abseil-cpp/absl/container/internal/hash_generator_testing.cc

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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
#include "absl/container/internal/hash_generator_testing.h"
 
#include <deque>
 
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
namespace hash_internal {
namespace {
 
class RandomDeviceSeedSeq {
 public:
  using result_type = typename std::random_device::result_type;
 
  template <class Iterator>
  void generate(Iterator start, Iterator end) {
    while (start != end) {
      *start = gen_();
      ++start;
    }
  }
 
 private:
  std::random_device gen_;
};
 
}  // namespace
 
std::mt19937_64* GetSharedRng() {
  static auto* rng = [] {
    RandomDeviceSeedSeq seed_seq;
    return new std::mt19937_64(seed_seq);
  }();
  return rng;
}
 
std::string Generator<std::string>::operator()() const {
  // NOLINTNEXTLINE(runtime/int)
  std::uniform_int_distribution<short> chars(0x20, 0x7E);
  std::string res;
  res.resize(32);
  std::generate(res.begin(), res.end(),
                [&]() { return chars(*GetSharedRng()); });
  return res;
}
 
absl::string_view Generator<absl::string_view>::operator()() const {
  static auto* arena = new std::deque<std::string>();
  // NOLINTNEXTLINE(runtime/int)
  std::uniform_int_distribution<short> chars(0x20, 0x7E);
  arena->emplace_back();
  auto& res = arena->back();
  res.resize(32);
  std::generate(res.begin(), res.end(),
                [&]() { return chars(*GetSharedRng()); });
  return res;
}
 
}  // namespace hash_internal
}  // namespace container_internal
ABSL_NAMESPACE_END
}  // namespace absl