Packet Queue Example Code

################## PacketBuffer.h

 

template <typename T>

class PacketBuffer

{

private:

    std::queue<T> mPackets;

    int mMaxSize;

public:

    PacketBuffer(size_t maxSize=0);

    virtual ~PacketBuffer(void);

    bool bufferPacket(const T& packet);

    T& getNextPacket();

};

 

template <typename T>

PacketBuffer<T>::PacketBuffer(size_t maxSize) : mMaxSize(maxSize)

{

}

 

template <typename T>

PacketBuffer<T>::~PacketBuffer(void)

{

}

 

template <typename T>

bool PacketBuffer<T>::bufferPacket(const T& packet)

{

    if (mMaxSize > 0 && mPackets.size() == mMaxSize ) {

        return false;

    }

    mPackets.push(packet);

    

    return true;

}

 

template <typename T>

T& PacketBuffer<T>::getNextPacket() throw (std::out_of_range)

{

    if (mPackets.empty()) {

        throw std::out_of_range("no packet in buffer");

    }

    T packet = mPackets.front(); // Read a last data from front.

    mPackets.pop(); // Remove the last data

    return packet;

}

####################### main.cpp

typedef struct {

    int id;

    char data[1000];

    int checksum;

} tcp_packet;

 

    PacketBuffer<tcp_packet> pb;

//    PacketBuffer<tcp_packet> pb(3);

 

    tcp_packet packet1 = {1,"welcome ", 3};

    if (!pb.bufferPacket(packet1))

        cout << "Queue Full";

        

    tcp_packet packet2 = {2,"to ", 3};

    pb.bufferPacket(packet2);

        

    tcp_packet packet3 = {3,"korea ", 3};

    pb.bufferPacket(packet3);

 

    tcp_packet packet4 = {4,"!! ", 3};

    pb.bufferPacket(packet4);

 

    while (true) {

        try {

            tcp_packet p1 = pb.getNextPacket();

            cout << "packet "<< p1.data << endl;

            }

        catch (const std::out_of_range) {

            cout << "queue empty" << endl;

            break;

        }

    }

 

}