Function appendBudgetFillSamples

app/src/Sessions/ReportData.cpp:386–416

* @brief Appends evenly-spaced samples until @p indices reaches @p budget. */

 * @brief Appends evenly-spaced samples until @p indices reaches @p budget.
 */
static void appendBudgetFillSamples(std::size_t count,
                                    std::size_t budget,
                                    std::vector<std::size_t>& indices)
{
  Q_ASSERT(count >= budget);
  Q_ASSERT(indices.size() <= budget);

  std::vector<unsigned char> used(count, 0);
  for (const auto index : indices) {
    Q_ASSERT(index < count);
    used[index] = 1;
  }

  const std::size_t divisor = budget - 1;
  for (std::size_t i = 0; i < budget && indices.size() < budget; ++i) {
    const std::size_t index = (i == divisor) ? count - 1 : (i * (count - 1)) / divisor;
    if (used[index])
      continue;

    used[index] = 1;
    indices.push_back(index);
  }

  for (std::size_t i = 0; i < count && indices.size() < budget; ++i) {
    if (used[i])
      continue;

    used[i] = 1;
    indices.push_back(i);
  }
}

/**
 * @brief Copies the selected samples into @p series in chronological order.