Struct DropStream

pub struct DropStream<S: Stream<Item = T>, T, U: FnOnce()> { /* private fields */ }

A stream that wraps another stream with a closure that is called once it is dropped. Very useful for libraries that use streams for data transfer and you need to connect when the opposite site drops the connection, thus dropping the stream.

Example

use futures::Stream;
use drop_stream::DropStream;

let test_stream = futures::stream::repeat(true);
{
    let wrapped_stream = DropStream::new(test_stream, move || {
        println!("Stream has been dropped!");
    });

    let mut wrapped_stream = Box::pin(wrapped_stream);

    let waker = futures::task::noop_waker();
    let mut context = futures::task::Context::from_waker(&waker);
    assert_eq!(
        wrapped_stream.as_mut().poll_next(&mut context),
        std::task::Poll::Ready(Some(true))
    );
}

Implementations

impl<S: Stream<Item = T>, T, U: FnOnce()> DropStream<S, T, U>

pub fn new(stream: S, dropper: U) -> Self

Trait Implementations

impl<S: Stream<Item = T>, T, U: FnOnce()> Drop for DropStream<S, T, U>

fn drop(&mut self)

Executes the destructor for this type.

impl<S: Stream<Item = T>, T, U: FnOnce()> Stream for DropStream<S, T, U>

type Item = T

Values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.

impl<'pin, S: Stream<Item = T>, T, U: FnOnce()> Unpin for DropStream<S, T, U>

where PinnedFieldsOf<__DropStream<'pin, S, T, U>>: Unpin,