update

core/storage/local/watcher.go

@@ -0,0 +1,57 @@
+package local
+
+import (
+	"context"
+	"errors"
+	"path/filepath"
+	"strings"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/rjeczalik/notify"
+)
+
+// Start starts a watcher on the whole FS and returns a channel to send detected changes.
+// It uses `notify` to detect changes in the filesystem, so it may not work on all platforms/use-cases.
+// Notoriously, it does not work on some networked mounts and Windows with WSL2.
+func (s *localStorage) Start(ctx context.Context) (<-chan string, error) {
+	if !s.watching.CompareAndSwap(false, true) {
+		return nil, errors.New("watcher already started")
+	}
+	input := make(chan notify.EventInfo, 1)
+	output := make(chan string, 1)
+
+	started := make(chan struct{})
+	go func() {
+		defer close(input)
+		defer close(output)
+
+		libPath := filepath.Join(s.u.Path, "...")
+		log.Debug(ctx, "Starting watcher", "lib", libPath)
+		err := notify.Watch(libPath, input, WatchEvents)
+		if err != nil {
+			log.Error("Error starting watcher", "lib", libPath, err)
+			return
+		}
+		defer notify.Stop(input)
+		close(started) // signals the main goroutine we have started
+
+		for {
+			select {
+			case event := <-input:
+				log.Trace(ctx, "Detected change", "event", event, "lib", s.u.Path)
+				name := event.Path()
+				name = strings.Replace(name, s.resolvedPath, s.u.Path, 1)
+				output <- name
+			case <-ctx.Done():
+				log.Debug(ctx, "Stopping watcher", "path", s.u.Path)
+				s.watching.Store(false)
+				return
+			}
+		}
+	}()
+	select {
+	case <-started:
+	case <-ctx.Done():
+	}
+	return output, nil
+}