Rework periodic tasks

Author: dshil

app.tsx

@@ -1,8 +1,7 @@
 import { Component } from "preact";
 
-import { Notificator } from "./src/lib/system/notificator";
-import { NotificationDispatcher } from "./src/lib/system/notification_dispatcher";
-import { NotificationComponent } from "./src/ui/preact/notification_component";
+import { Notificator } from "@device-ui/lib/system/notificator";
+import { NotificationDispatcher } from "@device-ui/lib/system/notification_dispatcher";
 
 import {
   AlertArrayQueue,
@@ -11,28 +10,32 @@ import {
   ConfirmMonitorNotificationQueue,
   AlertLimitNotificationQueue,
   ConfirmLimitNotificationQueue,
-} from "./src/lib/system/notification_types";
+} from "@device-ui/lib/system/notification_types";
 
-import { NotificationModality } from "./src/lib/system/notification";
+import { NotificationModality } from "@device-ui/lib/system/notification";
 
-import { SystemClock } from "./src/lib/system/system_clock";
-import { LocalSystemClock } from "./src/lib/system/local_system_clock";
+import { SystemClock } from "@device-ui/lib/system/system_clock";
+import { LocalSystemClock } from "@device-ui/lib/system/local_system_clock";
 
-import { Fetcher } from "./src/lib/http/fetcher";
-import { Formatter } from "./src/lib/fmt/formatter";
-import { HTTPFetcher } from "./src/lib/http/http_fetcher";
-import { PeriodicDataFetcher } from "./src/lib/device/periodic_data_fetcher";
-import { JSONFormatter } from "./src/lib/fmt/json_formatter";
-import { Config } from "./src/lib/device/config";
-import { HTTPConfig } from "./src/lib/device/http_config";
-import { AnalogSensorComponent } from "./src/ui/preact/sensor/soil/analog_sensor_component";
+import { Formatter } from "@device-ui/lib/fmt/formatter";
+import { HTTPFetcher } from "@device-ui/lib/http/http_fetcher";
+import { DataStore } from "@device-ui/lib/device/data_store";
+import { JSONFormatter } from "@device-ui/lib/fmt/json_formatter";
+import { Config } from "@device-ui/lib/device/config";
+import { HTTPConfig } from "@device-ui/lib/device/http_config";
 
-import { Rebooter } from "./src/lib/device/rebooter";
-import { Locator } from "./src/lib/device/locator";
-import { HTTPRebooter } from "./src/lib/device/http_rebooter";
-import { HTTPLocator } from "./src/lib/device/http_locator";
-import { NavigationComponent } from "./src/ui/preact/navigation_component";
-import { BonsaiLogo } from "./src/ui/preact/logo/bonsai";
+import { Rebooter } from "@device-ui/lib/device/rebooter";
+import { Locator } from "@device-ui/lib/device/locator";
+import { HTTPRebooter } from "@device-ui/lib/device/http_rebooter";
+import { HTTPLocator } from "@device-ui/lib/device/http_locator";
+
+import { PeriodicRunner } from "@device-ui/lib/scheduler/periodic_runner";
+import { FetchRunner } from "@device-ui/lib/http/fetch_runner";
+
+import { NotificationComponent } from "@device-ui/ui/preact/notification_component";
+import { AnalogSensorComponent } from "@device-ui/ui/preact/sensor/soil/analog_sensor_component";
+import { NavigationComponent } from "@device-ui/ui/preact/navigation_component";
+import { BonsaiLogo } from "@device-ui/ui/preact/logo/bonsai";
 
 import { html as helpContent } from "./help.md";
 
@@ -72,13 +75,15 @@ export class App extends Component<appProps, {}> {
     this.deviceRebooter = new HTTPRebooter(`${App.apiBaseURL}/system/reboot`);
     this.deviceLocator = new HTTPLocator(`${App.apiBaseURL}/system/locate`);
 
-    this.telemetryHTTPFetcher = new HTTPFetcher(`${App.apiBaseURL}/telemetry`);
-    this.telemetryFormatter = new JSONFormatter();
+    this.telemetryStore = new DataStore(new JSONFormatter());
 
-    this.telemetryDataFetcher = new PeriodicDataFetcher(
-      this.telemetryHTTPFetcher,
-      this.telemetryFormatter,
-      App.telemetryFetchInterval,
+    this.telemetryRunner = new PeriodicRunner(
+      new FetchRunner(
+        new HTTPFetcher(`${App.apiBaseURL}/telemetry`),
+        this.telemetryStore,
+      ),
+      null,
+      this.telemetryFetchInterval,
     );
 
     this.soilSensorConfig = new HTTPConfig(
@@ -88,11 +93,11 @@ export class App extends Component<appProps, {}> {
   }
 
   async componentDidMount() {
-    this.telemetryDataFetcher.start();
+    this.telemetryRunner.start();
   }
 
   componentWillUnmount() {
-    this.telemetryDataFetcher.stop();
+    this.telemetryRunner.stop();
   }
 
   render() {
@@ -110,8 +115,8 @@ export class App extends Component<appProps, {}> {
           <div className="card-large">
             <AnalogSensorComponent
               title="Soil Moisture"
-              prefix="sensor_soil"
-              fetcher={this.telemetryDataFetcher}
+              prefix="s"
+              store={this.telemetryStore}
               config={this.soilSensorConfig}
               notificator={this.notificationDispatcher}
             />
@@ -139,9 +144,8 @@ export class App extends Component<appProps, {}> {
   private deviceLocator: Locator;
 
   private static readonly telemetryFetchInterval: number = 10 * 1000;
-  private telemetryHTTPFetcher: Fetcher;
-  private telemetryFormatter: Formatter;
-  private telemetryDataFetcher: PeriodicDataFetcher;
+  private telemetryStore: DataStore;
+  private telemetryRunner: PeriodicRunner;
 
   private soilSensorConfig: Config;
 }

src/lib/device/connection_monitor.test.ts

@@ -33,7 +33,7 @@ class TestHolder implements DataHolder {
 }
 
 describe("Connection Monitor", () => {
-  test("Receive invalid timestamp on initialization", () => {
+  test("Receive invalid timestamp on initialization", async () => {
     const threshold: number = 10;
 
     const handler = new TestHandler();
@@ -51,13 +51,13 @@ describe("Connection Monitor", () => {
     expect(handler.connectedCallCount).toBe(0);
     expect(handler.disconnectedCallCount).toBe(0);
 
-    expect(monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
 
     expect(handler.connected).toBe(false);
     expect(handler.connectedCallCount).toBe(0);
     expect(handler.disconnectedCallCount).toBe(0);
   });
-  test("Handle connect-disconnect", () => {
+  test("Handle connect-disconnect", async () => {
     const threshold: number = 10;
 
     const handler = new TestHandler();
@@ -82,31 +82,31 @@ describe("Connection Monitor", () => {
     clock.ts = now;
     monitor.notifyChanged();
 
-    expect(monitor.run()).toBeNull();
-    expect(monitor.run()).toBeNull();
-    expect(monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
 
     expect(handler.connected).toBe(true);
     expect(handler.connectedCallCount).toBe(1);
     expect(handler.disconnectedCallCount).toBe(0);
 
     // Prepare for the disconnection process.
     clock.ts += threshold - 1;
-    expect(monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
     expect(handler.connected).toBe(true);
     expect(handler.connectedCallCount).toBe(1);
     expect(handler.disconnectedCallCount).toBe(0);
 
     // Begin the disconnection process.
     clock.ts += 1;
-    expect(monitor.run()).toBeNull();
-    expect(monitor.run()).toBeNull();
-    expect(monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
     expect(handler.connected).toBe(false);
     expect(handler.connectedCallCount).toBe(1);
     expect(handler.disconnectedCallCount).toBe(1);
   });
-  test("Disconnected after receiving invalid timestamp", () => {
+  test("Disconnected after receiving invalid timestamp", async () => {
     const threshold: number = 10;
 
     const handler = new TestHandler();
@@ -131,15 +131,15 @@ describe("Connection Monitor", () => {
     clock.ts = now;
     monitor.notifyChanged();
 
-    expect(monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
 
     expect(handler.connected).toBe(true);
     expect(handler.connectedCallCount).toBe(1);
     expect(handler.disconnectedCallCount).toBe(0);
 
     // Begin the disconnection process.
     holder.timestamp = -1;
-    expect(monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
     expect(handler.connected).toBe(false);
     expect(handler.connectedCallCount).toBe(1);
     expect(handler.disconnectedCallCount).toBe(1);
@@ -174,7 +174,7 @@ describe("Connection Monitor", () => {
     expect(handler.connectedCallCount).toBe(1);
     expect(handler.disconnectedCallCount).toBe(0);
   });
-  test("Ignore connection status updates on clock error", () => {
+  test("Ignore connection status updates on clock error", async () => {
     const threshold: number = 10;
 
     const handler = new TestHandler();
@@ -205,11 +205,11 @@ describe("Connection Monitor", () => {
     expect(handler.connectedCallCount).toBe(0);
     expect(handler.disconnectedCallCount).toBe(0);
 
-    expect(monitor.run()).toEqual(new Error("invalid timestamp"));
+    expect(await monitor.run()).toStrictEqual(new Error("invalid timestamp"));
 
     clock.error = null;
   });
-  test("Ignore connection status updates when there is no data update timestamp", () => {
+  test("Ignore connection status updates when there is no data update timestamp", async () => {
     const threshold: number = 10;
 
     const handler = new TestHandler();
@@ -240,11 +240,11 @@ describe("Connection Monitor", () => {
     expect(handler.connectedCallCount).toBe(0);
     expect(handler.disconnectedCallCount).toBe(0);
 
-    expect(monitor.run()).toEqual(new Error("invalid timestamp"));
+    expect(await monitor.run()).toStrictEqual(new Error("invalid timestamp"));
 
     clock.error = null;
 
-    expect(monitor.run()).toBeNull();
+    expect(await monitor.run()).toBeNull();
     expect(handler.connected).toBe(false);
     expect(handler.connectedCallCount).toBe(0);
     expect(handler.disconnectedCallCount).toBe(0);

src/lib/device/connection_monitor.ts

@@ -32,13 +32,17 @@ export class ConnectionMonitor implements ObjectMonitor, Runner {
 
     this.timestamp = timestampResult.timestamp;
 
-    const error = this.run();
+    const error = this.update();
     if (error) {
-      console.error(`connection_monitor: failed to run: ${error}`);
+      console.error(`connection_monitor: failed to update: ${error}`);
     }
   }
 
-  run(): Error | null {
+  async run(): Promise<Error | null> {
+    return this.update();
+  }
+
+  private update(): Error | null {
     const timestamp = this.holder.getTimestamp();
     if (timestamp == -1) {
       if (this.connected) {

src/lib/device/periodic_data_fetcher.ts src/lib/device/data_store.tssrc/lib/device/periodic_data_fetcher.ts renamed to src/lib/device/data_store.ts

@@ -3,39 +3,19 @@ import { ArrayQueue } from "@device-ui/lib/core/array_queue";
 import { Formatter } from "@device-ui/lib/fmt/formatter";
 import { Fetcher } from "@device-ui/lib/http/fetcher";
 import { FetchHandler } from "@device-ui/lib/http/fetch_handler";
-import { PeriodicFetcher } from "@device-ui/lib/http/periodic_fetcher";
 import { DataHolder } from "@device-ui/lib/device/data_holder";
 
-// Periodically fetches data from the source.
-export class PeriodicDataFetcher
+// Format received data to key-value pairs.
+export class DataStore
   extends ArrayQueue<ObjectMonitor>
   implements FetchHandler, DataHolder
 {
   // Initialize.
   //
   // @params
-  //  - @p fetcher to fetch actual data.
   //  - @p formatter to format fetched data.
-  //  - @p interval - how often to fetch data.
-  constructor(fetcher: Fetcher, formatter: Formatter, interval: number) {
+  constructor(private formatter: Formatter) {
     super();
-
-    this.formatter = formatter;
-    this.periodicFetcher = new PeriodicFetcher(this, fetcher, interval);
-  }
-
-  // Start fetching data periodically.
-  async start() {
-    this.stopped = false;
-
-    this.periodicFetcher.start();
-  }
-
-  // Stop fetching data periodically.
-  stop() {
-    this.stopped = true;
-
-    this.periodicFetcher.stop();
   }
 
   // Return formated key-value data.
@@ -45,15 +25,9 @@ export class PeriodicDataFetcher
 
   // Notify registered object monitors about new data.
   handleFetched(data: Uint8Array): void {
-    if (this.stopped) {
-      return;
-    }
-
     const result = this.formatter.format(data);
     if (result.error) {
-      console.error(
-        `periodic_data_fetcher: failed to format data: err=${result.error}`,
-      );
+      console.error(`data_handler: failed to format data: err=${result.error}`);
 
       return;
     }
@@ -65,9 +39,5 @@ export class PeriodicDataFetcher
     });
   }
 
-  private formatter: Formatter;
-  private periodicFetcher: PeriodicFetcher;
-
   private data: Record<string, any> | null = null;
-  private stopped: boolean = false;
 }

src/lib/http/fetch_runner.ts

@@ -0,0 +1,27 @@
+import { Runner } from "@device-ui/lib/scheduler/runner";
+import { Fetcher } from "@device-ui/lib/http/fetcher";
+import { FetchHandler } from "@device-ui/lib/http/fetch_handler";
+
+export class FetchRunner implements Runner {
+  // Initialize.
+  //
+  // @params
+  //  - @p handler to notify when data is received from @p fetcher.
+  //  - @p fetcher to fetch the actual data.
+  constructor(
+    private fetcher: Fetcher,
+    private handler: FetchHandler,
+  ) {}
+
+  // Fetch data and notify handler.
+  async run(): Promise<Error | null> {
+    const result = await this.fetcher.fetch();
+    if (result.error) {
+      return result.error;
+    }
+
+    this.handler.handleFetched(result.data!);
+
+    return null;
+  }
+}