You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: perf_btree_map.rs
    path of file: ./repos/rdms/src/bin/rdms
    
    the code of the file until where you have to start completion: use rand::{rngs::StdRng, Rng, SeedableRng};
use serde::Deserialize;

use std::{
    collections::BTreeMap,
    fmt,
    time::{self, SystemTime},
};

use crate::cmd_perf::{Generate, Opt};
use rdms::{dbs, util, Result};

const DEFAULT_KEY_SIZE: usize = 16;
const DEFAULT_VAL_SIZE: usize = 16;

#[derive(Clone, Deserialize)]
pub struct Profile {
    key_type:
    
pub fn perf(opts: Opt) -> Result<()> {
    let profile: Profile = util::files::load_toml(&opts.profile)?;

    let (kt, vt) = (&profile.key_type, &profile.value_type);

    match (kt.as_str(), vt.as_str()) {
        ("u64", "u64") => load_and_spawn::<u64, u64>(opts, profile),
        ("u64", "binary") => load_and_spawn::<u64, dbs::Binary>(opts, profile),
        ("binary", "binary") => load_and_spawn::<dbs::Binary, dbs::Binary>(opts, profile),
        (_, _) => unreachable!(),
    }
}