I want to view location about code qos algorithms in VyOS (ex : droptail, fairqueue ... )

Hi all
I’m doing my graduation project about VyOS.

I want to view location about code qos algorithms in VyOS (ex : droptail, fairqueue … ). I view module Droptal.pm,FairQueue.pm but they not show algorithms or direction to file have algorithms.

And can i edit them ?

And i want to know about architecture Qos when i set qos-policy (ex VyOS call module ?? first, the next module ?? )

Someone help me?

Tks so much.