TypePtr importFromArrow()

in velox/vector/arrow/Bridge.cpp [447:534]
70 lines of code
23 McCabe index (conditional complexity)

TypePtr importFromArrow(const ArrowSchema& arrowSchema) {
  const char* format = arrowSchema.format;
  VELOX_CHECK_NOT_NULL(format);

  switch (format[0]) {
    case 'b':
      return BOOLEAN();
    case 'c':
      return TINYINT();
    case 's':
      return SMALLINT();
    case 'i':
      return INTEGER();
    case 'l':
      return BIGINT();
    case 'f':
      return REAL();
    case 'g':
      return DOUBLE();

    // Map both utf-8 and large utf-8 string to varchar.
    case 'u':
    case 'U':
      return VARCHAR();

    // Same for binary.
    case 'z':
    case 'Z':
      return VARBINARY();

    case 't': // temporal types.
      // Mapping it to ttn for now.
      if (format[1] == 't' && format[2] == 'n') {
        return TIMESTAMP();
      }
      if (format[1] == 'd' && format[2] == 'D') {
        return DATE();
      }
      break;

    // Complex types.
    case '+': {
      switch (format[1]) {
        // Array/list.
        case 'L':
          VELOX_CHECK_EQ(arrowSchema.n_children, 1);
          VELOX_CHECK_NOT_NULL(arrowSchema.children[0]);
          return ARRAY(importFromArrow(*arrowSchema.children[0]));

        // Map.
        case 'm':
          VELOX_CHECK_EQ(arrowSchema.n_children, 2);
          VELOX_CHECK_NOT_NULL(arrowSchema.children[0]);
          VELOX_CHECK_NOT_NULL(arrowSchema.children[1]);
          return MAP(
              importFromArrow(*arrowSchema.children[0]),
              importFromArrow(*arrowSchema.children[1]));

        // Struct/rows.
        case 's': {
          // Loop collecting the child types and names.
          std::vector<TypePtr> childTypes;
          std::vector<std::string> childNames;
          childTypes.reserve(arrowSchema.n_children);
          childNames.reserve(arrowSchema.n_children);

          for (size_t i = 0; i < arrowSchema.n_children; ++i) {
            VELOX_CHECK_NOT_NULL(arrowSchema.children[i]);
            childTypes.emplace_back(importFromArrow(*arrowSchema.children[i]));
            childNames.emplace_back(
                arrowSchema.children[i]->name != nullptr
                    ? arrowSchema.children[i]->name
                    : "");
          }
          return ROW(std::move(childNames), std::move(childTypes));
        }

        default:
          break;
      }
    } break;

    default:
      break;
  }
  VELOX_USER_FAIL(
      "Unable to convert '{}' ArrowSchema format type to Velox.", format);
}