javascript - Nightmare Js 多次评估后评估超时

Question

我正在尝试设置一个我一直在开发的应用程序，其中涉及记录 HTML 小部件(带有动画)并将其转换为 mp4。在本地效果很好。我使用 Nightmare Js 处理屏幕截图，并使用 FFMPEG 将屏幕截图转换为 mp4，这在我的 PC 上大约需要 90 秒。

我通过托管服务将其设置在 Docker 容器中，但无法解决此问题。我现在的测试脚本看起来像这样:

const Nightmare = require('nightmare')
const Xvfb = require('xvfb')

module.exports = function(app) {
  app.get('/api/nightmare', async (req, res) => {
    console.log('GET request to /api/nightmare')

    try {
      // Start xvfb and create our nightmare object
      const close = await xvfb()
      const nightmare = Nightmare({ executionTimeout: 1000 })

      const [err, result] = await poss(run(nightmare))
      if (err) {
        // Cleanup before throwing error
        await nightmare.end()
        await close()
        throw err
      }

      // shut'er down
      await nightmare.end()
      await close()
      res.status(200).send('Completed')
    } catch (error) {
      console.log(error)
      res.status(500).send(error)
    }
  })  
}

async function run(nightmare) {
  var data = {
    'id': '2OWBTMUL',
    'somedata': 'blah'
    // More data pulled from the database goes here
  }

  // Create folder to hold images
  var procName = new Date().getTime() + '_testing_' + data.id
  fs.mkdirSync(path.resolve(__dirname, '../processing/', procName))

  // URL to inject into webpage so the webpage can access the data
  var url = `http://example.com?` +
    `id=${data.id}&` +
    `somedata=${data.somedata}`

  console.log('Starting NightmareJs')
  await nightmare
    .viewport(1920, 1080)
    .goto('file:///' + path.resolve(__dirname, '../templates/example.html'))
    .evaluate(newUrl => {
      // Set url and get the page ready for recording
      url = new URL(newUrl)
      initiate()
      start()
      timeline.pause()
    }, url)
    .catch(error => { console.log(error) })

  // Take 200 screenshots (8s @ 25fps)
  var frames = 200
  for (var i = 0; i < frames; i++) {
    console.log('Taking screenshot ' + i)

    await nightmare
      .screenshot(path.resolve(__dirname, '../processing/', procName, 'screen_' + i + '.png'))
      .evaluate(shot => { timeline.seek((8 / 200) * shot) }, i)
      .catch(error => { console.log(error) })
  }

  console.log('Done.')
}

// xvfb wrapper
function xvfb(options) {
  var xvfb = new Xvfb(options)

  function close() {
    return new Promise((resolve, reject) => {
      xvfb.stop(err => (err ? reject(err) : resolve()))
    })
  }

  return new Promise((resolve, reject) => {
    xvfb.start(err => (err ? reject(err) : resolve(close)))
  })
}

// try/catch helper
async function poss(promise) {
  try {
    const result = await promise
    return [null, result]
  } catch (err) {
    return [err, null]
  }
}

一些环境详细信息:
Ubuntu 18.04.1
主管
Node 8.12.0(DEBUG=* 设置)

问题:大约 17 次循环后，Nightmare 抛出两个不同的错误。在我的 nodejs-stderr.log 文件中，我得到了这个

Taking screenshot x
Error: Evaluation timed out after 1000msec.  Are you calling done() or resolving your promises?

在评估中使用done()回调或promise进行测试没有改变任何东西，所以我保持简单

在我的 nodejs-stdout.log 文件中，每次成功的循环都会得到此信息

Mon, 19 Nov 2018 09:37:06 GMT nightmare:actions .screenshot()
Mon, 19 Nov 2018 09:37:06 GMT nightmare:log subscribing to browser window frames
Mon, 19 Nov 2018 09:37:06 GMT nightmare:log Highlighting page to trigger rendering.
Mon, 19 Nov 2018 09:37:06 GMT nightmare:log unsubscribing from browser window frames
Mon, 19 Nov 2018 09:37:07 GMT nightmare:actions .screenshot() captured with length 1092963
Mon, 19 Nov 2018 09:37:07 GMT nightmare:actions .evaluate() fn on the page
Mon, 19 Nov 2018 09:37:07 GMT nightmare queueing action "screenshot"
Mon, 19 Nov 2018 09:37:07 GMT nightmare queueing action "evaluate"
Mon, 19 Nov 2018 09:37:07 GMT nightmare running

然后经过 17 个左右的循环后，我得到:

Mon, 19 Nov 2018 09:37:07 GMT nightmare:actions .screenshot()
Mon, 19 Nov 2018 09:37:07 GMT nightmare:log subscribing to browser window frames
Mon, 19 Nov 2018 09:37:07 GMT nightmare:log Highlighting page to trigger rendering.
Tue, 20 Nov 2018 02:11:43 GMT nightmare:log crashed [{},false]
Mon, 19 Nov 2018 09:37:12 GMT nightmare:log FrameManager timing out after 1000 ms with no new rendered frames
Mon, 19 Nov 2018 09:37:12 GMT nightmare:log unsubscribing from browser window frames
Mon, 19 Nov 2018 09:37:12 GMT nightmare:actions .screenshot() captured with length 0
Mon, 19 Nov 2018 09:37:12 GMT nightmare:actions .evaluate() fn on the page
Mon, 19 Nov 2018 09:37:13 GMT nightmare queueing action "screenshot"
Mon, 19 Nov 2018 09:37:13 GMT nightmare queueing action "evaluate"
Mon, 19 Nov 2018 09:37:13 GMT nightmare running

其余的全部失败，没有 crashed [{},false] 消息。
在循环中删除 .evaluate(shot => {timeline.seek((8/200) * shot) }, i) 可以解决问题，但我需要它，否则它只是一个静止的视频!我尝试过单独的调用(不是链接评估和屏幕截图)，将 .wait(200) 放在东西之间，但我无法弄清楚或找到有关此问题的任何帮助。

Answer 1

原来是共享内存太小了。我假设当图像全部加载时，它超出了内存限制并且 Electron 崩溃了。将共享内存从64MB增加到128MB后，问题解决。