add panic if internal watcher creation fails for gfsnotify; improve codes and change comment from chinese to english for gdb

os/gfsnotify/gfsnotify.go

@@ -61,16 +61,25 @@ const (
 )
 
 const (
-	REPEAT_EVENT_FILTER_DURATION = time.Millisecond // Duration for repeated event filter.
-	gFSNOTIFY_EVENT_EXIT         = "exit"           // Custom exit event for internal usage.
+	repeatEventFilterDuration = time.Millisecond // Duration for repeated event filter.
+	callbackExitEventPanicStr = "exit"           // Custom exit event for internal usage.
 )
 
 var (
-	defaultWatcher, _   = New()                   // Default watcher.
+	defaultWatcher      *Watcher                  // Default watcher.
 	callbackIdMap       = gmap.NewIntAnyMap(true) // Id to callback mapping.
 	callbackIdGenerator = gtype.NewInt()          // Atomic id generator for callback.
 )
 
+func init() {
+	var err error
+	defaultWatcher, err = New()
+	if err != nil {
+		// Default watcher object must be created, or else it panics.
+		panic(fmt.Sprintf(`creating default fsnotify watcher failed: %s`, err.Error()))
+	}
+}
+
 // New creates and returns a new watcher.
 // Note that the watcher number is limited by the file handle setting of the system.
 // Eg: fs.inotify.max_user_instances system variable in linux systems.
@@ -125,7 +134,8 @@ func RemoveCallback(callbackId int) error {
 	return nil
 }
 
-// Exit is only used in the callback function, which can be used to remove current callback from the watcher.
+// Exit is only used in the callback function, which can be used to remove current callback
+// of itself from the watcher.
 func Exit() {
-	panic(gFSNOTIFY_EVENT_EXIT)
+	panic(callbackExitEventPanicStr)
 }

os/gfsnotify/gfsnotify_watcher_loop.go

@@ -22,7 +22,6 @@ func (w *Watcher) startWatchLoop() {
 
 			// Event listening.
 			case ev := <-w.watcher.Events:
-				//intlog.Print(ev.String())
 				// Filter the repeated event in custom duration.
 				w.cache.SetIfNotExist(ev.String(), func() interface{} {
 					w.events.Push(&Event{
@@ -32,7 +31,7 @@ func (w *Watcher) startWatchLoop() {
 						Watcher: w,
 					})
 					return struct{}{}
-				}, REPEAT_EVENT_FILTER_DURATION)
+				}, repeatEventFilterDuration)
 
 			case err := <-w.watcher.Errors:
 				intlog.Error(err)
@@ -148,7 +147,7 @@ func (w *Watcher) startEventLoop() {
 						defer func() {
 							if err := recover(); err != nil {
 								switch err {
-								case gFSNOTIFY_EVENT_EXIT:
+								case callbackExitEventPanicStr:
 									w.RemoveCallback(callback.Id)
 								default:
 									panic(err)

os/gtime/gtime_time.go

@@ -28,7 +28,7 @@ func New(t ...time.Time) *Time {
 	}
 }
 
-// Now returns a time object for now.
+// Now creates and returns a time object of now.
 func Now() *Time {
 	return &Time{
 		time.Now(),
@@ -50,7 +50,8 @@ func NewFromStr(str string) *Time {
 	return nil
 }
 
-// NewFromStrFormat creates and returns a Time object with given string and custom format like: Y-m-d H:i:s.
+// NewFromStrFormat creates and returns a Time object with given string and
+// custom format like: Y-m-d H:i:s.
 func NewFromStrFormat(str string, format string) *Time {
 	if t, err := StrToTimeFormat(str, format); err == nil {
 		return t
@@ -58,7 +59,8 @@ func NewFromStrFormat(str string, format string) *Time {
 	return nil
 }
 
-// NewFromStrLayout creates and returns a Time object with given string and stdlib layout like: 2006-01-02 15:04:05.
+// NewFromStrLayout creates and returns a Time object with given string and
+// stdlib layout like: 2006-01-02 15:04:05.
 func NewFromStrLayout(str string, layout string) *Time {
 	if t, err := StrToTimeLayout(str, layout); err == nil {
 		return t
@@ -66,7 +68,8 @@ func NewFromStrLayout(str string, layout string) *Time {
 	return nil
 }
 
-// NewFromTimeStamp creates and returns a Time object with given timestamp, which can be in seconds to nanoseconds.
+// NewFromTimeStamp creates and returns a Time object with given timestamp,
+// which can be in seconds to nanoseconds.
 func NewFromTimeStamp(timestamp int64) *Time {
 	if timestamp == 0 {
 		return &Time{}