C++

Forum

 
A framework for saving and loading objects on disc

Skartik (4)
I have created a framework for persisting objects on c++ Need to implement with binary files as well. I am presenting here the code from my header file. Also the main body is provided here. Some feedback would definitely be appreciated here.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
 
   #include <iostream>
    #include <cstring>
    #include <typeinfo>
    #include <fstream>

    static const std::string FNAME = "Filename";

    template <class ObjectType> class ObjectStorage {
    protected:
        ObjectType obj;
        std::string filename;

        //Helper Functions
        virtual std::string get_object_heading() {
            return typeid(obj).name();
        }
    public:
        ObjectStorage(ObjectType obj) {
            this->obj = obj;
            filename = FNAME + "-" + typeid(obj).name()+".txt";
        }
        ObjectStorage(const ObjectStorage<ObjectType> &object) {
            this->obj = object.GetObj();
            this->filename = object.GetFilename();
        }
        virtual ~ObjectStorage() {

        }

        //Accessors
        ObjectType GetObj() const {return obj;}
        std::string GetFilename() const {return filename;}

        //Mutators
        void EditFilename(std::string new_name) {
            filename = new_name;
        }

        //Framework APIs
        virtual ObjectType ReadFromFile() {
            /* Read input from file. User shall override >> operator for reading from file */
            std::fstream f;
            f.open(filename.c_str(),std::fstream::in);
            filename>>&obj;
            f.close();
            return obj;
        }
        virtual void WriteToFile() {
            /* User shall provide his/her implementation for printing his/her object obj */
            std::ofstream f;
            f.open(filename.c_str(), std::ios::app);
            f<<"----------STORAGE FOR OBJECT TYPE: "<<get_object_heading()<<"------------\n";
            f<<&obj;
            f<<"\n-------------------------------------------------------------------------\n";
            f.close();
        }
    };
    template <class ObjectType> class ObjectStorage<ObjectType *> {
    protected:
        ObjectType *obj;
        std::string filename;

        //Helper Functions
        virtual std::string get_object_heading() {
            return typeid(obj).name();
        }
    public:
        ObjectStorage(ObjectType *obj) {
            this->obj = obj;
            filename = FNAME + "-" + typeid(obj).name()+".txt";
        }
        ObjectStorage(const ObjectStorage<ObjectType> &object) {
            this->obj = new ObjectType(*(object.GetObj()));
            this->filename = object.GetFilename();
        }
        virtual ~ObjectStorage() {
            delete obj;
        }

        //Accessors
        ObjectType *GetObj() const {return obj;}
        std::string GetFilename() const {return filename;}

        //Mutators
        void EditFilename(std::string new_name) {
            filename = new_name;
        }

        //Framework APIs
        virtual ObjectType *ReadFromFile(std::string filename, ObjectType *obj) {
            /* Read input from file. User shall override >> operator for reading from file */
            std::fstream f;
            f.open(filename.c_str(),std::fstream::in);
            filename>>obj;
            f.close();
            return obj;
        }
        virtual void WriteToFile() {
            /* User shall provide his/her implementation for printing his/her object obj */
            std::ofstream f;
            f.open(filename.c_str(), std::ios::app);
            f<<"----------STORAGE FOR OBJECT TYPE: "<<get_object_heading()<<"------------\n";
            f<<obj;
            f<<"\n-------------------------------------------------------------------------\n";
            f.close();
        }
    };

    std::ostream& operator<<(std::ostream &os, const int *obj) {
    os<<"1\n";
    os<<*obj<<"\n";
    return os;
}

int main()
{
    int *a = new int(10);
    int b = 20;
    //ObjectStorage<int*> storage(a);
    //storage.WriteToFile();

    return 0;
}
helios (17511)
Last edited on
Skartik (4)
Thanks for the input. Can you suggest some guidelines to design such a framework. Am new to these things.
helios (17511)
Don't. Just use what exists already.
Topic archived. No new replies allowed.