fixed performance issue

client.go

@@ -110,7 +110,8 @@ func (c *Client) pullDeltas() []Delta {
 		maxSize = 50
 	}
 
-	timeout := 10 * time.Microsecond
+	var timer <-chan time.Time
+	const timeout = 200 * time.Microsecond
 
 	var ds []Delta
 	for {
@@ -119,10 +120,12 @@ func (c *Client) pullDeltas() []Delta {
 
 		select {
 		case d, ok = <-c.ch:
-		case <-time.After(timeout):
+		case <-timer:
 			return ds
 		}
 
+		timer = time.After(timeout)
+
 		if !ok {
 			return ds
 		}