First working version. Just a POC.

1 files changed, 35 insertions, 0 deletions

diff --git a/common/retry.go b/common/retry.go
new file mode 100644
index 0000000..6b97ff3
--- /dev/null
+++ b/common/retry.go
@@ -0,0 +1,35 @@
+package common
+
+import (
+	"log"
+	"time"
+)
+
+// AutoRetry retries the supplier automatically, with given time limit and interval.
+// If maximum retry time limit is reached and the supplier still fails,
+// the last error will be returned.
+// If logger is not nil, retry information will be printed to it.
+func AutoRetry[T any](
+	supplier func() (T, error),
+	maxRetryTimes int,
+	retryInterval time.Duration,
+	logger *log.Logger) (T, error) {
+	var err error
+	for i := 0; i < maxRetryTimes; i++ {
+		ret, err := supplier()
+		if err != nil {
+			if logger != nil {
+				logger.Printf("Try %v/%v (sleep %vs): %v\n",
+					i, maxRetryTimes, retryInterval, err)
+			}
+			time.Sleep(retryInterval)
+			continue
+		}
+		// success
+		return ret, nil
+	}
+	if logger != nil {
+		logger.Printf("Max retry times reached, but it still fails. Last error: %v", err)
+	}
+	return *new(T), err
+}