change interface for clearity

paddle/go/pserver/lib/client/main.go

@@ -150,7 +150,7 @@ func paddle_send_grads(client C.client, grads *C.paddle_gradient, total C.int) C
 }
 
 //export paddle_get_params
-func paddle_get_params(client C.client, names **C.char, dst *C.paddle_parameter, reuse C.int, total C.int) C.int {
+func paddle_get_params(client C.client, names **C.char, dst **C.paddle_parameter, total C.int) C.int {
 	var ns []string
 	for i := 0; i < int(total); i++ {
 		name := *(**C.char)(unsafe.Pointer((uintptr(unsafe.Pointer(names)) + uintptr(i)*unsafe.Sizeof(*names))))
@@ -169,30 +169,36 @@ func paddle_get_params(client C.client, names **C.char, dst *C.paddle_parameter,
 		}
 
 		p := ps[i]
-		name := C.CString(p.Name)
-		param := (*C.paddle_parameter)(unsafe.Pointer((uintptr(unsafe.Pointer(dst)) + uintptr(i)*unsafe.Sizeof(*dst))))
-
-		if reuse != 0 && unsafe.Pointer(param.name) != nullPtr {
-			if n := C.GoString(param.name); n != p.Name {
-				log.Println("warning: pre-allocated parameter name not match parameter name, pre-allocated parameter name will be freed.", n, p.Name)
-				C.free(unsafe.Pointer(param.name))
-				param.name = name
-			}
+		param := *(**C.paddle_parameter)(unsafe.Pointer((uintptr(unsafe.Pointer(dst)) + uintptr(i)*unsafe.Sizeof(*dst))))
+		nameReady := false
+		contentAllocated := false
+
+		if unsafe.Pointer(param) == nullPtr {
+			param = (*C.paddle_parameter)(C.calloc(1, C.size_t(unsafe.Sizeof(*param))))
 		} else {
-			param.name = name
-		}
+			if unsafe.Pointer(param.name) != nullPtr {
+				if n := C.GoString(param.name); n != p.Name {
+					log.Println("warning: pre-allocated parameter name not match parameter name, pre-allocated parameter name will be freed.", n, p.Name)
+					C.free(unsafe.Pointer(param.name))
+				} else {
+					nameReady = true
+				}
+			}
 
-		memReady := false
-		if reuse != 0 && param.content != nullPtr {
-			if int(param.content_len) < len(p.Content) {
-				memReady = true
-			} else {
-				log.Println("warning: pre-allocated content len is smaller than parameter content len, pre-allocated content will be freed.", param.content_len, len(p.Content))
-				C.free(param.content)
+			if param.content != nullPtr {
+				if int(param.content_len) == len(p.Content) {
+					contentAllocated = true
+				} else {
+					log.Println("warning: pre-allocated content len does not match parameter content len, pre-allocated content will be freed.", param.content_len, len(p.Content))
+					C.free(param.content)
+				}
 			}
 		}
 
-		if !memReady {
+		if !nameReady {
+			param.name = C.CString(p.Name)
+		}
+		if !contentAllocated {
 			param.content = C.malloc(C.size_t(len(p.Content)))
 		}
 		C.memcpy(param.content, unsafe.Pointer(&p.Content[0]), C.size_t(len(p.Content)))

paddle/go/pserver/lib/client/test/main.c

@@ -45,9 +45,9 @@ int main() {
     panic();
   }
 
-  paddle_parameter params[2];
+  paddle_parameter* params[2] = {NULL, NULL};
   char* names[]={"param_a", "param_b"};
-  if (!paddle_get_params(c, names, params, 0, 2)) {
+  if (!paddle_get_params(c, names, params, 2)) {
     panic();
   }