content: /*
   * Copyright (C) 2016 The Android Open Source Project
   *
   * Licensed 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 com.google.android.exoplayer2.source.chunk;
  
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.Format;
  import com.google.android.exoplayer2.extractor.DefaultExtractorInput;
  import com.google.android.exoplayer2.extractor.Extractor;
  import com.google.android.exoplayer2.extractor.ExtractorInput;
  import com.google.android.exoplayer2.source.chunk.ChunkExtractor.TrackOutputProvider;
  import com.google.android.exoplayer2.upstream.DataSource;
  import com.google.android.exoplayer2.upstream.DataSourceUtil;
  import com.google.android.exoplayer2.upstream.DataSpec;
  import java.io.IOException;
  import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
  
  /**
   * A {@link Chunk} that uses an {@link Extractor} to decode initialization data for single track.
   */
  public final class InitializationChunk extends Chunk {
  
    private final ChunkExtractor chunkExtractor;
  
    private @MonotonicNonNull TrackOutputProvider trackOutputProvider;
    private long nextLoadPosition;
    private volatile boolean loadCanceled;
  
    /**
     * @param dataSource The source from which the data should be loaded.
     * @param dataSpec Defines the data to be loaded.
     * @param trackFormat See {@link #trackFormat}.
     * @param trackSelectionReason See {@link #trackSelectionReason}.
     * @param trackSelectionData See {@link #trackSelectionData}.
     * @param chunkExtractor A wrapped extractor to use for parsing the initialization data.
     */
    public InitializationChunk(
        DataSource dataSource,
        DataSpec dataSpec,
        Format trackFormat,
        @C.SelectionReason int trackSelectionReason,
        @Nullable Object trackSelectionData,
        ChunkExtractor chunkExtractor) {
      super(
          dataSource,
          dataSpec,
          C.DATA_TYPE_MEDIA_INITIALIZATION,
          trackFormat,
          trackSelectionReason,
          trackSelectionData,
          C.TIME_UNSET,
          C.TIME_UNSET);
      this.chunkExtractor = chunkExtractor;
    }
  
    /**
     * Initializes the chunk for loading, setting a {@link TrackOutputProvider} for track outputs to
     * which formats will be written as they are loaded.
     *
     * @param trackOutputProvider The {@link TrackOutputProvider} for track outputs to which formats
     *     will be written as they are loaded.
     */
    public void init(TrackOutputProvider trackOutputProvider) {
      this.trackOutputProvider = trackOutputProvider;
    }
  
    // Loadable implementation.
  
    @Override
    public void cancelLoad() {
      loadCanceled = true;
    }
  
    @SuppressWarnings("NonAtomicVolatileUpdate")
    @Override
    public void load() throws IOException {
      if (nextLoadPosition == 0) {
        chunkExtractor.init(
            trackOutputProvider, /* startTimeUs= */ C.TIME_UNSET, /* endTimeUs= */ C.TIME_UNSET);
      }
      try {
        // Create and open the input.
        DataSpec loadDataSpec = dataSpec.subrange(nextLoadPosition);
        ExtractorInput input =
            new DefaultExtractorInput(
                dataSource, loadDataSpec.position, dataSource.open(loadDataSpec));
        // Load and decode the initialization data.
        try {
          while (!loadCanceled && chunkExtractor.read(input)) {}
        } finally {
          nextLoadPosition = input.getPosition() - dataSpec.position;
        }
      } finally {
        DataSourceUtil.closeQuietly(dataSource);
      }
    }
  }
  