message pump optimization

src/textual/_queue.py

@@ -0,0 +1,49 @@
+from __future__ import annotations
+
+import asyncio
+from asyncio import Event
+from collections import deque
+from typing import Generic, TypeVar
+
+QueueType = TypeVar("QueueType")
+
+
+class Queue(Generic[QueueType]):
+    """A cut-down version of asyncio.Queue
+
+    This has just enough functionality to run the message pumps.
+
+    """
+
+    def __init__(self) -> None:
+        self.values: deque[QueueType] = deque()
+        self.ready_event = Event()
+
+    def put_nowait(self, value: QueueType) -> None:
+        self.values.append(value)
+        self.ready_event.set()
+
+    def qsize(self) -> int:
+        return len(self.values)
+
+    def empty(self) -> bool:
+        return not self.values
+
+    def task_done(self) -> None:
+        pass
+
+    async def get(self) -> QueueType:
+        if not self.ready_event.is_set():
+            await self.ready_event.wait()
+        value = self.values.popleft()
+        if not self.values:
+            self.ready_event.clear()
+        return value
+
+    def get_nowait(self) -> QueueType:
+        if not self.values:
+            raise asyncio.QueueEmpty()
+        value = self.values.popleft()
+        if not self.values:
+            self.ready_event.clear()
+        return value

src/textual/message_pump.py

@@ -36,6 +36,7 @@
 from textual._context import message_hook as message_hook_context_var
 from textual._context import prevent_message_types_stack
 from textual._on import OnNoWidget
+from textual._queue import Queue
 from textual._time import time
 from textual.constants import SLOW_THRESHOLD
 from textual.css.match import match
@@ -143,8 +144,8 @@ def __init__(self, parent: MessagePump | None = None) -> None:
         """
 
     @cached_property
-    def _message_queue(self) -> asyncio.Queue[Message | None]:
-        return asyncio.Queue()
+    def _message_queue(self) -> Queue[Message | None]:
+        return Queue()
 
     @cached_property
     def _mounted_event(self) -> asyncio.Event:

src/textual/widget.py

@@ -3904,12 +3904,12 @@ def post_render(
 
         return renderable
 
-    def watch_mouse_hover(self, value: bool) -> None:
+    def watch_mouse_hover(self, _mouse_over: bool) -> None:
         """Update from CSS if mouse over state changes."""
         if self._has_hover_style:
             self._update_styles()
 
-    def watch_has_focus(self, value: bool) -> None:
+    def watch_has_focus(self, _has_focus: bool) -> None:
         """Update from CSS if has focus state changes."""
         self._update_styles()