/**
* @brief Open library
* @param libName - [in] library file name
* @return true - loaded successfully, false otherwise
*/
bool DynamicLibrary::Open( const PDL_CHAR * libName, bool resolveSymbols )
{
if ( !libName ) { return false; }
library_ =
#if PLATFORM_WIN32
::LoadLibraryExA( libName, NULL,
( resolveSymbols ) ? 0 : DONT_RESOLVE_DLL_REFERENCES );
#elif PLATFORM_POSIX
dlopen( libName, RTLD_GLOBAL | ( ( resolveSymbols ) ? RTLD_NOW : RTLD_LAZY ) );
#endif
if ( library_ ) { libraryName_ = libName; }
else
{
const pdl_string nameWithExt( pdl_string( libName ) + pdl_string( GetDefaultExt() ) );
library_ =
#if PLATFORM_WIN32
::LoadLibraryExA( nameWithExt.c_str(), NULL,
( resolveSymbols ) ? 0 : DONT_RESOLVE_DLL_REFERENCES );
#elif PLATFORM_POSIX
dlopen( nameWithExt.c_str(), RTLD_GLOBAL | ( ( resolveSymbols ) ? RTLD_NOW : RTLD_LAZY ) );
#endif
if ( library_ ) { libraryName_ = libName; }
}
return ( library_ );
}
/**
* @brief Get dynamic library
* @param libName - [in] library file name
* @return dynamic library
* @throw LoaderException - cannot load library
*/
DynamicLibrary & DynamicLibraryManager::GetLibrary( const PDL_CHAR * libName )
{
DynamicLibrary & library = GetLibraryInstance( libName );
if ( !library.Opened() )
{
// We tried to load this library before, but we've failed
throw LoaderException( pdl_string( "Cannot load library `" ) +
pdl_string( libName ) + pdl_string( "`" ) );
}
return library;
}
/**
* @brief Get last error description
* @return last error description
*/
pdl_string DynamicLibrary::GetLastError() const
{
try
{
#if PLATFORM_WIN32
LPSTR lpMsgBuf = NULL;
const DWORD res =
::FormatMessageA( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
NULL, ::GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
reinterpret_cast< LPSTR >( &lpMsgBuf ), 0, NULL );
pdl_string errorText;
if ( res != 0 )
{
errorText.assign( lpMsgBuf );
( void ) ::LocalFree( lpMsgBuf );
}
#elif PLATFORM_POSIX
const pdl_string errorText( dlerror() );
#endif
return errorText;
}
catch ( ... )
{
return pdl_string();
}
}
/**
* @brief Get symbol by name
* @param symbolName - [in] symbol name
* @return pointer to symbol, 0 if not found
*/
void * DynamicLibrary::GetSymbolByName( const PDL_CHAR * symbolName )
{
if ( !library_ )
{
throw LoaderException( pdl_string( "Library is not opened" ) );
}
return
#if PLATFORM_WIN32
static_cast< void * >( ::GetProcAddress( library_, symbolName ) );
#elif PLATFORM_POSIX
dlsym( library_, symbolName );
#endif
}
/**
* @brief Get class instance
* @param className - [in] class name
* @return pointer to class instance
*/
DynamicClass * DynamicLibrary::GetInstance( const PDL_CHAR * className )
{
const InstanceMap::iterator loadedInstance( instances_.find( className ) );
if ( loadedInstance != instances_.end() ) { return ( loadedInstance -> second ); }
const pdl_string builderName( pdl_string( "Create" ) + pdl_string( className ) );
// Tricky code to prevent compiler error
// ISO C++ forbids casting between pointer-to-function and pointer-to-object
DynamicBuilder builder = 0;
void * symbol = GetSymbolByName( builderName.c_str() );
( void ) memcpy( &builder, &symbol, sizeof( void * ) );
if ( !builder )
{
instances_[ className ] = 0;
throw LoaderException( pdl_string( "Class `" ) + pdl_string( className ) +
pdl_string( "` not found in " ) + libraryName_ );
}
DynamicClass * instance = ( DynamicClass * )( *builder )();
instances_[ className ] = instance;
return instance;
}
/**
* @brief Get dynamic library instance
* @param libName - [in] library file name
* @return dynamic library instance
*/
DynamicLibrary & DynamicLibraryManager::GetLibraryInstance( const PDL_CHAR * libName )
{
if ( !libName )
{
throw LoaderException( pdl_string( "Library name is 0" ) );
}
DynamicLibrary * library = 0;
const LibraryMap::iterator libraryInstance( libraries_.find( libName ) );
if ( libraryInstance != libraries_.end() )
{
library = libraryInstance -> second;
}
else
{
library = new DynamicLibrary();
libraries_[ libName ] = library;
if ( ( library ) && ( !library -> Open( libName, true ) ) )
{
// This is the first time we try to load this library.
// We are able to specify the reason of failure.
throw LoaderException( pdl_string( "Cannot load library `" ) +
pdl_string( libName ) + pdl_string( "`: " ) +
library -> GetLastError() );
}
}
if ( !library )
{
// Actually, this should never happen.
// If it has happened, this means serious memory damage
throw LoaderException( pdl_string( "Internal error" ) );
}
return ( *library );
}
