Whether we're experienced developers or newcomers, we've all seen code that could/should have been done better. Many times it's even code we ourselves wrote and revisited later for one reason or another. I, for one, have seen my share of code written by a "past me" and wondered what on earth I was thinking when I wrote that. Of course there has also been times when I was hired to fix another developers code, and it can be scary also.

There's three posts in the series:

• Part 1, Dirty Code (cause/effect)
• Part 2, Dirty Code (why we do it)
• Part 3, Dirty Code (how to spot/smell it)

So, what does this mean for the CodeIgniter community? In short, absolutely nothing. Most CodeIgniter developers are building applications that will run on shared hosts, virtual private servers or a cloud-based virtualization system. Of that very large group of our community, an extremely small number have the capability to compile the HipHop binaries or alter their configuration in order to serve HipHop pages.

He points out that, for most developers and applications, time is better spent optimizing the actual application - things like reducing the I/O needs, caching, etc. HipHop, unless you have a very high demand and load on the application, won't give much of a gain. He gives the example of Facebook's load and how even it would only relatively recently would benefit from the tool.

We host a wide variety of sites, covering everything from converting your garage into a living space to video game addictions. Because we are such a small operation, being hit by a link from a big site such as Digg would be both a blessing and a curse.

In order to place our ads on each page, we use PHP's auto_append_file feature to run our advertisement code. By using PHP's other neato function, auto_prepend_file, I can create a small piece of PHP code to detect when the site is being hit by Digg. In this situation, I have chosen to use Lighttpd to handle the increased loads, because of its proven high performance with large numbers of concurrent connections.

In his example code, he shows how you can detect when a user is coming from a digg.com page and take them to a cached version of the page they've requested (with the .cache extension).