From 5e092b19fe113bdecd36b4e0184c82f4b3343bca Mon Sep 17 00:00:00 2001
From: Leo K <crowlkats@toaxl.com>
Date: Thu, 8 Jul 2021 13:33:01 +0200
Subject: feat(runtime/http): server side websocket support (#10359)

Co-authored-by: Nayeem Rahman <nayeemrmn99@gmail.com>
Co-authored-by: Luca Casonato <hello@lcas.dev>
---
 extensions/websocket/lib.rs | 98 +++++++++++++++++++++++++++++++++++++--------
 1 file changed, 81 insertions(+), 17 deletions(-)

(limited to 'extensions/websocket/lib.rs')

diff --git a/extensions/websocket/lib.rs b/extensions/websocket/lib.rs
index c6752d23b..f5bf15c79 100644
--- a/extensions/websocket/lib.rs
+++ b/extensions/websocket/lib.rs
@@ -64,13 +64,81 @@ impl WebSocketPermissions for NoWebSocketPermissions {
 }
 
 type WsStream = WebSocketStream<MaybeTlsStream<TcpStream>>;
-struct WsStreamResource {
-  tx: AsyncRefCell<SplitSink<WsStream, Message>>,
-  rx: AsyncRefCell<SplitStream<WsStream>>,
+pub enum WebSocketStreamType {
+  Client {
+    tx: AsyncRefCell<SplitSink<WsStream, Message>>,
+    rx: AsyncRefCell<SplitStream<WsStream>>,
+  },
+  Server {
+    tx: AsyncRefCell<
+      SplitSink<WebSocketStream<hyper::upgrade::Upgraded>, Message>,
+    >,
+    rx: AsyncRefCell<SplitStream<WebSocketStream<hyper::upgrade::Upgraded>>>,
+  },
+}
+
+pub struct WsStreamResource {
+  pub stream: WebSocketStreamType,
   // When a `WsStreamResource` resource is closed, all pending 'read' ops are
   // canceled, while 'write' ops are allowed to complete. Therefore only
   // 'read' futures are attached to this cancel handle.
-  cancel: CancelHandle,
+  pub cancel: CancelHandle,
+}
+
+impl WsStreamResource {
+  async fn send(self: &Rc<Self>, message: Message) -> Result<(), AnyError> {
+    match self.stream {
+      WebSocketStreamType::Client { .. } => {
+        let mut tx = RcRef::map(self, |r| match &r.stream {
+          WebSocketStreamType::Client { tx, .. } => tx,
+          WebSocketStreamType::Server { .. } => unreachable!(),
+        })
+        .borrow_mut()
+        .await;
+        tx.send(message).await?;
+      }
+      WebSocketStreamType::Server { .. } => {
+        let mut tx = RcRef::map(self, |r| match &r.stream {
+          WebSocketStreamType::Client { .. } => unreachable!(),
+          WebSocketStreamType::Server { tx, .. } => tx,
+        })
+        .borrow_mut()
+        .await;
+        tx.send(message).await?;
+      }
+    }
+
+    Ok(())
+  }
+
+  async fn next_message(
+    self: &Rc<Self>,
+    cancel: RcRef<CancelHandle>,
+  ) -> Result<
+    Option<Result<Message, tokio_tungstenite::tungstenite::Error>>,
+    AnyError,
+  > {
+    match &self.stream {
+      WebSocketStreamType::Client { .. } => {
+        let mut rx = RcRef::map(self, |r| match &r.stream {
+          WebSocketStreamType::Client { rx, .. } => rx,
+          WebSocketStreamType::Server { .. } => unreachable!(),
+        })
+        .borrow_mut()
+        .await;
+        rx.next().or_cancel(cancel).await.map_err(AnyError::from)
+      }
+      WebSocketStreamType::Server { .. } => {
+        let mut rx = RcRef::map(self, |r| match &r.stream {
+          WebSocketStreamType::Client { .. } => unreachable!(),
+          WebSocketStreamType::Server { rx, .. } => rx,
+        })
+        .borrow_mut()
+        .await;
+        rx.next().or_cancel(cancel).await.map_err(AnyError::from)
+      }
+    }
+  }
 }
 
 impl Resource for WsStreamResource {
@@ -79,8 +147,6 @@ impl Resource for WsStreamResource {
   }
 }
 
-impl WsStreamResource {}
-
 // This op is needed because creating a WS instance in JavaScript is a sync
 // operation and should throw error when permissions are not fulfilled,
 // but actual op that connects WS is async.
@@ -184,8 +250,10 @@ where
 
   let (ws_tx, ws_rx) = stream.split();
   let resource = WsStreamResource {
-    rx: AsyncRefCell::new(ws_rx),
-    tx: AsyncRefCell::new(ws_tx),
+    stream: WebSocketStreamType::Client {
+      rx: AsyncRefCell::new(ws_rx),
+      tx: AsyncRefCell::new(ws_tx),
+    },
     cancel: Default::default(),
   };
   let mut state = state.borrow_mut();
@@ -227,15 +295,13 @@ pub async fn op_ws_send(
     "pong" => Message::Pong(vec![]),
     _ => unreachable!(),
   };
-  let rid = args.rid;
 
   let resource = state
     .borrow_mut()
     .resource_table
-    .get::<WsStreamResource>(rid)
+    .get::<WsStreamResource>(args.rid)
     .ok_or_else(bad_resource_id)?;
-  let mut tx = RcRef::map(&resource, |r| &r.tx).borrow_mut().await;
-  tx.send(msg).await?;
+  resource.send(msg).await?;
   Ok(())
 }
 
@@ -266,8 +332,7 @@ pub async fn op_ws_close(
     .resource_table
     .get::<WsStreamResource>(rid)
     .ok_or_else(bad_resource_id)?;
-  let mut tx = RcRef::map(&resource, |r| &r.tx).borrow_mut().await;
-  tx.send(msg).await?;
+  resource.send(msg).await?;
   Ok(())
 }
 
@@ -294,9 +359,8 @@ pub async fn op_ws_next_event(
     .get::<WsStreamResource>(rid)
     .ok_or_else(bad_resource_id)?;
 
-  let mut rx = RcRef::map(&resource, |r| &r.rx).borrow_mut().await;
-  let cancel = RcRef::map(resource, |r| &r.cancel);
-  let val = rx.next().or_cancel(cancel).await?;
+  let cancel = RcRef::map(&resource, |r| &r.cancel);
+  let val = resource.next_message(cancel).await?;
   let res = match val {
     Some(Ok(Message::Text(text))) => NextEventResponse::String(text),
     Some(Ok(Message::Binary(data))) => NextEventResponse::Binary(data.into()),
-- 
cgit v1.2.3