content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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
   *
   *   http://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 org.apache.bifromq.basecluster.memberlist.agent;
  
  import io.reactivex.rxjava3.core.Observable;
  import java.util.Map;
  import java.util.concurrent.CompletableFuture;
  import org.apache.bifromq.basecluster.agent.proto.AgentEndpoint;
  import org.apache.bifromq.basecluster.agent.proto.AgentMemberAddr;
  import org.apache.bifromq.basecluster.agent.proto.AgentMemberMetadata;
  
  /**
   * The interface for an overlay agent cluster.
   */
  public interface IAgent {
      /**
       * The agent cluster id.
       *
       * @return the agent cluster id
       */
      String id();
  
      /**
       * The local agent address.
       *
       * @return the local agent address
       */
      AgentEndpoint local();
  
      /**
       * A hot observable of agent membership.
       *
       * @return an observable that emits the current membership map
       */
      Observable<Map<AgentMemberAddr, AgentMemberMetadata>> membership();
  
      /**
       * Register a local agent member. It's allowed to register same member name in same logical agent from different
       * agent hosts
       *
       * @param memberName the member name, should be unique in local host member
       */
      IAgentMember register(String memberName);
  
      /**
       * Deregister a member instance, the caller should never hold the reference to the instance after deregistered.
       *
       * @param member the member instance to deregister
       */
      CompletableFuture<Void> deregister(IAgentMember member);
  
      /**
       * Refresh the registration of the local agent member.
       */
      void refreshRegistration();
  }
  