Kraken: bugfix - don't use internal ticker map

It's up to the calling application to handle concurrency

Addresses https://github.com/thrasher-/gocryptotrader/issues/167

exchanges/kraken/kraken.go

@@ -50,7 +50,6 @@ const (
 type Kraken struct {
 	exchange.Base
 	CryptoFee, FiatFee float64
-	Ticker             map[string]Ticker
 }
 
 // SetDefaults sets current default settings
@@ -61,7 +60,6 @@ func (k *Kraken) SetDefaults() {
 	k.CryptoFee = 0.10
 	k.Verbose = false
 	k.RESTPollingDelay = 10
-	k.Ticker = make(map[string]Ticker)
 	k.RequestCurrencyPairFormat.Delimiter = ""
 	k.RequestCurrencyPairFormat.Uppercase = true
 	k.RequestCurrencyPairFormat.Separator = ","
@@ -202,6 +200,48 @@ func (k *Kraken) GetTicker(symbol string) (Ticker, error) {
 	return ticker, nil
 }
 
+// GetTickers supports fetching multiple tickers from Kraken
+// pairList must be in the format pairs separated by commas
+// ("LTCUSD,ETCUSD")
+func (k *Kraken) GetTickers(pairList string) (Tickers, error) {
+	values := url.Values{}
+	values.Set("pair", pairList)
+
+	type Response struct {
+		Error []interface{}             `json:"error"`
+		Data  map[string]TickerResponse `json:"result"`
+	}
+
+	resp := Response{}
+	path := fmt.Sprintf("%s/%s/public/%s?%s", krakenAPIURL, krakenAPIVersion, krakenTicker, values.Encode())
+
+	err := k.SendHTTPRequest(path, &resp)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(resp.Error) > 0 {
+		return nil, fmt.Errorf("Kraken error: %s", resp.Error)
+	}
+
+	tickers := make(Tickers)
+
+	for x, y := range resp.Data {
+		ticker := Ticker{}
+		ticker.Ask, _ = strconv.ParseFloat(y.Ask[0], 64)
+		ticker.Bid, _ = strconv.ParseFloat(y.Bid[0], 64)
+		ticker.Last, _ = strconv.ParseFloat(y.Last[0], 64)
+		ticker.Volume, _ = strconv.ParseFloat(y.Volume[1], 64)
+		ticker.VWAP, _ = strconv.ParseFloat(y.VWAP[1], 64)
+		ticker.Trades = y.Trades[1]
+		ticker.Low, _ = strconv.ParseFloat(y.Low[1], 64)
+		ticker.High, _ = strconv.ParseFloat(y.High[1], 64)
+		ticker.Open, _ = strconv.ParseFloat(y.Open, 64)
+		tickers[x] = ticker
+	}
+	return tickers, nil
+}
+
 // GetOHLC returns an array of open high low close values of a currency pair
 func (k *Kraken) GetOHLC(symbol string) ([]OpenHighLowClose, error) {
 	values := url.Values{}

exchanges/kraken/kraken_test.go

@@ -69,6 +69,14 @@ func TestGetTicker(t *testing.T) {
 	}
 }
 
+func TestGetTickers(t *testing.T) {
+	t.Parallel()
+	_, err := k.GetTickers("LTCUSD,ETCUSD")
+	if err != nil {
+		t.Error("Test failed - GetTickers() error", err)
+	}
+}
+
 func TestGetOHLC(t *testing.T) {
 	t.Parallel()
 	_, err := k.GetOHLC("BCHEUR")

exchanges/kraken/kraken_types.go

@@ -49,6 +49,9 @@ type Ticker struct {
 	Open   float64
 }
 
+// Tickers stores a map of tickers
+type Tickers map[string]Ticker
+
 // TickerResponse holds ticker information before its put into the Ticker struct
 type TickerResponse struct {
 	Ask    []string `json:"a"`

exchanges/kraken/kraken_wrapper.go

@@ -2,10 +2,7 @@ package kraken
 
 import (
 	"errors"
-	"fmt"
 	"log"
-	"net/url"
-	"strconv"
 	"sync"
 
 	"github.com/thrasher-/gocryptotrader/common"
@@ -80,13 +77,13 @@ func (k *Kraken) UpdateTicker(p pair.CurrencyPair, assetType string) (ticker.Pri
 	if err != nil {
 		return tickerPrice, err
 	}
-	err = k.SetTicker(pairsCollated.String())
+	tickers, err := k.GetTickers(pairsCollated.String())
 	if err != nil {
 		return tickerPrice, err
 	}
 
 	for _, x := range pairs {
-		for y, z := range k.Ticker {
+		for y, z := range tickers {
 			if common.StringContains(y, x.FirstCurrency.Upper().String()) && common.StringContains(y, x.SecondCurrency.Upper().String()) {
 				var tp ticker.Price
 				tp.Pair = x
@@ -103,44 +100,6 @@ func (k *Kraken) UpdateTicker(p pair.CurrencyPair, assetType string) (ticker.Pri
 	return ticker.GetTicker(k.GetName(), p, assetType)
 }
 
-// SetTicker sets ticker information from kraken
-func (k *Kraken) SetTicker(symbol string) error {
-	values := url.Values{}
-	values.Set("pair", symbol)
-
-	type Response struct {
-		Error []interface{}             `json:"error"`
-		Data  map[string]TickerResponse `json:"result"`
-	}
-
-	resp := Response{}
-	path := fmt.Sprintf("%s/%s/public/%s?%s", krakenAPIURL, krakenAPIVersion, krakenTicker, values.Encode())
-
-	err := k.SendHTTPRequest(path, &resp)
-	if err != nil {
-		return err
-	}
-
-	if len(resp.Error) > 0 {
-		return fmt.Errorf("Kraken error: %s", resp.Error)
-	}
-
-	for x, y := range resp.Data {
-		ticker := Ticker{}
-		ticker.Ask, _ = strconv.ParseFloat(y.Ask[0], 64)
-		ticker.Bid, _ = strconv.ParseFloat(y.Bid[0], 64)
-		ticker.Last, _ = strconv.ParseFloat(y.Last[0], 64)
-		ticker.Volume, _ = strconv.ParseFloat(y.Volume[1], 64)
-		ticker.VWAP, _ = strconv.ParseFloat(y.VWAP[1], 64)
-		ticker.Trades = y.Trades[1]
-		ticker.Low, _ = strconv.ParseFloat(y.Low[1], 64)
-		ticker.High, _ = strconv.ParseFloat(y.High[1], 64)
-		ticker.Open, _ = strconv.ParseFloat(y.Open, 64)
-		k.Ticker[x] = ticker
-	}
-	return nil
-}
-
 // GetTickerPrice returns the ticker for a currency pair
 func (k *Kraken) GetTickerPrice(p pair.CurrencyPair, assetType string) (ticker.Price, error) {
 	tickerNew, err := ticker.GetTicker(k.GetName(), p, assetType)