feat(events): simplify event classes

- Remove ABCs, they do not work well with pydantic
- Remove the event type classvar - unused
- Remove clever logic to require an event name - we already get validation for this during schema registration.
- Rename event bases to all end in "Base"

invokeai/app/api/sockets.py

@@ -10,14 +10,14 @@ from invokeai.app.services.events.events_common import (
     BatchEnqueuedEvent,
     BulkDownloadCompleteEvent,
     BulkDownloadErrorEvent,
-    BulkDownloadEvent,
+    BulkDownloadEventBase,
     BulkDownloadStartedEvent,
     FastAPIEvent,
     InvocationCompleteEvent,
     InvocationDenoiseProgressEvent,
     InvocationErrorEvent,
     InvocationStartedEvent,
-    ModelEvent,
+    ModelEventBase,
     ModelInstallCancelledEvent,
     ModelInstallCompleteEvent,
     ModelInstallDownloadProgressEvent,
@@ -26,7 +26,7 @@ from invokeai.app.services.events.events_common import (
     ModelLoadCompleteEvent,
     ModelLoadStartedEvent,
     QueueClearedEvent,
-    QueueEvent,
+    QueueEventBase,
     QueueItemStatusChangedEvent,
     SessionCanceledEvent,
     SessionCompleteEvent,
@@ -106,14 +106,14 @@ class SocketIO:
     async def _handle_unsub_bulk_download(self, sid: str, data: Any) -> None:
         await self._sio.leave_room(sid, BulkDownloadSubscriptionEvent(**data).bulk_download_id)
 
-    async def _handle_queue_event(self, event: FastAPIEvent[QueueEvent]):
+    async def _handle_queue_event(self, event: FastAPIEvent[QueueEventBase]):
         event_name, payload = event
         await self._sio.emit(event=event_name, data=payload.model_dump(), room=payload.queue_id)
 
-    async def _handle_model_event(self, event: FastAPIEvent[ModelEvent]) -> None:
+    async def _handle_model_event(self, event: FastAPIEvent[ModelEventBase]) -> None:
         event_name, payload = event
         await self._sio.emit(event=event_name, data=payload.model_dump())
 
-    async def _handle_bulk_image_download_event(self, event: FastAPIEvent[BulkDownloadEvent]) -> None:
+    async def _handle_bulk_image_download_event(self, event: FastAPIEvent[BulkDownloadEventBase]) -> None:
         event_name, payload = event
         await self._sio.emit(event=event_name, data=payload.model_dump(), room=payload.bulk_download_id)

invokeai/app/services/events/events_base.py

@@ -4,7 +4,6 @@
 from typing import TYPE_CHECKING, Optional
 
 from invokeai.app.services.events.events_common import (
-    BaseEvent,
     BatchEnqueuedEvent,
     BulkDownloadCompleteEvent,
     BulkDownloadErrorEvent,
@@ -14,6 +13,7 @@ from invokeai.app.services.events.events_common import (
     DownloadErrorEvent,
     DownloadProgressEvent,
     DownloadStartedEvent,
+    EventBase,
     InvocationCompleteEvent,
     InvocationDenoiseProgressEvent,
     InvocationErrorEvent,
@@ -35,7 +35,7 @@ from invokeai.app.services.events.events_common import (
 
 if TYPE_CHECKING:
     from invokeai.app.invocations.baseinvocation import BaseInvocation, BaseInvocationOutput
-    from invokeai.app.services.events.events_common import BaseEvent
+    from invokeai.app.services.events.events_common import EventBase
     from invokeai.app.services.model_install.model_install_common import ModelInstallJob
     from invokeai.app.services.session_processor.session_processor_common import ProgressImage
     from invokeai.app.services.session_queue.session_queue_common import (
@@ -50,7 +50,7 @@ if TYPE_CHECKING:
 class EventServiceBase:
     """Basic event bus, to have an empty stand-in when not needed"""
 
-    def dispatch(self, event: "BaseEvent") -> None:
+    def dispatch(self, event: "EventBase") -> None:
         pass
 
     # region: Invocation

invokeai/app/services/events/events_common.py

@@ -1,6 +1,4 @@
-from abc import ABC
+from typing import TYPE_CHECKING, Any, Coroutine, Optional, Protocol, TypeAlias, TypeVar
-from enum import Enum
-from typing import TYPE_CHECKING, Any, ClassVar, Coroutine, Optional, Protocol, TypeAlias, TypeVar
 
 from fastapi_events.handlers.local import local_handler
 from fastapi_events.registry.payload_schema import registry as payload_schema
@@ -22,39 +20,22 @@ if TYPE_CHECKING:
     from invokeai.app.services.model_install.model_install_common import ModelInstallJob
 
 
-class EventType(str, Enum):
+class EventBase(BaseModel):
-    QUEUE = "queue"
-    MODEL = "model"
-    DOWNLOAD = "download"
-    BULK_IMAGE_DOWNLOAD = "bulk_image_download"
-
-
-class BaseEvent(BaseModel, ABC):
     """Base class for all events. All events must inherit from this class.
 
-    Events must define the following class attributes:
+    Events must define a class attribute `__event_name__` to identify the event.
-    - `__event_name__: str`: The name of the event
-    - `__event_type__: EventType`: The type of the event
 
     All other attributes should be defined as normal for a pydantic model.
 
     A timestamp is automatically added to the event when it is created.
     """
 
-    __event_name__: ClassVar[str] = ...  # pyright: ignore [reportAssignmentType]
-    __event_type__: ClassVar[EventType] = ...  # pyright: ignore [reportAssignmentType]
-
     timestamp: int = Field(description="The timestamp of the event", default_factory=get_timestamp)
 
-    def __init_subclass__(cls, **kwargs: ConfigDict):
-        for required_attr in ("__event_name__", "__event_type__"):
-            if getattr(cls, required_attr) is ...:
-                raise TypeError(f"{cls.__name__} must define {required_attr}")
-
     model_config = ConfigDict(json_schema_serialization_defaults_required=True)
 
 
-TEvent = TypeVar("TEvent", bound=BaseEvent)
+TEvent = TypeVar("TEvent", bound=EventBase)
 
 FastAPIEvent: TypeAlias = tuple[str, TEvent]
 """
@@ -77,37 +58,28 @@ def register_events(events: set[type[TEvent]], func: FastAPIEventFunc) -> None:
         local_handler.register(event_name=event.__event_name__, _func=func)
 
 
-class QueueEvent(BaseEvent, ABC):
+class QueueEventBase(EventBase):
     """Base class for queue events"""
 
-    __event_type__ = EventType.QUEUE
-    __event_name__ = "queue_event"
-
     queue_id: str = Field(description="The ID of the queue")
 
 
-class QueueItemEvent(QueueEvent, ABC):
+class QueueItemEventBase(QueueEventBase):
     """Base class for queue item events"""
 
-    __event_name__ = "queue_item_event"
-
     item_id: int = Field(description="The ID of the queue item")
     batch_id: str = Field(description="The ID of the queue batch")
 
 
-class SessionEvent(QueueItemEvent, ABC):
+class SessionEventBase(QueueItemEventBase):
     """Base class for session (aka graph execution state) events"""
 
-    __event_name__ = "session_event"
-
     session_id: str = Field(description="The ID of the session (aka graph execution state)")
 
 
-class InvocationEvent(SessionEvent, ABC):
+class InvocationEventBase(SessionEventBase):
     """Base class for invocation events"""
 
-    __event_name__ = "invocation_event"
-
     queue_id: str = Field(description="The ID of the queue")
     item_id: int = Field(description="The ID of the queue item")
     batch_id: str = Field(description="The ID of the queue batch")
@@ -118,7 +90,7 @@ class InvocationEvent(SessionEvent, ABC):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class InvocationStartedEvent(InvocationEvent):
+class InvocationStartedEvent(InvocationEventBase):
     """Emitted when an invocation is started"""
 
     __event_name__ = "invocation_started"
@@ -137,7 +109,7 @@ class InvocationStartedEvent(InvocationEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class InvocationDenoiseProgressEvent(InvocationEvent):
+class InvocationDenoiseProgressEvent(InvocationEventBase):
     """Emitted at each step during denoising of an invocation."""
 
     __event_name__ = "invocation_denoise_progress"
@@ -170,7 +142,7 @@ class InvocationDenoiseProgressEvent(InvocationEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class InvocationCompleteEvent(InvocationEvent):
+class InvocationCompleteEvent(InvocationEventBase):
     """Emitted when an invocation is complete"""
 
     __event_name__ = "invocation_complete"
@@ -194,7 +166,7 @@ class InvocationCompleteEvent(InvocationEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class InvocationErrorEvent(InvocationEvent):
+class InvocationErrorEvent(InvocationEventBase):
     """Emitted when an invocation encounters an error"""
 
     __event_name__ = "invocation_error"
@@ -227,7 +199,7 @@ class InvocationErrorEvent(InvocationEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class SessionStartedEvent(SessionEvent):
+class SessionStartedEvent(SessionEventBase):
     """Emitted when a session has started"""
 
     __event_name__ = "session_started"
@@ -243,7 +215,7 @@ class SessionStartedEvent(SessionEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class SessionCompleteEvent(SessionEvent):
+class SessionCompleteEvent(SessionEventBase):
     """Emitted when a session has completed all invocations"""
 
     __event_name__ = "session_complete"
@@ -259,7 +231,7 @@ class SessionCompleteEvent(SessionEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class SessionCanceledEvent(SessionEvent):
+class SessionCanceledEvent(SessionEventBase):
     """Emitted when a session is canceled"""
 
     __event_name__ = "session_canceled"
@@ -275,7 +247,7 @@ class SessionCanceledEvent(SessionEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class QueueItemStatusChangedEvent(SessionEvent):
+class QueueItemStatusChangedEvent(SessionEventBase):
     """Emitted when a queue item's status changes"""
 
     __event_name__ = "queue_item_status_changed"
@@ -314,7 +286,7 @@ class QueueItemStatusChangedEvent(SessionEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class BatchEnqueuedEvent(QueueEvent):
+class BatchEnqueuedEvent(QueueEventBase):
     """Emitted when a batch is enqueued"""
 
     __event_name__ = "batch_enqueued"
@@ -338,7 +310,7 @@ class BatchEnqueuedEvent(QueueEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class QueueClearedEvent(QueueEvent):
+class QueueClearedEvent(QueueEventBase):
     """Emitted when a queue is cleared"""
 
     __event_name__ = "queue_cleared"
@@ -348,17 +320,14 @@ class QueueClearedEvent(QueueEvent):
         return cls(queue_id=queue_id)
 
 
-class DownloadEvent(BaseEvent, ABC):
+class DownloadEventBase(EventBase):
     """Base class for events associated with a download"""
 
-    __event_type__ = EventType.DOWNLOAD
-    __event_name__ = "download_event"
-
     source: str = Field(description="The source of the download")
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class DownloadStartedEvent(DownloadEvent):
+class DownloadStartedEvent(DownloadEventBase):
     """Emitted when a download is started"""
 
     __event_name__ = "download_started"
@@ -371,7 +340,7 @@ class DownloadStartedEvent(DownloadEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class DownloadProgressEvent(DownloadEvent):
+class DownloadProgressEvent(DownloadEventBase):
     """Emitted at intervals during a download"""
 
     __event_name__ = "download_progress"
@@ -386,7 +355,7 @@ class DownloadProgressEvent(DownloadEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class DownloadCompleteEvent(DownloadEvent):
+class DownloadCompleteEvent(DownloadEventBase):
     """Emitted when a download is completed"""
 
     __event_name__ = "download_complete"
@@ -400,7 +369,7 @@ class DownloadCompleteEvent(DownloadEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class DownloadCancelledEvent(DownloadEvent):
+class DownloadCancelledEvent(DownloadEventBase):
     """Emitted when a download is cancelled"""
 
     __event_name__ = "download_cancelled"
@@ -411,7 +380,7 @@ class DownloadCancelledEvent(DownloadEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class DownloadErrorEvent(DownloadEvent):
+class DownloadErrorEvent(DownloadEventBase):
     """Emitted when a download encounters an error"""
 
     __event_name__ = "download_error"
@@ -424,15 +393,12 @@ class DownloadErrorEvent(DownloadEvent):
         return cls(source=source, error_type=error_type, error=error)
 
 
-class ModelEvent(BaseEvent, ABC):
+class ModelEventBase(EventBase):
     """Base class for events associated with a model"""
 
-    __event_type__ = EventType.MODEL
-    __event_name__ = "model_event"
-
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class ModelLoadStartedEvent(ModelEvent):
+class ModelLoadStartedEvent(ModelEventBase):
     """Emitted when a model is requested"""
 
     __event_name__ = "model_load_started"
@@ -446,7 +412,7 @@ class ModelLoadStartedEvent(ModelEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class ModelLoadCompleteEvent(ModelEvent):
+class ModelLoadCompleteEvent(ModelEventBase):
     """Emitted when a model is requested"""
 
     __event_name__ = "model_load_complete"
@@ -460,7 +426,7 @@ class ModelLoadCompleteEvent(ModelEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class ModelInstallDownloadProgressEvent(ModelEvent):
+class ModelInstallDownloadProgressEvent(ModelEventBase):
     """Emitted at intervals while the install job is in progress (remote models only)."""
 
     __event_name__ = "model_install_download_progress"
@@ -496,7 +462,7 @@ class ModelInstallDownloadProgressEvent(ModelEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class ModelInstallDownloadsCompleteEvent(ModelEvent):
+class ModelInstallDownloadsCompleteEvent(ModelEventBase):
     """Emitted once when an install job becomes active."""
 
     __event_name__ = "model_install_downloads_complete"
@@ -510,7 +476,7 @@ class ModelInstallDownloadsCompleteEvent(ModelEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class ModelInstallStartedEvent(ModelEvent):
+class ModelInstallStartedEvent(ModelEventBase):
     """Emitted once when an install job becomes active."""
 
     __event_name__ = "model_install_started"
@@ -524,7 +490,7 @@ class ModelInstallStartedEvent(ModelEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class ModelInstallCompleteEvent(ModelEvent):
+class ModelInstallCompleteEvent(ModelEventBase):
     """Emitted when an install job is completed successfully."""
 
     __event_name__ = "model_install_complete"
@@ -541,7 +507,7 @@ class ModelInstallCompleteEvent(ModelEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class ModelInstallCancelledEvent(ModelEvent):
+class ModelInstallCancelledEvent(ModelEventBase):
     """Emitted when an install job is cancelled."""
 
     __event_name__ = "model_install_cancelled"
@@ -555,7 +521,7 @@ class ModelInstallCancelledEvent(ModelEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class ModelInstallErrorEvent(ModelEvent):
+class ModelInstallErrorEvent(ModelEventBase):
     """Emitted when an install job encounters an exception."""
 
     __event_name__ = "model_install_error"
@@ -572,19 +538,16 @@ class ModelInstallErrorEvent(ModelEvent):
         return cls(id=job.id, source=str(job.source), error_type=job.error_type, error=job.error)
 
 
-class BulkDownloadEvent(BaseEvent, ABC):
+class BulkDownloadEventBase(EventBase):
     """Base class for events associated with a bulk image download"""
 
-    __event_type__ = EventType.BULK_IMAGE_DOWNLOAD
-    __event_name__ = "bulk_image_download_event"
-
     bulk_download_id: str = Field(description="The ID of the bulk image download")
     bulk_download_item_id: str = Field(description="The ID of the bulk image download item")
     bulk_download_item_name: str = Field(description="The name of the bulk image download item")
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class BulkDownloadStartedEvent(BulkDownloadEvent):
+class BulkDownloadStartedEvent(BulkDownloadEventBase):
     """Emitted when a bulk image download is started"""
 
     __event_name__ = "bulk_download_started"
@@ -601,7 +564,7 @@ class BulkDownloadStartedEvent(BulkDownloadEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class BulkDownloadCompleteEvent(BulkDownloadEvent):
+class BulkDownloadCompleteEvent(BulkDownloadEventBase):
     """Emitted when a bulk image download is started"""
 
     __event_name__ = "bulk_download_complete"
@@ -618,7 +581,7 @@ class BulkDownloadCompleteEvent(BulkDownloadEvent):
 
 
 @payload_schema.register  # pyright: ignore [reportUnknownMemberType]
-class BulkDownloadErrorEvent(BulkDownloadEvent):
+class BulkDownloadErrorEvent(BulkDownloadEventBase):
     """Emitted when a bulk image download is started"""
 
     __event_name__ = "bulk_download_error"

invokeai/app/services/events/events_fastapievents.py

@@ -7,7 +7,7 @@ from queue import Empty, Queue
 from fastapi_events.dispatcher import dispatch
 
 from invokeai.app.services.events.events_common import (
-    BaseEvent,
+    EventBase,
 )
 
 from .events_base import EventServiceBase
@@ -16,7 +16,7 @@ from .events_base import EventServiceBase
 class FastAPIEventService(EventServiceBase):
     def __init__(self, event_handler_id: int) -> None:
         self.event_handler_id = event_handler_id
-        self._queue = Queue[BaseEvent | None]()
+        self._queue = Queue[EventBase | None]()
         self._stop_event = threading.Event()
         asyncio.create_task(self._dispatch_from_queue(stop_event=self._stop_event))
 
@@ -26,7 +26,7 @@ class FastAPIEventService(EventServiceBase):
         self._stop_event.set()
         self._queue.put(None)
 
-    def dispatch(self, event: BaseEvent) -> None:
+    def dispatch(self, event: EventBase) -> None:
         self._queue.put(event)
 
     async def _dispatch_from_queue(self, stop_event: threading.Event):

invokeai/app/services/session_processor/session_processor_default.py

@@ -9,7 +9,7 @@ from invokeai.app.services.events.events_common import (
     BatchEnqueuedEvent,
     FastAPIEvent,
     QueueClearedEvent,
-    QueueEvent,
+    QueueEventBase,
     QueueItemStatusChangedEvent,
     SessionCanceledEvent,
     register_events,
@@ -332,7 +332,7 @@ class DefaultSessionProcessor(SessionProcessorBase):
     def _poll_now(self) -> None:
         self._poll_now_event.set()
 
-    async def _on_queue_event(self, event: FastAPIEvent[QueueEvent]) -> None:
+    async def _on_queue_event(self, event: FastAPIEvent[QueueEventBase]) -> None:
         _event_name, payload = event
         if (
             isinstance(payload, SessionCanceledEvent)