mkarbo commented on code in PR #7535: URL: https://github.com/apache/arrow-rs/pull/7535#discussion_r2104557928
########## parquet-variant/src/variant.rs: ########## @@ -18,158 +109,223 @@ impl<'m> VariantMetadata<'m> { self.bytes } + pub fn try_new(bytes: &'m [u8]) -> Result<Self, ArrowError> { + let header = VariantMetadataHeader::try_new(bytes)?; + // Offset 1, index 0 because first element after header is dictionary size + let dict_size = header.offset_size.unpack_usize(bytes, 1, 0)?; + + // TODO: Refactor, add test for validation + let valid = (0..=dict_size) + .map(|i| header.offset_size.unpack_usize(bytes, 1, i + 1)) + .scan(0, |prev, cur| { + let Ok(cur_offset) = cur else { + return Some(false); + }; + // Skip the first offset, which is always 0 + if *prev == 0 { + *prev = cur_offset; + return Some(true); + } + + let valid = cur_offset > *prev; + *prev = cur_offset; + Some(valid) + }) + .all(|valid| valid); + + if !valid { + return Err(ArrowError::InvalidArgumentError( + "Offsets are not monotonically increasing".to_string(), + )); + } + Ok(Self { + bytes, + header, + dict_size, + }) + } + /// Whether the dictionary keys are sorted and unique pub fn is_sorted(&self) -> bool { - todo!() + self.header.is_sorted } - /// Get the dict length - pub fn dict_len(&self) -> Result<usize, ArrowError> { - let end_location = self.offset_size()? as usize + 1; - if self.bytes.len() < end_location { - let err_str = format!( - "Invalid metadata bytes, must have at least length {} but has length {}", - &end_location, - self.bytes.len() - ); - return Err(ArrowError::InvalidArgumentError(err_str)); - } - let dict_len_bytes = &self.bytes[1..end_location]; - let dict_len = usize::from_le_bytes(dict_len_bytes.try_into().map_err(|e| { - ArrowError::InvalidArgumentError(format!( - "Unable to convert dictionary_size bytes into usize: {}", - e, - )) - })?); - Ok(dict_len) + /// Get the dictionary size + pub fn dictionary_size(&self) -> usize { Review Comment: Np :D -- 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