package cidutil import ( "context" c "gitlab.dms3.io/dms3/go-cid" ) type Set = c.Set func NewSet() *Set { return c.NewSet() } // StreamingSet is an extension of Set which allows to implement back-pressure // for the Visit function type StreamingSet struct { Set *Set New chan c.Cid } // NewStreamingSet initializes and returns new Set. func NewStreamingSet() *StreamingSet { return &StreamingSet{ Set: c.NewSet(), New: make(chan c.Cid), } } // Visitor creates new visitor which adds a Cids to the set and emits them to // the set.New channel func (s *StreamingSet) Visitor(ctx context.Context) func(c c.Cid) bool { return func(c c.Cid) bool { if s.Set.Visit(c) { select { case s.New <- c: case <-ctx.Done(): } return true } return false } }