bsyk commented on code in PR #15340: URL: https://github.com/apache/druid/pull/15340#discussion_r1443335975
########## extensions-contrib/spectator-histogram/src/main/java/org/apache/druid/spectator/histogram/SpectatorHistogramAggregatorFactory.java: ########## @@ -0,0 +1,373 @@ +/* + * 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.spectator.histogram; + +import com.fasterxml.jackson.annotation.JsonCreator; +import com.fasterxml.jackson.annotation.JsonProperty; +import com.fasterxml.jackson.annotation.JsonTypeName; +import org.apache.druid.query.aggregation.AggregateCombiner; +import org.apache.druid.query.aggregation.Aggregator; +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.BufferAggregator; +import org.apache.druid.query.aggregation.ObjectAggregateCombiner; +import org.apache.druid.query.cache.CacheKeyBuilder; +import org.apache.druid.segment.ColumnSelectorFactory; +import org.apache.druid.segment.ColumnValueSelector; +import org.apache.druid.segment.column.ValueType; + +import javax.annotation.Nonnull; +import javax.annotation.Nullable; +import java.util.Collections; +import java.util.Comparator; +import java.util.List; +import java.util.Objects; + +@JsonTypeName(SpectatorHistogramAggregatorFactory.TYPE_NAME) +public class SpectatorHistogramAggregatorFactory extends AggregatorFactory +{ + + @Nonnull + private final String name; + @Nonnull + private final String fieldName; + + @Nonnull + private final byte cacheTypeId; + + public static final String TYPE_NAME = "spectatorHistogram"; + + @JsonCreator + public SpectatorHistogramAggregatorFactory( + @JsonProperty("name") final String name, + @JsonProperty("fieldName") final String fieldName + ) + { + this(name, fieldName, AggregatorUtil.SPECTATOR_HISTOGRAM_CACHE_TYPE_ID); + } + + public SpectatorHistogramAggregatorFactory( + final String name, + final String fieldName, + final byte cacheTypeId + ) + { + this.name = Objects.requireNonNull(name, "Must have a valid, non-null aggregator name"); + this.fieldName = Objects.requireNonNull(fieldName, "Parameter fieldName must be specified"); + this.cacheTypeId = cacheTypeId; + } + + + @Override + public byte[] getCacheKey() + { + return new CacheKeyBuilder( + cacheTypeId + ).appendString(fieldName).build(); + } + + + @Override + public Aggregator factorize(ColumnSelectorFactory metricFactory) + { + return new SpectatorHistogramAggregator(metricFactory.makeColumnValueSelector(fieldName)); + } + + @Override + public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory) + { + return new SpectatorHistogramBufferAggregator(metricFactory.makeColumnValueSelector(fieldName)); + } + + // This is used when writing metrics to segment files to check whether the column is sorted. + // Since there is no sensible way really to compare histograms, compareTo always returns 1. + public static final Comparator<SpectatorHistogram> COMPARATOR = (o, o1) -> { + if (o == null && o1 == null) { + return 0; + } else if (o != null && o1 == null) { + return -1; + } else if (o == null) { + return 1; + } + return Integer.compare(o.hashCode(), o1.hashCode()); + }; + + @Override + public Comparator getComparator() + { + return COMPARATOR; + } + + @Override + public Object combine(@Nullable Object lhs, @Nullable Object rhs) + { + if (lhs == null) { + return rhs; + } + if (rhs == null) { + return lhs; + } + SpectatorHistogram lhsHisto = (SpectatorHistogram) lhs; + SpectatorHistogram rhsHisto = (SpectatorHistogram) rhs; + lhsHisto.merge(rhsHisto); + return lhsHisto; + } + + @Override + public AggregatorFactory getCombiningFactory() + { + return new SpectatorHistogramAggregatorFactory(name, name); + } + + @Override + public AggregatorFactory getMergingFactory(AggregatorFactory other) throws AggregatorFactoryNotMergeableException + { + if (other.getName().equals(this.getName()) && this.getClass() == other.getClass()) { + return getCombiningFactory(); + } else { + throw new AggregatorFactoryNotMergeableException(this, other); + } + } + + @Override + public List<AggregatorFactory> getRequiredColumns() + { + return Collections.singletonList( + new SpectatorHistogramAggregatorFactory( + fieldName, + fieldName + ) + ); + } + + @Override + public Object deserialize(Object serializedHistogram) + { + return SpectatorHistogram.deserialize(serializedHistogram); + } + + @Nullable + @Override + public Object finalizeComputation(@Nullable Object object) + { + return object; + } + + @Override + @JsonProperty + public String getName() + { + return name; + } + + @JsonProperty + public String getFieldName() + { + return fieldName; + } + + @Override + public List<String> requiredFields() + { + return Collections.singletonList(fieldName); + } + + @Override + public String getComplexTypeName() + { + return TYPE_NAME; + } + + @Override + public ValueType getType() + { + return ValueType.COMPLEX; + } + + @Override + public ValueType getFinalizedType() + { + return ValueType.COMPLEX; + } + + @Override + public int getMaxIntermediateSize() + { + return SpectatorHistogram.getMaxIntermdiateHistogramSize(); + } + + @Override + public AggregateCombiner makeAggregateCombiner() + { + return new ObjectAggregateCombiner<SpectatorHistogram>() + { + private SpectatorHistogram combined = null; + + @Override + public void reset(final ColumnValueSelector selector) + { + combined = null; + fold(selector); + } + + @Override + public void fold(final ColumnValueSelector selector) + { + SpectatorHistogram other = (SpectatorHistogram) selector.getObject(); + if (other == null) { + return; + } + if (combined == null) { + combined = new SpectatorHistogram(); + } + combined.merge(other); + } + + @Nullable + @Override + public SpectatorHistogram getObject() + { + return combined; + } + + @Override + public Class<SpectatorHistogram> classOfObject() + { + return SpectatorHistogram.class; + } + }; + } + + @Override + public boolean equals(final Object o) + { + if (this == o) { + return true; + } + if (o == null || !getClass().equals(o.getClass())) { + return false; + } + final SpectatorHistogramAggregatorFactory that = (SpectatorHistogramAggregatorFactory) o; + + //TODO: samarth should we check for equality of contents in count arrays? Review Comment: This was left over from an earlier implementation and no longer relevant. -- 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]
