Subscribe endpoint consolidation; same behavior for all endpoints; keepalive

server/message.go

@@ -0,0 +1,43 @@
+package server
+
+import "time"
+
+// List of possible events
+const (
+	openEvent      = "open"
+	keepaliveEvent = "keepalive"
+)
+
+// message represents a message published to a topic
+type message struct {
+	Time    int64  `json:"time"`            // Unix time in seconds
+	Event   string `json:"event,omitempty"` // One of the above
+	Message string `json:"message,omitempty"`
+}
+
+// messageEncoder is a function that knows how to encode a message
+type messageEncoder func(msg *message) (string, error)
+
+// newMessage creates a new message with the current timestamp
+func newMessage(event string, msg string) *message {
+	return &message{
+		Time:    time.Now().Unix(),
+		Event:   event,
+		Message: msg,
+	}
+}
+
+// newOpenMessage is a convenience method to create an open message
+func newOpenMessage() *message {
+	return newMessage(openEvent, "")
+}
+
+// newKeepaliveMessage is a convenience method to create a keepalive message
+func newKeepaliveMessage() *message {
+	return newMessage(keepaliveEvent, "")
+}
+
+// newDefaultMessage is a convenience method to create a notification message
+func newDefaultMessage(msg string) *message {
+	return newMessage("", msg)
+}