Github user rmetzger commented on a diff in the pull request: https://github.com/apache/flink/pull/605#discussion_r28575968 --- Diff: flink-core/src/main/java/org/apache/flink/statistics/OperatorStatistics.java --- @@ -0,0 +1,154 @@ +/* + * 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.flink.statistics; + +import com.clearspring.analytics.stream.cardinality.CardinalityMergeException; +import com.clearspring.analytics.stream.cardinality.HyperLogLog; +import com.clearspring.analytics.stream.cardinality.ICardinality; +import com.clearspring.analytics.stream.cardinality.LinearCounting; +import org.apache.flink.statistics.heavyhitters.IHeavyHitter; +import org.apache.flink.statistics.heavyhitters.LossyCounting; +import org.apache.flink.statistics.heavyhitters.CountMinHeavyHitter; +import org.apache.flink.statistics.heavyhitters.HeavyHitterMergeException; + +import java.io.Serializable; +import java.util.Map; + +/** + * Data structure that encapsulates statistical information of data that has only been processed by one pass + * This statistical information is meant to help determine the distribution of the data that has been processed + * in an operator so that we can determine if it is necessary to repartition the data + * + * The statistics to be gathered are configurable and represented by a {@link OperatorStatisticsConfig} object. + * + * The information encapsulated in this class is min, max, a structure enabling estimation of count distinct and a + * structure holding the heavy hitters along with their frequency. + * + */ +public class OperatorStatistics implements Serializable { + + OperatorStatisticsConfig config; + + Object min; + Object max; + ICardinality countDistinct; + IHeavyHitter heavyHitter; + long cardinality = 0; + + public OperatorStatistics(OperatorStatisticsConfig config) { + this.config = config; + if (config.countDistinctAlgorithm.equals(OperatorStatisticsConfig.CountDistinctAlgorithm.LINEAR_COUNTING)) { + countDistinct = new LinearCounting(OperatorStatisticsConfig.COUNTD_BITMAP_SIZE); + } + if(config.countDistinctAlgorithm.equals(OperatorStatisticsConfig.CountDistinctAlgorithm.HYPERLOGLOG)){ + countDistinct = new HyperLogLog(OperatorStatisticsConfig.COUNTD_LOG2M); + } + if (config.heavyHitterAlgorithm.equals(OperatorStatisticsConfig.HeavyHitterAlgorithm.LOSSY_COUNTING)){ + heavyHitter = + new LossyCounting(OperatorStatisticsConfig.HEAVY_HITTER_FRACTION, OperatorStatisticsConfig.HEAVY_HITTER_ERROR); + } + if (config.heavyHitterAlgorithm.equals(OperatorStatisticsConfig.HeavyHitterAlgorithm.COUNT_MIN_SKETCH)){ + heavyHitter = + new CountMinHeavyHitter(OperatorStatisticsConfig.HEAVY_HITTER_FRACTION, + OperatorStatisticsConfig.HEAVY_HITTER_ERROR, + OperatorStatisticsConfig.HEAVY_HITTER_CONFIDENCE, + OperatorStatisticsConfig.HEAVY_HITTER_SEED); + } + } + + public void process(Object tupleObject){ + if (tupleObject instanceof Comparable) { + if (config.collectMin && (min == null || ((Comparable) tupleObject).compareTo(min) < 0)) { + min = tupleObject; + } + if (config.collectMax && (max == null || ((Comparable) tupleObject).compareTo(max) > 0)) { + max = tupleObject; + } + } + if (config.collectCountDistinct){ + countDistinct.offer(tupleObject); + } + if (config.collectHeavyHitters){ + heavyHitter.addObject(tupleObject); + } + cardinality+=1; + } + + public void merge(OperatorStatistics other){ + + if (this.config.collectMin && ((Comparable)this.min).compareTo(other.min) > 0 ) { + this.min = other.min; + } + if (this.config.collectMax && ((Comparable)this.max).compareTo(other.max) < 0 ) { + this.max = other.max; + } + + try { + this.heavyHitter.merge(other.heavyHitter); + } catch (HeavyHitterMergeException e) { + e.printStackTrace(); + } + + try { + ICardinality mergedCountDistinct = this.countDistinct.merge(new ICardinality[]{this.countDistinct,other.countDistinct}); + this.countDistinct = mergedCountDistinct; + } catch (CardinalityMergeException e) { + e.printStackTrace(); --- End diff -- same here
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