blob: 29065f9f9617591a000bd8992b89c932d1714acd [file] [log] [blame]
use std::io;
use futures::{Poll, Future, Async};
use AsyncWrite;
/// A future used to fully flush an I/O object.
///
/// Resolves to the underlying I/O object once the flush operation is complete.
///
/// Created by the [`flush`] function.
///
/// [`flush`]: fn.flush.html
#[derive(Debug)]
pub struct Flush<A> {
a: Option<A>,
}
/// Creates a future which will entirely flush an I/O object and then yield the
/// object itself.
///
/// This function will consume the object provided if an error happens, and
/// otherwise it will repeatedly call `flush` until it sees `Ok(())`, scheduling
/// a retry if `WouldBlock` is seen along the way.
pub fn flush<A>(a: A) -> Flush<A>
where A: AsyncWrite,
{
Flush {
a: Some(a),
}
}
impl<A> Future for Flush<A>
where A: AsyncWrite,
{
type Item = A;
type Error = io::Error;
fn poll(&mut self) -> Poll<A, io::Error> {
try_nb!(self.a.as_mut().unwrap().flush());
Ok(Async::Ready(self.a.take().unwrap()))
}
}