Frame.h

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#ifndef FRAME_H
#define FRAME_H

#include <stddef.h>
#include <vector>
#include <assert.h>

class Frame {
public:
    // CTOR and DTOR
    Frame(): m_BytesRemaining(0) {}
    virtual ~Frame(){}

    // Serializer and deserializer
    virtual const std::vector<unsigned char> Serialize() const = 0;
    size_t BytesNeeded() const { return m_BytesRemaining; }

    // true: no error, false: parser error
    bool ParseBytes(const unsigned char *a_ReadBuffer, size_t &a_ReadBufferOffset, size_t &a_BytesAvailable) {
        // Checks
        assert(a_ReadBuffer);
        assert(a_BytesAvailable);
        assert(m_BytesRemaining);

        // Parse the frame
        bool l_bSuccess = true;
        while ((m_BytesRemaining) && (a_BytesAvailable)) {
            // Determine the amount of bytes to consume
            size_t l_BytesToCopy = m_BytesRemaining;
            if (a_BytesAvailable < l_BytesToCopy) {
                l_BytesToCopy = a_BytesAvailable;
            } // if

            // Consume bytes from the provided buffer
            m_Buffer.insert(m_Buffer.end(), &a_ReadBuffer[a_ReadBufferOffset], (&a_ReadBuffer[a_ReadBufferOffset] + l_BytesToCopy));
            a_ReadBufferOffset += l_BytesToCopy;
            a_BytesAvailable   -= l_BytesToCopy;
            m_BytesRemaining   -= l_BytesToCopy;
            if (m_BytesRemaining == 0) {
                // A subsequent chunk of data is ready
                if (Deserialize() == false) {
                    // Failed to parse the received bytes
                    l_bSuccess = false;
                    break;
                } // else
            } // if
        } // while

        return l_bSuccess;
    }

protected:
    // Internal helpers
    virtual bool Deserialize() = 0;

    // Members
    std::vector<unsigned char> m_Buffer;
    size_t m_BytesRemaining;
};

#endif // FRAME_H