clockskew

clockskew

A smart algorithm to calculate clock skew from a timeserver.

Use it to synchronize your apps with millisecond accuracy.

See demo of synchronized note playing (open multiple tabs, modern browser required).

Time Server

# get the code
git clone [e-mail]:markmarijnissen/clockskew.git
# run the server
node server
# or run online
modules deploy

Client

var ClockSkew = require('clockskew/client');
# or just include the file 

var clockSkew = new ClockSkew({
	// REQUIRED :

	getServerTime: ClockSkew.getSocketTime('ws://...'),
	# or use HTTP protocol
	getServerTime: ClockSkew.getHttpTime.bind(null,'http://'),
	# or use Firebase
	getServerTime: ClockSkew.getFirebaseTime.bind(null,'https://xxx.firebaseio.com')

	// OPTIONAL:

	getTime: function(){...}, // get local time in ms.
	timeout: 10000, // ping timeout
	interval: 1000, // ping interval
	history: 10, 
	tolerance: 2, // is standard deviation of last `history` average skew is less then tolerance, wait longer before pinging.
	waitInteval: 30000, // wait interval
	minSkewValues: 5, // minimum values before averaging
	minRttValues: 5 // minimum Round-Trip-Time values before rejecting RTTs that are more than 1 standard deviation slower
	setTimeout: ... // custom setTimeout Implementation
	clearTimeout: ... // custom clearTimeout implementation
});

clockSkew.start();
clockSkew.stop();

Changelog

0.2.0 - Changed ClockSkew.js into client.js

Contribute

Feel free to contribute to this project in any way. The easiest way to support this project is by giving it a star.

Contact

• @markmarijnissen
• http://www.madebymark.nl
• [e-mail]

© 2015 - Mark Marijnissen