viirya commented on code in PR #3021: URL: https://github.com/apache/arrow-rs/pull/3021#discussion_r1014754383
########## arrow-cast/src/cast.rs: ########## @@ -344,16 +344,61 @@ fn cast_floating_point_to_decimal128<T: ArrowPrimitiveType>( array: &PrimitiveArray<T>, precision: u8, scale: u8, + cast_options: &CastOptions, ) -> Result<ArrayRef, ArrowError> where <T as ArrowPrimitiveType>::Native: AsPrimitive<f64>, { let mul = 10_f64.powi(scale as i32); - array - .unary::<_, Decimal128Type>(|v| (v.as_() * mul).round() as i128) - .with_precision_and_scale(precision, scale) - .map(|a| Arc::new(a) as ArrayRef) + if cast_options.safe { + let iter = array.iter().map(|v| { + v.and_then(|v| { + let mul_v = (mul * v.as_()).round(); + if mul_v == f64::INFINITY || mul_v == f64::NEG_INFINITY { + None + } else { + Some(mul_v as i128) + } + }) + }); + let casted_array = + unsafe { PrimitiveArray::<Decimal128Type>::from_trusted_len_iter(iter) }; + casted_array + .with_precision_and_scale(precision, scale) + .map(|a| Arc::new(a) as ArrayRef) + } else { + array + .try_unary::<_, Decimal128Type, _>(|v| { + mul.mul_checked(v.as_()).and_then(|value| { + let mul_v = value.round(); + if mul_v == f64::INFINITY || mul_v == f64::NEG_INFINITY { + Err(ArrowError::CastError(format!( + "Cannot cast to {}({}, {}). Overflowing on {:?}", + Decimal128Type::PREFIX, + precision, + scale, + v + ))) + } else { + let integer = mul_v as i128; + if integer == i128::MAX || integer == i128::MIN { Review Comment: Do you think we need to implement `From<f64>` for i128? ``` error[E0277]: the trait bound `i128: From<f64>` is not satisfied ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org