From a5d3154c04ca3167cfb99c256401cbe55ebb7fc7 Mon Sep 17 00:00:00 2001
From: David Venhoek <david@tweedegolf.com>
Date: Thu, 10 Aug 2023 14:40:38 +0200
Subject: [PATCH] Switch to own TimeOffset time to deal with signed offset.

---
 src/lib.rs  | 11 +++++++++--
 src/unix.rs | 40 +++++++++++++++++++---------------------
 2 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 6c91215..6d1725c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,8 +13,15 @@ pub mod unix;
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
 pub struct Timestamp {
     pub seconds: libc::time_t,
+    /// Nanos must be between 0 and 999999999 inclusive
+    pub nanos: u32,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
+pub struct TimeOffset {
+    pub seconds: libc::time_t,
+    /// Nanos must be between 0 and 999999999 inclusive
     pub nanos: u32,
-    pub subnanos: u32,
 }
 
 /// Indicate whether a leap second must be applied
@@ -56,7 +63,7 @@ pub trait Clock {
 
     /// Change the current time of the clock by an offset.
     /// Returns the time at which the change was applied.
-    fn step_clock(&self, offset: Duration) -> Result<Timestamp, Self::Error>;
+    fn step_clock(&self, offset: TimeOffset) -> Result<Timestamp, Self::Error>;
 
     /// Change the indicators for upcoming leap seconds.
     fn set_leap_seconds(&self, leap_status: LeapIndicator) -> Result<(), Self::Error>;
diff --git a/src/unix.rs b/src/unix.rs
index 2895ee0..c36520a 100644
--- a/src/unix.rs
+++ b/src/unix.rs
@@ -1,4 +1,4 @@
-use crate::{Clock, LeapIndicator, Timestamp};
+use crate::{Clock, LeapIndicator, TimeOffset, Timestamp};
 use std::{
     os::unix::prelude::{AsRawFd, FromRawFd, RawFd},
     path::Path,
@@ -157,17 +157,14 @@ impl UnixClock {
     }
 
     #[cfg_attr(target_os = "linux", allow(unused))]
-    fn step_clock_by_timespec(&self, offset: Duration) -> Result<Timestamp, Error> {
-        let offset_secs = offset.as_secs();
-        let offset_nanos = offset.subsec_nanos();
-
+    fn step_clock_by_timespec(&self, offset: TimeOffset) -> Result<Timestamp, Error> {
         let mut timespec = self.clock_gettime()?;
 
         // see https://github.com/rust-lang/libc/issues/1848
         #[cfg_attr(target_env = "musl", allow(deprecated))]
         {
-            timespec.tv_sec += offset_secs as libc::time_t;
-            timespec.tv_nsec += offset_nanos as libc::c_long;
+            timespec.tv_sec += offset.seconds as libc::time_t;
+            timespec.tv_nsec += offset.nanos as libc::c_long;
         }
 
         self.clock_settime(timespec)?;
@@ -191,13 +188,13 @@ impl UnixClock {
     }
 
     #[cfg(target_os = "linux")]
-    fn step_clock_timex(offset: Duration) -> libc::timex {
+    fn step_clock_timex(offset: TimeOffset) -> libc::timex {
         // we provide the offset in nanoseconds
         let modes = libc::ADJ_SETOFFSET | libc::ADJ_NANO;
 
         let time = libc::timeval {
-            tv_sec: offset.as_secs() as _,
-            tv_usec: offset.subsec_nanos() as libc::suseconds_t,
+            tv_sec: offset.seconds,
+            tv_usec: offset.nanos as libc::suseconds_t,
         };
 
         libc::timex {
@@ -208,7 +205,7 @@ impl UnixClock {
     }
 
     #[cfg(target_os = "linux")]
-    fn step_clock_by_timex(&self, offset: Duration) -> Result<Timestamp, Error> {
+    fn step_clock_by_timex(&self, offset: TimeOffset) -> Result<Timestamp, Error> {
         let mut timex = Self::step_clock_timex(offset);
         self.adjtime(&mut timex)?;
         self.extract_current_time(&timex)
@@ -378,12 +375,12 @@ impl Clock for UnixClock {
     }
 
     #[cfg(target_os = "linux")]
-    fn step_clock(&self, offset: Duration) -> Result<Timestamp, Self::Error> {
+    fn step_clock(&self, offset: TimeOffset) -> Result<Timestamp, Self::Error> {
         self.step_clock_by_timex(offset)
     }
 
     #[cfg(any(target_os = "freebsd", target_os = "macos"))]
-    fn step_clock(&self, offset: Duration) -> Result<Timestamp, Self::Error> {
+    fn step_clock(&self, offset: TimeOffset) -> Result<Timestamp, Self::Error> {
         self.step_clock_by_timespec(offset)
     }
 
@@ -537,7 +534,6 @@ fn current_time_timespec(timespec: libc::timespec, precision: Precision) -> Time
     Timestamp {
         seconds,
         nanos: nanos as u32,
-        subnanos: 0,
     }
 }
 
@@ -551,11 +547,7 @@ fn current_time_timeval(timespec: libc::timeval, precision: Precision) -> Timest
             .unwrap_or_default(),
     };
 
-    Timestamp {
-        seconds,
-        nanos,
-        subnanos: 0,
-    }
+    Timestamp { seconds, nanos }
 }
 
 const EMPTY_TIMESPEC: libc::timespec = libc::timespec {
@@ -694,7 +686,10 @@ mod tests {
     #[ignore = "requires permissions, useful for testing permissions"]
     fn step_clock() {
         UnixClock::CLOCK_REALTIME
-            .step_clock(Duration::new(0, 0))
+            .step_clock(TimeOffset {
+                seconds: 0,
+                nanos: 0,
+            })
             .unwrap();
     }
 
@@ -743,7 +738,10 @@ mod tests {
     #[cfg(target_os = "linux")]
     #[test]
     fn test_step_clock() {
-        let offset = Duration::from_secs_f64(1.2);
+        let offset = TimeOffset {
+            seconds: 1,
+            nanos: 200000000,
+        };
         let timex = UnixClock::step_clock_timex(offset);
 
         assert_eq!(timex.modes, libc::ADJ_SETOFFSET | libc::ADJ_NANO);