1 //=====================================================
2 // File   :  STL_Timer.hh
3 // Author :  L. Plagne <laurent.plagne@edf.fr)>
4 // Copyright (C) EDF R&D,  mar d�c 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:
STL_Timer()32   STL_Timer(){ baseline = false; };  // Default constructor
33   // Start a series of r trials:
start(unsigned int r)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:
start_baseline(unsigned int r)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
check()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
get_time(void)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