Use common Timestamp impl in Hermit

Author: stepancheg

library/std/src/sys/pal/hermit/time.rs

@@ -1,122 +1,23 @@
 #![allow(dead_code)]
 
-use core::hash::{Hash, Hasher};
+use core::hash::Hash;
 
 use super::hermit_abi::{self, CLOCK_MONOTONIC, CLOCK_REALTIME, timespec};
-use crate::cmp::Ordering;
 use crate::ops::{Add, AddAssign, Sub, SubAssign};
+use crate::sys::common::timespec::Timespec;
 use crate::time::Duration;
 
 const NSEC_PER_SEC: i32 = 1_000_000_000;
 
-#[derive(Copy, Clone, Debug)]
-struct Timespec {
-    t: timespec,
-}
-
-impl Timespec {
-    const fn zero() -> Timespec {
-        Timespec { t: timespec { tv_sec: 0, tv_nsec: 0 } }
-    }
-
-    const fn new(tv_sec: i64, tv_nsec: i32) -> Timespec {
-        assert!(tv_nsec >= 0 && tv_nsec < NSEC_PER_SEC);
-        // SAFETY: The assert above checks tv_nsec is within the valid range
-        Timespec { t: timespec { tv_sec, tv_nsec } }
-    }
-
-    fn sub_timespec(&self, other: &Timespec) -> Result<Duration, Duration> {
-        fn sub_ge_to_unsigned(a: i64, b: i64) -> u64 {
-            debug_assert!(a >= b);
-            a.wrapping_sub(b).cast_unsigned()
-        }
-
-        if self >= other {
-            // Logic here is identical to Unix version of `Timestamp::sub_timespec`,
-            // check comments there why operations do not overflow.
-            Ok(if self.t.tv_nsec >= other.t.tv_nsec {
-                Duration::new(
-                    sub_ge_to_unsigned(self.t.tv_sec, other.t.tv_sec),
-                    (self.t.tv_nsec - other.t.tv_nsec) as u32,
-                )
-            } else {
-                Duration::new(
-                    sub_ge_to_unsigned(self.t.tv_sec - 1, other.t.tv_sec),
-                    (self.t.tv_nsec + NSEC_PER_SEC - other.t.tv_nsec) as u32,
-                )
-            })
-        } else {
-            match other.sub_timespec(self) {
-                Ok(d) => Err(d),
-                Err(d) => Ok(d),
-            }
-        }
-    }
-
-    fn checked_add_duration(&self, other: &Duration) -> Option<Timespec> {
-        let mut secs = self.t.tv_sec.checked_add_unsigned(other.as_secs())?;
-
-        // Nano calculations can't overflow because nanos are <1B which fit
-        // in a u32.
-        let mut nsec = other.subsec_nanos() + u32::try_from(self.t.tv_nsec).unwrap();
-        if nsec >= NSEC_PER_SEC.try_into().unwrap() {
-            nsec -= u32::try_from(NSEC_PER_SEC).unwrap();
-            secs = secs.checked_add(1)?;
-        }
-        Some(Timespec { t: timespec { tv_sec: secs, tv_nsec: nsec as _ } })
-    }
-
-    fn checked_sub_duration(&self, other: &Duration) -> Option<Timespec> {
-        let mut secs = self.t.tv_sec.checked_sub_unsigned(other.as_secs())?;
-
-        // Similar to above, nanos can't overflow.
-        let mut nsec = self.t.tv_nsec as i32 - other.subsec_nanos() as i32;
-        if nsec < 0 {
-            nsec += NSEC_PER_SEC as i32;
-            secs = secs.checked_sub(1)?;
-        }
-        Some(Timespec { t: timespec { tv_sec: secs, tv_nsec: nsec as _ } })
-    }
-}
-
-impl PartialEq for Timespec {
-    fn eq(&self, other: &Timespec) -> bool {
-        self.t.tv_sec == other.t.tv_sec && self.t.tv_nsec == other.t.tv_nsec
-    }
-}
-
-impl Eq for Timespec {}
-
-impl PartialOrd for Timespec {
-    fn partial_cmp(&self, other: &Timespec) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for Timespec {
-    fn cmp(&self, other: &Timespec) -> Ordering {
-        let me = (self.t.tv_sec, self.t.tv_nsec);
-        let other = (other.t.tv_sec, other.t.tv_nsec);
-        me.cmp(&other)
-    }
-}
-
-impl Hash for Timespec {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        self.t.tv_sec.hash(state);
-        self.t.tv_nsec.hash(state);
-    }
-}
-
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
 pub struct Instant(Timespec);
 
 impl Instant {
     pub fn now() -> Instant {
-        let mut time: Timespec = Timespec::zero();
-        let _ = unsafe { hermit_abi::clock_gettime(CLOCK_MONOTONIC, &raw mut time.t) };
+        let mut time: timespec = timespec { tv_sec: 0, tv_nsec: 0 };
+        let _ = unsafe { hermit_abi::clock_gettime(CLOCK_MONOTONIC, &raw mut time) };
 
-        Instant(time)
+        Instant(Timespec::new(time.tv_sec, time.tv_nsec as i64).unwrap())
     }
 
     #[stable(feature = "time2", since = "1.8.0")]
@@ -210,14 +111,13 @@ pub const UNIX_EPOCH: SystemTime = SystemTime(Timespec::zero());
 
 impl SystemTime {
     pub fn new(tv_sec: i64, tv_nsec: i32) -> SystemTime {
-        SystemTime(Timespec::new(tv_sec, tv_nsec))
+        SystemTime(Timespec::new(tv_sec, tv_nsec as i64).unwrap())
     }
 
     pub fn now() -> SystemTime {
-        let mut time: Timespec = Timespec::zero();
-        let _ = unsafe { hermit_abi::clock_gettime(CLOCK_REALTIME, &raw mut time.t) };
-
-        SystemTime(time)
+        let mut time: timespec = timespec { tv_sec: 0, tv_nsec: 0 };
+        let _ = unsafe { hermit_abi::clock_gettime(CLOCK_REALTIME, &raw mut time) };
+        SystemTime::new(time.tv_sec, time.tv_nsec)
     }
 
     pub fn sub_time(&self, other: &SystemTime) -> Result<Duration, Duration> {