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

   1 // Copyright (C) 2004 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 2, 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 COPYING.  If not, write to the Free
  16 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17 // USA.
  18
  19 // As a special exception, you may use this file as part of a free software
  20 // library without restriction.  Specifically, if other files instantiate
  21 // templates or use macros or inline functions from this file, or you compile
  22 // this file and link it with other files to produce an executable, this
  23 // file does not by itself cause the resulting executable to be covered by
  24 // the GNU General Public License.  This exception does not however
  25 // invalidate any other reasons why the executable file might be covered by
  26 // the GNU General Public License.
  27
  28 #include <cstdio>
  29 #include <fstream>
  30 #include <testsuite_performance.h>
  31
  32 // libstdc++/11722
  33 int main()
  34 {
  35   using namespace std;
  36   using namespace __gnu_test;
  37
  38   time_counter time;
  39   resource_counter resource;
  40
  41   const int iterations = 500000;
  42   const int chunksize = 100;
  43
  44   char* chunk = new char[chunksize];
  45   const char* name1 = "/usr/share/dict/words";
  46   const char* name2 = "/usr/share/dict/linux.words";
  47   const char* name = name1;
  48
  49   // C
  50   FILE* file;
  51   if (!(file = fopen(name, "r")))
  52     {
  53       name = name2;
  54       if (!(file = fopen(name, "r")))
  55         exit(1);
  56     }
  57   setvbuf(file, 0, _IONBF, 0);
  58   start_counters(time, resource);
  59   for (int i = 0; i < iterations; ++i)
  60     if (fread(chunk, 1, chunksize, file) < chunksize)
  61       fseek(file, 0, SEEK_SET);
  62   stop_counters(time, resource);
  63   fclose(file);
  64   report_performance(__FILE__, "C", time, resource);
  65   clear_counters(time, resource);
  66
  67   // C unlocked
  68   file = fopen(name, "r");
  69   setvbuf(file, 0, _IONBF, 0);
  70   start_counters(time, resource);
  71   for (int i = 0; i < iterations; ++i)
  72     if (fread_unlocked(chunk, 1, chunksize, file) < chunksize)
  73       fseek(file, 0, SEEK_SET);
  74   stop_counters(time, resource);
  75   fclose(file);
  76   report_performance(__FILE__, "C unlocked", time, resource);
  77   clear_counters(time, resource);
  78
  79   // C++
  80   filebuf buf;
  81   buf.pubsetbuf(0, 0);
  82   buf.open(name, ios_base::in);
  83   start_counters(time, resource);
  84   for (int i = 0; i < iterations; ++i)
  85     if (buf.sgetn(chunk, chunksize) < chunksize)
  86       buf.pubseekoff(0, ios::beg);
  87   stop_counters(time, resource);
  88   report_performance(__FILE__, "C++", time, resource);
  89
  90   delete [] chunk;
  91
  92   return 0;
  93 }