// spreadsort key and data sorting example. // // Copyright Steven Ross 2009-2014. // // Distributed under the Boost Software License, Version 1.0. // (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) // See http://www.boost.org/libs/sort for library home page. #include #include #include #include #include #include #include #include #include #include using namespace boost::sort::spreadsort; struct DATA_TYPE { int key; std::string data; }; //functor example struct lessthan { inline bool operator()(const DATA_TYPE &x, const DATA_TYPE &y) const { return x.key < y.key; } }; struct rightshift { inline int operator()(const DATA_TYPE &x, const unsigned offset) { return x.key >> offset; } }; //Pass in an argument to test std::sort int main(int argc, const char ** argv) { size_t uSize = sizeof(int); bool stdSort = false; unsigned loopCount = 1; for (int u = 1; u < argc; ++u) { if (std::string(argv[u]) == "-std") stdSort = true; else loopCount = atoi(argv[u]); } std::ifstream input("input.txt", std::ios_base::in | std::ios_base::binary); if (input.fail()) { printf("input.txt could not be opened\n"); return 1; } input.seekg (0, std::ios_base::end); size_t length = input.tellg(); double total = 0.0; std::vector array; array.reserve(length/uSize); unsigned uCount = length/uSize; //Run multiple loops, if requested for (unsigned u = 0; u < loopCount; ++u) { input.seekg (0, std::ios_base::beg); unsigned v = 0; while (input.good() && v++ < uCount) { // EOF or failure stops the reading DATA_TYPE element; input.read(reinterpret_cast(&(element.key)), sizeof(element.key)); std::stringstream intstr; intstr << element.key; element.data = intstr.str(); array.push_back(element); } clock_t start, end; double elapsed; start = clock(); if (stdSort) std::sort(array.begin(), array.end(), lessthan()); else integer_sort(array.begin(), array.end(), rightshift(), lessthan()); end = clock(); elapsed = static_cast(end - start) ; std::ofstream ofile; if (stdSort) ofile.open("standard_sort_out.txt", std::ios_base::out | std::ios_base::binary | std::ios_base::trunc); else ofile.open("boost_sort_out.txt", std::ios_base::out | std::ios_base::binary | std::ios_base::trunc); if (ofile.good()) { for (unsigned v = 0; v < array.size(); ++v) { ofile.write(reinterpret_cast(&(array[v].key)), sizeof(array[v].key)); ofile << array[v].data; } ofile.close(); } total += elapsed; array.clear(); } input.close(); if (stdSort) printf("std::sort elapsed time %f\n", total / CLOCKS_PER_SEC); else printf("spreadsort elapsed time %f\n", total / CLOCKS_PER_SEC); return 0; }