adamreeve commented on PR #7111: URL: https://github.com/apache/arrow-rs/pull/7111#issuecomment-2753181854
I've tried to reduce the use of `#[cfg(feature = "encryption")]` within function bodies (https://github.com/apache/arrow-rs/pull/7111/commits/78ac7b25504ea0d23d1d612f0cb52e823c012bd5), but have been pretty consistently hampered by borrow checker issues. The borrow checker has no insight into which fields a function accesses and assumes all of self is borrowed by an `&self` function, so it's not possible to extract logic out to functions when there's a mutable reference to any field of `self` present. For example, in `arrow_writer/mod.rs`, we currently have this code: https://github.com/apache/arrow-rs/blob/78ac7b25504ea0d23d1d612f0cb52e823c012bd5/parquet/src/arrow/arrow_writer/mod.rs#L266-L288 The contents of the `x` branch of the match statement can't be extracted into a method, because a mutable reference to `self.in_progress` is live. This is the same reason why getting `row_group_index` has to come before the reference to `self.in_progress` is taken. I ran into a similar problem in `file/metadata/writer.rs` here: https://github.com/apache/arrow-rs/blob/78ac7b25504ea0d23d1d612f0cb52e823c012bd5/parquet/src/file/metadata/writer.rs#L73 I wanted to extract a `write_offset_index` method with different implementations depending on whether encryption is enabled, but this isn't possible due to there being a mutable reference to `self.row_groups`. I could instead have different implementations of the whole `write_offset_indexes` function, but that would lead to quite a bit of code duplication. I think the current state is a bit better than it was before, but any thoughts on how to work around this and improve the code readability further would be appreciated! `ThriftMetadataWriter::finish` is probably the ugliest part of the diff at the moment, mostly because of a workaround we have to return unencrypted row group metadata so that the statistics are usable by consumers, and we'd also appreciate any thoughts on that (https://github.com/apache/arrow-rs/pull/7111/files#r2009421835). -- 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
