Basic Rust HTTP Router

router.rs

#![allow(dead_code)]
use std::collections::HashMap;

type Headers = HashMap<String, String>;
type BoxedCallback = Box<Fn(Conn) -> Conn>;

#[derive(Default)]
struct Request {
    method: String,
    url: String,
    headers: Headers,
    body: Vec<u8>,
}

#[derive(Default)]
struct Response {
    status: u32,
    headers: Headers,
    body: Vec<u8>,
}

#[derive(Default)]
struct Conn {
    pub request: Request,
    pub response: Response,
}

struct Router {
    routes: HashMap<String, BoxedCallback>,
}

impl Router {
    fn new() -> Router {
        Router { routes: HashMap::new() }
    } 
   
    fn add_route<C>(&mut self, url: &str, callback: C)
        where C: Fn(Conn) -> Conn + 'static
    {
        self.routes.insert(url.to_string(), Box::new(callback));
    } 
    
    fn handle_request(&self, conn: Conn) -> Conn {
        match self.routes.get(&conn.request.url) {
            None => Conn::default(),
            Some(callback) => callback(conn)
        }
    }
}

fn main() {
    let mut router = Router::new();
    
    router.add_route("/", |conn| {
        println!("Serving /");
        conn
    });
    router.add_route("/hello", |conn| {
        println!("Serving /hello");
        conn
    });
    
    let mut conn = Conn::default(); 
    conn.request.url = "/hello".to_string();
    
    router.handle_request(conn);
}