RealmProtocol.h

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#ifndef __REALM_PROTOCOL__
#define __REALM_PROTOCOL__

#include <string>
#include <vector>
#ifdef _MSC_VER
#include "msc_stdint.h"
#else
#include <stdint.h>
#endif
#include <boost/shared_ptr.hpp>
#include <asio.hpp>

namespace realm {

namespace protocol {

enum handshake_response {
    HANDSHAKE_RESERVED = 0,             /* 0x00: reserved */
    HANDSHAKE_OK,                       /* 0x01: Login OK */
    HANDSHAKE_BAD_IDENTIFIER,           /* 0x02: Unrecognized protocol magic */
    HANDSHAKE_UNSUPPORTED_PROTOCOL,     /* 0x03: Unsupported protocol version */
    HANDSHAKE_INVALID_COOKIE            /* 0x04: Invalid cookie */
};

}

namespace protocolv1 {

class Packet;
typedef boost::shared_ptr<Packet> PacketPtr;
typedef boost::shared_ptr<asio::streambuf> StreamPtr;

// the packet type values must match up the corresponding body_size in
// RealmProtocol.cpp (ugly, but it's fast)!
enum packet_type {
    PACKET_RESERVED = 0x00,
    PACKET_ROUTE, // 0x01
    PACKET_DELIVER, // 0x02
    PACKET_USERJOINED, // 0x03
    PACKET_USERLEFT, // 0x04
    PACKET_SESSIONTAKEOVER, // 0x05
    __LAST_PACKET__
};

class Packet {
public:
    virtual ~Packet() {}

    static PacketPtr construct(uint8_t type);

    static bool s_valid(unsigned char type);
    static uint32_t s_body_size(unsigned char type);

    // Should be overwritten when the packet size is variable
    // Returns: the minimal number of bytes additionally needed before we can
    // re-assess if the packet is complete or not; -1 on error.
    // Note that this several complete() calls on the same buffer may return
    // several times with a value > 0. Only when complete() returns 0 the
    // buffer contains enough information to call parse().
    virtual int complete(const char* buf, size_t size);

    // should be overwritten when the packet 'has a body'
    // returns: the number of bytes read, -1 on error
    virtual int parse(const char* /*buf*/, size_t /*size*/) {
        return 0;
    }

    const uint8_t & type() const {
        return m_type;
    }

protected:
    Packet(uint8_t type);

private:
    uint8_t m_type;
};

class PayloadPacket : public Packet {
public:
    virtual int complete(const char* buf, size_t size);
    virtual int parse(const char* buf, size_t size);

    const uint32_t& getPayloadSize() const {
        return m_payload_size;
    }
protected:
    PayloadPacket(uint8_t t, uint32_t min_payload_size, uint32_t payload_size)
        : Packet(t),
        m_min_payload_size(min_payload_size),
        m_payload_size(payload_size)
    {}
    PayloadPacket(uint8_t t, uint32_t min_payload_size)
        : Packet(t),
        m_min_payload_size(min_payload_size),
        m_payload_size(0)
    {}
private:
    uint32_t m_min_payload_size;
    uint32_t m_payload_size;
};

class RoutingPacket : public PayloadPacket {
public:
    RoutingPacket();
    RoutingPacket(std::vector<uint8_t>& connection_ids, boost::shared_ptr<std::string> msg);
    virtual int parse(const char* buf, size_t size);

    const uint8_t& getAddressCount() const {
        return m_address_count;
    }

    const std::vector<uint8_t>& getConnectionIds() const {
        return m_connection_ids;
    }

    boost::shared_ptr<std::string> getMessage() const {
        return m_msg;
    }

private:
    uint8_t                 m_address_count;    // a bit redundant (as it can be derived from m_connection_ids.size()),
                                                // but it's convenient to be able to get a reference to this value
                                                // when sending this packet
    std::vector<uint8_t>    m_connection_ids;
    boost::shared_ptr<std::string> m_msg;
};

class DeliverPacket : public PayloadPacket {
public:
    DeliverPacket();
    DeliverPacket(uint8_t connection_id, boost::shared_ptr<std::string> msg);
    virtual int parse(const char* buf, size_t size);

    const uint8_t& getConnectionId() const {
        return m_connection_id;
    }

    boost::shared_ptr<std::string> getMessage() const {
        return m_msg;
    }

private:
    uint8_t         m_connection_id;
    boost::shared_ptr<std::string>  m_msg;
};

class UserJoinedPacket : public PayloadPacket {
public:
    UserJoinedPacket();
    UserJoinedPacket(uint8_t connection_id, bool master, boost::shared_ptr<std::string> userinfo);
    virtual int parse(const char* buf, size_t size);

    const uint8_t& getConnectionId() const {
        return m_connection_id;
    }

    const uint8_t& isMaster() const {
        return m_master;
    }

    boost::shared_ptr<std::string> getUserInfo() const {
        return m_userinfo;
    }

private:
    uint8_t         m_connection_id;
    uint8_t         m_master;
    boost::shared_ptr<std::string>      m_userinfo;
};

class UserLeftPacket : public Packet {
public:
    UserLeftPacket();
    UserLeftPacket(uint8_t connection_id);
    virtual int parse(const char* buf, size_t size);

    const uint8_t& getConnectionId() const {
        return m_connection_id;
    }

private:
    uint8_t m_connection_id;
};

class SessionTakeOverPacket : public Packet {
public:
    SessionTakeOverPacket();
};

}
}

#endif /* __REALM_PROTOCOL__ */