diff --git a/lib.mk b/lib.mk
index ba68680..f0d4e2b 100644
--- a/lib.mk
+++ b/lib.mk
@@ -2,7 +2,7 @@ include ../../var.mk
 main:$(LIB_OBJ) $(LIB_NAME)
 
 %.o: %.c
-		$(CC) $(LIB_CFLAGS) $(LIB_INC)  -fPIC $(LUA_H) -I$(REAL_PLUGINS_BASE) -c  $< -o $@
+		$(CC) $(LIB_CFLAGS) -D DEBUG $(LIB_INC)  -fPIC $(LUA_H) -I$(REAL_PLUGINS_BASE) -c  $< -o $@
 		
 %.$(LIB_EXT): %.o
 		-mkdir $(LIB_BUILD_DIR)
diff --git a/lib/ffi/example/example.lua b/lib/ffi/example/example.lua
index 34dcaa7..f4ae5ce 100644
--- a/lib/ffi/example/example.lua
+++ b/lib/ffi/example/example.lua
@@ -1,5 +1,5 @@
+local path = "/home/blackjack/workspace/ant-http/plugins/antd-lua-plugin/lib/ffi/example/libtest.so"
 require("cif")
-local path = "/Users/mrsang/Google Drive/ushare/cwp/ant-http/plugins/antd-lua-plugin/lib/ffi/example/libtest.so"
 local lib = nil
 local fn = nil
 local rettype = nil
@@ -7,38 +7,54 @@ local argtype = nil
 lib = FFI.load(path)
 if lib then
     -- now try to lookup for the greet function
-    echo("looking for greet")
     fn = FFI.lookup(lib,"greet")
     if fn then
-        -- now the function found
+        -- now the function
         -- tried to called it
-        rettype = FFI.atomic(FFI.type.VOID) -- void
-        if rettype then
-            argtype = {
-                FFI.atomic(FFI.type.POINTER),
-                FFI.atomic(FFI.type.DOUBLE),
-                FFI.atomic(FFI.type.SINT64),
-                FFI.atomic(FFI.type.SINT8)
-            } -- pointer
-            if(argtype) then
-                -- call the function
-                local r = FFI.call(rettype, argtype, fn, {"hello world", 0.987, -76, 65})
-                if r then
-                    echo("BIG SUCCESS")
-                else
-                    echo("HELL FAIL")
-                end
-            else
-                echo("argtype not found")
-            end
+        rettype = FFI.atomic(FFI.type.UINT8) -- voidn
+        argtype = {
+            FFI.atomic(FFI.type.POINTER),
+            FFI.atomic(FFI.type.DOUBLE),
+            FFI.atomic(FFI.type.SINT64),
+            FFI.atomic(FFI.type.SINT8)
+        } -- pointer
+        -- call the function
+        local r = FFI.call(rettype, argtype, fn, {"hello world", 0.987, -76, 65})
+        if r then
+            echo(r)
         else
-            echo("return type not found")
+            echo("HELL FAIL")
         end
-    else
-        echo("unable to find greet")
     end
+    fn = FFI.lookup(lib, "test_struct")
+    if fn then
+        local struct1 = FFI.struct({
+            FFI.atomic(FFI.type.UINT8), -- char
+            FFI.atomic(FFI.type.SINT32), -- char
+            FFI.atomic(FFI.type.SINT16), -- char
+            FFI.atomic(FFI.type.UINT8), -- char
+        })
+        local struct = FFI.struct({
+            FFI.atomic(FFI.type.UINT8), -- char
+            struct1,
+            FFI.atomic(FFI.type.SINT32), -- int 
+            FFI.atomic(FFI.type.UINT8), -- char
+        })
+        rettype = struct --FFI.atomic(FFI.type.DOUBLE)
+        echo("call with struct")
+       local r  = FFI.call(rettype,{struct},fn,{{65, {66, 2048, -97,67},-1024, 68}})
+        if r then echo(JSON.encode(r)) end
+        --echo(JSON.encode(FFI.meta(struct1)))
+    end
+    
+    fn = FFI.lookup(lib, "test_string")
+    if(fn) then
+        local buff = FFI.new(256)
+        FFI.call(FFI.atomic(FFI.type.VOID),{FFI.atomic(FFI.type.POINTER), FFI.atomic(FFI.type.POINTER)}, fn, {buff,"Hello world"})
+        echo(FFI.string(buff))
+        
+    end
+    
    FFI.unloadAll()
-else
-    echo("unable to load the lib")
 end
 echo("end the day")
\ No newline at end of file
diff --git a/lib/ffi/example/lib.c b/lib/ffi/example/lib.c
index e801162..caef882 100644
--- a/lib/ffi/example/lib.c
+++ b/lib/ffi/example/lib.c
@@ -1,6 +1,34 @@
 #include <stdio.h>
 
-void greet(const char* msg, float num, int sint, char c)
+
+typedef struct{
+    char a;
+    int b;
+    short c;
+    char d;
+} inner_t;
+
+typedef struct{
+    char a;
+    inner_t b;
+    int c;
+    char d;
+} test_t;
+
+char greet(const char* msg, float num, int sint, char c)
 {
     printf("%s: '%f' '%d' '%c'\n", msg, num, sint, c);
+    return 'A';
 }
+
+test_t test_struct(test_t data)
+{
+    printf("data is '%c' '%c' '%d' '%d' '%c' '%d' '%c'\n", data.a, data.b.a, data.b.b, data.b.c, data.b.d, data.c, data.d);
+    return data;
+}
+
+void test_string(char* buff, const char* a)
+{
+    sprintf(buff,"you say %s", a);
+    printf("%s\n", buff);
+}
\ No newline at end of file
diff --git a/lib/ffi/ffi.c b/lib/ffi/ffi.c
index b8d5f74..41e2be6 100644
--- a/lib/ffi/ffi.c
+++ b/lib/ffi/ffi.c
@@ -22,11 +22,6 @@
 
 #define MAX_FN_ARGC 32
 
-typedef struct {
-	uint8_t allocated;
-	uint8_t is_pointer;
-	void* data;
-} arg_pointer_t;
 // define atomic type
 typedef enum ffi_atomic_t {
 	L_FFI_TYPE_VOID,
@@ -146,84 +141,102 @@ static int l_ffi_prepare(lua_State* L, ffi_type** argvtype, int idx)
 	return argc;
 }
 
-void parser_value(lua_State* L, int idx, ffi_type* ffitype, arg_pointer_t * ptr)
+void parser_value(lua_State* L, int idx, ffi_type* ffitype, void * data)
 {
-	ptr->allocated = 1;
-	ptr->is_pointer = 0;
+	intptr_t address = (intptr_t) data;
+	int offset = 0;
+	int pad = 0;
+	int i = 0;
 	switch(ffitype->type)
 	{
 		case FFI_TYPE_POINTER:
-			ptr->allocated = 0;
-			ptr->is_pointer = 1;
-			ptr->data = (void*)lua_tostring(L, idx);
+			if(lua_isstring(L,idx))
+				*((void**)data) = (void*)lua_tostring(L, idx);
+			else
+				*((void**)data) = (void*)lua_touserdata(L, idx);
 			return;
 
 		case FFI_TYPE_UINT8:
-			ptr->data = (void*) malloc(ffitype->size);
-			*((uint8_t*)ptr->data) = (uint8_t)lua_tonumber(L,idx);
+			*((uint8_t*)data) = (uint8_t)lua_tonumber(L,idx);
 			return;
 
 		case FFI_TYPE_SINT8:
-			ptr->data = (void*) malloc(ffitype->size);
-			*((int8_t*)ptr->data) = (int8_t)lua_tonumber(L,idx);
+			*((int8_t*)data) = (int8_t)lua_tonumber(L,idx);
 			return;
 
 		case FFI_TYPE_UINT16:
-			ptr->data = (void*) malloc(ffitype->size);
-			*((uint16_t*)ptr->data) = (uint16_t)lua_tonumber(L,idx);
+			*((uint16_t*)data) = (uint16_t)lua_tonumber(L,idx);
 			return;
 
 		case FFI_TYPE_SINT16:
-			ptr->data = (void*) malloc(ffitype->size);
-			*((int16_t*)ptr->data) = (int16_t)lua_tonumber(L,idx);
+			*((int16_t*)data) = (int16_t)lua_tonumber(L,idx);
 			return;
 
 		case FFI_TYPE_UINT32:
-			ptr->data = (void*) malloc(ffitype->size);
-			*((uint32_t*)ptr->data) = (uint32_t)lua_tonumber(L,idx);
+			*((uint32_t*)data) = (uint32_t)lua_tonumber(L,idx);
 			return;
 
 		case FFI_TYPE_SINT32:
-			ptr->data = (void*) malloc(ffitype->size);
-			*((int32_t*)ptr->data) = (int32_t)lua_tonumber(L,idx);
+			*((int32_t*)data) = (int32_t)lua_tonumber(L,idx);
 			return;
 
 		case FFI_TYPE_UINT64:
-			ptr->data = (void*) malloc(ffitype->size);
-			*((uint64_t*)ptr->data) = (uint64_t)lua_tonumber(L,idx);
+			*((uint64_t*)data) = (uint64_t)lua_tonumber(L,idx);
 			return;
 
 		case FFI_TYPE_SINT64:
-			ptr->data = (void*) malloc(ffitype->size);
-			*((int64_t*)ptr->data) = (int64_t)lua_tonumber(L,idx);
+			*((int64_t*)data) = (int64_t)lua_tonumber(L,idx);
 			return; 
 
 		case FFI_TYPE_LONGDOUBLE:
 			/*This is bug in lua*/
-			ptr->data = (void*) malloc(ffitype->size);
-			*((long double*)ptr->data) = (long double)lua_tonumber(L,idx);
+			*((long double*)data) = (long double)lua_tonumber(L,idx);
 			return;
 
 		case FFI_TYPE_FLOAT:
 		case FFI_TYPE_DOUBLE:
-			ptr->data = (void*) malloc(ffitype->size);
-			*((float*)ptr->data) = (float)lua_tonumber(L,idx);
+			*((float*)data) = (float)lua_tonumber(L,idx);
 			return;
 
 		
-		/*case FFI_TYPE_STRUCT:
-			// not implemented yet
-			return NULL;
-			break;*/
-		default: 
-			ptr->allocated = 0;
-			ptr->is_pointer = 0;
-			ptr->data = NULL;
-			break;
+		case FFI_TYPE_STRUCT:
+			// loop through the table
+			lua_pushvalue(L,idx);
+			// stack now contains: -1 => table
+			lua_pushnil(L);
+			// stack now contains: -1 => nil, -2 => table
+			while(lua_next(L, -2))
+			{
+				// stack now contains: -1 => value; -2 key; -3 table
+				parser_value(L, -1, ffitype->elements[i],data+offset);
+				// pop the value, leaving the original key
+				lua_pop(L,1);
+				// stack now contains: -1 key; -2 table
+				// recalculate offs
+				address += ffitype->elements[i]->size;
+				if(ffitype->elements[i+1])
+				{
+					pad = address % ffitype->elements[i+1]->alignment;
+					if( pad != 0)
+					{
+						pad =  ffitype->elements[i+1]->alignment - pad;
+					}
+					
+					address +=  pad;
+					offset += ffitype->elements[i]->size + pad;
+				}
+				i++;
+			}
+			// lua_next return 0, it popout the key at -1, leaving the table
+			// so, popout the table
+			lua_pop(L,1);
+			return;
+			
+		default: return;
 	}
 }
 
-static void parser_arguments(lua_State* L, int idx, arg_pointer_t* argv, ffi_type** argvtype)
+static void parser_arguments(lua_State* L, int idx, void** argv, ffi_type** argvtype)
 {
 	// loop through table
 	lua_pushvalue(L,idx);
@@ -234,7 +247,8 @@ static void parser_arguments(lua_State* L, int idx, arg_pointer_t* argv, ffi_typ
 	while(lua_next(L, -2))
 	{
 		// stack now contains: -1 => value; -2 key; -3 table
-		parser_value(L, -1, argvtype[i],&argv[i]);
+		argv[i] = (void*)malloc(argvtype[i]->size);
+		parser_value(L, -1, argvtype[i],argv[i]);
 		i++;
 		// pop the value, leaving the original key
 		lua_pop(L,1);
@@ -245,25 +259,102 @@ static void parser_arguments(lua_State* L, int idx, arg_pointer_t* argv, ffi_typ
 	lua_pop(L,1);
 }
 
-static void free_arguments(arg_pointer_t* argv, int argc)
+
+static void ffi_post_call(lua_State* L, void* ret, ffi_type* rettype)
 {
-	for(int i = 0; i< argc; i++)
+	if(!ret)
 	{
-		if(argv[i].allocated)
-			free(argv[i].data);
+		lua_pushnil(L);
+		return;
+	}
+	int i = 0;
+	intptr_t address = (intptr_t) ret;
+	int offset = 0;
+	int pad = 0;
+	switch (rettype->type)
+	{
+		case FFI_TYPE_POINTER:
+			lua_pushlightuserdata(L,ret);
+			break;
+
+		case FFI_TYPE_UINT8:
+			lua_pushnumber(L, (lua_Number)(*((uint8_t*)ret)));
+			break;
+		case FFI_TYPE_SINT8:
+			lua_pushnumber(L, (lua_Number)(*((int8_t*)ret)));
+			break;
+		case FFI_TYPE_UINT16:
+			lua_pushnumber(L, (lua_Number)(*((uint16_t*)ret)));
+			break;
+		case FFI_TYPE_SINT16:
+			lua_pushnumber(L, (lua_Number)(*((int16_t*)ret)));
+			break;
+		case FFI_TYPE_UINT32:
+			lua_pushnumber(L, (lua_Number)(*((uint32_t*)ret)));
+			break;
+		case FFI_TYPE_SINT32:
+			lua_pushnumber(L, (lua_Number)(*((int32_t*)ret)));
+			break;
+		case FFI_TYPE_UINT64:
+			lua_pushnumber(L, (lua_Number)(*((uint64_t*)ret)));
+			break;
+		case FFI_TYPE_SINT64:
+			lua_pushnumber(L, (lua_Number)(*((int64_t*)ret)));
+			break;
+		case FFI_TYPE_LONGDOUBLE:
+		case FFI_TYPE_FLOAT:
+		case FFI_TYPE_DOUBLE:
+			lua_pushnumber(L, *((double*)ret));
+			break;
+		case FFI_TYPE_STRUCT:
+			lua_newtable(L);
+			for ( i = 0; rettype->elements[i] != NULL; i++)
+			{
+				lua_pushnumber(L,i);
+				ffi_post_call(L, ret + offset,rettype->elements[i]);
+				lua_settable(L, -3);
+				address += rettype->elements[i]->size;
+				if(rettype->elements[i+1])
+				{
+					pad = address % rettype->elements[i+1]->alignment;
+					if( pad != 0)
+					{
+						pad =  rettype->elements[i+1]->alignment - pad;
+					}
+					
+					address +=  pad;
+					offset += rettype->elements[i]->size + pad;
+				}
+			}
+			break;
+			
+		default:
+			lua_pushnil(L);
+			break;
+	}
+}
+/*
+static void dump(ffi_type* st)
+{
+	printf("Type: %d %d\n", st->size, st->alignment);
+	if(st->type == FFI_TYPE_STRUCT)
+	for (int i = 0; st->elements[i] != NULL; i++)
+	{
+		dump(st->elements[i]);
 	}
 	
 }
-
+*/
 static int l_ffi_call(lua_State* L)
 {
 	ffi_type * argvtype[MAX_FN_ARGC];
 	void* argv[MAX_FN_ARGC];
 	ffi_type * rettype = lua_touserdata(L,1);
 	int argc = l_ffi_prepare(L, argvtype, 2);
-	arg_pointer_t* args;
-	ffi_arg ret;
+	int len = lua_rawlen(L,4);
+	void* ret = NULL;
 	ffi_cif cif;
+	//dump(argvtype[0]);
 	if(ffi_prep_cif(&cif,FFI_DEFAULT_ABI,argc,rettype,argvtype) == FFI_OK)
 	{
 		void * fn = lua_touserdata(L,3);
@@ -273,34 +364,28 @@ static int l_ffi_call(lua_State* L)
 			lua_pushboolean(L,0);
 			return 1;
 		}
-		if(lua_rawlen(L,4) != argc)
+		if(len != argc)
 		{
-			LOG("%s\n", "Argument count does not not match");
+			LOG("Argument count does not not match: expected %d, but have: %d\n", argc, len);
 			lua_pushboolean(L,0);
 			return 1;
 		}
 		// the arguments of the function is at 4th position on the stack
 		// we need to loop through this table and check if argument type
 		// is correct to the definition in argvtype
-		args = (arg_pointer_t*)malloc(sizeof(arg_pointer_t)*(argc+1));
-		//ret = (void*)malloc(rettype->size);
-		// now parser the argument
-		parser_arguments(L,4,args,argvtype);
-		
+		parser_arguments(L,4,argv,argvtype);
+		if(rettype->type != FFI_TYPE_VOID)
+			ret = (void*)malloc(rettype->size);
+		ffi_call(&cif,fn, ret, argv);
 		for(int i = 0; i< argc; i++)
 		{
-			if(args[i].is_pointer && args[i].data)
-				argv[i] = &(args[i].data);
-			else
-				argv[i] = args[i].data;
+			if(argv[i]) free(argv[i]);
 		}
-		ffi_call(&cif,fn, &ret, argv);
-		free_arguments(args, argc);
-		if(args) free(args);
-		lua_pushboolean(L,1);
+		ffi_post_call(L,ret, rettype);
+		if(ret) free(ret);
+		//lua_pushboolean(L,1);
 		return 1;
 	}
-	printf("fail to prepare %d\n");
 	lua_pushboolean(L,0);
 	
 	return 1;
@@ -325,7 +410,9 @@ static int l_ffi_struct(lua_State* L)
 	// 1st element in the stack is the
 	// struct table
 	int len = lua_rawlen(L,1);
-	ffi_type* cstruct = lua_newuserdata(L,  (len+2) * sizeof(ffi_type)  );
+	ffi_type* cstruct = lua_newuserdata(L,sizeof(ffi_type) + (len+1) * sizeof(ffi_type*));
+	void *ptr = (void*)cstruct+(sizeof(ffi_type));
+	cstruct->elements = (ffi_type**)ptr;
 	int i = 0;
     cstruct->size = cstruct->alignment = 0;
     cstruct->type = FFI_TYPE_STRUCT;
@@ -353,6 +440,112 @@ static int l_ffi_struct(lua_State* L)
 	return 1;
 }
 
+static int l_ffi_new(lua_State* L)
+{
+	int size = luaL_checkinteger(L, 1);
+	void* ptr = lua_newuserdata(L, size);
+	memset(ptr,size,0);
+	return 1;
+}
+
+static int l_ffi_meta(lua_State* L)
+{
+	ffi_type* type = lua_touserdata(L,1);
+	if(type)
+	{
+		lua_newtable(L);
+		lua_pushstring(L,"size");
+		lua_pushnumber(L, type->size);
+		lua_settable(L, -3);
+
+		lua_pushstring(L,"alignment");
+		lua_pushnumber(L, type->alignment);
+		lua_settable(L, -3);
+
+		lua_pushstring(L,"type");
+		switch (type->type)
+		{
+			case FFI_TYPE_POINTER:
+				lua_pushstring(L, "POINTER");
+				break;
+
+			case FFI_TYPE_UINT8:
+				lua_pushstring(L, "UINT8");
+				break;
+			case FFI_TYPE_SINT8:
+				lua_pushstring(L, "SINT8");
+				break;
+			case FFI_TYPE_UINT16:
+				lua_pushstring(L, "UINT16");
+				break;
+			case FFI_TYPE_SINT16:
+				lua_pushstring(L, "SINT16");
+				break;
+			case FFI_TYPE_UINT32:
+				lua_pushstring(L, "UINT32");
+				break;
+			case FFI_TYPE_SINT32:
+				lua_pushstring(L, "SINT32");
+				break;
+			case FFI_TYPE_UINT64:
+				lua_pushstring(L, "UINT64");
+				break;
+			case FFI_TYPE_SINT64:
+				lua_pushstring(L, "SINT64");
+				break;
+			case FFI_TYPE_LONGDOUBLE:
+				lua_pushstring(L, "LONGDOUBLE");
+				break;
+			case FFI_TYPE_FLOAT:
+				lua_pushstring(L, "FLOAT");
+				break;
+			case FFI_TYPE_DOUBLE:
+				lua_pushstring(L, "DOUBLE");
+				break;
+			case FFI_TYPE_STRUCT:
+				lua_pushstring(L, "STRUCT");
+				break;
+		default:
+			lua_pushnil(L);
+			break;
+		}
+
+		lua_settable(L, -3);
+		return 1;
+	}
+	lua_pushnil(L);
+	return 1;
+}
+
+static int l_ffi_offset(lua_State* L)
+{
+	void* ptr = lua_touserdata(L, 1);
+	int off = luaL_checkinteger(L,2);
+	if(ptr)
+	{
+		lua_pushlightuserdata(L, ptr + off);
+		return 1;
+	}
+	lua_pushnil(L);
+	return 1;
+}
+static int l_ffi_string(lua_State* L)
+{
+	void* ptr = lua_touserdata(L,1);
+	if(ptr)
+		lua_pushstring(L, (const char*)ptr);
+	else
+		lua_pushstring(L, "");
+	return 1;
+}
+static int l_ffi_free(lua_State* L)
+{
+	void* ptr = lua_touserdata(L,1);
+	if(ptr)
+		free(ptr);
+	lua_pushboolean(L, 1);
+	return 1;
+}
 static const struct luaL_Reg _lib [] = {
 	{"dlopen", l_dlopen},
 	{"dlsym",l_dlsym},
@@ -360,6 +553,12 @@ static const struct luaL_Reg _lib [] = {
 	{"call",l_ffi_call},
 	{"atomic", l_ffi_atomic_type},
 	{"struct", l_ffi_struct },
+	{"new", l_ffi_new},
+	{"meta", l_ffi_meta},
+	{"at", l_ffi_offset},
+	// special case: pointer to string
+	{"string", l_ffi_string},
+	{"free", l_ffi_free},
 	{NULL,NULL}
 };