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.

``js
var progress = require('progress-stream');
var fs = require('fs');

var stat = fs.statSync(filename);
var str = progress({
length: stat.size,
time: 100 / ms /
});

str.on('progress', function(progress) {
console.log(progress);

/*
{
percentage: 9.05,
transferred: 949624,
length: 10485760,
remaining: 9536136,
eta: 42,
runtime: 3,
delta: 295396,
speed: 949624
}
*/
});

fs.createReadStream(filename)
.pipe(str)
.pipe(fs.createWriteStream(output));
`

Methods

$3

You can instantiate in two ways:

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

or inline the progress listener

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

Properties

$3

You can get the progress from the progress function.

` js
var str = progress({time:100});

console.log(str.progress());

/*
{
percentage: 9.05,
transferred: 949624,
length: 10485760,
remaining: 9536136,
eta: 10,
runtime: 0,
delta: 295396,
speed: 949624
}
*/
`

Events

$3

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

Options

$3

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

$3

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

$3

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

$3

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

$3

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

Examples

$3

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.

` js
var progress = require('progress-stream');
var req = require('request');
var fs = require('fs');

var str = progress({
time: 1000
});

str.on('progress', function(progress) {
console.log(Math.round(progress.percentage)+'%');
});

req('http://cachefly.cachefly.net/100mb.test', { headers: { 'user-agent': 'test' }})
.pipe(str)
.pipe(fs.createWriteStream('test.data'));
`

$3

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

Methods

$3

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.

`js
var str = progress({});
someFickleStreamInstance.pipe(str).pipe(fs.createWriteStream('test.data'));

someFickleStreamInstance.on('conviction', function nowIKnowMyLength (actualLength) {
str.setLength(actualLength);
});
``