1 #include "benchmark/benchmark.h"
2
3 #include <map>
4
5 namespace {
6
ConstructRandomMap(int size)7 std::map<int, int> ConstructRandomMap(int size) {
8 std::map<int, int> m;
9 for (int i = 0; i < size; ++i) {
10 m.insert(std::make_pair(rand() % size, rand() % size));
11 }
12 return m;
13 }
14
15 } // namespace
16
17 // Basic version.
BM_MapLookup(benchmark::State & state)18 static void BM_MapLookup(benchmark::State& state) {
19 const int size = state.range_x();
20 while (state.KeepRunning()) {
21 state.PauseTiming();
22 std::map<int, int> m = ConstructRandomMap(size);
23 state.ResumeTiming();
24 for (int i = 0; i < size; ++i) {
25 benchmark::DoNotOptimize(m.find(rand() % size));
26 }
27 }
28 state.SetItemsProcessed(state.iterations() * size);
29 }
30 BENCHMARK(BM_MapLookup)->Range(1 << 3, 1 << 12);
31
32 // Using fixtures.
33 class MapFixture : public ::benchmark::Fixture {
34 public:
SetUp(const::benchmark::State & st)35 void SetUp(const ::benchmark::State& st) {
36 m = ConstructRandomMap(st.range_x());
37 }
38
TearDown()39 void TearDown() {
40 m.clear();
41 }
42
43 std::map<int, int> m;
44 };
45
BENCHMARK_DEFINE_F(MapFixture,Lookup)46 BENCHMARK_DEFINE_F(MapFixture, Lookup)(benchmark::State& state) {
47 const int size = state.range_x();
48 while (state.KeepRunning()) {
49 for (int i = 0; i < size; ++i) {
50 benchmark::DoNotOptimize(m.find(rand() % size));
51 }
52 }
53 state.SetItemsProcessed(state.iterations() * size);
54 }
55 BENCHMARK_REGISTER_F(MapFixture, Lookup)->Range(1<<3, 1<<12);
56
57 BENCHMARK_MAIN()
58