// 设备注册服务核心接口定义
public interface DeviceRegistryService {
    /**

     * 设备注册方法
     * @param deviceInfo 设备信息对象
     * @return 注册结果，包含设备唯一标识
     */
    CompletableFuture<DeviceRegistrationResult> registerDevice(DeviceInfo deviceInfo);

    /**

     * 设备心跳更新
     * @param deviceId 设备ID
     * @param heartbeat 心跳数据
     */
    void updateHeartbeat(String deviceId, DeviceHeartbeat heartbeat);
}

// 设备状态管理服务实现
@Service
public class DeviceStateServiceImpl implements DeviceStateService {
    private final RedisTemplate<String, DeviceState> redisTemplate;
    private final DeviceStateRepository stateRepository;

    @Override
    @Transactional
    public void updateDeviceState(String deviceId, DeviceState newState) {
        // 使用Redis作为状态缓存
        redisTemplate.opsForValue().set(
            "device:state:" + deviceId, 
            newState, 
            Duration.ofMinutes(30)
        );

        // 异步持久化到数据库
        stateRepository.saveAsync(newState);
    }
}

public class ConnectionRateLimiter {
    private final AtomicLong tokens;
    private final long capacity;
    private final long refillRate; // tokens per second
    private volatile long lastRefillTimestamp;

    public ConnectionRateLimiter(long capacity, long refillRate) {
        this.capacity = capacity;
        this.refillRate = refillRate;
        this.tokens = new AtomicLong(capacity);
        this.lastRefillTimestamp = System.currentTimeMillis();
    }

    public boolean tryAcquire(int permits) {
        refillTokens();
        long currentTokens = tokens.get();
        while (currentTokens >= permits) {
            if (tokens.compareAndSet(currentTokens, currentTokens - permits)) {
                return true;
            }
            currentTokens = tokens.get();
        }
        return false;
    }

    private void refillTokens() {
        long currentTime = System.currentTimeMillis();
        long timeElapsed = currentTime - lastRefillTimestamp;

        if (timeElapsed > 1000) { // 至少1秒才刷新
            long newTokens = timeElapsed * refillRate / 1000;
            if (newTokens > 0) {
                tokens.updateAndGet(current -> 
                    Math.min(capacity, current + newTokens)
                );
                lastRefillTimestamp = currentTime;
            }
        }
    }
}

public class ConsistentHashRouter {
    private final SortedMap<Integer, String> circle = new TreeMap<>();
    private final int virtualNodeCount;

    public ConsistentHashRouter(Collection<String> nodes, int virtualNodeCount) {
        this.virtualNodeCount = virtualNodeCount;
        for (String node : nodes) {
            addNode(node);
        }
    }

    public void addNode(String node) {
        for (int i = 0; i < virtualNodeCount; i++) {
            String virtualNode = node + "#" + i;
            int hash = getHash(virtualNode);
            circle.put(hash, node);
        }
    }

    public String getRouteNode(String key) {
        if (circle.isEmpty()) {
            return null;
        }
        int hash = getHash(key);
        SortedMap<Integer, String> tailMap = circle.tailMap(hash);
        int nodeHash = tailMap.isEmpty() ? circle.firstKey() : tailMap.firstKey();
        return circle.get(nodeHash);
    }

    private int getHash(String key) {
        // 使用MurmurHash3确保分布均匀
        return Hashing.murmur3_32().hashString(key, StandardCharsets.UTF_8).asInt();
    }
}

// 内存优化示例：设备状态对象池
public class DeviceStatePool {
    private final ObjectPool<DeviceState> pool;

    public DeviceStatePool() {
        this.pool = new GenericObjectPool<>(new DeviceStateFactory());
    }

    public DeviceState borrowObject() throws Exception {
        return pool.borrowObject();
    }

    public void returnObject(DeviceState state) {
        state.reset(); // 重置对象状态
        pool.returnObject(state);
    }

    private static class DeviceStateFactory extends BasePooledObjectFactory<DeviceState> {
        @Override
        public DeviceState create() {
            return new DeviceState();
        }

        @Override
        public PooledObject<DeviceState> wrap(DeviceState obj) {
            return new DefaultPooledObject<>(obj);
        }
    }
}

// 简化的设备状态管理
@Entity
public class HomeDevice {
    @Id
    private String deviceId;
    private DeviceType type;
    private String room;
    private DeviceStatus status;
    private LocalDateTime lastSeen;

    // 使用位运算优化状态存储
    public void setStatusFlags(int flags) {
        this.status = DeviceStatus.fromFlags(flags);
    }
}

# AI模型集成示例
class AgriculturalPredictor:
    def __init__(self, model_path):
        self.model = load_model(model_path)
        self.device_client = DeviceClient()

    async def predict_irrigation(self, device_id):
        # 获取设备传感器数据
        sensor_data = await self.device_client.get_sensor_data(device_id)
        # 获取天气预测数据
        weather_data = await self.get_weather_forecast()
        # 组合特征并预测
        features = self.combine_features(sensor_data, weather_data)
        prediction = self.model.predict(features)

        # 根据预测结果控制设备
        if prediction > THRESHOLD:
            await self.device_client.control_device(device_id, 'irrigation', 'on')