I think Serhiy's PR is basically done, so now the question is do we want to merge it in and drop the C code? ;)

I obviously say yes because this is I/O-bound code and so the switch shouldn't be enough of a performance hit to warrant blocking the gain in maintainability long-term (especially if we try to clean the module up slowly).

Barry, since I know you work with zip files a lot at work did you want to check to make sure perf won't be an issue for your use-case?