RLPXFrameWriter.h

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/*
 This file is part of cpp-ethereum.
 
 cpp-ethereum is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.
 
 cpp-ethereum 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 General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
 */
#pragma once

#include <deque>
#include <libdevcore/Guards.h>
#include "RLPXFrameCoder.h"
#include "RLPXPacket.h"
namespace ba = boost::asio;
namespace bi = boost::asio::ip;

namespace dev
{
namespace p2p
{

class RLPXFrameWriter
{
        struct WriterState
        {
                std::deque<RLPXPacket> q;
                mutable Mutex x;
                
                RLPXPacket* writing = nullptr;
                size_t remaining = 0;
                bool multiFrame = false;
                uint16_t sequence = -1;
        };
        
public:
        enum PacketPriority { PriorityLow = 0, PriorityHigh };
        static const uint16_t EmptyFrameLength;
        static const uint16_t MinFrameDequeLength;

        RLPXFrameWriter(uint16_t _protocolType): m_protocolId(_protocolType) {}
        RLPXFrameWriter(RLPXFrameWriter const& _s): m_protocolId(_s.m_protocolId) {}
        
        size_t size() const { size_t l = 0; size_t h = 0; DEV_GUARDED(m_q.first.x) h = m_q.first.q.size(); DEV_GUARDED(m_q.second.x) l = m_q.second.q.size(); return l + h; }
        
        void enque(uint8_t _packetType, RLPStream& _payload, PacketPriority _priority = PriorityLow);

        size_t mux(RLPXFrameCoder& _coder, unsigned _size, std::deque<bytes>& o_toWrite);
        
        void enque(RLPXPacket&& _p, PacketPriority _priority = PriorityLow);

        uint16_t protocolId() const { return m_protocolId; }
        
private:
        uint16_t const m_protocolId;
        std::pair<WriterState, WriterState> m_q;                // High, Low frame queues
        uint16_t m_sequenceId = 0;                              // Sequence ID
};

}
}