Example #1
0
func (h *rpcHandler) getRowsFromRange(ctx *selectContext, ran kv.KeyRange, limit int64, desc bool) ([]*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
	if ran.IsPoint() {
		val, err := h.mvccStore.Get(startKey, ctx.sel.GetStartTs())
		if len(val) == 0 {
			return nil, nil
		} else if err != nil {
			return nil, errors.Trace(err)
		}
		handle, err := tablecodec.DecodeRowKey(kv.Key(startKey))
		if err != nil {
			return nil, errors.Trace(err)
		}
		row, err := h.handleRowData(ctx, handle, val)
		if err != nil {
			return nil, errors.Trace(err)
		}
		if row != nil {
			rows = append(rows, row)
		}
		return rows, nil
	}
	var seekKey []byte
	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, ctx.sel.GetStartTs())
		} else {
			pairs = h.mvccStore.Scan(seekKey, endKey, 1, ctx.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 = []byte(tablecodec.TruncateToRowKeyLen(kv.Key(pair.Key)))
		} else {
			if bytes.Compare(pair.Key, endKey) >= 0 {
				break
			}
			seekKey = []byte(kv.Key(pair.Key).PrefixNext())
		}
		handle, err := tablecodec.DecodeRowKey(pair.Key)
		if err != nil {
			return nil, errors.Trace(err)
		}
		row, err := h.handleRowData(ctx, handle, pair.Value)
		if err != nil {
			return nil, errors.Trace(err)
		}
		if row != nil {
			rows = append(rows, row)
			limit--
		}
	}
	return rows, nil
}
Example #2
0
func (rs *localRegion) getRowsFromRange(ctx *selectContext, ran kv.KeyRange, limit int64, desc bool) (count int64, err error) {
	if limit == 0 {
		return 0, nil
	}
	if ran.IsPoint() {
		var value []byte
		value, err = ctx.txn.Get(ran.StartKey)
		if terror.ErrorEqual(err, kv.ErrNotExist) {
			return 0, nil
		} else if err != nil {
			return 0, errors.Trace(err)
		}
		var h int64
		h, err = tablecodec.DecodeRowKey(ran.StartKey)
		if err != nil {
			return 0, errors.Trace(err)
		}
		gotRow, err1 := rs.handleRowData(ctx, h, value)
		if err1 != nil {
			return 0, errors.Trace(err1)
		}

		if gotRow {
			count++
		}
		return
	}
	var seekKey kv.Key
	if desc {
		seekKey = ran.EndKey
	} else {
		seekKey = ran.StartKey
	}
	for {
		if limit == 0 {
			break
		}
		var (
			it  kv.Iterator
			err error
		)
		if desc {
			it, err = ctx.txn.SeekReverse(seekKey)
		} else {
			it, err = ctx.txn.Seek(seekKey)
		}
		if err != nil {
			return 0, errors.Trace(err)
		}
		if !it.Valid() {
			break
		}
		if desc {
			if it.Key().Cmp(ran.StartKey) < 0 {
				break
			}
			seekKey = tablecodec.TruncateToRowKeyLen(it.Key())
		} else {
			if it.Key().Cmp(ran.EndKey) >= 0 {
				break
			}
			seekKey = it.Key().PrefixNext()
		}
		h, err := tablecodec.DecodeRowKey(it.Key())
		if err != nil {
			return 0, errors.Trace(err)
		}
		gotRow, err := rs.handleRowData(ctx, h, it.Value())
		if err != nil {
			return 0, errors.Trace(err)
		}
		if gotRow {
			limit--
			count++
		}
	}
	return count, nil
}
Example #3
0
func (rs *localRegion) getRowsFromRange(ctx *selectContext, ran kv.KeyRange, limit int64, desc bool) ([]*tipb.Row, error) {
	if limit == 0 {
		return nil, nil
	}
	var rows []*tipb.Row
	if ran.IsPoint() {
		_, err := ctx.txn.Get(ran.StartKey)
		if terror.ErrorEqual(err, kv.ErrNotExist) {
			return nil, nil
		} else if err != nil {
			return nil, errors.Trace(err)
		}
		h, err := tablecodec.DecodeRowKey(ran.StartKey)
		if err != nil {
			return nil, errors.Trace(err)
		}
		match, err := rs.evalWhereForRow(ctx, h)
		if err != nil {
			return nil, errors.Trace(err)
		}
		if !match {
			return nil, nil
		}
		row, err := rs.getRowByHandle(ctx, h)
		if err != nil {
			return nil, errors.Trace(err)
		}
		if row != nil {
			rows = append(rows, row)
		}
		return rows, nil
	}
	var seekKey kv.Key
	if desc {
		seekKey = ran.EndKey
	} else {
		seekKey = ran.StartKey
	}
	for {
		if limit == 0 {
			break
		}
		var (
			it  kv.Iterator
			err error
		)
		if desc {
			it, err = ctx.txn.SeekReverse(seekKey)
		} else {
			it, err = ctx.txn.Seek(seekKey)
		}
		if err != nil {
			return nil, errors.Trace(err)
		}
		if !it.Valid() {
			break
		}
		if desc {
			if it.Key().Cmp(ran.StartKey) < 0 {
				break
			}
			seekKey = tablecodec.TruncateToRowKeyLen(it.Key())
		} else {
			if it.Key().Cmp(ran.EndKey) >= 0 {
				break
			}
			seekKey = it.Key().PrefixNext()
		}
		h, err := tablecodec.DecodeRowKey(it.Key())
		if err != nil {
			return nil, errors.Trace(err)
		}
		match, err := rs.evalWhereForRow(ctx, h)
		if err != nil {
			return nil, errors.Trace(err)
		}
		if !match {
			continue
		}
		row, err := rs.getRowByHandle(ctx, h)
		if err != nil {
			return nil, errors.Trace(err)
		}
		if row != nil {
			rows = append(rows, row)
			limit--
		}
	}
	return rows, nil
}