Voxell's Timers

let data = time_eprintln!{hello mom, generate_data() };
// -> hello mom: 309ms

This library provides a simple and an advanced way to time code execution. Simply use the provided macros/functions to time your code to get a Duration and the result of the block/closure. Or use the advanced instrumentation and get a list of spans that took the most time to execute.

Simple example

This is the primary and recommended use case of the library. The brackets are literally treated like a new scope.

use voxell_timer::*;
use core::time::Duration;

let (result, time): (&str, Duration) = time! {
    for _ in 0..1_000_000 {
        // expensive operation ...
    }
    "hello, timers!"
};
eprintln!("Took {}ms", time.as_millis());
assert_eq!(result, "hello, timers!");

Complicated ScopedTimer example

This example uses ScopedTimer to profile nested loops. In the code below, the outer loop creates its own scope while the inner loop creates nested scopes. You can view the timings associated with each scope.

use voxell_timer::power_toys::ScopedTimer;
use std::thread;
use std::time::Duration;

fn sleep(ms: u64) {
    thread::sleep(Duration::from_millis(ms));
}

// create a performance session with identifier type &str
let mut session = ScopedTimer::<&str>::new("total");

let mut outer = session.fork("outer loop"); // <- give a unique name!
for _ in 0..3 {
    //          VVVVV you can nest scopes!
    let mut inner = outer.fork("inner loop"); // <- give a unique name!

    // expensive work...
    sleep(20);

    for _ in 0..4 {
        //           VVVVV so many nests...
        let innest = inner.fork("innest loop"); // <- give a unique name!

        // more work ...
        sleep(10);

        innest.join(); // <- times the innest scope.
    }
    inner.join(); // <- times the inner scope.
}
outer.join(); // <- times the outer scope

let results = session.join_and_finish_pretty();
println!("{}", results);
// +-------------+------------+--------------+
// | Identifier  | Duration   | Times Forked |
// +-------------+------------+--------------+
// | innest loop | 125.8265ms | 12           |
// | inner loop  | 61.3889ms  | 3            |
// | outer loop  | 2µs        | 1            |
// | total       | 700ns      | 1            |
// +-------------+-^^^--------+--------------+
//                 |||
//                 +++. scopes only time their own!

Example

use voxell_timer::*;

let haystack = vec![1, 2, 3, 4, 5, 6];
let result = time_println! {
    "Finding needle in haystack",
    let needle = 4;
    haystack.iter().find(|a| **a == needle)
};

assert_eq!(result, Some(&4));

Example

use voxell_timer::*;

let haystack = vec![1, 2, 3, 4, 5, 6];
let result = time_fn_println("Finding needle in haystack", || {
    let needle = 4;
    haystack.iter().find(|a| **a == needle)
});
assert_eq!(result, Some(&4));