Hi Terry, Thanks, but I didn't care because my password is not so long. I just want to illustrate real world bytes xor usage. BTW, New MySQL auth methods (sha256 and caching_sha2) use bytes xor too.
For performance point of view, websocket masking is performance critical. Tornado uses extension module only for it. If bytearray ^= bytes is supported, websocket frame masking may look like: frame ^= mask * ((len(frame)+3)//4) # mask is 4 bytes long On Sat, Jun 23, 2018 at 1:26 AM Terry Reedy <tjre...@udel.edu> wrote: > On 6/22/2018 7:08 AM, INADA Naoki wrote: > > Bitwise xor is used for "masking" code like these: > > > > > https://github.com/PyMySQL/PyMySQL/blob/37eba60439039eff17b32ef1a63b45c25ea28cec/pymysql/connections.py#L139-L146 > > This points to a function _my_crypt that is O(n*n) because of using > bytes.append. Using bytearray.append makes it O(n). > --- > import random > import struct > import timeit > > range_type = range > > def _my_crypt(message1, message2): > length = len(message1) > result = b'' > for i in range_type(length): > x = (struct.unpack('B', message1[i:i+1])[0] ^ > struct.unpack('B', message2[i:i+1])[0]) > result += struct.pack('B', x) > return result > > def _my_crypt2(message1, message2): > length = len(message1) > result = bytearray() > for i in range_type(length): > x = (struct.unpack('B', message1[i:i+1])[0] ^ > struct.unpack('B', message2[i:i+1])[0]) > result += struct.pack('B', x) > return bytes(result) > > def make(n): > result = bytearray() > for i in range(n): > result.append(random.randint(0, 255)) > return result > > for m in (10, 100, 1000, 10_000, 100_000, 1000_000): > m1 = make(m) > m2 = make(m) > > n = 1000_000 // m > print(f'bytes len {m}, timeit reps {n}') > print('old ', timeit.timeit('_my_crypt(m1, m2)', number = n, > globals=globals())) > print('new ', timeit.timeit('_my_crypt2(m1, m2)', number = n, > globals=globals())) > --- > prints > > bytes len 10, timeit reps 100000 > old 1.2277594129999998 > new 1.2174212309999999 > bytes len 100, timeit reps 10000 > old 1.145566423 > new 1.0924002120000003 > bytes len 1000, timeit reps 1000 > old 1.2860306190000002 > new 1.1168685839999999 > bytes len 10000, timeit reps 100 > old 1.6543344650000003 > new 1.118191714 > bytes len 100000, timeit reps 10 > old 4.2568492110000005 > new 1.1266137560000011 > bytes len 1000000, timeit reps 1 > old 60.651238144000004 > new 1.1315020199999992 > > I tried to submit this to https://github.com/PyMySQL/PyMySQL/issues/new > but [Submit] does not work for me. > > -- > Terry Jan Reedy > > _______________________________________________ > Python-ideas mailing list > Python-ideas@python.org > https://mail.python.org/mailman/listinfo/python-ideas > Code of Conduct: http://python.org/psf/codeofconduct/ > -- INADA Naoki <songofaca...@gmail.com>
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