text: /*
   * The MIT License (MIT)
   *
   * Copyright (c) 2015 Microsoft Corporation
   * 
   * -=- Robust Distributed System Nucleus (rDSN) -=- 
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  /*
   * Description:
   *     What is this file about?
   *
   * Revision history:
   *     xxxx-xx-xx, author, first version
   *     xxxx-xx-xx, author, fix bug about xxx
   */
  # pragma once
  # include "echo.code.definition.h"
  # include <iostream>
  
  
  namespace dsn { namespace example { 
  class echo_client 
      : public virtual ::dsn::clientlet
  {
  public:
      echo_client(::dsn::rpc_address server) { _server = server; }
      echo_client() { }
      virtual ~echo_client() {}
  
  
      // ---------- call RPC_ECHO_ECHO_PING ------------
      // - synchronous 
      std::pair< ::dsn::error_code, std::string> ping_sync(
          const std::string& val, 
          std::chrono::milliseconds timeout = std::chrono::milliseconds(0), 
          int thread_hash = 0,
          uint64_t partition_hash = 0,
          dsn::optional< ::dsn::rpc_address> server_addr = dsn::none)
      {
          return ::dsn::rpc::wait_and_unwrap<std::string>(
              ::dsn::rpc::call(
                  server_addr.unwrap_or(_server),
                  RPC_ECHO_ECHO_PING,
                  val,
                  nullptr,
                  empty_callback,
                  timeout,
                  thread_hash,
                  partition_hash
                  )
              );
      }
      
      // - asynchronous with on-stack std::string and std::string 
      template<typename TCallback>
      ::dsn::task_ptr ping(
          const std::string& val, 
          TCallback&& callback,
          std::chrono::milliseconds timeout = std::chrono::milliseconds(0),
          int thread_hash = 0,
          uint64_t partition_hash = 0,
          int reply_thread_hash = 0,
          dsn::optional< ::dsn::rpc_address> server_addr = dsn::none
          )
      {
          return ::dsn::rpc::call(
                      server_addr.unwrap_or(_server), 
                      RPC_ECHO_ECHO_PING, 
                      val, 
                      this,
                      std::forward<TCallback>(callback),
                      timeout,
                      thread_hash,
                      partition_hash,
                      reply_thread_hash
                      );
      }
  
  private:
      ::dsn::rpc_address _server;
  };
  
  } } 