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 }