def retryCall(fn,
args=None,
keywordArgs=None,
failureTester=None,
sleepManager=None):
"""Calls the given function, automatically retrying as necessary.
Arguments:
fn: The function to call.
failureTester: Function called with a failure. The failure should be re-raised if it is not allowable.
sleepManager: A sleep manager to control how long to sleep between retries.
args: Args to pass to the function.
keywordArgs: keywordArgs to pass to the function.
Returns:
A deferred that will be called on success.
"""
sleepManager = sleepManager or time.SleepManager()
while True:
try:
result = yield fn(*args, **keywordArgs)
defer.returnValue(result)
except Exception: # pylint: disable=W0703
failureTester(failure.Failure())
yield sleepManager.sleep()
def __init__(self, fn, failureTester, sleepManager, args, keywordArgs):
defer.Deferred.__init__(self)
self.__fn = fn
self.__failureTester = failureTester
self.__sleepManager = sleepManager or time.SleepManager()
self.__args = args or []
self.__keywordArgs = keywordArgs or {}
self.__currentTry = None
self.__tryCall()
def testTwoTries(self):
"""Test a two try cache."""
original = mox.MockAnything()
original.getHostByName('google.com').AndReturn(
defer.fail(
failure.Failure(error.DNSLookupError('Fake DNS failure'))))
original.getHostByName('google.com').AndReturn(
defer.succeed('1.2.3.4'))
mox.Replay(original)
cache = dnsRetry.RetryingDNS(original,
tries=2,
sleep=time.SleepManager(0, 0, 0))
result = cache.getHostByName('google.com')
self.assertEquals(result, '1.2.3.4')
mox.Verify(original)
def __init__(self, original, tries=5, sleep=time.SleepManager(5, 60, 10)):
self._original = original
self._tries = tries
self._sleep = sleep