MQ大牛成长课--从0到1手写分布式消息队列中间件学习指南

javapublic class CommitLog {
    private List<File> logFiles;
    private File currentFile;
    private int fileSize;

    public CommitLog(int fileSize) {
        this.fileSize = fileSize;
        this.logFiles = new ArrayList<>();
        this.currentFile = createNewFile();
        logFiles.add(currentFile);
    }

    private File createNewFile() {
        // 创建新的日志文件
    }

    public void appendMessage(String message) {
        if (currentFile.size() >= fileSize) {
            currentFile = createNewFile();
            logFiles.add(currentFile);
        }
        // 将消息写入当前文件
    }
}

javaimport java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;

public class MappedCommitLog {
    private MappedByteBuffer mappedByteBuffer;

    public MappedCommitLog(File file) throws IOException {
        try (FileChannel fileChannel = new RandomAccessFile(file, "rw").getChannel()) {
            this.mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, 0, file.length());
        }
    }

    public void appendMessage(String message) {
        byte[] bytes = message.getBytes(StandardCharsets.UTF_8);
        mappedByteBuffer.put(bytes);
    }
}

javapublic class AsyncCommitLog {
    private ByteBuffer buffer;
    private List<ByteBuffer> flushQueue;
    private Thread flushThread;

    public AsyncCommitLog(int bufferSize) {
        this.buffer = ByteBuffer.allocate(bufferSize);
        this.flushQueue = new LinkedList<>();
        this.flushThread = new Thread(this::flush);
        this.flushThread.start();
    }

    public void appendMessage(String message) {
        byte[] bytes = message.getBytes(StandardCharsets.UTF_8);
        buffer.put(bytes);
        if (buffer.remaining() < bytes.length) {
            flushQueue.add(buffer);
            buffer = ByteBuffer.allocate(buffer.capacity());
        }
    }

    private void flush() {
        while (true) {
            if (!flushQueue.isEmpty()) {
                ByteBuffer bufferToFlush = flushQueue.remove(0);
                // 将bufferToFlush中的数据写入磁盘
            }
        }
    }
}

javapublic class BrokerStartup {
    public static void main(String[] args) {
        Properties properties = loadProperties("brokerConfig.properties");
        Broker broker = new Broker(properties);
        broker.start();
    }

    private static Properties loadProperties(String filePath) {
        Properties properties = new Properties();
        try (InputStream input = new FileInputStream(filePath)) {
            properties.load(input);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return properties;
    }
}

javapublic class Broker {
    private NetworkModule networkModule;
    private StorageModule storageModule;
    private Properties properties;

    public Broker(Properties properties) {
        this.properties = properties;
        this.networkModule = new NetworkModule(properties);
        this.storageModule = new StorageModule(properties);
    }

    public void start() {
        networkModule.start();
        storageModule.start();
        // 启动其他模块
    }
}

javapublic class NetworkModule {
    private ExecutorService executorService;

    public NetworkModule(Properties properties) {
        int threadCount = Integer.parseInt(properties.getProperty("network.thread.count", "10"));
        this.executorService = Executors.newFixedThreadPool(threadCount);
    }

    public void start() {
        for (int i = 0; i < 10; i++) {
            executorService.submit(() -> {
                // 处理网络请求
            });
        }
    }
}

javapublic class ResourceMonitor {
    private ScheduledExecutorService scheduler;

    public ResourceMonitor() {
        this.scheduler = Executors.newScheduledThreadPool(1);
    }

    public void start() {
        scheduler.scheduleAtFixedRate(this::checkResources, 0, 5, TimeUnit.SECONDS);
    }

    private void checkResources() {
        // 检查系统资源使用情况
        // 如果超过阈值，进行相应处理
    }
}