codecutil: made zeroTicks global

codec/codecutil/lex.go

@@ -40,8 +40,23 @@ func NewByteLexer(bufSize *int) *ByteLexer {
 	return &ByteLexer{bufSize: bufSize}
 }
 
-// Lex reads *l.bufSize bytes from src and writes them to dst every t seconds.
+// zeroTicks can be used to create an instant ticker.
-func (l *ByteLexer) Lex(dst io.Writer, src io.Reader, t time.Duration) error {
+var zeroTicks chan time.Time
+
+func init() {
+	zeroTicks = make(chan time.Time)
+	close(zeroTicks)
+}
+
+func newTicker(d time.Duration) *time.Ticker {
+	if d == 0 {
+		return &time.Ticker{C: zeroTicks}
+	}
+	return time.NewTicker(d)
+}
+
+// Lex reads *l.bufSize bytes from src and writes them to dst every d seconds.
+func (l *ByteLexer) Lex(dst io.Writer, src io.Reader, d time.Duration) error {
 	if l.bufSize == nil {
 		return fmt.Errorf("buffer size has not been set")
 	}
@@ -49,22 +64,11 @@ func (l *ByteLexer) Lex(dst io.Writer, src io.Reader, t time.Duration) error {
 	if bufSize <= 0 {
 		return fmt.Errorf("invalid buffer size: %v", bufSize)
 	}
-	if t < 0 {
+	if d < 0 {
-		return fmt.Errorf("invalid delay: %v", t)
+		return fmt.Errorf("invalid delay: %v", d)
 	}
 
-	// Set up delay, make loop instant if t is 0.
+	ticker := newTicker(d)
-	var ticker *time.Ticker
-	var zeroTicks chan time.Time
-	if t > 0 {
-		ticker = time.NewTicker(t)
-	} else {
-		zeroTicks = make(chan time.Time)
-		close(zeroTicks)
-		ticker = &time.Ticker{C: zeroTicks}
-	}
-	defer ticker.Stop()
-
 	buf := make([]byte, bufSize)
 	for {
 		<-ticker.C