refactor: write attempt times

server.go

@@ -34,7 +34,7 @@ type Server struct {
 	printRoutes           bool
 	accepting             chan struct{}
 	stopped               chan struct{}
-	writeRetryTimes       int
+	writeAttemptTimes     int
 }
 
 // ServerOption is the option for Server.
@@ -49,16 +49,20 @@ type ServerOption struct {
 	ReqQueueSize          int           // sets the request channel size of router, DefaultReqQueueSize will be used if < 0.
 	RespQueueSize         int           // sets the response channel size of session, DefaultRespQueueSize will be used if < 0.
 	DoNotPrintRoutes      bool          // whether to print registered route handlers to the console.
-	WriteRetryTimes       int           // sets the max retry times for packet writing in each session, should >= 0.
+
+	// WriteAttemptTimes sets the max attempt times for packet writing in each session.
+	// The DefaultWriteAttemptTimes will be used if <= 0.
+	WriteAttemptTimes int
 }
 
 // ErrServerStopped is returned when server stopped.
 var ErrServerStopped = fmt.Errorf("server stopped")
 
 const (
-	DefaultReqQueueSize  = 1024
-	DefaultRespQueueSize = 1024
-	tempErrDelay         = time.Millisecond * 5
+	DefaultReqQueueSize      = 1024
+	DefaultRespQueueSize     = 1024
+	DefaultWriteAttemptTimes = 1
+	tempErrDelay             = time.Millisecond * 5
 )
 
 // NewServer creates a Server according to opt.
@@ -72,6 +76,9 @@ func NewServer(opt *ServerOption) *Server {
 	if opt.RespQueueSize < 0 {
 		opt.RespQueueSize = DefaultReqQueueSize
 	}
+	if opt.WriteAttemptTimes <= 0 {
+		opt.WriteAttemptTimes = DefaultWriteAttemptTimes
+	}
 	return &Server{
 		socketReadBufferSize:  opt.SocketReadBufferSize,
 		socketWriteBufferSize: opt.SocketWriteBufferSize,
@@ -85,7 +92,7 @@ func NewServer(opt *ServerOption) *Server {
 		router:                newRouter(opt.ReqQueueSize),
 		accepting:             make(chan struct{}),
 		stopped:               make(chan struct{}),
-		writeRetryTimes:       opt.WriteRetryTimes,
+		writeAttemptTimes:     opt.WriteAttemptTimes,
 	}
 }
 
@@ -168,8 +175,8 @@ func (s *Server) handleConn(conn net.Conn) {
 		go s.OnSessionCreate(sess)
 	}
 
-	go sess.readInbound(s.router.reqQueue, s.readTimeout)    // start reading message packet from connection.
-	go sess.writeOutbound(s.writeTimeout, s.writeRetryTimes) // start writing message packet to connection.
+	go sess.readInbound(s.router.reqQueue, s.readTimeout)      // start reading message packet from connection.
+	go sess.writeOutbound(s.writeTimeout, s.writeAttemptTimes) // start writing message packet to connection.
 
 	<-sess.closed                // wait for session finished.
 	Sessions().Remove(sess.ID()) // session has been closed, remove it.

session.go

@@ -123,7 +123,7 @@ func (s *Session) sendReq(ctx *Context, reqQueue chan<- *Context) (ok bool) {
 // writeOutbound fetches message from respQueue channel and writes to TCP connection in a loop.
 // Parameter writeTimeout specified the connection writing timeout.
 // The loop breaks if errors occurred, or the session is closed.
-func (s *Session) writeOutbound(writeTimeout time.Duration, retryTimes int) {
+func (s *Session) writeOutbound(writeTimeout time.Duration, attemptTimes int) {
 LOOP:
 	for {
 		select {
@@ -152,7 +152,7 @@ LOOP:
 				}
 			}
 
-			if err := s.attemptConnWrite(outboundMsg, retryTimes); err != nil {
+			if err := s.attemptConnWrite(outboundMsg, attemptTimes); err != nil {
 				Log.Errorf("session %s conn write err: %s", s.id, err)
 				break LOOP
 			}
@@ -162,12 +162,7 @@ LOOP:
 	Log.Tracef("session %s writeOutbound exit because of error", s.id)
 }
 
-func (s *Session) attemptConnWrite(outboundMsg []byte, retryTimes int) error {
-	attemptTimes := 1
-	if retryTimes > 0 {
-		attemptTimes += retryTimes
-	}
-	var err error
+func (s *Session) attemptConnWrite(outboundMsg []byte, attemptTimes int) (err error) {
 	for i := 0; i < attemptTimes; i++ {
 		time.Sleep(tempErrDelay * time.Duration(i))
 		_, err = s.conn.Write(outboundMsg)
@@ -189,9 +184,9 @@ func (s *Session) attemptConnWrite(outboundMsg []byte, retryTimes int) error {
 			Log.Errorf("session %s conn write err: %s; retrying in %s", s.id, err, tempErrDelay*time.Duration(i+1))
 			continue
 		}
-		break
+		break // if err is not temporary, break the loop.
 	}
-	return err
+	return
 }
 
 func (s *Session) pack(ctx *Context) ([]byte, error) {

session_test.go

@@ -390,7 +390,7 @@ func TestSession_attemptConnWrite_when_reach_last_try(t *testing.T) {
 	conn.EXPECT().Write(gomock.Any()).Return(0, fmt.Errorf("some err"))
 
 	s := newSession(conn, &SessionOption{})
-	assert.Error(t, s.attemptConnWrite([]byte("whatever"), 0))
+	assert.Error(t, s.attemptConnWrite([]byte("whatever"), 1))
 }
 
 func TestSession_attemptConnWrite_when_err_is_not_temp(t *testing.T) {