client/src/assets/player/webtorrent/webtorrent-plugin.ts

   1 import videojs from 'video.js'
   2 import * as WebTorrent from 'webtorrent'
   3 import { renderVideo } from './video-renderer'
   4 import { LoadedQualityData, PlayerNetworkInfo, WebtorrentPluginOptions } from '../peertube-videojs-typings'
   5 import { getRtcConfig, timeToInt, videoFileMaxByResolution, videoFileMinByResolution, isIOS, isSafari } from '../utils'
   6 import { PeertubeChunkStore } from './peertube-chunk-store'
   7 import {
   8   getAverageBandwidthInStore,
   9   getStoredMute,
  10   getStoredP2PEnabled,
  11   getStoredVolume,
  12   saveAverageBandwidth
  13 } from '../peertube-player-local-storage'
  14 import { VideoFile } from '@shared/models'
  15
  16 const CacheChunkStore = require('cache-chunk-store')
  17
  18 type PlayOptions = {
  19   forcePlay?: boolean,
  20   seek?: number,
  21   delay?: number
  22 }
  23
  24 const Plugin = videojs.getPlugin('plugin')
  25
  26 class WebTorrentPlugin extends Plugin {
  27   readonly videoFiles: VideoFile[]
  28
  29   private readonly playerElement: HTMLVideoElement
  30
  31   private readonly autoplay: boolean = false
  32   private readonly startTime: number = 0
  33   private readonly savePlayerSrcFunction: videojs.Player['src']
  34   private readonly videoDuration: number
  35   private readonly CONSTANTS = {
  36     INFO_SCHEDULER: 1000, // Don't change this
  37     AUTO_QUALITY_SCHEDULER: 3000, // Check quality every 3 seconds
  38     AUTO_QUALITY_THRESHOLD_PERCENT: 30, // Bandwidth should be 30% more important than a resolution bitrate to change to it
  39     AUTO_QUALITY_OBSERVATION_TIME: 10000, // Wait 10 seconds after having change the resolution before another check
  40     AUTO_QUALITY_HIGHER_RESOLUTION_DELAY: 5000, // Buffering higher resolution during 5 seconds
  41     BANDWIDTH_AVERAGE_NUMBER_OF_VALUES: 5 // Last 5 seconds to build average bandwidth
  42   }
  43
  44   private readonly webtorrent = new WebTorrent({
  45     tracker: {
  46       rtcConfig: getRtcConfig()
  47     },
  48     dht: false
  49   })
  50
  51   private currentVideoFile: VideoFile
  52   private torrent: WebTorrent.Torrent
  53
  54   private renderer: any
  55   private fakeRenderer: any
  56   private destroyingFakeRenderer = false
  57
  58   private autoResolution = true
  59   private autoResolutionPossible = true
  60   private isAutoResolutionObservation = false
  61   private playerRefusedP2P = false
  62
  63   private torrentInfoInterval: any
  64   private autoQualityInterval: any
  65   private addTorrentDelay: any
  66   private qualityObservationTimer: any
  67   private runAutoQualitySchedulerTimer: any
  68
  69   private downloadSpeeds: number[] = []
  70
  71   constructor (player: videojs.Player, options?: WebtorrentPluginOptions) {
  72     super(player)
  73
  74     this.startTime = timeToInt(options.startTime)
  75
  76     // Disable auto play on iOS
  77     this.autoplay = options.autoplay
  78     this.playerRefusedP2P = !getStoredP2PEnabled()
  79
  80     this.videoFiles = options.videoFiles
  81     this.videoDuration = options.videoDuration
  82
  83     this.savePlayerSrcFunction = this.player.src
  84     this.playerElement = options.playerElement
  85
  86     this.player.ready(() => {
  87       const playerOptions = this.player.options_
  88
  89       const volume = getStoredVolume()
  90       if (volume !== undefined) this.player.volume(volume)
  91
  92       const muted = playerOptions.muted !== undefined ? playerOptions.muted : getStoredMute()
  93       if (muted !== undefined) this.player.muted(muted)
  94
  95       this.player.duration(options.videoDuration)
  96
  97       this.initializePlayer()
  98       this.runTorrentInfoScheduler()
  99
 100       this.player.one('play', () => {
 101         // Don't run immediately scheduler, wait some seconds the TCP connections are made
 102         this.runAutoQualitySchedulerTimer = setTimeout(() => this.runAutoQualityScheduler(), this.CONSTANTS.AUTO_QUALITY_SCHEDULER)
 103       })
 104     })
 105   }
 106
 107   dispose () {
 108     clearTimeout(this.addTorrentDelay)
 109     clearTimeout(this.qualityObservationTimer)
 110     clearTimeout(this.runAutoQualitySchedulerTimer)
 111
 112     clearInterval(this.torrentInfoInterval)
 113     clearInterval(this.autoQualityInterval)
 114
 115     // Don't need to destroy renderer, video player will be destroyed
 116     this.flushVideoFile(this.currentVideoFile, false)
 117
 118     this.destroyFakeRenderer()
 119   }
 120
 121   getCurrentResolutionId () {
 122     return this.currentVideoFile ? this.currentVideoFile.resolution.id : -1
 123   }
 124
 125   updateVideoFile (
 126     videoFile?: VideoFile,
 127     options: {
 128       forcePlay?: boolean,
 129       seek?: number,
 130       delay?: number
 131     } = {},
 132     done: () => void = () => { /* empty */ }
 133   ) {
 134     // Automatically choose the adapted video file
 135     if (!videoFile) {
 136       const savedAverageBandwidth = getAverageBandwidthInStore()
 137       videoFile = savedAverageBandwidth
 138         ? this.getAppropriateFile(savedAverageBandwidth)
 139         : this.pickAverageVideoFile()
 140     }
 141
 142     if (!videoFile) {
 143       throw Error(`Can't update video file since videoFile is undefined.`)
 144     }
 145
 146     // Don't add the same video file once again
 147     if (this.currentVideoFile !== undefined && this.currentVideoFile.magnetUri === videoFile.magnetUri) {
 148       return
 149     }
 150
 151     // Do not display error to user because we will have multiple fallback
 152     this.disableErrorDisplay();
 153
 154     // Hack to "simulate" src link in video.js >= 6
 155     // Without this, we can't play the video after pausing it
 156     // https://github.com/videojs/video.js/blob/master/src/js/player.js#L1633
 157     (this.player as any).src = () => true
 158     const oldPlaybackRate = this.player.playbackRate()
 159
 160     const previousVideoFile = this.currentVideoFile
 161     this.currentVideoFile = videoFile
 162
 163     // Don't try on iOS that does not support MediaSource
 164     // Or don't use P2P if webtorrent is disabled
 165     if (isIOS() || this.playerRefusedP2P) {
 166       return this.fallbackToHttp(options, () => {
 167         this.player.playbackRate(oldPlaybackRate)
 168         return done()
 169       })
 170     }
 171
 172     this.addTorrent(this.currentVideoFile.magnetUri, previousVideoFile, options, () => {
 173       this.player.playbackRate(oldPlaybackRate)
 174       return done()
 175     })
 176
 177     this.changeQuality()
 178     this.trigger('resolutionChange', { auto: this.autoResolution, resolutionId: this.currentVideoFile.resolution.id })
 179   }
 180
 181   updateResolution (resolutionId: number, delay = 0) {
 182     // Remember player state
 183     const currentTime = this.player.currentTime()
 184     const isPaused = this.player.paused()
 185
 186     // Hide bigPlayButton
 187     if (!isPaused) {
 188       this.player.bigPlayButton.hide()
 189     }
 190
 191     // Audio-only (resolutionId === 0) gets special treatment
 192     if (resolutionId === 0) {
 193       // Audio-only: show poster, do not auto-hide controls
 194       this.player.addClass('vjs-playing-audio-only-content')
 195       this.player.posterImage.show()
 196     } else {
 197       // Hide poster to have black background
 198       this.player.removeClass('vjs-playing-audio-only-content')
 199       this.player.posterImage.hide()
 200     }
 201
 202     const newVideoFile = this.videoFiles.find(f => f.resolution.id === resolutionId)
 203     const options = {
 204       forcePlay: false,
 205       delay,
 206       seek: currentTime + (delay / 1000)
 207     }
 208
 209     this.updateVideoFile(newVideoFile, options)
 210   }
 211
 212   flushVideoFile (videoFile: VideoFile, destroyRenderer = true) {
 213     if (videoFile !== undefined && this.webtorrent.get(videoFile.magnetUri)) {
 214       if (destroyRenderer === true && this.renderer && this.renderer.destroy) this.renderer.destroy()
 215
 216       this.webtorrent.remove(videoFile.magnetUri)
 217       console.log('Removed ' + videoFile.magnetUri)
 218     }
 219   }
 220
 221   enableAutoResolution () {
 222     this.autoResolution = true
 223     this.trigger('resolutionChange', { auto: this.autoResolution, resolutionId: this.getCurrentResolutionId() })
 224   }
 225
 226   disableAutoResolution (forbid = false) {
 227     if (forbid === true) this.autoResolutionPossible = false
 228
 229     this.autoResolution = false
 230     this.trigger('autoResolutionChange', { possible: this.autoResolutionPossible })
 231     this.trigger('resolutionChange', { auto: this.autoResolution, resolutionId: this.getCurrentResolutionId() })
 232   }
 233
 234   isAutoResolutionPossible () {
 235     return this.autoResolutionPossible
 236   }
 237
 238   getTorrent () {
 239     return this.torrent
 240   }
 241
 242   getCurrentVideoFile () {
 243     return this.currentVideoFile
 244   }
 245
 246   private addTorrent (
 247     magnetOrTorrentUrl: string,
 248     previousVideoFile: VideoFile,
 249     options: PlayOptions,
 250     done: Function
 251   ) {
 252     if (!magnetOrTorrentUrl) return this.fallbackToHttp(options, done)
 253
 254     console.log('Adding ' + magnetOrTorrentUrl + '.')
 255
 256     const oldTorrent = this.torrent
 257     const torrentOptions = {
 258       // Don't use arrow function: it breaks webtorrent (that uses `new` keyword)
 259       store: function (chunkLength: number, storeOpts: any) {
 260         return new CacheChunkStore(new PeertubeChunkStore(chunkLength, storeOpts), {
 261           max: 100
 262         })
 263       }
 264     }
 265
 266     this.torrent = this.webtorrent.add(magnetOrTorrentUrl, torrentOptions, torrent => {
 267       console.log('Added ' + magnetOrTorrentUrl + '.')
 268
 269       if (oldTorrent) {
 270         // Pause the old torrent
 271         this.stopTorrent(oldTorrent)
 272
 273         // We use a fake renderer so we download correct pieces of the next file
 274         if (options.delay) this.renderFileInFakeElement(torrent.files[ 0 ], options.delay)
 275       }
 276
 277       // Render the video in a few seconds? (on resolution change for example, we wait some seconds of the new video resolution)
 278       this.addTorrentDelay = setTimeout(() => {
 279         // We don't need the fake renderer anymore
 280         this.destroyFakeRenderer()
 281
 282         const paused = this.player.paused()
 283
 284         this.flushVideoFile(previousVideoFile)
 285
 286         // Update progress bar (just for the UI), do not wait rendering
 287         if (options.seek) this.player.currentTime(options.seek)
 288
 289         const renderVideoOptions = { autoplay: false, controls: true }
 290         renderVideo(torrent.files[ 0 ], this.playerElement, renderVideoOptions, (err, renderer) => {
 291           this.renderer = renderer
 292
 293           if (err) return this.fallbackToHttp(options, done)
 294
 295           return this.tryToPlay(err => {
 296             if (err) return done(err)
 297
 298             if (options.seek) this.seek(options.seek)
 299             if (options.forcePlay === false && paused === true) this.player.pause()
 300
 301             return done()
 302           })
 303         })
 304       }, options.delay || 0)
 305     })
 306
 307     this.torrent.on('error', (err: any) => console.error(err))
 308
 309     this.torrent.on('warning', (err: any) => {
 310       // We don't support HTTP tracker but we don't care -> we use the web socket tracker
 311       if (err.message.indexOf('Unsupported tracker protocol') !== -1) return
 312
 313       // Users don't care about issues with WebRTC, but developers do so log it in the console
 314       if (err.message.indexOf('Ice connection failed') !== -1) {
 315         console.log(err)
 316         return
 317       }
 318
 319       // Magnet hash is not up to date with the torrent file, add directly the torrent file
 320       if (err.message.indexOf('incorrect info hash') !== -1) {
 321         console.error('Incorrect info hash detected, falling back to torrent file.')
 322         const newOptions = { forcePlay: true, seek: options.seek }
 323         return this.addTorrent(this.torrent[ 'xs' ], previousVideoFile, newOptions, done)
 324       }
 325
 326       // Remote instance is down
 327       if (err.message.indexOf('from xs param') !== -1) {
 328         this.handleError(err)
 329       }
 330
 331       console.warn(err)
 332     })
 333   }
 334
 335   private tryToPlay (done?: (err?: Error) => void) {
 336     if (!done) done = function () { /* empty */ }
 337
 338     const playPromise = this.player.play()
 339     if (playPromise !== undefined) {
 340       return playPromise.then(() => done())
 341                         .catch((err: Error) => {
 342                           if (err.message.indexOf('The play() request was interrupted by a call to pause()') !== -1) {
 343                             return
 344                           }
 345
 346                           console.error(err)
 347                           this.player.pause()
 348                           this.player.posterImage.show()
 349                           this.player.removeClass('vjs-has-autoplay')
 350                           this.player.removeClass('vjs-has-big-play-button-clicked')
 351                           this.player.removeClass('vjs-playing-audio-only-content')
 352
 353                           return done()
 354                         })
 355     }
 356
 357     return done()
 358   }
 359
 360   private seek (time: number) {
 361     this.player.currentTime(time)
 362     this.player.handleTechSeeked_()
 363   }
 364
 365   private getAppropriateFile (averageDownloadSpeed?: number): VideoFile {
 366     if (this.videoFiles === undefined) return undefined
 367
 368     const files = this.videoFiles.filter(f => f.resolution.id !== 0)
 369
 370     if (files.length === 0) return undefined
 371     if (files.length === 1) return files[0]
 372
 373     // Don't change the torrent if the player ended
 374     if (this.torrent && this.torrent.progress === 1 && this.player.ended()) return this.currentVideoFile
 375
 376     if (!averageDownloadSpeed) averageDownloadSpeed = this.getAndSaveActualDownloadSpeed()
 377
 378     // Limit resolution according to player height
 379     const playerHeight = this.playerElement.offsetHeight
 380
 381     // We take the first resolution just above the player height
 382     // Example: player height is 530px, we want the 720p file instead of 480p
 383     let maxResolution = files[0].resolution.id
 384     for (let i = files.length - 1; i >= 0; i--) {
 385       const resolutionId = files[i].resolution.id
 386       if (resolutionId !== 0 && resolutionId >= playerHeight) {
 387         maxResolution = resolutionId
 388         break
 389       }
 390     }
 391
 392     // Filter videos we can play according to our screen resolution and bandwidth
 393     const filteredFiles = files.filter(f => f.resolution.id <= maxResolution)
 394                                .filter(f => {
 395                                  const fileBitrate = (f.size / this.videoDuration)
 396                                  let threshold = fileBitrate
 397
 398                                  // If this is for a higher resolution or an initial load: add a margin
 399                                  if (!this.currentVideoFile || f.resolution.id > this.currentVideoFile.resolution.id) {
 400                                    threshold += ((fileBitrate * this.CONSTANTS.AUTO_QUALITY_THRESHOLD_PERCENT) / 100)
 401                                  }
 402
 403                                  return averageDownloadSpeed > threshold
 404                                })
 405
 406     // If the download speed is too bad, return the lowest resolution we have
 407     if (filteredFiles.length === 0) return videoFileMinByResolution(files)
 408
 409     return videoFileMaxByResolution(filteredFiles)
 410   }
 411
 412   private getAndSaveActualDownloadSpeed () {
 413     const start = Math.max(this.downloadSpeeds.length - this.CONSTANTS.BANDWIDTH_AVERAGE_NUMBER_OF_VALUES, 0)
 414     const lastDownloadSpeeds = this.downloadSpeeds.slice(start, this.downloadSpeeds.length)
 415     if (lastDownloadSpeeds.length === 0) return -1
 416
 417     const sum = lastDownloadSpeeds.reduce((a, b) => a + b)
 418     const averageBandwidth = Math.round(sum / lastDownloadSpeeds.length)
 419
 420     // Save the average bandwidth for future use
 421     saveAverageBandwidth(averageBandwidth)
 422
 423     return averageBandwidth
 424   }
 425
 426   private initializePlayer () {
 427     this.buildQualities()
 428
 429     if (this.autoplay) {
 430       this.player.posterImage.hide()
 431
 432       return this.updateVideoFile(undefined, { forcePlay: true, seek: this.startTime })
 433     }
 434
 435     // Proxy first play
 436     const oldPlay = this.player.play.bind(this.player);
 437     (this.player as any).play = () => {
 438       this.player.addClass('vjs-has-big-play-button-clicked')
 439       this.player.play = oldPlay
 440
 441       this.updateVideoFile(undefined, { forcePlay: true, seek: this.startTime })
 442     }
 443   }
 444
 445   private runAutoQualityScheduler () {
 446     this.autoQualityInterval = setInterval(() => {
 447
 448       // Not initialized or in HTTP fallback
 449       if (this.torrent === undefined || this.torrent === null) return
 450       if (this.autoResolution === false) return
 451       if (this.isAutoResolutionObservation === true) return
 452
 453       const file = this.getAppropriateFile()
 454       let changeResolution = false
 455       let changeResolutionDelay = 0
 456
 457       // Lower resolution
 458       if (this.isPlayerWaiting() && file.resolution.id < this.currentVideoFile.resolution.id) {
 459         console.log('Downgrading automatically the resolution to: %s', file.resolution.label)
 460         changeResolution = true
 461       } else if (file.resolution.id > this.currentVideoFile.resolution.id) { // Higher resolution
 462         console.log('Upgrading automatically the resolution to: %s', file.resolution.label)
 463         changeResolution = true
 464         changeResolutionDelay = this.CONSTANTS.AUTO_QUALITY_HIGHER_RESOLUTION_DELAY
 465       }
 466
 467       if (changeResolution === true) {
 468         this.updateResolution(file.resolution.id, changeResolutionDelay)
 469
 470         // Wait some seconds in observation of our new resolution
 471         this.isAutoResolutionObservation = true
 472
 473         this.qualityObservationTimer = setTimeout(() => {
 474           this.isAutoResolutionObservation = false
 475         }, this.CONSTANTS.AUTO_QUALITY_OBSERVATION_TIME)
 476       }
 477     }, this.CONSTANTS.AUTO_QUALITY_SCHEDULER)
 478   }
 479
 480   private isPlayerWaiting () {
 481     return this.player && this.player.hasClass('vjs-waiting')
 482   }
 483
 484   private runTorrentInfoScheduler () {
 485     this.torrentInfoInterval = setInterval(() => {
 486       // Not initialized yet
 487       if (this.torrent === undefined) return
 488
 489       // Http fallback
 490       if (this.torrent === null) return this.player.trigger('p2pInfo', false)
 491
 492       // this.webtorrent.downloadSpeed because we need to take into account the potential old torrent too
 493       if (this.webtorrent.downloadSpeed !== 0) this.downloadSpeeds.push(this.webtorrent.downloadSpeed)
 494
 495       return this.player.trigger('p2pInfo', {
 496         source: 'webtorrent',
 497         http: {
 498           downloadSpeed: 0,
 499           uploadSpeed: 0,
 500           downloaded: 0,
 501           uploaded: 0
 502         },
 503         p2p: {
 504           downloadSpeed: this.torrent.downloadSpeed,
 505           numPeers: this.torrent.numPeers,
 506           uploadSpeed: this.torrent.uploadSpeed,
 507           downloaded: this.torrent.downloaded,
 508           uploaded: this.torrent.uploaded
 509         }
 510       } as PlayerNetworkInfo)
 511     }, this.CONSTANTS.INFO_SCHEDULER)
 512   }
 513
 514   private fallbackToHttp (options: PlayOptions, done?: Function) {
 515     const paused = this.player.paused()
 516
 517     this.disableAutoResolution(true)
 518
 519     this.flushVideoFile(this.currentVideoFile, true)
 520     this.torrent = null
 521
 522     // Enable error display now this is our last fallback
 523     this.player.one('error', () => this.enableErrorDisplay())
 524
 525     const httpUrl = this.currentVideoFile.fileUrl
 526     this.player.src = this.savePlayerSrcFunction
 527     this.player.src(httpUrl)
 528
 529     this.changeQuality()
 530
 531     // We changed the source, so reinit captions
 532     this.player.trigger('sourcechange')
 533
 534     return this.tryToPlay(err => {
 535       if (err && done) return done(err)
 536
 537       if (options.seek) this.seek(options.seek)
 538       if (options.forcePlay === false && paused === true) this.player.pause()
 539
 540       if (done) return done()
 541     })
 542   }
 543
 544   private handleError (err: Error | string) {
 545     return this.player.trigger('customError', { err })
 546   }
 547
 548   private enableErrorDisplay () {
 549     this.player.addClass('vjs-error-display-enabled')
 550   }
 551
 552   private disableErrorDisplay () {
 553     this.player.removeClass('vjs-error-display-enabled')
 554   }
 555
 556   private pickAverageVideoFile () {
 557     if (this.videoFiles.length === 1) return this.videoFiles[0]
 558
 559     return this.videoFiles[Math.floor(this.videoFiles.length / 2)]
 560   }
 561
 562   private stopTorrent (torrent: WebTorrent.Torrent) {
 563     torrent.pause()
 564     // Pause does not remove actual peers (in particular the webseed peer)
 565     torrent.removePeer(torrent[ 'ws' ])
 566   }
 567
 568   private renderFileInFakeElement (file: WebTorrent.TorrentFile, delay: number) {
 569     this.destroyingFakeRenderer = false
 570
 571     const fakeVideoElem = document.createElement('video')
 572     renderVideo(file, fakeVideoElem, { autoplay: false, controls: false }, (err, renderer) => {
 573       this.fakeRenderer = renderer
 574
 575       // The renderer returns an error when we destroy it, so skip them
 576       if (this.destroyingFakeRenderer === false && err) {
 577         console.error('Cannot render new torrent in fake video element.', err)
 578       }
 579
 580       // Load the future file at the correct time (in delay MS - 2 seconds)
 581       fakeVideoElem.currentTime = this.player.currentTime() + (delay - 2000)
 582     })
 583   }
 584
 585   private destroyFakeRenderer () {
 586     if (this.fakeRenderer) {
 587       this.destroyingFakeRenderer = true
 588
 589       if (this.fakeRenderer.destroy) {
 590         try {
 591           this.fakeRenderer.destroy()
 592         } catch (err) {
 593           console.log('Cannot destroy correctly fake renderer.', err)
 594         }
 595       }
 596       this.fakeRenderer = undefined
 597     }
 598   }
 599
 600   private buildQualities () {
 601     const qualityLevelsPayload = []
 602
 603     for (const file of this.videoFiles) {
 604       const representation = {
 605         id: file.resolution.id,
 606         label: this.buildQualityLabel(file),
 607         height: file.resolution.id,
 608         _enabled: true
 609       }
 610
 611       this.player.qualityLevels().addQualityLevel(representation)
 612
 613       qualityLevelsPayload.push({
 614         id: representation.id,
 615         label: representation.label,
 616         selected: false
 617       })
 618     }
 619
 620     const payload: LoadedQualityData = {
 621       qualitySwitchCallback: (d: any) => this.qualitySwitchCallback(d),
 622       qualityData: {
 623         video: qualityLevelsPayload
 624       }
 625     }
 626     this.player.tech(true).trigger('loadedqualitydata', payload)
 627   }
 628
 629   private buildQualityLabel (file: VideoFile) {
 630     let label = file.resolution.label
 631
 632     if (file.fps && file.fps >= 50) {
 633       label += file.fps
 634     }
 635
 636     return label
 637   }
 638
 639   private qualitySwitchCallback (id: number) {
 640     if (id === -1) {
 641       if (this.autoResolutionPossible === true) this.enableAutoResolution()
 642       return
 643     }
 644
 645     this.disableAutoResolution()
 646     this.updateResolution(id)
 647   }
 648
 649   private changeQuality () {
 650     const resolutionId = this.currentVideoFile.resolution.id
 651     const qualityLevels = this.player.qualityLevels()
 652
 653     if (resolutionId === -1) {
 654       qualityLevels.selectedIndex = -1
 655       return
 656     }
 657
 658     for (let i = 0; i < qualityLevels.length; i++) {
 659       const q = qualityLevels[i]
 660       if (q.height === resolutionId) qualityLevels.selectedIndex_ = i
 661     }
 662   }
 663 }
 664
 665 videojs.registerPlugin('webtorrent', WebTorrentPlugin)
 666 export { WebTorrentPlugin }