source/fuzz/pseudo_random_generator.cpp

   1 // Copyright (c) 2019 Google LLC
   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 #include "source/fuzz/pseudo_random_generator.h"
  16
  17 #include <cassert>
  18
  19 namespace spvtools {
  20 namespace fuzz {
  21
  22 PseudoRandomGenerator::PseudoRandomGenerator(uint32_t seed) : mt_(seed) {}
  23
  24 PseudoRandomGenerator::~PseudoRandomGenerator() = default;
  25
  26 uint32_t PseudoRandomGenerator::RandomUint32(uint32_t bound) {
  27   assert(bound > 0 && "Bound must be positive");
  28   return std::uniform_int_distribution<uint32_t>(0, bound - 1)(mt_);
  29 }
  30
  31 uint64_t PseudoRandomGenerator::RandomUint64(uint64_t bound) {
  32   assert(bound > 0 && "Bound must be positive");
  33   return std::uniform_int_distribution<uint64_t>(0, bound - 1)(mt_);
  34 }
  35
  36 bool PseudoRandomGenerator::RandomBool() {
  37   return static_cast<bool>(std::uniform_int_distribution<>(0, 1)(mt_));
  38 }
  39
  40 uint32_t PseudoRandomGenerator::RandomPercentage() {
  41   // We use 101 because we want a result in the closed interval [0, 100], and
  42   // RandomUint32 is not inclusive of its bound.
  43   return RandomUint32(101);
  44 }
  45
  46 double PseudoRandomGenerator::RandomDouble() {
  47   return std::uniform_real_distribution<double>(0.0, 1.0)(mt_);
  48 }
  49
  50 }  // namespace fuzz
  51 }  // namespace spvtools