CGenericSensor.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 CGenericSensor_H
#define CGenericSensor_H

#include <mrpt/config/CConfigFileBase.h>
#include <mrpt/obs/CObservation.h>
#include <map>
#include <mutex>

namespace mrpt
{
/**   Contains classes for various device interfaces.
 * \ingroup mrpt_hwdrivers_grp
 */
namespace hwdrivers
{
class CGenericSensor;

/** A structure for runtime ID class type information in the context of
 * hwdrivers::CGenericSensor.
 */
struct TSensorClassId
{
    /** Class name */
    const char* className;
    /** Pointer to class constructor */
    CGenericSensor* (*ptrCreateObject)();
};

/** A generic interface for a wide-variety of sensors designed to be used in the
 *application RawLogGrabber.
 *  Derived classes should be designed with the following execution flow in
 *mind:
 *      - Object constructor
 *      - CGenericSensor::loadConfig: The following parameters are common to all
 *sensors in rawlog-grabber (they are automatically loaded by rawlog-grabber) -
 *see each class documentation for additional parameters:
 *          - "process_rate": (Mandatory) The rate in Hertz (Hz) at which the
 *sensor
 *thread should invoke "doProcess".
 *          - "max_queue_len": (Optional) The maximum number of objects in the
 *observations queue (default is 200). If overflow occurs, an error message
 *will be issued at run-time.
 *          - "grab_decimation": (Optional) Grab only 1 out of N observations
 *captured
 *by the sensor (default is 1, i.e. do not decimate).
 *      - CGenericSensor::initialize
 *      - CGenericSensor::doProcess
 *      - CGenericSensor::getObservations
 *
 *  Notice that there are helper methods for managing the internal list of
 *objects (see CGenericSensor::appendObservation).
 *
 *  <b>Class Factory:</b> This is also a factory of derived classes, through
 *the static method CGenericSensor::createSensor
 *
 *
 *  For more details on RawLogGrabber refer to the wiki page:
 *    http://www.mrpt.org/Application:RawLogGrabber
 * \ingroup mrpt_hwdrivers_grp
 */
class CGenericSensor
{
   public:
    using Ptr = std::shared_ptr<CGenericSensor>;
    virtual const mrpt::hwdrivers::TSensorClassId* GetRuntimeClass() const = 0;

    using TListObservations = std::multimap<
        mrpt::system::TTimeStamp, mrpt::serialization::CSerializable::Ptr>;
    using TListObsPair = std::pair<
        mrpt::system::TTimeStamp, mrpt::serialization::CSerializable::Ptr>;

    /** The current state of the sensor
     * \sa CGenericSensor::getState
     */
    enum TSensorState
    {
        ssInitializing = 0,
        ssWorking,
        ssError
    };

    /** The current state of the sensor  */
    inline TSensorState getState() const { return m_state; }
    inline double getProcessRate() const { return m_process_rate; }
    inline std::string getSensorLabel() const { return m_sensorLabel; }
    inline void setSensorLabel(const std::string& sensorLabel)
    {
        m_sensorLabel = sensorLabel;
    }

    /** Enable or disable extra debug info dumped to std::cout during sensor
     * operation.
     * Default: disabled unless the environment variable
     * "MRPT_HWDRIVERS_VERBOSE" is set to "1" during object creation.
     */
    inline void enableVerbose(bool enabled = true) { m_verbose = enabled; }
    inline bool isVerboseEnabled() const { return m_verbose; }
    /** Register a class into the internal list of "CGenericSensor" descendents.
     *  Used internally in the macros DEFINE_GENERIC_SENSOR, etc...
     *
     *  Can be used as "CGenericSensor::registerClass(
     * SENSOR_CLASS_ID(CMySensor) );" if
     *    building custom sensors outside mrpt libraries in user code.
     */
    static void registerClass(const TSensorClassId* pNewClass);

   private:
    /** The critical section for m_objList */
    std::mutex m_csObjList;
    /** The queue of objects to be returned by getObservations */
    TListObservations m_objList;

    /** Used in registerClass */
    using registered_sensor_classes_t =
        std::map<std::string, const TSensorClassId*>;
    /** Access to singleton */
    static registered_sensor_classes_t& get_registered_sensor_classes();

   protected:
    /** @name Common settings to any sensor, loaded in "loadConfig"
        @{ */

    /** See CGenericSensor */
    double m_process_rate;
    /** See CGenericSensor */
    size_t m_max_queue_len;
    /** If set to N>=2, only 1 out of N observations will be saved to m_objList.
     */
    size_t m_grab_decimation;
    /** See CGenericSensor */
    std::string m_sensorLabel;

    /** @} */

    /** Used when "m_grab_decimation" is enabled */
    size_t m_grab_decimation_counter;

    TSensorState m_state;
    bool m_verbose;

    // === Data for off-rawlog file external image directory ====
    //  Only used by a few sensor classes.
    /** The path where to save off-rawlog images: empty means save images
     * embedded in the rawlog. */
    std::string m_path_for_external_images;
    /** The extension ("jpg","gif","png",...) that determines the format of
     * images saved externally \sa setPathForExternalImages */
    std::string m_external_images_format;
    /** For JPEG images, the quality (default=95%). */
    unsigned int m_external_images_jpeg_quality;
    // ======================================

    /** This method must be called by derived classes to enqueue a new
      observation in the list to be returned by getObservations.
      *  Passed objects must be created in dynamic memory and a smart pointer
      passed. Example of creation:
      \code
        mrpt::obs::CObservationGPS::Ptr  o = CObservationGPS::Ptr( new
      CObservationGPS() );
        o-> .... // Set data
        appendObservation(o);
      \endcode
      * If several observations are passed at once in the vector, they'll be
      considered as a block regarding the grabbing decimation factor.
      */
    void appendObservations(
        const std::vector<mrpt::serialization::CSerializable::Ptr>& obj);

    //! Like appendObservations() but for just one observation.
    void appendObservation(const mrpt::serialization::CSerializable::Ptr& obj)
    {
        appendObservations(
            std::vector<mrpt::serialization::CSerializable::Ptr>(1, obj));
    }

    /** Auxiliary structure used for CSerializable runtime class ID support.
     */
    struct CLASSINIT_GENERIC_SENSOR
    {
        CLASSINIT_GENERIC_SENSOR(const TSensorClassId* pNewClass)
        {
            CGenericSensor::registerClass(pNewClass);
        }
    };

    /** Loads specific configuration for the device from a given source of
     * configuration parameters, for example, an ".ini" file, loading from the
     * section "[iniSection]" (see config::CConfigFileBase and derived classes)
     *  \exception This method must throw an exception with a descriptive
     * message if some critical parameter is missing or has an invalid value.
     */
    virtual void loadConfig_sensorSpecific(
        const mrpt::config::CConfigFileBase& configSource,
        const std::string& section) = 0;

   public:
    /** Creates a sensor by a name of the class.
     *  Typically the user may want to create a smart pointer around the
     * returned pointer, whis is made with:
     *  \code
     *   CGenericSensor::Ptr sensor = CGenericSensor::Ptr(
     * CGenericSensor::createSensor("XXX") );
     *  \endcode
     * \return A pointer to a new class, or nullptr if class name is unknown.
     */
    static CGenericSensor* createSensor(const std::string& className);

    /** Just like createSensor, but returning a smart pointer to the newly
     * created sensor object. */
    static inline CGenericSensor::Ptr createSensorPtr(
        const std::string& className)
    {
        return CGenericSensor::Ptr(createSensor(className));
    }

    /** Constructor */
    CGenericSensor();

    CGenericSensor(const CGenericSensor&) = delete;
    CGenericSensor& operator=(const CGenericSensor&) = delete;

    /** Destructor */
    virtual ~CGenericSensor();

    /** Loads the generic settings common to any sensor (See CGenericSensor),
     * then call to "loadConfig_sensorSpecific"
     *  \exception This method throws an exception with a descriptive message
     * if some critical parameter is missing or has an invalid value.
     */
    void loadConfig(
        const mrpt::config::CConfigFileBase& configSource,
        const std::string& section);

    /** This method can or cannot be implemented in the derived class, depending
     * on the need for it.
     *  \exception This method must throw an exception with a descriptive
     * message if some critical error is found.
     */
    virtual void initialize() {}  // Default method does nothing.
    /** This method will be invoked at a minimum rate of "process_rate" (Hz)
     *  \exception This method must throw an exception with a descriptive
     * message if some critical error is found.
     */
    virtual void doProcess() = 0;

    /** Returns a list of enqueued objects, emptying it (thread-safe). The
     * objects must be freed by the invoker.
     */
    void getObservations(TListObservations& lstObjects);

    /**  Set the path where to save off-rawlog image files (will be ignored in
     * those sensors where this is not applicable).
     *  An  empty string (the default value at construction) means to save
     * images embedded in the rawlog, instead of on separate files.
     * \exception std::exception If the directory doesn't exists and cannot be
     * created.
     */
    virtual void setPathForExternalImages(const std::string& directory)
    {
        MRPT_UNUSED_PARAM(directory);
        // In this base class, the default is to ignore image paths.
    }

    /**  Set the extension ("jpg","gif","png",...) that determines the format of
     * images saved externally
     *   The default is "jpg".
     * \sa setPathForExternalImages, setExternalImageJPEGQuality
     */
    void setExternalImageFormat(const std::string& ext)
    {
        m_external_images_format = ext;
    }

    /** The quality of JPEG compression, when external images is enabled and the
     * format is "jpg". \sa setExternalImageFormat */
    void setExternalImageJPEGQuality(const unsigned int quality)
    {
        m_external_images_jpeg_quality = quality;
    }
    unsigned int getExternalImageJPEGQuality() const
    {
        return m_external_images_jpeg_quality;
    }

   public:
    MRPT_MAKE_ALIGNED_OPERATOR_NEW

};  // end of class

static_assert(
    !std::is_copy_constructible<CGenericSensor>::value &&
        !std::is_copy_assignable<CGenericSensor>::value,
    "Copy Check");

#define SENSOR_CLASS_ID(class_name)                      \
    static_cast<const mrpt::hwdrivers::TSensorClassId*>( \
        &mrpt::hwdrivers::class_name::class##class_name)

#define SENSOR_IS_CLASS(ptrObj, class_name) \
    (ptrObj->GetRuntimeClass() == SENSOR_CLASS_ID(class_name))

/** This declaration must be inserted in all CGenericSensor classes definition,
 * within the class declaration.
 */
#define DEFINE_GENERIC_SENSOR(class_name)                                   \
   protected:                                                               \
    static mrpt::hwdrivers::CGenericSensor::CLASSINIT_GENERIC_SENSOR        \
        _init_##class_name;                                                 \
                                                                            \
   public:                                                                  \
    static mrpt::hwdrivers::TSensorClassId class##class_name;               \
    virtual const mrpt::hwdrivers::TSensorClassId* GetRuntimeClass() const; \
    static mrpt::hwdrivers::CGenericSensor* CreateObject();                 \
    static void doRegister()                                                \
    {                                                                       \
        CGenericSensor::registerClass(SENSOR_CLASS_ID(class_name));         \
    }

/** This must be inserted in all CGenericSensor classes implementation files:
 */
#define IMPLEMENTS_GENERIC_SENSOR(class_name, NameSpace)                       \
    mrpt::hwdrivers::CGenericSensor* NameSpace::class_name::CreateObject()     \
    {                                                                          \
        return static_cast<hwdrivers::CGenericSensor*>(                        \
            new NameSpace::class_name);                                        \
    }                                                                          \
    mrpt::hwdrivers::TSensorClassId NameSpace::class_name::class##class_name = \
        {#class_name, NameSpace::class_name::CreateObject};                    \
    const mrpt::hwdrivers::TSensorClassId*                                     \
        NameSpace::class_name::GetRuntimeClass() const                         \
    {                                                                          \
        return SENSOR_CLASS_ID(class_name);                                    \
    }

}  // namespace hwdrivers
}  // namespace mrpt

#endif