websockets for python and twisted
August 7, 2010
RestMQ has a unique endpoint for consumers which uses websockets. As such, I implemented websockets for cyclone and twisted some time ago. Last July there was an upgrade to the protocol to implement a ‘secure’ handshake. This new spec broke most of the implementations because it mixed the upgrade headers part and the first 8 bytes from the content.
I’ve upgraded both cyclone and txwebsockets to understand the ‘old’ spec (hixie 75) and the new one. Basically the handshake involves extracting numbers from two headers (Sec-Websocket-Key1 and Sec-Websocket-Key2), dividing the resulting number by the number of spaces, concatenating them with 8 bytes read from the socket and sending back the md5 digest of this mess back after the new headers. Code to test and calculate the handshake from the headers value can be found here .
The rewrite ritual
June 6, 2010
Not that I am a fan of rewriting stuff, but there are some applications that I use to showcase technologies and from time to time I set up to rewrite them. As there is already a specification, its a matter of an exercise for new technologies. No over-specification and a very delimited time box.
Lately, two of these apps are a pastie clone and an url shortener. First I wrote them in ruby, them in python, python with twisted and now using Erlang and Mochiweb.
The code is on http://github.com/gleicon at uurl-erl and pasteme-erl repos, and as usual the html/css part is barely minimal. Also they are online at http://7co.cc and http://pasteme.7co.cc.
Both of them use Redis as a global increment and cache server, along with MongoDB for storing documents and stats. I find this to be a good match due to Redis atomic operations and pub/sub capabilities.
Node.js and COMET
January 31, 2010
Today I started to study node.js, for these last days there was a lot of interesting posts about it.
So to begin understanding it, I setup to port two COMET based examples I did back when I started using twisted to do it.
Note that this may contain javascript misconceptions, as I’m not experienced with it and my js idiom is more geared towards python than proper js.
The first example is a basic comet server which prints a string to each connected user
The other example sends the result of twitter searchs to all connected users:
Node.JS presents a different toolset to solve the current problems we have. It used the excellent libev, among V8 and other cool stuff, and JS is a very modern and flexible language (at least more than I thought about it when trying to do web stuff).
Cheers
Web Sockets for Python
December 29, 2009
With all the fuzz around chrome and web sockets I’ve bundled up together a simple web sockets implementation for twisted. It’s a really easy way to interact with browsers.
In the next days I will run benchmarks, because I think it will stir up a bit the webserver scene a bit, and possibly, the assynchronous network frameworks too. On the bright side, its really easy to work on, and good ideas come up.
Enjoy and keep watching for new releases, as I have not finished it yet.
Repo URL: http://github.com/gleicon/txwebsockets