Method getOutput

bolt/exec/HashProbe.cpp:1131–1270

}

RowVectorPtr HashProbe::getOutput() {
  if (isFinished()) {
    return nullptr;
  }
  checkRunning();

  clearProjectedOutput();
  if (!input_) {
    if (!hasMoreInput()) {
      if (needLastProbe() && lastProber_) {
        auto output = getBuildSideOutput();
        if (output != nullptr) {
          return output;
        }
      }
      if (hasMoreSpillData()) {
        prepareForSpillRestore();
        asyncWaitForHashTable();
      } else {
        setState(ProbeOperatorState::kFinish);
        resetHashTable();
      }
      return nullptr;
    }
    return nullptr;
  }

  const auto inputSize = input_->size();

  if (replacedWithDynamicFilter_) {
    addRuntimeStat("replacedWithDynamicFilterRows", RuntimeCounter(inputSize));
    auto output = Operator::fillOutput(inputSize, nullptr);
    input_ = nullptr;
    return output;
  }

  const bool isLeftSemiOrAntiJoinNoFilter = !filter_ &&
      (isLeftSemiFilterJoin(joinType_) || isLeftSemiProjectJoin(joinType_) ||
       isAntiJoin(joinType_));

  const bool emptyBuildSide = (table_->numDistinct() == 0);

  // Left semi and anti joins are always cardinality reducing, e.g. for a
  // given row of input they produce zero or 1 row of output. Therefore, if
  // there is no extra filter we can process each batch of input in one go.
  auto outputBatchSize = (isLeftSemiOrAntiJoinNoFilter || emptyBuildSide)
      ? inputSize
      : outputBatchSize_;
  auto mapping =
      initializeRowNumberMapping(outputRowMapping_, outputBatchSize, pool());
  outputTableRows_.resize(outputBatchSize);

  for (;;) {
    int numOut = 0;

    if (emptyBuildSide) {
      // When build side is empty, anti and left joins return all probe side
      // rows, including ones with null join keys.