pfrazee/index.html Secret

## index.html
<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Hello World!</title>
  </head>
  <body>
    <pre id="pre"></pre>

    <script>
      // You can also require other files to run in this process
      require('./renderer.js')
    </script>
  </body>
</html>

## main.js
const {app, BrowserWindow, protocol} = require('electron')
const stream = require('stream')
const url = require('url')
let mainWindow

protocol.registerSchemesAsPrivileged([
  { scheme: 'custom', privileges: { standard: true, secure: true, allowServiceWorkers: true, supportFetchAPI: true, corsEnabled: true } }
])

function getStream (chunkSize, data) {
  const body = new stream.PassThrough()
  console.log('getStream()')

  async function sendChunks () {
    let buf = Buffer.from(data)
    for (let i=0; i < Infinity; i++) {
      console.log('send', i)
      await new Promise(r => setTimeout(r, 150))
      body.push(buf.slice(0, chunkSize))
      buf = buf.slice(chunkSize)
      if (!buf.length) {
        break
      }
    }
    body.push(null)
  }

  sendChunks()
  return body
}

function dumbPassthrough () {
  var i = 0
  return new stream.Transform({
    async transform (chunk, encoding, cb) {
      await new Promise(r => setTimeout(r, 100))
      console.log('passthrough', i++)
      cb(null, chunk)
    }
  })
}

function createWindow () {
  protocol.registerStreamProtocol("custom", async (request, cb) => {
    const u = new url.URL(request.url)
    await new Promise(r => setTimeout(r, 500))
    cb({
      statusCode: 200,
      headers: { 'Content-Type': 'text/plain' },
      data: getStream(parseInt(u.searchParams.get('chunkSize')), Buffer.alloc(1024*1024*16)).pipe(dumbPassthrough())
    })
  })

  // DEBUG test to prove the pipe is correct:
  // getStream(1024 * 1024, Buffer.alloc(1024*1024*16)).pipe(dumbPassthrough()).pipe(new stream.Writable({
  //   write(chunk, encoding, cb) {
  //     console.log('got chunk', chunk.length)
  //     cb()
  //   },
  //   final (cb) {
  //     console.log('done')
  //     cb()
  //   }
  // }))

  // Create the browser window.
  mainWindow = new BrowserWindow({
    width: 800,
    height: 600,
    webPreferences: {
      nodeIntegration: true
    }
  })

  // and load the index.html of the app.
  mainWindow.loadFile('index.html')

  // Open the DevTools.
  // mainWindow.webContents.openDevTools()

  // Emitted when the window is closed.
  mainWindow.on('closed', function () {
    // Dereference the window object, usually you would store windows
    // in an array if your app supports multi windows, this is the time
    // when you should delete the corresponding element.
    mainWindow = null
  })
}

// This method will be called when Electron has finished
// initialization and is ready to create browser windows.
// Some APIs can only be used after this event occurs.
app.on('ready', createWindow)

// Quit when all windows are closed.
app.on('window-all-closed', function () {
  // On OS X it is common for applications and their menu bar
  // to stay active until the user quits explicitly with Cmd + Q
  if (process.platform !== 'darwin') {
    app.quit()
  }
})

app.on('activate', function () {
  // On OS X it's common to re-create a window in the app when the
  // dock icon is clicked and there are no other windows open.
  if (mainWindow === null) {
    createWindow()
  }
})

// In this file you can include the rest of your app's specific main process
// code. You can also put them in separate files and require them here.

## renderer.js
// This file is required by the index.html file and will
// be executed in the renderer process for that window.
// All of the Node.js APIs are available in this process.

;
(async function() {
  try {
    let chunkSize = 1024 * 1024
    const r = await fetch(`custom://u?chunkSize=${chunkSize}`)
    const t = await r.text()
    pre.textContent += `\n${t.length} @ chunkSize=${chunkSize}`
  } catch (e) {
    console.log('Failed', e)
  }
})()
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="UTF-8">
	<title>Hello World!</title>
	</head>
	<body>
	<pre id="pre"></pre>

	<script>
	// You can also require other files to run in this process
	require('./renderer.js')
	</script>
	</body>
	</html>
	const {app, BrowserWindow, protocol} = require('electron')
	const stream = require('stream')
	const url = require('url')
	let mainWindow

	protocol.registerSchemesAsPrivileged([
	{ scheme: 'custom', privileges: { standard: true, secure: true, allowServiceWorkers: true, supportFetchAPI: true, corsEnabled: true } }
	])

	function getStream (chunkSize, data) {
	const body = new stream.PassThrough()
	console.log('getStream()')

	async function sendChunks () {
	let buf = Buffer.from(data)
	for (let i=0; i < Infinity; i++) {
	console.log('send', i)
	await new Promise(r => setTimeout(r, 150))
	body.push(buf.slice(0, chunkSize))
	buf = buf.slice(chunkSize)
	if (!buf.length) {
	break
	}
	}
	body.push(null)
	}

	sendChunks()
	return body
	}

	function dumbPassthrough () {
	var i = 0
	return new stream.Transform({
	async transform (chunk, encoding, cb) {
	await new Promise(r => setTimeout(r, 100))
	console.log('passthrough', i++)
	cb(null, chunk)
	}
	})
	}

	function createWindow () {
	protocol.registerStreamProtocol("custom", async (request, cb) => {
	const u = new url.URL(request.url)
	await new Promise(r => setTimeout(r, 500))
	cb({
	statusCode: 200,
	headers: { 'Content-Type': 'text/plain' },
	data: getStream(parseInt(u.searchParams.get('chunkSize')), Buffer.alloc(1024102416)).pipe(dumbPassthrough())
	})
	})

	// DEBUG test to prove the pipe is correct:
	// getStream(1024 * 1024, Buffer.alloc(1024102416)).pipe(dumbPassthrough()).pipe(new stream.Writable({
	// write(chunk, encoding, cb) {
	// console.log('got chunk', chunk.length)
	// cb()
	// },
	// final (cb) {
	// console.log('done')
	// cb()
	// }
	// }))

	// Create the browser window.
	mainWindow = new BrowserWindow({
	width: 800,
	height: 600,
	webPreferences: {
	nodeIntegration: true
	}
	})

	// and load the index.html of the app.
	mainWindow.loadFile('index.html')

	// Open the DevTools.
	// mainWindow.webContents.openDevTools()

	// Emitted when the window is closed.
	mainWindow.on('closed', function () {
	// Dereference the window object, usually you would store windows
	// in an array if your app supports multi windows, this is the time
	// when you should delete the corresponding element.
	mainWindow = null
	})
	}

	// This method will be called when Electron has finished
	// initialization and is ready to create browser windows.
	// Some APIs can only be used after this event occurs.
	app.on('ready', createWindow)

	// Quit when all windows are closed.
	app.on('window-all-closed', function () {
	// On OS X it is common for applications and their menu bar
	// to stay active until the user quits explicitly with Cmd + Q
	if (process.platform !== 'darwin') {
	app.quit()
	}
	})

	app.on('activate', function () {
	// On OS X it's common to re-create a window in the app when the
	// dock icon is clicked and there are no other windows open.
	if (mainWindow === null) {
	createWindow()
	}
	})

	// In this file you can include the rest of your app's specific main process
	// code. You can also put them in separate files and require them here.
	// This file is required by the index.html file and will
	// be executed in the renderer process for that window.
	// All of the Node.js APIs are available in this process.

	;
	(async function() {
	try {
	let chunkSize = 1024 * 1024
	const r = await fetch(`custom://u?chunkSize=${chunkSize}`)
	const t = await r.text()
	pre.textContent += `\n${t.length} @ chunkSize=${chunkSize}`
	} catch (e) {
	console.log('Failed', e)
	}
	})()