Method evalArgsDefaultNulls

bolt/expression/Expr.cpp:388–457

template <typename EvalArg>
bool Expr::evalArgsDefaultNulls(
    MutableRemainingRows& rows,
    EvalArg evalArg,
    EvalCtx& context,
    VectorPtr& result) {
  ErrorVectorPtr argumentErrors;
  ErrorVectorPtr originalErrors;
  LocalDecodedVector decoded(context);
  // Store pre-existing errors locally and clear them from
  // 'context'. We distinguish between argument errors and
  // pre-existing ones.
  if (context.errors()) {
    context.swapErrors(originalErrors);
  }

  inputValues_.resize(inputs_.size());
  {
    ScopedVarSetter throwErrors(
        context.mutableThrowOnError(), throwArgumentErrors(context));

    for (int32_t i = 0; i < inputs_.size(); ++i) {
      evalArg(i);
      const uint64_t* flatNulls = nullptr;
      auto& arg = inputValues_[i];
      if (arg->mayHaveNulls()) {
        decoded.get()->decode(*arg, rows.rows());
        flatNulls = decoded.get()->nulls(&rows.rows());
      }
      // A null with no error deselects the row.
      // An error adds itself to argument errors.
      if (context.errors()) {
        // There are new errors.
        context.ensureErrorsVectorSize(*context.errorsPtr(), rows.rows().end());
        auto newErrors = context.errors();
        assert(newErrors); // lint
        if (flatNulls) {
          // There are both nulls and errors. Only a null with no error removes
          // a row.
          auto errorNulls = newErrors->rawNulls();
          auto rowBits = rows.mutableRows().asMutableRange().bits();
          auto nwords = bits::nwords(rows.rows().end());
          for (auto j = 0; j < nwords; ++j) {
            auto nullNoError =
                errorNulls ? flatNulls[j] | errorNulls[j] : flatNulls[j];
            rowBits[j] &= nullNoError;
          }
          rows.mutableRows().updateBounds();
        }
        context.moveAppendErrors(argumentErrors);
      } else if (flatNulls) {
        rows.deselectNulls(flatNulls);
      }

      if (!rows.rows().hasSelections()) {
        break;
      }
    }
  }