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.plugin.subbroker;
  
  import java.util.concurrent.CompletableFuture;
  import org.pf4j.ExtensionPoint;
  
  /**
   * A sub broker is a downstream multi-tenant system which is capable of receiving subscribed messages in a batched way.
   */
  public interface ISubBroker extends ExtensionPoint {
      /**
       * The id of the subscription broker.
       *
       * @return the statically assigned id for the downstream sub broker system
       */
      int id();
  
      /**
       * Check if the subscriptions exists.
       *
       * @param request subscriptions check request
       * @return a future of check results
       */
      CompletableFuture<CheckReply> check(CheckRequest request);
  
      /**
       * Open deliverer instance for delivering messages to the containing inboxes. It's guaranteed to have singleton
       * instance for each deliverer key.
       *
       * @param delivererKey the key of delivery group
       * @return the deliverer instance
       */
      IDeliverer open(String delivererKey);
  
      /**
       * Close the inbox broker.
       */
      void close();
  }
  