embassy/embassy/src/io/util/read_buf.rs
Michael Beaumont d3673886b3
Run cargo fmt
2021-03-18 20:02:42 +01:00

35 lines
926 B
Rust

use super::super::error::Result;
use super::super::traits::AsyncBufRead;
use core::pin::Pin;
use futures::future::Future;
use futures::ready;
use futures::task::{Context, Poll};
pub struct ReadBuf<'a, R: ?Sized> {
reader: Option<&'a mut R>,
}
impl<R: ?Sized + Unpin> Unpin for ReadBuf<'_, R> {}
impl<'a, R: AsyncBufRead + ?Sized + Unpin> ReadBuf<'a, R> {
pub(super) fn new(reader: &'a mut R) -> Self {
ReadBuf {
reader: Some(reader),
}
}
}
impl<'a, R: AsyncBufRead + ?Sized + Unpin> Future for ReadBuf<'a, R> {
type Output = Result<&'a [u8]>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
let this = &mut *self;
let buf = ready!(Pin::new(this.reader.as_mut().unwrap()).poll_fill_buf(cx))?;
let buf: &'a [u8] = unsafe { core::mem::transmute(buf) };
this.reader = None;
Poll::Ready(Ok(buf))
}
}