1 files changed, 63 insertions, 0 deletions
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<St> {
+        #[pin]
+        stream: St,
+        remaining: usize,
+    }
+}
+
+impl<St> fmt::Debug for Skip<St>
+where
+    St: fmt::Debug,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Skip")
+            .field("stream", &self.stream)
+            .finish()
+    }
+}
+
+impl<St> Skip<St> {
+    pub(super) fn new(stream: St, remaining: usize) -> Self {
+        Self { stream, remaining }
+    }
+}
+
+impl<St> Stream for Skip<St>
+where
+    St: Stream,
+{
+    type Item = St::Item;
+
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
+        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<usize>) {
+        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)
+    }
+}