// Epoch returns the current mutation epoch of the volume.
//
// Returned value is valid after the transaction.
func (v *Volume) Epoch() (clock.Epoch, error) {
val := v.b.Get(volumeStateEpoch)
var epoch clock.Epoch
if err := epoch.UnmarshalBinary(val); err != nil {
return 0, err
}
return epoch, nil
}
func (v *Volume) setEpoch(epoch clock.Epoch) error {
buf, err := epoch.MarshalBinary()
if err != nil {
return err
}
if err := v.b.Put(volumeStateEpoch, buf); err != nil {
return err
}
return nil
}