Method PrepareRead

be/src/runtime/sorter.cc:452–479

}

Status Sorter::Run::PrepareRead() {
  DCHECK(is_finalized_);
  DCHECK(is_sorted_);

  fixed_len_pages_index_ = 0;
  fixed_len_page_offset_ = 0;
  var_len_pages_index_ = 0;
  end_of_fixed_len_page_ = end_of_var_len_page_ = fixed_len_pages_.empty();
  num_tuples_returned_ = 0;

  buffered_batch_.reset(new RowBatch(
      sorter_->output_row_desc_, sorter_->state_->batch_size(), sorter_->mem_tracker_));

  // If the run is pinned, all pages are already pinned, so we're ready to read.
  if (is_pinned_) return Status::OK();

  // Pins the first fixed len page.
  if (!fixed_len_pages_.empty()) {
    RETURN_IF_ERROR(fixed_len_pages_[0].Pin(sorter_->buffer_pool_client_));
  }

  // Pins the first var len page if there is any.
  if (HasVarLenPages()) {
    RETURN_IF_ERROR(var_len_pages_[0].Pin(sorter_->buffer_pool_client_));
  }

  return Status::OK();
}

Status Sorter::Run::GetNextBatch(RowBatch** output_batch) {
  DCHECK(buffered_batch_ != nullptr);