FEATURE: [okx] add new kline stream

pkg/exchange/okex/kline_stream.go

@@ -0,0 +1,87 @@
+package okex
+
+import (
+	"context"
+
+	"github.com/c9s/bbgo/pkg/exchange/okex/okexapi"
+	"github.com/c9s/bbgo/pkg/types"
+)
+
+//go:generate callbackgen -type KLineStream -interface
+type KLineStream struct {
+	types.StandardStream
+
+	kLineEventCallbacks []func(candle KLineEvent)
+}
+
+func NewKLineStream() *KLineStream {
+	k := &KLineStream{
+		StandardStream: types.NewStandardStream(),
+	}
+
+	k.SetParser(parseWebSocketEvent)
+	k.SetDispatcher(k.dispatchEvent)
+	k.SetEndpointCreator(func(_ context.Context) (string, error) { return okexapi.PublicBusinessWebSocketURL, nil })
+	k.SetPingInterval(pingInterval)
+
+	// K line channel is public only
+	k.SetPublicOnly()
+	k.OnConnect(k.handleConnect)
+	k.OnKLineEvent(k.handleKLineEvent)
+
+	return k
+}
+
+func (s *KLineStream) handleConnect() {
+	var subs []WebsocketSubscription
+	for _, subscription := range s.Subscriptions {
+		if subscription.Channel != types.KLineChannel {
+			continue
+		}
+
+		sub, err := convertSubscription(subscription)
+		if err != nil {
+			log.WithError(err).Errorf("subscription convert error")
+			continue
+		}
+
+		subs = append(subs, sub)
+	}
+	if len(subs) == 0 {
+		return
+	}
+
+	log.Infof("subscribing channels: %+v", subs)
+	err := s.Conn.WriteJSON(WebsocketOp{
+		Op:   "subscribe",
+		Args: subs,
+	})
+
+	if err != nil {
+		log.WithError(err).Error("subscribe error")
+	}
+}
+
+func (s *KLineStream) handleKLineEvent(k KLineEvent) {
+	for _, event := range k.Events {
+		kline := kLineToGlobal(event, types.Interval(k.Interval), k.Symbol)
+		if kline.Closed {
+			s.EmitKLineClosed(kline)
+		} else {
+			s.EmitKLine(kline)
+		}
+	}
+}
+
+func (s *KLineStream) dispatchEvent(e interface{}) {
+	switch et := e.(type) {
+	case *WebSocketEvent:
+		if err := et.IsValid(); err != nil {
+			log.Errorf("invalid event: %v", err)
+			return
+		}
+
+	case *KLineEvent:
+		s.EmitKLineEvent(*et)
+	}
+}

pkg/exchange/okex/okexapi/client.go

@@ -21,6 +21,7 @@ const defaultHTTPTimeout = time.Second * 15
 const RestBaseURL = "https://www.okex.com/"
 const PublicWebSocketURL = "wss://ws.okex.com:8443/ws/v5/public"
 const PrivateWebSocketURL = "wss://ws.okex.com:8443/ws/v5/private"
+const PublicBusinessWebSocketURL = "wss://wsaws.okx.com:8443/ws/v5/business"
 
 type SideType string
 

pkg/exchange/okex/stream.go

@@ -35,6 +35,7 @@ type WebsocketLogin struct {
 //go:generate callbackgen -type Stream -interface
 type Stream struct {
 	types.StandardStream
+	kLineStream *KLineStream
 
 	client          *okexapi.RestClient
 	balanceProvider types.ExchangeAccountService
@@ -52,20 +53,21 @@ func NewStream(client *okexapi.RestClient, balanceProvider types.ExchangeAccount
 		client:          client,
 		balanceProvider: balanceProvider,
 		StandardStream:  types.NewStandardStream(),
+		kLineStream:     NewKLineStream(),
 	}
 
 	stream.SetParser(parseWebSocketEvent)
 	stream.SetDispatcher(stream.dispatchEvent)
 	stream.SetEndpointCreator(stream.createEndpoint)
 	stream.SetPingInterval(pingInterval)
 
-	stream.OnKLineEvent(stream.handleKLineEvent)
 	stream.OnBookEvent(stream.handleBookEvent)
 	stream.OnAccountEvent(stream.handleAccountEvent)
 	stream.OnMarketTradeEvent(stream.handleMarketTradeEvent)
 	stream.OnOrderTradesEvent(stream.handleOrderDetailsEvent)
 	stream.OnConnect(stream.handleConnect)
 	stream.OnAuth(stream.subscribePrivateChannels(stream.emitBalanceSnapshot))
+
 	return stream
 }
 
@@ -250,17 +252,6 @@ func (s *Stream) handleMarketTradeEvent(data []MarketTradeEvent) {
 	}
 }
 
-func (s *Stream) handleKLineEvent(k KLineEvent) {
-	for _, event := range k.Events {
-		kline := kLineToGlobal(event, types.Interval(k.Interval), k.Symbol)
-		if kline.Closed {
-			s.EmitKLineClosed(kline)
-		} else {
-			s.EmitKLine(kline)
-		}
-	}
-}
-
 func (s *Stream) createEndpoint(ctx context.Context) (string, error) {
 	var url string
 	if s.PublicOnly {
@@ -288,8 +279,6 @@ func (s *Stream) dispatchEvent(e interface{}) {
 			s.EmitBookEvent(*et)
 		}
 		s.EmitBookTickerUpdate(et.BookTicker())
-	case *KLineEvent:
-		s.EmitKLineEvent(*et)
 
 	case *okexapi.Account:
 		s.EmitAccountEvent(*et)