func (r *TableDefaultPlan) toSeekKey(seekVal interface{}) (kv.Key, error) {
var handle int64
var err error
if seekVal == nil {
handle = math.MinInt64
} else {
handle, err = types.ToInt64(seekVal)
if err != nil {
return nil, errors.Trace(err)
}
}
return tables.EncodeRecordKey(r.T.TableID(), handle, 0), nil
}
func (ts *testSuite) TestRowKeyCodec(c *C) {
table := []struct {
tableID int64
h int64
ID int64
}{
{1, 1234567890, 0},
{2, 1, 0},
{3, -1, 0},
{4, -1, 1},
}
for _, t := range table {
b := tables.EncodeRecordKey(t.tableID, t.h, t.ID)
tableID, handle, columnID, err := tables.DecodeRecordKey(b)
c.Assert(err, IsNil)
c.Assert(tableID, Equals, t.tableID)
c.Assert(handle, Equals, t.h)
c.Assert(columnID, Equals, t.ID)
handle, err = tables.DecodeRecordKeyHandle(b)
c.Assert(err, IsNil)
c.Assert(handle, Equals, t.h)
}
// test error
tbl := []string{
"",
"x",
"t1",
"t12345678",
"t12345678_i",
"t12345678_r1",
"t12345678_r1234567",
"t12345678_r123456781",
}
for _, t := range tbl {
_, err := tables.DecodeRecordKeyHandle(kv.Key(t))
c.Assert(err, NotNil)
}
}
func (e *TableScanExec) seek() (kv.Key, error) {
seekKey := tables.EncodeRecordKey(e.t.TableID(), e.seekHandle, 0)
txn, err := e.ctx.GetTxn(false)
if err != nil {
return nil, errors.Trace(err)
}
if e.iter != nil {
e.iter.Close()
}
e.iter, err = txn.Seek(seekKey)
if err != nil {
return nil, errors.Trace(err)
}
if !e.iter.Valid() || !e.iter.Key().HasPrefix(e.t.RecordPrefix()) {
// No more records in the table, skip to the end.
e.cursor = len(e.ranges)
return nil, nil
}
return e.iter.Key(), nil
}
