| // Copyright 2020 Google LLC |
| // |
| // 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 LOCATION_NEARBY_CPP_PLATFORM_PUBLIC_FUTURE_H_ |
| #define LOCATION_NEARBY_CPP_PLATFORM_PUBLIC_FUTURE_H_ |
| |
| #include "platform/public/settable_future.h" |
| |
| namespace location { |
| namespace nearby { |
| |
| template <typename T> |
| class Future final { |
| public: |
| virtual bool Set(T value) { return impl_->Set(std::move(value)); } |
| virtual bool SetException(Exception exception) { |
| return impl_->SetException(exception); |
| } |
| virtual ExceptionOr<T> Get() { return impl_->Get(); } |
| virtual ExceptionOr<T> Get(absl::Duration timeout) { |
| return impl_->Get(timeout); |
| } |
| void AddListener(Runnable runnable, api::Executor* executor) { |
| impl_->AddListener(std::move(runnable), executor); |
| } |
| bool IsSet() const { |
| return impl_->IsSet(); |
| } |
| |
| private: |
| // Instance of future implementation is wrapped in shared_ptr<> to make |
| // it possible to pass Future by value and share the implementation. |
| // This allows for the following constructions: |
| // 1) |
| // Future<bool> future; |
| // RunOnXyzThread([future]() { future.Set(DoTheJobAndReport()); }); |
| // if (future.Get().Ok()) { /*...*/ } |
| // 2) |
| // Future<bool> future = DoSomeAsyncWork(); // Returns future, but keeps copy. |
| // if (future.Get().Ok()) { /*...*/ } |
| std::shared_ptr<SettableFuture<T>> impl_{new SettableFuture<T>()}; |
| }; |
| |
| } // namespace nearby |
| } // namespace location |
| |
| #endif // LOCATION_NEARBY_CPP_PLATFORM_PUBLIC_FUTURE_H_ |