refactor(http1): move upgrade state from body to head (hyperium#2353)

Move state required for protocol upgrades to head
representations, instead of associating it with the body.

Closes hyperium#2340.

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

src/body/body.rs

@@ -23,7 +23,6 @@ use crate::common::{task, watch, Pin, Poll};
 use crate::common::{Future, Never};
 #[cfg(all(feature = "http2", any(feature = "client", feature = "server")))]
 use crate::proto::h2::ping;
-use crate::upgrade::OnUpgrade;
 
 type BodySender = mpsc::Sender<Result<Bytes, crate::Error>>;
 
@@ -70,7 +69,6 @@ struct Extra {
     /// a brand new connection, since the pool didn't know about the idle
     /// connection yet.
     delayed_eof: Option<DelayEof>,
-    on_upgrade: OnUpgrade,
 }
 
 #[cfg(any(feature = "http1", feature = "http2"))]
@@ -187,17 +185,6 @@ impl Body {
         Body::new(Kind::Wrapped(SyncWrapper::new(Box::pin(mapped))))
     }
 
-    // TODO: Eventually the pending upgrade should be stored in the
-    // `Extensions`, and all these pieces can be removed. In v0.14, we made
-    // the breaking changes, so now this TODO can be done without breakage.
-    pub(crate) fn take_upgrade(&mut self) -> OnUpgrade {
-        if let Some(ref mut extra) = self.extra {
-            std::mem::replace(&mut extra.on_upgrade, OnUpgrade::none())
-        } else {
-            OnUpgrade::none()
-        }
-    }
-
     fn new(kind: Kind) -> Body {
         Body { kind, extra: None }
     }
@@ -217,14 +204,6 @@ impl Body {
         body
     }
 
-    #[cfg(feature = "http1")]
-    pub(crate) fn set_on_upgrade(&mut self, upgrade: OnUpgrade) {
-        debug_assert!(!upgrade.is_none(), "set_on_upgrade with empty upgrade");
-        let extra = self.extra_mut();
-        debug_assert!(extra.on_upgrade.is_none(), "set_on_upgrade twice");
-        extra.on_upgrade = upgrade;
-    }
-
     #[cfg(any(feature = "http1", feature = "http2"))]
     #[cfg(feature = "client")]
     pub(crate) fn delayed_eof(&mut self, fut: DelayEofUntil) {
@@ -239,12 +218,8 @@ impl Body {
 
     #[cfg(any(feature = "http1", feature = "http2"))]
     fn extra_mut(&mut self) -> &mut Extra {
-        self.extra.get_or_insert_with(|| {
-            Box::new(Extra {
-                delayed_eof: None,
-                on_upgrade: OnUpgrade::none(),
-            })
-        })
+        self.extra
+            .get_or_insert_with(|| Box::new(Extra { delayed_eof: None }))
     }
 
     fn poll_eof(&mut self, cx: &mut task::Context<'_>) -> Poll<Option<crate::Result<Bytes>>> {

src/proto/h1/dispatch.rs

@@ -10,6 +10,7 @@ use crate::common::{task, Future, Pin, Poll, Unpin};
 use crate::proto::{
     BodyLength, Conn, Dispatched, MessageHead, RequestHead,
 };
+use crate::upgrade::OnUpgrade;
 
 pub(crate) struct Dispatcher<D, Bs: HttpBody, I, T> {
     conn: Conn<I, Bs::Data, T>,
@@ -243,8 +244,8 @@ where
         }
         // dispatch is ready for a message, try to read one
         match ready!(self.conn.poll_read_head(cx)) {
-            Some(Ok((head, body_len, wants))) => {
-                let mut body = match body_len {
+            Some(Ok((mut head, body_len, wants))) => {
+                let body = match body_len {
                     DecodedLength::ZERO => Body::empty(),
                     other => {
                         let (tx, rx) = Body::new_channel(other, wants.contains(Wants::EXPECT));
@@ -253,7 +254,10 @@ where
                     }
                 };
                 if wants.contains(Wants::UPGRADE) {
-                    body.set_on_upgrade(self.conn.on_upgrade());
+                    let upgrade = self.conn.on_upgrade();
+                    debug_assert!(!upgrade.is_none(), "empty upgrade");
+                    debug_assert!(head.extensions.get::<OnUpgrade>().is_none(), "OnUpgrade already set");
+                    head.extensions.insert(upgrade);
                 }
                 self.dispatch.recv_msg(Ok((head, body)))?;
                 Poll::Ready(Ok(()))
@@ -488,6 +492,7 @@ cfg_server! {
                     version: parts.version,
                     subject: parts.status,
                     headers: parts.headers,
+                    extensions: http::Extensions::default(),
                 };
                 Poll::Ready(Some(Ok((head, body))))
             } else {
@@ -506,6 +511,7 @@ cfg_server! {
             *req.uri_mut() = msg.subject.1;
             *req.headers_mut() = msg.headers;
             *req.version_mut() = msg.version;
+            *req.extensions_mut() = msg.extensions;
             let fut = self.service.call(req);
             self.in_flight.set(Some(fut));
             Ok(())
@@ -570,6 +576,7 @@ cfg_client! {
                                 version: parts.version,
                                 subject: crate::proto::RequestLine(parts.method, parts.uri),
                                 headers: parts.headers,
+                                extensions: http::Extensions::default(),
                             };
                             *this.callback = Some(cb);
                             Poll::Ready(Some(Ok((head, body))))
@@ -594,6 +601,7 @@ cfg_client! {
                         *res.status_mut() = msg.subject;
                         *res.headers_mut() = msg.headers;
                         *res.version_mut() = msg.version;
+                        *res.extensions_mut() = msg.extensions;
                         cb.send(Ok(res));
                         Ok(())
                     } else {

src/proto/h1/role.rs

@@ -276,6 +276,7 @@ impl Http1Transaction for Server {
                 version,
                 subject,
                 headers,
+                extensions: http::Extensions::default(),
             },
             decode: decoder,
             expect_continue,
@@ -720,6 +721,7 @@ impl Http1Transaction for Client {
                 version,
                 subject: status,
                 headers,
+                extensions: http::Extensions::default(),
             };
             if let Some((decode, is_upgrade)) = Client::decoder(&head, ctx.req_method)? {
                 return Ok(Some(ParsedMessage {

src/proto/mod.rs

@@ -16,14 +16,17 @@ cfg_http2! {
 }
 
 /// An Incoming Message head. Includes request/status line, and headers.
-#[derive(Clone, Debug, Default, PartialEq)]
+#[derive(Debug, Default)]
 pub struct MessageHead<S> {
     /// HTTP version of the message.
     pub version: http::Version,
     /// Subject (request line or status line) of Incoming message.
     pub subject: S,
     /// Headers of the Incoming message.
     pub headers: http::HeaderMap,
+
+    /// Extensions.
+    extensions: http::Extensions,
 }
 
 /// An incoming request message.

src/upgrade.rs

@@ -317,26 +317,34 @@ mod sealed {
     }
 
     impl CanUpgrade for http::Request<crate::Body> {
-        fn on_upgrade(self) -> OnUpgrade {
-            self.into_body().take_upgrade()
+        fn on_upgrade(mut self) -> OnUpgrade {
+            self.extensions_mut()
+                .remove::<OnUpgrade>()
+                .unwrap_or_else(OnUpgrade::none)
         }
     }
 
     impl CanUpgrade for &'_ mut http::Request<crate::Body> {
         fn on_upgrade(self) -> OnUpgrade {
-            self.body_mut().take_upgrade()
+            self.extensions_mut()
+                .remove::<OnUpgrade>()
+                .unwrap_or_else(OnUpgrade::none)
         }
     }
 
     impl CanUpgrade for http::Response<crate::Body> {
-        fn on_upgrade(self) -> OnUpgrade {
-            self.into_body().take_upgrade()
+        fn on_upgrade(mut self) -> OnUpgrade {
+            self.extensions_mut()
+                .remove::<OnUpgrade>()
+                .unwrap_or_else(OnUpgrade::none)
         }
     }
 
     impl CanUpgrade for &'_ mut http::Response<crate::Body> {
         fn on_upgrade(self) -> OnUpgrade {
-            self.body_mut().take_upgrade()
+            self.extensions_mut()
+                .remove::<OnUpgrade>()
+                .unwrap_or_else(OnUpgrade::none)
         }
     }
 }