OpenCL in MacRuby (hack, not very useful)

Quick post to let you know about my latest hack: basic support for <a href="http://en.wikipedia.org/wiki/OpenCL">OpenCL</a> on <a href="http://macruby.org">MacRuby</a> and Snow Leopard. <ul> <li>it is my first Ruby C extension ever <li>it is my first OpenCL approach ever <li>it is my first MacRuby hack (ever)</ul> With this in mind, don’t expect real world usage from this code, nor that it will get merged into upstream: it was just written for fun! The MacRuby branch with the changes is located <a href="http://github.com/rubenfonseca/macruby">here</a> <h4>Example</h4> The hello world on OpenCL is probably “calculate each element’s square on a given array”. The code below shows how this can be done in MacRuby: <script src="http://gist.github.com/284779.js?file=test_macruby_opencl.rb"></script>This code runs the same computation on all available OpenCL devices on your hardware. The results on my hardware (2 GPUs, 1CPU) are: <script src="http://gist.github.com/284792.js?file=gistfile1.txt"></script>It was fun, and maybe it can inspire someone :) The OpenCL API is kinda complex and I’m not sure if there’s a good way of making it Rubyish enough. Suggestions are welcome! Have fun :) 127 opencl-in-macruby-hack-not-very-useful

2010-01-23T12:39:00-08:00

OpenCL in MacRuby (hack, not very useful) HTML5 is here! Urray! I was tired of hearing about one of the new innovation in HTML5: the <a href="http://dev.w3.org/html5/websockets/">WebSocket API</a>. After reading the excelent blog post about <a href="http://www.igvita.com/2009/12/22/ruby-websockets-tcp-for-the-browser/">WebSockets and Ruby</a> by Ilya Grigorik I got inspired by <a href="http://rfw.posterous.com/musictweets-a-rediswebsocket-powered-experime">this experiment</a> which is a simple example of a twitter-to-browser usage of websockets. Since the excelent <a href="http://github.com/igrigorik/em-websocket">em-websocket</a> was available on github, I decided to write my own “from twitter to the browser” real time updates, with no polling. You can check the final result on <a href="http://github.com/rubenfonseca/twitter-amqp-websocket-example">my github repo</a>. <h3>General overview</h3> Twitter Stream API → Filter → RabbitMQ → AMQP → Eventmachine → WebSocket → HTML5 Brwser Too much buzzwords? Lets look at some code. <h3>Filter</h3> The filter is responsible for eating the <a href="http://apiwiki.twitter.com/Streaming-API-Documentation">Twitter Stream API</a> and puting the tweets on a queue (RabbitMQ in my case) using AMQP: <script src="http://gist.github.com/264450.js?file=gistfile1.rb"></script>Pretty easy right? Notice I am using a fanout exchange, which will allow me to broadcast the same message to all queues (clients) latter on. <h3>Server</h3> Now we just need to build a server that accepts websocket connections, and for each client deliver each message that arrives on the fanout exchange. The code will make this clear: <script src="http://gist.github.com/264453.js?file=gistfile1.rb"></script>So simple, yet so awesome! <h3>Client</h3> The client just have to connect the websocket, and for each JSON piece that arrives on the socket, present them on the screen: <script src="http://gist.github.com/264454.js?file=gistfile1.js"></script>It seems we’ve ended writing almost more JS than Ruby :P Note that I’ve only tested this on Webkit nightly and latest Google Chrome beta for Mac. Overall it was a great and easy experience building this simple system, but it allowed me to realize how simple we can build scalable push systems with the WebSocket API! update: seems like <a href="http://twitter.com/igrigorik/status/7107086085">Ilya Grigorik liked it</a> :) 126 twitter-amqp-websocket-example-no-polling

2009-12-28T10:18:00-08:00

Twitter AMQP WebSocket Example (no polling) Are you tired of calling your friends and family at prices from the last century? Do you feel frustrated every time you have to top-up the credit of your mobile phone, just because you are obliged to? Do you hate the obvious portuguese cartel around mobile operators? Well, fell no more! Enter the VoIP world! <a href="http://www.betamax.com">Betamax</a> created <a href="http://backsla.sh/betamax">lots of</a> providers specialized in VoIP. Although almost all of them offer free calls to Portuguese landline numbers, I never realized how competitive they were on the mobile side. So I dig a little, and found some pretty competitive Betamax VoIP providers: <ul> <li>12voip.com – 4.5 cent/min</li> </ul> <ul> <li>voipraider.com – 5.0 cent/min</li> </ul> <ul> <li>webcalldirect.com – 6.0 cent/min</li> </ul> The best thing about these providers is <ul> <li>No required monthly payment</li> </ul> <ul> <li>You can use your own phone number as Caller ID (so people still answer your calls).</li> </ul> <ul> <li>They all support the SIP protocol (great for non-windows users like me)</li> </ul> <ul> <li>Same price for all the mobile operators (so you can jump the wall garden)</li> </ul> I hope that this information helps you lowering your phone bill. Spread the word, and maybe your mobile operator starts lowering the prices too! 125 cheap-calls-to-any-portuguese-mobile-network

2009-07-17T13:18:00-07:00

Cheap calls to any Portuguese mobile network I am a client of the <a href="http://www.optimustag.pt">optimus tag</a> service (for English users, it’s a phone plan that includes free calls for any other phone using the same network plan). Recently, I discovered they have a <a href="http://www.optimustag.pt/Servicos/Webphone.jsp">softphone like system</a> called Webphone (Windows only), that allows you to place and receive calls, SMS, MMS, and other stuff, right from your computer. My first thought was “this must use some kind of SIP service”. Since the SIP settings are not posted anywhere on the internet, and I don’t want to use Windows to use their client, I decided to dig deeper and try to find the SIP configurations so it can work on any regular softphone. Although it was easier than I thought (<a href="http://www.wireshark.org">Wireshark</a>, I love you), there is one serious limitation that I couldn’t solve without hacking some open source code. Anyway here’s the main settings: <h3>Optimus Tag SIP settings (to use with a SIP softphone)</h3> <ul> <li>server address: sip.optimus.pt</li> <li>username: 351 your number@sip.optimus.pt</li> <li>password: your webphone password</li> <li>SIP proxy: asbg.sip.optimus.pt</li> <li>User Agent: Optimus-SoftPhone/7.0.1.4124</li> </ul> Now, the last item is the worst part. If you don’t specify a User-Agent that starts with <code>Optimus-SoftPhone</code>, you’ll receive a “403 Forbidden User Agent” message. I tried to find a SIP softphone that allowed me to change the UserAgent but didn’t found one (I didn’t try hard). So I decided to take the <a href="http://www.twinklephone.com">Twinkle</a> open source SIP client, changed the hard coded User Agent, and got surprised when it worked flawlessly from the first time! I tried placing and receiving calls and it worked perfectly :) If you’re interested on the trivial patch (I used Twinkle version 1.4.2) you can find it <a href="http://gist.github.com/116644">here</a>. If you know a SIP client for OS X or Linux that allows me to change the User Agent, don’t hesitate to comment bellow! 124 optimus-webphone-sip-settings

2009-05-23T07:41:00-07:00

Optimus Webphone SIP settings quick post to let you know my latest two mini-projects on <a href="http://www.github.com">github</a>: <h3>Ruby library to whit.me service API</h3> <a href="http://whit.me">whit.me</a> is a wonderful service to shorten URLs. They have a <a href="http://www.whit.me/api/docs">public API</a>, and I wrote this library that allows you to use the service in the middle of any Ruby script. The project is available <a href="http://github.com/rubenfonseca/whitme/tree/master">here</a>. It is compatible with Ruby 1.9 and JRuby, and contains a full RSpec test suite. <h3>newzbin XMPP search agent</h3> After spending some time learning <a href="http://xmpp.org">XMPP</a>, I decided to try it and build something useful. So I hacked a simple search agent for the <a href="http://newzbin.com">newzbin</a> website to be used by me and my friends. It is poorly written, but it works. Maybe you can learn something from the simple example. In case you’re interested, the code is available <a href="http://github.com/rubenfonseca/newzbin_xmpp/tree/master">again on github</a>. It uses the XMPP4R gem and CouchDB (overkill, I know). Feel free to comment on any of the code and send me suggestions on how to improve it. 123 two-more-contributions-to-the-open-source-world

2009-05-22T14:22:00-07:00

Two more contributions to the open source world