better comments

config.go

@@ -92,14 +92,18 @@ type Config struct {
  // When zero Centrifuge uses default 30 days which we believe is more than enough
  // for most use cases.
  HistoryMetaTTL time.Duration
- // GetChannelNamespaceLabel if set will be used by Centrifuge to extract channel_group label
- // for channel related metrics. Make sure to maintain low cardinality of returned
+ // GetChannelNamespaceLabel if set will be used by Centrifuge to extract channel_group
+ // label for channel related metrics. Make sure to maintain low cardinality of returned
  // values to avoid issues with Prometheus performance. This function may introduce
- // sufficient overhead since it's called in hot paths.
+ // sufficient overhead since it's called in hot paths - so should be fast.
  GetChannelNamespaceLabel func(channel string) string
- // ChannelNamespaceLabelForMessagesSent ...
+ // ChannelNamespaceLabelForMessagesSent enables using GetChannelNamespaceLabel
+ // function for extracting channel_namespace label for transport_messages_sent and
+ // transport_messages_sent_size.
  ChannelNamespaceLabelForMessagesSent bool
- // ChannelNamespaceLabelForMessagesReceived ...
+ // ChannelNamespaceLabelForMessagesReceived enables using GetChannelNamespaceLabel
+ // function for extracting channel_namespace label for transport_messages_received and
+ // transport_messages_received_size.
  ChannelNamespaceLabelForMessagesReceived bool
 }