privval: migrate to protobuf (#4985)

libs/math/safemath.go

@@ -7,6 +7,7 @@ import (
 
 var ErrOverflowInt32 = errors.New("int32 overflow")
 var ErrOverflowUint8 = errors.New("uint8 overflow")
+var ErrOverflowInt8 = errors.New("int8 overflow")
 
 // SafeAddInt32 adds two int32 integers
 // If there is an overflow this will panic
@@ -51,3 +52,14 @@ func SafeConvertUint8(a int64) (uint8, error) {
 	}
 	return uint8(a), nil
 }
+
+// SafeConvertInt8 takes an int64 and checks if it overflows
+// If there is an overflow it returns an error
+func SafeConvertInt8(a int64) (int8, error) {
+	if a > math.MaxInt8 {
+		return 0, ErrOverflowInt8
+	} else if a < math.MinInt8 {
+		return 0, ErrOverflowInt8
+	}
+	return int8(a), nil
+}