How to get the file copy speed using NodeJS?

Question

How to get the file copy speed using NodeJS?

I created a simple webpage using NodeJS and Socket.IO. The server needs to copy some files from a remote server to local server. I want to show this progress on the webpage, especially I want to show the file copying speed and give an estimated time. How can I do this using NodeJS?

node.js
file
stream
socket.io

Answer 1

Without seeing your relevant code, we can only offer a generic answer.

To calculate the copying file speed, you start with two initial pieces of information which you must store for future reference during the operation:

The current system time (startTime).
The total amount of data to be copied (totalBytes).

Then, at any point while you are copying, you can get the current system time and the amount of data copied so far and create some calculations:

var elapsedTime = currentTime - startTime;
var portionComplete = bytesCopiedSoFar / totalBytes;
var percentComplete = portionComplete * 100;
var estimatedTotalTime = (elapsedTime / bytesCopiedSoFar) * totalBytes;
var estimatedTimeRemaining = estimatedTotalTime - elapsedTime;