sodiumCompatAutoloader

    function sodiumCompatAutoloader($class)
    {
        $namespace = 'ParagonIE_Sodium_';
        // Does the class use the namespace prefix?
        $len = strlen($namespace);
        if (strncmp($namespace, $class, $len) !== 0) {
            // no, move to the next registered autoloader
            return false;
        }

        // Get the relative class name
        $relative_class = substr($class, $len);

        // Replace the namespace prefix with the base directory, replace namespace
        // separators with directory separators in the relative class name, append
        // with .php
        $file = dirname(__FILE__) . '/src/' . str_replace('_', '/', $relative_class) . '.php';
        // if the file exists, require it
        if (file_exists($file)) {
            require_once $file;
            return true;
        }
        return false;
    }