FastStringSearch

FastStringSearch is a PHP extension for fast string search and replace. It is used by StringUtils.php. It supports multiple search terms. It is used as a replacement for PHP's strtr, which was extremely slow in certain cases prior to PHP 5.5. Chinese script conversion is one of those cases. This extension uses a Commentz-Walter style algorithm for multiple search terms, or a Boyer-Moore algorithm for single search terms. If you are using PHP5.5+, MediaWiki will use the default strtr implementation instead of FSS.

See https://github.com/wikimedia/php-ffs/blob/master/README.

Puppet installation
If you use puppet, the following code can compile and enable FastStringSearch without license worries (using  from MediaWiki-Vagrant).