test_utils.py 文件源码

def test_decode_bytes_padding(self):
        "test decode_bytes() ignores padding bits"
        bchr = (lambda v: bytes([v])) if PY3 else chr
        engine = self.engine
        m = self.m
        decode = engine.decode_bytes
        BNULL = b("\x00")

        # length == 2 mod 4: 4 bits of padding
        self.assertEqual(decode(m(0,0)), BNULL)
        for i in range(0,6):
            if engine.big: # 4 lsb padding
                correct = BNULL if i < 4 else bchr(1<<(i-4))
            else: # 4 msb padding
                correct = bchr(1<<(i+6)) if i < 2 else BNULL
            self.assertEqual(decode(m(0,1<<i)), correct, "%d/4 bits:" % i)

        # length == 3 mod 4: 2 bits of padding
        self.assertEqual(decode(m(0,0,0)), BNULL*2)
        for i in range(0,6):
            if engine.big: # 2 lsb are padding
                correct = BNULL if i < 2 else bchr(1<<(i-2))
            else: # 2 msg are padding
                correct = bchr(1<<(i+4)) if i < 4 else BNULL
            self.assertEqual(decode(m(0,0,1<<i)), BNULL + correct,
                             "%d/2 bits:" % i)