Add max queue size setting

Author: Archmonger

src/reactpy/config.py

@@ -130,3 +130,11 @@ def boolean(value: str | bool | int) -> bool:
     validator=str,
 )
 """The prefix for all ReactPy routes"""
+
+REACTPY_MAX_QUEUE_SIZE = Option(
+    "REACTPY_MAX_QUEUE_SIZE",
+    default=1000,
+    mutable=True,
+    validator=int,
+)
+"""The maximum size for internal queues used by ReactPy"""

src/reactpy/core/layout.py

@@ -34,6 +34,7 @@
     REACTPY_ASYNC_RENDERING,
     REACTPY_CHECK_VDOM_SPEC,
     REACTPY_DEBUG,
+    REACTPY_MAX_QUEUE_SIZE,
 )
 from reactpy.core._life_cycle_hook import HOOK_STACK, LifeCycleHook
 from reactpy.core.vdom import validate_vdom_json
@@ -117,7 +118,8 @@ async def deliver(self, event: LayoutEventMessage | dict[str, Any]) -> None:
         target = event["target"]
         if target not in self._event_queues:
             self._event_queues[target] = cast(
-                "Queue[LayoutEventMessage | dict[str, Any]]", Queue()
+                "Queue[LayoutEventMessage | dict[str, Any]]",
+                Queue(REACTPY_MAX_QUEUE_SIZE.current),
             )
             self._event_processing_tasks[target] = create_task(
                 self._process_event_queue(target, self._event_queues[target])
@@ -759,7 +761,7 @@ class _LifeCycleState(NamedTuple):
 class _ThreadSafeQueue(Generic[_Type]):
     def __init__(self) -> None:
         self._loop = get_running_loop()
-        self._queue: Queue[_Type] = Queue()
+        self._queue: Queue[_Type] = Queue(REACTPY_MAX_QUEUE_SIZE.current)
         self._pending: set[_Type] = set()
 
     def put(self, value: _Type) -> None:

src/reactpy/executors/asgi/middleware.py

@@ -186,7 +186,9 @@ def __init__(
         super().__init__(scope=scope, receive=receive, send=send)  # type: ignore
         self.scope = scope
         self.parent = parent
-        self.rendering_queue: asyncio.Queue[dict[str, str]] = asyncio.Queue()
+        self.rendering_queue: asyncio.Queue[dict[str, str]] = asyncio.Queue(
+            config.REACTPY_MAX_QUEUE_SIZE.current
+        )
         self.dispatcher: asyncio.Task[Any] | None = None
 
     async def __aenter__(self) -> ReactPyWebsocket:

tests/test_core/test_serve.py

@@ -7,6 +7,7 @@
 from jsonpointer import set_pointer
 
 import reactpy
+from reactpy.config import REACTPY_MAX_QUEUE_SIZE
 from reactpy.core.hooks import use_effect
 from reactpy.core.layout import Layout
 from reactpy.core.serve import serve_layout
@@ -130,8 +131,8 @@ def set_did_render():
             reactpy.html.button({"onClick": handle_event}),
         )
 
-    send_queue = asyncio.Queue()
-    recv_queue = asyncio.Queue()
+    send_queue = asyncio.Queue(REACTPY_MAX_QUEUE_SIZE.current)
+    recv_queue = asyncio.Queue(REACTPY_MAX_QUEUE_SIZE.current)
 
     task = asyncio.create_task(
         serve_layout(