Add limiter

src/bots/limiter/index.ts

@@ -0,0 +1,46 @@
+import { createClient, RedisClientType } from 'redis';
+
+import env from '@/config';
+
+import Sentry from '@/sentry';
+
+
+export default class Limiter {
+    static MAX_PROCESSING_COUNT: number = 3;
+    static _redisClient: RedisClientType | null = null;
+
+    static async _getClient() {
+        if (this._redisClient === null) {
+            this._redisClient = createClient({
+                url: `redis://${env.REDIS_HOST}:${env.REDIS_PORT}/${env.REDIS_DB}`
+            });
+
+            this._redisClient.on('error', (err) => {
+                console.log(err);
+                Sentry.captureException(err);
+            });
+
+            await this._redisClient.connect();
+        }
+
+        return this._redisClient;
+    }
+
+    static _getKey(updateId: number) {
+        return `update_${updateId}`;
+    }
+
+    static async _getCount(updateId: number): Promise<number> {
+        const key = this._getKey(updateId);
+        
+        const client = await this._getClient();
+
+        await client.set(key, 0, {EX: 5 * 60, NX: true});
+        return client.incr(key);
+    }
+
+    static async isLimited(updateId: number): Promise<boolean> {
+        const count = await this._getCount(updateId);
+        return count <= this.MAX_PROCESSING_COUNT;
+    }
+}