1 use {Poll, Async, Future}; 2 use sink::Sink; 3 4 /// Future for the `Sink::flush` combinator, which polls the sink until all data 5 /// has been flushed. 6 #[derive(Debug)] 7 #[must_use = "futures do nothing unless polled"] 8 pub struct Flush<S> { 9 sink: Option<S>, 10 } 11 new<S: Sink>(sink: S) -> Flush<S>12pub fn new<S: Sink>(sink: S) -> Flush<S> { 13 Flush { sink: Some(sink) } 14 } 15 16 impl<S: Sink> Flush<S> { 17 /// Get a shared reference to the inner sink. get_ref(&self) -> &S18 pub fn get_ref(&self) -> &S { 19 self.sink.as_ref().expect("Attempted `Flush::get_ref` after the flush completed") 20 } 21 22 /// Get a mutable reference to the inner sink. get_mut(&mut self) -> &mut S23 pub fn get_mut(&mut self) -> &mut S { 24 self.sink.as_mut().expect("Attempted `Flush::get_mut` after the flush completed") 25 } 26 27 /// Consume the `Flush` and return the inner sink. into_inner(self) -> S28 pub fn into_inner(self) -> S { 29 self.sink.expect("Attempted `Flush::into_inner` after the flush completed") 30 } 31 } 32 33 impl<S: Sink> Future for Flush<S> { 34 type Item = S; 35 type Error = S::SinkError; 36 poll(&mut self) -> Poll<S, S::SinkError>37 fn poll(&mut self) -> Poll<S, S::SinkError> { 38 let mut sink = self.sink.take().expect("Attempted to poll Flush after it completed"); 39 if sink.poll_complete()?.is_ready() { 40 Ok(Async::Ready(sink)) 41 } else { 42 self.sink = Some(sink); 43 Ok(Async::NotReady) 44 } 45 } 46 } 47