retrieve all sessions

hub.go

@@ -78,3 +78,14 @@ func (h *hub) len() int {
 
 	return len(h.sessions)
 }
+
+func (h *hub) all() []*Session {
+	h.rwmutex.RLock()
+	defer h.rwmutex.RUnlock()
+
+	s := make([]*Session, 0, len(h.sessions))
+	for k := range h.sessions {
+		s = append(s, k)
+	}
+	return s
+}

melody.go

@@ -274,6 +274,14 @@ func (m *Melody) BroadcastBinaryOthers(msg []byte, s *Session) error {
 	})
 }
 
+// Sessions returns all sessions. An error is returned if the melody session is closed.
+func (m *Melody) Sessions() ([]*Session, error) {
+	if m.hub.closed() {
+		return nil, errors.New("melody instance is closed")
+	}
+	return m.hub.all(), nil
+}
+
 // Close closes the melody instance and all connected sessions.
 func (m *Melody) Close() error {
 	if m.hub.closed() {

melody_test.go

@@ -163,6 +163,56 @@ func TestLen(t *testing.T) {
 	}
 }
 
+func TestGetSessions(t *testing.T) {
+	rand.Seed(time.Now().UnixNano())
+
+	connect := int(rand.Int31n(100))
+	disconnect := rand.Float32()
+	conns := make([]*websocket.Conn, connect)
+	defer func() {
+		for _, conn := range conns {
+			if conn != nil {
+				conn.Close()
+			}
+		}
+	}()
+
+	echo := NewTestServerHandler(func(session *Session, msg []byte) {})
+	server := httptest.NewServer(echo)
+	defer server.Close()
+
+	disconnected := 0
+	for i := 0; i < connect; i++ {
+		conn, err := NewDialer(server.URL)
+
+		if err != nil {
+			t.Error(err)
+		}
+
+		if rand.Float32() < disconnect {
+			conns[i] = nil
+			disconnected++
+			conn.Close()
+			continue
+		}
+
+		conns[i] = conn
+	}
+
+	time.Sleep(time.Millisecond)
+
+	connected := connect - disconnected
+
+	allsess, err := echo.m.Sessions()
+	if err != nil {
+		t.Fatalf("error retrieving sessions: %v", err.Error())
+	}
+
+	if len(allsess) != connected {
+		t.Errorf("melody sessions %d should equal %d", len(allsess), connected)
+	}
+}
+
 func TestEchoBinary(t *testing.T) {
 	echo := NewTestServer()
 	echo.m.HandleMessageBinary(func(session *Session, msg []byte) {