Added Websocket support for Coinbase.

coinbase.go

@@ -116,9 +116,14 @@ func (c *Coinbase) GetFee(maker bool) (float64) {
 
 func (c *Coinbase) Run() {
 	if c.Verbose {
+		log.Printf("%s Websocket: %s.\n", c.GetName(), IsEnabled(c.Websocket))
 		log.Printf("%s polling delay: %ds.\n", c.GetName(), c.PollingDelay)
 	}
 
+	if c.Websocket {
+		go c.WebsocketClient()
+	}
+
 	for c.Enabled {
 		go func() {
 			CoinbaseStats := c.GetStats("BTC-USD")

coinbasewebsocket.go

@@ -0,0 +1,170 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"github.com/gorilla/websocket"
+)
+
+const (
+	COINBASE_WEBSOCKET_URL = "wss://ws-feed.exchange.coinbase.com"
+)
+
+type CoinbaseWebsocketSubscribe struct {
+	Type string `json:"type"`
+	ProductID string `json:"product_id"`
+}
+
+type CoinbaseWebsocketReceived struct {
+	Type string `json:"type"`
+	Time string `json:"time"`
+	Sequence int `json:"sequence"`
+	OrderID string `json:"order_id"`
+	Size float64 `json:"size,string"`
+	Price float64 `json:"price,string"`
+	Side string `json:"side"`
+}
+
+type CoinbaseWebsocketOpen struct {
+	Type string `json:"type"`
+	Time string `json:"time"`
+	Sequence int `json:"sequence"`
+	OrderID string `json:"order_id"`
+	Price float64 `json:"price,string"`
+	RemainingSize float64 `json:"remaining_size,string"`
+	Side string `json:"side"`
+}
+
+type CoinbaseWebsocketDone struct {
+	Type string `json:"type"`
+	Time string `json:"time"`
+	Sequence int `json:"sequence"`
+	Price float64 `json:"price,string"`
+	OrderID string `json:"order_id"`
+	Reason string `json:"reason"`
+	Side string `json:"side"`
+	RemainingSize float64 `json:"remaining_size,string"`
+}
+
+type CoinbaseWebsocketMatch struct {
+	Type string `json:"type"`
+	TradeID int `json:"trade_id"`
+	Sequence int `json:"sequence"`
+	MakerOrderID string `json:"maker_order_id"`
+	TakerOrderID string `json:"taker_order_id"`
+	Time string `json:"time"`
+	Size float64 `json:"size,string"`
+	Price float64 `json:"price,string"`
+	Side string `json:"side"`
+}
+
+type CoinbaseWebsocketChange struct {
+	Type string `json:"type"`
+	Time string `json:"time"`
+	Sequence int `json:"sequence"`
+	OrderID string `json:"order_id"`
+	NewSize float64 `json:"new_size,string"`
+	OldSize float64 `json:"old_size,string"`
+	Price float64 `json:"price,string"`
+	Side string `json:"side"`
+}
+
+func (c *Coinbase) WebsocketClient() {
+	var Dialer websocket.Dialer
+	conn, resp, err := Dialer.Dial(COINBASE_WEBSOCKET_URL, http.Header{})
+
+	if err != nil {
+		log.Println(err)
+		return
+	}
+
+	if c.Verbose {
+		log.Printf("%s Connected to Websocket.", c.GetName())
+		log.Println(resp)
+	}
+
+	subscribe := CoinbaseWebsocketSubscribe{"subscribe", "BTC-USD"}
+	json, err := JSONEncode(subscribe)
+	if err != nil {
+		log.Println(err)
+		conn.Close()
+		return
+	}
+
+	err = conn.WriteMessage(websocket.TextMessage, json)
+
+	if err != nil {
+		log.Println(err)
+		conn.Close()
+		return
+	}
+
+	if c.Verbose {
+		log.Printf("%s Subscribed to product messages.", c.GetName())
+	}
+
+	for {
+		msgType, resp, err := conn.ReadMessage()
+		if err != nil {
+			log.Println(err)
+			break
+		}
+
+		switch msgType {
+		case websocket.TextMessage:
+			type MsgType struct {
+				Type string `json:"type"`
+			}
+
+			msgType := MsgType{}
+			err := JSONDecode(resp, &msgType)
+			if err != nil {
+				log.Println(err)
+				continue
+			}
+
+			switch msgType.Type {
+			case "error":
+				log.Println(string(resp))
+				break
+			case "received":
+				received := CoinbaseWebsocketReceived{}
+				err := JSONDecode(resp, &received)
+				if err != nil {
+					log.Println(err)
+					continue
+				}
+			case "open":
+				open := CoinbaseWebsocketOpen{}
+				err := JSONDecode(resp, &open)
+				if err != nil {
+					log.Println(err)
+					continue
+				}
+			case "done":
+				done := CoinbaseWebsocketDone{}
+				err := JSONDecode(resp, &done)
+				if err != nil {
+					log.Println(err)
+					continue
+				}
+			case "match":
+				match := CoinbaseWebsocketMatch{}
+				err := JSONDecode(resp, &match)
+				if err != nil {
+					log.Println(err)
+					continue
+				}
+			case "change":
+				change := CoinbaseWebsocketMatch{}
+				err := JSONDecode(resp, &change)
+				if err != nil {
+					log.Println(err)
+					continue
+				}
+			}
+		}
+	}
+	conn.Close()
+	log.Printf("%s Websocket client disconnected.", c.GetName())
+}

config_example.json

@@ -75,7 +75,7 @@
       "BaseCurrencies": "USD",
       "Enabled": true,
       "Verbose": false,
-      "Websocket": false,
+      "Websocket": true,
       "PollingDelay": 10
     },
     {