feat: automatically restart daemon on global settings change (#88)

Author: georgeh0

src/cocoindex_code/client.py

@@ -302,20 +302,37 @@ def _wait_for_daemon(timeout: float = 30.0) -> None:
     raise TimeoutError("Daemon did not start in time")
 
 
+def _needs_restart(resp: HandshakeResponse) -> bool:
+    """Check if the daemon needs to be restarted.
+
+    Returns True if the version mismatches or if global_settings.yml has been
+    modified since the daemon loaded it.
+    """
+    if not resp.ok:
+        return True
+    from .settings import global_settings_mtime_us
+
+    current_mtime = global_settings_mtime_us()
+    if current_mtime != resp.global_settings_mtime_us:
+        return True
+    return False
+
+
 def ensure_daemon() -> DaemonClient:
     """Connect to daemon, starting or restarting as needed.
 
     1. Try to connect to existing daemon.
     2. If connection refused: start daemon, retry connect with backoff.
-    3. If connected but version mismatch: stop old daemon, start new one.
+    3. If connected but version mismatch or global settings changed:
+       stop old daemon, start new one.
     """
     # Try connecting to existing daemon
     try:
         client = DaemonClient.connect()
         resp = client.handshake()
-        if resp.ok:
+        if not _needs_restart(resp):
             return client
-        # Version mismatch — restart
+        # Version or settings mismatch — restart
         client.close()
         stop_daemon()
     except (ConnectionRefusedError, OSError):
@@ -326,14 +343,15 @@ def ensure_daemon() -> DaemonClient:
     _wait_for_daemon()
 
     # Connect with retries
-    for attempt in range(10):
+    for _attempt in range(10):
         try:
             client = DaemonClient.connect()
             resp = client.handshake()
-            if resp.ok:
+            if not _needs_restart(resp):
                 return client
             raise RuntimeError(
-                f"Daemon version mismatch: expected {__version__}, got {resp.daemon_version}"
+                f"Daemon mismatch after fresh start: version={resp.daemon_version}, "
+                f"settings_mtime={resp.global_settings_mtime_us}"
             )
         except (ConnectionRefusedError, OSError):
             time.sleep(0.5)

src/cocoindex_code/daemon.py

@@ -45,6 +45,7 @@
 )
 from .query import query_codebase
 from .settings import (
+    global_settings_mtime_us,
     load_project_settings,
     load_user_settings,
     user_settings_dir,
@@ -288,6 +289,7 @@ async def handle_connection(
     registry: ProjectRegistry,
     start_time: float,
     shutdown_event: asyncio.Event,
+    settings_mtime_us: int | None,
 ) -> None:
     """Handle a single client connection."""
     loop = asyncio.get_event_loop()
@@ -322,7 +324,11 @@ def _recv() -> bytes:
                     break
 
                 ok = req.version == __version__
-                resp = HandshakeResponse(ok=ok, daemon_version=__version__)
+                resp = HandshakeResponse(
+                    ok=ok,
+                    daemon_version=__version__,
+                    global_settings_mtime_us=settings_mtime_us,
+                )
                 conn.send_bytes(encode_response(resp))
                 if not ok:
                     break
@@ -419,8 +425,9 @@ def run_daemon() -> None:
     """Main entry point for the daemon process (blocking)."""
     daemon_dir().mkdir(parents=True, exist_ok=True)
 
-    # Load user settings
+    # Load user settings and record mtime for staleness detection
     user_settings = load_user_settings()
+    settings_mtime_us = global_settings_mtime_us()
 
     # Set environment variables from settings
     for key, value in user_settings.envs.items():
@@ -445,7 +452,7 @@ def run_daemon() -> None:
     logger.info("Daemon starting (PID %d, version %s)", os.getpid(), __version__)
 
     try:
-        asyncio.run(_async_daemon_main(embedder))
+        asyncio.run(_async_daemon_main(embedder, settings_mtime_us))
     finally:
         # Clean up PID file and socket (named pipes on Windows clean up automatically)
         try:
@@ -461,7 +468,7 @@ def run_daemon() -> None:
         logger.info("Daemon stopped")
 
 
-async def _async_daemon_main(embedder: Embedder) -> None:
+async def _async_daemon_main(embedder: Embedder, settings_mtime_us: int | None) -> None:
     """Async main loop for the daemon."""
     start_time = time.monotonic()
     registry = ProjectRegistry(embedder)
@@ -496,7 +503,7 @@ async def _spawn_handler(
         evt: asyncio.Event,
         task_set: set[asyncio.Task[Any]],
     ) -> None:
-        task = asyncio.create_task(handle_connection(conn, reg, st, evt))
+        task = asyncio.create_task(handle_connection(conn, reg, st, evt, settings_mtime_us))
         task_set.add(task)
         task.add_done_callback(task_set.discard)
 

src/cocoindex_code/protocol.py

@@ -61,6 +61,7 @@ class StopRequest(_msgspec.Struct, tag="stop"):
 class HandshakeResponse(_msgspec.Struct, tag="handshake"):
     ok: bool
     daemon_version: str
+    global_settings_mtime_us: int | None = None
 
 
 class IndexResponse(_msgspec.Struct, tag="index"):

src/cocoindex_code/settings.py

@@ -195,6 +195,19 @@ def find_parent_with_marker(start: Path) -> Path | None:
         current = parent
 
 
+def global_settings_mtime_us() -> int | None:
+    """Return the mtime of ``global_settings.yml`` as integer microseconds.
+
+    Returns ``None`` if the file does not exist.  Used by the daemon to record
+    the mtime at startup and by the client to detect staleness.
+    """
+    path = user_settings_path()
+    try:
+        return int(path.stat().st_mtime * 1_000_000)
+    except FileNotFoundError:
+        return None
+
+
 def load_gitignore_spec(project_root: Path) -> GitIgnoreSpec | None:
     """Load a GitIgnoreSpec for the project's ``.gitignore`` if present."""
     gitignore = project_root / ".gitignore"