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.upstream.cache;
  
  import android.net.Uri;
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.C;
  
  /** Interface for an immutable snapshot of keyed metadata. */
  public interface ContentMetadata {
  
    /**
     * Prefix for custom metadata keys. Applications can use keys starting with this prefix without
     * any risk of their keys colliding with ones defined by the ExoPlayer library.
     */
    @SuppressWarnings("unused")
    String KEY_CUSTOM_PREFIX = "custom_";
    /** Key for redirected uri (type: String). */
    String KEY_REDIRECTED_URI = "exo_redir";
    /** Key for content length in bytes (type: long). */
    String KEY_CONTENT_LENGTH = "exo_len";
  
    /**
     * Returns a metadata value.
     *
     * @param key Key of the metadata to be returned.
     * @param defaultValue Value to return if the metadata doesn't exist.
     * @return The metadata value.
     */
    @Nullable
    byte[] get(String key, @Nullable byte[] defaultValue);
  
    /**
     * Returns a metadata value.
     *
     * @param key Key of the metadata to be returned.
     * @param defaultValue Value to return if the metadata doesn't exist.
     * @return The metadata value.
     */
    @Nullable
    String get(String key, @Nullable String defaultValue);
  
    /**
     * Returns a metadata value.
     *
     * @param key Key of the metadata to be returned.
     * @param defaultValue Value to return if the metadata doesn't exist.
     * @return The metadata value.
     */
    long get(String key, long defaultValue);
  
    /** Returns whether the metadata is available. */
    boolean contains(String key);
  
    /**
     * Returns the value stored under {@link #KEY_CONTENT_LENGTH}, or {@link C#LENGTH_UNSET} if not
     * set.
     */
    static long getContentLength(ContentMetadata contentMetadata) {
      return contentMetadata.get(KEY_CONTENT_LENGTH, C.LENGTH_UNSET);
    }
  
    /**
     * Returns the value stored under {@link #KEY_REDIRECTED_URI} as a {@link Uri}, or {code null} if
     * not set.
     */
    @Nullable
    static Uri getRedirectedUri(ContentMetadata contentMetadata) {
      @Nullable String redirectedUri = contentMetadata.get(KEY_REDIRECTED_URI, (String) null);
      return redirectedUri == null ? null : Uri.parse(redirectedUri);
    }
  }
  