www.pudn.com > c_delaunay.rar > QPerformanceTimer.h, change:2004-12-18,size:2418b

/******************************************************************************** 
	Copyright (C) 2004 Sjaak Priester	 
 
	This is free software; you can redistribute it and/or modify 
	it under the terms of the GNU General Public License as published by 
	the Free Software Foundation; either version 2 of the License, or 
	(at your option) any later version. 
 
	This file is distributed in the hope that it will be useful, 
	but WITHOUT ANY WARRANTY; without even the implied warranty of 
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
	GNU General Public License for more details. 
 
	You should have received a copy of the GNU General Public License 
	along with Tinter; if not, write to the Free Software 
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
********************************************************************************/ 
 
// QPerformanceTimer 
// Class to measure performance time 
// 
// Usage: simply define a QPerformanceTimer variable in a C++ block. 
// At construction, it measures the start time. 
// At destruction, it measures the stop time. It calculates the difference 
// and puts the result (in milliseconds) in the associated int. 
// In other words: this class measures and records its own lifetime. 
// If the output is set to -1, it's an indication of overflow, but this 
// will only occur after more than three weeks (!). 
// 
// Example: 
// 
// 
//	SomeFunction() 
//	{ 
//		... some code... 
// 
//		int elapsedTime; 
//		{	// start of the block we want to monitor 
//			QPerformanceTimer(elapsedTime); 
// 
//			... some lengthy process... 
// 
//		}	// end of block, elapsed time is recorded in elapsedTime 
// 
//		printf("Time = %d milliseconds", elapsedTime); 
//	} 
// 
// Version 1.0 (C) 2004, Sjaak Priester, Amsterdam. 
// mailto:sjaak@sjaakpriester.nl 
 
#pragma once 
 
class QPerformanceTimer 
{ 
public: 
	QPerformanceTimer(int& MilliSeconds) 
		: m_Output(MilliSeconds) 
	{ 
		::QueryPerformanceCounter(&m_Start); 
	} 
 
	~QPerformanceTimer(void) 
	{ 
		LARGE_INTEGER stop; 
		LARGE_INTEGER freq; 
		::QueryPerformanceCounter(&stop); 
		::QueryPerformanceFrequency(&freq); 
 
		stop.QuadPart -= m_Start.QuadPart; 
		stop.QuadPart *= 1000; 
		stop.QuadPart /= freq.QuadPart; 
 
		if (stop.HighPart != 0) m_Output = -1; 
		else m_Output = stop.LowPart; 
	} 
protected: 
	LARGE_INTEGER m_Start; 
	int& m_Output; 
};