问使用结构化(或protobuf消息)作为数据更新Golang中的修复文档

EN

syntax = "proto3";

service FooService {
  rpc UpdateFoo(UpdateFooRequest) returns (Foo) {}
}

message Foo {
  string name = 1;
  string description = 2;
  string action = 3;
}

message UpdateFooRequest {
  Foo foo = 1;
  // The list of fields to be updated. For the `FieldMask` definition,
  // see https://developers.google.com/protocol-buffers/docs/reference/google.protobuf#fieldmask
  google.protobuf.FieldMask update_mask = 2;
}

type Update struct {
    Path      string // Will be split on dots, and must not contain any of "˜*/[]".
    FieldPath FieldPath
    Value     interface{}
}

func (s *Server) UpdateFoo(ctx context.Context, req *pb.UpdateFooRequest) (*pb.Foo, error) {

var updates []firestore.Update
// Loop all paths in the update_mask
for _, p := range req.GetUpdateMask().GetPaths() {
   // Check that path is valid field of Foo message.
   // How to do this?
   ...
   ...
   if path is not valid {
       return nil, status.Errorf(codes.InvalidArgument, "invalid path %s", p)
   }
   // When path is valid, I need to take the value from the req.GetFoo() message
   // How to do this?
   newValue := req.GetFoo().Get????<this is p variable>

   update = append(update, &firestore.Update{Path: p, Value: newValue}
}