ceph/src/boost/libs/sort/example/sample.cpp

   1 // spreadsort sorting example
   2 //
   3 //  Copyright Steven Ross 2009-2014.
   4 //
   5 // Distributed under the Boost Software License, Version 1.0.
   6 //    (See accompanying file LICENSE_1_0.txt or copy at
   7 //          http://www.boost.org/LICENSE_1_0.txt)
   8
   9 //  See http://www.boost.org/libs/sort for library home page.
  10
  11 #include <boost/sort/spreadsort/spreadsort.hpp>
  12 #include <time.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <algorithm>
  16 #include <vector>
  17 #include <string>
  18 #include <fstream>
  19 #include <sstream>
  20 #include <iostream>
  21 using namespace boost::sort::spreadsort;
  22
  23 #define DATA_TYPE int
  24
  25
  26 //Pass in an argument to test std::sort
  27 int main(int argc, const char ** argv) {
  28   size_t uCount,uSize=sizeof(DATA_TYPE);
  29   bool stdSort = false;
  30   unsigned loopCount = 1;
  31   for (int u = 1; u < argc; ++u) {
  32     if (std::string(argv[u]) == "-std")
  33       stdSort = true;
  34     else
  35       loopCount = atoi(argv[u]);
  36   }
  37   std::ifstream input("input.txt", std::ios_base::in | std::ios_base::binary);
  38   if (input.fail()) {
  39     printf("input.txt could not be opened\n");
  40     return 1;
  41   }
  42   double total = 0.0;
  43   std::vector<DATA_TYPE> array;
  44   input.seekg (0, std::ios_base::end);
  45     size_t length = input.tellg();
  46   uCount = length/uSize;
  47   //Run multiple loops, if requested
  48   for (unsigned u = 0; u < loopCount; ++u) {
  49     input.seekg (0, std::ios_base::beg);
  50     //Conversion to a vector
  51     array.resize(uCount);
  52     unsigned v = 0;
  53     while (input.good() && v < uCount)
  54       input.read(reinterpret_cast<char *>(&(array[v++])), uSize );
  55     if (v < uCount)
  56       array.resize(v);
  57     clock_t start, end;
  58     double elapsed;
  59     start = clock();
  60     if (stdSort)
  61       std::sort(array.begin(), array.end());
  62     else
  63       boost::sort::spreadsort::spreadsort(array.begin(), array.end());
  64     end = clock();
  65     elapsed = static_cast<double>(end - start);
  66     std::ofstream ofile;
  67     if (stdSort)
  68       ofile.open("standard_sort_out.txt", std::ios_base::out |
  69                  std::ios_base::binary | std::ios_base::trunc);
  70     else
  71       ofile.open("boost_sort_out.txt", std::ios_base::out |
  72                  std::ios_base::binary | std::ios_base::trunc);
  73     if (ofile.good()) {
  74       for (unsigned v = 0; v < array.size(); ++v) {
  75         ofile.write(reinterpret_cast<char *>(&(array[v])), sizeof(array[v]) );
  76       }
  77       ofile.close();
  78     }
  79     total += elapsed;
  80     array.clear();
  81   }
  82   input.close();
  83   if (stdSort)
  84     printf("std::sort elapsed time %f\n", total / CLOCKS_PER_SEC);
  85   else
  86     printf("spreadsort elapsed time %f\n", total / CLOCKS_PER_SEC);
  87   return 0;
  88 }