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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.search.aggregations.bucket;
import org.elasticsearch.common.collect.HppcMaps;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.search.aggregations.InternalAggregations;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
/**
* A base class for all the single bucket aggregations.
*/
public abstract class InternalSingleBucketAggregation extends InternalAggregation implements SingleBucketAggregation {
private long docCount;
private InternalAggregations aggregations;
protected InternalSingleBucketAggregation() {} // for serialization
/**
* Creates a single bucket aggregation.
*
* @param name The aggregation name.
* @param docCount The document count in the single bucket.
* @param aggregations The already built sub-aggregations that are associated with the bucket.
*/
protected InternalSingleBucketAggregation(String name, long docCount, InternalAggregations aggregations, Map<String, Object> metaData) {
super(name, metaData);
this.docCount = docCount;
this.aggregations = aggregations;
}
@Override
public long getDocCount() {
return docCount;
}
@Override
public InternalAggregations getAggregations() {
return aggregations;
}
/**
* Create a <b>new</b> empty sub aggregation. This must be a new instance on each call.
*/
protected abstract InternalSingleBucketAggregation newAggregation(String name, long docCount, InternalAggregations subAggregations);
@Override
public InternalAggregation reduce(ReduceContext reduceContext) {
List<InternalAggregation> aggregations = reduceContext.aggregations();
long docCount = 0L;
List<InternalAggregations> subAggregationsList = new ArrayList<>(aggregations.size());
for (InternalAggregation aggregation : aggregations) {
assert aggregation.getName().equals(getName());
docCount += ((InternalSingleBucketAggregation) aggregation).docCount;
subAggregationsList.add(((InternalSingleBucketAggregation) aggregation).aggregations);
}
final InternalAggregations aggs = InternalAggregations.reduce(subAggregationsList, reduceContext);
return newAggregation(getName(), docCount, aggs);
}
@Override
protected void doReadFrom(StreamInput in) throws IOException {
docCount = in.readVLong();
aggregations = InternalAggregations.readAggregations(in);
}
@Override
protected void doWriteTo(StreamOutput out) throws IOException {
out.writeVLong(docCount);
aggregations.writeTo(out);
}
@Override
public XContentBuilder doXContentBody(XContentBuilder builder, Params params) throws IOException {
builder.field(CommonFields.DOC_COUNT, docCount);
aggregations.toXContentInternal(builder, params);
return builder;
}
}