diff options
Diffstat (limited to 'Lib/test/test_int.py')
| -rw-r--r-- | Lib/test/test_int.py | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/Lib/test/test_int.py b/Lib/test/test_int.py index 6fdf52e..cbbddf5 100644 --- a/Lib/test/test_int.py +++ b/Lib/test/test_int.py @@ -1,4 +1,5 @@ import sys +import time import unittest from test import support @@ -571,5 +572,200 @@ class IntTestCases(unittest.TestCase): self.assertEqual(int('1_2_3_4_5_6_7', 32), 1144132807) +class IntStrDigitLimitsTests(unittest.TestCase): + + int_class = int # Override this in subclasses to reuse the suite. + + def setUp(self): + super().setUp() + self._previous_limit = sys.get_int_max_str_digits() + sys.set_int_max_str_digits(2048) + + def tearDown(self): + sys.set_int_max_str_digits(self._previous_limit) + super().tearDown() + + def test_disabled_limit(self): + self.assertGreater(sys.get_int_max_str_digits(), 0) + self.assertLess(sys.get_int_max_str_digits(), 20_000) + with support.adjust_int_max_str_digits(0): + self.assertEqual(sys.get_int_max_str_digits(), 0) + i = self.int_class('1' * 20_000) + str(i) + self.assertGreater(sys.get_int_max_str_digits(), 0) + + def test_max_str_digits_edge_cases(self): + """Ignore the +/- sign and space padding.""" + int_class = self.int_class + maxdigits = sys.get_int_max_str_digits() + + int_class('1' * maxdigits) + int_class(' ' + '1' * maxdigits) + int_class('1' * maxdigits + ' ') + int_class('+' + '1' * maxdigits) + int_class('-' + '1' * maxdigits) + self.assertEqual(len(str(10 ** (maxdigits - 1))), maxdigits) + + def check(self, i, base=None): + with self.assertRaises(ValueError): + if base is None: + self.int_class(i) + else: + self.int_class(i, base) + + def test_max_str_digits(self): + maxdigits = sys.get_int_max_str_digits() + + self.check('1' * (maxdigits + 1)) + self.check(' ' + '1' * (maxdigits + 1)) + self.check('1' * (maxdigits + 1) + ' ') + self.check('+' + '1' * (maxdigits + 1)) + self.check('-' + '1' * (maxdigits + 1)) + self.check('1' * (maxdigits + 1)) + + i = 10 ** maxdigits + with self.assertRaises(ValueError): + str(i) + + def test_denial_of_service_prevented_int_to_str(self): + """Regression test: ensure we fail before performing O(N**2) work.""" + maxdigits = sys.get_int_max_str_digits() + assert maxdigits < 50_000, maxdigits # A test prerequisite. + get_time = time.process_time + if get_time() <= 0: # some platforms like WASM lack process_time() + get_time = time.monotonic + + huge_int = int(f'0x{"c"*65_000}', base=16) # 78268 decimal digits. + digits = 78_268 + with support.adjust_int_max_str_digits(digits): + start = get_time() + huge_decimal = str(huge_int) + seconds_to_convert = get_time() - start + self.assertEqual(len(huge_decimal), digits) + # Ensuring that we chose a slow enough conversion to measure. + # It takes 0.1 seconds on a Zen based cloud VM in an opt build. + if seconds_to_convert < 0.005: + raise unittest.SkipTest('"slow" conversion took only ' + f'{seconds_to_convert} seconds.') + + # We test with the limit almost at the size needed to check performance. + # The performant limit check is slightly fuzzy, give it a some room. + with support.adjust_int_max_str_digits(int(.995 * digits)): + with self.assertRaises(ValueError) as err: + start = get_time() + str(huge_int) + seconds_to_fail_huge = get_time() - start + self.assertIn('conversion', str(err.exception)) + self.assertLess(seconds_to_fail_huge, seconds_to_convert/8) + + # Now we test that a conversion that would take 30x as long also fails + # in a similarly fast fashion. + extra_huge_int = int(f'0x{"c"*500_000}', base=16) # 602060 digits. + with self.assertRaises(ValueError) as err: + start = get_time() + # If not limited, 8 seconds said Zen based cloud VM. + str(extra_huge_int) + seconds_to_fail_extra_huge = get_time() - start + self.assertIn('conversion', str(err.exception)) + self.assertLess(seconds_to_fail_extra_huge, seconds_to_convert/8) + + def test_denial_of_service_prevented_str_to_int(self): + """Regression test: ensure we fail before performing O(N**2) work.""" + maxdigits = sys.get_int_max_str_digits() + assert maxdigits < 100_000, maxdigits # A test prerequisite. + get_time = time.process_time + if get_time() <= 0: # some platforms like WASM lack process_time() + get_time = time.monotonic + + digits = 133700 + huge = '8'*digits + with support.adjust_int_max_str_digits(digits): + start = get_time() + int(huge) + seconds_to_convert = get_time() - start + # Ensuring that we chose a slow enough conversion to measure. + # It takes 0.1 seconds on a Zen based cloud VM in an opt build. + if seconds_to_convert < 0.005: + raise unittest.SkipTest('"slow" conversion took only ' + f'{seconds_to_convert} seconds.') + + with support.adjust_int_max_str_digits(digits - 1): + with self.assertRaises(ValueError) as err: + start = get_time() + int(huge) + seconds_to_fail_huge = get_time() - start + self.assertIn('conversion', str(err.exception)) + self.assertLess(seconds_to_fail_huge, seconds_to_convert/8) + + # Now we test that a conversion that would take 30x as long also fails + # in a similarly fast fashion. + extra_huge = '7'*1_200_000 + with self.assertRaises(ValueError) as err: + start = get_time() + # If not limited, 8 seconds in the Zen based cloud VM. + int(extra_huge) + seconds_to_fail_extra_huge = get_time() - start + self.assertIn('conversion', str(err.exception)) + self.assertLess(seconds_to_fail_extra_huge, seconds_to_convert/8) + + def test_power_of_two_bases_unlimited(self): + """The limit does not apply to power of 2 bases.""" + maxdigits = sys.get_int_max_str_digits() + + for base in (2, 4, 8, 16, 32): + with self.subTest(base=base): + self.int_class('1' * (maxdigits + 1), base) + assert maxdigits < 100_000 + self.int_class('1' * 100_000, base) + + def test_underscores_ignored(self): + maxdigits = sys.get_int_max_str_digits() + + triples = maxdigits // 3 + s = '111' * triples + s_ = '1_11' * triples + self.int_class(s) # succeeds + self.int_class(s_) # succeeds + self.check(f'{s}111') + self.check(f'{s_}_111') + + def test_sign_not_counted(self): + int_class = self.int_class + max_digits = sys.get_int_max_str_digits() + s = '5' * max_digits + i = int_class(s) + pos_i = int_class(f'+{s}') + assert i == pos_i + neg_i = int_class(f'-{s}') + assert -pos_i == neg_i + str(pos_i) + str(neg_i) + + def _other_base_helper(self, base): + int_class = self.int_class + max_digits = sys.get_int_max_str_digits() + s = '2' * max_digits + i = int_class(s, base) + if base > 10: + with self.assertRaises(ValueError): + str(i) + elif base < 10: + str(i) + with self.assertRaises(ValueError) as err: + int_class(f'{s}1', base) + + def test_int_from_other_bases(self): + base = 3 + with self.subTest(base=base): + self._other_base_helper(base) + base = 36 + with self.subTest(base=base): + self._other_base_helper(base) + + +class IntSubclassStrDigitLimitsTests(IntStrDigitLimitsTests): + int_class = IntSubclass + + if __name__ == "__main__": unittest.main() |