content: /*
   * Copyright (C) 2018 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.offline;
  
  import android.os.Parcel;
  import android.os.Parcelable;
  import androidx.annotation.Nullable;
  
  /**
   * A key for a subset of media that can be separately loaded (a "stream").
   *
   * <p>The stream key consists of a period index, a group index within the period and a stream index
   * within the group. The interpretation of these indices depends on the type of media for which the
   * stream key is used. Note that they are <em>not</em> the same as track group and track indices,
   * because multiple tracks can be multiplexed into a single stream.
   *
   * <p>Application code should not generally attempt to build StreamKey instances directly. Instead,
   * {@code DownloadHelper.getDownloadRequest} can be used to generate download requests with the
   * correct StreamKeys for the track selections that have been configured on the helper. {@code
   * MediaPeriod.getStreamKeys} provides a lower level way of generating StreamKeys corresponding to a
   * particular track selection.
   */
  public final class StreamKey implements Comparable<StreamKey>, Parcelable {
  
    /** The period index. */
    public final int periodIndex;
    /** The group index. */
    public final int groupIndex;
    /** The stream index. */
    public final int streamIndex;
  
    /**
     * @deprecated Use {@link #streamIndex}.
     */
    @Deprecated public final int trackIndex;
  
    /**
     * Creates an instance with {@link #periodIndex} set to 0.
     *
     * @param groupIndex The group index.
     * @param streamIndex The stream index.
     */
    public StreamKey(int groupIndex, int streamIndex) {
      this(0, groupIndex, streamIndex);
    }
  
    /**
     * Creates an instance.
     *
     * @param periodIndex The period index.
     * @param groupIndex The group index.
     * @param streamIndex The stream index.
     */
    @SuppressWarnings("deprecation")
    public StreamKey(int periodIndex, int groupIndex, int streamIndex) {
      this.periodIndex = periodIndex;
      this.groupIndex = groupIndex;
      this.streamIndex = streamIndex;
      trackIndex = streamIndex;
    }
  
    @SuppressWarnings("deprecation")
    /* package */ StreamKey(Parcel in) {
      periodIndex = in.readInt();
      groupIndex = in.readInt();
      streamIndex = in.readInt();
      trackIndex = streamIndex;
    }
  
    @Override
    public String toString() {
      return periodIndex + "." + groupIndex + "." + streamIndex;
    }
  
    @Override
    public boolean equals(@Nullable Object o) {
      if (this == o) {
        return true;
      }
      if (o == null || getClass() != o.getClass()) {
        return false;
      }
  
      StreamKey that = (StreamKey) o;
      return periodIndex == that.periodIndex
          && groupIndex == that.groupIndex
          && streamIndex == that.streamIndex;
    }
  
    @Override
    public int hashCode() {
      int result = periodIndex;
      result = 31 * result + groupIndex;
      result = 31 * result + streamIndex;
      return result;
    }
  
    // Comparable implementation.
  
    @Override
    public int compareTo(StreamKey o) {
      int result = periodIndex - o.periodIndex;
      if (result == 0) {
        result = groupIndex - o.groupIndex;
        if (result == 0) {
          result = streamIndex - o.streamIndex;
        }
      }
      return result;
    }
  
    // Parcelable implementation.
  
    @Override
    public int describeContents() {
      return 0;
    }
  
    @Override
    public void writeToParcel(Parcel dest, int flags) {
      dest.writeInt(periodIndex);
      dest.writeInt(groupIndex);
      dest.writeInt(streamIndex);
    }
  
    public static final Parcelable.Creator<StreamKey> CREATOR =
        new Parcelable.Creator<StreamKey>() {
  
          @Override
          public StreamKey createFromParcel(Parcel in) {
            return new StreamKey(in);
          }
  
          @Override
          public StreamKey[] newArray(int size) {
            return new StreamKey[size];
          }
        };
  }
  