A simple function for profiling Rust code

profiler.rs

use lazy_static::lazy_static;

lazy_static! {
    static ref PROFILED_SPEEDS: Mutex<HashMap<String, Vec<u64>>> = Mutex::new(HashMap::new());
}

fn profile<T>(name: &str, test: &mut impl FnMut() -> T) -> T {
    let start = SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .unwrap()
        .as_millis() as u64;

    let ret: T = test();

    let finish_time: u64 = SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .unwrap()
        .as_millis() as u64
        - start;

    let mut map = PROFILED_SPEEDS.lock().unwrap();

    let avg = if map.contains_key(name) {
        let times = map.get(name).unwrap();
        let mut sum = 0;

        for time in times {
            sum += time;
        }

        sum / times.len() as u64
    } else {
        0
    };

    println!("{} finished in {}ms, avg: {}ms", name, finish_time, avg);

    if map.contains_key(name) {
        map.get_mut(name).unwrap().push(finish_time);
    } else {
        map.insert(name.to_owned(), vec![finish_time]);
    }

    ret
}