docs-mcp-server

/** * Central event bus service for application-wide event distribution. * * This service provides a pub/sub mechanism that can be used by any service * to emit and listen for events. Events emitted here can be: * - Consumed locally by in-process subscribers * - Broadcast to remote processes via tRPC subscriptions * - Forwarded to SSE clients via the web service * * This decouples event producers (like DocumentManagementService) from * consumers (like the Web UI), enabling a clean, scalable architecture. */ import EventEmitter from "node:events"; import { logger } from "../utils/logger"; import type { EventListener, EventPayloads, EventType } from "./types"; /** * Central event bus for application-wide events. */ export class EventBusService { private emitter: EventEmitter; constructor() { this.emitter = new EventEmitter(); // Increase max listeners to support multiple subscribers this.emitter.setMaxListeners(100); } /** * Emit an event to all subscribers. */ emit<T extends EventType>(eventType: T, payload: EventPayloads[T]): void { logger.debug(`Event emitted: ${eventType}`); this.emitter.emit(eventType, payload); } /** * Subscribe to events of a specific type. * Returns an unsubscribe function. */ on<T extends EventType>(eventType: T, listener: EventListener<T>): () => void { this.emitter.on(eventType, listener); return () => this.emitter.off(eventType, listener); } /** * Subscribe to events once (auto-unsubscribes after first event). */ once<T extends EventType>(eventType: T, listener: EventListener<T>): void { this.emitter.once(eventType, listener); } /** * Remove a specific listener. */ off<T extends EventType>(eventType: T, listener: EventListener<T>): void { this.emitter.off(eventType, listener); } /** * Remove all listeners for a specific event type, or all listeners if no type specified. */ removeAllListeners(eventType?: EventType): void { if (eventType === undefined) { this.emitter.removeAllListeners(); } else { this.emitter.removeAllListeners(eventType); } } /** * Get the count of listeners for a specific event type. */ listenerCount(eventType: EventType): number { return this.emitter.listenerCount(eventType); } }