1 files changed, 89 insertions, 0 deletions
diff --git a/src/pybind/mgr/dashboard/frontend/src/app/shared/services/summary.service.ts b/src/pybind/mgr/dashboard/frontend/src/app/shared/services/summary.service.ts
new file mode 100644
index 000000000..f8282ae97
--- /dev/null
+++ b/src/pybind/mgr/dashboard/frontend/src/app/shared/services/summary.service.ts
@@ -0,0 +1,89 @@
+import { HttpClient } from '@angular/common/http';
+import { Injectable } from '@angular/core';
+
+import _ from 'lodash';
+import { BehaviorSubject, Observable, Subscription } from 'rxjs';
+import { filter, first } from 'rxjs/operators';
+
+import { ExecutingTask } from '../models/executing-task';
+import { Summary } from '../models/summary.model';
+import { TimerService } from './timer.service';
+
+@Injectable({
+  providedIn: 'root'
+})
+export class SummaryService {
+  readonly REFRESH_INTERVAL = 5000;
+  // Observable sources
+  private summaryDataSource = new BehaviorSubject<Summary>(null);
+  // Observable streams
+  summaryData$ = this.summaryDataSource.asObservable();
+
+  constructor(private http: HttpClient, private timerService: TimerService) {}
+
+  startPolling(): Subscription {
+    return this.timerService
+      .get(() => this.retrieveSummaryObservable(), this.REFRESH_INTERVAL)
+      .subscribe(this.retrieveSummaryObserver());
+  }
+
+  refresh(): Subscription {
+    return this.retrieveSummaryObservable().subscribe(this.retrieveSummaryObserver());
+  }
+
+  private retrieveSummaryObservable(): Observable<Summary> {
+    return this.http.get<Summary>('api/summary');
+  }
+
+  private retrieveSummaryObserver(): (data: Summary) => void {
+    return (data: Summary) => {
+      this.summaryDataSource.next(data);
+    };
+  }
+
+  /**
+   * Subscribes to the summaryData and receive only the first, non undefined, value.
+   */
+  subscribeOnce(next: (summary: Summary) => void, error?: (error: any) => void): Subscription {
+    return this.summaryData$
+      .pipe(
+        filter((value) => !!value),
+        first()
+      )
+      .subscribe(next, error);
+  }
+
+  /**
+   * Subscribes to the summaryData,
+   * which is updated periodically or when a new task is created.
+   * Will receive only non undefined values.
+   */
+  subscribe(next: (summary: Summary) => void, error?: (error: any) => void): Subscription {
+    return this.summaryData$.pipe(filter((value) => !!value)).subscribe(next, error);
+  }
+
+  /**
+   * Inserts a newly created task to the local list of executing tasks.
+   * After that, it will automatically push that new information
+   * to all subscribers.
+   */
+  addRunningTask(task: ExecutingTask) {
+    const current = this.summaryDataSource.getValue();
+    if (!current) {
+      return;
+    }
+
+    if (_.isArray(current.executing_tasks)) {
+      const exists = current.executing_tasks.find((element: any) => {
+        return element.name === task.name && _.isEqual(element.metadata, task.metadata);
+      });
+      if (!exists) {
+        current.executing_tasks.push(task);
+      }
+    } else {
+      current.executing_tasks = [task];
+    }
+
+    this.summaryDataSource.next(current);
+  }
+}