reuse_nodes.cpp

#include <string>
#include <iterator>
#include <list>
#include <map>
#include <unordered_map>
#include <vector>
#include <random>
#include <benchmark/benchmark.h>

using namespace std;

const int stringSize = 20;
const int stringCount = 10000;
const char letters[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

struct DataFixture {
    vector<string> data;

    DataFixture() {
        random_device rd;
        uniform_int_distribution<int> dist(0, static_cast<int>(size(letters) - 1));
        data.reserve(stringCount);
        for (int str = 0; str < stringCount; ++str) {
            for (char& ch : data.emplace_back(stringSize, '\0')) {
                ch = letters[dist(rd)];
            }
        }
    }
};

DataFixture fixture;

void ListAssign(benchmark::State& state) {
    list<string> unitUnderTest;
    for (auto&& _ : state) {
        (void)_;
        unitUnderTest.assign(fixture.data.begin(), fixture.data.end());
    }
}

BENCHMARK(ListAssign);

template<template <class...> class MapType>
struct MapDataFixture {
    MapType<int, string> data;
    MapDataFixture() {
        int num = 0;
        for (auto&& entry : fixture.data) {
            data.emplace(num++, entry);
        }
    }
};

template<template <class...> class MapType>
    MapDataFixture<MapType> mapFixture;

template<template <class...> class MapType>
void MapCopyAssign(benchmark::State& state) {
    MapType<int, string> unitUnderTest;
    for (auto&& _ : state) {
        (void)_;
        unitUnderTest = mapFixture<MapType>.data;
    }
}

BENCHMARK_TEMPLATE1(MapCopyAssign, map);
BENCHMARK_TEMPLATE1(MapCopyAssign, unordered_map);

BENCHMARK_MAIN();