func (dl directoryLayer) subdirNames(rtr fdb.ReadTransaction, node subspace.Subspace) ([]string, error) {
sd := node.Sub(_SUBDIRS)
rr := rtr.GetRange(sd, fdb.RangeOptions{})
ri := rr.Iterator()
var ret []string
for ri.Advance() {
kv := ri.MustGet()
p, e := sd.Unpack(kv.Key)
if e != nil {
return nil, e
}
ret = append(ret, p[0].(string))
}
return ret, nil
}
func (dl directoryLayer) nodeContainingKey(rtr fdb.ReadTransaction, key []byte) (subspace.Subspace, error) {
if bytes.HasPrefix(key, dl.nodeSS.Bytes()) {
return dl.rootNode, nil
}
bk, _ := dl.nodeSS.FDBRangeKeys()
kr := fdb.KeyRange{bk, fdb.Key(append(dl.nodeSS.Pack(tuple.Tuple{key}), 0x00))}
kvs := rtr.GetRange(kr, fdb.RangeOptions{Reverse: true, Limit: 1}).GetSliceOrPanic()
if len(kvs) == 1 {
pp, e := dl.nodeSS.Unpack(kvs[0].Key)
if e != nil {
return nil, e
}
prevPrefix := pp[0].([]byte)
if bytes.HasPrefix(key, prevPrefix) {
return dl.nodeWithPrefix(prevPrefix), nil
}
}
return nil, nil
}
func isRangeEmpty(rtr fdb.ReadTransaction, r fdb.Range) bool {
kvs := rtr.GetRange(r, fdb.RangeOptions{Limit: 1}).GetSliceOrPanic()
return len(kvs) == 0
}