"Fabio M. Di Nitto" fdinitto@redhat.com writes:
AFAIR all plugins accept an int value for compress_level so from that perspective it shouldn´t be too much of a problem (aka no API/ABI changes).
The plugins do accept an integer compress level because that's what they get from libknet. And this is a good fit for most, but requires an arbitrary mapping for lzo2, which has no concept of compress level, only different compression algorithms, directly selectable by the user.
I think Feri´s suggestion to drop the filter completely might be too much, instead, after thinking a bit, it might be perfectly reason to change the internals of val_level to try and compress a small buffer to test that the value is good. The val_level is used only at configuration time, so it´s not too expensive to compress one small data chunk for validation and it would remove the whole hardcoded filter of different compress_levels.
While I can imagine it work, it still somehow feels conceptually backwards to me. What if we let a "bad" value through? The first send will fail, I guess. Is that really worse than filtering during configuration?
For special plugins like lzo2, I think it´s important we improve the logging at configuration time to make sure users at least warned of supported values (as you can see each values map to a specific lzo2 API call to compress).
It's easy to do and maintain and saves a round trip to the fine documentation, so why not?