working ffi

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")

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);
+}