func (vc *VolumeClock) UpdateFromChild(parentInode uint64, name string, child *clock.Clock) (changed bool, err error) {
key := vc.pathToKey(parentInode, name)
val := vc.b.Get(key)
if val == nil {
return false, &ClockNotFoundError{ParentInode: parentInode, Name: name}
}
var parentClock clock.Clock
if err := parentClock.UnmarshalBinary(val); err != nil {
return false, fmt.Errorf("corrupt clock for %d:%q", parentInode, name)
}
if changed := parentClock.UpdateFromChild(child); !changed {
// no need to persist anything
return false, nil
}
buf, err := parentClock.MarshalBinary()
if err != nil {
return false, err
}
if err := vc.b.Put(key, buf); err != nil {
return false, err
}
return true, nil
}
