progress-stream

Read the progress of a stream. Supports speed and eta.

Gets the length of the stream automatically if you're using the request or http module. You can also pass the length on initiation. Progress-stream will also check to see if the stream already has a length property.

npm install progress-stream

Usage

This example copies a large file, and prints out the percentage, speed and remaining every 100ms.

1var progress = require('progress-stream');
2var fs = require('fs');
3
4var stat = fs.statSync(filename);
5var str = progress({
6	length: stat.size,
7	time: 100 /* ms */
8});
9
10str.on('progress', function(progress) {
11	console.log(progress);
12
13	/*
14	{
15		percentage: 9.05,
16		transferred: 949624,
17		length: 10485760,
18		remaining: 9536136,
19		eta: 42,
20		runtime: 3,
21		delta: 295396,
22		speed: 949624
23	}
24	*/
25});
26
27fs.createReadStream(filename)
28	.pipe(str)
29	.pipe(fs.createWriteStream(output));

Methods

progress([options], [onprogress])

You can instantiate in two ways:

1var str = progress({time:100});
2str.on('progress', function(progress) { ... });

or inline the progress listener

1var str = progress({time:100}, function(progress) { ... });

Properties

.progress()

You can get the progress from the progress function.

1var str = progress({time:100});
2
3console.log(str.progress());
4
5/*
6{
7	percentage: 9.05,
8	transferred: 949624,
9	length: 10485760,
10	remaining: 9536136,
11	eta: 10,
12	runtime: 0,
13	delta: 295396,
14	speed: 949624
15}
16*/

Events

on('progress', function(progress) { ... })

1var str = progress({time:100});
2str.on('progress', function(progress) { ... });

Options

time(integer)

Sets how often progress events are emitted in ms. If omitted then the default is to do so every time a chunk is received.

speed(integer)

Sets how long the speedometer needs to calculate the speed. Defaults to 5 sec.

length(integer)

If you already know the length of the stream, then you can set it. Defaults to 0.

drain(boolean)

In case you don't want to include a readstream after progress-stream, set to true to drain automatically. Defaults to false.

transferred(integer)

If you want to set the size of previously downloaded data. Useful for a resumed download.

Examples

Using the request module

This example uses request to download a 100 MB file, and writes out the percentage every second.

You can also find an example in test/request.js.

1var progress = require('progress-stream');
2var req = require('request');
3var fs = require('fs');
4
5var str = progress({
6	time: 1000
7});
8
9str.on('progress', function(progress) {
10	console.log(Math.round(progress.percentage)+'%');
11});
12
13req('http://cachefly.cachefly.net/100mb.test', { headers: { 'user-agent': 'test' }})
14	.pipe(str)
15	.pipe(fs.createWriteStream('test.data'));

Using the http module

In test/http.js it's shown how to do it with the http module.

Methods

setLength(newLength)

Sometimes, you don't know how big a stream is right away (e.g. multipart file uploads). You might find out after a few chunks have already passed through the stream, seconds or even minutes later. In this case, you can use the setLength method to recalculate the relevant tracked progress data.

1var str = progress({});
2someFickleStreamInstance.pipe(str).pipe(fs.createWriteStream('test.data'));
3
4someFickleStreamInstance.on('conviction', function nowIKnowMyLength (actualLength) {
5  str.setLength(actualLength);
6});