chore: Remove state engine (#5752)

The state engine mechanism, designed for the player class, was over-engineered. The structure of the class makes debugging player errors unnecessarily annoying, by obfuscating the code-path the error followed, and in general has created a significant amount of technical debt. This changes the player to use an async-await setup for the top-level operations, laying things out much more cleanly and linearly. --------- Co-authored-by: Álvaro Velad Galván <ladvan91@hotmail.com>
shaka-project · Oct 31, 2023 · 4425dca · 4425dca
1 parent c457db8
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diff --git a/build/types/core b/build/types/core
@@ -53,10 +53,6 @@
 
 +../../lib/polyfill/all.js
 
-+../../lib/routing/node.js
-+../../lib/routing/payload.js
-+../../lib/routing/walker.js
-
 +../../lib/cea/dummy_cea_parser.js
 +../../lib/cea/dummy_caption_decoder.js
 
@@ -101,6 +97,7 @@
 +../../lib/util/mp4_generator.js
 +../../lib/util/mp4_parser.js
 +../../lib/util/multi_map.js
++../../lib/util/mutex.js
 +../../lib/util/networking.js
 +../../lib/util/object_utils.js
 +../../lib/util/operation_manager.js

diff --git a/demo/main.js b/demo/main.js
@@ -709,15 +709,15 @@ shakaDemo.Main = class {
 
     // Does the browser support the asset's manifest type?
     if (asset.features.includes(shakaAssets.Feature.DASH) &&
-        !this.support_.manifest['mpd']) {
+        !this.support_.manifest['application/dash+xml']) {
       return 'Your browser does not support MPEG-DASH manifests.';
     }
     if (asset.features.includes(shakaAssets.Feature.HLS) &&
-        !this.support_.manifest['m3u8']) {
+        !this.support_.manifest['application/x-mpegurl']) {
       return 'Your browser does not support HLS manifests.';
     }
     if (asset.features.includes(shakaAssets.Feature.MSS) &&
-        !this.support_.manifest['ism']) {
+        !this.support_.manifest['application/vnd.ms-sstr+xml']) {
       return 'Your browser does not support MSS manifests.';
     }
 

diff --git a/docs/tutorials/basic-usage.md b/docs/tutorials/basic-usage.md
@@ -52,7 +52,8 @@ function initApp() {
 async function initPlayer() {
   // Create a Player instance.
   const video = document.getElementById('video');
-  const player = new shaka.Player(video);
+  const player = new shaka.Player();
+  async player.attach(video);
 
   // Attach player to the window to make it easy to access in the JS console.
   window.player = player;

diff --git a/docs/tutorials/errors.md b/docs/tutorials/errors.md
@@ -17,7 +17,8 @@ const handleError = (error) => {
   }
 };
 
-const player = new shaka.Player(video);
+const player = new shaka.Player();
+await player.attach(video);
 
 // handle errors that occur after load
 player.addEventListener('error', handleError);

diff --git a/docs/tutorials/offline.md b/docs/tutorials/offline.md
@@ -79,14 +79,14 @@ the end of the tutorial.
 ```js
 // myapp.js
 
-function initApp() {
+async function initApp() {
   // Install built-in polyfills to patch browser incompatibilities.
   shaka.polyfill.installAll();
 
   // Check to see if the browser supports the basic APIs Shaka needs.
   if (shaka.Player.isBrowserSupported()) {
     // Everything looks good!
-    initPlayer();
+    await initPlayer();
   } else {
     // This browser does not have the minimum set of APIs we need.
     console.error('Browser not supported!');
@@ -99,10 +99,11 @@ function initApp() {
   window.addEventListener('offline', updateOnlineStatus);
 }
 
-function initPlayer() {
+async function initPlayer() {
   // Create a Player instance.
   const video = document.getElementById('video');
-  const player = new shaka.Player(video);
+  const player = new shaka.Player();
+  await player.attach(video);
 
   // Attach player and storage to the window to make it easy to access
   // in the JS console and so we can access it in other methods.
@@ -437,14 +438,14 @@ That’s it! For your convenience, here is the completed code:
 ```js
 // myapp.js
 
-function initApp() {
+async function initApp() {
   // Install built-in polyfills to patch browser incompatibilities.
   shaka.polyfill.installAll();
 
   // Check to see if the browser supports the basic APIs Shaka needs.
   if (shaka.Player.isBrowserSupported()) {
     // Everything looks good!
-    initPlayer();
+    await initPlayer();
   } else {
     // This browser does not have the minimum set of APIs we need.
     console.error('Browser not supported!');
@@ -457,10 +458,11 @@ function initApp() {
   window.addEventListener('offline', updateOnlineStatus);
 }
 
-function initPlayer() {
+async function initPlayer() {
   // Create a Player instance.
   const video = document.getElementById('video');
-  const player = new shaka.Player(video);
+  const player = new shaka.Player();
+  await player.attach(video);
 
   // Attach player and storage to the window to make it easy to access
   // in the JS console and so we can access it in other methods.

diff --git a/docs/tutorials/ui.md b/docs/tutorials/ui.md
@@ -203,7 +203,8 @@ constructor.
 ```js
 // "local" because it is for local playback only, as opposed to the player proxy
 // object, which will route your calls to the ChromeCast receiver as necessary.
-const localPlayer = new shaka.Player(videoElement);
+const localPlayer = new shaka.Player();
+await localPlayer.attach(videoElement);
 // "Overlay" because the UI will add DOM elements inside the container,
 // to visually overlay the video element
 const ui = new shaka.ui.Overlay(localPlayer, videoContainerElement,

diff --git a/lib/cast/cast_receiver.js b/lib/cast/cast_receiver.js
@@ -408,7 +408,7 @@ shaka.cast.CastReceiver = class extends shaka.util.FakeEventTarget {
       } catch (error) {
         // Pass any errors through to the app.
         goog.asserts.assert(error instanceof shaka.util.Error,
-            'Wrong error type!');
+            'Wrong error type! Error: ' + error);
         const eventType = shaka.util.FakeEvent.EventName.Error;
         const data = (new Map()).set('detail', error);
         const event = new shaka.util.FakeEvent(eventType, data);

diff --git a/lib/dash/dash_parser.js b/lib/dash/dash_parser.js
@@ -2254,8 +2254,6 @@ shaka.dash.DashParser.GenerateSegmentIndexFunction;
 shaka.dash.DashParser.StreamInfo;
 
 
-shaka.media.ManifestParser.registerParserByExtension(
-    'mpd', () => new shaka.dash.DashParser());
 shaka.media.ManifestParser.registerParserByMime(
     'application/dash+xml', () => new shaka.dash.DashParser());
 shaka.media.ManifestParser.registerParserByMime(

diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
@@ -4003,8 +4003,6 @@ shaka.hls.HlsParser.PresentationType_ = {
   LIVE: 'LIVE',
 };
 
-shaka.media.ManifestParser.registerParserByExtension(
-    'm3u8', () => new shaka.hls.HlsParser());
 shaka.media.ManifestParser.registerParserByMime(
     'application/x-mpegurl', () => new shaka.hls.HlsParser());
 shaka.media.ManifestParser.registerParserByMime(

diff --git a/lib/media/manifest_parser.js b/lib/media/manifest_parser.js
@@ -6,10 +6,8 @@
 
 goog.provide('shaka.media.ManifestParser');
 
-goog.require('goog.Uri');
+goog.require('shaka.Deprecate');
 goog.require('shaka.log');
-goog.require('shaka.net.NetworkingEngine');
-goog.require('shaka.net.NetworkingUtils');
 goog.require('shaka.util.Error');
 goog.require('shaka.util.Platform');
 
@@ -29,7 +27,9 @@ shaka.media.ManifestParser = class {
    * @export
    */
   static registerParserByExtension(extension, parserFactory) {
-    shaka.media.ManifestParser.parsersByExtension[extension] = parserFactory;
+    shaka.Deprecate.deprecateFeature(5,
+        'ManifestParser',
+        'Please use an ManifestParser with registerParserByMime function.');
   }
 
 
@@ -71,9 +71,6 @@ shaka.media.ManifestParser = class {
       for (const type in ManifestParser.parsersByMime) {
         support[type] = true;
       }
-      for (const type in ManifestParser.parsersByExtension) {
-        support[type] = true;
-      }
     }
 
     // Make sure all well-known types are tested as well, just to show an
@@ -87,14 +84,6 @@ shaka.media.ManifestParser = class {
       // SmoothStreaming
       'application/vnd.ms-sstr+xml',
     ];
-    const testExtensions = {
-      // DASH
-      'mpd': 'application/dash+xml',
-      // HLS
-      'm3u8': 'application/x-mpegurl',
-      // SmoothStreaming
-      'ism': 'application/vnd.ms-sstr+xml',
-    };
 
     for (const type of testMimeTypes) {
       // Only query our parsers for MSE-enabled platforms.  Otherwise, query a
@@ -106,18 +95,6 @@ shaka.media.ManifestParser = class {
       }
     }
 
-    for (const extension in testExtensions) {
-      // Only query our parsers for MSE-enabled platforms.  Otherwise, query a
-      // temporary media element for native support for these MIME type for the
-      // extension.
-      if (shaka.util.Platform.supportsMediaSource()) {
-        support[extension] = !!ManifestParser.parsersByExtension[extension];
-      } else {
-        const type = testExtensions[extension];
-        support[extension] = shaka.util.Platform.supportsMediaType(type);
-      }
-    }
-
     return support;
   }
 
@@ -127,12 +104,10 @@ shaka.media.ManifestParser = class {
    * parse the manifest at |uri|.
    *
    * @param {string} uri
-   * @param {!shaka.net.NetworkingEngine} netEngine
-   * @param {shaka.extern.RetryParameters} retryParams
    * @param {?string} mimeType
-   * @return {!Promise.<shaka.extern.ManifestParser.Factory>}
+   * @return {shaka.extern.ManifestParser.Factory}
    */
-  static async getFactory(uri, netEngine, retryParams, mimeType) {
+  static getFactory(uri, mimeType) {
     const ManifestParser = shaka.media.ManifestParser;
 
     // Try using the MIME type we were given.
@@ -146,34 +121,6 @@ shaka.media.ManifestParser = class {
           'Could not determine manifest type using MIME type ', mimeType);
     }
 
-    const extension = ManifestParser.getExtension(uri);
-    if (extension) {
-      const factory = ManifestParser.parsersByExtension[extension];
-      if (factory) {
-        return factory;
-      }
-
-      shaka.log.warning(
-          'Could not determine manifest type for extension ', extension);
-    } else {
-      shaka.log.warning('Could not find extension for ', uri);
-    }
-
-    if (!mimeType) {
-      mimeType = await shaka.net.NetworkingUtils.getMimeType(
-          uri, netEngine, retryParams);
-
-      if (mimeType) {
-        const factory = shaka.media.ManifestParser.parsersByMime[mimeType];
-        if (factory) {
-          return factory;
-        }
-
-        shaka.log.warning('Could not determine manifest type using MIME type',
-            mimeType);
-      }
-    }
-
     throw new shaka.util.Error(
         shaka.util.Error.Severity.CRITICAL,
         shaka.util.Error.Category.MANIFEST,
@@ -183,35 +130,15 @@ shaka.media.ManifestParser = class {
 
 
   /**
-   * @param {string} uri
-   * @return {string}
-   */
-  static getExtension(uri) {
-    const uriObj = new goog.Uri(uri);
-    const uriPieces = uriObj.getPath().split('/');
-    const uriFilename = uriPieces.pop();
-    const filenamePieces = uriFilename.split('.');
-
-    // Only one piece means there is no extension.
-    if (filenamePieces.length == 1) {
-      return '';
-    }
-
-    return filenamePieces.pop().toLowerCase();
-  }
-
-
-  /**
-   * Determines whether or not this URI and MIME type are supported by our own
+   * Determines whether or not the MIME type is supported by our own
    * manifest parsers on this platform.  This takes into account whether or not
    * MediaSource is available, as well as which parsers are registered to the
    * system.
    *
-   * @param {string} uri
    * @param {string} mimeType
    * @return {boolean}
    */
-  static isSupported(uri, mimeType) {
+  static isSupported(mimeType) {
     // Without MediaSource, our own parsers are useless.
     if (!shaka.util.Platform.supportsMediaSource()) {
       return false;
@@ -221,11 +148,6 @@ shaka.media.ManifestParser = class {
       return true;
     }
 
-    const extension = shaka.media.ManifestParser.getExtension(uri);
-    if (extension in shaka.media.ManifestParser.parsersByExtension) {
-      return true;
-    }
-
     return false;
   }
 };
@@ -273,11 +195,3 @@ shaka.media.ManifestParser.AccessibilityPurpose = {
 shaka.media.ManifestParser.parsersByMime = {};
 
 
-/**
- * Contains the parser factory functions indexed by file extension.
- *
- * @type {!Object.<string, shaka.extern.ManifestParser.Factory>}
- */
-shaka.media.ManifestParser.parsersByExtension = {};
-
-
diff --git a/lib/media/media_source_engine.js b/lib/media/media_source_engine.js
@@ -514,8 +514,8 @@ shaka.media.MediaSourceEngine = class {
             shaka.util.Error.Category.MEDIA,
             shaka.util.Error.Code.MEDIA_SOURCE_OPERATION_THREW,
             exception,
-            'The mediaSource_ status was' + this.mediaSource_.readyState +
-            'expected \'open\'');
+            'The mediaSource_ status was ' + this.mediaSource_.readyState +
+            ' expected \'open\'');
       }
 
       if (this.sequenceMode_) {

diff --git a/lib/mss/mss_parser.js b/lib/mss/mss_parser.js
@@ -1086,7 +1086,5 @@ shaka.mss.MssParser.Context;
  */
 shaka.mss.MssParser.TimeRange;
 
-shaka.media.ManifestParser.registerParserByExtension(
-    'ism', () => new shaka.mss.MssParser());
 shaka.media.ManifestParser.registerParserByMime(
     'application/vnd.ms-sstr+xml', () => new shaka.mss.MssParser());
diff --git a/lib/offline/storage.js b/lib/offline/storage.js
@@ -12,6 +12,7 @@ goog.require('shaka.log');
 goog.require('shaka.media.DrmEngine');
 goog.require('shaka.media.ManifestParser');
 goog.require('shaka.net.NetworkingEngine');
+goog.require('shaka.net.NetworkingUtils');
 goog.require('shaka.offline.DownloadInfo');
 goog.require('shaka.offline.DownloadManager');
 goog.require('shaka.offline.OfflineUri');
@@ -271,10 +272,13 @@ shaka.offline.Storage = class {
       goog.asserts.assert(
           this.networkingEngine_, 'Should not call |store| after |destroy|');
 
-      const factory = await shaka.media.ManifestParser.getFactory(
+      if (!mimeType) {
+        mimeType = await shaka.net.NetworkingUtils.getMimeType(
+            uri, this.networkingEngine_, config.manifest.retryParameters);
+      }
+
+      const factory = shaka.media.ManifestParser.getFactory(
           uri,
-          this.networkingEngine_,
-          config.manifest.retryParameters,
           mimeType || null);
 
       return factory();