Re: [Libguestfs] [PATCH libnbd] api: nbd_get_version, nbd_supports_uri and nbd_get_package_name.

On 6/3/19 4:59 AM, Richard W.M. Jones wrote: > nbd_get_version returns the library version as a string. > > nbd_supports_uri returns whether or not the library was compiled with > NBD URI support (ie. with libxml2). > > nbd_get_package_name is fairly useless as it always returns the string > "libnbd", however it replaces a function that was written for the > Python bindings. > > These take a handle parameter but don't need to use it. Changing the > generator to support a whole new class of API calls which don't need a > handle is a massive pain. Should we permit and/or document that these functions may pass NULL (at least in C bindings) for the nbd_handle? (It's harder in other languages, where you would treat it as more of a static method rather than an instance method - hence I agree with your comment that refactoring the generator to support that is harder)

Looks good to me. I agree that supports_uri should be a runtime question. Having the version as a runtime answer is sane enough (even if being a string requires a bit of parsing to interpret the version). There's still the question if additionally exposing the version as a compile-time constant can also make it easier to conditionally use other API (such as nbd_supports_uri) based on version-number checks for whether it is known to be present (not as nice as a configure-check for the actual function, in case it was backported across version numbers, but having compile-time constants allows skipping the development of the configure-time check).