Add proper shutdown, rate limits, config validation, cors config, fix dangling cursors, cache regex, merge created texts

sync-server/src/app_state.rs

@@ -2,6 +2,8 @@ pub mod cursors;
 pub mod database;
 pub mod websocket;
 
+use std::sync::{Arc, atomic::AtomicUsize};
+
 use anyhow::Result;
 use cursors::Cursors;
 use database::Database;
@@ -15,21 +17,42 @@ pub struct AppState {
     pub database: Database,
     pub cursors: Cursors,
     pub broadcasts: Broadcasts,
+    /// Tracks WebSocket connections that have upgraded but not yet completed
+    /// the authentication handshake
+    pub pending_ws_connections: Arc<AtomicUsize>,
+    /// Send on this channel to stop background tasks (cursor cleanup,
+    /// idle-pool cleanup)
+    shutdown_tx: Arc<tokio::sync::watch::Sender<()>>,
 }
 
 impl AppState {
     pub async fn try_new(config: Config) -> Result<Self> {
+        let (shutdown_tx, shutdown_rx) = tokio::sync::watch::channel(());
+
         let broadcasts = Broadcasts::new(&config.server);
-        let database = Database::try_new(&config.database, &broadcasts).await?;
+        let database =
+            Database::try_new(&config.database, &broadcasts, shutdown_rx.clone()).await?;
         let cursors: Cursors = Cursors::new(&config.database, &broadcasts);
 
-        Cursors::start_background_task(cursors.clone());
+        Cursors::start_background_task(cursors.clone(), shutdown_rx);
 
         Ok(Self {
             config,
             database,
             cursors,
             broadcasts,
+            pending_ws_connections: Arc::new(AtomicUsize::new(0)),
+            shutdown_tx: Arc::new(shutdown_tx),
         })
     }
+
+    /// Signal all background tasks (idle pool cleanup, cursor cleanup) to stop
+    pub fn shutdown(&self) {
+        let _ = self.shutdown_tx.send(());
+    }
+
+    /// Get a receiver to be notified when shutdown is triggered
+    pub fn subscribe_shutdown(&self) -> tokio::sync::watch::Receiver<()> {
+        self.shutdown_tx.subscribe()
+    }
 }