Windows-only: refresh open directories using notifications

internal/cfg/config.go

@@ -106,6 +106,7 @@ type FlagStorage struct {
 	PreferPatchUploads    bool
 	NoPreloadDir          bool
 	NoVerifySSL           bool
+	WinRefreshDirs        bool
 
 	// Debugging
 	DebugMain  bool

internal/cfg/flags.go

@@ -140,6 +140,11 @@ MISC OPTIONS:
 			Value: gid,
 			Usage: "Drop root group and change to this group ID (defaults to --gid).",
 		},
+
+		cli.BoolFlag{
+			Name:  "refresh-dirs",
+			Usage: "Automatically refresh open directories using notifications under Windows",
+		},
 	}
 
 	s3Flags := []cli.Flag{
@@ -845,6 +850,7 @@ func PopulateFlags(c *cli.Context) (ret *FlagStorage) {
 		Gid:                    uint32(c.Int("gid")),
 		Setuid:                 c.Int("setuid"),
 		Setgid:                 c.Int("setgid"),
+		WinRefreshDirs:         c.Bool("refresh-dirs"),
 
 		// Tuning,
 		MemoryLimit:            uint64(1024*1024*c.Int("memory-limit")),

internal/goofys_windows.go

@@ -76,6 +76,9 @@ func NewGoofysWin(fs *Goofys) *GoofysWin {
 	fs.NotifyCallback = func(notifications []interface{}) {
 		go fsint.Notify(notifications)
 	}
+	if fs.flags.WinRefreshDirs {
+		go fsint.WinDirRefresher()
+	}
 	return fsint
 }
 
@@ -995,6 +998,34 @@ func (fs *GoofysWin) Notify(notifications []interface{}) {
 	}
 }
 
+func (fs *GoofysWin) WinDirRefresher() {
+	for atomic.LoadInt32(&fs.shutdown) == 0 {
+		select {
+		case <-time.After(1 * time.Second):
+		case <-fs.shutdownCh:
+			return
+		}
+		fs.mu.Lock()
+		var dirs []*Inode
+		for _, dh := range fs.dirHandles {
+			dirs = append(dirs, dh.inode)
+		}
+		fs.mu.Unlock()
+		expireUnix := time.Now().Add(-fs.flags.StatCacheTTL)
+		notifications := make(map[string]struct{})
+		for _, dir := range dirs {
+			dir.mu.Lock()
+			if dir.Parent != nil && dir.dir.DirTime.Before(expireUnix) {
+				notifications["/"+dir.FullName()] = struct{}{}
+			}
+			dir.mu.Unlock()
+		}
+		for dir := range notifications {
+			fs.host.Notify(dir, fuse.NOTIFY_CHMOD | fuse.NOTIFY_CHOWN | fuse.NOTIFY_UTIME | fuse.NOTIFY_CHFLAGS | fuse.NOTIFY_TRUNCATE)
+		}
+	}
+}
+
 // Mount the file system based on the supplied arguments, returning a
 // MountedFS that can be joined to wait for unmounting.
 func MountWin(