streamspeed

A simple way to keep track of the speed of your readable streams.

Usage

const StreamSpeed = require('streamspeed');

let rs = fs.createReadStream('somefile.avi');
let ss = new StreamSpeed();
ss.add(rs);

// Listen for events emitted by streamspeed on the given stream.
ss.on('speed', (speed) => {
  console.log('Reading at', speed, 'bytes per second');
});

Keep track of a group of streams

let group = new Streamspeed();
group.add(stream1);
group.add(stream2);
group.add(stream3);

group.on('speed', (speed) => {
  console.log('now reading at', speed, 'bps');
});

API

new StreamSpeed([options])

A group that can be used to watch several streams. Will emit speed events. options can have the following properties,

• timeUnit - Defaults to 1000 for speed per second. If you want another unit such as per hour, use 1000 * 60 * 60.
• range - The time in ms to calculate speed over. Defaults to 1000. The longer this is, the more stable speed will be for a big stream. The shorter it is, the more responsive it is to sudden speed changes.

StreamSpeed#add(stream)

Adds stream to group.

StreamSpeed#remove(stream)

Removes stream from group.

StreamSpeed#getSpeed()

Get current speed.

StreamSpeed#getStreamSpeed(stream)

Get an individual's stream's current speed.

StreamSpeed#getStreams()

Returns a list of all streams in the group.

StreamSpeed.toHuman(bytes, options)

Helper method to convert bytes to a human readable string.

StreamSpeed.toHuman(1500);                                  // 1.46KB
StreamSpeed.toHuman(1024 * 1024);                           // 1MB
StreamSpeed.toHuman(1024 * 1024 * 20.5, { timeUnit: 's' }); // 20.5MB/s
StreamSpeed.toHuman(1024 * 1024 * 20.5, { precision: 3 });  // 20.50MB

Event: 'speed'

• number - Speed at which streams in the group are being read.

Will be emitted every time a stream is read and only if there is a change in speed.

Install

npm install streamspeed

Tests

Tests are written with mocha

npm test