Facebook Announces a Better, Faster PHP: HipHop PHP

Digitivity — Wed, 03 Feb 2010 17:52:31 +0000

PHP is the programming language that runs many web applications, including WordPress. PHP’s slower than many other languages, but it’s fast to develop in.

Now Facebook, which also runs on PHP, has announced a new version of PHP that runs twice as fast.

This also means that if you have a popular WordPress blog, you might only have to have half the server size you use now.

How PHP Works

PHP, in its usual incarnation, is an interpreted language. This means that a program (such as a PHP module in the Apache webserver) reads the PHP instructions in your script and executes them in turn. Every time the PHP script is executed, it has to be turned into machine code, even if the script runs 1000 times per hour. Obviously, this is inefficient, but people put up with it because PHP is considered easier to develop in than other languages.

By comparison, C++ is a language which is usually compiled (changed to machine instructions which run directly on the CPU). This happens only once, and every time the program runs, it runs directly on the processor. Because there’s no intermediate interpretation step, C++ programs run much faster.

Facebook’s HipHop PHP

Facebook announced what they are calling HipHop PHP, which translates PHP into C++. Then you use g++, the GNU C++ compiler, to compile the C++ program.

Here’s how the process works:

HipHop PHP Transformation Process

Facebook says compilation of their PHP code results in savings of 50% in server usage.

They also released HPHPi, which is an optimized PHP interpreter that doesn’t require you re-compile your code.