Add SystemTime

Author: tomaka

Cargo.toml

@@ -2,13 +2,14 @@
 name = "wasm-timer"
 edition = "2018"
 description = "Abstraction over std::time::Instant and tokio_timer that works on WASM"
-version = "0.1.1"
+version = "0.1.2"
 authors = ["Pierre Krieger <pierre.krieger1708@gmail.com>"]
 license = "MIT"
 repository = "https://github.com/tomaka/wasm-timer"
 
 [target.'cfg(any(target_arch = "wasm32"))'.dependencies]
 futures = "0.1"
+js-sys = "0.3.14"
 send_wrapper = "0.2"
 wasm-bindgen = "0.2.37"
 web-sys = { version = "0.3.14", features = ["Performance", "Window"] }

src/lib.rs

@@ -19,7 +19,7 @@
 // DEALINGS IN THE SOFTWARE.
 
 #[cfg(not(target_arch = "wasm32"))]
-pub use std::time::Instant;
+pub use std::time::{Instant, SystemTime, UNIX_EPOCH};
 #[cfg(not(target_arch = "wasm32"))]
 pub use tokio_timer::*;
 #[cfg(target_arch = "wasm32")]

src/wasm.rs

@@ -24,7 +24,7 @@
 use futures::{prelude::*, sync::oneshot, try_ready};
 use std::{error, fmt};
 use std::cmp::{Eq, PartialEq, Ord, PartialOrd, Ordering};
-use std::ops::{Add, Sub};
+use std::ops::{Add, Sub, AddAssign, SubAssign};
 use std::time::Duration;
 use wasm_bindgen::{prelude::*, JsCast};
 
@@ -105,6 +105,95 @@ impl Sub<Instant> for Instant {
     }
 }
 
+pub const UNIX_EPOCH: SystemTime = SystemTime { inner: 0.0 };
+
+#[derive(Debug, Copy, Clone)]
+pub struct SystemTime {
+    /// Unit is milliseconds.
+    inner: f64,
+}
+
+impl PartialEq for SystemTime {
+    fn eq(&self, other: &SystemTime) -> bool {
+        // Note that this will most likely only compare equal if we clone an `SystemTime`,
+        // but that's ok.
+        self.inner == other.inner
+    }
+}
+
+impl Eq for SystemTime {}
+
+impl PartialOrd for SystemTime {
+    fn partial_cmp(&self, other: &SystemTime) -> Option<Ordering> {
+        self.inner.partial_cmp(&other.inner)
+    }
+}
+
+impl Ord for SystemTime {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.inner.partial_cmp(&other.inner).unwrap()
+    }
+}
+
+impl SystemTime {
+    pub const UNIX_EPOCH: SystemTime = SystemTime { inner: 0.0 };
+
+    pub fn now() -> SystemTime {
+        let val = js_sys::Date::now();
+        SystemTime { inner: val }
+    }
+
+    pub fn duration_since(&self, earlier: SystemTime) -> Result<Duration, ()> {
+        let dur_ms = self.inner - earlier.inner;
+        if dur_ms < 0.0 {
+            return Err(())
+        }
+        Ok(Duration::from_millis(dur_ms as u64))
+    }
+
+    pub fn elapsed(&self) -> Result<Duration, ()> {
+        self.duration_since(SystemTime::now())
+    }
+
+    pub fn checked_add(&self, duration: Duration) -> Option<SystemTime> {
+        Some(*self + duration)
+    }
+
+    pub fn checked_sub(&self, duration: Duration) -> Option<SystemTime> {
+        Some(*self - duration)
+    }
+}
+
+impl Add<Duration> for SystemTime {
+    type Output = SystemTime;
+
+    fn add(self, other: Duration) -> SystemTime {
+        let new_val = self.inner + other.as_millis() as f64;
+        SystemTime { inner: new_val as f64 }
+    }
+}
+
+impl Sub<Duration> for SystemTime {
+    type Output = SystemTime;
+
+    fn sub(self, other: Duration) -> SystemTime {
+        let new_val = self.inner - other.as_millis() as f64;
+        SystemTime { inner: new_val as f64 }
+    }
+}
+
+impl AddAssign<Duration> for SystemTime {
+    fn add_assign(&mut self, rhs: Duration) {
+        *self = *self + rhs;
+    }
+}
+
+impl SubAssign<Duration> for SystemTime {
+    fn sub_assign(&mut self, rhs: Duration) {
+        *self = *self - rhs;
+    }
+}
+
 #[derive(Debug)]
 pub struct Error;