content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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
   *
   *      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 com.alibaba.csp.sentinel.cluster;
  
  import com.alibaba.csp.sentinel.cluster.request.ClusterRequest;
  import com.alibaba.csp.sentinel.cluster.response.ClusterResponse;
  
  /**
   * Synchronous transport client for distributed flow control.
   *
   * @author Eric Zhao
   * @since 1.4.0
   */
  public interface ClusterTransportClient {
  
      /**
       * Start the client.
       *
       * @throws Exception some error occurred (e.g. initialization failed)
       */
      void start() throws Exception;
  
      /**
       * Stop the client.
       *
       * @throws Exception some error occurred (e.g. shutdown failed)
       */
      void stop() throws Exception;
  
      /**
       * Send request to remote server and get response.
       *
       * @param request Sentinel cluster request
       * @return response from remote server
       * @throws Exception some error occurs
       */
      ClusterResponse sendRequest(ClusterRequest request) throws Exception;
  
      /**
       * Check whether the client has been started and ready for sending requests.
       *
       * @return true if the client is ready to send requests, otherwise false
       */
      boolean isReady();
  }
  