From c4ebc21da248ec64df9c83622e57abe42dcdc2b9 Mon Sep 17 00:00:00 2001
From: Daiki Ueno <dueno@redhat.com>
Date: Sun, 26 Nov 2023 11:13:07 +0900
Subject: [PATCH] event-broker: Turn listening task into a separate async
 function

Signed-off-by: Daiki Ueno <dueno@redhat.com>
---
 event-broker/src/main.rs | 57 ++++++++++++++++++++++------------------
 1 file changed, 32 insertions(+), 25 deletions(-)

diff --git a/event-broker/src/main.rs b/event-broker/src/main.rs
index 4dec61d..5b09c2b 100644
--- a/event-broker/src/main.rs
+++ b/event-broker/src/main.rs
@@ -114,41 +114,41 @@ impl Publisher {
         Ok(StdUnixListener::bind(&self.socket_path)?)
     }
 
-    async fn publish(&self, receiver: Receiver<EventGroup>) -> Result<()> {
+    async fn listen(&self) -> Result<()> {
         let std_listener = self.get_std_listener()?;
         std_listener.set_nonblocking(true)?;
         let listener = UnixListener::from_std(std_listener)?;
-        let subscriptions = self.subscriptions.clone();
 
-        tokio::spawn(async move {
-            while let Ok((stream, _sock_addr)) = listener.accept().await {
-                let subscriber_fd = stream.as_raw_fd();
+        while let Ok((stream, _sock_addr)) = listener.accept().await {
+            let subscriber_fd = stream.as_raw_fd();
 
-                debug!(socket = subscriber_fd, "subscriber connected");
+            debug!(socket = subscriber_fd, "subscriber connected");
 
-                let (de, ser) = stream.into_split();
+            let (de, ser) = stream.into_split();
 
-                let ser = FramedWrite::new(ser, LengthDelimitedCodec::new());
-                let de = FramedRead::new(de, LengthDelimitedCodec::new());
+            let ser = FramedWrite::new(ser, LengthDelimitedCodec::new());
+            let de = FramedRead::new(de, LengthDelimitedCodec::new());
 
-                let ser = SymmetricallyFramed::new(ser, SymmetricalCbor::<EventGroup>::default());
-                let mut de =
-                    SymmetricallyFramed::new(de, SymmetricalCbor::<Vec<String>>::default());
+            let ser = SymmetricallyFramed::new(ser, SymmetricalCbor::<EventGroup>::default());
+            let mut de =
+                SymmetricallyFramed::new(de, SymmetricalCbor::<Vec<String>>::default());
 
-                // Populate the scopes
-                if let Some(scopes) = de.try_next().await.unwrap() {
-                    subscriptions.write().unwrap().insert(
-                        subscriber_fd,
-                        Subscription {
-                            stream: ser,
-                            scopes,
-                            errored: Default::default(),
-                        },
-                    );
-                }
+            // Populate the scopes
+            if let Some(scopes) = de.try_next().await.unwrap() {
+                self.subscriptions.write().unwrap().insert(
+                    subscriber_fd,
+                    Subscription {
+                        stream: ser,
+                        scopes,
+                        errored: Default::default(),
+                    },
+                );
             }
-        });
+        }
+        Ok(())
+    }
 
+    async fn publish(&self, receiver: Receiver<EventGroup>) -> Result<()> {
         let mut stream = ReceiverStream::new(receiver);
         while let Some(group) = stream.next().await {
             let mut subscriptions = self.subscriptions.write().unwrap();
@@ -171,6 +171,9 @@ impl Publisher {
 
             // Remove errored subscriptions
             subscriptions.retain(|_, v| !v.errored);
+            if subscriptions.is_empty() {
+                break;
+            }
         }
 
         Ok(())
@@ -190,5 +193,9 @@ async fn main() -> anyhow::Result<()> {
     let publisher = Publisher::new(&config.socket_path);
 
     let (tx, rx) = mpsc::channel::<EventGroup>(10);
-    try_join!(reader.read(tx), publisher.publish(rx),).map(|_| ())
+    try_join!(
+        reader.read(tx),
+        publisher.listen(),
+        publisher.publish(rx),
+    ).map(|_| ())
 }