coze-studio/frontend/packages/arch/web-context/src/event-bus.ts

114 lines
3.0 KiB
TypeScript

/*
* Copyright 2025 coze-dev Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import EventEmitter from 'eventemitter3';
interface EventWithData<T extends EventEmitter.ValidEventTypes> {
event: EventEmitter.EventNames<T>;
args: Parameters<EventEmitter.EventListener<T, EventEmitter.EventNames<T>>>;
}
type ValidEventTypes = EventEmitter.ValidEventTypes;
export class GlobalEventBus<T extends ValidEventTypes> {
private eventEmitter = new EventEmitter<T>();
private started = true;
private buffer: EventWithData<T>[] = [];
private static instances = new Map<string, GlobalEventBus<ValidEventTypes>>();
static create<T extends ValidEventTypes>(key: string): GlobalEventBus<T> {
if (GlobalEventBus.instances.has(key)) {
return GlobalEventBus.instances.get(key) as unknown as GlobalEventBus<T>;
}
const instance = new GlobalEventBus<T>();
GlobalEventBus.instances.set(
key,
instance as unknown as GlobalEventBus<ValidEventTypes>,
);
return instance;
}
/**
* trigger event
* @param event name
* @param args parameter
*/
emit<P extends EventEmitter.EventNames<T>>(
event: P,
...args: Parameters<EventEmitter.EventListener<T, P>>
) {
if (!this.started) {
this.buffer.push({
event,
args,
});
return;
}
this.eventEmitter.emit(event, ...args);
}
/**
* subscribe to events
* @param event name
* @param fn event callback
*/
on<P extends EventEmitter.EventNames<T>>(
event: P,
fn: EventEmitter.EventListener<T, P>,
) {
this.eventEmitter.on(event, fn);
}
/**
* unsubscribe from the event
* @param event name
* @param fn event callback
*/
off<P extends EventEmitter.EventNames<T>>(
event: P,
fn: EventEmitter.EventListener<T, P>,
) {
this.eventEmitter.off(event, fn);
}
/**
* Turn on the cached event subscriber, and when turned on, the callbacks corresponding to the events received when closed will be fired one by one in sequence
*/
start() {
this.started = true;
for (const { event, args } of this.buffer) {
this.emit(event, ...args);
}
}
/**
* Close the cached event subscriber. Events received during shutdown will be cached and delayed until the next time it is turned on
*/
stop() {
this.started = false;
}
/**
* Clears the cached events of the event subscriber so that the callback corresponding to the event received at stop is not triggered when starting again
*/
clear() {
this.buffer = [];
}
}