Add batch_size_hint field to RCResponse message. (#110)

Fixes #109

conanfile.py

@@ -3,7 +3,7 @@
 
 class NuRaftGrpcConan(ConanFile):
     name = "nuraft_grpc"
-    version = "6.1.3"
+    version = "6.2.0"
     homepage = "https://github.com/eBay/nuraft_mesg"
     description = "A gRPC service for NuRAFT"
     topics = ("ebay", "nublox", "raft")
@@ -53,7 +53,7 @@ def requirements(self):
         self.requires("sisl/8.6.8")
 
         self.requires("lz4/1.9.4", override=True)
-        self.requires("grpc/1.50.1",    override=True)
+        self.requires("grpc/1.50.1", override=True)
 
     def build(self):
         cmake = CMake(self)

src/lib/grpc_client.cpp

@@ -50,6 +50,7 @@ inline shared< nuraft::resp_msg > toResponse(RaftMessage const& raft_msg) {
     auto const& resp = raft_msg.rc_response();
     auto message = std::make_shared< grpc_resp >(base.term(), (nuraft::msg_type)base.type(), base.src(), base.dest(),
                                                  resp.next_index(), resp.accepted());
+    message->set_next_batch_size_hint_in_bytes(resp.batch_size_hint());
     message->set_result_code((nuraft::cmd_result_code)(0 - resp.result_code()));
     if (nuraft::cmd_result_code::NOT_LEADER == message->get_result_code()) {
         LOGINFOMOD(nuraft_mesg, "Leader has changed!");

src/lib/grpc_server.cpp

@@ -26,6 +26,7 @@ static RCResponse* fromRCResponse(nuraft::resp_msg& rcmsg) {
     auto req = new RCResponse;
     req->set_next_index(rcmsg.get_next_idx());
     req->set_accepted(rcmsg.get_accepted());
+    req->set_batch_size_hint(rcmsg.get_next_batch_size_hint_in_bytes());
     req->set_result_code((ResultCode)(0 - rcmsg.get_result_code()));
     auto ctx = rcmsg.get_ctx();
     if (ctx) { req->set_context(ctx->data(), ctx->container_size()); }

src/proto/raft_types.proto

@@ -73,6 +73,7 @@ message RCResponse {
     bytes context = 3;
     string dest_addr = 4;
     ResultCode result_code = 5;
+    uint64 batch_size_hint = 6;
 }
 
 message RaftMessage {