init

rpc/src/utils/emitter.ts

@@ -0,0 +1,54 @@
+import { RPCErrors } from './types'
+
+export class Emitter {
+	/** Map<event, [callback function, once]> */
+	private _storage: Map<string, [(...args: any[]) => any, boolean]>
+
+	constructor() {
+		this._storage = new Map()
+	}
+
+	get _raw_storage() {
+		return this._storage
+	}
+
+	public on(event: string, cb: (...args: any[]) => any): this {
+		this._storage.set(event, [cb, false])
+		return this
+	}
+
+	public once(event: string, cb: (...args: any[]) => any): this {
+		this._storage.set(event, [cb, true])
+		return this
+	}
+
+	public off(event: string): this {
+		this._storage.delete(event)
+		return this
+	}
+
+	public has(event: string): boolean {
+		return this._storage.has(event)
+	}
+
+	public async emit<R>(event: string, ...args: any[]): Promise<R> {
+		return new Promise((res, rej) => {
+			if (!this._storage.has(event)) {
+				rej(RPCErrors.EVENT_NOT_REGISTERED)
+			}
+
+			const [cb, once] = this._storage.get(event) as [
+				(...args: any[]) => any,
+				boolean,
+			]
+
+			if (once) {
+				this._storage.delete(event)
+			}
+
+			Promise.resolve(cb(...args))
+				.then(res)
+				.catch(rej)
+		})
+	}
+}