[sheepdog] Why not add snapshot operations for Sheepdog storage driver in Libvirt

[harryxiyou]

Hi all,

Virsh has following operations about snapshot.

 Snapshot (help keyword 'snapshot')
    snapshot-create                Create a snapshot from XML
    snapshot-create-as             Create a snapshot from a set of args
    snapshot-current               Get or set the current snapshot
    snapshot-delete                Delete a domain snapshot
    snapshot-dumpxml               Dump XML for a domain snapshot
    snapshot-edit                  edit XML for a snapshot
    snapshot-info                  snapshot information
    snapshot-list                  List snapshots for a domain
    snapshot-parent                Get the name of the parent of a snapshot
    snapshot-revert                Revert a domain to a snapshot

But i cannot find relevant realization in Sheepdog storage driver in Libvirt.
I am sure Sheepdog storage driver, now, cannot support snapshot operations
in Libvirt. I wonder whether Sheepdog can realize snapshot operations
in Libvirt?
Maybe i can finish these jobs. I am not clear about how to let Sheepdog storage
driver support snapshot operations. Could anyone give me some suggestions?
Thanks in advance.

-- 
Thanks
Harry Wei