feat(body): add Body::wrap_body

src/body/body.rs

@@ -13,7 +13,6 @@ use http::HeaderMap;
 use http_body::{Body as HttpBody, SizeHint};
 
 use super::DecodedLength;
-#[cfg(feature = "stream")]
 use crate::common::sync_wrapper::SyncWrapper;
 use crate::common::Future;
 #[cfg(all(feature = "client", any(feature = "http1", feature = "http2")))]
@@ -62,6 +61,7 @@ enum Kind {
             Pin<Box<dyn Stream<Item = Result<Bytes, Box<dyn StdError + Send + Sync>>> + Send>>,
         >,
     ),
+    WrappedBody(SyncWrapper<http_body::combinators::UnsyncBoxBody<Bytes, crate::Error>>),
 }
 
 struct Extra {
@@ -139,6 +139,24 @@ impl Body {
         Self::new_channel(DecodedLength::CHUNKED, /*wanter =*/ false)
     }
 
+    /// Create a `Body` by wrapping another body.
+    #[inline]
+    #[cfg(any(feature = "http1", feature = "http2"))]
+    pub fn wrap_body<B>(body: B) -> Self
+    where
+        B: HttpBody<Data = Bytes> + Send + 'static,
+        B::Error: Into<Box<dyn std::error::Error + Send + Sync>>,
+    {
+        // if `B` is already a `Body` just return that and avoid additional boxing
+        match super::try_downcast(body) {
+            Ok(body) => body,
+            Err(body) => {
+                let body = body.map_err(crate::Error::new_user_body).boxed_unsync();
+                Self::new(Kind::WrappedBody(SyncWrapper::new(body)))
+            }
+        }
+    }
+
     pub(crate) fn new_channel(content_length: DecodedLength, wanter: bool) -> (Sender, Body) {
         let (data_tx, data_rx) = mpsc::channel(0);
         let (trailers_tx, trailers_rx) = oneshot::channel();
@@ -329,12 +347,12 @@ impl Body {
 
             #[cfg(feature = "ffi")]
             Kind::Ffi(ref mut body) => body.poll_data(cx),
-
             #[cfg(feature = "stream")]
             Kind::Wrapped(ref mut s) => match ready!(s.get_mut().as_mut().poll_next(cx)) {
                 Some(res) => Poll::Ready(Some(res.map_err(crate::Error::new_body))),
                 None => Poll::Ready(None),
             },
+            Kind::WrappedBody(ref mut body) => Pin::new(body.get_mut()).poll_data(cx),
         }
     }
 
@@ -393,6 +411,7 @@ impl HttpBody for Body {
             },
             #[cfg(feature = "ffi")]
             Kind::Ffi(ref mut body) => body.poll_trailers(cx),
+            Kind::WrappedBody(ref mut body) => Pin::new(body.get_mut()).poll_trailers(cx),
             _ => Poll::Ready(Ok(None)),
         }
     }
@@ -407,6 +426,9 @@ impl HttpBody for Body {
             Kind::Ffi(..) => false,
             #[cfg(feature = "stream")]
             Kind::Wrapped(..) => false,
+            // we cannot get a `&UnsyncBoxBody` through a `SyncWrapper<UnsyncBoxBody>`
+            // so we have no way of calling the method on the inner body
+            Kind::WrappedBody(..) => false,
         }
     }
 
@@ -433,6 +455,9 @@ impl HttpBody for Body {
             Kind::H2 { content_length, .. } => opt_len!(content_length),
             #[cfg(feature = "ffi")]
             Kind::Ffi(..) => SizeHint::default(),
+            // we cannot get a `&UnsyncBoxBody` through a `SyncWrapper<UnsyncBoxBody>`
+            // so we have no way of calling the method on the inner body
+            Kind::WrappedBody(..) => SizeHint::default(),
         }
     }
 }

src/body/mod.rs

@@ -56,6 +56,19 @@ pub(crate) fn take_full_data<T: HttpBody + 'static>(body: &mut T) -> Option<T::D
     }
 }
 
+pub(crate) fn try_downcast<T, K>(k: K) -> Result<T, K>
+where
+    T: 'static,
+    K: Send + 'static,
+{
+    let mut k = Some(k);
+    if let Some(k) = <dyn std::any::Any>::downcast_mut::<Option<T>>(&mut k) {
+        Ok(k.take().unwrap())
+    } else {
+        Err(k.unwrap())
+    }
+}
+
 fn _assert_send_sync() {
     fn _assert_send<T: Send>() {}
     fn _assert_sync<T: Sync>() {}

src/common/mod.rs

@@ -18,10 +18,6 @@ pub(crate) mod io;
 #[cfg(all(feature = "client", any(feature = "http1", feature = "http2")))]
 mod lazy;
 mod never;
-#[cfg(any(
-    feature = "stream",
-    all(feature = "client", any(feature = "http1", feature = "http2"))
-))]
 pub(crate) mod sync_wrapper;
 pub(crate) mod task;
 pub(crate) mod watch;

src/error.rs

@@ -48,7 +48,6 @@ pub(super) enum Kind {
     #[cfg(all(feature = "http1", feature = "server", feature = "runtime"))]
     HeaderTimeout,
     /// Error while reading a body from connection.
-    #[cfg(any(feature = "http1", feature = "http2", feature = "stream"))]
     Body,
     /// Error while writing a body to connection.
     #[cfg(any(feature = "http1", feature = "http2"))]
@@ -92,7 +91,6 @@ pub(super) enum Header {
 #[derive(Debug)]
 pub(super) enum User {
     /// Error calling user's HttpBody::poll_data().
-    #[cfg(any(feature = "http1", feature = "http2"))]
     Body,
     /// The user aborted writing of the outgoing body.
     BodyWriteAborted,
@@ -367,7 +365,6 @@ impl Error {
         Error::new_user(User::Service).with(cause)
     }
 
-    #[cfg(any(feature = "http1", feature = "http2"))]
     pub(super) fn new_user_body<E: Into<Cause>>(cause: E) -> Error {
         Error::new_user(User::Body).with(cause)
     }
@@ -440,7 +437,6 @@ impl Error {
             Kind::Accept => "error accepting connection",
             #[cfg(all(feature = "http1", feature = "server", feature = "runtime"))]
             Kind::HeaderTimeout => "read header from client timeout",
-            #[cfg(any(feature = "http1", feature = "http2", feature = "stream"))]
             Kind::Body => "error reading a body from connection",
             #[cfg(any(feature = "http1", feature = "http2"))]
             Kind::BodyWrite => "error writing a body to connection",
@@ -451,7 +447,6 @@ impl Error {
             #[cfg(any(feature = "http1", feature = "http2"))]
             Kind::Io => "connection error",
 
-            #[cfg(any(feature = "http1", feature = "http2"))]
             Kind::User(User::Body) => "error from user's HttpBody stream",
             Kind::User(User::BodyWriteAborted) => "user body write aborted",
             #[cfg(any(feature = "http1", feature = "http2"))]