diff options
Diffstat (limited to 'third_party/rust/futures-util/src/io/write_all.rs')
-rw-r--r-- | third_party/rust/futures-util/src/io/write_all.rs | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/third_party/rust/futures-util/src/io/write_all.rs b/third_party/rust/futures-util/src/io/write_all.rs new file mode 100644 index 0000000000..08c025f94d --- /dev/null +++ b/third_party/rust/futures-util/src/io/write_all.rs @@ -0,0 +1,43 @@ +use futures_core::future::Future; +use futures_core::ready; +use futures_core::task::{Context, Poll}; +use futures_io::AsyncWrite; +use std::io; +use std::mem; +use std::pin::Pin; + +/// Future for the [`write_all`](super::AsyncWriteExt::write_all) method. +#[derive(Debug)] +#[must_use = "futures do nothing unless you `.await` or poll them"] +pub struct WriteAll<'a, W: ?Sized> { + writer: &'a mut W, + buf: &'a [u8], +} + +impl<W: ?Sized + Unpin> Unpin for WriteAll<'_, W> {} + +impl<'a, W: AsyncWrite + ?Sized + Unpin> WriteAll<'a, W> { + pub(super) fn new(writer: &'a mut W, buf: &'a [u8]) -> Self { + Self { writer, buf } + } +} + +impl<W: AsyncWrite + ?Sized + Unpin> Future for WriteAll<'_, W> { + type Output = io::Result<()>; + + fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<io::Result<()>> { + let this = &mut *self; + while !this.buf.is_empty() { + let n = ready!(Pin::new(&mut this.writer).poll_write(cx, this.buf))?; + { + let (_, rest) = mem::take(&mut this.buf).split_at(n); + this.buf = rest; + } + if n == 0 { + return Poll::Ready(Err(io::ErrorKind::WriteZero.into())); + } + } + + Poll::Ready(Ok(())) + } +} |