gnss_messages_common.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */
#pragma once

#include <mrpt/obs/gnss_messages_type_list.h>
#include <mrpt/serialization/CArchive.h>
#include <mrpt/system/datetime.h>
#include <cstring>  // memset()
#include <iosfwd>

namespace mrpt
{
namespace obs
{
/** GNSS (GPS) data structures, mainly for use within mrpt::obs::CObservationGPS
 */
namespace gnss
{
/** Pure virtual base for all message types. \sa mrpt::obs::CObservationGPS  */
struct gnss_message
{
    /** Type of GNSS message */
    gnss_message_type_t message_type;

    gnss_message(gnss_message_type_t msg_type_id) : message_type(msg_type_id) {}
    /** Save to binary stream. Launches an exception upon error */
    void writeToStream(mrpt::serialization::CArchive& out) const;
    /** Load from binary stream into this existing object. Launches an exception
     * upon error. */
    void readFromStream(mrpt::serialization::CArchive& in);

    bool isOfType(const gnss_message_type_t type_id) const;
    template <class MSG_CLASS>
    bool isOfClass() const
    {
        return isOfType(MSG_CLASS::msg_type);
    }

    /** Load from binary stream and creates object detecting its type (class
     * factory). Launches an exception upon error */
    static gnss_message* readAndBuildFromStream(
        mrpt::serialization::CArchive& in);
    /** Creates message \return nullptr on unknown msg type */
    static gnss_message* Factory(const gnss_message_type_t msg_id);
    /** Returns true if Factory() has a registered constructor for this msg type
     */
    static bool FactoryKnowsMsgType(const gnss_message_type_t msg_id);

    /** Dumps the contents of the observation in a human-readable form to a
     * given output stream \sa dumpToConsole() */
    virtual void dumpToStream(std::ostream& out) const = 0;

    /** If we are in a big endian system, reverse all fields >1 byte to fix its
     * representation. Only in binary frames, text-based derived classes
     * obviously do not need to reimplement this one. */
    virtual void fixEndianness() {}

    /** Dumps the contents of the observation in a human-readable form to an
     * std::ostream (set to std::cout to print to console) */
    virtual void dumpToConsole(std::ostream& o) const;

    /** Dumps a header for getAllFieldValues() \return false if not implemented
     * for this message type */
    virtual bool getAllFieldDescriptions([[maybe_unused]] std::ostream& o) const
    {
        return false;
    }
    /** Dumps a line with the sequence of all field values (without a line feed
     * at the end). \sa getAllFieldDescriptions() \return false if not
     * implemented for this message type */
    virtual bool getAllFieldValues([[maybe_unused]] std::ostream& o) const
    {
        return false;
    }
    /** Returns "NMEA_GGA", etc. */
    const std::string& getMessageTypeAsString() const;
    virtual ~gnss_message() = default;

   protected:
    /** Save to binary stream. Launches an exception upon error */
    virtual void internal_writeToStream(
        mrpt::serialization::CArchive& out) const = 0;
    /** Save to binary stream. Launches an exception upon error */
    virtual void internal_readFromStream(mrpt::serialization::CArchive& in) = 0;
};

/** A smart pointer to a GNSS message. \sa gnss_message,
 * mrpt::obs::CObservationGPS  */
struct gnss_message_ptr
{
   protected:
    gnss_message* ptr{nullptr};

   public:
    /** Ctor (default: nullptr pointer) */
    gnss_message_ptr();
    /** Makes a copy of the pointee */
    gnss_message_ptr(const gnss_message_ptr& o);
    /** Assigns a pointer. Memory now belongs to this class. */
    explicit gnss_message_ptr(const gnss_message* p);
    gnss_message_ptr& operator=(
        const gnss_message_ptr& o);  // Makes a copy of the pointee
    /** Dtor: it frees the pointee memory */
    virtual ~gnss_message_ptr();
    bool operator==(const gnss_message* o) const { return o == ptr; }
    bool operator==(const gnss_message_ptr& o) const { return o.ptr == ptr; }
    bool operator!=(const gnss_message* o) const { return o != ptr; }
    bool operator!=(const gnss_message_ptr& o) const { return o.ptr != ptr; }
    gnss_message*& get() { return ptr; }
    const gnss_message* get() const { return ptr; }
    gnss_message*& operator->()
    {
        ASSERT_(ptr);
        return ptr;
    }
    const gnss_message* operator->() const
    {
        ASSERT_(ptr);
        return ptr;
    }
    /** Replaces the pointee with a new pointer. Its memory now belongs to this
     * object, do not free manually. */
    void set(gnss_message* p);
};

#define GNSS_MESSAGE_BINARY_BLOCK(DATA_PTR, DATA_LEN)                        \
   protected:                                                                \
    void internal_writeToStream(mrpt::serialization::CArchive& out)          \
        const override                                                       \
    {                                                                        \
        out.WriteAs<uint32_t>(DATA_LEN);                                     \
        auto nonconst_this = const_cast<std::remove_const<                   \
            std::remove_reference<decltype(*this)>::type>::type*>(this);     \
        /* Temporarily switch to little endian for serialization only */     \
        nonconst_this->fixEndianness();                                      \
        out.WriteBuffer(DATA_PTR, DATA_LEN);                                 \
        nonconst_this->fixEndianness();                                      \
    }                                                                        \
    void internal_readFromStream(mrpt::serialization::CArchive& in) override \
    {                                                                        \
        const uint32_t nBytesInStream = in.ReadAs<uint32_t>();               \
        ASSERT_EQUAL_(nBytesInStream, DATA_LEN);                             \
        in.ReadBuffer(DATA_PTR, DATA_LEN);                                   \
        fixEndianness();                                                     \
    }                                                                        \
                                                                             \
   public:

#define GNSS_BINARY_MSG_DEFINITION_START(_MSG_ID)                      \
    struct Message_##_MSG_ID : public gnss_message                     \
    {                                                                  \
        GNSS_MESSAGE_BINARY_BLOCK(&fields, sizeof(fields))             \
        enum : uint32_t                                                \
        {                                                              \
            msg_type = _MSG_ID                                         \
        }; /* Static msg type (member expected by templates)*/         \
        Message_##_MSG_ID()                                            \
            : gnss_message(static_cast<gnss_message_type_t>(msg_type)) \
        {                                                              \
        }                                                              \
        struct content_t                                               \
        {
#define GNSS_BINARY_MSG_DEFINITION_MID                                       \
    content_t() = default;                                                   \
    }                                                                        \
    ;                                                                        \
    content_t fields; /** Message content, accesible by individual fields */ \
    void dumpToStream(std::ostream& out) const override;

#define GNSS_BINARY_MSG_DEFINITION_MID_END \
    }                                      \
    ;

#define GNSS_BINARY_MSG_DEFINITION_END \
    GNSS_BINARY_MSG_DEFINITION_MID     \
    GNSS_BINARY_MSG_DEFINITION_MID_END

// Pragma to ensure we can safely serialize some of these structures
#pragma pack(push, 1)

/** UTC (Coordinated Universal Time) time-stamp structure for GPS messages. \sa
 * mrpt::obs::CObservationGPS */
struct UTC_time
{
    uint8_t hour{0};
    uint8_t minute{0};
    double sec{0};

    UTC_time();
    /** Build an MRPT timestamp with the hour/minute/sec of this structure and
     * the date from the given timestamp. */
    mrpt::system::TTimeStamp getAsTimestamp(
        const mrpt::system::TTimeStamp& date) const;
    bool operator==(const UTC_time& o) const
    {
        return hour == o.hour && minute == o.minute && sec == o.sec;
    }
    bool operator!=(const UTC_time& o) const
    {
        return hour != o.hour || minute != o.minute || sec != o.sec;
    }
    /** Save to binary stream. Launches an exception upon error */
    void writeToStream(mrpt::serialization::CArchive& out) const;
    /** Save to binary stream. Launches an exception upon error */
    void readFromStream(mrpt::serialization::CArchive& in);
};

#pragma pack(pop)  // End of pack = 1
}  // namespace gnss
}  // namespace obs
}  // namespace mrpt