up

src/lib/schedule.ts

@@ -0,0 +1,57 @@
+class SimpleSchedule {
+
+    private task_is_running: boolean;
+    private taskCaller: () => Promise<any>;
+    private trackInterval: NodeJS.Timeout | null;
+    private checkInterval: number; //default
+
+    constructor(taskFn: () => Promise<any>, checkInterval: number = 5) {
+        this.taskCaller = taskFn;
+        this.task_is_running = false;
+        this.trackInterval = null;
+        this.checkInterval = checkInterval;
+    }
+
+    start = () => {
+        console.log(`Schedule ${this.taskCaller.name} started at ${this.timeNow()}`);
+
+        this.trackInterval = setInterval(async () => {
+            // flag for long-running task so another instance wont start
+            if(this.task_is_running) {
+                console.log(`Task ${this.taskCaller.name} is still running. Check time ${this.timeNow()}`);
+                return;
+            }
+
+            this.task_is_running = true;
+            console.log(`OK invoke ${this.taskCaller.name} at ${this.timeNow()}`);
+            await this.taskCaller();
+            this.task_is_running = false;
+        }, this.checkInterval * 1000 );
+    }
+
+    getInterval = (): number => this.checkInterval;
+
+    changeInterval = (new_interval: number) => {
+        if(new_interval === this.checkInterval) {
+            return; // nothing change!
+        }
+
+        // remove running
+        if(this.trackInterval) clearInterval(this.trackInterval);
+
+        // set and start
+        this.checkInterval = new_interval;
+        this.start();
+    }
+
+    stop = () => {
+        console.log(`Schedule ${this.taskCaller.name} stoped at ${this.timeNow()}`);
+        if(this.trackInterval) clearInterval(this.trackInterval);
+    }
+
+    timeNow = () => {
+        return Math.floor(Date.now() / 1000);
+    }
+}
+
+export default SimpleSchedule;