Function ValidateLegacy64

src/DartsDict.cpp:84–97

Mirror of Darts::DoubleArray::validate(); checks root sanity, offset bounds, and leaf value bounds to catch malformed legacy files before any traversal.

// Mirror of Darts::DoubleArray::validate(); checks root sanity, offset bounds,
// and leaf value bounds to catch malformed legacy files before any traversal.
bool ValidateLegacy64(const LegacyUnit64* arr, size_t numUnits, int maxValueLimit) {
  if (numUnits == 0) return false;
  if (arr[0].label() != 0 || arr[0].has_leaf() || arr[0].offset() == 0) return false;
  if (((static_cast<size_t>(arr[0].offset())) | 0xFFu) >= numUnits) return false;
  for (size_t i = 1; i < numUnits; ++i) {
    uint64_t lbl = arr[i].label();
    if (lbl <= 0xFF) {
      if (((i ^ static_cast<size_t>(arr[i].offset())) | 0xFFu) >= numUnits) return false;
    } else if (maxValueLimit >= 0) {
      if (arr[i].value() >= maxValueLimit) return false;
    }
  }
  return true;
}

}  // namespace