void mergePriorityQueues()

in cpp/src/std_utils.h [118:142]

• 19 lines of code
• 7 McCabe index (conditional complexity)

void mergePriorityQueues(
    std::priority_queue<std::tuple<dist_t, indexID_t, label_t>> &dest,
    std::priority_queue<std::pair<dist_t, label_t>> &src, size_t maxElements,
    indexID_t indexID, const label_t idMask, const std::set<label_t> &labels,
    const dist_t maximumDistance) {
  std::vector<std::pair<dist_t, hnswlib::labeltype>> &items =
      GetContainerForQueue(src);
  for (auto i = items.begin(); i != items.end(); i++) {
    // To avoid copying unnecessarily, only move elements if:
    // - We don't have maxElements in `dest` yet
    // - `dest` is full, but the element being added would not be the new `top`
    // (i.e.: it's smaller)

    if (dest.size() < maxElements || i->first < std::get<0>(dest.top())) {
      if (idMask == 0 || labels.count(i->second & idMask) != 0) {
        if (i->first <= maximumDistance) {
          dest.push({i->first, indexID, i->second});
        }
      }
    }
  }

  while (dest.size() > maxElements)
    dest.pop();
}