bande: Statistics.cc Source File

00001 /*
00002  *  Copyright 2007 Martin von Gagern
00003  *
00004  *
00005  *  This file is part of bande.
00006  *
00007  *  bande is free software; you can redistribute it and/or modify
00008  *  it under the terms of the GNU General Public License as published by
00009  *  the Free Software Foundation; either version 3 of the License, or
00010  *  (at your option) any later version.
00011  *
00012  *  bande is distributed in the hope that it will be useful,
00013  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  *  GNU General Public License for more details.
00016  *
00017  *  You should have received a copy of the GNU General Public License
00018  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
00019  */
00020 
00021 
00022 /**
00023  * @file
00024  * Implementation of class bande::Statistics.
00025  */
00026 
00027 #include "bande.hh"
00028 
00029 namespace bande {
00030 
00031   /**
00032    * Get current user time in seconds.
00033    *
00034    * The time will be reported as a floating point number, allowing
00035    * for fractions of a second. Only the CPU time dedicated to this
00036    * process will count, so that the time as returned by this function
00037    * will pass slower the more other processes occupy the CPU. As the
00038    * returned value is intended for difference calculation, the
00039    * initial offset is irrelevant.
00040    *
00041    * @return the current user time as a floating point number.
00042    */
00043   double Statistics::getTime() {
00044     struct rusage usage;
00045     getrusage(RUSAGE_SELF, &usage);
00046     return usage.ru_utime.tv_sec + usage.ru_utime.tv_usec*1e-6;
00047   }
00048 
00049   /**
00050    * A solution has been found.
00051    *
00052    * @param depth the depth in the search tree at which the solution
00053    *              has been found.
00054    */
00055   void Statistics::solution(int depth) {
00056     double now = getTime();
00057     ++numSolutions;
00058     std::cout << "Solution " << numSolutions << ", ";
00059     if (now == startTime) {
00060       std::cout << "just started";
00061     }
00062     else {
00063       double clk = now - startTime;
00064       if (numSolutions > clk)
00065         std::cout << numSolutions/clk << " solutions per second";
00066       else
00067         std::cout << "new solution every " << clk/numSolutions << " seconds";
00068     }
00069     std::cout << std::endl;
00070   }
00071 
00072 }