Method test_unpickler

Lib/test/test_pickle.py:526–570

(self)

                0)  # Write buffer is cleared after every dump().

        def test_unpickler(self):
            basesize = support.calcobjsize('2P2n3P 2P2n2i5P 2P3n8P2n3i')
            unpickler = _pickle.Unpickler
            P = struct.calcsize('P')  # Size of memo table entry.
            n = struct.calcsize('n')  # Size of mark table entry.
            check = self.check_sizeof
            for encoding in 'ASCII', 'UTF-16', 'latin-1':
                for errors in 'strict', 'replace':
                    u = unpickler(io.BytesIO(),
                                  encoding=encoding, errors=errors)
                    self.assertEqual(object.__sizeof__(u), basesize)
                    check(u, basesize +
                             32 * P +  # Minimal memo table size.
                             len(encoding) + 1 + len(errors) + 1)

            stdsize = basesize + len('ASCII') + 1 + len('strict') + 1
            def check_unpickler(data, memo_size, marks_size):
                dump = pickle.dumps(data)
                u = unpickler(io.BytesIO(dump),
                              encoding='ASCII', errors='strict')
                u.load()
                check(u, stdsize + memo_size * P + marks_size * n)

            check_unpickler(0, 32, 0)
            # 20 is minimal non-empty mark stack size.
            check_unpickler([0] * 100, 32, 20)
            # 128 is memo table size required to save references to 100 objects.
            check_unpickler([chr(i) for i in range(100)], 128, 20)
            def recurse(deep):
                data = 0
                for i in range(deep):
                    data = [data, data]
                return data
            check_unpickler(recurse(0), 32, 0)
            check_unpickler(recurse(1), 32, 20)
            check_unpickler(recurse(20), 32, 20)
            check_unpickler(recurse(50), 64, 60)
            if not (support.is_wasi and support.Py_DEBUG):
                # stack depth too shallow in pydebug WASI.
                check_unpickler(recurse(100), 128, 140)

            u = unpickler(io.BytesIO(pickle.dumps('a', 0)),
                          encoding='ASCII', errors='strict')
            u.load()
            check(u, stdsize + 32 * P + 2 + 1)


ALT_IMPORT_MAPPING = {