// Ceres Solver - A fast non-linear least squares minimizer

// Copyright 2015 Google Inc. All rights reserved.

// http://ceres-solver.org/

//

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are met:

//

// * Redistributions of source code must retain the above copyright notice,

//   this list of conditions and the following disclaimer.

// * Redistributions in binary form must reproduce the above copyright notice,

//   this list of conditions and the following disclaimer in the documentation

//   and/or other materials provided with the distribution.

// * Neither the name of Google Inc. nor the names of its contributors may be

//   used to endorse or promote products derived from this software without

//   specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

// POSSIBILITY OF SUCH DAMAGE.

//

// Author: strandmark@google.com (Petter Strandmark)

#ifndef CERES_INTERNAL_WALL_TIME_H_

#define CERES_INTERNAL_WALL_TIME_H_

#include <map>

#include <string>

#include "ceres/internal/port.h"

#include "ceres/stringprintf.h"

#include "glog/logging.h"

namespace ceres {

namespace internal {

// Returns time, in seconds, from some arbitrary starting point. If

// OpenMP is available then the high precision openmp_get_wtime()

// function is used. Otherwise on unixes, gettimeofday is used. The

// granularity is in seconds on windows systems.

double WallTimeInSeconds();

// Log a series of events, recording for each event the time elapsed

// since the last event and since the creation of the object.

//

// The information is output to VLOG(3) upon destruction. A

// name::Total event is added as the final event right before

// destruction.

//

// Example usage:

//

//  void Foo() {

//    EventLogger event_logger("Foo");

//    Bar1();

//    event_logger.AddEvent("Bar1")

//    Bar2();

//    event_logger.AddEvent("Bar2")

//    Bar3();

//  }

//

// Will produce output that looks like

//

//  Foo

//      Bar1:  time1  time1

//      Bar2:  time2  time1 + time2;

//     Total:  time3  time1 + time2 + time3;

class EventLogger {

 public:

  explicit EventLogger(const std::string& logger_name);

  ~EventLogger();

  void AddEvent(const std::string& event_name);

 private:

  const double start_time_;

  double last_event_time_;

  std::string events_;

};

}  // namespace internal

}  // namespace ceres

#endif  // CERES_INTERNAL_WALL_TIME_H_