Function deserialize

bolt/common/hyperloglog/DenseHll.cpp:248–275

}

DenseHllView deserialize(const char* serialized) {
  common::InputByteStream stream(serialized);

  auto version = stream.read<int8_t>();
  BOLT_CHECK_EQ(kPrestoDenseV2, version);

  auto indexBitLength = stream.read<int8_t>();
  auto baseline = stream.read<int8_t>();

  auto numBuckets = 1 << indexBitLength;
  // next numBuckets / 2 bytes are deltas
  const int8_t* deltas = stream.read<int8_t>(numBuckets / 2);

  auto overflows = stream.read<int16_t>();

  const uint16_t* overflowBuckets =
      overflows ? stream.read<uint16_t>(overflows) : nullptr;
  const int8_t* overflowValues =
      overflows ? stream.read<int8_t>(overflows) : nullptr;

  return DenseHllView{
      indexBitLength,
      baseline,
      deltas,
      overflows,
      overflowBuckets,
      overflowValues};
}
} // namespace

int64_t DenseHll::cardinality() const {