xslibraryloader.h

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/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          http://www.mrpt.org/                             |
   |                                                                           |
   | Copyright (c) 2005-2017, 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 XSLIBRARYLOADER_H
#define XSLIBRARYLOADER_H

#include "xstypesconfig.h"
#include "xsstring.h"

struct XsLibraryLoader;

#ifdef __cplusplus
extern "C" {
#else
#define XSLIBRARYLOADER_INITIALIZER { NULL }
typedef struct XsLibraryLoader XsLibraryLoader;
#endif

XSTYPES_DLL_API int XsLibraryLoader_load(XsLibraryLoader* thisp, const XsString* libraryName);
XSTYPES_DLL_API void* XsLibraryLoader_resolve(const XsLibraryLoader* thisp, const char *functionName);
XSTYPES_DLL_API int XsLibraryLoader_unload(XsLibraryLoader* thisp);
XSTYPES_DLL_API int XsLibraryLoader_isLoaded(const XsLibraryLoader* thisp);
XSTYPES_DLL_API void XsLibraryLoader_getErrorString(XsString* error);

#ifdef __cplusplus
}
#endif

/*! \brief The Xsens dynamic library loader base class
*/
struct XsLibraryLoader {
#ifdef __cplusplus
public:
        /*! \brief Create a library loader */
        inline XsLibraryLoader() :
                m_handle(NULL)
        {
                // avoid compiler warnings about
                // an unused handle. It is used in the c implementations
                (void)m_handle;
        }

        /*! \brief Destroy a library loader */
        inline ~XsLibraryLoader()
        {
                unload();
        }

        /*! \brief Load the library
          \param[in] libraryName the name of the library to load
          \return true if the library could be loaded, false otherwise
        */
        inline bool load(const XsString& libraryName)
        {
                return XsLibraryLoader_load(this, &libraryName) != 0;
        }

        /*! \brief Return true if a library has been loaded

          \return true if a library has been loaded, false otherwise
        */
        inline bool isLoaded() const
        {
                return XsLibraryLoader_isLoaded(this) != 0;
        }

        /*! \brief Resolve a function from the library

          \param[in] functionName the name of the function to resolve
          \return a pointer to the resolved function, NULL if nothing could be resolved
        */
        inline void* resolve(const char *functionName) const
        {
                return XsLibraryLoader_resolve(this, functionName);
        }

        /*! \brief Unload the loaded library
        */
        inline void unload() throw()
        {
                XsLibraryLoader_unload(this);
        }

        /*! \brief Return a string describing the error that occurred

          Use this function after a function returned with an error to
          receive some extra information about what went wrong.

          \returns a string describing the error that occurred
        */
        inline static XsString errorString()
        {
                XsString rv;
                XsLibraryLoader_getErrorString(&rv);
                return rv;
        }
private:
#endif
        void* m_handle;
};

#endif //XSLIBRARYLOADER_H