1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef CHRE_WIFI_OFFLOAD_TEST_RANDOM_GENERATOR_H_ 18 #define CHRE_WIFI_OFFLOAD_TEST_RANDOM_GENERATOR_H_ 19 20 #include <cinttypes> 21 #include <random> 22 23 namespace wifi_offload_test { 24 25 /** 26 * @class RandomGenerator A class to generate random values for any uint type: 27 * (uint8_t, ..., uint64_t). Also supports resetting to its initial 28 * state to be able to reproduce the same random sequence. 29 */ 30 class RandomGenerator { 31 public: 32 /** 33 * Default constructs a RandomGenerator object 34 */ 35 RandomGenerator(); 36 37 /** 38 * Resets the object to its initial state. Useful if we want to reproduce the 39 * exact same sequenct again. 40 */ 41 void Reset(); 42 43 /** 44 * Generates a random number of type IntType 45 * 46 * @return A random number of type IntType 47 */ 48 template <typename IntType> get()49 IntType get() { 50 return static_cast<IntType>(uniform_distribution_(random_engine_)); 51 } 52 53 private: 54 /* The initial seed kept to use again when need to reset */ 55 std::random_device::result_type initial_seed_; 56 57 /* Standard mersenne_twister_engine */ 58 std::mt19937 random_engine_; 59 60 /** 61 * Use uniform_distribution_ to transform the random unsigned int generated by 62 * random_engine_ into an uint64_t 63 */ 64 std::uniform_int_distribution<uint64_t> uniform_distribution_; 65 }; 66 67 } // namespace wifi_offload_test 68 69 #endif // CHRE_WIFI_OFFLOAD_TEST_RANDOM_GENERATOR_H_ 70