tkaymak commented on code in PR #38255: URL: https://github.com/apache/beam/pull/38255#discussion_r3122585749
########## runners/spark/4/src/main/java/org/apache/beam/runners/spark/structuredstreaming/translation/batch/GroupByKeyHelpers.java: ########## @@ -0,0 +1,107 @@ +/* + * 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.spark.structuredstreaming.translation.batch; + +import static org.apache.beam.runners.spark.structuredstreaming.translation.utils.ScalaInterop.tuple; +import static org.apache.beam.sdk.transforms.windowing.PaneInfo.NO_FIRING; +import static org.apache.beam.sdk.transforms.windowing.TimestampCombiner.END_OF_WINDOW; + +import java.util.Collection; +import org.apache.beam.runners.spark.structuredstreaming.translation.utils.ScalaInterop; +import org.apache.beam.runners.spark.structuredstreaming.translation.utils.ScalaInterop.Fun1; +import org.apache.beam.sdk.transforms.windowing.BoundedWindow; +import org.apache.beam.sdk.transforms.windowing.GlobalWindows; +import org.apache.beam.sdk.transforms.windowing.TimestampCombiner; +import org.apache.beam.sdk.values.KV; +import org.apache.beam.sdk.values.WindowedValue; +import org.apache.beam.sdk.values.WindowedValues; +import org.apache.beam.sdk.values.WindowingStrategy; +import scala.Tuple2; +import scala.collection.IterableOnce; + +/** + * Package private helpers to support translating grouping transforms using `groupByKey` such as + * {@link GroupByKeyTranslatorBatch} or {@link CombinePerKeyTranslatorBatch}. + */ +class GroupByKeyHelpers { + + private GroupByKeyHelpers() {} + + /** + * Checks if it's possible to use an optimized `groupByKey` that also moves the window into the + * key. + * + * @param windowing The windowing strategy + * @param endOfWindowOnly Flag if to limit this optimization to {@link + * TimestampCombiner#END_OF_WINDOW}. + */ + static boolean eligibleForGroupByWindow( + WindowingStrategy<?, ?> windowing, boolean endOfWindowOnly) { + return !windowing.needsMerge() + && (!endOfWindowOnly || windowing.getTimestampCombiner() == END_OF_WINDOW) + && windowing.getWindowFn().windowCoder().consistentWithEquals(); + } + + /** + * Checks if it's possible to use an optimized `groupByKey` for the global window. + * + * @param windowing The windowing strategy + * @param endOfWindowOnly Flag if to limit this optimization to {@link + * TimestampCombiner#END_OF_WINDOW}. + */ + static boolean eligibleForGlobalGroupBy( + WindowingStrategy<?, ?> windowing, boolean endOfWindowOnly) { + return windowing.getWindowFn() instanceof GlobalWindows + && (!endOfWindowOnly || windowing.getTimestampCombiner() == END_OF_WINDOW); + } + + /** + * Explodes a windowed {@link KV} assigned to potentially multiple {@link BoundedWindow}s to a + * traversable of composite keys {@code (BoundedWindow, Key)} and value. + */ + static <K, V, T> + Fun1<WindowedValue<KV<K, V>>, IterableOnce<Tuple2<Tuple2<BoundedWindow, K>, T>>> + explodeWindowedKey(Fun1<WindowedValue<KV<K, V>>, T> valueFn) { + return v -> { + T value = valueFn.apply(v); + K key = v.getValue().getKey(); + Collection<BoundedWindow> windows = (Collection<BoundedWindow>) v.getWindows(); Review Comment: Done in ecd260f5 — dropped the local variable along with the cast, in both the Spark 4 override and the shared base (the line was identical in both). Verified the bare `v.getWindows()` form compiles cleanly with `-Xlint:unchecked` (Java's wildcard capture handles it via target typing). -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
