autosnippet/dist/lib/infrastructure/event/EventBus.js

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/**
 * EventBus — 应用事件总线
 * 支持 emit/emitAsync、事件历史日志、统计
 */
import { EventEmitter } from 'node:events';
export class EventBus extends EventEmitter {
    #history;
    #historyLimit;
    constructor(options = {}) {
        super();
        this.setMaxListeners(options.maxListeners || 20);
        this.#history = [];
        this.#historyLimit = options.historyLimit || 100;
    }
    /** 同步 emit + 记录历史 */
    emit(eventName, ...args) {
        this.#recordEvent(eventName, args);
        return super.emit(eventName, ...args);
    }
    /** 异步 emit — 串行等待所有 listener 完成 */
    async emitAsync(eventName, ...args) {
        this.#recordEvent(eventName, args);
        const listeners = this.listeners(eventName);
        for (const listener of listeners) {
            await listener(...args);
        }
    }
    /** 获取事件历史 */
    getHistory(limit = 10) {
        return this.#history.slice(-limit);
    }
    /** 清空历史 */
    clearHistory() {
        this.#history = [];
    }
    /** 获取统计 */
    getStats() {
        const events = {};
        for (const entry of this.#history) {
            const key = String(entry.event);
            events[key] = (events[key] || 0) + 1;
        }
        return {
            totalEvents: this.#history.length,
            uniqueEvents: Object.keys(events).length,
            byEvent: events,
            activeListeners: this.eventNames().reduce((sum, name) => sum + this.listenerCount(name), 0),
        };
    }
    // ─── 私有 ─────────────────────────────────────────────
    #recordEvent(eventName, args) {
        this.#history.push({
            event: eventName,
            timestamp: new Date().toISOString(),
            argCount: args.length,
        });
        if (this.#history.length > this.#historyLimit) {
            this.#history = this.#history.slice(-this.#historyLimit);
        }
    }
}