From 335c52015e725f890e347481d89c39915c5b64de Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ren=C3=A9e=20Kooi?= <renee@kooi.me>
Date: Sat, 7 Dec 2024 11:47:39 +0100
Subject: [PATCH] Tweak guest counting

---
 src/SocketServer.js           | 35 +++++++++++++++++++----------------
 src/sockets/LostConnection.js | 27 +++++++++++----------------
 2 files changed, 30 insertions(+), 32 deletions(-)

diff --git a/src/SocketServer.js b/src/SocketServer.js
index 7b9ebb56..c5a1ed55 100644
--- a/src/SocketServer.js
+++ b/src/SocketServer.js
@@ -3,7 +3,6 @@ import lodash from 'lodash';
 import sjson from 'secure-json-parse';
 import { WebSocketServer } from 'ws';
 import Ajv from 'ajv';
-import ms from 'ms';
 import { stdSerializers } from 'pino';
 import { socketVote } from './controllers/booth.js';
 import { disconnectUser } from './controllers/users.js';
@@ -13,10 +12,13 @@ import AuthedConnection from './sockets/AuthedConnection.js';
 import LostConnection from './sockets/LostConnection.js';
 import { serializeUser } from './utils/serialize.js';
 
-const { debounce, isEmpty } = lodash;
+const { isEmpty } = lodash;
 
 export const REDIS_ACTIVE_SESSIONS = 'users';
 
+const PING_INTERVAL = 10_000;
+const GUEST_COUNT_INTERVAL = 2_000;
+
 /**
  * @typedef {import('./schema.js').User} User
  */
@@ -102,10 +104,10 @@ class SocketServer {
 
   #pinger;
 
-  /**
-   * Update online guests count and broadcast an update if necessary.
-   */
-  #recountGuests;
+  /** Update online guests count and broadcast an update if necessary. */
+  #guestCountInterval;
+
+  #guestCountDirty = true;
 
   /**
    * Handlers for commands that come in from clients.
@@ -187,16 +189,17 @@ class SocketServer {
 
     this.#pinger = setInterval(() => {
       this.ping();
-    }, ms('10 seconds'));
+    }, PING_INTERVAL);
 
-    this.#recountGuests = debounce(() => {
-      if (this.#closing) {
+    this.#guestCountInterval = setInterval(() => {
+      if (!this.#guestCountDirty) {
         return;
       }
-      this.#recountGuestsInternal().catch((error) => {
+
+      this.#recountGuests().catch((error) => {
         this.#logger.error({ err: error }, 'counting guests failed');
       });
-    }, ms('2 seconds'));
+    }, GUEST_COUNT_INTERVAL);
 
     this.#clientActions = {
       sendChat: (user, message) => {
@@ -629,7 +632,7 @@ class SocketServer {
     this.#logger.trace({ type: connection.constructor.name, userID, sessionID }, 'add connection');
 
     this.#connections.push(connection);
-    this.#recountGuests();
+    this.#guestCountDirty = true;
   }
 
   /**
@@ -647,7 +650,7 @@ class SocketServer {
     this.#connections.splice(i, 1);
 
     connection.removed();
-    this.#recountGuests();
+    this.#guestCountDirty = true;
   }
 
   /**
@@ -703,12 +706,12 @@ class SocketServer {
     clearInterval(this.#pinger);
 
     this.#closing = true;
+    clearInterval(this.#guestCountInterval);
+
     for (const connection of this.#connections) {
       connection.close();
     }
 
-    this.#recountGuests.cancel();
-
     const closeWsServer = promisify(this.#wss.close.bind(this.#wss));
     await closeWsServer();
     await this.#redisSubscription.quit();
@@ -779,7 +782,7 @@ class SocketServer {
     return parseInt(rawCount, 10);
   }
 
-  async #recountGuestsInternal() {
+  async #recountGuests() {
     const { redis } = this.#uw;
     const guests = this.#connections
       .filter((connection) => connection instanceof GuestConnection)
diff --git a/src/sockets/LostConnection.js b/src/sockets/LostConnection.js
index cf66c3bf..32733e0a 100644
--- a/src/sockets/LostConnection.js
+++ b/src/sockets/LostConnection.js
@@ -3,6 +3,8 @@ import EventEmitter from 'node:events';
 class LostConnection extends EventEmitter {
   #logger;
 
+  #removeTimer;
+
   /**
    * @param {import('../Uwave.js').default} uw
    * @param {import('../schema.js').User} user
@@ -19,7 +21,11 @@ class LostConnection extends EventEmitter {
     });
 
     this.initQueued();
-    this.setTimeout(timeout);
+
+    this.#removeTimer = setTimeout(() => {
+      this.close();
+      this.uw.redis.del(this.key, this.messagesKey);
+    }, timeout * 1000);
   }
 
   /**
@@ -52,17 +58,6 @@ class LostConnection extends EventEmitter {
       .exec();
   }
 
-  /**
-   * @param {number} timeout
-   * @private
-   */
-  setTimeout(timeout) {
-    this.removeTimer = setTimeout(() => {
-      this.close();
-      this.uw.redis.del(this.key, this.messagesKey);
-    }, timeout * 1000);
-  }
-
   /**
    * @param {string} command
    * @param {import('type-fest').JsonValue} data
@@ -78,13 +73,13 @@ class LostConnection extends EventEmitter {
 
   close() {
     this.#logger.info('close');
-    this.emit('close');
+    queueMicrotask(() => {
+      this.emit('close');
+    });
   }
 
   removed() {
-    if (this.removeTimer) {
-      clearTimeout(this.removeTimer);
-    }
+    clearTimeout(this.#removeTimer);
   }
 
   toString() {