THUAI6/CAPI/cpp/grpc/include/grpcpp/impl/codegen/time.h

/*
 *
 * Copyright 2015 gRPC 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
 *
 *     http://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 GRPCPP_IMPL_CODEGEN_TIME_H
#define GRPCPP_IMPL_CODEGEN_TIME_H

// IWYU pragma: private, include <grpcpp/support/time.h>

#include <chrono>

#include <grpc/impl/codegen/grpc_types.h>
#include <grpcpp/impl/codegen/config.h>

namespace grpc
{

    /** If you are trying to use CompletionQueue::AsyncNext with a time class that
        isn't either gpr_timespec or std::chrono::system_clock::time_point, you
        will most likely be looking at this comment as your compiler will have
        fired an error below. In order to fix this issue, you have two potential
        solutions:

          1. Use gpr_timespec or std::chrono::system_clock::time_point instead
          2. Specialize the TimePoint class with whichever time class that you
             want to use here. See below for two examples of how to do this.
     */
    template<typename T>
    class TimePoint
    {
    public:
        // If you see the error with methods below, you may need either
        // i) using the existing types having a conversion class such as
        // gpr_timespec and std::chrono::system_clock::time_point or
        // ii) writing a new TimePoint<YourType> to address your case.
        TimePoint(const T& /*time*/) = delete;
        gpr_timespec raw_time() = delete;
    };

    template<>
    class TimePoint<gpr_timespec>
    {
    public:
        /* NOLINTNEXTLINE(google-explicit-constructor) */
        TimePoint(const gpr_timespec& time) :
            time_(time)
        {
        }
        gpr_timespec raw_time()
        {
            return time_;
        }

    private:
        gpr_timespec time_;
    };

}  // namespace grpc

namespace grpc
{

    // from and to should be absolute time.
    void Timepoint2Timespec(const std::chrono::system_clock::time_point& from, gpr_timespec* to);
    void TimepointHR2Timespec(
        const std::chrono::high_resolution_clock::time_point& from,
        gpr_timespec* to
    );

    std::chrono::system_clock::time_point Timespec2Timepoint(gpr_timespec t);

    template<>
    class TimePoint<std::chrono::system_clock::time_point>
    {
    public:
        /* NOLINTNEXTLINE(google-explicit-constructor) */
        TimePoint(const std::chrono::system_clock::time_point& time)
        {
            Timepoint2Timespec(time, &time_);
        }
        gpr_timespec raw_time() const
        {
            return time_;
        }

    private:
        gpr_timespec time_;
    };

}  // namespace grpc

#endif  // GRPCPP_IMPL_CODEGEN_TIME_H