Method evalSpecialForm

bolt/expression/SwitchExpr.cpp:73–186

}

void SwitchExpr::evalSpecialForm(
    const SelectivityVector& rows,
    EvalCtx& context,
    VectorPtr& finalResult) {
  VectorPtr localResult;
  LocalSelectivityVector remainingRows(context, rows);

  LocalSelectivityVector thenRows(context);

  // SWITCH: fix finalSelection at "rows" unless already fixed
  ScopedFinalSelectionSetter scopedFinalSelectionSetter(context, &rows);
  if (propagatesNulls_) {
    // If propagates nulls, we load lazies before conditions so that we can
    // avoid errors for null rows. Null propagation is on only if all thens and
    // else load access the same vectors, so there is no extra loading.
    auto& remaining = *remainingRows.get();
    for (auto* field : distinctFields_) {
      context.ensureFieldLoaded(field->index(context), remaining);
      const auto& vector = context.getField(field->index(context));
      if (vector->mayHaveNulls()) {
        LocalDecodedVector decoded(context, *vector, remaining);
        addNulls(remaining, decoded->nulls(&remaining), context, localResult);
        remaining.deselectNulls(
            decoded->nulls(&remaining), remaining.begin(), remaining.end());
      }
    }
  }

  VectorPtr condition;
  const uint64_t* values;

  for (auto i = 0; i < numCases_; i++) {
    context.releaseVector(condition);

    if (!remainingRows.get()->hasSelections()) {
      break;
    }

    // evaluate the case condition
    inputs_[2 * i]->eval(*remainingRows.get(), context, condition);

    if (context.errors()) {
      context.deselectErrors(*remainingRows);
      if (!remainingRows->hasSelections()) {
        break;
      }
    }

    const auto booleanMix = getFlatBool(
        condition.get(),
        *remainingRows.get(),
        context,
        &tempValues_,
        nullptr,
        true,
        &values,
        nullptr);
    switch (booleanMix) {