1 files changed, 103 insertions, 0 deletions
diff --git a/vendor/tower/src/util/ready.rs b/vendor/tower/src/util/ready.rs
new file mode 100644
index 00000000..750db872
--- /dev/null
+++ b/vendor/tower/src/util/ready.rs
@@ -0,0 +1,103 @@
+use std::{fmt, marker::PhantomData};
+
+use futures_core::ready;
+use std::{
+    future::Future,
+    pin::Pin,
+    task::{Context, Poll},
+};
+use tower_service::Service;
+
+/// A [`Future`] that yields the service when it is ready to accept a request.
+///
+/// [`ReadyOneshot`] values are produced by [`ServiceExt::ready_oneshot`].
+///
+/// [`ServiceExt::ready_oneshot`]: crate::util::ServiceExt::ready_oneshot
+pub struct ReadyOneshot<T, Request> {
+    inner: Option<T>,
+    _p: PhantomData<fn() -> Request>,
+}
+
+// Safety: This is safe because `Services`'s are always `Unpin`.
+impl<T, Request> Unpin for ReadyOneshot<T, Request> {}
+
+impl<T, Request> ReadyOneshot<T, Request>
+where
+    T: Service<Request>,
+{
+    #[allow(missing_docs)]
+    pub const fn new(service: T) -> Self {
+        Self {
+            inner: Some(service),
+            _p: PhantomData,
+        }
+    }
+}
+
+impl<T, Request> Future for ReadyOneshot<T, Request>
+where
+    T: Service<Request>,
+{
+    type Output = Result<T, T::Error>;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        ready!(self
+            .inner
+            .as_mut()
+            .expect("poll after Poll::Ready")
+            .poll_ready(cx))?;
+
+        Poll::Ready(Ok(self.inner.take().expect("poll after Poll::Ready")))
+    }
+}
+
+impl<T, Request> fmt::Debug for ReadyOneshot<T, Request>
+where
+    T: fmt::Debug,
+{
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_struct("ReadyOneshot")
+            .field("inner", &self.inner)
+            .finish()
+    }
+}
+
+/// A future that yields a mutable reference to the service when it is ready to accept a request.
+///
+/// [`Ready`] values are produced by [`ServiceExt::ready`].
+///
+/// [`ServiceExt::ready`]: crate::util::ServiceExt::ready
+pub struct Ready<'a, T, Request>(ReadyOneshot<&'a mut T, Request>);
+
+// Safety: This is safe for the same reason that the impl for ReadyOneshot is safe.
+impl<'a, T, Request> Unpin for Ready<'a, T, Request> {}
+
+impl<'a, T, Request> Ready<'a, T, Request>
+where
+    T: Service<Request>,
+{
+    #[allow(missing_docs)]
+    pub fn new(service: &'a mut T) -> Self {
+        Self(ReadyOneshot::new(service))
+    }
+}
+
+impl<'a, T, Request> Future for Ready<'a, T, Request>
+where
+    T: Service<Request>,
+{
+    type Output = Result<&'a mut T, T::Error>;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        Pin::new(&mut self.0).poll(cx)
+    }
+}
+
+impl<'a, T, Request> fmt::Debug for Ready<'a, T, Request>
+where
+    T: fmt::Debug,
+{
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("Ready").field(&self.0).finish()
+    }
+}