multipart_write/write/
feed.rs

1use std::fmt::{self, Debug, Formatter};
2use std::pin::Pin;
3use std::task::{Context, Poll};
4
5use futures_core::future::{FusedFuture, Future};
6use futures_core::ready;
7
8use crate::{FusedMultipartWrite, MultipartWrite};
9
10/// Future for [`feed`](super::MultipartWriteExt::feed).
11#[must_use = "futures do nothing unless polled"]
12pub struct Feed<'a, Wr: ?Sized, Part> {
13    writer: &'a mut Wr,
14    buffered: Option<Part>,
15}
16
17impl<Wr: ?Sized + Unpin, Part> Unpin for Feed<'_, Wr, Part> {}
18
19impl<'a, Wr: ?Sized + MultipartWrite<Part> + Unpin, Part> Feed<'a, Wr, Part> {
20    pub(super) fn new(writer: &'a mut Wr, part: Part) -> Self {
21        Self { writer, buffered: Some(part) }
22    }
23
24    pub(super) fn writer_pin_mut(&mut self) -> Pin<&mut Wr> {
25        Pin::new(self.writer)
26    }
27
28    pub(super) fn is_part_pending(&self) -> bool {
29        self.buffered.is_some()
30    }
31}
32
33impl<Wr, Part> FusedFuture for Feed<'_, Wr, Part>
34where
35    Wr: FusedMultipartWrite<Part> + Unpin,
36{
37    fn is_terminated(&self) -> bool {
38        self.writer.is_terminated()
39    }
40}
41
42impl<Wr: ?Sized + MultipartWrite<Part> + Unpin, Part> Future
43    for Feed<'_, Wr, Part>
44{
45    type Output = Result<Wr::Recv, Wr::Error>;
46
47    fn poll(
48        mut self: Pin<&mut Self>,
49        cx: &mut Context<'_>,
50    ) -> Poll<Self::Output> {
51        let this = &mut *self;
52
53        ready!(Pin::new(&mut this.writer).poll_ready(cx))?;
54        let part = this.buffered.take().expect("polled Feed after completion");
55        let ret = Pin::new(&mut this.writer).start_send(part);
56        Poll::Ready(ret)
57    }
58}
59
60impl<Wr: Debug, Part: Debug> Debug for Feed<'_, Wr, Part> {
61    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
62        f.debug_struct("Feed")
63            .field("writer", &self.writer)
64            .field("buffered", &self.buffered)
65            .finish()
66    }
67}
multipart_write/write/feed.rs

multipart_write/write/
feed.rs
