Try Rust Descriptor Parsing
While ago we looked into using Go parsers to speed up our ability to parse descriptors. This didn't work out (Python/Go integration turns out to be really weak) but seems that's not the case with RUst...
http://www.infoworld.com/article/3208391/python/how-rust-can-replace-c-with-pythons-help.html
Lets give it a try! If it works out Rust parsing might be shareable with core tor.