1 use crate::io::AsyncWrite;
2
3 use bytes::Buf;
4 use pin_project_lite::pin_project;
5 use std::future::Future;
6 use std::io;
7 use std::marker::PhantomPinned;
8 use std::pin::Pin;
9 use std::task::{Context, Poll};
10
11 pin_project! {
12 /// A future to write some of the buffer to an `AsyncWrite`.
13 #[derive(Debug)]
14 #[must_use = "futures do nothing unless you `.await` or poll them"]
15 pub struct WriteAllBuf<'a, W, B> {
16 writer: &'a mut W,
17 buf: &'a mut B,
18 #[pin]
19 _pin: PhantomPinned,
20 }
21 }
22
23 /// Tries to write some bytes from the given `buf` to the writer in an
24 /// asynchronous manner, returning a future.
write_all_buf<'a, W, B>(writer: &'a mut W, buf: &'a mut B) -> WriteAllBuf<'a, W, B> where W: AsyncWrite + Unpin, B: Buf,25 pub(crate) fn write_all_buf<'a, W, B>(writer: &'a mut W, buf: &'a mut B) -> WriteAllBuf<'a, W, B>
26 where
27 W: AsyncWrite + Unpin,
28 B: Buf,
29 {
30 WriteAllBuf {
31 writer,
32 buf,
33 _pin: PhantomPinned,
34 }
35 }
36
37 impl<W, B> Future for WriteAllBuf<'_, W, B>
38 where
39 W: AsyncWrite + Unpin,
40 B: Buf,
41 {
42 type Output = io::Result<()>;
43
poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>>44 fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> {
45 let me = self.project();
46 while me.buf.has_remaining() {
47 let n = ready!(Pin::new(&mut *me.writer).poll_write(cx, me.buf.chunk())?);
48 me.buf.advance(n);
49 if n == 0 {
50 return Poll::Ready(Err(io::ErrorKind::WriteZero.into()));
51 }
52 }
53
54 Poll::Ready(Ok(()))
55 }
56 }
57