onUploadProgress & onDownloadProgress for node

[alxhotel]

It would be useful to have the feature of onUploadProgress and onDownloadProgress also in NodeJS.

Example:

const fs = require('fs');
const axios = require('axios');

var data = fs.readFileSync('test.txt');
axios.post('https://example.com/upload', data, {
  onUploadProgress: function (progressEvent) {
    console.log(Math.floor((progressEvent.loaded * 100) / progressEvent.total));
  }
}).then(function (response) {
  console.log(response);
}).catch(function (error) {
  console.log(error);
});

[RikkiGibson]

I wrote an adapter for axios to provide uniform behavior for these handlers among other things. You may benefit from seeing the code for it:

https://github.com/Azure/ms-rest-js/blob/3c131b37/lib/axiosHttpClient.ts#L103

BTW, your code may work better with fs.createReadStream as you won't have to wait for the file to be completely read before starting to upload it.

[alxhotel]

Thanks @RikkiGibson !

Although I'm trying the code and it feels like the onUploadProgress is only triggered when reading the file and not in the actual uploading, right?

[RikkiGibson]

That's right. It's not perfectly accurate, but convenient to implement. I think the discrepancy between the amount of file content read and the amount of content received so far by the server will be at most the socket.highWaterMark (defaults to 16 KB).

In case you find it interesting, node.js has built in backpressure mechanisms to prevent the system from running out of memory e.g. when the disk is faster than the network on a large upload, or the network is faster than the disk on a large download.

[alxhotel]

Ah got it. Still in my case the differences is seems to be bigger than 16KB. I guess there isn't an easy solution for this.

[jacargentina]

@chinesedfan any advance on this ?

[jasonsaayman]

Please check if this has been fixed with #3694

[marek-siemieniuk-morawski]

Hi @jasonsaayman , I've checked and the problem still occurs.