perf: cache catchupped status

cmd/submit.go

@@ -118,6 +118,7 @@ func (s *submitter) shipFileRoutine(ctx context.Context, name string, sendQueue
 		return fmt.Errorf("tailing file: %w", err)
 	}
 
+	var catchUpped bool // cache
 	for {
 		select {
 		case err := <-errChan:
@@ -128,12 +129,16 @@ func (s *submitter) shipFileRoutine(ctx context.Context, name string, sendQueue
 				return nil
 			}
 
-			if line.EndOffset > startSize {
+			if !catchUpped {
+				catchUpped = line.EndOffset > startSize
+
+				if catchUpped {
 					select {
 					case sigCatchupped <- struct{}{}:
 					default:
 					}
 				}
+			}
 
 			if line.String == "" {
 				continue