Jaslabs: High performance Software

By Justin silverton

In a recent decision by the people over at mysql, the latest community (Open source) edition of the database system will no longer be available for download in binary form (it looks like both windows and linux binaries are still on 5.27 and the lastest is 5.33). This means that if you want to use the latest version, you will have to have the following installed on your system to first compile it from source:

• Visual Studio .Net 2003 (7.1) compiler system




• Between 3GB and 5GB disk space.




• Windows XP, Windows 2000 or higher.

Another interesting statement found here says the following:

“Providing and verifying binaries is a paid-for service for those who want to spent money to save time”

It looks like if you want the official binaries, you need to pay to download them. It appears that mysql is starting to make it harder and harder to use their software without paying a licensing fee.

By Justin Silverton

If you have a wordpress blog and have gotten to the front page of digg, you may have seen the following error message:

This is usually caused by a large amount of traffic that is overloading your database (because each page that is loaded requires a query or multiple queries).

A great way to not only improve the speed of your entire blog, but help prevent the above error from occuring is to install a plugin called WP-Cache.

Installing

Installing is pretty easy and straight forward:

1. Upload to your plugins folder, usually wp-content/plugins/ and unzip the file, it will create a wp-content/plugins/wp-cache/ directory.
2. If you have Gzip Compression enabled turn it off (in Options->Reading).
3. Activate the plugin on the plugin screen.
4. Go to “Options” administration menu, select “WP-Cache” from the submenu, the plugin will try to autoconfigure everything. The plugin will try to autoconfigure everything and guide you through the process. In case of failure –normally due to the lack of files’ privilegies– it tell you and give the instructions to solve the problems.
5. A way to make things even faster is to enable gzip compression for wp-cache.  It can done by doing the following: (within wp-cache-phase1.php) add the following line: if ( extension_loaded(’zlib’) ) ob_start(’ob_gzhandler’); before this line: foreach ($meta->headers as $header) {

The wp-cache wordpress plugin can be downloaded here

By Justin Silverton

The following are 5 javascript apps that I thought would never be possible. They are all written using the canvas HTML element.

The canvas element is a third party extension that allows for dynamic rendering of scriptable bitmap images.

It was initially introduced by Apple or use inside their own Mac OS X Webkit component, powering applications like Dashboard widgets and the Safari browser. Later, it was adopted by Gecko browsers (notably Mozilla and Firefox) and standardized by the WHATWG on new proposed specifications for next generation web technologies. Support is also present in the Opera 9.0 browser. Novell manufactures an XForms processor plugin for Internet Explorer, which also provides support for the canvas element. Independent efforts to support the canvas feature on Internet Explorer do not require plugins and are based solely on VML and Google has also begun a project to add canvas abilities to Internet Explorer using the same techniques.

Canvas consists of a drawable region defined in HTML code with height and width attributes. JavaScript code may access the area through a full set of drawing functions similar to other common 2D APIs, thus allowing for dynamically generated graphics. Some anticipated uses of the canvas include building graphs, animations, and image composition. Source

Note: Most of these examples are *not* compatible with Internet Explorer

1) Canvascape

A proof of concept of a 3D FPS. There is a textured and non-textured version available.

2) MSX Emulator

This project shows us the true power of javascript and the canvas element. It is an MSX emulator, which includes the ability to load and play game roms.

3) Unreal Soccer

A soccer game.

4) Plasma Demo

This is a port of an RGB C plasma demo

5) An Arkanoid clone

A clone of the game Arakanoid.

By Justin Silverton

In a recent article here a recent issue has been discovered with the latest version of wordpress and feedburner:

After upgrading to WordPress 2.0.6 or WordPress 2.1 Beta, your FeedBurner feed will, at times, give you an “invalid xml” error, and “FeedMedic” will show you something like this:

Your server disconnected us before sending the full source feed content.

The Fix

There is a simple way to fix this issue, which involves the following steps:

1) Open /wp-includes/functions.php and find the following code (around line 2231):

if ( substr(php_sapi_name(), 0, 3) == 'cgi')
                @header("HTTP/1.1 $header $text");
        else
                @header("Status: $header $text");
}

2) change to the following:

//      if ( substr(php_sapi_name(), 0, 3) == 'cgi')
                @header("HTTP/1.1 $header $text");
//      else
//            @header("Status: $header $text");
}

3) Save the file and exit. Resync your feed at FeedBurner

By Justin Silverton

Wordpress 2.0.6 has been released! 

From the official wordpress site:

“We have a pretty important release available for everyone, it includes an important security fix and it’s recommended that everyone upgrade. This is the latest release in our stable 2.0 line, which we’ve committed to maintaining for several more years.

Here’s what’s new:

• The aforementioned security fixes.
• HTML quicktags now work in Safari browsers.
• Comments are filtered to prevent them from messing up your blog layout.
• Compatibility with PHP/FastCGI setups.

For developers, there’s a new anti-XSS function called attribute_escape(), and a new filter called “query” which allows you filter any SQL at runtime. (Which is pretty powerful.) Thanks to Mark Jaquith for handling this release and Stefan Esser for responsibly reporting the security issue.”

It can be downloaded here