def ConcatCrc32c(crc_a, crc_b, num_bytes_in_b):
  if not num_bytes_in_b:
    return crc_a

  return _ExtendByZeros(crc_a, 8 * num_bytes_in_b) ^ crc_b
Computes CRC32C for concat(A, B) given crc(A), crc(B) and len(B).
dataset/ETHPy150Open GoogleCloudPlatform/gsutil/gslib/hashing_helper.py/ConcatCrc32c