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 android.support.annotation.NonNull;
  import android.support.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 original stream.
     */
    public final String key;
    /**
     * The position of the {@link CacheSpan} in the original stream.
     */
    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.
     */
    public final @Nullable File file;
    /**
     * The last access timestamp, or {@link C#TIME_UNSET} if {@link #isCached} is false.
     */
    public final long lastAccessTimestamp;
  
    /**
     * Creates a hole CacheSpan which isn't cached, has no last access time and no file associated.
     *
     * @param key The cache key that uniquely identifies the original stream.
     * @param position The position of the {@link CacheSpan} in the original stream.
     * @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 original stream.
     * @param position The position of the {@link CacheSpan} in the original stream.
     * @param length The length of the {@link CacheSpan}, or {@link C#LENGTH_UNSET} if this is an
     *     open-ended hole.
     * @param lastAccessTimestamp The last access 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 lastAccessTimestamp, @Nullable File file) {
      this.key = key;
      this.position = position;
      this.length = length;
      this.isCached = file != null;
      this.file = file;
      this.lastAccessTimestamp = lastAccessTimestamp;
    }
  
    /**
     * 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(@NonNull 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);
    }
  
  }
  