Add pluggable codec support

server/rpc_codec.go

@@ -2,11 +2,9 @@ package server
 
 import (
 	"bytes"
-	"fmt"
+
 	"github.com/micro/go-micro/transport"
 	rpc "github.com/youtube/vitess/go/rpcplus"
-	js "github.com/youtube/vitess/go/rpcplus/jsonrpc"
-	pb "github.com/youtube/vitess/go/rpcplus/pbrpc"
 )
 
 type rpcPlusCodec struct {
@@ -36,30 +34,21 @@ func (rwc *readWriteCloser) Close() error {
 	return nil
 }
 
-func newRpcPlusCodec(req *transport.Message, socket transport.Socket) rpc.ServerCodec {
+func newRpcPlusCodec(req *transport.Message, socket transport.Socket, cf codecFunc) rpc.ServerCodec {
+	rwc := &readWriteCloser{
+		rbuf: bytes.NewBuffer(req.Body),
+		wbuf: bytes.NewBuffer(nil),
+	}
 	r := &rpcPlusCodec{
-		socket: socket,
+		buf:    rwc,
+		codec:  cf(rwc),
 		req:    req,
-		buf: &readWriteCloser{
-			rbuf: bytes.NewBuffer(req.Body),
-			wbuf: bytes.NewBuffer(nil),
-		},
+		socket: socket,
 	}
-
-	switch req.Header["Content-Type"] {
-	case "application/octet-stream":
-		r.codec = pb.NewServerCodec(r.buf)
-	case "application/json":
-		r.codec = js.NewServerCodec(r.buf)
-	}
-
 	return r
 }
 
 func (c *rpcPlusCodec) ReadRequestHeader(r *rpc.Request) error {
-	if c.codec == nil {
-		return fmt.Errorf("unsupported content type %s", c.req.Header["Content-Type"])
-	}
 	return c.codec.ReadRequestHeader(r)
 }
 
@@ -68,19 +57,14 @@ func (c *rpcPlusCodec) ReadRequestBody(r interface{}) error {
 }
 
 func (c *rpcPlusCodec) WriteResponse(r *rpc.Response, body interface{}, last bool) error {
-	if c.codec == nil {
-		return fmt.Errorf("unsupported request type: %s", c.req.Header["Content-Type"])
-	}
 	c.buf.wbuf.Reset()
 	if err := c.codec.WriteResponse(r, body, last); err != nil {
 		return err
 	}
-
 	return c.socket.Send(&transport.Message{
 		Header: map[string]string{"Content-Type": c.req.Header["Content-Type"]},
 		Body:   c.buf.wbuf.Bytes(),
 	})
-
 }
 
 func (c *rpcPlusCodec) Close() error {