add `retry.Do0` (#12194)

* add retry.Do0

* update code to use Do0

op-node/node/conductor.go

@@ -91,12 +91,11 @@ func (c *ConductorClient) CommitUnsafePayload(ctx context.Context, payload *eth.
 	ctx, cancel := context.WithTimeout(ctx, c.cfg.ConductorRpcTimeout)
 	defer cancel()
 
-	// extra bool return value is required for the generic, can be ignored.
-	_, err := retry.Do(ctx, 2, retry.Fixed(50*time.Millisecond), func() (bool, error) {
+	err := retry.Do0(ctx, 2, retry.Fixed(50*time.Millisecond), func() error {
 		record := c.metrics.RecordRPCClientRequest("conductor_commitUnsafePayload")
 		err := c.apiClient.CommitUnsafePayload(ctx, payload)
 		record(err)
-		return true, err
+		return err
 	})
 	return err
 }

op-node/node/node.go

@@ -262,12 +262,12 @@ func (n *OpNode) initRuntimeConfig(ctx context.Context, cfg *Config) error {
 	}
 
 	// initialize the runtime config before unblocking
-	if _, err := retry.Do(ctx, 5, retry.Fixed(time.Second*10), func() (eth.L1BlockRef, error) {
-		ref, err := reload(ctx)
+	if err := retry.Do0(ctx, 5, retry.Fixed(time.Second*10), func() error {
+		_, err := reload(ctx)
 		if errors.Is(err, errNodeHalt) { // don't retry on halt error
 			err = nil
 		}
-		return ref, err
+		return err
 	}); err != nil {
 		return fmt.Errorf("failed to load runtime configuration repeatedly, last error: %w", err)
 	}

op-service/retry/operation.go

@@ -40,25 +40,38 @@ func Do2[T, U any](ctx context.Context, maxAttempts int, strategy Strategy, op f
 // Strategy.
 func Do[T any](ctx context.Context, maxAttempts int, strategy Strategy, op func() (T, error)) (T, error) {
 	var empty, ret T
+	f := func() (err error) {
+		ret, err = op()
+		return
+	}
+	err := Do0(ctx, maxAttempts, strategy, f)
+	if err != nil {
+		return empty, err
+	}
+	return ret, err
+}
+
+// Do0 is similar to Do and Do2, execept that `op` only returns an error
+func Do0(ctx context.Context, maxAttempts int, strategy Strategy, op func() error) error {
 	var err error
 	if maxAttempts < 1 {
-		return empty, fmt.Errorf("need at least 1 attempt to run op, but have %d max attempts", maxAttempts)
+		return fmt.Errorf("need at least 1 attempt to run op, but have %d max attempts", maxAttempts)
 	}
 
 	for i := 0; i < maxAttempts; i++ {
 		if ctx.Err() != nil {
-			return empty, ctx.Err()
+			return ctx.Err()
 		}
-		ret, err = op()
+		err = op()
 		if err == nil {
-			return ret, nil
+			return nil
 		}
 		// Don't sleep when we are about to exit the loop & return ErrFailedPermanently
 		if i != maxAttempts-1 {
 			time.Sleep(strategy.Duration(i))
 		}
 	}
-	return empty, &ErrFailedPermanently{
+	return &ErrFailedPermanently{
 		attempts: maxAttempts,
 		LastErr:  err,
 	}