github.com/jbunds/progress/standard.go

func (s *standardTracker) init() {

	s.lo = defaultLayout()
	s.status.Store(new(""))
	c, err := lru.New[string, *string](1024)
	if err != nil { panic(err) }
	s.cache = c
}

func (s *standardTracker) store(_ uint64, status string) {

	if cachedPointer, ok := s.cache.Get(status); ok {
		s.status.Store(cachedPointer)
		return
	}
	strCopy := status // zero-alloc local copy to isolate the string header
	s.cache.Add(status, &strCopy)
	s.status.Store(&strCopy)
}

func (s *standardTracker) load() string {

	if ptr := s.status.Load(); ptr != nil { return *ptr }
	return ""
}

func (s *standardTracker) layout() layout { return s.lo }

func (s *standardTracker) setLayout(lo *layout) { s.lo = *lo }

func (s *standardTracker) Equal(other *standardTracker) bool { // work around cmp's draconian strictures

	if s == nil || other == nil { return s == other }
	return s.load()              == other.load()              &&
	       s.lo.staticWidth      == other.lo.staticWidth      &&
	       s.lo.colorBlockFactor == other.lo.colorBlockFactor &&
	       s.lo.prefix           == other.lo.prefix           &&
	       s.lo.suffix           == other.lo.suffix           &&
	       s.lo.clearSeq         == other.lo.clearSeq         &&
	       s.lo.doneSeq          == other.lo.doneSeq          &&
	       s.lo.lineTerminator   == other.lo.lineTerminator   &&
	       s.lo.finalStatus      == other.lo.finalStatus
}