fix: outdated Client::server_info after reconnect

Author: paolobarbolini

watermelon/src/client/mod.rs

@@ -2,7 +2,7 @@
 use std::net::{IpAddr, Ipv4Addr};
 use std::{fmt::Write, num::NonZero, process::abort, sync::Arc, time::Duration};
 
-use arc_swap::ArcSwap;
+use arc_swap::ArcSwapOption;
 use bytes::Bytes;
 use tokio::{
     select,
@@ -77,7 +77,7 @@ pub struct Client {
 #[derive(Debug)]
 struct ClientInner {
     sender: mpsc::Sender<HandlerCommand>,
-    info: Arc<ArcSwap<ServerInfo>>,
+    info: Arc<ArcSwapOption<ServerInfo>>,
     quick_info: Arc<RawQuickInfo>,
     multiplexed_subscription_prefix: Subject,
     next_subscription_id: AtomicU64,
@@ -199,7 +199,7 @@ impl Client {
         let builder = Self::builder();
         let (sender, receiver) = mpsc::channel(client_to_handler_chan_size);
         let (shutdown_sender, _shutdown_receiver) = mpsc::channel(1);
-        let info = Arc::new(ArcSwap::new(Arc::from(ServerInfo {
+        let info = Arc::new(ArcSwapOption::new(Some(Arc::new(ServerInfo {
             id: "1234".to_owned(),
             name: "watermelon-test".to_owned(),
             version: "2.10.17".to_owned(),
@@ -226,7 +226,7 @@ impl Client {
             domain: None,
 
             non_standard: NonStandardServerInfo::default(),
-        })));
+        }))));
         let quick_info = Arc::new(RawQuickInfo::new());
         let multiplexed_subscription_prefix = create_inbox_subject(&builder.inbox_prefix);
 
@@ -418,8 +418,12 @@ impl Client {
     /// Consider calling [`Client::quick_info`] if you only need
     /// information about Lame Duck Mode.
     #[must_use]
+    #[expect(
+        clippy::missing_panics_doc,
+        reason = "we don't expect the panic to ever happen"
+    )]
     pub fn server_info(&self) -> Arc<ServerInfo> {
-        self.inner.info.load_full()
+        self.inner.info.load_full().expect("never connected")
     }
 
     /// Get information about the client

watermelon/src/client/tests.rs

@@ -1,6 +1,6 @@
 use std::{collections::BTreeSet, sync::Arc};
 
-use arc_swap::ArcSwap;
+use arc_swap::ArcSwapOption;
 use tokio::sync::mpsc;
 use watermelon_proto::{ServerInfo, Subject};
 
@@ -12,7 +12,7 @@ use crate::{
 #[derive(Debug)]
 pub(crate) struct TestHandler {
     pub(crate) receiver: mpsc::Receiver<HandlerCommand>,
-    pub(crate) _info: Arc<ArcSwap<ServerInfo>>,
+    pub(crate) _info: Arc<ArcSwapOption<ServerInfo>>,
     pub(crate) quick_info: Arc<RawQuickInfo>,
 }
 

watermelon/src/handler/mod.rs

@@ -9,7 +9,7 @@ use std::{
     task::{Context, Poll},
 };
 
-use arc_swap::ArcSwap;
+use arc_swap::ArcSwapOption;
 use bytes::Bytes;
 use thiserror::Error;
 use tokio::{
@@ -52,7 +52,7 @@ pub(crate) struct Handler {
         ConnectionCompression<ConnectionSecurity<TcpStream>>,
         ConnectionSecurity<TcpStream>,
     >,
-    info: Arc<ArcSwap<ServerInfo>>,
+    info: Arc<ArcSwapOption<ServerInfo>>,
     quick_info: Arc<RawQuickInfo>,
     delayed_write: Delayed,
     writing: bool,
@@ -75,6 +75,7 @@ pub(crate) struct Handler {
 #[derive(Debug)]
 pub(crate) struct RecycledHandler {
     commands: mpsc::Receiver<HandlerCommand>,
+    info: Arc<ArcSwapOption<ServerInfo>>,
     quick_info: Arc<RawQuickInfo>,
 
     multiplexed_subscription_prefix: Subject,
@@ -202,9 +203,10 @@ impl Handler {
 
         let delayed_write = Delayed::new(builder.write_delay);
 
+        recycle.info.store(Some(Arc::from(info)));
         Ok(Some(Self {
             conn,
-            info: Arc::new(ArcSwap::new(Arc::from(info))),
+            info: recycle.info,
             quick_info: recycle.quick_info,
             delayed_write,
             writing: false,
@@ -227,14 +229,15 @@ impl Handler {
 
         RecycledHandler {
             commands: self.commands,
+            info: self.info,
             quick_info: self.quick_info,
             subscriptions: self.subscriptions,
             multiplexed_subscription_prefix: self.multiplexed_subscription_prefix,
             shutdown_recv: self.shutdown_recv,
         }
     }
 
-    pub(crate) fn info(&self) -> &Arc<ArcSwap<ServerInfo>> {
+    pub(crate) fn info(&self) -> &Arc<ArcSwapOption<ServerInfo>> {
         &self.info
     }
 
@@ -341,7 +344,7 @@ impl Handler {
             }
             ServerOp::Info { info } => {
                 self.quick_info.store_is_lameduck(info.lame_duck_mode);
-                self.info.store(Arc::from(info));
+                self.info.store(Some(Arc::from(info)));
             }
         }
 
@@ -680,6 +683,7 @@ impl RecycledHandler {
     ) -> Self {
         Self {
             commands,
+            info: Arc::new(ArcSwapOption::new(None)),
             quick_info,
             subscriptions: BTreeMap::new(),
             multiplexed_subscription_prefix: create_inbox_subject(&builder.inbox_prefix),