1use super::MAX_SAFE_MILLIS_DURATION;
2use crate::time::{Clock, Duration, Instant};
3
4/// A structure which handles conversion from Instants to `u64` timestamps.
5#[derive(Debug)]
6pub(crate) struct TimeSource {
7 start_time: Instant,
8}
9
10impl TimeSource {
11 pub(crate) fn new(clock: &Clock) -> Self {
12 Self {
13 start_time: clock.now(),
14 }
15 }
16
17 pub(crate) fn deadline_to_tick(&self, t: Instant) -> u64 {
18 // Round up to the end of a ms
19 self.instant_to_tick(t + Duration::from_nanos(999_999))
20 }
21
22 pub(crate) fn instant_to_tick(&self, t: Instant) -> u64 {
23 // round up
24 let dur: Duration = t.saturating_duration_since(self.start_time);
25 let ms = dur
26 .as_millis()
27 .try_into()
28 .unwrap_or(MAX_SAFE_MILLIS_DURATION);
29 ms.min(MAX_SAFE_MILLIS_DURATION)
30 }
31
32 pub(crate) fn tick_to_duration(&self, t: u64) -> Duration {
33 Duration::from_millis(t)
34 }
35
36 pub(crate) fn now(&self, clock: &Clock) -> u64 {
37 self.instant_to_tick(clock.now())
38 }
39
40 #[cfg(test)]
41 #[allow(dead_code)]
42 pub(super) fn start_time(&self) -> Instant {
43 self.start_time
44 }
45}
46