groundhog/
std_timer.rs

1use crate::RollingTimer;
2use std::time::{Instant, Duration};
3
4use once_cell::sync::Lazy;
5static T0: Lazy<Instant> = Lazy::new(|| {
6    Instant::now()
7});
8
9#[derive(Default, Clone)]
10pub struct Timer<const TPS: u32>;
11
12impl<const TPS: u32> Timer<TPS> {
13    // TODO: evaluate if we're losing precision here
14    const NANOS_PER_TICK: u128 = 1_000_000_000 / (TPS as u128);
15
16    pub fn new() -> Self {
17        Timer
18    }
19}
20
21impl<const TPS: u32> RollingTimer for Timer<TPS>
22{
23    type Tick = u32;
24    const TICKS_PER_SECOND: Self::Tick = TPS;
25
26    fn is_initialized(&self) -> bool {
27        true
28    }
29
30    fn get_ticks(&self) -> Self::Tick {
31        let ticks = Instant::now()
32            .checked_duration_since(*T0)
33            .unwrap_or_else(|| Duration::from_secs(0));
34
35        let tnanos = ticks.as_nanos();
36        let div = tnanos / Self::NANOS_PER_TICK;
37        (div & 0xFFFF_FFFF) as u32
38    }
39}
40
41#[cfg(test)]
42mod test {
43    use super::Timer;
44    use std::time::{Instant, Duration};
45    use std::thread::sleep;
46    use crate::RollingTimer;
47
48    #[test]
49    fn sanity_test_1m() {
50        let timer: Timer<1_000_000> = Timer::new();
51        let start_gh = timer.get_ticks();
52        let start = Instant::now();
53        sleep(Duration::from_secs(1));
54        let stop_gh = timer.millis_since(start_gh);
55        let stop = start.elapsed();
56
57        assert!(
58            (stop >= Duration::from_millis(998))
59            && (stop <= Duration::from_millis(1002))
60        );
61        assert!(
62            (stop_gh >= 998) && (stop_gh <= 1002)
63        );
64    }
65
66    #[test]
67    fn sanity_test_1k() {
68        let timer: Timer<1_000> = Timer::new();
69        let start_gh = timer.get_ticks();
70        let start = Instant::now();
71        sleep(Duration::from_secs(1));
72        let stop_gh = timer.millis_since(start_gh);
73        let stop = start.elapsed();
74
75        assert!(
76            (stop >= Duration::from_millis(998))
77            && (stop <= Duration::from_millis(1002))
78        );
79        assert!(
80            (stop_gh >= 998) && (stop_gh <= 1002)
81        );
82    }
83
84    #[test]
85    fn sanity_test_330() {
86        let timer: Timer<330> = Timer::new();
87        let start_gh = timer.get_ticks();
88        let start = Instant::now();
89        sleep(Duration::from_secs(1));
90        let stop_gh = timer.millis_since(start_gh);
91        let stop = start.elapsed();
92
93        assert!(
94            (stop >= Duration::from_millis(998))
95            && (stop <= Duration::from_millis(1002))
96        );
97        assert!(
98            (stop_gh >= 998) && (stop_gh <= 1002)
99        );
100    }
101}
groundhog/std_timer.rs

groundhog/
std_timer.rs
