| /* |
| * 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; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import java.util.ArrayList; |
| import java.util.IdentityHashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.function.Supplier; |
| import lombok.Getter; |
| import lombok.RequiredArgsConstructor; |
| import org.apache.pulsar.common.api.proto.MessageMetadata; |
| |
| /** |
| * The assigner to assign entries to the proper {@link Consumer} in the shared subscription. |
| */ |
| @RequiredArgsConstructor |
| public class SharedConsumerAssignor { |
| |
| // The cache to map uuid to a consumer because we need to guarantee all chunks with the same uuid to be dispatched |
| // to a fixed consumer until the whole chunked message is dispatched. |
| @Getter |
| @VisibleForTesting |
| private final Map<String, Consumer> uuidToConsumer = new ConcurrentHashMap<>(); |
| |
| // A temporary cache that is cleared each time `assign()` is called |
| private final Map<Consumer, Integer> consumerToPermits = new IdentityHashMap<>(); |
| |
| // The selector for entries without uuid. The Consumer returned must have at least 1 permit. |
| private final Supplier<Consumer> defaultSelector; |
| |
| // Process the unassigned messages, e.g. adding them to the replay queue |
| private final java.util.function.Consumer<EntryAndMetadata> unassignedMessageProcessor; |
| |
| public Map<Consumer, List<EntryAndMetadata>> assign(final List<EntryAndMetadata> entryAndMetadataList, |
| final int numConsumers) { |
| assert numConsumers >= 0; |
| consumerToPermits.clear(); |
| final Map<Consumer, List<EntryAndMetadata>> consumerToEntries = new IdentityHashMap<>(); |
| |
| Consumer consumer = getConsumer(numConsumers); |
| if (consumer == null) { |
| entryAndMetadataList.forEach(EntryAndMetadata::release); |
| return consumerToEntries; |
| } |
| // The actual available permits might change, here we use the permits at the moment to assign entries |
| int availablePermits = consumerToPermits.computeIfAbsent(consumer, Consumer::getAvailablePermits); |
| int index = 0; |
| for (; index < entryAndMetadataList.size(); index++) { |
| final EntryAndMetadata entryAndMetadata = entryAndMetadataList.get(index); |
| final MessageMetadata metadata = entryAndMetadata.getMetadata(); |
| |
| // Select another consumer to ensure `consumer != null` and `availablePermits > 0` |
| if (availablePermits <= 0) { |
| consumerToPermits.put(consumer, availablePermits); |
| consumer = getConsumer(numConsumers); |
| if (consumer == null) { |
| break; |
| } |
| availablePermits = consumer.getAvailablePermits(); |
| } |
| |
| if (metadata == null || !metadata.hasUuid() || !metadata.hasChunkId() || !metadata.hasNumChunksFromMsg()) { |
| consumerToEntries.computeIfAbsent(consumer, __ -> new ArrayList<>()).add(entryAndMetadata); |
| } else { |
| final Consumer consumerForUuid = getConsumerForUuid(metadata, consumer, availablePermits); |
| if (consumerForUuid == null) { |
| unassignedMessageProcessor.accept(entryAndMetadata); |
| continue; |
| } |
| consumerToEntries.computeIfAbsent(consumerForUuid, __ -> new ArrayList<>()).add(entryAndMetadata); |
| } |
| availablePermits--; |
| } |
| |
| for (; index < entryAndMetadataList.size(); index++) { |
| unassignedMessageProcessor.accept(entryAndMetadataList.get(index)); |
| } |
| |
| return consumerToEntries; |
| } |
| |
| private Consumer getConsumer(final int numConsumers) { |
| for (int i = 0; i < numConsumers; i++) { |
| final Consumer consumer = defaultSelector.get(); |
| if (consumer == null) { |
| return null; |
| } |
| final int permits = consumerToPermits.computeIfAbsent(consumer, Consumer::getAvailablePermits); |
| if (permits > 0) { |
| return consumer; |
| } |
| } |
| return null; |
| } |
| |
| private Consumer getConsumerForUuid(final MessageMetadata metadata, |
| final Consumer defaultConsumer, |
| final int currentAvailablePermits) { |
| final String uuid = metadata.getUuid(); |
| Consumer consumer = uuidToConsumer.get(uuid); |
| if (consumer == null) { |
| if (metadata.getChunkId() != 0) { |
| // Not the first chunk, skip it |
| return null; |
| } |
| consumer = defaultConsumer; |
| uuidToConsumer.put(uuid, consumer); |
| } |
| final int permits = consumerToPermits.computeIfAbsent(consumer, Consumer::getAvailablePermits); |
| if (permits <= 0) { |
| return null; |
| } |
| if (metadata.getChunkId() == metadata.getNumChunksFromMsg() - 1) { |
| // The last chunk is received, we should remove the cache |
| uuidToConsumer.remove(uuid); |
| } |
| consumerToPermits.put(consumer, currentAvailablePermits - 1); |
| return consumer; |
| } |
| } |