Method apply

bolt/functions/prestosql/ArrayConstructor.cpp:43–126

  }

  void apply(
      const SelectivityVector& rows,
      std::vector<VectorPtr>& args,
      const TypePtr& outputType,
      exec::EvalCtx& context,
      VectorPtr& result) const override {
    auto numArgs = args.size();

    context.ensureWritable(rows, outputType, result);
    result->clearNulls(rows);
    auto arrayResult = result->as<ArrayVector>();
    auto sizes = arrayResult->mutableSizes(rows.end());
    auto rawSizes = sizes->asMutable<int32_t>();
    auto offsets = arrayResult->mutableOffsets(rows.end());
    auto rawOffsets = offsets->asMutable<int32_t>();

    auto elementsResult = arrayResult->elements();

    // append to the end of the "elements" vector
    auto baseOffset = elementsResult->size();

    if (args.empty()) {
      rows.applyToSelected([&](vector_size_t row) {
        rawSizes[row] = 0;
        rawOffsets[row] = baseOffset;
      });
    } else {
      elementsResult->resize(baseOffset + numArgs * rows.countSelected());

      if (shouldCopyRanges(elementsResult->type())) {
        std::vector<BaseVector::CopyRange> ranges;
        ranges.reserve(rows.end());

        vector_size_t offset = baseOffset;
        rows.applyToSelected([&](vector_size_t row) {
          rawSizes[row] = numArgs;
          rawOffsets[row] = offset;
          ranges.push_back({row, offset, 1});
          offset += numArgs;
        });

        elementsResult->copyRanges(args[0].get(), ranges);

        for (int i = 1; i < numArgs; i++) {
          for (auto& range : ranges) {
            ++range.targetIndex;
          }
          elementsResult->copyRanges(args[i].get(), ranges);
        }
      } else {
        SelectivityVector targetRows(elementsResult->size(), false);
        std::vector<vector_size_t> toSourceRow(elementsResult->size());

        vector_size_t offset = baseOffset;
        rows.applyToSelected([&](vector_size_t row) {
          rawSizes[row] = numArgs;
          rawOffsets[row] = offset;