dllbase.h

C++ patterns设计模式

/*****************************************************************************/
//File name: dllbase.h
//Author: Darkay Li
//Version: 1.0
//Date: 2004/11/5
//Description: 提供动态连接库的基本操作，可以屏蔽WIN32和UNIX的不一致。
//Others: 
//Function List: 

//Class List: 
//History: 
/*****************************************************************************/
#ifndef INCLUDED_DLLBASE
#define INCLUDED_DLLBASE

#if defined(HAS_PRAGMA_ONCE)
#pragma PRAGMA_ONCE_DECLARE
#endif

#ifdef WIN32
#include <Windows.h>
#define RTLD_LAZY 0
#else
#include <dlfcn.h>
#endif

namespace stk
{
	class DllBase
	{
	public:
#ifdef WIN32
		bool open(const char *dll, int flag = RTLD_LAZY)
		{
			m_handle = ::LoadLibrary(dll);
			return m_handle != NULL;
		}
		bool close()
		{
			if(m_handle)
				return ::FreeLibrary(m_handle) == TRUE;
			else
				return false;
		}
		void *getsym(const char *symbol)
		{
			if(m_handle)
				return ::GetProcAddress(m_handle, symbol);
			else
				return NULL;
		}
		void geterror(std::string &strError)
		{
			DWORD error = ::GetLastError();
			LPVOID buf = NULL;
			BOOL ok = FormatMessage( 
				FORMAT_MESSAGE_ALLOCATE_BUFFER | 
				FORMAT_MESSAGE_FROM_SYSTEM | 
				FORMAT_MESSAGE_IGNORE_INSERTS,
				NULL,
				error,
				MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
				(LPTSTR) &buf,
				0,
				NULL 
				);
			if(!ok)
			{
				//try to load network error message library
				HMODULE dll = LoadLibraryEx(TEXT("netmsg.dll"), NULL, DONT_RESOLVE_DLL_REFERENCES);
				if(dll)
				{
					FormatMessage( 
						FORMAT_MESSAGE_ALLOCATE_BUFFER | 
						FORMAT_MESSAGE_FROM_SYSTEM | 
						FORMAT_MESSAGE_IGNORE_INSERTS,
						dll,
						error,
						MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
						(LPTSTR) &buf,
						0,
						NULL 
						);
					FreeLibrary(dll);
				}
			}
			if(buf)
			{
				//format :"error code : description"
				char temp[16];
				sprintf(temp, "%d", error);
				strError = temp;
				strError += " : ";
				strError += (LPCTSTR)buf;
				//remove the "\n"--0x0D0A
				strError[strError.size() - 2] = '\0';
				LocalFree(buf);
			}
		}
#else
		bool open(const char *dll, int flag = RTLD_LAZY)
		{
			m_handle = ::dlopen(dll, flag);
			return m_handle != NULL;
		}
		bool close()
		{
			if(m_handle)
				return dlclose(m_handle) == 0;
			else
				return false;
		}
		void *getsym(const char *symbol)
		{
			if(m_handle)
				return ::dlsym(m_handle, symbol);
			else
				return NULL;
		}
		void geterror(std::string &strError)
		{
			strError = ::dlerror();
		}
#endif
	private:
#ifdef WIN32
		HMODULE m_handle;
#else
		void *  m_handle;
#endif
	};
};
#endif