nsivabalan commented on code in PR #18585: URL: https://github.com/apache/hudi/pull/18585#discussion_r3399775512
########## hudi-common/src/main/java/org/apache/hudi/common/engine/HoodiePreCommitValidatorEngineContext.java: ########## @@ -0,0 +1,252 @@ +/* + * 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.hudi.common.engine; + +import org.apache.hudi.common.config.TypedProperties; +import org.apache.hudi.common.data.HoodieAccumulator; +import org.apache.hudi.common.data.HoodieData; +import org.apache.hudi.common.data.HoodieData.HoodieDataCacheKey; +import org.apache.hudi.common.data.HoodiePairData; +import org.apache.hudi.common.function.FunctionWrapper; +import org.apache.hudi.common.function.SerializableBiFunction; +import org.apache.hudi.common.function.SerializableConsumer; +import org.apache.hudi.common.function.SerializableFunction; +import org.apache.hudi.common.function.SerializablePairFlatMapFunction; +import org.apache.hudi.common.function.SerializablePairFunction; +import org.apache.hudi.common.table.HoodieTableMetaClient; +import org.apache.hudi.common.util.Functions; +import org.apache.hudi.common.util.Option; +import org.apache.hudi.common.util.collection.ImmutablePair; +import org.apache.hudi.common.util.collection.Pair; +import org.apache.hudi.keygen.KeyGenerator; +import org.apache.hudi.storage.StorageConfiguration; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.util.Iterator; +import java.util.List; +import java.util.Map; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.CompletionException; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.ForkJoinPool; +import java.util.function.Function; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +/** + * An engine context for running pre-commit validators in parallel. + * + * <p>Uses a dedicated classloader-aware {@link ExecutorService} so that validator classes loaded + * by the application classloader can be resolved inside worker threads on Java 11+. All methods + * except {@link #map} are delegated to an internal {@link HoodieLocalEngineContext} instance. + * The pool is lazily created once per JVM and shared across all instances. + */ +public class HoodiePreCommitValidatorEngineContext extends HoodieEngineContext { + + private static final Logger LOG = LoggerFactory.getLogger(HoodiePreCommitValidatorEngineContext.class); + + // Lazy-initialized fixed thread pool whose workers explicitly carry the classloader of this + // class, preventing ClassNotFoundException on Java 11+ where thread-pool workers do not inherit + // the submitting thread's context classloader. + // JLS 12.4.2 guarantees thread-safe initialization via class-loading locks. + private static class PoolHolder { + static final ExecutorService INSTANCE = createExecutorService(); + } + + private static ExecutorService createExecutorService() { + int parallelism = ForkJoinPool.commonPool().getParallelism(); + ClassLoader cl = HoodiePreCommitValidatorEngineContext.class.getClassLoader(); + ExecutorService executor = Executors.newFixedThreadPool(parallelism, r -> { + Thread t = Executors.defaultThreadFactory().newThread(r); + t.setContextClassLoader(cl); + t.setDaemon(true); + return t; + }); + LOG.info("Created pre-commit validator executor service with {} threads", parallelism); + return executor; + } + + // Delegate for all methods except map() — avoids inheriting from final HoodieLocalEngineContext. + private final HoodieLocalEngineContext delegate; + + public HoodiePreCommitValidatorEngineContext(StorageConfiguration<?> conf) { + super(conf, new LocalTaskContextSupplier()); + this.delegate = new HoodieLocalEngineContext(conf); + } + + /** + * Runs {@code func} over {@code data} in parallel using a classloader-aware fixed thread pool. + * Results are returned in input order. Unchecked exceptions are re-thrown as-is; checked + * exceptions are wrapped in {@link org.apache.hudi.exception.HoodieException}. + */ + @Override + public <I, O> List<O> map(List<I> data, SerializableFunction<I, O> func, int parallelism) { + return mapAsync(data, FunctionWrapper.throwingMapWrapper(func)); + } + + private <I, O> List<O> mapAsync(List<I> data, Function<I, O> func) { + List<CompletableFuture<O>> futures = data.stream() + .map(item -> CompletableFuture.supplyAsync(() -> func.apply(item), PoolHolder.INSTANCE)) + .collect(Collectors.toList()); + try { + CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).join(); + } catch (CompletionException e) { + throw rethrowUnwrapped(e); + } + return futures.stream().map(CompletableFuture::join).collect(Collectors.toList()); + } + + private static RuntimeException rethrowUnwrapped(CompletionException e) { + Throwable cause = e.getCause(); + if (cause instanceof RuntimeException) { + throw (RuntimeException) cause; + } + if (cause instanceof Error) { + throw (Error) cause; + } + throw e; + } + + // ---- All remaining methods delegate to HoodieLocalEngineContext ---- + + @Override + public HoodieAccumulator newAccumulator() { + return delegate.newAccumulator(); + } + + @Override + public <T> HoodieData<T> emptyHoodieData() { + return delegate.emptyHoodieData(); + } + + @Override + public <K, V> HoodiePairData<K, V> emptyHoodiePairData() { + return delegate.emptyHoodiePairData(); + } + + @Override + public <T> HoodieData<T> parallelize(List<T> data, int parallelism) { + return delegate.parallelize(data, parallelism); + } + + @Override + public <I, K, V> List<V> mapToPairAndReduceByKey(List<I> data, SerializablePairFunction<I, K, V> mapToPairFunc, + SerializableBiFunction<V, V, V> reduceFunc, int parallelism) { Review Comment: we should move all these methods to use the executor service. that would be the clean solution -- This is an automated message from the Apache Git Service. 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