feat: Add embassy-based sleeper for no_std

backon/Cargo.toml

@@ -25,9 +25,11 @@ std = ["fastrand/std"]
 std-blocking-sleep = []
 gloo-timers-sleep = ["gloo-timers/futures"]
 tokio-sleep = ["tokio/time"]
+embassy-sleep = ["embassy-time"]
 
 [dependencies]
 fastrand = { version = "2", default-features = false }
+embassy-time = { version = "0.3", optional = true }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 tokio = { version = "1", optional = true }

backon/src/blocking_sleep.rs

@@ -24,13 +24,18 @@ impl<F: Fn(Duration) + 'static> BlockingSleeper for F {
 /// The default implementation of `Sleeper` when no features are enabled.
 ///
 /// It will fail to compile if a containing [`Retry`][crate::Retry] is `.await`ed without calling [`Retry::sleep`][crate::Retry::sleep] to provide a valid sleeper.
-#[cfg(not(feature = "std-blocking-sleep"))]
+#[cfg(all(not(feature = "std-blocking-sleep"), not(feature = "embassy-sleep")))]
 pub type DefaultBlockingSleeper = PleaseEnableAFeatureOrProvideACustomSleeper;
 /// The default implementation of `Sleeper` while feature `std-blocking-sleep` enabled.
 ///
 /// it uses [`std::thread::sleep`].
 #[cfg(feature = "std-blocking-sleep")]
 pub type DefaultBlockingSleeper = StdSleeper;
+/// The default implementation of `Sleeper` while feature `embassy-sleep` enabled.
+///
+/// it uses [`embassy_time::block_for`].
+#[cfg(all(not(feature = "std-blocking-sleep"), feature = "embassy-sleep"))]
+pub type DefaultBlockingSleeper = EmbassySleeper;
 
 /// A placeholder type that does not implement [`Sleeper`] and will therefore fail to compile if used as one.
 ///
@@ -53,3 +58,15 @@ impl BlockingSleeper for StdSleeper {
         std::thread::sleep(dur)
     }
 }
+
+/// The no_std implementation of `StdSleeper`.
+#[cfg(feature = "embassy-sleep")]
+#[derive(Clone, Copy, Debug, Default)]
+pub struct EmbassySleeper;
+
+#[cfg(feature = "embassy-sleep")]
+impl BlockingSleeper for EmbassySleeper {
+    fn sleep(&self, dur: Duration) {
+        embassy_time::block_for(embassy_time::Duration::from_millis(dur.as_millis() as u64));
+    }
+}

backon/src/lib.rs

@@ -45,6 +45,7 @@
 //! |---------------------|--------------------|-------------|---------------|
 //! | [`TokioSleeper`]    | tokio-sleep        | non-wasm32  |  Yes          |
 //! | [`GlooTimersSleep`] | gloo-timers-sleep  |   wasm32    |  Yes          |
+//! | [`EmbassySleep`]    | embassy-sleep      |   no_std    |  Yes          |
 //! | [`StdSleeper`]      | std-blocking-sleep |    std      |  No           |
 //!
 //! ## Custom Sleeper
@@ -166,6 +167,8 @@ pub use retry_with_context::RetryableWithContext;
 
 mod sleep;
 pub use sleep::DefaultSleeper;
+#[cfg(all(not(feature = "std"), feature = "embassy-sleep"))]
+pub use sleep::EmbassySleep;
 #[cfg(all(target_arch = "wasm32", feature = "gloo-timers-sleep"))]
 pub use sleep::GlooTimersSleep;
 pub use sleep::Sleeper;

backon/src/sleep.rs

@@ -36,7 +36,11 @@ impl<F: Fn(Duration) -> Fut + 'static, Fut: Future<Output = ()>> Sleeper for F {
 /// The default implementation of `Sleeper` when no features are enabled.
 ///
 /// It will fail to compile if a containing [`Retry`][crate::Retry] is `.await`ed without calling [`Retry::sleep`][crate::Retry::sleep] to provide a valid sleeper.
-#[cfg(all(not(feature = "tokio-sleep"), not(feature = "gloo-timers-sleep"),))]
+#[cfg(all(
+    not(feature = "tokio-sleep"),
+    not(feature = "gloo-timers-sleep"),
+    not(feature = "embassy-sleep")
+))]
 pub type DefaultSleeper = PleaseEnableAFeatureOrProvideACustomSleeper;
 /// The default implementation of `Sleeper` while feature `tokio-sleep` enabled.
 ///
@@ -48,6 +52,11 @@ pub type DefaultSleeper = TokioSleeper;
 /// It uses `gloo_timers::sleep::sleep`.
 #[cfg(all(target_arch = "wasm32", feature = "gloo-timers-sleep"))]
 pub type DefaultSleeper = GlooTimersSleep;
+/// The default implementation of `Sleeper` while feature `embassy-sleep` enabled.
+///
+/// It uses `embassy_time::Timer`.
+#[cfg(all(not(feature = "std"), feature = "embassy-sleep"))]
+pub type DefaultSleeper = EmbassySleep;
 
 /// A placeholder type that does not implement [`Sleeper`] and will therefore fail to compile if used as one.
 ///
@@ -91,3 +100,17 @@ impl Sleeper for GlooTimersSleep {
         gloo_timers::future::sleep(dur)
     }
 }
+
+/// The default implementation of `Sleeper` utilizes `embassy-time::Timer`.
+#[cfg(all(not(feature = "std"), feature = "embassy-sleep"))]
+#[derive(Clone, Copy, Debug, Default)]
+pub struct EmbassySleep;
+
+#[cfg(all(not(feature = "std"), feature = "embassy-sleep"))]
+impl Sleeper for EmbassySleep {
+    type Sleep = embassy_time::Timer;
+
+    fn sleep(&self, dur: Duration) -> Self::Sleep {
+        embassy_time::Timer::after_millis(dur.as_millis() as u64)
+    }
+}