feat: redis identify throttler

package.json

@@ -51,6 +51,9 @@
 		"lint:fix": "eslint src --fix",
 		"prepack": "pnpm run build"
 	},
+	"dependencies": {
+		"redlock-universal": "^0.8.4"
+	},
 	"devDependencies": {
 		"@discordjs/ws": "^2.0.4",
 		"@types/node": "^25.9.1",
@@ -59,6 +62,7 @@
 		"eslint": "^10.4.1",
 		"eslint-config-neon": "^0.4.0",
 		"eslint-import-resolver-typescript": "^4.4.5",
+		"ioredis": "^5.11.1",
 		"lodash.merge": "^4.6.2",
 		"oxfmt": "^0.53.0",
 		"tsdown": "^0.22.1",

src/throttlers/RedisIdentifyThrottler.ts

@@ -0,0 +1,35 @@
+import type { IIdentifyThrottler } from "@discordjs/ws";
+import type Redis from "ioredis";
+import { createLock, IoredisAdapter } from "redlock-universal";
+
+export interface RedisIdentifyThrottlerOptions {
+	maxConcurrency: number;
+	redis: Redis;
+	retryDelay?: number;
+}
+
+export class RedisIdentifyThrottler implements IIdentifyThrottler {
+	private readonly adapter: IoredisAdapter;
+
+	private readonly maxConcurrency: number;
+
+	private readonly retryDelay: number;
+
+	public constructor(options: RedisIdentifyThrottlerOptions) {
+		this.adapter = new IoredisAdapter(options.redis);
+		this.maxConcurrency = options.maxConcurrency;
+		this.retryDelay = options.retryDelay ?? 5_500;
+	}
+
+	public async waitForIdentify(shardId: number): Promise<void> {
+		const key = shardId % this.maxConcurrency;
+		const lock = createLock({
+			adapter: this.adapter,
+			key: `indomitable:identify:shard:${key}`,
+			retryDelay: this.retryDelay,
+			ttl: 6_000,
+		});
+
+		await lock.acquire();
+	}
+}