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Elasticsearch subproject :server
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.search.aggregations.metrics;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.aggregations.InternalAggregation;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.Objects;
public class InternalWeightedAvg extends InternalNumericMetricsAggregation.SingleValue implements WeightedAvg {
private final double sum;
private final double weight;
InternalWeightedAvg(String name, double sum, double weight, DocValueFormat format, Map metadata) {
super(name, metadata);
this.sum = sum;
this.weight = weight;
this.format = format;
}
/**
* Read from a stream.
*/
public InternalWeightedAvg(StreamInput in) throws IOException {
super(in);
format = in.readNamedWriteable(DocValueFormat.class);
sum = in.readDouble();
weight = in.readDouble();
}
@Override
protected void doWriteTo(StreamOutput out) throws IOException {
out.writeNamedWriteable(format);
out.writeDouble(sum);
out.writeDouble(weight);
}
@Override
public double value() {
return getValue();
}
@Override
public double getValue() {
return sum / weight;
}
double getSum() {
return sum;
}
double getWeight() {
return weight;
}
DocValueFormat getFormatter() {
return format;
}
@Override
public String getWriteableName() {
return WeightedAvgAggregationBuilder.NAME;
}
@Override
public InternalWeightedAvg reduce(List aggregations, ReduceContext reduceContext) {
CompensatedSum sumCompensation = new CompensatedSum(0, 0);
CompensatedSum weightCompensation = new CompensatedSum(0, 0);
// Compute the sum of double values with Kahan summation algorithm which is more
// accurate than naive summation.
for (InternalAggregation aggregation : aggregations) {
InternalWeightedAvg avg = (InternalWeightedAvg) aggregation;
weightCompensation.add(avg.weight);
sumCompensation.add(avg.sum);
}
return new InternalWeightedAvg(getName(), sumCompensation.value(), weightCompensation.value(), format, getMetadata());
}
@Override
public XContentBuilder doXContentBody(XContentBuilder builder, Params params) throws IOException {
builder.field(CommonFields.VALUE.getPreferredName(), weight != 0 ? getValue() : null);
if (weight != 0 && format != DocValueFormat.RAW) {
builder.field(CommonFields.VALUE_AS_STRING.getPreferredName(), format.format(getValue()));
}
return builder;
}
@Override
public int hashCode() {
return Objects.hash(super.hashCode(), sum, weight, format.getWriteableName());
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (obj == null || getClass() != obj.getClass()) return false;
if (super.equals(obj) == false) return false;
InternalWeightedAvg other = (InternalWeightedAvg) obj;
return Objects.equals(sum, other.sum) &&
Objects.equals(weight, other.weight) &&
Objects.equals(format.getWriteableName(), other.format.getWriteableName());
}
}