Improve loading speed of desktop app (#4865)

# Description of Changes Improve loading speed of desktop app by loading a default config until the backend has spawned.
2026-07-16 11:23:10 +02:00 · 2025-11-11 11:54:43 +00:00
parent 4d349c047b
commit 044bf3c2aa
21 changed files with 622 additions and 137 deletions
@@ -0,0 +1,125 @@
+import i18n from '@app/i18n';
+import { tauriBackendService } from '@app/services/tauriBackendService';
+import type { BackendHealthState } from '@app/types/backendHealth';
+
+type Listener = (state: BackendHealthState) => void;
+
+class BackendHealthMonitor {
+  private listeners = new Set<Listener>();
+  private intervalId: ReturnType<typeof setInterval> | null = null;
+  private readonly intervalMs: number;
+  private state: BackendHealthState = {
+    status: tauriBackendService.getBackendStatus(),
+    isChecking: false,
+    error: null,
+    isHealthy: tauriBackendService.getBackendStatus() === 'healthy',
+  };
+
+  constructor(pollingInterval = 5000) {
+    this.intervalMs = pollingInterval;
+
+    // Reflect status updates from the backend service immediately
+    tauriBackendService.subscribeToStatus((status) => {
+      this.updateState({
+        status,
+        error: status === 'healthy' ? null : this.state.error,
+        message: status === 'healthy'
+          ? i18n.t('backendHealth.online', 'Backend Online')
+          : this.state.message ?? i18n.t('backendHealth.offline', 'Backend Offline'),
+        isChecking: status === 'healthy' ? false : this.state.isChecking,
+      });
+    });
+  }
+
+  private updateState(partial: Partial<BackendHealthState>) {
+    const nextStatus = partial.status ?? this.state.status;
+    this.state = {
+      ...this.state,
+      ...partial,
+      status: nextStatus,
+      isHealthy: nextStatus === 'healthy',
+    };
+    this.listeners.forEach((listener) => listener(this.state));
+  }
+
+  private ensurePolling() {
+    if (this.intervalId !== null) {
+      return;
+    }
+    void this.pollOnce();
+    this.intervalId = setInterval(() => {
+      void this.pollOnce();
+    }, this.intervalMs);
+  }
+
+  private stopPolling() {
+    if (this.intervalId) {
+      clearInterval(this.intervalId);
+      this.intervalId = null;
+    }
+  }
+
+  private async pollOnce(): Promise<boolean> {
+    this.updateState({
+      isChecking: true,
+      lastChecked: Date.now(),
+      error: this.state.error ?? 'Backend offline',
+    });
+
+    try {
+      const healthy = await tauriBackendService.checkBackendHealth();
+      if (healthy) {
+        this.updateState({
+          status: 'healthy',
+          isChecking: false,
+          message: i18n.t('backendHealth.online', 'Backend Online'),
+          error: null,
+          lastChecked: Date.now(),
+        });
+      } else {
+        this.updateState({
+          status: 'unhealthy',
+          isChecking: false,
+          message: i18n.t('backendHealth.offline', 'Backend Offline'),
+          error: i18n.t('backendHealth.offline', 'Backend Offline'),
+          lastChecked: Date.now(),
+        });
+      }
+      return healthy;
+    } catch (error) {
+      console.error('[BackendHealthMonitor] Health check failed:', error);
+      this.updateState({
+        status: 'unhealthy',
+        isChecking: false,
+        message: 'Backend is unavailable',
+        error: 'Backend offline',
+        lastChecked: Date.now(),
+      });
+      return false;
+    }
+  }
+
+  subscribe(listener: Listener): () => void {
+    this.listeners.add(listener);
+    listener(this.state);
+    if (this.listeners.size === 1) {
+      this.ensurePolling();
+    }
+    return () => {
+      this.listeners.delete(listener);
+      if (this.listeners.size === 0) {
+        this.stopPolling();
+      }
+    };
+  }
+
+  getSnapshot(): BackendHealthState {
+    return this.state;
+  }
+
+  async checkNow(): Promise<boolean> {
+    return this.pollOnce();
+  }
+}
+
+export const backendHealthMonitor = new BackendHealthMonitor();