HG: Add HG_Class_get_init_info

[mdorier]

Is your feature request related to a problem? Please describe.

In the context of Margo, to fill up the JSON configuration that represents the parameters used to initialize Mercury, we would need to be able to retrieve the hg_init_info that was used to initialized Mercury if the user provided their own hg_class to Margo (or a default hg_init_info if HG_Init was used).

Describe the solution you'd like

struct hg_init_info* HG_Class_get_init_info(struct hg_class*)

[soumagne]

OK. We currently do not keep that info around but that's probably possible to do it.

[soumagne]

@mdorier let me know if you still need that feature. I've been looking at it recently and it's almost impossible to support it because of some the init info fields that would need to be copied and kept around. Some fields are cached but that's only a small part of them.

[mdorier]

It's definitely not a priority. I have modified margo to prevent it from assuming/reporting default values when HG was initialized externally.