1//! [`Stream<Item = Request>`][stream] + [`Service<Request>`] => [`Stream<Item = Response>`][stream].
2//!
3//! [`Service<Request>`]: crate::Service
4//! [stream]: https://docs.rs/futures/latest/futures/stream/trait.Stream.html
5
6use super::common;
7use futures_core::Stream;
8use futures_util::stream::FuturesUnordered;
9use pin_project_lite::pin_project;
10use std::{
11 future::Future,
12 pin::Pin,
13 task::{Context, Poll},
14};
15use tower_service::Service;
16
17pin_project! {
18 /// A stream of responses received from the inner service in received order.
19 ///
20 /// Similar to [`CallAll`] except, instead of yielding responses in request order,
21 /// responses are returned as they are available.
22 ///
23 /// [`CallAll`]: crate::util::CallAll
24 #[derive(Debug)]
25 pub struct CallAllUnordered<Svc, S>
26 where
27 Svc: Service<S::Item>,
28 S: Stream,
29 {
30 #[pin]
31 inner: common::CallAll<Svc, S, FuturesUnordered<Svc::Future>>,
32 }
33}
34
35impl<Svc, S> CallAllUnordered<Svc, S>
36where
37 Svc: Service<S::Item>,
38 S: Stream,
39{
40 /// Create new [`CallAllUnordered`] combinator.
41 ///
42 /// [`Stream`]: https://docs.rs/futures/latest/futures/stream/trait.Stream.html
43 pub fn new(service: Svc, stream: S) -> CallAllUnordered<Svc, S> {
44 CallAllUnordered {
45 inner: common::CallAll::new(service, stream, FuturesUnordered::new()),
46 }
47 }
48
49 /// Extract the wrapped [`Service`].
50 ///
51 /// # Panics
52 ///
53 /// Panics if [`take_service`] was already called.
54 ///
55 /// [`take_service`]: crate::util::CallAllUnordered::take_service
56 pub fn into_inner(self) -> Svc {
57 self.inner.into_inner()
58 }
59
60 /// Extract the wrapped `Service`.
61 ///
62 /// This [`CallAllUnordered`] can no longer be used after this function has been called.
63 ///
64 /// # Panics
65 ///
66 /// Panics if [`take_service`] was already called.
67 ///
68 /// [`take_service`]: crate::util::CallAllUnordered::take_service
69 pub fn take_service(self: Pin<&mut Self>) -> Svc {
70 self.project().inner.take_service()
71 }
72}
73
74impl<Svc, S> Stream for CallAllUnordered<Svc, S>
75where
76 Svc: Service<S::Item>,
77 S: Stream,
78{
79 type Item = Result<Svc::Response, Svc::Error>;
80
81 fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
82 self.project().inner.poll_next(cx)
83 }
84}
85
86impl<F: Future> common::Drive<F> for FuturesUnordered<F> {
87 fn is_empty(&self) -> bool {
88 FuturesUnordered::is_empty(self)
89 }
90
91 fn push(&mut self, future: F) {
92 FuturesUnordered::push(self, future)
93 }
94
95 fn poll(&mut self, cx: &mut Context<'_>) -> Poll<Option<F::Output>> {
96 Stream::poll_next(self:Pin::new(self), cx)
97 }
98}
99