SAPessi » Network http://sapessi.com Perfection of means and confusion of aims... Thu, 12 Aug 2010 10:35:56 +0000 en hourly 1 http://wordpress.org/?v=3.0.1 Server side JavaScript with node.js http://sapessi.com/2009/11/server-side-javascript-with-node-js/ http://sapessi.com/2009/11/server-side-javascript-with-node-js/#comments Sat, 21 Nov 2009 17:01:12 +0000 Stefano Buliani http://sapessi.com/?p=337
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While skimming through my RSS feed I stumbled upon an interesting article on Ajaxian about server side JavaScript programming.

I really, really enjoy writing JavaScript code so I decided to read through the article and take a look at the node.js library linked there.

node.js logo

Node is a framework to build server-side event-driven JavaScript applications. Developed in C++ on top of Google’s V8 JavaScript engine and accompanied by a set of JavaScript libraries Node seems to make building distributed (over a network), fast applications a piece of cake even for inexperienced developers.
Event-driven here really is the keyword because it represent a big change in the way applications are built (and architected in your brain).

Node is similar in design to and influenced by systems like Ruby’s Event Machine or Python’s Twisted. Node takes the event model a bit further—it presents the event loop as a language construct instead of as a library. In other systems there is always a blocking call to start the event-loop. Typically one defines behavior through callbacks at the beginning of a script and at the end starts a server through a blocking call like

EventMachine::run()

. In Node there is no such start-the-event-loop call. Node simply enters the event loop after executing the input script.

The example below (taken from Node’s website) will make everything clear… hopefully.

var sys = require(‘sys’),
     http = require(‘http’);

http.createServer(function (req, res) {
  setTimeout(function () {
    res.sendHeader(200, {‘Content-Type’: ‘text/plain’});
    res.sendBody(‘Hello World’);
    res.finish();
  }, 2000);
}).listen(8000);
sys.puts(‘Server running at http://127.0.0.1:8000/’);

Can you see the beauty?!

I have only one worry. This is an open-source effort. The community behind it on Google groups is just 181 members strong (so far). What if node.js suddenly stops being the cool thing and the community disappears.

As much as I love writing JavaScript and I can really see the value in what they are building I’ll still wait until there are 100 Google Groups for node.js and a trillion members in each before using it in anything close to a production system.

Having said that I’m going back to writing silly node.js apps now. Well done to all the developers involved in the project and keep it up!

]]> http://sapessi.com/2009/11/server-side-javascript-with-node-js/feed/ 15 JavaScript games – more thoughts on O3D http://sapessi.com/2009/10/javascript-games-more-thoughts-on-o3d/ http://sapessi.com/2009/10/javascript-games-more-thoughts-on-o3d/#comments Sat, 31 Oct 2009 15:23:56 +0000 Stefano Buliani http://sapessi.com/?p=255

This week I wrote a post comparing O3D and WebGL.

Today I have finally spent some time playing with O3D and managed to implement some very simple applications.

Now that I have a clearer understanding of what O3D can and can’t do I have given some thought to the possibility of writing videogames in JavaScript. As I mentioned in my previous post I can’t see myself playing something like Fallout in a browser window. Nonetheless I can imagine simple multiplayer games, something like Monopoly or Risk, working this way.

I have developed quite a few JS applications that allowed users connected at the same time to interact with each other. It’s very simple, constant AJAX posts and gets with a server keeping the state of the interaction. Imagine something like GTalk integrated inside GMail.

This is all well and good when the interaction is limited to a few chat messages or coordinates of the mouse pointer on the screen, but multiplayer videogames have to shift a massive amount of data every second. When you play Gran Turismo online the position, speed and state of each player’s car must e synched across all the participants as often as possible. Add chat/voice data to that and you’ll soon realise that 30 players for one game calling your server at the same time to get and post data is just not manageable. Furthermore to ensure the timely delivery of the data to each client you are much better off pushing the data to the client rather than relying on it to call your server.

What O3D should add to its APIs is a DirectPlay alternative. Multiplayer support built straight into O3D. This way your JavaScript game will be able to establish peer-to-peer communication between all the clients without having to stress your servers. Simple socket communication giving the developers the ability to push data between all the peers connected.
Network support by being built inside the O3D plugin could also deal with all the annoying connectivity issues such as “punching” through NATs.

Without properly implemented network play I don’t think we’ll ever see 3D games flourish in your browser window.

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