C++风格与C风格文件读写效率测试-vs2015,vs2017

void test_write()
{
    const int TEST_SIZE = 100000000;
    const char* c_plus_write_file = "H://c_plus_write_file.txt";
    const char* c_write_file = "g://c_write_file.txt";

    cout << "Test size :" << TEST_SIZE << endl;
    //c++ style writing file  
    ofstream of(c_plus_write_file);
    //assert(of);
    time_t start, end;
    start = clock();
    for (int i = 0; i < TEST_SIZE; ++i)
    {
        char tmp[1];
        tmp[0] = char(i);
        of.write(tmp, 1);
    }
    end = clock();
    of.close();
    cout << "C++ style: " << end - start << " ms" << endl;
    //c style writing file  
    FILE* fp;
    fopen_s(&fp, c_write_file, "w");
    start = clock();
    for (int i = 0; i < TEST_SIZE; ++i)
    {
        char tmp[1];
        tmp[0] = char(i);
        fwrite(tmp, 1, 1, fp);
    }
    end = clock();
    fclose(fp);
    cout << "C style: " << end - start << " ms" << endl;
    cin.get();
}

//机器配置：
//vs2015,vs2017
//intel(R)Core(TM)i7-6700HQ CPU@2.6GHZ 2.59GHZ
//16.0GB内存 64位操作系统
//测试结果：BUF_SIZE越大，C++与C风格时间差越大，数据如下：
//BUF_SIZE= 1000: c++平均90ms c平均80ms
//BUF_SIZE= 100000000: c++平均70ms c平均30ms
//这是读取测试，对于写入操作二者相关则更显著：BUF_SIZE= 100000000: c++平均25秒 c平均20秒
void test_read()
{
    const char* read_file = "g://c_write_file.txt";
    const int BUF_SIZE = 100000000;
    //char buf[BUF_SIZE];
    char* buf = new char[BUF_SIZE];
    time_t start, end;

    //c style writing file  
    FILE* fp = fopen(read_file, "rb");
    assert(fp);
    start = clock();
    int len = 0;
    do
    {
        len = fread(buf, 1, BUF_SIZE, fp);
        //cout<<len<<endl;  
    } while (len != 0);
    end = clock();
    fclose(fp);
    cout << "C style: " << end - start << " ms" << endl;

    //c++ style writing file  
    ifstream ifs(read_file, ios::binary);
    assert(ifs);
    start = clock();
    while (!ifs.eof())
    {
        ifs.read(buf, BUF_SIZE);
    }
    end = clock();
    ifs.close();
    cout << "C++ style: " << end - start << " ms" << endl;
    
    delete[] buf;
    cin.get();
}