raboof/pekko
1
0
Fork 0
Code Issues Pull requests Projects Releases 6 Packages Wiki Activity Actions 10

#30191 - Actualization of docs for "Resumable projections" (#30197)

Browse source
This commit is contained in:
Sergey Morgunov 2021-04-22 18:27:25 +03:00 • committed by GitHub
parent e74f77236c
commit fc4e84a322
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 4 additions and 192 deletions
Download patch file Download diff file Expand all files Collapse all files

112
akka-docs/src/test/java/jdocs/persistence/ResumableProjectionExample.java
View file

@ -1,112 +0,0 @@
/*
* Copyright (C) 2019-2021 Lightbend Inc. <https://www.lightbend.com>
*/
package jdocs.persistence;
import akka.Done;
import akka.actor.typed.ActorRef;
import akka.actor.typed.ActorSystem;
import akka.actor.typed.Behavior;
import akka.actor.typed.javadsl.AbstractBehavior;
import akka.actor.typed.javadsl.ActorContext;
import akka.actor.typed.javadsl.Behaviors;
import akka.actor.typed.javadsl.Receive;
import akka.actor.typed.javadsl.AskPattern;
import akka.persistence.query.PersistenceQuery;
import akka.persistence.query.Sequence;
import akka.stream.javadsl.Sink;
import java.time.Duration;
import java.util.concurrent.CompletionStage;
import java.util.concurrent.TimeUnit;
import static jdocs.persistence.PersistenceQueryDocTest.*;
public interface ResumableProjectionExample {
public static void runQuery(
ActorSystem<?> system, ActorRef<TheOneWhoWritesToQueryJournal.Command> writer)
throws Exception {
final MyJavadslReadJournal readJournal =
PersistenceQuery.get(system)
.getReadJournalFor(
MyJavadslReadJournal.class, "akka.persistence.query.my-read-journal");
// #projection-into-different-store-actor-run
final Duration timeout = Duration.ofSeconds(3);
final MyResumableProjection bidProjection = new MyResumableProjection("bid");
long startFromOffset =
bidProjection.latestOffset().toCompletableFuture().get(3, TimeUnit.SECONDS);
readJournal
.eventsByTag("bid", new Sequence(startFromOffset))
.mapAsync(
8,
envelope -> {
final CompletionStage<Done> f =
AskPattern.ask(
writer,
(ActorRef<Done> replyTo) ->
new TheOneWhoWritesToQueryJournal.Update(envelope.event(), replyTo),
timeout,
system.scheduler());
return f.thenApplyAsync(in -> envelope.offset(), system.executionContext());
})
.mapAsync(1, offset -> bidProjection.saveProgress(offset))
.runWith(Sink.ignore(), system);
}
// #projection-into-different-store-actor-run
// #projection-into-different-store-actor
static final class TheOneWhoWritesToQueryJournal
extends AbstractBehavior<TheOneWhoWritesToQueryJournal.Command> {
interface Command {}
static class Update implements Command {
public final Object payload;
public final ActorRef<Done> replyTo;
Update(Object payload, ActorRef<Done> replyTo) {
this.payload = payload;
this.replyTo = replyTo;
}
}
public static Behavior<Command> create(String id, ExampleStore store) {
return Behaviors.setup(context -> new TheOneWhoWritesToQueryJournal(context, store));
}
private final ExampleStore store;
private ComplexState state = new ComplexState();
private TheOneWhoWritesToQueryJournal(ActorContext<Command> context, ExampleStore store) {
super(context);
this.store = store;
}
@Override
public Receive<Command> createReceive() {
return newReceiveBuilder().onMessage(Update.class, this::onUpdate).build();
}
private Behavior<Command> onUpdate(Update msg) {
state = updateState(state, msg);
if (state.readyToSave()) store.save(Record.of(state));
return this;
}
ComplexState updateState(ComplexState state, Update msg) {
// some complicated aggregation logic here ...
return state;
}
}
// #projection-into-different-store-actor
}