存档模式 Memento

定义：在不破坏封装性的前提下，捕获一个对象的内部状态，并在该对象之外保存这个状态。这样就可以将该对象恢复到原先保存的状态

类型：行为类

类图：

 

class Memento{

public:

    Memento(int level,int life,int time):m_level(level),m_life(life),m_time(time){}

    Memento * GetState(){

        return this;

    }

    int GetLevel(){

        return m_level;

    }

    int Getlife(){

        return m_life;

    }

    int Gettime(){

        return m_time;

    }

private:

    int m_level;

    int m_life;

    int m_time;

};



class Role{

public:

    Role(int level,int life,int time):m_level(level),m_life(life),m_time(time){}

    void LoadMem(Memento * pmem){

        m_level = pmem->GetLevel();

        m_life = pmem->Getlife();

        m_time = pmem->Gettime();

    }



    Memento * CreateMem(){

        return new Memento(m_level,m_life,m_time);

    }



    void Upgrade(){

        this->m_level += 1 ;

        this->m_life += 10;

        this->m_time += 10;

    }

    void show(){

        cout<<"~~~~~~~~state~~~~~~~~~~"<<endl;

        cout<<"level : "<<m_level<<endl;

        cout<<"life : "<<m_life<<endl;

        cout<<"time : "<<m_time<<endl;

    }

private:

    int m_level;

    int m_life;

    int m_time;

};



class ManagerMem{

public:

    void AddMem(Memento * p){

        memvec.push_back(p);

    }

    Memento * GetMem(int index){

        return memvec[index];

    }

    ~ManagerMem(){

        vector<Memento *>::iterator it = memvec.begin();

        for(; it != memvec.end();it++)

            delete *it;

    }

private:

    vector<Memento *>  memvec;

};



int main(int argc,char * argv[]){

    ManagerMem * pmanager = new ManagerMem;

    Role * prole = new Role(1,20,30);

    prole->show();



    prole->Upgrade();

    prole->show();

    

    cout<<"存档管理器添加存档："<<endl;

    pmanager->AddMem(prole->CreateMem());



    prole->Upgrade(); prole->show();

    prole->Upgrade(); prole->show();

    //断电了，升级失败，只能恢复原来的存档

    

    cout<<"加载存档："<<endl;

    prole->LoadMem(pmanager->GetMem(0));

    prole->show();



    delete prole;

    delete pmanager;

}