Simon Willison’s Weblog

Making Facebook 2x Faster. Facebook have a system called BigPipe which allows them to progressively send their pages to the browser as the server-side processing completes to optimise client loading time. Anyone reverse engineered this yet to figure out how they actually do it?

# 19th February 2010, 9:14 am / bigpage, facebook, optimisation, performance

HipHop for PHP: Move Fast. Facebook have open-sourced their internally developed PHP to C++ compiler. They serve 400 billion PHP pages a month (that’s more than 150,000 a second) so any performance improvement dramatically reduces their hardware costs, and HipHop drops the CPU usage on their web servers by an average of 50%. “We are serving over 90% of our Web traffic using HipHop, all only six months after deployment”.

# 2nd February 2010, 6:59 pm / facebook, hiphop, optimisation, performance, php, traffic

Gmail for Mobile: Reducing Startup Latency. Cheeky iPhone optimisation trick—parsing 200 KB of JavaScript takes an iPhone 2.2 device 2.6 seconds, so Gmail embeds code components in /* comments */ in a script tag and evals them on demand later on when the features are needed.

# 23rd September 2009, 10:29 pm / google, iphone, javascript, optimisation, performance

quipt (via) Extremely clever idea: Cache JavaScript in window.name (which persists between page views and can hold several MB of data), but use document.referrer to check that an external domain hasn’t loaded the cache with malicious code for an XSS attack. UPDATE: Jesse Ruderman points out a fatal flaw in the comments.

# 4th July 2008, 3:49 pm / caching, javascript, optimisation, quipt, referrer, security, windowname, xss

Faster JavaScript Trim. Neat optimisation post—it turns out that while regular expressions are great for removing leading whitespace you can do a lot better at trailing whitespace by manually looping backwards from the end of the string.

# 3rd February 2008, 10:12 pm / javascript, optimisation, steven-levithan, trim, whitespace

YSlow. New extension for Firebug (yes, an extension on top of another extension) from the Yahoo! performance team which provides improved performance measurement tools and optimisation advice.

# 25th July 2007, 4:48 am / extension, firebug, firefox, http, optimisation, performance, yahoo, yslow