Pulsar源码解析-客户端-多消费者MultiTopicsConsumerImpl创建底层实现

最新推荐文章于 2023-03-16 00:38:33 发布

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最新推荐文章于 2023-03-16 00:38:33 发布 · 置顶 · 1.7k 阅读

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文章标签：

#java #分布式 #消息队列

上一篇介绍了单个消费者的创建实现，本章介绍多个消费者

一、MultiTopicsConsumerImpl创建入口

public class PulsarClientImpl {
   
   

public <T> CompletableFuture<Consumer<T>> subscribeAsync(ConsumerConfigurationData<T> conf, Schema<T> schema, ConsumerInterceptors<T> interceptors) {
   
   
        // 配置的正则
        if (conf.getTopicsPattern() != null) {
   
   
            return patternTopicSubscribeAsync(conf, schema, interceptors);
        } 
      	// 单个消费者
		else if (conf.getTopicNames().size() == 1) {
   
   
            return singleTopicSubscribeAsync(conf, schema, interceptors);
        } 
        // 多个
        else {
   
   
            return multiTopicSubscribeAsync(conf, schema, interceptors);
        }
    }
}

继续multiTopicSubscribeAsync(...)

public class PulsarClientImpl {
   
   

    private <T> CompletableFuture<Consumer<T>> multiTopicSubscribeAsync(ConsumerConfigurationData<T> conf, Schema<T> schema, ConsumerInterceptors<T> interceptors) {
   
   
        CompletableFuture<Consumer<T>> consumerSubscribedFuture = new CompletableFuture<>();

		// 创建多消费者实现
        ConsumerBase<T> consumer = new MultiTopicsConsumerImpl<>(PulsarClientImpl.this, conf,
                externalExecutorProvider, consumerSubscribedFuture, schema, interceptors,
                true);
		// 添加多消费者
        consumers.add(consumer);

        return consumerSubscribedFuture;
    }
}

PulsarClient维护的是最外层消费者实现，MultiTopicsConsumerImpl内部又有多个则由它自己维护
可以看到，核心实现都在MultiTopicsConsumerImpl构造中。
继续new MultiTopicsConsumerImpl<>(...)

二、MultiTopicsConsumerImpl构造

public class MultiTopicsConsumerImpl<T> extends ConsumerBase<T> {
   
   

MultiTopicsConsumerImpl(PulsarClientImpl client, String singleTopic, ConsumerConfigurationData<T> conf,
            ExecutorProvider executorProvider, CompletableFuture<Consumer<T>> subscribeFuture, Schema<T> schema,
            ConsumerInterceptors<T> interceptors, boolean createTopicIfDoesNotExist, MessageId startMessageId,
            long startMessageRollbackDurationInSec) {
   
   
            // 封装消费者常用的几乎所有api，跟consumerImpl一样
        super(client, singleTopic, conf, Math.max