Abacn commented on code in PR #31795: URL: https://github.com/apache/beam/pull/31795#discussion_r1669518329
########## runners/prism/java/src/main/java/org/apache/beam/runners/prism/PrismExecutor.java: ########## @@ -0,0 +1,199 @@ +/* + * 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.prism; + +import static org.apache.beam.sdk.util.Preconditions.checkStateNotNull; + +import com.google.auto.value.AutoValue; +import java.io.File; +import java.io.IOException; +import java.io.OutputStream; +import java.lang.reflect.Field; +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; +import java.util.Optional; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.Future; +import java.util.concurrent.TimeUnit; +import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.io.ByteStreams; +import org.checkerframework.checker.nullness.qual.MonotonicNonNull; +import org.checkerframework.checker.nullness.qual.Nullable; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * {@link PrismExecutor} builds and executes a {@link ProcessBuilder} for use by the {@link + * PrismRunner}. Prism is a {@link org.apache.beam.runners.portability.PortableRunner} maintained at + * <a href="https://github.com/apache/beam/tree/master/sdks/go/cmd/prism";>sdks/go/cmd/prism</a>. + */ +@AutoValue +abstract class PrismExecutor { + + private static final Logger LOG = LoggerFactory.getLogger(PrismExecutor.class); + + protected @MonotonicNonNull Process process; + protected ExecutorService executorService = Executors.newSingleThreadExecutor(); + protected @MonotonicNonNull Future<?> future = null; + + static Builder builder() { + return new AutoValue_PrismExecutor.Builder(); + } + + /** The command to execute the Prism binary. */ + abstract String getCommand(); + + /** + * Additional arguments to pass when invoking the Prism binary. Defaults to an {@link + * Collections#emptyList()}. + */ + abstract List<String> getArguments(); + + /** Stops the execution of the {@link Process}, created as a result of {@link #execute}. */ + void stop() { + LOG.info("Stopping Prism..."); + if (future != null) { + future.cancel(true); + } + executorService.shutdown(); + try { + boolean ignored = executorService.awaitTermination(1000L, TimeUnit.MILLISECONDS); + } catch (InterruptedException ignored) { + } + if (process == null) { + return; + } + if (!process.isAlive()) { + return; + } + process.destroy(); + try { + process.waitFor(); + } catch (InterruptedException ignored) { + } + } + + /** + * Execute the {@link ProcessBuilder} that starts the Prism service. Redirects output to STDOUT. + */ + void execute() throws IOException { + execute(createProcessBuilder().inheritIO()); + } + + /** + * Execute the {@link ProcessBuilder} that starts the Prism service. Redirects output to the + * {@param outputStream}. + */ + void execute(OutputStream outputStream) throws IOException { + execute(createProcessBuilder().redirectErrorStream(true)); + this.future = + executorService.submit( + () -> { + try { + ByteStreams.copy(checkStateNotNull(process).getInputStream(), outputStream); + } catch (IOException e) { + throw new RuntimeException(e); + } + }); + } + + /** + * Execute the {@link ProcessBuilder} that starts the Prism service. Redirects output to the + * {@param file}. + */ + void execute(File file) throws IOException { + execute( + createProcessBuilder() + .redirectErrorStream(true) + .redirectOutput(ProcessBuilder.Redirect.appendTo(file))); + } + + private void execute(ProcessBuilder processBuilder) throws IOException { + this.process = processBuilder.start(); + LOG.info( + "started {}, pid: {}", + String.join(" ", getCommandWithArguments()), + getPidOrNotAvailableWarning()); + } + + private List<String> getCommandWithArguments() { + List<String> commandWithArguments = new ArrayList<>(); + commandWithArguments.add(getCommand()); + commandWithArguments.addAll(getArguments()); + + return commandWithArguments; + } + + private ProcessBuilder createProcessBuilder() { + return new ProcessBuilder(getCommandWithArguments()); + } + + private String getPidOrNotAvailableWarning() { Review Comment: these three private methods look very strange to me. Why need reflection to get a pid from a process? Doesn't process.pid() work? -- 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: github-unsubscr...@beam.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
