libstdc++-v3/testsuite/performance/27_io/ifstream_extract_chars.cc

   1 // Copyright (C) 2005-2019 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 #include <unistd.h>
  19 #include <cstdio>
  20 #include <fstream>
  21 #include <string>
  22 #include <testsuite_performance.h>
  23
  24 // libstdc++/22515
  25 int main()
  26 {
  27   using namespace std;
  28   using namespace __gnu_test;
  29
  30   time_counter time;
  31   resource_counter resource;
  32
  33   const char filename[] = "tmp_perf_chars.txt";
  34   const unsigned lines = 200000;
  35   const unsigned line_length = 200;
  36
  37   char* line = new char[line_length + 2];
  38
  39   // Construct data.
  40   {
  41     memset(line, 'x', line_length);
  42     line[line_length] = '\n';
  43     line[line_length + 1] = '\0';
  44
  45     ofstream out(filename);
  46     for (unsigned i = 0; i < lines; ++i)
  47       out << line;
  48   }
  49
  50   // operator>>(basic_istream<char>& __in, basic_string<char>& __str)
  51   {
  52     start_counters(time, resource);
  53     for (int iter = 0; iter < 25; ++iter)
  54       {
  55         ifstream file(filename);
  56         string string_line;
  57
  58         while (file >> string_line);
  59       }
  60     stop_counters(time, resource);
  61     report_performance(__FILE__, "string&", time, resource);
  62     clear_counters(time, resource);
  63   }
  64
  65   // operator>>(basic_istream<char>& __in, char* __s)
  66   {
  67     start_counters(time, resource);
  68     for (int iter = 0; iter < 25; ++iter)
  69       {
  70         ifstream file(filename);
  71
  72         while (file >> line);
  73       }
  74     stop_counters(time, resource);
  75     report_performance(__FILE__, "char*", time, resource);
  76     clear_counters(time, resource);
  77   }
  78
  79   delete[] line;
  80   unlink(filename);
  81   return 0;
  82 }