diff options
author | Cas <6506529+ThaUnknown@users.noreply.github.com> | 2021-08-20 00:41:34 +0300 |
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committer | GitHub <noreply@github.com> | 2021-08-20 00:41:34 +0300 |
commit | 604943e325c68721251a71c29d94e6a07ce0b31c (patch) | |
tree | d6728521ed5d4f13e5a3484f7d670756e89a832b /lib | |
parent | a46a7a51d9fd8efef86533c5868a2d23b1346b6e (diff) |
feat: add service worker server as an alternative to renderMedia (#2098)
* feat: add service worker server as an alternative to renderMedia
* code QL
* thanks gh auto merge
Co-authored-by: Diego RodrÃguez Baquero <github@diegorbaquero.com>
Diffstat (limited to 'lib')
-rw-r--r-- | lib/file.js | 76 | ||||
-rw-r--r-- | lib/worker-server.js | 75 | ||||
-rw-r--r-- | lib/worker.js | 16 |
3 files changed, 167 insertions, 0 deletions
diff --git a/lib/file.js b/lib/file.js index fd9ac7c..f3de744 100644 --- a/lib/file.js +++ b/lib/file.js @@ -7,6 +7,9 @@ const streamToBlobURL = require('stream-to-blob-url') const streamToBuffer = require('stream-with-known-length-to-buffer') const FileStream = require('./file-stream') const queueMicrotask = require('queue-microtask') +const rangeParser = require('range-parser') +const mime = require('mime') +const eos = require('end-of-stream') class File extends EventEmitter { constructor (torrent, file) { @@ -33,6 +36,8 @@ class File extends EventEmitter { this.done = true this.emit('done') } + + this._serviceWorker = torrent.client.serviceWorker } get downloaded () { @@ -144,6 +149,77 @@ class File extends EventEmitter { render.render(this, elem, opts, cb) } + _serve (req) { + const res = { + status: 200, + headers: { + // Support range-requests + 'Accept-Ranges': 'bytes', + 'Content-Type': mime.getType(this.name), + 'Cache-Control': 'no-cache, no-store, must-revalidate, max-age=0', + Expires: '0' + }, + body: req.method === 'HEAD' ? '' : 'STREAM' + } + // force the browser to download the file if if it's opened in a new tab + if (req.destination === 'document') { + res.headers['Content-Type'] = 'application/octet-stream' + res.headers['Content-Disposition'] = 'attachment' + res.body = 'DOWNLOAD' + } + + // `rangeParser` returns an array of ranges, or an error code (number) if + // there was an error parsing the range. + let range = rangeParser(this.length, req.headers.range || '') + + if (range.constructor === Array) { + res.status = 206 // indicates that range-request was understood + + // no support for multi-range request, just use the first range + range = range[0] + + res.headers['Content-Range'] = `bytes ${range.start}-${range.end}/${this.length}` + res.headers['Content-Length'] = `${range.end - range.start + 1}` + } else { + res.headers['Content-Length'] = this.length + } + + const stream = req.method === 'GET' && this.createReadStream(range) + + let pipe = null + if (stream) { + this.emit('stream', { stream, req, file: this }, piped => { + pipe = piped + + // piped stream might not close the original filestream on close/error, this is agressive but necessary + eos(piped, () => { + if (piped) piped.destroy() + stream.destroy() + }) + }) + } + + return [res, pipe || stream, pipe && stream] + } + + getStreamURL (cb = () => {}) { + if (typeof window === 'undefined') throw new Error('browser-only method') + if (!this._serviceWorker) throw new Error('No worker registered') + if (this._serviceWorker.state !== 'activated') throw new Error('Worker isn\'t activated') + const workerPath = this._serviceWorker.scriptURL.substr(0, this._serviceWorker.scriptURL.lastIndexOf('/') + 1).slice(window.location.origin.length) + const url = `${workerPath}webtorrent/${this._torrent.infoHash}/${encodeURI(this.path)}` + cb(null, url) + } + + streamTo (elem, cb = () => {}) { + if (typeof window === 'undefined') throw new Error('browser-only method') + if (!this._serviceWorker) throw new Error('No worker registered') + if (this._serviceWorker.state !== 'activated') throw new Error('Worker isn\'t activated') + const workerPath = this._serviceWorker.scriptURL.substr(0, this._serviceWorker.scriptURL.lastIndexOf('/') + 1).slice(window.location.origin.length) + elem.src = `${workerPath}webtorrent/${this._torrent.infoHash}/${encodeURI(this.path)}` + cb(null, elem) + } + _getMimeType () { return render.mime[path.extname(this.name).toLowerCase()] } diff --git a/lib/worker-server.js b/lib/worker-server.js new file mode 100644 index 0000000..5e6e56a --- /dev/null +++ b/lib/worker-server.js @@ -0,0 +1,75 @@ +/* global clients, MessageChannel, ReadableStream, Response */ +/* eslint-env serviceworker */ + +const portTimeoutDuration = 5000 + +module.exports = event => { + const { request } = event + const { url, method, headers, destination } = request + if (!url.includes(self.registration.scope + 'webtorrent/')) return null + if (url.includes(self.registration.scope + 'webtorrent/keepalive/')) return new Response() + + return clients.matchAll({ type: 'window', includeUncontrolled: true }) + .then(clients => { + return new Promise(resolve => { + // Use race condition for whoever controls the response stream + for (const client of clients) { + const messageChannel = new MessageChannel() + const { port1, port2 } = messageChannel + port1.onmessage = event => { + resolve([event.data, messageChannel]) + } + client.postMessage({ + url, + method, + headers: Object.fromEntries(headers.entries()), + scope: self.registration.scope, + destination, + type: 'webtorrent' + }, [port2]) + } + }) + }) + .then(([data, messageChannel]) => { + if (data.body === 'STREAM' || data.body === 'DOWNLOAD') { + let timeOut = null + return new Response(new ReadableStream({ + pull (controller) { + return new Promise(resolve => { + messageChannel.port1.onmessage = event => { + if (event.data) { + controller.enqueue(event.data) // event.data is Uint8Array + } else { + clearTimeout(timeOut) + controller.close() // event.data is null, means the stream ended + messageChannel.port1.onmessage = null + } + resolve() + } + + // 'media player' does NOT signal a close on the stream and we cannot close it because it's locked to the reader, + // so we just empty it after 5s of inactivity, the browser will request another port anyways + clearTimeout(timeOut) + if (data.body === 'STREAM') { + timeOut = setTimeout(() => { + controller.close() + messageChannel.port1.postMessage(false) // send timeout + messageChannel.port1.onmessage = null + resolve() + }, portTimeoutDuration) + } + + messageChannel.port1.postMessage(true) // send a pull request + }) + }, + cancel () { + // This event is never executed + messageChannel.port1.postMessage(false) // send a cancel request + } + }), data) + } + + return new Response(data.body, data) + }) + .catch(console.error) +} diff --git a/lib/worker.js b/lib/worker.js new file mode 100644 index 0000000..47c1127 --- /dev/null +++ b/lib/worker.js @@ -0,0 +1,16 @@ +/* eslint-env serviceworker */ + +const fileResponse = require('./worker-server') + +self.addEventListener('install', () => { + self.skipWaiting() +}) + +self.addEventListener('fetch', event => { + const res = fileResponse(event) + if (res) event.respondWith(res) +}) + +self.addEventListener('activate', evt => { + evt.waitUntil(self.clients.claim()) +}) |