m-trieu commented on code in PR #30764: URL: https://github.com/apache/beam/pull/30764#discussion_r1575763051
########## runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/streaming/ComputationStateCache.java: ########## @@ -0,0 +1,127 @@ +/* + * 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.dataflow.worker.streaming; + +import static java.util.stream.Collectors.toMap; +import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList.toImmutableList; +import static org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableSet.toImmutableSet; + +import java.io.PrintWriter; +import java.util.Map; +import java.util.Optional; +import java.util.concurrent.ExecutionException; +import javax.annotation.concurrent.ThreadSafe; +import org.apache.beam.runners.dataflow.worker.status.StatusDataProvider; +import org.apache.beam.runners.dataflow.worker.windmill.work.budget.GetWorkBudget; +import org.apache.beam.sdk.annotations.Internal; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.annotations.VisibleForTesting; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.cache.CacheBuilder; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.cache.CacheLoader; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.cache.LoadingCache; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableList; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableSet; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** Cache of {@link String} computationId to {@link ComputationState} objects. */ +@Internal +@ThreadSafe +public final class ComputationStateCache implements StatusDataProvider { + + private static final Logger LOG = LoggerFactory.getLogger(ComputationStateCache.class); + + private final LoadingCache<String, Optional<ComputationState>> computationCache; + + private ComputationStateCache(LoadingCache<String, Optional<ComputationState>> computationCache) { + this.computationCache = computationCache; + } + + public static ComputationStateCache create( + CacheLoader<String, Optional<ComputationState>> cacheLoader) { + return new ComputationStateCache(CacheBuilder.newBuilder().build(cacheLoader)); + } + + /** + * Returns the {@link ComputationState} associated with the given computationId. May perform IO if + * a value is not present, and it is possible that after IO is performed there is no value + * correlated with that computationId. + */ + public Optional<ComputationState> getComputationState(String computationId) { + try { + Optional<ComputationState> computationState = + computationCache.getAll(ImmutableList.of(computationId)).get(computationId); Review Comment: our cache usage is a bit different here, LoadingCache.get() will call CacheLoader.load() and load 1 key. Based on previous code, we possibly load multiple computations for 1 get call https://github.com/apache/beam/blob/master/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/StreamingDataflowWorker.java#L1448, so we want the CacheLoader to call loadAll here. I was thinking about throwing an exception for CacheLoader.load(), but opted not. -- 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]
