b += 1L
q_try = 2L**b
# Now try modulus = modulus_max explicitly
N = 1L
q_try = modulus_max
assert modulus_max >= modulus_min
a = 1L
X = 2L**a
logging.info("Trying modulus = modulus_max = {}".format(q_try))
logging.info(
"Unsigned to signed counter conversion, modulus = {}:".format(q_try))
try_adjust_count_signed(q_try)
logging.info("Success!")
# we interpret values >= modulus/2 as negative
# So make sure that modulus is larger than 2*(N*X + 1)
while X < q_try // 2L:
logging.debug("Trying count 2**{} = {} < modulus/2 ({})".format(
a, X, q_try // 2))
try_counters(counters, q_try, N, X, multi_bin=False)
# This should terminate in at most ~log2(modulus) steps
a += 1L
X = 2L**a
logging.info(
"Reached modulus = modulus_max = {} without overflow or inaccuracy".format(
q_try))
logging.info("Hard-coded counter values: {}".format(
add_counter_limits_to_config({})))
def check_stop_config(self, stop_config, counts):
'''
When the round stops, perform common client actions:
- log a message
- tell the collection_delay
'''
end_time = time()
response = {}
round_successful = False
wants_counters = stop_config.get('send_counters', False)
logging.info("tally server {} final counts".format(
"wants" if wants_counters else "does not want"))
if wants_counters and counts is not None:
logging.info("sending counts from {} counters ({} bins)".format(
len(counts), count_bins(counts)))
response['Counts'] = counts
# only delay a round if we have sent our counters
round_successful = True
else:
logging.info("No counts available")
# even though the counter limits are hard-coded, include them anyway
response['Config'] = add_counter_limits_to_config(self.config)
# and include the config sent by the tally server in do_start
if self.start_config is not None:
response['Config']['Start'] = deepcopy(self.start_config)
PrivCountNode.summarise_config_lists(response['Config']['Start'])
# and include the config sent by the tally server to stop
if stop_config is not None:
response['Config']['Stop'] = stop_config
# if we never started, there's no point in registering end of round
if (self.collect_period is None or self.last_noise_config is None
or self.collection_start_time is None):
logging.warning("TS sent stop command before start command")
return response
# Using the collect_period from the tally server is inaccurate,
# because the DCs and SKs do not check that the actual collection time
# requested by the TS matches the collection period it claims
actual_collect = end_time - self.collection_start_time
# add this info to the context
response['Config']['Time'] = {}
response['Config']['Time']['Start'] = self.collection_start_time
response['Config']['Time']['Stop'] = end_time
response['Config']['Time']['Collect'] = actual_collect
# Register the stop with the collection delay
self.collection_delay.set_delay_for_stop(
round_successful,
# set when the round started
self.last_noise_config,
self.collection_start_time,
end_time,
self.config['delay_period'],
always_delay=self.config['always_delay'],
tolerance=self.config['sigma_decrease_tolerance'])
logging.info("collection phase was stopped")
return response