1# Copyright 2014 Google Inc. All rights reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14 15"""fastrand.py - Python wrapper for _fastrand.""" 16 17# NOTE: We could retire this module in favor of the C++ client? One reason to 18# keep it is if it supports a wider range of params (e.g. more than 32 or 64 19# bits.) 20 21import random 22 23import _fastrand 24 25 26class FastIrrRand(object): 27 """Fast insecure version of rappor.SecureIrrRand.""" 28 29 def __init__(self, params): 30 randbits = _fastrand.randbits # accelerated function 31 num_bits = params.num_bloombits 32 33 # IRR probabilities 34 self.p_gen = lambda: randbits(params.prob_p, num_bits) 35 self.q_gen = lambda: randbits(params.prob_q, num_bits) 36