safe truncation

cart-grain.go

@@ -238,7 +238,6 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*CallResult,
 				if item.Id == int(msg.Id) {
 					if item.Quantity <= int(msg.Quantity) {
 						c.Items = append(c.Items[:i], c.Items[i+1:]...)
-
 					} else {
 						item.Quantity -= int(msg.Quantity)
 					}
@@ -253,13 +252,15 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) (*CallResult,
 		if !ok {
 			err = fmt.Errorf("expected RemoveItem")
 		} else {
-			for i, item := range c.Items {
+			items := make([]*CartItem, 0, len(c.Items))
+			for _, item := range c.Items {
 				if item.Id == int(msg.Id) {
 					c.TotalPrice -= item.Price * int64(item.Quantity)
-					c.Items = append(c.Items[:i], c.Items[i+1:]...)
-					break
+				} else {
+					items = append(items, item)
 				}
 			}
+			c.Items = items
 		}
 	case SetDeliveryType:
 		msg, ok := message.Content.(*messages.SetDelivery)

grain-pool.go

@@ -87,12 +87,21 @@ func (p *GrainLocalPool) Purge() {
 		if item.Expires.Before(time.Now()) {
 			if item.Grain.GetLastChange() > keepChanged {
 				log.Printf("Expired item %s changed, keeping", item.Grain.GetId())
-				p.expiry = append(p.expiry[:i], p.expiry[i+1:]...)
-				p.expiry = append(p.expiry, item)
+				if i < len(p.expiry)-1 {
+					p.expiry = append(p.expiry[:i], p.expiry[i+1:]...)
+					p.expiry = append(p.expiry, item)
+				} else {
+					p.expiry = append(p.expiry[:i], item)
+				}
+
 			} else {
 				log.Printf("Item %s expired", item.Grain.GetId())
 				delete(p.grains, item.Grain.GetId())
-				p.expiry = append(p.expiry[:i], p.expiry[i+1:]...)
+				if i < len(p.expiry)-1 {
+					p.expiry = append(p.expiry[:i], p.expiry[i+1:]...)
+				} else {
+					p.expiry = p.expiry[:i]
+				}
 			}
 		} else {
 			break

synced-pool.go

@@ -255,14 +255,19 @@ func (p *SyncedPool) ExcludeKnown(hosts []string) []string {
 }
 
 func (p *SyncedPool) RemoveHost(host *RemoteHost) {
-	for i, r := range p.remotes {
+	toKeep := make([]*RemoteHost, 0, len(p.remotes))
+	for _, r := range p.remotes {
 		if r == host {
 			p.RemoveHostMappedCarts(r)
-			p.remotes = append(p.remotes[:i], p.remotes[i+1:]...)
-			connectedRemotes.Set(float64(len(p.remotes)))
-			return
+
+		} else {
+			toKeep = append(toKeep, r)
 		}
 	}
+
+	p.remotes = toKeep
+
+	connectedRemotes.Set(float64(len(p.remotes)))
 }
 
 func (p *SyncedPool) RemoveHostMappedCarts(host *RemoteHost) {