merlimat commented on a change in pull request #538: Make broker configurable to own non-persistent topic URL: https://github.com/apache/incubator-pulsar/pull/538#discussion_r129387559
########## File path: pulsar-broker/src/main/java/org/apache/pulsar/broker/service/nonpersistent/NonPersistentDispatcherMultipleConsumers.java ########## @@ -0,0 +1,195 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * 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.pulsar.broker.service.nonpersistent; + +import java.util.List; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.atomic.AtomicIntegerFieldUpdater; + +import org.apache.bookkeeper.mledger.Entry; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import com.carrotsearch.hppc.ObjectHashSet; +import com.carrotsearch.hppc.ObjectSet; +import org.apache.pulsar.broker.service.BrokerServiceException; +import org.apache.pulsar.broker.service.Consumer; +import org.apache.pulsar.common.api.proto.PulsarApi.CommandSubscribe.SubType; +import org.apache.pulsar.utils.CopyOnWriteArrayList; + +/** + */ +public class NonPersistentDispatcherMultipleConsumers implements NonPersistentDispatcher { + + private final NonPersistentTopic topic; + private final CopyOnWriteArrayList<Consumer> consumerList = new CopyOnWriteArrayList<>(); + private final ObjectSet<Consumer> consumerSet = new ObjectHashSet<>(); + private int currentConsumerRoundRobinIndex = 0; + + private CompletableFuture<Void> closeFuture = null; + + private final String name; + + private static final int FALSE = 0; + private static final int TRUE = 1; + private static final AtomicIntegerFieldUpdater<NonPersistentDispatcherMultipleConsumers> IS_CLOSED_UPDATER = AtomicIntegerFieldUpdater + .newUpdater(NonPersistentDispatcherMultipleConsumers.class, "isClosed"); + private volatile int isClosed = FALSE; + private static final AtomicIntegerFieldUpdater<NonPersistentDispatcherMultipleConsumers> TOTAL_AVAILABLE_PERMITS_UPDATER = AtomicIntegerFieldUpdater + .newUpdater(NonPersistentDispatcherMultipleConsumers.class, "totalAvailablePermits"); + private volatile int totalAvailablePermits = 0; + + public NonPersistentDispatcherMultipleConsumers(NonPersistentTopic topic, String dispatcherName) { + this.name = topic.getName() + " / " + dispatcherName; + this.topic = topic; + } + + @Override + public synchronized void addConsumer(Consumer consumer) { + if (IS_CLOSED_UPDATER.get(this) == TRUE) { + log.warn("[{}] Dispatcher is already closed. Closing consumer ", name, consumer); + consumer.disconnect(); + return; + } + + consumerList.add(consumer); + consumerSet.add(consumer); + } + + @Override + public synchronized void removeConsumer(Consumer consumer) throws BrokerServiceException { + if (consumerSet.removeAll(consumer) == 1) { + consumerList.remove(consumer); + log.info("Removed consumer {}", consumer); + if (consumerList.isEmpty()) { + if (closeFuture != null) { + log.info("[{}] All consumers removed. Subscription is disconnected", name); + closeFuture.complete(null); + } + TOTAL_AVAILABLE_PERMITS_UPDATER.set(this, 0); + } + } else { + if (log.isDebugEnabled()) { + log.debug("[{}] Trying to remove a non-connected consumer: {}", name, consumer); + } + TOTAL_AVAILABLE_PERMITS_UPDATER.addAndGet(this, -consumer.getAvailablePermits()); + } + } + + @Override + public boolean isConsumerConnected() { + return !consumerList.isEmpty(); + } + + @Override + public CopyOnWriteArrayList<Consumer> getConsumers() { + return consumerList; + } + + @Override + public synchronized boolean canUnsubscribe(Consumer consumer) { + return consumerList.size() == 1 && consumerSet.contains(consumer); + } + + @Override + public CompletableFuture<Void> close() { + IS_CLOSED_UPDATER.set(this, TRUE); + return disconnectAllConsumers(); + } + + @Override + public synchronized void consumerFlow(Consumer consumer, int additionalNumberOfMessages) { + if (!consumerSet.contains(consumer)) { + if (log.isDebugEnabled()) { + log.debug("[{}] Ignoring flow control from disconnected consumer {}", name, consumer); + } + return; + } + + totalAvailablePermits += additionalNumberOfMessages; + if (log.isDebugEnabled()) { + log.debug("[{}] Trigger new read after receiving flow control message", consumer); + } + } + + @Override + public synchronized CompletableFuture<Void> disconnectAllConsumers() { + closeFuture = new CompletableFuture<>(); + if (consumerList.isEmpty()) { + closeFuture.complete(null); + } else { + consumerList.forEach(Consumer::disconnect); + } + return closeFuture; + } + + @Override + public void reset() { + IS_CLOSED_UPDATER.set(this, FALSE); + } + + @Override + public SubType getType() { + return SubType.Shared; + } + + @Override + public void sendMessages(List<Entry> entries) { + Consumer consumer = TOTAL_AVAILABLE_PERMITS_UPDATER.get(this) > 0 ? getNextConsumer() : null; + if (consumer != null) { + TOTAL_AVAILABLE_PERMITS_UPDATER.addAndGet(this, -consumer.sendMessages(entries).getRight()); + } else { + entries.forEach(Entry::release); + } + } + + @Override + public boolean hasPermits() { + return TOTAL_AVAILABLE_PERMITS_UPDATER.get(this) > 0; + } + + private Consumer getNextConsumer() { Review comment: Great, you can introduce some base class like `AbstractDispatcherMultipleConsumers` with the common logic. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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