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* 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.
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package org.elasticsearch.search.aggregations.metrics.geocentroid;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.spatial.util.GeoEncodingUtils;
import org.elasticsearch.common.geo.GeoPoint;
import org.elasticsearch.common.lease.Releasables;
import org.elasticsearch.common.util.BigArrays;
import org.elasticsearch.common.util.LongArray;
import org.elasticsearch.index.fielddata.MultiGeoPointValues;
import org.elasticsearch.search.aggregations.Aggregator;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.search.aggregations.LeafBucketCollector;
import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
import org.elasticsearch.search.aggregations.metrics.MetricsAggregator;
import org.elasticsearch.search.aggregations.metrics.geobounds.InternalGeoBounds;
import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
import org.elasticsearch.search.aggregations.support.AggregationContext;
import org.elasticsearch.search.aggregations.support.ValuesSource;
import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
import java.io.IOException;
import java.util.List;
import java.util.Map;
/**
* A geo metric aggregator that computes a geo-centroid from a {@code geo_point} type field
*/
public final class GeoCentroidAggregator extends MetricsAggregator {
private final ValuesSource.GeoPoint valuesSource;
LongArray centroids;
LongArray counts;
protected GeoCentroidAggregator(String name, AggregationContext aggregationContext, Aggregator parent,
ValuesSource.GeoPoint valuesSource, List<PipelineAggregator> pipelineAggregators,
Map<String, Object> metaData) throws IOException {
super(name, aggregationContext, parent, pipelineAggregators, metaData);
this.valuesSource = valuesSource;
if (valuesSource != null) {
final BigArrays bigArrays = context.bigArrays();
centroids = bigArrays.newLongArray(1, true);
counts = bigArrays.newLongArray(1, true);
}
}
@Override
public LeafBucketCollector getLeafCollector(LeafReaderContext ctx, LeafBucketCollector sub) throws IOException {
if (valuesSource == null) {
return LeafBucketCollector.NO_OP_COLLECTOR;
}
final BigArrays bigArrays = context.bigArrays();
final MultiGeoPointValues values = valuesSource.geoPointValues(ctx);
return new LeafBucketCollectorBase(sub, values) {
@Override
public void collect(int doc, long bucket) throws IOException {
centroids = bigArrays.grow(centroids, bucket + 1);
counts = bigArrays.grow(counts, bucket + 1);
values.setDocument(doc);
final int valueCount = values.count();
if (valueCount > 0) {
double[] pt = new double[2];
// get the previously accumulated number of counts
long prevCounts = counts.get(bucket);
// increment by the number of points for this document
counts.increment(bucket, valueCount);
// get the previous GeoPoint if a moving avg was computed
if (prevCounts > 0) {
final GeoPoint centroid = GeoPoint.fromIndexLong(centroids.get(bucket));
pt[0] = centroid.lon();
pt[1] = centroid.lat();
}
// update the moving average
for (int i = 0; i < valueCount; ++i) {
GeoPoint value = values.valueAt(i);
pt[0] = pt[0] + (value.getLon() - pt[0]) / ++prevCounts;
pt[1] = pt[1] + (value.getLat() - pt[1]) / prevCounts;
}
centroids.set(bucket, GeoEncodingUtils.mortonHash(pt[0], pt[1]));
}
}
};
}
@Override
public InternalAggregation buildAggregation(long bucket) {
if (valuesSource == null || bucket >= centroids.size()) {
return buildEmptyAggregation();
}
final long bucketCount = counts.get(bucket);
final GeoPoint bucketCentroid = (bucketCount > 0) ? GeoPoint.fromIndexLong(centroids.get(bucket)) :
new GeoPoint(Double.NaN, Double.NaN);
return new InternalGeoCentroid(name, bucketCentroid , bucketCount, pipelineAggregators(), metaData());
}
@Override
public InternalAggregation buildEmptyAggregation() {
return new InternalGeoCentroid(name, null, 0l, pipelineAggregators(), metaData());
}
@Override
public void doClose() {
Releasables.close(centroids, counts);
}
public static class Factory extends ValuesSourceAggregatorFactory.LeafOnly<ValuesSource.GeoPoint> {
protected Factory(String name, ValuesSourceConfig<ValuesSource.GeoPoint> config) {
super(name, InternalGeoBounds.TYPE.name(), config);
}
@Override
protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent,
List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData) throws IOException {
return new GeoCentroidAggregator(name, aggregationContext, parent, null, pipelineAggregators, metaData);
}
@Override
protected Aggregator doCreateInternal(ValuesSource.GeoPoint valuesSource, AggregationContext aggregationContext, Aggregator parent,
boolean collectsFromSingleBucket, List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData)
throws IOException {
return new GeoCentroidAggregator(name, aggregationContext, parent, valuesSource, pipelineAggregators, metaData);
}
}
}