From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 21:33:14 +0200 Subject: Adding upstream version 115.7.0esr. Signed-off-by: Daniel Baumann --- .../rust/tokio-stream/src/stream_ext/skip.rs | 63 ++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 third_party/rust/tokio-stream/src/stream_ext/skip.rs (limited to 'third_party/rust/tokio-stream/src/stream_ext/skip.rs') diff --git a/third_party/rust/tokio-stream/src/stream_ext/skip.rs b/third_party/rust/tokio-stream/src/stream_ext/skip.rs new file mode 100644 index 0000000000..80a0a0aff0 --- /dev/null +++ b/third_party/rust/tokio-stream/src/stream_ext/skip.rs @@ -0,0 +1,63 @@ +use crate::Stream; + +use core::fmt; +use core::pin::Pin; +use core::task::{Context, Poll}; +use pin_project_lite::pin_project; + +pin_project! { + /// Stream for the [`skip`](super::StreamExt::skip) method. + #[must_use = "streams do nothing unless polled"] + pub struct Skip { + #[pin] + stream: St, + remaining: usize, + } +} + +impl fmt::Debug for Skip +where + St: fmt::Debug, +{ + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("Skip") + .field("stream", &self.stream) + .finish() + } +} + +impl Skip { + pub(super) fn new(stream: St, remaining: usize) -> Self { + Self { stream, remaining } + } +} + +impl Stream for Skip +where + St: Stream, +{ + type Item = St::Item; + + fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll> { + loop { + match ready!(self.as_mut().project().stream.poll_next(cx)) { + Some(e) => { + if self.remaining == 0 { + return Poll::Ready(Some(e)); + } + *self.as_mut().project().remaining -= 1; + } + None => return Poll::Ready(None), + } + } + } + + fn size_hint(&self) -> (usize, Option) { + let (lower, upper) = self.stream.size_hint(); + + let lower = lower.saturating_sub(self.remaining); + let upper = upper.map(|x| x.saturating_sub(self.remaining)); + + (lower, upper) + } +} -- cgit v1.2.3