std::shared_ptr ScanResultCache::CreateCompleteResult()

in src/hbase/client/scan-result-cache.cc [82:121]

• 28 lines of code
• 9 McCabe index (conditional complexity)

std::shared_ptr<Result> ScanResultCache::CreateCompleteResult(
    const std::vector<std::shared_ptr<Result>> &partial_results) {
  if (partial_results.empty()) {
    return std::make_shared<Result>(std::vector<std::shared_ptr<Cell>>{}, false, false, false);
  }
  std::vector<std::shared_ptr<Cell>> cells{};
  bool stale = false;
  std::string prev_row = "";
  std::string current_row = "";
  size_t i = 0;
  for (const auto &r : partial_results) {
    current_row = r->Row();
    if (i != 0 && prev_row != current_row) {
      throw new std::runtime_error(
          "Cannot form complete result. Rows of partial results do not match.");
    }
    // Ensure that all Results except the last one are marked as partials. The last result
    // may not be marked as a partial because Results are only marked as partials when
    // the scan on the server side must be stopped due to reaching the maxResultSize.
    // Visualizing it makes it easier to understand:
    // maxResultSize: 2 cells
    // (-x-) represents cell number x in a row
    // Example: row1: -1- -2- -3- -4- -5- (5 cells total)
    // How row1 will be returned by the server as partial Results:
    // Result1: -1- -2- (2 cells, size limit reached, mark as partial)
    // Result2: -3- -4- (2 cells, size limit reached, mark as partial)
    // Result3: -5- (1 cell, size limit NOT reached, NOT marked as partial)
    if (i != partial_results.size() - 1 && !r->Partial()) {
      throw new std::runtime_error("Cannot form complete result. Result is missing partial flag.");
    }
    prev_row = current_row;
    stale = stale || r->Stale();
    for (const auto &c : r->Cells()) {
      cells.push_back(c);
    }
    i++;
  }

  return std::make_shared<Result>(cells, false, stale, false);
}