fix: memory leak caused by many unclosed redis subscriptions (#750)

* fix: memory leak caused by many unclosed redis subscriptions

* chore: address pull request feedback

packages/api/src/router/cron-jobs.ts

@@ -21,21 +21,22 @@ export const cronJobsRouter = createTRPCRouter({
   }),
   subscribeToStatusUpdates: publicProcedure.subscription(() => {
     return observable<TaskStatus>((emit) => {
-      let isConnectionClosed = false;
+      const unsubscribes: (() => void)[] = [];
 
       for (const job of jobGroup.getJobRegistry().values()) {
         const channel = createCronJobStatusChannel(job.name);
-        channel.subscribe((data) => {
-          if (isConnectionClosed) return;
-
+        const unsubscribe = channel.subscribe((data) => {
           emit.next(data);
         });
+        unsubscribes.push(unsubscribe);
       }
 
       logger.info("A tRPC client has connected to the cron job status updates procedure");
 
       return () => {
-        isConnectionClosed = true;
+        unsubscribes.forEach((unsubscribe) => {
+          unsubscribe();
+        });
       };
     });
   }),

packages/api/src/router/log.ts

@@ -9,16 +9,13 @@ import { createTRPCRouter, publicProcedure } from "../trpc";
 export const logRouter = createTRPCRouter({
   subscribe: publicProcedure.subscription(() => {
     return observable<LoggerMessage>((emit) => {
-      let isConnectionClosed = false;
-
-      loggingChannel.subscribe((data) => {
-        if (isConnectionClosed) return;
+      const unsubscribe = loggingChannel.subscribe((data) => {
         emit.next(data);
       });
       logger.info("A tRPC client has connected to the logging procedure");
 
       return () => {
-        isConnectionClosed = true;
+        unsubscribe();
       };
     });
   }),

packages/api/src/router/widgets/app.ts

@@ -27,19 +27,15 @@ export const appRouter = createTRPCRouter({
       const pingResult = await sendPingRequestAsync(input.url);
 
       return observable<{ url: string; statusCode: number } | { url: string; error: string }>((emit) => {
-        let isConnectionClosed = false;
-
         emit.next({ url: input.url, ...pingResult });
-        pingChannel.subscribe((message) => {
-          if (isConnectionClosed) return;
-
+        const unsubscribe = pingChannel.subscribe((message) => {
           // Only emit if same url
           if (message.url !== input.url) return;
           emit.next(message);
         });
 
         return () => {
-          isConnectionClosed = true;
+          unsubscribe();
           void pingUrlChannel.removeAsync(input.url);
         };
       });

packages/api/src/router/widgets/media-server.ts

@@ -25,20 +25,21 @@ export const mediaServerRouter = createTRPCRouter({
     .unstable_concat(createManyIntegrationMiddleware("jellyfin", "plex"))
     .subscription(({ ctx }) => {
       return observable<{ integrationId: string; data: StreamSession[] }>((emit) => {
-        let isConnectionClosed = false;
-
+        const unsubscribes: (() => void)[] = [];
         for (const integration of ctx.integrations) {
           const channel = createItemAndIntegrationChannel<StreamSession[]>("mediaServer", integration.id);
-          void channel.subscribeAsync((sessions) => {
-            if (isConnectionClosed) return;
+          const unsubscribe = channel.subscribe((sessions) => {
             emit.next({
               integrationId: integration.id,
               data: sessions,
             });
           });
+          unsubscribes.push(unsubscribe);
         }
         return () => {
-          isConnectionClosed = true;
+          unsubscribes.forEach((unsubscribe) => {
+            unsubscribe();
+          });
         };
       });
     }),

packages/api/src/router/widgets/smart-home.ts

@@ -13,10 +13,7 @@ export const smartHomeRouter = createTRPCRouter({
       entityId: string;
       state: string;
     }>((emit) => {
-      let isConnectionClosed = false;
-
-      homeAssistantEntityState.subscribe((message) => {
-        if (isConnectionClosed) return;
+      const unsubscribe = homeAssistantEntityState.subscribe((message) => {
         if (message.entityId !== input.entityId) {
           return;
         }
@@ -24,7 +21,7 @@ export const smartHomeRouter = createTRPCRouter({
       });
 
       return () => {
-        isConnectionClosed = true;
+        unsubscribe();
       };
     });
   }),