content: /*
   * 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.samza;
  
  import static org.apache.beam.runners.core.metrics.MetricsContainerStepMap.asAttemptedOnlyMetricResults;
  import static org.apache.samza.config.TaskConfig.TASK_SHUTDOWN_MS;
  
  import org.apache.beam.sdk.Pipeline;
  import org.apache.beam.sdk.PipelineResult;
  import org.apache.beam.sdk.metrics.MetricResults;
  import org.apache.beam.sdk.util.UserCodeException;
  import org.apache.samza.config.Config;
  import org.apache.samza.job.ApplicationStatus;
  import org.apache.samza.runtime.ApplicationRunner;
  import org.checkerframework.checker.nullness.qual.Nullable;
  import org.joda.time.Duration;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /** The result from executing a Samza Pipeline. */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  public class SamzaPipelineResult implements PipelineResult {
    private static final Logger LOG = LoggerFactory.getLogger(SamzaPipelineResult.class);
    // allow some buffer on top of samza's own shutdown timeout
    private static final long SHUTDOWN_TIMEOUT_BUFFER = 5000L;
    private static final long DEFAULT_TASK_SHUTDOWN_MS = 30000L;
  
    private final SamzaExecutionContext executionContext;
    private final ApplicationRunner runner;
    private final SamzaPipelineLifeCycleListener listener;
    private final long shutdownTiemoutMs;
  
    public SamzaPipelineResult(
        ApplicationRunner runner,
        SamzaExecutionContext executionContext,
        SamzaPipelineLifeCycleListener listener,
        Config config) {
      this.executionContext = executionContext;
      this.runner = runner;
      this.listener = listener;
      this.shutdownTiemoutMs =
          config.getLong(TASK_SHUTDOWN_MS, DEFAULT_TASK_SHUTDOWN_MS) + SHUTDOWN_TIMEOUT_BUFFER;
    }
  
    @Override
    public State getState() {
      return getStateInfo().state;
    }
  
    @Override
    public State cancel() {
      LOG.info("Start to cancel samza pipeline...");
      runner.kill();
      LOG.info("Start awaiting finish for {} ms.", shutdownTiemoutMs);
      return waitUntilFinish(Duration.millis(shutdownTiemoutMs));
    }
  
    @Override
    public State waitUntilFinish(@Nullable Duration duration) {
      try {
        if (duration == null) {
          runner.waitForFinish();
        } else {
          runner.waitForFinish(java.time.Duration.ofMillis(duration.getMillis()));
        }
      } catch (Exception e) {
        throw new Pipeline.PipelineExecutionException(e);
      }
  
      final StateInfo stateInfo = getStateInfo();
  
      if (listener != null && (stateInfo.state == State.DONE || stateInfo.state == State.FAILED)) {
        listener.onFinish();
      }
  
      if (stateInfo.state == State.FAILED) {
        throw stateInfo.error;
      }
  
      LOG.info("Pipeline finished. Final state: {}", stateInfo.state);
      return stateInfo.state;
    }
  
    @Override
    public State waitUntilFinish() {
      return waitUntilFinish(null);
    }
  
    @Override
    public MetricResults metrics() {
      return asAttemptedOnlyMetricResults(executionContext.getMetricsContainer().getContainers());
    }
  
    @SuppressWarnings("Slf4jDoNotLogMessageOfExceptionExplicitly")
    private StateInfo getStateInfo() {
      final ApplicationStatus status = runner.status();
      switch (status.getStatusCode()) {
        case New:
          return new StateInfo(State.STOPPED);
        case Running:
          return new StateInfo(State.RUNNING);
        case SuccessfulFinish:
          return new StateInfo(State.DONE);
        case UnsuccessfulFinish:
          LOG.error(status.getThrowable().getMessage(), status.getThrowable());
          return new StateInfo(
              State.FAILED,
              new Pipeline.PipelineExecutionException(getUserCodeException(status.getThrowable())));
        default:
          return new StateInfo(State.UNKNOWN);
      }
    }
  
    private static class StateInfo {
      private final State state;
      private final Pipeline.PipelineExecutionException error;
  
      private StateInfo(State state) {
        this(state, null);
      }
  
      private StateInfo(State state, Pipeline.PipelineExecutionException error) {
        this.state = state;
        this.error = error;
      }
    }
  
    /**
     * Some of the Beam unit tests relying on the exception message to do assertion. This function
     * will find the original UserCodeException so the message will be exposed directly.
     */
    private static Throwable getUserCodeException(Throwable throwable) {
      Throwable t = throwable;
      while (t != null) {
        if (t instanceof UserCodeException) {
          return t;
        }
  
        t = t.getCause();
      }
  
      return throwable;
    }
  }
  