// next gives the left boundary of the union of all requests which don't
// affect keys less than the given key.
// TODO(tschottdorf): again, better on BatchRequest itself, but can't pull
// 'keys' into 'proto'.
func next(ba roachpb.BatchRequest, k roachpb.RKey) (roachpb.RKey, error) {
candidate := roachpb.RKeyMax
for _, union := range ba.Requests {
h := union.GetInner().Header()
addr, err := keys.Addr(h.Key)
if err != nil {
return nil, err
}
if addr.Less(k) {
eAddr, err := keys.AddrUpperBound(h.EndKey)
if err != nil {
return nil, err
}
if k.Less(eAddr) {
// Starts below k, but continues beyond. Need to stay at k.
return k, nil
}
// Affects only [KeyMin,k).
continue
}
// We want the smallest of the surviving candidates.
if addr.Less(candidate) {
candidate = addr
}
}
return candidate, nil
}
// prev gives the right boundary of the union of all requests which don't
// affect keys larger than the given key.
// TODO(tschottdorf): again, better on BatchRequest itself, but can't pull
// 'keys' into 'roachpb'.
func prev(ba roachpb.BatchRequest, k roachpb.RKey) (roachpb.RKey, error) {
candidate := roachpb.RKeyMin
for _, union := range ba.Requests {
h := union.GetInner().Header()
addr, err := keys.Addr(h.Key)
if err != nil {
return nil, err
}
eAddr, err := keys.AddrUpperBound(h.EndKey)
if err != nil {
return nil, err
}
if len(eAddr) == 0 {
eAddr = addr.Next()
}
if !eAddr.Less(k) {
if !k.Less(addr) {
// Range contains k, so won't be able to go lower.
return k, nil
}
// Range is disjoint from [KeyMin,k).
continue
}
// We want the largest surviving candidate.
if candidate.Less(addr) {
candidate = addr
}
}
return candidate, nil
}