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 com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.Format;
  import com.google.android.exoplayer2.upstream.DataSource;
  import com.google.android.exoplayer2.upstream.DataSpec;
  import com.google.android.exoplayer2.util.Util;
  import java.io.IOException;
  import java.util.Arrays;
  
  /**
   * A base class for {@link Chunk} implementations where the data should be loaded into a
   * {@code byte[]} before being consumed.
   */
  public abstract class DataChunk extends Chunk {
  
    private static final int READ_GRANULARITY = 16 * 1024;
  
    private byte[] data;
    private int limit;
  
    private volatile boolean loadCanceled;
  
    /**
     * @param dataSource The source from which the data should be loaded.
     * @param dataSpec Defines the data to be loaded.
     * @param type See {@link #type}.
     * @param trackFormat See {@link #trackFormat}.
     * @param trackSelectionReason See {@link #trackSelectionReason}.
     * @param trackSelectionData See {@link #trackSelectionData}.
     * @param data An optional recycled array that can be used as a holder for the data.
     */
    public DataChunk(DataSource dataSource, DataSpec dataSpec, int type, Format trackFormat,
        int trackSelectionReason, Object trackSelectionData, byte[] data) {
      super(dataSource, dataSpec, type, trackFormat, trackSelectionReason, trackSelectionData,
          C.TIME_UNSET, C.TIME_UNSET);
      this.data = data;
    }
  
    /**
     * Returns the array in which the data is held.
     * <p>
     * This method should be used for recycling the holder only, and not for reading the data.
     *
     * @return The array in which the data is held.
     */
    public byte[] getDataHolder() {
      return data;
    }
  
    @Override
    public long bytesLoaded() {
      return limit;
    }
  
    // Loadable implementation
  
    @Override
    public final void cancelLoad() {
      loadCanceled = true;
    }
  
    @Override
    public final boolean isLoadCanceled() {
      return loadCanceled;
    }
  
    @Override
    public final void load() throws IOException, InterruptedException {
      try {
        dataSource.open(dataSpec);
        limit = 0;
        int bytesRead = 0;
        while (bytesRead != C.RESULT_END_OF_INPUT && !loadCanceled) {
          maybeExpandData();
          bytesRead = dataSource.read(data, limit, READ_GRANULARITY);
          if (bytesRead != -1) {
            limit += bytesRead;
          }
        }
        if (!loadCanceled) {
          consume(data, limit);
        }
      } finally {
        Util.closeQuietly(dataSource);
      }
    }
  
    /**
     * Called by {@link #load()}. Implementations should override this method to consume the loaded
     * data.
     *
     * @param data An array containing the data.
     * @param limit The limit of the data.
     * @throws IOException If an error occurs consuming the loaded data.
     */
    protected abstract void consume(byte[] data, int limit) throws IOException;
  
    private void maybeExpandData() {
      if (data == null) {
        data = new byte[READ_GRANULARITY];
      } else if (data.length < limit + READ_GRANULARITY) {
        // The new length is calculated as (data.length + READ_GRANULARITY) rather than
        // (limit + READ_GRANULARITY) in order to avoid small increments in the length.
        data = Arrays.copyOf(data, data.length + READ_GRANULARITY);
      }
    }
  
  }
  