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| * distributed with this work for additional information * |
| * regarding copyright ownership. The ASF licenses this file * |
| * to you under the Apache License, Version 2.0 (the * |
| * "License"); you may not use this file except in compliance * |
| * with the License. You may obtain a copy of the License at * |
| * * |
| * http://www.apache.org/licenses/LICENSE-2.0 * |
| * * |
| * Unless required by applicable law or agreed to in writing, * |
| * software distributed under the License is distributed on an * |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * |
| * KIND, either express or implied. See the License for the * |
| * specific language governing permissions and limitations * |
| * under the License. * |
| ****************************************************************/ |
| |
| package org.apache.james.events; |
| |
| import static org.apache.james.backends.rabbitmq.Constants.ALLOW_QUORUM; |
| import static org.apache.james.backends.rabbitmq.Constants.AUTO_DELETE; |
| import static org.apache.james.backends.rabbitmq.Constants.DURABLE; |
| import static org.apache.james.backends.rabbitmq.Constants.EMPTY_ROUTING_KEY; |
| import static org.apache.james.backends.rabbitmq.Constants.EXCLUSIVE; |
| import static org.apache.james.backends.rabbitmq.Constants.REQUEUE; |
| import static org.apache.james.events.GroupRegistration.DEFAULT_RETRY_COUNT; |
| |
| import java.util.Collection; |
| import java.util.Map; |
| import java.util.Objects; |
| import java.util.Optional; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.function.Predicate; |
| |
| import org.apache.commons.lang3.tuple.Pair; |
| import org.apache.james.backends.rabbitmq.RabbitMQConfiguration; |
| import org.apache.james.backends.rabbitmq.ReactorRabbitMQChannelPool; |
| import org.apache.james.backends.rabbitmq.ReceiverProvider; |
| import org.apache.james.util.ReactorUtils; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import com.google.common.collect.ImmutableList; |
| |
| import reactor.core.Disposable; |
| import reactor.core.publisher.Flux; |
| import reactor.core.publisher.Mono; |
| import reactor.core.scheduler.Scheduler; |
| import reactor.core.scheduler.Schedulers; |
| import reactor.rabbitmq.AcknowledgableDelivery; |
| import reactor.rabbitmq.BindingSpecification; |
| import reactor.rabbitmq.ConsumeOptions; |
| import reactor.rabbitmq.QueueSpecification; |
| import reactor.rabbitmq.Receiver; |
| import reactor.rabbitmq.Sender; |
| import reactor.util.retry.Retry; |
| |
| class GroupRegistrationHandler { |
| private static final Logger LOGGER = LoggerFactory.getLogger(GroupRegistrationHandler.class); |
| |
| public static class GroupRegistrationHandlerGroup extends Group { |
| |
| } |
| |
| static final Group GROUP = new GroupRegistrationHandlerGroup(); |
| |
| private final NamingStrategy namingStrategy; |
| private final Map<Group, GroupRegistration> groupRegistrations; |
| private final EventSerializer eventSerializer; |
| private final ReactorRabbitMQChannelPool channelPool; |
| private final Sender sender; |
| private final ReceiverProvider receiverProvider; |
| private final RetryBackoffConfiguration retryBackoff; |
| private final EventDeadLetters eventDeadLetters; |
| private final ListenerExecutor listenerExecutor; |
| private final RabbitMQConfiguration configuration; |
| private final GroupRegistration.WorkQueueName queueName; |
| private final Scheduler scheduler; |
| private Optional<Disposable> consumer; |
| |
| GroupRegistrationHandler(NamingStrategy namingStrategy, EventSerializer eventSerializer, ReactorRabbitMQChannelPool channelPool, Sender sender, ReceiverProvider receiverProvider, |
| RetryBackoffConfiguration retryBackoff, |
| EventDeadLetters eventDeadLetters, ListenerExecutor listenerExecutor, EventBusId eventBusId, RabbitMQConfiguration configuration) { |
| this.namingStrategy = namingStrategy; |
| this.eventSerializer = eventSerializer; |
| this.channelPool = channelPool; |
| this.sender = sender; |
| this.receiverProvider = receiverProvider; |
| this.retryBackoff = retryBackoff; |
| this.eventDeadLetters = eventDeadLetters; |
| this.listenerExecutor = listenerExecutor; |
| this.configuration = configuration; |
| this.groupRegistrations = new ConcurrentHashMap<>(); |
| this.queueName = namingStrategy.workQueue(GROUP); |
| this.scheduler = Schedulers.newBoundedElastic(EventBus.EXECUTION_RATE, ReactorUtils.DEFAULT_BOUNDED_ELASTIC_QUEUESIZE, "groups-handler"); |
| this.consumer = Optional.empty(); |
| } |
| |
| GroupRegistration retrieveGroupRegistration(Group group) { |
| return Optional.ofNullable(groupRegistrations.get(group)) |
| .orElseThrow(() -> new GroupRegistrationNotFound(group)); |
| } |
| |
| public void start() { |
| channelPool.createWorkQueue( |
| QueueSpecification.queue(queueName.asString()) |
| .durable(DURABLE) |
| .exclusive(!EXCLUSIVE) |
| .autoDelete(!AUTO_DELETE) |
| .arguments(configuration.workQueueArgumentsBuilder(!ALLOW_QUORUM) |
| .deadLetter(namingStrategy.deadLetterExchange()) |
| .build()), |
| BindingSpecification.binding() |
| .exchange(namingStrategy.exchange()) |
| .queue(queueName.asString()) |
| .routingKey(EMPTY_ROUTING_KEY)) |
| .retryWhen(Retry.backoff(retryBackoff.getMaxRetries(), retryBackoff.getFirstBackoff()).jitter(retryBackoff.getJitterFactor()).scheduler(Schedulers.boundedElastic())) |
| .block(); |
| |
| this.consumer = Optional.of(consumeWorkQueue()); |
| } |
| |
| private Disposable consumeWorkQueue() { |
| return Flux.using( |
| receiverProvider::createReceiver, |
| receiver -> receiver.consumeManualAck(queueName.asString(), new ConsumeOptions().qos(EventBus.EXECUTION_RATE)), |
| Receiver::close) |
| .filter(delivery -> Objects.nonNull(delivery.getBody())) |
| .flatMap(this::deliver, EventBus.EXECUTION_RATE) |
| .subscribeOn(scheduler) |
| .subscribe(); |
| } |
| |
| private Mono<Void> deliver(AcknowledgableDelivery acknowledgableDelivery) { |
| byte[] eventAsBytes = acknowledgableDelivery.getBody(); |
| |
| return deserializeEvent(eventAsBytes) |
| .flatMapIterable(aa -> groupRegistrations.values() |
| .stream() |
| .map(group -> Pair.of(group, aa)) |
| .collect(ImmutableList.toImmutableList())) |
| .flatMap(event -> event.getLeft().runListenerReliably(DEFAULT_RETRY_COUNT, event.getRight())) |
| .then(Mono.<Void>fromRunnable(acknowledgableDelivery::ack).subscribeOn(Schedulers.boundedElastic())) |
| .then() |
| .onErrorResume(e -> { |
| LOGGER.error("Unable to process delivery for group {}", GROUP, e); |
| return Mono.fromRunnable(() -> acknowledgableDelivery.nack(!REQUEUE)) |
| .subscribeOn(Schedulers.boundedElastic()) |
| .then(); |
| }); |
| } |
| |
| private Mono<Event> deserializeEvent(byte[] eventAsBytes) { |
| return Mono.fromCallable(() -> eventSerializer.fromBytes(eventAsBytes)); |
| } |
| |
| void stop() { |
| groupRegistrations.values().forEach(groupRegistration -> Mono.from(groupRegistration.unregister()).block()); |
| consumer.ifPresent(Disposable::dispose); |
| Optional.ofNullable(scheduler).ifPresent(Scheduler::dispose); |
| } |
| |
| void restart() { |
| Optional<Disposable> previousConsumer = consumer; |
| consumer = Optional.of(consumeWorkQueue()); |
| previousConsumer |
| .filter(Predicate.not(Disposable::isDisposed)) |
| .ifPresent(Disposable::dispose); |
| |
| groupRegistrations.values() |
| .forEach(GroupRegistration::restart); |
| } |
| |
| Registration register(EventListener.ReactiveEventListener listener, Group group) { |
| if (groupRegistrations.isEmpty()) { |
| start(); |
| } |
| return groupRegistrations |
| .compute(group, (groupToRegister, oldGroupRegistration) -> { |
| if (oldGroupRegistration != null) { |
| throw new GroupAlreadyRegistered(group); |
| } |
| return newGroupRegistration(listener, groupToRegister); |
| }) |
| .start(); |
| } |
| |
| private GroupRegistration newGroupRegistration(EventListener.ReactiveEventListener listener, Group group) { |
| return new GroupRegistration( |
| namingStrategy, channelPool, sender, |
| receiverProvider, |
| eventSerializer, |
| listener, |
| group, |
| retryBackoff, |
| eventDeadLetters, |
| () -> groupRegistrations.remove(group), |
| listenerExecutor, configuration); |
| } |
| |
| Collection<Group> registeredGroups() { |
| return groupRegistrations.keySet(); |
| } |
| } |