content: /*
   * Copyright 2020-2023 the original author or authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.jun.mqttx.consumer;
  
  import com.jun.mqttx.constants.InternalMessageEnum;
  
  /**
   * 观察者，实现此接口.
   *
   * @author Jun
   * @since 1.0.4
   */
  public interface Watcher {
  
      /**
       * 每当有新的集群消息达到是，触发行为。
       * 注意：实现方法不应该有耗时操作(e.g. 访问数据库)
       *
       * @param msg 集群消息
       */
      void action(byte[] msg);
  
      /**
       * Watcher 支持的 channel 类别
       *
       * @param channel {@link InternalMessageEnum}
       * @return true if Watcher support
       */
      boolean support(String channel);
  }
  