class ScheduledCallTest(unittest.TestCase):
default_args = (10, 'hello')
default_kwargs = {'a': 47, 'b': 'c'}
def setUp(self):
self.clock = Clock()
self.obj = ModifiedObject()
self.sc = ScheduledCall(self.obj.func, clock=self.clock,
*self.default_args,
**self.default_kwargs)
def _check(self, args, kwargs):
if args is None:
self.assertIsNone(self.obj.args)
else:
self.assertTupleEqual(self.obj.args, args)
if kwargs is None:
self.assertIsNone(self.obj.kwargs)
else:
self.assertEqual(self.obj.kwargs, kwargs)
def test_init(self):
# test initializing ScheduledCall without overriding its clock
sc = ScheduledCall(self.obj.func, *self.default_args,
**self.default_kwargs)
sc.schedule()
sc.cancel()
def test_get_time_and_is_scheduled(self):
self.clock.advance(10)
self.assertFalse(self.sc.is_scheduled())
self.assertEqual(self.sc.get_time(), 0)
self.sc.schedule(5)
self.assertTrue(self.sc.is_scheduled())
self.assertEqual(self.sc.get_time(), 15)
self.clock.advance(5)
self.assertFalse(self.sc.is_scheduled())
self.assertEqual(self.sc.get_time(), 0)
def test_no_delay(self):
self.sc.schedule()
self._check(None, None)
self.clock.advance(0)
self._check(self.default_args, self.default_kwargs)
def test_default(self):
self.assertTrue(self.sc.schedule(5))
self._check(None, None)
self.clock.advance(1)
self.assertFalse(self.sc.schedule(1))
self.clock.advance(2)
self._check(None, None)
self.clock.advance(3)
self._check(self.default_args, self.default_kwargs)
def test_cancel(self):
self.sc.schedule(5)
self.clock.advance(3)
self.sc.cancel()
self.clock.advance(3)
self._check(None, None)
self.assertTrue(self.sc.schedule(1))
self.clock.advance(1)
self._check(self.default_args, self.default_kwargs)
def test_overwrite(self):
over_args = ('crawlmi',)
over_kwargs = {'a': 50, 'd': 'e'}
self.sc.schedule(5, *over_args, **over_kwargs)
self.clock.advance(5)
self._check(over_args, over_kwargs)
def test_partial_overwrite(self):
over_args = ('crawlmi',)
self.sc.schedule(5, *over_args)
self.clock.advance(5)
self._check(over_args, {})
def test_nested_schedule(self):
def func(*args, **kwargs):
self.obj.func(*args, **kwargs)
self.sc.schedule()
self.sc.func = func
self.sc.schedule()
self.assertEqual(self.obj.num_calls, 0)
self.clock.advance(0)
self.assertEqual(self.obj.num_calls, 1)
self.clock.advance(0)
self.assertEqual(self.obj.num_calls, 2)
def test_nested_schedule_delay(self):
args1 = ('a',)
kwargs1 = {'a': 'b'}
args2 = ('b',)
kwargs2 = {'b': 'c'}
def func(*args, **kwargs):
self.obj.func(*args, **kwargs)
self.sc.schedule(4, *args2, **kwargs2)
self.sc.func = func
self.sc.schedule(3, *args1, **kwargs1)
self.clock.advance(3)
self.assertIsNotNone(self.sc._call)
self._check(args1, kwargs1)
self.clock.advance(3)
self._check(args1, kwargs1)
self.clock.advance(1)
self._check(args2, kwargs2)
class Slot(object):
'''Slot represents a queue of requests for one particular domain.
It respects both DOWNLOAD_DELAY and CONCURRENT_REQUESTS_PER_DOMAIN.
'''
def __init__(self, download_handler, concurrency, delay, randomize_delay,
clock=None):
self.download_handler = download_handler
self.concurrency = concurrency
self.delay = delay
self.randomize_delay = randomize_delay
self.in_progress = set() # request waiting to be downloaded
self.transferring = set() # requests being downloaded (subset of `in_progress`)
self.last_download_time = 0
self.queue = MemoryQueue() # queue of (request, deferred)
# clock is used in unittests
self.clock = clock or reactor
self.delayed_processing = ScheduledCall(self._process, clock=self.clock)
def enqueue(self, request, dfd):
'''Main entry point.
Put the new request to the queue and if possible, start downloading it.
'''
def remove_in_progress(response):
self.in_progress.remove(request)
return response
self.in_progress.add(request)
dfd.addBoth(remove_in_progress)
self.queue.push((request, dfd))
self._process()
@property
def free_slots(self):
return self.concurrency - len(self.transferring)
def is_idle(self):
return len(self.in_progress) == 0
def _process(self):
'''Process the requests in the queue, while respecting the delay and
concurrency.
'''
if self.delayed_processing.is_scheduled() or self._schedule_delay():
return
while self.queue and self.free_slots > 0:
self.last_download_time = self.clock.seconds()
request, downloaded_dfd = self.queue.pop()
dfd = self._download(request)
dfd.chainDeferred(downloaded_dfd)
if self._schedule_delay():
return
def _schedule_delay(self):
if self.delay:
penalty = (self.last_download_time + self.get_download_delay() -
self.clock.seconds())
if penalty > 0:
# following schedule should always be successfull, because
# `_schedule_delay()` is only called from within `_process()`
self.delayed_processing.schedule(penalty)
return True
return False
def _download(self, request):
dfd = defer.succeed(request)
# download the response
dfd.addCallback(self.download_handler.download_request)
# it is VERY important to wrap the failure into a new object!
# For errors like ConnectionLost, the same Failure object is returned
# everytime and we cannot use 'failure.request' field.
def wrap_failure(failure):
return Failure(failure.value)
dfd.addErrback(wrap_failure)
# put the request into the set of `transferring` to block other requests
# after the response is downloaded, remove it from `transferring`
def remove_transferring(response):
self.transferring.remove(request)
self._process() # process unblocked requests
return response
self.transferring.add(request)
dfd.addBoth(remove_transferring)
return dfd
def get_download_delay(self):
if self.randomize_delay:
return random.uniform(0.5 * self.delay, 1.5 * self.delay)
return self.delay
class ScheduledCallTest(unittest.TestCase):
default_args = (10, 'hello')
default_kwargs = {'a': 47, 'b': 'c'}
def setUp(self):
self.clock = Clock()
self.obj = ModifiedObject()
self.sc = ScheduledCall(self.obj.func,
clock=self.clock,
*self.default_args,
**self.default_kwargs)
def _check(self, args, kwargs):
if args is None:
self.assertIsNone(self.obj.args)
else:
self.assertTupleEqual(self.obj.args, args)
if kwargs is None:
self.assertIsNone(self.obj.kwargs)
else:
self.assertEqual(self.obj.kwargs, kwargs)
def test_init(self):
# test initializing ScheduledCall without overriding its clock
sc = ScheduledCall(self.obj.func, *self.default_args,
**self.default_kwargs)
sc.schedule()
sc.cancel()
def test_get_time_and_is_scheduled(self):
self.clock.advance(10)
self.assertFalse(self.sc.is_scheduled())
self.assertEqual(self.sc.get_time(), 0)
self.sc.schedule(5)
self.assertTrue(self.sc.is_scheduled())
self.assertEqual(self.sc.get_time(), 15)
self.clock.advance(5)
self.assertFalse(self.sc.is_scheduled())
self.assertEqual(self.sc.get_time(), 0)
def test_no_delay(self):
self.sc.schedule()
self._check(None, None)
self.clock.advance(0)
self._check(self.default_args, self.default_kwargs)
def test_default(self):
self.assertTrue(self.sc.schedule(5))
self._check(None, None)
self.clock.advance(1)
self.assertFalse(self.sc.schedule(1))
self.clock.advance(2)
self._check(None, None)
self.clock.advance(3)
self._check(self.default_args, self.default_kwargs)
def test_cancel(self):
self.sc.schedule(5)
self.clock.advance(3)
self.sc.cancel()
self.clock.advance(3)
self._check(None, None)
self.assertTrue(self.sc.schedule(1))
self.clock.advance(1)
self._check(self.default_args, self.default_kwargs)
def test_overwrite(self):
over_args = ('crawlmi', )
over_kwargs = {'a': 50, 'd': 'e'}
self.sc.schedule(5, *over_args, **over_kwargs)
self.clock.advance(5)
self._check(over_args, over_kwargs)
def test_partial_overwrite(self):
over_args = ('crawlmi', )
self.sc.schedule(5, *over_args)
self.clock.advance(5)
self._check(over_args, {})
def test_nested_schedule(self):
def func(*args, **kwargs):
self.obj.func(*args, **kwargs)
self.sc.schedule()
self.sc.func = func
self.sc.schedule()
self.assertEqual(self.obj.num_calls, 0)
self.clock.advance(0)
self.assertEqual(self.obj.num_calls, 1)
self.clock.advance(0)
self.assertEqual(self.obj.num_calls, 2)
def test_nested_schedule_delay(self):
args1 = ('a', )
kwargs1 = {'a': 'b'}
args2 = ('b', )
kwargs2 = {'b': 'c'}
def func(*args, **kwargs):
self.obj.func(*args, **kwargs)
self.sc.schedule(4, *args2, **kwargs2)
self.sc.func = func
self.sc.schedule(3, *args1, **kwargs1)
self.clock.advance(3)
self.assertIsNotNone(self.sc._call)
self._check(args1, kwargs1)
self.clock.advance(3)
self._check(args1, kwargs1)
self.clock.advance(1)
self._check(args2, kwargs2)
class Slot(object):
'''Slot represents a queue of requests for one particular domain.
It respects both DOWNLOAD_DELAY and CONCURRENT_REQUESTS_PER_DOMAIN.
'''
def __init__(self, download_handler, concurrency, delay, randomize_delay,
clock=None):
self.download_handler = download_handler
self.concurrency = concurrency
self.delay = delay
self.randomize_delay = randomize_delay
self.in_progress = set() # request waiting to be downloaded
self.transferring = set() # requests being downloaded (subset of `in_progress`)
self.last_download_time = 0
self.queue = MemoryQueue() # queue of (request, deferred)
# clock is used in unittests
self.clock = clock or reactor
self.delayed_processing = ScheduledCall(self._process, clock=self.clock)
def enqueue(self, request, dfd):
'''Main entry point.
Put the new request to the queue and if possible, start downloading it.
'''
def remove_in_progress(response):
self.in_progress.remove(request)
return response
self.in_progress.add(request)
dfd.addBoth(remove_in_progress)
self.queue.push((request, dfd))
self._process()
@property
def free_slots(self):
return self.concurrency - len(self.transferring)
def is_idle(self):
return len(self.in_progress) == 0
def _process(self):
'''Process the requests in the queue, while respecting the delay and
concurrency.
'''
if self.delayed_processing.is_scheduled() or self._schedule_delay():
return
while self.queue and self.free_slots > 0:
self.last_download_time = self.clock.seconds()
request, downloaded_dfd = self.queue.pop()
dfd = self._download(request)
dfd.chainDeferred(downloaded_dfd)
if self._schedule_delay():
return
def _schedule_delay(self):
if self.delay:
penalty = (self.last_download_time + self.get_download_delay() -
self.clock.seconds())
if penalty > 0:
# following schedule should always be successfull, because
# `_schedule_delay()` is only called from within `_process()`
self.delayed_processing.schedule(penalty)
return True
return False
def _download(self, request):
dfd = defer.succeed(request)
# download the response
dfd.addCallback(self.download_handler.download_request)
# it is VERY important to wrap the failure into a new object!
# For errors like ConnectionLost, the same Failure object is returned
# everytime and we cannot use 'failure.request' field.
def wrap_failure(failure):
return Failure(failure.value)
dfd.addErrback(wrap_failure)
# put the request into the set of `transferring` to block other requests
# after the response is downloaded, remove it from `transferring`
def remove_transferring(response):
self.transferring.remove(request)
self._process() # process unblocked requests
return response
self.transferring.add(request)
dfd.addBoth(remove_transferring)
return dfd
def get_download_delay(self):
if self.randomize_delay:
return random.uniform(0.5 * self.delay, 1.5 * self.delay)
return self.delay