Separate receiving and processing a message

conn.go

@@ -38,10 +38,10 @@ func Connect(options map[string]string) (c *conn, err error) {
 	c.txStartupMessage(msg)
 
 	var response interface{}
-	response, err = c.rxMsg()
+	response, err = c.processMsg()
 
 	for {
-		response, err = c.rxMsg()
+		response, err = c.processMsg()
 		if err != nil {
 			return nil, err
 		}
@@ -69,7 +69,7 @@ func (c *conn) Query(sql string) (rows []map[string]string, err error) {
 
 	var response interface{}
 	for {
-		response, err = c.rxMsg()
+		response, err = c.processMsg()
 		if err != nil {
 			fmt.Println(err)
 			return nil, err
@@ -95,34 +95,33 @@ func (c *conn) sendSimpleQuery(sql string) (err error) {
 	return err
 }
 
-func (c *conn) rxMsg() (msg interface{}, err error) {
+func (c *conn) processMsg() (msg interface{}, err error) {
 	var t byte
-	var bodySize int32
-	t, bodySize, err = c.rxMsgHeader()
+	var body []byte
+	t, body, err = c.rxMsg()
 	if err != nil {
-		return nil, err
+		return
 	}
 
-	var buf []byte
-	if buf, err = c.rxMsgBody(bodySize); err != nil {
-		return nil, err
-	}
+	return c.parseMsg(t, body)
+}
 
+func (c *conn) parseMsg(t byte, body []byte) (msg interface{}, err error) {
 	switch t {
 	case 'K':
-		return c.rxBackendKeyData(buf), nil
+		return c.rxBackendKeyData(body), nil
 	case 'R':
-		return c.rxAuthenticationX(buf)
+		return c.rxAuthenticationX(body)
 	case 'S':
-		return c.rxParameterStatus(buf)
+		return c.rxParameterStatus(body)
 	case 'Z':
-		return c.rxReadyForQuery(buf), nil
+		return c.rxReadyForQuery(body), nil
 	case 'T':
-		return c.rxRowDescription(buf)
+		return c.rxRowDescription(body)
 	case 'D':
-		return c.rxDataRow(buf)
+		return c.rxDataRow(body)
 	case 'C':
-		return c.rxCommandComplete(buf), nil
+		return c.rxCommandComplete(body), nil
 	default:
 		return nil, fmt.Errorf("Received unknown message type: %c", t)
 	}
@@ -130,6 +129,17 @@ func (c *conn) rxMsg() (msg interface{}, err error) {
 	panic("Unreachable")
 }
 
+func (c *conn) rxMsg() (t byte, body []byte, err error) {
+	var bodySize int32
+	t, bodySize, err = c.rxMsgHeader()
+	if err != nil {
+		return
+	}
+
+	body, err = c.rxMsgBody(bodySize)
+	return
+}
+
 func (c *conn) rxMsgHeader() (t byte, bodySize int32, err error) {
 	buf := c.buf[:5]
 	if _, err = io.ReadFull(c.conn, buf); err != nil {