feat: add tokio::NamedTask util

Cargo.toml

@@ -14,11 +14,13 @@ disallowed_methods = "warn"
 
 [features]
 default = []
+tokio = ["dep:tokio"]
 tracing = ["dep:const_format", "dep:tracing", "dep:tracing-appender", "dep:tracing-subscriber"]
 version = ["dep:const_format"]
 
 [dependencies]
 const_format = { version = "0.2.32", optional = true }
+tokio = { version = "1.0", features = ["rt"], optional = true }
 tracing = { version = "0.1.40", optional = true }
 tracing-appender = { version = "0.2.3", optional = true }
 tracing-subscriber = { version = "0.3.18", features = ["env-filter", "json"], optional = true }

src/lib.rs

@@ -1,5 +1,7 @@
 pub mod fs;
 #[cfg(feature = "tracing")]
+pub mod tokio;
+#[cfg(feature = "tracing")]
 pub mod tracing;
 #[cfg(feature = "version")]
 pub mod version;

src/tokio.rs

@@ -0,0 +1,40 @@
+use std::future::Future;
+use std::pin::Pin;
+
+use tokio::task::JoinError;
+
+/// A wrapper around a [tokio::task::JoinHandle] that attaches a name.
+///
+/// This enables a parent task to await all children simultaneously but still
+/// determine what child has exited for logging/diagnosis purposes.
+#[derive(Debug)]
+pub struct NamedTask<Ret = (), Id = String>
+where
+    Id: Clone + Unpin,
+{
+    task: Pin<Box<tokio::task::JoinHandle<Ret>>>,
+    id: Id,
+}
+
+impl<R, I> NamedTask<R, I>
+where
+    I: Clone + Unpin,
+{
+    pub fn new(task: tokio::task::JoinHandle<R>, id: I) -> Self {
+        NamedTask { task: Box::pin(task), id }
+    }
+}
+
+impl<R, I> Future for NamedTask<R, I>
+where
+    I: Clone + Unpin,
+{
+    type Output = (I, Result<R, JoinError>);
+
+    fn poll(
+        mut self: Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+    ) -> std::task::Poll<Self::Output> {
+        self.task.as_mut().poll(cx).map(|v| (self.id.clone(), v))
+    }
+}