leerho commented on code in PR #84: URL: https://github.com/apache/datasketches-rust/pull/84#discussion_r2778054604
########## datasketches/src/hash/mod.rs: ########## @@ -37,6 +37,19 @@ pub(crate) use self::xxhash::XxHash64; /// a history of stored sketches you are stuck with it. pub(crate) const DEFAULT_UPDATE_SEED: u64 = 9001; +/// Computes and checks the 16-bit seed hash from the given long seed. +/// +/// The seed hash may not be zero in order to maintain compatibility with older serialized +/// versions that did not have this concept. Review Comment: It is exactly what the comment says. It is to remain compatible with older versions of CPC (in other languages) that did not have the concept of the seedHash. Once you have serialized a sketch, it no longer retains any information about what language generated the serialized image. That is the whole idea and quite powerful! Once you have properly created this sketch in Rust, you will be able to import CPC sketch images created years ago from Java, C++, or whatever. The fact that "older versions of Rust" don't have this problem is irrelevant. :) -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
