Implementing custom serialization and deserialization in C++ using raw byte streams

19 Sep 2023

Serialization is the process of converting an object into a byte stream, while deserialization is the reverse process of converting the byte stream back into an object. These processes are crucial when working with data persistence, transmission, or storage. C++ provides a mechanism for serialization and deserialization using raw byte streams, allowing you to have full control over the process.

In this blog post, we will explore how to implement custom serialization and deserialization in C++ using raw byte streams, giving you the flexibility to define your own serialization format.

1. Designing the Serializable Class

To enable serialization and deserialization, you need to design your class in a way that allows the object’s state to be represented as a byte stream. Consider the following example:

class Person {
private:
    std::string name;
    int age;
    // ... other members

public:
    // ... constructors, getters, setters, etc.

    // Serialize the object into a byte stream
    std::vector<uint8_t> serialize() const {
        std::vector<uint8_t> bytes;
        // Convert the object's state to byte representation
        // and append to the byte vector
        // ...

        return bytes;
    }

    // Deserialize the object from a byte stream
    void deserialize(const std::vector<uint8_t>& bytes) {
        // Extract the object's state from the byte stream
        // and update the object's members accordingly
        // ...
    }
};

2. Serializing and Deserializing Functions

Next, let’s implement the serialization and deserialization functions for our Person class. These functions will be responsible for converting the object’s state into a byte stream and vice versa.

class Person {
    // ... members

public:
    // ...

    // Serialize the object into a byte stream
    std::vector<uint8_t> serialize() const {
        std::vector<uint8_t> bytes;

        // Serialize the name
        std::string serializedName = name;
        bytes.insert(bytes.end(), serializedName.begin(), serializedName.end());

        // Serialize the age
        uint8_t* ageBytes = reinterpret_cast<uint8_t*>(&age);
        bytes.insert(bytes.end(), ageBytes, ageBytes + sizeof(age));

        // ...

        return bytes;
    }

    // Deserialize the object from a byte stream
    void deserialize(const std::vector<uint8_t>& bytes) {
        size_t index = 0;

        // Deserialize the name
        std::string deserializedName(bytes.begin() + index, bytes.begin() + index + sizeof(name));
        name = deserializedName;
        index += sizeof(name);

        // Deserialize the age
        uint8_t* ageBytes = reinterpret_cast<uint8_t*>(&age);
        std::copy(bytes.begin() + index, bytes.begin() + index + sizeof(age), ageBytes);
        index += sizeof(age);

        // ...
    }
};

3. Using Custom Serialization and Deserialization

With the serialize and deserialize functions implemented, we can now use them to convert Person objects into byte streams and vice versa.

int main() {
    Person john("John Doe", 30);

    // Serialize the object
    std::vector<uint8_t> serializedData = john.serialize();

    // ... Store the serializedData or transmit it over a network

    Person deserializedPerson;
    // Deserialize the object from the byte stream
    deserializedPerson.deserialize(serializedData);

    // Now, deserializedPerson represents the original 'john' object
    // with the same state

    return 0;
}

Conclusion

Implementing custom serialization and deserialization in C++ using raw byte streams provides you with fine-grained control over the process. By defining your own serialization format, you can adapt it to your specific needs and easily store, transmit, or restore objects. Remember to handle different data types and ensure consistency between the serialization and deserialization implementations.

#C++ #CustomSerialization #ByteStreams