func getIndexRowFromRange(idxInfo *tipb.IndexInfo, txn kv.Transaction, ran kv.KeyRange, desc bool, limit int64) ([]*tipb.Row, error) {
var rows []*tipb.Row
var seekKey kv.Key
if desc {
seekKey = ran.EndKey
} else {
seekKey = ran.StartKey
}
for {
if limit == 0 {
break
}
var it kv.Iterator
var err error
if desc {
it, err = txn.SeekReverse(seekKey)
if err != nil {
return nil, errors.Trace(err)
}
seekKey = it.Key()
} else {
it, err = txn.Seek(seekKey)
if err != nil {
return nil, errors.Trace(err)
}
seekKey = it.Key().PrefixNext()
}
if !it.Valid() {
break
}
if desc {
if it.Key().Cmp(ran.StartKey) < 0 {
break
}
} else {
if it.Key().Cmp(ran.EndKey) >= 0 {
break
}
}
datums, err := tablecodec.DecodeIndexKey(it.Key())
if err != nil {
return nil, errors.Trace(err)
}
var handle types.Datum
if len(datums) > len(idxInfo.Columns) {
handle = datums[len(idxInfo.Columns)]
datums = datums[:len(idxInfo.Columns)]
} else {
var intHandle int64
intHandle, err = decodeHandle(it.Value())
if err != nil {
return nil, errors.Trace(err)
}
handle.SetInt64(intHandle)
}
data, err := codec.EncodeValue(nil, datums...)
if err != nil {
return nil, errors.Trace(err)
}
handleData, err := codec.EncodeValue(nil, handle)
if err != nil {
return nil, errors.Trace(err)
}
row := &tipb.Row{Handle: handleData, Data: data}
rows = append(rows, row)
limit--
}
return rows, nil
}
func (h *rpcHandler) getIndexRowFromRange(sel *tipb.SelectRequest, ran kv.KeyRange, desc bool, limit int64) ([]*tipb.Row, error) {
startKey := maxStartKey(ran.StartKey, h.startKey)
endKey := minEndKey(ran.EndKey, h.endKey)
if limit == 0 || bytes.Compare(startKey, endKey) >= 0 {
return nil, nil
}
var rows []*tipb.Row
var seekKey kv.Key
if desc {
seekKey = endKey
} else {
seekKey = startKey
}
for {
if limit == 0 {
break
}
var (
pairs []Pair
pair Pair
err error
)
if desc {
pairs = h.mvccStore.ReverseScan(startKey, seekKey, 1, sel.GetStartTs())
} else {
pairs = h.mvccStore.Scan(seekKey, endKey, 1, sel.GetStartTs())
}
if len(pairs) > 0 {
pair = pairs[0]
}
if pair.Err != nil {
// TODO: handle lock error.
return nil, errors.Trace(pair.Err)
}
if pair.Key == nil {
break
}
if desc {
if bytes.Compare(pair.Key, startKey) < 0 {
break
}
seekKey = pair.Key
} else {
if bytes.Compare(pair.Key, endKey) >= 0 {
break
}
seekKey = []byte(kv.Key(pair.Key).PrefixNext())
}
datums, err := tablecodec.DecodeIndexKey(pair.Key)
if err != nil {
return nil, errors.Trace(err)
}
var handle types.Datum
columns := sel.IndexInfo.Columns
if len(datums) > len(columns) {
handle = datums[len(columns)]
datums = datums[:len(columns)]
} else {
var intHandle int64
intHandle, err = decodeHandle(pair.Value)
if err != nil {
return nil, errors.Trace(err)
}
handle.SetInt64(intHandle)
}
data, err := codec.EncodeValue(nil, datums...)
if err != nil {
return nil, errors.Trace(err)
}
handleData, err := codec.EncodeValue(nil, handle)
if err != nil {
return nil, errors.Trace(err)
}
row := &tipb.Row{Handle: handleData, Data: data}
rows = append(rows, row)
limit--
}
return rows, nil
}
