1 //! \brief Integer sort with a rightshift functor sorting example.
2 //! \file
3 //
4 // Copyright Steven Ross 2009-2014.
5 //
6 // Distributed under the Boost Software License, Version 1.0.
7 // (See accompanying file LICENSE_1_0.txt or copy at
8 // http://www.boost.org/LICENSE_1_0.txt)
9
10 // See http://www.boost.org/libs/sort for library home page.
11
12 // Caution: this file contains Quickbook markup as well as code
13 // and comments, don't change any of the special comment markups!
14
15 #include <boost/sort/spreadsort/spreadsort.hpp>
16 #include <time.h>
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <algorithm>
20 #include <vector>
21 #include <string>
22 #include <fstream>
23 #include <iostream>
24 using namespace boost::sort::spreadsort;
25
26 #define DATA_TYPE int
27
28 //[rightshift_int_functor
29 struct rightshift {
operator ()rightshift30 inline int operator()(DATA_TYPE x, unsigned offset) { return x >> offset; }
31 };
32 //] [/rightshift_int_functor]
33
34 //Pass in an argument to test std::sort
main(int argc,const char ** argv)35 int main(int argc, const char ** argv) {
36 size_t uCount,uSize=sizeof(DATA_TYPE);
37 bool stdSort = false;
38 unsigned loopCount = 1;
39 for (int u = 1; u < argc; ++u) {
40 if (std::string(argv[u]) == "-std")
41 stdSort = true;
42 else
43 loopCount = atoi(argv[u]);
44 }
45 std::ifstream input("input.txt", std::ios_base::in | std::ios_base::binary);
46 if (input.fail()) {
47 printf("input.txt could not be opened\n");
48 return 1;
49 }
50 double total = 0.0;
51 std::vector<DATA_TYPE> array;
52 input.seekg (0, std::ios_base::end);
53 size_t length = input.tellg();
54 uCount = length/uSize;
55 //Run multiple loops, if requested
56 for (unsigned u = 0; u < loopCount; ++u) {
57 input.seekg (0, std::ios_base::beg);
58 //Conversion to a vector
59 array.resize(uCount);
60 unsigned v = 0;
61 while (input.good() && v < uCount)
62 input.read(reinterpret_cast<char *>(&(array[v++])), uSize );
63 if (v < uCount)
64 array.resize(v);
65 clock_t start, end;
66 double elapsed;
67 start = clock();
68 if (stdSort) {
69 std::sort(array.begin(), array.end());
70 } else {
71 //[rightshift_1
72 integer_sort(array.begin(), array.end(), rightshift());
73 //] [/rightshift_1]
74 }
75 end = clock();
76 elapsed = static_cast<double>(end - start) ;
77 std::ofstream ofile;
78 if (stdSort)
79 ofile.open("standard_sort_out.txt", std::ios_base::out |
80 std::ios_base::binary | std::ios_base::trunc);
81 else
82 ofile.open("boost_sort_out.txt", std::ios_base::out |
83 std::ios_base::binary | std::ios_base::trunc);
84 if (ofile.good()) {
85 for (unsigned v = 0; v < array.size(); ++v) {
86 ofile.write(reinterpret_cast<char *>(&(array[v])), sizeof(array[v]) );
87 }
88 ofile.close();
89 }
90 total += elapsed;
91 array.clear();
92 }
93 if (stdSort)
94 printf("std::sort elapsed time %f\n", total / CLOCKS_PER_SEC);
95 else
96 printf("spreadsort elapsed time %f\n", total / CLOCKS_PER_SEC);
97 return 0;
98 }
99