From 793bd17cc15c53e80cbb14c9303c54012702598f Mon Sep 17 00:00:00 2001
From: Florian Uekermann <florian@uekermann.me>
Date: Sat, 1 Jun 2024 09:13:53 +0200
Subject: [PATCH] consolidate shared quic trait methods and distinguish open
 errors from accept errors (#173)

Co-authored-by: ruben <ruben.buehler@t-online.de>
---
 h3-quinn/src/lib.rs           | 48 ++++++++++++++++++++---------------
 h3-webtransport/src/server.rs |  4 +--
 h3/src/quic.rs                | 44 +++++++-------------------------
 h3/src/server/mod.rs          |  2 +-
 4 files changed, 39 insertions(+), 59 deletions(-)

diff --git a/h3-quinn/src/lib.rs b/h3-quinn/src/lib.rs
index daec2057..7819b383 100644
--- a/h3-quinn/src/lib.rs
+++ b/h3-quinn/src/lib.rs
@@ -151,16 +151,14 @@ impl<B> quic::Connection<B> for Connection
 where
     B: Buf,
 {
-    type SendStream = SendStream<B>;
     type RecvStream = RecvStream;
-    type BidiStream = BidiStream<B>;
     type OpenStreams = OpenStreams;
-    type Error = ConnectionError;
+    type AcceptError = ConnectionError;
 
     fn poll_accept_bidi(
         &mut self,
         cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Option<Self::BidiStream>, Self::Error>> {
+    ) -> Poll<Result<Option<Self::BidiStream>, Self::AcceptError>> {
         let (send, recv) = match ready!(self.incoming_bi.poll_next_unpin(cx)) {
             Some(x) => x?,
             None => return Poll::Ready(Ok(None)),
@@ -174,7 +172,7 @@ where
     fn poll_accept_recv(
         &mut self,
         cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Option<Self::RecvStream>, Self::Error>> {
+    ) -> Poll<Result<Option<Self::RecvStream>, Self::AcceptError>> {
         let recv = match ready!(self.incoming_uni.poll_next_unpin(cx)) {
             Some(x) => x?,
             None => return Poll::Ready(Ok(None)),
@@ -182,10 +180,27 @@ where
         Poll::Ready(Ok(Some(Self::RecvStream::new(recv))))
     }
 
+    fn opener(&self) -> Self::OpenStreams {
+        OpenStreams {
+            conn: self.conn.clone(),
+            opening_bi: None,
+            opening_uni: None,
+        }
+    }
+}
+
+impl<B> quic::OpenStreams<B> for Connection
+where
+    B: Buf,
+{
+    type SendStream = SendStream<B>;
+    type BidiStream = BidiStream<B>;
+    type OpenError = ConnectionError;
+
     fn poll_open_bidi(
         &mut self,
         cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Self::BidiStream, Self::Error>> {
+    ) -> Poll<Result<Self::BidiStream, Self::OpenError>> {
         if self.opening_bi.is_none() {
             self.opening_bi = Some(Box::pin(stream::unfold(self.conn.clone(), |conn| async {
                 Some((conn.clone().open_bi().await, conn))
@@ -196,14 +211,14 @@ where
             ready!(self.opening_bi.as_mut().unwrap().poll_next_unpin(cx)).unwrap()?;
         Poll::Ready(Ok(Self::BidiStream {
             send: Self::SendStream::new(send),
-            recv: Self::RecvStream::new(recv),
+            recv: RecvStream::new(recv),
         }))
     }
 
     fn poll_open_send(
         &mut self,
         cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Self::SendStream, Self::Error>> {
+    ) -> Poll<Result<Self::SendStream, Self::OpenError>> {
         if self.opening_uni.is_none() {
             self.opening_uni = Some(Box::pin(stream::unfold(self.conn.clone(), |conn| async {
                 Some((conn.open_uni().await, conn))
@@ -214,14 +229,6 @@ where
         Poll::Ready(Ok(Self::SendStream::new(send)))
     }
 
-    fn opener(&self) -> Self::OpenStreams {
-        OpenStreams {
-            conn: self.conn.clone(),
-            opening_bi: None,
-            opening_uni: None,
-        }
-    }
-
     fn close(&mut self, code: h3::error::Code, reason: &[u8]) {
         self.conn.close(
             VarInt::from_u64(code.value()).expect("error code VarInt"),
@@ -278,15 +285,14 @@ impl<B> quic::OpenStreams<B> for OpenStreams
 where
     B: Buf,
 {
-    type RecvStream = RecvStream;
     type SendStream = SendStream<B>;
     type BidiStream = BidiStream<B>;
-    type Error = ConnectionError;
+    type OpenError = ConnectionError;
 
     fn poll_open_bidi(
         &mut self,
         cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Self::BidiStream, Self::Error>> {
+    ) -> Poll<Result<Self::BidiStream, Self::OpenError>> {
         if self.opening_bi.is_none() {
             self.opening_bi = Some(Box::pin(stream::unfold(self.conn.clone(), |conn| async {
                 Some((conn.open_bi().await, conn))
@@ -297,14 +303,14 @@ where
             ready!(self.opening_bi.as_mut().unwrap().poll_next_unpin(cx)).unwrap()?;
         Poll::Ready(Ok(Self::BidiStream {
             send: Self::SendStream::new(send),
-            recv: Self::RecvStream::new(recv),
+            recv: RecvStream::new(recv),
         }))
     }
 
     fn poll_open_send(
         &mut self,
         cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Self::SendStream, Self::Error>> {
+    ) -> Poll<Result<Self::SendStream, Self::OpenError>> {
         if self.opening_uni.is_none() {
             self.opening_uni = Some(Box::pin(stream::unfold(self.conn.clone(), |conn| async {
                 Some((conn.open_uni().await, conn))
diff --git a/h3-webtransport/src/server.rs b/h3-webtransport/src/server.rs
index 435963e9..05970b61 100644
--- a/h3-webtransport/src/server.rs
+++ b/h3-webtransport/src/server.rs
@@ -251,13 +251,13 @@ where
 
 /// Streams are opened, but the initial webtransport header has not been sent
 type PendingStreams<C, B> = (
-    BidiStream<<C as quic::Connection<B>>::BidiStream, B>,
+    BidiStream<<C as quic::OpenStreams<B>>::BidiStream, B>,
     WriteBuf<&'static [u8]>,
 );
 
 /// Streams are opened, but the initial webtransport header has not been sent
 type PendingUniStreams<C, B> = (
-    SendStream<<C as quic::Connection<B>>::SendStream, B>,
+    SendStream<<C as quic::OpenStreams<B>>::SendStream, B>,
     WriteBuf<&'static [u8]>,
 );
 
diff --git a/h3/src/quic.rs b/h3/src/quic.rs
index bb382a33..6e8722cb 100644
--- a/h3/src/quic.rs
+++ b/h3/src/quic.rs
@@ -31,22 +31,13 @@ impl<'a, E: Error + 'a> From<E> for Box<dyn Error + 'a> {
 }
 
 /// Trait representing a QUIC connection.
-pub trait Connection<B: Buf> {
-    /// The type produced by `poll_accept_bidi()`
-    type BidiStream: SendStream<B> + RecvStream;
-    /// The type of the sending part of `BidiStream`
-    type SendStream: SendStream<B>;
+pub trait Connection<B: Buf>: OpenStreams<B> {
     /// The type produced by `poll_accept_recv()`
     type RecvStream: RecvStream;
     /// A producer of outgoing Unidirectional and Bidirectional streams.
-    type OpenStreams: OpenStreams<
-        B,
-        SendStream = Self::SendStream,
-        RecvStream = Self::RecvStream,
-        BidiStream = Self::BidiStream,
-    >;
-    /// Error type yielded by this trait methods
-    type Error: Into<Box<dyn Error>>;
+    type OpenStreams: OpenStreams<B, SendStream = Self::SendStream, BidiStream = Self::BidiStream>;
+    /// Error type yielded by these trait methods
+    type AcceptError: Into<Box<dyn Error>>;
 
     /// Accept an incoming unidirectional stream
     ///
@@ -54,7 +45,7 @@ pub trait Connection<B: Buf> {
     fn poll_accept_recv(
         &mut self,
         cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Option<Self::RecvStream>, Self::Error>>;
+    ) -> Poll<Result<Option<Self::RecvStream>, Self::AcceptError>>;
 
     /// Accept an incoming bidirectional stream
     ///
@@ -62,25 +53,10 @@ pub trait Connection<B: Buf> {
     fn poll_accept_bidi(
         &mut self,
         cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Option<Self::BidiStream>, Self::Error>>;
-
-    /// Poll the connection to create a new bidirectional stream.
-    fn poll_open_bidi(
-        &mut self,
-        cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Self::BidiStream, Self::Error>>;
-
-    /// Poll the connection to create a new unidirectional stream.
-    fn poll_open_send(
-        &mut self,
-        cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Self::SendStream, Self::Error>>;
+    ) -> Poll<Result<Option<Self::BidiStream>, Self::AcceptError>>;
 
     /// Get an object to open outgoing streams.
     fn opener(&self) -> Self::OpenStreams;
-
-    /// Close the connection immediately
-    fn close(&mut self, code: crate::error::Code, reason: &[u8]);
 }
 
 /// Extends the `Connection` trait for sending datagrams
@@ -116,22 +92,20 @@ pub trait OpenStreams<B: Buf> {
     type BidiStream: SendStream<B> + RecvStream;
     /// The type produced by `poll_open_send()`
     type SendStream: SendStream<B>;
-    /// The type of the receiving part of `BidiStream`
-    type RecvStream: RecvStream;
     /// Error type yielded by these trait methods
-    type Error: Into<Box<dyn Error>>;
+    type OpenError: Into<Box<dyn Error>>;
 
     /// Poll the connection to create a new bidirectional stream.
     fn poll_open_bidi(
         &mut self,
         cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Self::BidiStream, Self::Error>>;
+    ) -> Poll<Result<Self::BidiStream, Self::OpenError>>;
 
     /// Poll the connection to create a new unidirectional stream.
     fn poll_open_send(
         &mut self,
         cx: &mut task::Context<'_>,
-    ) -> Poll<Result<Self::SendStream, Self::Error>>;
+    ) -> Poll<Result<Self::SendStream, Self::OpenError>>;
 
     /// Close the connection immediately
     fn close(&mut self, code: crate::error::Code, reason: &[u8]);
diff --git a/h3/src/server/mod.rs b/h3/src/server/mod.rs
index f9d62764..a4663d5b 100644
--- a/h3/src/server/mod.rs
+++ b/h3/src/server/mod.rs
@@ -9,7 +9,7 @@
 //! async fn doc<C>(conn: C)
 //! where
 //! C: h3::quic::Connection<bytes::Bytes>,
-//! <C as h3::quic::Connection<bytes::Bytes>>::BidiStream: Send + 'static
+//! <C as h3::quic::OpenStreams<bytes::Bytes>>::BidiStream: Send + 'static
 //! {
 //!     let mut server_builder = h3::server::builder();
 //!     // Build the Connection