// DecodeRecordKey decodes the key and gets the tableID, handle and columnID.
func DecodeRecordKey(key kv.Key) (tableID int64, handle int64, columnID int64, err error) {
k := key
if !key.HasPrefix(TablePrefix) {
return 0, 0, 0, errors.Errorf("invalid record key - %q", k)
}
key = key[len(TablePrefix):]
key, tableID, err = codec.DecodeInt(key)
if err != nil {
return 0, 0, 0, errors.Trace(err)
}
if !key.HasPrefix(recordPrefixSep) {
return 0, 0, 0, errors.Errorf("invalid record key - %q", k)
}
key = key[len(recordPrefixSep):]
key, handle, err = codec.DecodeInt(key)
if err != nil {
return 0, 0, 0, errors.Trace(err)
}
if len(key) == 0 {
return
}
key, columnID, err = codec.DecodeInt(key)
if err != nil {
return 0, 0, 0, errors.Trace(err)
}
return
}
// DecodeRowKey decodes the key and gets the handle.
func DecodeRowKey(key kv.Key) (handle int64, err error) {
k := key
if !key.HasPrefix(tablePrefix) {
return 0, errInvalidRecordKey.Gen("invalid record key - %q", k)
}
key = key[len(tablePrefix):]
// Table ID is not needed.
key, _, err = codec.DecodeInt(key)
if err != nil {
return 0, errors.Trace(err)
}
if !key.HasPrefix(recordPrefixSep) {
return 0, errInvalidRecordKey.Gen("invalid record key - %q", k)
}
key = key[len(recordPrefixSep):]
key, handle, err = codec.DecodeInt(key)
if err != nil {
return 0, errors.Trace(err)
}
return
}
// mvccSeek seeks for the first key in db which has a k >= key and a version <=
// snapshot's version, returns kv.ErrNotExist if such key is not found. If exact
// is true, only k == key can be returned.
func (s *dbSnapshot) mvccSeek(key kv.Key, exact bool) (kv.Key, []byte, error) {
// Key layout:
// ...
// Key_verMax -- (1)
// ...
// Key_ver+1 -- (2)
// Key_ver -- (3)
// Key_ver-1 -- (4)
// ...
// Key_0 -- (5)
// NextKey_verMax -- (6)
// ...
// NextKey_ver+1 -- (7)
// NextKey_ver -- (8)
// NextKey_ver-1 -- (9)
// ...
// NextKey_0 -- (10)
// ...
// EOF
for {
mvccKey := MvccEncodeVersionKey(key, s.version)
mvccK, v, err := s.store.Seek([]byte(mvccKey), s.version.Ver) // search for [3...EOF)
if err != nil {
if terror.ErrorEqual(err, engine.ErrNotFound) { // EOF
return nil, nil, errors.Trace(kv.ErrNotExist)
}
return nil, nil, errors.Trace(err)
}
k, ver, err := MvccDecode(mvccK)
if err != nil {
return nil, nil, errors.Trace(err)
}
// quick test for exact mode
if exact {
if key.Cmp(k) != 0 || isTombstone(v) {
return nil, nil, errors.Trace(kv.ErrNotExist)
}
return k, v, nil
}
if ver.Ver > s.version.Ver {
// currently on [6...7]
key = k // search for [8...EOF) next loop
continue
}
// currently on [3...5] or [8...10]
if isTombstone(v) {
key = k.Next() // search for (5...EOF) or (10..EOF) next loop
continue
}
// target found
return k, v, nil
}
}
func (t *testMvccSuite) scanRawEngine(c *C, f func([]byte, []byte)) {
// scan raw db
var k kv.Key
var v []byte
for {
var err error
k, v, err = t.s.(*dbStore).db.Seek(k)
if err != nil {
break
}
f(k, v)
k = k.Next()
}
}
func count(db engine.DB) int {
var k kv.Key
totalCnt := 0
for {
var err error
k, _, err = db.Seek(k)
if err != nil {
break
}
k = k.Next()
totalCnt++
}
return totalCnt
}