tower/util/call_all/
unordered.rs

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    Svc::Error: Into<crate::BoxError>,
39    S: Stream,
40{
41    /// Create new [`CallAllUnordered`] combinator.
42    ///
43    /// [`Stream`]: https://docs.rs/futures/latest/futures/stream/trait.Stream.html
44    pub fn new(service: Svc, stream: S) -> CallAllUnordered<Svc, S> {
45        CallAllUnordered {
46            inner: common::CallAll::new(service, stream, FuturesUnordered::new()),
47        }
48    }
49
50    /// Extract the wrapped [`Service`].
51    ///
52    /// # Panics
53    ///
54    /// Panics if [`take_service`] was already called.
55    ///
56    /// [`take_service`]: crate::util::CallAllUnordered::take_service
57    pub fn into_inner(self) -> Svc {
58        self.inner.into_inner()
59    }
60
61    /// Extract the wrapped `Service`.
62    ///
63    /// This [`CallAllUnordered`] can no longer be used after this function has been called.
64    ///
65    /// # Panics
66    ///
67    /// Panics if [`take_service`] was already called.
68    ///
69    /// [`take_service`]: crate::util::CallAllUnordered::take_service
70    pub fn take_service(self: Pin<&mut Self>) -> Svc {
71        self.project().inner.take_service()
72    }
73}
74
75impl<Svc, S> Stream for CallAllUnordered<Svc, S>
76where
77    Svc: Service<S::Item>,
78    Svc::Error: Into<crate::BoxError>,
79    S: Stream,
80{
81    type Item = Result<Svc::Response, crate::BoxError>;
82
83    fn poll_next(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
84        self.project().inner.poll_next(cx)
85    }
86}
87
88impl<F: Future> common::Drive<F> for FuturesUnordered<F> {
89    fn is_empty(&self) -> bool {
90        FuturesUnordered::is_empty(self)
91    }
92
93    fn push(&mut self, future: F) {
94        FuturesUnordered::push(self, future)
95    }
96
97    fn poll(&mut self, cx: &mut Context<'_>) -> Poll<Option<F::Output>> {
98        Stream::poll_next(Pin::new(self), cx)
99    }
100}
tower/util/call_all/unordered.rs

tower/util/call_all/
unordered.rs
