FECHeaderSupport.h

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 * Copyright (c) 2009-2010 Philipp Werner <philipp.werner@st.ovgu.de>
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#ifndef __FECHEADERSUPPORT_H_62EF7504454E4B__
#define __FECHEADERSUPPORT_H_62EF7504454E4B__


#include "util/endianness.h"


namespace famouso {
    namespace mw {
        namespace afp {
            namespace defrag {


                template <class DCP>
                class FECHeaderSupport {

                        typedef typename DCP::SizeProp::flen_t   flen_t;
                        typedef typename DCP::SizeProp::fcount_t fcount_t;

                        struct __attribute__((packed)) Header1001 {
                            uint8_t head;           
                            uint8_t red;            
                            uint32_t k;             
                            uint16_t len_rest;      
                        };

                        uint8_t red;            
                        fcount_t k;             
                        flen_t len_rest;        

                    public:

                        FECHeaderSupport()
                                : k(0) {
                        }

                        bool check(const uint8_t * data) {
                            return (*data & 0xbf) == 0x29;
                        }

                        flen_t read_header(const uint8_t * data) {
                            const Header1001 * h = reinterpret_cast<const Header1001 *>(data);

                            red = h->red;

                            // If fcount_t or flen_t are to small we may cut
                            // away information... check this.
                            bool error = false;

                            uint32_t k32 = ntohl(h->k);
                            k = k32;
                            if (k != k32)
                                error = true;

                            uint16_t len_rest16 = ntohs(h->len_rest);
                            len_rest = len_rest16;
                            if (len_rest != len_rest16)
                                error = true;

                            return error ? 0 : sizeof(Header1001);
                        }

                        bool occurs() const {
                            return k != 0;
                        }

                        uint32_t get_red() const {
                            return red;
                        }

                        uint32_t get_k() const {
                            return k;
                        }

                        uint32_t get_len_rest() const {
                            return len_rest;
                        }
                };


            } // namespace defrag
        } // namespace afp
    } // namespace mw
} // namespace famouso


#endif // __FECHEADERSUPPORT_H_62EF7504454E4B__