uncrc32.py 文件源码

def compensate(buf, wanted):
    wanted ^= FINALXOR

    newBits = 0
    for i in range(32):
        if newBits & 1:
           newBits >>= 1
           newBits ^= CRCPOLY
        else:
           newBits >>= 1

        if wanted & 1:
           newBits ^= CRCINV

        wanted >>= 1

    newBits ^= crc32(buf) ^ FINALXOR
    return pack('<L', newBits)