void var_opt_sketch::serialize()

in sampling/include/var_opt_sketch_impl.hpp [400:459]
43 lines of code
13 McCabe index (conditional complexity)

void var_opt_sketch<T, A>::serialize(std::ostream& os, const SerDe& sd) const {
  const bool empty = (h_ == 0) && (r_ == 0);

  const uint8_t preLongs = (empty ? PREAMBLE_LONGS_EMPTY
                                  : (r_ == 0 ? PREAMBLE_LONGS_WARMUP : PREAMBLE_LONGS_FULL));
  const uint8_t first_byte = (preLongs & 0x3F) | ((static_cast<uint8_t>(rf_)) << 6);
  uint8_t flags = (marks_ != nullptr ? GADGET_FLAG_MASK : 0);

  if (empty) {
    flags |= EMPTY_FLAG_MASK;
  }

  // first prelong
  const uint8_t ser_ver(SER_VER);
  const uint8_t family(FAMILY_ID);
  write(os, first_byte);
  write(os, ser_ver);
  write(os, family);
  write(os, flags);
  write(os, k_);

  if (!empty) {
    // second and third prelongs
    write(os, n_);
    write(os, h_);
    write(os, r_);
    
    // fourth prelong, if needed
    if (r_ > 0) {
      write(os, total_wt_r_);
    }

    // write the first h_ weights
    write(os, weights_, h_ * sizeof(double));

    // write the first h_ marks as packed bytes iff we have a gadget
    if (marks_ != nullptr) {
      uint8_t val = 0;
      for (uint32_t i = 0; i < h_; ++i) {
        if (marks_[i]) {
          val |= 0x1 << (i & 0x7);
        }

        if ((i & 0x7) == 0x7) {
          write(os, val);
          val = 0;
        }
      }

      // write out any remaining values
      if ((h_ & 0x7) > 0) {
        write(os, val);
      }
    }

    // write the sample items, skipping the gap. Either h_ or r_ may be 0
    sd.serialize(os, data_, h_);
    sd.serialize(os, &data_[h_ + 1], r_);
  }
}