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use crate::error::Error;
use core::pin::Pin;
use futures::stream::Stream;
use futures::task::{Context, Poll};
use pin_project::pin_project;
use std::time::Duration;
use tokio::time::timeout;
use tokio_stream::StreamExt;
#[pin_project]
pub struct TimeoutStream<R: Stream> {
#[pin]
source: R,
buffer: Vec<R::Item>,
}
impl<R: Stream> TimeoutStream<R> {
pub async fn with_stream(source: R) -> Result<TimeoutStream<R>, Error> {
Ok(TimeoutStream {
source,
buffer: Vec::new(),
})
}
pub async fn peek_timeout(self: Pin<&mut Self>, duration: Duration) -> Result<&R::Item, Error> {
match timeout(duration, self.peek()).await {
Ok(Some(item)) => Ok(item),
Ok(None) => Err(Error::Disconnected),
Err(_) => Err(Error::TimedOut),
}
}
pub async fn next_timeout(
mut self: Pin<&mut Self>,
duration: Duration,
) -> Result<R::Item, Error> {
match timeout(duration, self.next()).await {
Ok(Some(item)) => Ok(item),
Ok(None) => Err(Error::Disconnected),
Err(_) => Err(Error::TimedOut),
}
}
pub async fn peek(mut self: Pin<&mut Self>) -> Option<&R::Item> {
if self.as_mut().project().buffer.is_empty() {
match self.next().await {
Some(item) => self.as_mut().project().buffer.push(item),
None => return None,
}
}
self.project().buffer.first()
}
}
impl<R: Stream> Stream for TimeoutStream<R> {
type Item = R::Item;
fn poll_next(
self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Option<<Self as Stream>::Item>> {
if !self.buffer.is_empty() {
return Poll::Ready(Some(self.project().buffer.remove(0)));
}
self.project().source.poll_next(cx)
}
}
#[cfg(all(test, feature = "async"))]
mod tests {
use super::*;
use assert_matches::assert_matches;
use futures::stream::iter;
use std::io::BufRead;
#[tokio::test]
async fn iterates() {
let realistic_message = r"1
2
3
4
5";
let lines_iterator = iter((Box::new(realistic_message.as_bytes())).lines());
let mut ti = TimeoutStream::with_stream(lines_iterator).await.unwrap();
assert_eq!(ti.next().await.unwrap().unwrap(), "1");
assert_eq!(ti.next().await.unwrap().unwrap(), "2");
assert_eq!(ti.next().await.unwrap().unwrap(), "3");
assert_eq!(ti.next().await.unwrap().unwrap(), "4");
assert_eq!(ti.next().await.unwrap().unwrap(), "5");
}
#[tokio::test]
async fn next_timeout() {
let realistic_message = r"1
2
3
4
5";
let lines_iterator = iter((Box::new(realistic_message.as_bytes())).lines());
let mut pinned_stream = Box::pin(TimeoutStream::with_stream(lines_iterator).await.unwrap());
let mut ti = pinned_stream.as_mut();
assert_eq!(ti.next().await.unwrap().unwrap(), "1");
assert_eq!(ti.next().await.unwrap().unwrap(), "2");
assert_eq!(ti.next().await.unwrap().unwrap(), "3");
assert_eq!(ti.next().await.unwrap().unwrap(), "4");
assert_eq!(ti.next().await.unwrap().unwrap(), "5");
let timeout_result = ti.as_mut().next_timeout(Duration::from_secs(1)).await;
assert!(timeout_result.is_err());
}
#[tokio::test]
async fn peek_timeout_doesnt_remove() {
let realistic_message = r"1
2
3
4
5";
let lines_iterator = iter((Box::new(realistic_message.as_bytes())).lines());
let mut ti = Box::pin(TimeoutStream::with_stream(lines_iterator).await.unwrap());
assert_eq!(ti.next().await.unwrap().unwrap(), "1");
assert_eq!(ti.next().await.unwrap().unwrap(), "2");
assert_eq!(
ti.as_mut()
.peek_timeout(Duration::from_secs(1))
.await
.unwrap()
.as_ref()
.unwrap(),
"3"
);
assert_eq!(ti.as_mut().next().await.unwrap().unwrap(), "3");
assert_eq!(ti.as_mut().next().await.unwrap().unwrap(), "4");
assert_eq!(
ti.as_mut()
.peek_timeout(Duration::from_secs(1))
.await
.unwrap()
.as_ref()
.unwrap(),
"5"
);
assert_eq!(
ti.as_mut()
.peek_timeout(Duration::from_secs(1))
.await
.unwrap()
.as_ref()
.unwrap(),
"5"
);
assert_eq!(ti.as_mut().next().await.unwrap().unwrap(), "5");
let timeout_result = ti.as_mut().next_timeout(Duration::from_secs(1)).await;
assert!(timeout_result.is_err());
}
#[tokio::test]
async fn peek_doesnt_remove() {
let realistic_message = r"1
2
3
4
5";
let lines_iterator = iter((Box::new(realistic_message.as_bytes())).lines());
let mut ti = Box::pin(TimeoutStream::with_stream(lines_iterator).await.unwrap());
assert_eq!(ti.as_mut().next().await.unwrap().unwrap(), "1");
assert_eq!(ti.as_mut().next().await.unwrap().unwrap(), "2");
assert_eq!(ti.as_mut().peek().await.unwrap().as_ref().unwrap(), "3");
assert_eq!(
ti.as_mut()
.peek_timeout(Duration::from_secs(1))
.await
.unwrap()
.as_ref()
.unwrap(),
"3"
);
assert_eq!(ti.as_mut().next().await.unwrap().unwrap(), "3");
assert_eq!(ti.as_mut().next().await.unwrap().unwrap(), "4");
assert_eq!(
ti.as_mut()
.peek_timeout(Duration::from_secs(1))
.await
.unwrap()
.as_ref()
.unwrap(),
"5"
);
assert_eq!(ti.as_mut().peek().await.unwrap().as_ref().unwrap(), "5");
assert_eq!(ti.as_mut().next().await.unwrap().unwrap(), "5");
let timeout_result = ti.as_mut().next_timeout(Duration::from_secs(1)).await;
assert!(timeout_result.is_err());
}
#[tokio::test]
async fn item_iterator() {
let numbers: Vec<u32> = vec![1, 2, 3, 4, 5];
let mut ti = Box::pin(
TimeoutStream::with_stream(iter(numbers.into_iter()))
.await
.unwrap(),
);
assert_eq!(ti.as_mut().next().await.unwrap(), 1);
assert_eq!(ti.as_mut().next().await.unwrap(), 2);
assert_eq!(
*ti.as_mut()
.peek_timeout(Duration::from_secs(1))
.await
.unwrap(),
3
);
assert_eq!(ti.as_mut().next().await.unwrap(), 3);
assert_eq!(ti.as_mut().next().await.unwrap(), 4);
assert_eq!(
*ti.as_mut()
.peek_timeout(Duration::from_secs(1))
.await
.unwrap(),
5
);
assert_eq!(
*ti.as_mut()
.peek_timeout(Duration::from_secs(1))
.await
.unwrap(),
5
);
assert_eq!(ti.as_mut().next().await.unwrap(), 5);
let timeout_result = ti.as_mut().next_timeout(Duration::from_secs(1)).await;
assert!(timeout_result.is_err());
}
#[tokio::test]
async fn timedout_future_doesnt_drop_item() {
let numbers: Vec<u32> = vec![1, 2, 3, 4, 5];
let throttled_numbers = Box::pin(
iter(numbers.into_iter())
.throttle(Duration::from_secs(1)),
);
let mut pinned_stream =
Box::pin(TimeoutStream::with_stream(throttled_numbers).await.unwrap());
let mut ti = pinned_stream.as_mut();
assert_eq!(ti.as_mut().next().await.unwrap(), 1);
assert_matches!(
ti.as_mut()
.next_timeout(Duration::from_millis(500))
.await
.unwrap_err(),
Error::TimedOut
);
assert_eq!(ti.as_mut().next().await.unwrap(), 2);
assert_matches!(
ti.as_mut()
.peek_timeout(Duration::from_millis(500))
.await
.unwrap_err(),
Error::TimedOut
);
assert_eq!(*ti.as_mut().peek().await.unwrap(), 3);
assert_eq!(ti.as_mut().next().await.unwrap(), 3);
assert_matches!(
ti.as_mut()
.next_timeout(Duration::from_millis(500))
.await
.unwrap_err(),
Error::TimedOut
);
assert_eq!(ti.as_mut().next().await.unwrap(), 4);
assert_matches!(
ti.as_mut()
.next_timeout(Duration::from_millis(100))
.await
.unwrap_err(),
Error::TimedOut
);
assert_matches!(
ti.as_mut()
.next_timeout(Duration::from_millis(100))
.await
.unwrap_err(),
Error::TimedOut
);
assert_matches!(
ti.as_mut()
.next_timeout(Duration::from_millis(100))
.await
.unwrap_err(),
Error::TimedOut
);
assert_matches!(
ti.as_mut()
.next_timeout(Duration::from_millis(100))
.await
.unwrap_err(),
Error::TimedOut
);
assert_matches!(
ti.as_mut()
.next_timeout(Duration::from_millis(100))
.await
.unwrap_err(),
Error::TimedOut
);
assert_matches!(
ti.as_mut()
.next_timeout(Duration::from_millis(100))
.await
.unwrap_err(),
Error::TimedOut
);
assert_eq!(ti.as_mut().next().await.unwrap(), 5);
let timeout_result = ti.as_mut().next_timeout(Duration::from_secs(1)).await;
assert!(timeout_result.is_err());
}
}
