IModule* ModuleManager::load( const std::string& moduleName )
{
SystemState systemState = getSystem()->getState();
if( systemState < SystemState_Initializing )
throw IllegalStateException( "cannot load modules before the system is set up" );
if( systemState > SystemState_Running )
throw IllegalStateException( "cannot load modules while the system is being torn down" );
if( _loaders.empty() )
throw ModuleLoadException( "there are no installed module loaders" );
// check if the module was already loaded
IModule* alreadyLoaded = findModule( moduleName );
if( alreadyLoaded )
return alreadyLoaded;
/*
Load and initialize ModuleParts. Notice that once we initialize a part,
it may register a new ModulePartLoader that must also be considered.
*/
// the IModule is created on demand
Module* module = NULL;
// for error handling: whether a part was being loaded (true) or initialized (false)
bool wasLoading = true;
try
{
size_t numLoaders = _loaders.size();
for( size_t i = 0; i < numLoaders; ++i )
{
IModulePartLoader* loader = _loaders[i].get();
if( !loader->canLoadModulePart( moduleName ) )
continue;
// load the module part
wasLoading = true;
RefPtr<IModulePart> part( loader->loadModulePart( moduleName ) );
if( !part.isValid() )
throw ModuleLoadException( "loader returned a null IModulePart" );
if( !module )
module = createModule( moduleName );
module->addPart( part.get() );
// initialize the module part
wasLoading = false;
part->initialize( module );
// this module part may have added a new IModulePartLoader
size_t newNumLoaders = _loaders.size();
assert( newNumLoaders >= numLoaders );
numLoaders = newNumLoaders;
}
}
catch( std::exception& e )
{
// any error while loading or initializing a part aborts the whole module
if( module )
module->abort();
std::stringstream ss;
if( wasLoading )
ss << "error loading module '" << moduleName << "': ";
else
ss << "exception raised by module '" << moduleName << "' during initialization: ";
ss << e.what();
throw ModuleLoadException( ss.str() );
}
if( !module )
{
CORAL_THROW( ModuleLoadException, "no module loader recognized '" << moduleName <<
"' as a module (perhaps it was not compiled in " CORAL_BUILD_MODE " mode?)" );
}
module->initialize();
syncModuleWithSystemState( module );
return module;
}
