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.dataflow.worker.streaming;
  
  import com.google.auto.value.AutoValue;
  import java.util.HashMap;
  import java.util.Optional;
  import javax.annotation.concurrent.NotThreadSafe;
  import org.apache.beam.runners.core.metrics.ExecutionStateTracker;
  import org.apache.beam.runners.dataflow.worker.DataflowMapTaskExecutor;
  import org.apache.beam.runners.dataflow.worker.DataflowWorkExecutor;
  import org.apache.beam.runners.dataflow.worker.StreamingModeExecutionContext;
  import org.apache.beam.runners.dataflow.worker.streaming.sideinput.SideInputStateFetcher;
  import org.apache.beam.runners.dataflow.worker.util.common.worker.ElementCounter;
  import org.apache.beam.runners.dataflow.worker.util.common.worker.OutputObjectAndByteCounter;
  import org.apache.beam.runners.dataflow.worker.windmill.Windmill;
  import org.apache.beam.runners.dataflow.worker.windmill.state.WindmillStateReader;
  import org.apache.beam.sdk.annotations.Internal;
  import org.apache.beam.sdk.coders.Coder;
  import org.checkerframework.checker.nullness.qual.Nullable;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Used to process {@link Work} by executing user DoFns for a specific computation. May be reused to
   * process future work items owned a computation.
   *
   * <p>Should only be accessed by 1 thread at a time.
   *
   * @implNote Once closed, it cannot be reused.
   */
  // TODO(m-trieu): See if this can be combined/cleaned up with StreamingModeExecutionContext as the
  // separation of responsibilities are unclear.
  @AutoValue
  @Internal
  @NotThreadSafe
  public abstract class ComputationWorkExecutor {
    private static final Logger LOG = LoggerFactory.getLogger(ComputationWorkExecutor.class);
  
    public static ComputationWorkExecutor.Builder builder() {
      return new AutoValue_ComputationWorkExecutor.Builder();
    }
  
    public abstract DataflowWorkExecutor workExecutor();
  
    public abstract StreamingModeExecutionContext context();
  
    public abstract Optional<Coder<?>> keyCoder();
  
    public abstract ExecutionStateTracker executionStateTracker();
  
    /**
     * Executes DoFns for the Work. Blocks the calling thread until DoFn(s) have completed execution.
     */
    public final void executeWork(
        @Nullable Object key,
        Work work,
        WindmillStateReader stateReader,
        SideInputStateFetcher sideInputStateFetcher,
        Windmill.WorkItemCommitRequest.Builder outputBuilder)
        throws Exception {
      context().start(key, work, stateReader, sideInputStateFetcher, outputBuilder);
      workExecutor().execute();
    }
  
    /**
     * Callers should only invoke invalidate() when execution of work fails. Once closed, the instance
     * cannot be reused.
     */
    public final void invalidate() {
      context().invalidateCache();
      try {
        workExecutor().close();
      } catch (Exception e) {
        LOG.warn("Failed to close map task executor: ", e);
      }
    }
  
    public final long computeSourceBytesProcessed(String sourceBytesCounterName) {
      HashMap<String, ElementCounter> counters =
          ((DataflowMapTaskExecutor) workExecutor())
              .getReadOperation()
              .receivers[0]
              .getOutputCounters();
  
      return Optional.ofNullable(counters.get(sourceBytesCounterName))
          .map(counter -> ((OutputObjectAndByteCounter) counter).getByteCount().getAndReset())
          .orElse(0L);
    }
  
    @AutoValue.Builder
    public abstract static class Builder {
      public abstract Builder setWorkExecutor(DataflowWorkExecutor workExecutor);
  
      public abstract Builder setContext(StreamingModeExecutionContext context);
  
      public abstract Builder setKeyCoder(Coder<?> keyCoder);
  
      public abstract Builder setExecutionStateTracker(ExecutionStateTracker executionStateTracker);
  
      public abstract ComputationWorkExecutor build();
    }
  }
  