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/*
* 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.apache.lucene.index.LeafReader;
import org.apache.lucene.index.PointValues;
import org.apache.lucene.search.CollectionTerminatedException;
import org.apache.lucene.search.ScoreMode;
import org.apache.lucene.util.Bits;
import org.elasticsearch.common.util.DoubleArray;
import org.elasticsearch.core.Releasables;
import org.elasticsearch.index.fielddata.NumericDoubleValues;
import org.elasticsearch.index.fielddata.SortedNumericDoubleValues;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.MultiValueMode;
import org.elasticsearch.search.aggregations.AggregationExecutionContext;
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.support.AggregationContext;
import org.elasticsearch.search.aggregations.support.ValuesSource;
import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
import java.io.IOException;
import java.util.Map;
import java.util.function.Function;
public class MinAggregator extends NumericMetricsAggregator.SingleValue {
private static final int MAX_BKD_LOOKUPS = 1024;
final ValuesSource.Numeric valuesSource;
final DocValueFormat format;
final String pointField;
final Function pointConverter;
DoubleArray mins;
MinAggregator(String name, ValuesSourceConfig config, AggregationContext context, Aggregator parent, Map metadata)
throws IOException {
super(name, context, parent, metadata);
assert config.hasValues();
this.valuesSource = (ValuesSource.Numeric) config.getValuesSource();
mins = context.bigArrays().newDoubleArray(1, false);
mins.fill(0, mins.size(), Double.POSITIVE_INFINITY);
this.format = config.format();
this.pointConverter = pointReaderIfAvailable(config);
if (pointConverter != null) {
pointField = config.fieldContext().field();
} else {
pointField = null;
}
}
@Override
public ScoreMode scoreMode() {
return valuesSource.needsScores() ? ScoreMode.COMPLETE : ScoreMode.COMPLETE_NO_SCORES;
}
@Override
public LeafBucketCollector getLeafCollector(AggregationExecutionContext aggCtx, final LeafBucketCollector sub) throws IOException {
if (pointConverter != null) {
Number segMin = findLeafMinValue(aggCtx.getLeafReaderContext().reader(), pointField, pointConverter);
if (segMin != null) {
/*
* There is no parent aggregator (see {@link MinAggregator#getPointReaderOrNull}
* so the ordinal for the bucket is always 0.
*/
double min = mins.get(0);
min = Math.min(min, segMin.doubleValue());
mins.set(0, min);
// the minimum value has been extracted, we don't need to collect hits on this segment.
return LeafBucketCollector.NO_OP_COLLECTOR;
}
}
final SortedNumericDoubleValues allValues = valuesSource.doubleValues(aggCtx.getLeafReaderContext());
final NumericDoubleValues values = MultiValueMode.MIN.select(allValues);
return new LeafBucketCollectorBase(sub, allValues) {
@Override
public void collect(int doc, long bucket) throws IOException {
if (bucket >= mins.size()) {
long from = mins.size();
mins = bigArrays().grow(mins, bucket + 1);
mins.fill(from, mins.size(), Double.POSITIVE_INFINITY);
}
if (values.advanceExact(doc)) {
final double value = values.doubleValue();
double min = mins.get(bucket);
min = Math.min(min, value);
mins.set(bucket, min);
}
}
};
}
@Override
public double metric(long owningBucketOrd) {
if (owningBucketOrd >= mins.size()) {
return Double.POSITIVE_INFINITY;
}
return mins.get(owningBucketOrd);
}
@Override
public InternalAggregation buildAggregation(long bucket) {
if (bucket >= mins.size()) {
return buildEmptyAggregation();
}
return new Min(name, mins.get(bucket), format, metadata());
}
@Override
public InternalAggregation buildEmptyAggregation() {
return Min.createEmptyMin(name, format, metadata());
}
@Override
public void doClose() {
Releasables.close(mins);
}
/**
* Returns the minimum value indexed in the fieldName
field or null
* if the value cannot be inferred from the indexed {@link PointValues}.
*/
static Number findLeafMinValue(LeafReader reader, String fieldName, Function converter) throws IOException {
final PointValues pointValues = reader.getPointValues(fieldName);
if (pointValues == null) {
return null;
}
final Bits liveDocs = reader.getLiveDocs();
if (liveDocs == null) {
return converter.apply(pointValues.getMinPackedValue());
}
final Number[] result = new Number[1];
try {
pointValues.intersect(new PointValues.IntersectVisitor() {
private short lookupCounter = 0;
@Override
public void visit(int docID) {
throw new UnsupportedOperationException();
}
@Override
public void visit(int docID, byte[] packedValue) {
if (liveDocs.get(docID)) {
result[0] = converter.apply(packedValue);
// this is the first leaf with a live doc so the value is the minimum for this segment.
throw new CollectionTerminatedException();
}
if (++lookupCounter > MAX_BKD_LOOKUPS) {
throw new CollectionTerminatedException();
}
}
@Override
public PointValues.Relation compare(byte[] minPackedValue, byte[] maxPackedValue) {
return PointValues.Relation.CELL_CROSSES_QUERY;
}
});
} catch (CollectionTerminatedException e) {}
return result[0];
}
}