Method flush

bolt/serializers/PrestoSerializer.cpp:1493–1572

Writes out the accumulated contents. Does not change the state.

  // Writes out the accumulated contents. Does not change the state.
  void flush(OutputStream* out) {
    out->write(reinterpret_cast<char*>(header_.buffer), header_.size);

    if (encoding_.has_value()) {
      switch (encoding_.value()) {
        case VectorEncoding::Simple::CONSTANT: {
          writeInt32(out, nonNullCount_);
          children_[0]->flush(out);
          return;
        }
        case VectorEncoding::Simple::DICTIONARY: {
          writeInt32(out, nonNullCount_);
          children_[0]->flush(out);
          values_.flush(out);

          // Write 24 bytes of 'instance id'.
          int64_t unused{0};
          writeInt64(out, unused);
          writeInt64(out, unused);
          writeInt64(out, unused);
          return;
        }
        default:
          break;
      }
    }

    switch (type_->kind()) {
      case TypeKind::ROW:
      case TypeKind::VARIANT:
        if (isTimestampWithTimeZoneType(type_)) {
          writeInt32(out, nullCount_ + nonNullCount_);
          flushNulls(out);
          values_.flush(out);
          return;
        }

        writeInt32(out, children_.size());
        for (auto& child : children_) {
          child->flush(out);
        }
        writeInt32(out, nullCount_ + nonNullCount_);
        lengths_.flush(out);
        flushNulls(out);
        return;

      case TypeKind::ARRAY:
        children_[0]->flush(out);
        writeInt32(out, nullCount_ + nonNullCount_);
        lengths_.flush(out);
        flushNulls(out);
        return;

      case TypeKind::MAP: {
        children_[0]->flush(out);
        children_[1]->flush(out);
        // hash table size. -1 means not included in serialization.
        writeInt32(out, -1);