1 files changed, 57 insertions, 0 deletions
diff --git a/third-party/benchmark/test/map_test.cc b/third-party/benchmark/test/map_test.cc
new file mode 100644
index 000000000000..86391b36016f
--- /dev/null
+++ b/third-party/benchmark/test/map_test.cc
@@ -0,0 +1,57 @@
+#include "benchmark/benchmark.h"
+
+#include <cstdlib>
+#include <map>
+
+namespace {
+
+std::map<int, int> ConstructRandomMap(int size) {
+  std::map<int, int> m;
+  for (int i = 0; i < size; ++i) {
+    m.insert(std::make_pair(std::rand() % size, std::rand() % size));
+  }
+  return m;
+}
+
+}  // namespace
+
+// Basic version.
+static void BM_MapLookup(benchmark::State& state) {
+  const int size = static_cast<int>(state.range(0));
+  std::map<int, int> m;
+  for (auto _ : state) {
+    state.PauseTiming();
+    m = ConstructRandomMap(size);
+    state.ResumeTiming();
+    for (int i = 0; i < size; ++i) {
+      benchmark::DoNotOptimize(m.find(std::rand() % size));
+    }
+  }
+  state.SetItemsProcessed(state.iterations() * size);
+}
+BENCHMARK(BM_MapLookup)->Range(1 << 3, 1 << 12);
+
+// Using fixtures.
+class MapFixture : public ::benchmark::Fixture {
+ public:
+  void SetUp(const ::benchmark::State& st) BENCHMARK_OVERRIDE {
+    m = ConstructRandomMap(static_cast<int>(st.range(0)));
+  }
+
+  void TearDown(const ::benchmark::State&) BENCHMARK_OVERRIDE { m.clear(); }
+
+  std::map<int, int> m;
+};
+
+BENCHMARK_DEFINE_F(MapFixture, Lookup)(benchmark::State& state) {
+  const int size = static_cast<int>(state.range(0));
+  for (auto _ : state) {
+    for (int i = 0; i < size; ++i) {
+      benchmark::DoNotOptimize(m.find(std::rand() % size));
+    }
+  }
+  state.SetItemsProcessed(state.iterations() * size);
+}
+BENCHMARK_REGISTER_F(MapFixture, Lookup)->Range(1 << 3, 1 << 12);
+
+BENCHMARK_MAIN();