| // |
| // 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. |
| // |
| #ifndef ABSL_RANDOM_INTERNAL_MOCKING_BIT_GEN_BASE_H_ |
| #define ABSL_RANDOM_INTERNAL_MOCKING_BIT_GEN_BASE_H_ |
| |
| #include <atomic> |
| #include <deque> |
| #include <string> |
| #include <typeinfo> |
| |
| #include "absl/random/random.h" |
| #include "absl/strings/str_cat.h" |
| |
| namespace absl { |
| ABSL_NAMESPACE_BEGIN |
| namespace random_internal { |
| |
| // MockingBitGenExpectationFormatter is invoked to format unsatisfied mocks |
| // and remaining results into a description string. |
| template <typename DistrT, typename FormatT> |
| struct MockingBitGenExpectationFormatter { |
| std::string operator()(absl::string_view args) { |
| return absl::StrCat(FormatT::FunctionName(), "(", args, ")"); |
| } |
| }; |
| |
| // MockingBitGenCallFormatter is invoked to format each distribution call |
| // into a description string for the mock log. |
| template <typename DistrT, typename FormatT> |
| struct MockingBitGenCallFormatter { |
| std::string operator()(const DistrT& dist, |
| const typename DistrT::result_type& result) { |
| return absl::StrCat( |
| FormatT::FunctionName(), "(", FormatT::FormatArgs(dist), ") => {", |
| FormatT::FormatResults(absl::MakeSpan(&result, 1)), "}"); |
| } |
| }; |
| |
| class MockingBitGenBase { |
| template <typename> |
| friend struct DistributionCaller; |
| using generator_type = absl::BitGen; |
| |
| public: |
| // URBG interface |
| using result_type = generator_type::result_type; |
| static constexpr result_type(min)() { return (generator_type::min)(); } |
| static constexpr result_type(max)() { return (generator_type::max)(); } |
| result_type operator()() { return gen_(); } |
| |
| MockingBitGenBase() : gen_(), observed_call_log_() {} |
| virtual ~MockingBitGenBase() = default; |
| |
| protected: |
| const std::deque<std::string>& observed_call_log() { |
| return observed_call_log_; |
| } |
| |
| // CallImpl is the type-erased virtual dispatch. |
| // The type of dist is always distribution<T>, |
| // The type of result is always distribution<T>::result_type. |
| virtual bool CallImpl(const std::type_info& distr_type, void* dist_args, |
| void* result) = 0; |
| |
| template <typename DistrT, typename ArgTupleT> |
| static const std::type_info& GetTypeId() { |
| return typeid(std::pair<absl::decay_t<DistrT>, absl::decay_t<ArgTupleT>>); |
| } |
| |
| // Call the generating distribution function. |
| // Invoked by DistributionCaller<>::Call<DistT, FormatT>. |
| // DistT is the distribution type. |
| // FormatT is the distribution formatter traits type. |
| template <typename DistrT, typename FormatT, typename... Args> |
| typename DistrT::result_type Call(Args&&... args) { |
| using distr_result_type = typename DistrT::result_type; |
| using ArgTupleT = std::tuple<absl::decay_t<Args>...>; |
| |
| ArgTupleT arg_tuple(std::forward<Args>(args)...); |
| auto dist = absl::make_from_tuple<DistrT>(arg_tuple); |
| |
| distr_result_type result{}; |
| bool found_match = |
| CallImpl(GetTypeId<DistrT, ArgTupleT>(), &arg_tuple, &result); |
| |
| if (!found_match) { |
| result = dist(gen_); |
| } |
| |
| // TODO(asoffer): Forwarding the args through means we no longer need to |
| // extract them from the from the distribution in formatter traits. We can |
| // just StrJoin them. |
| observed_call_log_.push_back( |
| MockingBitGenCallFormatter<DistrT, FormatT>{}(dist, result)); |
| return result; |
| } |
| |
| private: |
| generator_type gen_; |
| std::deque<std::string> observed_call_log_; |
| }; // namespace random_internal |
| |
| } // namespace random_internal |
| ABSL_NAMESPACE_END |
| } // namespace absl |
| |
| #endif // ABSL_RANDOM_INTERNAL_MOCKING_BIT_GEN_BASE_H_ |