产生全服唯一id

string tirm_number(int n)
{
    stringstream _ss;
    _ss.str("");
    if (n < 10)
    {
        _ss << "0" << n;
    }
    else
    {
        _ss << n;
    }
    return _ss.str();
}


unsigned int g_increase_id = 1000;
string get_uuid(string server_name)
{       
    stringstream _ss;
    _ss.str("");

    if (g_increase_id++ > 2000)
    {
        g_increase_id = 1000;
    }

    struct tm *ptr; 
    time_t lt; 

    lt = time(NULL); 
    ptr = localtime(&lt); 

    _ss << server_name  << ptr->tm_year<<tirm_number(ptr->tm_mon) << tirm_number(ptr->tm_mday);
    _ss << tirm_number(ptr->tm_hour) << tirm_number(ptr->tm_min) << tirm_number(ptr->tm_sec);
    _ss << g_increase_id;

    return _ss.str();
}