perf: fix store mem leak, batch DB flushes, and remove double-clones

server/src/store.rs

@@ -5,21 +5,32 @@ use std::sync::{Arc, RwLock};
 pub const STORE_TABLE: TableDefinition<&str, &[u8]> = TableDefinition::new("store");
 
 pub struct Store<T> {
-    pub cache: RwLock<T>,
-    tx: tokio::sync::mpsc::UnboundedSender<Vec<u8>>,
+    pub cache: Arc<RwLock<T>>,
+    tx: tokio::sync::mpsc::Sender<()>,
 }
 
-impl<T: DeserializeOwned + Default + Serialize + Clone + Send + 'static> Store<T> {
+impl<T: DeserializeOwned + Default + Serialize + Clone + Send + Sync + 'static> Store<T> {
     pub fn new(key: &str, db: Arc<Database>) -> Self {
         let initial_data = Self::load_from_db(key, &db);
-        let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel::<Vec<u8>>();
+        let cache = Arc::new(RwLock::new(initial_data));
+        let (tx, mut rx) = tokio::sync::mpsc::channel::<()>(1);
         
         let db_clone = db.clone();
         let key_clone = key.to_string();
+        let cache_clone = cache.clone();
+        
         tokio::spawn(async move {
-            while let Some(json_data) = rx.recv().await {
+            while rx.recv().await.is_some() {
+                // Drain any other pending notifications so we batch writes
+                while let Ok(_) = rx.try_recv() {}
+
                 let db_inner = db_clone.clone();
                 let key_inner = key_clone.clone();
+                let json_data = {
+                    let lock = cache_clone.read().unwrap();
+                    serde_json::to_vec(&*lock).unwrap()
+                };
+                
                 let _ = tokio::task::spawn_blocking(move || {
                     let write_txn = db_inner.begin_write().unwrap();
                     {
@@ -32,7 +43,7 @@ impl<T: DeserializeOwned + Default + Serialize + Clone + Send + 'static> Store<T
         });
         
         Self {
-            cache: RwLock::new(initial_data),
+            cache,
             tx,
         }
     }
@@ -61,13 +72,11 @@ impl<T: DeserializeOwned + Default + Serialize + Clone + Send + 'static> Store<T
     }
 
     pub fn modify<F: FnOnce(&mut T)>(&self, f: F) {
-        let json_data = {
+        {
             let mut lock = self.cache.write().unwrap();
             f(&mut lock);
-            // Serialize while holding lock to avoid expensive deep clone of T
-            serde_json::to_vec(&*lock).unwrap()
-        };
-        let _ = self.tx.send(json_data);
+        }
+        let _ = self.tx.try_send(());
     }
 }