Merge pull request #3953 from Abestanis/freature/instant_try_constructor

Add `Instant::try_from_*` constructor functions

2 files changed, 109 insertions, 2 deletions

diff --git a/embassy-time/src/duration.rs b/embassy-time/src/duration.rs
index 647d208e3..dcda705d3 100644
--- a/embassy-time/src/duration.rs
+++ b/embassy-time/src/duration.rs
@@ -64,9 +64,9 @@ impl Duration {
 
     /// Creates a duration from the specified number of nanoseconds, rounding up.
     /// NOTE: Delays this small may be inaccurate.
-    pub const fn from_nanos(micros: u64) -> Duration {
+    pub const fn from_nanos(nanoseconds: u64) -> Duration {
         Duration {
-            ticks: div_ceil(micros * (TICK_HZ / GCD_1G), 1_000_000_000 / GCD_1G),
+            ticks: div_ceil(nanoseconds * (TICK_HZ / GCD_1G), 1_000_000_000 / GCD_1G),
         }
     }
 
@@ -90,6 +90,82 @@ impl Duration {
         }
     }
 
+    /// Try to create a duration from the specified number of seconds, rounding up.
+    /// Fails if the number of seconds is too large.
+    pub const fn try_from_secs(secs: u64) -> Option<Duration> {
+        let Some(ticks) = secs.checked_mul(TICK_HZ) else {
+            return None;
+        };
+        Some(Duration { ticks })
+    }
+
+    /// Try to create a duration from the specified number of milliseconds, rounding up.
+    /// Fails if the number of milliseconds is too large.
+    pub const fn try_from_millis(millis: u64) -> Option<Duration> {
+        let Some(value) = millis.checked_mul(TICK_HZ / GCD_1K) else {
+            return None;
+        };
+        Some(Duration {
+            ticks: div_ceil(value, 1000 / GCD_1K),
+        })
+    }
+
+    /// Try to create a duration from the specified number of microseconds, rounding up.
+    /// Fails if the number of microseconds is too large.
+    /// NOTE: Delays this small may be inaccurate.
+    pub const fn try_from_micros(micros: u64) -> Option<Duration> {
+        let Some(value) = micros.checked_mul(TICK_HZ / GCD_1M) else {
+            return None;
+        };
+        Some(Duration {
+            ticks: div_ceil(value, 1_000_000 / GCD_1M),
+        })
+    }
+
+    /// Try to create a duration from the specified number of nanoseconds, rounding up.
+    /// Fails if the number of nanoseconds is too large.
+    /// NOTE: Delays this small may be inaccurate.
+    pub const fn try_from_nanos(nanoseconds: u64) -> Option<Duration> {
+        let Some(value) = nanoseconds.checked_mul(TICK_HZ / GCD_1G) else {
+            return None;
+        };
+        Some(Duration {
+            ticks: div_ceil(value, 1_000_000_000 / GCD_1G),
+        })
+    }
+
+    /// Try to create a duration from the specified number of seconds, rounding down.
+    /// Fails if the number of seconds is too large.
+    pub const fn try_from_secs_floor(secs: u64) -> Option<Duration> {
+        let Some(ticks) = secs.checked_mul(TICK_HZ) else {
+            return None;
+        };
+        Some(Duration { ticks })
+    }
+
+    /// Try to create a duration from the specified number of milliseconds, rounding down.
+    /// Fails if the number of milliseconds is too large.
+    pub const fn try_from_millis_floor(millis: u64) -> Option<Duration> {
+        let Some(value) = millis.checked_mul(TICK_HZ / GCD_1K) else {
+            return None;
+        };
+        Some(Duration {
+            ticks: value / (1000 / GCD_1K),
+        })
+    }
+
+    /// Try to create a duration from the specified number of microseconds, rounding down.
+    /// Fails if the number of microseconds is too large.
+    /// NOTE: Delays this small may be inaccurate.
+    pub const fn try_from_micros_floor(micros: u64) -> Option<Duration> {
+        let Some(value) = micros.checked_mul(TICK_HZ / GCD_1M) else {
+            return None;
+        };
+        Some(Duration {
+            ticks: value / (1_000_000 / GCD_1M),
+        })
+    }
+
     /// Creates a duration corresponding to the specified Hz.
     /// NOTE: Giving this function a hz >= the TICK_HZ of your platform will clamp the Duration to 1
     /// tick. Doing so will not deadlock, but will certainly not produce the desired output.
diff --git a/embassy-time/src/instant.rs b/embassy-time/src/instant.rs
index 7fc93c2ec..6571bea62 100644
--- a/embassy-time/src/instant.rs
+++ b/embassy-time/src/instant.rs
@@ -50,6 +50,37 @@ impl Instant {
         }
     }
 
+    /// Try to create an Instant from a microsecond count since system boot.
+    /// Fails if the number of microseconds is too large.
+    pub const fn try_from_micros(micros: u64) -> Option<Self> {
+        let Some(value) = micros.checked_mul(TICK_HZ / GCD_1M) else {
+            return None;
+        };
+        Some(Self {
+            ticks: value / (1_000_000 / GCD_1M),
+        })
+    }
+
+    /// Try to create an Instant from a millisecond count since system boot.
+    /// Fails if the number of milliseconds is too large.
+    pub const fn try_from_millis(millis: u64) -> Option<Self> {
+        let Some(value) = millis.checked_mul(TICK_HZ / GCD_1K) else {
+            return None;
+        };
+        Some(Self {
+            ticks: value / (1000 / GCD_1K),
+        })
+    }
+
+    /// Try to create an Instant from a second count since system boot.
+    /// Fails if the number of seconds is too large.
+    pub const fn try_from_secs(seconds: u64) -> Option<Self> {
+        let Some(ticks) = seconds.checked_mul(TICK_HZ) else {
+            return None;
+        };
+        Some(Self { ticks })
+    }
+
     /// Tick count since system boot.
     pub const fn as_ticks(&self) -> u64 {
         self.ticks