inotify, readdcw: zero cost isdir function for Create/Delete(windows)…

… and All(linux) events

event_inotify.go

@@ -77,8 +77,10 @@ func (e *event) Event() Event     { return e.event }
 func (e *event) Path() string     { return e.path }
 func (e *event) Sys() interface{} { return e.sys }
 
-// isdir TODO(ppknap): native implementation for inotify
 func isdir(ei EventInfo) (bool, error) {
+	if _, ok := ei.Sys().(syscall.InotifyEvent); ok {
+		return ei.Sys().(syscall.InotifyEvent).Mask&syscall.IN_ISDIR != 0, nil
+	}
 	fi, err := os.Stat(ei.Path())
 	if err != nil {
 		return false, err

event_readdcw.go

@@ -69,27 +69,29 @@ var osestr = map[Event]string{
 var ekind = map[Event]Event{}
 
 const (
-	ObjectUnknown uint8 = iota
-	ObjectFile
-	ObjectDirectory
+	fTypeUnknown uint8 = iota
+	fTypeFile
+	fTypeDirectory
 )
 
 // TODO(ppknap) : doc.
 type event struct {
-	pathw   []uint16
-	name    string
-	objtype uint8
-	action  uint32
-	filter  uint32
-	e       Event
+	pathw  []uint16
+	name   string
+	ftype  uint8
+	action uint32
+	filter uint32
+	e      Event
 }
 
 func (e *event) Event() Event     { return e.e }
 func (e *event) Path() string     { return filepath.Join(syscall.UTF16ToString(e.pathw), e.name) }
-func (e *event) Sys() interface{} { return e.objtype }
+func (e *event) Sys() interface{} { return e.ftype }
 
-// isdir TODO(ppknap): native implementation for readdcw
 func isdir(ei EventInfo) (bool, error) {
+	if ftype, ok := ei.Sys().(uint8); ok && ftype != fTypeUnknown {
+		return ftype == fTypeDirectory, nil
+	}
 	fi, err := os.Stat(ei.Path())
 	if err != nil {
 		return false, err

watcher_inotify.go

@@ -191,10 +191,12 @@ func (i *inotify) loop(esch chan<- []*event) {
 			if err := syscall.Close(int(fd)); err != nil {
 				// Panic? error?
 				panic(err)
-			} else {
-				atomic.StoreInt32(&i.fd, invalidDescriptor)
 			}
-			i.epollclose()
+			atomic.StoreInt32(&i.fd, invalidDescriptor)
+			if err := i.epollclose(); err != nil {
+				// Panic? error?
+				panic(err)
+			}
 			close(esch)
 			return
 		}

watcher_readdcw.go

@@ -401,12 +401,12 @@ func (r *readdcw) send(es []*event) {
 		switch Event(e.action) {
 		case (FileActionAdded >> 12), (FileActionRemoved >> 12):
 			if e.filter&uint32(dirmarker) != 0 {
-				e.objtype = ObjectDirectory
+				e.ftype = fTypeDirectory
 			} else {
-				e.objtype = ObjectFile
+				e.ftype = fTypeFile
 			}
 		default:
-			e.objtype = ObjectUnknown
+			e.ftype = fTypeUnknown
 		}
 		r.c <- e
 	}