| /* |
| * 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.ArrayList; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import org.apache.beam.runners.core.SideInputReader; |
| import org.apache.beam.sdk.options.PipelineOptions; |
| import org.apache.beam.sdk.transforms.windowing.BoundedWindow; |
| import org.apache.beam.sdk.transforms.windowing.PaneInfo; |
| import org.apache.beam.sdk.transforms.windowing.TimestampCombiner; |
| import org.apache.beam.sdk.transforms.windowing.WindowFn; |
| import org.apache.beam.sdk.util.WindowedValue; |
| import org.apache.beam.sdk.values.KV; |
| import org.apache.beam.sdk.values.WindowingStrategy; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.Iterables; |
| import org.apache.flink.api.java.tuple.Tuple2; |
| import org.apache.flink.util.Collector; |
| import org.joda.time.Instant; |
| |
| /** |
| * A Flink combine runner that builds a map of merged windows and produces output after seeing all |
| * input. This is similar to what{@link org.apache.beam.runners.core.ReduceFnRunner} does. |
| */ |
| public class HashingFlinkCombineRunner<K, InputT, AccumT, OutputT, W extends BoundedWindow> |
| extends AbstractFlinkCombineRunner<K, InputT, AccumT, OutputT, W> { |
| |
| @Override |
| public void combine( |
| FlinkCombiner<K, InputT, AccumT, OutputT> flinkCombiner, |
| WindowingStrategy<Object, W> windowingStrategy, |
| SideInputReader sideInputReader, |
| PipelineOptions options, |
| Iterable<WindowedValue<KV<K, InputT>>> elements, |
| Collector<WindowedValue<KV<K, OutputT>>> out) |
| throws Exception { |
| |
| @SuppressWarnings("unchecked") |
| TimestampCombiner timestampCombiner = windowingStrategy.getTimestampCombiner(); |
| WindowFn<Object, W> windowFn = windowingStrategy.getWindowFn(); |
| |
| // Flink Iterable can be iterated over only once. |
| List<WindowedValue<KV<K, InputT>>> inputs = new ArrayList<>(); |
| Iterables.addAll(inputs, elements); |
| |
| Set<W> windows = collectWindows(inputs); |
| Map<W, W> windowToMergeResult = mergeWindows(windowingStrategy, windows); |
| |
| // Combine all windowedValues into map |
| Map<W, Tuple2<AccumT, Instant>> mapState = new HashMap<>(); |
| Iterator<WindowedValue<KV<K, InputT>>> iterator = inputs.iterator(); |
| WindowedValue<KV<K, InputT>> currentValue = iterator.next(); |
| K key = currentValue.getValue().getKey(); |
| do { |
| for (BoundedWindow w : currentValue.getWindows()) { |
| @SuppressWarnings("unchecked") |
| W currentWindow = (W) w; |
| W mergedWindow = windowToMergeResult.get(currentWindow); |
| mergedWindow = mergedWindow == null ? currentWindow : mergedWindow; |
| Set<W> singletonW = Collections.singleton(mergedWindow); |
| Tuple2<AccumT, Instant> accumAndInstant = mapState.get(mergedWindow); |
| if (accumAndInstant == null) { |
| AccumT accumT = |
| flinkCombiner.firstInput( |
| key, currentValue.getValue().getValue(), options, sideInputReader, singletonW); |
| Instant windowTimestamp = |
| timestampCombiner.assign( |
| mergedWindow, windowFn.getOutputTime(currentValue.getTimestamp(), mergedWindow)); |
| accumAndInstant = new Tuple2<>(accumT, windowTimestamp); |
| mapState.put(mergedWindow, accumAndInstant); |
| } else { |
| accumAndInstant.f0 = |
| flinkCombiner.addInput( |
| key, |
| accumAndInstant.f0, |
| currentValue.getValue().getValue(), |
| options, |
| sideInputReader, |
| singletonW); |
| accumAndInstant.f1 = |
| timestampCombiner.combine( |
| accumAndInstant.f1, |
| timestampCombiner.assign( |
| mergedWindow, |
| windowingStrategy |
| .getWindowFn() |
| .getOutputTime(currentValue.getTimestamp(), mergedWindow))); |
| } |
| } |
| if (iterator.hasNext()) { |
| currentValue = iterator.next(); |
| } else { |
| break; |
| } |
| } while (true); |
| |
| // Output the final value of combiners |
| for (Map.Entry<W, Tuple2<AccumT, Instant>> entry : mapState.entrySet()) { |
| AccumT accumulator = entry.getValue().f0; |
| Instant windowTimestamp = entry.getValue().f1; |
| out.collect( |
| WindowedValue.of( |
| KV.of( |
| key, |
| flinkCombiner.extractOutput( |
| key, |
| accumulator, |
| options, |
| sideInputReader, |
| Collections.singleton(entry.getKey()))), |
| windowTimestamp, |
| entry.getKey(), |
| PaneInfo.NO_FIRING)); |
| } |
| } |
| |
| private Map<W, W> mergeWindows(WindowingStrategy<Object, W> windowingStrategy, Set<W> windows) |
| throws Exception { |
| WindowFn<Object, W> windowFn = windowingStrategy.getWindowFn(); |
| |
| if (windowingStrategy.getWindowFn().isNonMerging()) { |
| // Return an empty map, indicating that every window is not merged. |
| return Collections.emptyMap(); |
| } |
| |
| Map<W, W> windowToMergeResult = new HashMap<>(); |
| windowFn.mergeWindows(new MergeContextImpl(windowFn, windows, windowToMergeResult)); |
| return windowToMergeResult; |
| } |
| |
| private class MergeContextImpl extends WindowFn<Object, W>.MergeContext { |
| |
| private Set<W> windows; |
| private Map<W, W> windowToMergeResult; |
| |
| MergeContextImpl(WindowFn<Object, W> windowFn, Set<W> windows, Map<W, W> windowToMergeResult) { |
| windowFn.super(); |
| this.windows = windows; |
| this.windowToMergeResult = windowToMergeResult; |
| } |
| |
| @Override |
| public Collection<W> windows() { |
| return windows; |
| } |
| |
| @Override |
| public void merge(Collection<W> toBeMerged, W mergeResult) throws Exception { |
| for (W w : toBeMerged) { |
| windowToMergeResult.put(w, mergeResult); |
| } |
| } |
| } |
| |
| private Set<W> collectWindows(Iterable<WindowedValue<KV<K, InputT>>> values) { |
| Set<W> windows = new HashSet<>(); |
| for (WindowedValue<?> value : values) { |
| for (BoundedWindow untypedWindow : value.getWindows()) { |
| @SuppressWarnings("unchecked") |
| W window = (W) untypedWindow; |
| windows.add(window); |
| } |
| } |
| return windows; |
| } |
| } |