Disruptor：让你的程序飞一般快

后端

2023-08-28 12:45:53

高性能队列：揭秘 Disruptor 的魅力

在软件开发领域，队列是一种用于在不同线程或进程之间传递数据的关键组件。然而，传统队列在高并发场景下常常面临性能瓶颈，限制了系统的整体效率。

Disruptor：高性能队列的秘密武器

Disruptor 是一款高性能队列，专为解决传统队列的性能问题而设计。它采用环形缓冲区和发布-订阅模式，为数据传输提供了极高的效率和可靠性。

Disruptor 的特点

高性能： 环形缓冲区和发布-订阅模式赋予了 Disruptor 极高的吞吐量，即使在超高并发场景下也能保持稳定运行。
可靠性： 通过序列号机制，Disruptor 保证了数据的可靠传输，即使发生故障，数据也不会丢失。
可扩展性： Disruptor 可以轻松地扩展其容量，以适应不断变化的负载需求。

Disruptor 的应用

Disruptor 广泛应用于各种知名开源项目，如 canal、log4j2 和 Storm。这些项目对性能和可靠性有着极高的要求，Disruptor 的加入极大地提升了它们的效率。

深入浅出，两个示例带你领略 Disruptor 的风采

示例一：使用 Disruptor 实现一个简单的消息队列

import com.lmax.disruptor.BlockingWaitStrategy;
import com.lmax.disruptor.EventFactory;
import com.lmax.disruptor.RingBuffer;
import com.lmax.disruptor.dsl.Disruptor;
import com.lmax.disruptor.dsl.ProducerType;

public class SimpleMessageQueue {

    public static void main(String[] args) {
        // 创建一个事件工厂，用于创建消息事件
        EventFactory<MessageEvent> eventFactory = new MessageEventFactory();

        // 创建一个 Disruptor 实例，并指定环形缓冲区的长度
        Disruptor<MessageEvent> disruptor = new Disruptor<>(eventFactory, 1024, new BlockingWaitStrategy());

        // 创建一个消费者，用于消费消息事件
        MessageConsumer consumer = new MessageConsumer();

        // 将消费者添加到 Disruptor 中
        disruptor.handleEventsWith(consumer);

        // 启动 Disruptor
        disruptor.start();

        // 创建一个生产者，用于生产消息事件
        MessageProducer producer = new MessageProducer(disruptor.getRingBuffer());

        // 生产消息事件
        for (int i = 0; i < 1000; i++) {
            producer.produce("Hello, Disruptor!");
        }

        // 停止 Disruptor
        disruptor.shutdown();
    }

    private static class MessageEvent {
        private String message;

        public String getMessage() {
            return message;
        }

        public void setMessage(String message) {
            this.message = message;
        }
    }

    private static class MessageEventFactory implements EventFactory<MessageEvent> {

        @Override
        public MessageEvent newInstance() {
            return new MessageEvent();
        }
    }

    private static class MessageConsumer implements EventHandler<MessageEvent> {

        @Override
        public void onEvent(MessageEvent event, long sequence, boolean endOfBatch) {
            System.out.println("Received message: " + event.getMessage());
        }
    }

    private static class MessageProducer {

        private final RingBuffer<MessageEvent> ringBuffer;

        public MessageProducer(RingBuffer<MessageEvent> ringBuffer) {
            this.ringBuffer = ringBuffer;
        }

        public void produce(String message) {
            long sequence = ringBuffer.next();
            MessageEvent event = ringBuffer.get(sequence);
            event.setMessage(message);
            ringBuffer.publish(sequence);
        }
    }
}

示例二：使用 Disruptor 实现一个高性能的日志队列

import com.lmax.disruptor.BlockingWaitStrategy;
import com.lmax.disruptor.EventFactory;
import com.lmax.disruptor.RingBuffer;
import com.lmax.disruptor.dsl.Disruptor;
import com.lmax.disruptor.dsl.ProducerType;

public class HighPerformanceLogQueue {

    public static void main(String[] args) {
        // 创建一个事件工厂，用于创建日志事件
        EventFactory<LogEntryEvent> eventFactory = new LogEntryEventFactory();

        // 创建一个 Disruptor 实例，并指定环形缓冲区的长度
        Disruptor<LogEntryEvent> disruptor = new Disruptor<>(eventFactory, 1024 * 1024, new BlockingWaitStrategy());

        // 创建一个消费者，用于消费日志事件
        LogEntryConsumer consumer = new LogEntryConsumer();

        // 将消费者添加到 Disruptor 中
        disruptor.handleEventsWith(consumer);

        // 启动 Disruptor
        disruptor.start();

        // 创建一个生产者，用于生产日志事件
        LogEntryProducer producer = new LogEntryProducer(disruptor.getRingBuffer());

        // 生产日志事件
        for (int i = 0; i < 1000000; i++) {
            producer.produce("This is a log entry: " + i);
        }

        // 停止 Disruptor
        disruptor.shutdown();
    }

    private static class LogEntryEvent {
        private String message;

        public String getMessage() {
            return message;
        }

        public void setMessage(String message) {
            this.message = message;
        }
    }

    private static class LogEntryEventFactory implements EventFactory<LogEntryEvent> {

        @Override
        public LogEntryEvent newInstance() {
            return new LogEntryEvent();
        }
    }

    private static class LogEntryConsumer implements EventHandler<LogEntryEvent> {

        @Override
        public void onEvent(LogEntryEvent event, long sequence, boolean endOfBatch) {
            System.out.println("Received log entry: " + event.getMessage());
        }
    }

    private static class LogEntryProducer {

        private final RingBuffer<LogEntryEvent> ringBuffer;

        public LogEntryProducer(RingBuffer<LogEntryEvent> ringBuffer) {
            this.ringBuffer = ringBuffer;
        }

        public void produce(String message) {
            long sequence = ringBuffer.next();
            LogEntryEvent event = ringBuffer.get(sequence);
            event.setMessage(message);
            ringBuffer.publish(sequence);
        }
    }
}