Comet Breakthrough: Socket for JavaScript in the Browser

http://cometdaily.com/2008/07/01/sockets-in-the-browser/

by jacobolus • 18 years ago

34 16 18 years ago

nirmal2• 18 years ago

So this is just a better framework on top of HTTP Bind? It's not true sockets because I still can't open up many simultaneous connections. The max-persistent-connections-per-server was what always annoyed me when it came to using this type of architecture.

Has anyone seen code that manages to multiplex a single connection of this type across multiple tabs within a browser? Is that even possible?

From: http://www.orbited.org/wiki/CherryChat

"Then point your browser at http://localhost:4700/static/chat.html, and then open a second browser window and point it at http://127.0.0.1:4700/static/chat.html, and test the application. It’s important to use the two different hostnames localhost and 127.0.0.1 because some browsers limit the number of open connections you can have to each hostname to two. With this limit it is impossible to run two instances of the chat application on the same host. Of course, 127.0.0.1 and localhost should refer to the same local machine, so its a good way of tricking the browser into thinking its talking to separate servers."

dhotson• 18 years ago

I wonder if this could be combined with this javascript jabber library to make a fully fledged chat client: http://zeank.in-berlin.de/jsjac/

.. currently that library is restricted by the same domain policy. I wonder how this Comet library manages to get around it.

Anyone here care to explain?

Tichy• 18 years ago

I think it proxies through a server, it is not a real socket.

jherber• 18 years ago

this is exactly what it is doing. it's a javascript lib that exposes an ajax connection (fancifully named "TCPSocket") that is proxying a socket connection through the Orbitd server. if there isn't strict control of client IP addresses and outgoing IP/port at Orbitd, then you should expect folks are going to abuse/hack your server for proxying who knows what from where.

nirmal2• 18 years ago

My guess would be that they use nested iFrames. It would be similar to the Google Data APIs.

axod2• 18 years ago

Misleading title. Not a breakthrough, no new technology, just a different way of explaining it.

brooksbp• 18 years ago

Can't stand crap like this. People who reinvent the wheel (poorly), or try to, make the world a worse place... something related to 'visualization' -- psychological stuff. People who fail to visualize and truely, intimately understand things will often invent breakthrough technology as JavaScript 'sockets.'

franksalim• 18 years ago

Hi, Many of the comments here are negative, probably due to the overly sensational title ;-) Since this is a project I have been working on, however, I will do my best to clarify and respond candidly.

This is clearly not a breakthrough. Sockets (or socket-like interfaces) are the most obvious way to communicate a bi-directional stream of bytes. This has been true for decades. The problem is that everybody has been trying to reinvent the wheel for AJAX. So yes, this is not new, just something that had been missing from the web for a long time!

We have been very mindful of the security implications. Orbited uses a strict whitelist and will not allow outgoing connections to addresses (hostname:port) that are not listed in the access configuration.

Feel free to ask me any questions.

-Frank Salim

bsaunder• 18 years ago

I can't wait for UDP over HTTP in Cometd 0.6 ;)

axod2• 18 years ago

In case this wasn't obvious, but UDP is simple as it's sent from the server, not the browser.

tlrobinson• 18 years ago

Ok, neat, but this has ridiculous security implications. Anyone can now open up a socket on my server for any purpose they want (hax0ring, etc)

At the very least there should be ways to limit the hosts and ports of the sockets, but even then I'd be very cautious about using this.

heyadayo• 18 years ago

This isn't new technology, but its a more reasonable way of thinking about real-time communication in a browser. Developers know how to use sockets, so we give them a socket.

In a years time this will be native in all browsers anyway: http://www.whatwg.org/specs/web-apps/current-work/#network

Comet Breakthrough: Socket for JavaScript in the Browser

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