ambient_sys/native/
time.rs

1#![allow(clippy::disallowed_types)]
2use std::{
3    ops::{Add, AddAssign, Sub},
4    time::{Duration, SystemTimeError},
5};
6
7/// A measurement of a monotonically nondecreasing clock. Opaque and useful only with [Duration].
8///
9/// This is intentionally a newtype to discourage mixing with StdInstant as it is not supported on
10/// wasm.
11#[derive(From, Into, Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
12pub struct Instant(pub(crate) std::time::Instant);
13
14impl Sub<Instant> for Instant {
15    type Output = Duration;
16
17    fn sub(self, rhs: Instant) -> Self::Output {
18        self.0 - rhs.0
19    }
20}
21
22impl Sub<Duration> for Instant {
23    type Output = Instant;
24
25    fn sub(self, rhs: Duration) -> Self::Output {
26        Self(self.0.checked_sub(rhs).unwrap())
27    }
28}
29
30impl Add<Duration> for Instant {
31    type Output = Instant;
32
33    fn add(self, rhs: Duration) -> Self::Output {
34        Self(self.0 + rhs)
35    }
36}
37
38impl AddAssign<Duration> for Instant {
39    fn add_assign(&mut self, rhs: Duration) {
40        *self = *self + rhs;
41    }
42}
43
44impl Instant {
45    pub fn from_tokio(instant: tokio::time::Instant) -> Self {
46        Self(instant.into())
47    }
48
49    pub fn now() -> Self {
50        Self(std::time::Instant::now())
51    }
52
53    pub fn elapsed(&self) -> Duration {
54        self.0.elapsed()
55    }
56
57    pub fn duration_since(&self, earlier: Self) -> Duration {
58        self.0.duration_since(earlier.0)
59    }
60}
61
62/// A measurement of the system clock, useful for talking to external entities like the file system or other processes.
63///
64/// Distinct from the [Instant] type, this time measurement is not monotonic. This means that you can save a file to the file system,
65/// then save another file to the file system, and the second file has a [SystemTime] measurement earlier than the first.
66/// In other words, an operation that happens after another operation in real time may have an earlier [SystemTime]!
67#[derive(From, Into, Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
68pub struct SystemTime(pub(crate) std::time::SystemTime);
69
70impl Add<Duration> for SystemTime {
71    type Output = SystemTime;
72
73    fn add(self, rhs: Duration) -> Self::Output {
74        Self(self.0 + rhs)
75    }
76}
77
78impl Sub<Duration> for SystemTime {
79    type Output = SystemTime;
80
81    fn sub(self, rhs: Duration) -> Self::Output {
82        Self(self.0 - rhs)
83    }
84}
85
86impl SystemTime {
87    pub const UNIX_EPOCH: Self = SystemTime(std::time::SystemTime::UNIX_EPOCH);
88    pub fn now() -> Self {
89        Self(std::time::SystemTime::now())
90    }
91
92    pub fn duration_since(&self, earlier: Self) -> Result<Duration, SystemTimeError> {
93        self.0.duration_since(earlier.0)
94    }
95}
96
97use derive_more::{From, Into};
ambient_sys/native/time.rs

ambient_sys/native/
time.rs
