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.ParsingException;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.common.xcontent.ObjectParser;
import org.elasticsearch.common.xcontent.ToXContent;
import org.elasticsearch.common.xcontent.ToXContentObject;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.mapper.KeywordFieldMapper;
import org.elasticsearch.index.mapper.MappedFieldType;
import org.elasticsearch.index.mapper.NumberFieldMapper;
import org.elasticsearch.index.query.InnerHitBuilder;
import org.elasticsearch.index.query.QueryShardContext;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
/**
* A builder that enables field collapsing on search request.
*/
public class CollapseBuilder implements Writeable, ToXContentObject {
public static final ParseField FIELD_FIELD = new ParseField("field");
public static final ParseField INNER_HITS_FIELD = new ParseField("inner_hits");
public static final ParseField MAX_CONCURRENT_GROUP_REQUESTS_FIELD = new ParseField("max_concurrent_group_searches");
private static final ObjectParser PARSER =
new ObjectParser<>("collapse", CollapseBuilder::new);
static {
PARSER.declareString(CollapseBuilder::setField, FIELD_FIELD);
PARSER.declareInt(CollapseBuilder::setMaxConcurrentGroupRequests, MAX_CONCURRENT_GROUP_REQUESTS_FIELD);
PARSER.declareField((parser, builder, context) -> {
XContentParser.Token currentToken = parser.currentToken();
if (currentToken == XContentParser.Token.START_OBJECT) {
builder.setInnerHits(InnerHitBuilder.fromXContent(parser));
} else if (currentToken == XContentParser.Token.START_ARRAY) {
List innerHitBuilders = new ArrayList<>();
for (currentToken = parser.nextToken(); currentToken != XContentParser.Token.END_ARRAY; currentToken = parser.nextToken()) {
if (currentToken == XContentParser.Token.START_OBJECT) {
innerHitBuilders.add(InnerHitBuilder.fromXContent(parser));
} else {
throw new ParsingException(parser.getTokenLocation(), "Invalid token in inner_hits array");
}
}
builder.setInnerHits(innerHitBuilders);
}
}, INNER_HITS_FIELD, ObjectParser.ValueType.OBJECT_ARRAY);
}
private String field;
private List innerHits = Collections.emptyList();
private int maxConcurrentGroupRequests = 0;
private CollapseBuilder() {}
/**
* Public constructor
* @param field The name of the field to collapse on
*/
public CollapseBuilder(String field) {
Objects.requireNonNull(field, "field must be non-null");
this.field = field;
}
public CollapseBuilder(StreamInput in) throws IOException {
this.field = in.readString();
this.maxConcurrentGroupRequests = in.readVInt();
this.innerHits = in.readList(InnerHitBuilder::new);
}
@Override
public void writeTo(StreamOutput out) throws IOException {
out.writeString(field);
out.writeVInt(maxConcurrentGroupRequests);
out.writeList(innerHits);
}
public static CollapseBuilder fromXContent(XContentParser parser) {
return PARSER.apply(parser, null);
}
// for object parser only
private CollapseBuilder setField(String field) {
if (Strings.isEmpty(field)) {
throw new IllegalArgumentException("field name is null or empty");
}
this.field = field;
return this;
}
public CollapseBuilder setInnerHits(InnerHitBuilder innerHit) {
this.innerHits = Collections.singletonList(innerHit);
return this;
}
public CollapseBuilder setInnerHits(List innerHits) {
this.innerHits = innerHits;
return this;
}
public CollapseBuilder setMaxConcurrentGroupRequests(int num) {
if (num < 1) {
throw new IllegalArgumentException("maxConcurrentGroupRequests` must be positive");
}
this.maxConcurrentGroupRequests = num;
return this;
}
/**
* The name of the field to collapse against
*/
public String getField() {
return this.field;
}
/**
* The inner hit options to expand the collapsed results
*/
public List getInnerHits() {
return this.innerHits;
}
/**
* Returns the amount of group requests that are allowed to be ran concurrently in the inner_hits phase.
*/
public int getMaxConcurrentGroupRequests() {
return maxConcurrentGroupRequests;
}
@Override
public XContentBuilder toXContent(XContentBuilder builder, ToXContent.Params params) throws IOException {
builder.startObject();
innerToXContent(builder);
builder.endObject();
return builder;
}
private void innerToXContent(XContentBuilder builder) throws IOException {
builder.field(FIELD_FIELD.getPreferredName(), field);
if (maxConcurrentGroupRequests > 0) {
builder.field(MAX_CONCURRENT_GROUP_REQUESTS_FIELD.getPreferredName(), maxConcurrentGroupRequests);
}
if (innerHits.isEmpty() == false) {
if (innerHits.size() == 1) {
builder.field(INNER_HITS_FIELD.getPreferredName(), innerHits.get(0));
} else {
builder.startArray(INNER_HITS_FIELD.getPreferredName());
for (InnerHitBuilder innerHit : innerHits) {
innerHit.toXContent(builder, ToXContent.EMPTY_PARAMS);
}
builder.endArray();
}
}
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
CollapseBuilder that = (CollapseBuilder) o;
if (maxConcurrentGroupRequests != that.maxConcurrentGroupRequests) return false;
if (!field.equals(that.field)) return false;
return Objects.equals(innerHits, that.innerHits);
}
@Override
public int hashCode() {
int result = Objects.hash(field, innerHits);
result = 31 * result + maxConcurrentGroupRequests;
return result;
}
public CollapseContext build(QueryShardContext queryShardContext) {
MappedFieldType fieldType = queryShardContext.fieldMapper(field);
if (fieldType == null) {
throw new IllegalArgumentException("no mapping found for `" + field + "` in order to collapse on");
}
if (fieldType instanceof KeywordFieldMapper.KeywordFieldType == false &&
fieldType instanceof NumberFieldMapper.NumberFieldType == false) {
throw new IllegalArgumentException("unknown type for collapse field `" + field +
"`, only keywords and numbers are accepted");
}
if (fieldType.hasDocValues() == false) {
throw new IllegalArgumentException("cannot collapse on field `" + field + "` without `doc_values`");
}
if (fieldType.indexOptions() == IndexOptions.NONE && (innerHits != null && !innerHits.isEmpty())) {
throw new IllegalArgumentException("cannot expand `inner_hits` for collapse field `"
+ field + "`, " + "only indexed field can retrieve `inner_hits`");
}
return new CollapseContext(field, fieldType, innerHits);
}
}