Add example for exponential backoff

autopaho/examples/backoff/backoff.go

@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2024 Contributors to the Eclipse Foundation
+ *
+ *  All rights reserved. This program and the accompanying materials
+ *  are made available under the terms of the Eclipse Public License v2.0
+ *  and Eclipse Distribution License v1.0 which accompany this distribution.
+ *
+ * The Eclipse Public License is available at
+ *    https://www.eclipse.org/legal/epl-2.0/
+ *  and the Eclipse Distribution License is available at
+ *    http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ *  SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package main
+
+import (
+	"fmt"
+	"math"
+
+	"github.com/eclipse/paho.golang/autopaho"
+)
+
+func main() {
+	// used to calculate the number of iterations
+	const interationBase = 1
+
+	backoffStrategy := autopaho.DefaultExponentialBackoffStrategy()
+
+	backoff := backoffStrategy.Backoff()
+
+	minBackoff := int64(math.MaxInt64)
+	maxBackoff := int64(0)
+	iterationsTotal := 0
+	for i := 0; i < 22; i++ {
+		iterations := interationBase << i
+		for j := 0; j < iterations; j++ {
+			backoffTime := backoff.Next().Milliseconds()
+			if backoffTime < minBackoff {
+				minBackoff = backoffTime
+			}
+			if backoffTime > maxBackoff {
+				maxBackoff = backoffTime
+			}
+		}
+		iterationsTotal += iterations
+
+		fmt.Printf("After % 8d iterations, min: %d, max: % 7d\n", iterationsTotal, minBackoff, maxBackoff)
+	}
+}