Add uniqueId property to Representations

src/manifest/representation.ts

@@ -23,19 +23,44 @@ import {
 } from "../parsers/manifest";
 import { IHDRInformation } from "../public_types";
 import areArraysOfNumbersEqual from "../utils/are_arrays_of_numbers_equal";
+import idGenerator from "../utils/id_generator";
 import { IRepresentationIndex } from "./representation_index";
 import {
   IAdaptationType,
 } from "./types";
 
+const generateRepresentationUniqueId = idGenerator();
+
 /**
  * Normalized Representation structure.
  * @class Representation
  */
 class Representation {
-  /** ID uniquely identifying the Representation in the Adaptation. */
+  /**
+   * ID uniquely identifying the `Representation` in its parent `Adaptation`.
+   *
+   * This identifier might be linked to an identifier present in the original
+   * Manifest file, it is thus the identifier to use to determine if a
+   * `Representation` from a refreshed `Manifest` is actually the same one than
+   * one in the previously loaded Manifest (as long as the `Adaptation` and
+   * `Period` are also the same).
+   *
+   * For a globally unique identifier regardless of the `Adaptation`, `Period`
+   * or even `Manifest`, you can rely on `uniqueId` instead.
+   */
   public readonly id : string;
 
+  /**
+   * Globally unique identifier for this `Representation` object.
+   *
+   * This identifier is guaranteed to be unique for any `Representation`s of all
+   * `Manifest` objects created in the current JS Realm.
+   * As such, it can be used as an identifier for the JS object itself, whereas
+   * `id` is the identifier for the original Manifest's Representation in the
+   * scope of its parent `Adaptation`.
+   */
+  public readonly uniqueId : string;
+
   /**
    * Interface allowing to get information about segments available for this
    * Representation.
@@ -115,6 +140,7 @@ class Representation {
    */
   constructor(args : IParsedRepresentation, opts : { type : IAdaptationType }) {
     this.id = args.id;
+    this.uniqueId = generateRepresentationUniqueId();
     this.bitrate = args.bitrate;
     this.codec = args.codecs;
 

src/manifest/utils.ts

@@ -37,9 +37,7 @@ export function areSameContent(
   content2: IBufferedChunkInfos
 ): boolean {
   return (content1.segment.id === content2.segment.id &&
-          content1.representation.id === content2.representation.id &&
-          content1.adaptation.id === content2.adaptation.id &&
-          content1.period.id === content2.period.id);
+          content1.representation.uniqueId === content2.representation.uniqueId);
 }
 
 /**