test_random_number_generator.cc 806 B

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  1. // Copyright 2018 The Chromium Authors. All rights reserved.
  2. // Use of this source code is governed by a BSD-style license that can be
  3. // found in the LICENSE file.
  4. #include "media/learning/impl/test_random_number_generator.h"
  5. namespace media {
  6. TestRandomNumberGenerator::TestRandomNumberGenerator(uint32_t seed) {
  7. seed_ = seed & 0x7fffffff; // make this a non-negative number
  8. if (seed_ == 0 || seed_ == M) {
  9. seed_ = 1;
  10. }
  11. }
  12. TestRandomNumberGenerator::~TestRandomNumberGenerator() = default;
  13. uint64_t TestRandomNumberGenerator::Generate() {
  14. static const uint64_t A = 16807; // bits 14, 8, 7, 5, 2, 1, 0
  15. uint64_t result = seed_ = static_cast<int32_t>((seed_ * A) % M);
  16. result <<= 32;
  17. result |= seed_ = static_cast<int32_t>((seed_ * A) % M);
  18. return result;
  19. }
  20. } // namespace media