Method Slice

cpp/src/arrow/array/data.cc:189–207

}

std::shared_ptr<ArrayData> ArrayData::Slice(int64_t off, int64_t len) const {
  ARROW_CHECK_LE(off, length) << "Slice offset (" << off
                              << ") greater than array length (" << length << ")";
  len = std::min(length - off, len);
  off += offset;

  auto copy = this->Copy();
  copy->length = len;
  copy->offset = off;
  if (null_count == length) {
    copy->null_count = len;
  } else if (off == offset && len == length) {  // A copy of current.
    copy->null_count = null_count.load();
  } else {
    copy->null_count = null_count != 0 ? kUnknownNullCount : 0;
  }
  copy->statistics = nullptr;
  return copy;
}

Result<std::shared_ptr<ArrayData>> ArrayData::SliceSafe(int64_t off, int64_t len) const {
  RETURN_NOT_OK(internal::CheckSliceParams(length, off, len, "array"));