/*

 * 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

 *

 *      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.

 */

// This library defines a simplified clock interface that wraps the abseil

// functions for looking at the current time. This is intended to enable more

// testability in code that needs to track the current time by allowing you to

// supply fake/mock clocks that give the test control over when time advances.

#ifndef THIRD_PARTY_ECCLESIA_LIB_TIME_CLOCK_H_

#define THIRD_PARTY_ECCLESIA_LIB_TIME_CLOCK_H_

#include "absl/time/clock.h"

#include "absl/time/time.h"

namespace ecclesia {

class Clock {

 public:

  // Return a pointer to a global thread-safe singleton clock implemented using

  // the actual abseil time functions.

  static Clock* RealClock();

  virtual ~Clock() = default;

  virtual void Sleep(absl::Duration d) = 0;

  // Returns current time.

  virtual absl::Time Now() const = 0;

};

}  // namespace ecclesia

#endif  // THIRD_PARTY_ECCLESIA_LIB_TIME_CLOCK_H_