Of course. I reserved the space for the std::vector, just as I would with monotonic::vector. We all understand the cost of pre-allocating instead of re-allocating on the fly. The question is, how much can we gain with monotonic::vector (and its related containers) compared to a reserved std::vector? E.g., how much would the locality of reference between two containers give us (in cache hit increase)? /David On Jun 10, 2009, at 11:27 PM, Christian Schladetsch wrote:
You will note that I made a mistake, and used the same timer for both. This gave an incorrect result, as the std:: timer included the time for the first test. Even so, it was 9x faster rather than 10x faster.
Another test, this time with more list insertions:
void test_speed() { typedef monotonic::map<int, monotonic::list<int> > map_with_list; monotonic::inline_storage<1000000> storage; map_with_list m(storage); size_t count = 10000; boost::timer timer; for (size_t i = 0; i < count; ++i) { int random = rand() % 100; map_with_list::iterator iter = m.find(random); if (iter == m.end()) m.insert(make_pair(random, monotonic::list<int>(storage))); else iter->second.push_back(i); } double elapsed = timer.elapsed(); cout << "monotonic: " << elapsed << endl;
// do the same thing, with std::containers { typedef std::map<int, std::list<int> > map_with_list; map_with_list m; boost::timer timer; for (size_t i = 0; i < count; ++i) { int random = rand() % 100; map_with_list::iterator iter = m.find(random); if (iter == m.end()) m[random] = std::list<int>(); else iter->second.push_back(i); } double elapsed = timer.elapsed(); cout << "std: " << elapsed << endl; } }
monotonic: 0.001 std: 0.017 _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost