Switch to processing connections via unified message select-loop

src/net/server.rs

@@ -1,7 +1,7 @@
 use super::*;
 use anyhow::{Context, Error, Result};
 use future::{abortable, AbortHandle};
-use futures::{channel::mpsc::*, future::try_join, lock::Mutex, prelude::*};
+use futures::{channel::mpsc::*, lock::Mutex, prelude::*};
 use serde_json::json;
 use std::sync::Arc;
 use stream::iter;
@@ -204,10 +204,12 @@ impl Server {
 
 pub async fn run_client(
     handle: Handle,
-    socket: &mut (impl Stream<Item = Result<ClientMessage, Error>> + Sink<ServerMessage, Error = Error> + Send + Unpin),
+    socket: &mut (impl Stream<Item = Result<ClientMessage, Error>>
+              + Sink<ServerMessage, Error = Error>
+              + Send
+              + Unpin),
 ) -> Result<()> {
-    let (sink, mut source) = socket.split();
-    let (sender, receiver) = channel(CHANNEL_BUFFER);
+    let (sender, mut receiver) = channel(CHANNEL_BUFFER);
 
     // register player
     let player_id = handle
@@ -217,24 +219,22 @@ pub async fn run_client(
         .add_player(sender, &handle)
         .await?;
 
-    let (output_task, output_handle) = abortable(receiver.map(Ok).forward(sink));
-
-    let input_task = async {
-        loop {
-            match source.try_next().await? {
-                Some(msg) => handle.server.lock().await.process_message(player_id, msg),
-                None => break,
+    // main message loop
+    let result: Result<()> = async { loop {
+        tokio::select! {
+            client_message = socket.next() => {
+                match client_message {
+                    Some(msg) =>
+                    handle.server.lock().await.process_message(player_id, msg?),
+                    None => break Ok(()),
                 }
+            },
+            Some(server_message) = receiver.next() => {
+                socket.send(server_message).await?
+            },
+            else => break Ok(()),
         }
-        // stop the sink so it won't error
-        output_handle.abort();
-        Ok(())
-    };
-
-    // intentional aborting is not a reportable error
-    let output_task = output_task.map(|result| result.unwrap_or(Ok(())));
-
-    let result = try_join(output_task, input_task).await.map(|((), ())| ());
+    }}.await;
 
     // deregister player, whether normally or due to error
     handle.server.lock().await.remove_player(player_id);