Client

Example: function

In the normal we register methods as services'methods. Methods must follow the below rules:

• exported method of exported type
• three arguments, the first is of context.Context, both of exported type for three arguments
• the third argument is a pointer
• one return value, of type error

And rpcx can also register raw functions as services and functions must follow the below rules:

• the function can be exported or not
• three arguments, the first is of context.Context, both of exported type for three arguments
• the third argument is a pointer
• one return value, of type error

There is an example.

Server must use RegisterFunction to register a function and provides a service name.

```go server.go type Args struct { A int B int }

type Reply struct { C int }

func mul(ctx context.Context, args Args, reply Reply) error { reply.C = args.A * args.B return nil }

func main() { flag.Parse()

s := server.NewServer()
s.RegisterFunction("a.fake.service", mul, "")
s.Serve("tcp", *addr)

}

Client use the service name and function name to access:

```go client.go
    d := client.NewPeer2PeerDiscovery("tcp@"+*addr, "")
    xclient := client.NewXClient("a.fake.service", client.Failtry, client.RandomSelect, d, client.DefaultOption)
    defer xclient.Close()

    args := &example.Args{
        A: 10,
        B: 20,
    }

    reply := &example.Reply{}
    err := xclient.Call(context.Background(), "mul", args, reply)
    if err != nil {
        log.Fatalf("failed to call: %v", err)
    }

    log.Printf("%d * %d = %d", args.A, args.B, reply.C)