codecutil: updated logic for 0 delay lexing

codec/codecutil/lex.go

@@ -53,16 +53,19 @@ func (l *ByteLexer) Lex(dst io.Writer, src io.Reader, t time.Duration) error {
 		return fmt.Errorf("invalid delay: %v", t)
 	}
 	var ticker *time.Ticker
+	var zeroTicks chan time.Time
 	if t > 0 {
 		ticker = time.NewTicker(t)
-		defer ticker.Stop()
+	} else {
+		zeroTicks = make(chan time.Time)
+		close(zeroTicks)
+		ticker = &time.Ticker{C: zeroTicks}
 	}
+	defer ticker.Stop()
 
 	buf := make([]byte, bufSize)
 	for {
-		if t != 0 {
 		<-ticker.C
-		}
 		off, err := src.Read(buf)
 		if err != nil {
 			return err
@@ -73,3 +76,28 @@ func (l *ByteLexer) Lex(dst io.Writer, src io.Reader, t time.Duration) error {
 		}
 	}
 }
+
+func main() {
+	for _, delay := range []time.Duration{0, 10 * time.Millisecond} {
+		t := newTicker(delay)
+		for i := 0; i < 10; i++ {
+			<-t.C
+			fmt.Println(time.Now(), i)
+		}
+		fmt.Println()
+	}
+}
+
+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)
+}