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.upstream.cache;
  
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.C;
  import java.io.File;
  
  /** Defines a span of data that may or may not be cached (as indicated by {@link #isCached}). */
  public class CacheSpan implements Comparable<CacheSpan> {
  
    /** The cache key that uniquely identifies the resource. */
    public final String key;
    /** The position of the {@link CacheSpan} in the resource. */
    public final long position;
    /**
     * The length of the {@link CacheSpan}, or {@link C#LENGTH_UNSET} if this is an open-ended hole.
     */
    public final long length;
    /** Whether the {@link CacheSpan} is cached. */
    public final boolean isCached;
    /** The file corresponding to this {@link CacheSpan}, or null if {@link #isCached} is false. */
    @Nullable public final File file;
    /** The last touch timestamp, or {@link C#TIME_UNSET} if {@link #isCached} is false. */
    public final long lastTouchTimestamp;
  
    /**
     * Creates a hole CacheSpan which isn't cached, has no last touch timestamp and no file
     * associated.
     *
     * @param key The cache key that uniquely identifies the resource.
     * @param position The position of the {@link CacheSpan} in the resource.
     * @param length The length of the {@link CacheSpan}, or {@link C#LENGTH_UNSET} if this is an
     *     open-ended hole.
     */
    public CacheSpan(String key, long position, long length) {
      this(key, position, length, C.TIME_UNSET, null);
    }
  
    /**
     * Creates a CacheSpan.
     *
     * @param key The cache key that uniquely identifies the resource.
     * @param position The position of the {@link CacheSpan} in the resource.
     * @param length The length of the {@link CacheSpan}, or {@link C#LENGTH_UNSET} if this is an
     *     open-ended hole.
     * @param lastTouchTimestamp The last touch timestamp, or {@link C#TIME_UNSET} if {@link
     *     #isCached} is false.
     * @param file The file corresponding to this {@link CacheSpan}, or null if it's a hole.
     */
    public CacheSpan(
        String key, long position, long length, long lastTouchTimestamp, @Nullable File file) {
      this.key = key;
      this.position = position;
      this.length = length;
      this.isCached = file != null;
      this.file = file;
      this.lastTouchTimestamp = lastTouchTimestamp;
    }
  
    /** Returns whether this is an open-ended {@link CacheSpan}. */
    public boolean isOpenEnded() {
      return length == C.LENGTH_UNSET;
    }
  
    /** Returns whether this is a hole {@link CacheSpan}. */
    public boolean isHoleSpan() {
      return !isCached;
    }
  
    @Override
    public int compareTo(CacheSpan another) {
      if (!key.equals(another.key)) {
        return key.compareTo(another.key);
      }
      long startOffsetDiff = position - another.position;
      return startOffsetDiff == 0 ? 0 : ((startOffsetDiff < 0) ? -1 : 1);
    }
  
    @Override
    public String toString() {
      return "[" + position + ", " + length + "]";
    }
  }
  