pluginhelper.cpp

linux下C++实现插件技术,详情请见http://masterdog.bokee.com/563395.html

#include "pluginhelper.h"

CPluginHelper::CPluginHelper()
{
}

CPluginHelper::~CPluginHelper()
{
}

std::vector< std::string > CPluginHelper::GetFileNameByPattern( std::string dir, const std::string & pattern )
{
    std::vector<std::string> file_name_set;
    
    if( dir.empty() )
    {
        dir = "./";
    }
    else if( dir[dir.length()-1] != '/' )
    {
        dir += '/';
    }
    
    std::string strCmd = "ls " +	dir + pattern;
	
	FILE * fp = popen(strCmd.c_str(), "r" );
	
	if(!fp)
	{
		std::cerr << "fail to gain file-list" << std::endl;
		return file_name_set;
	}

	char buf[BUF_SIZE];
	while( fgets(buf, BUF_SIZE, fp) )
	{
		char * ws = strpbrk(buf, " \t\n");
		
		if(ws)
		{
		    *ws = '\0';
		}

		file_name_set.push_back( std::string(buf) );
	}
	
	pclose(fp);
	
    return file_name_set;
}

void CPluginHelper::Load( const std::string & dir, const std::string & pattern )
{
    std::vector<std::string> soNameList = GetFileNameByPattern(dir, pattern);
    
    int	i;
    for( i = 0; i < soNameList.size(); i++ )
	{
	    std::map< std::string, void* >::iterator itrSoName = m_SoNameTable.find( soNameList[i] );
	    
	    /* so-library has already loaded */
	    if( itrSoName != m_SoNameTable.end() )
	    {
	        continue;
	    }
	    
		void * handle = dlopen( soNameList[i].c_str(), RTLD_LAZY );
		
		/* the very so-library file not exist */
		if( !handle )
    	{
    		std::cerr << dlerror() << std::endl;
    		continue;
    	}
    	
    	/* insert to SoNameTable */
    	m_SoNameTable[ soNameList[i] ] = handle;
	}
	
    return;
}

void CPluginHelper::Unload( const std::string & dir, const std::string & pattern )
{
    std::vector<std::string> soNameList = GetFileNameByPattern(dir, pattern);
    
    int	i;
    for( i = 0; i < soNameList.size(); i++ )
	{
	    std::map< std::string, void* >::iterator itrSoName = m_SoNameTable.find( soNameList[i] );

	    if( itrSoName != m_SoNameTable.end() )
	    {
	        void * handle = itrSoName->second;
	        
	        /* remove SoName */
    	    m_SoNameTable.erase(itrSoName);
    	    
    		/* close so-library */
    		dlclose(handle);
	    }	    
	}
	
    return;
}

void * CPluginHelper::Create( const std::string & className )
{
    std::map< std::string, void* >::iterator itrClassName = m_ClassNameTable.find( className );
    
    CreateOBJ_T	*  create = 0;
    void * pObj = 0;
   
    /* class name found in ClassNameTable */
    if( itrClassName != m_ClassNameTable.end() )
	{
	    if( 0 != itrClassName->second )
	    {
	        create = (CreateOBJ_T *)dlsym(itrClassName->second, "createByClassName");
	        
	        if( create )
            {
	            pObj = create( className.c_str() );
	        }
	    }
	}
	/* class name not found in ClassNameTable */
	else
	{
        std::map< std::string, void* >::iterator itrSoName = m_SoNameTable.begin();
        
        /* traverse through SoNameTable */
        for( ; itrSoName != m_SoNameTable.end(); ++itrSoName )
        {
            create = (CreateOBJ_T *)dlsym(itrSoName->second, "createByClassName");
            
            if( create )
            {
                pObj = create( className.c_str() );
                
                if( pObj )
                {
                    break;
                }
            }         
        }
	}
      
    return pObj;
}