kafka-streams-internals-ProcessorContextImpl.adoc

ProcessorContextImpl — ProcessorContext for StreamTask

ProcessorContextImpl is a concrete ProcessorContext (as a AbstractProcessorContext) that is created exclusively for a StreamTask.

ProcessorContextImpl is a concrete RecordCollector.Supplier that supplies the given RecordCollector when requested.

Accessing State Store by Name — getStateStore Method

StateStore getStateStore(String name)

Note	getStateStore is part of ProcessorContext Contract to access the state store by name.

getStateStore…​FIXME

Scheduling Cancellable Periodic Action (Punctuator) — schedule Method

Cancellable schedule(
  Duration interval,
  PunctuationType type,
  Punctuator callback)

Note	schedule is part of ProcessorContext Contract to schedule a Punctuator (a periodic action) that can be cancelled.

schedule simply requests the StreamTask to schedule the specified Punctuator.

Creating ProcessorContextImpl Instance

ProcessorContextImpl takes the following to be created (most for AbstractProcessorContext):

• TaskId

• StreamTask

• StreamsConfig

• RecordCollector

• ProcessorStateManager

• StreamsMetricsImpl

• ThreadCache

ProcessorContextImpl initializes the internal properties.

forward Method

void forward(final K key, final V value)
void forward(final K key, final V value, final int childIndex)
void forward(final K key, final V value, final String childName)
void forward(final K key, final V value, final To to)
void forward(
  final ProcessorNode child,
  final K key,
  final V value) // (1)

1. Private API

Note	forward is part of the ProcessorContext Contract to…​FIXME.

forward…​FIXME

Committing StreamTask — commit Method

void commit()

Note	commit is part of the ProcessorContext Contract to request a commit.

commit simply requests the StreamTask to commit.