Improve performance of client presence monitor (#18645)

app/ui-sidenav/client/userPresence.js

@@ -1,12 +1,12 @@
 import { Meteor } from 'meteor/meteor';
-// import { ReactiveVar } from 'meteor/reactive-var';
+import { Accounts } from 'meteor/accounts-base';
 import { Template } from 'meteor/templating';
 import { Tracker } from 'meteor/tracker';
 import _ from 'underscore';
 import mem from 'mem';
 
 import { APIClient } from '../../utils/client';
-import { saveUser } from '../../../imports/startup/client/listenActiveUsers';
+import { saveUser, interestedUserIds } from '../../../imports/startup/client/listenActiveUsers';
 
 import './userPresence.html';
 
@@ -45,6 +45,7 @@ const getAll = _.debounce(async function getAll() {
 }, 1000);
 
 const get = mem(function get(id) {
+	interestedUserIds.add(id);
 	const promise = pending.get(id) || new Promise((resolve, reject) => {
 		promises.set(id, { resolve, reject });
 	});
@@ -71,11 +72,17 @@ const featureExists = !!window.IntersectionObserver;
 
 const observer = featureExists && new IntersectionObserver(handleEntries, options);
 
+let wasConnected = Meteor.status().connected;
+
 Tracker.autorun(() => {
-	if (!Meteor.userId() || !Meteor.status().connected) {
-		return Meteor.users.update({}, { $unset: { status: '' } }, { multi: true });
+	// Only clear statuses on disconnect, prevent process it on reconnect again
+	const isConnected = Meteor.status().connected;
+	if (!Meteor.userId() || (wasConnected && !isConnected)) {
+		wasConnected = isConnected;
+		return Meteor.users.update({ status: { $exists: true } }, { $unset: { status: true } }, { multi: true });
 	}
 	mem.clear(get);
+	wasConnected = isConnected;
 
 	if (featureExists) {
 		for (const node of data.keys()) {
@@ -85,6 +92,10 @@ Tracker.autorun(() => {
 		return;
 	}
 	getAll();
+
+	Accounts.onLogout(() => {
+		interestedUserIds.clear();
+	});
 });
 
 Template.userPresence.onRendered(function() {
@@ -95,7 +106,4 @@ Template.userPresence.onRendered(function() {
 	if (featureExists) {
 		return observer.observe(this.firstNode);
 	}
-
-	get(this.data.uid);
-	getAll();
 });

imports/startup/client/listenActiveUsers.js

@@ -1,8 +1,7 @@
 import { Meteor } from 'meteor/meteor';
-import { debounce } from 'underscore';
+import { Accounts } from 'meteor/accounts-base';
 
 import { Notifications } from '../../../app/notifications/client';
-import { APIClient } from '../../../app/utils/client';
 
 // mirror of object in /imports/users-presence/server/activeUsers.js - keep updated
 const STATUS_MAP = [
@@ -12,13 +11,18 @@ const STATUS_MAP = [
 	'busy',
 ];
 
+export const interestedUserIds = new Set();
+
 export const saveUser = (user, force = false) => {
 	// do not update my own user, my user's status will come from a subscription
-	if (user._id === Meteor.userId()) {
+	if (user._id === Accounts.connection?._userId) {
 		return;
 	}
-	if (force) {
-		return Meteor.users.upsert({ _id: user._id }, {
+
+	const found = Meteor.users._collection._docs._map[user._id];
+
+	if (found && force) {
+		return Meteor.users.update({ _id: user._id }, {
 			$set: {
 				username: user.username,
 				// name: user.name,
@@ -30,66 +34,17 @@ export const saveUser = (user, force = false) => {
 		});
 	}
 
-	const found = Meteor.users.findOne(user._id, { fields: { _id: 1 } });
-	if (found) {
-		return;
+	if (!found) {
+		Meteor.users.insert(user);
 	}
-
-	Meteor.users.insert(user);
 };
 
-let lastStatusChange = null;
-let retry = 0;
-const getUsersPresence = debounce(async (isConnected) => {
-	try {
-		const params = {};
-
-		if (lastStatusChange) {
-			params.from = lastStatusChange.toISOString();
-		}
-
-		const {
-			users,
-			full,
-		} = await APIClient.v1.get('users.presence', params);
-
-		// if is reconnecting, set everyone else to offline
-		if (full && isConnected) {
-			Meteor.users.update({
-				_id: { $ne: Meteor.userId() },
-			}, {
-				$set: {
-					status: 'offline',
-				},
-			}, { multi: true });
-		}
-
-		users.forEach((user) => saveUser(user, full));
-
-		lastStatusChange = new Date();
-	} catch (e) {
-		setTimeout(() => getUsersPresence(isConnected), retry++ * 2000);
-	}
-}, 1000);
-
 Meteor.startup(function() {
 	Notifications.onLogged('user-status', ([_id, username, status, statusText]) => {
-		// only set after first request completed
-		if (lastStatusChange) {
-			lastStatusChange = new Date();
+		if (!interestedUserIds.has(_id)) {
+			return;
 		}
 
 		saveUser({ _id, username, status: STATUS_MAP[status], statusText }, true);
 	});
-
-	Notifications.onLogged('Users:NameChanged', ({ _id, username }) => {
-		if (!username) {
-			return;
-		}
-		Meteor.users.upsert({ _id }, {
-			$set: {
-				username,
-			},
-		});
-	});
 });