On Thu, 9 Apr 2020, John Mulligan wrote: > Hello ceph-devel, > > I'm one of the members of the team currently maintaining, and hopefully > improving, go-ceph (ceph library bindings for Go) [1]. > > An issue I keep returning to is the nature of api calls such as: > - rados_mon_command > - rados_mgr_command > - ceph_mds_command > ... etc > > The argument named cmd for these functions is of type `const char **cmd` and > is followed by a `size_t cmdlen`. I'd like to better understand the rationale > for array-of-char* strings and how this is intended to be used. It's purely historical. The command used to be an array of strings/arguments directly from the CLI so that the parsing was done on the mon. Way back when we changed it to JSON, but never cleaned up the message strcture. sage > > When I first saw the function I initially thought it was meant to support > multiple "commands" getting issued at once but later started thinking that a > single command could be split across multiple strings, and experimentation > demonstrated that this does indeed work. I've attempted reading the sources > but nothing jumps out at me to explain this approach. Most callers of these > functions seem to only use a single "command string". > > I also tried looking to see how the code makes use of the array (or vector > after the transition to C++) but I will admit I'm not very familiar with C++ > and get a bit lost in some of the templates and overloading. > > Could someone who is familiar with this better explain how this argument and > it's type is meant to be used? > I want to make sure we're making good use of the apis that ceph provides in > the wrapper library, or at the very least I want to make sure we're not mis- > using the apis. :-) > > Thank you for your time. > > 1 - https://github.com/ceph/go-ceph > > _______________________________________________ > Dev mailing list -- dev@xxxxxxx > To unsubscribe send an email to dev-leave@xxxxxxx > > _______________________________________________ Dev mailing list -- dev@xxxxxxx To unsubscribe send an email to dev-leave@xxxxxxx
