Wikimedia Bugzilla is closed!

I noticed this in config/index.php:getLanguageList()

The current method of opendir/readdir causes an excessive number of fstat calls. With network based filesystems (glusterfs specifically) this causes a lot of unnecessary delay.

I propose caching the results of those lookups in session variables to reduce that impact, for example:

function getLanguageList() {
        global $wgLanguageNames, $IP;
        if( isset( $_SESSION['getLanguageListcodes'] ) )
                return $_SESSION['getLanguageListcodes']
        if( !isset( $wgLanguageNames ) ) {
                require_once( "$IP/languages/Names.php" );
        }

        $codes = array();

        $d = opendir( "../languages/messages" );
        /* In case we are called from the root directory */
        if (!$d)
                $d = opendir( "languages/messages");
        while( false !== ($f = readdir( $d ) ) ) {
                $m = array();
                if( preg_match( '/Messages([A-Z][a-z_]+)\.php$/', $f, $m ) ) {
                        $code = str_replace( '_', '-', strtolower( $m[1] ) );
                        if( isset( $wgLanguageNames[$code] ) ) {
                                $name = $code . ' - ' . $wgLanguageNames[$code];
                        } else {
                                $name = $code;
                        }
                        $codes[$code] = $name;
                }
        }
        closedir( $d );
        ksort( $codes );
        $_SESSION['getLanguageListcodes'] = $codes
        return $codes;
}