Package io.smallrye.reactive.messaging.kafka.commit

Class StateStore<T>

java.lang.Object

io.smallrye.reactive.messaging.kafka.commit.StateStore<T>

Type Parameters:

T - type of the processing state

public class StateStore<T>
extends Object

State store metadata type for injecting state store interactions into received messages. This allows accessing the current processing state restored from the state store, and produce the next state. The next state can be saved locally or persisted into the external store.

A sample processing method with checkpointing would be:

 @Incoming("in")
 public CompletionStage<Void> process(Message<String> msg) {
     StateStore<Integer> stateStore = StateStore.fromMessage(msg);
     if (stateStore != null) {
         stateStore.transformAndStoreOnAck(0, current -> current + msg.getPayload());
     }
     return CompletableFuture.completed(null);
 }
 

Field Summary

Fields

Modifier and Type	Field	Description
protected KafkaLogging	log

Constructor Summary

Constructors

Constructor	Description
StateStore(org.apache.kafka.common.TopicPartition topicPartition, long recordOffset, Supplier<ProcessingState<T>> stateSupplier)

Method Summary

Modifier and Type	Method	Description
static <S> StateStore<S>	fromMessage(org.eclipse.microprofile.reactive.messaging.Message<?> message)
Optional<ProcessingState<T>>	getCurrent()
Optional<ProcessingState<T>>	getNext()
static <S> ProcessingState<S>	getProcessingState(org.eclipse.microprofile.reactive.messaging.Message<?> message)
long	getRecordOffset()
org.apache.kafka.common.TopicPartition	getTopicPartition()
boolean	isPersist()
static boolean	isPersist(org.eclipse.microprofile.reactive.messaging.Message<?> message)
T	storeLocal(T state)
T	storeLocal(T state, long offset)
T	storeOnAck(T state)
T	storeOnAck(T state, long offset)
T	transformAndStoreLocal(T initialState, Function<T,T> transformation)
T	transformAndStoreOnAck(T initialState, Function<T,T> transformation)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

log

protected KafkaLogging log

Constructor Detail

StateStore

public StateStore(org.apache.kafka.common.TopicPartition topicPartition,
                  long recordOffset,
                  Supplier<ProcessingState<T>> stateSupplier)

Method Detail

getProcessingState

public static <S> ProcessingState<S> getProcessingState(org.eclipse.microprofile.reactive.messaging.Message<?> message)

isPersist

public static boolean isPersist(org.eclipse.microprofile.reactive.messaging.Message<?> message)

fromMessage

public static <S> StateStore<S> fromMessage(org.eclipse.microprofile.reactive.messaging.Message<?> message)

getTopicPartition

public org.apache.kafka.common.TopicPartition getTopicPartition()

getRecordOffset

public long getRecordOffset()

isPersist

public boolean isPersist()

getCurrent

public Optional<ProcessingState<T>> getCurrent()

getNext

public Optional<ProcessingState<T>> getNext()

storeLocal

public T storeLocal(T state,
                    long offset)

storeLocal

public T storeLocal(T state)

transformAndStoreLocal

public T transformAndStoreLocal(T initialState,
                                Function<T,T> transformation)

storeOnAck

public T storeOnAck(T state,
                    long offset)

storeOnAck

public T storeOnAck(T state)

transformAndStoreOnAck

public T transformAndStoreOnAck(T initialState,
                                Function<T,T> transformation)