auto kll_sketch::serialize()

in kll/include/kll_sketch_impl.hpp [400:438]

• 39 lines of code
• 10 McCabe index (conditional complexity)

auto kll_sketch<T, C, A>::serialize(unsigned header_size_bytes, const SerDe& sd) const -> vector_bytes {
  const bool is_single_item = n_ == 1;
  const size_t size = header_size_bytes + get_serialized_size_bytes(sd);
  vector_bytes bytes(size, 0, allocator_);
  uint8_t* ptr = bytes.data() + header_size_bytes;
  const uint8_t* end_ptr = ptr + size;
  const uint8_t preamble_ints(is_empty() || is_single_item ? PREAMBLE_INTS_SHORT : PREAMBLE_INTS_FULL);
  ptr += copy_to_mem(preamble_ints, ptr);
  const uint8_t serial_version(is_single_item ? SERIAL_VERSION_2 : SERIAL_VERSION_1);
  ptr += copy_to_mem(serial_version, ptr);
  const uint8_t family(FAMILY);
  ptr += copy_to_mem(family, ptr);
  const uint8_t flags_byte(
      (is_empty() ? 1 << flags::IS_EMPTY : 0)
    | (is_level_zero_sorted_ ? 1 << flags::IS_LEVEL_ZERO_SORTED : 0)
    | (is_single_item ? 1 << flags::IS_SINGLE_ITEM : 0)
  );
  ptr += copy_to_mem(flags_byte, ptr);
  ptr += copy_to_mem(k_, ptr);
  ptr += copy_to_mem(m_, ptr);
  ptr += sizeof(uint8_t); // unused
  if (!is_empty()) {
    if (!is_single_item) {
      ptr += copy_to_mem(n_, ptr);
      ptr += copy_to_mem(min_k_, ptr);
      ptr += copy_to_mem(num_levels_, ptr);
      ptr += sizeof(uint8_t); // unused
      ptr += copy_to_mem(levels_.data(), ptr, sizeof(levels_[0]) * num_levels_);
      ptr += sd.serialize(ptr, end_ptr - ptr, &*min_item_, 1);
      ptr += sd.serialize(ptr, end_ptr - ptr, &*max_item_, 1);
    }
    const size_t bytes_remaining = end_ptr - ptr;
    ptr += sd.serialize(ptr, bytes_remaining, &items_[levels_[0]], get_num_retained());
  }
  const size_t delta = ptr - bytes.data();
  if (delta != size) throw std::logic_error("serialized size mismatch: " + std::to_string(delta)
      + " != " + std::to_string(size));
  return bytes;
}