On 8 Mar 2022, at 11:53, Jim Laskey wrote: >> I'm not sure I see anything here that would prevent the user from building a >> carrier and casting to Object[] ?
> Clarified the comment. You are right. When I reworked the original code I > dropped the intermediate object. For my purposes, it was about performance. > If the object needs to be protected then it's up to the client to protect. > The same would be true if I add byte[] for all binary carriers. I would prefer protecting the Object[] inside a non-public-class envelope object. It’s a performance hit, but only on a path (no class spun b/c a high number of components) where there is no detailed optimization strategy anyway. For the less-optimized path, putting everything into an Object[] (boxing primitives as well?) suggests that performance (+ footprint) is not an issue anyway. In that case, the extra cost of adding the envelope object (indirection cost + footprint) not be a unique cost. The best reason to put an envelope around the Object[] array (or other user-crackable representation) is the same reason we randomize encounter order in Set.of and Map.of. It’s extra work, but it prevents users from building in out-of-contract dependencies in their code. If this API exposes Object[] values, even temporarily, is is possible (even likely) that users will notice and build in out-of-contract dependencies. The sad result of “optimizing” the Object[] representation by omitting the envelope will be that further optimizations (real ones!) will be harder to get accepted. Summary: Put the envelope around the Object, on paths which use Object[]. Second suggestion, as a follow-on task for later, is add a long[] array into that same envelope and use the long[] array for all primitive values, instead of boxing them as Integer, Long, etc. (Or put the long[] array as the first item in the Object[] array.) It probably doesn’t matter, but 32-bit values could be stored in high or low halves of the long elements. (I think I’m not the only one to prototype it that way; I’ll bet Remi did something similar.)
