TimestampedTupleForwarder¶

TimestampedTupleForwarder is used by processors to determine whether or not to forward records to child nodes (downstream processors) (that happens only with no caching).

Creating Instance¶

TimestampedTupleForwarder takes the following to be created:

• StateStore
• ProcessorContext
• TimestampedCacheFlushListener
• sendOldValues flag

TimestampedTupleForwarder is created when:

• KStreamAggregateProcessor is requested to initialize
• KStreamSlidingWindowAggregateProcessor is requested to initialize
• KStreamWindowAggregateProcessor is requested to initialize
• KTableSource is requested to initialize
• others

cachingEnabled Flag¶

TimestampedTupleForwarder requests the StateStore to setFlushListener when created. The returned value is used to initialize cachingEnabled internal flag for maybeForward.

maybeForward¶

void maybeForward(
  K key,
  V newValue,
  V oldValue) // (1)
void maybeForward(
  K key,
  V newValue,
  V oldValue,
  long timestamp)
void maybeForward(
  Record<K, Change<V>> record)

maybeForward requests the InternalProcessorContext to forward a record only with the cachingEnabled flag disabled.