.. _program_listing_file_include_mapviz_stopwatch.h:

Program Listing for File stopwatch.h
====================================

|exhale_lsh| :ref:`Return to documentation for file <file_include_mapviz_stopwatch.h>` (``include/mapviz/stopwatch.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   // *****************************************************************************
   //
   // Copyright (c) 2017, Southwest Research Institute® (SwRI®)
   // All rights reserved.
   //
   // 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 Southwest Research Institute® (SwRI®) 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 <COPYRIGHT HOLDER> 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.
   //
   // *****************************************************************************
   #ifndef MAPVIZ__STOPWATCH_H_
   #define MAPVIZ__STOPWATCH_H_
   
   #include <rclcpp/rclcpp.hpp>
   
   #include <algorithm>
   #include <string>
   
   
   namespace mapviz
   {
   /* This class measures the wall time of an interval and keeps track of
    * the number of intervals, the average duration, and the maximum
    * duration.  This is used to provide some simple measurements to keep
    * an eye on performance.
    */
   class Stopwatch
   {
    public:
     Stopwatch()
       :
       count_(0),
       clock(),
       total_time_(0, 0),
       max_time_(0, 0),
       start_(0, 0)
     {
     }
   
     /* Start measuring a new time interval. */
     void start()
     {
       start_ = clock.now();
     }
   
     /* End the current time interval and update the measurements.
      * Behavior is undefined if start() was not called prior to this.
      */
     void stop()
     {
       rclcpp::Duration dt = clock.now() - start_;
       count_ += 1;
       total_time_ = total_time_ + dt;
       max_time_ = std::max(max_time_, dt);
     }
   
     /* Return the number of intervals measured. */
     int count() const { return count_; }
   
     /* Returns the longest observed duration. */
     rclcpp::Duration maxTime() const {return max_time_;}
   
     /* Returns the average duration spent in the interval. */
     rclcpp::Duration avgTime() const
     {
       if (count_) {
         return total_time_*(1.0/count_);
       } else {
         return rclcpp::Duration(0, 0);
       }
     }
   
     /* Print measurement info to the ROS console. */
     void printInfo(rclcpp::Logger logger, const std::string &name) const
     {
       if (count_) {
         RCLCPP_INFO(logger,
                   "%s -- calls: %d, avg time: %.2fms, max time: %.2fms",
                   name.c_str(),
                   count_,
                   avgTime().seconds()*1000.0,
                   maxTime().seconds()*1000.0);
       } else {
         RCLCPP_INFO(logger,
                   "%s -- calls: %d, avg time: --ms, max time: --ms",
                   name.c_str(),
                   count_);
       }
     }
   
    private:
     int count_;
     rclcpp::Clock clock;
     rclcpp::Duration total_time_;
     rclcpp::Duration max_time_;
   
     rclcpp::Time start_;
   };  // class PluginInstrumentation
   }  // namespace mapviz
   
   #endif  // MAPVIZ__STOPWATCH_H_