fn poll_next()

in core/src/layers/retry.rs [793:841]
47 lines of code
3 McCabe index (conditional complexity)

    fn poll_next(&mut self, cx: &mut Context<'_>) -> Poll<Option<Result<Bytes>>> {
        if let Some(sleep) = self.sleep.as_mut() {
            ready!(sleep.poll_unpin(cx));
            self.sleep = None;
        }

        match ready!(self.inner.poll_next(cx)) {
            None => {
                self.current_backoff = None;
                Poll::Ready(None)
            }
            Some(Ok(v)) => {
                self.current_backoff = None;
                Poll::Ready(Some(Ok(v)))
            }
            Some(Err(err)) if !err.is_temporary() => {
                self.current_backoff = None;
                Poll::Ready(Some(Err(err)))
            }
            Some(Err(err)) => {
                let backoff = match self.current_backoff.as_mut() {
                    Some(backoff) => backoff,
                    None => {
                        self.current_backoff = Some(self.builder.build());
                        self.current_backoff.as_mut().unwrap()
                    }
                };

                match backoff.next() {
                    None => {
                        self.current_backoff = None;
                        Poll::Ready(Some(Err(err)))
                    }
                    Some(dur) => {
                        self.notify.intercept(
                            &err,
                            dur,
                            &[
                                ("operation", ReadOperation::Next.into_static()),
                                ("path", &self.path),
                            ],
                        );
                        self.sleep = Some(Box::pin(tokio::time::sleep(dur)));
                        self.poll_next(cx)
                    }
                }
            }
        }
    }