TODOs for Cross-Languaged RPC

[jovany-wang]

• [ ] Handle the overloading of methods.
• [ ] Auto-handle the schema of a method(args and return type, etc).
• [x] Custom class arguments and return type for both Cpp and Java.

[jovany-wang]

Java RPC Server

1. Extract Executor implementation

   class Executor {
   Executor(std::function<void(std::buffer &encoded_bytes)> func) :on_request_coming_callback_(func) {
   }
   
   std::function<void(std::buffer &encoded_bytes)> on_request_coming_callback_;
   };

2. C++ RPC Server

   class RpcServer {
   void CreateService(service_name service) {
   
   }
   
   Executor executor_ = Executor([](std::buffer &encoded_byte) {
        auto rpc_request = codec_.decode();
        str service = rpc_request.service_name();
        str method = rpc_request.method_name();
        tuple args = rpc_request.args();
        Invoke(service, method, args);
   });
   
   CppCodec codec_;
   map<service_name, service_instance> services_;
   };

[jovany-wang]

Since we should write much code for JNI implementation. It's more graceful to use netty for Java if we define the protocol.