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529090e | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 | import { EventEmitter } from 'events';
import os from 'os';
type Handler = (payload: any) => Promise<void> | void;
interface EventBusOptions {
redisUrl?: string;
streamKey?: string;
groupName?: string;
consumerName?: string;
readCount?: number;
blockMs?: number;
}
class PersistentEventBus extends EventEmitter {
private redis: any;
private ready = false;
private handlers: Map<string, Set<Handler>> = new Map();
private polling = false;
private readonly streamKey: string;
private readonly group: string;
private readonly consumer: string;
private readonly blockMs: number;
private readonly readCount: number;
private readonly redisUrl: string;
constructor(options: EventBusOptions = {}) {
super();
this.redisUrl = options.redisUrl || process.env.REDIS_URL || 'redis://localhost:6379';
this.streamKey = options.streamKey || 'widgetdc:events';
this.group = options.groupName || 'widgetdc-consumers';
this.consumer = options.consumerName || `${os.hostname()}-${process.pid}`;
this.blockMs = options.blockMs ?? 1000;
this.readCount = options.readCount ?? 20;
}
isReady(): boolean {
return this.ready;
}
async init(): Promise<void> {
if (this.ready) return;
try {
const Redis = (await import('ioredis')).default;
this.redis = new Redis(this.redisUrl, { maxRetriesPerRequest: 3 });
await this.ensureGroup();
this.ready = true;
console.log('🔴 PersistentEventBus: Redis Streams ready');
} catch (err: any) {
console.warn(`⚠️ PersistentEventBus fallback to in-memory: ${err?.message || err}`);
this.ready = false;
}
}
async publish(eventType: string, payload: any): Promise<void> {
const entry = JSON.stringify({ eventType, payload, ts: Date.now() });
if (!this.ready || !this.redis) {
// in-memory fallback
this.emit(eventType, payload);
this.emit('*', { eventType, payload });
return;
}
try {
await this.redis.xadd(this.streamKey, '*', 'type', eventType, 'data', entry);
} catch (err: any) {
console.error('Failed to publish event, falling back to memory:', err?.message || err);
this.emit(eventType, payload);
this.emit('*', { eventType, payload });
}
}
subscribe(eventType: string, handler: Handler): void {
if (!this.handlers.has(eventType)) this.handlers.set(eventType, new Set());
this.handlers.get(eventType)!.add(handler);
// Local immediate delivery
this.on(eventType, handler);
if (this.ready && !this.polling) {
this.startPolling();
}
}
remove(eventType: string, handler: Handler): void {
this.off(eventType, handler);
this.handlers.get(eventType)?.delete(handler);
}
private async ensureGroup(): Promise<void> {
try {
await this.redis.xgroup('CREATE', this.streamKey, this.group, '0', 'MKSTREAM');
} catch (err: any) {
// Ignore BUSYGROUP
if (!String(err?.message).includes('BUSYGROUP')) {
throw err;
}
}
}
private async startPolling(): Promise<void> {
if (this.polling || !this.redis) return;
this.polling = true;
const loop = async () => {
while (this.polling && this.redis) {
try {
const entries = await this.redis.xreadgroup(
'GROUP', this.group, this.consumer,
'COUNT', this.readCount,
'BLOCK', this.blockMs,
'STREAMS', this.streamKey,
'>'
);
if (entries) {
const [_, messages] = entries[0];
for (const [id, fields] of messages) {
const payload = this.parseFields(fields as any[]);
this.dispatch(payload);
await this.redis.xack(this.streamKey, this.group, id);
}
}
} catch (err: any) {
console.error('PersistentEventBus poll error:', err?.message || err);
await new Promise(r => setTimeout(r, 500));
}
}
};
loop();
}
private parseFields(fields: any[]): { eventType: string; payload: any } {
const obj: Record<string, any> = {};
for (let i = 0; i < fields.length; i += 2) {
obj[fields[i]] = fields[i + 1];
}
try {
const parsed = JSON.parse(obj['data']);
return { eventType: parsed.eventType, payload: parsed.payload };
} catch {
return { eventType: obj['type'] || 'unknown', payload: obj['data'] };
}
}
private dispatch(entry: { eventType: string; payload: any }) {
const handlers = this.handlers.get(entry.eventType);
if (handlers) {
handlers.forEach(async (handler) => {
try {
await handler(entry.payload);
} catch (err: any) {
console.error(`Handler error for ${entry.eventType}:`, err?.message || err);
}
});
}
}
async shutdown(): Promise<void> {
this.polling = false;
if (this.redis) {
await this.redis.quit();
}
}
}
export const persistentEventBus = new PersistentEventBus();
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