1 | use futures_core::future::Future; |
2 | use futures_core::ready; |
3 | use futures_core::task::{Context, Poll}; |
4 | use futures_io::AsyncWrite; |
5 | use std::io; |
6 | use std::mem; |
7 | use std::pin::Pin; |
8 | |
9 | /// Future for the [`write_all`](super::AsyncWriteExt::write_all) method. |
10 | #[derive (Debug)] |
11 | #[must_use = "futures do nothing unless you `.await` or poll them" ] |
12 | pub struct WriteAll<'a, W: ?Sized> { |
13 | writer: &'a mut W, |
14 | buf: &'a [u8], |
15 | } |
16 | |
17 | impl<W: ?Sized + Unpin> Unpin for WriteAll<'_, W> {} |
18 | |
19 | impl<'a, W: AsyncWrite + ?Sized + Unpin> WriteAll<'a, W> { |
20 | pub(super) fn new(writer: &'a mut W, buf: &'a [u8]) -> Self { |
21 | Self { writer, buf } |
22 | } |
23 | } |
24 | |
25 | impl<W: AsyncWrite + ?Sized + Unpin> Future for WriteAll<'_, W> { |
26 | type Output = io::Result<()>; |
27 | |
28 | fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> { |
29 | let this: &mut WriteAll<'_, W> = &mut *self; |
30 | while !this.buf.is_empty() { |
31 | let n: usize = ready!(Pin::new(&mut this.writer).poll_write(cx, this.buf))?; |
32 | { |
33 | let (_, rest: &[u8]) = mem::take(&mut this.buf).split_at(mid:n); |
34 | this.buf = rest; |
35 | } |
36 | if n == 0 { |
37 | return Poll::Ready(Err(io::ErrorKind::WriteZero.into())); |
38 | } |
39 | } |
40 | |
41 | Poll::Ready(Ok(())) |
42 | } |
43 | } |
44 | |