blob: 71173fa8369943058e94aae86efe6635ea9c3c51 [file] [log] [blame]
use {Poll, Async, Future, AsyncSink};
use sink::Sink;
/// Future for the `Sink::send` combinator, which sends a value to a sink and
/// then waits until the sink has fully flushed.
#[derive(Debug)]
#[must_use = "futures do nothing unless polled"]
pub struct Send<S: Sink> {
sink: Option<S>,
item: Option<S::SinkItem>,
}
pub fn new<S: Sink>(sink: S, item: S::SinkItem) -> Send<S> {
Send {
sink: Some(sink),
item: Some(item),
}
}
impl<S: Sink> Send<S> {
/// Get a shared reference to the inner sink.
pub fn get_ref(&self) -> &S {
self.sink.as_ref().take().expect("Attempted Send::get_ref after completion")
}
/// Get a mutable reference to the inner sink.
pub fn get_mut(&mut self) -> &mut S {
self.sink.as_mut().take().expect("Attempted Send::get_mut after completion")
}
fn sink_mut(&mut self) -> &mut S {
self.sink.as_mut().take().expect("Attempted to poll Send after completion")
}
fn take_sink(&mut self) -> S {
self.sink.take().expect("Attempted to poll Send after completion")
}
}
impl<S: Sink> Future for Send<S> {
type Item = S;
type Error = S::SinkError;
fn poll(&mut self) -> Poll<S, S::SinkError> {
if let Some(item) = self.item.take() {
if let AsyncSink::NotReady(item) = self.sink_mut().start_send(item)? {
self.item = Some(item);
return Ok(Async::NotReady);
}
}
// we're done sending the item, but want to block on flushing the
// sink
try_ready!(self.sink_mut().poll_complete());
// now everything's emptied, so return the sink for further use
Ok(Async::Ready(self.take_sink()))
}
}