cmtmessage.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2018, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#ifndef _CMTMESSAGE_H_2006_05_24
#define _CMTMESSAGE_H_2006_05_24

#ifndef _CMT_MONOLITHIC
#include "cmtdef.h"
#include "cmt1.h"
#endif

namespace xsens
{
//////////////////////////////////////////////////////////////////////////////////////////
/*! \brief Compute the checksum of the given byte string.
*/
uint8_t computeChecksum(const uint8_t* buffer, uint32_t length);

//////////////////////////////////////////////////////////////////////////////////////////
/* different alignment commands for gcc / MSVS, the structure needs to be 1-byte
 * aligned.
*/
#ifdef _MSC_VER
#pragma pack(push, 1)
#endif
/*! \brief A message header.

    DO NOT REORDER THE MEMBERS!
*/
struct MessageHeader
{
    uint8_t m_preamble;
    uint8_t m_busId;
    uint8_t m_messageId;
    uint8_t m_length;
    union _mdl {
        struct _mextd
        {
            struct _mlen
            {
                uint8_t m_high;
                uint8_t m_low;
            } m_length;
            uint8_t m_data[CMT_MAXDATALEN];
        } m_extended;
        uint8_t m_data[254];
    } m_datlen;
}
// different alignment commands for gcc / MSVS
#ifdef _MSC_VER
;
#pragma pack(pop)
#else
/*! \cond NODOXYGEN */ __attribute__((__packed__)) /*! \endcond */;
#endif

#if defined(_DEBUG) && defined(_CMT_CHECK_MSG_DATA_INTEGRITY)
#define CMT_CHECKVAR uint32_t m_checkvar;
#define CMT_CHECKVAL 10101010
#define CMT_CHECKASSIGN m_checkvar = CMT_CHECKVAL;
#define CMT_CHECKASSERT \
    if (m_checkvar != CMT_CHECKVAL) throw "Message assertion failed!";
#else
#define CMT_CHECKVAR
#define CMT_CHECKVAL
#define CMT_CHECKASSIGN
#define CMT_CHECKASSERT
#endif

#define swapEndian16(src) (((src) >> 8) | ((src) << 8))
#define swapEndian32(src)                                              \
    (((src) >> 24) | ((src) >> 8 & 0xFF00) | ((src) << 8 & 0xFF0000) | \
     ((src) << 24))

//////////////////////////////////////////////////////////////////////////////////////////
//! \brief Class for storing a single message.
class Message
{
   protected:
    CMT_CHECKVAR

    //! The message header is the data buffer with interpretation
    MessageHeader* m_buffer;
    //! The checksum in the m_data or m_extendedData buffer
    uint8_t* m_checksum;
    //! The maximum size of the message, including header and footer
    uint32_t m_maxLength;

    //! Internal checksum computation
    uint8_t calcChecksum(void) const
    {
        return computeChecksum(
            ((uint8_t*)m_buffer) + 1, getTotalMessageSize() - 2);
    }
    //! Internal function to get the start of the data buffer.
    uint8_t* getDataStart(void) const;

   public:
    bool m_autoUpdateChecksum;

    /*! \brief Create a Message object with the given data length and message
       Id.

        The function allocates enough memory to hold an entire message with the
       given
        data length.
        \param msgId    The message Id that will be assigend to the m_messageId
       field.
        \param length   The length of the data in the message. This value is
       stored in
                        \c m_createdLength as well as \c m_length or \c
       m_extendedLength.
        \param maxLength    The maximum data length that can be stored in the
       structure.
    */
    Message(
        const uint8_t msgId = 0, const uint16_t length = 0,
        const uint16_t maxLength = CMT_MAXMSGLEN);

    /*! \brief Create a message from the given source string

        This is done through a simple memory copy. The number of bytes copied is
       taken
        from the data in the message (so the message is interpreted first).
        Note that this does NOT recompute the checksum, nor is it checked.

        \param source       The source string containing message data
        \param size         The size of the source string
        \param maxLength    The maximum data length that can be stored in the
       structure.
    */
    Message(
        const uint8_t* source, const uint16_t size,
        const uint16_t maxLength = CMT_MAXMSGLEN);

    Message(const Message& src);

    //! Destructor
    ~Message();

    //! Clear all data in the message
    void clear(void);

    //! Return the current value of the m_busId field.
    uint8_t getBusId(void) const { return m_buffer->m_busId; }
    /*! \brief Return a pointer to the data buffer.

        \param offset An optional offset in the data buffer from where to start
       reading.
    */
    uint8_t* getDataBuffer(const uint16_t offset = 0)
    {
        return &((getDataStart())[offset]);
    }
    const uint8_t* getDataBuffer(const uint16_t offset = 0) const
    {
        return &((getDataStart())[offset]);
    }
    /*! \brief Return the current value of the data as an unsigned byte (8
       bits).

        \param offset An optional offset in the data buffer from where to start
       reading.
    */
    uint8_t getDataByte(const uint16_t offset = 0) const
    {
        return (getDataStart()[offset]);
    }
    /*! \brief Return the current value of the data as a double (64 bits).

        \param offset An optional offset in the data buffer from where to start
       reading.
    */
    double getDataDouble(const uint16_t offset = 0) const;
    /*! \brief Return the current value of the data as a float (32 bits).

        \param offset An optional offset in the data buffer from where to start
       reading.
    */
    float getDataFloat(const uint16_t offset = 0) const;
    /*! \brief Return the current value of the data as a double, converting it
       from FP 12.20

        \param offset An optional offset in the data buffer from where to start
       reading.
    */
    double getDataF1220(const uint16_t offset = 0) const;
    /*! \brief Return the current value of the data as a double, converting it
       from FP 16.32

        \param offset An optional offset in the data buffer from where to start
       reading.
    */
    double getDataFP1632(const uint16_t offset = 0) const;
    /*! \brief Return current data value as double, conversion depends on
       outputSettings.

        \param outputSettings MT output settings
        \param offset An optional offset in the data buffer from where to start
       reading.
    */
    double getDataFPValue(
        const uint64_t outputSettings, const uint16_t offset = 0) const;
    /*! \brief Return current data values as double, conversion depends on
       outputSetting.

        \param dest destination array
        \param outputSettings MT output settings
        \param offset offset in the data buffer from where to start reading.
        \param numValues number of values to be read
    */
    void getDataFPValue(
        double* dest, const uint64_t outputSettings, uint16_t offset,
        const int16_t numValues) const;
    /*! \brief Return the current value of the data as an uint32_t (32 bits).

        \param offset An optional offset in the data buffer from where to start
       reading.
    */
    uint32_t getDataLong(const uint16_t offset = 0) const;
    /*! \brief Return the current value of the data as an uint16_t (16 bits).

        \param offset An optional offset in the data buffer from where to start
       reading.
    */
    uint16_t getDataShort(const uint16_t offset = 0) const;
    //! Return the length of the data part of the message.
    uint16_t getDataSize(void) const;
    //! Return the current value of the m_messageId field.
    uint8_t getMessageId(void) const { return m_buffer->m_messageId; }
    /*! \brief Return the start of the message buffer.

        The function returns the address of the \c m_preamble member.
    */
    const uint8_t* getMessageStart(void) const { return (uint8_t*)m_buffer; }
    /*! \brief Return the length of the message buffer.

        The function returns the total size of the message, including the
       checksum. This
        is in effect the number of bytes that would be transferred if the
       message were to
        be sent over a communications channel.
    */
    uint16_t getTotalMessageSize(void) const;
    //! Compute the checksum and compare it with the stored checksum. Equal is
    //! ok.
    bool isChecksumOk(void) const;
    /*! \brief Read the entire message from the given source string

        This is done through a simple memory copy. The number of bytes copied is
       \c
        m_createdLength.
        \param source       The source string containing message data
        \param size         The size of the source string
    */
    XsensResultValue loadFromString(const uint8_t* source, const uint16_t size);
    /*! \brief Compute the checksum field and fill it.

        The checksum field should normally be correct at all times, but if you
       have
        somehow managed to mess it up, this function can be used to recompute
       it.
    */
    void recomputeChecksum(void) { m_checksum[0] = calcChecksum(); }
    //! Resize the data area to the given size
    void resizeData(const uint16_t newSize);
    //! Set the new value of the m_busId field and update the checksum.
    void setBusId(const uint8_t busId);
    /*! \brief Write a string of bytes into the data buffer.

        \param data     The data to write to the buffer.
        \param offset   An optional offset in the data buffer from where to
       start writing.
        \param count    An optional number of bytes to write, if set to 0 (not
       set), as
                        many bytes as will fit into the buffer from the given
       point will
                        be written.
    */
    void setDataBuffer(
        const uint8_t* data, const uint16_t offset = 0,
        const uint16_t count = 0);
    /*! \brief Write an unsigned byte (8 bits) into the data buffer.

        \param data     The data to write to the buffer.
        \param offset   An optional offset in the data buffer from where to
       start writing.
    */
    void setDataByte(const uint8_t data, const uint16_t offset = 0);
    /*! \brief Write a double (64 bits) into the data buffer.

        \param data     The data to write to the buffer.
        \param offset An optional offset in the data buffer from where to start
       writing.
    */
    void setDataDouble(const double data, const uint16_t offset = 0);
    /*! \brief Write a float (32 bits) into the data buffer.

        \param data     The data to write to the buffer.
        \param offset An optional offset in the data buffer from where to start
       writing.
    */
    void setDataFloat(const float data, const uint16_t offset = 0);
    /*! \brief Write a double (64 bits) into the data buffer, after converting
       it to F1220.

        \param data     The data to write to the buffer.
        \param offset   An optional offset in the data buffer from where to
       start writing.
    */
    void setDataF1220(const double data, const uint16_t offset = 0);
    /*! \brief Write a double (64 bits) into the data buffer, after converting
       it to FP1632.

        \param data     The data to write to the buffer.
        \param offset   An optional offset in the data buffer from where to
       start writing.
    */
    void setDataFP1632(const double data, const uint16_t offset = 0);
    /*! \brief Write a floating/fixed point value into to the data buffer,
       conversion depends on outputSettings

        \param outputSettings MT output settings
        \param data     The data to write to the buffer.
        \param offset An optional offset in the data buffer from where to start
       writing.
    */
    void setDataFPValue(
        const uint64_t outputSettings, const double data,
        const uint16_t offset = 0);
    /*! \brief Write a floating/fixed point value into to the data buffer,
       conversion depends on outputSettings

        \param outputSettings MT output settings
        \param data     The data array to be written to the buffer.
        \param offset Offset in the data buffer from where to start writing.
        \param numValues number of values to be written
    */
    void setDataFPValue(
        const uint64_t outputSettings, const double* data, uint16_t offset,
        const uint16_t numValues);
    /*! \brief Write an uint32_t (32 bits) into the data buffer.

        \param data     The data to write to the buffer.
        \param offset An optional offset in the data buffer from where to start
       writing.
    */
    void setDataLong(const uint32_t data, const uint16_t offset = 0);
    /*! \brief Write an uint16_t (16 bits) into the data buffer.

        \param data     The data to write to the buffer.
        \param offset An optional offset in the data buffer from where to start
       writing.
    */
    void setDataShort(const uint16_t data, const uint16_t offset = 0);
    //! Set the new value of the m_messageId field and update the checksum.
    void setMessageId(const uint8_t msgId);

    //! Copy message src into this
    void operator=(const Message& src);

    //! Remove a number of bytes from the message (this will reduce the message
    //! size)
    void deleteData(uint16_t size, uint16_t offset = 0);
    //! Insert a number of bytes into the message (this will increase the
    //! message size)
    void insertData(uint16_t size, uint16_t offset = 0);
};

}  // end of xsens namespace

#endif  // _CMTMESSAGE_H_2006_05_24