library/std/src/sys/wasi/time.rs

   1 use crate::time::Duration;
   2
   3 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
   4 pub struct Instant(Duration);
   5
   6 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
   7 pub struct SystemTime(Duration);
   8
   9 pub const UNIX_EPOCH: SystemTime = SystemTime(Duration::from_secs(0));
  10
  11 fn current_time(clock: u32) -> Duration {
  12     let ts = unsafe {
  13         wasi::clock_time_get(
  14             clock, 1, // precision... seems ignored though?
  15         )
  16         .unwrap()
  17     };
  18     Duration::new((ts / 1_000_000_000) as u64, (ts % 1_000_000_000) as u32)
  19 }
  20
  21 impl Instant {
  22     pub fn now() -> Instant {
  23         Instant(current_time(wasi::CLOCKID_MONOTONIC))
  24     }
  25
  26     pub const fn zero() -> Instant {
  27         Instant(Duration::from_secs(0))
  28     }
  29
  30     pub fn actually_monotonic() -> bool {
  31         true
  32     }
  33
  34     pub fn checked_sub_instant(&self, other: &Instant) -> Option<Duration> {
  35         self.0.checked_sub(other.0)
  36     }
  37
  38     pub fn checked_add_duration(&self, other: &Duration) -> Option<Instant> {
  39         Some(Instant(self.0.checked_add(*other)?))
  40     }
  41
  42     pub fn checked_sub_duration(&self, other: &Duration) -> Option<Instant> {
  43         Some(Instant(self.0.checked_sub(*other)?))
  44     }
  45 }
  46
  47 impl SystemTime {
  48     pub fn now() -> SystemTime {
  49         SystemTime(current_time(wasi::CLOCKID_REALTIME))
  50     }
  51
  52     pub fn from_wasi_timestamp(ts: wasi::Timestamp) -> SystemTime {
  53         SystemTime(Duration::from_nanos(ts))
  54     }
  55
  56     pub fn sub_time(&self, other: &SystemTime) -> Result<Duration, Duration> {
  57         self.0.checked_sub(other.0).ok_or_else(|| other.0 - self.0)
  58     }
  59
  60     pub fn checked_add_duration(&self, other: &Duration) -> Option<SystemTime> {
  61         Some(SystemTime(self.0.checked_add(*other)?))
  62     }
  63
  64     pub fn checked_sub_duration(&self, other: &Duration) -> Option<SystemTime> {
  65         Some(SystemTime(self.0.checked_sub(*other)?))
  66     }
  67 }