gianm commented on code in PR #12498: URL: https://github.com/apache/druid/pull/12498#discussion_r943081979
########## extensions-core/datasketches/src/main/java/org/apache/druid/query/aggregation/datasketches/kll/KllFloatsSketchAggregatorFactory.java: ########## @@ -0,0 +1,234 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF 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.apache.druid.query.aggregation.datasketches.kll; + +import com.fasterxml.jackson.annotation.JsonCreator; +import com.fasterxml.jackson.annotation.JsonProperty; +import org.apache.datasketches.kll.KllFloatsSketch; +import org.apache.druid.query.aggregation.AggregatorFactory; +import org.apache.druid.query.aggregation.AggregatorFactoryNotMergeableException; +import org.apache.druid.query.aggregation.AggregatorUtil; +import org.apache.druid.query.aggregation.VectorAggregator; +import org.apache.druid.segment.ColumnProcessors; +import org.apache.druid.segment.ColumnValueSelector; +import org.apache.druid.segment.VectorColumnProcessorFactory; +import org.apache.druid.segment.column.ColumnCapabilities; +import org.apache.druid.segment.column.ColumnType; +import org.apache.druid.segment.vector.MultiValueDimensionVectorSelector; +import org.apache.druid.segment.vector.SingleValueDimensionVectorSelector; +import org.apache.druid.segment.vector.VectorColumnSelectorFactory; +import org.apache.druid.segment.vector.VectorObjectSelector; +import org.apache.druid.segment.vector.VectorValueSelector; + +import javax.annotation.Nullable; +import java.util.Collections; +import java.util.Comparator; +import java.util.List; + +public class KllFloatsSketchAggregatorFactory extends KllSketchAggregatorFactory<KllFloatsSketch, Float> +{ + public static final Comparator<KllFloatsSketch> COMPARATOR = + Comparator.nullsFirst(Comparator.comparingLong(KllFloatsSketch::getN)); + + @JsonCreator + public KllFloatsSketchAggregatorFactory( + @JsonProperty("name") final String name, + @JsonProperty("fieldName") final String fieldName, + @JsonProperty("k") @Nullable final Integer k, + @JsonProperty("maxStreamLength") @Nullable final Long maxStreamLength + ) + { + this(name, fieldName, k, maxStreamLength, AggregatorUtil.KLL_FLOATS_SKETCH_BUILD_CACHE_TYPE_ID); + } + + KllFloatsSketchAggregatorFactory( + final String name, + final String fieldName, + @Nullable final Integer k, + @Nullable final Long maxStreamLength, + final byte cacheTypeId + ) + { + super( + name, + fieldName, + k, + maxStreamLength, + cacheTypeId + ); + } + + @Override + public Comparator<KllFloatsSketch> getComparator() + { + return COMPARATOR; + } + + @Override + public List<AggregatorFactory> getRequiredColumns() + { + return Collections.singletonList( + new KllFloatsSketchAggregatorFactory( + getFieldName(), + getFieldName(), + getK(), + getMaxStreamLength() + ) + ); + } + + @Override + public AggregatorFactory getMergingFactory(final AggregatorFactory other) + throws AggregatorFactoryNotMergeableException + { + if (other.getName().equals(this.getName()) && other instanceof KllFloatsSketchAggregatorFactory) { + // KllSketch supports merging with different k. + // The result will have effective k between the specified k and the minimum k from all input sketches + // to achieve higher accuracy as much as possible. + return new KllFloatsSketchMergeAggregatorFactory( + getName(), + Math.max(getK(), ((KllFloatsSketchAggregatorFactory) other).getK()), + getMaxStreamLength() Review Comment: Thanks for letting us know. We took long enough to review this, so we can certainly wait a week to continue the conversation. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
