QList与std::vector性能比较

测试环境:windows11
测试IDE:qt creator 13.0.1 Qt:6.2.3
测试编译器:MSVC 2019 64bit

代码

#include <chrono>
#include <iostream>
using namespace std;
using namespace std::chrono;
#include <QDebug>
#include <random>
using namespace std;

class Test {
  public:
    int m_key;
    QString m_v;
};

#define NUM 10000000
#define START 5000
#define END 60000

static random_device rd;
static mt19937 gen(rd());
static uniform_int_distribution<> random(1, NUM - 2);

static QList<QSharedPointer<Test>> list1;
static std::vector<QSharedPointer<Test>> vector1;

void init() {
    for (int i = 0; i < NUM; ++i) {
        auto v = QSharedPointer<Test>(new Test());
        v->m_key = i;
        v->m_v = QString::number(i);
        list1.push_back(v);
        vector1.push_back(v);
    }
}

void testInsertHead() {
    cout << "insert head" << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        list1.push_front(v);

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        vector1.insert(vector1.begin(), v);

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

void testInsertTail() {
    cout << "insert tail" << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        list1.push_back(v);

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        vector1.push_back(v);

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

void testInsertAnyPosi() {
    int posi = random(gen);
    cout << "insert" << posi << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        list1.insert(posi, v);

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        vector1.insert(vector1.cbegin() + posi, v);

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

void testDeleteHead() {
    cout << "delete head" << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        list1.pop_front();

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        vector1.erase(vector1.begin());

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

void testDeleteTail() {
    cout << "delete tail" << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        list1.pop_back();

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        vector1.pop_back();

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

void testDeleteAnyPosi() {
    int posi = random(gen);
    cout << "delete" << posi << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        list1.remove(posi);

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = QSharedPointer<Test>(new Test());
        v->m_key = 0;
        v->m_v = QString::number(0);

        vector1.erase(vector1.cbegin() + posi);

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

void testCopyLoop() {
    cout << "copy loop" << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        QList<QSharedPointer<Test>> list2;
        list2.resize(END - START + 1);
        for (int i = START; i < END; ++i) {
            list2.push_back(list1.at(i));
        }

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        std::vector<QSharedPointer<Test>> vector2;
        vector2.resize(END - START + 1);
        std::copy(vector1.begin() + START, vector1.begin() + END, vector2.begin());

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

void testCopyIt() {
    cout << "copy iterator constructor" << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        QList<QSharedPointer<Test>> list2(list1.begin() + START, list1.begin() + END);

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        std::vector<QSharedPointer<Test>> vector2;
        vector2.resize(END - START + 1);
        std::copy(vector1.begin() + START, vector1.begin() + END, vector2.begin());

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

void testQueryHead() {
    cout << "query head" << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = list1[0];

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = vector1[0];

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

void testQueryTail() {
    cout << "query tail" << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = list1[list1.size() - 1];

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = vector1[vector1.size() - 1];

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

void testQueryAnyPosi() {
    int posi = random(gen);
    cout << "query" << posi << endl;
    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = list1[posi];

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }

    {
        auto m1 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();

        auto v = vector1[posi];

        auto m2 = duration_cast<microseconds>(system_clock::now().time_since_epoch()).count();
        cout << m2 - m1 << endl;
    }
}

int main(int argc, char* argv[]) {
    init();
    testInsertHead();
    testInsertTail();
    testInsertAnyPosi();
    testDeleteHead();
    testDeleteTail();
    testDeleteAnyPosi();
    testQueryHead();
    testQueryTail();
    testQueryAnyPosi();
    testCopyLoop();
    testCopyIt();

    return 0;
}

运行结果

结论

QList性能能满足大部分场景,vector在删除头时性能逊于QList