-// a sorting example that uses the worst-case distribution for spreadsort.\r
-//\r
-// Copyright Steven Ross 2009-2014.\r
-//\r
-// Distributed under the Boost Software License, Version 1.0.\r
-// (See accompanying file LICENSE_1_0.txt or copy at\r
-// http://www.boost.org/LICENSE_1_0.txt)\r
-\r
-// See http://www.boost.org/libs/sort for library home page.\r
-\r
-#include <boost/sort/spreadsort/spreadsort.hpp>\r
-#include <time.h>\r
-#include <stdio.h>\r
-#include <stdlib.h>\r
-#include <algorithm>\r
-#include <vector>\r
-#include <string>\r
-#include <fstream>\r
-#include <sstream>\r
-#include <iostream>\r
-using namespace boost::sort::spreadsort;\r
-using namespace std;\r
-\r
-#define DATA_TYPE boost::uint64_t\r
-\r
-#define ALR_THRESHOLD 3\r
-\r
-const unsigned max_count = ALR_THRESHOLD - 1;\r
-const unsigned bit_shift = detail::rough_log_2_size(max_count) -\r
- detail::int_log_mean_bin_size;\r
-const unsigned radix_threshold = detail::rough_log_2_size(max_count) + 1;\r
-\r
-const DATA_TYPE typed_one = 1;\r
-\r
-void\r
-fill_vector(vector<DATA_TYPE> & input, const DATA_TYPE base_value,\r
- unsigned remaining_bits, const vector<unsigned> & indices,\r
- int index)\r
-{\r
- if (index < 0) {\r
- for (unsigned u = 0; u < max_count; ++u)\r
- input.push_back((base_value << remaining_bits) +\r
- (rand() % (1 << remaining_bits)));\r
- }\r
- else {\r
- unsigned shift = indices[index];\r
- fill_vector(input, (base_value << shift) + ((1 << shift) - 1),\r
- remaining_bits - shift, indices, index - 1);\r
- fill_vector(input, base_value << shift, remaining_bits - shift, indices,\r
- index - 1);\r
- }\r
-}\r
-\r
-//Generates a random index from 0 up to but not including count.\r
-unsigned\r
-get_index(unsigned count)\r
-{\r
- unsigned result = unsigned((rand() % (1 << 16))*uint64_t(count)/(1 << 16));\r
- if (result >= count)\r
- return count - 1;\r
- return result;\r
-}\r
-\r
-//Tests std::sort vs boost::sort::spreadsort on boost::sort's worst distribution.\r
-int main(int, const char **) {\r
- unsigned total_length = sizeof(DATA_TYPE) * 8;\r
- double std_sort_time = 0;\r
- double spreadsort_time = 0;\r
- for (int repetition = 0; repetition < 10; ++repetition) {\r
- vector<DATA_TYPE> input;\r
- vector<unsigned> offsets;\r
- unsigned bit_length = total_length - radix_threshold;\r
- unsigned bit_offset = bit_shift;\r
- for (; bit_length >= ++bit_offset; bit_length -= bit_offset)\r
- offsets.push_back(bit_offset);\r
- for (int ii = (1 << bit_length) - 1; ii >= 0; --ii)\r
- fill_vector(input, ii, total_length - bit_length,\r
- offsets, offsets.size() - 1);\r
-\r
- //Randomize the inputs slightly so they aren't in reverse-sorted order, for\r
- //which std::sort is very fast.\r
- for (unsigned u = 0; u < input.size() / 10; ++u)\r
- std::swap(input[get_index(input.size())], input[get_index(input.size())]);\r
-\r
- //Run both std::sort and boost::sort::spreadsort.\r
- for (unsigned u = 0; u < 2; ++u) {\r
- vector<DATA_TYPE> array = input;\r
- clock_t start, end;\r
- double elapsed;\r
- start = clock();\r
- if (u)\r
- std::sort(array.begin(), array.end());\r
- else\r
- boost::sort::spreadsort::spreadsort(array.begin(), array.end());\r
- end = clock();\r
- elapsed = static_cast<double>(end - start);\r
- if (u)\r
- std_sort_time += elapsed / CLOCKS_PER_SEC;\r
- else\r
- spreadsort_time += elapsed / CLOCKS_PER_SEC;\r
- array.clear();\r
- }\r
- }\r
-\r
- printf("std::sort elapsed time %f\n", std_sort_time);\r
- printf("spreadsort elapsed time %f\n", spreadsort_time);\r
- return 0;\r
-}\r
+// a sorting example that uses the worst-case distribution for spreadsort.
+//
+// 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 <boost/sort/spreadsort/spreadsort.hpp>
+#include <time.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <algorithm>
+#include <vector>
+#include <string>
+#include <fstream>
+#include <sstream>
+#include <iostream>
+using namespace boost::sort::spreadsort;
+using namespace std;
+
+#define DATA_TYPE boost::uint64_t
+
+#define ALR_THRESHOLD 3
+
+const unsigned max_count = ALR_THRESHOLD - 1;
+const unsigned bit_shift = detail::rough_log_2_size(max_count) -
+ detail::int_log_mean_bin_size;
+const unsigned radix_threshold = detail::rough_log_2_size(max_count) + 1;
+
+const DATA_TYPE typed_one = 1;
+
+void
+fill_vector(vector<DATA_TYPE> & input, const DATA_TYPE base_value,
+ unsigned remaining_bits, const vector<unsigned> & indices,
+ int index)
+{
+ if (index < 0) {
+ for (unsigned u = 0; u < max_count; ++u)
+ input.push_back((base_value << remaining_bits) +
+ (rand() % (1 << remaining_bits)));
+ }
+ else {
+ unsigned shift = indices[index];
+ fill_vector(input, (base_value << shift) + ((1 << shift) - 1),
+ remaining_bits - shift, indices, index - 1);
+ fill_vector(input, base_value << shift, remaining_bits - shift, indices,
+ index - 1);
+ }
+}
+
+//Generates a random index from 0 up to but not including count.
+unsigned
+get_index(unsigned count)
+{
+ unsigned result = unsigned((rand() % (1 << 16))*uint64_t(count)/(1 << 16));
+ if (result >= count)
+ return count - 1;
+ return result;
+}
+
+//Tests std::sort vs boost::sort::spreadsort on boost::sort's worst distribution.
+int main(int, const char **) {
+ unsigned total_length = sizeof(DATA_TYPE) * 8;
+ double std_sort_time = 0;
+ double spreadsort_time = 0;
+ for (int repetition = 0; repetition < 10; ++repetition) {
+ vector<DATA_TYPE> input;
+ vector<unsigned> offsets;
+ unsigned bit_length = total_length - radix_threshold;
+ unsigned bit_offset = bit_shift;
+ for (; bit_length >= ++bit_offset; bit_length -= bit_offset)
+ offsets.push_back(bit_offset);
+ for (int ii = (1 << bit_length) - 1; ii >= 0; --ii)
+ fill_vector(input, ii, total_length - bit_length,
+ offsets, offsets.size() - 1);
+
+ //Randomize the inputs slightly so they aren't in reverse-sorted order, for
+ //which std::sort is very fast.
+ for (unsigned u = 0; u < input.size() / 10; ++u)
+ std::swap(input[get_index(input.size())], input[get_index(input.size())]);
+
+ //Run both std::sort and boost::sort::spreadsort.
+ for (unsigned u = 0; u < 2; ++u) {
+ vector<DATA_TYPE> array = input;
+ clock_t start, end;
+ double elapsed;
+ start = clock();
+ if (u)
+ std::sort(array.begin(), array.end());
+ else
+ boost::sort::spreadsort::spreadsort(array.begin(), array.end());
+ end = clock();
+ elapsed = static_cast<double>(end - start);
+ if (u)
+ std_sort_time += elapsed / CLOCKS_PER_SEC;
+ else
+ spreadsort_time += elapsed / CLOCKS_PER_SEC;
+ array.clear();
+ }
+ }
+
+ printf("std::sort elapsed time %f\n", std_sort_time);
+ printf("spreadsort elapsed time %f\n", spreadsort_time);
+ return 0;
+}
projects / ceph.git / blobdiff