Improve performance of SystemTime by using Duration internally

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Changed
+
+- Improve performance of `SystemTime` by using `Duration` internally.
+
 ## [0.2.3] - 2023-10-23
 
 ### Changed

src/web/system_time.rs

@@ -7,37 +7,30 @@ use std::time::Duration;
 
 /// See [`std::time::SystemTime`].
 #[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
-pub struct SystemTime(i64);
+pub struct SystemTime(Duration);
 
 impl SystemTime {
  /// See [`std::time::SystemTime::UNIX_EPOCH`].
- pub const UNIX_EPOCH: Self = Self(0);
+ pub const UNIX_EPOCH: Self = Self(Duration::ZERO);
 
  /// See [`std::time::SystemTime::now()`].
  #[must_use]
+ #[allow(clippy::missing_panics_doc)]
  pub fn now() -> Self {
  #[allow(clippy::as_conversions, clippy::cast_possible_truncation)]
- Self(js_sys::Date::now() as i64)
+ let ms = js_sys::Date::now() as i64;
+ let ms = ms.try_into().expect("found negative timestamp");
+
+ Self(Duration::from_millis(ms))
  }
 
  /// See [`std::time::SystemTime::duration_since()`].
- #[allow(
- clippy::missing_errors_doc,
- clippy::missing_panics_doc,
- clippy::trivially_copy_pass_by_ref
- )]
+ #[allow(clippy::missing_errors_doc, clippy::trivially_copy_pass_by_ref)]
  pub fn duration_since(&self, earlier: Self) -> Result<Duration, SystemTimeError> {
  if self.0 < earlier.0 {
- let duration = (earlier.0 - self.0)
- .try_into()
- .expect("`self` bigger then `earlier` despite earlier check");
-
- Err(SystemTimeError(Duration::from_millis(duration)))
+ Err(SystemTimeError(earlier.0 - self.0))
  } else {
- let duration = (self.0 - earlier.0)
- .try_into()
- .expect("`earlier` bigger then `self` despite earlier check");
- Ok(Duration::from_millis(duration))
+ Ok(self.0 - earlier.0)
  }
  }
 
@@ -50,14 +43,12 @@ impl SystemTime {
  /// See [`std::time::SystemTime::checked_add()`].
  #[allow(clippy::trivially_copy_pass_by_ref)]
  pub fn checked_add(&self, duration: Duration) -> Option<Self> {
- let duration = duration.as_millis().try_into().ok()?;
  self.0.checked_add(duration).map(SystemTime)
  }
 
  /// See [`std::time::SystemTime::checked_sub()`].
  #[allow(clippy::trivially_copy_pass_by_ref)]
  pub fn checked_sub(&self, duration: Duration) -> Option<Self> {
- let duration = duration.as_millis().try_into().ok()?;
  self.0.checked_sub(duration).map(SystemTime)
  }
 }