/*
* 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.metrics.percentiles.tdigest;
import com.tdunning.math.stats.AVLTreeDigest;
import com.tdunning.math.stats.Centroid;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import java.io.IOException;
/**
* Extension of {@link com.tdunning.math.stats.TDigest} with custom serialization.
*/
public class TDigestState extends AVLTreeDigest {
private final double compression;
public TDigestState(double compression) {
super(compression);
this.compression = compression;
}
@Override
public double compression() {
return compression;
}
public static void write(TDigestState state, StreamOutput out) throws IOException {
out.writeDouble(state.compression);
out.writeVInt(state.centroidCount());
for (Centroid centroid : state.centroids()) {
out.writeDouble(centroid.mean());
out.writeVLong(centroid.count());
}
}
public static TDigestState read(StreamInput in) throws IOException {
double compression = in.readDouble();
TDigestState state = new TDigestState(compression);
int n = in.readVInt();
for (int i = 0; i < n; i++) {
state.add(in.readDouble(), in.readVInt());
}
return state;
}
}