| /* |
| * 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.wayang.spark.operators; |
| |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Optional; |
| import org.apache.spark.api.java.JavaPairRDD; |
| import org.apache.spark.api.java.JavaRDD; |
| import org.apache.spark.api.java.function.Function; |
| import org.apache.spark.api.java.function.Function2; |
| import org.apache.spark.api.java.function.PairFunction; |
| import org.apache.wayang.basic.operators.ReduceByOperator; |
| import org.apache.wayang.core.api.Configuration; |
| import org.apache.wayang.core.function.ReduceDescriptor; |
| import org.apache.wayang.core.function.TransformationDescriptor; |
| import org.apache.wayang.core.optimizer.OptimizationContext; |
| import org.apache.wayang.core.optimizer.costs.LoadProfileEstimator; |
| import org.apache.wayang.core.optimizer.costs.LoadProfileEstimators; |
| import org.apache.wayang.core.plan.wayangplan.ExecutionOperator; |
| import org.apache.wayang.core.platform.ChannelDescriptor; |
| import org.apache.wayang.core.platform.ChannelInstance; |
| import org.apache.wayang.core.platform.lineage.ExecutionLineageNode; |
| import org.apache.wayang.core.types.DataSetType; |
| import org.apache.wayang.core.util.Tuple; |
| import org.apache.wayang.spark.channels.BroadcastChannel; |
| import org.apache.wayang.spark.channels.RddChannel; |
| import org.apache.wayang.spark.execution.SparkExecutor; |
| |
| /** |
| * Spark implementation of the {@link ReduceByOperator}. |
| */ |
| public class SparkReduceByOperator<Type, KeyType> |
| extends ReduceByOperator<Type, KeyType> |
| implements SparkExecutionOperator { |
| |
| |
| /** |
| * Creates a new instance. |
| * |
| * @param type type of the reduce elements (i.e., type of {@link #getInput()} and {@link #getOutput()}) |
| * @param keyDescriptor describes how to extract the key from data units |
| * @param reduceDescriptor describes the reduction to be performed on the elements |
| */ |
| public SparkReduceByOperator(DataSetType<Type> type, TransformationDescriptor<Type, KeyType> keyDescriptor, |
| ReduceDescriptor<Type> reduceDescriptor) { |
| super(keyDescriptor, reduceDescriptor, type); |
| } |
| |
| /** |
| * Copies an instance (exclusive of broadcasts). |
| * |
| * @param that that should be copied |
| */ |
| public SparkReduceByOperator(ReduceByOperator<Type, KeyType> that) { |
| super(that); |
| } |
| |
| @Override |
| public Tuple<Collection<ExecutionLineageNode>, Collection<ChannelInstance>> evaluate( |
| ChannelInstance[] inputs, |
| ChannelInstance[] outputs, |
| SparkExecutor sparkExecutor, |
| OptimizationContext.OperatorContext operatorContext) { |
| assert inputs.length == this.getNumInputs(); |
| assert outputs.length == this.getNumOutputs(); |
| |
| RddChannel.Instance input = (RddChannel.Instance) inputs[0]; |
| RddChannel.Instance output = (RddChannel.Instance) outputs[0]; |
| |
| final JavaRDD<Type> inputStream = input.provideRdd(); |
| final PairFunction<Type, KeyType, Type> keyExtractor = |
| sparkExecutor.getCompiler().compileToKeyExtractor(this.keyDescriptor); |
| Function2<Type, Type, Type> reduceFunc = |
| sparkExecutor.getCompiler().compile(this.reduceDescriptor, this, operatorContext, inputs); |
| final JavaPairRDD<KeyType, Type> pairRdd = inputStream.mapToPair(keyExtractor); |
| this.name(pairRdd); |
| final JavaPairRDD<KeyType, Type> reducedPairRdd = |
| pairRdd.reduceByKey(reduceFunc, sparkExecutor.getNumDefaultPartitions()); |
| this.name(reducedPairRdd); |
| final JavaRDD<Type> outputRdd = reducedPairRdd.map(new TupleConverter<>()); |
| this.name(outputRdd); |
| |
| output.accept(outputRdd, sparkExecutor); |
| |
| return ExecutionOperator.modelLazyExecution(inputs, outputs, operatorContext); |
| } |
| |
| @Override |
| protected ExecutionOperator createCopy() { |
| return new SparkReduceByOperator<>(this.getType(), this.getKeyDescriptor(), this.getReduceDescriptor()); |
| } |
| |
| /** |
| * Extracts the value from a {@link scala.Tuple2}. |
| * <p><i>TODO: See, if we can somehow dodge all this conversion, which is likely to happen a lot.</i></p> |
| */ |
| private static class TupleConverter<InputType, KeyType> |
| implements Function<scala.Tuple2<KeyType, InputType>, InputType> { |
| |
| @Override |
| public InputType call(scala.Tuple2<KeyType, InputType> scalaTuple) throws Exception { |
| return scalaTuple._2; |
| } |
| } |
| |
| @Override |
| public String getLoadProfileEstimatorConfigurationKey() { |
| return "wayang.spark.reduceby.load"; |
| } |
| |
| @Override |
| public Optional<LoadProfileEstimator> createLoadProfileEstimator(Configuration configuration) { |
| final Optional<LoadProfileEstimator> optEstimator = |
| SparkExecutionOperator.super.createLoadProfileEstimator(configuration); |
| LoadProfileEstimators.nestUdfEstimator(optEstimator, this.keyDescriptor, configuration); |
| LoadProfileEstimators.nestUdfEstimator(optEstimator, this.reduceDescriptor, configuration); |
| return optEstimator; |
| } |
| |
| @Override |
| public List<ChannelDescriptor> getSupportedInputChannels(int index) { |
| if (index == 0) { |
| return Arrays.asList(RddChannel.UNCACHED_DESCRIPTOR, RddChannel.CACHED_DESCRIPTOR); |
| } else { |
| return Collections.singletonList(BroadcastChannel.DESCRIPTOR); |
| } |
| } |
| |
| @Override |
| public List<ChannelDescriptor> getSupportedOutputChannels(int index) { |
| assert index <= this.getNumOutputs() || (index == 0 && this.getNumOutputs() == 0); |
| return Collections.singletonList(RddChannel.UNCACHED_DESCRIPTOR); |
| } |
| |
| @Override |
| public boolean containsAction() { |
| return false; |
| } |
| |
| } |