Optimizing variables cache in Drupal 6

In Drupal 6, a number of caching strategies are incorporated to handle large traffic. One of them is the serialization of the whole variable table. It is being cached in the database and gets extracted into global $conf variable in each invoke.

In one of our production sites, we faced hard time to keep up with the memory requirement of PHP for the unserialization of this variable from the cache. The variables table was so large that we had to assign around 1GB memory to each PHP thread so that the value can be unserialized without memory exhaustion. This made it much harder to scale the application.

So, we decided to do something about it and successfully handled it by doing the following:

1. First of all, we installed the memcache module to move the cache storage from DB to memory

2. We then edited the memcache module’s cache_get and cache_set functions to store/retrieve individual items from the variables array and split/join them when requested.

3. This requires a memcache call for each of the items in the variable array, but consumes a small amount of memory as there is no huge unserialize operation going on.

4. We performed a few tests to see if the site is working as before, and found its working perfectly!

Here is the code in case you are facing similar issue: (more…)

JSONize your PHP classes using traits

I was having a discussion with a colleague regarding how to add generic JSON based representation to a number of classes without making a big effort. The immediate solution that came in my mind is to use the Traits for it (introduced in PHP 5.4).

So I wrote the following example for him:




The result of running the above code will be like this:

Using Mockery as a mocking framework with PHPUnit

A few days ago I was explaining mocking to a few colleagues. I came up with the following quick n dirty code to show them the elegance of Mockery as a mocking framework.

The code is straight-forward: it checks the health of a server using a tiny heart beat script.

1. The script residing in the remote server:


2. The class that tries to fetch the status from the remote server:



Node access rebuild using Drush

In one of our Drupal production site, we have around 84K nodes. Periodically we need to rebuild the content access permission, which takes around 6 hours to complete when done through the browser. Being very unhappy with it, today found the following drush use:

The results were immediate, the whole rebuild now takes only 20 minutes!

A clean way of integrating PHPUnit 3.5.x with CodeIgniter 2.x

Now a days, my default choice of framework is always Zend Framework. However, I have to maintain a couple live projects in CodeIgniter from early days. I feel its very important to have tests around critical applications, so I have attempted a couple times to integrate PHPUnit with CodeIgniter but failed every time – well, until now.

I’ve managed it this time with hooks. It provides a clean way of bootstrapping the framework and then performing tests on the Model layer – for me testing the model layer has been sufficient. The use is very simple as it does not require any change in how a regular CodeIgniter application is built.

Grab the code from github.

Example – /tests/PostTest.php


Quick start on new Facebook PHP SDK (IFrame based)

This post is more than couple year old. It solved the issues when the SDK was first released and facebook had lack of documentation. However, now facebook has very rich set of documnetation and you should follow that instead!

The new Facebook API has already spread over the application developers and if you’re like me, you’ve already got your hands dirty to see how this new thing works. If you have tried to follow the documentation to authorize/get session in your canvas application, it is likely you have already hit roadblocks. Well, I am no savior but I have glued together a few clues and got it working for myself.

I am assuming that you have already created your application by following the Getting Started section from the official documentation. Also, this is for IFrame based applications only.

Enough talking, let’s get some code.

Step 1: Get the new SDK

Download the new SDK from github. We will only need the facebook.php file from the src folder. In our project directory, let’s create a folder called “lib” and put the file there.

Step 2: A configuration file

Let’s now create a configuration file to store our facebook configuration. Let’s name it config.php. Here goes the source:

Step 3: Application Main Page

This file will be the main entry point to our facebook application. It just instantiates the facebook object, sets the configuration and checks for a valid session. If it does not find a valid session, it redirects to the login page. For first time visitors, it will be the authorization page. On later requests, the operation will occur in the background – without any user interaction.


Enterprise PHP

I presented this talk on the Soft Expo 2010 – the largest software fair in Bangladesh. The intention was to clear some of the misconception about PHP, the growth of PHP, how it can fit in the enterprise now, etc.

After these, I shed light on some topics that a company/developer should keep in mind in order to write good software in PHP. This was followed by live session on caching, mysql query optimization, use of Xdebug, etc.

So here goes the presentation:

And a big thanks to Ivo Jansch’s “PHP in the real wolrd” presentation, from where I took inspiration.


Changing the default controller naming convention in CodeIgniter

CodeIgniter is one of my favorite framework and I often use it for developing application quickly. Although it is very flexible in most cases, I find its naming convention to be strict. Many times I have faced this problem when my controller’s class name and a model/library’s class names are the same – a Fatal error is inevitable and I have to forcefully change the name of the conflicting class to something less desirable (say from Users to UsersModel). Today I wanted to end this problem.

So I extended the CI_Router core class and made change to the _validate_request method. Now I can name my controller classes in this fashion: UsersController and it resides on the file system as controllers/UsersController.php. If you’ve tried other established frameworks, you should notice that this naming convention is widely used. So, if you have the same need, then just download the MY_Router.php file and put it on your application/libraries folder. That’s it.

Here is how your controller would start:

[cc lang=’php’]
< ?php class UsersController extends Controller { public function __construct() { parent::__construct(); } } [/cc] (more…)

Facebook Developer Garage Dhaka โ€“ Open Stream API

The first ever “Facebook Developer Garage” took place in Dhaka, Bangladesh and I am proud to be a part of it. I was one of the speakers of this spectacular event organized by Facebook and IBT bangladesh. I spoke about the recently released Open Stream API from Facebook. It was more of an overview rather than a detail one. Here goes the slides:

I have created a quick start example which outlines both Facebook Connect and the Open Stream API. You can check that here. A blog post covering the steps is coming soon in 3-4 days.

Stay tuned if you have interest in them.


Code Updates (HTTP class, Extended CodeIgniter Model, Cross-domain AJAX transport)

Greetings to all the readers of my blog.

Many of you have been writing to me in the last couple days when I took the site down. The main objective was to add the new theme and push a few code updates of the existing libraries. I really appreciate your concern and would like to reassure you that the site is up and will be up as usual ๐Ÿ™‚ Now, besides the slightly customized theme from Elegant Themes, I have put a few code updates. They are detailed below:

Extended Model for CodeIgniter

The original version of the Extended Model for CodeIgniter has been serving many people well. Although most users loved the nifty functions of the Model, many (including me) didn’t like the hacking of CI core to get this functionality. With the release of CodeIgniter 1.7, we can avoid that as we can now overload the Model class of CI like the other libraries. Follow this instruction:

1. Download the updated version from here
2. Put it in your application/libraries folder
3. In your model files, use it this way: class Product extends MY_Model
4. Everything else is same just like the original one

HTTP Class

There is not much update in this class except for a few bug fixes (thanks to you guys). Also, I have included a license file in the package as many of you have asked. It’s released under the MIT license. The original post is here for reference.

Download the update from here and the API reference is here.

Cross-domain AJAX calls using PHP

A minor bug fix in the code. Thanks to a few of you who pointed them out. Original post is here. Download the update from here.

I have accelerated plans for the blog in 2009 so stay tuned for some worthy posts in this month. And do write to me if you feel you have any questions/ideas/suggestions.