Allow for performance monitoring

src/pushMonitor.ts

@@ -1,4 +1,4 @@
-import { sendHeartbeat, sendShutdownNotification } from "./requestHandler";
+import { sendHeartbeat, sendDownNotification } from "./requestHandler";
 
 /**
  * Defines an uptime kuma monitor
@@ -64,6 +64,12 @@ export class PushMonitor {
      */
     private _debug: boolean = false;
 
+    /**
+     * Performance measurment function
+     * @private
+     */
+    private _performance: (() => (Promise<number> | number)) | undefined;
+
     /**
      * Returns the singleton instance of the PushMonitor
      */
@@ -103,7 +109,7 @@ export class PushMonitor {
                 url,
                 heartbeatIntervall,
             },
-            lastHeartbeat: new Date(0),
+            lastHeartbeat: new Date(new Date().getTime() + 10000 - heartbeatIntervall * 1000),
         });
         return this;
     }
@@ -128,6 +134,16 @@ export class PushMonitor {
         return this;
     }
 
+    /**
+     * Sets the performance handler
+     * @param handler The performance handler
+     * @returns This instance
+     */
+    public setPerformanceHandler(handler?: () => (Promise<number> | number)): this {
+        this._performance = handler;
+        return this;
+    }
+
     /**
      * Initializes the timer
      * @private
@@ -137,13 +153,29 @@ export class PushMonitor {
             clearInterval(this._checkInterval);
         }
 
-        this._checkInterval = setInterval(() => {
-            this._monitors.forEach((monitor) => {
-                if (new Date().getTime() - monitor.lastHeartbeat.getTime() > monitor.monitor.heartbeatIntervall * 1000) {
-                    sendHeartbeat(monitor.monitor.url, this._debug);
-                    monitor.lastHeartbeat = new Date();
-                }
-            });
+        let isRunning = false;
+
+        this._checkInterval = setInterval(async () => {
+            if (isRunning) return;
+            isRunning = true;
+
+            try {
+                let performance: number | undefined = undefined;
+
+                if (this._performance) performance = await this._performance();
+
+                this._monitors.forEach((monitor) => {
+                    if (new Date().getTime() - monitor.lastHeartbeat.getTime() > monitor.monitor.heartbeatIntervall * 1000) {
+                        sendHeartbeat(monitor.monitor.url, performance, this._debug);
+                        monitor.lastHeartbeat = new Date();
+                    }
+                });
+            } catch (error) {
+                console.error(`[eu.astrogd.uptime-kuma-push-monitor] (${new Date().toISOString()}) <internal.interval>: ${error}`);
+            }
+
+
+            isRunning = false;
         }, 1000);
     }
 
@@ -168,7 +200,7 @@ export class PushMonitor {
         const promises: Promise<void>[] = [];
 
         this._monitors.forEach((monitor) => {
-            promises.push(sendShutdownNotification(monitor.monitor.url, msg, this._debug));
+            promises.push(sendDownNotification(monitor.monitor.url, msg, this._debug));
         });
 
         return Promise.all(promises);