Implement the websocket adaptor, a version of kataras/go-websocket, and refactor all of the previous websocket examples.

https://github.com/kataras/go-websocket/issues/27

Former-commit-id: 0b7e52e0a61150a8bba973ef653986d8b3ddd26b

adaptors/websocket/emitter.go

@@ -0,0 +1,49 @@
+package websocket
+
+// -------------------------------------------------------------------------------------
+// -------------------------------------------------------------------------------------
+// --------------------------------Emitter implementation-------------------------------
+// -------------------------------------------------------------------------------------
+// -------------------------------------------------------------------------------------
+
+const (
+	// All is the string which the Emitter use to send a message to all
+	All = ""
+	// Broadcast is the string which the Emitter use to send a message to all except this connection
+	Broadcast = ";gowebsocket;to;all;except;me;"
+)
+
+type (
+	// Emitter is the message/or/event manager
+	Emitter interface {
+		// EmitMessage sends a native websocket message
+		EmitMessage([]byte) error
+		// Emit sends a message on a particular event
+		Emit(string, interface{}) error
+	}
+
+	emitter struct {
+		conn *connection
+		to   string
+	}
+)
+
+var _ Emitter = &emitter{}
+
+func newEmitter(c *connection, to string) *emitter {
+	return &emitter{conn: c, to: to}
+}
+
+func (e *emitter) EmitMessage(nativeMessage []byte) error {
+	e.conn.server.emitMessage(e.conn.id, e.to, nativeMessage)
+	return nil
+}
+
+func (e *emitter) Emit(event string, data interface{}) error {
+	message, err := websocketMessageSerialize(event, data)
+	if err != nil {
+		return err
+	}
+	e.EmitMessage([]byte(message))
+	return nil
+}