libstdc++-v3/testsuite/performance/27_io/ifstream_getline-2.cc

   1 // Copyright (C) 2004-2018 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++/15002
  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_getline.txt";
  34   const unsigned lines = 1000000;
  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   // C
  51   {
  52     // Fill the cache.
  53     FILE *file = fopen(filename, "r");
  54     while (fgets(line, line_length + 2, file));
  55     fclose(file);
  56
  57     file = fopen(filename, "r");
  58     start_counters(time, resource);
  59     while (fgets(line, line_length + 2, file));
  60     stop_counters(time, resource);
  61     fclose(file);
  62     report_performance(__FILE__, "C (fgets)", time, resource);
  63     clear_counters(time, resource);
  64   }
  65
  66   // getline(basic_istream<_CharT, _Traits>& __in,
  67   //         basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim)
  68   {
  69     ifstream file(filename);
  70     string string_line;
  71
  72     start_counters(time, resource);
  73     while (getline(file, string_line));
  74     stop_counters(time, resource);
  75     report_performance(__FILE__, "C++ (string)", time, resource);
  76     clear_counters(time, resource);
  77   }
  78
  79   // getline(char_type* __s, streamsize __n, char_type __delim)
  80   {
  81     ifstream file(filename);
  82
  83     start_counters(time, resource);
  84     while (file.getline(line, line_length + 2));
  85     stop_counters(time, resource);
  86     report_performance(__FILE__, "C++ (char array)", time, resource);
  87     clear_counters(time, resource);
  88   }
  89
  90   delete[] line;
  91   unlink(filename);
  92   return 0;
  93 }