UDPPacket.h

/*
 * Copyright (c) 2015 Pavel Vainerman.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, version 2.1.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
// -----------------------------------------------------------------------------
#ifndef UDPPacket_H_
#define UDPPacket_H_
// -----------------------------------------------------------------------------
#include <list>
#include <limits>
#include <ostream>
#include "UniSetTypes.h"
// --------------------------------------------------------------------------
namespace uniset
{
    // -----------------------------------------------------------------------------
    namespace UniSetUDP
    {
        const uint32_t UNETUDP_MAGICNUM = 0x1348A5F; // идентификатор протокола
 
        struct UDPHeader
        {
            UDPHeader() noexcept;
            uint32_t magic;
            uint8_t _be_order; // 1 - BE byte order, 0 - LE byte order
            size_t num; // порядковый номер сообщения
            int64_t nodeID;
            int64_t procID;
            size_t dcount; 
            size_t acount; 
            uint16_t dcrc; 
            uint16_t acrc; 
        } __attribute__((packed));
 
        std::ostream& operator<<( std::ostream& os, UDPHeader& p );
        std::ostream& operator<<( std::ostream& os, UDPHeader* p );
 
        const size_t MaxPacketNum = std::numeric_limits<size_t>::max();
 
        struct UDPAData
        {
            UDPAData() noexcept: id(uniset::DefaultObjectId), val(0) {}
            UDPAData(int32_t id, int64_t val) noexcept: id(id), val(val) {}
 
            int32_t id;
            int64_t val;
 
        } __attribute__((packed));
 
        std::ostream& operator<<( std::ostream& os, UDPAData& p );
 
        // Теоретический размер данных в UDP пакете (исключая заголовки) 65507
        // Фактически желательно не вылезать за размер MTU (обычно 1500) - заголовки = 1432 байта
        // т.е. надо чтобы sizeof(UDPPacket) < 1432
        //
        static const size_t MaxACount = 2000;
        static const size_t MaxDCount = 4000;
        static const size_t MaxDDataCount = 1 + MaxDCount / (8 * sizeof(uint8_t));
 
        struct UDPMessage
        {
            // net to host
            void ntoh() noexcept;
            bool isOk() noexcept;
 
            // \warning в случае переполнения возвращается MaxDCount
            size_t addDData( int32_t id, bool val ) noexcept;
 
            bool setDData( size_t index, bool val ) noexcept;
 
            long dID( size_t index ) const noexcept;
 
            bool dValue( size_t index ) const noexcept;
 
            // функции addAData возвращают индекс, по которому потом можно напрямую писать при помощи setAData(index)
            // \warning в случае переполнения возвращается MaxACount
            size_t addAData( const UDPAData& dat ) noexcept;
            size_t addAData( int32_t id, int64_t val ) noexcept;
 
            bool setAData( size_t index, int64_t val ) noexcept;
 
            long getDataID( ) const noexcept; 
            inline bool isAFull() const noexcept
            {
                return (header.acount >= MaxACount);
            }
            inline bool isDFull() const noexcept
            {
                return (header.dcount >= MaxDCount);
            }
 
            inline bool isFull() const noexcept
            {
                return !((header.dcount < MaxDCount) && (header.acount < MaxACount));
            }
 
            inline size_t dsize() const noexcept
            {
                return header.dcount;
            }
 
            inline size_t asize() const noexcept
            {
                return header.acount;
            }
 
            uint16_t calcDcrc() const noexcept;
            uint16_t calcAcrc() const noexcept;
            void updatePacketCrc() noexcept;
 
            UDPHeader header;
            UDPAData a_dat[MaxACount]; 
            int32_t d_id[MaxDCount];      
            uint8_t d_dat[MaxDDataCount];  
        } __attribute__((packed));
 
        std::ostream& operator<<( std::ostream& os, UDPMessage& p );
 
        uint16_t makeCRC( unsigned char* buf, size_t len ) noexcept;
    }
    // --------------------------------------------------------------------------
} // end of namespace uniset
// -----------------------------------------------------------------------------
#endif // UDPPacket_H_
// -----------------------------------------------------------------------------