| /* |
| * 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.java.operators; |
| |
| import org.apache.wayang.basic.operators.SampleOperator; |
| import org.apache.wayang.core.function.FunctionDescriptor; |
| import org.apache.wayang.core.optimizer.OptimizationContext; |
| 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.java.channels.CollectionChannel; |
| import org.apache.wayang.java.channels.JavaChannelInstance; |
| import org.apache.wayang.java.channels.StreamChannel; |
| import org.apache.wayang.java.execution.JavaExecutor; |
| |
| import java.util.Arrays; |
| import java.util.BitSet; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Random; |
| import java.util.function.IntUnaryOperator; |
| import java.util.function.LongUnaryOperator; |
| import java.util.function.Predicate; |
| |
| /** |
| * Java implementation of the {@link JavaRandomSampleOperator}. This sampling method is with replacement (i.e., duplicates may appear in the sample). |
| */ |
| public class JavaRandomSampleOperator<Type> |
| extends SampleOperator<Type> |
| implements JavaExecutionOperator { |
| |
| private Random rand; |
| |
| /** |
| * Creates a new instance. |
| * |
| * @param sampleSizeFunction udf-based size of sample |
| */ |
| public JavaRandomSampleOperator(FunctionDescriptor.SerializableIntUnaryOperator sampleSizeFunction, DataSetType<Type> type, FunctionDescriptor.SerializableLongUnaryOperator seedFunction) { |
| super(sampleSizeFunction, type, Methods.RANDOM, seedFunction); |
| } |
| |
| /** |
| * Copies an instance (exclusive of broadcasts). |
| * |
| * @param that that should be copied |
| */ |
| public JavaRandomSampleOperator(SampleOperator<Type> that) { |
| super(that); |
| } |
| |
| @Override |
| @SuppressWarnings("unchecked") |
| public Tuple<Collection<ExecutionLineageNode>, Collection<ChannelInstance>> evaluate( |
| ChannelInstance[] inputs, |
| ChannelInstance[] outputs, |
| JavaExecutor javaExecutor, |
| OptimizationContext.OperatorContext operatorContext) { |
| assert inputs.length == this.getNumInputs(); |
| assert outputs.length == this.getNumOutputs(); |
| |
| |
| Integer sampleSize = (Integer) this.getSampleSize(operatorContext); |
| Long datasetSize = this.isDataSetSizeKnown() ? this.getDatasetSize() : |
| ((CollectionChannel.Instance) inputs[0]).provideCollection().size(); |
| |
| if (sampleSize >= datasetSize) { //return all |
| ((StreamChannel.Instance) outputs[0]).accept(((JavaChannelInstance) inputs[0]).provideStream()); |
| } |
| else { |
| long seed = this.getSeed(operatorContext); |
| rand = new Random(seed); |
| |
| final int[] sampleIndices = new int[sampleSize]; |
| final BitSet data = new BitSet(); |
| for (int i = 0; i < sampleSize; i++) { |
| sampleIndices[i] = rand.nextInt(datasetSize.intValue()); |
| while (data.get(sampleIndices[i])) //without replacement |
| sampleIndices[i] = rand.nextInt(datasetSize.intValue()); |
| data.set(sampleIndices[i]); |
| } |
| Arrays.sort(sampleIndices); |
| |
| ((StreamChannel.Instance) outputs[0]).accept(((JavaChannelInstance) inputs[0]).<Type>provideStream().filter(new Predicate<Type>() { |
| int streamIndex = 0; |
| int sampleIndex = 0; |
| |
| @Override |
| public boolean test(Type element) { |
| if (sampleIndex == sampleIndices.length) //we already picked all our samples |
| return false; |
| if (streamIndex == sampleIndices[sampleIndex]) { |
| sampleIndex++; |
| streamIndex++; |
| return true; |
| } |
| streamIndex++; |
| return false; |
| } |
| }) |
| ); |
| } |
| |
| return ExecutionOperator.modelLazyExecution(inputs, outputs, operatorContext); |
| } |
| |
| @Override |
| public Collection<String> getLoadProfileEstimatorConfigurationKeys() { |
| return Collections.singletonList("wayang.java.random-sample.load"); |
| } |
| |
| @Override |
| protected ExecutionOperator createCopy() { |
| return new JavaRandomSampleOperator<>(this); |
| } |
| |
| |
| @Override |
| public List<ChannelDescriptor> getSupportedInputChannels(int index) { |
| assert index <= this.getNumInputs() || (index == 0 && this.getNumInputs() == 0); |
| return this.isDataSetSizeKnown() ? |
| Arrays.asList(CollectionChannel.DESCRIPTOR, StreamChannel.DESCRIPTOR) : |
| Collections.singletonList(CollectionChannel.DESCRIPTOR); |
| |
| } |
| |
| @Override |
| public List<ChannelDescriptor> getSupportedOutputChannels(int index) { |
| assert index <= this.getNumOutputs() || (index == 0 && this.getNumOutputs() == 0); |
| return Collections.singletonList(StreamChannel.DESCRIPTOR); |
| } |
| |
| } |