From ec751f3696882889e65a00c234da70e5254a8048 Mon Sep 17 00:00:00 2001
From: Sean McArthur <sean@seanmonstar.com>
Date: Fri, 6 Dec 2019 11:26:36 -0800
Subject: [PATCH] Remove Unpin requirement for the send Buf

---
 src/client.rs                   | 10 +++++-----
 src/codec/framed_write.rs       |  5 ++++-
 src/codec/mod.rs                |  7 +++----
 src/proto/connection.rs         |  4 ++--
 src/proto/go_away.rs            |  2 +-
 src/proto/ping_pong.rs          |  4 ++--
 src/proto/settings.rs           |  8 ++++----
 src/proto/streams/prioritize.rs |  2 +-
 src/proto/streams/recv.rs       |  8 ++++----
 src/proto/streams/send.rs       |  2 +-
 src/proto/streams/streams.rs    |  3 +--
 src/server.rs                   | 12 ++++++------
 12 files changed, 34 insertions(+), 33 deletions(-)

diff --git a/src/client.rs b/src/client.rs
index f09b786..63514e3 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -336,7 +336,7 @@ pub(crate) struct Peer;
 
 impl<B> SendRequest<B>
 where
-    B: Buf + Unpin + 'static,
+    B: Buf + 'static,
 {
     /// Returns `Ready` when the connection can initialize a new HTTP/2.0
     /// stream.
@@ -566,7 +566,7 @@ where
 
 impl<B> Future for ReadySendRequest<B>
 where
-    B: Buf + Unpin + 'static,
+    B: Buf + 'static,
 {
     type Output = Result<SendRequest<B>, crate::Error>;
 
@@ -1063,7 +1063,7 @@ impl Builder {
     ) -> impl Future<Output = Result<(SendRequest<B>, Connection<T, B>), crate::Error>>
     where
         T: AsyncRead + AsyncWrite + Unpin,
-        B: Buf + Unpin + 'static,
+        B: Buf + 'static,
     {
         Connection::handshake2(io, self.clone())
     }
@@ -1123,7 +1123,7 @@ where
 impl<T, B> Connection<T, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    B: Buf + Unpin + 'static,
+    B: Buf + 'static,
 {
     async fn handshake2(
         mut io: T,
@@ -1229,7 +1229,7 @@ where
 impl<T, B> Future for Connection<T, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    B: Buf + Unpin + 'static,
+    B: Buf + 'static,
 {
     type Output = Result<(), crate::Error>;
 
diff --git a/src/codec/framed_write.rs b/src/codec/framed_write.rs
index 072e471..b9a06c6 100644
--- a/src/codec/framed_write.rs
+++ b/src/codec/framed_write.rs
@@ -281,7 +281,7 @@ impl<T, B> FramedWrite<T, B> {
     }
 }
 
-impl<T: AsyncRead + Unpin, B: Unpin> AsyncRead for FramedWrite<T, B> {
+impl<T: AsyncRead + Unpin, B> AsyncRead for FramedWrite<T, B> {
     unsafe fn prepare_uninitialized_buffer(&self, buf: &mut [std::mem::MaybeUninit<u8>]) -> bool {
         self.inner.prepare_uninitialized_buffer(buf)
     }
@@ -303,6 +303,9 @@ impl<T: AsyncRead + Unpin, B: Unpin> AsyncRead for FramedWrite<T, B> {
     }
 }
 
+// We never project the Pin to `B`.
+impl<T: Unpin, B> Unpin for FramedWrite<T, B> {}
+
 #[cfg(feature = "unstable")]
 mod unstable {
     use super::*;
diff --git a/src/codec/mod.rs b/src/codec/mod.rs
index 3ed65bb..9bd4e73 100644
--- a/src/codec/mod.rs
+++ b/src/codec/mod.rs
@@ -27,7 +27,7 @@ pub struct Codec<T, B> {
 impl<T, B> Codec<T, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    B: Buf + Unpin,
+    B: Buf,
 {
     /// Returns a new `Codec` with the default max frame size
     #[inline]
@@ -118,7 +118,7 @@ impl<T, B> Codec<T, B> {
 impl<T, B> Codec<T, B>
 where
     T: AsyncWrite + Unpin,
-    B: Buf + Unpin,
+    B: Buf,
 {
     /// Returns `Ready` when the codec can buffer a frame
     pub fn poll_ready(&mut self, cx: &mut Context) -> Poll<io::Result<()>> {
@@ -149,7 +149,6 @@ where
 impl<T, B> Stream for Codec<T, B>
 where
     T: AsyncRead + Unpin,
-    B: Unpin,
 {
     type Item = Result<Frame, RecvError>;
 
@@ -161,7 +160,7 @@ where
 impl<T, B> Sink<Frame<B>> for Codec<T, B>
 where
     T: AsyncWrite + Unpin,
-    B: Buf + Unpin,
+    B: Buf,
 {
     type Error = SendError;
 
diff --git a/src/proto/connection.rs b/src/proto/connection.rs
index 8a6f34c..49c123e 100644
--- a/src/proto/connection.rs
+++ b/src/proto/connection.rs
@@ -73,7 +73,7 @@ impl<T, P, B> Connection<T, P, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
     P: Peer,
-    B: Buf + Unpin,
+    B: Buf,
 {
     pub fn new(codec: Codec<T, Prioritized<B>>, config: Config) -> Connection<T, P, B> {
         let streams = Streams::new(streams::Config {
@@ -394,7 +394,7 @@ where
 impl<T, B> Connection<T, server::Peer, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    B: Buf + Unpin,
+    B: Buf,
 {
     pub fn next_incoming(&mut self) -> Option<StreamRef<B>> {
         self.streams.next_incoming()
diff --git a/src/proto/go_away.rs b/src/proto/go_away.rs
index 3d934b5..91d37b6 100644
--- a/src/proto/go_away.rs
+++ b/src/proto/go_away.rs
@@ -128,7 +128,7 @@ impl GoAway {
     ) -> Poll<Option<io::Result<Reason>>>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
+        B: Buf,
     {
         if let Some(frame) = self.pending.take() {
             if !dst.poll_ready(cx)?.is_ready() {
diff --git a/src/proto/ping_pong.rs b/src/proto/ping_pong.rs
index 43cd2d7..0022d4a 100644
--- a/src/proto/ping_pong.rs
+++ b/src/proto/ping_pong.rs
@@ -142,7 +142,7 @@ impl PingPong {
     ) -> Poll<io::Result<()>>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
+        B: Buf,
     {
         if let Some(pong) = self.pending_pong.take() {
             if !dst.poll_ready(cx)?.is_ready() {
@@ -165,7 +165,7 @@ impl PingPong {
     ) -> Poll<io::Result<()>>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
+        B: Buf,
     {
         if let Some(ref mut ping) = self.pending_ping {
             if !ping.sent {
diff --git a/src/proto/settings.rs b/src/proto/settings.rs
index 46bb3f6..014dbf7 100644
--- a/src/proto/settings.rs
+++ b/src/proto/settings.rs
@@ -43,8 +43,8 @@ impl Settings {
     ) -> Result<(), RecvError>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
-        C: Buf + Unpin,
+        B: Buf,
+        C: Buf,
         P: Peer,
     {
         if frame.is_ack() {
@@ -100,8 +100,8 @@ impl Settings {
     ) -> Poll<Result<(), RecvError>>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
-        C: Buf + Unpin,
+        B: Buf,
+        C: Buf,
         P: Peer,
     {
         if let Some(settings) = &self.remote {
diff --git a/src/proto/streams/prioritize.rs b/src/proto/streams/prioritize.rs
index ddaec8f..a133932 100644
--- a/src/proto/streams/prioritize.rs
+++ b/src/proto/streams/prioritize.rs
@@ -474,7 +474,7 @@ impl Prioritize {
     ) -> Poll<io::Result<()>>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
+        B: Buf,
     {
         // Ensure codec is ready
         ready!(dst.poll_ready(cx))?;
diff --git a/src/proto/streams/recv.rs b/src/proto/streams/recv.rs
index ac2120c..f0e23a4 100644
--- a/src/proto/streams/recv.rs
+++ b/src/proto/streams/recv.rs
@@ -846,7 +846,7 @@ impl Recv {
     ) -> Poll<io::Result<()>>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
+        B: Buf,
     {
         if let Some(stream_id) = self.refused {
             ready!(dst.poll_ready(cx))?;
@@ -918,7 +918,7 @@ impl Recv {
     ) -> Poll<io::Result<()>>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
+        B: Buf,
     {
         // Send any pending connection level window updates
         ready!(self.send_connection_window_update(cx, dst))?;
@@ -937,7 +937,7 @@ impl Recv {
     ) -> Poll<io::Result<()>>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
+        B: Buf,
     {
         if let Some(incr) = self.flow.unclaimed_capacity() {
             let frame = frame::WindowUpdate::new(StreamId::zero(), incr);
@@ -968,7 +968,7 @@ impl Recv {
     ) -> Poll<io::Result<()>>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
+        B: Buf,
     {
         loop {
             // Ensure the codec has capacity
diff --git a/src/proto/streams/send.rs b/src/proto/streams/send.rs
index 33aa443..a1199b2 100644
--- a/src/proto/streams/send.rs
+++ b/src/proto/streams/send.rs
@@ -279,7 +279,7 @@ impl Send {
     ) -> Poll<io::Result<()>>
     where
         T: AsyncWrite + Unpin,
-        B: Buf + Unpin,
+        B: Buf,
     {
         self.prioritize
             .poll_complete(cx, buffer, store, counts, dst)
diff --git a/src/proto/streams/streams.rs b/src/proto/streams/streams.rs
index 49bbe71..527969b 100644
--- a/src/proto/streams/streams.rs
+++ b/src/proto/streams/streams.rs
@@ -94,7 +94,7 @@ struct SendBuffer<B> {
 
 impl<B, P> Streams<B, P>
 where
-    B: Buf + Unpin,
+    B: Buf,
     P: Peer,
 {
     pub fn new(config: Config) -> Self {
@@ -596,7 +596,6 @@ where
     ) -> Poll<io::Result<()>>
     where
         T: AsyncWrite + Unpin,
-        B: Unpin,
     {
         let mut me = self.inner.lock().unwrap();
         let me = &mut *me;
diff --git a/src/server.rs b/src/server.rs
index e99abe0..513a975 100644
--- a/src/server.rs
+++ b/src/server.rs
@@ -356,7 +356,7 @@ where
 impl<T, B> Connection<T, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    B: Buf + Unpin + 'static,
+    B: Buf + 'static,
 {
     fn handshake2(io: T, builder: Builder) -> Handshake<T, B> {
         // Create the codec.
@@ -523,7 +523,7 @@ where
 impl<T, B> futures_core::Stream for Connection<T, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    B: Buf + Unpin + 'static,
+    B: Buf + 'static,
 {
     type Item = Result<(Request<RecvStream>, SendResponse<B>), crate::Error>;
 
@@ -921,7 +921,7 @@ impl Builder {
     pub fn handshake<T, B>(&self, io: T) -> Handshake<T, B>
     where
         T: AsyncRead + AsyncWrite + Unpin,
-        B: Buf + Unpin + 'static,
+        B: Buf + 'static,
     {
         Connection::handshake2(io, self.clone())
     }
@@ -1108,7 +1108,7 @@ impl<T, B: Buf> Flush<T, B> {
 impl<T, B> Future for Flush<T, B>
 where
     T: AsyncWrite + Unpin,
-    B: Buf + Unpin,
+    B: Buf,
 {
     type Output = Result<Codec<T, B>, crate::Error>;
 
@@ -1137,7 +1137,7 @@ impl<T, B: Buf> ReadPreface<T, B> {
 impl<T, B> Future for ReadPreface<T, B>
 where
     T: AsyncRead + Unpin,
-    B: Buf + Unpin,
+    B: Buf,
 {
     type Output = Result<Codec<T, B>, crate::Error>;
 
@@ -1174,7 +1174,7 @@ where
 impl<T, B: Buf> Future for Handshake<T, B>
 where
     T: AsyncRead + AsyncWrite + Unpin,
-    B: Buf + Unpin + 'static,
+    B: Buf + 'static,
 {
     type Output = Result<Connection<T, B>, crate::Error>;