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use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};
pub(crate) struct Backoff(usize, bool);
pub(crate) fn backoff(n: usize) -> impl Future<Output = ()> {
Backoff(n, false)
}
/// Back off, but clone the waker each time
pub(crate) fn backoff_clone(n: usize) -> impl Future<Output = ()> {
Backoff(n, true)
}
impl Future for Backoff {
type Output = ();
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
if self.0 == 0 {
return Poll::Ready(());
}
self.0 -= 1;
if self.1 {
cx.waker().clone().wake();
} else {
cx.waker().wake_by_ref();
}
Poll::Pending
}
}
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