update orderbook to use pointers to orders instead

cmd/golem/main.go

@@ -30,9 +30,9 @@ func main() {
 			accts := &accounts.InMemoryManager{}
 
 			// setup channels for wrapping our market
-			in := make(chan orderbook.Order)
+			in := make(chan *orderbook.Order)
 			out := make(chan *orderbook.Match)
-			status := make(chan []orderbook.Order)
+			status := make(chan []*orderbook.Order)
 
 			// Run the book
 			go orderbook.Run(ctx, accts, in, out, status)

pkg/orderbook/orderbook.go

@@ -50,13 +50,12 @@ type Orderbook interface {
 func Run(
 	ctx context.Context,
 	accounts accounts.AccountManager,
-	in chan Order,
+	in chan *Order,
 	out chan *Match,
-	status chan []Order,
+	status chan []*Order,
 ) {
 	// NB: buy and sell are not accessible anywhere but here for safety.
-	var buy, sell []Order
-
+	var buy, sell []*Order
 	handleMatches(ctx, accounts, buy, sell, in, out, status)
 }
 
@@ -65,10 +64,10 @@ func Run(
 func handleMatches(
 	ctx context.Context,
 	accts accounts.AccountManager,
-	buy, sell []Order,
-	in chan Order,
+	buy, sell []*Order,
+	in chan *Order,
 	out chan *Match,
-	status chan []Order,
+	status chan []*Order,
 ) {
 	for {
 		// feed off the orders that accumulated since the last loop
@@ -80,7 +79,7 @@ func handleMatches(
 			}
 		}
 		// create the orderlist for state updates
-		orderlist := []Order{}
+		orderlist := []*Order{}
 		orderlist = append(orderlist, buy...)
 		orderlist = append(orderlist, sell...)
 		status <- orderlist
@@ -100,7 +99,7 @@ func handleMatches(
 // matching sell options are exhausted,
 // * When it exhausts all f it ratchets up the buy index again and finds all matching
 // orders.
-func MatchOrders(accts accounts.AccountManager, buyOrders []Order, sellOrders []Order) []Match {
+func MatchOrders(accts accounts.AccountManager, buyOrders []*Order, sellOrders []*Order) []Match {
 	sort.Slice(buyOrders, func(i, j int) bool {
 		return buyOrders[i].Price > buyOrders[j].Price
 	})
@@ -118,8 +117,8 @@ func MatchOrders(accts accounts.AccountManager, buyOrders []Order, sellOrders []
 		// Check if the current Buy order matches the current Sell order
 		if buyOrders[buyIndex].Price >= sellOrders[sellIndex].Price {
 			// Create a match and add it to the matches
-			sell := &sellOrders[sellIndex]
-			buy := &buyOrders[buyIndex]
+			sell := sellOrders[sellIndex]
+			buy := buyOrders[buyIndex]
 			m := Match{
 				Buy:   buy,
 				Sell:  sell,

pkg/orderbook/orderbook_test.go

@@ -73,15 +73,15 @@ func newTestAccountManager(t *testing.T, num int) (accounts.AccountManager, []st
 // price between minPrice and maxPrice, an open quantity between minOpen
 // and maxOpen, an equal chance to be owned by foo or bar,
 // and with an even chance of being a buy or sell order.
-func newTestOrders(count int) (buyOrders []Order, sellOrders []Order) {
+func newTestOrders(count int) (buyOrders, sellOrders []*Order) {
 	log.Printf("count %d", count)
 	rand.Seed(time.Now().UnixNano())
 
 	var minPrice, maxPrice = 100, 10_000
 	var minOpen, maxOpen = 10, 1_000_000
 
 	for i := 0; i < count; i++ {
-		o := Order{
+		o := &Order{
 			ID:      fmt.Sprintf("%d", i),
 			Kind:    "market",
 			Price:   uint64(rand.Intn(maxPrice-minPrice) + minPrice),
@@ -133,9 +133,9 @@ var numTestOrders = 10_000_000
 var numTestAccounts = 1_000_000
 
 func TestRunLoad(t *testing.T) {
-	in := make(chan Order, 1)
+	in := make(chan *Order, 1)
 	out := make(chan *Match, 1)
-	status := make(chan []Order, 1)
+	status := make(chan []*Order, 1)
 
 	// Generate default random accounts for testing
 	accts, ids := newTestAccountManager(t, numTestAccounts)

pkg/server/server.go

@@ -14,20 +14,20 @@ var defaultPort = ":1323"
 
 type Engine struct {
 	srv    *echo.Echo
-	state  []orderbook.Order
-	in     chan orderbook.Order
+	state  []*orderbook.Order
+	in     chan *orderbook.Order
 	out    chan *orderbook.Match
-	status chan []orderbook.Order
+	status chan []*orderbook.Order
 }
 
 // NewServer returns a new server.Engine that wires together
 // API requests to the orderbook.
 // startingx
 func NewServer(
 	accounts accounts.AccountManager,
-	in chan orderbook.Order,
+	in chan *orderbook.Order,
 	out chan *orderbook.Match,
-	status chan []orderbook.Order,
+	status chan []*orderbook.Order,
 ) *Engine {
 	engine := &Engine{
 		in:     in,
@@ -52,7 +52,7 @@ func NewServer(
 			return echo.NewHTTPError(http.StatusBadRequest, err.Error())
 		}
 		e.Logger.Infof("order received: %+v", o)
-		engine.in <- *o
+		engine.in <- o
 		return nil
 	})
 
@@ -75,8 +75,8 @@ func (eng *Engine) Run() error {
 
 // handleState updates the Engine's view of the Orderbooks
 // so that it can be fetched by the server.
-func handleState(e *Engine, status chan []orderbook.Order) {
-	go func(e *Engine, status chan []orderbook.Order) {
+func handleState(e *Engine, status chan []*orderbook.Order) {
+	go func(e *Engine, status chan []*orderbook.Order) {
 		for stats := range status {
 			e.state = stats
 			e.srv.Logger.Debugf("state: %+v\n", e.state)