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use core::fmt::{Debug, Formatter, Result as FmtResult};
use futures_core::{Async, Poll};
use futures_core::task;
use futures_sink::{ Sink};
pub struct Fanout<A: Sink, B: Sink> {
left: A,
right: B
}
impl<A: Sink, B: Sink> Fanout<A, B> {
pub fn into_inner(self) -> (A, B) {
(self.left, self.right)
}
}
impl<A: Sink + Debug, B: Sink + Debug> Debug for Fanout<A, B>
where A::SinkItem: Debug,
B::SinkItem: Debug
{
fn fmt(&self, f: &mut Formatter) -> FmtResult {
f.debug_struct("Fanout")
.field("left", &self.left)
.field("right", &self.right)
.finish()
}
}
pub fn new<A: Sink, B: Sink>(left: A, right: B) -> Fanout<A, B> {
Fanout {left, right}
}
impl<A, B> Sink for Fanout<A, B>
where A: Sink,
A::SinkItem: Clone,
B: Sink<SinkItem=A::SinkItem, SinkError=A::SinkError>
{
type SinkItem = A::SinkItem;
type SinkError = A::SinkError;
fn poll_ready(&mut self, cx: &mut task::Context) -> Poll<(), Self::SinkError> {
let left_ready = self.left.poll_ready(cx)?.is_ready();
let right_ready = self.right.poll_ready(cx)?.is_ready();
let ready = left_ready && right_ready;
Ok(if ready {Async::Ready(())} else {Async::Pending})
}
fn start_send(&mut self, item: Self::SinkItem) -> Result<(), Self::SinkError> {
self.left.start_send(item.clone())?;
self.right.start_send(item)?;
Ok(())
}
fn poll_flush(&mut self, cx: &mut task::Context) -> Poll<(), Self::SinkError> {
let left_ready = self.left.poll_flush(cx)?.is_ready();
let right_ready = self.right.poll_flush(cx)?.is_ready();
let ready = left_ready && right_ready;
Ok(if ready {Async::Ready(())} else {Async::Pending})
}
fn poll_close(&mut self, cx: &mut task::Context) -> Poll<(), Self::SinkError> {
let left_ready = self.left.poll_close(cx)?.is_ready();
let right_ready = self.right.poll_close(cx)?.is_ready();
let ready = left_ready && right_ready;
Ok(if ready {Async::Ready(())} else {Async::Pending})
}
}
#[cfg(test)]
#[cfg(feature = "std")]
mod tests {
use future::FutureExt;
use futures_channel::mpsc;
use futures_executor::block_on;
use sink::SinkExt;
use std::iter::Iterator;
use std::vec::Vec;
use stream::{self, StreamExt};
#[test]
fn it_works() {
let src = stream::iter_ok::<_, ()>(0..10);
let (sender0, receiver0) = mpsc::channel(1);
let (sender1, receiver1) = mpsc::channel(2);
let senders = sender0.fanout(sender1).sink_map_err(|_| ());
let fwd = src.forward(senders).map(|_| ());
let list0 = receiver0.collect::<Vec<_>>().map_err(|_| ());
let list1 = receiver1.collect::<Vec<_>>().map_err(|_| ());
let lists = fwd.join(list0.join(list1)).map(|(_, lists)| lists);
let lists = block_on(lists);
let lists = lists.as_ref()
.map(|&(ref list0, ref list1)| (&**list0, &**list1));
let expected = (0..10).collect::<Vec<_>>();
assert_eq!(lists, Ok((&*expected, &*expected)));
}
}