Add message batch sending

registry.go

@@ -64,6 +64,21 @@ func SendToTarget(m Messagable, sessionID SessionID) error {
 	return session.queueForSend(msg)
 }
 
+// SendBatchToTarget sends a batch of messages based on the sessionID. This allows for better mutex contention if we're sending large batches of messages repeatedly.
+func SendBatchToTarget(messages []Messagable, sessionID SessionID) error {
+	session, ok := lookupSession(sessionID)
+	if !ok {
+		return errUnknownSession
+	}
+	msgs := make([]*Message, 0, len(messages))
+	for _, m := range messages {
+		msg := m.ToMessage()
+		msgs = append(msgs, msg)
+	}
+
+	return session.queueBatchForSend(msgs)
+}
+
 // ResetSession resets session's sequence numbers.
 func ResetSession(sessionID SessionID) error {
 	session, ok := lookupSession(sessionID)

session.go

@@ -225,6 +225,20 @@ func (s *session) resend(msg *Message) bool {
 
 // queueForSend will validate, persist, and queue the message for send.
 func (s *session) queueForSend(msg *Message) error {
+	if err := s.queueForSendLocked(msg); err != nil {
+		return err
+	}
+
+	select {
+	case s.messageEvent <- true:
+	default:
+	}
+
+	return nil
+}
+
+// queueForSendLocked is the critical section portion of queueForSend.
+func (s *session) queueForSendLocked(msg *Message) error {
 	s.sendMutex.Lock()
 	defer s.sendMutex.Unlock()
 
@@ -235,6 +249,13 @@ func (s *session) queueForSend(msg *Message) error {
 
 	s.toSend = append(s.toSend, msgBytes)
 
+	return nil
+}
+
+// queueBatchForSend will validate, persist, and queue a batch of messages for send.
+func (s *session) queueBatchForSend(msgs []*Message) error {
+	s.queueBatchForSendLocked(msgs)
+
 	select {
 	case s.messageEvent <- true:
 	default:
@@ -243,6 +264,22 @@ func (s *session) queueForSend(msg *Message) error {
 	return nil
 }
 
+// queueBatchForSendLocked is the critical section portion of queueBatchForSend.
+func (s *session) queueBatchForSendLocked(msgs []*Message) error {
+	s.sendMutex.Lock()
+	defer s.sendMutex.Unlock()
+
+	for _, msg := range msgs {
+		msgBytes, err := s.prepMessageForSend(msg, nil)
+		if err != nil {
+			return err
+		}
+		s.toSend = append(s.toSend, msgBytes)
+	}
+
+	return nil
+}
+
 // send will validate, persist, queue the message. If the session is logged on, send all messages in the queue.
 func (s *session) send(msg *Message) error {
 	return s.sendInReplyTo(msg, nil)

session_test.go

@@ -821,6 +821,17 @@ func (suite *SessionSendTestSuite) TestQueueForSendAppMessage() {
 	suite.NextSenderMsgSeqNum(2)
 }
 
+func (suite *SessionSendTestSuite) TestQueueBatchForSendAppMessage() {
+	suite.MockApp.On("ToApp").Return(nil)
+	require.Nil(suite.T(), suite.queueBatchForSend([]*Message{suite.NewOrderSingle(), suite.NewOrderSingle(), suite.NewOrderSingle()}))
+
+	suite.MockApp.AssertExpectations(suite.T())
+	suite.NoMessageSent()
+	suite.MessagePersisted(suite.MockApp.lastToApp)
+	suite.FieldEquals(tagMsgSeqNum, 3, suite.MockApp.lastToApp.Header)
+	suite.NextSenderMsgSeqNum(4)
+}
+
 func (suite *SessionSendTestSuite) TestQueueForSendDoNotSendAppMessage() {
 	suite.MockApp.On("ToApp").Return(ErrDoNotSend)
 	suite.Equal(ErrDoNotSend, suite.queueForSend(suite.NewOrderSingle()))