Function BitmapEquals

cpp/src/arrow/util/bitmap_ops.cc:273–310

}

bool BitmapEquals(const uint8_t* left, int64_t left_offset, const uint8_t* right,
                  int64_t right_offset, int64_t length) {
  if (left_offset % 8 == 0 && right_offset % 8 == 0) {
    // byte aligned, can use memcmp
    bool bytes_equal =
        std::memcmp(left + left_offset / 8, right + right_offset / 8, length / 8) == 0;
    if (!bytes_equal) {
      return false;
    }
    for (int64_t i = (length / 8) * 8; i < length; ++i) {
      if (bit_util::GetBit(left, left_offset + i) !=
          bit_util::GetBit(right, right_offset + i)) {
        return false;
      }
    }
    return true;
  }

  // Unaligned slow case
  auto left_reader = internal::BitmapWordReader<uint64_t>(left, left_offset, length);
  auto right_reader = internal::BitmapWordReader<uint64_t>(right, right_offset, length);

  auto nwords = left_reader.words();
  while (nwords--) {
    if (left_reader.NextWord() != right_reader.NextWord()) {
      return false;
    }
  }
  auto nbytes = left_reader.trailing_bytes();
  while (nbytes--) {
    int valid_bits;
    if (left_reader.NextTrailingByte(valid_bits) !=
        right_reader.NextTrailingByte(valid_bits)) {
      return false;
    }
  }
  return true;
}

bool OptionalBitmapEquals(const uint8_t* left, int64_t left_offset, const uint8_t* right,
                          int64_t right_offset, int64_t length) {