LZH-YS1998
51 lines
1.7 KiB
Python
51 lines
1.7 KiB
Python
"""In-process event bus for OPC system."""
|
|
|
|
from __future__ import annotations
|
|
|
|
import asyncio
|
|
from collections import defaultdict
|
|
from typing import Any, Callable, Coroutine
|
|
|
|
from opc.core.models import OPCEvent
|
|
|
|
|
|
Listener = Callable[[OPCEvent], Coroutine[Any, Any, None]]
|
|
|
|
|
|
class EventBus:
|
|
"""Simple async pub/sub event bus for inter-layer communication."""
|
|
|
|
def __init__(self) -> None:
|
|
self._listeners: dict[str, list[Listener]] = defaultdict(list)
|
|
self._global_listeners: list[Listener] = []
|
|
self._history: list[OPCEvent] = []
|
|
self._lock: asyncio.Lock | None = None
|
|
|
|
def _get_lock(self) -> asyncio.Lock:
|
|
if self._lock is None:
|
|
self._lock = asyncio.Lock()
|
|
return self._lock
|
|
|
|
def subscribe(self, event_type: str, listener: Listener) -> None:
|
|
self._listeners[event_type].append(listener)
|
|
|
|
def subscribe_all(self, listener: Listener) -> None:
|
|
self._global_listeners.append(listener)
|
|
|
|
async def publish(self, event: OPCEvent) -> None:
|
|
async with self._get_lock():
|
|
self._history.append(event)
|
|
# Snapshot listener lists under lock to avoid mutation during iteration
|
|
typed = list(self._listeners.get(event.event_type, []))
|
|
globl = list(self._global_listeners)
|
|
# Execute listeners outside lock to avoid holding it during async work
|
|
tasks = [fn(event) for fn in typed + globl]
|
|
if tasks:
|
|
await asyncio.gather(*tasks, return_exceptions=True)
|
|
|
|
def get_history(self, event_type: str | None = None, limit: int = 50) -> list[OPCEvent]:
|
|
events = self._history
|
|
if event_type:
|
|
events = [e for e in events if e.event_type == event_type]
|
|
return events[-limit:]
|