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.spark.util;
  
  import java.io.ByteArrayInputStream;
  import java.io.IOException;
  import java.io.Serializable;
  import org.apache.beam.runners.spark.translation.SparkPCollectionView;
  import org.apache.beam.sdk.coders.Coder;
  import org.apache.spark.api.java.JavaSparkContext;
  import org.apache.spark.broadcast.Broadcast;
  import org.apache.spark.util.SizeEstimator;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Broadcast helper for side inputs. Helps to do the transformation from bytes transform to
   * broadcast transform to value by coder
   */
  @SuppressWarnings({
    "nullness" // TODO(https://github.com/apache/beam/issues/20497)
  })
  public class SideInputBroadcast<T> implements Serializable {
  
    private static final Logger LOG = LoggerFactory.getLogger(SideInputBroadcast.class);
    private Broadcast<byte[]> bcast;
    private final Coder<T> coder;
    private transient T value;
    private transient byte[] bytes = null;
    private SparkPCollectionView.Type sparkPCollectionViewType;
  
    private SideInputBroadcast(
        byte[] bytes, Coder<T> coder, SparkPCollectionView.Type sparkPCollectionViewType) {
      this.bytes = bytes;
      this.coder = coder;
      this.sparkPCollectionViewType = sparkPCollectionViewType;
    }
  
    public static <T> SideInputBroadcast<T> create(
        byte[] bytes, SparkPCollectionView.Type type, Coder<T> coder) {
      return new SideInputBroadcast<>(bytes, coder, type);
    }
  
    public synchronized T getValue() {
      if (value == null) {
        value = deserialize();
      }
      return value;
    }
  
    public void broadcast(JavaSparkContext jsc) {
      this.bcast = jsc.broadcast(bytes);
    }
  
    public SparkPCollectionView.Type getSparkPCollectionViewType() {
      return sparkPCollectionViewType;
    }
  
    public void unpersist() {
      this.bcast.unpersist();
    }
  
    @SuppressWarnings("Slf4jDoNotLogMessageOfExceptionExplicitly")
    private T deserialize() {
      T val;
      try {
        val = coder.decode(new ByteArrayInputStream(bcast.value()));
      } catch (IOException ioe) {
        // this should not ever happen, log it if it does.
        LOG.warn(ioe.getMessage());
        val = null;
      }
      return val;
    }
  
    public long getBroadcastSizeEstimate() {
      return SizeEstimator.estimate(bytes);
    }
  }
  