Github user dfdemar commented on a diff in the pull request:
https://github.com/apache/storm/pull/2790#discussion_r207649108
--- Diff:
external/storm-kafka-client/src/main/java/org/apache/storm/kafka/bolt/KafkaBolt.java
---
@@ -62,6 +62,7 @@
private OutputCollector collector;
private TupleToKafkaMapper<K,V> mapper;
private KafkaTopicSelector topicSelector;
+ private Callback providedCallback;
--- End diff --
What about something like this? Not sure if `OutputCollector` is necessary
or not.
```java
public interface PreparedCallback extends Callback, Serializable {
void prepare(Map<String, Object> topoConf, TopologyContext context,
OutputCollector outputCollector);
}
```
So if the `PreparedCallback` is not null, then KafkaBolt would call
`.prepare()` during `KafkaBolt.prepare()`.
The one concern I have is that it might be open for abuse by tempting
people to use it to inject logic into the bolt preparation that's unrelated to
Kafka publishing.
---
