func (gc *localstoreCompactor) getAllVersions(k kv.Key) ([]kv.EncodedKey, error) {
startKey := MvccEncodeVersionKey(k, kv.MaxVersion)
endKey := MvccEncodeVersionKey(k, kv.MinVersion)
it, err := gc.db.Seek(startKey)
if err != nil {
return nil, errors.Trace(err)
}
defer it.Release()
var ret []kv.EncodedKey
for it.Next() {
if kv.EncodedKey(it.Key()).Cmp(endKey) < 0 {
ret = append(ret, bytes.CloneBytes(kv.EncodedKey(it.Key())))
}
}
return ret, nil
}
func (s *dbSnapshot) MvccGet(k kv.Key, ver kv.Version) ([]byte, error) {
// engine Snapshot return nil, nil for value not found,
// so here we will check nil and return kv.ErrNotExist.
// get newest version, (0, MaxUint64)
// Key arrangement:
// Key -> META
// ...
// Key_ver
// Key_ver-1
// Key_ver-2
// ...
// Key_ver-n
// Key_0
// NextKey -> META
// NextKey_xxx
startKey := MvccEncodeVersionKey(k, ver)
endKey := MvccEncodeVersionKey(k, kv.MinVersion)
// get raw iterator
it, err := s.db.Seek(startKey)
if err != nil {
return nil, errors.Trace(err)
}
defer it.Release()
var rawKey []byte
var v []byte
if it.Next() {
// If scan exceed this key's all versions
// it.Key() > endKey.
if kv.EncodedKey(it.Key()).Cmp(endKey) < 0 {
// Check newest version of this key.
// If it's tombstone, just skip it.
if !isTombstone(it.Value()) {
rawKey = it.Key()
v = it.Value()
}
}
}
// No such key (or it's tombstone).
if rawKey == nil {
return nil, kv.ErrNotExist
}
return v, nil
}
func (s *dbSnapshot) MvccGet(k kv.Key, ver kv.Version) ([]byte, error) {
// engine Snapshot return nil, nil for value not found,
// so here we will check nil and return kv.ErrNotExist.
// get newest version, (0, MaxUint64)
// Key arrangement:
// Key -> META
// ...
// Key_ver
// Key_ver-1
// Key_ver-2
// ...
// Key_ver-n
// Key_0
// NextKey -> META
// NextKey_xxx
startKey := MvccEncodeVersionKey(k, ver)
endKey := MvccEncodeVersionKey(k, kv.MinVersion)
it, err := s.internalSeek(startKey)
if err != nil {
return nil, errors.Trace(err)
}
var rawKey []byte
var v []byte
// Check if the scan is not exceed this key's all versions and the value is not
// tombstone.
if kv.EncodedKey(it.Key()).Cmp(endKey) < 0 && !isTombstone(it.Value()) {
rawKey = it.Key()
v = it.Value()
}
// No such key (or it's tombstone).
if rawKey == nil {
return nil, kv.ErrNotExist
}
return bytes.CloneBytes(v), nil
}