perf(daemon): Arc<Names> + tokio RwLock, O(1) clone per IPC request

Was: Arc<std::sync::RwLock<Names>>; each dispatch clone_names() copied
4 HashMaps (~100KB for a user with 2700 contacts) and used std RwLock
which blocks the tokio worker thread during the clone.

Now: Arc<tokio::sync::RwLock<Arc<Names>>>; dispatch takes the read
guard, does Arc::clone (pointer bump), drops the guard, then spawns
the query work. Names is immutable after daemon startup; Arc is ideal.

Smoke tested: `wx sessions --json` returns correct data including
chat_type; 8 concurrent clients finish in 12ms.

src/daemon/mod.rs

@@ -75,7 +75,10 @@ async fn async_run() -> Result<()> {
     let _ = db.get("session/session.db").await;
     eprintln!("[daemon] 预热完成，联系人 {} 个", names.map.len());
 
-    let names_arc = Arc::new(std::sync::RwLock::new(names));
+    // 包一层内部 Arc：IPC 请求取 guard 后只做 Arc::clone（O(1)），
+    // 避免每次请求都全量 clone 几千个联系人的 HashMap。
+    // 用 tokio::sync::RwLock 允许 guard 跨 await（当前不跨，为未来 reload 留余地）。
+    let names_arc = Arc::new(tokio::sync::RwLock::new(Arc::new(names)));
 
     // 启动 IPC server（阻塞）
     server::serve(Arc::clone(&db), Arc::clone(&names_arc)).await?;

src/daemon/server.rs

@@ -9,7 +9,7 @@ use super::query::Names;
 /// 启动 IPC server（Unix socket / Windows named pipe）
 pub async fn serve(
     db: Arc<DbCache>,
-    names: Arc<std::sync::RwLock<Names>>,
+    names: Arc<tokio::sync::RwLock<Arc<Names>>>,
 ) -> Result<()> {
     #[cfg(unix)]
     serve_unix(db, names).await?;
@@ -21,7 +21,7 @@ pub async fn serve(
 #[cfg(unix)]
 async fn serve_unix(
     db: Arc<DbCache>,
-    names: Arc<std::sync::RwLock<Names>>,
+    names: Arc<tokio::sync::RwLock<Arc<Names>>>,
 ) -> Result<()> {
     use tokio::net::UnixListener;
     let sock_path = crate::config::sock_path();
@@ -58,7 +58,7 @@ async fn serve_unix(
 async fn handle_connection_unix(
     stream: tokio::net::UnixStream,
     db: Arc<DbCache>,
-    names: Arc<std::sync::RwLock<Names>>,
+    names: Arc<tokio::sync::RwLock<Arc<Names>>>,
 ) -> Result<()> {
     let (reader, mut writer) = stream.into_split();
     let mut lines = BufReader::new(reader).lines();
@@ -86,7 +86,7 @@ async fn handle_connection_unix(
 #[cfg(windows)]
 async fn serve_windows(
     db: Arc<DbCache>,
-    names: Arc<std::sync::RwLock<Names>>,
+    names: Arc<tokio::sync::RwLock<Arc<Names>>>,
 ) -> Result<()> {
     use interprocess::local_socket::{
         tokio::prelude::*, GenericNamespaced, ListenerOptions,
@@ -117,7 +117,7 @@ async fn serve_windows(
 async fn handle_connection_windows(
     conn: interprocess::local_socket::tokio::Stream,
     db: Arc<DbCache>,
-    names: Arc<std::sync::RwLock<Names>>,
+    names: Arc<tokio::sync::RwLock<Arc<Names>>>,
 ) -> Result<()> {
     let (reader, mut writer) = tokio::io::split(conn);
     let mut lines = BufReader::new(reader).lines();
@@ -144,79 +144,59 @@ async fn handle_connection_windows(
 async fn dispatch(
     req: Request,
     db: &DbCache,
-    names: &std::sync::RwLock<Names>,
+    names: &tokio::sync::RwLock<Arc<Names>>,
 ) -> Response {
     use crate::ipc::Request::*;
     use super::query;
 
+    // 取 guard → O(1) clone Arc → 立即 drop 锁。后续 await 期间不持有锁，
+    // 多个并发 IPC 请求可以真正并行。Names 本身不可变（由 daemon 启动时
+    // 一次性构建），共享 Arc 即可。
+    let names_arc: Arc<Names> = {
+        let guard = names.read().await;
+        Arc::clone(&*guard)
+    };
+
     match req {
         Ping => Response::ok(serde_json::json!({ "pong": true })),
         Sessions { limit } => {
-            let names_snapshot = match clone_names(names) {
+            match query::q_sessions(db, &names_arc, limit).await {
-                Ok(n) => n,
-                Err(e) => return Response::err(e),
-            };
-            match query::q_sessions(db, &names_snapshot, limit).await {
                 Ok(v) => Response::ok(v),
                 Err(e) => Response::err(e.to_string()),
             }
         }
         History { chat, limit, offset, since, until, msg_type } => {
-            let names_snapshot = match clone_names(names) {
+            match query::q_history(db, &names_arc, &chat, limit, offset, since, until, msg_type).await {
-                Ok(n) => n,
-                Err(e) => return Response::err(e),
-            };
-            match query::q_history(db, &names_snapshot, &chat, limit, offset, since, until, msg_type).await {
                 Ok(v) => Response::ok(v),
                 Err(e) => Response::err(e.to_string()),
             }
         }
         Search { keyword, chats, limit, since, until, msg_type } => {
-            let names_snapshot = match clone_names(names) {
+            match query::q_search(db, &names_arc, &keyword, chats, limit, since, until, msg_type).await {
-                Ok(n) => n,
-                Err(e) => return Response::err(e),
-            };
-            match query::q_search(db, &names_snapshot, &keyword, chats, limit, since, until, msg_type).await {
                 Ok(v) => Response::ok(v),
                 Err(e) => Response::err(e.to_string()),
             }
         }
         Contacts { query, limit } => {
-            let names_snapshot = match clone_names(names) {
+            match query::q_contacts(&names_arc, query.as_deref(), limit).await {
-                Ok(n) => n,
-                Err(e) => return Response::err(e),
-            };
-            match query::q_contacts(&names_snapshot, query.as_deref(), limit).await {
                 Ok(v) => Response::ok(v),
                 Err(e) => Response::err(e.to_string()),
             }
         }
         Unread { limit, filter } => {
-            let names_snapshot = match clone_names(names) {
+            match query::q_unread(db, &names_arc, limit, filter).await {
-                Ok(n) => n,
-                Err(e) => return Response::err(e),
-            };
-            match query::q_unread(db, &names_snapshot, limit, filter).await {
                 Ok(v) => Response::ok(v),
                 Err(e) => Response::err(e.to_string()),
             }
         }
         Members { chat } => {
-            let names_snapshot = match clone_names(names) {
+            match query::q_members(db, &names_arc, &chat).await {
-                Ok(n) => n,
-                Err(e) => return Response::err(e),
-            };
-            match query::q_members(db, &names_snapshot, &chat).await {
                 Ok(v) => Response::ok(v),
                 Err(e) => Response::err(e.to_string()),
             }
         }
         NewMessages { state, limit } => {
-            let names_snapshot = match clone_names(names) {
+            match query::q_new_messages(db, &names_arc, state, limit).await {
-                Ok(n) => n,
-                Err(e) => return Response::err(e),
-            };
-            match query::q_new_messages(db, &names_snapshot, state, limit).await {
                 Ok(v) => Response::ok(v),
                 Err(e) => Response::err(e.to_string()),
             }
@@ -228,25 +208,10 @@ async fn dispatch(
             }
         }
         Stats { chat, since, until } => {
-            let names_snapshot = match clone_names(names) {
+            match query::q_stats(db, &names_arc, &chat, since, until).await {
-                Ok(n) => n,
-                Err(e) => return Response::err(e),
-            };
-            match query::q_stats(db, &names_snapshot, &chat, since, until).await {
                 Ok(v) => Response::ok(v),
                 Err(e) => Response::err(e.to_string()),
             }
         }
     }
 }
-
-/// 克隆 Names 以避免 RwLockGuard 跨 await
-fn clone_names(names: &std::sync::RwLock<Names>) -> Result<Names, String> {
-    let guard = names.read().map_err(|_| "内部错误: names lock poisoned".to_string())?;
-    Ok(Names {
-        map: guard.map.clone(),
-        md5_to_uname: guard.md5_to_uname.clone(),
-        msg_db_keys: guard.msg_db_keys.clone(),
-        verify_flags: guard.verify_flags.clone(),
-    })
-}