chore(poll): return NotModifiedTimeoutErr on 304

client.go

@@ -22,6 +22,7 @@ const CausalityTokenHeader = "X-Garage-Causality-Token"
 var TombstoneItemErr = errors.New("item is a tombstone")
 var NoSuchItemErr = errors.New("item does not exist")
 var ConcurrentItemsErr = errors.New("item has multiple concurrent values")
+var NotModifiedTimeoutErr = errors.New("not modified within timeout")
 
 var awsSigner = v4.NewSigner()
 
@@ -300,6 +301,8 @@ func (c *Client) readItemSingle(ctx context.Context, b Bucket, pk string, sk str
 		return nil, "", NoSuchItemErr
 	case http.StatusConflict:
 		return nil, ct, ConcurrentItemsErr
+	case http.StatusNotModified:
+		return nil, "", NotModifiedTimeoutErr
 	default:
 		return nil, "", fmt.Errorf("http status code %d", resp.StatusCode)
 	}