DllHelper.h

/*
 *  Copyright (C) 2005-2018 Team Kodi
 *  This file is part of Kodi - https://kodi.tv
 *
 *  SPDX-License-Identifier: GPL-2.0-or-later
 *  See LICENSES/README.md for more information.
 */
 
#pragma once
 
#ifdef __cplusplus
 
#include <string>
 
#include <dlfcn.h>
#include <kodi/AddonBase.h>
#include <kodi/Filesystem.h>
 
//==============================================================================
#define REGISTER_DLL_SYMBOL(functionPtr) \
  kodi::tools::CDllHelper::RegisterSymbol(functionPtr, #functionPtr)
//------------------------------------------------------------------------------
 
namespace kodi
{
namespace tools
{
 
//==============================================================================
class ATTR_DLL_LOCAL CDllHelper
{
public:
  //============================================================================
  CDllHelper() = default;
  //----------------------------------------------------------------------------
 
  //============================================================================
  virtual ~CDllHelper()
  {
    if (m_dll)
      dlclose(m_dll);
  }
  //----------------------------------------------------------------------------
 
  //============================================================================
  bool LoadDll(std::string path)
  {
#if defined(TARGET_ANDROID)
    if (kodi::vfs::FileExists(path))
    {
      // Check already defined for "xbmcaltbinaddons", if yes no copy necassary.
      std::string xbmcaltbinaddons =
          kodi::vfs::TranslateSpecialProtocol("special://xbmcaltbinaddons/");
      if (path.compare(0, xbmcaltbinaddons.length(), xbmcaltbinaddons) != 0)
      {
        bool doCopy = true;
        std::string dstfile = xbmcaltbinaddons + kodi::vfs::GetFileName(path);
 
        kodi::vfs::FileStatus dstFileStat;
        if (kodi::vfs::StatFile(dstfile, dstFileStat))
        {
          kodi::vfs::FileStatus srcFileStat;
          if (kodi::vfs::StatFile(path, srcFileStat))
          {
            if (dstFileStat.GetSize() == srcFileStat.GetSize() &&
                dstFileStat.GetModificationTime() > srcFileStat.GetModificationTime())
              doCopy = false;
          }
        }
 
        if (doCopy)
        {
          kodi::Log(ADDON_LOG_DEBUG, "Caching '%s' to '%s'", path.c_str(), dstfile.c_str());
          if (!kodi::vfs::CopyFile(path, dstfile))
          {
            kodi::Log(ADDON_LOG_ERROR, "Failed to cache '%s' to '%s'", path.c_str(),
                      dstfile.c_str());
            return false;
          }
        }
 
        path = dstfile;
      }
    }
    else
    {
      return false;
    }
#endif
 
    m_dll = dlopen(path.c_str(), RTLD_LOCAL | RTLD_LAZY);
    if (m_dll == nullptr)
    {
      kodi::Log(ADDON_LOG_ERROR, "Unable to load %s", dlerror());
      return false;
    }
    return true;
  }
  //----------------------------------------------------------------------------
 
  //============================================================================
  template<typename T>
  bool RegisterSymbol(T& functionPtr, const char* strFunctionPtr)
  {
    functionPtr = reinterpret_cast<T>(dlsym(m_dll, strFunctionPtr));
    if (functionPtr == nullptr)
    {
      kodi::Log(ADDON_LOG_ERROR, "Unable to assign function %s", dlerror());
      return false;
    }
    return true;
  }
  //----------------------------------------------------------------------------
 
private:
  void* m_dll = nullptr;
};
//------------------------------------------------------------------------------
 
} /* namespace tools */
} /* namespace kodi */
 
#endif /* __cplusplus */