Patch for https://github.com/Doist/bitmapist-server/ allowing one to disable autmated periodic saving and initiate save by SIGUSR2

noautosave.patch

diff --git i/bitmapist.go w/bitmapist.go
index 0e22f2c..345ae31 100644
--- i/bitmapist.go
+++ w/bitmapist.go
@@ -18,10 +18,11 @@ import (
 
 func main() {
 	args := struct {
-		Addr string `flag:"addr,address to listen"`
-		File string `flag:"db,path to database file"`
-		Bak  string `flag:"bak,file to save backup to on SIGUSR1"`
-		Dbg  bool   `flag:"debug,log incoming commands"`
+		Addr   string `flag:"addr,address to listen"`
+		File   string `flag:"db,path to database file"`
+		Bak    string `flag:"bak,file to save backup to on SIGUSR1"`
+		Dbg    bool   `flag:"debug,log incoming commands"`
+		Nosave bool   `flag:"noautosave,disable automated periodic saving, force saving by sending SIGUSR2"`
 	}{
 		Addr: "localhost:6379",
 		File: "bitmapist.db",
@@ -38,6 +39,16 @@ func main() {
 	}
 	log.Println("loaded in", time.Since(begin))
 	s.WithLogger(log)
+	if args.Nosave {
+		s.WithoutAutosave()
+		go func() {
+			sigCh := make(chan os.Signal, 1)
+			signal.Notify(sigCh, syscall.SIGUSR2)
+			for range sigCh {
+				s.Save()
+			}
+		}()
+	}
 
 	srv := red.NewServer()
 	srv.WithLogger(log)
diff --git i/internal/bitmapist/bitmapist.go w/internal/bitmapist/bitmapist.go
index 4c8eb23..7404876 100644
--- i/internal/bitmapist/bitmapist.go
+++ w/internal/bitmapist/bitmapist.go
@@ -34,9 +34,10 @@ func New(dbFile string) (*Server, error) {
 		rm:    make(map[string]struct{}),
 		cache: make(map[string]cacheItem),
 
-		done:    make(chan struct{}),
-		doneAck: make(chan struct{}),
-		save:    make(chan struct{}),
+		done:       make(chan struct{}),
+		doneAck:    make(chan struct{}),
+		save:       make(chan struct{}),
+		noautosave: make(chan struct{}, 1),
 	}
 	err = s.db.View(func(tx *bolt.Tx) error {
 		if bkt := tx.Bucket([]byte("aux")); bkt != nil {
@@ -107,6 +108,8 @@ type Server struct {
 	doneAck chan struct{}
 	save    chan struct{}
 
+	noautosave chan struct{}
+
 	mu    sync.Mutex
 	keys  map[string]struct{}  // all known keys
 	rm    map[string]struct{}  // removed but not yet purged
@@ -202,6 +205,9 @@ func (s *Server) loop() {
 		case <-s.done:
 			fn("final saving...", s.persist)
 			return
+		case <-s.noautosave:
+			ticker.Stop()
+			s.log.Println("periodic saving disabled")
 		}
 	}
 }
@@ -294,6 +300,24 @@ func (s *Server) persist() error {
 	return err
 }
 
+// Save has the same effect as issuing BGSAVE command over connected client
+func (s *Server) Save() {
+	select {
+	case s.save <- struct{}{}:
+	default:
+	}
+}
+
+// WithoutAutosave disables automated periodic state saving. State is only
+// persisted when explicitly told calling Save() method or issuing BGSAVE
+// command over connected client.
+func (s *Server) WithoutAutosave() {
+	select {
+	case s.noautosave <- struct{}{}:
+	default:
+	}
+}
+
 func (s *Server) handleSlurp(req red.Request) (interface{}, error) {
 	if len(req.Args) != 1 {
 		return nil, red.ErrWrongArgs