xslibraryloader.h

Go to the documentation of this file.

/* +------------------------------------------------------------------------+
   |                     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 XSLIBRARYLOADER_H
#define XSLIBRARYLOADER_H
 
#include "xstypesconfig.h"
#include "xsstring.h"
 
struct XsLibraryLoader;
 
#ifdef __cplusplus
extern "C" {
#else
#define XSLIBRARYLOADER_INITIALIZER \
    {                               \
        nullptr                     \
    }
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(nullptr)
    {
        // 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, nullptr 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