Re: [libvirt] [RFC][scale] new API for querying domains stats

For the async API design, I could see two potential designs 1. A custom callback to run per API typedef (void)(*virDomainBlockInfoCallback)(virDomainPtr dom, bool isError, virDomainBlockInfoPtr info, void *opaque); int virDomainGetBlockInfoAsync(virDomainPtr dom, const char *disk, virDomainBlockInfoCallback cb, void *opaque, unsigned int flags); 2. A standard callback and a pair of APIs typedef void *virDomainAsyncResult; typedef (void)(*virDomainAsyncCallback)(virDomainPtr dom, virDomainAsyncResult res); void virDomainGetBlockInfoAsync(virDomainPtr dom, const char *disk, virDomainBlockInfoCallback cb, void *opaque, unsigned int flags); int virDomainGetBlockInfoFinish(virDomainPtr dom, virDomainAsyncResult res, virDomainBlockInfoPtr info);