QPerformanceTimer.h
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- /********************************************************************************
- 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;
- };