all files migrated; tweaks needed

invokeai/app/api/events.py

@@ -0,0 +1,54 @@
+# Copyright (c) 2022 Kyle Schouviller (https://github.com/kyle0654)
+
+import asyncio
+from queue import Empty, Queue
+from typing import Any
+from fastapi_events.dispatcher import dispatch
+from ..services.events import EventServiceBase
+import threading
+
+class FastAPIEventService(EventServiceBase):
+    event_handler_id: int
+    __queue: Queue
+    __stop_event: threading.Event
+
+    def __init__(self, event_handler_id: int) -> None:
+        self.event_handler_id = event_handler_id
+        self.__queue = Queue()
+        self.__stop_event = threading.Event()
+        asyncio.create_task(self.__dispatch_from_queue(stop_event = self.__stop_event))
+
+        super().__init__()
+
+
+    def stop(self, *args, **kwargs):
+        self.__stop_event.set()
+        self.__queue.put(None)
+
+
+    def dispatch(self, event_name: str, payload: Any) -> None:
+        self.__queue.put(dict(
+            event_name = event_name,
+            payload = payload
+        ))
+
+
+    async def __dispatch_from_queue(self, stop_event: threading.Event):
+        """Get events on from the queue and dispatch them, from the correct thread"""
+        while not stop_event.is_set():
+            try:
+                event = self.__queue.get(block = False)
+                if not event: # Probably stopping
+                    continue
+
+                dispatch(
+                    event.get('event_name'),
+                    payload       = event.get('payload'),
+                    middleware_id = self.event_handler_id)
+
+            except Empty:
+                await asyncio.sleep(0.001)
+                pass
+
+            except asyncio.CancelledError as e:
+                raise e # Raise a proper error