| /* |
| * 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.beam.runners.flink.translation.functions; |
| |
| import java.util.Map; |
| import org.apache.beam.runners.core.construction.SerializablePipelineOptions; |
| import org.apache.beam.sdk.io.FileSystems; |
| import org.apache.beam.sdk.options.PipelineOptions; |
| import org.apache.beam.sdk.transforms.CombineFnBase; |
| import org.apache.beam.sdk.transforms.windowing.BoundedWindow; |
| import org.apache.beam.sdk.transforms.windowing.IntervalWindow; |
| import org.apache.beam.sdk.util.WindowedValue; |
| import org.apache.beam.sdk.values.KV; |
| import org.apache.beam.sdk.values.PCollectionView; |
| import org.apache.beam.sdk.values.WindowingStrategy; |
| import org.apache.flink.api.common.functions.RichGroupReduceFunction; |
| import org.apache.flink.configuration.Configuration; |
| import org.apache.flink.util.Collector; |
| |
| /** |
| * This is the second part for executing a {@link org.apache.beam.sdk.transforms.Combine.PerKey} on |
| * Flink, the second part is {@link FlinkReduceFunction}. This function performs the final |
| * combination of the pre-combined values after a shuffle. |
| * |
| * <p>The input to {@link #reduce(Iterable, Collector)} are elements of the same key but for |
| * different windows. We have to ensure that we only combine elements of matching windows. |
| */ |
| public class FlinkReduceFunction<K, AccumT, OutputT, W extends BoundedWindow> |
| extends RichGroupReduceFunction<WindowedValue<KV<K, AccumT>>, WindowedValue<KV<K, OutputT>>> { |
| |
| protected final CombineFnBase.GlobalCombineFn<?, AccumT, OutputT> combineFn; |
| |
| protected final WindowingStrategy<Object, W> windowingStrategy; |
| |
| // TODO: Remove side input functionality since liftable Combines no longer have side inputs. |
| protected final Map<PCollectionView<?>, WindowingStrategy<?, ?>> sideInputs; |
| |
| protected final SerializablePipelineOptions serializedOptions; |
| |
| public FlinkReduceFunction( |
| CombineFnBase.GlobalCombineFn<?, AccumT, OutputT> combineFn, |
| WindowingStrategy<Object, W> windowingStrategy, |
| Map<PCollectionView<?>, WindowingStrategy<?, ?>> sideInputs, |
| PipelineOptions pipelineOptions) { |
| |
| this.combineFn = combineFn; |
| |
| this.windowingStrategy = windowingStrategy; |
| this.sideInputs = sideInputs; |
| |
| this.serializedOptions = new SerializablePipelineOptions(pipelineOptions); |
| } |
| |
| @Override |
| public void open(Configuration parameters) { |
| // Initialize FileSystems for any coders which may want to use the FileSystem, |
| // see https://issues.apache.org/jira/browse/BEAM-8303 |
| FileSystems.setDefaultPipelineOptions(serializedOptions.get()); |
| } |
| |
| @Override |
| public void reduce( |
| Iterable<WindowedValue<KV<K, AccumT>>> elements, Collector<WindowedValue<KV<K, OutputT>>> out) |
| throws Exception { |
| |
| PipelineOptions options = serializedOptions.get(); |
| |
| FlinkSideInputReader sideInputReader = |
| new FlinkSideInputReader(sideInputs, getRuntimeContext()); |
| |
| AbstractFlinkCombineRunner<K, AccumT, AccumT, OutputT, W> reduceRunner; |
| |
| if (!windowingStrategy.getWindowFn().isNonMerging() |
| && !windowingStrategy.getWindowFn().windowCoder().equals(IntervalWindow.getCoder())) { |
| reduceRunner = new HashingFlinkCombineRunner<>(); |
| } else { |
| reduceRunner = new SortingFlinkCombineRunner<>(); |
| } |
| reduceRunner.combine( |
| new AbstractFlinkCombineRunner.FinalFlinkCombiner<>(combineFn), |
| windowingStrategy, |
| sideInputReader, |
| options, |
| elements, |
| out); |
| } |
| } |