fix: download event not updated in client

Author: namchuai

cortex-js/src/app.module.ts

@@ -15,8 +15,8 @@ import { SeedService } from './usecases/seed/seed.service';
 import { FileManagerModule } from './infrastructure/services/file-manager/file-manager.module';
 import { AppLoggerMiddleware } from './infrastructure/middlewares/app.logger.middleware';
 import { EventEmitterModule } from '@nestjs/event-emitter';
-import { AppController } from './infrastructure/controllers/app.controller';
 import { DownloadManagerModule } from './download-manager/download-manager.module';
+import { EventsController } from './infrastructure/controllers/events.controller';
 
 @Module({
   imports: [
@@ -40,7 +40,7 @@ import { DownloadManagerModule } from './download-manager/download-manager.modul
     ModelRepositoryModule,
     DownloadManagerModule,
   ],
-  controllers: [AppController],
+  controllers: [EventsController],
   providers: [SeedService],
 })
 export class AppModule implements NestModule {

cortex-js/src/download-manager/download-manager.service.ts

@@ -19,12 +19,7 @@ export class DownloadManagerService {
   constructor(
     private readonly httpService: HttpService,
     private readonly eventEmitter: EventEmitter2,
-  ) {
-    // start emitting download state each 500ms
-    // setInterval(() => {
-    //   this.eventEmitter.emit('download.event', this.allDownloadStates);
-    // }, 500);
-  }
+  ) {}
 
   async abortDownload(downloadId: string) {
     if (!this.abortControllers[downloadId]) {
@@ -37,6 +32,7 @@ export class DownloadManagerService {
     this.allDownloadStates = this.allDownloadStates.filter(
       (downloadState) => downloadState.id !== downloadId,
     );
+    this.eventEmitter.emit('download.event.aborted', this.allDownloadStates);
   }
 
   async submitDownloadRequest(
@@ -160,6 +156,7 @@ export class DownloadManagerService {
           (downloadState) => downloadState.id !== downloadId,
         );
       }
+      this.eventEmitter.emit('download.event', this.allDownloadStates);
     });
 
     writer.on('error', (error) => {
@@ -186,6 +183,7 @@ export class DownloadManagerService {
       this.allDownloadStates = this.allDownloadStates.filter(
         (downloadState) => downloadState.id !== downloadId,
       );
+      this.eventEmitter.emit('download.event', this.allDownloadStates);
     });
 
     response.data.on('data', (chunk: any) => {
@@ -202,8 +200,13 @@ export class DownloadManagerService {
       if (downloadItem) {
         downloadItem.size.transferred = transferredBytes;
       }
+      this.eventEmitter.emit('download.event', this.allDownloadStates);
     });
 
     response.data.pipe(writer);
   }
+
+  getDownloadStates() {
+    return this.allDownloadStates;
+  }
 }

cortex-js/src/infrastructure/controllers/app.controller.ts

@@ -0,0 +1,43 @@
+import {
+  DownloadState,
+  DownloadStateEvent,
+} from '@/domain/models/download.interface';
+import { DownloadManagerService } from '@/download-manager/download-manager.service';
+import { Controller, Sse } from '@nestjs/common';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { Observable, fromEvent, map, merge, of, throttleTime } from 'rxjs';
+
+@Controller('events')
+export class EventsController {
+  constructor(
+    private readonly downloadManagerService: DownloadManagerService,
+    private readonly eventEmitter: EventEmitter2,
+  ) {}
+
+  @Sse('download')
+  downloadEvent(): Observable<DownloadStateEvent> {
+    // Welcome message Observable
+    const latestDownloadState$: Observable<DownloadStateEvent> = of({
+      data: this.downloadManagerService.getDownloadStates(),
+    });
+
+    const downloadAbortEvent$ = fromEvent<DownloadState[]>(
+      this.eventEmitter,
+      'download.event.aborted',
+    ).pipe(map((downloadState) => ({ data: downloadState })));
+
+    const downloadEvent$ = fromEvent<DownloadState[]>(
+      this.eventEmitter,
+      'download.event',
+    ).pipe(
+      map((downloadState) => ({ data: downloadState })),
+      throttleTime(1000),
+    );
+
+    return merge(
+      latestDownloadState$,
+      downloadEvent$,
+      downloadAbortEvent$,
+    ).pipe();
+  }
+}