/*
Execution timer class.
*/
class ExecuteTimer
{
public:
       ExecuteTimer();
       ~ExecuteTimer();

       /*\brief: Get char* type time.
       *\return: char* type time, unit:second.
       */
       char*      GetCTime();

       /*\brief: Get double type time.
       *\return: double type time, unit:second.
       */
       double     GetDTime();

       /*\brief: Reset the begin time.
       */
       void Reset();

       /*\brief: ostream << operator friend function.
       *\param:  os, The left operation.
       *\param:  obj, The right operation.
       *\return: std::ostream object ref..
       */
       friend std::ostream& operator << (std::ostream& os, ExecuteTimer& obj);

       /*\brief: ofstream << operator friend function.
       *\param:  os, The left operation.
       *\param:  obj, The right operation.
       *\return: std::ofstream object ref..
       */
       friend std::ofstream& operator << (std::ofstream& ofs, ExecuteTimer& obj);

private:
       struct timespec       m_begin;
       char m_ctime[32];
};