The aim is to build a minimal protobuf RPC lib using Google's Protocol Buffers.

libpbrpc is flexible as it is not bound to the http server, it's a lightweight middleware.

The only dependency is Protocol Buffers.

To use this lib is really simple. First define ServiceManager some where in your code.

ServiceManager srvMan;

Then the ServiceManager only provides two functions:

1. Register a service:

   void regService(Service *service);

2. Handle the RPC message:

   void handleRPC(const char *data, const size_t len, string &ret);

   • data is the raw Protobuf binary,
   • len is the length of the data,
   • ret is the result generated, you can send it back directly. (Note: use ret.length() to get the correct length.)

The over all design is really simple:

• Protocol. The RPC protocol is defined in the "pbrpc.proto" file. The protocol took the JSON RPC 2.0 as a reference.
• Services. The RPC server provides several Services, and each Service has some Methods.
• Methods. Each Method should have input(params) and output(results).

Please take a look of my other repository pbrpc as a demo which implements a simple RPC server.

One major limitation of this library is it's synchronous. It is possible to adapt task queue for asynchronous message handling.