Method GetNext

be/src/exec/unnest-node.cc:174–214

}

Status UnnestNode::GetNext(RuntimeState* state, RowBatch* row_batch, bool* eos) {
  SCOPED_TIMER(runtime_profile_->total_time_counter());
  // Avoid expensive query maintenance overhead for small collections.
  if (item_idx_ > 0) {
    RETURN_IF_CANCELLED(state);
    RETURN_IF_ERROR(QueryMaintenance(state));
  }
  *eos = false;

  // Populate the output row_batch with tuples from the collections.
  while (item_idx_ < longest_collection_size_) {
    int row_idx = row_batch->AddRow();
    TupleRow* row = row_batch->GetRow(row_idx);
    for (int i = 0; i < coll_values_.size(); ++i) {
      const CollectionValue* coll_value = coll_values_[i];
      DCHECK(coll_value != nullptr);
      DCHECK_GE(coll_value->num_tuples, 0);
      Tuple* input_tuple;
      if (coll_value->num_tuples <= item_idx_) {
        input_tuple = CreateNullTuple(i, row_batch);
      } else {
        input_tuple =
            reinterpret_cast<Tuple*>(coll_value->ptr + item_idx_ * item_byte_sizes_[i]);
      }
      row->SetTuple(output_coll_tuple_idxs_[i], input_tuple);
    }
    ++item_idx_;
    DCHECK_EQ(conjuncts_.size(), conjunct_evals_.size());
    if (EvalConjuncts(conjunct_evals_.data(), conjuncts_.size(), row)) {
      row_batch->CommitLastRow();
      // The limit is handled outside of this loop.
      if (row_batch->AtCapacity()) break;
    }
  }

  // Checking the limit here is simpler/cheaper than doing it in the loop above.
  const bool reached_limit = CheckLimitAndTruncateRowBatchIfNeeded(row_batch, eos);
  if (!reached_limit && item_idx_ == longest_collection_size_) *eos = true;
  COUNTER_SET(rows_returned_counter_, rows_returned());
  return Status::OK();
}

int UnnestNode::GetCollTupleIdx(const SlotDescriptor* slot_desc) const {
  DCHECK(slot_desc != nullptr);