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.windmill.client.getdata;
  
  import java.io.PrintWriter;
  import javax.annotation.concurrent.ThreadSafe;
  import org.apache.beam.runners.dataflow.worker.windmill.Windmill;
  import org.apache.beam.runners.dataflow.worker.windmill.Windmill.GlobalDataRequest;
  import org.apache.beam.runners.dataflow.worker.windmill.Windmill.KeyedGetDataRequest;
  import org.apache.beam.runners.dataflow.worker.windmill.client.CloseableStream;
  import org.apache.beam.runners.dataflow.worker.windmill.client.WindmillStream.GetDataStream;
  import org.apache.beam.runners.dataflow.worker.windmill.client.WindmillStreamPool;
  import org.apache.beam.sdk.annotations.Internal;
  
  /**
   * StreamingEngine implementation of {@link GetDataClient}.
   *
   * @implNote Uses {@link WindmillStreamPool} to send requests.
   */
  @Internal
  @ThreadSafe
  public final class StreamPoolGetDataClient implements GetDataClient {
  
    private final WindmillStreamPool<GetDataStream> getDataStreamPool;
    private final ThrottlingGetDataMetricTracker getDataMetricTracker;
  
    public StreamPoolGetDataClient(
        ThrottlingGetDataMetricTracker getDataMetricTracker,
        WindmillStreamPool<GetDataStream> getDataStreamPool) {
      this.getDataMetricTracker = getDataMetricTracker;
      this.getDataStreamPool = getDataStreamPool;
    }
  
    @Override
    public Windmill.KeyedGetDataResponse getStateData(
        String computationId, KeyedGetDataRequest request) {
      try (AutoCloseable ignored = getDataMetricTracker.trackStateDataFetchWithThrottling();
          CloseableStream<GetDataStream> closeableStream = getDataStreamPool.getCloseableStream()) {
        return closeableStream.stream().requestKeyedData(computationId, request);
      } catch (Exception e) {
        throw new GetDataException(
            "Error occurred fetching state for computation="
                + computationId
                + ", key="
                + request.getShardingKey(),
            e);
      }
    }
  
    @Override
    public Windmill.GlobalData getSideInputData(GlobalDataRequest request) {
      try (AutoCloseable ignored = getDataMetricTracker.trackSideInputFetchWithThrottling();
          CloseableStream<GetDataStream> closeableStream = getDataStreamPool.getCloseableStream()) {
        return closeableStream.stream().requestGlobalData(request);
      } catch (Exception e) {
        throw new GetDataException(
            "Error occurred fetching side input for tag=" + request.getDataId(), e);
      }
    }
  
    @Override
    public void printHtml(PrintWriter writer) {
      getDataMetricTracker.printHtml(writer);
    }
  }
  