cmd/cart/main.go

@@ -151,7 +151,12 @@ func main() {
 		log.Fatalf("Error creating inventory service: %v\n", err)
 	}
 
-	syncedServer := NewPoolServer(pool, fmt.Sprintf("%s, %s", name, podIp), klarnaClient, inventoryService, rdb)
+	inventoryReservationService, err := inventory.NewRedisCartReservationService(rdb)
+	if err != nil {
+		log.Fatalf("Error creating inventory reservation service: %v\n", err)
+	}
+
+	syncedServer := NewPoolServer(pool, fmt.Sprintf("%s, %s", name, podIp), klarnaClient, inventoryService, inventoryReservationService)
 
 	app := &App{
 		pool:         pool,

cmd/cart/pool-server.go

@@ -19,7 +19,6 @@ import (
 	"github.com/matst80/go-redis-inventory/pkg/inventory"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
-	"github.com/redis/go-redis/v9"
 	"go.opentelemetry.io/contrib/bridges/otelslog"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"google.golang.org/protobuf/types/known/anypb"
@@ -50,12 +49,13 @@ type PoolServer struct {
 	reservationService inventory.CartReservationService
 }
 
-func NewPoolServer(pool actor.GrainPool[*cart.CartGrain], pod_name string, klarnaClient *KlarnaClient, inventoryService inventory.InventoryService, inventoryRedisClient *redis.Client) *PoolServer {
+func NewPoolServer(pool actor.GrainPool[*cart.CartGrain], pod_name string, klarnaClient *KlarnaClient, inventoryService inventory.InventoryService, inventoryReservationService inventory.CartReservationService) *PoolServer {
 	srv := &PoolServer{
-		GrainPool:        pool,
-		pod_name:         pod_name,
-		klarnaClient:     klarnaClient,
-		inventoryService: inventoryService,
+		GrainPool:          pool,
+		pod_name:           pod_name,
+		klarnaClient:       klarnaClient,
+		inventoryService:   inventoryService,
+		reservationService: inventoryReservationService,
 	}
 
 	return srv
@@ -80,6 +80,10 @@ func (s *PoolServer) AddSkuToCartHandler(w http.ResponseWriter, r *http.Request,
 	if err != nil {
 		return err
 	}
+	err = s.HandleReservations(r.Context(), id, msg)
+	if err != nil {
+		return err
+	}
 	data, err := s.ApplyLocal(r.Context(), id, msg)
 	if err != nil {
 		return err
@@ -254,7 +258,14 @@ func (s *PoolServer) AddMultipleItemHandler(w http.ResponseWriter, r *http.Reque
 		return err
 	}
 
-	reply, err := s.ApplyLocal(r.Context(), id, getMultipleAddMessages(r.Context(), setCartItems.Items, setCartItems.Country)...)
+	msgs := getMultipleAddMessages(r.Context(), setCartItems.Items, setCartItems.Country)
+
+	err = s.HandleReservations(r.Context(), id, msgs...)
+	if err != nil {
+		return err
+	}
+
+	reply, err := s.ApplyLocal(r.Context(), id, msgs...)
 	if err != nil {
 		return err
 	}
@@ -274,11 +285,16 @@ func (s *PoolServer) GetReservationTime(item *messages.AddItem) time.Duration {
 	//return nil
 }
 
-func (s *PoolServer) HandleReservations(ctx context.Context, cartId cart.CartId, msgs ...*messages.AddItem) error {
+func (s *PoolServer) HandleReservations(ctx context.Context, cartId cart.CartId, msgs ...proto.Message) error {
 	if s.reservationService == nil {
 		return nil
 	}
-	for _, item := range msgs {
+	for _, msg := range msgs {
+		item, ok := msg.(*messages.AddItem)
+		if !ok {
+			log.Printf("not an AddItem message, skipping reservation, was of type: %T", msg)
+			continue
+		}
 		timeout := s.GetReservationTime(item)
 		if timeout == 0 {
 			continue
@@ -290,6 +306,7 @@ func (s *PoolServer) HandleReservations(ctx context.Context, cartId cart.CartId,
 			locationId = inventory.LocationID(*item.StoreId)
 		}
 		span.AddEvent("reserving item", trace.WithAttributes(attribute.String("sku", item.Sku), attribute.String("locationId", string(locationId))))
+		log.Printf("reserving item %s at location %s for cart %s", item.Sku, string(locationId), cartId.String())
 		end := time.Now().Add(timeout)
 		err := s.reservationService.ReserveForCart(ctx, inventory.CartReserveRequest{
 			CartID: inventory.CartID(cartId.String()),
@@ -320,8 +337,9 @@ func (s *PoolServer) AddSkuRequestHandler(w http.ResponseWriter, r *http.Request
 	if err != nil {
 		return err
 	}
-	if s.reservationService != nil {
-
+	err = s.HandleReservations(r.Context(), id, msg)
+	if err != nil {
+		return err
 	}
 	reply, err := s.ApplyLocal(r.Context(), id, msg)
 	if err != nil {

deployment/deployment.yaml

@@ -462,3 +462,14 @@ spec:
               value: "redis.home:6379"
             - name: REDIS_PASSWORD
               value: "slaskredis"
+---
+kind: Service
+apiVersion: v1
+metadata:
+  name: inventory
+spec:
+  selector:
+    app: cart-inventory
+  ports:
+    - name: web
+      port: 8080

pkg/cart/mutation_add_item.go

@@ -38,16 +38,24 @@ func (c *CartMutationContext) AddItem(g *CartGrain, m *messages.AddItem) error {
 		if !sameStore {
 			continue
 		}
-		existing.Quantity += int(m.Quantity)
+		if m.ReservationEndTime != nil {
+			t := m.ReservationEndTime.AsTime()
+			if existing.ReservationEndTime == nil || existing.ReservationEndTime.Before(m.ReservationEndTime.AsTime()) {
+				existing.ReservationEndTime = &t
+				existing.Quantity += int(m.Quantity)
+			} else {
+				existing.ReservationEndTime = &t
+			}
+
+		} else {
+			existing.Quantity += int(m.Quantity)
+		}
 		existing.Stock = uint16(m.Stock)
 		// If existing had nil store but new has one, adopt it.
 		if existing.StoreId == nil && m.StoreId != nil {
 			existing.StoreId = m.StoreId
 		}
-		if m.ReservationEndTime != nil {
-			t := m.ReservationEndTime.AsTime()
-			existing.ReservationEndTime = &t
-		}
+
 		return nil
 	}
 

pkg/cart/mutation_change_quantity.go

@@ -48,8 +48,15 @@ func (c *CartMutationContext) ChangeQuantity(g *CartGrain, m *messages.ChangeQua
 		g.UpdateTotals()
 		return nil
 	}
-
-	g.Items[foundIndex].Quantity = int(m.Quantity)
-	g.UpdateTotals()
+	item := g.Items[foundIndex]
+	if item == nil {
+		return fmt.Errorf("ChangeQuantity: item id %d not found", m.Id)
+	}
+	if item.ReservationEndTime != nil {
+		return fmt.Errorf("ChangeQuantity: cannot change quantity of reserved item id %d", m.Id)
+	} else {
+		item.Quantity = int(m.Quantity)
+		g.UpdateTotals()
+	}
 	return nil
 }

pkg/cart/mutation_initialize_checkout.go

@@ -2,6 +2,7 @@ package cart
 
 import (
 	"fmt"
+	"time"
 
 	messages "git.k6n.net/go-cart-actor/pkg/messages"
 )
@@ -36,6 +37,14 @@ func InitializeCheckout(g *CartGrain, m *messages.InitializeCheckout) error {
 	if m.OrderId == "" {
 		return fmt.Errorf("InitializeCheckout: missing orderId")
 	}
+	now := time.Now()
+	for _, item := range g.Items {
+		if item.ReservationEndTime != nil {
+			if now.After(*item.ReservationEndTime) {
+				return fmt.Errorf("InitializeCheckout: item id %d reservation has expired", item.Id)
+			}
+		}
+	}
 
 	g.OrderReference = m.OrderId
 	g.PaymentStatus = m.Status