class ExponentialBackoffTests(TestCase):
TEST_CASES = [
{"attempts": 0, "expected_delay": 0},
{"attempts": 1, "expected_delay": BASE_DELAY},
{"attempts": 4, "expected_delay": BASE_DELAY * fake_pick_up_to(2**4-1)}
]
def setUp(self):
self.backoff = ExponentialBackoff(BASE_DELAY)
@patch.object(ExponentialBackoff, "_pick_up_to", side_effect=fake_pick_up_to)
def test_delay(self, mock):
for each_case in self.TEST_CASES:
self._do_test_delay(**each_case)
def _do_test_delay(self, attempts, expected_delay):
delay = self.backoff.delay(attempts)
self.assertEqual(expected_delay, delay,
"Error! delay({0:d}) = {1:d} (found {2:d})".format(attempts, expected_delay, delay))
def test_pick_up_to(self):
limit = BASE_DELAY * (2 ** 5 - 1)
for i in range(100):
delay = self.backoff.delay(5)
self.assertGreaterEqual(limit, delay)
def create_backoff(self, delay):
if delay.strategy == delay.CONSTANT:
return ConstantBackoff(delay.base_delay)
elif delay.strategy == delay.EXPONENTIAL:
return ExponentialBackoff(delay.base_delay)
else:
raise ValueError("Unknown backoff strategy '{0:s}' (options are 'constant' and 'exponential')")
class ExponentialBackoffTests(TestCase):
TEST_CASES = [{
"attempts": 0,
"expected_delay": 0
}, {
"attempts": 1,
"expected_delay": BASE_DELAY
}, {
"attempts": 4,
"expected_delay": BASE_DELAY * fake_pick_up_to(2**4 - 1)
}]
def setUp(self):
self.backoff = ExponentialBackoff(BASE_DELAY)
@patch.object(ExponentialBackoff,
"_pick_up_to",
side_effect=fake_pick_up_to)
def test_delay(self, mock):
for each_case in self.TEST_CASES:
self._do_test_delay(**each_case)
def _do_test_delay(self, attempts, expected_delay):
delay = self.backoff.delay(attempts)
self.assertEqual(
expected_delay, delay,
"Error! delay({0:d}) = {1:d} (found {2:d})".format(
attempts, expected_delay, delay))
def test_pick_up_to(self):
limit = BASE_DELAY * (2**5 - 1)
for i in range(100):
delay = self.backoff.delay(5)
self.assertGreaterEqual(limit, delay)
def setUp(self):
self.backoff = ExponentialBackoff(BASE_DELAY)
def setUp(self):
self.backoff = ExponentialBackoff(BASE_DELAY)
