stdbin_decoder.h

Go to the documentation of this file.

#pragma once

#include "data_models/nav_header.h"
#include "data_models/stdbin.h"
#include "memory_block_parser.h"

#include <boost/circular_buffer.hpp>
#include <boost/noncopyable.hpp>

#include <functional>
#include <set>

namespace ixblue_stdbin_decoder
{

class StdBinDecoder : private boost::noncopyable
{
    // we sort the parsers list by offsetMask because this is a design constraint. We need
    // to process parser in the same order than data are filled in memory.
    typedef std::set<
        MemoryBlockParserPtr,
        std::function<bool(const MemoryBlockParserPtr&, const MemoryBlockParserPtr&)>>
        tParsersSet;

    static constexpr size_t HEADER_SIZE_V2 = 21;
    static constexpr size_t HEADER_SIZE_V3 = 25;
    static constexpr size_t HEADER_SIZE_V4 = 27;
    static constexpr size_t HEADER_SIZE_V5 = 27;
    static constexpr size_t ANSWER_HEADER_SIZE = 5;
    static constexpr size_t CHECKSUM_SIZE = 4;

public:
    StdBinDecoder();

    void addNewData(const uint8_t* data, std::size_t length);

    void addNewData(const std::vector<uint8_t>& data);

    bool parseNextFrame();

    Data::BinaryNav getLastNavData(void) const { return lastParsed; }
    Data::NavHeader getLastHeaderData(void) const { return lastHeader; }
    const std::vector<uint8_t>& getLastAnswerData(void) const { return lastAnswer; }

protected:
    Data::NavHeader parseHeader(boost::asio::const_buffer& buffer) const;
    Data::NavHeader::MessageType getHeaderType(boost::asio::const_buffer& buffer) const;
    bool haveEnoughBytesToParseHeader();
    void compareChecksum();
    // We set the parsers set "constant" to be sure that the content of this set will be
    // the same during all the lifetime of this object. We can only add memory bloc parser
    // at construction.
    const tParsersSet navigationParsers;
    const tParsersSet extendedNavigationParsers;
    const tParsersSet externalDataParsers;

    Data::BinaryNav lastParsed;
    Data::NavHeader lastHeader;
    std::vector<uint8_t> lastAnswer;

    // We store in this buffer the current frame's data. This memory chunk is managed by
    // the parsing state machine. See function \c parse.
    boost::circular_buffer<uint8_t> internalBuffer;
};
} // namespace ixblue_stdbin_decoder