| use futures_core::future::Future; |
| use futures_core::task::{self, Poll}; |
| use futures_io::AsyncWrite; |
| use std::io; |
| use std::marker::Unpin; |
| use std::mem::{self, PinMut}; |
| |
| /// A future used to write the entire contents of some data to a stream. |
| /// |
| /// This is created by the [`write_all`] top-level method. |
| /// |
| /// [`write_all`]: fn.write_all.html |
| #[derive(Debug)] |
| pub struct WriteAll<'a, W: ?Sized + 'a> { |
| writer: &'a mut W, |
| buf: &'a [u8], |
| } |
| |
| // Pinning is never projected to fields |
| impl<W: ?Sized> Unpin for WriteAll<'_, W> {} |
| |
| impl<'a, W: AsyncWrite + ?Sized> WriteAll<'a, W> { |
| pub(super) fn new(writer: &'a mut W, buf: &'a [u8]) -> Self { |
| WriteAll { writer, buf } |
| } |
| } |
| |
| fn zero_write() -> io::Error { |
| io::Error::new(io::ErrorKind::WriteZero, "zero-length write") |
| } |
| |
| impl<W: AsyncWrite + ?Sized> Future for WriteAll<'_, W> { |
| type Output = io::Result<()>; |
| |
| fn poll(mut self: PinMut<Self>, cx: &mut task::Context) -> Poll<io::Result<()>> { |
| let this = &mut *self; |
| while !this.buf.is_empty() { |
| let n = try_ready!(this.writer.poll_write(cx, this.buf)); |
| { |
| let (_, rest) = mem::replace(&mut this.buf, &[]).split_at(n); |
| this.buf = rest; |
| } |
| if n == 0 { |
| return Poll::Ready(Err(zero_write())) |
| } |
| } |
| |
| Poll::Ready(Ok(())) |
| } |
| } |