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

   1 // spreadsort fully sorted data 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   //Sorts the data once, then times sorting of already-sorted data
  38   loopCount += 1;
  39   std::ifstream input("input.txt", std::ios_base::in | std::ios_base::binary);
  40   if (input.fail()) {
  41     printf("input.txt could not be opened\n");
  42     return 1;
  43   }
  44   double total = 0.0;
  45   std::vector<DATA_TYPE> array;
  46   input.seekg (0, std::ios_base::end);
  47     size_t length = input.tellg();
  48   uCount = length/uSize;
  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) // EOF or failure stops the reading
  54     input.read(reinterpret_cast<char *>(&(array[v++])), uSize );
  55   //Run multiple loops, if requested
  56   for (unsigned u = 0; u < loopCount; ++u) {
  57     clock_t start, end;
  58     double elapsed;
  59     start = clock();
  60     if (stdSort)
  61       //std::sort(&(array[0]), &(array[0]) + uCount);
  62       std::sort(array.begin(), array.end());
  63     else {
  64       printf("call\n");
  65       //integer_sort(&(array[0]), &(array[0]) + uCount);
  66       integer_sort(array.begin(), array.end());
  67     }
  68     end = clock();
  69     elapsed = static_cast<double>(end - start) ;
  70     std::ofstream ofile;
  71     if (stdSort)
  72       ofile.open("standard_sort_out.txt", std::ios_base::out |
  73                  std::ios_base::binary | std::ios_base::trunc);
  74     else
  75       ofile.open("boost_sort_out.txt", std::ios_base::out |
  76                  std::ios_base::binary | std::ios_base::trunc);
  77     if (ofile.good()) {
  78       for (unsigned v = 0; v < array.size(); ++v) {
  79         ofile.write(reinterpret_cast<char *>(&(array[v])), sizeof(array[v]) );
  80       }
  81       ofile.close();
  82     }
  83     if (u)
  84       total += elapsed;
  85   }
  86   if (stdSort)
  87     printf("std::sort elapsed time %f\n", total / CLOCKS_PER_SEC);
  88   else
  89     printf("spreadsort elapsed time %f\n", total / CLOCKS_PER_SEC);
  90   return 0;
  91 }