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      1 //=====================================================
      2 // File   :  STL_Timer.hh
      3 // Author :  L. Plagne <laurent.plagne (at) edf.fr)>
      4 // Copyright (C) EDF R&D,  mar dc 3 18:59:35 CET 2002
      5 //=====================================================
      6 //
      7 // This program is free software; you can redistribute it and/or
      8 // modify it under the terms of the GNU General Public License
      9 // as published by the Free Software Foundation; either version 2
     10 // of the License, or (at your option) any later version.
     11 //
     12 // This program is distributed in the hope that it will be useful,
     13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
     14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     15 // GNU General Public License for more details.
     16 // You should have received a copy of the GNU General Public License
     17 // along with this program; if not, write to the Free Software
     18 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
     19 //
     20 // STL Timer Class. Adapted (L.P.) from the timer class by Musser et Al
     21 // described int the Book : STL Tutorial and reference guide.
     22 // Define a timer class for analyzing algorithm performance.
     23 #include <iostream>
     24 #include <iomanip>
     25 #include <vector>
     26 #include <map>
     27 #include <algorithm>
     28 using namespace std;
     29 
     30 class STL_Timer {
     31 public:
     32   STL_Timer(){ baseline = false; };  // Default constructor
     33   // Start a series of r trials:
     34   void start(unsigned int r){
     35     reps = r;
     36     count = 0;
     37     iterations.clear();
     38     iterations.reserve(reps);
     39     initial = time(0);
     40   };
     41   // Start a series of r trials to determine baseline time:
     42   void start_baseline(unsigned int r)
     43   {
     44     baseline = true;
     45     start(r);
     46   }
     47   // Returns true if the trials have been completed, else false
     48   bool check()
     49   {
     50     ++count;
     51     final = time(0);
     52     if (initial < final) {
     53       iterations.push_back(count);
     54       initial = final;
     55       count = 0;
     56     }
     57     return (iterations.size() < reps);
     58   };
     59   // Returns the results for external use
     60   double get_time( void )
     61   {
     62     sort(iterations.begin(), iterations.end());
     63     return 1.0/iterations[reps/2];
     64   };
     65 private:
     66   unsigned int reps;  // Number of trials
     67   // For storing loop iterations of a trial
     68   vector<long> iterations;
     69   // For saving initial and final times of a trial
     70   time_t initial, final;
     71   // For counting loop iterations of a trial
     72   unsigned long count;
     73   // true if this is a baseline computation, false otherwise
     74   bool baseline;
     75   // For recording the baseline time
     76   double baseline_time;
     77 };
     78 
     79