Re: [libvirt] [PATCH v2] Add two NUMA tuning python bindings APIs

On 01/24/2012 05:07 AM, Guan Nan Ren wrote: I finally realized _why_ we do it - that's because we want to pass the correct types to libvirt.c, but python is not strongly typed. That is, if libvirt is expecting a particular named value to be VIR_TYPED_PARAM_ULLONG, but the python code passes '1', we should be able to properly convert that python value to C's 1ULL, rather than rejecting the python code for using an incorrect type, since there is not quite a notion of incorrect type in python. That means that either we hard-code the list of all known parameter names and their type, or we make things done via a runtime query by getting all parameters to learn their types before formatting the user's settings back into something that libvirt will parse. It may also mean that libvirt itself should be a bit nicer about things - now that we have virTypedParam.c, maybe that function should be taught to do some type conversions (if the user passes in VIR_TYPED_PARAM_INT, but the code wanted VIR_TYPED_PARAM_ULLONG, libvirt could do the type conversion on the user's behalf); if libvirt is made smarter, then the python glue code might be simpler. But there's still the issue of back-compat - a newer python library talking to an older libvirt that didn't do automatic type conversion would still be stuck needing to query for types first. -- Eric Blake eblake(a)redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org