Function GetReversedBlock

cpp/src/arrow/util/bitmap_ops.cc:122–124

Get a reverse block of byte(uint8) using offsets, the result can be part of a left block and right block, length indicates the number of bits to be taken from the right block

// part of a left block and right block, length indicates the number of bits
// to be taken from the right block
uint8_t GetReversedBlock(uint8_t block_left, uint8_t block_right, uint8_t length) {
  return ReverseUint8(((block_right << 8) + block_left) >> length);
}

template <TransferMode mode>
void TransferBitmap(const uint8_t* data, int64_t offset, int64_t length,