PerformanceTests/Media/media-source-loader.js

   1 class MediaSourceLoader {
   2     constructor(url)
   3     {
   4         this._url = url;
   5         this.onload = null;
   6         this.onerror = null;
   7     }
   8
   9     loadManifest()
  10     {
  11         return new Promise((resolve, reject) => {
  12             if (this._manifest) {
  13                 resolve();
  14                 return;
  15             }
  16
  17             var request = new XMLHttpRequest();
  18             request.open('GET', this._url, true);
  19             request.responseType = 'json';
  20             request.onload = (event) => {
  21                 this.loadManifestSucceeded(event);
  22                 resolve();
  23             }
  24             request.onerror = (event) => {
  25                 this.loadManifestFailed(event);
  26                 reject(event);
  27             }
  28             request.send();
  29         })
  30     }
  31
  32     loadManifestSucceeded(event)
  33     {
  34         this._manifest = event.target.response;
  35
  36         if (!this._manifest || !this._manifest.url) {
  37             if (this.onerror)
  38                 this.onerror();
  39             return;
  40         }
  41     }
  42
  43     loadManifestFailed()
  44     {
  45         if (this.onerror)
  46             this.onerror();
  47     }
  48
  49     loadMediaData()
  50     {
  51         return new Promise((resolve, reject) => {
  52             this.loadManifest().then(() => {
  53                 var request = new XMLHttpRequest();
  54                 request.open('GET', this._manifest.url, true);
  55                 request.responseType = 'arraybuffer';
  56                 request.onload = (event) => {
  57                     this.loadMediaDataSucceeded(event);
  58                     resolve();
  59                 }
  60                 request.onerror = (event) => {
  61                     this.loadMediaDataFailed(event);
  62                     reject(event);
  63                 }
  64                 request.send();
  65             });
  66         });
  67     }
  68
  69     loadMediaDataSucceeded(event)
  70     {
  71         this._mediaData = event.target.response;
  72
  73         if (this.onload)
  74             this.onload();
  75     }
  76
  77     loadMediaDataFailed()
  78     {
  79         if (this.onerror)
  80             this.onerror();
  81     }
  82
  83     get type()
  84     {
  85         return this._manifest ? this._manifest.type : "";
  86     }
  87
  88     get duration()
  89     {
  90         if (!this._manifest)
  91             return 0;
  92         return this._manifest.media.reduce((duration, media) => { return duration + media.duration }, 0);
  93     }
  94
  95     get initSegment()
  96     {
  97         if (!this._manifest || !this._manifest.init || !this._mediaData)
  98             return null;
  99         var init = this._manifest.init;
 100         return this._mediaData.slice(init.offset, init.offset + init.size);
 101     }
 102
 103     get mediaSegmentsLength()
 104     {
 105         if (!this._manifest || !this._manifest.media)
 106             return 0;
 107         return this._manifest.media.length;
 108     }
 109
 110     *mediaSegments()
 111     {
 112         if (!this._manifest || !this._manifest.media || !this._mediaData)
 113             return;
 114
 115         for (var media of this._manifest.media)
 116             yield this._mediaData.slice(media.offset, media.offset + media.size);
 117     }
 118
 119     get everyMediaSegment()
 120     {
 121         if (!this._manifest || !this._manifest.media || !this._mediaData)
 122             return null;
 123
 124         return this._mediaData.slice(this._manifest.media[0].offset);
 125     }
 126 };