lnrpc: extract fee limit calculation

rpcserver.go

@@ -2908,27 +2908,6 @@ type rpcPaymentRequest struct {
 	route *route.Route
 }
 
-// calculateFeeLimit returns the fee limit in millisatoshis. If a percentage
-// based fee limit has been requested, we'll factor in the ratio provided with
-// the amount of the payment.
-func calculateFeeLimit(feeLimit *lnrpc.FeeLimit,
-	amount lnwire.MilliSatoshi) lnwire.MilliSatoshi {
-
-	switch feeLimit.GetLimit().(type) {
-	case *lnrpc.FeeLimit_Fixed:
-		return lnwire.NewMSatFromSatoshis(
-			btcutil.Amount(feeLimit.GetFixed()),
-		)
-	case *lnrpc.FeeLimit_Percent:
-		return amount * lnwire.MilliSatoshi(feeLimit.GetPercent()) / 100
-	default:
-		// If a fee limit was not specified, we'll use the payment's
-		// amount as an upper bound in order to avoid payment attempts
-		// from incurring fees higher than the payment amount itself.
-		return amount
-	}
-}
-
 // SendPayment dispatches a bi-directional streaming RPC for sending payments
 // through the Lightning Network. A single RPC invocation creates a persistent
 // bi-directional stream allowing clients to rapidly send payments through the
@@ -3114,7 +3093,7 @@ func extractPaymentIntent(rpcPayReq *rpcPaymentRequest) (rpcPaymentIntent, error
 		}
 
 		// Calculate the fee limit that should be used for this payment.
-		payIntent.feeLimit = calculateFeeLimit(
+		payIntent.feeLimit = lnrpc.CalculateFeeLimit(
 			rpcPayReq.FeeLimit, payIntent.msat,
 		)
 
@@ -3154,7 +3133,7 @@ func extractPaymentIntent(rpcPayReq *rpcPaymentRequest) (rpcPaymentIntent, error
 	)
 
 	// Calculate the fee limit that should be used for this payment.
-	payIntent.feeLimit = calculateFeeLimit(
+	payIntent.feeLimit = lnrpc.CalculateFeeLimit(
 		rpcPayReq.FeeLimit, payIntent.msat,
 	)