hash_generator_testing.cc (2141B)
1 // Copyright 2018 The Abseil Authors. 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 // https://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 "absl/container/internal/hash_generator_testing.h" 16 17 #include <deque> 18 19 #include "absl/base/no_destructor.h" 20 21 namespace absl { 22 ABSL_NAMESPACE_BEGIN 23 namespace container_internal { 24 namespace hash_internal { 25 namespace { 26 27 class RandomDeviceSeedSeq { 28 public: 29 using result_type = typename std::random_device::result_type; 30 31 template <class Iterator> 32 void generate(Iterator start, Iterator end) { 33 while (start != end) { 34 *start = gen_(); 35 ++start; 36 } 37 } 38 39 private: 40 std::random_device gen_; 41 }; 42 43 } // namespace 44 45 std::mt19937_64* GetSharedRng() { 46 static absl::NoDestructor<std::mt19937_64> rng([] { 47 RandomDeviceSeedSeq seed_seq; 48 return std::mt19937_64(seed_seq); 49 }()); 50 return rng.get(); 51 } 52 53 std::string Generator<std::string>::operator()() const { 54 // NOLINTNEXTLINE(runtime/int) 55 std::uniform_int_distribution<short> chars(0x20, 0x7E); 56 std::string res; 57 res.resize(32); 58 std::generate(res.begin(), res.end(), 59 [&]() { return chars(*GetSharedRng()); }); 60 return res; 61 } 62 63 absl::string_view Generator<absl::string_view>::operator()() const { 64 static absl::NoDestructor<std::deque<std::string>> arena; 65 // NOLINTNEXTLINE(runtime/int) 66 std::uniform_int_distribution<short> chars(0x20, 0x7E); 67 arena->emplace_back(); 68 auto& res = arena->back(); 69 res.resize(32); 70 std::generate(res.begin(), res.end(), 71 [&]() { return chars(*GetSharedRng()); }); 72 return res; 73 } 74 75 } // namespace hash_internal 76 } // namespace container_internal 77 ABSL_NAMESPACE_END 78 } // namespace absl