hash map rust bench

hash bench.rs

use std::collections::HashMap;



fn add_rand_strings(keys:&mut Vec<String>, amnt:usize, l:usize) {
    const CHARSET: &[u8] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
    let mut rnd = 548324;
    for i in 0..amnt {
        let mut s = String::new();
        for j in 0..l {
            rnd = i ^ rnd + j * 5;
            s.push(CHARSET[rnd % CHARSET.len()] as char);
        }
        keys.push(s);
    }
}

fn my_function_to_measure(keys:Vec<String>, to_insert:&mut HashMap<String, String>) {
    for key in keys {
        to_insert.insert(key, "foobar".to_string());
    }
}


fn main() {
    use std::time::Instant;
    let now = Instant::now();
    let mut my_vec = Vec::new();
    let mut my_map = HashMap::new();
    add_rand_strings(&mut my_vec, 400000, 20);
    // Code block to measure.
    {
        my_function_to_measure(my_vec, &mut my_map);
    }

    let elapsed = now.elapsed();
    println!("Elapsed: {:.2?}", elapsed);
}