jon-wei commented on a change in pull request #8487: Add initial SQL support for non-expression sketch postaggs URL: https://github.com/apache/incubator-druid/pull/8487#discussion_r335718002
########## File path: extensions-core/datasketches/src/main/java/org/apache/druid/query/aggregation/datasketches/hll/HllSketchToEstimatePostAggregator.java ########## @@ -0,0 +1,135 @@ +/* + * 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.hll; + +import com.fasterxml.jackson.annotation.JsonCreator; +import com.fasterxml.jackson.annotation.JsonProperty; +import com.yahoo.sketches.hll.HllSketch; +import org.apache.druid.query.aggregation.AggregatorFactory; +import org.apache.druid.query.aggregation.PostAggregator; +import org.apache.druid.query.aggregation.post.ArithmeticPostAggregator; +import org.apache.druid.query.aggregation.post.PostAggregatorIds; +import org.apache.druid.query.cache.CacheKeyBuilder; + +import java.util.Comparator; +import java.util.Map; +import java.util.Objects; +import java.util.Set; + +/** + * Returns a distinct count estimate a from a given {@link HllSketch}. + * The result will be a double value. + */ +public class HllSketchToEstimatePostAggregator implements PostAggregator +{ + private final String name; + private final PostAggregator field; + + @JsonCreator + public HllSketchToEstimatePostAggregator( + @JsonProperty("name") final String name, + @JsonProperty("field") final PostAggregator field + ) + { + this.name = name; + this.field = field; + } + + @Override + @JsonProperty + public String getName() + { + return name; + } + + @JsonProperty + public PostAggregator getField() + { + return field; + } + + @Override + public Set<String> getDependentFields() + { + return field.getDependentFields(); + } + + @Override + public Comparator<Double> getComparator() + { + return ArithmeticPostAggregator.DEFAULT_COMPARATOR; + } + + @Override + public Object compute(final Map<String, Object> combinedAggregators) + { + final HllSketch sketch = (HllSketch) field.compute(combinedAggregators); + return sketch.getEstimate(); + } + + @Override + public PostAggregator decorate(final Map<String, AggregatorFactory> aggregators) + { + return this; + } + + @Override + public String toString() + { + return getClass().getSimpleName() + "{" + + "name='" + name + '\'' + + ", field=" + field + + "}"; + } + + @Override + public boolean equals(final Object o) + { + if (this == o) { + return true; + } + if (!(o instanceof HllSketchToEstimatePostAggregator)) { + return false; + } + + final HllSketchToEstimatePostAggregator that = (HllSketchToEstimatePostAggregator) o; + + if (!name.equals(that.name)) { + return false; + } + return field.equals(that.field); + } + + @Override + public int hashCode() + { + return Objects.hash(name, field); + } + + @Override + public byte[] getCacheKey() + { + return new CacheKeyBuilder(PostAggregatorIds.HLL_SKETCH_TO_ESTIMATE_CACHE_TYPE_ID) + .appendString(name) Review comment: Removed, thanks ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@druid.apache.org For additional commands, e-mail: commits-h...@druid.apache.org
