| use std::{future::Future, mem::replace}; |
|
|
| use pin_project_lite::pin_project; |
| use tracing::Span; |
|
|
| pin_project! { |
| pub struct With<T, H> |
| where |
| T: Future, |
| { |
| #[pin] |
| future: T, |
| span: Span, |
| handle: Option<H>, |
| } |
| } |
|
|
| impl<T, H> With<T, H> |
| where |
| T: Future, |
| { |
| pub fn new(future: T, span: Span, handle: H) -> Self { |
| Self { |
| future, |
| span, |
| handle: Some(handle), |
| } |
| } |
| } |
|
|
| impl<T, H> Future for With<T, H> |
| where |
| T: Future, |
| { |
| type Output = (H, Span, T::Output); |
|
|
| fn poll( |
| self: std::pin::Pin<&mut Self>, |
| cx: &mut std::task::Context<'_>, |
| ) -> std::task::Poll<Self::Output> { |
| let this = self.project(); |
| let guard = this.span.enter(); |
| match this.future.poll(cx) { |
| std::task::Poll::Ready(result) => { |
| drop(guard); |
| std::task::Poll::Ready(( |
| this.handle.take().expect("polled after completion"), |
| replace(this.span, Span::none()), |
| result, |
| )) |
| } |
| std::task::Poll::Pending => std::task::Poll::Pending, |
| } |
| } |
| } |
|
|
