Method clear

bolt/serializers/PrestoSerializer.cpp:1589–1610

  }

  void clear() {
    encoding_ = std::nullopt;
    initializeHeader(typeToEncodingName(type_), *streamArena_);
    nonNullCount_ = 0;
    nullCount_ = 0;
    totalLength_ = 0;
    if (hasLengths_) {
      lengths_.startWrite(lengths_.size());
      if (type_->kind() == TypeKind::ROW || type_->kind() == TypeKind::ARRAY ||
          type_->kind() == TypeKind::MAP) {
        // The first element in the offsets in the wire format is always 0 for
        // nested types. Set upon construction/reset in case empty (no append
        // calls will be made).
        lengths_.appendOne<int32_t>(0);
      }
    }
    nulls_.startWrite(nulls_.size());
    values_.startWrite(values_.size());
    for (auto& child : children_) {
      child->clear();
    }
  }

 private:
  const TypePtr type_;