// newTableReader creates a tableReader.
func newTableReader(
flowCtx *FlowCtx, spec *TableReaderSpec, output RowReceiver,
) (*tableReader, error) {
tr := &tableReader{
output: output,
hardLimit: spec.HardLimit,
softLimit: spec.SoftLimit,
}
if tr.hardLimit != 0 && tr.hardLimit < tr.softLimit {
return nil, errors.Errorf("soft limit %d larger than hard limit %d", tr.softLimit,
tr.hardLimit)
}
err := tr.readerBase.init(flowCtx, &spec.Table, int(spec.IndexIdx), spec.Filter,
spec.OutputColumns, spec.Reverse)
if err != nil {
return nil, err
}
tr.ctx = log.WithLogTagInt(tr.flowCtx.Context, "TableReader", int(tr.desc.ID))
tr.spans = make(roachpb.Spans, len(spec.Spans))
for i, s := range spec.Spans {
tr.spans[i] = s.Span
}
return tr, nil
}
func newJoinReader(
flowCtx *FlowCtx, spec *JoinReaderSpec, input RowSource, output RowReceiver,
) (*joinReader, error) {
if spec.IndexIdx != 0 {
// TODO(radu): for now we only support joining with the primary index
return nil, errors.Errorf("join with index not implemented")
}
jr := &joinReader{
input: input,
output: output,
}
err := jr.readerBase.init(flowCtx, &spec.Table, int(spec.IndexIdx), spec.Filter,
spec.OutputColumns, false)
if err != nil {
return nil, err
}
jr.ctx = log.WithLogTagInt(jr.flowCtx.Context, "JoinReader", int(jr.desc.ID))
return jr, nil
}