Rich-T-kid commented on code in PR #10736: URL: https://github.com/apache/arrow-rs/pull/10736#discussion_r3806426130
########## arrow-buffer/src/error.rs: ########## @@ -0,0 +1,89 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +//! Errors returned by `arrow-buffer`. + +/// An arithmetic overflow. +/// +/// Returned by the `try_` alternatives to the functions that panic on overflow, +/// for instance [`OffsetBuffer::try_from_lengths`](crate::OffsetBuffer::try_from_lengths). +/// +/// ``` +/// # use arrow_buffer::OffsetBuffer; +/// // 32 bit offsets cannot describe more than 2 GiB of data: +/// let err = OffsetBuffer::<i32>::try_from_lengths([u32::MAX as usize]).unwrap_err(); +/// assert_eq!(err.to_string(), "offset overflow: 4294967295 does not fit in i32"); +/// +/// // 64 bit offsets can: +/// assert!(OffsetBuffer::<i64>::try_from_lengths([u32::MAX as usize]).is_ok()); +/// ``` +#[derive(Clone, Copy, Debug, PartialEq, Eq)] +pub struct OverflowError { + what: &'static str, + value: Option<usize>, + type_name: &'static str, +} Review Comment: what are your thoughts on consildating this error types with the enum introduced in https://github.com/apache/arrow-rs/pull/10317/changes#diff-371342744df1b634b0bd9d90f4fe38c1eb0096df322fd3cc2fbc513f3428046cR38, I.E adding another variant. I think this is different enough to warrent a seperate type but I thought id throw the idea out there ########## arrow-buffer/src/buffer/offset.rs: ########## @@ -153,28 +184,45 @@ impl<O: ArrowNativeType> OffsetBuffer<O> { /// /// # Panics /// - /// Panics on overflow + /// Panics on overflow. Use [`Self::try_from_repeated_length`] for a fallible version. pub fn from_repeated_length(length: usize, n: usize) -> Self { + Self::try_from_repeated_length(length, n).unwrap_or_else(|err| panic!("{err}")) + } + + /// Create a new [`OffsetBuffer`] where each slice has the same length + /// `length`, repeated `n` times. + /// + /// ``` + /// # use arrow_buffer::OffsetBuffer; + /// let offsets = OffsetBuffer::<i32>::try_from_repeated_length(4, 3).unwrap(); + /// assert_eq!(offsets.as_ref(), &[0, 4, 8, 12]); + /// ``` + /// + /// # Errors + /// + /// Errors if `length * n` overflows `usize` or `O`. + pub fn try_from_repeated_length(length: usize, n: usize) -> Result<Self, OverflowError> { if n == 0 { - return Self::new_empty(); + return Ok(Self::new_empty()); } if length == 0 { - return Self::new_zeroed(n); + return Self::try_new_zeroed(n); } - // Check for overflow // Making sure we don't overflow usize or O when calculating the total length - length.checked_mul(n).expect("usize overflow"); + let total_length = length + .checked_mul(n) + .ok_or_else(|| OverflowError::new::<usize>("total length"))?; - // Check for overflow Review Comment: nit: we should try and keep the comments from `main` -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
