Fixes multiple client connection data freshness.

src/lib/server/dataPolling.ts

@@ -3,8 +3,7 @@ import { getServiceRecord } from '$lib/services/services';
 import { readable } from 'svelte/store';
 import { serverConfig } from './config';
 import { rootLogger } from './logger';
-
-export type MayAsyncServiceData = Partial<ServiceData> | Promise<Partial<ServiceData>>;
+import type { Unsubscriber } from 'svelte/motion';
 
 const logger = rootLogger.child({ name: 'ServiceData' });
 
@@ -14,15 +13,22 @@ export interface ServiceDataEvent {
 	data: ServiceData;
 }
 
-export const serviceDataEvents = readable<ServiceDataEvent>(undefined, (set) => {
+export function subscribeToDataEvent(onEvent: (event: ServiceDataEvent) => void): Unsubscriber {
+	for (const [group, items] of serviceData.entries()) {
+		for (const [item, data] of items.entries()) {
+			onEvent({ group, item, data: data as ServiceData });
+		}
+	}
+	return serviceDataEvents.subscribe(onEvent);
+}
+
+const serviceDataEvents = readable<ServiceDataEvent>(undefined, (set) => {
 	logger.debug({ interval: pollInterval }, 'starting polling loop');
 
 	pushServiceData = set;
 
-	if (serviceData.length == 0) {
-		logger.debug('polling for initial state');
-		pollAllServices();
-	}
+	logger.debug('polling for initial state');
+	pollAllServices();
 	const timer = setInterval(() => {
 		logger.debug('polling for service update');
 		pollAllServices();
@@ -47,9 +53,9 @@ let pushServiceData: ((value: ServiceDataEvent) => void) | undefined = undefined
 
 const pollInterval = 30000;
 
-let serviceData: Array<Array<MayAsyncServiceData>> = [];
+let serviceData: Array<Array<Partial<ServiceData>>> = [];
 
-function pollAllServices(): Array<Array<MayAsyncServiceData>> {
+function pollAllServices() {
 	logger.trace('pollAllServices()');
 	const config = serverConfig();
 
@@ -61,7 +67,8 @@ function pollAllServices(): Array<Array<MayAsyncServiceData>> {
 		for (const [idxItem, service] of group.items.entries()) {
 			const poller: ServicePoller = getServiceRecord(service.type || '').poll;
 			const serviceLogger = logger.child({ group: idxGroup, item: idxItem, service });
-			serviceData[idxGroup][idxItem] = poller(service)
+			serviceData[idxGroup][idxItem] = {};
+			poller(service)
 				.then((data: ServiceData) => {
 					serviceLogger.trace({ data }, 'pollAllService:result()');
 					serviceData[idxGroup][idxItem] = data;
@@ -76,6 +83,4 @@ function pollAllServices(): Array<Array<MayAsyncServiceData>> {
 				});
 		}
 	}
-
-	return serviceData;
 }

src/routes/api/updates/+server.ts

@@ -1,5 +1,5 @@
-import { serviceDataEvents } from '$lib/server/dataPolling';
-import { requestLogger, rootLogger } from '$lib/server/logger';
+import { subscribeToDataEvent } from '$lib/server/dataPolling';
+import { requestLogger } from '$lib/server/logger';
 import type { RequestHandler } from '@sveltejs/kit';
 import type { Unsubscriber } from 'svelte/store';
 
@@ -17,7 +17,7 @@ export const GET: RequestHandler = ({ getClientAddress }) => {
 		start: (controller) => {
 			logger.info('new update request stream started');
 
-			unsubscribe = serviceDataEvents.subscribe((event) => {
+			unsubscribe = subscribeToDataEvent((event) => {
 				logger.trace({ event: event }, 'sending new event');
 				const data = `event:message\ndata:${JSON.stringify(event)}\n\n`;
 				controller.enqueue(data);