聊聊nacos的DelegateConsistencyServiceImpl

public interface ConsistencyService {
​
    /**
     * Put a data related to a key to Nacos cluster
     *
     * @param key   key of data, this key should be globally unique
     * @param value value of data
     * @throws NacosException
     * @see
     */
    void put(String key, Record value) throws NacosException;
​
    /**
     * Remove a data from Nacos cluster
     *
     * @param key key of data
     * @throws NacosException
     */
    void remove(String key) throws NacosException;
​
    /**
     * Get a data from Nacos cluster
     *
     * @param key key of data
     * @return data related to the key
     * @throws NacosException
     */
    Datum get(String key) throws NacosException;
​
    /**
     * Listen for changes of a data
     *
     * @param key      key of data
     * @param listener callback of data change
     * @throws NacosException
     */
    void listen(String key, RecordListener listener) throws NacosException;
​
    /**
     * Cancel listening of a data
     *
     * @param key      key of data
     * @param listener callback of data change
     * @throws NacosException
     */
    void unlisten(String key, RecordListener listener) throws NacosException;
​
    /**
     * Tell the status of this consistency service
     *
     * @return true if available
     */
    boolean isAvailable();
}

@Service("consistencyDelegate")
public class DelegateConsistencyServiceImpl implements ConsistencyService {
​
    @Autowired
    private PersistentConsistencyService persistentConsistencyService;
​
    @Autowired
    private EphemeralConsistencyService ephemeralConsistencyService;
​
    @Override
    public void put(String key, Record value) throws NacosException {
        mapConsistencyService(key).put(key, value);
    }
​
    @Override
    public void remove(String key) throws NacosException {
        mapConsistencyService(key).remove(key);
    }
​
    @Override
    public Datum get(String key) throws NacosException {
        return mapConsistencyService(key).get(key);
    }
​
    @Override
    public void listen(String key, RecordListener listener) throws NacosException {
​
        // this special key is listened by both:
        if (KeyBuilder.SERVICE_META_KEY_PREFIX.equals(key)) {
            persistentConsistencyService.listen(key, listener);
            ephemeralConsistencyService.listen(key, listener);
            return;
        }
​
        mapConsistencyService(key).listen(key, listener);
    }
​
    @Override
    public void unlisten(String key, RecordListener listener) throws NacosException {
        mapConsistencyService(key).unlisten(key, listener);
    }
​
    @Override
    public boolean isAvailable() {
        return ephemeralConsistencyService.isAvailable() && persistentConsistencyService.isAvailable();
    }
​
    private ConsistencyService mapConsistencyService(String key) {
        return KeyBuilder.matchEphemeralKey(key) ? ephemeralConsistencyService : persistentConsistencyService;
    }
}