add some locks

cart-grain.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"slices"
+	"sync"
 	"time"
 
 	messages "git.tornberg.me/go-cart-actor/proto"
@@ -41,6 +42,7 @@ type CartDelivery struct {
 }
 
 type CartGrain struct {
+	mu              sync.RWMutex
 	lastItemId      int
 	lastDeliveryId  int
 	storageMessages []Message
@@ -111,6 +113,8 @@ func (c *CartGrain) AddItem(sku string, qty int) ([]byte, error) {
 func (c *CartGrain) GetStorageMessage(since int64) []StorableMessage {
 
 	ret := make([]StorableMessage, 0)
+	c.mu.RLock()
+	defer c.mu.RUnlock()
 	for _, message := range c.storageMessages {
 		if *message.TimeStamp > since {
 			ret = append(ret, message)
@@ -189,6 +193,7 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) ([]byte, erro
 				}
 			}
 			if !found {
+				c.mu.Lock()
 				c.lastItemId++
 				c.Items = append(c.Items, &CartItem{
 					Id:       c.lastItemId,
@@ -199,6 +204,7 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) ([]byte, erro
 					Image:    msg.Image,
 				})
 				c.TotalPrice += msg.Price * int64(msg.Quantity)
+				c.mu.Unlock()
 			}
 		}
 	case ChangeQuantityType:
@@ -269,8 +275,11 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) ([]byte, erro
 	if err != nil {
 		return nil, err
 	}
+
 	if !isReplay {
+		c.mu.Lock()
 		c.storageMessages = append(c.storageMessages, *message)
+		c.mu.Unlock()
 	}
 	return json.Marshal(c)
 }