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use futures::channel::{mpsc, oneshot};
use futures::executor::block_on;
use futures::future::{self, poll_fn, Future, FutureExt, TryFutureExt};
use futures::never::Never;
use futures::ready;
use futures::sink::{self, Sink, SinkErrInto, SinkExt};
use futures::stream::{self, Stream, StreamExt};
use futures::task::{self, ArcWake, Context, Poll, Waker};
use futures_test::task::panic_context;
use std::cell::{Cell, RefCell};
use std::collections::VecDeque;
use std::fmt;
use std::mem;
use std::pin::Pin;
use std::rc::Rc;
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::Arc;
fn sassert_next<S>(s: &mut S, item: S::Item)
where
S: Stream + Unpin,
S::Item: Eq + fmt::Debug,
{
match s.poll_next_unpin(&mut panic_context()) {
Poll::Ready(None) => panic!("stream is at its end"),
Poll::Ready(Some(e)) => assert_eq!(e, item),
Poll::Pending => panic!("stream wasn't ready"),
}
}
fn unwrap<T, E: fmt::Debug>(x: Poll<Result<T, E>>) -> T {
match x {
Poll::Ready(Ok(x)) => x,
Poll::Ready(Err(_)) => panic!("Poll::Ready(Err(_))"),
Poll::Pending => panic!("Poll::Pending"),
}
}
// An Unpark struct that records unpark events for inspection
struct Flag(AtomicBool);
impl Flag {
fn new() -> Arc<Self> {
Arc::new(Self(AtomicBool::new(false)))
}
fn take(&self) -> bool {
self.0.swap(false, Ordering::SeqCst)
}
fn set(&self, v: bool) {
self.0.store(v, Ordering::SeqCst)
}
}
impl ArcWake for Flag {
fn wake_by_ref(arc_self: &Arc<Self>) {
arc_self.set(true)
}
}
fn flag_cx<F, R>(f: F) -> R
where
F: FnOnce(Arc<Flag>, &mut Context<'_>) -> R,
{
let flag = Flag::new();
let waker = task::waker_ref(&flag);
let cx = &mut Context::from_waker(&waker);
f(flag.clone(), cx)
}
// Sends a value on an i32 channel sink
struct StartSendFut<S: Sink<Item> + Unpin, Item: Unpin>(Option<S>, Option<Item>);
impl<S: Sink<Item> + Unpin, Item: Unpin> StartSendFut<S, Item> {
fn new(sink: S, item: Item) -> Self {
Self(Some(sink), Some(item))
}
}
impl<S: Sink<Item> + Unpin, Item: Unpin> Future for StartSendFut<S, Item> {
type Output = Result<S, S::Error>;
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
let Self(inner, item) = self.get_mut();
{
let mut inner = inner.as_mut().unwrap();
ready!(Pin::new(&mut inner).poll_ready(cx))?;
Pin::new(&mut inner).start_send(item.take().unwrap())?;
}
Poll::Ready(Ok(inner.take().unwrap()))
}
}
// Immediately accepts all requests to start pushing, but completion is managed
// by manually flushing
struct ManualFlush<T: Unpin> {
data: Vec<T>,
waiting_tasks: Vec<Waker>,
}
impl<T: Unpin> Sink<Option<T>> for ManualFlush<T> {
type Error = ();
fn poll_ready(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
Poll::Ready(Ok(()))
}
fn start_send(mut self: Pin<&mut Self>, item: Option<T>) -> Result<(), Self::Error> {
if let Some(item) = item {
self.data.push(item);
} else {
self.force_flush();
}
Ok(())
}
fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
if self.data.is_empty() {
Poll::Ready(Ok(()))
} else {
self.waiting_tasks.push(cx.waker().clone());
Poll::Pending
}
}
fn poll_close(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
self.poll_flush(cx)
}
}
impl<T: Unpin> ManualFlush<T> {
fn new() -> Self {
Self { data: Vec::new(), waiting_tasks: Vec::new() }
}
fn force_flush(&mut self) -> Vec<T> {
for task in self.waiting_tasks.drain(..) {
task.wake()
}
mem::take(&mut self.data)
}
}
struct ManualAllow<T: Unpin> {
data: Vec<T>,
allow: Rc<Allow>,
}
struct Allow {
flag: Cell<bool>,
tasks: RefCell<Vec<Waker>>,
}
impl Allow {
fn new() -> Self {
Self { flag: Cell::new(false), tasks: RefCell::new(Vec::new()) }
}
fn check(&self, cx: &mut Context<'_>) -> bool {
if self.flag.get() {
true
} else {
self.tasks.borrow_mut().push(cx.waker().clone());
false
}
}
fn start(&self) {
self.flag.set(true);
let mut tasks = self.tasks.borrow_mut();
for task in tasks.drain(..) {
task.wake();
}
}
}
impl<T: Unpin> Sink<T> for ManualAllow<T> {
type Error = ();
fn poll_ready(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
if self.allow.check(cx) {
Poll::Ready(Ok(()))
} else {
Poll::Pending
}
}
fn start_send(mut self: Pin<&mut Self>, item: T) -> Result<(), Self::Error> {
self.data.push(item);
Ok(())
}
fn poll_flush(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
Poll::Ready(Ok(()))
}
fn poll_close(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
Poll::Ready(Ok(()))
}
}
fn manual_allow<T: Unpin>() -> (ManualAllow<T>, Rc<Allow>) {
let allow = Rc::new(Allow::new());
let manual_allow = ManualAllow { data: Vec::new(), allow: allow.clone() };
(manual_allow, allow)
}
#[test]
fn either_sink() {
let mut s =
if true { Vec::<i32>::new().left_sink() } else { VecDeque::<i32>::new().right_sink() };
Pin::new(&mut s).start_send(0).unwrap();
}
#[test]
fn vec_sink() {
let mut v = Vec::new();
Pin::new(&mut v).start_send(0).unwrap();
Pin::new(&mut v).start_send(1).unwrap();
assert_eq!(v, vec![0, 1]);
block_on(v.flush()).unwrap();
assert_eq!(v, vec![0, 1]);
}
#[test]
fn vecdeque_sink() {
let mut deque = VecDeque::new();
Pin::new(&mut deque).start_send(2).unwrap();
Pin::new(&mut deque).start_send(3).unwrap();
assert_eq!(deque.pop_front(), Some(2));
assert_eq!(deque.pop_front(), Some(3));
assert_eq!(deque.pop_front(), None);
}
#[test]
fn send() {
let mut v = Vec::new();
block_on(v.send(0)).unwrap();
assert_eq!(v, vec![0]);
block_on(v.send(1)).unwrap();
assert_eq!(v, vec![0, 1]);
block_on(v.send(2)).unwrap();
assert_eq!(v, vec![0, 1, 2]);
}
#[test]
fn send_all() {
let mut v = Vec::new();
block_on(v.send_all(&mut stream::iter(vec![0, 1]).map(Ok))).unwrap();
assert_eq!(v, vec![0, 1]);
block_on(v.send_all(&mut stream::iter(vec![2, 3]).map(Ok))).unwrap();
assert_eq!(v, vec![0, 1, 2, 3]);
block_on(v.send_all(&mut stream::iter(vec![4, 5]).map(Ok))).unwrap();
assert_eq!(v, vec![0, 1, 2, 3, 4, 5]);
}
// Test that `start_send` on an `mpsc` channel does indeed block when the
// channel is full
#[test]
fn mpsc_blocking_start_send() {
let (mut tx, mut rx) = mpsc::channel::<i32>(0);
block_on(future::lazy(|_| {
tx.start_send(0).unwrap();
flag_cx(|flag, cx| {
let mut task = StartSendFut::new(tx, 1);
assert!(task.poll_unpin(cx).is_pending());
assert!(!flag.take());
sassert_next(&mut rx, 0);
assert!(flag.take());
unwrap(task.poll_unpin(cx));
assert!(!flag.take());
sassert_next(&mut rx, 1);
})
}));
}
// test `flush` by using `with` to make the first insertion into a sink block
// until a oneshot is completed
#[test]
fn with_flush() {
let (tx, rx) = oneshot::channel();
let mut block = rx.boxed();
let mut sink = Vec::new().with(|elem| {
mem::replace(&mut block, future::ok(()).boxed())
.map_ok(move |()| elem + 1)
.map_err(|_| -> Never { panic!() })
});
assert_eq!(Pin::new(&mut sink).start_send(0).ok(), Some(()));
flag_cx(|flag, cx| {
let mut task = sink.flush();
assert!(task.poll_unpin(cx).is_pending());
tx.send(()).unwrap();
assert!(flag.take());
unwrap(task.poll_unpin(cx));
block_on(sink.send(1)).unwrap();
assert_eq!(sink.get_ref(), &[1, 2]);
})
}
// test simple use of with to change data
#[test]
fn with_as_map() {
let mut sink = Vec::new().with(|item| future::ok::<i32, Never>(item * 2));
block_on(sink.send(0)).unwrap();
block_on(sink.send(1)).unwrap();
block_on(sink.send(2)).unwrap();
assert_eq!(sink.get_ref(), &[0, 2, 4]);
}
// test simple use of with_flat_map
#[test]
fn with_flat_map() {
let mut sink = Vec::new().with_flat_map(|item| stream::iter(vec![item; item]).map(Ok));
block_on(sink.send(0)).unwrap();
block_on(sink.send(1)).unwrap();
block_on(sink.send(2)).unwrap();
block_on(sink.send(3)).unwrap();
assert_eq!(sink.get_ref(), &[1, 2, 2, 3, 3, 3]);
}
// Check that `with` propagates `poll_ready` to the inner sink.
// Regression test for the issue #1834.
#[test]
fn with_propagates_poll_ready() {
let (tx, mut rx) = mpsc::channel::<i32>(0);
let mut tx = tx.with(|item: i32| future::ok::<i32, mpsc::SendError>(item + 10));
block_on(future::lazy(|_| {
flag_cx(|flag, cx| {
let mut tx = Pin::new(&mut tx);
// Should be ready for the first item.
assert_eq!(tx.as_mut().poll_ready(cx), Poll::Ready(Ok(())));
assert_eq!(tx.as_mut().start_send(0), Ok(()));
// Should be ready for the second item only after the first one is received.
assert_eq!(tx.as_mut().poll_ready(cx), Poll::Pending);
assert!(!flag.take());
sassert_next(&mut rx, 10);
assert!(flag.take());
assert_eq!(tx.as_mut().poll_ready(cx), Poll::Ready(Ok(())));
assert_eq!(tx.as_mut().start_send(1), Ok(()));
})
}));
}
// test that the `with` sink doesn't require the underlying sink to flush,
// but doesn't claim to be flushed until the underlying sink is
#[test]
fn with_flush_propagate() {
let mut sink = ManualFlush::new().with(future::ok::<Option<i32>, ()>);
flag_cx(|flag, cx| {
unwrap(Pin::new(&mut sink).poll_ready(cx));
Pin::new(&mut sink).start_send(Some(0)).unwrap();
unwrap(Pin::new(&mut sink).poll_ready(cx));
Pin::new(&mut sink).start_send(Some(1)).unwrap();
{
let mut task = sink.flush();
assert!(task.poll_unpin(cx).is_pending());
assert!(!flag.take());
}
assert_eq!(sink.get_mut().force_flush(), vec![0, 1]);
assert!(flag.take());
unwrap(sink.flush().poll_unpin(cx));
})
}
// test that `Clone` is implemented on `with` sinks
#[test]
fn with_implements_clone() {
let (mut tx, rx) = mpsc::channel(5);
{
let mut is_positive = tx.clone().with(|item| future::ok::<bool, mpsc::SendError>(item > 0));
let mut is_long =
tx.clone().with(|item: &str| future::ok::<bool, mpsc::SendError>(item.len() > 5));
block_on(is_positive.clone().send(-1)).unwrap();
block_on(is_long.clone().send("123456")).unwrap();
block_on(is_long.send("123")).unwrap();
block_on(is_positive.send(1)).unwrap();
}
block_on(tx.send(false)).unwrap();
block_on(tx.close()).unwrap();
assert_eq!(block_on(rx.collect::<Vec<_>>()), vec![false, true, false, true, false]);
}
// test that a buffer is a no-nop around a sink that always accepts sends
#[test]
fn buffer_noop() {
let mut sink = Vec::new().buffer(0);
block_on(sink.send(0)).unwrap();
block_on(sink.send(1)).unwrap();
assert_eq!(sink.get_ref(), &[0, 1]);
let mut sink = Vec::new().buffer(1);
block_on(sink.send(0)).unwrap();
block_on(sink.send(1)).unwrap();
assert_eq!(sink.get_ref(), &[0, 1]);
}
// test basic buffer functionality, including both filling up to capacity,
// and writing out when the underlying sink is ready
#[test]
fn buffer() {
let (sink, allow) = manual_allow::<i32>();
let sink = sink.buffer(2);
let sink = block_on(StartSendFut::new(sink, 0)).unwrap();
let mut sink = block_on(StartSendFut::new(sink, 1)).unwrap();
flag_cx(|flag, cx| {
let mut task = sink.send(2);
assert!(task.poll_unpin(cx).is_pending());
assert!(!flag.take());
allow.start();
assert!(flag.take());
unwrap(task.poll_unpin(cx));
assert_eq!(sink.get_ref().data, vec![0, 1, 2]);
})
}
#[test]
fn fanout_smoke() {
let sink1 = Vec::new();
let sink2 = Vec::new();
let mut sink = sink1.fanout(sink2);
block_on(sink.send_all(&mut stream::iter(vec![1, 2, 3]).map(Ok))).unwrap();
let (sink1, sink2) = sink.into_inner();
assert_eq!(sink1, vec![1, 2, 3]);
assert_eq!(sink2, vec![1, 2, 3]);
}
#[test]
fn fanout_backpressure() {
let (left_send, mut left_recv) = mpsc::channel(0);
let (right_send, mut right_recv) = mpsc::channel(0);
let sink = left_send.fanout(right_send);
let mut sink = block_on(StartSendFut::new(sink, 0)).unwrap();
flag_cx(|flag, cx| {
let mut task = sink.send(2);
assert!(!flag.take());
assert!(task.poll_unpin(cx).is_pending());
assert_eq!(block_on(left_recv.next()), Some(0));
assert!(flag.take());
assert!(task.poll_unpin(cx).is_pending());
assert_eq!(block_on(right_recv.next()), Some(0));
assert!(flag.take());
assert!(task.poll_unpin(cx).is_pending());
assert_eq!(block_on(left_recv.next()), Some(2));
assert!(flag.take());
assert!(task.poll_unpin(cx).is_pending());
assert_eq!(block_on(right_recv.next()), Some(2));
assert!(flag.take());
unwrap(task.poll_unpin(cx));
// make sure receivers live until end of test to prevent send errors
drop(left_recv);
drop(right_recv);
})
}
#[test]
fn sink_map_err() {
{
let cx = &mut panic_context();
let (tx, _rx) = mpsc::channel(1);
let mut tx = tx.sink_map_err(|_| ());
assert_eq!(Pin::new(&mut tx).start_send(()), Ok(()));
assert_eq!(Pin::new(&mut tx).poll_flush(cx), Poll::Ready(Ok(())));
}
let tx = mpsc::channel(0).0;
assert_eq!(Pin::new(&mut tx.sink_map_err(|_| ())).start_send(()), Err(()));
}
#[test]
fn sink_unfold() {
block_on(poll_fn(|cx| {
let (tx, mut rx) = mpsc::channel(1);
let unfold = sink::unfold((), |(), i: i32| {
let mut tx = tx.clone();
async move {
tx.send(i).await.unwrap();
Ok::<_, String>(())
}
});
futures::pin_mut!(unfold);
assert_eq!(unfold.as_mut().start_send(1), Ok(()));
assert_eq!(unfold.as_mut().poll_flush(cx), Poll::Ready(Ok(())));
assert_eq!(rx.try_next().unwrap(), Some(1));
assert_eq!(unfold.as_mut().poll_ready(cx), Poll::Ready(Ok(())));
assert_eq!(unfold.as_mut().start_send(2), Ok(()));
assert_eq!(unfold.as_mut().poll_ready(cx), Poll::Ready(Ok(())));
assert_eq!(unfold.as_mut().start_send(3), Ok(()));
assert_eq!(rx.try_next().unwrap(), Some(2));
assert!(rx.try_next().is_err());
assert_eq!(unfold.as_mut().poll_ready(cx), Poll::Ready(Ok(())));
assert_eq!(unfold.as_mut().start_send(4), Ok(()));
assert_eq!(unfold.as_mut().poll_flush(cx), Poll::Pending); // Channel full
assert_eq!(rx.try_next().unwrap(), Some(3));
assert_eq!(rx.try_next().unwrap(), Some(4));
Poll::Ready(())
}))
}
#[test]
fn err_into() {
#[derive(Copy, Clone, Debug, PartialEq, Eq)]
struct ErrIntoTest;
impl From<mpsc::SendError> for ErrIntoTest {
fn from(_: mpsc::SendError) -> Self {
Self
}
}
{
let cx = &mut panic_context();
let (tx, _rx) = mpsc::channel(1);
let mut tx: SinkErrInto<mpsc::Sender<()>, _, ErrIntoTest> = tx.sink_err_into();
assert_eq!(Pin::new(&mut tx).start_send(()), Ok(()));
assert_eq!(Pin::new(&mut tx).poll_flush(cx), Poll::Ready(Ok(())));
}
let tx = mpsc::channel(0).0;
assert_eq!(Pin::new(&mut tx.sink_err_into()).start_send(()), Err(ErrIntoTest));
}