平时写程序，总想知道自己的程序跑得有多快，虽然程序用的时间的大小不仅和算法的复杂度有关，也和其他方面有关，但是，总是忍不住想去看看运行的时间。
而且，在运行机器学习和图像处理的程序的时候，也是需要对比不同算法的复杂度的，直接在算法层面上进行复杂度分析比较困难，因此，可以简单地采用不同算法的运行时间来确定。
上面啰嗦了那么多写这个类的原因，下面就把我写的这个类，请大家赐教。
下面是Timer类的定义
/**
* @file timer.h
* @brief The definition of the timer class.
*/
#ifndef TIMER_H
#define TIMER_H
#include <time.h>
namespace Utility
{
/**
* @class Timer
* @brief The Timer class which be used to timing.
*/
class Timer
{
public:
Timer();
bool Start();
bool Finish();
long GetDurationInClocks();
double GetDuration();
private:
clock_t Starting;
clock_t Finished;
clock_t DurationInClocks;
double Duration;
bool IsStarted;
bool IsEnded;
};
}
#endif // TIMER_H
下面是Timer类的实现
/**
* @file timer.cpp
* @brief The implement of the timer class.
*
*/
#include "timer.h"
#include <assert.h>
/**
* @brief The defualt constructor
*
* @author sheng
* @version 0.1.0
* @history author version date description \n
* sheng 0.1.0 2014/03/08 build the function
*
*/
Utility::Timer::Timer():
Starting(0),Finished(-1), DurationInClocks(-1),
Duration(-1.0), IsStarted(false), IsEnded(false)
{
}
/**
* @brief Start to timing
* @return true if the timer is never started befor
* false otherwise
*
* @author sheng
* @version 0.1.0
* @history author version date description \n
* sheng 0.1.0 2014/03/08 build the function
*
*/
bool Utility::Timer::Start()
{
// if the timer is not started befor, starting the timer.
assert(!IsStarted);
if (IsStarted == false)
{
IsStarted = true;
IsEnded = false;
Starting = clock();
return true;
}
return false;
}
/**
* @brief Finishing the timer
* @return true if the timer is started and never finished before.
* false otherwise
*
* @author sheng
* @version 0.1.0
* @history author version date description \n
* sheng 0.1.0 2014/03/08 build the function
*
*/
bool Utility::Timer::Finish()
{
// if the timer is started and never finished before, return true.
assert(IsStarted && (!IsEnded));
if (IsStarted && (!IsEnded))
{
IsEnded = true;
Finished = clock();
DurationInClocks = Finished - Starting;
Duration = (double)DurationInClocks / CLOCKS_PER_SEC;
}
return false;
}
/**
* @brief Get the duration in clocks.
* @return the duration in clocks.
*
* @author sheng
* @version 0.1.0
* @history author version date description \n
* sheng 0.1.0 2014/03/08 build the function
*
*/
long Utility::Timer::GetDurationInClocks()
{
return DurationInClocks;
}
/**
* @brief Get the duration in seconds.
* @return the duration in seconds
*
* @author sheng
* @version 0.1.0
* @history author version date description \n
* sheng 0.1.0 2014/03/08 build the function
*
*/
double Utility::Timer::GetDuration()
{
return Duration;
}
下面是测试这个类的函数
#include "timer.h"
#include <iostream>
using namespace std;
/**
* @brief The unit test for the Timer
*/
void Timer_Test()
{
// test in normol way
Utility::Timer timer;
timer.Start();
for (int i = 0; i < 200; i++)
{
cout << i << endl;
}
timer.Finish();
cout << "Duration in timer is " << timer.GetDuration() << endl;
// test the finish before start
Utility::Timer timer_finish;
timer_finish.Finish();
// test the started after finished.
timer.Start();
// test the get duration before start
Utility::Timer timer_GetDuration;
cout << "Duration before started in clocks is" <<
timer_GetDuration.GetDurationInClocks() << endl;
cout << "Duration before strated in second is" <<
timer_GetDuration.GetDuration() << endl;
// test the get duration after start but before finished.
timer_GetDuration.Start();
cout << "Duration before started in clocks is" <<
timer_GetDuration.GetDurationInClocks() << endl;
cout << "Duration before strated in second is" <<
timer_GetDuration.GetDuration() << endl;
}